1. Mechanisms Design MECN 4110
Professor: Dr. Omar E. Meza Castillo
Department of Mechanical Engineering
Inter American University of Puerto Rico
Bayamon Campus

2. Tentative Lectures Schedule
Topic
Lecture
Introduction of Mechanism and Kinematics
1, 2 and 3
Position Analysis 4
Velocity Analysis 5
Acceleration Analysis 6
CAMS 7

3. Topic: CAMs Cam and Follower
One thing you learn in science is that there is no perfect answer, no perfect measure.
A. O. Beckman
Topic: CAMs
Cam and Follower

4. Up on completion of this chapter, the student will be able to
Chapters Objectives
Up on completion of this chapter, the student will be able to
Understand how to design a CAM-FOLLOWER Systems.

6. Cam
Follower

7. Cam
A cam is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion or vice versa. It is often a part of a rotating wheel (eg. an eccentric wheel) or shaft (eg a cylinder with an irregular shape) that strikes a lever at one or more points on its circular path. The cam can be a simple tooth, as is used to deliver pulses of power to a steam hammer, for example, or an eccentric disc or other shape that produces a smooth reciprocating (back and forth) motion in the follower which is a lever making contact with the cam.
The reason the cam acts as a lever is because the hole is not directly in the centre, therefore moving the cam rather than just spinning. On the other hand, some cams are made with a hole exactly in the centre and their sides act as cams to move the levers touching them to move up and down or to go back and forth.

8. Design of Cam Systems
The first stage in designing a cam system is the creation of a displacement diagram. A typical plate cam with an in-line roller follower is shown below with a displacement diagram. This figure shows the following characteristic features.
Rise- This is when the follower is moving away from the cam centre. The slope reflects the follower velocity.
Dwell- the is the period when the follower is stationary
Return - This is when the follower moves back towards the cam centre
Base circle on the cam is the smallest full diameter of the cam
Prime circle is centered on the cam rotation centre with radius at the follower roller centre when the follower is on the base circle
Cam profile is the shaped surface of the cam defining the follower motion

10. Cam Design

11. Types of Cams

12. Types of Joint Closers (cam/follower joint)

13. Follower Motion

14. Types of Followers

15. Obtaining the S Diagram

16. Unwrapping/Linearizing a Cam

17. Unwrapping/Linearizing a Cam

18. The S Diagram

19. Why S Diagram Cannot Have Negative Values
New

20. SVAJ Diagram

21. SVAJ Diagram

22. SVAJ Diagram

23. SVAJ Diagram

24. SVAJ Diagram

25. Type of Motion Constraints

26. RDFD = rise-dwell-fall-dwell
Type of Motion Program
RF = rise-fall
RFD = rise-fall-dwell
RDFD = rise-dwell-fall-dwell

27. Double-Dwell Cam Design- Choosing SVAJ Functions

28. How Not Meet Cam Design Specifications (Linear Function)

29. SVAJ Diagram

30. SVAJ Diagram

31. Cycloidal Motion

32. Cycloidal Motion – SVAJ Diagram

33. a Diagram

34. v Diagram

35. s Diagram

36. Cycloidal Displacement Function

37. Polynomial Function

38. Polynomial Function

39. Polynomial Function

40. SVAJ Diagram

41. Polynomial Function

42. Polynomial Function

43. Polynomial Function

44. Polynomial Function

45. Double Dwell Cam Design

46. Double Dwell Cam Design

47. Double Dwell Cam Design

48. Double Dwell Cam Design

49. Double Dwell Cam Design

50. Single Dwell Cam Design

51. Single Dwell Cam Design

52. Single Dwell Cam Design

53. Single Dwell Cam Design

54. Single Dwell Cam Design

55. Single Dwell Cam Design

56. Homework7  Web
Omar E. Meza Castillo Ph.D.