Does anybody have a parts list with numbers for the gearbox?
Kevin Alderman
Tracy's gear box? I can give you part numbers on the planetaries.
His prop shaft and flange was based on a modified GM truck rear axle
and bearing.
The rest of the parts are custom made.
The rear planet is Slauson Transmission Parts E4D 40. Front planet is
E4D 30 Sun Gear E4D 28 Rear ring gear E4D 74. Front Ring gear E4D 61.
Paul Lamar
Paul, if memory serves, the only thing that holds the axle bearing to
the axle was a light press fit on the axle, and then a press fit lock
ring. Is that right, NAW, could not be just that, right?
Steve Carlisle
It is not a light press fit. It was done with a 20 ton press.
That takes all of the prop thrust. That also holds the wheel in and the
axle on in the truck.
Paul Lamar
Paul, on this type of axle, I believe the bearing is held in the diff
housing by a bearing retainer plate, usually attached with 4 bolts. The
axle is held into the side gear with a heavy clip , which fits into a
groove at the start of the axle. On the redrive in question, it seems
the output propeller shaft, with propellor is only held in with the
proper interference fit.
It seems to work , so far !
Steve Carlisle
No. Tracy holds it in with a retainer plate that is screwed to the
housings with a bunch of 10-32 screws. These screws take all thrust
loads. See the attached jpg.
BTW I finally figured out why Tracy was using that O-ring that Scott
mention.
My guess is he had a bunch of cases machined for the 2.12:1 wherein the
ring gear rotated. Those cases were bored to a large enough inner
diameter for the ring gear to rotate.
Tracy finally realized that 2.12:1 was not going to cut it with a
rotary. The tip speed on the prop was limiting the RPM and the HP. We
talked a lot about that on the newsletter and I have all those old
messages. He had to lock the ring gear and take power out of the planet
holder instead.
So he used the same front planet
carrier because he had them in stock and used that powdered metal
bulkhead to keep the ring gear stationary in the now over sized case .
The ring gear is a sloppy fit on the bulkhead so he needed a way to damp
that out. It probably rattled when he ran the 2.85:1 for the first time.
No problem for the operation because planetares are self aligning. Hence
the O-ring.
My fix for the bulkhead is to coat the ring gear with RTV. In theory
that alone would prevent the ring gear from rotating as the adhesive
strength is 3,000 pounds per square inch, The half inch extended point
set screws are belt and suspenders and the RTV does the damping.
I suggest the rear planet instead as that will yield 3.12 to one gear
reduction.
Much more power.
Paul Lamar
Hi Paul,
I have a couple of reservations about using RTV to lock/dampen the
ring gear in the housing. 1) how will you ensure that you get the RTV
into the gap all the way round evenly ? 2) how will you know if it has
cured properly right through, it will take forever. Wouldn't it be
better to use Locktite retaining compound 648 or a two part glue like
Araldite construction adhesive (the blue/yellow stuff). You wouldn't
need set screws.
Chris Hoskins
You can leave out. You don't really need it.
How's the run-out on your lathe?
Assuming you have a nice slip fit for the ring gear in the housing
the extended point set screws will do it all.
It is better if there is nothing in there then you can take it apart for
service.
If there is some small lack of concentricity for the assemble you will
notice it
when you turn it over by hand. Then if you have some you can bore the
housing
a few thou over size and use the extended point set screws to adjust the
centering. I did the chuck on my lathe that way and it is down to near
zero run out.
In Tracy's case there is a large gap between the ring gear OD and the
housing ID.
Paul Lamar
The Rotary Engine free News Letter. Powered by Linux. If you want off
the list PLEASE let me know and I will remove you. ACRE NL web
site.
http://www.rotaryeng.net You Tube
http://tinyurl.com/beqqxas
Copyright 1998-2017 All world wide rights reserved.