YC’s self-aligning ball bearing has a spherical raceway in the outer ring and a double-raceway in the inner ring. This feature gives the bearings the self-aligning property, which can keep the machine operating well even when angular misalignment of the shaft relative to the housing occurs. Values of permissible misalignment errors of double row self-aligning ball bearings are given in the section “selection of bearing type”. The self-aligning ball bearing is mainly used to carry radial loads and light axial loads, but they can not carry pure axial loads.
Minimum Load-self-aligning Ball Bearing
In order to keep bearings working in a good condition, a minimum load must be imposed on bearings, particularly on bearings working at high speeds, high accelerations, or with the load direction changing frequently, because under these working conditions, inertial force of balls and cage and lubricant friction will have bad influence on the rotation of bearings, and detrimental sliding movement may be caused.
The minimum axial load of a self-aligning ball bearing can be obtained from
Fmin = 0.01C0
Where
C0-kN Basic static load rating
Dimension Series |
Kr |
10 |
2、3、4 |
22 |
23 |
100
|
150 |
200 |
250 |
When bearings are started at low ambient temperatures or in the condition where the viscosity of lubricant is very high, a larger minimum load probably is needed. Usually, the weight of bearing supporting parts plus the load on the bearing have been over the minimum load. If the weight can’t be up to the required minimum load, then extra radial load must be imposed on this type of bearing in order to meet the requirement of minimum load, e.g. increase the tension for driving belt, or other similar methods.