clutches in automobiles

CLUTCH

WHY DO WE NEED CLUTCH?

• Because engine run all the time but wheel don’t• To stop car without killing the engine• Transfer the power from engine to wheel• Gradual engagement without sudden jerks

CLUTCH

WHAT IS CLUTCH?

• Clutch is a part of Transmission system• Clutch is a mechanism which enables the rotary motion of one shaft

to be transmitted when desired to a second shaft

LOCATION OF CLUTCH

WORKING PRINCIPLE OF CLUTCH

FUNCTION OF CLUTCH

• Torque transmission• Gradual engagement• Heat dissipation• To absorb shock and vibration during power transmission• Disengage engine from transmission• Release engine from transmission during gear shifts

TYPES OF CLUTCH

• Friction Clutch• Fluid flywheel/Hydraulic Clutch• Electromagnetic Clutch

FRICTION CLUTCH

DRY FRICTION WET FRICTION

DRY FRICTION CLUTCH

• Cone clutch• Single plate clutch• Multiplate clutch• Centrifugal clutch

CONE CLUTCH

• WORKING

ADVANTAGE

• Normal force acting on the contact surfaces is larger than the axial force.

DISADVANTAGE

• If the angle of cone is made smaller than about 20 deg. The male cone tends to bind or join the female cone and it becomes difficult to disengage the clutch.• A small amount of wear on the cone surface results in a considerable

amount of the axial movement of the male cone for which it will be difficult to allow

SINGLE PLATE CLUTCH

• WORKING

ADVANTAGE

• With the single plate clutch gear changing is easier than the cone clutch because the pedal movement is less in this case.• It does not suffer from disadvantage of cone clutch i.e binding of

cones etc. and hence it is more reliable.

DISADVANTAGE

• As compared to cone clutch the spring have to more stiff and this means grater force required to be applied by the driver while disengaging.

MULTIPLATE CLUTCH

• WORKING

CENTRIFUGAL CLUTCH

• WORKING

MAIN PARTS OF CLUTCH

• Fly wheel• Clutch plate• Pressure plate• Springs• Throw-out bearing

Flywheel

• Flywheel connected with the engine crank• Clutch cover bolted with the flywheel• Clutch turn with the flywheel

Clutch plate

• material= steel• Mounted on splined hub• Friction facing material- asbestos• And non asbestos

Pressure plate

• Material- high tensile gray iron• The pressure plate should also have sufficient mass and thermal

conductivity

SPRING

• The stiffness of the clutch springs should be the maximum• Spring material- steel• Used to absorb shock and vibration during initial contact

THROW-OUT BEARING

• The clutch pedal is connected either mechanically or hydraulically to a fork mechanism which loops around the throw-out bearing• When the clutch pedal is pressed, the fork pushes on the throw-out

bearing and it slides along the layshaft putting pressure on the innermost edges of the diaphragm springs• This leads to disengage of clutch

EXPLODED VIEW OF CAR CLUTCH

CLUTCH PLATE LINING AND MATERIAL

• Clutch disc/plate- Steel• Clutch lining- Asbestos and copper wire grit, ceramics• Rivets- Aluminums-copper• Springs- Steel• Hub- Steel

ACCIDENTAL CASES OF CLUTCH

• Burning a Clutch• Clutch Slipping

BURNING A CLUTCH

• When clutch is not totally engaged with the flywheel• Resting a foot on the clutch pedal during normal drive

CLUTCH SLIPPING

• Diaphragm spring has weakened• Wearing down the friction material on the clutch plate• The clutch is not properly engaged with the flywheel• Under heavy load accelerating in a high gear or up a hill• Do this long result a burning a clutch

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