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Improving efficiency
Parker-Hannifin is running a competition among college students to
design a hydraulic drivetrain for bikes that's more efficient than chain drive. "The challenge is to make the bike more efficient using improved power transmission and energy recovery..." http://tinyurl.com/5q32l Feel free to lie about where you're located. -- Ray Heindl (remove the Xs to reply) |
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Ray Heindl wrote:
Parker-Hannifin is running a competition among college students to design a hydraulic drivetrain for bikes that's more efficient than chain drive. "The challenge is to make the bike more efficient using improved power transmission and energy recovery..." http://tinyurl.com/5q32l Feel free to lie about where you're located. Excerpt: "A hydraulic system has potential for capturing and storing energy as the bike goes downhill. The pump forces the fluid into a chamber called an accumulator that later is released to provide a burst of power in going uphill." I'm thinking about a different kind of BURST of power one might get. Don't think I'm gonna wanna ride one of these. Mark Janeba |
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Per Mark Janeba:
Excerpt: "A hydraulic system has potential for capturing and storing energy as the bike goes downhill. The pump forces the fluid into a chamber called an accumulator that later is released to provide a burst of power in going uphill." Wasn't this the stuff of an April Fool's joke in one of the bike mags some years back? -- PeteCresswell |
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On Sat, 22 Jan 2005 17:32:50 -0800, Mark Janeba
wrote: Ray Heindl wrote: Parker-Hannifin is running a competition among college students to design a hydraulic drivetrain for bikes that's more efficient than chain drive. "The challenge is to make the bike more efficient using improved power transmission and energy recovery..." http://tinyurl.com/5q32l Feel free to lie about where you're located. Excerpt: "A hydraulic system has potential for capturing and storing energy as the bike goes downhill. The pump forces the fluid into a chamber called an accumulator that later is released to provide a burst of power in going uphill." I'm thinking about a different kind of BURST of power one might get. Don't think I'm gonna wanna ride one of these. Mark Janeba Dear Mark, Actually, accumulators are quite safe, though a tad heavy--look into the hydraulic ram pump invented by MontFogelir--er, Montgolfier. http://science.howstuffworks.com/question318.htm Regrettably, I can't find the site with the really elegant picture of a j-bend pipe with a cannon-ball that makes the operation of these impossibly simple pumps clear even to me. Joe Montgolfier |
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Accumulators are a mature 'technology' at much higher power levels than
appropriate to bicycles. If there is a hazard then it is due to the particular design. I don't intend to visit the site but their project specifications will be interesting if they really expect to improve on the chain/cog system. For instance, the below, "power transmission and energy recovery..." "Mark Janeba" wrote in message ... Ray Heindl wrote: Parker-Hannifin is running a competition among college students to design a hydraulic drivetrain for bikes that's more efficient than chain drive. "The challenge is to make the bike more efficient using improved power transmission and energy recovery..." http://tinyurl.com/5q32l Feel free to lie about where you're located. Excerpt: "A hydraulic system has potential for capturing and storing energy as the bike goes downhill. The pump forces the fluid into a chamber called an accumulator that later is released to provide a burst of power in going uphill." I'm thinking about a different kind of BURST of power one might get. Don't think I'm gonna wanna ride one of these. Mark Janeba |
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On Sun, 23 Jan 2005 13:07:59 -0800, Mark Janeba
wrote: wrote: On Sat, 22 Jan 2005 17:32:50 -0800, Mark Janeba wrote: Ray Heindl wrote: Parker-Hannifin is running a competition among college students to design a hydraulic drivetrain for bikes ... Excerpt: "A hydraulic system has potential for capturing and storing energy as the bike goes downhill. The pump forces the fluid into a chamber called an accumulator that later is released to provide a burst of power in going uphill." I'm thinking about a different kind of BURST of power one might get. Don't think I'm gonna wanna ride one of these. Dear Mark, Actually, accumulators are quite safe, though a tad heavy... I'm trying to imagine one that is **light enough** to be practical on a bicycle - it still adds up to BOOM!, at least IMHO. Side note to "Junkyard Wars" viewers - did you ever notice how the hydraulic designs almost always lose - not because hydraulics are inherently a bad idea, there's just some things they weren't meant for - I think bikes and bodge jobs go in this category. Mark Janeba Dear Mark, If you're going to try to drag this hydraulic bicycle drive train thread off into the weeds of "practical," then I for one refuse to pursue it! Indignantly, Carl Fogel |
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Per Mark Janeba:
Side note to "Junkyard Wars" viewers - did you ever notice how the hydraulic designs almost always lose - not because hydraulics are inherently a bad idea, there's just some things they weren't meant for - Can anybody offer a ballpark figure for hydraulic drive efficiency vs gear? It always seemed to me like the ideal multi-use walkbehind garden tractor would be hydraulic drive and hydraulic PTO... Drive bc brakes/power could be integrated into a single handgrip for each wheel (as belt systems are today...) PTO bc it would enable separating the accessory-joining mechanism from the PTO power transfer mechanism - enabling a vastly simpler more trouble-free docking system. But nobody's doing that - and my first thought is that hydraulic systems just soak up too many horsepower for small applications. -- PeteCresswell |
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On Mon, 24 Jan 2005 00:47:41 GMT, "(Pete Cresswell)"
wrote: Per Mark Janeba: Side note to "Junkyard Wars" viewers - did you ever notice how the hydraulic designs almost always lose - not because hydraulics are inherently a bad idea, there's just some things they weren't meant for - Can anybody offer a ballpark figure for hydraulic drive efficiency vs gear? It always seemed to me like the ideal multi-use walkbehind garden tractor would be hydraulic drive and hydraulic PTO... Drive bc brakes/power could be integrated into a single handgrip for each wheel (as belt systems are today...) PTO bc it would enable separating the accessory-joining mechanism from the PTO power transfer mechanism - enabling a vastly simpler more trouble-free docking system. But nobody's doing that - and my first thought is that hydraulic systems just soak up too many horsepower for small applications. Dear Pete, While this page is probably discussing engines much larger than bicycles (40 horsepower), it finds 60-85% overall efficiency for hydraulic drives (see section 4.3): http://www.omax.com/drive_pump.html Derailleur-style bicycle chains have been tested at 90% to 95% efficiency: http://www.ihpva.org/pubs/HP52.pdf Carl Fogel |
#10
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On Sun, 23 Jan 2005 13:07:59 -0800, Mark Janeba
wrote: wrote: On Sat, 22 Jan 2005 17:32:50 -0800, Mark Janeba wrote: Ray Heindl wrote: Parker-Hannifin is running a competition among college students to design a hydraulic drivetrain for bikes ... Excerpt: "A hydraulic system has potential for capturing and storing energy as the bike goes downhill. The pump forces the fluid into a chamber called an accumulator that later is released to provide a burst of power in going uphill." I'm thinking about a different kind of BURST of power one might get. Don't think I'm gonna wanna ride one of these. Dear Mark, Actually, accumulators are quite safe, though a tad heavy... I'm trying to imagine one that is **light enough** to be practical on a bicycle - it still adds up to BOOM!, at least IMHO. Side note to "Junkyard Wars" viewers - did you ever notice how the hydraulic designs almost always lose - not because hydraulics are inherently a bad idea, there's just some things they weren't meant for - I think bikes and bodge jobs go in this category. I also notice that the junkyard teams using pneumatics and hydraulics always get fresh plumbing, fitments and nubbins. Ron |
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