Manufacturing a double row ball slewing ring with uniform ball sizes requires precise control over internal geometry to prevent load imbalance. Here is how our technical approach ensures superior reliability:
The defining feature of this bearing is its dual-row symmetry. By using balls of the exact same diameter in both rows, we create a balanced contact pattern that maximizes resistance to tilting moments. This is crucial for applications like crane booms or antenna masts where off-center loads are common. The load is shared equally, doubling the effective contact points compared to a single row.
A common failure mode in double-row bearings is uneven hardness between the two raceways. Our proprietary induction hardening process ensures that both the upper and lower raceways achieve an identical hardness profile (58-62 HRC) and depth (3-5mm). This consistency guarantees that neither row becomes the "weak link," extending the overall fatigue life of the slewing bearing.
To prevent ball-to-ball friction and ensure smooth rotation under high speeds, we utilize segmented nylon or steel retainers designed specifically for the tight packing density of double-row configurations. These cages maintain precise ball spacing, reducing heat generation and wear, which is vital for continuous operation in wind energy and automation sectors.
Given the increased height of double-row designs, sealing integrity is paramount. We employ a multi-stage labyrinth seal system reinforced with high-grade nitrile rubber lips. Some models include a secondary felt wiper to scrape off fine dust before it reaches the primary seal, offering IP66 protection suitable for dusty mining sites or salty marine environments.
We offer seamless integration of external or internal spur gears. Our gear cutting process aligns the gear pitch circle perfectly with the bearing's rotational axis, minimizing runout. This ensures smooth torque transmission from the slew motor, reducing vibration and noise in the final assembly.
| Parameter | Specification Range | Notes |
|---|---|---|
| Product Series | DRS-Series (Double Row Same Diameter) | Balanced design for combined loads. |
| Outer Diameter (OD) | 500 mm – 3,500 mm | Custom sizes up to 4,000mm available. |
| Inner Diameter (ID) | 400 mm – 3,100 mm | Dependent on cross-section height. |
| Overall Height | 80 mm – 200 mm | Higher profile than single-row for added rigidity. |
| Ball Configuration | Dual Row: Identical Diameter Balls | Symmetrical load sharing. |
| Static Axial Load | Up to 3,000 kN | Bidirectional capacity. |
| Static Radial Load | Up to 1,500 kN | Enhanced lateral stability. |
| Static Tilting Moment | Up to 2,200 kNm | Superior resistance to overturning. |
| Dynamic Load Rating | Calculated per ISO 76 / DIN 798 | Based on L10 life of 30,000+ hours. |
| Ring Material | 42CrMo4, 50Mn, Q345E (Forged) | Vacuum degassed for purity. |
| Ball Material | GCr15SiMn / 100Cr6 | Grade 10 precision balls. |
| Raceway Hardness | 58 – 62 HRC | Uniform hardness across both rows. |
| Core Hardness | ≤ 30 HRC | Tough core for shock absorption. |
| Gear Module (m) | m = 5 to m = 30 | External or Internal options. |
| Gear Accuracy | DIN Class 9 (Standard), Class 8 (Optional) | Low backlash available. |
| Sealing System | Multi-lip Nitrile + Labyrinth | IP66 rated; optional purge ports. |
| Operating Temp | -40°C to +80°C (Standard) | Special seals for extreme cold/heat. |
| Surface Treatment | Zinc Plated, Black Oxide, C5-M Epoxy | Marine grade corrosion protection. |
| Lubrication | Lithium Complex Grease (NLGI 2) | Standard grease nipples included. |
| Mounting Bolts | Grade 10.9 / 12.9 | Custom hole patterns & counterbores. |
| Certifications | ISO 9001, CE, EN 13814, DNV/GL | Full material traceability (3.1). |
Our double row same diameter ball slewing bearings are trusted in sectors where stability and predictable performance are non-negotiable:
In 30-ton+ excavators and truck cranes, the boom often swings with heavy, offset loads. The symmetrical design of our same diameter ball bearings provides the necessary rigidity to prevent deflection, ensuring precise positioning and operator safety.
For medium-to-large wind turbines, the yaw system must hold the nacelle steady against strong, shifting winds. Our bearings handle the complex combination of axial wind thrust and massive tilting moments caused by gusts, offering reliable locking capability.
These giants operate 24/7 in corrosive marine environments. Our bearings, equipped with marine-grade coatings and robust seals, withstand the constant cycle of heavy lifting and saltwater exposure, minimizing downtime for port operators.
Safety and smoothness are paramount. The double row same diameter configuration ensures that the passenger cabins remain level even when the wheel is partially loaded (uneven weight distribution). This symmetry prevents jerky movements, enhancing the visitor experience.
Military and civilian radar dishes require pinpoint accuracy. The high rigidity of our bearings minimizes wind-induced vibration, ensuring the antenna stays locked on target regardless of weather conditions.
Tag: XCMG crane swing ring | Liebherr crane bearing parts | High precision slewing ring for positioner | Indexing table bearing | Wind turbine yaw bearing | Wind turbine pitch bearing | Pitch bearing for wind generator
