slewing bearing manufacturer - LDB

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Why Lubricating Oil Is Important for Slewing Bearings

April 4, 2025/in Bearing Knowledge /by wang

In the vast system of industrial machinery, lubricating oil and bearings, although seemingly minor components, play a crucial role. They are the core elements ensuring the stable and efficient operation of machinery.

What is a Slewing Bearing?

Slew Bearing, as the hubs of mechanical operation, are responsible for supporting and guiding rotating or oscillating components. There is a wide variety of slew bearings. From common deep – groove ball slew bearings to tapered roller slew bearings suitable for heavy loads, different types meet the specific requirements of various machines. For example, in an automotive engine, the crankshaft slew bearing has to withstand huge pressure and high – speed rotation. Its precision and reliability directly affect the engine’s performance. In precision instruments, miniature slew bearings need to ensure minimal friction and high – precision operation.

What is Lubricating Oil?

Lubricating oil is like the “blood” of machinery and is crucial for the normal operation of slew bearings. Its primary function is to reduce friction. When a slew bearing is in operation, the lubricating oil forms an oil film between the rolling elements and the raceway. This transforms the direct metal – to – metal friction into the internal friction of the oil film, greatly reducing friction, minimizing wear, and extending the slew bearing’s service life. Take the motor slew bearing as an example. Good lubrication can reduce energy consumption and improve the motor’s efficiency.

Functions of Lubricating Oil

Lubricating oil also has a heat – dissipation function. During the operation of a slew bearing, heat is generated due to friction. If the heat cannot be dissipated in time, a continuous increase in temperature will affect the slew bearing’s precision and material properties, and may even cause the slew bearing to seize. The lubricating oil can absorb heat during the circulation process and transfer it to the surrounding environment, maintaining the normal operating temperature of the slew bearing. For example, the gearbox slew bearings of large – scale wind turbines generate a large amount of heat under high – load operation, and a dedicated lubricating oil cooling system is essential.

In addition, lubricating oil can also act as a seal and anti – rust agent. It can fill the gaps in the slew bearing, preventing the intrusion of external dust, moisture, and other impurities and protecting the internal structure of the slew bearing. At the same time, the anti – rust additives in the lubricating oil can form a protective film on the metal surface, preventing the slew bearing from rusting and corroding, ensuring its stable operation in harsh environments, such as the slew bearings of mechanical equipment by the sea.

To achieve the best combination of lubricating oil and slew bearings, it is necessary to select the appropriate lubricating oil according to the type of slew bearing and working conditions. High – speed slew bearings are suitable for low – viscosity lubricating oil, which can reduce the stirring resistance. Heavy – load and low – speed slew bearings require high – viscosity lubricating oil with excellent extreme – pressure resistance to ensure the strength of the oil film. For example, low – viscosity precision machine tool oil is selected for the high – speed spindle slew bearings of machine tools, while high – viscosity lubricating oil with special anti – wear additives is used for the large heavy – load slew bearings of mining machinery.

At the same time, the correct lubrication method is also of great importance. Common lubrication methods include oil bath lubrication, splash lubrication, oil injection lubrication, and grease lubrication. Oil bath lubrication is suitable for medium – and low – speed slew bearings, where the slew bearing is partially immersed in oil for lubrication. Splash lubrication relies on rotating components to splash oil onto the slew bearing. Oil injection lubrication is used for high – speed, heavy – load, and important slew bearings, and oil is supplied precisely through an oil injection nozzle. Grease lubrication is often used for small, low – speed, and hard – to – lubricate slew bearings, using lubricating grease for lubrication.

In practical use, it is also necessary to regularly check the condition of the lubricating oil and the operation of the slew bearing. The lubricating oil will gradually age and become contaminated during use, and its performance will decline. Therefore, it needs to be replaced regularly. By checking the wear and clearance changes of the slew bearing, problems can be detected in a timely manner, and maintenance or replacement can be carried out to effectively avoid equipment failures and ensure the continuity of production.

Lubricating oil and slew bearings are interdependent and jointly safeguard the stable operation of machinery. In today’s continuously developing industry, in – depth research and rational application of lubricating oil and slew bearing technologies are of great significance for improving mechanical performance, reducing energy consumption, and extending the service life of equipment. They are a key link in promoting the efficient development of the industry.

The Price of Slewing Slew bearings

The price of slewing slew bearings is affected by many factors. Material is a key factor. Slewing slew bearings made of high – quality steel and special alloys have better strength and wear resistance and are more expensive. For example, those made of high – grade alloy steel are more expensive than those made of ordinary steel. Processing precision is also very important. High – precision processing requires advanced equipment and sophisticated technology, which can ensure slewing accuracy and reduce vibration. Accordingly, the cost and selling price are also high. When the demand from industries such as construction and wind power is high and the supply is insufficient, the price rises. If the demand is weak and the supply is excessive, the price will fall.

Supplier of Slewing Slew bearings

LDB bearing is an outstanding model in the slew bearing industry! Over the past twenty – odd years, it has adhered to quality, growing from an inexperienced enterprise to a mainstay in the industry. Its products combine technology and craftsmanship. High – precision slewing slew bearings, slewing drive devices, etc. are widely used in many fields and perform remarkably in areas such as industrial welding robots. It always adheres to the vision of “meticulous manufacturing, serving the world”, constantly innovates and breaks through, and has leading technical strength. With reliable product quality and excellent services, it has won the trust of global customers. In the future, it will surely continue to lead the industry trend and contribute more to the development of the world’s industry!

The Importance of Sealing in Slewing Bearings

April 3, 2025/in Bearing Knowledge /by wang

The sealing technology of slewing supports is of great significance to the operation and lifespan of equipment. It ensures the normal operation of components by preventing the intrusion of pollutants and the leakage of lubricating oil.

What is the Sealing of a Slewing Bearing?

Slewing bearings are widely used in mechanical equipment such as cranes, excavators, and wind turbines. During operation, they need to withstand complex loads and harsh working environments. As an important part of slewing bearings, sealing technology mainly serves to prevent external pollutants such as dust, moisture, and impurities from entering the interior of the slewing bearing and to prevent the leakage of internal lubricating oil, thereby ensuring the normal operation of various components of the slewing bearing and extending the service life of the equipment.

The Principle of Slewing Bearing Sealing Technology

The sealing principle of slewing bearings is mainly based on preventing or reducing the leakage and intrusion of substances. Sealing devices usually form an effective sealing barrier at key parts such as between the inner and outer rings of the slewing bearing and between the rolling elements and the raceways to achieve the sealing function.

Take contact – type seals as an example. The seal contacts the slewing components tightly, and the elastic deformation of the seal is used to fill the gaps, preventing external pollutants from entering and internal lubricating oil from leaking. Non – contact – type seals, on the other hand, achieve sealing by setting up special structures, such as labyrinth – type structures. By utilizing air resistance and multiple barriers, it is difficult for pollutants to enter the interior of the slewing bearing, and at the same time, the leakage of lubricating oil is reduced.

Types of Slewing Bearing Seals

Contact – Type Seals

Lip – Seal: The lip – seal is one of the most common types of contact – type seals, usually made of elastic materials such as rubber. It has one or more lips that fit tightly against the surface of the slewing component to form a seal. The advantages of the lip – seal are its simple structure and good sealing performance, which can effectively prevent pollutants such as dust and moisture from entering the interior of the slewing bearing. However, during high – speed rotation, the friction between the lip and the slewing component is relatively large, which can easily cause wear of the seal and reduce the sealing life.

– O – Ring Seal: The O – ring seal is a circular rubber seal installed in a sealing groove. It achieves sealing through its own elastic deformation. The O – ring seal has good sealing performance, can withstand a certain pressure, and is easy to install with a low cost. However, in high – temperature, high – pressure, or chemically corrosive environments, the performance of the O – ring may be affected, leading to seal failure.

Non – Contact – Type Seals

– Labyrinth Seal: The labyrinth seal creates a labyrinth – like passage by setting up a series of interlaced grooves and protrusions between the inner and outer rings of the slewing bearing. When pollutants attempt to enter the interior of the slewing bearing, they need to pass through a tortuous path. During this process, the pollutants are blocked by air resistance, and most of them are blocked outside the labyrinth, thus achieving sealing. The advantages of the labyrinth seal are no contact friction, suitability for high – speed rotation, and a long service life. However, its sealing effect is relatively weak, and its ability to block fine particles is limited.

– Centrifugal Seal: The centrifugal seal uses the centrifugal force generated by the high – speed rotation of the slewing component to throw away the pollutants near the sealing part, thereby achieving the purpose of sealing. This sealing method is usually used in combination with other sealing methods to improve the overall sealing performance. The centrifugal seal has a good sealing effect when the rotation speed is high and the pollutant particles are large, but it has a poor sealing effect for low – speed rotation or fine particles.

The Impact of Sealing Technology on Equipment Performance

Impact on the Service Life of the Slewing Bearing

Good sealing technology can effectively prevent external pollutants from entering the interior of the slewing bearing, reducing the wear and corrosion of components such as rolling elements and raceways, thus extending the service life of the slewing bearing. Conversely, if the seal fails and pollutants such as dust and moisture enter the interior of the slewing bearing, it will intensify the wear of the components and cause the slewing bearing to be damaged prematurely.

Impact on the Operating Stability of the Equipment

The quality of the sealing technology directly affects the operating stability of the equipment. When poor sealing leads to the leakage of lubricating oil, the lubrication effect between the components of the slewing bearing will deteriorate, resulting in additional friction and vibration, which affects the normal operation of the equipment. In addition, the entry of pollutants into the interior of the slewing bearing may also cause changes in the gaps between the components, further affecting the operating accuracy and stability of the equipment.

Impact on the Equipment Maintenance Cost

Effective sealing technology can reduce the frequency and cost of equipment maintenance. For slewing bearings with good sealing, the internal components are less polluted, and there is no need for frequent maintenance work such as cleaning and replacement of components. However, for slewing bearings with seal failure, not only frequent maintenance is required, but it may also be necessary to replace the entire slewing bearing due to component damage, thus increasing the equipment maintenance cost.

The sealing technology of slewing bearings is a key factor in ensuring the normal operation of equipment and extending its service life. Different types of sealing technologies have their own advantages and disadvantages. In practical applications, it is necessary to comprehensively select the appropriate sealing method according to factors such as the working environment, rotation speed, and load of the slewing bearing. At the same time, with the continuous development of science and technology, new sealing materials and sealing structures are constantly emerging. Relevant technicians should pay close attention to the development trends of sealing technology and continuously optimize the sealing design to improve the sealing performance of slewing bearings and further enhance the overall performance and reliability of the equipment.

The Price of Slewing Bearings

There are many factors that affect the price of slewing bearings. Firstly, the type and structure, such as different structures like single – row, double – row, or triple – row roller types, have price differences due to different design and manufacturing complexities. Secondly, the accuracy grade is crucial. High – precision slewing bearings are more difficult to process and thus more expensive. Moreover, the choice of materials has a significant impact. Slewing bearings made of high – quality alloy steel or special materials have high costs and correspondingly higher prices. Finally, market supply – and – demand relationships can cause price fluctuations. When supply is in short supply, prices rise, and when there is an oversupply, prices may fall.

Supplier of Slewing Bearings

LDB bearing compan!Since its establishment, it has been shining all the way. Empowered by multiple sets of advanced equipment, it can handle the processing of various bearings with ease. With many professional talents delving into research, it has created a legend of quality. Products such as the S – series slewing drives have excellent performance, with precise transmission and strong load – bearing capacity, and have shown their prowess in fields such as industrial robots. With strict quality control, it has passed authoritative certifications. It has partnered with many well – known enterprises. LDB bearing leads the bearing industry with its strength and will surely create more brilliance in the future!

Preventive Measures for the Failure of Slewing Bearing

April 3, 2025/in Bearing Knowledge /by wang

Slewing bearings are widely used in various types of equipment.Once a failure occurs, it will not only lead to equipment downtime and increased maintenance costs but may also cause safety accidents. Therefore, it is of great significance to analyze the failure modes of slewing bearings.

What is the Failure of a Slewing Bearing?

Slewing bearings play a crucial role in the slewing function of various mechanical devices. Their failure can seriously affect the operation of the equipment. This article deeply analyzes the common failure modes of slewing bearings, including wear, fatigue fracture, corrosion, and seal failure, and proposes corresponding preventive measures and suggestions for each failure mode, providing a reference for ensuring the reliable operation of slewing bearings.

Common Failure Modes of Slewing Bearings

Abrasive Wear:Impurities such as dust and sand in the working environment enter the interior of the slewing bearing and form abrasive particles between the rolling elements and the raceways. As the slewing motion occurs, these abrasive particles continuously scrape the surface, causing the surface material to gradually peel off and resulting in wear. In the slewing bearings of mining machinery, abrasive wear is relatively common due to the dusty working environment.

Adhesive Wear:Under heavy – load, high – speed, or poor – lubrication conditions, the oil film on the surfaces of the rolling elements and the raceways is damaged, and the metals come into direct contact. Local high temperatures and pressures are generated, causing the surface materials to adhere to each other. Subsequently, the adhered points are torn apart during relative motion, resulting in adhesive wear.

Under long – term alternating loads, fatigue cracks will occur on the surface or inside of the slewing bearing. These cracks continue to expand and eventually lead to component fracture. Fatigue fractures usually occur in stress – concentration areas, such as the edges of the raceways and around the bolt holes. For example, during the frequent lifting of heavy objects by a crane, the load on the slewing bearing changes frequently, making it prone to fatigue fracture.

Chemical Corrosion:When slewing bearings are exposed to environments containing corrosive media, such as humid air, seawater, and chemical solutions, the surface metal will react chemically with the corrosive media, resulting in corrosion. In marine engineering equipment, slewing bearings are easily corroded by seawater.

Electrochemical Corrosion:When there is a potential difference between different metal components of a slewing bearing and they are in an electrolyte solution, an electrochemical corrosion cell is formed, accelerating the corrosion of the metal. For example, if the bolts of a slewing bearing are made of a different material from the base material, electrochemical corrosion is likely to occur in a humid environment.

The aging, damage, or improper installation of the seals can lead to seal failure of the slewing bearing. After the seal fails, external impurities such as dust and moisture can easily enter the interior, exacerbating wear and corrosion. At the same time, the internal lubricating oil will leak, affecting the lubrication effect and further leading to the failure of the slewing bearing.

Preventive Measures and Suggestions for Failure

Strengthen Sealing Protection:Use high – quality sealing devices and regularly inspect and replace the seals to prevent dust and impurities from entering the interior of the slewing bearing. For example, combine labyrinth seals and lip – type seals to improve the sealing effect.

Optimize the Lubrication System:Select the appropriate lubricating oil and lubrication method, and regularly add and replace the lubricating oil to ensure a good oil film is formed between the rolling elements and the raceways. Depending on the working conditions, a forced lubrication or automatic lubrication system can be used.

Improve Component Machining Accuracy：Strictly control the machining accuracy of the rolling elements and raceways, reduce the surface roughness, and reduce the occurrence of abrasive wear and adhesive wear.

Rationalize the Structure Design：Optimize the structural design of the slewing bearing to reduce stress – concentration areas. For example, use rounded corners at the edges of the raceways to avoid sharp corners, and rationally design the position and size of the bolt holes to reduce the stress – concentration factor.

Control the Working Load：Arrange work tasks reasonably according to the rated load of the equipment to avoid overloading. In equipment such as cranes, install overload protection devices to prevent the slewing bearing from bearing excessive alternating loads due to overloading.

Conduct Regular Inspections and Maintenance：Regularly perform non – destructive testing on slewing bearings, such as ultrasonic testing and magnetic particle testing, to detect fatigue cracks in a timely manner and repair or replace them.

Apply Surface Protection Treatments：Carry out anti – corrosion treatments on the surface of the slewing bearing, such as spraying anti – corrosion paint, electroplating, and hot – dip galvanizing, to form a protective film and isolate the corrosive media. In a marine environment, coatings resistant to seawater corrosion can be used for surface spraying.

Select Corrosion – Resistant Materials：Select appropriate corrosion – resistant materials to manufacture the key components of the slewing bearing according to the working environment. For example, in chemical equipment, stainless – steel materials can be used to manufacture slewing bearings.

Control Environmental Factors：Try to improve the working environment of the slewing bearing and reduce contact with corrosive media. For example, in a humid environment, take moisture – proof measures and install dehumidifying equipment.

Select High – Quality Seals：Select reliable, age – resistant, and wear – resistant seals according to the working conditions of the slewing bearing. In high – temperature environments, choose high – temperature – resistant rubber seals; in high – pressure environments, choose seals with good sealing performance.

Install Seals Correctly：Install the seals strictly in accordance with the installation instructions to ensure the correct installation position and that the seals are free from distortion and deformation. During the installation process, pay attention to protecting the surface of the seals to avoid scratches.

Regularly Inspect and Replace Seals：Regularly inspect the condition of the seals. If aging, damage, or leakage is found, replace them in a timely manner.

The failure of slewing bearings can seriously affect the normal operation of equipment. By analyzing common failure modes and taking corresponding preventive measures, such as strengthening sealing protection, optimizing the lubrication system, rationally designing the structure, controlling the working load, and applying surface protection treatments, the failure risk of slewing bearings can be effectively reduced, their service life can be extended, and the reliability and safety of the equipment can be improved. In practical applications, a variety of preventive measures should be comprehensively applied according to the specific working conditions of the slewing bearing to ensure its stable operation.

The Price of Slewing Bearings

Larger – sized slewing bearings with strong load – bearing capacity are relatively more expensive because they require more raw materials and more complex processing techniques. For example, the slewing bearings used in large – scale cranes can have a diameter of several meters and are much more expensive than those used in small – scale equipment..Slewing bearings made of high – quality materials have better wear resistance, corrosion resistance, and strength, ensuring long – term stable operation under harsh working conditions. Their prices also increase due to the higher material costs. For example, slewing bearings made of high – strength alloy steel or stainless – steel materials are more expensive than those made of ordinary carbon – steel materials.

Supplier of Slewing Bearings

Since its establishment in Luoyang, Henan Province, a bearing production base in China, in 1999, LDB bearing company has been deeply engaged in the bearing manufacturing field and achieved remarkable results. In terms of products, LDB bearing company has been highly productive. From the strict screening of raw materials entering the factory, to every process in the production process, and finally to the product leaving the factory, strict process control and quality control are implemented to ensure that each product leaving the factory meets high – quality standards. With its professional strength, excellent products, strict quality control, and wide market, LDB bearing company has become a leader in the bearing manufacturing industry. It is expected to continue to explore and innovate in the future and contribute more to the global industrial development.

The Applications of Dynamics of Slewing Bearings

April 3, 2025/in Bearing Knowledge /by wang

Slewing bearings is a crucial component of mechanical equipment, and its dynamic characteristics have a significant impact on the performance of the equipment. It consists of an inner ring, an outer ring, rolling elements, and a cage. It has been found that the force and vibration characteristics vary under different working conditions.

What is Slew Bearing in the Dynamics?

Slewing bearings are widely used in equipment such as cranes, excavators, and wind turbines. They are responsible for transmitting axial forces, radial forces, and overturning moments. Their dynamic characteristics are of great significance for the stability, reliability, and service life of the equipment. Under different working conditions, the stress and motion states of slewing bearings are complex and variable. In – depth research on their dynamic characteristics helps to accurately grasp the working performance, provides strong support for optimized design, and thus enhances the competitiveness of the equipment.

Working Principle and Structural Types of Slewing Bearings

A slewing bearing usually consists of an inner ring, an outer ring, rolling elements, and a cage. The inner ring is connected to the fixed part of the equipment, and the outer ring is connected to the slewing part. When the equipment is operating, relative slewing motion is achieved through the rolling of the rolling elements between the raceways of the inner and outer rings, while bearing loads in different directions.

Common slewing bearings include single – row four – point contact ball type, double – row non – uniform diameter ball type, and crossed roller type. The single – row four – point contact ball type has a simple structure and low cost, and can withstand large axial forces and overturning moments. The double – row non – uniform diameter ball type has a strong load – bearing capacity and is suitable for heavy – load working conditions. The crossed roller type has good rigidity and high precision and is often used in equipment with strict requirements for slewing accuracy.

Analysis of the Dynamic Characteristics of Slewing Bearings under Different Working Conditions

Static Working Conditions

Under static working conditions, slewing bearings mainly bear the self – weight of the equipment, the weight of fixed components, and external loads in a stationary state. At this time, the stress distribution at the contact points between the rolling elements and the raceways depends on the magnitude and direction of the load. Through the elastic contact theory, the contact stress and deformation can be calculated, providing a theoretical basis for determining the load – bearing capacity and fatigue life of the slewing bearing.

Dynamic Working Conditions

Uniform Rotation Working Conditions

During uniform rotation, in addition to static loads, slewing bearings are also subjected to centrifugal forces and frictional forces. The centrifugal force causes additional pressure on the raceways by the rolling elements, and the frictional force affects the smoothness of rotation. Using the multi – body dynamics theory, a dynamic model of the slewing bearing is established to analyze its motion parameters and stress changes during uniform rotation, such as the rotational speed, acceleration of the rolling elements, and contact force fluctuations.

Starting and Braking Working Conditions

During the starting and braking processes, slewing bearings will generate impact loads. When starting, the driving torque overcomes the static friction force to accelerate the rotation of the slewing part; when braking, the braking torque decelerates the slewing part until it stops. In these two processes, the impact load may cause an instantaneous increase in the contact stress between the rolling elements and the raceways, affecting the service life of the slewing bearing. By using a dynamic simulation software to simulate the starting and braking processes, the magnitude and action time of the impact load are analyzed, providing a reference for optimizing the braking and starting strategies.

Variable Load Working Conditions

In actual work, slewing bearings often bear variable loads. For example, when a crane hoists a heavy object, the magnitude and direction of the load change with the working state. Variable loads can cause vibrations in slewing bearings, and in severe cases, affect the normal operation of the equipment. Modal analysis and response spectrum analysis methods are used to study the vibration characteristics of slewing bearings under variable loads, determine their natural frequencies and vibration responses, and provide a direction for structural optimization.

Research Methods

Theories such as material mechanics, elasticity mechanics, and contact mechanics are used to derive the calculation formulas for the stress and deformation of slewing bearings under different working conditions. Combined with the basic equations of dynamics, a dynamic model of the slewing bearing is established to analyze its motion and stress characteristics. Theoretical analysis provides a basis and direction for subsequent research.

Professional software such as ANSYS and ADAMS is used to establish a virtual model of the slewing bearing. The working states under different working conditions are simulated to obtain detailed dynamic parameters such as stress, strain, displacement, velocity, and acceleration. By changing the model parameters, the influence of various factors on the dynamic characteristics is studied, providing data support for optimized design.

An experimental platform for slewing bearings is built to simulate actual working conditions for loading tests. Sensors are used to measure parameters such as the stress, vibration, and rotational speed of the slewing bearing. The experimental results can verify the accuracy of theoretical analysis and simulation, and provide a basis for improving the research model.

Optimization Design Strategies Based on Dynamic Characteristics

Structural Parameter Optimization

According to the research results of dynamic characteristics, the structural parameters of slewing bearings are optimized, such as the number and diameter of rolling elements, and the radius of curvature of the raceways. Through optimization, the contact stress can be reduced, the vibration can be decreased, and the load – bearing capacity and service life can be improved.

Material Selection Optimization

Appropriate materials are selected to improve the strength, hardness, and wear resistance of slewing bearings. The use of new materials or surface treatment of existing materials can improve their mechanical properties to meet the requirements of different working conditions.

Manufacturing Process Improvement

The manufacturing process is optimized to improve the machining accuracy and assembly quality of slewing bearings. High – precision machining and assembly can reduce the gaps and errors between components, reduce vibration and noise, and enhance the dynamic performance of slewing bearings.

The Price of Slewing Bearings

There are many factors affecting the price of slewing bearings. Firstly, the specifications and dimensions are key factors. Large – sized slewing bearings with high load – bearing capacity are expensive due to high material consumption and complex processes. Secondly, the accuracy grade is also important. High – precision products are often more expensive due to strict processing requirements. Moreover, the quality of materials has a significant impact. Slewing bearings made of high – quality materials have good performance and a correspondingly higher price. In addition, the reputation of brand manufacturers, market supply – and – demand relationships, and surface treatment and protection requirements can all cause fluctuations in the price of slewing bearings. Products with special surface treatments usually have a higher price.

Supplier of Slewing Bearings

Since its establishment in 1999, LDB bearing company has been shining in the bearing manufacturing field. It is located in Luoyang, Henan Province, which is a bearing production base in China. Taking advantage of favorable geographical location and gathering industry elites, its slewing bearings, slewing drives and other products, with precise design and high – quality material selection, have high performance and reliability. This is best proved by its ISO9001:2015 certification and German TUV certification. Its products are exported to 73 countries and regions, serving many fields such as industrial robots and solar power generation equipment. It has partnered with many well – known international enterprises. From pre – sales customization, in – sales strict control to after – sales worry – free service, LDB bearing company interprets the responsibility of an industry model with comprehensive services, and is worthy of being a dazzling star in the bearing industry.

Why Evaluate the Performance of Slew bearings?

April 2, 2025/in Bearing Knowledge /by wang

Rotary bearings are crucial basic components of mechanical equipment.The evaluation content covers multiple aspects, and corresponding professional tools and methods are used for measurement and analysis respectively to determine whether they can meet the operating requirements of the equipment.

What is the Performance Evaluation of Slew bearings?

The performance evaluation of slew bearings is a process of comprehensively assessing the quality, reliability, and other performance aspects of slew bearings using professional methods. The evaluation covers multi – dimensional indicators. For example, dimensional accuracy ensures precise coordination with equipment components; material properties, including hardness, toughness, and wear resistance, are related to load – bearing capacity and durability; clearance accuracy affects rotational accuracy and load – bearing capacity; rotational flexibility, fatigue life, vibration and noise characteristics, and lubrication performance are also within the scope of evaluation. Through various methods such as micrometer measurement, hardness testing, clearance measuring instrument detection, and fatigue life testing, data is obtained and analyzed to determine whether the slew bearing can meet the operating requirements of the equipment.

Dimensional Accuracy Evaluation

Dimensional accuracy is a fundamental indicator for measuring the quality of slew bearings. The inner diameter, outer diameter, and width of slew bearings must strictly comply with design standards. Taking the inner diameter as an example, its tolerance range is extremely crucial as it directly determines the fitting accuracy between the slew bearing and the shaft. If the inner diameter size error is too large, it will cause problems such as loose fitting or improper interference between the slew bearing and the shaft. A loose fit will cause the slew bearing to experience radial run – out during operation, affecting the processing accuracy of the equipment; while excessive interference may damage the shaft and increase the assembly difficulty. The accuracy of the outer diameter size is equally important, as it is closely related to the fitting accuracy of the mounting hole and affects the positioning accuracy of the slew bearing in the equipment. The accuracy of the width dimension also has a significant impact on the axial positioning of the slew bearing and its coordination with other components. In actual evaluation, high – precision measuring tools such as micrometers and internal diameter gauges are usually used to measure the various dimensions of the slew bearing, and it is determined whether it is qualified according to relevant standards.

Clearance Evaluation

The radial clearance refers to the radial gap between the inner ring, outer ring, and rolling elements of a slew bearing. It has an important impact on the rotational accuracy and load – bearing capacity of the slew bearing. When the radial clearance is too large, the slew bearing will experience significant radial run – out during rotation, which not only affects the processing accuracy of the equipment but also increases vibration and noise. For example, in the spindle slew bearings of precision machine tools, an excessive radial clearance will cause the dimensional accuracy and surface roughness of the processed parts to fail to meet the requirements. Conversely, if the radial clearance is too small, the slew bearing will experience increased friction and heat generation during operation, leading to accelerated wear and even possible jamming. When evaluating the radial clearance, a special measuring instrument such as a clearance measuring instrument is usually used. The clearance value is determined by measuring the amount of movement of the inner ring relative to the outer ring in the radial direction, and it is judged whether it is appropriate according to the type of slew bearing and the application scenario.

The axial clearance plays a key role in the axial positioning and stability of the shaft. An appropriate axial clearance can ensure that the shaft has an appropriate moving space when subjected to an axial force, avoiding excessive load on the slew bearing due to the large axial force, which may lead to premature damage. In some equipment that requires precise axial positioning, such as the crankshaft slew bearings of automotive engines, the precise control of the axial clearance is particularly important. The method for evaluating the axial clearance is similar to that for the radial clearance, which is also measured by a special measuring tool and judged according to relevant standards.

Fatigue Life Evaluation

Fatigue life is a key indicator for measuring the service life of slew bearings under actual working conditions. During the operation of a slew bearing, due to the continuous action of alternating loads, fatigue cracks gradually form in its internal materials. When the cracks expand to a certain extent, the slew bearing will fail. To evaluate the fatigue life of a slew bearing, a fatigue life test is usually carried out. During the test, the slew bearing is installed on a special test bench and operated under specified load, speed, and lubrication conditions until the slew bearing fails (such as cracks or fractures in the rolling elements or rings). By recording the time or number of revolutions from the start of operation to failure of the slew bearing, its fatigue life is determined. The results of the fatigue life test can not only provide a basis for the selection of slew bearings but also help enterprises optimize the design and manufacturing process of slew bearings, improving the quality and reliability of slew bearings.

Vibration and Noise Characteristics Evaluation

The vibration and noise characteristics of slew bearings directly affect the operation stability of the equipment and the comfort of the working environment. During the evaluation, vibration sensors and other devices are usually used to measure the vibration signals of the slew bearing during operation. By analyzing the vibration signals, parameters such as vibration frequency and amplitude are extracted to determine whether there are any abnormalities in the slew bearing. For example, when a slew bearing has local wear, a peak at a specific frequency will appear in the vibration signal. At the same time, noise analysis is also an important means of evaluating the vibration and noise characteristics of slew bearings. By performing spectral analysis on the noise generated during the operation of the slew bearing, the noise source and fault type can be more accurately identified. In some applications with strict requirements for vibration and noise, such as precision instruments and high – speed trains, the evaluation of the vibration and noise characteristics of slew bearings is particularly important.

Lubrication Performance Evaluation

The lubrication performance of slew bearings has an important impact on aspects such as friction, wear, and heat dissipation. When evaluating the lubrication performance, the first consideration is whether the selected lubricant is appropriate. Different types of slew bearings and working conditions require different lubricants. For example, lubricating oil is suitable for high – speed and light – load applications, while lubricating grease is more suitable for low – speed and heavy – load or long – term lubrication situations. When evaluating the distribution of the lubricant in the slew bearing, simulation tests or advanced visualization techniques can be used to observe whether the flow and distribution of the lubricant inside the slew bearing are uniform. In addition, it is also necessary to evaluate the formation of the lubricating film. A good lubricating film can effectively reduce the friction coefficient and reduce wear. By measuring the friction coefficient of the slew bearing during operation and observing the shape and depth of the wear marks, the quality of the lubricating film and the pros and cons of the lubrication performance can be judged. At the same time, the compatibility between the lubricant and the slew bearing material is also an important aspect of evaluating the lubrication performance. Incompatible lubricants may cause corrosion or deterioration of the slew bearing material, affecting the normal operation of the slew bearing.

The performance evaluation of slew bearings is a complex and systematic project, involving multiple key indicators and various evaluation methods. Only through comprehensive and scientific performance evaluation can it be ensured that slew bearings can operate reliably under various working conditions, providing solid support for the efficient development of modern industry. With the continuous progress of industrial technology, the requirements for the performance evaluation of slew bearings will become increasingly higher, and relevant evaluation technologies and methods also need to be continuously innovated and improved.

The Price of Slew bearing Performance Evaluation

There are many factors that affect the price of slew bearing performance evaluation. Firstly, the evaluation items and accuracy requirements are crucial. If comprehensive and high – precision tests are required, such as microstructure analysis and high – precision dimensional measurement, the price will increase due to high technical and equipment costs. Secondly, the specifications and types of bearings have an impact. Large – sized or bearings with special structures have higher evaluation prices due to the difficulty of testing and the need for special equipment. Thirdly, the qualifications and reputation of the evaluation agency also play a role. Agencies with high qualifications and good reputations usually charge more. Finally, the market supply – and – demand relationship can cause price fluctuations. When the demand is high, the price rises, and vice versa.

Supplier of Slew bearing

As a leader in the bearing field, LDB Bearing Company takes innovation and quality as its core and continuously provides global customers with products and services that exceed expectations. Its products, with high – precision design, strict production processes, and durability, perform outstandingly under extreme working conditions such as heavy loads and high speeds, becoming the “core guardians” in the high – end manufacturing field.

How to Ensure the Reliability of Slewing Bearings in Medical Equipment

April 2, 2025/in Bearing Knowledge /by wang

To ensure the reliability of slewing bearings in medical equipment, multiple aspects need to be considered comprehensively. Quality control should be strict, and reliability can also be guaranteed through redundant design and life assessment.

What are Slewing Bearings in Medical Equipment?

Slewing bearing for medical equipment are key mechanical components used in medical devices. They mainly function to connect and support rotatable parts, enabling the equipment to achieve smooth and precise slewing motion. For example, in large – scale imaging diagnostic equipment such as CT scanners and magnetic resonance imaging (MRI) machines, the slewing support ensures the stable rotation of the scanning components, accurately obtaining images of different angles of the human body, which helps doctors make accurate diagnoses. It features high precision to guarantee the accuracy of equipment operation, high load – bearing capacity to support heavy components of the equipment, and excellent reliability and durability, reducing equipment failures and maintenance costs. It is of great significance for the normal operation of medical equipment and diagnostic accuracy.

Material Selection

Biocompatibility:For slew bearings in medical equipment that come into direct or indirect contact with the human body, the biocompatibility of the material is of utmost importance. Medical – grade stainless steel, for instance, has good strength and corrosion resistance, and it causes minimal irritation to human tissues. Titanium alloy has even more advantages. Not only does it have excellent biocompatibility, but it also has a low elastic modulus, which can better match human bones and reduce the stress – shielding effect. Ceramic materials such as alumina and zirconia ceramics, in addition to good biocompatibility, have extremely high hardness and wear resistance, which can effectively reduce the generation of wear particles and minimize potential harm to human tissues. In addition, some biocompatible polymer materials are also applied to specific medical bearings, as they possess good flexibility and chemical stability.

Corrosion Resistance:The medical environment contains various corrosive substances, such as hydrogen peroxide and chlorine – containing disinfectants used for disinfection. The bearing material must have excellent corrosion resistance to prevent surface corrosion. For example, nickel – based alloys are used in some medical equipment bearings with high corrosion – resistance requirements due to their good anti – corrosion properties. Even when in long – term contact with corrosive substances or in a humid environment, these materials can maintain the integrity and performance of the bearings, avoiding problems such as increased surface roughness and dimensional changes caused by corrosion, thus ensuring the reliability of the bearings.

Mechanical Properties:Different medical equipment has varying requirements for the mechanical properties of bearings. In high – load medical equipment such as large – scale radiotherapy equipment, the bearings need to withstand huge weights and dynamic loads. Therefore, the material is required to have high strength and toughness to prevent fracture or deformation during operation. For some high – precision diagnostic equipment, such as the fine – tuning mechanism bearings of optical microscopes, in addition to a certain strength requirement, more emphasis is placed on the hardness and wear resistance of the material to ensure that it can achieve precise micro – displacement adjustment and maintain accuracy during long – term use.

Precision Requirements

Dimensional Accuracy:The dimensional accuracy of bearings in medical equipment directly affects the overall performance of the equipment. For example, in the joint parts of surgical robots, the dimensional tolerances of the inner and outer diameters of the bearings usually need to be controlled within a few microns to ensure the motion accuracy of the robotic arm. If the dimensional accuracy is insufficient, it may lead to joint looseness or poor movement, affecting the accuracy of surgical operations. Similarly, in some precision medical testing instruments, the width accuracy of the bearings also needs to be strictly controlled to ensure their fit accuracy with other components, enabling stable operation and accurate measurement.

Rotational Accuracy:For medical equipment that relies on high – speed rotation to function, such as CT scanners and centrifuges, the rotational accuracy of the bearings is crucial. Take high – end CT scanners as an example. The bearings of their rotating parts need to ensure that the radial and axial run – outs during high – speed rotation are controlled within the micron level. This can ensure that the relative positions of the X – ray source and the detector remain precisely unchanged, thus obtaining high – quality scan images. If the rotational accuracy does not meet the standard, problems such as blurred and distorted images will occur, affecting doctors’ accurate judgment of the condition.

Lubrication and Sealing

Lubrication Method:Selecting the appropriate lubrication method and lubricant is one of the key factors in ensuring the reliability of bearings. For some low – speed and light – load medical equipment bearings, grease lubrication is a commonly used method. High – quality lubricating grease has good adhesion and lubrication performance, which can form a uniform oil film on the bearing surface, reducing friction and wear. For high – speed and heavy – load bearings, such as those in the transmission systems of some large – scale medical equipment, oil mist lubrication or circulating oil lubrication may be adopted to provide better heat dissipation and lubrication effects. At the same time, the lubricant must meet medical safety standards, be non – toxic, odorless, and have good chemical stability, and should not deteriorate or produce harmful substances during long – term use.

Sealing Design:A reliable sealing structure is crucial for preventing lubricant leakage and the entry of external contaminants into the bearings. In medical equipment, common sealing methods include mechanical seals and lip seals. For example, in some medical equipment that needs to operate in a sterile environment, a double – sealing structure is used. This can not only effectively prevent lubricant leakage from contaminating the environment but also prevent external bacteria, dust, etc. from entering the inside of the bearings, ensuring that the bearings operate in a clean environment. In addition, the selection of sealing materials is also crucial. They should have good aging resistance and chemical corrosion resistance to adapt to different medical environments and working conditions.

Cleaning and Sterilization

Cleanability:The structural design of the bearings should facilitate cleaning, avoiding complex shapes and hard – to – reach corners to prevent the accumulation of dirt and bacteria. For example, a smooth surface design can be adopted to reduce surface roughness, making it difficult for contaminants to adhere. At the same time, during the installation and maintenance of the bearings, strict cleaning procedures should be developed, and special cleaning tools and cleaning agents should be used to ensure the cleanliness of the bearing surface and interior. For some disassemblable bearings, they should be regularly disassembled and cleaned to remove internal impurities and wear particles.

Sterilization Compatibility:Medical equipment needs to be strictly sterilized before use, and the bearings must be able to withstand common sterilization methods. High – temperature and high – pressure steam sterilization is a common sterilization method. The bearing materials and structures need to maintain stable performance in a high – temperature and high – pressure environment and should not deform or crack. Although ethylene oxide sterilization causes less damage to the equipment, the bearing materials also need to have good tolerance to ethylene oxide and should not be affected in performance due to the absorption of ethylene oxide. Gamma – ray sterilization requires that the bearing materials have good radiation stability and should not change in performance under the action of radiation.

Quality Control and Inspection

Production Process Control:During the production process of bearings, strictly controlling various process parameters is the basis for ensuring product quality. From the melting and forging of raw materials to mechanical processing, heat treatment, and other links, parameters such as temperature, pressure, and processing speed need to be accurately controlled. For example, during the forging process, an appropriate forging ratio can make the internal structure of the material more compact, improving the strength and toughness of the bearings. In the heat treatment process, precisely controlling the heating temperature and cooling rate can enable the bearings to obtain the desired metallographic structure and hardness, thus ensuring the consistency and stability of their performance.

Stringent Inspection:Comprehensive inspection of bearings through various inspection methods is an important measure to ensure their reliability. Visual inspection can detect defects such as cracks and sand holes on the bearing surface. Dimensional accuracy measurement uses high – precision measuring tools, such as coordinate measuring machines, to accurately measure various dimensions of the bearings to ensure they meet the design requirements. Hardness testing can check whether the hardness of the bearing material is within the specified range to ensure its wear resistance and strength. Rotational performance testing uses special equipment to simulate the rotation of the bearings in actual operation and detect parameters such as rotational accuracy and friction torque. Only bearings that meet all the indicators can be used in medical equipment.

Reliability Design and Life Assessment

Redundancy Design:For some critical medical equipment, such as extracorporeal circulation equipment used in heart surgery, to ensure the safe operation of the equipment in case of bearing failure, a redundant bearing design can be adopted. That is, multiple bearings are installed to share the load. When one bearing fails, other bearings can temporarily replace it, buying time for equipment maintenance and replacement and avoiding endangering the patient’s life due to bearing failure and equipment shutdown.

Life Assessment:The service life of bearings in specific medical equipment is evaluated through theoretical calculations and actual simulation tests. Theoretical calculations are based on parameters such as the bearing load, rotation speed, and working temperature, and methods such as fatigue life theory are used to predict its life. The actual simulation test is to simulate the working environment of medical equipment in the laboratory and conduct long – term operation tests on the bearings, observing their wear, fatigue, and other conditions to more accurately evaluate their actual service life. According to the life assessment results, a reasonable maintenance and replacement plan is developed to ensure that the bearings always maintain reliable performance during the equipment operation.

The Price of Slewing Bearings for Medical Equipment

The price of slewing supports for medical equipment is affected by many factors. The material is the foundation. Slewing supports made of high – quality steel have high strength, good toughness, and excellent wear resistance, which can ensure the long – term stable operation of medical equipment, and their prices are relatively high. If ordinary materials are used, although the cost is reduced, the performance and durability may be compromised. The manufacturing process is also crucial. Advanced and precise processes can strictly control the dimensional accuracy and surface roughness. The slewing supports produced by such processes have better performance and naturally come at a higher price. While products produced by simple processes may have a price advantage, there may be potential problems in terms of quality and reliability.

Supplier of Slewing Bearings for Medical Equipment

LDB bearing is also outstanding in terms of service. The company has established a complete pre – sales, in – sales, and after – sales service system to provide customers with comprehensive and one – stop services. Before sales, a professional technical team will communicate in – depth with customers to understand their actual needs and provide customers with personalized product solutions. During sales, the production progress is strictly controlled in accordance with the production management system to ensure on – time product delivery, and the product quality is strictly inspected, with each processing step being tested.

Surface Treatment of Slewing Bearing is important.

April 2, 2025/in Bearing Knowledge /by wang

The surface treatment of slewing bearings involves processing the surfaces of their components to enhance performance and extend lifespan, which can improve the wear resistance, corrosion resistance, and fatigue strength of slewing bearings.

What is the Surface Treatment of Slewing Bearings?

The surface treatment of slewing bearings refers to the processing of the surfaces of slewing bearing components to enhance their performance and service life. Common surface treatment methods include quenching, carburizing, nitriding, etc. Quenching can impart high hardness and wear resistance to the surface; carburizing can increase the carbon content on the surface, improving hardness and fatigue strength; nitriding forms a nitride layer on the surface, enhancing wear resistance, corrosion resistance, and anti – galling properties. In addition, treatments such as hard chromium plating can increase surface hardness and finish, and enhance corrosion resistance. Through these surface treatments, slewing bearings can better adapt to various harsh working conditions, reduce the friction coefficient, minimize wear, and extend their service life in mechanical engineering and other fields.

Types of Surface Treatment Technologies for Slewing Bearings

Thermal Spraying Technology

Thermal spraying is a technology that heats metal or non – metal materials until they are melted or softened, atomizes them through high – speed gas flow, and sprays them onto the surface of slewing bearings to form a coating. Common thermal spraying materials include metals (such as zinc, aluminum) and ceramics (such as alumina, zirconia). According to different heat sources, thermal spraying can be divided into flame spraying, arc spraying, and plasma spraying.

Flame spraying has simple equipment and low costs, but the coating bonding strength is relatively weak; arc spraying has high efficiency and is suitable for large – area spraying; plasma spraying can obtain high – quality coatings with high bonding strength and can spray high – melting – point materials. The coatings formed by thermal spraying have good wear resistance, corrosion resistance, and heat – insulation properties.

Electroplating Technology

Electroplating is a method of depositing a layer of metal or alloy on the surface of slewing bearings using the principle of electrolysis. Common electroplated layers include chromium plating, zinc plating, nickel plating, etc. The chromium – plated layer has high hardness and good wear resistance, which can significantly improve the hardness and anti – scuffing ability of the slewing bearing surface; the zinc – plated layer has good corrosion resistance and can effectively protect the slewing bearing substrate in the atmospheric environment; the nickel – plated layer has both good corrosion resistance and decorative properties. The electroplated layer is closely bonded to the substrate and can evenly cover the complex shapes of the slewing bearing surface, effectively enhancing the surface protection performance.

Chemical Heat Treatment Technology

Chemical heat treatment involves placing slewing bearings in a specific chemical medium. Through processes such as heating, holding, and cooling, the active atoms in the medium penetrate into the surface, changing the surface chemical composition and microstructure, thereby improving surface properties. Common chemical heat treatment methods include carburizing, nitriding, and carbonitriding.

Carburizing can improve the hardness, wear resistance, and fatigue strength of the slewing bearing surface, and is suitable for applications that endure high loads and wear; the surface after nitriding treatment has high hardness, a low friction coefficient, good anti – galling properties, and good corrosion resistance; carbonitriding combines the advantages of carburizing and nitriding, and can obtain a surface layer with excellent properties in a relatively short time, improving the comprehensive performance of slewing bearings.

Surface Quenching Technology

Surface quenching is a method of rapidly heating the surface of slewing bearings to the quenching temperature and then rapidly cooling it to obtain a martensite structure on the surface, thereby increasing surface hardness and wear resistance. Common surface quenching technologies include induction quenching and flame quenching. Induction quenching has a fast heating speed, high production efficiency, and can precisely control the depth and hardness distribution of the quenched layer; flame quenching has simple equipment and is easy to operate, making it suitable for single – piece or small – batch production. After surface quenching, the surface hardness of slewing bearings is significantly increased, while the core still maintains good toughness, effectively improving its wear resistance and fatigue resistance.

The Role of Surface Treatment Technologies

Improving Wear Resistance

The ceramic coatings of thermal spraying, the hard chromium layers of electroplating, the high – hardness penetration layers formed by chemical heat treatment, and the martensite structure after surface quenching can all significantly increase the surface hardness of slewing bearings, reduce the friction coefficient, and minimize surface wear. During the frequent slewing of cranes, slewing bearings with surface treatment can effectively resist the friction and wear between rolling elements and raceways, extending their service life.

Enhancing Corrosion Resistance

The zinc and nickel layers of electroplating, as well as the zinc and aluminum coatings of thermal spraying, form a dense protective film on the surface of slewing bearings, effectively blocking corrosive media such as moisture and oxygen from contacting the substrate and preventing electrochemical corrosion. The nitride layer formed on the surface during nitriding in chemical heat treatment also has certain corrosion resistance, enabling slewing bearings to maintain good performance in harsh environments such as humid and saline conditions.

Improving Fatigue Strength

Surface quenching and chemical heat treatment create residual compressive stress on the surface of slewing bearings, which can effectively counteract the tensile stress generated during operation and delay the initiation and propagation of fatigue cracks. The coatings formed by thermal spraying and electroplating can also improve surface quality, reduce surface defects, and enhance the fatigue strength of slewing bearings, making them more reliable when subjected to alternating loads.

The surface treatment technologies for slewing bearings are diverse, and each technology improves their protective performance in a unique way. In practical applications, surface treatment technologies should be selected rationally based on factors such as the working environment, load characteristics, and cost requirements of slewing bearings to achieve the best protection effect. With the continuous development of materials science and surface treatment technologies, more efficient and environmentally friendly surface treatment technologies will be applied to the slewing bearing field in the future, further enhancing their performance and reliability to meet the growing demands of various mechanical equipment.

The Price of Surface Treated Slewing Bearing

Different surface treatment methods for slewing bearings can affect their prices. Generally, slewing bearings with conventional surface treatments such as quenching and carburizing have relatively moderate prices. This is because these processes are relatively mature and the costs are relatively controllable. However, if more complex or special surface treatment processes such as nitriding and hard chromium plating are used, the prices are usually higher. Nitriding treatment requires special equipment and process control, and the treatment time is long. Hard chromium plating involves costs related to environmental protection, etc. All these factors will increase production costs, resulting in higher product prices. In addition, some high – end surface treatment technologies can significantly improve the performance and service life of slewing bearings, which will also increase the price accordingly.

Suppliers of Slewing Bearing

In the bearing manufacturing field, LDB bearing is a leading company. Since its establishment in Luoyang, China’s bearing production base, in 1999, it has achieved numerous honors. From the incoming inspection of raw materials to the final product leaving the factory, every process is strictly controlled and inspected to ensure reliable product quality, and its products are highly recognized internationally. Whether in terms of product quality, technical level, or market influence, LDB bearing has demonstrated extraordinary strength. We look forward to its continued innovation in the future, contributing more to the development of the global bearing industry.

The Influence on Materials of Slewing Bearing

March 31, 2025/in Bearing Knowledge /by wang

The slewing support is a crucial part of large-scale mechanical equipment. Commonly used materials include medium-carbon alloy steel, alloy structural steel, and special-performance materials, each with its own characteristics and application scenarios.

What is a Slewing Bearing?

A slewing bearing is a large – scale bearing capable of withstanding comprehensive loads. It plays a vital connecting and supporting role in numerous large – scale mechanical equipment. Its structure mainly consists of an inner ring, an outer ring, rolling elements, and a cage. The relative rotation is achieved through the rolling of the rolling elements between the inner and outer rings, thereby supporting the smooth rotation of equipment components. Slewing bearings can withstand large axial forces, radial forces, and overturning moments and are widely used in equipment such as cranes, excavators, wind turbines, and solar tracking systems. It not only ensures the structural stability of the equipment but also enables the equipment to operate flexibly under complex working conditions, playing a key role in enhancing the overall performance and work efficiency of the equipment.

Characteristics and Applications of Commonly Used Materials

Medium – Carbon Alloy Steel: The Balance of Strength and Toughness

Medium – carbon alloy steel is one of the commonly used materials for slewing bearings, with 42CrMo steel being a typical representative. The carbon content of such steel is between 0.3% – 0.6%. After appropriate quenching and tempering treatments, it can possess excellent strength and toughness. In large – scale port cranes, the slewing bearing needs to bear a lifting weight of dozens to hundreds of tons and also withstand the impacts caused by frequent starting, stopping, and turning. With a yield strength of over 930MPa and a tensile strength of over 1080MPa, 42CrMo steel firmly supports the upper structure of the crane, ensuring the normal rotation of the turntable under heavy workloads, avoiding deformation or fracture due to excessive stress, and ensuring the efficient and safe operation of cargo handling operations.

Alloy Structural Steel: The Combination of Wear Resistance and Toughness

20CrMnTi, a low – carbon alloy carburizing steel, is also an ideal material for slewing bearings. Its carbon content is approximately 0.2%. After carburizing, quenching, and low – temperature tempering treatments, the surface hardness can reach HRC58 – 62, forming a hard and wear – resistant surface layer, while the core still maintains good toughness. In the construction machinery field, such as the slewing platform support of excavators, during operation, it not only has to withstand the strong impact force generated by excavation operations but also resist the wear caused by long – term rotation. The high – hardness surface layer of 20CrMnTi steel after carburization effectively reduces the degree of wear and extends the service life, and the toughness of the core ensures that it will not undergo brittle fracture when subjected to instantaneous impacts, guaranteeing the stable operation of the excavator.

Special – Performance Materials: Coping with Extreme Working Conditions

In some special environments, ordinary alloy steels are difficult to meet the requirements, so special – performance materials have emerged. In the slewing bearings of high – temperature furnaces in the metallurgical industry, high – temperature alloys come into play. For example, the Inconel 718 alloy can still maintain a relatively high yield strength and tensile strength at a high temperature of 650°C. With its good high – temperature strength, oxidation resistance, and thermal stability, it can work stably in a high – temperature environment for a long time, ensuring the normal operation of the furnace. In the marine engineering field, since the equipment is long – term exposed to high – humidity and highly corrosive seawater, 316L stainless steel has become one of the preferred materials for slewing bearings. It is rich in nickel and molybdenum elements and has excellent seawater corrosion resistance, which can effectively resist seawater erosion, prevent rust and corrosion, extend the service life of the equipment, and reduce maintenance costs.

Consideration Factors in Material Selection

The selection of slewing bearing materials is a comprehensive trade – off process. First, the working conditions of the equipment are key factors. The magnitude of the working load, the speed of rotation, and the temperature, humidity, and pH value of the operating environment all determine the required properties of the materials. For example, in the slewing bearings of high – speed centrifuges, the materials not only need to have high strength and hardness but also good dynamic balance performance to avoid vibrations and noises generated by high – speed rotation. Second, the machinability of the materials cannot be ignored, including cutting machinability, forging performance, and heat treatment performance. Materials that are easy to process can reduce manufacturing costs and improve production efficiency. Finally, cost factors also play an important role in material selection. Under the premise of meeting performance requirements, choosing materials with high cost – performance can effectively control the overall cost of the equipment and improve the competitiveness of products.

New Trends in Material Development

With the continuous progress of industrial technology, slewing bearings face more complex working conditions and higher performance requirements, and material development also shows new trends. On the one hand, high – performance materials are constantly emerging. For example, ceramic – matrix composites combine the high hardness and high – temperature resistance of ceramics with the high strength and high toughness of composites, and are expected to be widely used in slewing bearings in fields such as aerospace and high – speed precision machinery. On the other hand, the greening and sustainable development of materials have also become an important direction. The development of environmentally friendly and recyclable materials can not only reduce the impact on the environment but also achieve the recycling of resources. At the same time, the development of material surface treatment technology has opened up new ways to improve the performance of slewing bearings. Through advanced technologies such as nano – coatings and ion implantation, a special – performance layer can be formed on the surface of the materials, further improving their wear resistance, corrosion resistance, and fatigue life.

The Price of Slewing Bearing Materials

The prices of slewing bearing materials are affected by multiple factors. First, the cost of raw materials is a major factor. The price fluctuations of alloying elements such as chromium and molybdenum directly affect the cost of steel. If the steel contains scarce elements such as tungsten and vanadium, the price will increase due to the high difficulty of mining and acquisition. Second, the production process difficulty is also crucial. Advanced smelting and high – precision processing not only require specialized equipment but also rely on high – tech personnel, greatly increasing the cost. Finally, market supply and demand have a significant impact. With the development of the wind power and construction machinery industries, the demand for slewing bearings has increased. When the demand exceeds the supply, the material price rises. Conversely, if the production capacity of material manufacturers is sufficient and the output is high, resulting in oversupply, the price will decline.

Supplier of Slewing Bearings

LDB Bearing always adheres to the concept of “win – win with customers” and embodies the responsibility of modern industry. With innovation and quality at its core, LDB Bearing continuously provides global customers with products and services beyond expectations. LDB Bearing is not only a link in mechanical transmission but also a powerful engine driving the industrial civilization to a higher level.

What is the slewing bearing of a CT scanner?

March 31, 2025/in Bearing Knowledge /by wang

The slewing bearing of a CT scanner is composed of components such as inner and outer rings and rolling elements. Strict requirements are placed on its accuracy, speed, smoothness, reliability, durability, as well as noise and vibration control.

What are the characteristics of the slewing bearing of a CT scanner?

High precision: It needs to reach sub – millimeter or even higher precision to ensure the precise position of the X – ray tube and detector during rotation, avoid image artifacts, and provide accurate data for diagnosis. High speed: It can achieve rapid rotation, greatly shortening the scanning time, improving the inspection efficiency, and reducing the waiting and inspection time of patients. High stability: It operates stably, reducing vibrations and preventing interference with the scanning results due to shaking, ensuring clear and accurate images. High reliability: It can work continuously and stably for a long time, has good fatigue resistance and wear resistance, and reduces equipment failures and maintenance times. Low noise: It produces low noise during operation, creating a quiet inspection environment for patients, reducing psychological stress, and facilitating patient cooperation.

Structural composition

The slewing bearing is mainly composed of core components such as inner and outer rings and rolling elements. The outer ring can be toothed or non – toothed, and the same applies to the inner ring. The sealing strip can effectively prevent dust, impurities, etc. from entering the interior, protecting the rolling elements and raceways. The rolling elements are divided into two forms: balls and rollers, which roll between the raceways of the inner and outer rings to realize the rotation function of the slewing bearing. The oil filling nozzle is used to add lubricant to reduce friction between components; the plugs and plug pins are used to seal relevant oil passages or mounting holes. In addition, there are spacers or cages, whose function is to evenly separate the rolling elements and ensure the orderly movement of the rolling elements.

Model classification

Slewing bearings have a variety of model classifications, and different models are suitable for different working scenarios. The single – row four – point contact ball slewing bearing consists of two raceways, is compact in structure and light in weight. The steel balls contact the circular arc raceways at four points, and it can simultaneously withstand axial force, radial force, and overturning moment. It is commonly used in construction machinery such as rotary conveyors. The double – row ball slewing bearing with different diameters has three raceways. According to the force conditions, two rows of steel balls with different diameters are arranged up and down. It is convenient for open – type assembly and can withstand a large axial force and overturning moment. It is mostly used in handling machinery such as tower cranes with medium – sized or larger diameters. The single – row crossed roller slewing bearing consists of two raceways, is compact in structure, light in weight, high in manufacturing precision, and small in assembly clearance. The rollers are arranged in a 1:1 cross – pattern and can withstand axial force, overturning moment, and a large radial force. It is widely used in fields such as hoisting and transportation, construction machinery, and military products. The three – row roller slewing bearing has three raceways, and the upper, lower, and radial raceways are separated from each other. It can simultaneously withstand various loads and has the largest load – bearing capacity. It is suitable for heavy machinery such as bucket – wheel excavators. The light – type series slewing bearing has the same structural form as the ordinary slewing bearing, but it is lighter in weight and more flexible in rotation. It is applied to fields such as food machinery that have high requirements for weight and flexibility.

Construction and structural features

The slewing bearing usually forms a slewing drive device together with components such as worms, housings, and motors. Its core slewing bearing can simultaneously withstand axial force, radial force, and overturning moment. Some slewing drive products, such as NFB slewing drives, have advantages such as easy installation, easy maintenance, and space – saving installation.

Heat treatment

The raceways are processed by surface induction hardening, and the quenching hardness reaches HRC55 – 62 to ensure a sufficient hardened layer depth, enhancing wear resistance and load – bearing capacity. The teeth on the slewing bearing rings are generally in the heat – treatment state of normalizing or quenching and tempering. The tooth surface can be quenched as required, and the quenching hardness is HRC50 – 60. According to the application scenarios, it is divided into full – tooth quenching and single – tooth induction quenching (which is further divided into tooth – surface – and – root quenching and tooth – surface quenching).

Working mode

The slewing bearing has two basic working modes: one is that the inner ring is fixed to play a supporting role, and the outer ring rotates; the other is that the outer ring is fixed to play a supporting role, and the inner ring rotates.

CT Scanner: The “X – Ray Eye” of Modern Medicine

A CT scanner, that is, a computed tomography device, is an indispensable and important tool in modern medical diagnosis. It emits and receives X – rays from multiple angles around the patient’s body to obtain tomographic images of the human body’s interior, providing doctors with extremely detailed and accurate information for disease diagnosis.

The core role of the slewing bearing in a CT scanner

Driving component rotation

When the CT scanner is working, the slewing bearing shoulders the important task of driving the X – ray tube and detector to rotate rapidly and accurately around the patient. During this process, the slewing bearing must ensure that the position accuracy of the X – ray tube and detector reaches the sub – millimeter level. Only in this way can the X – ray attenuation data inside the human body be accurately collected from different angles, providing a solid guarantee for the subsequent reconstruction of high – quality three – dimensional tomographic images of the human body. For example, in a head CT scan, the slewing bearing drives the X – ray tube and detector to rotate rapidly around the patient’s head, obtaining scan data from multiple angles in a very short time, thus clearly presenting the internal structure of the head.

Ensuring operation stability

CT scanners often need to work continuously for a long time, and the slewing bearing must have excellent anti – fatigue performance. It needs to be able to withstand long – term, high – intensity operation to ensure the stable operation of the CT machine. At the same time, the good rigidity and accuracy retention of the slewing bearing are also crucial, because any vibration or deformation may have a negative impact on the image quality. Take the CT inspection room of a large general hospital as an example. The CT scanner examines a large number of patients every day, and the stable operation of the slewing bearing is directly related to the smooth progress of the inspection work.

Achieving precise positioning

When scanning different parts or executing different scanning protocols, the slewing bearing needs to precisely control the rotation angle and position to make the X – ray tube and detector accurately aim at the target area. For example, in a high – resolution CT scan of the lungs, the slewing bearing needs to accurately adjust the angle to ensure that the X – ray tube and detector can obtain clear images of the fine structures of the lungs, providing accurate basis for doctors to diagnose lung diseases.

Special requirements of CT scanners for slewing bearings

High precision

CT scanning has extremely high requirements for image quality, and the precision of the slewing bearing directly affects the accuracy of the scanning data. Its manufacturing and installation precision requirements reach sub – millimeter or even higher levels to ensure the stable and precise position of the X – ray tube and detector during rotation. Even a slight deviation may lead to image artifacts and affect the doctor’s diagnosis.

High speed rotation and stability

To improve the scanning efficiency, the slewing bearing needs to be able to achieve high – speed rotation while ensuring a stable rotation process. High – speed rotation can shorten the scanning time, reduce the patient’s discomfort and motion artifacts. And stability is the key to ensuring image quality, avoiding impacts on the scanning results due to vibrations, jams, etc. For example, in a cardiac CT scan, only a fast and stable rotation can capture the accurate shape of the heart at different times.

High reliability and durability

CT scanners are used frequently, and the slewing bearing needs to have high reliability and a long service life to reduce equipment maintenance and downtime. This requires the use of high – quality materials and strict quality inspection and durability testing, with good anti – fatigue, wear – resistant and other properties. Once the CT equipment in a hospital fails, it will affect the inspections and diagnoses of a large number of patients. Therefore, the reliability and durability of the slewing bearing are of great significance.

Low noise and low vibration

In order to provide patients with a quiet and comfortable inspection environment and avoid interference with the scanning results, the slewing bearing should minimize noise and vibration during operation. This can be achieved by optimizing the structural design, selecting appropriate rolling elements, and using proper lubrication methods. When patients are examined in a quiet environment, their psychological stress is relatively low, which is also more conducive to their cooperation.

In conclusion, the slewing bearing and the CT scanner are closely connected. The performance of the slewing bearing is directly related to the imaging quality and operation efficiency of the CT scanner. With the continuous development of medical technology, the requirements for slewing bearings and CT scanners will become higher and higher, and they will also play a more important role in the medical field.

The price of the slewing bearing of a CT scanner

The price of the slewing bearing of a CT scanner is affected by many factors. The material is crucial. Slewing bearings made of high – quality steel or special alloys have a relatively high price due to high costs. Precision requirements are also important. The high – precision slewing bearings required for CT scanners have complex manufacturing processes and strict inspections, increasing costs and thus driving up prices. The price also varies depending on the load – bearing capacity. Slewing bearings that can withstand greater axial, radial forces, and overturning moments have more complex structures and materials, resulting in higher prices.

The supplier of the slewing bearing of a CT scanner

Looking to the future, LDB bearing will continue to adhere to the corporate vision of “meticulous manufacturing, serving the world”, continuously increase R & D investment, improve product quality and technical levels, expand market areas, strengthen international cooperation, and strive towards the goal of becoming a world – class bearing manufacturer. It is believed that with the joint efforts of all employees of LDB bearing, this enterprise, which carries numerous honors and dreams, will surely write an even more glorious chapter in the industrial bearing field and make greater contributions to the development of the global industry.

Why Slew bearings Are So Important?

March 29, 2025/in Bearing Knowledge /by wang

Bearings are of great significance in the industrial system. They support mechanical rotating bodies, reduce friction, and ensure rotational accuracy. They work based on the principle of rolling friction. There is a wide variety of bearing types.

What Is a Slew bearing

The main function of a slew bearing is to support a mechanical rotating body, reduce the friction coefficient during its motion, and ensure its rotational accuracy. Simply put, it’s like a bridge connecting the rotating components and the fixed machine body, allowing the components to rotate smoothly. Its working principle is based on replacing sliding friction with rolling friction. By placing rolling elements (such as balls or rollers) between the shaft and the slew bearing housing, the friction is greatly reduced. Take the deep – groove ball slew bearing as an example. It is the most representative rolling slew bearing. When the shaft rotates, the balls roll between the inner and outer rings with minimal friction, enabling the shaft to rotate at high speed and smoothly. This design not only improves the mechanical efficiency but also extends the service life of the equipment.

Types of Slew bearings

There is a wide variety of slew bearing types, and different types have different characteristics and application scenarios. Common types include deep – groove ball slew bearings, self – aligning ball slew bearings, cylindrical roller slew bearings, and tapered roller slew bearings.

Deep – groove ball slew bearings have a simple structure, low manufacturing cost, small friction coefficient, and high limiting speed. They are the most widely used, often applied in fields such as motors, automobiles, and home appliances.

Self -aligning ball slew bearings have excellent self – aligning performance and can compensate for coaxiality errors. They are suitable for situations where the shaft is bent under stress or misaligned during installation, such as in mining machinery and metallurgical machinery.

Cylindrical roller slew bearings have a large radial load – carrying capacity and are suitable for heavy – load applications. They can often be found in equipment like machine tool spindles and large – scale motors.

Tapered roller slew bearings can withstand both radial and single – direction axial loads. They are commonly used in industries such as automotive, rolling mills, and mining machinery.

Applications of Slew bearings in Various Fields

Transportation Field: In automobiles, slew bearings are widely used in components such as engines, transmissions, and wheel hubs. The slew bearings in the engine support the rotation of the crankshaft to ensure the normal operation of the engine, and those in the transmission enable efficient power transmission between different gears. It is estimated that an ordinary car requires approximately 100 – 150 slew bearings. In rail transportation, high – precision slew bearings are essential for key parts of high – speed trains, such as traction motor slew bearings and bogie axle box slew bearings. These slew bearings not only need to withstand huge loads but also maintain stable performance at high speeds to ensure the safe and smooth operation of the train.

Energy and Power Field: Wind turbines are an important representative of clean energy. Their main shaft slew bearings, pitch and yaw slew bearings, etc., are core components of the turbines. For a 3MW wind turbine, the outer diameter of the main shaft slew bearing can exceed 2m, and it needs to withstand significant axial and radial loads. The requirements for slew bearings in the nuclear power field are even more stringent. The main pump thrust slew bearing needs to support hundreds of tons of weight, and the control rod drive mechanism slew bearings need to work stably in a high – radiation environment.

High – end Manufacturing Field: In CNC machine tools, the rotational speed of the motorized spindle slew bearings can reach over 40,000 rpm, and the ball screw support slew bearings ensure the high – precision positioning of the machine tool. The crossed roller slew bearings in the RV reducers of industrial robots need to meet an accuracy requirement of ABEC7 or above to ensure the precise and stable movement of the robots. The magnetic levitation slew bearings in semiconductor equipment’s vacuum coating machines can achieve high – precision rotation in a dust – free environment, meeting the strict requirements of semiconductor manufacturing.

Consumer Goods and Daily Life Field: In daily life, slew bearings are also everywhere. The annual demand for air – conditioner compressor slew bearings exceeds 500 million sets, ensuring the efficient operation of air conditioners. The silent slew bearings in washing machines reduce the noise during operation, enhancing the user experience. The slip ring slew bearings in CT machines in medical devices adopt an integrated design of conductive slip rings, enabling 360 – degree rotational scanning of the CT machines.

Development Status and Trends of the Slew bearing Industry

With the continuous development of the global manufacturing industry, the slew bearing industry is also making continuous progress. Currently, the global slew bearing market is huge. In 2023, it reached 143.6 billion US dollars and maintained an annual compound growth rate of 8.3%. Among them, the automotive industry is the largest application field for slew bearings, accounting for 32%, followed by the industrial machinery and energy fields.

In terms of technological development, slew bearings are moving towards the direction of intelligence, lightweight, and high – performance. By using new materials and optimizing the structure, the weight of slew bearings is reduced, and energy consumption is decreased. High – performance slew bearings continue to break through in terms of high – speed, high – precision, and high – reliability.

As the joints of industry, slew bearings, despite their small size, play an irreplaceable role in various fields. Their development not only promotes the progress of industry but also brings convenience to people’s lives. With continuous technological innovation and the expansion of application fields, it is believed that slew bearings will continue to shine in future industrial development and contribute to the goal of becoming a manufacturing powerhouse.

The Price of Slew bearing

Slew bearing prices are affected by multiple factors. In terms of raw materials, the type of steel (such as high – carbon chromium steel or special alloys) and fluctuations in the supply chain directly determine the cost. In the manufacturing process, the higher the precision level, the more stringent the requirements for processing, heat treatment (quenching, carburizing), and surface treatment (plating, nitriding), which increases the production cost. At the same time, import tariffs and transportation costs also significantly affect the final pricing, ultimately forming a price system jointly influenced by materials, technology, and the market.

Supplier of Slew bearing

In terms of product quality, LDB bearing always adheres to the attitude of striving for excellence and has established a strict quality control system. Starting from the procurement of raw materials, it strictly selects high – quality steel to ensure the basic performance of the products. Ensure that every product can meet your needs.

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