1. Shaft and housing requirements

     Lower shaft housing accuracy bad situation, bearing affected, can not play the desired properties. For example, the mounting portion retaining the shoulder if the accuracy is not good, it will produce inner and outer rings relative inclination. In addition to bearing the load increases the stress concentration, the bearing fatigue life drops, more serious cause holder breakage, sintering.

     2. Shaft and bearing housing complex

     Motor tolerance bearings and shaft or with the general k5 k6. Bearing and housing tolerances commonly used K7. Precision bearings for 6309 with the shaft and housing are as follows:

     Roundness tolerance axes: 4 ~ 7μm, cylindrical tolerance: 4 ~ 7μm, retaining shoulder runout tolerance: 4μm

     Shell roundness tolerance: 7 ~ 11μm, cylindrical tolerance: 7 ~ 11μm, shoulder block runout tolerance: 4 ~ 7μm

     Shaft and housing chamfer must not interfere with the bearing chamfer, chamfer radius value must not exceed the minimum bearing chamfer dimensions.