Friction
Linear ball bearings are frequently used where high positional accuracy and high efficiency are a priority. The bearings must therefore run without stick-slip and with only low friction.
The linear ball bearings KN..-B, KNO..-B, KS, KSO, KB, KBS, KBO have particularly low friction.
Coefficient of friction
The total friction consists of:
- rolling and sliding friction at the rolling contacts
(sliding friction in linear plain bearings) - friction in the return zones and recirculation guides
- lubricant friction
- seal friction.
The factors on which the coefficient of friction depends may act in a reciprocal manner, may act in a single direction or may counteract each other.
Coefficient of friction in unsealed bearings
The coefficients of friction for unsealed linear bearings with oil lubrication are given in the table.
In the case of linear plain bearings, the coefficient of friction is between 0,02 and 0,2.
Series and coefficient of friction
Series | Coefficient of friction |
|---|---|
KH | 0,003 – 0,005 |
KN..-B, KNO..-B | 0,001 – 0,0025 |
KS, KSO | 0,001 – 0,0025 |
KB, KBS, KBO | 0,001 – 0,0025 |