The motion of one cycle of a knife edge follower is given in

The motion of one cycle of a knife edge follower is given in table 1. The rotational speed is 4 Hz (rev/sec). Find the displacement and velocity of the follower after the cam has routed 162 degrees from the 0 degree position. Find the dwell time and rise time in seconds What is the time for one complete rotation? What will be time for one complete rotation if roller follower is replaced by roller follower (diameter of roller 1 cm). Find the displacement and velocity of the follower after the cam has rotated 360 degrees from the 0 degree position.

Solution

GIVEN:- ROTATIONAL SPEED OF CAM W = 4 Hz (rev/sec) and the values mentioned in the table

SOLUTION:-

(a) The CAM speed is W=4Hz, so time taken (T) by the CAM to complete 1 rev = 360 degree = 0.25 sec.

The dwell time of the follower is in the range from 160 to 200 degree, which means there is no linear displacement of the follower during this degree range.

So the displacement of the follower will be that upto 160 degree of CAM i.e. = 4 cm rise (ANSWER) and since displacement at 162 degrees is zero cm, so velocity = 0 (ANSWER)

(b) Dwelling degree is from 160 to 200 degrees, so based on T = 0.25 secs, dwelling time of the follower is given as follows Dwell time td = (200-160) x 0.25 / 360 = 0.027 = approx 0.03 secs (ANSWER)

Similarly, rise time tr = (160-0) x 0.25 / 360 = 0.11 secs (ANSWER)

(c) Time taken for 1 complete rotation of the CAM as computed earlier in part-a = T = 0.25 secs (ANSWER)

(d) Changing the follower type to roller follower will not impact the rotation time of the CAM, hence the period i.e. T remains the same i.e. T = 0.25 secs (ANSWER)

(e) Displacement d of the follower immediatly after 360 degree will be 0 cm (For roller follower) (ANSWER)

Linear velocity of the roller follower = 0/0 = 0 (ANSWER)