Motor manufacturers ensure the concentricity of motor bearings through the machining accuracy of motor shell and end cover. If it is found that the old motor is not concentric, it is necessary to take the motor body to the boring machine for alignment.

Motor bearing, also known as motor bearing or motor bearing, is a special bearing specially applied to motor or motor. The bearing used in the motor is a part that supports the shaft, which can guide the rotation of the shaft and bear the idle parts on the shaft. The concept of bearing is very broad. There are four kinds of bearings commonly used in motors, namely rolling bearings, sliding bearings, joint bearings and oil-bearing bearings. The most common motor bearings are rolling bearings, that is, bearings with rolling bodies.