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My dear chap/girl, a standard car clutch either transmits power or it doesn't. It converts nothing. It slips only momentarily for smooth modulation. It is designed to be either 'on' or 'off'. It is a method of breaking the transmission of power just like a light switch. It is not like a transformer. You just don't get it. Frankly you should read those links I kindly provided you and stop making such a damned fool of yourself, albeit anonymously.
Huw
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switch.
Give
like
I
You don't appear to understand what a clutch is used for when in *operation*. Its function is to provide a *smooth* conversion of torque from minimum to maximum, hence to convert torque(smoothly). It is not at all lilke a switch, that it its whole point, to avoid the abruptness of a switch which would stall and/or damage the engine/gearbox.

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It is a switch and the smoothness of modulation is irrelevant. There are many types of clutches but a car clutch is very similar to an aircon compressor clutch. It is a simple switch, with some refinements. You think otherwise. Quite simply you are wrong. A car clutch is not designed to be slipped other than a minimum for smooth full engagement and the refinement is to facilitate this and cushion shock loads. Of course there are clutches that have no facility for smooth modulation. An example of these is a dog clutch which has fierce teeth which engage. It is nevertheless a clutch. A torque converter is as described and is designed to slip almost constantly and facilitates a very high first gear in the case of a motor vehicle so that the power input can be a converted to a greater torque output at lower revs. It is NOT a clutch. In fact it is common industrial practice to fit a converter in conjunction with a dry clutch. In this case the clutch can be fully engaged at low revs while the vehicle pulls away simply by increasing the revs. The conventional clutch is nevertheless used to facilitate the changing of the conventional synchromesh gearbox while on the move. Also common on modern cars is the fitment of a clutch to the torque converter to lock both halves together. In the torque converter itself there is no mechanical link between the drive and driven sides. The drive is purely through the fluid which is thrown from one side to the other. Read the articles to which I provided a link!
Huw
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car
of
links
An
is
constantly
lower
a
increasing
there
The point is they both act as and are used at clutches the only difference is one is manual and the other automatic.
A clutch and a convertor is like wearing a belt and braces!

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A car clutch disengages drive. Its primary function is NOT to slip unless it is a different type such as a torque limiting device which suddenly disengages upon overload [a torque limiting clutch used instead of say a shear bolt, but not generally fitted to cars]. A torque converter has no facility to disengage drive fully and is designed primarily to variably slip and increase torque. Neither does it have the facility to lock up fully to provide a direct mechanical drive without an additional clutch to facilitate this. The clutch can only transmit the torque that is input. These are fundamental differences. In an automatic transmission clutches are used to engage and disengage the gears. They are either engaged or disengaged apart from a short slip period as they are modulated for smoothness and convenience. The slip causes heat and wear which are undesirable so in some cases the modulation from release to drive is quite sharp with shock loads being taken by the slipping torque converter between engine and transmission
Fundamentally and contrary to your initial claim, a conventional car clutch is not designed to convert torque. It just transmits torque or not. Clutching is actually a means to disengage drive, not a means to multiply torque or vary gearing ratio. Give up and stop digging.
Huw
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of
designed
period
release
torque
clutch
Yes as I have reached sufficient depth to final bury your arguement there is no need to dig futher!! (see below!!).
http://www.tciauto.com/tech_info/torque_converters_explained.htm
"the sprag is a one-way mechanical *clutch* mounted on races and fits inside the stator" (pump, turbine, stator and cover are the four components of a torque convertor).
I rest my case M'Lud.
Better luck next time :O)

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Actually it says that the stator contains a one way clutch, a sprag in fact. All cars have a number of clutches. This does not mean that the car is a big clutch any more than it means that just because a converter contains a clutch or two, that it is actually a clutch in itself.
For Dave, the first sentence defining a converter describes it as a fluid coupling device that also acts as a torque multiplier during initial acceleration.
Never any mention of a converter being a clutch, which of course it is not and if a converter allied to a conventional synchromesh gearbox there must be an actual clutch in the driveline to allow disconnection during a gearchange. While synchro boxes in conjunction with torque convertors are not common in cars they are not uncommon per-se. In an automatic or power-shift gearbox, there is of course no need to disconnect drive to achieve a ratio change because the clutch is integral to the gearbox in that it replaces a synchro unit in effect, whether in a constant mesh or planetary unit. From this it should be obvious that it does not matter which side of the converter a clutch is fitted, either on the input shaft or the output.
Please do try again your widescreenness :-)
Huw
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Not a good analogy. Better to consider it as a variable resistor that allows the light to be fully on or off and anywhere inbetween.
A clutch which is only 'on' or 'off' is called a dog clutch and you find them in most motor cycle gearboxes - as opposed to the more normal synchromesh clutches in cars.
--
*7up is good for you, signed snow white*

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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wrote:

That is not correct because it is not designed to be operated anywhere in-between except momentarily as it is modulated. Try driving and regulating your speed by slipping the clutch and see how long it lasts.

I have mentioned dogs elsewhere. The only practical operating difference between a dog and a conventional traction automobile clutch is in the smoothness of engagement. Both are designed to operate either engaged or disengaged. Neither multiplies torque or alters gearing in operation.
Huw
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On Mon, 13 Mar 2006 11:12:52 -0000, "Huw"

Try holding the car on a hill with clutch that can only be "on" or "off".
--
Alex Heney, Global Villager
Love is grand. Divorce is twenty grand.
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wrote:

Oh you can certainly abuse it in all kinds of ingenious ways. Nevertheless it is not meant to be used in such a way and it will hit you where it hurts, your wallet, if you do so.
Huw
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On Mon, 13 Mar 2006 13:45:20 -0000, "Huw"

No doubt.
But the point is that it is NOT a simple on/off switch, or you couldn't do that.
--
Alex Heney, Global Villager
Sleep is a poor substitute for caffeine.
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wrote:

But that is just what it is. There are a multitude of drive clutch types designed for all kinds of jobs but when it comes down to it they have two working modes, on and off. Any intermediate mode or delay in transition from on to off or visa versa is purely a refinement to the fundamental operation of the switch in the same way as most dry driven plates also have springs to dampen shock loads which result from sudden near-slip-free engagement.
Huw
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By using it as an on off switch you'd not do it any good either.;-)

A standard car friction clutch allows the transfer of torque from zero to the output of the engine and anywhere inbetween. A dog clutch doesn't. Either nothing or maximum.
--
*Remember, no-one is listening until you fart.*

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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On Sun, 12 Mar 2006 19:33:52 -0000, "Huw"

Yes. Unlike a rheostat, which has a function that is more analogous to a standard car clutch.
--
Cynic


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wrote:

Whereas a torque converter is more like a variable transformer...
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wrote:

A *true* torque convertor perhaps, but not the type under discussion which, like both a rheostat and a plate clutch, dissipates the unused power as heat.
--
Cynic



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wrote:

Which I call a "fluid clutch".
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wrote:

Which is IMO the more correct term. Nevertheless we are stuck with the label that is commonly applied.
--
Cynic



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Since it doesn't declutch or clutch it is not a clutch. It is properly a fluid flywheel coupling or more commonly called a torque converter, never called a clutch and for a reason.
Huw
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