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Hi Ernest.
<Is the pictured shaft the input or output shaft?
The shaft pictured is the input shaft. It's 8.42 inches long. Spline at one
end of shaft mated with drive plate. Helical gear at other end is the sun gear
for planet cage.
<Is the basic idea to just put a stiff
<spring between the input
and output shaft
Yes, that's the basic concept. Except the "spring"
is solid if flex exceeds .005"
3 basic concepts to the redesign:
1) The original design controlled input shaft fore
aft thrust by stopping movement at the two ends of the shaft. 8.42" apart. This
makes the design sensitive to temperature. Clearance changed with temp. I
controlled thrust on both ends of sun gear, only 1" apart. So temperature can no
longer affect end thrust clearance. This also allows reduced clearance.
2) The "cage cap" I used acts like both a spring
and stop. It flexes .005", then becomes solid when it touches end of output
shaft. Wear marks on cage cap told me how often it flexed that .005".
3) I didn't allow any assumptions. I found ways to
prove clearances...modeling clay is great way to measure clearance. Found ways
to prove how just how much difference design made. Measured spline wear pattern
width, etc. You could prove how much fore aft movement you have just by
measuring wear pattern on your sun gear. Great way to forecast future fatigue
failure. I even put a few kernels of white Styrofoam at thrust bearing to prove
I had adequate oil flow. Operate drive for 3 seconds, take apart, foam moved
from key location.
I know it's tough to follow my descriptions. One of
those things you have to see to understand fully.
-al wick
----- Original Message -----
Sent: Wednesday, July 13, 2011 8:19
AM
Subject: [FlyRotary] Re: RD-1B
failure
Al Wick wrote:
> I also came up with this wild idea I
could have zero clearance at end of
> input shaft. I tried it and
surprise, it worked. I called it a "cage
> cap". See my web site.
> http://www.maddyhome.com/canardpages/pages/alwick/index_files/Page404.htm
>
I'm not sure I understand. Is the pictured shaft the input or
output shaft? Is the basic idea to just put a stiff
spring between
the input and output shaft so that one is always pushed forward and the other
always pushed to the
rear...eliminating the possibility of the input shaft
building inertia?
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