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Explain with neat sketch compound type Gear Train. Derive the equation for velocity ratio of gear train. Write it's application.

Compound Gear Train:
When there are more than one gear on a shaft, as shown in Fig. , it is called a compound
train of gear. In a simple train of gears do not affect the speed ratio of the system. But these gears
are useful in bridging over the space between the driver and the driven.
Gear trains inside a mechanical watch
But whenever the distance between the driver and the driven or follower has to be bridged
over by intermediate gears and at the same time a great ( or much less ) speed ratio is required,

Define following terms (i) (ii) (iii) (iv) (v) (vi) Kinematic link Kinematic pair Kinematic chain Mechanism Machine Inversion

(i) Kinematic link: Each part of a machine, which moves relative to some other part, is known as a
kinematic link.
(ii) Kinematic pair: The two links or elements of a machine, when in contact with each other, are said to
form a pair. If the relative motion between them is completely or successfully constrained (i.e. in a
definite direction), the pair is known as kinematic pair.
(iii) Kinematic chain: When the kinematic pairs are coupled in such a way that the last link is joined to the

Draw and explain the turning moment diagram of 4-stroke I.C. Engine.

A turning moment diagram for a four stroke cycle internal combustion engine is shown. We know
that in a four stroke cycle internal combustion engine, there is one working stroke after the crank
has turned through two revolutions, i.e. 720° (or 4 ð radians). Turning moment diagram for a four
stroke cycle internal combustion engine.
Since the pressure inside the engine cylinder is less than the atmospheric pressure during
the suction stroke, therefore a negative loop is formed as shown in Fig. During the compression

Write the classification of follower (i) As per shape (ii) As per motion. Draw sketch of any one follower.

Classification of follower:
i) As per shape:

Knife-edge follower: When the contacting end of the follower has a sharp knife edge, it is
called a knife edge follower.
• Roller follower: When the contacting end of the follower is a roller, it is called a roller follower.
• Flat faced or mushroom follower: When the contacting end of the follower is a perfectly flat
face, it is called a flat faced follower and when the flat faced follower is circular, it is then called a
mushroom follower.

Write any two functions and applications of clutch.

Functions of clutch:
i) A clutch is a device used to transmit rotary motion of one shaft to the other shaft when desired.
ii) A clutch is a device used for engaging and disengaging the engine crank shaft instantaneously
when desired by the driver.

Differentiate between mechanism and machine.

Difference between Mechanism & machine

Primary function is used to transmit or
modify the motion.
It is not used to transmit the force.
A mechanism is a single system to
transfer the motion
eg.i) In watch, energy stored on winding
the spring is used to move hands.
ii) An indicator is used to draw P-V
diagram of engine


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