The recommended maximum speed limits for bearings and bearing units with Solid Oil is limited by the maximum continuous operating temperature of 85 °C (185 °F). Table 1 provides the recommended speed limits for bearings with Solid Oil operating in an ambient temperature of 20 °C (70 °F).
Ambient temperature is the temperature closest to the bearing position, not necessarily room temperature. For bearing types or variants not listed in table 1, contact the SKF application engineering service.
For bearings with Solid Oil operating at the recommended speed limits, an increase in the operating temperature of approximately 65 °C (115 °F) above ambient is to be expected.
For ambient temperatures above 20 °C (70 °F), the speed limit should be reduced. The applicable reduction factor is set forth in diagram 1.
A deep groove ball bearing 6208/W64 is to operate at an ambient temperature of 50 °C (120 °F). What is the reduced speed limit?
Recommended maximum speed for 20°C ambient temperature
Speed limit for 20 °C ambient temperature from table 1: 300 000 / dm, single row deep groove ball bearing with stamped metal cage dimensions d = 40 mm, D = 80 mm
n = 300 000 / (0,5 (40+80)) = 5 000 r/min
Reduction for 50°C ambient temperature
Speed reduction factor fT ≈ 0,53 from diagram 1
nreduced = 5 000 fT = 5 000 × 0,53
= 2 650 r/min