Fitting and clamping bearing rings
The tightening torque Mt, for precision lock nuts or end plate bolts, must be sufficient to keep all components, including the bearings, in place without causing distortions or other damage.
For information about precision lock nuts, refer to Precision lock nuts.
The required axial clamping force for a precision lock nut or the bolts in an end plate can be estimated from
|Mt||=||required tightening torque [Nmm]|
|Pa||=||required axial clamping force [N]|
|Fc||=||axial fitting force [N]
|Fs||=||minimum axial clamping force [N]|
|GA,B,C,D||=||pre-set bearing preload, prior to mounting [N] (→ product table)|
|K||=||calculation factor dependent on the thread (table 4)|
|Ncp||=||number of bearings in the same orientation as the bearing that the precision lock nut or end plate is in direct contact with1)|
|Nb||=||number of end plate bolts|
1) This is not the total number of bearings in the arrangement, only those that require to be moved to close gaps between rings to achieve pre-set preload. Refer also to Locking procedure.
Locking procedureWhen locating super-precision angular contact ball bearings axially using a precision lock nut or end plate, the following procedure should be applied to be sure that all of the bearings are fully seated and the clamping force is re-set to the estimated required level.
- Tighten the lock nut / end plate bolts 2 to 3 times tighter than the value for Mt.
- Loosen the lock nut / end plate bolts.
- Retighten the lock nut / end plate bolts to the value of Mt.