CLUTCH ANATOMY - SKengineers

 

CLUTCH ANATOMY -

The four parts that make up the clutch are -

Clutch Plate.

Clutch Cover.

Clutch Bearing (Release bearing)

Release Fork (clutch fork)

WHAT IS A CLUTCH? ITS PARTS, FUNCTION, WORKING PRINCIPLE, REQUIREMENTS & MORE -

What is Clutch?

Clutch is a mechanical device used in the transmission system of a vehicle. It engages and disengages the transmission system from the engine. It is fixed between the engine and the transmission.

The power produced inside the engine cylinder is ultimately aimed to turn the wheels so that the vehicle can move on the road. The reciprocating motion of the piston rotates a crankshaft by rotating the flywheel through the connecting rod.

Clutch -

The circular movement of the crankshaft is now to be transferred to the rear wheels. It is transmitted through the clutch, gearbox, universal points propeller shaft or driveshaft, differential, and axles extending to the wheels.

With the help of all these parts, the use of engine power for the driving wheel is called power transmission. The utilisation of engine power to the driving wheels through all these parts is called power transmission.

The power transmission system is normally the same on all passenger cars and trucks. But its design and arrangement may vary according to the method of drive and type of transmission units.

Main Part of A Clutch -

The main parts of a clutch are classified into three groups -

The main parts of a clutch are mainly divided into three groups.

1. Driving members

2. Driven members

3. Operating members

 1. Driving Members -

 The driving members consists of a flywheel which is mounted on the engine crankshaft

The flywheel is bolted to a cover which carries pressure plate, pressure springs and releasing levers.

As the flywheel is bolted to the cover assembly, thus, the entire assembly of the flywheel and the cover rotate all the times.

The clutch housing and cover provided with openings so that the heat produced during the function dissipates easily.

2. Driven Members -

The driven members consists of a disc or plate called clutch plate.

The clutch is free to slide on the splines of the clutch shaft.

It carries friction materials on both of its surfaces.

When the clutch plate is gripped between the flywheel and the pressure plate, it rotates the clutch shaft through splines.

3. Operating Members -

The operating members consists of a foot pedal, linkage, release or throw out bearings.

Functions of Various Component’s of Transmission Power -

Automobile Power Transmission System -

The function of various components of the transmission system as follows -

Clutch -

Its main function is to enable the driver to disconnect the engine from the driving wheels. Instantaneously and to engage drive from the engine to the driving wheels gradually while moving the vehicle from rest.

Gearbox (Transmission) -

It helps to vary the speed ratios and hence torque between the engine and the driving wheels to suit the road condition.

Universal Joint -

A universal joint is used where two shafts connected at an angle to transmit torque. The universal joint permits the torque transmission at an angle, and also while this angle is changing constantly while the vehicle is moving on the road.

Propeller Shaft -

The propeller shaft connected between the gearbox and the differential with a universal joint at each end. It transmits the rotary motion of the gearbox output shaft to the differential.

Differential -

While turning at the corners, the driving wheels must turn at different speeds. This is done with the help of differential.

How Clutch Works in a Vehicle -

Clutch is a mechanical device used in the transmission system of a vehicle. It engages and disengages the transmission system from the engine. It is fixed between the engine and the transmission.

Working Principle of Clutch -

The clutch works on the principles of friction, when two friction surfaces are bought in contact with each other and pressed they are united due to the friction between them. If one is revolved, the other will also revolve.

The friction between the two surfaces depends upon the area of the surfaces, the pressure applied upon them and coefficient of friction of the surface materials, The two surfaces can be separated and brought into contact when required.

One surface is considered as a driving member and the other as a driven number. The driving member is kept rotating when the driven member is brought in contact with the driving member, it also starts rotating. When the driven member is separated from the driving member it stops revolving. This is how a clutch operates.

The friction surfaces of the clutch are so designed that the driven member slips on the driving member when the pressure is first applied. As pressure increases the driven member is brought slowly to the speed of the driving member.

When the speeds of the members become equal, there’s no slip, the two members are in firm contact and the clutch is now fully engaged.

The driving member of a clutch is the flywheel. It is mounted on the crankshaft the driven member is the pressure plate. This is mounted on the transmission shaft. The clutch plates are between the two members.

When the clutch is engaged, the engine to the rear wheels through the transmission system. When the clutch is disengaged by pushing a clutch pedal, the engine is disconnected from the transmission. Thus, the power stops flowing to the rear wheels while the engine is still running.

THE ANATOMY OF A CAR CLUTCH -

Any manual vehicle consists of a mechanical device that transfers the rotational power from the engine to the wheels known as the clutch. It bridges two or more rotating shafts and controls the connection between the shafts coming from the engine and the shafts that turn the wheels. Once the clutch pedal is released, the engine and gearbox come in contact, and when the clutch is applied, the engine spins but not the car as the engine and gearbox are separated.

The car clutch is comprised of the following 6 parts -

Flywheel -

Flywheel is the part permanently fixed to the engine’s crank. Every time the engine rotates, so does this rotating mechanical device. The teeth that cover the edge engage the starter motor with a pinion and start the car.

Friction Surface -

The face of the flywheel has a rough surface and the clutch plate acts against it. They play a very crucial role.

Clutch Plate -

The disc used in the clutch plate has high friction materials attached around its perimeter. Both sides of the disc have the friction products installed where one side is forced against the face of the flywheel, and the other on the pressure plate. These friction products are an integral part of the clutch system and hence, clutch friction product suppliers design them very meticulously so that they are flawless.

Clutch Plate Springs -

The springs in the clutch system ensure smooth and linear power delivery. They remain mounted on the inner side of the clutch plate for easy movement when the clutch is engaged. By dampening the torsional vibrations it absorbs any fluctuation in the engine’s power delivery.

Pressure Plate -

The plate attached to the flywheel is called a pressure plate. It spins along with the flywheel. Covering the clutch plate from one side, it presses it against the friction plate. When the clutch pedal is applied, it clamps down on the clutch plate and enables swift gear movements and prevents vibrations that result in wear and tear.

Diaphragm Spring -

When we apply the clutch pedal, the motion is directly transmitted to the diaphragm spring. This makes the diaphragm spring to pull the pressure plate away from the clutch plate and allow free movement of gears.

The Requirement of a Clutch -

Torque Transmission -

The clutch should be able to transfer maximum torque to the engine.

Gradual Engagement -

The clutch should engage gradually to avoid sudden jerks.

Heat Dissipation -

The clutch should be able to dissipate a large amount of heat which is generated during the clutch operation due to friction.

Dynamic Balancing -

The clutch should be dynamically balanced. This is especially required in the case of high-speed engine clutches.

Vibration Damping -

The clutch should have a suitable mechanism to damp vibrations and to eliminate the noise produced during the power transmission.

Size -

The clutch should be as small as possible in size so that t will occupy minimum space.

Free Pedal Play -

To reduce effective clamping load on the carbon thrust bearing and wear on it. The clutch should have a free pedal play.

Easy in Operation -

The clutch should be easy to operate requiring as little effort as possible on the part of the driver.

Lightness -

The driven member of the clutch should be built as light as possible so that it will not continue to rotate for any time after the clutch has been disengaged.

Clutch Plate or Disc -

The clutch plate is the driving member of the clutch and is gripped between the flywheel and the pressure plate. It is mounted on the clutch shaft through the splines. When it is gripped, rotates the clutch shaft and the power is transmitted from the engine to the transmission through the clutch.

Clutch plate -

A pressure plate consists of two sets of facing or friction material mounted on steel cushion springs. The facing and cushion springs are riveted to a spring base disc and spring retainer plate which are slotted for the insertion of the torsion spring.

Clutch plate assembly -

These springs contact the hub flanges that fit between the spring retainer plate and the disc and serve to transmit the twisting force applied to the facings to the splined hub. The spring action serves to reduce torsional vibrations and shocks between the engine and the transmission during clutch operation.

The facing and the plates rotate with respect to the hub to the limit of the compression of the springs or to the limit of the spring stops.

When the clutch is engaged, the pressure on the facing compresses the cushion springs sufficiently to cause the unit to decrease in thickness by 1 to 1.5 mm. This construction helps to make engagement smooth and chatter-less.