Temperature limits

SKF motor encoder units have been tested successfully under various speeds and loads:
  • 500 hours at 120 °C (250 °F) with intermittent peaks of up to 10 minutes at 150 °C (300 °F)
  • 100 hours at –40 °C (–40 °F)
The permissible operating temperature for SKF motor encoder units can be limited by:
  • the dimensional stability of the bearing rings and balls
  • the cage
  • the seal
  • the lubricant
  • the sensor

When temperatures outside the permissible range are expected, contact the SKF application engineering service.

Bearing rings and balls

The bearing rings and balls undergo a special heat treatment. The bearings are heat stabilized up to at least 120 °C (250 °F).


Steel cages can be used at the same operating temperatures as the bearing rings and balls. For temperature limits of polymer cages, refer to Cage materials.


The permissible operating temperature for NBR seals is –40 to +100 °C (–40 to +210 °F).


Temperature limits for the WT grease used in SKF motor encoder units are provided under Deep groove ball bearings (table 1).


The permissible operating temperature for the sensor is –40 to +150 °C (–40 to +300 °F).

For applications where the voltage supply is above 18 V and temperature exceeds 85 °C (185 °F), SKF recommends placing a 1 kΩ resistor in series with the supply line to limit heat generated by the electronic components.

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