You could improve it by making the cylinders have sticky-out bits that would scoosh the fluid around better, like little paddle wheels, and if you wanted to get some serious torque transfer you'd push the two paddle wheels so close together that the paddles actually kind of intersect.
It's not new that you could set up co- or counter-rotation in such a system. This seems like the sort of thing G. I. Taylor had as a bath toy.
Maybe impossibly tiny and unresponsive torques are useful somewhere?
The article is so full of hype it doesn't bother to explain how this is different from the "fluid gears" invented in 1905.
Well, this car is automatic
It's systematic
It's hydromatic
Why it's greased lightnin' (greased lightnin')
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.
That's as close to fluid gearing as you can imagine.
Not as funny as with CVTs though where you can have the road speed increasing as the engine RPM decreases. Or there was a guy about 20 years ago who had a Volvo 340 automatic fitted with a Volvo 760GLT 2.3 litre turbocharged engine, which he used to compete with at drag races at the local raceway. It did not too bad against similar vehicles in its class, but it sounded pretty funny because it would just race up to about 4500RPM and stay there for the whole run, as you had a rising howl from the drive belts at the back.
Of course my car has a torque converter and two viscous couplings - the TC between the engine and gearbox, one viscous coupling that makes the centre diff act like a very stiff LSD, and of course one that works the other way (eases off as it slips) to let the cooling fan stay at a steady speed.
Are you sure?
https://en.wikipedia.org/wiki/Continuously_variable_transmis...:
“The most common type of CVT uses a V-belt which runs between two variable-diameter pulleys.
[…]
A belt-driven design offers approximately 88% efficiency, which, while lower than that of a manual transmission, can be offset by enabling the engine to run at its most efficient speed regardless of the vehicle's speed.
[…]
Disadvantages of a hydrostatic CVT include:
Reduced efficiency. Gears are one of the most efficient methods of mechanical power transmission, with efficiencies as high as 90 percent in many cases. In contrast, few hydrostatic transmission systems achieve more than about 65 percent efficiency”
https://en.wikipedia.org/wiki/Automatic_transmission#Hydraul...
> "A continuously variable transmission (CVT) is an automatic transmission ..."
https://en.wikipedia.org/wiki/Continuously_variable_transmis...
"Automatic transmission" just means that you do not change gears manually, which is also true for CVT.
As an American (land of the pickup truck) I can't think of any
More like SUVs with beds
But yes, sibling is correct, I'm talking about commercial vehicles.
Used since the 60s lol
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.
Alternate: New Ways to Understand, Control, and Exploit Hydrodynamic Spin-spin Interactions in Applications
The article doesn't really deliver on either headline, but that's the fault of the article, not the study.
(Can't tell what the submission title was, but the byline (with quotes) works too: “Fluid gears” invention offers promise for improving mechanical devices)
vlachen•3w ago
Aardwolf•2w ago
If the gears don't at least require an app with a subscription and regular updates to use, they must be old tech
/sarcasm