Introduction to clutches, types of clutches and its instruction.

1. Gandhinagar Institute of Technology
A presentation on subject of
Theory Of Machines
&
Topic is
“Types of Clutches”

2. Content……..
• Introduction to Clutches
• Types of Clutches
• Positive clutches
• Friction clutches
• Plate Clutch
• Cone clutch
• Centrifugal clutch

3. Introduction…..
• The clutch is mechanical device used to connect or disconnect the
driven shaft from the driving shaft at the will of the operator while the
power is transmitted from driving to driven shaft.
• It is mounted between driving and driven shaft and power is
transmitted from one to another shaft which is required to be started
and stop frequently.
• In automobiles, where vehicle can be stopped for a while or to change
the gear, the requirement is that the driven shaft should stop but engine
should run naturally under the no load condition.
• It is achieved by using shaft and lever engine shaft and gearbox shaft.

4. Types of clutches……
Types of
clutches
Positive clutch Friction clutch
Plate or disc clutch
Single plate
clutch
Multiplate clutch
Cone clutch Centrifugal clutch

5. Positive Clutch……
• When positive drive is required this type of
clutch is used.
• Jaw clutch is simplest type of clutch and
transmit the torque from one to another
shaft.
• It consist of two segment. One of which
permanently fastened to driving shaft and
other is free to slide axially.
• This arrangement permits it to engage and
disengage.
• Square shaped jaw can transmit the power
in two direction where spiral shaped jaw
can transmit the power in single direction.

6. • Spiral shape jaw used when occasionally engagement and disengagement
is required.
• Gear tooth shaped jaw have better engagement and disengagement as
compare to square jaw.
• Some plus points:-
 They do not slip.
 No heat generated at the surface of clutch during engagement.
• Some negative marks:-
 Shock & noise are there during engagement in motion. And can not be
engaged at high speed & sometimes can’t engaged at rest if the jaws
are not aligned.
• Application:-
 Power presses, punches and some machine tools.

7. Friction Clutch……..
• They transmit the torque by the help of
frictional force developed. It consist of
two plates.
• One of them is fixed with driving shaft
and other is free to slide axially on the
driven splined shaft.
• The compression spring used to hold the
plates together and it will produce the
friction between them.
• Torque is transmitted from driving to
driven shaft due to the friction between the
two plates.

8. • Slip may be occur in these type of clutches.
• They can be mounted while the driving shaft is rotating and driven
shaft is stationary.
• If the frequent engagement and disengagement is required this type of
clutch may be used.
• Advantages:-
• Frequent engagement and disengagement is possible.
• It can transmit partial or full power.
• Ease to operate.
• Limitations:-
• They do not give positive engagement.
• Due to slip between contacting surface, heat is generated during
engagement.

9. Single plate or dry Clutch…….
• It consist of pressure plate, friction plate,
driving shaft splined hub and brash bush.
• Driving plate includes pressure plate on the
other hand driven plate has friction plate.
• Friction plate has ring of friction material
and it is attached with hub which is free to
slide axially on driven shaft and rotate with
driven shaft.
• Spring is placed between pressure plate and
cover. Brass bush is press fitted inside
pressure plate so it can rotate freely.

10. • When the clutch paddle is pressed, the disengagement sleeve moves
to the right and the clutch is disengaged. In this condition, there is no
axial force between friction plate and pressure plate.
• And when the paddle is released, it moves to left and engaged with the
driven shaft. And the torque is transmitted due to friction between
friction plate and the pressure plate.
• The engagement and disengagement is done by foot peddle.
• It is used when the radial distance is large. So, the more area is
available to heat transfer which is produced at the contact area of
plates.
• So, no cooling oil is required. This is why it is known as Dry
Clutches.
• They are used in buses, trucks and etc due to large radial space.

11. Multiplate Clutch……..
• It consist of two sets of plates in which
driving and driven plates are arranged
alternatively. So contacting surface is
more.
• Friction plates are mounted on their
outer circumference and engaged with
corresponding spline on the casing.
• Friction plate having friction rings on
both the side except the first plate near
to the casing.
• Pressure plates are mounted on their
inner circumference. And engaged with
driven shaft.

12. • Both friction plates and pressure plates are free to move axially.
• When the clutch peddle is pressed, the sleeve moves to right and the
clutch is disengaged.
• No axial force is developed between friction and pressure plate.
• When peddle is released, the clutch is engaged because the sleeve
moves left.
• Compression due to spring press the pressure plate to come in contact
with friction plate. And torque is transmitted due to friction.
• The capacity of the clutch of transmission of the torque is more due to
more number of plates.
• It is used in cars, scooters, motor cycles because of the small radial
distance and where the large torque is required.

13. Cone Clutch……
• It consist of driving shaft, driven shaft, outer
cone or cup, inner cone and helical spring.
• The cup is keyed on driving shaft and cone is
free to move axially on driven shaft.
• To engage the clutch axial force is provided
by helical spring.
• Clutch is disengaged by means of fork fitted
in shifting collar or grooves.
• The outer surface of cone consist of leather,
cork or asbestos is used as friction material.
It has high capacity to transmit the torque for
smaller distance compared to plate clutches.

14. Centrifugal Clutch……
• It works on the principle of centrifugal force
which is increase with increase in the speed.
• It consist of spider having radial guide,
sliding shoes, helical tension spring and drum.
• The spider has four equi-spaced radial guides
keyed to the driving shaft. Sliding shoes can
slide radially in guides.
• These shoes are covered with the frictional
material. These shoes are held against spider
on driving shaft by helical tension spring.
• All these assembly is covered by coaxial
drum mounted on driven shaft.

15. • The shoes exerts radially outward centrifugal force. And the
magnitude is directly proportional to square of angular speed.
• As speed increases, shoes start moving outward on which radial
inward spring force is applied.
• When the speed is slow, the CF is less than the radial inward spring
force. There is no contact between shoe friction lining and drum
• When the two forces are become equal the shoe start floating and there
is just contact between them.
• When speed further increases the CF will be grater than spring force
and shoe is pressed against inside surface of drum.
• The torque is transmitted due to the friction between shoe lining and
inside surface of drum.
• Therefore with increasing in speed, the torque transmitting capacity of
these clutches increase.

16. THANK YOU