2 DefinitionA clutch is a mechanism for connecting and disconnecting an engine and the transmission system in a vehicle, or the working parts of any machine. It allows a temporary separation of drive between drive source and driven mechanisms. When engaged this will allow for a smooth take up of drive as the clutch is gradually engaged.
3 Clutch Action Clutch action can be demonstrated by two discs Drive DiscInput Shaft to TransmissionDrive disc attached to engineDriven disc attached to transmission input shaftEngineDriven DiscDriven disc disconnected, no driveDriven disc in contact with drive disc, drive appliednext
5 Clutch System Parts Clutch system consists of: Flywheel Clutch Plate Clutch HousingClutch PlateFlywheelPressure Plate AssemblyRelease BearingRelease BearingClutch ForkClutch PlateClutch housing protects clutch components from outside elementsPressure Plate AssemblyClutch ForkClutch Housingnext
6 Clutch System Parts - Clutch Plate - 1 Friction MaterialRivetsLocated between flywheel and pressure plateSplined HubSplines mesh with input shaftFriction RingFrictional material riveted to cushion springs on either side of friction ringCushion Springsnext
7 Clutch System Parts - Clutch Plate - 2 Cushioning springs cushion force as pressure plate pushes clutch plate onto flywheelTorsional SpringCushion SpringsTorsional springs soften load applied to clutch plate as it begins to turnCushion Springsnext
8 Clutch Operating Mechanisms - Hydraulic Master CylinderPipe connected between foot pedal and clutch forkTwo cylinders: master cylinder and slave cylinderSlave CylinderPipeAs foot pedal depressed, master cylinder builds pressure in system, slave cylinder activatedAs foot pedal released, springs return system to rest positionend
10 Clutch Types & Applications Single Plate clutch is used in almost all motor vehicles where manual transmission takes placeCone clutch was used in some automobiles in the past, but now is restricted to racing / rally car & power boatsCentrifugal clutch is used on a petrol powered lawn mower-as the lawn mower is revved at a higher speed, the centrifugal force spreads the clutch shoes apart so the clutch mechanism engagesMulti Plate clutches are used in extreme car racing and in automatic gearboxes.
12 Cone clutch α = semi-apex angle of the cone w T = μWrm cosecα Only one pair of driving surfaces is possible, n =1αwDriving shaftDriven shaftFriction liningThe maximum torque transmitted =T = μWrm cosecα
13 Centrifugal clutch F=mrω2 ω Driven shaft Driving shaft Friction lining Total friction torque , T = nµR(F-P)F=mrω2ωPR
14 Multi plate clutchesIn a multi plate clutch, the torque is transmitted by friction between several pairs of co-axial annular driving faces maintained in contact by an axial thrust.Both sides of each plate are lined with friction material, so that a single-plate clutch has two pairs of driving faces in contact.The advantages of using these types of clutch are due to the frictional surface area used, a lesser diameter clutch plate can be used thus less space is used.