1. THOERY OF MECHANISMS AND MACHINES
Module-10
CAMS
Instructed by:
Dr. Anupam Saxena
Associate Professor
Department of Mechanical Engineering
Indian Institute of Technology Kanpur
FB 361
Prepared by:
Abhishek Attal & Abhishek Sharma
Final Year Dual Degree Student
Department of Mechanical Engineering
Indian Institute of Technology Kanpur
NL312, FB369

2. M08- Recap Gears Terminology Gear Trains Simple Compound Epicyclic
12 Oct 2015
ME352A

3. Cam and Follower What are they? Why are they used?
A higher pair joint, with one driver and one follower
Why are they used?
To transmit complex coordinated periodic motions
Which one would be the driver?
Cam!
Which one would be driven?
Follower!
12 Oct 2015
ME352A

4. Classification of Followers
Radial Translating Follower
Offset Translating Follower
Oscillating Follower
Nature of contact surface
According to type of motion
Knife Edge Follower
Flat Face Follower
Roller Follower
Spherical Face Follower
12 Oct 2015
ME352A

5. Classification of Cams
Disk/Radial Cam
Wedge & Plate Cam
Cylindrical Cam
What would they look like?
Observe! Most of the followers you’ve seen will need a spring to maintain contact. But those who don’t need a spring are called positive acting cams. Can you think of an example?
12 Oct 2015
ME352A

6. Radial Cam Nomenclature
Traces motion of the follower
Smallest circle that can be drawn tangential to the pitch curve
Corresponding to point of maximum pressure angle, also decides the pitch circle
Angle between direction of follower movement & normal to the pitch curve at any point
Curve generated by trace point when we fix the cam (with reference to the cam)
Smallest circle that can be drawn tangential to the cam profile
12 Oct 2015
ME352A

7. Displacement Diagram (Introduction & Terminologies)
When follower moves away from cam centre
When follower moves towards cam centre
Maximum velocity pitch point
When follower is as calm as Buddha!
Minimum velocity pitch point
It plots follower displacement against cam rotation
12 Oct 2015
ME352A

8. Displacement Diagram (Introduction & Terminologies)q y y q x
12 Oct 2015
ME352A

9. Displacement Diagram (Introduction & Terminologies)q y y x
12 Oct 2015
ME352A

10. How to Design a Cam 12 Oct 2015 ME352A Desired Motion
Displacement Diagram
Cam Type & Features
Cam Profile
12 Oct 2015
ME352A

11. Constructing Displacement Diagram -Uniform Motion
Sharp edges, infinite acceleration!
NO!
Uniform motion! Uniform velocity! Straight line graph!
12 Oct 2015
ME352A

12. Constructing Displacement Diagram -SHM
L=5cm
ϴ=0
ϴ=130
12 Oct 2015
ME352A

13. Constructing Displacement Diagram -Parabolic (y = aϴ2) & Polynomials
L = 6cm
ϴ = 80
12 Oct 2015
ME352A

14. Hungry for MORE? Go ahead and watch this Dude:
[Seems like he got some money from Bentley to teach kinematics using MicroStation- an engineering software platform developed by the mammoth itself.]
12 Oct 2015
ME352A