Slewing bearings

Slewing bearing
Slewing bearings comprise an inner ring and an outer ring, one of which usually incorporates a gear. Together with attachment holes in both rings, they enable an optimized power transmission with a simple and quick connection between adjacent machine components. The bearing raceways, in conjunction with the rolling elements and cages or spacers, are designed to accommodate loads acting singly or in combination, and in any direction.
SKF application engineering service
Selecting the appropriate slewing bearing can be a challenge, particularly if there are stringent technical, reliability or economic demands. In these cases, for example, SKF application engineering service can provide advanced calculations and simulations utilizing state-of-the-art analyse methods to optimize and validate the best design to meet the customer requirements.
SKF remanufacturing service
SKF also offers worldwide a wide range of added value services for slewing bearings, including remanufacturing. A slewing bearing with only 30% left of its calculated service life can be well worth remanufacturing. SKF's standardized remanufacturing processes can extend significantly the service life of critical equipment.
All of these combine to improve rotating equipment performance and reduce total cost of ownership.

Bearing features

Depending on their design, slewing bearings have the following features: 

  • High load carrying capacity
  • High stiffness for rigid bearing application
  • Low friction
  • Long service life
  • Surface protection and corrosion resistance
  • Integration of additional features, including:
    • driving mechanism
    • control devices
    • lubrication systems
    • monitoring systems
    • sealing cassettes

Designs

SKF manufactures standard and customized slewing bearings in various designs with outside diameters from 0,1 to 18 m to meet the demands of particular applications. The most common designs are:

  • Four-point contact ball bearings (fig. 1)
    Optimal economy and capacity for given dimensions or when replacing existing multi-bearing arrangements
  • Eight-point contact ball bearings (fig. 2)
    80% increase in capacity compared to a same-sized single-row four-point contact ball bearings
  • Crossed cylindrical roller bearings (fig. 3)
    High stiffness and constant resistance to rotation
  • Triple row roller bearings (fig. 4)
    Provide highest capacity for a given diameter
  • Wire race bearings (fig. 5 and fig. 6)
    60% lighter compared to same-sized all-steel bearings

SKF has extensive experience in designing and manufacturing customized or special slewing bearings. Examples are:

  • Combined roller/ball bearings (fig. 7)
  • Segmented bearings
  • Inserted raceways bearings

Applications

SKF offers high-performance slewing bearings for a wide range of applications, including: 

  • Wind turbines 
  • Tunnel boring machines 
  • Excavators
  • Forestry vehicles
  • Rail vehicles 
  • Dockside and deck cranes
  • Mobile cranes
  • Water treatment equipment
  • Bottle filling systems
  • Metals
  • Material handling
  • Marine pods
  • Offshore buoys
  • Stacker reclaimers
  • Surveillance systems (e.g. radars, cameras)
  • Medical equipment
  • Tidal turbines
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