ADD:No.789,liming South Road,RongCheng City,Shandong Province,China.
The working principle of the motor
An electric motor (Motors) is a device that converts electrical energy into mechanical energy. It produces a rotating magnetic field by using an electric coil (the stator winding) and acts on the rotor squirrel cage type closed aluminum frame to form a magnetoelectric rotating torque. The motor is divided into DC motor and AC motor according to the power supply. Most of the motors in the power system are AC motors. They can be synchronous motors or asynchronous motors (motor stator magnetic field speed and rotor rotation speed do not keep synchronous speed). The motor is mainly composed of the stator and the rotor. The direction of the force motion of the electric wire in the magnetic field is related to the direction of the current and the direction of the magnetic sense (magnetic field direction). The principle of the motor is the effect of the magnetic field on the force of the current, so that the motor is rotated.
The motor is a rotary electric machine, which transforms electric energy into mechanical energy. It mainly consists of an electromagnet winding or a distributed stator winding for generating magnetic field and a rotating armature or rotor. Under the action of the rotating magnetic field of the stator winding, it has the current passing through the armature squirrel cage type aluminum frame and is rotated by the effect of the magnetic field. Some of these machines can be used as motors or alternator. It is a machine that transforms electrical energy into mechanical energy. Usually the work part of the motor is rotated, the motor is called the rotor motor, and there is also a straight line motor, which is called a linear motor.
The structure of the three phase asynchronous motor is composed of the stator, the rotor and other accessories.
(1) stator (stationary part)
1. Stator core
Function: a part of the magnetic circuit of the motor, and the stator winding is placed on it.
Structure: stator core is usually made by punching and stacking the silicon steel sheet with insulation layer on the surface of 0.35~0.5 millimeter thick, and punching evenly distributed slot inside the core, so as to embed the stator windings.
The stator core groove type has the following several kinds:
Half closed groove: the efficiency and power factor of the motor are high, but the winding and insulation of the winding are difficult. It is generally used in small low voltage motor.
Half open slot: can be embedded and formed winding, generally used for large and medium low voltage motor. The so-called forming windings, that is, can be placed in the slot in advance after the insulation is treated.
Open slot: it is used to inlay the forming winding, and the insulation method is convenient. It is mainly used in the high voltage motor.
2. Stator windings
Function: it is the circuit part of the motor, which passes into the three-phase alternating current and produces the rotating magnetic field.
The structure is made up of three identical structures with the same structure in the space of 120 degrees, which are arranged in the same space. The coils of these windings are embedded in each slot of the stator according to certain rules.
The main insulation of the stator windings is the following three kinds: (the reliable insulation between the conductive parts and the core of the winding and the reliable insulation between the winding itself).
(1) to the ground insulation: the insulation between the stator winding and the stator core.
(2) interphase insulation: the insulation between the stator windings of each phase.
(3) interturn insulation: insulation between each phase of the stator winding in each phase.
The wiring in the electric motor junction box:
The motor terminal box has a wiring board, six ends of three-phase windings arranged on the two row, and the provisions of the top three wiring pile from left to right are numbered 1 (U1), 2 (V1), 3 (W1), while three binding posts arranged from left to right the number 6 (W2), 4 (U2), 5 (V2), the three-phase windings are connected to star connection or delta connection. In the course of manufacture and maintenance, the number should be arranged in accordance with this serial number.
Role: fixed stator core and front end cover to support the rotor, and play the role of protection, heat dissipation and so on.
Structure: the frame is usually cast iron, the large asynchronous motor base is usually welded with steel plate, and the machine base of the micro motor is cast aluminum. There are cooling ribs outside the frame of the closed type motor to increase the heat dissipation area. The ends of the two ends of the chassis of the protective motor are provided with ventilation holes, so that the air inside and outside the motor can be directly convection, which is conducive to heat dissipation.