I. Jitter caused by mechanical structure can be divided into two cases:
1) No-load jitter:
a. The foundation of the motor is not strong, the stiffness is not enough or the fixing is not tight.
b. The fan blade is damaged, which damages the mechanical balance of the rotor.
c. The machine shaft is bent or cracked. You can fix the problem by fastening screws, replacing fan blades, or replacing machine shafts.
2) If the jitter after loading is generally caused by the fault of the transmission device, it can be determined that there are defects in the following parts:
a. The rotation of the belt wheel or coupling is unbalanced.
b. The center line of the coupling is inconsistent, so that the motor does not coincide with the mechanical axis driven.
c. The transmission belt connector is unbalanced. It can be solved by correcting the transmission device to balance it.
II. Jitter caused by speed ring problem:
Velocity loop integral gain, velocity loop proportional gain, acceleration feedback gain and other parameters are improper. The greater the gain, the greater the velocity, the greater the inertia force, the smaller the deviation, and the more prone to jitter. Setting a small gain can maintain the speed response, less jitter.
III. Jitter caused by fault of compensation board and servo amplifier of servo system:
The motor suddenly stops power and produces a lot of jitter, which is related to the improper setting of servo amplifier BRK terminal and parameters. The acceleration and deceleration time constant can be increased, and the motor can be started or stopped slowly by PLC without jitter.
IV. Jitter caused by load inertia:
The load inertia increases due to the problems of guide rail and lead screw. The moment of inertia of guide rail and lead screw has a great influence on the rigidity of servo motor drive system. Under fixed gain, the larger the moment of inertia is, the greater the rigidity is, the easier the motor jitter will be caused. The smaller the moment of inertia, the smaller the rigidity, the more difficult the motor jitter. By replacing the smaller diameter guide rail and lead screw to reduce the moment of inertia and reduce the load inertia to achieve the motor does not jitter.
V. Jitter caused by the electrical part:
a. The brake is not opened, and the feedback voltage is unstable. Check whether the brake is on, add the encoder vector to control the zero servo function, and reduce the torque to output a certain torque to solve the jitter. If the feedback voltage is abnormal, check whether the vibration cycle is related to the speed first. If it is, check whether there is a fault in the connection between the spindle and the spindle motor, and whether the spindle and the pulse generator installed at the tail of the AC spindle motor are damaged. If not, check whether there is a fault on the printed circuit board, which needs to be checked or readjust.
b. The motor's sudden jitter during operation is mostly caused by the lack of phase. It should be focused on checking whether the fuse melt is fused or not, whether the switch contact is good, and measuring whether each phase of the power grid has electricity.
