When the concentricity is very good when the motor and the reducer are installed, the output bearing of the motor receives only the rotating force, and it will be smooth during operation.
However, when not concentric, the output shaft must bear the radial force from the input end of the reducer. This radial force will cause the motor output shaft to be twisted for a long time. Each time the output shaft rotates once, the direction of the lateral force changes by 360 degrees. If the concentricity error is large, the radial force causes the temperature of the motor output shaft to rise, and its metal structure is continuously destroyed. Eventually, the radial force will exceed the radial force that the motor output shaft can withstand, resulting in driving The motor output shaft is broken.