I don't think I've ever seen a 'mule drive' done with roller chain.
It's damn hard on v-belts, so I wouldn't expect long life.
However, I think I've seen drawings of roller chain with twisted links, so the chain could flex in two planes. Never seen it in real life, but ISTR some of Berg's variants on cable chain having the right symmetry to do it, as of course does common 'bead chain'.
Greg - mostly relative rpm (+/-10%)control for the output shafts
- 90 degree drive not necessary
Thanks Tmoose - for posting a video site that works for type 2
-- there also is a type 1 diff. video somewhere.
Standard differentials that handle 100-200 hp are pretty heavy - these differentials because of the large diameter gears might be lighter and if operated in a clear environment would not need much cooling oil because of the large exposed to ambient surface.