Abstract: In the paper, the properties of plane magnetism clutch transferring torque are through studied by the theory of equivalent magnetic charge, calculating formular of the transfer toque is established and tested by experiments. According to the calculating formular, the effect of magnet arrangement, number of magnetic poles and geometric dimensions of magnet on transfer torque is studied, the obtained results are useful for the theoretical study and engineering design of magnetism clutchs.

Key words: Clutch, Permanent magnet, Torque