The Clutch is the most important part of the engine in an automobile. A clutch uses to transfer rotating motion or torque from one shaft to another shaft when requires. The torque developed by the engine at the initial speed is very low. Therefore it is impossible to start the engine under load.
It requires that the transmission system should provide a means of connecting and disconnecting the engine from the rest of the transmission system. Such an operation must be smooth and without shock to the passengers of the vehicle.
Hence a device that use to engage and disengage the engine from the transmission system is called a clutch. The clutch permits the gradual taking of load when adequately operated, thereby it prevents jerky motion of the vehicle, and this avoids undue strain on the parts of the vehicle as well as passengers.
In the transmission system, the system by which power developed by the engine is transmitted to road wheels to propel the vehicle.
In automobiles, the power is developed by the engine which is used to turn wheels. Therefore, the engine is to be connected to the transmission systems for transferring power to wheels.
Also, there should be a system using which the engine could be engaged and disengaged with the transmission system smoothly and without shock so that the vehicle mechanism is not damaged and passengers do not feel inconvenience. A clutch is employed in automobiles for this purpose.
PARTS OF CLUTCH
The parts of clutch consists of the following parts. We will discuss it in detail.
1. Flywheel
The flyWheel is an integral part of the engine, which also use as a part of the clutch. It is a driving member and connects to the pressure plate of the clutch shaft is houses with bearings in a flywheel. The flywheel rotates as the engine crankshaft rotates.
2. Pilot Bearing
The pilot bearing or bushing press into the end of the crankshaft to support the end of the transmission input shaft.
The pilot bearing prevents the transmission shaft and clutch disc from wobbling up and down when the clutch releases. It also assists the input shaft center of the disc on the flywheel.
3. Clutch plate or Disc plate
It is the driven member of the single-plate clutch and line with friction material on both surfaces. It has a central hub with internal splines to limit the axial travel along the splined gearbox driving shaft.
This helps to provide damping actions against torsional vibrations or variations of the driving torque between engine and transmission.
A clutch disc is a plate between flywheel and friction or pressure plate. It has a series of facings inverters on each side to enlarge the friction. These clutch facings are made of asbestos material. They are highly worn and heat resistant.
4. Pressure plate
The pressure plate is made of special cast iron. It is the heaviest part of the clutch assembly. The main function of the pressure plate is to establish even contact with the driven plate facing through which the pressure springs can exert a sufficient force to transmit the full torque of the engine.
The pressure plate presses the clutch plate on to the flywheel from its machined surface. Between the pressure plate and clutch cover assembly, pressure springs are fits. The pressure will be withdrawn from the flywheel whenever release levers depress by the toggle or release levers pivots accordingly.
5. Clutch cover
The clutch cover assembly bolts to the flywheel. It consists of a pressure plate, release lever mechanism, clutch cover, and pressure springs. Generally, the clutch plate revolves with the flywheel.
However, when the clutch has disengaged, the flywheel, as well as the pressure plates, are free to rotate independently from the driven plate and driving shaft.
6. Release levers
These pivots on pins to the clutch cover, their outer ends locate and positions on pressure plate legs, and the inner ends are projecting towards the clutch shaft. A careful and accurate adjustment of the release mechanism is one of the most important factors governing the performance of a clutch assembly.
7. Clutch shaft
It is a component of the gearbox. Since it is a splined shaft to the hub of the clutch plate, which is sliding on it. One end of the clutch shaft attaches to the crankshaft or flywheel and the other end connects to the gearbox or forms a part of the gearbox.
WORKING OF CLUTCH
A Clutch is defined as a system that is used to connect or disconnect the engine from the rest of the transmission elements.
It is located between the engine and gearbox. During normal running and stationary position, it is always in the engaged condition.
The clutch disengages when the driver processes the clutch pedal. The clutch disengages for starting, changing gears, stopping, and idling.
When the clutch engages, the engine will connect to the transmission, and power flows from the engine to rear wheels through a transmission system When the clutch disengages by pressing the clutch pedal, the engine will disengage from the transmission. Thus, the power does not flow to rear wheels while the engine is still running.
NECESSITY OF CLUTCH IN AUTOMOBILE
The clutch is a device that is necessary to transmit power from the engine to the wheels of the vehicle by engaging the engine to the transmission system gradually without giving the jerks to the body of the vehicle.