Design considerations

Abutment dimensions

Abutment dimensions should fulfill the following:

  • Support surfaces in housings and on shafts should be at right angles to the shaft axis and provide uninterrupted support over the entire washer face.
  • The abutment diameter on the shaft should be ≥ da min and in the housing ≤ Da max (fig. 1). Values for da min and Da max are listed in the product table.
  • Shafts and housings should be manufactured to suitable tolerance classes (table 1)
    to provide satisfactory radial guidance for the individual thrust bearing components.
    • Housing centred washers require a radial gap between the shaft and washer bore.
    • Shaft centred washers require a radial gap between the washer and the housing bore.

Cylindrical roller and cage thrust assemblies are generally centred radially by the shaft to reduce the circumferential speed at which the cage slides against the guiding surface. This is particularly important for higher-speed applications. The guiding surface should be ground.

Raceways on shafts and in housings

  • should have the same hardness, surface finish and axial run-out as a bearing washer, if the load carrying capacity of a cylindrical roller and cage thrust assembly is to be fully exploited
  • should be designed using the dimensions Ea and Eb (→ product table), which take radial displacement of the roller set into consideration
For additional information, refer to Raceways on shafts and in housings.
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