Frictional clutch

BY :
CHANDRESH SUTHAR ,
MANAV SONANI,
GOVIND TADE

1. GANDHINAGAR INSTITUTE OF
TECHNOLOGY


THEORY OF MACHINES (2151902)
Active Learning Assignment
On
MECHANICAL DEPARTMENT
FRICTIONAL CLUCHES
PREPAIRED BY:

MANAV SONANI
(140120119223)
CHANDRESH SUTHAR (140120119229)
GOVIND TADE
(140120119230)
GUIDED BY:
PROF. VIPAL PANCHAL

2. CONTENT
•Introduction to clutch
•Types of clutch
•Disc clutch
Single plate clutch
Multi plate clutch
•Cone clutch
•Centrifugal clutch

3. WHAT IS CLUTCHES ?
•A Clutch is a mechanical device that engages and disengages the
power transmission , especially from driving shaft to driven shaft.
•In the simplest application, clutches connect and disconnect two
rotating shafts (drive shafts or line shafts). In these devices, one
shaft is typically attached to an engine or other power unit (the
driving member) while the other shaft (the driven member) provides
output power for work.

4. TYPES OF CLUTCHES
1)Mechanical clutches
2)Pneumatic clutches
3)Hydraulic clutches
4)Electromagnetic clutches
Mechanical clutches
1)Positive contact clutches
i. jaw clutches
ii.toothed clutches
2)Friction clutches
Disc clutches
• Single plate clutches
• Multi plate clutches
Cone clutches
Centrifugal clutches

6. SINGLE PLATE CLUTCH

7.  USED IN CARS AND LIGHT VEHICLES.
 IT HAS ONLY ONE CLUTCH PLATE WHICH IS MOUNTED ON
THE SPLINES OF THE CLUTCH SHAFT.
WHEN CLUTCH IS IN ENGAGED POSITION, THE CLUTCH
PLATE REMAINS GRIPPED BETWEEN FLYWHEEL AND
PRESSURE PLATE. FRICTION LININGS ARE PROVIDED ON BOTH
THE SIDES OF CLUTCH PLATE.

8. Single Plate Clutch
•W=total axial load
•R1=External radius of clutch plate
•R2=internal radius of the clutch plate
•P=intensity of pressure between contacting surfaces.
•µ=coefficient of friction between contacting surfaces
1
R
1
R

9. Single Plate Clutch
•Consider a elemental ring of radius ‘r’ and
thickness δr on the contacting surface.
therefore,
•Area of the ring on contacting surface is,
•Axial load on the ring is,
δW=pressure×Area of the ring
δrr 2πpδW ´=

10. Single Plate Clutch
•Frictional resistance offered by ring is,
•Frictional torque acting on the ring is,
δWμ F
r
=
δrr pμ 2πδr)r 2π μ(pF
r ==
r
2
r
rr
δr pμ 2πδr.rr pμ 2πT
r FT
==
=

11. Single Plate Clutch
•Torque transmitted by single plate clutch is
obtained by considering following two
assumptions
(a)uniform pressure theory
(b)uniform wear theory

12. Single Plate Clutch
(a)uniform pressure theory:
•Assuming that the intensity of pressure over the
entire contacting surface area is constant,
•Total torque transmitted by single plate clutch
can be obtain by integrating Equation
Then, p=constant
( )
2
2
2
1
RRπ
W
area surface contacting
load
p
-
==

13. Single Plate Clutch
•(1)within limit R2 to R1 we
[ p=Constant]
∵
òò
=
1
2
R
R
2
T
0
r
δr r pμ 2πΤ
òò
=
1
2
R
R
2
T
0
r
δr rpμ 2πΤ
( )
3
2
3
1
R
R
3
RR pμ π
3
2
3
r
pμ 2πΤ
2
1
-=
÷
÷
ø
ö
ç
ç
è
æ
=

14. …….(A)
• Equation (A) gives the torque transmitted by single plate
clutch due to friction considering uniform pressure theory.
( )
( )
3
2
3
12
2
2
1
RR
RRπ
W
μ π
3
2
Τ -´
-
=
( )
÷
÷
ø
ö
ç
ç
è
æ
-
=
2
2
2
1
RRπ
W
p
( )
( )
ú
û
ù
ê
ë
é
-
-
=
2
2
2
1
3
2
3
1
RR
RR
μ W
3
2
Τ

15. Single Plate Clutch
(b) Uniform Wear Theory
•In this theory, we are considering that wear
which take place is uniform over the entire
contacting surface i.e.
P.r=constant
P.r=C
P=C/r …...(3)

16. Single Plate Clutch
•Axial load acting on the ring is
δW=p 2π r δr
δW=2 π C δr …(4)
•Integrating above Equation(4) within limit we get,
δr C 2π
r
C
δW=
òò
=
w
0
R
R
1
2
δr C 2πδW

17. Single Plate Clutch
•We know that frictional torque acting on ring is,
……….(5)
…….(6)
[] ( )
( )
21
21
R
R
RR 2π
W
C
RR C 2r C 2πW
1
2
-
=
-== p
δr r Cμ 2πΤδrr
r
C
μ π2Τ
δr r pμ 2πΤ
r
2
r
2
r
===
=

18. Single Plate Clutch
•Torque transmitted by single plate clutch can be
obtain by integrating the Equation (4 ) within the
limit R2 to R1 we get,
( )
2
RR
Cμ 2π
2
r
Cμ 2πΤ
δrr Cμ 2πΤ
δrr Cμ 2πΤ
2
2
2
1
R
R
2
R
R
T
0
r
R
R
T
0
r
1
2
2
2
2
2
-
=
÷
÷
ø
ö
ç
ç
è
æ
=
=
=
òò
òò

19. Single Plate Clutch
•This is the torque transmitted by single plate
due to friction considering uniform wear theory.
( )
( )
( )
( )
μW π
2
1
Τ
RR
RR
μW π
2
1
Τ
RR
RR2π
W
μ πΤ
21
2
2
2
1
2
2
2
1
21
=
-
-
=
-´
-
=

20. Single Plate Clutch
•Power transmitted by single plate clutch is
given by,
rpmin shaft of SpeedN where,
Watt
60
NΤ 2π
P
Τ ωP
=
=
=

21. MULTIPLATE CLUTCH
Multi-plate clutch consists of more than one clutch plates
contrary to single plate clutch which consists of only one plate.
Friction surfaces are made in case of multi-plate clutch. Due to
increased number of friction surfaces, a multi-plate clutch can
transmit large torque.

23. For multiplate clutch
•For uniform pressure theory,
•For uniform wear theory,
( )
( )
ú
û
ù
ê
ë
é
-
-
´=
2
2
2
1
3
2
3
1
RR
RR
μ W
3
2
nΤ
( )
21
RRμW
2
1
nΤ +´=

24. Multiplate Clutch
Notes:
•In case of new clutch ,the intensity of pressure is uniform
along the surface of clutch but in case of old clutch
uniform theory is more correct.
•For single plate clutch normally both sides of the plate
are effective .there for single plate clutch has two pairs of
contacting surface i.e. n=2.
•In actual practice, usually the theory of uniform wear is
used in analysis of clutch.

25. •Intensity of pressure is maximum at the inner radius R2 of the
friction or contact surface,
•Intensity of pressure is minimum at the inner radius R1 of the
friction or contact surface,

2
max2max
R
C
P OR CRP ==´
1
max1max
R
C
P OR CRP ==´

26. In mutilate disc clutch
no of disc on driving shaft
no of disc on driven shaft
So no. of pairs in contact,

1nnn
21 -+=
=
1n
=
2n

27. CONE CLUTCH

28. CONE CLUTCH
•A cone clutch serves the same purpose as a disk or
plate clutch. However, instead of mating two spinning
disks, the cone clutch uses two conical surfaces to
transmit friction and torque. The cone clutch transfers a
higher torque than plate or disk clutches of the same
size due to the wedging action and increased surface
area.

29. CONE CLUTCH
•Cone clutches are generally now only used in low peripheral
speed applications although they were once common in
automobiles and other combustion engine transmissions. They
are usually now confined to very specialist transmissions in
racing, rallying, or in extreme off-road vehicles, although they are
common in power boats.

30. CONE CLUTCH

31. Notation of cone clutch

32. CONE CLUTCH
An element of cone clutch

33. CONE CLUTCH

34. CONE CLUTCH

35. CONE CLUTCH
•According to uniform pressure theory,
(where p is constant)
•According to uniform wear theory,
(where p*r is constant)

36. Centrifugal Clutch

37. Centrifugal clutch
Driving
shaft
Driven
shaft
Friction
lining
Total friction torque , T = nµR(F-P)
F=mrω
2
ω
ω
CENTRIFUGAL CLUTCH

38. CENTRIFUGAL CLUTCH
•A centrifugal clutch works on the principle of centrifugal force.
•The clutch's purpose is to disengage when the engine is idling so
that the chain does not move .
•These clutches are particularly useful in internal combustion
engines, which can not be started under load.

39. •The clutch consists of three parts:
•An outer drum that turns freely - This drum includes
a sprocket that engages the chain. When the drum
turns, the chain turns.
•A centre shaft attached directly to the engine's
crankshaft - If the engine is turning, so is the shaft.
•A pair of cylindrical clutch weights attached to the
centre shaft, along with a spring that keeps them
retracted against the shaft
CENTRIFUGAL CLUTCH

40. •There are several advantages to a centrifugal clutch
•It is automatic. (In a car with a manual
transmission, you need a clutch pedal. A centrifugal
clutch doesn't.)
•It slips automatically to avoid stalling the engine.
(In a car, the driver must slip the clutch.)
•Once the engine is spinning fast enough, there is no
slip in the clutch.
•It lasts forever.
CENTRIFUGAL CLUTCH

41. CENTRIFUGAL CLUTCH

42. CENTRIFUGAL CLUTCH
•The centrifugal force acting on each shoe,
•Just before engagement with shoe,

43. CENTRIFUGAL CLUTCH
•During running condition, the net force