Is There a Fundamental Difference Between Hypoid Gears and Worm Gears

[Nate]

I've been tinkering with hypoid gears lately, and it seems like it should be possible to set up a pair of hypoid gears with an extreme gear ratio, and "perpendicular" axes so that they would be very similar to a double enveloping worm gear.  Obviously, it's possible to have non-worm hypoids, and non-hypoid worms, but can they overlap or is there some distinction that I'm not aware of?

[ArtF]

Well, your making my head hurt a bit, but yes, it sounds reasonable that a 90 degree hypoid would
make a kind of worm, so one on each side woudl make it double enveloped.. but the tooth of the worm would be a bit thin wouldnt it? Due to the curvature of the worms engaging tooth? Trying to imagine the algorithm that generates the profile is a touch painfull.. like a headache starting way back there.. :) )

Art

[JustinO]

Gear terms can be hard to define, but loosely ....

If you cut away parts of doubly enveloping gear pairs, you can wind up with gear pairs that look like hypoid gear pairs.

[Nate]

... Trying to imagine the algorithm that generates the profile is a touch painfull.. like a headache starting way back there.. :) )

My initial thought about the hypoid worm thing didn't turn out to be true,  I'll have to try something less optimistic about the meshing.  I did get this nifty rack and pinion thing along the way:

[ArtF]

lol

[MBrez]

I'd like to see that printed.  Ever try shapeways.com?

Cheers,
Mark

[Nate]

I'd like to see that printed.  Ever try shapeways.com?

I usually use an FDM printer that I have access to.  I've slowly been improving the printability of the rack.  You're welcome to download and print the STLs yourself if you like.

http://www.pedantic.org/~nate/stls/

[Nate]

I'd like to see that printed.  Ever try shapeways.com?

... only took me 2 years to get around to it. :/