Spiroid,Globoid Gears 1

[MrGear]

Could someone help me about the spiroid and globoid gears.
can we used them instead of hypoid gears. what are the advantages and disadvantages, including design and manufacturing...
The papers i've been looking so far (most of them are Russian) claming that they would be much more efficient and cheap?! basically it looked like a worm gears, and there should be too much sliding so heat generation. I;ll apprciate if someone can help me on the issue (for automotive applications)

 

[Hippo41]

Have you triued a company called DAVALL GEAR in the UK? They have a device called a SPIRADRIVE gearbox which sounds like what you are talking about.

Lester Milton
Telford, Shropshire, UK

 

[EnglishMuffin]

Since only one other person has responded so far, and since I am currently listed as a "top expert" (although I'm not sure how I achieved such exalted status), I will give this a shot.

To a casual observer, a Spiroid and a Hypoid look similar, since the shaft axes are non intersecting and both have similarly tapered pinions. However, Spiroid gears have a primarily screw action, whereas Hypoids have a primarily rolling action. The pinion of a Spiroid set resembles a worm, but Spiroids are more efficient. So they tend to fit somewhere between worms and bevels. They are best used for things like positioning drives - the minimum possible ratio is about 10:1, so they are not an appropriate choice for a typical automotive rear axle. Just as Gleason introduced the Hypoid, I think it was ITW that invented the Spiroid. See

http://www.itwspiroid.com.

Globoid gears, on the other hand, are supposed to be very efficient, and are touted as being ideal for automotive applications that currently use hypoids. See

http://www.zakgear.com/Condrive.html

for example. But I don't know much more about them than that. I hope that "hype" - oids is not also a good description for Globoids.

 

[spiroid]

May I suggest you contact a Spanish company 'Engranajes Especiales', near to Barcelona. Click on

http://www.spiroide.com.

In the 1950's, they built their own machine to cut this type of gearing and have continued to do so since then. I know they manufacture the tapered (worm) shaft pinion with the spiral bevel wheel but I am not sure if they manufacture the parallel(worm) shafts, that Davall supply as the 'spiradrive'.

 

[DrZak]

Worm face gear or Spiroid gear was tested on a car in Russia in 1970 as a replacement of hypoid gear. The worm face gear is not as sensitive as hypoid for mounting. With tapered pinion it is easy to minimize backlash by adjusting the pinion location along its axis. The efficiency is close to hypoid gear with the same ratio. Even better: high ratio hypoid gear may be not back derivable. The manufacturing is less expensive. You do not need a $600000 Gleason machine and use a regular worm gear cutting machine. But there are some problems also. For more information go to

http://www.stepanlunin.com/

For globoid gears do to

http://www.zakgear.com