This document provides an overview of clutches and their operation. It discusses the basic components and functions of clutches, including engaging and disengaging the transmission from the engine. It then describes different types of clutches in more detail, including single plate clutches, multi-plate clutches, and cone clutches. The key principles of how these clutches work to connect or disconnect power transmission are explained.

1. THEORY OF MACHINES
(DME 5201)
UNIVERSITY POLYTECHNIC
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MATHURA
LECTURE 9-12

2. MODULE -1_Lecture 9-12: Contents
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• Introduction to clutches and its working principle
• Single plate Clutch
• Multi-plate clutch
• Cone clutches

3. Introduction to clutches
• The transmission system takes power from engine-crankshaft and transmits it to the
wheels. While transmiting this power, it is required to continue or discontinue the
power transmission process by engaging and disengaging the transmission system to
engine crankshaft. This enganement and disengagement is performed by clutch.
• In short, the motion of the crankshaft is transmitted to the gearbox through the
clutch.
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4. • A Clutch is a mechanism used to connect or
disconnect the engine from the rest of the
transmission elements. It is located between the
engine and gearbox.
• During normal running and stationary position, it is
always in the engaged condition. The clutch is
disengaged when the driver processes the clutch
pedal. The clutch is disengaged for starting, changing
gears, stopping and idling.
• When the clutch is engaged, the engine will be
connected to the transmission, and power flows from
engine to rear wheels through a transmission system.
• When the clutch is disengaged by pressing the clutch
pedal, the engine will be disengaged from the
transmission. Thus, the power does not flow to rear
wheels while the engine is still running.
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Introduction to clutches continued...

5. • Consider twi plates, C and D are atteched to shafts A and B respectively with aim to transmit
motion from shaft A to Shaft B.
• In the figure (a), when there is a gap between plates C and D, there will be no motion
transmission.
• Now if small force F is appied to make plate D to connect with plate C, the motion of shaft A
starts transmitting to shaft B, because of frictionm between two plates C and D.
• This is how clutches work.
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Principal of Operation of Friction Clutch...
F

6. 1. To engage and disengage the transmission from engine to the remaining parts of the
transmission. This is required when:
(a) Starting and running the engine at a sufficiently high speed lo generate sufficient
power necessary for moving the vehicle from rest.
(b) Shifting the gears so that damage to gear teeth can be avoided.
(c) Stopping the vehicle after applying brakes.
2. The second function of the clutch is to allow the engine to take up the driving load of
the vehicle gradually and without shock.
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Functions of Clutch...

7. • It should be able to transmit the maximum torque of the engine.
• It should engage gradually to avoid sudden jerks.
• It should be able to dissipate a large amount of heat generated during clutch operation.
• It should be dynamically balanced, particularly in the case of high-speed engine clutches.
• It should have a suitable mechanism to damp vibrations and to eliminate noise produced during power
transmission.
• It should be as small as possible so that it will occupy minimum space.
• It should be easy to operate requiring as little exertion as possible on the part of the driver.
• It should be made as light as possible so that it will continue to rotate for any length of time after the clutch
has been disengaged.
• It must be trouble-free and have longer life.
• It must be easy to inspect, adjust, and repair.
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Requirements of Clutch

8. The materials for clutch lining are:
1. Leather
2. Cork
3. Fabric
4. Asbestos
5. Raybestos and Ferodo
6. Non- asbestos clutch lining material.
Necessity of clutch lining:
1. To transmit maximum power from engine flywheel transmission without jerk
2. To dissipate the heat and able to withstand higher heat generated
3. It should have a higher coefficient of friction
4. It should be cheap and easy to manufacture.
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9. Main parts of Clutch
• DRIVING MEMBER
– A flywheel which is mounted on the engine crankshaft.
– The flywheel is bolted to a cover which carries pressure plate, pressure springs, and release levers.
– As the flywheel is bolted to the cover assembly, thus, the entire assembly of the flywheel and the
cover rotate all the time.
– The clutch housing and cover provided with openings so that the heat produced during the function
dissipates easily
• DRIVEN MEMBER
– The driven members consist of a disc or plate called a clutch plate.
– The clutch is free to slide on the splines of the clutch shaft.
– It carries friction materials on both of its surfaces.
– When the clutch plate is gripped between the flywheel and the pressure plate, it rotates the clutch
shaft through splines.
• OPERATING MEMBER
– The operating member consists of a pedal or lever which can be pressed to disengage the driving and
driven plate.
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10. UNIVERSITY POLYTECHNIC,
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11. TYPES OF CLUTCH
ACCORDING TO METHOD OF TRANSMITTING TORQUE
1. Positive or Dog Clutch
2. Friction Cluch
I. Single Plate Clutch
II. Multiplate Clutch
III. Cone Clutch
IV. Diaphragm Clutch
3. Hydraulic Clutch
I. Fluid Coupling
II. Hydraulic Torque Convertor
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12. TYPES OF CLUTCH Continued..
ACCORDING TO METHOD OF ENGAGING FORCE
1. Spring type clutch
2. Centrifugal clutch
3. Semicentrifugal clutch
4. Electromagnetic clutch
ACCORDING TO METHOD OF CONTROL
1. Automatic Clutch
2. Manual Clutch
ACCORDING TO METHOD OF OPERATION
1. Cable operated clutch
2. Mechanical linkage operated clutch
3. Hydraulic operated clutch
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13. Single Plate Clutch
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• Single plate clutch is the most common type of
clutch plate used in automobiles.
• It consists only one clutch plate which is mounted
on the splines of the clutch plate and assembled to
the flywheel and rotates with it.
• All the parts and their arrangement id shown in the
line diagram.
• All the time the clutch plate remains in contact
with the flywheel. During gear shifting or starting
the vehicle force is applied on the pedal to
disengage the clutch plate from flywheel it results
interruption in power supply from engine to
transmission system of vehicle.
• When force from pedal is removed, the power
supply is continued to gearbox.

14. Multiplate Clutch
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• It is used in heavy vehicles and also in racing cars
but most commonly in scooters and bikes.
• It consists more than one clutch plate which is
mounted on the splines of the clutch plate and
assembled to the flywheel and rotates with it.
• All the parts and their arrangement id shown in
the line diagram.
• All the time the clutch plate remains in contact
with the flywheel. During gear shifting or starting
the vehicle force is applied on the pedal to
disengage the clutch plate from flywheel it results
interruption in power supply from engine to
transmission system of vehicle.
• When force from pedal is removed, the power
supply is continued to gearbox.

15. Cone Clutch
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• Cone clutch consists of friction surfaces in the
form of a cone.
• The engine shaft consists of the female cone.
• The male cone is mounted on the splined
clutch shaft. It has friction surfaces on the
conical portion.
• The male cone can slide on the clutch shaft.
When the clutch is engaged, the friction
surfaces of the male cone are in contact with
that of the female cone due to force of the
spring. When the clutch pedal is pressed, the
male cone slides against the spring force, and
the clutch is disengaged.