On Mon, 15 Jun 1998 18:00:21 -0400, Sean Breheny wrote:

>While on the subject of engines and cars, I would like to ask a slightly
>related OT question that has been bugging me for a long time: How can a
>car sit still on a hill with the engine holding it from rolling
>backwards? The engine, of course, needs to keep its crankshaft turning in
>order not to stall. However, the wheels are not turning in this case.
>Somehow, the torque is being transferred from the engine to the wheels
>while alowing them to move independently of the crankshaft. How is this
>possible? What component in the drivetrain allows this?

In a car with an automatic transmission,,, the :"torque converter" of course.

It is hard to explain, but it is an oil filled cavitiy in which two matched
turbines are attached to the input and output shafts.  Oils fills the voids
between the "vanes".  When the input shaft turns one turbine, the oil drags
the output turbine along.  It sort of takes the place of the clutch in a
manual transmission.

That's the best description I can give you as I am a non-mechanic!

>
>Thanks,
>
>Sean
>

Dan