Too small load and insufficient lubrication will cause the rolling element to slip, resulting in bearing damage.
The small load coefficient P / C of cage bearing is 0.02, while the small load coefficient P / C of fully loaded bearing is 0.04 (P is the equivalent dynamic load and C is the rated dynamic load)
Calculating the static load factor FS helps to determine whether the Small Load selected bearing has sufficient rated static load.
Where, FS static load coefficient, CO rated static load [kn], Po equivalent static load [kn]
The static load factor FS is a factor to prevent permanent deformation in the contact area of rolling parts. For Small Load bearings that must run smoothly and have very low noise, the value of FS is required to be high; When only medium operation noise is required, a smaller FS can be selected; The following values are generally recommended:
FS = 1.5 ~ 2.5, applicable to low noise level
FS = 1.0 ~ 1.5, applicable to conventional noise level
FS = 0.7 ~ 1.0, applicable to medium noise level
The rated static load CO [kn] has been listed in the table for each type and specification of bearing. The Small Load theoretical pressure generated by this load (radial force for radial bearing and axial force for thrust bearing) at the center of the contact area between rolling element and raceway is:
-4600 n / mm2 self-aligning ball bearing
-4200 n / mm2 other types of ball bearings
-4000 n / mm2 all roller bearings
Under the action of rated static load Co, the total plastic deformation at the large bearing part of the contact area between the rolling element and the raceway is about one ten thousandth of the diameter of the rolling element.
Equivalent static load Po [kn] is a theoretical value, which is radial force for radial bearing and axial and radial force for thrust bearing. The stress generated by Po in the center of the large bearing contact area of the rolling element and raceway is the same as that generated by the actual load combination.
Among them, Po equivalent static load, FR radial load and FA axial load are all in Kilonewtons, XO radial coefficient and yo axial coefficient.