Cams And Followers

Question 1

What are cams?

Answer 1

They are mechanisms which are used to change rotary motion into reciprocating motion

Question 2

What are followers?

Answer 2

They are the pieces that rest on top of the cam and travel up and down with each rotation

Question 3

Name all the types of cams

Answer 3

Eccentric cams - it’s a circle but the centre of rotation is not the centre of the cam
Heart shaped cams- this cam profile causes the follower to rise slowly until it reaches the dip where it then falls sharply before repeating the whole cycle again.
Pear shaped cams - this cam profile makes the follower rise quickly as it gets to the bump then fall with equal speed.
Snail cams - this profile causes a steady rise then a sharp fall as the follower reaches the vertical point of the cam.

Question 4

Name the different followers

Answer 4

Flat followers - this type has a flat surface at its base and it’s used when precision is not a big concern.
Knife followers - this type can follow a very detailed cam profile e.g. heart shaped cam.
Roller followers - this type has a small roller bearing on the end and it’s useful if we are trying to reduce friction between the cam and the follower

Question 5

Definitions of rise, fall and dwell

Answer 5

Rise - the part of the cam that makes the follower go up
Fall - the part of the cam that makes the follower go down
Dwell - the part of the cam where the follower does not rise of fall