Dry Friction Clutches :

The following types of dry friction clutches will be described here :

1. Cone Clutch
2. Single plate clutch
3. Multiplate clutch
4. Semi-centrifugal clutch
5. Centrifugal clutch

In cone clutch the contact surfaces are in the form of cones . In the engaged position, the male cone is fully inside the female cone so that the friction surfaces are in complete contact. This is done by means of springs which keep the male cone pressed all the time.

When the clutch is engaged, the torque is transmitted from the engine via the fly wheel and the male cone to the splined gear box shaft. For disengaging the clutch the male cone is pulled out by means of the lever system operated through the clutch pedal thereby separating the contact surfaces.

1. The only advantage of the clone clutch is that the normal force acting on the contact surfaces in this case is larger than the axial force, as compared to the simple single plate clutch in which the normal force acting on the contact surfaces is equal to the axial force.

1. If the angle of cone is made smaller than about 20 degree the male cone tends to bind or join in the female cone and it becomes difficult to disengage the clutch.
2. 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.

• A simplified single page clutch is given. Friction plate is held between the flywheel and the pressure plate.
• There are springs (the numbers may vary, depending upon design) arranged circumferential, which provide axial force to keep the clutch is engaged position.
• The friction plate is mounted on a hub which is splined from inside and is thus free to slide over the gearbox shaft.
• Friction facing is attached to the friction plate on both sides to provide two annular friction surfaces for the transmission of power.
• A pedal is provided to pull the pressure plate against the spring force whenever it is required to be disengaged.
• Ordinarily it remains in engaged position.
• When the clutch pedal is pressed, the pressure plate is moved to the right against the force of the springs.
• This is achieved by means of a suitable linkage and a thrust bearing.
• With this movement of the pressure plate, the friction plate is released and the clutch is disengaged.

1. With the single plate clutch, gear changing is easier than with the cone clutch, because the pedal movement is less in this case.
2. It does not suffer from disadvantages of cone clutch i.e., binding of cones etc. and hence it is more reliable.

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

• The multiplate clutch is an extension of single plate type where the number of frictional and the metal plates is increased.
• The increase in the number of friction surfaces obviously increases capacity of the clutch to transmit torque, the size remaining fixed.
• Alternatively, the overall diameter of the clutch is reduced for the same torque transmission as a single plate clutch.
• This type of clutch is, therefore, used in some heavy transport vehicles and racing cars where high torque is to be transmitted.
• Besides, this finds application in case of scooters and motor cycles, where space available is limited.
• The construction is similar to that of single plate type except that all the friction plates in this case are in two sets, i.e., one set of plates slides in grooves on the flywheel and the other one slides on splines on the pressure plate hub.
• Alternate plates belong to each set.

ive always had 16" on mine as i think 17 are to big, i need to get rid of my old alloys which have a fair few scratches but they look nice if n e one wants them for nothing.

16 is the biggest you can fit

are you still giving away your alloys? and were abouts do you live?