Detailed introduction of micro-motor

Micromotors have a wide variety of categories, which can be broadly divided into DC motors, AC motors, self-angle motors, stepper motors, resolvers, shaft angle encoders, AC/DC motors, tachogenerators, inductive synchronizers, linear motors, Piezoelectric motors, motor units, vibration motors and other special motors and other 13 categories.

Stepper motor micro motor in the structure can be roughly divided into three categories:

1. Electromagnetic type. The basic composition is similar to that of ordinary motors, including stators, rotors, armature windings, brushes, etc., but the structure is extremely compact.

2. Combination. There are two common types: the combination of the above-mentioned various micro-motors; the combination of micro-motors and electronic circuits. For example, a combination of a DC motor and a sensor, a combination of an X-direction and a Y-direction linear motor, and the like.

3. Non-electromagnetic. The exterior structure is the same as the electromagnetic one. For example, the rotary product is made into a cylindrical shape, and the linear product is made into a square shape. However, the internal structure differs greatly depending on the working principle.

The performance of various types of micro-motors varies greatly, and the performance parameters of servo motors are difficult to interpret. In general terms, the drive machinery is focused on the indicators of power and energy at the time of operation and start-up; the output power, waveform, and stability are taken into account for the power supply; and the micro-motors for control are emphasised on static and dynamic characteristics. The characteristics of the first two types of motors are similar to those of ordinary motors. The only control micromotor has its unique characteristic parameters.

1 work characteristics. Common output and input, or the relationship between one output and another. From the perspective of control requirements, the static characteristic curve should be continuous, smooth and without abrupt changes; the dynamic characteristic is often represented by a frequency curve or a response curve. The frequency curve should be smooth, without sudden oscillation point; the response curve should converge quickly.

2 sensitivity. Corresponds to the size of the output of the unit input signal. Commonly used than the torque, the ratio of the electromotive force, amplification factor, etc.

3 accuracy. Under certain input conditions, the difference between the actual value of the output signal and the theoretical value represents the accuracy of the micromotor, which is represented by the magnitude of the common error.

4 impedance or resistance. In the system, the input and output impedances of the micro-motors should be matched with corresponding circuits to ensure the running performance and accuracy of the system.

5 reliability. It is not only the special requirements of the control micromotor, but also the requirements for driving the micromotor and the power micromotor. The useful life, failure rate, reliability, and mean time between failures are used to characterize the micro-motor's operational reliability.