As an actuator for position control, stepper motor may be used in many occasions. In other words, it is a special motor that converts electrical pulse signals into linear displacement or angular displacement. For example, it is used in air conditioners. When it comes to micro stepper motors used to adjust the angle of the fan blades of the air outlet of the air conditioner, the stepper motors are also used in the pop-in and ejection of computer optical drives and economical CNC machine tools. Today let's talk about some questions about stepper motors.

Classification of stepper motors

There are many types of stepping motors. Generally speaking, they can be divided into three types: reactive stepping motors, permanent magnet stepping motors and hybrid stepping motors. Among these three stepping motors, the most widely used one It is a hybrid stepping motor. This motor has the advantages of the first two motors. For example, the hybrid stepping motor has large torque, good dynamic performance, and high precision of control position. It is widely used in industry.

Structure and working principle of stepper motor

Now let's take the four-phase permanent magnet stepping motor model as an example to talk about the structure of the stepping motor. Let's take a look at the schematic diagram of the internal structure of the stepping motor. We can see from the figure that there is a stepping motor in the stepping motor. The part that can be rotated, its private capital is called "rotor". In order to explain the problem better, a number is coded on the teeth of each rotor. It can be seen from the picture that it has six teeth. We are looking at its outer ring which does not rotate, we call it "stator", there are eight teeth on the stator.

 

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We can see from the physical picture of the stepper motor that a coil winding is wound on each tooth of the stator. We can see from the schematic diagram of the stepper motor that the windings on the two teeth are in series. Together, they can be powered and powered off at the same time, thus forming a four-phase winding. We label it with ABCD on the schematic. Therefore, this kind of stepper motor is called "four-phase" stepper motor. We assume that the B-phase winding is closed and turned on first, which will generate magnetic poles on the corresponding stator winding teeth. At this time, the "0" and "3" numbers of the rotor are closest to them, which will produce the strongest attraction force . Then turn off phase B and turn on phase C with the rotor's "1" and "4" closer to them so they align with the C-phase windings. In this way, the rotor will rotate a certain angle in a counterclockwise direction. In this way, if we energize the windings of the stepper motor in the order of phase B-phase C-phase D-phase A, the rotor of the stepper motor will keep running in a counterclockwise direction.

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