Project Description

Fanuc Servo Motor Repair

Every Fanuc servo motor that is refurbished at our facility goes through an extensive evaluation. We find the reason your Fanuc servo motor is failing and confirm we can repair your motor – and bring it back to the condition it was brand new from the factory. During the evaluation, we look for any dynamic or static parts that do not meet Fanuc specifications.

Servotech maintains a good working relationship with the Fanuc factory and has original technical data sheets so we can obtain finite specifications needed in the repair of your Fanuc servo motor. Without this information, a motor can only be repaired to “running” condition. Using this data, we ensure your servo motor will perform to its factory specifications in your machine.

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

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1. Evaluation of Your Fanuc Servo Motor

Servotech inspects all electrical and mechanical parts on all Fanuc servo motors, checking bearing and housing fits, worn output shafts and corroded and/or broken flanges.

  • Bearing fits
  • Housing fits
  • Worn output shafts
  • Corroded and/or broken flanges
Broken Fanuc servo motorRepair Fanuc servo motor
A typical Fanuc servo motor when it arrives it 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. Often we:

  • Remagnetize rotor magnets.
  • Re-manufacture a new Fanuc servo motor front flange using the old flange and factory dimensions.
  • Repair all the windings. Both AC and DC servomotors windings are washed, baked and tested.
  • Repair or replace brush holders and Bake-O-Lite insulation tubes on DC motors.
Fanuc Servo Motor Repair OscilloscopeRepaired Fanuc Servo Motor Repair Oscilloscope Readings
Oscilloscope printout of the BEMF (back electromotive force) of a Fanuc servo motor with bad magnets, & readout after remagnetization, with proper BEMF.

3. Preliminary Testing

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

  • Test to confirm there are no grounded electrical parts in the servomotor.
  • All AC stators are surge tested to at least 1500 volts.
  • After the backing 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. Fanuc Motor Assembly

Our Fanuc servo motor repair and assembly processes often improves a motor’s internal components, utilizing:

  • High-grade sealed bearings – we feel that each Fanuc 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 Fanuc servo motor is protected from liquid contamination.
  • Two-part epoxy coating for an added protection – the same coating used on Navy submarines.
Broken Fanuc servo brush riggingRepaired Fanuc servo motor brush
A Fanuc 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 Fanuc servo motor repair process is to run your motor on a Fanuc drive just like the one in your machine. We confirm the servo motor repair process were done correctly, and allows us to run your Fanuc 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.