ofrotation and velocity of precession of the rotational
axis op.

b) An aeroplane flying at 200 km/h turns towards the left and

10

11

12

completes a quarter (6) circle of 50m radius. The mass of
the rotary engine and the propeller of the plane is 450 kg
with a radius of gyration of 320 mm. The engine speed is
2000 rpm clockwise when viewed from the rear. Determine the
gyroscopic couple on the

aircraft and state its effect.
Turning moment diagram for a petrol engine is drawn to the following scales: (10) turning
moment, I mm = 5 Nm, crank angle Imm = I'. The turning moment diagram repeats itself at
every half revolution of the engine and the area of above and below the mean turning moment
line taken in order are 295, 685,40, 340, 960,
270 mm. The rotating parts are equivalent to a mass of 36 kg at a radius of gyration
of 150mrn. Determine the coefficient of fluctuation of speed when the engne runs at
1800 rpm.
a) Derive an expression for the energy stored in a flywheel. (7) b) Explain and derive an
expression for the coefficient of fluctuation of speed of a (3) flywheel in tenns ofboth angular
and linear speeds.
PART ^

Answer anyfourfull questions, each carries 10 marks
The cam follov,a mechanism is used to Yansmit motion by direct contact. How (10) are
followers classified according to their shape, movement and location of line of movement?
Explain each with the help of simple figures.
Draw the profile of the cam with edge follower. The cam lifts the follower (10) for 120°with
SYLI followed by a dwell period of 40'. Then the follower lowers down during 150° of the
cam rotation witl uniform acceleration and deceleraaon followed by dwell period. Given that
the minimum radius of the carn is 25 mm, lift is 30rn_m. If the cam rotates at a uniform
speed of 150 rpm calculate the maximum velocity and accelffaiion of the follower during
the descent period.
A cam with a radial roller follower Imparts the following motion to the follower (10) To
raise the follower 30 mm with uniform acceleration and deceleration during the 120' rotation
of the cam. Dwell for the next 30' of cam rotation md to lower the follower with simple
harmonic motion during the next 100° rotation of the cam and dwell for rest of the cam
rotation.
The cam has a minimum radius of 30 mm and rotates in the clockwise direction at uniform
speed of 800 rpm. The roller diuneter is 14mm.
a) What do you mean by pitch circle of a gear? (2) b) Define module in a gear. Can two gear
of different modules mesh? (2)

c) What is contact ratio in the context of gears? What is its significance? (2) d) State and explain

the law of geartng. (4) 13 a) What are the different types of gear trains? (2) b) An epicyclic
gear train as shown in figure has 100 teeth on A and 250 teeth on B. (8) Determine the speed
of arm ‘a’, if A rotates at 100 rpm clockwise and B at 50 rpm counter clockwise.

ra

14 a) Define add
help of a diagram. (4)