Motors (Motors) is a device to convert electrical energy into mechanical energy. It is the use of energized coil (that is, the stator windings) and generates a rotating magnetic field acting on the rotor (such as squirrel-cage closed aluminum frame) forming a magnetic-powered rotary torque. Divided by the use of different motor power DC motors and AC motors, most of the power system of the motor is an AC motor, can be synchronous or asynchronous motors motor (motor stator and the rotor speed of rotation speed of the magnetic field does not maintain synchronous speed). The main motor is composed of the stator and the rotor, the movement direction of the force of the current supply conductor in a magnetic field with magnetic induction lines and the current direction (magnetic field direction) on. Working principle of the motor current is limited by the force of the magnetic field, the rotation of the motor. The motor is a rotary motor, a mechanical energy into electrical energy it, which includes an electromagnet for generating a magnetic field distribution in the stator winding or windings and a rotary armature or rotor. Under the effect of a rotating magnetic field of the stator windings, through which a current and a magnetic field that is rotated in the squirrel-cage armature aluminum box. These machines can be used in some types of motors can also be used as a generator. It is a machine that converts electrical energy to mechanical energy. Typically part of the motor for power for rotation, the motor rotor of this motor is known; rectilinearly also called linear motor. Motor can provide power range widely, from milliwatts to kilowatts level. Machine tools, pumps, belts, fans and other needs of the motor drive; electric locomotives, elevators, traction motors need. Family life fans, refrigerators, washing machines, and even a variety of motor toys are inseparable motors. Motor has been used in modern social life in all its aspects. Many of the motor speed control method, able to adapt to different production machine speed changing requirements. The output power will change with the speed of the motor when the governor general. Look from the perspective of energy consumption, speed roughly divided into two types: ① keep the input power constant. By changing the consumption of energy control devices to regulate the output power to adjust the motor speed. ② to adjust the input power to control the motor speed of the motor. Motors, electric motors, brake motors, variable frequency motor, motor speed, three-phase asynchronous motors, high voltage motors, multi-speed motor, two-speed motors and explosion-proof motor.