The guys at Nye Thermodynamics seem to have been pursuing
turbomachinery as a hobby/business for years (at least as of 1997-8
when I discovered their site), and in the last several years seem to
be interested in getting usable electrical or hydraulic power from
their gas generators. Specifically, they have a design for gear
reduction of an auto turbocharger turbine to be used with an electric
generator:

http://www.gas-turbines.com/nt-pu37/index.html

http://www.gas-turbines.com/t18a40/index.html


Now my question is this: what, if any, design flaws (weight aside)
prevent this very simple means of gear reduction from being used for
turbocompounding?

The potentially obvious to me would be driven gear rigidity and shaft
alignment, and of course engine overall diameter limitations in
practical applications. Do gears experience unusual stresses at high
speeds that make this a complete bust? Are there efficiency or
durability concerns that make this design impractical for some reason
I can't see?

-Chris Wood

None that I know about. Interesting work.

Paul Lamar


I can see an issue with startup of the rotary engine having to spin up
the turbo if it's directly geared.  The inertia of the turbo would place
quite a load on the starter motor.  I can see where a Sprague clutch
might be required to prevent the bull gear from driving the turbo.  This
wouldn't be an issue with the arrangement they show where the turbo
drives the bull gear attached to the generator.

Maybe the ring gear that the starter uses could be adapted for use as
the turbo driven gear.  Sealing the required lubrication oil inside will
be a challenge.

Mark LaPierre

One uses one way clutch.

Paul Lamar