OMEC MOTORS
OMT1 & OMT2 Mounting & Maintenance Instructions
Page 13
10.
BEARING GREASE INTERVALS
By the term “ greasing interval” we mean the number of working hours after which
the bearing lubricant has to be replaced.
Electric motors have such a wide range of application that they must cope with many
adverse conditions as for instance dust, moisture, vibration, temperature, chemicals,
marine atmosphere and of course, the mounting position and loading of the driven
machine.
Generally we can say lubrication life is a product of time, speed and the bearing size. Due
to the impact of all these factors, it is practically impossible to determine any exact values
that are valid under all circumstances. Nevertheless it is necessary to provide at least
some guidelines concerning greasing to the user.
Under normal load and environmental conditions the quality of the grease ensures proper
operation of the motor for about 10000 service hours with 2-pole designs and 20000
service hours with multi pole designs. If not otherwise agreed upon the grease need not
be refilled during this period. Nevertheless the condition of the grease filling should be
occasionally checked also within the said lubricating intervals.
The stated service hours are only current under operation with rated speed. For
relubrication thoroughly clean the bearings with a suitable solvent and use the same or
substitute grades specified by the motor manufacturer. Bear in mind, however, that the
bearings should be filled only up to about 2/3 of their free space as a complete filling of the
bearings and bearing covers results in an increased bearing temperature and therefore in
increased wear. For bearings with relubrication facility regrease at the grease fitting with
the motor running according to the grease amount required for the motor in case. The
relubrication intervals should be looked up in the following table:
Construction size
Two pole motors
Four-pole and multi-pole motors
80 up to and including 400
2000 hours
4000 hours
