George Lendich wrote:
Paul,
Well I received my Planetary yesterday looks ideal for the 2.85, all
up
weight is 6.5 lbs.
E4D 15FN C6/E4D Planet Front with bearing
E4D 30AN Gear Front Ring
E4D 41BN Hub Front Ring Gear
E4D 3887AN Sun gear forward
The Ring gear (with the usual plate) and in this case there is a
needle
roller bearing between
this plate and the planetary housing which has a female spline
housing
(all part of the planetary
housing) which goes through (the usual plate) and will be good for
driving the prop shaft (i.e.
driving from the planetary housing)
I don't know if the needle roller bearing will be strong enough, or
should be replaced with a
larger ball bearing?
Depends on the overall design of your gear box. Do you have a screen
capture
of the drawing? PL
Then there is sun gear (however no thrust gear between the sun and
palanetary housing) - I believe
one will be required here and there should be sufficient room for
one.
Tracy if your reading this, I would be buying one of yours, if it
weren't for the terrible
exchange rate - but necessity is the mother of invention in this
case !!
The ring gear doesn't have the larger flat teeth, as seen on some
C6,
however it has smaller
spline teeth which will be quite well suited for holding the ring
gear
in place.
George (down under)
No problem George, I like to see people do their own thing and I know
the
exchange rate problem.
I found that the needle thrust bearing (stock) will work fine but the
life
span was less than I wanted (using industry standard formula for L10
life)
so I went to a roller bearing (larger diameter "needles"). I tried
ball
bearings before the roller and they were a disaster, at least at input
shaft
speeds. You can see a picture of my ball bearing failure on my website.
I'd suggest sticking with rollers.
Let us know how the project progresses.
Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com
I think you two are talking about two different needle bearings.
I think George is referring to the one between bulkhead
and planet carrier. Very low RPM compared to the helical
sun gear thrust bearing. Unless of course he is using it
for a prop load thrust bearing. Not likely because of
the spline on the planet carrier.
You, I think, are talking about the high RPM helical
sun gear thrust bearing.
Also several needle bearings back to back will work
for the helical sun gear thrust bearing as the RPM of
any individual one is reduced consequently the life is
increased.
BTW Tracy, I am getting some bounces on your email. Did
you get the latest schematic of the RS232 switch today?
Paul Lamar
Paul/ Tracy,
Thanks for the feed back- see drawing.
I was concerned about the size of the (yellow) bearing but it would appear
that I have little option but to leave it the same size because of limited
space. From what Paul says it should do the job - it's just that it looks
mighty thin at 5/32"
Tell me if I'm wrong:-
With the sun gear turning it tends to push the sun gear and planetary
apart - so thrust bearing behind the sun gear ?
Needle bearing can tolerate very high thrust loads but only
at moderate to low RPM's. The big problem is the thrust bearing on
the engine side as it is rotating at 6000 to 7500 RPM while
the planet carrier is rotating at 2000 to 2600 RPM in the same
direction. A difference of 5000 RPM. Needle bearings don't
like to rotate at those speeds. So you need at least two back
to back on the engine side. Three would be better.
this slows the RPM of each individual needle bearings to
one third of the total.
On the prop side the problem is not so severe as the housing
is stationary of course and the planet carrier and prop shaft
are rotating at a difference of only 2600 RPM. So the stock
needle bearing that came with the Ford planet set is fine.
Do you think a bearing is required between the sun and planetary housing?
there is sufficient room for a small bearing.
Yes. Absolutely see above.
I haven't figured out how to attach the planetary housing to the prop shaft
yet -still pondering, any/all advice is welcome.
Well you could use the stock splines or do a trick like Power
Sport does and bolt a flange to the inner end of a thick wall
prop shaft using s slew of small bolts. Then bolt the flange
to the planet carrier with six larger bolts.
The attached drawing psru5a shows the 2.17:1 configuration where
power is removed from the ring gear. In your case the
ring gear is locked to the housing and power is removed
from the planet carrier.
Also what are the attachment points to the housing ?
I don't follow you here?
George(down under)
George, Please display the drawing on your screen and do the screen
capture trick. Then send us the gif or jpg so we can all read
it. dwg files are not compatible from ACAD version to ACAD version
and it is a lot of work for me to convert them to gifs.
Do I have any volunteers?
Paul Lamar
The AirCraft Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/
Copyright 1998-2002 All world wide rights reserved.
