Topic: Theory of Machines
A cam and oscillating follower mechanism is shown in the figure below. The Mobility of the mechanism is
- A. -1
- B. 0
- C. 1
- D. 2
Answer: C. 1
Explanation: The mechanism has 4 links: Ground (1), Cam (2), Follower (3), and Roller (4). It has 3 lower pairs (ground-cam, ground-follower, follower-roller) and 1 higher pair (cam-roller). Using Kutzbach criterion: F = 3(L-1) - 2J1 - J2 = 3(4-1) - 2(3) - 1 = 2. However, the rotation of the roller is a redundant degree of freedom that does not affect the input-output kinematic relationship. Thus, the effective mobility (functional degree of freedom) is 2 - 1 = 1.