A clutch connects and disconnects an engine's drive to a vehicle's transmission system. It allows for temporary separation of the drive between the drive source and driven mechanisms. The clutch system includes a flywheel, clutch plate, pressure plate assembly, release bearing, and clutch fork. When the clutch pedal is depressed, hydraulic pressure is applied to disengage the clutch plate from the flywheel, disconnecting the engine from the transmission. Common clutch types include single plate used in most vehicles, cone clutches previously used but now only for racing, and multi-plate clutches used in racing and automatic transmissions.

1. Clutches

2. Definition
A clutch is a mechanism for connecting and disconnecting an engine
drive and the transmission system in a vehicle, or the working parts of
any machine.
It allows a temporary separation of drive between drive source and
driven mechanisms.
When engaged this will allow for a smooth take up of drive as the
clutch is gradually engaged.

3. Clutch Action
next
 Drive disc attached to
engine
 Clutch action can be
demonstrated by two
discs
 Driven disc disconnected,
no drive
Drive Disc
Driven Disc
Input Shaft to
Transmission
Engine
 Driven disc attached to
transmission input shaft
 Driven disc in contact with
drive disc, drive applied

5. Clutch System Parts
 Clutch housing protects
clutch components from
outside elements
 Clutch system consists of:
next
Flywheel
Clutch Plate
Pressure Plate Assembly
Release Bearing
Clutch Fork
Flywheel
Clutch Plate
Pressure Plate
Assembly
Release Bearing
Clutch Fork
Clutch Housing
Clutch
Housing

6. Clutch System Parts - Clutch Plate - 1
next
 Splines mesh with
input shaft
 Located between flywheel
and pressure plate
 Frictional material riveted
to cushion springs on
either side of friction ring
Rivets
Friction
Material
Splined Hub
Friction
Ring
Cushion
Springs

7. Clutch System Parts - Clutch Plate - 2
next
 Cushioning springs cushion
force as pressure plate pushes
clutch plate onto flywheel
 Torsional springs soften load
applied to clutch plate as it
begins to turn
Torsional
Spring
Cushion
Springs
Cushion
Springs

8. Clutch Operating Mechanisms - Hydraulic
 Pipe connected between
foot pedal and clutch fork
 As foot pedal released,
springs return system to
rest position
end
 Two cylinders: master
cylinder and slave cylinder
 As foot pedal depressed,
master cylinder builds
pressure in system, slave
cylinder activated
Pipe
Master
Cylinder
Slave
Cylinder

10. Clutch Types & Applications
1. Single Plate clutch is used in almost all motor vehicles where
manual transmission takes place
2. Cone clutch was used in some automobiles in the past, but now is
restricted to racing / rally car & power boats
3. Centrifugal clutch is used on a petrol powered lawn mower-as the
lawn mower is revved at a higher speed, the centrifugal force
spreads the clutch shoes apart so the clutch mechanism engages
4. Multi Plate clutches are used in extreme car racing and in
automatic gearboxes.

11. Flat Plate Clutch

12. Driving
shaft
Driven
shaft
Friction
lining
α
The maximum torque transmitted =
α = semi-apex angle of
the cone
Only one pair of driving
surfaces is possible, n =1
Cone clutch
T = μWrm cosecα
w

13. Centrifugal clutch
Driving
shaft
Driven
shaft
Friction lining
https://www.youtube.com/watch?v=qMj_UxfmJ68

14. In a multi plate clutch, the torque is transmitted by friction between
several pairs of co-axial annular driving faces maintained in contact
by an axial thrust.
Both sides of each plate are lined with friction material, so that a
single-plate clutch has two pairs of driving faces in contact.
The advantages of using these types of clutch are due to the frictional
surface area used, a lesser diameter clutch plate can be used thus
less space is used.
Multi plate clutches

15. driver driven
Pressure plates
Friction plates
https://www.youtube.com/watch?v=TcYsV063lk8
2
1 4
3 6
5
Multi plate clutch