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“Fluid gears” invention offers promise for improving mechanical devices
- dvh 8mo agoVirtually zero torque right?
- ErroneousBosh 8mo agoI don't see how it could even have any measurable torque. 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.
- beeflet 8mo agoyou could increase fluid viscosity
- dcanelhas 8mo agoIndeed, then this design will truly have come full circle.
- like_any_other 8mo agoThat's a slippery slope that leads right back to traditional gears.
- zahlman 8mo agoDo we understand fluid mechanics well enough now to just design things like this from scratch, or is it still mostly trial and error? TFA seems to imply the latter, but....
- operation_moose 8mo agoThis could have been designed in CFD in an afternoon. Building it in real life is always somewhat cool but the amount of hype they're putting on this is crazy.
- debatem1 8mo agoHow is this different from slushomatics? Sounds exactly like old school fluid couplings.
- angled 8mo agoOr slushboxes …
- Y_Y 8mo agoThere must be some reason PRL chose to publish this, but it's not apparent to me from TFA or the abstract, and I'm not interested enough to login via my institution. 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?
- mcherm 8mo agoEver 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.
- jgrahamc 8mo agoAs 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 https://en.wikipedia.org/wiki/Hydramatic).
- donw 8mo agoIf it’s a hydramatic, be careful to only lubricate it with snake oil.
- ZeroGravitas 8mo ago1978 film (based on a 1971 musical) set in 1958 with the high school kids repairing a beaten up 1948 model year car.
- ErroneousBosh 8mo agoExcept 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.
- yason 8mo agoYeah, 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.
- globalnode 8mo agoreminds me of a tesla turbine -- only less efficient
- bluGill 8mo agoAs what efficency? The artical doesn't say, but hydraulics and automatic transmissions have been around for a long time and are less efficient than regular gears or electric motors. Cars got a good efficieny boost then the locking torque converter was developed.
- mrbn100ful 8mo agoNice to see that they have discovered the Torque converter https://en.wikipedia.org/wiki/Torque_converter https://en.wikipedia.org/wiki/Torque_converter Used since the 60s lol
- kleiba 8mo agoCheck out what this dude came up with 120 years earlier: https://en.wikipedia.org/wiki/Hermann_F%C3%B6ttinger https://en.wikipedia.org/wiki/Hermann_F%C3%B6ttinger
- pfdietz 8mo agoDied 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 https://www.youtube.com/watch?v=NcI67pZe_Ss
- snow_flake 8mo agoThe phys.org article and headlines are misleading, the authors did not investigate systems to actually transmit torque. From what I gather, the interesting findings are the parameters for co-rotation and counterrotation of the driving and driven cylinder, depending on the Reynolds number, distance and so on. To illustrate one of the images of their publication: https://i.imgur.com/m8P2iVw.png https://i.imgur.com/m8P2iVw.png
- MadnessASAP 8mo agoThat would make much more sense then what the article seems to imply (scientists reinvent a 100 year old torque converter! But worse!!). Of course that headline isn't nearly as fun (scientists develop better model for fluid dynamics in torque converter).
- dang 8mo agoCan someone suggest a better (i.e. more accurate and neutral) title?
- bwoah 8mo agoMapping out How Fluid Mechanical Spin-coupling Interactions Depend on Proximity, Confinement, and Flow State 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.
- dang 8mo agoThe limit is 80 chars and I'm not sure how to squeeze those in. I've taken a crack at something simpler in the title above. Does it work?
- gnabgib 8mo agoFrom the original source: Scientists Put Teeth Into Water-Driven Gears https://www.nyu.edu/about/news-publications/news/2026/january/scientists-put-teeth-into-water-driven-gears.html https://www.nyu.edu/about/news-publications/news/2026/januar... (Can't tell what the submission title was, but the byline (with quotes) works too: “Fluid gears” invention offers promise for improving mechanical devices)
- simonjgreen 8mo agoI’m super confused how this any more useful than an oil based hydrodynamic torque converter like you’d find in a “slush box” automatic transmission. The video in the article shows such a low rate of transmission it’s crazy, I can’t think of a purpose!
- meindnoch 8mo agohttps://en.wikipedia.org/wiki/Torque_converter https://en.wikipedia.org/wiki/Torque_converter
- pshirshov 8mo agoEhm, isn't it the same thing as https://en.wikipedia.org/wiki/Torque_converter https://en.wikipedia.org/wiki/Torque_converter ?
- kazinator 8mo agoTorque transfer through a fluid, per se, is old hat: it's been deployed in automatic transmissions starting in the 1940's. Buick's "Dynaflow", etc.
- vlachen 8mo agoI'm not a fan of the bias towards "Gears are old tech, and that makes them bad" but I can see a lot of interesting possibilities with fluid coupling. The variables involved in power transmission for these things would be pretty wild to characterize, and the article video clearly shows inefficiencies in the system with the driven cylinder having counter rotational flow against it.
- Aardwolf 8mo ago> I'm not a fan of the bias towards "Gears are old tech, and that makes them bad" If the gears don't at least require an app with a subscription and regular updates to use, they must be old tech /sarcasm