1. CLUTCH

2. CLUTCHES
A clutch is a mechanism for transmitting rotation,
which can be engaged and disengaged. Clutches are
useful in devices that have two rotating shafts. In these
devices, one shaft is typically driven by a motor or
pulley, and the other shaft drives another device. In a
drill, for instance, one shaft is driven by a motor, and the
other drives a drill chuck. The clutch connects the two
shafts so that they can either be locked together and spin
at the same speed (engaged), or be decoupled and spin at
different speeds (disengaged).

3. CLUTCH EXPLOSION

4. TYPES OF CLUTCHES
Multiple plate friction clutch
 Vehicular
Wet and dry
 Automobiles
 Non-power train in automobiles
 Motorcycles
Centrifugal

5. MULTIPLATE FRICTION CLUTCH
This type of clutch has several driving members
interleaved with several driven members. It is
used in motorcycles, automatic transmissions and
in some diesel locomotives with mechanical
transmission. It is also used in some electronically
controlled all-wheel drive systems. It is the most
common type of clutch on modern types of
vehicles.

6. VEHICULAR
There are different designs of vehicle clutch, but
most are based on one or more friction discs,
pressed tightly together or against a flywheel
using springs. The friction material varies in
composition depending on whether the clutch is
dry or wet, and on other considerations. Friction
discs once contained asbestos, but this has been
largely eliminated. Clutches found in heavy duty
applications such as trucks and competition cars
use ceramic clutches that have a greatly increased
friction coefficient.

7.  However, these have a "grabby" action and are unsuitable for road
cars. The spring pressure is released when the clutch pedal is
depressed thus either pushing or pulling the diaphragm of the
pressure plate, depending on type, and the friction plate is released
and allowed to rotate freely.
When engaging the clutch, the engine speed may need to be
increased from idle, using the manual throttle, so that the engine
does not stall (although in some cars, especially diesels, there is
enough torque at idling speed that the car can move; this requires
fine control of the clutch). However, raising the engine speed too
high while engaging the clutch will cause excessive clutch plate wear.
Engaging the clutch abruptly when the engine is turning at high speed
causes a harsh, jerky start. This kind of start is necessary and desirable
in drag racing and other competitions, where speed is more
important than comfort.

8. Clutch disc

9. Wet and dry
A 'wet clutch' is immersed in a cooling lubricating
fluid, which also keeps the surfaces clean and gives
smoother performance and longer life. Wet
clutches, however, tend to lose some energy to the
liquid. A 'dry clutch', as the name implies, is not
bathed in fluid. Since the surfaces of a wet clutch
can be slippery (as with a motorcycle clutch bathed
in transmission oil), stacking multiple clutch disks
can compensate for the lower coefficient of friction
and so eliminate slippage when fully engaged.

10. Automobiles
This plastic pilot shaft
guide tool is used to align
the clutch disk as the
spring-loaded pressure
plate is installed. The
transmission's drive splines
and pilot shaft have an
identical shape. A number
of such devices fit various
makes and models of
drivetrains

11. FORD COLOGNE V_6_ 2_9_BACK

12. In a car the clutch is operated by the left-most pedal
using a hydraulic or cable connection from the pedal to
the clutch mechanism. On older cars the clutch would
be operated by a mechanical linkage. Even though the
clutch may physically be located very close to the pedal,
such remote means of actuation are necessary to
eliminate the effect of vibrations and slight engine
movement, engine mountings being flexible by design.
With a rigid mechanical linkage, smooth engagement
would be near-impossible, because engine movement
inevitably occurs as the drive is "taken up." No
pressure on the pedal means that the clutch plates are
engaged (driving), while pressing the pedal disengages
the clutch plates, allowing the driver to shift gears or
coast.

13. WORKING:

14. A manual transmission contains cogs for selecting
gears. These cogs have matching teeth, called dog
teeth, which means that the rotation speeds of the
two parts have a synchronizer, a device that uses
frictional contact to bring the two parts to the
same speed, and a locking mechanism called a
blocker ring to prevent engagement of the teeth
(full movement of the shift lever into gear) until
the speeds are synchronized.

15. Non-powertrain in
automobiles
There are other clutches found in a car. For example, a belt-
driven engine cooling fan may have a clutch that is heat-
activated. The driving and driven elements are separated by a
silicone-based fluid and a valve controlled by a bimetallic
spring. When the temperature is low, the spring winds and
closes the valve, which allows the fan to spin at about 20% to
30% of the shaft speed. As the temperature of the spring
rises, it unwinds and opens the valve, allowing fluid past the
valve which allows the fan to spin at about 60% to 90% of
shaft speed depending on whether it's a regular or heavy-duty
clutch. There are also electronically engaged clutches (such as
for an air conditioning compressor) that use magnetic force to
lock the drive and driven shafts together

16. MOTORCYCLES
On most motorcycles, the clutch is operated by the clutch
lever, located on the left handlebar. No pressure on the lever
means that the clutch plates are engaged (driving), while
pulling the lever back towards the rider will disengage the
clutch plates, allowing the rider to shift gears.
 Motorcycle clutches are usually made up of a stack of
alternating plain steel and friction plates. One type of plate
has lugs on its inner diameter that key it to the engine
crankshaft, while the other type of plate has lugs on its outer
diameter that key it to a basket that turns the transmission
input shaft. The plates are forced together by a set of coil
springs when the clutch is engaged. Racing motorcycles often
use slipper clutches to eliminate the effects of engine
braking.

17. CENTRIFUGAL CLUTCH
centrifugal clutch is
a clutch that uses
centrifugal force to
connect two concentric
shafts, with the driving
shaft nested inside the
driven shaft.

18. WORKING OF CENTRIFUGAL CLUTCH
The input of the clutch is connected to the engine
crankshaft while the output may drive a shaft, chain, or
belt. As engine RPM increases, weighted arms in the
clutch swing outward and force the clutch to engage.
The most common types have friction pads or shoes
radially mounted that engage the inside of the rim of a
housing. On the centre shaft there are an assorted
amount of extension springs, which connect to a clutch
shoe. When the centre shaft spins fast enough, the
springs extend causing the clutch shoes to engage the
friction face.

19. It can be compared to a drum brake in reverse. This type can
be found on most home built karts, lawn and garden
equipment, fuel powered model cars and low power
chainsaws. Another type used in racing karts has friction and
clutch disks stacked together like a motorcycle clutch. The
weighted arms force these disks together and engage the clutch
When the engine reaches a certain RPM, the clutch activates,
working almost like a continuously variable transmission. As
the load increases the rpm drops, disengaging the clutch,
letting the rpm rise again and reengaging the clutch. If tuned
properly, the clutch will tend to keep the engine at or near the
torque peak of the engine. This results in a fair bit of waste
heat, but over a broad range of speeds it is much more useful
than a direct drive in many applications.

20. Centrifugal clutches are often used in mopeds,
underbones, lawnmowers, go-karts, chainsaws,
and mini bikes to:
keep the internal combustion engine from stalling
when the blade is stopped abruptly
disengage load during starting and idle
Thomas Fogarty, who also invented the balloon
catheter, is most often credited with first inventing
the centrifugal clutch in the 1940s, although
automobiles were being manufactured with
centrifugal clutches as early as 1936.

21. 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 torque by friction.
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.
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. This is because the clutch doesn't have to
be pushed in all the way and the gears will be changed quicker.
Small cone clutches are used in synchronizer mechanisms in
manual transmissions.

22. DIAGRAM OF CONE CLUTCH
1-Cones: female cone (green),
male cone(blue)
2-Shaft: male cone is sliding on
splines.
3-Friction material: usually on
female cone, here on male cone
4-Spring: brings the male cone
back after using the clutch
control
5-Clutch control: separating
both cones by pressing
6-Rotating direction: both
direction of the axis are possible

23. Other clutches
Dog clutches
Torque limiter or Safety clutch: This device allows a rotating
shaft to "slip" when higher than normal resistance is
encountered on a machine. An example of a safety clutch is
the one mounted on the driving shaft of a large grass mower.
The clutch will "slip" or "give" if the blades hit a rock,
stump, or other immobile object.
Overrunning clutch or freewheel
Hydraulic clutch
Electromagnetic clutch
E-Clutch

24. DOG CLUTCHES
A dog clutch is a type of
clutch that couples two
rotating shafts or other
rotating components not
by friction but by
interference. The two parts
of the clutch are designed
such that one will push the
other, causing both to
rotate at the same speed
and will never slip.

25. Dog clutches
Dog clutches are used where slip is undesirable
and/or the clutch is not used to control torque.
Without slippage, dog clutches are not affected by
wear in the same way that friction clutches are.
Dog clutches are used inside manual automotive
transmissions to lock different gears to the rotating
input and output shafts. A synchromesh arrangement
ensures smooth engagement by matching the shaft
speeds before the dog clutch is allowed to engage.

26. Dog clutches
A good example of a simple dog clutch
can be found in a Sturmey-Archer
bicycle hub gear, where a sliding cross-
shaped clutch is used to lock the driver
assembly to different parts of the
planetary geartrain.

27. Torque Limiter
A torque limiter is an automatic device that protects
mechanical equipment, or its work, from damage by
mechanical overload. A torque limiter may limit the
torque by slipping (as in a friction plate slip-clutch), or
uncouple the load entirely (as in a shear pin). The
action of a torque limiter is especially useful to limit
any damage due to crash stops and jams.
Torque limiters may be packaged as a shaft coupling or
as a hub for sprocket or sheave. A torque limiting
device is also known as an overload clutch.

28. TYPES OF TORQUE LIMITOR
Disconnect types
 Shear pin
Synchronous magnetic
Ball detent
Pawl and spring
Torque limiting types
Friction plate
Magnetic particle
Magnetic hysteresis

29. Slipper Clutch
A slipper clutch (also known as a slider clutch or back-
torque limiter) is a specialized clutch developed for
performance oriented motorcycles to mitigate the effects of
engine braking when riders decelerate as they enter corners.
Slipper clutches have been used in most high displacement
four stroke racing motorcycles since the early 1980s. Slipper
clutches were introduced in the 1970s by John Gregory and
TC Christenson on "Hogslayer" the most successful drag
racing motorcycle of the 70s. Made of bronze sintered plates
from an earthmover and a Rambler 2 speed transmission, the
drivetrain let TC reach 180 mph in the quarter mile.

30. WORKING
They are designed to partially disengage or "slip" when the rear
wheel tries to drive the engine faster than it would run under its
own power. The engine braking forces in conventional clutches will
normally be transmitted back along the drive chain causing the rear
wheel to hop, chatter or lose traction. This is especially noted on
larger displacement four-stroke engines, which have greater engine
braking than their two-stroke or smaller displacement counterparts.
 Slipper clutches eliminate this extra loading on the rear suspension
giving riders a more predictable ride and minimize the risk of over-
reving the engine during downshifts. Slipper clutches can also
prevent a catastrophic rear wheel lockup in case of engine seizure or
transmission failure. Generally, the amount of force needed to
disengage the clutch is adjustable to suit the application.

31. USES:
Slipper clutches were also used in the Honda Interceptor 750 .
Before long slipper clutches could be found in nearly every big
bore four-stroke race bike, and notably (due to the cruiser-style
and riding position) the 1983-1985 Honda Shadow
VT750/VT700 models. Another street bike application was in
the 1990-1997 Suzuki VX800. Slipper clutches are now gradually
being factory installed on production motorcycles such as the
Aprilia RSV Mille, Ducati 1198, Honda CBR1000RR 2008+,
Yamaha YZF-R6 2006-2008, Yamaha YZF-R1 SP 2006 , Yamaha
YZF-R1 2007-2009, Yamaha V-Max 2009, Kawasaki ZX-10R,
Kawasaki ZX-6R, Suzuki SV1000 and GSX-R1000 2005-2007,
Suzuki Hayabusa 2008, Suzuki RM125 2008,
Harley Davidson V-Rod VRSC 2008, and are available as retrofit
for many other models.

32. HYSTERESIS CLUTCH

33. Magnetic Particle Clutch
A magnetic particle clutch is a special type
of electromagnetic clutch which does not use
friction plates. Instead, it uses a fine powder of
magnetically susceptible material (typically
stainless steel) to mechanically link an otherwise
free wheeling disc attached to one shaft, to a
rotor attached to the other shaft

34. WORKING:
When a magnetic field is applied to the powder, it forms
chains connecting the disc and rotor. The strength of the
chains depends on the strength of the magnetic field.
Some advantages over friction plate clutch is:
it doesn't exhibit stick-slip phenomenon or stiction
the torque may be easily and quickly controlled
it is more resistant to wear
may be used for continuous slip applications
has a very fast response time

35. DIAGRAMS OF ELECTROMAGNETIC CLUTCH

36. ELECTROMAGNETIC PARTICLE CLUTCH

37. TRIPPLE FLUX WITH ROTOR WITH
BANANA SLOTS

38. Fluid Coupling
A fluid coupling is a hydrodynamic device used to
transmit rotating mechanical power. It has been
used in automobile transmissions as an alternative to
a mechanical clutch. It also has widespread
application in marine and industrial machine drives,
where variable speed operation and/or controlled
start-up without shock loading of the power
transmission system is essential.

39.  History
 Overview
 Stall speed
 Slip
 Hydraulic fluid
 Hydrodynamic braking
Applications
 Industrial
 Rail transportation
 Automotive
 Aviation

40. History
The fluid coupling originates from the work of Dr. Hermann
Föttinger, who was the chief designer at the Vulcan Works in Stettin.
His patents from 1905 covered both fluid couplings and torque
converters.
In 1930 Harold Sinclair, working with the Daimler company, devised a
transmission system using a fluid coupling and planetary gearing for
buses in an attempt to mitigate the lurching he had experienced while
riding on London buses during the 1920s.
In 1939 General Motors Corporation introduced Hydramatic drive, the
first fully automatic automotive transmission system installed in a mass
produced automobile. The Hydramatic employed a fluid coupling.
The first Diesel locomotives using fluid couplings were also produced in
the 1930s.

41. Overview
A fluid coupling consists of three components, plus the
hydraulic fluid:
The housing, (which must have an oil tight seal around
the drive shafts) - contains the fluid and turbines. (also
known as the shell)
Two turbines (fan like components):
One connected to the input shaft; known as the pump or
impellor, primary wheel input turbine
The other connected to the output shaft, known as the turbine,
output turbine, secondary wheel or runner

42. Stall speed
Stall speed
An important characteristic of a fluid coupling is
its stall speed. The stall speed is defined as the
highest speed at which the pump can turn when
the output turbine is locked and maximum input
power is applied. Under stall conditions all of the
engine's power would be dissipated in the fluid
coupling as heat, possibly leading to damage.

43. SLIP
 A fluid coupling cannot develop output torque
when the input and output angular velocities are
identical.Hence a fluid coupling cannot achieve
100 percent power transmission efficiency. Due
to slippage that will occur in any fluid coupling
under load, some power will always be lost in
fluid friction and turbulence, and dissipated as
heat.

44. Hydraulic fluid
As a fluid coupling operates kinetically, low
viscosity fluids are preferred.Generally speaking,
multi-grade motor oils or automatic transmission
fluids are used. Increasing density of the fluid
increases the amount of torque that can be
transmitted at a given input speed.

45. Hydrodynamic braking
Fluid couplings can also act as hydrodynamic
brakes, dissipating rotational energy as heat
through frictional forces (both viscous and
fluid/container). When a fluid coupling is used
for braking it is also known as a retarder.

46. Applications

47. Industrial
Fluid couplings are used in many industrial
application involving rotational power,
especially in machine drives that involve
high-inertia starts or constant cyclic loading.

48. Rail transportation
Fluid couplings are found in some
Diesel locomotives as part of the
power transmission system.

49. Automotive
In automotive applications, the pump typically is
connected to the flywheel of the engine—in fact,
the coupling's enclosure may be part of the
flywheel proper, and thus is turned by the
engine's crankshaft. The turbine is connected to
the input shaft of the transmission. While the
transmission is in gear, as engine speed increases
torque is transferred from the engine to the input
shaft by the motion of the fluid, propelling the
vehicle. In this regard, the behaviour of the fluid
coupling strongly resembles that of a mechanical
clutch driving a manual transmission.

50. Aviation
The most prominent use of fluid couplings in
aeronautical applications was in the Wright
turbo-compound reciprocating engine, in which
three power recovery turbines extracted
approximately 20 percent of the energy or about
500 horsepower (370 kW) from the engine's
exhaust gases and then, using three fluid
couplings and gearing, converted low-torque
high-speed turbine rotation to low-speed, high-
torque output to drive the propeller.

51. Any Quarries

52. Thank you