Inspection of a machine's bearings during operation is important to prevent unnecessary bearing failure. The following methods are generally adopted to inspect the bearing.

(1) Check of bearings in operation
Included are the check of bearing temperature, noise, and vibration, and the examination of the properties of lubricant to determine when lubricant should be replenished or exchanged.

(2) Inspection of bearings after operation
Any change of the bearing is carefully examined after operation and during periodic inspections so as to take measures to prevent recurrence.

It is important for proper bearing maintenance to determine inspection requirements and intervals, according to the importance of the system or machine, and adhere to the established schedule.