Understanding Variable Pitch Fans: Get Help Here

[Shawnzyoo]

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
Thanks!

 

[roamer]

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.

 

[Averagesupernova]

Just do a little research on how helicopters work.

 

[Mech_Engineer]

Just do a little research on how helicopters work.

Or a turbo-prop airplane...

Or a wind-power generator...

 

[kleinjahr]

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.