Servo Motor Repair

Expert Servo Motor Repair & Refurbishment

Servo Motor RepairEvery servo motor repair job goes through an extensive evaluation process, not only to find the problem with your servo motor, but also to be sure we can repair your old or broken down motor to “like new” condition – as if the factory just sold you a new servo.

After the servo motor repair evaluation, we examine the motor and look for any dynamic or static parts that do not meet factory specifications. In order to properly repair your servo motor we maintain a good working relationship with the factory and obtain original technical data sheets so we have specifications needed for your servo motor’s repair. This makes the difference between whether your servo motor runs okay or whether it runs as if it were new from the factory.

Our goal is to give you a servo motor that is not only repaired but has been refurbished back to like new condition. Our servo motor repair procedure follows these steps:

1. Servo Evaluation

Servotech inspects all electrical and mechanical parts on your servo motor. During our evaluation, we check and look for:

  • bearing fits
  • housing fits
  • worn output shafts
  • corroded and/or broken flanges
Repairing Servo MotorsRepaired Servo Motor
A typical Fanuc servo motor when it arrives in the shop, and then after we service it.

2. Servo Motor Repair

We repair any problems found during our evaluation, fixing any part that does not meet the factory specifications. Our servo motor repair services often include:

  • remagnetize servo rotor magnets.
  • re-manufacture a new servo motor front flange using the old flange and factory dimensions.
  • repair all the servo motor windings, and complete motor rewinding. Both AC and DC servo motors windings are washed, baked and tested.
  • repair or replace servo motor brush holders and Bake-O-Lite insulation tubes on DC motors.
Servomotor Repair EvaluationServo Motor Repair Evaluation
Oscilloscope printout of the BEMF (back electromotive force) from a Fanuc servo motor with bad magnets, and readout after remagnetization, with proper BEMF.

3. Preliminary Servo Motor Repair Testin

Throughout the assembly process each servo motor repair will be meggered numerous times. Some of our tests include:

  • test to confirm there are no grounded electrical parts in the servo motor.
  • all AC stators are surge tested to at least 1500 volts This ensures that the insulation and windings will withstand the loads put on the servo motor when running on a machine.
  • after the bakin g process, DC Servo motor armatures go through a bar to bar test. This test will show if there are any shorts or opens in the winding.
  • servo motor alignment.

4. Servo Assembly

After servo motor repair and preliminary testing, the motors are reassembled. Our assembly process often improves the internal motor components. Our assembled servo motors utilize:

  • high-grade sealed bearings – we feel that each servo motor repair will have a longer life with sealed bearings, because the seals keep dirt and contamination from getting into the bearing races.
  • double lip seals in the front flange – these seals keep coolant from getting to the bearing.
  • all new seals, O-rings, gaskets and connectors – ensure that your servo motor is protected from liquid contamination.
  • two part epoxy coating for an added protection – the same coating used on Navy submarines.
Servo Motor AssemblyAssembling and Repairing Servo Motor
A Fanuc servo motor brush rigging repair before and after a complete rebuild with new brush holders and lead wires.

5. Final Testing on Fanuc Drives

The final step in the servo motor repair process is to run your motor on a drive just like the one in your machine. This allows us to make sure all the previous steps in our servo motor repair process were done correctly. It also allows us to run the servo motor at full voltages and full currents of the motors capability. We are constantly buying new drives in order to stay up to date with the manufacturer’s changes.

6. Name Plating

Before shipping, Servotech makes all new name plates for each of our servo motors repaired. We put all of the original data on the name plate, even contacting the manufacturer if necessary. We also put Servotech’s name and job number on the tag for traceability along with date codes so you as the customer know exactly when your servo motor repair was done.