In practical application, a large number of different FAG spindle bearing arrangements are used. The selection and arrangement are determined by their specific use in turning, milling and grinding or in high frequency motor spindles. The design of the bearing arrangement is also influenced in relation to the bearing size and bearing type by the operating conditions. Finally, consideration of the cost-effectiveness of various technical design possibilities also plays a major role.
The bearing arrangement must run clearance-free and normally with preload in operation in order to fulfil the high accuracy requirements (P4 and above). In addition, very high speeds are required (with grease lubrication, up to n · dM = 2 · 106 min–1 · mm and with pneumatic oil lubrication up to n · dM = 3,1 · 106 min–1 · mm) at the lowest possible operating temperatures. This requires the use of super precision bearings and correspondingly accurate adjacent parts.
The following guidelines are intended to assist in the selection of FAG bearings and FAG bearing arrangements.
The following aspects are considered:
- preload
- rigidity
- bearing contact angle
- ball size and material
- distance between the bearings
- sealing
- stages in bearing arrangement design
- comparison of bearing arrangements
- examples of bearing arrangements.
