Delivery of CAT Excavator Slewing Bearing to South America
In June 2023, our company successfully delivered a Four-Point Contact Ball Slewing Bearing for a CAT excavator to a client in South America. The customer required a reliable slewing ring to support heavy-duty applications such as mining and earthmoving. We supplied a four-point contact ball slewing bearing, which features a single raceway design with four contact points per ball, allowing it to simultaneously handle axial loads, radial loads, and tilting moments.
This bearing type offers a compact cross-section, high load efficiency, and smooth rotation, making it an ideal match for CAT excavators. After rigorous factory testing—including dimensional accuracy, hardness, and gear inspection—we prepared the bearing for shipment. In June 2023, we shipped the unit via a dedicated South America logistics route, applying anti-corrosion treatment and reinforced packaging to ensure safe delivery.
Upon arrival, the client confirmed successful installation and reported excellent performance. The four-point contact ball slewing bearing delivered stable slewing, low vibration, and reduced noise during daily excavator operations. This case once again demonstrates our ability to provide application-specific slewing bearings for leading brands like CAT, with on-time delivery to customers across South America.
What Is a Four-Point Contact Ball Slewing Bearing?
A Four-Point Contact Ball Slewing Bearing is a large-scale precision bearing that supports heavy rotating structures. It mainly consists of an inner ring, an outer ring, a single row of steel balls, a cage (or spacer), and a sealing device. Both the inner and outer rings come in either integral or split structures. The integral ring offers strong rigidity, while the split design allows for easy adjustment. For split structures, LDB uses bolts to connect the two split rings before the product leaves the factory.
Most four-point contact ball slewing bearings include a cage or spacer. However, we use a full-ball structure only when the application demands a relatively large load capacity. The full-ball design provides higher bearing capacity but creates greater frictional resistance, which can easily cause scratches on the surface of the steel balls. The basic structure of a four-point contact ball slewing bearing may include no gear, external gear, or internal gear teeth, delivering high static load capacity for demanding applications.
How Does a Four-Point Contact Ball Slewing Bearing Work?
The working principle of a four-point contact ball slewing bearing relies on a single row of steel balls running in arc-shaped raceways. Each steel ball makes contact with the raceway at four points—two on the inner ring and two on the outer ring. This unique geometry allows the bearing to accept axial loads from either direction, radial loads, and tilting moments simultaneously.
When an external load applies to the bearing, the steel balls transfer forces across the four contact points. The distribution of load changes depending on the direction of the force. For vertical axial loads, all four contact points share the load. For combined loads, some contact points carry more force while others unload. This dynamic load distribution gives the bearing its ability to handle complex loading conditions in a single raceway.
The drive mechanism—usually a pinion gear—engages the internal or external gear teeth on the bearing ring. As the pinion rotates, it drives the bearing ring to turn, allowing the attached structure to rotate smoothly with minimal friction.
Key Features of Four-Point Contact Ball Slewing Bearings
Four-point contact ball slewing bearings from LDB offer several distinctive features that make them suitable for a wide range of applications:
- Compact structure: The single-row design combines two seat rings into a lightweight, space-saving package.
- Four-point contact geometry: Steel balls contact arc raceways at four points, enabling the bearing to bear axial force, radial force, and tilting moment at the same time.
- Dual ring structure options: Choose between integral rings for maximum rigidity or split rings for easier adjustment during installation.
- Flexible gear configurations: Available without gear, with internal gear, or with external gear teeth.
- Wide size range: Outer diameters from 200mm to 10,000mm, inner diameters from 100mm to 8,000mm, ball diameters from 30mm to 75mm, and rated loads from 129kN to 3,410kN.
- High-quality materials: LDB uses 42CrMo and 50Mn steel for superior strength and durability.
- Effective sealing: Nitrile rubber seals protect the bearing from contaminants and retain lubricant.
- Precision heat treatment: Normalizing hardness reaches 187HB-241HB, quenched and tempered hardness reaches 229HB-269HB, and raceway quenching hardness achieves HRC 55-62.
- Short delivery time: LDB offers delivery within 10 to 30 days.
- 12-month warranty: Every bearing comes with a full one-year warranty against manufacturing defects.
Main Types of Four-Point Contact Ball Slewing Bearings
Based on gear configuration, four-point contact ball slewing bearings fall into three main types:
1. Non-Gear Type (No Gear)
This type has no gear teeth machined into the inner or outer ring. It suits applications where an external drive mechanism provides rotation independently of the bearing.
2. External Gear Type
The outer ring features gear teeth on its external surface. A pinion gear engages these teeth from outside the bearing. This configuration works well when the drive motor sits outside the rotating structure.
3. Internal Gear Type
The inner ring carries gear teeth on its internal surface. The pinion gear mounts inside the bearing ring. This design offers a cleaner layout and better protection for the gear system.
Each type allows LDB to match the bearing precisely to your mechanical design. We also offer both integral ring and split ring structures for each gear configuration.
Core Advantages of Four-Point Contact Ball Slewing Bearings
Four-point contact ball slewing bearings provide significant advantages over other bearing types:
Single bearing replaces multiple bearings
One four-point contact ball slewing bearing handles axial loads, radial loads, and tilting moments simultaneously. You do not need separate thrust bearings and radial bearings in your assembly.
Compact and lightweight design
The single-row structure occupies minimal space and adds little weight to your equipment. This helps you design more compact machinery.
High static load capacity
The four-point contact geometry distributes loads efficiently, allowing the bearing to support very high static loads without permanent deformation.
Bi-directional axial load capability
Unlike many bearings that handle axial load in only one direction, the four-point contact design accepts axial forces from either direction equally well.
Smooth rotation with low torque
Precision-ground raceways and high-quality steel balls deliver quiet, low-friction rotation, reducing power consumption and wear.
Long service life
With proper lubrication and maintenance, LDB’s four-point contact ball slewing bearings provide years of reliable continuous operation.
Customizable sealing and cage design
Based on your working environment, LDB can optimize the sealing structure and internal fixator to match your specific conditions.
Common Applications of Four-Point Contact Ball Slewing Bearings
Four-point contact ball slewing bearings from LDB serve a wide variety of industries and equipment:
Construction machinery
These bearings perform excellently in rotary conveyors, welding robots, manipulators, small and medium cranes, and excavators. The ability to handle combined loads makes them ideal for equipment that rotates under heavy weight.
Tower garage parking systems
Automated parking systems rely on four-point contact ball slewing bearings to rotate car-carrying platforms smoothly and accurately.
Crane and hoist equipment
Mobile cranes, tower cranes, and shipboard cranes use these bearings for their slewing mechanisms.
Excavators and earthmoving machines
Both medium and small excavators benefit from the compact size and high load capacity of four-point contact bearings.
Wind turbines
Some yaw and pitch systems in wind turbines use four-point contact slewing bearings for their ability to handle combined loads in outdoor environments.
Medical equipment
Large medical imaging devices and robotic surgery systems use these bearings for precise rotational positioning.
How to Select the Right Four-Point Contact Ball Slewing Bearing?
Selecting the correct four-point contact ball slewing bearing requires careful consideration of several factors:
Load requirements
Calculate the maximum axial load, radial load, and tilting moment your application will generate. LDB’s rated load range of 129kN to 3,410kN covers most medium to heavy-duty applications. Provide your load data to our engineers for accurate sizing.
Gear configuration
Decide whether you need no gear, internal gear, or external gear teeth based on your drive system layout. Internal gears suit designs where the motor mounts inside the bearing ring. External gears work when the motor sits outside.
Ring structure
Choose between integral ring for maximum rigidity or split ring for easier adjustment during installation. LDB pre-assembles split rings with bolts before delivery.
Size dimensions
Specify your required inner diameter (100mm to 8,000mm) and outer diameter (200mm to 10,000mm). Ball diameter (30mm to 75mm) affects load capacity and rotational smoothness.
Sealing requirements
Standard nitrile rubber seals suit most environments. For harsh conditions, LDB can design special sealing structures to protect against dust, moisture, and contaminants.
Heat treatment specifications
Verify that hardness levels meet your application needs. LDB provides normalizing hardness of 187HB-241HB, quenched and tempered hardness of 229HB-269HB, and raceway quenching hardness of HRC 55-62.
Cage or full-ball design
Use a cage design for most applications. Choose full-ball structure only when you need maximum load capacity and can accept higher friction.
Delivery time
LDB offers standard delivery within 10 to 30 days. For urgent requirements, please contact us to discuss expedited options.
Non-standard models
If your application requires a non-standard model, LDB can design and manufacture according to your specific requirements. We have commonly used standard models in stock, and our engineering team can develop custom solutions for any project.
LDB: Custom Four-Point Contact Ball Slewing Bearings Manufacturer
LDB specializes in the design, production, and supply of high-quality four-point contact ball slewing bearings. We serve customers across Asia, South America, Europe, and the Middle East, providing reliable components for construction machinery, parking systems, cranes, excavators, and more.
Our manufacturing capabilities
We produce four-point contact ball slewing bearings with outer diameters from 200mm to 10,000mm and inner diameters from 100mm to 8,000mm. Ball diameters range from 30mm to 75mm, and rated loads span from 129kN to 3,410kN. Our materials include 42CrMo and 50Mn steel, both known for their excellent strength, toughness, and wear resistance.
Quality assurance
Every bearing undergoes rigorous quality testing before leaving our factory. We inspect dimensional accuracy, hardness, gear teeth, and raceway surface quality. Our heat treatment process includes normalizing, quenching and tempering, and raceway induction hardening to achieve the required hardness levels.
Customization options
LDB provides a complete set of slewing bearings without gears, with external gears, with internal gears, or individual ring gears according to your requirements. For split ring designs, we connect the two split rings with bolts before shipment to simplify your installation. We can also optimize the sealing structure and internal fixator based on your working environment.
Packaging and delivery
We package each bearing using metal brackets or export standard fumigation-free wooden boxes. This ensures safe transportation to any global destination. Our standard delivery time is 10 to 30 days.
Technical support
Our engineering team can recommend the exact bearing model for your design or develop a fully custom solution. Whether you need a standard model or a non-standard design, we work closely with you to meet your specifications.
Warranty
All LDB four-point contact ball slewing bearings come with a 12-month warranty against manufacturing defects. We stand behind the quality and reliability of every product we ship.
Contact LDB today to discuss your four-point contact ball slewing bearing requirements. Provide your load data, size specifications, gear configuration, and any special requirements. We will respond with a competitive quote, technical recommendations, and a reliable delivery schedule.
