Abstract:

In the trunnion bearing of a Hooke’s universal joint,the crown drop on the needle roller determines thecontact pressure distribution between the needle and the raceway，and is one of the most important factors to affect the capability and life of the joint. In order to improve the capability of Hooke’s universal joints,the effects of structural parameters on the contact pressure distribution are analyzed based on Lundberg’s logarithmic equation and the numerical calculation of three-dimension elastic contact problems in finite length. It is suggested that,in the design of crown drop,both the chamfer radius and the grinding undercut width should be considered. More-over,the corresponding numerical method to calculate the crown drop is presented,by means of which the trunnion bearings can be designed without the“edge effects”of the contact pressure distribution and the high-pressure con-centration in the contact region. As a result,the capability and service life of the designed Hooke’s universal joint are improved.

Key words: Hooke’s universal joint, needle roller, crown drop, grinding undercut, stress concentration