There are three types of stepping motors: permanent magnet (PM), reactive (VR) and hybrid (HB). Reactive stepping motors are generally two-phase, with small torque and volume, and the step angle is generally 7.5 degrees or 1.5 degrees; permanent magnet stepping motors are generally three-phase, which can achieve large torque output, and the step angle is general It is 1.5 degrees, but the noise and vibration are very large; the hybrid stepping motor is divided into two-phase, three-phase and five-phase, the two-phase stepping angle is generally 1.8 degrees, the three-phase stepping angle is generally 1.2 degrees and the five-phase stepping motor The step angle is generally 0.72 degrees. The hybrid stepping motor combines the advantages of both reactive and permanent magnet stepping motors: the number of pole pairs is equal to the number of rotor teeth, which can be changed in a large range according to needs; the winding inductance changes little with the rotor position, which is easy to achieve Optimal operation control; the axial magnetizing magnetic circuit uses a new type of permanent magnet material with high magnetic energy product, which is conducive to the improvement of the motor performance; the rotor magnet provides excitation; there is no obvious oscillation in the entire operating area.