This document discusses cams and their classification. It defines a cam as a machine element that converts rotary motion into reciprocating or oscillating motion via direct contact with a follower. Cams are classified based on the follower motion, cam shape, and follower constraint. Examples of classifications include knife edge, roller, and flat faced followers; dwell-rise-dwell-return-dwell, cylindrical, and globoidal cam shapes; and pre-loaded spring, positive-drive, and gravity cam constraints. Key cam terminology is also defined, such as cam profile, base circle, pitch curve, pressure angle, pitch point, and pitch circle.

1. GURUMURTHY M
ASSISTANT PROFESSOR

2. CAMS

3. CAM - Definition
Cam is a mechanical member or machine element used to convert rotary
motion into reciprocating or oscillating motion to a follower by means of
direct contact.

4. Examples for cam (Applications)
• In IC engines to operate the inlet and
exhaust valves

5. Classification of followers
• Knife edge follower
• Roller follower
• Flat faced follower
• Spherical faced follower
a. According to the surface in contact or shape of
follower

6. a) Knife edge follower

7. b) Roller follower

8. c) Flat faced follower

9. d) Spherical faced follower

10. According to the motion or movement of the
follower
a. Translation or Reciprocating follower
b. Oscillation or Oscillating follower

11. c. According to the path of motion of follower
a) Radial follower
b) Offset follower

12. a) Radial follower
• When the motion of the follower is along an axis passing
through the centre of the cam, it is known as radial followers.
Above figures are examples of this type.

13. b) Offset follower
When the motion of the follower is along an axis away from
the axis of the cam centre, it is called off-set follower. Above
figures are examples of this type.

14. CAMS
BY
Gurumurthy M
Assistant Professor
Jyothy Institute of Technology

15. Classification of CAM
a. According to the type of follower motion
b. According to the shape of cam
c. According to the manner of constraint of the follower

16. According to the type of follower motion
a. Dwell- Rise- Dwell- Return- Dwell [D-R-D-R-D]

18. b. Dwell- Rise- Return- Dwell [D-R-R-D] Cam

19. Rise-Return-Rise Cam [R-R-R]

20. According to the shape of cam
• Wedge or Flat
• Radial
• Cylindrical or Drum
• Globoidal
• Spherical
• Conjugate
• Spiral

21. Wedge or Flat

22. Radial or Disc Yoke Cam

23. Cylindrical or Drum

24. Globoidal Cams

25. Spherical

26. Conjugate
Conjugate cams also called dual cams or double disc cam that are bolted
together. Because of the 2 rollers always in contact with the double disc cam the
follower makes less noise and has better control at high speed.
Application: Shaft motion carpet weaving machines

27. Spiral

28. According to the manner of constraint of the
follower
• Pre-loaded Spring Cam
• Positive-drive Cam
• Gravity Cam

29. Pre-loaded Spring Cam

30. Positive-drive Cam

31. Gravity Cam

32. 2. CAM Nomenclature
• 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.
Prime circle

33. CAM Nomenclature
• 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
Prime circle

34. CAM Nomenclature
• 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.
Prime circle

35. CAM Nomenclature
• 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
Prime circle