Introduce you to the disassembly of the motor housing

Introduce the disassembly work of the motor shell to you:

(1) when extracting the rotor, be careful not to damage the stator coil. If the rotor weight is small, you can extract it by hand; If the weight is large, it should be lifted out with hoisting equipment. First, put the two ends of the rotor shaft with hoisting wire rope, hang the rotor with hoisting equipment and move it out slowly, paying attention to prevent damaging the coil. Then put a steel pipe on one end of the shaft. In order not to scratch the shaft neck, the steel pipe can be lined with a layer of thick cardboard to continue to move the rotor out gradually. When the center of gravity of the rotor has moved outside the stator, put a support under the end of the rotor shaft and put the steel wire rope in the middle of the rotor, and then all the rotors can be pulled out

(2) for the motor equipped with rolling bearing, remove the bearing outer cover first, then loosen the fastening screws of the end cover, mark the joint between the end cover and the base shell (the marks of the front and rear end covers shall not be the same), screw the removed fastening screws of the end cover into the two screw holes specially set on the motor end cover, and push the end cover out. For motors without such screw holes, they can only knock the joint between the end cover and the base with a chisel (also known as a flat shovel) and a hammer to remove the end cover from the base. If the end cap is heavy, lift the end cap with lifting equipment and remove it gradually

(3) use tools to remove the pulley or coupling on the motor shaft. Sometimes it is necessary to add some kerosene into the gap between the motor shafts of the pulley to make it penetrate and lubricate for easy disassembly. Some shafts and wheels are closely matched, and the wheel needs to be heated (at the same time, wrap the rotating shaft with a wet cloth) before the wheel can be removed

(4) first remove the external wiring of the motor and mark it. For example, for asynchronous motor, mark corresponding to the three-phase power line. For DC motor, mark corresponding to the external wiring such as shunt winding and armature winding. Then loosen the foot screw to separate the motor from the transmission machinery

in the working process of asynchronous motor, it often can not work because the motor shell temperature is too high. So what are the reasons for this

(1) there is a short circuit between motor winding turns, between phase windings and between winding and grounding resistance, resulting in the increase of current in winding and the sharp rise of its temperature, resulting in the over temperature of motor shell

(2) the insulation between the motor core pieces is damaged, which increases the eddy current loss in the core and the heating of the core, resulting in the excessive temperature of the motor shell

(3) when the three-phase motor is working without phase, the current in the other two-phase windings will increase, resulting in too high winding temperature. When the starting winding of single-phase motor is disconnected, the temperature of the main winding will also be too high

(4) if the motor operates for a long time under overload, it will also cause excessive winding current, increase winding heating and cause excessive temperature

(5) if the motor is started too frequently, the current at the time of starting is more than twice the normal working current, which will also increase the heating of the winding and cause the temperature to be too high

(6) poor electrical contact of the motor increases the heating at the connecting parts, resulting in excessive temperature

(7) when the grid voltage is too high or too low, the current in the motor winding will increase, resulting in heating and excessive temperature

(8) when the bearing at the rotating part is damaged or lack of oil, the friction of the rotating parts increases or the temperature is too high due to impact

(9) the temperature is too high due to the failure of motor cooling parts or the blockage of ventilation duct

(10) the ambient temperature is too high when the motor is working