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“Fluid gears” invention offers promise for improving mechanical devices

phys.org

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Re: “Fluid gears” invention offers promise for improving mechanical devices

#31

Post by yason »

ErroneousBosh wrote: post #10
mcherm wrote: post #7

Ever driven a vehicle with an automatic transmission rather than a manual gearshift with a clutch? Then you almost certainly used a fluid coupling: basically two fans in a can with oil so turning one turns the other. The article is so full of hype it doesn't bother to explain how this is different from the "fluid gears" invented in 1905.

Except a fluid clutch actually works, and a torque converter works even better and has three fans inside it ;-) I can see the "passive" cylinder getting dragged around a little by viscosity but I don't see how this could transfer even the tiniest amount of power.

Yeah, and like it's name a torque converter can actually not only transmit torque as well but also convert rpms to torque. Running the engine at high rpm at standstill converts revolutions of the input shaft to torque on the output shaft, thus allowing the car to start accelerating at slow speed but with high torque, operating without a clutch.

That's as close to fluid gearing as you can imagine.

Re: “Fluid gears” invention offers promise for improving mechanical devices

#32

Post by pfdietz »

kleiba wrote: post #22

Check out what this dude came up with 120 years earlier: https://en.wikipedia.org/wiki/Hermann_F%C3%B6ttinger

Died at age 68 on April 28, 1945 in Berlin, from shrapnel. The Soviets had begun shelling of Berlin on April 20.

This sort of coupling was used to drive the supercharger on the German BF 109, enabling it to maintain manifold pressure from sea level up to 20,000 ft. with a single stage supercharger without throttling. Use of such couplings in automobiles didn't occur until after the war.

https://www.youtube.com/watch?v=NcI67pZe_Ss

Re: “Fluid gears” invention offers promise for improving mechanical devices

#33

Post by formerly_proven »

ROOFLES wrote: post #28
bluGill wrote: post #17

Earlier quoted context omitted.

Many automatics these days are manual transmissions with a computer controlling the clutch. They have nothing in common with the slushboxes of old, the oil is just for lubrication.

ZF 8HP is still a traditional torque converter transmission. Most high performance or high torque applications use that design. Dual clutch automatics or automated manuals can't take it.

Virtually every truck has an automated manual transmission, every EV 2-speed is a DCT, Porsche uses PDKs etc.

Re: “Fluid gears” invention offers promise for improving mechanical devices

#34

Post by bluedino »

formerly_proven wrote: post #33
ROOFLES wrote: post #28

Earlier quoted context omitted.

ZF 8HP is still a traditional torque converter transmission. Most high performance or high torque applications use that design. Dual clutch automatics or automated manuals can't take it.

Virtually every truck has an automated manual transmission, every EV 2-speed is a DCT, Porsche uses PDKs etc.

Every truck? Like which ones?

As an American (land of the pickup truck) I can't think of any

Re: “Fluid gears” invention offers promise for improving mechanical devices

#35

Post by bluedino »

ROOFLES wrote: post #28
bluGill wrote: post #17

Earlier quoted context omitted.

Many automatics these days are manual transmissions with a computer controlling the clutch. They have nothing in common with the slushboxes of old, the oil is just for lubrication.

ZF 8HP is still a traditional torque converter transmission. Most high performance or high torque applications use that design. Dual clutch automatics or automated manuals can't take it.

Tremec makes DCTs that are used in 800hp Mustangs and 1000hp Corvettes

Re: “Fluid gears” invention offers promise for improving mechanical devices

#36

Post by gambiting »

bluGill wrote: post #17
mcherm wrote: post #7

Ever driven a vehicle with an automatic transmission rather than a manual gearshift with a clutch? Then you almost certainly used a fluid coupling: basically two fans in a can with oil so turning one turns the other. The article is so full of hype it doesn't bother to explain how this is different from the "fluid gears" invented in 1905.

Many automatics these days are manual transmissions with a computer controlling the clutch. They have nothing in common with the slushboxes of old, the oil is just for lubrication.

I mean, certainly the VAG group likes to use their dual clutch automatics, but "true" torque converters are still very common. ZF makes them for like a million different cars, and AISIN makes them for the Volvo and Geely group.

Re: “Fluid gears” invention offers promise for improving mechanical devices

#38

Post by gottorf »

bluedino wrote: post #34
formerly_proven wrote: post #33

Earlier quoted context omitted.

Virtually every truck has an automated manual transmission, every EV 2-speed is a DCT, Porsche uses PDKs etc.

Every truck? Like which ones? As an American (land of the pickup truck) I can't think of any

I think GP meant eighteen-wheelers and the like.

Re: “Fluid gears” invention offers promise for improving mechanical devices

#39

Post by ZeroGravitas »

jgrahamc wrote: post #9
mcherm wrote: post #7

Ever driven a vehicle with an automatic transmission rather than a manual gearshift with a clutch? Then you almost certainly used a fluid coupling: basically two fans in a can with oil so turning one turns the other. The article is so full of hype it doesn't bother to explain how this is different from the "fluid gears" invented in 1905.

As immortalised in the 1978 song "Greased Ligthnin'" from the film Grease: Well, this car is automatic It's systematic It's hydromatic Why it's greased lightnin' (greased lightnin') I am pretty sure that "hydromatic" there is actually "Hydramatic" ( https://en.wikipedia.org/wiki/Hydramatic ).

1978 film (based on a 1971 musical) set in 1958 with the high school kids repairing a beaten up 1948 model year car.

Re: “Fluid gears” invention offers promise for improving mechanical devices

#40

Post by formerly_proven »

bluedino wrote: post #34
formerly_proven wrote: post #33

Earlier quoted context omitted.

Virtually every truck has an automated manual transmission, every EV 2-speed is a DCT, Porsche uses PDKs etc.

Every truck? Like which ones? As an American (land of the pickup truck) I can't think of any

> American (land of the pickup truck)

More like SUVs with beds

But yes, sibling is correct, I'm talking about commercial vehicles.

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