2.5—Thrust Bearings

Thrust bearings use balls or rollers to support axial loads (loads in the direction of the rotating shaft).

Thrust Ball Bearings

  • The raceways of thrust ball bearings lie on housing washers and shaft washers, which serve the same function as the outer and inner ring in radial bearings.
  • Double-direction types feature a central washer attached to the shaft.
  • Single-direction types can support axial loads in one direction, while double- direction types support axial loads in both directions.
  • Some models have an aligning seat attached to the housing washer to reduce the effect of mounting errors.
  • Cages are typically made of pressed steel for small bearings, while large bearings use machined cages.
Various cross-sections of thrust ball bearings. The bearings are oriented horizontally, and parts are identified from top to bottom as shaft washer, ball, housing washer, and aligning seat washer.

Spherical Roller Thrust Bearings

  • The barrel-shaped rollers in spherical roller thrust bearings are arranged to create diagonal rolling surfaces. Since the housing raceway is spherical, the bearing is self-aligning.
  • Spherical roller thrust bearings have very high capacity for axial (thrust) loads and can carry some radial load when an axial load is applied.
  • Oil lubrication is recommended even at low speeds to maintain proper lubrication in areas such as the contact surfaces between the roller and shaft washer rib.
  • The raceways of thrust roller bearings lie on housing washers and shaft washers, which serve the same function as the outer and inner ring in radial bearings.
3D models and cross-section of thrust roller bearings. The bearings are oriented horizontally, with the housing washer, shaft washer, rollers, and cage visible.