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Hydraulic hybrids

Discussion in 'Off Topic' started by TEG, Sep 11, 2007.

  1. TEG

    TEG TMC Moderator

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  2. mt2

    mt2 Member

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    A Ford F-150 getting 60 mpg city? That's impressive. Of course it does squat for the highway mileage. The good news is that this can be easily incorporated into existing production lines and can greatly improve the efficiencies (and financial bottom line) of fleet vehicles. Think 'garbage truck'.

    The bad news is that it will be used to justify buying a Canyonaro to haul the kids to Cub Scouts.
     
  3. JRP3

    JRP3 Hyperactive Member

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    I'm very skeptical of most of the efficiency claims for hydraulics. Since hydraulic fluid is not compressible the hydraulics are not actually containing any energy, it has to be a pressurized gas system or something like that. It might be good for stop and go traffic in large vehicles but won't do much once you go any distance.
     
  4. tonybelding

    tonybelding Active Member

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    It could be either a compressible gas (like air, remember the Air Car?) or it could be the walls of the storage tank that are elastic. If you are stretching the walls of the tank, then the tank itself is the energy storage device and the hydraulic fluid merely transfers energy to and from it.
     
  5. JRP3

    JRP3 Hyperactive Member

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    Don't get me started on the ridiculousness of the "Air" car. The inefficiencies of using a power source to create electricity, to then compress air with an air pump that has the same frictional losses as an ICE, then decompress it in a motor with the same frictional losses as an ICE, etc. Then you have people running around all excited by a car that runs on "AIR".
    Anyway, back on topic, I think the hydraulic systems I've seen use nitrogen as the compression gas.
     
  6. mt2

    mt2 Member

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    From Wikipedia
    The hydraulic fluid you buy at an auto parts store is designed not to compress. The fluids used in hydraulic regenerative braking are chosen to compress. The term hydraulic does not imply a particular type of fluid.
     
  7. tonybelding

    tonybelding Active Member

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    I've never heard of a compressible liquid. It's hard for me to picture how that could work.
     
  8. JRP3

    JRP3 Hyperactive Member

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    I'm sorry but I'm pretty sure you're incorrect. Follow some of the links in this thread and you'll see they are specifically using nitrogen gas as the compressive medium, not the hydraulic fluid. Unless they are mixing the gas into the fluid, which doesn't make much sense, and still would be the gas that's compressing not the fluid.
     
  9. mt2

    mt2 Member

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    Yeah, I knew that. But I edited the word "gasses" out of my post and put in "fluid" because it fit with the Wikipedia snippet better. The engineers in my family are always correcting me on such things. I can ruin an entire Thanksgiving dinner by saying something about "centrifugal force".

    Point is that a hydraulic system doesn't mean they use hydraulic fluid from Auto Zone.
     

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