Cylindrical Maximum Permissible Axial Loads
Cylindrical roller bearings having inner and outer rings with ribs, loose ribs or thrust collars are capable of sustaining radial loads and limited axial loads simultaneously. The maximum permissible axial load is limited by an abnormal temperature rise or heat seizure due to sliding friction between the end faces of the rollers and rib face.
The maximum permissible axial load for bearings of diameter series 3 that are continuously loaded and lubricated with grease or oil is obtained by the following equations.
Grease lubrication (Empirical equation)
Oil lubrication (Empirical equation)
where 
| f : Load Factor |
k : Size Factor |
| Loading Interval |
Value of f |
Diameter series |
Value of k |
| Continuous |
1 |
2 |
0.75 |
| Intermittent |
2 |
3 |
1 |
| Short time only |
3 |
4 |
1.2 |
In addition, for cylindrical roller bearings to have a stable axial load-carrying capacity, the following precautions are required for the bearings and their surroundings:
- When axial loads are applied, radial loads must also be applied.
- Sufficient lubricant must exist between the roller end faces and ribs.
- Superior extreme-pressure grease must be used.
- Sufficient running-in should be done.
- The mounting accuracy must be good.
- The radial clearance should not be more than necessary.
In cases where either the bearing speed is extremely slow, the speed exceeds the limiting speed by more than 50%, or the bore diameter is more than 200 mm, careful study is necessary for each case regarding lubrication, cooling, etc.. |
