On May 18, 6:44*am, routund wrote:
wrote:
On May 16, 4:13 pm, bildan wrote:
Re. PSRU's
There is a gear reduction unit that handles massive torque and power
the size of a a one-pound coffee can - it's the planetary gearset from
an automatic transmission. *I have two in my Jeep Grand Cherokee
'airport car' transmission that have lasted 300,000 miles - so far.
These things are built to very tight tolerances and are VERY tough.
If you want still tougher, speed shops sell replacement planetaries
that can handle 1500HP or more. *Ask *one to handle only 100HP and
they should last forever. *You can specify just about any reduction
ratio you want.
All you have to do is machine a nose case from billet aluminum to hold
the planetary gearset and the thrust bearing.
* I wish it was so simple. Without a flywheel and/or torque converter
to damp the engine's power pulses, the engine's desire to run in a
vibratory fashion will conflict with the prop's desire to run
Seriously, Tracy Crook and others have done a lot of work on the planetary gear
redrive in conjunction with the Wankel rotary, which BTW is a much better
solution to the overall search for the optimal aircraft engine. *Their
conclusions are similar to the ones you pointed to.
One of Tracy's non-intuitive conclusions was that zero lash was NOT
necessary, and that increasing lash reduced the natural frequency of
the system. Increase the lash enough, and the "rattle" is below idle
speed. Tracy DOES use a rubber damping element on the drive side of
his units.
http://www.rotaryaviation.com/psru_development.htm
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Tracy's units are based on the Ford C-6 truck transmission, and are
too heavy for a 40 - 60 HP engine. How about something lighter? I
propose we take a look at the Toyota A131L, which was in production
FOREVER
Applications:
* 1984-2002 Toyota Corolla (1.6L 4A-FE / 3 spd.) (includes FX)
* 1985–1988 Chevrolet Nova
* 1990-1992 geo prizm
Another possible choice would be the A40
Applications:
* Carina 1600 rwd 08/75-04/84
* Carina 1800 rwd 04/81-04/84
* Celica 2000 rwd 01/78-07/82
* Corolla 1300 03/80-09/83
* Corona liftback 04/79-03/81
* Cressida 12/77-06/81
* Cressida 2000 05/81-09/82
* Crown 2600 05/77-03/80
* Starlet 1300 02/82-02/85
or the 245E
Applications:* 1993-2007 Corolla 1.8L 7A-FE