Static Load Ratings
When subjected to an excessive load or a strong shock load, rolling bearings may incur a local permanent deformation of the rolling elements and raceway surface if the elastic limit is exceeded. The nonelastic deformation increases in area and depth as the load increases, and when the load exceeds a certain limit, the smooth running of the bearing is impeded. The basic static load rating is defined as that static load which produces the following calculated contact stress at the center of the contact area between the rolling elements subjeted to the maximum stress and raceway surface.
For self-aligning ball bearings: |
4 600MPa |
For other ball bearings: |
4 200MPa |
For roller bearings: |
4 000MPa |
In this most heavily stressed contact area, the sum of the permanent deformation of a rolling element and that of the raceway is nearly 0.0001 times the rolling element's diameter. The basic static load rating C 0 is written C 0r for radial bearings and C 0a for thrust bearings in the bearing tables. |
