A7018

PART 13
Answer any threefull questions, each carries 1 Omarks.

5 Explain any three types of centrifugal governors with the help of neat figures (10) 6 Arrive at the

condition for the vehicle's stabilityby considering the effect of (10) gyroscopic couple and centrifugal

couple for an automobile taking a turn

7 a) Explain the turning moment diagram of a multi cylinder engine. (3) b) The turning moment
diagram for a petol engine is drawn to a vertical scale of I (7) mm— 500Nm and a horizontal
scale of Imm = 3°. The turning moment diagram repeats itself after every half revolution of
the crankshaft. The areas above and below the mean torque line are 260, -580, 80, -380, 870
and -250 17022. The rotating parts have a mass of 55 kd and radius of gyration of 2.1 m. If
engine speed is 1600 rpm, determine the coefficient of fluctuation of speed.

8 a) How inertia governors are different from centrifugal governors. Comment (5) b) Comment
on the following terms: (2)

i) Sensitiveness of governor ii) Hunting
c) It is stated that a governor can have the same equilibrium speed for all the positions (3)
of sleeve or balls. Comment on this particular condition.
PART ^
Answer anyfourfull questions, each carries 1 Omarks.

9 Derive the expression to calculate the path of contact and arc of contact for gear (10) teeth
with involute profile.

10 An epicyclic gear train consists of an arm and two gears A and B having 30 and 40 (10) teeth
respectively. The arm rotates about the of the gear A at a speed of 80 rpm counter clockwise.
Determine the speed of the gear B if-

i) The gear A is fixed.
ii) The gear A revolves at 240 rpm clockwise instead of being fLxed.

11 a) State and prove the law to maintain a constant angular velocity ratio between two (7) gears.

b) What is meant by undercutting in gears? (3)

12 Draw iile profile of a cam operating a knife-edge follower having a lift of 30 mm. (10) The
cam raises the follower with S}-nvT for 150° of the rotation followed by a period of dwell for
609 . The follower descends for the next 100 ° rotation of 41௦ cam with uniform velocity, again
followed by a dwell period. The cam rotates at a uniform velocity of 120 rpm and has a least
radius of 20 mm. What will be the maxunum velocity and acceleration of the follower during
the lift and the return?

13 Detail the classification of cams according to their shape witl the help of neat (10) figures.

14 a) Explain the different terms and definitions regarding a cam with roller follower (7) with the
help of a neat figure.

b) Explain the classification of follower according to location of line of movement. (3)