The structure of the rotor of the motor:
The rotor is the rotating part of the three-phase asynchronous motor, which is composed of the rotor core, the rotor winding, the rotating shaft and the fan. The core of the rotor is also part of the magnetic circuit of the motor, which is made of a silicon steel sheet with a uniform trunking punched around the outer circumference and fixed on the rotating shaft. The rotor windings are placed in the trunking of the rotor core. According to the different rotor winding structure, the three-phase asynchronous motor can be divided into two types: squirrel cage type and winding type. The rotor winding of the squirrel cage asynchronous motor is named because it is shaped like a squirrel cage, and its structure is embedded in the trunking with a copper strip as a conductor, and the two ends of the copper strip are welded together with a short circuit ring. Small and medium-sized squirrel cage asynchronous motors use cheaper aluminum instead of copper, and cast the rotor conductor, short-circuit ring and fan into one to become a cast aluminum squirrel cage rotor.
The core of a wound rotor is the same as that of a squirrel cage rotor.
The rotor winding is similar to the stator winding, which is wound by insulated wires and embedded in the rotor slot according to a certain rule to form three symmetrical windings. Usually the ends of the three windings are connected together, and the first end is connected to three copper slip rings fixed on the shaft and connected into a star. The rotor winding is connected with the external three-phase rheostat through the slip ring and the brushes on it, and the power supply motor is used for starting and speed regulation in a small range. The working principle of squirrel cage and wound three-phase asynchronous motors is the same, and the difference is only in the rotor winding structure.