Paul,

 I found a good paper on traction drives (34MB) complete with
 illustration. It is interesting to note the researchers
references to
 the bearing like attributes of the device and the need for similar
 alloys, hardness and tolerances.


http://www.grc.nasa.gov/WWW/StructuresMaterials/TribMech/research/A_gear_high_speed.html
 Regards

 Doug in Japan



BTW I notice they mentioned 15,000 feet per minute pitch line velocity
which is a lot faster than I could find previously. Encouraging for
a simple turbo charger based turbo compound engine.


Paul Lamar

Paul, I'm not finding anything more than a webpage at that link,
is there more 'in-depth' info other than the webpage? I'd love
to see how they are lubricating gears at 15k-fpm..  I've got
an app that is about 1/2 that.. and it looks impossible..

Jarrett Johnson

http://www.grc.nasa.gov/WWW/StructuresMaterials/TribMech/publications.html#aerodrive

Try this one.

http://gltrs.grc.nasa.gov/cgi-bin/GLTRS/browse.pl?1985/RP-1152.html

Paul Lamar