The most comprehensive explanation of motor types in history

Electric motor, a device that converts electrical energy into mechanical energy. The old commonly known as Motor, is the transliteration of motor. The circuit is represented by the letter 

"M" (the old standard was "D"). [1]

In 1821, Faraday invented the first electric motor, the first device to use current to move objects, relatively simple.

In 1873, the Belgian Gram invented the high-power motor, and the motor began to be used in large-scale industrial production.

The prototype of the DC motor appeared in the 1830s. Due to the inherent shortcomings of the DC motor itself (mainly the commutation problem, especially in the case of high voltage),

 after the 1880s, AC motors have been rapidly developed.

The production of electric motors in China began in 1917.

Motor concept

Motor: An electromagnetic device that converts or transmits electrical energy according to the law of electromagnetic induction. Including mechanical energy → electric energy; Electrical 

energy → mechanical energy; Electrical energy → Electrical energy.

Basic structure: mainly includes a stator winding used to generate a magnetic field and a rotating armature (rotor) plus other accessories. Under the action of the rotating magnetic field 

of the stator winding, the armature has current passing through and is rotated by the magnetic field. Generate driving torque as a power source for electrical appliances or various 

machinery.

Motor principle dynamic diagram

2. Motor classification: according to the mode of motion

Stationary motor: transformer

Rotating motor: DC motor, AC motor (asynchronous motor, synchronous motor)

Linear motor: linear synchronous (permanent magnet) motor, linear asynchronous motor

Basic series, derived series, special motor, special motor and so on.

Function classification: generator, motor, transformer, converter, inverter, phase shifter

Control motor: Used in automatic control systems, as a control element or for signal transmission and conversion.

Type of motor

According to different standards, there are many different types of electric motors. To do work, the motor needs to have two basic conditions: one is that there is a magnetic field, and the 

other is that there is a moving current in the magnetic field.

1. According to the working power supply: divided into DC motor and AC motor.

According to the different number of phases of the power supply, AC motors are divided into single-phase motors and three-phase motors.

2. According to the structure and working principle: divided into DC motor, asynchronous motor and synchronous motor.

(1) Synchronous motor can also be divided into permanent magnet synchronous motor, reluctance synchronous motor and hysteresis synchronous motor.

(2) Asynchronous motors can be divided into induction motors and AC commutator motors. Induction motor is divided into three phase asynchronous motor, single phase asynchronous 

motor and shield pole asynchronous motor. Ac commutator motors are divided into single-phase series motors, AC-DC dual-purpose motors and repulsion motors.

(3) DC motor according to the structure and working principle can be divided into brushless DC motor and brushless DC motor. Brush DC motor can be divided into permanent magnet 

DC motor and electromagnetic DC motor.

Electromagnetic DC motors are divided into series excited DC motors, shunt excited DC motors, separately excited DC motors and compound excited DC motors.

According to the different magnetic materials used, permanent magnet DC motors are divided into rare earth permanent magnet DC motors, ferrite permanent magnet DC motors and 

aluminum nickel cobalt permanent magnet DC motors.

3. According to the starting and running mode, single-phase asynchronous motors can be divided into

Capacitance-start single-phase asynchronous motor, capacitance-run single-phase asynchronous motor, capacitance-start single-phase asynchronous motor and split phase single-phase 

asynchronous motor.

4. According to the use occasion or purpose: divided into drive motor and control motor.

The control motor is divided into selsyn, stepper motor and servo motor.

(5) Induction motors can be divided into cage induction motors (formerly known as squirrel cage induction motors) and wound rotor induction motors (formerly known as wound linear 

induction motors) according to the structure of the rotor.

6. According to the running speed classification of high-speed motor, low-speed motor, constant speed motor, speed control motor.

Low speed motor is divided into gear motor, electromagnetic reduction motor, torque motor and claw pole synchronous motor.

In addition to being divided into graded constant speed motor, stepless constant speed motor, graded variable speed motor and stepless variable speed motor, there are electromagnetic 

variable speed motor, DC variable speed motor, PWM variable frequency motor, switched reluctance variable speed motor and so on.

According to the shape of the stator (copper wire) winding of the motor, the motor is divided into round wire motor and flat wire motor, flat wire motor is an important trend in the 

industry. The cross section shape of the wire used in the stator winding of the flat wire motor is rectangular, and several wires are thicker. The stator winding of a circular motor uses many 

thin round wires. [2]

Direct current motor

A DC motor is an electric motor that operates on a DC voltage.

1. Electromagnetic DC motor Electromagnetic DC motor is composed of stator magnetic pole, rotor (commonly known as armature), commutator (commonly known as commutator), 

brush, housing, bearings and so on. The brush is a conductive part connecting the power supply and the rotor winding, which has two properties of conduction and wear resistance.

The stator magnetic pole (main magnetic pole) of an electromagnetic DC motor is composed of an iron core and an exciting winding.

The DC motor is classified according to the excitation mode: the power supply mode to the excitation winding, that is, the excitation mode, can be divided into series excited DC motor, 

shunt excited DC motor, separately excited DC motor and compound excited DC motor.

(1) DC separate excitation motor: the excitation winding is supplied by an independent excitation power supply, and the excitation winding has no electrical connection with the armature. 

Therefore, the excitation current is not affected by the armature terminal voltage or armature current. The excitation current is relatively constant, and the starting torque is proportional 

to the armature current. The speed can be increased by weakening the constant power of the magnetic field or reduced by reducing the voltage of the rotor winding.

(2) DC shunt motor: the excitation winding is in parallel with the rotor winding, and the excitation current is relatively constant; The voltage at both ends of the excitation winding is the 

voltage at both ends of the armature, but the excitation winding is wound with a thin wire, and the number of turns is also many, so it has a large resistance, making the excitation current 

through it small. The starting torque is proportional to the armature current, and the starting current is about 2.5 times the rated current. The speed will decrease slightly with the increase

 of current and torque, and the short-term overload torque is 1.5 times of the rated torque.

(3) DC series motor: excitation winding and rotor winding (armature) through the brush and commutator phase series, voltage division, excitation current is proportional to the armature 

current, stator flux with