Function and Requirement Of Automobile Clutches | Types Of Clutches
The power developed by the engine in automobiles should be transmitted to the road wheel efficiently. The power transmission system basically needs a clutch to transmit the power from the engine to the remaining parts of the transmission. The power transmission system is different for different types of vehicles.
In case of two wheelers with gears the power is transmitted from the clutch to the gearbox and then transmitted to the wheels by means of chain drive or gear drive. In case of non geared two wheelers the power is transmitted from the clutch directly to the wheels through the chain drive / gear drive or sometimes through the variator mechanism.
In case of LMVs and HTVs the power transmission consists of clutch and gearbox as the common features. In the conventional (front engine rear wheel drive) the power is transmitted from gearbox to road wheels by means of universal joint, propeller shaft, sliding joint, differential and half shaft. In case of front engine front wheel drive transaxle is commonly used. In this case the gear box is arranged transversely and power transmission may not be provided with propeller shaft and bevel gear arrangement. This type of arrangement is compact and also contains less number of moving parts. In the case of four wheel drive, the arrangement is similar to conventional power transmission with transfer gear box or transfer case as the additional features. The transfer gear box transmits the power to both the axles uniformly.
Functions of a Clutch:
The torque developed b the engine at starting speed is very low. Therefore, it is not possible to start the engine under load. This requires that the transmission system should provide a means of connecting and disconnecting the engine from rest of the transmission system. Such an operation must be smooth and without shock to the occupants of the vehicle.
Thus the two main functions of a clutch are:
1. To engage and disengage the transmission from engine to the remaining parts of transmission. (To allow the engine to be separated from rest of the transmission system) This is required when:
(a) Starting and running the engine at a sufficiently high speed lo generate sufficient power necessary for moving the vehicle from rest.
(b) Shifting the gears so that damage to gear teeth can be avoided.
(c) Stopping the vehicle after applying brakes.
2. The second function of the clutch is to allow the engine to take up the driving load of the vehicle gradually and without shock.
Classification of clutches:
|Classification Of Automobile Clutches|
Requirements of clutch:
The main requirements of a clutch are as follows:
- It should be able to transmit maximum torque of the engine.
- It should engage gradually to avoid sudden jerks.
- It should be able to dissipate large amount of heat generated during clutch operation.
- It should be dynamically balanced, particularly in the case of high speed engine clutches.
- It should have suitable mechanism to damp vibrations and to eliminate noise produced during power transmission.
- It should be as small as possible so that it will occupy minimum space.
- It should be easy to operate requiring as little exertion as possible on the part of the driver.
- It should be made as light as possible so that it will continue to rotate for any length of time after the clutch has been disengaged.
- It must be trouble free and have longer life.
- It must be easy to inspect, adjust and repair.