What Are Thrust Ball Bearings?

Thrust ball bearings are a type of separable rolling bearing designed to handle axial (thrust) loads exclusively. To ensure smooth operation, the applied axial load must not fall below the minimum required axial load.

Types of Thrust Ball Bearings

Based on structure and load direction, thrust ball bearings are classified into two types:

1. Single-Direction Thrust Ball Bearings

  • Consist of a housing washer (seat ring), shaft washer (shaft ring), and a ball-cage assembly.
  • The housing washer fits into the housing, while the shaft washer mounts onto the shaft.
  • Designed to handle unidirectional axial loads — cannot support radial loads.

2. Double-Direction Thrust Ball Bearings

  • Feature two shaft washers, one central housing washer, and two ball-cage assemblies (one on each side).
  • Capable of handling bidirectional axial forces (both forward and reverse directions).

Advantages of Thrust Ball Bearings

  • ✔ Low friction, allowing higher speeds (though lower than radial bearings like deep groove ball bearings).
  • ✔ Simple structure, cost-effective manufacturing, and easy installation/maintenance.
  • ✔ Precise axial force transmission, ideal for applications requiring high axial positioning accuracy.

Limitations

  • ✖ Cannot withstand radial loads — must be paired with radial bearings.
  • ✖ High alignment requirements — misalignment can cause uneven load distribution, reducing lifespan.

Common Applications

  • Machine tool spindles & lead screws (handling axial feed forces).
  • Automotive transmissions & clutches (absorbing gear-shifting axial forces).
  • Pumps & compressors (managing impeller thrust).
  • Cranes & elevators (supporting vertical axial loads).