Is clutch necessary in all vehicles?

I'm wondering if clutch is necessary for all vehicles? I've noticed that it's present in both two and four wheelers.

I think, electric cars do not need clutch. Because the electric motors have variable power so we can drive the wheels directly.

P.S: correct me if I am wrong

there is no clutch for "TVS JIVE BIKE"

clutch is merely a mechanism used for engaging or disengaging the engine from the driven wheels.

it is analogous to a switch in an electrical circuit.

each time you press down the clutch pedal while driving, the engine is disconnnected from the driving wheels.

it is used to prevent the engine from stalling while braking.

this is how it happens :

when the vehicle moves, the engine crankshaft is connected to the driven wheels.

when the brakes are applied the motion of the driven wheels are retarded. in the absence of the clutch, the crankshaft would be retarded too, and hence the engine would stall.

but with a clutch, when the vehicle is made to stop , the engine is cut off from the driven wheels and rotates independently at its idle speed.

actually bikes like tvs jive, honda activa and other automatic scooters all have a special type of clutch called the centrifugal pivoted clutch.

this is an automatic type of clutch, and does not require any human interface.

not only motors, even engines have variable speeds. but yet the clutch is required for the smooth functioning of the gear box and the engine, and for the reason which i have already mentioned above.

what is function of clutch in bike?

obviously the same function, which it serves in cars or any other automobile.

read my previous replies

THE system goes like this, Engine(two or four stroke or multi..)-crank shaft-flywheel-clutch-gear box(sliding mesh or constant mesh gear box )-(universal and slip joint )propeller shaft(universal joint)-final drive . the main function of clutch is to transmit the torque and speed that is developed in the engine, the clutch serves as a good transmitter of both.
Technology has grown up
now there is fluid flywheel, which acts as clutch and reduces friction between contact surfaces, by serving a liquid as a transmitting medium.

yes, without clutch, there is no possibility of variable speed.

It has auto clutch.. means when you will change gear it will use clutch first to detach shaft- piston and then change the gear.

If you don't have clutch then changing gear will be like changing a bolt of a wheel in running car.
Don't you drive bike, try changing gear without using clutch and your father will be waiting at home for your achievement.

i am not understand what you say? plse be specfic..

If there is no clutch then it will be very difficult to change your gear. It is possible to change gear in a manual transmision without disengaging your clutch, BUT, the lever will be hard to push and if you do this you will be doing some serious damage to your transmission espeacially to the syncromesh. The purpose of the clutch is to ensure that this damage does not occur.

Check this video out. The syncromesh is what locks on to the gears on the output shaft. Usually if you do not disengage the clutch before changing the gear you hear a grinding sound. That is the grinding of the syncromesh and thats is what will wear it out.

actually, a vehicle could not run without the clutch assembly unless it is electric. Every vehicle that has gearing systems would require it. It disconnects and connects the engine to the transmission shaft(propeller shaft). Well, in the case of a centrifugal clutch, the clutch could disengage and engage by itself- preferrably called as centrifugal action. This is similar to the action you see in governers. This type of system is called as Continuous Variable Transmission. While you could aslo see in some mopeds like Scooty and similar ones- the ones without clutch, they depend entirely on the fuel input to the cylinders that varies with the acceleration given. While am still not sure on the torque that results from it.. because in geared systems, a seperate torque is added whereas in non-geared system, they should be lacking it i suppose.

for single speed vehicles,clutch isn't necessary.But for variable speeds,you need a clutch for engagement and disengagement of the engine shaft.!!