Why does a car engine keeps running idle even when the car is not in neutral gear no pedals are pressed ?

Question

I’ve seen several animations and gone through explanations that a transmission isolates engine shaft from the drive shaft for several purposes but how does a car engine keeps running even when it is not in neutral gear(any gear like R, 1, 2, 3…6) and no pedal has been pressed, so clutch is not pressed too so this means the engine shaft is connected to the transmission and if it is in any gear other than R the drive shaft is coonected to the transmission, right ?

If yes, then why doesen’t the car moves and how does the engine still keeps running idle ?

In: 6

Answer 1

If you have the neutral gear you have an automatic gearbox and then there is no clutch. What you instead have is a torque converter that hydraulically transfers the motion. It is not a fixed connection so the engine can round and the wheel can be still while you are in a gear.

If you have a clutch you have a manual gearbox and it has not had neutral gear. If you are not in a great there you have moved the cogwheels so there is no engagement and because of that, there is no connection between the input and output axis.

The is a connection between the input and output of the gearbox if you are in a gear, that includes if you are in R. But the gearbox can be out of any gear and then there is no connection.

So the answer to your question is that with the church release the engine is connected to the input of the gearbox. The output of the gearbox is connected to the wheel. But if you are not in one of the gears there is no connection between the input and output of the gearbox.

The clutch is there so when you put the gearbox into a gear one of the sides is not connected to anything that forces it to rotate. That way you can put it fully into gear and slowly reapply the engine power. If you would do that with the engine connected you will have a lot of forces on the initial part of the gear in contact and will damage them.

So the gearbox can remove the direct connection between wheels and engines. But it can be used to reengage the connection without damaging parts unless the car is stationary with the engine off.