Load carrying capacity
- the housing material and design and, where applicable, cap bolt strength
- the direction of the load
- the strength of the attachment bolts and support structure
- the condition of the support surface
Breaking loadsFor most SKF housings, guideline values for the breaking loads P are provided in the relevant product section. To obtain the permissible load for a housing, the guideline value should be divided by a factor based on the safety requirements and operating conditions of the application. In general engineering, a safety factor of 6 is typical. The permissible load can only be exploited if the housing is mounted properly and all bolts are tightened to the specified torque values. For split housings, the strength of the cap bolts should also be considered. A minimum safety factor of 2 against cap bolt yield should be used.
Safe loadsIn some regions, safe loads are used instead of breaking loads. These guideline values have been established using accepted engineering practices, taking safety and ultimate tensile strength of the materials into account. They reflect a safety factor of 5 against housing fracture, and where applicable, a minimum factor of 2 against cap bolt yield. The safe loads can only be fully exploited if the housing is mounted properly and all bolts are tightened to the correct torque values.
Axial load carrying capacity for bearings on a sleeveWhen using a bearing on a sleeve on a plain shaft, the axial load carrying capacity is limited either by the bearing, sleeve or housing.
For the axial load carrying capacity of the bearing, refer to Bearings, units and housings. For the sleeve, the permissible axial load to safely prevent slippage on the shaft is determined by the friction between the shaft and sleeve. Provided the bearing is mounted correctly (→ skf.com/mount), the permissible axial load can be calculated from
Fap = 0,003 B d
|Fap||=||maximum permissible axial load [kN]|
|B||=||bearing width [mm]|
|d||=||bearing bore diameter [mm]|