Jixie chuandong (May 2023)
Contact Analysis of Sprag-type Overrunning Clutches
Abstract
Sprag-type overrunning clutches are widely used in aeroengines and the helicopter transmission system. The research on the contact properties of sprag-type overrunning clutches has important significance to the design of high reliability clutch. In order to study the effects of torque and coefficient of friction on the contact properties of sprag-type overrunning clutches, Hertz contact theory and finite element method are used to investigate the dynamic contact properties of sprag-type overrunning clutches. The results show that both rolling and sliding occur when friction is considered, the contact stress between sprags and races is elliptically distributed with a large eccentricity, the contact stress is distributed in the parabolic shape along the length of the sprags, maximum contact stress couldn't reflect the effects of torque on contact stress, the torque transmitted beyond the clutch is positively correlated with its torsion angle, the coefficient of friction doesn't affect the maximum contact stress and the torsion angle of the clutch, the coefficient of friction is nonlinear with the sliding distance and linear with the maximum friction stress.
