Basic concepts and classifications of motor maintenance

Basic concepts and classifications of motor maintenance

Motor maintenance refers to the frequent occurrence of motor failures due to long-term continuous use and improper user operation. Motor maintenance should be carried out by professional personnel to ensure the good operation of the motor. Motor maintenance can save costs and improve motor utilization.

  Basic concepts

An electric motor refers to an electromagnetic device that converts or transmits electrical energy based on the law of electromagnetic induction. Electric motors (commonly known as motors) are represented by the letter "M" in the circuit (the old standard used "D"). Its main function is to generate driving torque as a power source for electrical appliances or various machinery.

Classification

According to the different working power sources of electric motors, they can be classified into DC motors and AC motors. Among them, AC motors are also divided into single-phase motors and three-phase motors.

 According to the structure and working principle, electric motors can be classified into DC motors, asynchronous motors, and synchronous motors.

Classification details

Synchronous motor: It can also be divided into permanent magnet synchronous motor, reluctance synchronous motor, and hysteresis synchronous motor.

Asynchronous motor: can be divided into induction motor and AC commutator motor.

Induction motors are divided into three-phase asynchronous motors, single-phase asynchronous motors, and shielded pole asynchronous motors.

AC commutator motor: divided into single-phase series excited motor, AC/DC dual-purpose motor, and repulsion motor.

DC motor: According to its structure and working principle, it can be divided into brushless DC motor and brushed DC motor.

Brushed DC: can be divided into permanent magnet DC motors and electromagnetic DC motors. Electromagnetic DC motors are divided into series excited DC motors, parallel excited DC motors, separately excited DC motors, and compound excited DC motors. 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.

Classified by start-up and operation mode

According to the different starting and operating modes, electric motors can be divided into capacitor starting single-phase asynchronous motors, capacitor running single-phase asynchronous motors, capacitor starting single-phase asynchronous motors, and phase separated single-phase asynchronous motors.

 Classified by purpose, it can be divided into drive motors and control motors.

Electric motors for driving are further divided into electric motors for power tools (including drilling, polishing, grinding, slotting, cutting, and expanding tools), electric motors for household appliances (including washing machines, electric fans, refrigerators, air conditioners, recorders, video recorders, DVD players, vacuum cleaners, cameras, electric blowers, electric shavers, etc.), and electric motors for other general small mechanical equipment (including various small machine tools, small machinery, medical equipment, electronic instruments, etc.).

Control motors are divided into stepper motors and servo motors.

  According to the structure of the rotor, electric motors can be classified into cage induction motors (formerly known as squirrel cage asynchronous motors) and wound rotor induction motors (formerly known as wound rotor asynchronous motors).

 According to the operating speed, electric motors can be classified into high-speed motors, low-speed motors, constant speed motors, and speed regulating motors.

Low speed motors are divided into gear reduction motors, electromagnetic reduction motors, torque motors, and claw pole synchronous motors.

Adjustable speed motors can be divided into stepped constant speed motors, continuously variable speed motors, stepped variable speed motors, and continuously variable speed motors. They can also be divided into electromagnetic speed motors, DC speed motors, PWM frequency conversion speed motors, and switched reluctance speed motors.

The rotor speed of an asynchronous motor is always slightly lower than the synchronous speed of the rotating magnetic field.

The rotor speed of a synchronous motor remains synchronous regardless of the load size.