SEM Servo Motor Repair
Authorized SEM Servo Motor Repair Center
Servotech proudly boasts our status as an officially authorized service agent for SEM. Our meticulous process has been investigated by SEM and their staff has named us authorized service repair agent in the United States.
Each motor that enters our shop is very thoroughly evaluated. Our goal is to not just fix the cause of failure but to refurbish the motor back up to a factory new standard – or better! In order to complete effective repairs on SEM it behooves us to have a good relationship with the manufacturer. It is impossible to fix a motor back to the factory standard performance if you do not have documentation to confirm that performance to be within specification.
Without good data, a motor can only ever achieve a condition we refer to as “running.” Running does not equate to factory new, and has no guarantee of performance. Our stockpile of technical datasheets and position as an authorized service agent for SEM affords us the capability to be a top repair facility for SEM servo motors.
1. Servo Motor Evaluation
Our process begins with perhaps the most important part: evaluation. Servotech technicians carefully check each motor’s condition looking for the following:
- Bearing fits
- Housing fits
- Worn output shafts
- Corroded and/or broken flanges
A typical SEM when it arrives in the shop, and then after we service it.
We are an Authorized SEM Repair Facility
We manufacture or repair any problems identified during our evaluation. Any part that does not meet the factory specifications is repaired. Often we:
- Remagnetize tachometer field frames to bring up low tach output.
- Re-epoxy field frame magnets that have come loose on DC motors.
- Re-manufacture a new SEM servo motor front flange using the old flange and factory dimensions.
- Repair all the windings. Both AC and DC servo motors windings are washed, baked and tested.
- Repair or replace brush holders and Bake-O-Lite insulation tubes on DC motors.
A corroded, defective endbell next two a brand new Servotech fabricated endbell.
Some parts don’t need machine work but benefit greatly from our parts cleaning process which allows us to remove dirt, and grime with may be corrosive.
Clean parts means we have a good surface to paint the motors which improves sealing and external protection.
3. Preliminary Testing
It is important that your SEM servo motor be meggered frequently throughout the repair. Some of our other electrical 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.
- After the baking process DC Servo motor armatures go through a bar to bar test. This test will show if there are any shorts or openings in the winding.
- Servo motor alignment.
- Check neutral on DC servo motors.
4. Motor Assembly
After repair and preliminary testing, SEM motors are reassembled. Our assembly process utilizes high quality components. Our assembled motors incorporate:
- High-grade sealed bearings – we feel that each SEM 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 SEM servo motor is protected from liquid contamination.
- Two-part epoxy coating for an added protection – the same coating used on Navy submarines.
Servotech will re-epoxy field frame magnets into your SEM DC servo motor if they become dislodged or loose. Special care is taken to reset neutral so that your motor will run properly in both directions.
Worn out old SEM armature that needs to be turned and undercut.
5. Final SEM Servo Testing
The final step in the SEM servo motor repair process is to run your motor on a factory drive just like the one in your machine. SEM servo motors are run at full voltages and full currents of the motors capability. This provides accountability to all the previous steps in our servo motor repair process. Motors do not pass the final test step unless repairs were done correctly. New drives are purchased regularly to stay on top of changes in manufacturer’s technology, and to keep our final test procedures accurate.
6. Name Plating
Before shipping, Servotech makes all new name plates for each of our servomotor repairs. These new name plates include all the original data from the motor, as well as Servotech’s name, job number, and date codes. This gives customers traceability in regards to their servo motor repair.