Main Classification of Stepper Motors

- Oct 17, 2019-

The stepping motor can be divided into reactive stepping motor (VR), permanent magnet stepping motor (PM), hybrid stepping motor (HS), single phase Stepper motor, plane stepper motor and other types from its structure form. Reaction stepping motor is the main step motor used in China.The running performance of stepping motor is closely related to the control mode. The stepping motor control system can be divided into the following three categories according to its control mode: open loop control system, closed loop control system and semi-closed loop control system. Semi-closed loop control systems are generally classified in open loop or closed loop systems in practical applications.


Reaction type: There are windings on the stator, and the rotor is composed of soft magnetic material. The utility model has the advantages of simple structure, low cost, small step angle, up to 1.2°, but poor dynamic performance, low efficiency, large heat generation and reliable reliability.

 

Permanent magnet type: The rotor of the permanent magnet stepping motor is made of permanent magnet material, and the number of poles of the rotor is the same as the number of poles of the stator. It is characterized by good dynamic performance and large output torque, but this motor has poor precision and a large step angle (typically 7.5° or 15°).

 

Hybrid: Hybrid stepper motor combines the advantages of reactive and permanent magnets. It has multi-phase windings on the stator, permanent magnet materials on the rotor, and multiple small teeth on the rotor and stator to improve step accuracy. The utility model has the advantages of large output torque, good dynamic performance and small step angle, but the structure is complex and the cost is relatively high.

 

According to the winding on the stator, there are two phases, three phases and five equal series. The most popular is the two-phase hybrid stepping motor, which accounts for more than 97% of the market share. The reason is that it is cost-effective and works well with the subdivision driver. The basic step angle of the motor is 1.8°/step. If  With the half-step drive, the step angle is reduced to 0.9°. if With the subdivision driver, the step angle can be subdivided by 256 times (0.007°/μ step). The actual control accuracy is slightly lower due to friction and manufacturing precision. The same stepper motor can be equipped with different subdivision drivers to change the accuracy and effect.