What is a micro motor?

1. Definition

Micro motors generally refer to motors with small volume and capacity and output power generally below hundreds of watts. They are usually smaller than 160mm in size or less than 750mW in power, with a voltage of 1-24V. The most common ones are only a dozen millimeters, and micro motors of hundreds of millimeters are relatively rare.

2. Composition

Although the micro motor is small in size, its internal structure is very complete. For example, the micro DC motor is composed of the following:

Armature core: The main part of the main magnetic circuit of the micro DC motor, used to place the armature winding, mostly made of stacked silicon steel sheets to reduce the eddy current loss and hysteresis loss generated in the armature core when the micro motor is running.

Armature winding: The main function of the armature winding of the micro motor is to generate electromagnetic torque and induced electromotive force. In the micro DC motor, the armature winding is made of multiple coils, generally using enameled wire, and copper wire or silver wire if there are special requirements.

Commutator: In a micro DC motor, the commutator and brushes are the key factors for the micro motor to rotate continuously. Their main function is to change the direction of the current so that the micro motor can rotate continuously (the brushless DC motor is commutated by Hall electronics, without commutators and brushes).

Shaft: In a micro DC motor, the commutator and brushes are the key factors for the micro motor to rotate continuously. Their main function is to change the direction of the current so that the micro motor can rotate continuously (the brushless DC motor is commutated by Hall electronics, without commutators and brushes).

III. Classification

1. According to the usage, it is divided into three categories

a. Driving micro motors: including micro asynchronous motors, micro synchronous motors, micro AC commutator motors, micro DC motors, etc.

b. Controlling micro motors: including self-synchronous machines, rotary transformers, AC and DC tachometer generators, AC and DC servo motors, stepper motors, torque motors, etc.

c. Power supply micro motors include micro electric generator sets and single-axis AC motors, etc.

2. According to the structure, it is divided into three categories

a. Electromagnetic type: The basic composition is similar to that of ordinary motors, including stators, rotors, armature windings, brushes and other components, but the structure is extremely compact.

b. Combination type: The combination of micro motors and electronic circuits, etc. For example, the combination of DC motors and sensors, the combination of linear motors in the X direction and the Y direction, etc.

c. Non-electromagnetic type: The appearance structure is the same as the electromagnetic type, such as rotating products are made into cylindrical shapes, and linear products are made into square shapes, but the internal structure varies greatly due to their different working principles.

IV. Features

High torque, low noise, small size, light weight, easy to use, constant speed operation, can be matched with various gearboxes to achieve the purpose of changing the output speed and torque.

V. Scope of use

Micro motors are generally used in control systems to realize the detection, solution, amplification, execution or conversion of electromechanical signals or energy, or used to transmit mechanical loads, and can also be used as AC and DC power supplies for equipment. It can be applied to all low-power constant speed and high torque equipment such as food machinery, textile machinery, medical equipment, smart doors and windows, monitor PTZ, advertising light boxes, household appliances, air conditioner blades, actuator control, etc.

VI. Application fields

1. As a power source for moving mechanical loads in driving occasions without special control requirements.

2. Audio and video equipment. For example, in a video cassette recorder, the micro motor is not only a key component of the magnetic drum assembly, but also an important component of its main shaft drive, automatic loading of the supply and receiving tape and tape cassette, and tape tension control.

3. Office automation equipment, computer peripherals and industrial automation equipment. For example, disk drives, copiers, CNC machine tools, robots, etc. all use micro motors.