Slewing Ring Bearings


Slewing ring bearings, or turntable bearings, are ball or roller-style bearings composed of two concentric rings, either of which may include a gear. This type of bearing enhances load support and power transmission in all directions, and they are typically employed to support heavy loads for slow applications and large equipment such as earth excavators and construction cranes. The unique power and versatility of slewing ring bearings have made them increasingly valuable in a wide array of industries, including construction, industrial, robotics, machine tooling, and medical applications.

Slewing Ring Bearing Types

Emerson Bearing is pleased to offer slewing ring bearings from high-end brands, including Rothe Erde® (Rotek), Silver Thin™, and Scheerer Bearing Corporation. Depending on your application needs, these bearings are available in a variety of designs.

Series 1000 Single Row Ball Slewing Ring

The Series 1000 is a gearless-only bearing model composed of chrome-alloy steel balls without spacers in unhardened raceways within steel rings.

Series 2100 Single Row Ball Slewing Ring

The Series 2100’s single-row design offers four-point contact in induction-hardened, offset raceways.

Series 3000 Single Row Ball Slewing Ring

The Series 3000 is an adaptation of the four-point contact slewing ring constructed with offset hardened raceways, quality raceway wrap, and sturdy ball separators.

Series 4000 Two Row Ball Slewing Ring

Series 4000 is built with greater internal clearance than the series 3000 model for enhanced mobility.

Series 5000 Cross Roller Slewing Ring

The Series 5000 Cross Roller is built with V-groove style raceways to provide two paths for rollers in each ring.

Series 6000 High Speed Slewing Ring

Our single row Series 6000 is a high-speed radial ball slewing ring that can provide raceway velocities up to 3,000 feet per minute with sufficient lubrication.

Series 7100 Vertical Thrust Slewing Ring

Series 7100 Vertical Thrust Slewing Rings are single-row ball bearings specifically designed to support applications in which the center of force stays inside the diameter of the slewing ring during standard operation.

Series 8000 Vertical Thrust Slewing Ring

Similar to the 7100, the 8000 is a single-row ball bearing that supports vertical movement within the slewing ring’s diameter. The 8000 model offers the lowest cost per unit diameter for heavy, pure-thrust loads.

Series 10,000 Three Row Roller Slewing Ring

The series 10,000 is built with three rows of rollers that move independently for optimal support and freedom of movement in the desired direction.

Series 12,000 Roller and Ball Combination Slewing Ring

The Series 12,000 combines both rollers and balls to account for small movement eccentricities at relatively high axial loads for enhanced load support and stability.

Series 15,000 Wire-Race™ Slewing Ring

Our Series 15,000 Wire-Race™ Slewing Ring includes a replaceable hardened wire raceway, which allows the supporting rings to be created using a wider assortment of materials.

Precision Slewing Rings

Emerson Bearing’s precision slewing rings are designed to facilitate highly accurate support and mobility to exacting specifications, including:

  • Run-out tolerances within .0003″
  • Concentricity within .0003″
  • Surface flatness within .0003″
  • Parallelism within .0003″
  • Bolt hole positions .010″ diameter
  • Gear precision equals or exceeds AGMA 10 standards

Slewing Bearing Applications

Slewing ring bearings are often relied upon to support loads in very large, heavy-duty equipment. Their exceptional combination of heavy load support and mobility enhancement makes them useful in a variety of industries and applications, including:

  • Heavy-Duty Machinery. Slewing ring bearings are prevalent in heavy-duty equipment like cranes, excavators, and other machinery that require considerable load-bearing abilities and smooth rotation. They offer the necessary strength and stability to handle the extreme stresses and forces encountered during swinging, rotating, and lifting operations. 
  • Wind Turbines. Wind turbines rely on rotating nacelles to efficiently capture wind energy. Slewing ring bearings support the nacelle and allow for smooth rotation, even under harsh weather conditions.
  • Mining Equipment. Slewing ring bearings are used in various types of mining equipment, including conveyors, shovels, excavators, and stacker reclaimers.
  • Aerospace. Slewing bearings support movements in critical aerospace equipment, including satellite antennas, space exploration machinery, and aircraft landing gear. 
  • Tunnel-Borers. Slewing bearings are the main shield bearings in tunnel-borers and serve as the connective part of the cutter head to ensure that it rotates.
  • Water Treatment Facilities. Slewing ring bearings are commonly used in wastewater treatment systems, such as circular scraper clarifiers.
  • Robotics Equipment. Robotic joints and arms depend on slewing bearings to facilitate precise movement and positioning.
  • Medical Diagnostic Equipment. Slewing bearings are used in CT scanners and other advanced medical imaging equipment.

Other applications of slewing ring bearings include:


  • Bottling Equipment
  • Fifth Wheels on Trailers and Farm Vehicles
  • Cranes & Excavators
  • Machining Tools
  • Radar Antennas
  • Log Debarkers
  • Coil Winders
  • Pay-Off Reels
  • High-Speed Capstans
  • Large, Precision, and Index Turntables
  • Clarifiers, Thickeners, and Rotary Distributors
  • Mooring Buoys

Slewing Ring Bearings From Emerson Bearing

For more than 50 years, Emerson Bearing has been the go-to provider of top-quality roller and ball bearings for customers around the world. Our selection includes everything from miniature precision bearings to five-foot mill bearings in a variety of styles and materials to suit the needs of your applications. We are dedicated to providing our customers with the right bearings at competitive prices.

We offer a wide range of services, including:

  • One-Stop Shopping Experience
  • Extensive Inventory
  • Worldwide Sourcing Network
  • Bearing Troubleshooting Capabilities
  • Online Product Catalog
  • Comprehensive Online Reference Tool
  • Same-Day Shipping
  • Fixed Price Program
  • Guaranteed Customer Support 24/7
  • OEM and MRO Expertise
  • OEM Parts Interchange Services

Emerson Bearing provides personalized and professional service to our customers worldwide. To learn more about our top-of-the-line bearing products and solutions, contact us today or request a quote!

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