Manual for Induction Motors and Generators
Maintenance -
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3BFP 000 050 R0101 REV E
***Following chapters for bearing type: Sleeve bearing
7.5.1 Sleeve bearings
In normal operating conditions, sleeve bearings require little maintenance. To ensure reliable
operation, the oil level and the amount of oil leakage should be regularly checked.
7.5.1.1 Oil level
The oil level of a self-lubricated sleeve bearing needs to be checked regularly. The correct oil
level is in the middle of the oil sight glass, but as long as the oil level is within the oil sight glass,
the level is acceptable.
If necessary, refill with suitable lubricant, see
The correct oil level of a flood-lubricated sleeve bearing is the same as for a self-lubricated
bearing. In flood-lubricated bearings, the oil sight glass might be exchanged for an oil outlet
flange.
7.5.1.2 Bearing temperature
The bearing temperatures are measured by Pt-100 resistance temperature detectors. Since a
temperature rise above the alarm limit can be caused either by increased losses in the bearing, or
by decreased cooling capacity, it often indicates a problem somewhere in the machine or in the
lubrication system, and should therefore be closely monitored.
The reasons for abnormal bearing temperature vary, but for some possible reason see
7.5.2 Lubrication of sleeve bearings
Chapter 8.1.2 Lubrication system and bearings
. If the
temperature rise is followed by an increase in vibration levels, the problem might also be related
to the machine's alignment, see
Chapter 3 Installation and Alignment
or to damage in the
bearing shells in which case the bearing needs to be dismantled and checked.
7.5.2 Lubrication of sleeve bearings
The machines are equipped with sleeve bearings with a very long service life provided that the
lubrication functions continuously and that the oil type and quality are as per ABB
recommendations, and that the oil change instructions are followed.
7.5.2.1 Lubrication oil temperature
The correct lubrication oil temperature is essential in keeping the bearing at the correct
operating temperature, and in ensuring sufficient lubrication effect and the correct viscosity of
the lubrication oil. For machines equipped with oil supply, the poor operation of oil cooler or
heater and incorrect oil flow can cause oil temperature problems. For all bearings, the correct oil
quality and quantity need to be checked if temperature problems appear. For more information,
see
Chapter 7.5.2.3 Recommended control values for the lubricating oil
and
NOTE: The minimum ambient temperature in starting (without oil heater) is 0°C (32° F).
