Contents :-

Definition and function of clutches. Operation of clutch. Classification of clutch.

Definition :- A clutch is a mechanism which is used to

transmit the rotary motion from one shaft to another shaft , whose axis is coincident with first one.

The clutch is located between the engine and gear box .When the clutch is engaged , the power is transmitted from engine to rear wheels through transmission system , and the vehicle starts moving . On the other hand , when the clutch is disengaged , the power is not transmitted to the rear wheel so the vehicle stops moving.

Functions :- To permit proper engagement and

disengagement . To transmit smooth engine power to the wheels. To permit the shifting of gears without any

damage.

Working operation of clutch:-

The clutch principle is based on the friction.when the two frictional surfaces are brought in contact and pressed,then they are united.if one is revolved the other will also revolve.

When the driven member is brought in contact with driving member,it starts rotating.When separated it stops revolving.This is how a clutch operates.

Classification of clutches :-

The clutch are classified in two categories :- 1) Positive clutches. 2) Gradual engagement clutches.

Positive clutches:- In this the clutches are either “in” (fig. 1)

so that the two shafts are rigidly connected and must revolve at the same speed ; or it is “out”(fig.2) when the shafts are disconnected . It is not suitably used.

Gradual engagement clutch :-

In this type of clutch it is possible for one shaft to revolve , while other may be stationary or revolving at low speed. As the engagement occurs, the shafts are united and speed becomes equal . Such clutch is also known as “friction clutch”.

Types of gradual engagement clutch :-

Friction clutch :-A. Cone clutch.B. Single plate clutch.C. Multi plate clutch.

Other forms of clutch :-A. Centrifugal clutch.

Cone clutch :- The cone clutch is consist of a flywheel and a

cone mounted on driving and driven shaft respectively . The shape of side of flywheel facing cone is such to unite the cone readily when the clutch is engaged. The cone can be disengaged from flywheel by the lever mechanism.

1. Flywheel .2. Conical groove.3. Friction lining.4. Spring .5. Lever mechanism.

Single plate clutch :-

It is consist of flywheel connected to the engine or driving shaft and the driven shaft connected to transmission . Both are connected through the spigot bearing . During disengaged position the flywheel is free to rotate without linking the clutch plate , but when the pressure is applied through the lever mechanism , the clutch plate and flywheel are united and the transmission occurs.

Multi-plate clutch :- When a great amount of torque is to be transmitted instead of

single plate, a no of friction plates are used. This will increase the no of mating surfaces , hence it is called the “multi-plate clutch”.

These clutches are used in heavy commercial vehicles , racing cars , etc.

Centrifugal clutch :- In this type of clutch the centrifugal force instead

of spring force ,is used to keep it in engaged . Such type of clutch is operated automatically depending upon the engine speed . The vehicle can be started in any gear.

Thank you