Inspection, installation and cleaning methods of motor bearings

Inspection and installation methods of motor bearings：

1.Before inspecting the bearing, first remove the old lubricating oil from the inner and outer small covers of the bearing, and then clean the inner and outer small covers of the bearing with a brush and gasoline. After cleaning, clean the bristles or cotton filaments and do not leave them in the bearing.

2.Carefully inspect the cleaned bearings. The bearings should be clean and intact, without overheating, cracks, peeling, grooves, impurities, etc. The inner and outer raceways are smooth, and the clearances everywhere are qualified. If the support frame is loose and causes friction between the support frame and the bearing sleeve, Bearings should be replaced with new ones.

3.After maintenance, the bearing should rotate flexibly without jamming.

4.Check that there is no wear on the inner and outer small covers of the bearing. If there is wear, the cause should be found out and dealt with.

5.The fit between the inner sleeve of the bearing and the shaft should be tight, otherwise it should be dealt with.

6.When assembling a new bearing, use oil heating or eddy current heating to heat the bearing. The heating temperature is preferably 90 to 100°C. Set the bearing on the motor shaft at high temperature and ensure that the bearing is assembled in place. It is strictly forbidden to heat the bearing in a cold state. Go up to avoid damaging the bearings.

Motor bearings should generally be cleaned and refueled after 2,000 hours of use. There are two methods for cleaning motor bearings:

1.Hot oil cleaning method

Mainly use soft dry oil or anti-rust paste to harden motor bearings. They should be immersed in hot engine oil at 100-200°C. Clamp the motor bearings with pliers and use a brush to clean the oil stains on the motor bearings. Soft dry oil or anti-rust paste melts when heated to 100-200°C, and is easily washed out from the gaps in the motor bearings. Sometimes as long as the motor bearing is shaken in the oil many times, the oil dirt will flow away from the gaps.

When cleaning the centripetal spherical motor bearings of the motor, the balls, bead frames, and inner rings should be turned laterally out of the outer ring and then immersed in hot oil. When cleaning the short cylindrical roller motor bearings, the rollers, beads should also be removed. The frame, inner ring and outer ring are detached.

During hot oil cleaning, the bearing temperature of the oil should not exceed 200°C. If an open flame is used for direct heating, care should be taken to prevent the oil from burning. The motor bearings should be suspended in the oil pan. If they sink to the bottom, they will cause overheating and reduce the hardness.

2 General cleaning method

Soak the motor bearings in kerosene for 5-10 minutes. Hold the inner ring with one hand and rotate the outer ring with the other hand. The dry oil or anti-rust paste on the motor bearings will fall off. Then put the motor bearings into cleaner kerosene, scrub with a soft brush to clean the oil in the balls and gaps, then put them in gasoline to clean them once, take them out and put them on clean paper.

When cleaning radial ball motor bearings and short cylindrical roller motor bearings, the balls, ball frames, inner rings and outer rings should be separated and cleaned. The motor bearings mounted on the shaft are mainly cleaned by spraying oil or spraying with an oil gun. Oil stains that are easy to be cleaned are first treated with kerosene and then gasoline; oil stains that are difficult to be cleaned are first sprayed with hot engine oil at 100-200°C. Wash or spray with oil gun, then clean with gasoline. Be careful not to use sharp tools to scrape hardened grease or rust on the motor bearings to avoid damaging the motor.
Check the smoothness of the rolling elements and groove rings of the motor bearings. Clean the motor bearings and wipe them dry with a clean cloth.