Cone Clutch is a type of frictional clutch. It is used to engage and disengage the engine shaft to the transmission box shaft while changing the gear ratio.
|For those who do not know what actually clutch is used for let’s see what is a clutch.|
In a transmission system, an engine cannot be directly connected to a gearbox because in some conditions like changing of gears and other conditions disengagement of the two is required. So, a clutch is used to engage and disengage the engine and the gearbox as per requirement.
The cone clutch uses two conical surfaces to transmit torque by friction. One surface is called a male member and another one is called a female member. The male cone is the inner member, it is also known as the inner cone and the female cone is the outer member, it is also known as the outer cone.
A cone clutch is easier to engage and disengage as compared to a positive displacement clutch which was used before cone clutches were invented.
The cone clutch was invented in the year 1914.
Higher torque can be transferred using the cone clutch than the same size plate clutch due to greater contact area.
The driving shaft and the driven shaft must be perfectly coaxial for the efficient functioning of the clutch.
This clutch can be used where high torque transmission is required at low rotating speed. So, this type of clutch is widely is heavy vehicles.
Parts of Cone Clutch:
1) Female Cone or Outer Cone:- It is part of the cone clutch that is connected to the flywheel of the engine and also rotates with it.
This part is always in a rotating condition as the engine shaft rotates continuously.
The female cone has an inner cutting cone-shaped groove that has a friction lining over which the male cone interlocks and make frictional contact with it in order to engage the drive.
This female cone is mounted over the solid shaft.
2) Male Cone or Inner Cone:-
This cone is connected to the transmission system or the gearbox. The inner cone has a friction lining in the outer part which creates frictional contact with the inner friction lining of the outer cone. By default, the inner cone remains in contact with the outer cone with the help of pressure springs which are placed behind the inner cone.
When the clutch pedal is pressed in conditions like changing gear, the spring is compressed and the inner cone moves away from the outer cone and disengages from the outer cone and hence the engine is disengaged from the transmission box. This inner cone has inner splines and moves over lines of the shaft for to and fro motion.
Springs are located behind the male cone which are used to keep the inner cone engaged with the outer cone.
When the clutch pedal is pressed, the spring compresses and the inner cone disengages with the outer cone and hence the driving shaft is disconnected from the driven shaft.
Sleeves are part of the clutch which is attached to the male cone and mounted on the splines and these sleeves are used for the to and fro motion of the male cone.
A clutch pedal is used to operate the clutch. When the clutch pedal is pressed, the spring is compressed through the fulcrum attached at its other end.
6) Throw Out Bearing:-
A throw-out bearing is a component of the cone clutch that helps the spring to put pressure on the clutch so that the clutch remains in the engaged position.
Throw Out Bearing is fixed in its position and it also supports the spring during the clutch disengagement.
Working of Cone Clutch:-
By default, the male cone is engaged with the female cone due to the pressure of the spring which is present behind the male cone.
When the clutch pedal is pressed in order to change the gear or for some other cause, the fulcrum which is attached to the pedal rotates which in turn compresses the spring and also the male cone is pulled away from the female cone. Thus the contact between the male cone and the female cone will break. So, the engine shaft will be disengaged from the transmission system and the rotation of the engine shaft or driving shaft will not be transferred to the transmission shaft or the driven shaft.
Now after the disengagement when the clutch pedal is released slowly by the driver after changing the gears, the fulcrum which is attached to the pedal rotates and the spring expands and the male cone starts moving towards the female cone over splines. After that, the male cone makes contact with the female clutch and friction force acts between the inner friction lining of the outer cone and the outer friction lining of the inner cone. Now the cone clutch is said to be in engaged position and the rotation of the engine shaft or driving shaft is transferred to the transmission shaft or driven shaft and both the shaft start rotating at the same speed.
The stiffness of the spring keeps the male cone and female cone of the cone clutch in the engaged position.
As the male cone and female cone are in cone shape. So, the engagement of the two does not take place in one go. The engagement of the two happens slowly after proper synchronization of the rotation of the male one and the female cone.
The use of cone clutch slowly decreases due to its limitation that the cone angle cannot be less than 20 degrees as at angles lesser than 20 degrees the disengagement of the clutch becomes difficult and at higher angles, there are power transmission losses. Although it was more efficient in the transmission of torque but due to this limitation the use of this clutch decreased over time.
Difference between Cone Clutch and Single Plate Clutch:
|Cone Clutch||Single Plate Clutch|
|1) Less axial force is required in a cone clutch to get a particular normal force.||1) Large axial force is required in a single plate clutch to get the same normal force as compared to a cone clutch.|
|2) The chances of slipping between mating surface is very less. So almost 100% torque transfer is guaranteed.||2) The slip between the mating surface is higher in a single plate clutch as compared to a cone clutch. So, less torque is transferred comparatively.|
|3) The disengagement of the clutch becomes difficult in a cone clutch when the cone angle is lesser than 20°.||3) There is no such problem in single plate clutch as the surface of the clutch plate is flat.|
|4) High torque transmission capacity.||4) Lesser torque transmission capacity.|
Advantages of Cone Clutch:-
1) The normal force acting on the contact surface is greater than the axial force.
2) Higher torque can be transferred than the same size of plate clutch due to the large amount of frictional force involved.
3) It creates less noise than a plate clutch.
4) Less wear and tear as compared to displacement clutch.
Disadvantages of Cone Clutch:-
1) High maintenance is required because very little wear can cause a considerable amount of axial movement of the inner cone.
2) It becomes very difficult to disengage if the cone angle is smaller than required. For easy disengagement, the cone angle should be exactly as required.
Applications of Cone Clutch:-
1) Cone clutches are used in heavy vehicles as they can transmit high torque.
2) Cone clutches are used in racing boats.
3) Cone clutch is also used in extreme off-road vehicles.
4) It is also used in low peripheral speed applications.
5) It is also used as a synchronizer in various manual transmissions.
6) They are used in various heavy machinery.