Periodic Check of Earth Bearing

It is difficult to inspect the bearing directly without dismantling the entire bearing assembly. As dismantling itself is a major operation, indirect methods are therefore relied upon during routine inspection and these are dealt with below. For detailed instructions on dismantling of bearing, for Inspection or for removal, refer to section Overhauling.

1. Grease lubricated bearings
It is necessary to ensure that the bearing do not get over heated. This should be tested from time to time by placing the hand on the bearing cap, or which is more after grease filling is done. The temperature should subsequently come down. A sudden increase in temperature (The Bearing Temperature should not exceed 95oC) or noise is a sure sign that the bearing needs immediate attention. While removal or addition of a small amount of grease will arrest trouble arising from higher or lower temperature respectively, a sudden rise in bearing temperature preceded or accompanied by rise in bearing noise and vibration is a warning of bearing failure.

For inspection and cleaning of bearing first remove all dust and foreign matter from the neighborhood of the bearing caps. The caps should then be removed, and the bearing, caps and housing thoroughly washed with kerosene, used grease being removed in the process. If the bearing is in good condition, re-lubricate it. If the bearing appears to be in poor condition or if the grease has become hard or disintegrated, the bearing should be removed from the shaft, withdrawn from the housing and inspected closely for any signs of wear. Grease replenishment should be done with a grease gun suitable for grease nipple (M 10 x 1size) at the grease inlet at regular intervals which depends on the temperature rise of the bearings, the speed of the motor and the duration of running. However an exact schedule will have to be determined in each case considering all relevant factors. Grease replenishment has to be carried out only when the motor is running, keeping the grease outlet open, which has to be closed after a few hours of running of motor. After every 30,000 hours (roughly 3 years) of running or 5 years. Whichever is earlier, bearing assemblies should be dismantled and all the components carefully cleaned to remove old grease and any foreign matter that may have accumulated.

Inspection of the bearing is hardly required unless there is excessive temperature, noise or vibration of the bearings.