The types of electric motors are rich and diverse and can be classified in various ways.
Firstly, according to the difference in working power supply, electric motors can be divided into DC motors and AC motors. Among AC motors, they are further divided into single-phase motors and three-phase motors.
From the perspective of structure and working principle, electric motors are classified into DC motors, asynchronous motors and synchronous motors. Synchronous motors further include permanent magnet synchronous motors, reluctance synchronous motors and hysteresis synchronous motors. Asynchronous motors include induction motors and AC commutator motors. Among them, induction motors include three-phase asynchronous motors, single-phase asynchronous motors and shaded-pole asynchronous motors, etc. AC commutator motors include single-phase series-excited motors, AC and DC universal motors and repulsion motors. In DC motors, according to structure and working principle, they can be divided into brushless DC motors and brushed DC motors. Brushed DC motors include permanent magnet DC motors and electromagnetic DC motors. Electromagnetic DC motors can be further divided into series-excited DC motors, shunt-excited DC motors, separately-excited DC motors and compound-excited DC motors. Permanent magnet DC motors are further divided into rare-earth permanent magnet DC motors, ferrite permanent magnet DC motors and alnico permanent magnet DC motors.
According to the starting and operating methods, electric motors can be divided into capacitor-start single-phase asynchronous motors, capacitor-run single-phase asynchronous motors, capacitor-start and run single-phase asynchronous motors and split-phase single-phase asynchronous motors.
In terms of application, electric motors can be divided into driving motors and control motors. Driving motors are used in power tools, such as drilling, polishing, grinding, slotting, cutting, reaming and other tools, as well as household appliances, such as washing machines, electric fans, refrigerators, air conditioners, tape recorders, video recorders, DVD players, vacuum cleaners, cameras, hair dryers, electric shavers, etc., and other general small mechanical equipment, such as various small machine tools, small machinery, medical equipment, electronic instruments, etc. Control motors include stepper motors and servo motors, etc.
Divided by the structure of the rotor, electric motors have cage induction motors (formerly known as squirrel-cage asynchronous motors in the old standard) and wound rotor induction motors (formerly known as wound asynchronous motors in the old standard).
According to the different operating speeds, electric motors are divided into high-speed motors, low-speed motors, constant-speed motors and speed regulating motors. Low-speed motors include gear reduction motors, electromagnetic reduction motors, torque motors and claw-pole synchronous motors, etc. Speed regulating motors can be divided not only into stepped constant-speed motors, stepless constant-speed motors, stepped variable-speed motors and stepless variable-speed motors, but also into electromagnetic speed regulating motors, DC speed regulating motors, PWM frequency conversion speed regulating motors and switched reluctance speed regulating motors.