Servo Motor Torque Loss
Posted by Michael Norman on Thu, Nov 05, 2009 @ 07:12 AM
Your servo motor does not have the power it once had. You are starting to encounter current and torque alarms on your machine. You check the couplings, bearings, maybe even swap drives. Nothing seems wrong and the problem is probably in the motor. Now what?
There are several reasons that your servo could be losing torque. Figuring out what is wrong with your motor will determine how difficult it is to fix, and who is even capable of fixing it.
- Does your servo motor have a brake? If there is a brake in your motor then you need to check the voltage going to the brake. Most motors will have the brake voltage written on the label. If the brake is not opened when the motor runs, then you will lose significant torque and also destroy the brake. This is a common problem and is often caused by faulty relays in the cabinet.
- Are your servos magnets demagnetized? This can be determined by checking the BEMF of the servo, which will probably require you to send the motor out to be evaluated. If the servo is demagnetized then you will need to find a company that can re-magnetize your servos' magnets.
- Has your Servo ever been disassembled? If the encoder has been removed and reinstalled the alignment might be off. A bad alignment can cause you servo to run, but run poorly drawing high current. If this is your problem then you need to have your servo serviced and realigned.
Torque Loss is a common problem. The root cause needs to be determined so that you can be sure you are fixing the right problem. If you find you have to send your servo out for repair, it is best to make sure they have the equipment to do the job.
If you don't know what to do or where to have your servo repaired, Servotech has the equipment and knowledge to restore your servo motors torque to its original factory specifications.