Variable Cam Stuff

[Ludis Langens]

cosmic.ray at juno.com (Raymond C Drouillard) wrote:
> I like that idea!  It should work well.  The only challenge would be
> getting it to physically fit the area available.
>
> Another variation on that idea would be a planetary gear system.  Drive
> the sun gear with the engine crank, and use the planet gears to drive the
> cam.  Move the ring gear back and forth (with a stepper motor or
> hydraulically) to advance or retard the cam.

Hey, I like your improvement.  It should be easier to get or build a
small planetary gear set than a full differential.  Plus, I think it
simplifies providing bearings.  However, I'd swap the gear usage around:
timing belt/chain over the ring gear, and the stepper/servo on the sun
gear.

As to physical size:  If a 5" diameter / 6" long combination planetary
gear set and differential can handle 150-200 HP, then it should be
possible to build something about the size of a cam gear.  (However,
that 5x6 package seemed to be from a Ford AXOD, so maybe not...)

BTW, my original idea was a FWD style differential, not a RWD style.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/