Inspection and cleaning
As with all other important machine components, ball and roller bearings must be frequently cleaned and examined. The intervals between such examinations depend entirely on the operating conditions.
If it is possible to ascertain the condition of the bearing during service, e.g. by listening to the sound of the bearing when it is running and measuring the temperature or examining the lubricant. It is then usually found sufficient if the bearings (rings, cage and rolling elements) and other parts of the bearing arrangement are thoroughly cleaned and inspected annually. Where the load is heavy, the frequency of inspection must be increased, e.g. rolling mill bearings are often inspected when the rolls are changed.
After the bearing components have been cleaned with a suitable solvent (white spirit, paraffin etc.) they should be oiled or greased immediately to prevent corrosion. This is particularly important for bearings in machines that are left to stand for considerable periods.