Abstract
Conjugate cam mechanisms are one of cam mechanisms, with two different cams contact with the follower in two or more than point simultaneously, keeping the follower positive. Generally, there might be the clearance between the cam and the follower. However, it can cause the follower to impact the cam, generate the noise and decrease the precision of the mechanism. In order to avoid this situation for the conjugate cam mechanisms, this work researches how to adjust the distance from cam center to the follower pivot to create preload and eliminate the clearance between the cam and roller follower. First, based on the concepts of the velocity instant centers, calculating the cam profiles in different distances from the cam center to the follower pivot. Next, in the principle of taking the original cam profile as the standard profile, calculating the variation of the contact point between the cam and roller in the direction of the normal line of the contact point. Finally, from the concepts of the Hertz contact theory, calculating the force of the preload, the contact force and the maximum contact stress in different distances between the two rotation centers. According to the researching result, the force of preload, created after adjusting the distance from the cam center to the follower pivot point, can eliminate the clearance between the cam and the roller effectively. In the assumption that only the contact point between the conjugate cam and roller follower is not rigid body, avoiding the material damage caused by the excessive force of preload, as the material of the cam and roller follower is AISI 1045 steel cold drawn and the angular velocity of the cam is 1200 rpm, the appropriate adjustment distance between two rotation centers should be less than .