Design of bearing arrangements
The abutment dimensions da min and Da max listed in the product table apply for axial bearing loads Fa ≤ 0,1 C0. If the bearings are subjected to heavier loads, it may be necessary to support the shaft and housing washers over their entire side faces (da = d1 and Da = D1). For heavy loads, where P > 0,1 C0, the shaft washer bore must be fully supported by the shaft, preferably by an interference fit. Even the housing washer should be radially supported (fig. 1).
For additional information about dimensioning washer supports, contact the SKF application engineering service.
Recessed housing bore for bearings with a stamped cage
For bearings fitted with a stamped window-type steel cage, the housing bore must be recessed (fig. 2) to prevent the cage from contacting the housing during possible misalignment. SKF recommends the following guideline values for the diameter of that recess:
- D + 15 mm for bearings with an outside diameter D ≤ 380 mm
- D + 20 mm for bearings with an outside diameter D > 380 mm
SKF spherical roller thrust bearings must be subjected to a minimum load. However, at relatively low speeds, in the zone below the blue line (diagram 1) the application can be designed to operate with a small axial clearance. For these applications, bearings with a modified shaft washer (designation suffix VU029) should be used. Small axial clearance enables simple and cost-effective bearing arrangements e.g. for horizontal shaft applications at relatively low speeds, as no external preload is necessary.
For additional information about bearing arrangements with axial clearance, contact the SKF application engineering service.