Delivery of Volvo Excavator Slewing Bearing to South America
In July 2022, our company successfully delivered a Four-Point Contact Ball Slewing Bearing for a Volvo excavator to a client in South America. The customer required a high-performance slewing ring to support demanding applications such as earthmoving, construction, and infrastructure projects. We supplied a four-point contact ball slewing bearing, which features a single raceway design with four contact points per ball, allowing it to handle axial loads, radial loads, and tilting moments simultaneously.
This bearing type offers a compact cross-section, high load efficiency, and smooth rotation, making it an ideal match for Volvo excavators. After rigorous factory testing—including dimensional accuracy, hardness, gear inspection, and raceway quenching hardness verification (HRC 55-62)—we prepared the bearing for shipment. In July 2022, we shipped the unit via a dedicated South America logistics route, applying anti-corrosion treatment and reinforced export-standard fumigation-free wooden box 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 Volvo, with on-time delivery to customers across South America. LDB offers a 12-month warranty, delivery within 10-30 days, and full customization including internal gear, external gear, or non-gear options.
What Are Four-Point Contact Ball Slewing Bearings?
Four-point contact ball slewing bearings are large-scale precision bearings that support heavy rotating structures in demanding machinery. A four-point contact ball slewing bearing 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, manufacturers 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. This friction can easily cause scratches on the surface layer 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.
Structural Features of Four-Point Contact Ball Slewing Bearings
Four-point contact ball slewing bearings possess several distinctive structural features that make them suitable for a wide range of applications. The single-row four-point contact ball slewing bearing consists of two seat rings, offering a compact structure and light weight. The four-point contact between the steel ball and the arc raceway enables the bearing to bear axial force, radial force, and tilting moment at the same time.
LDB manufactures these bearings with outer diameters ranging from 300mm to 10,000mm and ball diameters from 30mm to 75mm. Rated loads span from 129kN to 3,410kN, covering most medium to heavy-duty applications. The materials used include 42CrMo and 50Mn steel, both known for their excellent strength and wear resistance. The seal type is nitrile rubber, which provides effective protection against contaminants while retaining lubricant. The rolling body is a steel ball, and the heat treatment process delivers normalizing hardness of 187HB-241HB, quenched and tempered hardness of 229HB-269HB, and raceway quenching hardness of HRC 55-62. LDB offers a 12-month warranty on all products, with delivery times of 10 to 30 days.
Main Configuration 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 Tooth)
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 (External Tooth)
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 (Internal Tooth)
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. The features include four-point contact with internal tooth, external tooth, or no tooth options.
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 consists of two seat rings, occupying minimal space and adding 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
This series of slewing ring suits main engines that require large axial load capacity, high overturning moment resistance, long service life, and continuous operation.
Customizable sealing and cage design
According to the requirements of the supporting working environment, LDB can optimize the design of the sealing structure and the internal fixator.
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.
Key Factors When Choosing a 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
LDB has commonly used standard models available. For non-standard models, we can design and manufacture according to customer requirements.
LDB: Custom Four-Point Contact Ball Slewing Bearings Manufacturer
LDB is an enterprise specializing in the design, development, manufacture, and sales of precision slewing bearings (slewing rings) and precision slewing drives. As a professional slewing ring supplier, we provide high-performance small and large slewing rings to customers worldwide.
Unlike other providers of slewing bearings, LDB can offer fully tailored slewing bearing solutions with integrated advanced monitoring, lubrication, and sealing systems for higher reliability and longer service life. Our wide range of expert slewing bearing services also helps cut costs and optimize performance, while our global presence allows slewing bearing solutions and services to be delivered quickly around the world.
Customization capabilities
LDB provides a complete set of slewing bearings without gears, external gears, internal gears, or individual ring gears according to customer requirements. We can optimize the sealing structure and internal fixator based on your specific working environment. For split ring designs, we connect the two split rings with bolts before shipment to simplify your on-site installation.
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 of HRC 55-62 on the raceway.
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, and we offer a 12-month warranty on all products.
Technical support
LDB has commonly used standard models in stock. For non-standard requirements, our engineering team can design and manufacture according to your specifications. Whether you need a standard model or a fully custom solution, we work closely with you to meet your requirements.
Contact LDB today to discuss your four-point contact ball slewing bearing needs. 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.
