The friction type torque limiter uses the lock nut to make the spring produce elastic force and act on the friction plate. The sprocket and other wheel like objects are sandwiched between the two friction plates. Due to the effect of elastic force, the friction force between the friction plate and the sprocket is generated, so that the torque can be transmitted.

When the equipment is overloaded, there is relative sliding between the sprocket and friction plate, but the torque of sliding is still maintained between them.

The preset torque of the torque limiter is set according to the whole transmission system when it is delivered from the factory. Different torques are set with springs of different strength. The preset value is higher than the peak torque of the motor, but within the range of the safety factor of the motor.