Abstract
A non-contact gear mechanism is important for the non-contact transmission of a torque and a motion. In this paper, a magnetic gear system without contact which requires no lubricant oil is proposed. The driving gear consists of some iron discs with gear teeth whose shape is an involute curve. The discs of the follower gear are inserted in the gaps between the discs of the driving gear, and the attractive forces between the discs generate the torque transmission. Using the magnetic gear system, a magnetically connected planetary gear device is developed. Moreover we measure and study the slip torque as static property, and the step-out torque as dynamic property due to implication of rotational speed.