Research On Mechnical Characteristics Of The Skewed-Roller Overrunning Clutch

Overrunning clutch with skewed rollers is a new kind of variable torque clutch, which provides double function of clutch and bearing and has good bearing capacity and reliability. The research in China is still in the initial stage, so further enquiry of the related research and product structural design has important practical significance.Taking the overrunning clutch with skewed rollers as the research object, firstly, according to the contact relationship, the mathematical model of inner and outer rings was established. The equation of the inner surface was solved with enveloping surface method, and the equation of the outer surface was solved with theory of engagement. Besides, the conclusion that the inner and outer curved surfaces are all offset surface of the hyperboloid were verified. The equation of the contact line was solved so as to establish geometry model, which completed the theoretical solution of digital product designing.Secondly, analysis in mechanical characteristics of the overrunning clutch with skewed rollers was made. By the analysis of the kinematic relationships, the expression of the velocity and the axial and tangential sliding rate was obtained, and the impact of the included angle of the rollers on the axial liding rate, the tangential sliding rate and the ratio of axial force to friction torque, and the relationships between axial force and friction torque were analysed.Thirdly, according to the axial hatching line, the solid model of the inner and outer rings were established based on three-dimensional design software PROE. Then the assembly relation among the rollers, retainer, inner and outer rings was established based on the contact relations. Consequently, the virtual entity model was created, which was able to provide effective way for product structural design.Finally, the contact stress of the overrunning clutch with skewed rollers was analysed based on finite element analysis software ABAQUS, the maximum contact stress was obtained under postulated conditions. Besides, a simplified contact model of rollers and rings under certain loading conditions was established, then the impact of the dip angle and radius of the rollers on the maximum contact stress was analysed, which can provide an efficacious device for reducing the local stress and raising the product lifetime of the overrunning clutch with skewed rollers.