[adson]

Does shaft temperature of a centrifugal pump, affects bearing heat load?
I feel the fluid temperature is conducted through shaft to bearing, and that will give increased heat load on bearings. So better one should keep fluid temperature check, if unusual bearing temperature rise without known abnormalities.

[professor_jonny]

In one of our high speed aeration motors we use a c3 class bearing that has a greater tollerance to take into acount heat genrated in the bearing races caused by very high motor shaft speeds.
The bearing does swell due to thermal expansion and causes reduction in the max shaft speed when the motor temp increases.

[adson]

Thank you professor_jonny
Pump is pumping fluid at temperature about 120°C. Bearing temperature goes beyond 70°C. External cooling is provided.
My concern is that if fluid is made colder, pump bearing temperature may reduce. But I am not exact on it. Thus put my doubt in the forum.