Single-row four-point contact ball type selection calculation:

The selection calculation of single-row four-point contact ball slewing bearing is carried out according to the bearing Angle of 45°and 60°respectively.
Selection according to static condition:

Ⅰα=60°                 Ⅱα=45°

Fa’=（Fa+5.046Fr）fs     Fa’=(1.225Fa+2.676Fr)fs

M’=Mfs                   M’=1.225Mfs

Check life according to dynamic working conditions:

Ⅰα=60°                 Ⅱα=45°

Fa’=（Fa+5.046Fr）fd    Fa’=(1.225Fa+2.676Fr)fd

M’=Mfd                   M’=1.225Mfd

Then find the above two points on the bearing curve, one of which is below the curve.

Double diameter ball type selection calculation:

Selection according to static condition:

Fa’=Fafs

M’=Mfs

Check life according to dynamic working conditions:

Fa’=Fafd

M’=Mfd

Single row cross roller type selection calculation:

Selection according to static condition:

Fa’=(Fa+2.05Fr)fs

M’=Mfs

Check life according to dynamic working conditions:

Fa’=(Fa+2.05Fr)fd

M’=Mfd

Calculation of three-row roller type selection:

For the selection calculation of three-row roller slewing bearing, the radial force Fr is assumed to be borne by the radial roller, and only the effects of axial raceway load and overturning moment are calculated.

Selection according to static condition:

Fa’=Fafs

M’=Mfs

Check life according to dynamic working conditions:

Fa’=Fafd

M’=Mfd