Mechanical Engineering - Theory of machines - Discussion

@All.

I will explain where all these motions are used:

1) SHM:- In these motion, there is an infinite jerk, vibration and noise so it would be suited for low and moderate speed.

2) Constant acceleration and deceleration (parabolic) :-There are abrupt changes in the acceleration at beginning, midway and the end of the follower motion. At midway, an infinite jerk is produced. So best suited up to moderate speed.

3) Constant velocity:-Due to the infinite inertia forces, it is not suited from the practical point of view.

4) Cycloidal:- There are no abrupt changes in the velocity and the acceleration at any stage of the motion, so it is an ideal programme for high-speed follower motion.

The graph represents of SHM that of uniformity rather than other types of profile.

Low and moderate speed Follows SHM.

All the first 3 motions have infinite acceleration at starting of the motion so this induces thrust which damages the cam so to avoid this we use cycloidal motion.

When the cam is rotating with high speed then the follower has ability to escape from above the cam to avoid it we used cycloidal follower in case of high speed.

So when the first 3 motions are used ?

A beam having dimensions 75x75x6000 mm using this data how can we find out the weight?

At high speed the acceleration at the start become infinity at all speed so only cycloidal manner is best suited for this action.

So when the first 3 motions are used ?

Constant velocity is not practically applicable. SHM and constant acceleration can be used for low or moderate speeds; but there will be jerks.