Servo drive motors run erratically, and the causes of this kind of failure are as follows:

1. Improper adjustment of servo drive parameters, the regulator has not reached the optimal working condition.

2. The speed feedback signal is unstable due to interference and poor connection.

3. The installation of the speed measuring generator is bad, or the connection between the speed measuring generator and the motor shaft is bad.

4. The carbon brush of the servo motor is worn.

5. The armature winding is locally shorted or shorted to ground.

6.The speed given input voltage is disturbed or connected badly