Motor regular maintenance content

Regular maintenance of asynchronous motors is an important measure to eliminate hidden troubles and prevent failures. Regular maintenance can be divided into regular minor repairs and regular overhauls. The former does not disassemble the motor, and the latter requires all the motors to be disassembled for maintenance.

1. Regular minor repairs Regular minor repairs are general cleaning and inspection of the motor and should be carried out frequently. Minor repairs include:

①Clean the motor casing to remove the dirt accumulated during operation.

②Measure the insulation resistance of the motor. After the measurement, pay attention to reconnect the wires and tighten the terminal screws.

③ Check whether the motor end cover and anchor bolts are fastened.

④ Check whether the motor grounding wire is reliable.

⑤ Check whether the transmission between the motor and the load machine is in good condition.

⑥ Remove the bearing cover, check whether the lubricating oil is dirty and dry, and refuel or change the oil in time. After processing, pay attention to the end cover and tighten the screws.

⑦ Check whether the auxiliary starting and protection equipment of the motor is in good condition.

Second, regular overhaul The regular overhaul of the asynchronous motor should be carried out in conjunction with the overhaul of the load machinery. The agricultural motor can be combined with the agricultural time, and it is carried out once a year in winter. During overhaul, the motor should be disassembled for inspection and repair of the following items:

① Check whether there is any mechanical damage to each part of the motor, if so, it should be repaired accordingly.

②Clean up the disassembled motor and starting equipment to remove all sludge and dirt. During cleaning, pay attention to observe the winding insulation condition. If the insulation is dark brown or dark brown, it means that the insulation has aged, and special attention should be paid to this insulation not to knock it off. If it is found to be falling off, local insulation repair and painting should be carried out.

③Remove the bearing and wash it thoroughly in kerosene or gasoline. After washing off the grease and dirt remaining between the bearing frame and the steel ball, clean it with clean coal (gas) oil. After cleaning, the bearing should be able to rotate freely, and the bearing clearance should be measured. If the bearing surface is rough, it means that the grease is unqualified; if the bearing surface is discolored (blue), it means that it has been thermally annealed. According to the inspection results, the grease or bearing should be replaced, and the cause of the failure should be eliminated (such as removing sand, iron filings and other debris in the oil; correctly installing the bearing, etc.).

When the bearing is newly installed, oil should be added from one side. Grease can account for 1/2 to 2/3 of the bearing volume. Overfilling the oil will cause heat to flow out. The lubricating oil can be calcium-based grease, sodium-based grease or lithium-based grease.

④ Check whether the stator winding is faulty. Use a megohmmeter to measure the winding insulation resistance to determine whether the winding insulation is damp or whether there is a short circuit. If so, it should be dealt with accordingly. Use a bridge to measure whether the three-phase resistance is balanced. If it is not balanced, it should be dealt with accordingly.

⑤ Check whether the stator and rotor iron cores are worn or deformed. If there is wear or bright spots, it means that there may be friction between the stator and rotor iron cores. Use a file or scraper to scrape down the bright spots. If there is deformation, it should be repaired accordingly.

⑥ After the above repairs and inspections, assemble and install the motor.

⑦Installed motor should be inspected after repair. After each test item is completed and meets the requirements, it can be run with load.