Answer to Question #158931 in Mechanical Engineering for MANIKANDA RAJAN

Question

what is meant by jump phenomenon in cam follower mechanism

Answer 1

We know very well that a (reciprocating)cam and follower is generally used to achieve reciprocating motion in vertical direction in any system. Eg.(IC Engine Valve Operation)

In most of the cams such as disc cams, plate cams, the cam is responsible for upward movement of the follower. But interestingly the cam is not responsible for the downward movement (return) of the follower. Instead of cam, acceleration due to gravity “g” is responsible for the downward motion.

As we know, “g” is limited by 9.81 m/s2. Here comes the problem, if the rotational speed of the cam is very high, it leads to accelerate the follower at a very high rate.

No problem about the upward acceleration of the follower, the cam will take care. We cannot expect the cam to move downward in an acceleration greater than “g”. It makes the follower to lose contact with the cam. This is called as jump phenomenon.

Resource: https://www.quora.com/What-is-jump-phenomenon-in-cam