Teeth-type electromagnetic clutch: teeth-type electromagnetic clutch is placed between the active and driven parts. When the power is not on, the magnetic powder is in a loose state. When the power is on, the magnetic powder is combined, and the active part and the driven part rotate at the same time. Advantages: Torque can be adjusted by adjusting the current, allowing greater slip. Disadvantages: large slip when the temperature rise is larger, the relative price is high.