Bearing friction coefficient

In order to facilitate comparison with plain bearings, the frictional moment of a rolling bearing can be calculated from the following formula according to the inner diameter of the bearing:
M=uPd/2
  Here,
M: friction torque, mN.m
u: friction coefficient, Table 1
P: bearing load, N
d: nominal bearing inner diameter, mm
The friction coefficient u is greatly affected by the bearing type, bearing load, rotation speed, lubrication method, etc. The reference values ​​of the friction coefficient when the rotation is stable under normal conditions are shown in Table 1.
For plain bearings, u = 0.01-0.02, and sometimes 0.1-0.2.
Friction coefficient of various types of bearings
Bearing type friction coefficient u
Deep groove ball bearings 0.0010-0.0015
Angular contact ball bearings 0.0012-0.0020
Self-aligning ball bearing 0.0008-0.0012
Cylindrical roller bearing 0.0008-0.0012
Full complement needle roller bearings 0.0025-0.0035
Needle roller bearing with cage 0.0020-0.0030
Tapered roller bearing 0.0017-0.0025
Spherical roller bearings 0.0020-0.0025
Thrust ball bearings 0.0010-0.0015
Thrust spherical roller bearings 0.0020-0.0025