The Role Of Spindle Motors In Electrical Machines

By Author: Repair Zone
Total Articles: 17
Comment this article

Most manufacturing industries use electrical machines which are run by spindle motors. This important part influences the torque speed and dynamic performance that make the machine operate efficiently and at high speed.

Uses of Spindle Motors
Spindle motors are incorporated in machine designs to achieve different tasks that require high speed, power and precision. These actions include turning an axle that drills holes, cuts metals, mills, grinds, turns, enlarges holes or reams. The spindle is held together by bearings which prevent wobbling and vibrating while the machine is operating. The use of spindles can raise the unit productivity and reduce machining time by half.

Due to the important role that the spindle motor plays in electrical machines used in manufacturing, it is vital that the spindle works flawlessly to ensure consistency of output and high quality products. In cases when it breaks down, there is a need for proper spindle motor repairs in order for the manufacturing processes to continue running and proceed smoothly.

Repairing faulty spindles
Repair of faulty spindles requires ...
... a qualified engineer with state-of -the art tools to perform effective repairs. The repair takes place in different steps outlined below.

1.Spindle motor evaluation
When the spindle motor is received, a detailed evaluation is performed on all mechanical and electrical parts. Some of the items checked on the motor include:

* The state of the bearing and how it fits on the rotor
* The integrity of the end-bell cooling jacket.
* Imperfections in the mounting surface and flange fits.
* Fractures in the terminal blocks, flanges and conduit boxes.
* Cracks in the output shafts, pulleys and key ways.
* The condition of the windings and cooling fan.

2.Spindle motor repairs
Following the evaluation, any component that does not meet factory standards has to be worked on and repaired. The procedures used in spindle motor repairs include:

Washing, baking and testing of windings in both AC and DC spindle motors.
If any windings are discovered to be shorted or contaminated extensively, rewinding must be done by a qualified engineer.

Any bearing fits that fell short of the required tolerance levels during testing have to be bored afresh and bushed. Faulty bearing journals need chroming and grinding.
Faulty rotors have to be balanced to reduce vibration.
Defective cooling fans have to be replaced with new ones or rebuilt to factory standards.

3.Testing
After the spindle motor is repaired, it has to be tested again to see whether it has been effective. Tests performed include vibration analysis, the megger test (to test for any grounded parts), surge testing, bar to bar test and spindle sensor testing. These tests confirm that the repairs were successful and that the part is working like new.

4.Spindle motor assembly
Once the components have been tested to satisfaction, the motor has to be rebuilt. The process includes degreasing and proper sealing to protect the components from air and liquid contamination. Items used include new seals, connectors, gaskets and 2-part epoxy coating.

5.Final testing
Testing has to be done on a machine or drive that is similar to the one the motor belongs to. The engineer has several drives from notable manufacturers to use for this purpose.

6.Name plating
Each motor comes with a nameplate that will hold factory data which is important for the customer and the next service. This data will be used as a reference for procedures that have been performed before and that will be performed in the future.

The author of this article is associated with Repair Zone, a servo motor and industrial electronic repair specialist that offers reliable equipment repair services.