RUN-IN PROCEDURE FOR GREASED BEARINGS A proper run-in procedure will provide the following results:
Expel the excess grease found in the system
Orient the lubricating film on each contact surface
Establish a low equilibrium operating temperature
Achieve a sealed-for-life lubrication condition
Start at a reasonable low speed, typically 10% of the maximum operating speed.
Increase speed incrementally when a stable temperature is reached.
Continue incremental increase in speed as described. If a rapid temperature increase occurs, stop the run-in process. This temperature spike indicates a preload due to thermal expansion.
Maximum bearing temperatures should not exceed 70C (158F). Temperatures in excess of 70C will cause excessive bearing preloads and possible permanent grease bearing damage.
Allow the system to cool to room temperature.
Restart procedure at the last speed prior to the temperature spike.
Continue repeating the above cycle until an equilibrium temperature is reached at the maximum operating speed of the application. The ideal equilibrium operating tempera- ture is 35C to 40C (95F to 105F).
Alternative Run-In Procedure Run-in at constant speed is also possible. In this operation, the bearing should run at full speed for about 30 seconds. After stopping, the heat in the bearing dissipates. In this way, a dangerous temperature rise is prevented. The non-running time depends on the various design factors, but it should be at least 5 times greater than the running time. This process is repeated until the bearing temperature becomes constant.