<VV> alternate fans

[Dale Dewald]

On 3/17/2013 10:05, Jay wrote:

>>snip<<


> If you could take a Corvair (or other) blower that would supply more
> than enough volume and pressure, then drive it with a variable ratio
> system (like snowmobile?) and control ratio by head temp?
> Then you'd never waste power by pumping more air than needed, and always
> have enough cooling.
>
This is done all the time on heavy equipment (dozers, loaders, graders, 
etc) using hydraulic drive.  Of course, all of these machines have large 
hydraulic pumps and systems already in place from which to tap hydraulic 
flow to run a fan drive.  I would not want to add the complexity of an 
additional hydraulic system to my Corvair, however.

On the other hand, I think Jay may have an idea with some merit. How 
about a compact CVT (variable diameter pulley perhaps?) that is adjusted 
by servo (stepper) motor to maintain a set RPM based on head 
temperature.  It could use  engine RPM and the motor position/pulley 
ratio function to keep the fan speed at the desired setpoint. It might 
be desirable for this mechanism to adjust quickly to account for engine 
speed changes when shifting gears (for belt life), but I don't think it 
would be necessary.  The system would just need to maintain a 
time-weighted average fan speed based on head temperature.

Dale Dewald
Hancock, MI