GearHeads Forum

John:

  Im my intent to relase the roots blower with a casing around it so it can be used as a pump
as it meant to be. GT will re-extrude the blower, and all other gears to correct problems as well
as to add some more functionallity to the whole thing.

  Glad to see the backlash is better. The planetary doesnt actually spread anytime in backlash, all backlash really
does is add shaft distance so it draw the inside gear away from planetaries edge.. even that can cause hard running
in some situations.. Ive noted this on my list to look at as well.

Thx, good work..

Art

Hi Art,
I've done some more experimenting with the backlash on a standard spur gear planetary and the inner gears handle the backlash perfectly however that backlash does not seem to translate to the outer ring gear,  that is probably one of the reasons my planetary was too tight, the inner gears were spreading out and the outer ring gear wasn't accomodating the new spacing, I'll probably have better luck with a very minimal backlash.

I've also created a roots blower - Now that I've built it, any hints on what to do with it?  (be polite)

John

John:

  Planetary backlash does work in spurs, I may not have it turned on it noncircular. This is because backlashing a planetary gear is
very dififcult when its round, let alone when its noncircular. Its the natue of a planetary that it has concave interferance. That is
to say that in any position, the inside gear is seeing a convex surface. So moveing the gear even slightly away from mesh
can tighten the teeth on the sides of the main engaging tooth. (Its sort of like the trouble requireing fewer teeth on a shaper when doing an inside gear..)
  The real solution is probably to have a very slight ly lower mod or higher dp on the inside gear. Im not sure I allow that, I cant recall
if I have it error out on differing modules or dp's in noncirculars.. Ill check when next in the code base for that.

Thx
Art

HI John;

I'm pretty sure Art implied backlash functionality with these as I ran onto the same problem in our planetary gear tests. I will verify and get back to you however, maybe something got turned off in later revisions.


Cheers
Bob

Hi Art,
I've built a couple of standard spur gear planetaries.  They mesh like a glove, however my question is - does the backlash work when making a planetary?  The Planetaries I have built are really tight, and they free up a little when worked but I would like to build in some backlash.  I've tried a couple of settings on backlash but it doesn't seem to make any difference.