1. CAM MACHINE ELEMENT Prepared by R.A.ARUL RAJA, ASSISTANT PROFESSOR,
SRM UNIVERSITY.

2. OPERATION OF CAM

4. CAM SHAFT OF I.C ENGINE

5. Type of cam rod

6. CAMS
A CAM IS A MACHINE ELEMENT HAVING A CURVED OUTLINE WHICH BY ITS ROTATION MOTION GIVES A PREDETERMINED SPECIFIED MOTION TO ANOTHER ELEMENT CALLED FOLLOWER.
IN OTHER WORDS CAMS ARE USED TO CONVERT ROTARY MOTION INTO RECIPROCATING MOTION.

7. APPLICATIONS
Used to operate the inlet and exhaust valves of I.C engines
Feed mechanism of automatic lathes
In spinning and weaving textile machineries
In paper cutting machines.

8. CLASSIFICATION OF CAMS
Disc or radial cams
Grooved or closed cam
Cylindrical or Barrel cam
End cam

9. Disc or radial cams
In radial cams the follower reciprocates or oscillates in the direction perpendicular to the cam axis.

10. Grooved or closed cam
This is a plate cam in which the follower moves in a groove in the face of the cam

11. Cylindrical or Barrel cam
In cylindrical cams the follower reciprocates in the direction parallel to the cam axis. The follower rides in a groove at its cylindrical surface.
In cylindrical cams the follower reciprocates in the direction parallel to the cam axis. The follower rides in a groove at its cylindrical surface.

12. End cam

13. END CAM
It is also similar to cylindrical cams, but the follower makes contact at periphery of the cam as shown in fig. This cam is rarely used because of its cost and the difficulty in cutting its contour.
END CAM

14. TYPES OF FOLLOWERS According to the surface in contact
1) Knife edge follower
2) Roller follower
3) flat faced follower
4) Spherical faced follower
b) According to the motion of the follower
1) Reciprocating or translating follower

15. b) According to the motion of the follower 1) Reciprocating or translating follower 2)Oscillating follower
c) According to the path of motion of the follower 1)Radial follower 2)Off-set follower

16. KNIFE EDGE FOLLOWER
If the contacting end of the follower has a sharp edge it is called knife edge follower
If the contacting end of the follower has a sharp edge it is called knife edge follower

17. ROLLER FOLLOWER
If the contacting end of the follower is a roller it is called as roller follower

18. FLAT FACED FOLLOWER

19. SPHERICAL FACED FOLLOWER

20. RECIRROCATING FOLLOWERS

21. OSCILATING FOLLOWER

22. RADIAL FOLLOWER

23. OFF SET FOLLOWER
If the motion of the follower is along an axis away from the axis of the cam it is called as offset follower.

24. 2. CAM Nomenclature

25. Cam profile: The outer surface of the disc cam.
Base circle : The circle with the shortest radius from the cam center to any part of the cam profile.
Trace point: It is a point on the follower, and its motion describes the movement of the follower. It is used to generate the pitch curve.

26. Pitch curve : The path generated by the trace point as the follower is rotated about a stationery cam.
Prime circle: The smallest circle from the cam center through the pitch curve
Pressure angle: The angle between the direction of the follower movement and the normal to the pitch curve.
Pitch point: Pitch point corresponds to the point of maximum pressure angle.

27. Pitch circle: A circle drawn from the cam center and passes through the pitch point is called Pitch circle.
Stroke: The greatest distance or angle through which the follower moves or rotates

28. Motion of the follower
As the cam rotates the follower moves upward and downward.
The upward movement of follower is called rise (Out stroke)
The downward movement is called fall (Return stroke).
When the follower is not moving upward and downward even when the cam rotates, it is called dwell.

29. a) Uniform motion (constant velocity)
Displacement diagram
Since the follower moves with uniform velocity during its rise and fall, the slope of the displacement curve must be constant as shown in fig

30. b) Simple harmonic motion

31. c) Uniform acceleration and retardation

32. Since the acceleration and retardation are uniform, therefore the velocity varies directly with time.

33. CAM Profile

34. THANK YOU