Three phase asynchronous motors mainly consist of stator, rotor, fan, fan cover, end cover, junction box, and bearings. Some special motors also come with brakes, fans, and encoders.

Insert the rotor into the middle of the stator, install the bearings, support the rotor with end caps, install the fan and fan cover, and a three-phase AC asynchronous motor is formed. The rotating magnetic field generated by the stator after connecting to the three-phase AC power supply can drive the rotation of the squirrel cage rotor.

After installing the end cover on the machine base, the rotor, stator, and stator winding are sealed inside the machine base, which can effectively prevent dust. The heat generated by the stator and rotor is dissipated by the outer shell of the machine base, and the fan blades on the rotor stir the air inside the machine to quickly transfer the heat to the outer shell. The heat dissipation fins on the outer shell increase the heat dissipation area.

There is also a fan and a fan cover installed outside the motor end cover. The end of the fan cover has ventilation holes, and when the fan rotates, it is like a centrifugal fan. Air enters from the end of the fan cover, blows out through the gap between the fan cover and the end cover, and blows towards the heat sink on the machine base, greatly accelerating the heat dissipation of the motor.  

stator

Stator core: It is a part of the magnetic circuit, made by punching and laminating silicon steel sheets with insulation layers on the surface of 0.35-0.5mm thickness. There are evenly distributed slots punched in the inner circle of the iron core, which are used to embed the stator winding and are an important component of the motor magnetic circuit. The stator core slot types include semi closed slot, semi open slot, and open slot. Half closed slot motors have higher efficiency and power factor, but winding embedding and insulation are more difficult, and are usually used for small low-voltage motors; The semi open slot can accommodate molded windings and is generally used for large and medium-sized low-voltage motors; The open slot insulation method is convenient and mainly used in high-voltage motors.

Stator winding: It is the circuit part of an electric motor that can generate a rotating magnetic field when three-phase AC power is applied. Composed of three identical windings arranged symmetrically at an electrical angle of 120 ° in space, each coil of these windings is embedded in a certain pattern in each slot of the stator. There are three main insulation projects for stator windings: ground insulation (insulation between the entire stator winding and the stator core), phase to phase insulation (insulation between each phase of the stator winding), and turn to turn insulation (insulation between each wire turn of each phase of the stator winding).

Machine frame: Its main function is to fix and support the stator iron core, while also bearing the reaction force generated during the operation of the entire motor. Small and medium-sized three-phase asynchronous motors generally use cast iron bases, while large motors often use steel plate welded bases.