Before the equipment is put into operation measure and record the tilting clearance of the bearing. This will establish a base measurement for subsequent repeat measurements, which should be taken periodically in order to determine the amount of wear that has occurred in the bearing. The wear present in the bearing raceway is evidenced by the change in the axial motion of the bearing.

Tilting clearance can be measured on equipment that allows both a positive and negative application of moment loads. Measuring points as depicted in Figure 3 should be permanently marked around the circumference while the center of gravity of the load is kept in a specified position. Measurements are then taken between the lower mating structure and the bearing mounted to the upper structure, as shown in Figure 4.

Take the measurements as close as possible to the outer bearing race to eliminate mounting surface deflection as a possible contributor to clearance measurement.

Using dial gages that have an accuracy of at least 0.001" begin by applying the maximum backward moment and set the dial gages to zero. Next, apply a forward turning moment. Record the first measurement.

At least once every twelve months repeat the measurement procedure, using the same loads as originally used, and compare the reading with the base values originally recorded. The difference between the two represents the wear that has occurred in the bearing. Shorten the time intervals in between measurements as the wear increases.

Tables 3 and 4 on the Maximum Clearance Values page show the maximum allowable clearance from initial base measurement. If wear values are exceeded, contact Avon Bearings to discuss bearing repair or replacement recommendations.