Development of Mechanical Torque Limiter used for Space Manipulators : 1st Report, Geometrical Study on the Structure

Abstract

The structure of a mechanical torque limiter for space manipulators, which is used for tightening and loosening bolts, was studied geometrically, and the design method for obtaining a high reliability was clarified. The results of this study are as follows. 1)A claw made of balls and rollers is the best clutch structure for the torque limiter. 2)The condition for obtaining a difference between the operation torque of loosening and tightening bolts was clarified by introducing a structure factor S. 3)In order to keep a change of the operation torque small over a long period, the contact angle of the ball and the roller when thetorque limiter operates should be made as small as possible, and the friction coefficient between them should be kept small.