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Slewing Ring Bearings

AUB offers slewing rings in imperial and metric sizes, as well as custom mounting configurations and lubricants. Slewing ring bearings are specially designed for large load capacity and are widely used in various heavy machinery and equipment. These devices are capable of horizontal, vertical or tilted operation in many different applications. AUB's slewing ring bearings are easily interchangeable with all major brands. Standard sizes are available from stock, of course, AUB is fully capable of providing you with customized slewing ring bearing solutions.

Reliable Delivery: Customize your slewing ring bearing orders with inventory and fulfillment services such as just-in-time delivery, private labeling, blanket orders, and recurring releases.

Technical Support: Our team of engineers provides slewing bearing application engineering solutions such as 3D modeling, 2D drawing, FEA and technical manual assistance.

High Quality: AUB high quality slewing ring bearings are closely monitored throughout the manufacturing process and meet or exceed the quality of all major brands.

Fair price: take advantage of the Chinese industrial chain to keep you on budget.

Slewing ring, also known as slewing ring bearing, mainly refers to heavy-duty bearings that can withstand combined loads. Its diameter varies from 0.4m to 10m, and can withstand large axial and radial loads and overturning moments.

Slewing ring bearing type

The slewing ring consists of the following parts: inner ring, outer ring, rolling elements, spacer or cage, and seals. According to the external structure, there are three types of slewing bearings: gearless, external gear and internal gear. According to the internal structure, the slewing bearing can be divided into single row cross roller slewing bearing, single row four point contact ball slewing bearing, double row four point contact ball slewing bearing, double row angular contact thrust ball slewing bearing, cross cylindrical roller, cross cone Roller slewing bearings, three-row cylindrical roller slewing bearings, and slewing bearings of combined structure. Of these, the most common types are:

Single row cross roller slewing ring. The single row cross roller slewing ring is composed of two bearing rings, with compact structure, high manufacturing precision and small assembly clearance. The rollers are arranged crosswise, which can bear axial force, overturning moment and large radial force at the same time. Therefore, cross roller slewing bearings are widely used in transportation, engineering machinery, military products and other fields.

Single row ball bearings, also known as four-point contact bearings, consist of an inner ring, an outer ring, steel balls and spacer cages. It has a relatively compact structure and light weight. The steel ball is in four-point contact with the arc raceway and can bear similar axial, radial and moment loads.
It is the most common type in the slewing bearing industry; nearly 90% of the slewing bearings on the market are of this type. It is a cost-effective design and the most flexible choice for most mechanical applications. This type of bearing is used in many industries including cranes, positioners, turntables, excavators, water purification and many other applications. Compared with the cross roller slewing ring, it is characterized by the four-point contact between the steel ball and the raceway, so the rotation is more flexible. But its carrying capacity and precision are not as good as cross roller slewing bearings.

Double row angular contact ball bearing, easy to assemble, can withstand large axial force and overturning moment, suitable for medium and heavy loading and unloading machinery, such as tower cranes, truck cranes, etc.

Crossed Roller Slewing Bearing, With high dynamic load capacity, high support rigidity and rotational accuracy can be achieved through preload.

Three-row Cylindrical Roller Combined Bearing, It has a very high load-carrying capacity, and the bearing diameter can be greatly reduced under the same force, which makes the mechanism structure more compact. It consists of three separate rows of rollers, with separate upper and lower raceways and radial raceways, so that the load on each row of rollers can be accurately determined. The three-row roller slewing bearing can bear multiple loads at the same time, and it has the largest bearing capacity among all types of slewing bearings. With its large size and solid construction, it is especially suitable for heavy machinery requiring larger diameters. Such as bucket wheel excavators, cranes, ship cranes, port cranes, molten steel mobile platforms, large tonnage truck cranes and other machinery.


The performance and quality of raw materials have a great influence on the performance and service life of bearings. AUB only uses bearing raw materials from qualified suppliers. We will carry out strict inspection on bearing forgings, including ultrasonic inspection, hardness inspection and metallographic inspection. Most slewing rings use 42CrMo, 50Mn as raw materials, GCr15 bearing steel is usually used for small sizes, and AUB can also produce slewing ring bearings with customized materials such as stainless steel and coated aluminum alloys.

GCr15 steel

For precision slewing bearing materials, such as cross roller bearings, harmonic reducer bearings, etc., AUB uses GCr15 bearing steel as raw material. GCr15, as a representative steel grade of high carbon chromium bearing steel, has less alloy content and good comprehensive performance. GCr15 bearing steel has high hardness, uniform structure, good wear resistance and good contact fatigue performance after quenching and low temperature tempering. Usually used in the manufacture of precision bearing rings and rolling elements.

  • The normal quenching temperature of GCr15 steel is 830-860°C.
  • The tempering temperature of GCr15 steel is generally 160-180°C.

GCr15 steel has good hot workability, moderate cold workability and general cutting performance. In addition, GCr15 has poor weldability and temper brittleness. As a bearing steel, GCr15 has high requirements on smelting quality, and the content and distribution of sulfur, phosphorus and non-metallic inclusions need to be strictly controlled, which has a great impact on the service life of bearing steel.


For slewing bearing materials, AUB usually uses 50Mn or 42CrMo as raw materials. 50Mn is a high-quality carbon structural steel. It has high strength, elasticity and hardness, and is often used after quenching and tempering treatment. The welding performance of 50Mn is poor, and it has a tendency of overheating sensitivity and temper brittleness. 50Mn is usually used in the manufacture of parts that require high wear resistance and load carrying capacity, such as gears and gear shafts.

42CrMo steel

42CrMo material is an alloy steel, very suitable for forging processing. It has high strength, high hardenability and good toughness. 42CrMo has small quenching deformation, high creep strength and durable strength at high temperature. Compared with 50Mn, 42CrMo has better fatigue durability, but its cost is higher.

Installation of slewing bearing

The mating surface should be checked before installing the slewing ring. The parts supporting the slewing ring should have sufficient rigidity. The mating surface should be machined to achieve the required flatness and inclination. Each set of slewing bearings will be marked with "S" on the soft point, and should be placed in the non-stressed area during installation. When installing, first position the bearing radially, then tighten the mounting bolts crosswise, and check the rotation of the slewing bearing. To ensure smooth rotation, the gear mesh should be checked before the bolts are fully tightened. The prestress of tightening bolts should be 70% of the yield limit of the bolt material.

The slewing ring of AUB has been well lubricated before leaving the factory. Under normal circumstances, after the bearing is installed and put into operation for 100 hours, it should be checked and relubricated once (how to add grease), and relubricated every 500 hours after continuous operation. For slewing bearings under high temperature environment, the cycle of replenishing grease should be appropriately shortened. When the bearing is stored for a long time, or the machine stops running for a long time, it should also be refilled with grease.

Slewing bearing application

Slewing bearings are widely used in heavy slewing devices such as lifting machinery, mining machinery, construction machinery, port machinery, ship machinery, high-precision radar antenna mounts, missile launchers, and wind power generators. AUB can design, develop and produce slewing bearings of various special structures according to the specific requirements of users.

Typical applications include:

• Material handling • Bottling and palletizing equipment

• Semiconductors • Manufacturing automation and robotics

• Mining and off-road • Medical systems and imaging

• Oil and gas • Utility cranes and bucket trucks

• steel mills • wind energy

• Telescope • Satellite Dish

• Defense (tanks/turrets) • Stage and entertainment

•Drilling equipment

•Wind power plant

•Mobile robot expansion

•Satellite equipment and mobile weapons onboard spacecraft

•Spatial Tracking Devices

•Solar tracking device

•Packaging and bottling equipment

•Medical packaging equipment

•and more