1. Cams
Cams are used to convert rotary motion to oscillatory motion (almost always) or oscillatory motion to rotary motion (rarely)
For high speed applications – example, internal combustion engines
Objectives of this chapter:
Learn fundamental concepts and terminology
Learn how to design a cam and follower set to achieve a desired output motion.

2. Cam types
Plate cam
Wedge cam
Barrel cam
Face cam  y

3. Cam and Follower
The cam and follower is a device which can convert rotary motion (circular motion) into linear motion (movement in a straight line).
Cam
Follower
Cams
Followers (valves)

4. Cam and Follower follower Cam Pear Heart Circular Drop
The cam can have various shapes. These are know as cam profiles.
Cam
Pear
Heart
Circular
Drop

5. Cam and Follower Follower cam Knife edge Follower Flat foot follower
A follower is a component which is designed to move up and down as it follows the edge of the cam.
cam
Knife edge
Follower
Flat foot
follower
Off set
follower
Roller
follower

6. Cam and Follower Follower Square cam
The 'bumps' on a cam are called lobes.
The square cam illustrated has four lobes, and lifts the follower four times each revolution.
Follower
Square cam
Examples of other rotary cam profiles.

7. Cam and Follower Examples of a Rotary cams in operation.
Cams used in a pump.
Control the movement of the engine valves.

8. Cam and Follower Linear cam Distance moved by the follower
The linear cam moves backwards and forwards in a reciprocating motion.
Cam Follower
Linear cam
Distance moved by the follower

9. Cam and Follower Cams can also be cylindrical in shape
Below a cylindrical cam and roller follower.
Cam rise and Fall
Max Lift
Min Lift
The cam follower does not have to move up and down - it can be an oscillating lever as shown above.  

10. Followers
Knife-edge
Flat-face
Roller
Sperical-face

11. Displacement diagrams
Cam-follower: usually 1-DOF system y
rise
dwell
return
dwell 

12. Displacement diagram types
Uniform motion,
Constant velocity
Problem: infinity acceleration at point where dwell portion starts
Parabolic-uniform
Can be shown that acceleration is constant
Sinusoidal (simple harmonic motion)
Cycloidal

13. Cycloidal displacement diagram

14. Graphical layout of cam profiles
Terminology
Trace point: on follower; point of fictitious knife-edge follower. Center of roller, surface of flat-faced follower.
Pitch curve
Locus generated by trace point as follower moves relative to cam
Prime circle
Smallest circle that can be drawn with center at the cam rotation axis and is tangent to the pitch circle
Base circle
Smallest circle centered on cam rotation axis and is tangent to the cam surface

15. Layout of cam profile: roller follower

16. Constructing cam profile: kinematic inversion principle
Consider that cam is stationary and that follower rotates in the opposite direction than the cam does in reality

19. SVAJ diagrams: show displacement, velocity, acceleration versus 