Temperature rise is very common during bearings application, but there is a normal range of the rise. Generally speaking, bearing temperature rises with start-up and stabilizes at a temperature slightly lower than at start-up in a certain time. A desirable bearing temperature is generally below 100 °C. The stabilizing time of bearing temperature raise various based on bearings size, structure, rotation speed, lubrication system and operating conditions. Usually it ranges from about 20 minutes to as long as several hours.

The situation above belongs to normal temperature raise. If bearing temperature does not stabilize but continues to rise, users shall pay close attention to it and stop the machine when necessary to take corrective actions. Because high temperature will affect bearings service life and may cause lubricatn deteriotation.

Major causes of obnormal bearing temperature rise

1. Extremely insufficient or excessive lubricant
2. Poor installation of the bearings or improper lubricant type
3. High friction between lip and seal groove
4. Too small bearing clearance or extremely heavy load
5. Creeping between the fitting surfaces

After find out the major reasons, what shall we do to improve the situation? Please check solutions to bearings overheating.