Service life and bearings for motor

under favorable conditions: more than10'000 hours

Influencing factors
electrical load:
higher currents = higher electro erosion (brush fire)
speed:
higher speed = higher mechanical wear
operation mode:
continuous operation
start-stop operation
reverse operation = reduced service life
temperature
humidity of the air
load on the shaft (bearing)

Ball and sleeve bearings: characteristics
Ball bearing
well suited for high radial and axial loads
well suited for all operating modes, for start-stop and reversing operation
on larger motors
more audible noise if not preloaded
when preloaded higher friction
more expensive
Sintered sleeve bearings
suited for low radial and axial loads
suited for continuous operation at higher speeds
smaller motors
low friction and noise
cost effective
not suited for start-stop operation