X hits on this document

636 views

0 shares

0 downloads

0 comments

142 / 168

ENGINEERING

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

Run-In Procedure

  • 1.

    Start at a reasonable low speed, typically 10% of the maximum operating speed.

  • 2.

    Increase speed incrementally when a stable temperature is reached.

  • 3.

    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.

  • 4.

    Allow the system to cool to room temperature.

  • 5.

    Restart procedure at the last speed prior to the temperature spike.

  • 6.

    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.

E40

102800

Document info
Document views636
Page views636
Page last viewedWed Dec 07 14:51:05 UTC 2016
Pages168
Paragraphs26843
Words61533

Comments