Power loss and bearing temperature

The power loss in a bearing as a result of bearing friction can be estimated using

NR = 1,05 x 10–4 M n

where
NR =power loss [W]
=total frictional moment of the bearing [Nmm] 
=rotational speed [r/min]

The cooling factor Ws is defined as the heat being removed from the bearing per degree of temperature difference between the bearing and ambient. If the value of Ws is known, a rough estimate of the temperature increase in the bearing can be obtained using

ΔT = NR/Ws

where
ΔT =temperature increase [°C]
NR =power loss [W]
Ws =cooling factor [W/°C]
SKF logo