What material is good for the slewing bearing and how should it be selected?

The material of the slewing bearing directly determines the performance and service life of the bearing. At present, the main structure of bearings on the market is mostly made of bearing steel, which has the characteristics of corrosion resistance and stability. Of course, in addition to bearing steel, there are also metal materials such as aluminum alloy or copper. In addition, the sealing ring and cage of the bearing may be different from the material of the main body of the bearing. The following slewing bearing manufacturers will share what material is good for the slewing bearing.

What material is good for the slewing bearing?

Slewing Bearings

1. Material of ferrule and rolling element

The early slewing bearing used 45# steel, but it was gradually eliminated due to poor modulation performance in the later period. In the current more common processing technology, the slewing bearing rolling element adopts integrally hardened carbon chromium bearing steel. The grade is made of GCr15 or GCr15SiMn steel; the ring of the slewing bearing is made of surface hardened steel, and if there is no special requirement, it is made of 50Mn steel. But sometimes customers also choose to customize other grades such as 42CrMo, 40Cr, etc. The following describes the characteristics of these grades of steel.

(1) As a high-carbon steel, 42CrMo has good quenching and quenching properties and is an ideal material for slewing bearings.

(2) 50Mn has good hardenability and is also a high-quality choice for slewing bearings.

(3) 40Cr is also good in terms of mechanical properties, and it is still in the exploration and practice stage.

(4) GCr15 small slewing bearing can be selected, but it is generally not recommended to use it because of the troubles caused by full quenching in the process of milling and drilling.

2. Material of cage

Cages for slewing bearings have structural forms such as integral, segmented, and isolated block types. The types of cage materials are: low carbon steel stainless steel cage, bakelite/plastic (nylon) cage, brass/bronze/aluminum alloy cage, etc. The spacer type is made of polyamide 1010 resin, ZL102 cast aluminum alloy, etc. .

The characteristics of various material bearing cages are as follows:

(1) Steel bearing cage: It is often cold stamped from 08 and 10 carbon steel sheets. Commonly used steel cage materials include 20, 30, 45, 0Cr18Ni9, 1Cr18Ni9Ti, 40CrNiMo, ML15, ML20, etc., which are commonly used materials in bearing cages, which are solid, durable and stable.

(2) Non-ferrous metal bearing cage: Different from steel, non-ferrous metal has its special properties. For example, aluminum alloy has the characteristics of low density, good thermal conductivity, and good corrosion resistance; copper alloy has good thermal conductivity, low friction coefficient, Features such as good formability and high use temperature; zinc-aluminum alloy has the advantages of low cost, low density, and excellent performance.

(3) Non-metallic cage: non-metallic cage materials mainly include polymers and their composite materials, including nylon, phenolic tape, polytetrafluoroethylene, etc. The polymer material has good strength and elasticity matching, which can effectively reduce the heating and wear of the bearing.

3. Material of sealing ring

Bearing sealing materials are generally commonly used sealing materials, mainly: nitrile rubber, silicone rubber, fluorine rubber, EPDM, fluorobutadiene rubber, polytetrafluoroethylene, polyurethane rubber, acrylic rubber, Anaerobic glue, etc.

The sealing ring of the slewing bearing is made of oil-resistant rubber or NBR nitrile rubber. Compared with nitrile rubber, hydrogenated nitrile rubber has better oil resistance, but if you are not too demanding on oil resistance, use nitrile rubber, because hydrogenated nitrile rubber is relatively expensive. Nitrile rubber also has a certain degree of acid and alkali resistance. However, silica gel should be selected if the requirements for oil resistance and acid and alkali are higher, but its price is higher.

How to choose the material of the slewing bearing

Slewing Bearings

The slewing bearing manufacturer said that the materials used in slewing bearings should be analyzed based on the current level of slewing bearing production technology. It is recommended that the materials of bearing rings, rolling elements, cages, and sealing rings should first consider the following materials.

1. Material of rolling element: GCr15SiMn is generally used for rolling element.

2. Ring material: 50Mn is used for the slewing bearing ring, but sometimes 42CrMo is used to meet the needs of the host in special applications.

3. Cage material: The cage has different structure types such as integral type, segmented type and isolated block type. The integral or segmented retainer adopts 20# steel or ZL102 cast aluminum alloy. The isolating block holder adopts polyamide 1010 resin, ZL102 cast aluminum alloy or QA110-3-1.

4. Sealing ring material: The slewing bearing should be made of oil-resistant rubber, fluorine-containing rubber, and oil-resistant nitrile rubber. The clearance of the slewing bearing The clearance of the slewing bearing is mainly used to compensate the manufacturing error and installation error of the slewing bearing supporting parts and the relevant host assembly parts to ensure the normal use of the bearing. According to the structure type/tolerance class of the slewing bearing and the pitch circle diameter of the rolling element group, the clearance value or the interference amount of the slewing bearing.

The above is the introduction of the slewing bearing manufacturer on the material of the slewing bearing. The bearing materials mentioned are all suitable for slewing bearings, but the specific use environment and performance requirements may have different requirements for the bearing materials. Please follow the actual situation. Choose the situation.

What is a slewing drive, what are its classification and application areas?

The slewing drive is a slewing reduction mechanism with an integrated driving power source. The slewing ring is used as the main transmission part and the mechanism attachment. Its essence is a permanent magnet motor with large torque. This product is also called a slewing reducer, a slewing drive, Compared with traditional rotary products, it is easy to install, easy to maintain, and save installation space to a greater extent. It is mainly used in beam trucks, aerial work vehicles, industrial robots, photovoltaic power generation, wind power generation, and construction machinery claws, etc. field.

What is a slewing drive

The slewing drive device is also called a slewing reducer, a gear reducer, a turntable reducer, a slewing mechanism, and a slewing drive pair. They are all types of reducers that use slewing bearings as the main support, and the auxiliary drive source uses gears or worms as the driving parts to achieve deceleration and full-circle rotation functions. The composition of the slewing drive mainly includes gears (or worms), slewing bearings, motors, housings, and bases. Slewing drive can be basically divided into single worm drive slewing drive, double worm drive slewing drive and special type of slewing drive.

Classification of slewing drives

WE Series Slewing Drive

1. Classification according to the transmission form

According to the variable transmission form of slewing drive, it can be divided into gear slewing drive and worm gear slewing drive, inheriting the characteristics of gear drive and worm gearing. These two slewing drives can be adapted to medium-high and low-speed applications respectively. In terms of carrying capacity, the performance of the worm gear type is better than that of the tooth type, and when the envelope worm transmission is adopted, its carrying capacity, anti-deformation ability and transmission rigidity are further improved, but the worm gear type slewing drive is more efficient in terms of efficiency. Inferior to the gear type slewing drive, the gear type slewing drive is divided into a straight tooth type slewing drive, a helical tooth type slewing drive, and a volute type slewing drive.

2. Classification according to the openness of the slewing drive

According to the openness of the slewing drive transmission mechanism, the slewing drive can be divided into open and closed. Generally, the open structure is mostly used in applications where the environment is too harsh and the maintenance and maintenance cycle is short. The open structure is more convenient for parts. The inspection, maintenance and maintenance of the product are also more convenient for replacement. However, the closed structure can provide a longer maintenance life cycle in occasions where the environmental conditions have not changed much and the environmental pollution level is below the medium level.

3. Classification according to driving power

According to the structure operation type of the slewing drive, it can be divided into light slewing drive, medium slewing drive and heavy slewing drive. According to the slewing drive’s power, size, dead weight, and application in different fields and machines to achieve its own functions, the light-duty slewing drive is light in weight, and its load and deceleration capabilities are suitable for high-speed (≥10rpm), vibration, impact loads, etc. Working conditions: The medium-sized slewing drive is suitable for high-speed (≥10rpm), vibration, impact load and other working conditions, and the heavy-duty slewing drive is suitable for high-speed (≤3rpm), heavy-duty, and intermittent working conditions.

4. Classification according to the structure of the drive composition

According to the composition of the drive device, it is divided into vertical drive and horizontal slewing drive. Vertical slewing drive means that the traction motor and the traveling wheel are vertical, and the traction motor is upright above the traveling wheel. It has the advantages of small gyration radius, high protection level, convenient maintenance, etc., but high manufacturing cost; horizontal drive means that the traction motor and the traveling wheel are parallel, and the traction motor is mostly coaxial with the traveling wheel and is horizontal. It has the advantages of compact structure, simplicity, and low installation height.

Application of slewing drive

SE Series Slewing Drive

After understanding what the slewing drive is, let’s take a look at its specific application. The slewing reducer can be used in the occasions that require full-circle rotation and variable speed requirements. When it is necessary to achieve larger torque power transmission, higher precision motion transmission, or the selection of a mechanism with a compact body structure and a higher requirement for integration, the slewing drive Is a good solution.

1. The field of beam transport vehicles

The core components of the traditional beam truck slewing assembly mostly use traditional slewing ring products. Compared with the slewing drive, the slewing ring does not have an outer shell, and the corrosion resistance is not ideal, and hydraulic cylinders are used to drive the steering of the tires. In terms of the system, the rotation angle range of the tire is also greatly restricted. The selection of a slewing drive device as a slewing component can not only improve the corrosion resistance of the component, but also increase the steering angle of each group of tires.

2. The field of aerial work vehicles

Aerial work trucks are an important application area of ​​slewing drive. Generally, high-altitude work trucks require the host to have a higher safety factor. The high safety of slewing drive (self-locking of worm gears) is the majority of users choose it as an aerial work platform accessory On the other hand, the worm gear transmission has a larger transmission speed ratio, so that while improving the safety factor of the main engine, a set of worm gear reducers can also be omitted for the main engine, thereby reducing the manufacturing cost of the main engine.

3. The field of photovoltaic power generation

Photovoltaic power generation is an important application field of slewing drive. Solar photovoltaic modules with slewing drive as a rotating part can accurately adjust the rotation and elevation angle of the host according to the different positions of the sun during the day. The solar panels are always in good condition. Receiving angle.

4. Wind power generation

Similar to photovoltaic power generation, the slewing drive can be applied to the yaw part of the wind generator to realize the horizontal 360° rotation of the mechanism, so as to better adjust the receiving angle.

5. The field of construction machinery claws

Construction machinery auxiliary equipment is a new application field of slewing drive. The slewing drive is used as the claw of the rotating mechanism, which makes the design structure more concise, which is more conducive to use and maintenance. At the same time, the worm gear drive has a larger reduction ratio, which makes the claws, etc. The positioning accuracy of construction machinery aids has also been greatly improved.

6. The field of industrial robots

Due to the compact structure and short transmission chain, the slewing drive is easier to achieve higher accuracy and easier to carry out digital control, so it is also widely used in the field of industrial robots. Recently, robots derived from AGV (mobile robots), spot welding robots, welding robots, arc welding robots, laser processing robots, vacuum robots, clean robots and other varieties have slewing drive applications.

Slewing bearing maintenance methods and maintenance precautions

There are many types of bearings, and the fields and equipment used by each type of bearing will be different. Among them, the slewing bearing can be rotated and used in many equipment and machines. It can be said to be the scope of use. There is a very wide range of bearings, so what are the maintenance methods of the slewing ring and what are the precautions in the maintenance process? The slewing ring manufacturer gave us the following detailed introduction.

Maintenance method of slewing bearing

1. After 100 hours of operation of the slewing ring, the pre-tightening force of the bolts should be checked, and every 500 hours of operation thereafter, sufficient pre-tightening force must be maintained.

2. When the slewing ring is in use, if noise, impact, or power suddenly increases, it should be shut down immediately for inspection, troubleshooting, and disassembly and inspection if necessary.

3. The raceways of the slewing bearing are regularly filled with grease. Generally, the ball bearings are refueled every 100 hours of operation, and the roller bearings are refueled every 50 hours.

4. The tooth surface of the slewing bearing should be cleaned of debris frequently and coated with corresponding grease.

5. The slewing bearing and slewing ring tooth surface should be cleaned up for 10 shifts, and grease should be reapplied.

Matters needing attention in maintenance of slewing bearing

news2

1. The mounting support of the slewing ring must have sufficient rigidity and the mounting surface should be flat. The support should be subjected to stress relief before assembling the slewing ring. The slewing bearing and slewing ring should be repaired and maintained to reduce the deformation of the slewing ring support. The support should be assembled during assembly. The contact surface with the slewing bearing must be cleaned.

2. When using slewing bearings and slewing bearings, attention should be paid to changes in noise and slewing resistance torque. If there is any abnormality in the maintenance of slewing bearings and slewing bearings, they should be disassembled for inspection. The slewing bearings must be hoisted or stored horizontally, not vertically. Lift or store to avoid deformation.

3. Before the bolts are tightened, the slewing bearing and slewing support should be checked for gear meshing. The meshing condition should meet the requirements of gear accuracy, that is, the contact spots distributed on the tooth surface after the gear pair runs under slight braking. The tooth height direction is not less than 25%, and the tooth length direction is not less than 30%.

4. Slewing bearing and slewing ring In order to ensure the reliability of bolt work and avoid the lack of bolt pre-tightening force, the slewing bearing and slewing ring should be checked for the pre-tightening torque of the bolts after 100 hours and 500 hours of operation of the slewing ring. The pre-tightening torque should be checked every 1000 hours of work.

The service life of the slewing ring during work is directly proportional to the maintenance performed on it. Good maintenance of the slewing ring is also a way to avoid the failure of the slewing ring. The maintenance methods of the slewing ring above are only part of it. Friends who want to know can check our company website. The slewing ring produced by LDB Bearing Co., Ltd. is of good quality, which can effectively improve labor productivity and equipment stability. You are welcome to call our hotline or leave a message at the bottom of the website.

Causes and solutions of common failures of slewing drive devices

In the current transmission mechanism, the application range of slewing drive is very wide, including the application of products such as high-altitude lifting platforms, fire trucks, marine cranes, and log transfer machines. In a complex application environment, the slewing drive device will inevitably fail due to various reasons. The editor below has sorted out some common faults and solutions of the slewing drive device and hopes to be helpful to everyone.

Common causes of failures of slewing drive devices

Spur Gear Drive

1. Rotary drive string shaft

(1) Shaft tandem caused by broken teeth causing the input shaft to lose its axial restraining force;

(2) The slewing drive driven gear is not tightly fastened to the shaft, resulting in insufficient bearing interference, resulting in a series of shafts, and the steering problem of the slewing drive is affected;

(3) Gear machining deflection;

(4) Gear helix angle error;

(5) Tooth thickness error, uneven wear of tooth surface and premature wear, deformation of tooth back.

The rotary drive oil temperature is too high

(1) The lubricating oil used by the rotary drive is unqualified or has been used for too long;

(2) Too much lubricating oil is used in the rotary drive;

(3) Damage to the slewing drive components, including severe pitting of gears, broken teeth, damage to the bearing cage, inner and outer rings, balls, as well as bearing seizure or severe shaft deformation;

(4) The outside of the rotary drive is covered by debris or dust. When things are piled around or the surface of the machine body has not been cleaned for a long time, the cover of debris or dust may cause incomplete heat dissipation of the reducer and increase the oil temperature;

(5) The cooling device fails or is blocked. If the cooling device is blocked or the cooling device is broken due to long-term work without cleaning the internal pipeline, it will cause the temperature of the rotary drive oil to rise;

(6) Overload operation of rotary drive.

Oil leakage of rotary drive

The oil leakage of the slewing drive: the driving shaft seal ring, the driven shaft seal ring, the slewing drive box, the sight hole cover, the oil drain hole at the bottom, and the oil leakage of the breather. Possible reasons include the fixing bolts are not tightened; there is iron filings on the joint box surface and the closure is not tight; the rotary drive housing is deformed and does not fit tightly and leaks oil; or the ventilator has too much oil.

The slewing drive is overheated or there is noise in the bearing part

(1) Insufficient lubricating oil. When the lubrication oil level is insufficient or the reducer cannot reach a reasonable height due to oil leakage, it may cause high temperature or noise in the bearing part of the reducer;

(2) The bearing cap or seal part is rubbed. When the bearing cover or the sealing part and the connecting part are worn due to improper installation, improper bearing cover or long-term use, the bearing temperature of the reducer may be high or there may be noise;

(3) The bearing is damaged or worn. This item mainly includes damage to the cage of the bearing, wear or deformation of the inner and outer rings, wear or fall of the balls, these reasons will make the reducer unable to work normally;

(4) The bearing clearance is too large or too small. The above symptoms may be caused when the gap between the ball of the reducer bearing and the inner and outer rings, the gap between the bearing inner ring and the shaft, and the gap between the bearing and the end cover increase due to long-term use;

(5) The key handle of the helical gear is loose. The looseness of the helical gear key handle will cause the lack of tight fit between the gear and the shaft, resulting in overheating or noise in the bearing;

Large vibration of the rotary drive body

The possible reasons for the vibration of the slewing drive body include: the anchor screw is loose; the coupler is damaged; the motor screw is loose; the bearing is severely worn; the gear is damaged; the shaft is deformed and out of balance. These conditions may be due to loose screws or coupler failures, bearing wear and other reasons caused by long-term operation.

The bearing of the slewing drive device is broken

The slewing drive bearing cracks mainly occur in the driving shaft bearing. The main reason is that when the driving shaft moves, axial sliding will occur between the bearing inner ring and the rollers, causing the bearing inner ring to move axially, causing the inner bearing rollers to move first. Damage to the bearing.

Damage to the slewing drive gear

Rotary drives have different reasons for broken teeth, gear pitting, spalling, and wear. It can be roughly divided into insufficient contact fatigue strength of the gear; gear material defects, poor precision, inadequate lubrication, impurities in the lubricating oil, and errors in the center distance of the gears.

The slewing drive device has abnormal noise

Possible causes The reducer is overloaded; the load of the working machine is unbalanced; the lubricating oil is deteriorated; the gear tooth surface is worn or the manufacturing quality is poor; the bearing clearance is too large or too small; there is adhesion on the tooth surface; there is debris in the box.

After understanding the causes of common failures of the slewing drive device, the editor briefly introduces the repair methods of the slewing drive device failure. You can check the fault according to the specific situation. If you can’t solve it by yourself, you still need to contact the manufacturer for repair.

Solutions to common failures of slewing drive devices

1. Rotary drive string shaft

It can improve the strength and manufacturing accuracy of the gear, and reduce the roughness value of the gear and shaft. Improving the installation accuracy and tightness of the driven gear and the shaft is mainly to achieve a reasonable interference fit.

2. The rotary drive oil temperature is too high

(1) The staff can perform a detailed inspection on the actual load of the slewing drive and adjust it to the specified value, or it can be replaced with a larger power slewing drive.

(2) Use lubricating oil to remove excess oil in strict accordance with the prescribed amount of oil; or replace the lubricating oil.

(3) Remove the debris and dust around the rotary drive, replace the cooling device to remove the blockage.

3. Oil leakage of rotary drive

(1) The sealing ring gland adopts an open structure or an easily disassembled structure.

(2) Install gaskets and fastening bolts on the sight hole cover.

(3) The oil return hole at the input shaft bearing should be appropriately enlarged.

(4) Replace the deformed drive housing.

(5) Correctly install and correct the oil level of the ventilator.

(6) An annular oil groove is cast or machined on the box surface of the rotary drive base, and there are multiple oil return holes communicating with the annular oil groove. When the reducer is working, once the oil penetrates into the joint box surface, it will enter the annular oil groove, and then flow into the oil tank through the oil return hole, and the lubricating oil will not leak along the box surface to the outside of the reducer housing.

(7) Apply a layer of sealant (such as D05 silicone rubber sealant) on the surface of the box to effectively prevent oil leakage at the surface of the box.

(8) Improve the ventilation cap and inspection hole cover. The internal pressure of the reducer is greater than the external atmospheric pressure is one of the main reasons for oil leakage. If you try to balance the pressure inside and outside the machine, oil leakage can be prevented. Although the reducer has a vent cap, the vent hole is too small, and it is easy to be blocked by dust and oil. Moreover, the inspection hole cover must be opened every time the oil is refueled. Once opened, the possibility of oil leakage will increase once, so that the original place does not leak. Leaks also occurred. The vent hole can be enlarged to equalize the pressure inside and outside.

4. The slewing drive is overheated or there is noise in the bearing part

(1) Check the rotary drive oil level and add lubricating oil;

(2) Tighten the bolts of the bearing and the connecting part, and check the installation of the seal;

(3) Check the bearing and replace it immediately if it is damaged;

(4) If the clearance is not suitable, adjust the bearing clearance, and replace the bearing if it cannot be adjusted;

(5) If the key handle of the helical gear is loose, send it for repair in time;

5. The vibration of the rotating drive body is large

The fault can be eliminated by tightening the foot bolts and the loose screws of the motor; repairing the coupler; replacing the bearing; replacing the gear.

6. The slewing drive bearing is broken

Increase the interference between the inner ring and the shaft, or add a retaining ring on the outer side of the inner ring of the bearing to prevent axial movement.

7. Rotary drive gear damage

Gear damage can be strengthened or the viscosity of the regular lubricant can be used to reduce the loss of lubricant and prevent rust. Clean the gear to keep the surface free of impurities, replace the gear that cannot be repaired, and pay attention to daily maintenance.

8. The slewing drive device has abnormal noise

When there is abnormal noise, you can replace the new lubricant to adjust the bearing gap, check the bearing and do the cleaning work, or replace the new parts in time.

The above is the sorting and summary of the common failure causes and solutions of the rotary drive device. I hope it will be helpful to everyone.

How to distinguish the authenticity of a slewing bearing from its appearance?

Fake goods are a hateful existence for all walks of life. Many fake and inferior products carry the same outer packaging as the regular brand, but they are among the failures of Jinyu. Not only the product quality cannot be guaranteed, but it may even be in use. During the process, the maintenance and shutdown of the machine caused unpredictable economic losses. So how should we distinguish the true and false of the slewing ring from the appearance when we buy the slewing ring every day? The editor is here today.

First, eight counterfeit methods of slewing ring

Slewing Bearings

1. Material fraud: use iron or carbon steel to make slewing bearings, or repair scrap bearings. The former will cause insufficient hardness of the bearing, and the latter will cause insufficient bearing accuracy. Once these slewing bearings are used on bearings that require high accuracy and bearing hardness, they can easily cause machine failures.

2. Falsified outer packaging: Brand the inferior slewing ring or bearing produced by a small factory with the trademark of a large manufacturer, and counterfeit the inner and outer packaging and the certificate of conformity of the large-brand product. In this way, you can use the brand influence of major manufacturers to broaden the sales of your products.

3. Falsified sales channels: users, distributors, agents, or even counterfeit manufacturers’ spot sales outlets of well-known brands. Let consumers not be able to judge true and false, and make wrong judgments.

4. Pretend to be inferior: use inferior bearings as bearings. In the production process of bearings, defective products will be more or less produced, and they will generally be scrapped. Some black-hearted businesses will pretend to be defective products for sale, but the quality of the products is difficult to guarantee.

5. Accuracy fraud: use ordinary bearings to pretend to be high-precision bearings. Precision bearings have different requirements for the accuracy of various parts during production. Compared with ordinary bearings, the requirements will be relaxed. This way, the common means of posing as precision slewing bearings is also very abhorrent.

6. Fake goods for sale: slewing bearings are usually purchased in large quantities when they are sold. Some merchants take advantage of the buyer’s mentality that they will not check one by one, and sell them together with fake goods, and the product quality will vary. There is a bad situation.

7. Price fraud: In order to increase profits, businesses sell fake goods at high prices and use fake prices.

8. Look at people to deliver goods: When selling slewing bearings, merchants will provide selective supplies according to the seller’s specific conditions. If buyers want cheap goods, they will give fake goods. If they want good quality, they will give genuine goods. I don’t know how to do it. Those who only bargain think that they are taking advantage of it, but they don’t know that they may buy fakes.

Second, the method of identifying the true and false from the appearance of the slewing ring

Slewing Bearings

1. Look at the clarity of the stamp

How to distinguish the authenticity of a slewing bearing from its appearance? Each bearing product will have its brand name, label, etc. printed on the bearing product body. Although the fonts are very small, the products produced by regular manufacturers are printed with steel stamping technology, and they are pressed before heat treatment. Therefore, although the fonts are small, they are deeply recessed and very clear. Normally, the fonts of counterfeit products are not only blurred. Due to the rough printing technology, the fonts float on the surface, and some of them can even be easily erased by hand or have serious manual traces.

2. Listen to the noise inside the bearing

Hold the inner sleeve of the bearing with your left hand, and turn the outer sleeve with your right hand to make it rotate slightly. Listen for noise during the operation of the bearing. Due to the backward production conditions of most counterfeit products and the purely hand-made workshop operation, the bearing body will inevitably be mixed with impurities such as dust and sand during the production process. Therefore, noise or unsmooth operation may occur when the bearing rotates. phenomenon. This is the key to judging whether the product comes from a regular manufacturer’s brand product that has strict production standards and is operated by a machine.

3. See if the surface is clean

Whether there are turbid oil stains on the surface, we should pay special attention to it when buying imported bearings. Since there is still a certain gap between domestic anti-rust technology and foreign advanced manufacturing countries, it is easy to leave thick oil marks when anti-rust treatment on the bearing body, which feels sticky and sticky when touched by hand, while foreign original There is almost no trace of anti-rust oil on the imported bearings. According to industry insiders, particularly careful people can smell a special smell on imported bearings, which is the smell of anti-rust oil.

4. Look at the chamfer

Whether the chamfer of the slewing ring is produced is also closely related to the production technology level of the bearing manufacturer. Therefore, the neat degree of the chamfer can judge the technological level of the bearing. The so-called chamfer of the bearing is the junction of the horizontal plane and the vertical plane. Due to the limitation of production technology, the counterfeit bearing products are not handled satisfactorily at these corners, which we can easily distinguish.

5. Look at the packaging of the bearing

The packaging is divided into inner packaging and outer packaging. After the bearings are manufactured and passed the inspection, they will be cleaned and anti-rust treated, and then placed in the inner packaging to achieve waterproof, moisture-proof, dust-proof, shock-proof, and maintain the quality and accuracy of the bearing And the purpose of facilitating use and sales.

The inner packaging of the bearing is divided into three categories according to the anti-rust period:

(1) Short anti-rust period packaging: The anti-rust period is 3 to 6 months, which is suitable for bearings that are shipped to the same subscriber in large quantities and put into use in a short period of time. The two parties have agreed to use simple packaging based on the principle of ease of use.

(2) General anti-rust period packaging: one year anti-rust period, suitable for general-purpose bearings.

(3) Long anti-rust period packaging: two years anti-rust period, suitable for special and precision bearings.

The inner packaging materials of the bearing include polyethylene plastic tube (box), kraft paper, plain and wrinkled polyethylene composite paper, paper box, polyethylene or polyethylene plastic film, nylon fastening tape or plastic woven fastening tape, waterproof high-strength plastic tape , Burlap bags, etc. All of the above materials need to ensure that the corrosion resistance test of the material is qualified.

How to distinguish the true and false of the slewing ring from the appearance can be judged from the above aspects. In addition, you can judge the approximate price range based on the understanding of the bearing and the market situation of the bearing. As long as you are not greedy and bargaining excessively, you can also confirm the place of purchase. It is difficult to distinguish true from false sources through informal sources, and bearings can basically be bought. The slewing bearings produced by our Kuoyi Longda Bearing Co., Ltd. are all qualified products that have passed quality inspections. If you have any needs, please feel free to inquire.

What are the installation methods of the spur gear slewing drive? And installation precautions

Spur gear slewing drive is a rotary drive. Due to the different types of drive teeth, it can be divided into straight-tooth rotary drive and helical-tooth drive, both of which are full-circle rotary drive reduction transmission mechanisms that inherit the driving power source. The previous article has already introduced the difference between the spur gear drive and the slew drive. I will not introduce it in detail here. Today, the Lunda bearing manufacturer will give a brief introduction on the installation methods of the spur gear drive. I hope it will be helpful to everyone.

Installation method of spur gear drive

1. Fixed installation with solid shaft

This installation method is to connect the output shaft driven by the spur gear with the metallurgical machinery through couplings, sprockets, gears, pulleys, etc., and the spur gear drives the bottom anchor bolts to firmly install the spur gear drive on the structure On a solid, vibration-free foundation. At present, most spur gear drives can adopt this installation method.

For large spur gear drives, threaded holes should be machined on the body feet to adjust the installation position with adjusting bolts; for the spur gear drive of the luffing mechanism, pins should also be used for locking to prevent movement during installation .

2. Single-point floating installation of hollow shaft

This installation method uses the output shaft driven by the spur gear as a hollow shaft and is connected to the transmission shaft of the working machine through an expansion sleeve. The entire driving device, including the motor, coupling, brake, and reducer, is installed on the support of the transmission device. Seat, and then supported by a ball hinge or bearing.
The installation principle is that the bearing point of the spherical hinge deviates from the center of gravity of the transmission device by a certain distance. In the working state, the bending moment caused by the eccentricity of the support point can be balanced with the bending moment caused by the load of the driving device. Therefore, the transmission shaft is not affected by the theory. Additional force.

3. Hollow shaft suspension installation

In this installation method, the output shaft driven by the spur gear and the metallurgical machinery shaft are connected by an expansion sleeve, and the support is completed by the output shaft and another torsion rod. This installation method is relatively simple, saves floor space, and can reduce the weight of the whole machine, and is suitable for transmission devices that transmit power from a vertical direction.

Spur gear drive installation is a delicate and complex task with high technical requirements. The operating procedures and design data must be strictly observed during operation. The general installation sequence is: equipment leveling and alignment, cleaning and assembly, adjustment and trial operation.

After understanding the installation methods of spur gear drives, the spur gear drive manufacturers will introduce some precautions in the installation of spur gear drives. I hope it will be helpful to everyone.

Precautions for installation of spur gear drive

WE Series Slewing Drive

1. Cleaning and inspection: clean the spur gear drive installation shaft before installation and use, and check whether the installation shaft is bruised or dirty. When the spur gear drive is installed in an inclined manner, ensure that the high position of the gear shaft bearing is lubricated by the gear oil in the box, and ensure that the gas in the box can be discharged from the high position of the box.

2. Keep the mating interface flat: When assembling the spur gear drive with the actuator and the prime mover, the connecting flange should be cleaned and polished to ensure the flatness of the connecting part of the connecting flange, to ensure that it is flush, and all bolts on the flange circumference should be matched. , Fastening.

3. Keep balance: The assembled transmission components (couplings, sprocket) should be kept in rotation balance, so as not to cause impermissible radial force or axial force. The internal thread of the assembly fixture and the shaft end is usually used, and the transmission part is pressed in with a bolt, otherwise it may cause damage to the internal parts of the spur gear drive.

4. Do a good job of leveling: The spur gear drive installation must be rigidly fixed on a solid horizontal foundation or a vertical frame, and the leveling must be done. It is necessary to ensure that the coaxiality of the prime mover, coupling, spur gear drive, and actuator is consistent, so as to avoid additional stress on the input and output shafts and bearings of the equipment and cause damage to the equipment input and output shafts and bearings.

5. Control the shaft gap: the coaxiality of the two connected shaft extensions should be controlled within the range of φ0.1mm, and there should be a gap of 2-8mm between the end faces of the two shaft extensions. The value of the gap depends on the specific equipment connected to the spur gear drive. Depending on the situation, it is necessary to ensure sufficient load transfer capacity and to ensure that the bearings driven by the spur gear are not subject to additional axial force.

6. Add gear oil: The grade of oil should be the spur gear drive value, or the oil equivalent to the oil should be used. And the amount of oil must be correct, and each spur gear drive has a sign with the grade and quantity of oil attached. The oil mirror is a display mirror of the oil level driven by the spur gear. On the side of the spur gear drive, the oil level should reach the upper and lower positions of the middle of the oil mirror when filling oil.

Spur gear drive lubrication and oil injection method

The lubrication effect has a great influence on the spur gear drive. If the lubrication conditions are not good, the heat generated by the spur gear drive will increase and its carrying capacity will decrease. Therefore, the lubricating oil and the amount of oil must be selected correctly to effectively ensure the normal operation of the spur gear drive transmission and prolong its service life.

Under normal circumstances, the lubrication method adopts oil pool lubrication and natural cooling; and for high-power spur gear drive or insufficient thermal power, pressure circulating oil lubrication or additional cooling devices can be used for cooling.

Under normal operating conditions, when the ambient temperature is (0~35)℃, or using circulating oil lubrication, choose medium-duty industrial gear oil 220#; when the ambient temperature is (35~50)℃, it is recommended to select medium-load Industrial gear oil 320#. In addition, the spur gear drive should be replaced with lubricating oil after the first 400 hours of operation.

What are the installation methods of spur gear drive? I believe you already know it. During installation, you can choose a suitable installation method according to the specific conditions of the machine to which the spur gear drive is adapted. Of course, some precautions during the installation process have been introduced by the spur gear drive manufacturer. Up. In addition, if you have any questions about the installation or use of other spur gear drives, you can call us Longda Bearings, and welcome your calls.

Process flow and processing method of spur drive gear processing

Spur gear drive is a kind of gear reducer we often say. It is divided into spur gear and helical gear. Its working principle is mainly a reduction gear that drives the ring gear of the rotary drive to rotate through the pinion gear. So how much do you know about the technological process of gear processing for devices that use gears to complete the deceleration work? The following drive manufacturers will introduce to you the processing process and tooth profile processing methods of spur drive gears.

Machining process of spur drive gear

The processing process of spur drive gear includes: forging blank, normalizing, turning processing, gear shaving, hobbing, gear shaping, grinding processing, heat treatment, and trimming. The specific processes are as follows.

1. Forging billet

In recent years, hot die forging has been widely promoted in shaft processing, and is suitable for making blanks for more complex stepped shafts. It not only has high precision, small subsequent machining allowances, and high production efficiency.

Slewing Drive

2. Normalizing

The purpose of the normalizing process is to obtain a hardness suitable for subsequent gear cutting to reduce deformation. The material of the gear steel used is usually 20CrMnTi. The process is affected by factors such as equipment, environment, and workpiece cooling rate, and the hardness dispersion is large.

3. Turning

In order to meet the high-precision positioning requirements of gears, CNC lathes are used for gear blank processing to maintain the verticality requirements of the end face, outer diameter, and bore diameter, which can improve the precision of the gear blank and improve work efficiency.

4. Shaving

Radial gear shaving technology is widely used in the production of high-volume automobile gears due to its high efficiency, design tooth profile, and easy realization of tooth profile modification requirements.

5. Rolling and shaping

Common gear hobbing machines and gear shaping machines are still widely used for processing gears. Although it is easy to adjust and maintain, the production efficiency is low. If a large capacity is completed, multiple machines are required to produce at the same time. With the development of coating technology, the re-coating after sharpening of hobs and inserts is very convenient. Coated tools can significantly increase the service life, generally by more than 90%, effectively reducing the number of tool changes And sharpening time, the benefit is significant.

6. Grinding

It is mainly to finish the heat-treated gear inner hole, end face, shaft outer diameter and other parts to improve the dimensional accuracy and reduce the form and position tolerance. The gear processing technology adopts the pitch circle fixture to position and clamp, which can effectively ensure the processing accuracy of the tooth part and the installation datum, and obtain satisfactory product quality.

7. Heat treatment

Gears require carburizing and quenching to ensure good mechanical properties. For products that no longer need to be ground after being heated, stable and reliable heat treatment equipment is essential.

8. Trimming

This is the inspection and cleaning of the bumps and burrs of the gears before assembly of the transmission and gear drive to eliminate the abnormal noise caused by them after assembly. It is completed by listening to the sound of a single pair of meshing or observing the meshing deviation on a comprehensive inspection instrument.

SG-I Spur Gear Slewing Drive

Machining method of spur drive gear

The choice of spur drive tooth profile processing method mainly depends on the gear’s accuracy grade, structural shape, production type and production conditions. For gears of different accuracy grades, the commonly used tooth profile processing methods are as follows.

1. Gears below grade 8 accuracy

Hardened and tempered gears can meet the requirements with gear hobbing or gear shaping. For hardened gears, a machining plan of rolling (shaping) teeth-tooth end processing-quenching-correction hole can be used. However, the machining accuracy of the tooth profile should be improved by one level before quenching.

SG-H Spur Gear Slewing Drive

2. 6-7 grade precision gear

For hardened gears, the following can be used: rough hobbing-fine hobbing-tooth end machining-fine shaving-surface hardening-calibration reference-honing.

3. Gears with accuracy above grade 5

Generally used: rough gear hobbing-fine gear hobbing-tooth end machining-quenching-calibration standard-rough grinding gear-fine grinding gear. Gear grinding is currently a high-precision machining method in tooth profile machining with a small surface roughness value, and the accuracy can be as high as 3-4.

The above is the introduction about the processing process and processing methods of the spur drive gear. I hope it can help everyone to have a certain understanding of the processing of the drive gear.

What are the repair processes for slewing bearings?

The slewing bearing is also called the slewing ring. It is a new type of mechanical parts. It is composed of inner and outer rings, rolling elements, etc. The slewing ring is a large-scale bearing that can withstand comprehensive loads, and can withstand larger axial and diameter at the same time. Bearing for load and overturning moment.

Generally, it is widely used in industry, and the effect of use is very good. The application of slewing bearings is special, and it must be operated under continuous shock, vibration, and overload. Therefore, the control of production technical parameters in the product manufacturing process is also It is more rigorous, with high bonding strength, no shedding, no hard spots, high surface finish, and adjustable hardness. However, damage is still inevitable, which requires special repair techniques to ensure the flexibility of the later application of the slewing ring.

Repair process of slewing bearing

Slewing Bearings

1. Low temperature iron plating method

Low-temperature iron plating is a commonly used method for repairing shaft parts in the industry, and it has a long history of application in other mechanical maintenance industries. Low-temperature iron plating is an electroplating technology with a fast iron plating speed. The one-time iron plating has a large thickness, a relatively mature process and high production efficiency. It is suitable for repairing the surface of agricultural machinery transmission shafts or parts.

2. Thermal spraying method

Thermal spraying method mainly uses high-speed airflow to spray molten metal material on the surface of partially worn parts, and then the size can be restored after processing. Thermal spraying technology includes many methods such as flame spraying, electric spraying and plasma spraying. The additional materials for spraying are often better than the raw materials, so after the slewing bearing is repaired, the parts in terms of wear resistance and corrosion resistance have been greatly improved.

ceshi

3. Surfacing method

The surfacing method is to use the welding process to surfacing a layer of welding material on the worn parts of the part, and then restore the original matching size of the part through mechanical processing. The surfacing process can achieve different material repair effects through the selection of welding rods or wires. The process has the advantages of high material strength after repair and faster repair speed, and is suitable for repairing parts with greater wear.

The performance of the correctly repaired bearing is equivalent to that of the new bearing, and all parameters such as clearance can meet the requirements of use. It is important to understand and identify the degree of damage to choose the correct repair plan. Bearing repair requires long-term technical accumulation and comprehensive basic data storage. Professionally trained personnel can judge whether the bearing needs to be repaired. Timely routine inspections, preventive maintenance and vibration analysis can grasp the appropriate repair time in time, so as to help companies economically repair damaged bearings.

Inventory of common slewing bearing damage failure causes analysis and solutions

It is common for bearings to fail during operation, so there is no need to make a fuss. In the event of a failure, the key to determining the cause of the damage and handling it Today, the editor has counted some common slewing bearing damage failure causes analysis and solutions.

 Crack defects

Trouble phenomenon: partly notched and cracked.

1. The cause of the failure

①Excessive impact load; ②Excessive interference; ③Large peeling; ④Friction cracks; ⑤Poor accuracy of the installation side (too large corner round); ⑥Poor use (a copper hammer is used to insert large foreign objects).

2. Solutions

①Check the conditions of use; ②Set appropriate interference and check materials; ③Improve installation and use methods; ④Prevent friction cracks (check lubricant); ⑤Check the design around the bearing.

Rotation of slewing bearing is not flexible

Trouble phenomenon: bearing heating, jitter, stuck.

1. The cause of the failure

①The clearance is too small (including the clearance of the deformed part); ②Insufficient lubrication or improper lubricant; ③Excessive load (excessive preload); ④The roller is skewed.

Slewing Bearings

2. Solutions

①Set proper clearance (increase the clearance); ②Check the type of lubricant to ensure the amount of injection; ③Check the conditions of use; ④Prevent positioning errors; ⑤Check the design around the bearing (including heating of the bearing).

The hardness layer falls off

Trouble phenomenon: the running surface is peeled off, and it is obviously convex and concave after peeling off.

1. Reason

①Improper use due to excessive load; ②Poor installation; ③Poor precision of shaft or bearing box; ④Too small clearance; ⑤Intrusion of foreign matter; ⑥rusting; ⑦Hardness reduction caused by abnormal high temperature

2. Solutions

①Re-study the operating conditions; ②Re-select the bearing; ③Reconsider the clearance; ④Check the machining accuracy of the shaft and the bearing housing; ⑤Research the design around the bearing; ⑥Check the installation method; ⑦Check the lubricant and lubrication method.

Slewing Bearings

Scratches and jams

Trouble phenomenon: rough surface, accompanied by micro-dissolving; scratches between ring ribs and roller end faces are called jams

1. Reason

① Poor lubrication; ② Foreign matter intrusion; ③ Roller deflection caused by bearing tilt; ④ Oil breaking on rib surface caused by large axial load; ④ Surface roughness; ⑤ Large rolling element sliding.

2. Solutions

①Re-study lubricants and lubrication methods; ②Check the conditions of use; ③Set appropriate preload; ④Strengthen the sealing performance; ⑤Use the bearing normally.

The cage is damaged

Trouble phenomenon: loose or broken rivet, broken cage.

1. Reason

①Excessive torque load; ②High-speed rotation or frequent speed changes; ③Poor lubrication; ④Entrapped foreign objects; ⑤Large vibration; ⑥Poor installation (installation in tilted state); ⑦Abnormal temperature rise (resin cage).

2. Solutions

①Check the operating conditions; ②Check the lubrication conditions; ③Re-study the selection of the cage; ④Pay attention to the use of bearings; ⑤Study the rigidity of the shaft and the bearing box.

Rusty corrosion on the surface of the slewing bearing

Trouble phenomenon: Part or all of the surface is rusty, and it is rusty in the form of pitch of rolling elements.

1. Reason

①Poor storage condition; ②Improper packaging; ③Insufficient rust inhibitor; ④Intrusion of moisture, acid solution, etc.; ⑤Hold the bearing directly by hand.

2. Solutions

①Prevent rust during storage; ②Strengthen the sealing performance; ③Check the lubricating oil regularly; ④Pay attention to the use of bearings.

Abrasion

Trouble phenomenon: red rust-colored wear particles are produced on the mating surface.

1. Reason

①Insufficient interference; ②Small bearing swing angle; ③Insufficient lubrication (or in a non-lubricated state); ④Unstable load; ⑤Vibration during transportation.

2. Solutions

①Check the interference and lubricant coating status; ②The inner and outer rings are packaged separately during transportation, and pre-pressure is applied if they cannot be separated; ③Reselect the lubricant; ④Reselect the bearing.

Slewing Bearings

Wear

Phenomenon: Surface wear, resulting in dimensional changes, often accompanied by abrasion and wear marks

1. Reason

①The lubricant is mixed with foreign matter; ②The lubrication is poor; ③The roller is skewed.

2. Solutions

①Check lubricant and lubrication method; ②Strengthen sealing performance; ③Prevent positioning error.

Indentation bruises

Trouble phenomenon: surface pits caused by stuck solid foreign objects or impact and scratches caused by installation

1. Reason

①Intrusion of solid foreign matter; ②Insert the peeling sheet; ③Shock and fall off caused by poor installation; ④Install in an inclined state.

2. Solutions

①Improve the installation and use methods; ②Prevent foreign matter from entering; ③If it is caused by metal sheets, check other parts.

Electric erosion

Resolve the phenomenon: the rolling surface has a pit-like pit, and the further development is in a wave plate shape.

1. Reason

The rolling surface is energized.

2. Solutions

Make a current bypass valve; take insulation measures to prevent current from passing through the inside of the bearing.

The above is the explanation of the common slewing bearing damage failure phenomenon, the reason analysis and the solution measures. I hope everyone will be helpful after reading it. Analyzing the damage and failure forms of the slewing bearing can provide a detailed reference for the design and selection of the bearing, and then improve the design, rationally select the bearing, give full play to the function of the bearing, increase economic benefits, and increase the service life.

What is a slewing drive? Classification and application of slewing drive

The rotary reducer is a rotary reducer with integrated driving power source. The rotary bearing is used as the main transmission part and the mechanism attachment. Its essence is a permanent magnet motor with large torque. This product is also called rotary reducer. Drive, compared with traditional rotary products, it has simple installation, easy maintenance, and saves installation space to a greater extent. It is mainly used in beam trucks, aerial work vehicles, industrial robots, photovoltaic power generation, wind power generation and construction machinery claws. Tools and other fields.

What is the slewing drive

Slewing Drive

1. Definition of slewing drive

The slewing drive device is also called a slewing reducer, a gear reducer, a turntable reducer, a slewing mechanism, and a slewing drive pair. They are all types of reducers that use slewing bearings as the main support, and the auxiliary drive source uses gears or worms as the driving parts, so as to realize the deceleration and full-circle slewing functions. The composition of the slewing drive mainly includes gears (or worms), slewing bearings, motors, housings, and bases. Slewing drive can be basically divided into single worm drive slewing drive, double worm drive slewing drive and special type of slewing drive.

2. Classification of slewing drives

Spur Gear Drive

(1) Classification according to transmission form

According to the variable transmission form of slewing drive, it can be divided into gear slewing drive and worm gear slewing drive, inheriting the characteristics of gear drive and worm gearing. These two slewing drives can be adapted to medium-high and low-speed applications respectively. In terms of carrying capacity, the performance of the worm gear type is better than that of the tooth type, and when the envelope worm transmission is adopted, its carrying capacity, anti-deformation ability and transmission rigidity are further improved, but the worm gear type rotary drive is more efficient in terms of efficiency. Inferior to the gear type slewing drive, the gear type slewing drive is divided into a straight tooth type slewing drive, a helical tooth type slewing drive, and a volute type slewing drive.

(2) Classification according to the openness of slewing drive

According to the openness of the slewing drive transmission mechanism, the slewing drive can be divided into open and closed. Generally, the open structure is mostly used in applications where the environment is too harsh and the maintenance and maintenance cycle is short. The open structure is more convenient for parts. The inspection, maintenance and maintenance of the product are also more convenient for replacement. However, the closed structure can provide a longer maintenance life cycle in occasions where the environmental conditions have not changed much and the environmental pollution level is below the medium level.

①Customized double-gear high-precision, negative-clearance precision helical (grinding) slewing drive, to achieve zero backlash for customers.

(3) Classification according to driving power

According to the structure operation type of the slewing drive, it can be divided into light slewing drive, medium slewing drive and heavy slewing drive. According to the slewing drive’s power, size, dead weight, and application in different fields and machines to achieve its own functions, the light-duty slewing drive is light in weight, and its load and deceleration capabilities are suitable for high-speed (≥10rpm), vibration, impact loads, etc. Working conditions: The medium-sized rotary drive is suitable for high-speed (≥10rpm), vibration, impact load and other working conditions, and the heavy-duty rotary drive is suitable for high-speed (≤3rpm), heavy-duty, and intermittent working conditions.

(4) Classification according to the drive composition structure

According to the composition of the driving device, it is divided into vertical drive and horizontal slewing drive. Vertical slewing drive means that the traction motor and the traveling wheel are vertical, and the traction motor is upright above the traveling wheel. It has the advantages of small gyration radius, high protection level, convenient maintenance, etc., but high manufacturing cost; horizontal drive means that the traction motor and the traveling wheel are parallel, and the traction motor is mostly coaxial with the traveling wheel and is horizontal. It has the advantages of compact structure, simplicity, and low installation height.