How to maintain the motor

Many motors have faults during operation, which are not caused by their own quality problems, but by improper maintenance in motor application. Therefore, doing a good job in the maintenance of motors during daily use is an important part of extending the service life of motors.

Routine maintenance

Clean the dust, dirt and brush dust inside and outside the motor to ensure that the motor operating environment is in a good state.

For the wound rotor motor, the brush pressure should be adjusted and checked, and the damaged brush should be replaced or ground to ensure the reliable operation of the motor collector ring system. When replacing the carbon brush, ensure that the carbon brush material and the contact area between the carbon brush and the collector ring (more than 70%) meet the requirements.

Clean and wipe the brush holder, brush holder and slip ring, especially the surface of the collector ring, which must be smooth and clean. When the surface of the collector ring is damaged (with pits or corrosion points), it should be polished with fine sandpaper.

Comprehensively check the lubrication system, replenish lubricating grease and replace lubricating oil. This is one of the most critical items of motor maintenance. Regularly supplement the motor with grease to ensure that the motor operates under good lubrication and prevent the motor from stalling due to poor lubrication.

Check and adjust the ventilation and cooling system of the motor. The ventilation and cooling system of the motor is related to the temperature rise control of the motor, especially for the independent power supply of ventilation and cooling systems such as high-voltage motor and variable-frequency speed regulation motor, we must ensure that the ventilation and cooling system is in good condition when the motor is running.

Check and adjust the transmission mechanism. The transmission of the motor is basically belt pulley transmission and coupling transmission. First, check the connection state of the two, and second, check whether the equipment is blocked.

Disassembly inspection and maintenance

Disassemble the motor and remove the dust from the motor winding, ventilation duct, terminal board, etc. Some motors are used in a bad environment, and a large amount of dust will accumulate on the motor winding. Some dust includes conductive foreign matters, which will do great harm to the motor performance.

Measure the insulation resistance of the winding and dry the motor winding if necessary. Especially for the motors used in warm and open environment, the first is that the motor protection should be selected according to the actual needs, and the second is that the necessary dehumidification treatment should be carried out according to the regulations.

Check the flatness and relative stability of the collector ring, and turn it if necessary. When the motor is running, the wear of carbon brush, dust and foreign matters in the process will lead to the wear or ablation of the collector ring surface to varying degrees. During maintenance, the collector ring should be polished as necessary, and a new collector ring should be replaced if necessary.

According to the wear degree of the carbon brush, the distance between the brush holder and the slip ring should be adjusted to ensure good contact between the carbon brush and the collector ring; Check the stability of the brush rod to prevent poor contact between the carbon brush and the collector ring due to the loosening of the brush rod.

Clean the bearing lubrication system and check its working condition, measure the bearing clearance, replace the worn rolling bearings, scrape and adjust the sliding bearings, and replace the pads or repair and weld the hanging pads when they are damaged.

For the rotor of wound motor, the binding state of the rotor should be checked and necessary reinforcement should be carried out.

ance of motor in winter

1. When the motor operates for a long time in winter, the shaft extension end transmits power, and the bearing temperature of the load end is often higher, and the bearing temperature of the motor at the non shaft extension end is lower. In winter, especially when it operates outdoors, it is not easy to form an oil film, so it is necessary to replenish oil in time. If the temperature is too low, low-temperature lubricating oil should be added.

2. The general motor is 3# lithium grease, and the oil filling amount is as follows: for 2-pole high-speed motor, the general oil filling amount is about 40~50% of the total volume; For 4-pole medium speed motor, the general refueling volume is about 60~70% of the total volume; For low-speed motors with more than 6 poles, the general refueling volume is 80~90% of the total volume.

3. Large motors generally adopt sliding bearing structure due to large shaft extension load. When the motor is working, a thin oil film is required between the bearing bush and the rotating shaft for lubrication; When the motor runs in winter, it is easy to have problems such as shaft stringing and oil leakage. It is necessary to regularly strengthen the inspection, timely replace the vulnerable parts of the floating seal, check the matching size between the bearing bush and the rotating shaft, ensure the oil storage area on the surface of the bearing Bush, and prevent the bearing bush from burning out due to temperature caused by friction.

4. In winter, especially in snowy weather, after the motor is shut down, due to the great difference between the motor temperature and the ambient temperature, condensation is easy to occur in a high humidity environment, especially at the motor terminals, leads, etc., they should be wiped clean to prevent three-phase short circuit; If the motor is equipped with a heater, it should be turned on for 1-2 minutes before starting again for dew removal.

5.In winter, the load of the motor should also be checked in time. If there is ice on the loads such as the non running water pump, the load of the motor will be increased, and the sudden start of the load will cause the burning of the motor winding and other problems.