Bearing Torque

There are two basic kinds of torque: Starting torque and Running torque. Starting torque comprises two main elements which need to be overcome before rotation occurs.

 

(1) Metal to metal contacr between Raceways and Balls,

 

(2) Lubricant shearing

Running torque is comprised retainer drag (on both rings and balls) and lubricant churning caused by couplings between balls and retainer, and retainer and raceways. Torque has a direct effect upon the following: temperature generation, speed variation, power consumption (at start-up and during running), and also power consumption variations caused by unstable rotation, etc.

 

   Relationship between Speed and Running Torque

 

   Torque increases with speed.

 

   Relationship Between Grease Quantity and Running Torque

 

   Generally, if the lubricant quantity is increased, the running torque is increased.

 

   Relationship Between Temperature and Running Torque

 

   Generally, as temperature decreases, Bearing Torque increases.