Hitachi Excavator Slewing Bearing Shipped to Europe
In November 2023, LDB successfully shipped a high-performance slewing bearing to a European customer for a Hitachi excavator. The product supplied was a four point contact ball slewing bearing, specifically selected for its ability to handle the demanding working conditions of excavator turntables.
The four point contact ball slewing bearing features a single-row design with a Gothic arch raceway, allowing each ball to contact the raceway at four points. This unique geometry enables the bearing to simultaneously support axial loads, radial loads, and tilting moments—exactly what an excavator turntable requires during digging, lifting, and slewing operations.
For this Hitachi excavator application, LDB provided a fully customized solution. The bearing was precisely engineered to match the customer’s dimensional and load specifications, ensuring a perfect fit and reliable performance. By choosing LDB, the European customer received a durable, high-precision slewing bearing that minimizes downtime and extends service life.
This November 2023 delivery to Europe demonstrates LDB’s ability to supply quality four point contact ball slewing bearings for major excavator brands like Hitachi, with custom solutions and reliable global shipping.
What is a Four Point Contact Ball Slewing Bearing?
A four point contact ball slewing bearing is a precision rotary component primarily composed of an inner ring, an outer ring, a single row of steel balls, a cage (or spacer), and sealing devices. Both the inner and outer rings can be manufactured as either integral or split structures. Integral rings offer higher rigidity, while split rings allow for easier adjustment. For split structures, bolts are used to connect the two split rings before the product leaves the factory.
This type of slewing bearing generally includes a cage or spacer to separate the balls. However, a full-ball (no cage) structure is used when load requirements are relatively high. The full-ball design provides larger load capacity but comes with higher frictional resistance, which can potentially cause scratches on the surface of the steel balls.
The basic structure of a four point contact ball slewing bearing is available in three gear configurations: without gear, with external gear, or with internal gear. All configurations offer high static load capacity.
Key specifications:
| Parameter | Range |
|---|---|
| Outer diameter | 300 mm – 10,000 mm |
| Ball diameter | 30 mm – 75 mm |
| Rated load | 129 kN – 3,410 kN |
| Gear type | No gear, internal gear, external gear |
| Delivery time | 10 – 30 days |
How Does a Four Point Contact Ball Slewing Bearing Work?
The working principle of a four point contact ball slewing bearing is based on its unique Gothic arch raceway geometry. Unlike conventional ball bearings where the ball contacts the raceway at two points, this design allows each steel ball to make contact at four points – two on the inner ring and two on the outer ring.
When loads are applied, the contact points engage as follows:
- Pure axial load in one direction: Two of the four contact points become active
- Reversed axial load: The opposite pair of contact points engages
- Combined loads (axial + radial + tilting moment): All four contact points share the load simultaneously
This load distribution mechanism enables a single-row bearing to perform functions that would otherwise require two separate rows. The single-row four-point contact ball slewing bearing consists of two seat rings, offering compact structure and light weight, while the four-point contact between the steel ball and the arc raceway allows it to bear axial force, radial force, and tilting moment at the same time.
Key Features of Four Point Contact Ball Slewing Bearings
The four point contact ball slewing bearing offers a range of distinctive engineering features:
- Single-row compact design: Consists of only two seat rings (inner and outer), providing a compact structure with light weight
- Four-point contact geometry: Steel balls contact the arc raceway at four points, enabling combined load handling
- Multiple gear options: Available as no gear, internal gear, or external gear to suit various drive configurations
- Flexible ring structure: Choice between integral rings (higher rigidity) and split rings (easier adjustment)
- Cage or full-ball options: Caged designs for standard applications; full-ball designs for higher load capacity
- High static load capacity: Engineered to withstand demanding static and dynamic conditions
- Wide size range: Outer diameters from 300 mm to 10,000 mm, ball diameters from 30 mm to 75 mm
- Fast delivery: Standard lead time of 10–30 days for custom orders
Material specifications:
| Material Property | Value |
|---|---|
| Base material | 42CrMo, 50Mn |
| Seal type | Nitrile rubber |
| Normalizing hardness | 187 HB – 241 HB |
| Quenched and tempered hardness | 229 HB – 269 HB |
| Raceway quenching hardness | HRC 55 – 62 |
Main Types of Four Point Contact Ball Slewing Bearings
Four point contact ball slewing bearings can be classified based on two main criteria: gear configuration and ring structure.
1. By gear configuration:
- No gear (plain): For applications where the drive system does not require gear engagement
- Internal gear: Gear teeth cut on the inner ring, suitable for compact drive designs
- External gear: Gear teeth cut on the outer ring, commonly used in excavators and cranes
2. By ring structure:
- Integral ring design: Higher rigidity, suitable for heavy-duty applications
- Split ring design: Allows for easier adjustment; bolts connect the two split rings before shipment
3. By ball arrangement:
- Caged design: Standard configuration with spacers or cages to reduce friction
- Full-ball design: No cage, higher load capacity but increased frictional resistance
Core Advantages of Four Point Contact Ball Slewing Bearings
The four point contact ball slewing bearing offers several distinct advantages over other slewing bearing types:
- Combined load capability: Can simultaneously bear axial force, radial force, and tilting moment within a single row
- Compact and lightweight: The single-row two-seat-ring design saves space and reduces overall machine weight
- Bidirectional axial load support: Handles thrust loads from both directions without additional raceways
- High static load capacity: Suitable for applications with heavy shock loads and intermittent rotation
- Design flexibility: Customizable gear type, ring structure, and ball arrangement to meet specific requirements
- Long service life: Optimized sealing and lubrication options extend operational life, especially in harsh environments
- Cost-effective: Lower manufacturing and maintenance costs compared to double-row alternatives
- Fast customization: 10–30 day delivery for custom orders enables rapid project execution
Product advantages from LDB:
- The single-row four-point contact ball slewing bearing is suitable for main engines requiring large axial load, high overturning moment, long service life, and continuous operation
- Sealing structure and internal fixator can be optimized based on the operating environment
- Both standard and non-standard models available – non-standard models designed and manufactured to customer requirements
- Complete sets available without gears, with external gears, with internal gears, or individual ring gears
- Secure packaging: metal bracket or export-standard fumigation-free wooden box
Common Applications of Four Point Contact Ball Slewing Bearings
Four point contact ball slewing bearings are widely used across various industries, particularly in construction machinery. Common applications include:
Construction and heavy machinery:
- Rotary conveyors
- Welding robots and manipulators
- Small and medium cranes
- Excavators (turntable applications)
- Aerial work platforms
Other industrial applications:
- Solar tracking systems
- Wind turbine yaw and pitch systems
- Industrial turntables and indexing tables
- Medical imaging equipment (CT scanners)
- Material handling equipment
- Radar and antenna rotators
The four point contact ball slewing bearing is especially suitable for applications that demand high axial load capacity, resistance to overturning moment, and continuous operation with extended service life.
How to Select the Right Four Point Contact Ball Slewing Bearing?
Selecting the correct four point contact ball slewing bearing for your application requires careful consideration of the following factors:
| Selection Factor | Considerations |
|---|---|
| Load requirements | Calculate axial load, radial load, and tilting moment (kN·m). Ensure rated load (129–3,410 kN) meets your needs. |
| Dimensional constraints | Verify outer diameter (300–10,000 mm) and ball diameter (30–75 mm) fit your mounting space. |
| Gear configuration | Choose no gear, internal gear, or external gear based on your drive system design. |
| Ring structure | Select integral ring for higher rigidity or split ring for easier adjustment. |
| Ball arrangement | Choose caged design for standard applications or full-ball design for higher load capacity. |
| Operating environment | Consider temperature, dust, moisture, and chemical exposure. Sealing and lubrication can be customized. |
| Precision requirements | Specify required axial/radial runout and backlash tolerances. |
| Delivery schedule | Confirm that the standard 10–30 day lead time aligns with your project timeline. |
Additional selection tips:
- For large axial loads and overturning moments with continuous operation, the single-row four-point contact ball slewing bearing is highly recommended
- LDB can optimize sealing structure and internal fixator design based on your specific working environment
- Both standard and non-standard models are available
LDB – Custom Four Point Contact Ball Slewing Bearings Manufacturer
LDB (Luoyang Longda) is a professional enterprise specializing in the production and sales of slewing bearings (slewing rings), slew drives, and gear transmission devices. As a reliable supplier of high-performance rotary components, LDB serves industries ranging from construction machinery to renewable energy.
Our four point contact ball slewing bearing capabilities:
| Parameter | LDB Offering |
|---|---|
| Outer diameter | 300 mm – 10,000 mm |
| Ball diameter | 30 mm – 75 mm |
| Rated load | 129 kN – 3,410 kN |
| Gear type | No gear, internal gear, external gear |
| Delivery lead time | 10 – 30 days |
| Material | 42CrMo, 50Mn |
| Seal type | Nitrile rubber (customizable) |
| Inner diameter | 100 mm – 8,000 mm |
| Warranty | 12 months |
| Rolling element | Steel ball |
| Raceway hardness | HRC 55 – 62 |
Why choose LDB?
- Complete customization: We provide non-standard models designed and manufactured to your exact requirements
- Optimized designs: Sealing structure and internal fixator can be optimized based on your working environment
- Flexible gear options: Supply complete slewing bearings without gears, with external gears, with internal gears, or individual ring gears
- Standard and non-standard models: Commonly used standard models in stock; non-standard models manufactured on demand
- Secure packaging: Metal bracket or export-standard fumigation-free wooden box for safe international shipping
- Global delivery: Reliable logistics network supporting delivery to Europe, North America, Southeast Asia, the Middle East, and beyond
Whether you need a four point contact ball slewing bearing for an excavator turntable, a crane, a welding robot, or any other rotary application, LDB delivers custom-engineered solutions with fast lead times and dependable quality.
Contact LDB today to discuss your specific requirements.
