What are the maintenance methods for electric machinery faults?

What checks should be done on the motor before troubleshooting? The following small series will teach you to start from a few aspects:

In order to find out the cause and approximate scope of the failure, before repairing the mechanical failure of the motor, the following inspections should be carried out on the outside of the motor.

Check the frame and end caps for cracks, and the shaft for cracks or bending deformation.

Check whether the rotor rotates flexibly and smoothly, whether it swims axially, and whether there is any abnormal noise.

Check for loose or seized bearings.

Check whether the air duct is blocked, and whether the blades and heat sink are in good condition.

For large-capacity motors, the end caps generally have air gap measurement holes. Through the air gap measurement holes, it is possible to detect whether the average air gap unevenness is within 15%.

Power on and run, and check whether the motor is normal by touching, listening, smelling and seeing. Once an abnormality is found, the power supply should be cut off immediately to prevent the failure from expanding.

Only after the nature of the fault has been roughly determined and the scope of repair determined, the motor can be disassembled for further detailed inspection and repair.

For mechanical parts in electric motors, the following checks should be made:

Check the stator and rotor core surfaces for scratches. When there is only one scratch on the rotor surface, and the stator surface is completely scratched, it is caused by the bending of the shaft or the imbalance of the rotor; when there is only one scratch on the surface of the stator, and there are scratches on the surface of the rotor, the stator and the rotor are not right. If there are large scratches on the surface of the stator and rotor, it is caused by the above two reasons.

Check that the stator and rotor cores are aligned. If it is not aligned, it means that the iron core is shortened and the magnetic flux density is increased, causing the iron core to overheat, which is caused by the axial displacement of the rotor core or the inappropriate replacement of a new rotor. Also, check that the stator and rotor cores move in the circumferential direction. If there is movement, it means that the screws for tightening the fastener are loose or damaged or lost, or the rotor core and the shaft are not tightly fitted.

Check for cracked or broken rotor end rings, damaged or deformed blades, and bent shafts.

(4) Check whether the matching between the inner and outer sleeves of the bearing, the journal and the bearing chamber meets the requirements, and whether it is too tight or too loose; check the degree of bearing wear, whether the bearing is in good condition, and whether the lubricating oil (grease) is too little or dry.

The above method is a motor service company specializing in providing you with motor solutions.