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Variable Pitch Fans

  1. Sep 15, 2006 #1
    I was hoping that someone here would be able to help me understand variable pitch blade systems for fans/turbines and how they work
    I have already searched the internet quite a bit without much luck
    There are a few mechanical drawings but they leave a lot to the imagination
    Any help is greatly appreciated
  2. jcsd
  3. Sep 21, 2006 #2
    I bet there are many different design strategies to make a variable pitch fan, but the one I saw was somewhat simple. Essentially the rotor could be pushed in and out about 3" axially by a hydraulic piston. The rotor was attached to "lever arms" and the "lever arms" were attached to the blades. When the "lever arms" are pushed in or out they rotate the blades which are mounted in an outer hub assembly. By rotating the orientation angle of the blades the pitch is effectively changed. It is confusing to talk about but when seen it is quite simple.
  4. Sep 21, 2006 #3


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    Just do a little research on how helicopters work.
  5. Sep 25, 2006 #4


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    Or a turbo-prop airplane...

    Or a wind-power generator...
  6. Sep 27, 2006 #5
    Controlled pitch propellors. Both aircraft and ships.
    For fans you might be able to do it with mechanical linkage to some variant of a swash plate. If you don't know what a swash plate is look it up under hydraulics, axial flow piston pumps/motors.
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