Variable Cam Timing....

[ducharme at eiss1.psf.ge.com]

Paul Beam wrote:

> You would have to have one on both the cam and the crank.  Slipping the
> crank would counteract slipping the cam.  


Maybe I've been lurking too long, but *HOW* can you advance the cam if you
use two clutches?  The crank is the driving member, and de-coupling anywhere
in the drive train would still retard the cam timing further.

How about a "differential",  i.e. a gear mixer driven by a stepper motor?

You could use a planetary gear set.  The crankshaft driving input would come 
through the sun gear, the camshaft would be attached to the planet carrier, 
and the stepper motor would index the ring gear to advance/retard timing.

Not bad for a EE...


Cliff Ducharme