CAM & FOLLOWER MECHANISM ASSIGNMENT

EXAMPLE PROBLEM

QUESTION

Consider the displacement graph below. It shows the linear displacement of the follower compared to the rotation angle of the cam. When the follower is at its closest to the cam’s shaft, it is 3cm away. Use the degree line diagram to create a profile of the cam. Assume the cam rotates clockwise.

Degree line diagram

SOLUTION

STEP 1

Since the cam will be moving clockwise, we label degrees in the counterclockwise direction.

STEP 2

Since the follower is at its lowest point when it is 3cm from the shaft, we start by drawing a circle with a radius of 3cm. This is called the base circle.

When the follower is elevated by a certain amount, then we simply add that amount beyond the base circle to determine the location of the cam for that angle.

STEP 3

We can now start placing points on the graph lines. At angle zero (and angle 360), the elevation of the follower is zero. So we place our point zero cm above the base circle.

STEP 4

On the graph, at angle 30, the elevation is about 0.7cm (above the base circle). At angle 60, it is about 1.4cm and at angle 90, it is 2cm. We place those dots below.

STEP 5

We continue adding more dots all the way around the angled lines.

STEP 6

We now connect the dots to see the profile of the cam.

CONCLUSION

The cam looks like this: