Mailing List flyrotary@lancaironline.net Message #27385
From: george lendich <lendich@optusnet.com.au>
Subject: Re: [FlyRotary] Re: Richard Sohn's housings
Date: Thu, 3 Nov 2005 07:49:37 +1000
To: Rotary motors in aircraft <flyrotary@lancaironline.net>

Russell Duffy wrote:

> There are a few planes that can accept a single rotor as is, but I
> think we're going to need aluminum housings to ever make it into the
> mainstream.  I had always hoped Racing Beat would finally get theirs
> done, but I've all but given up hope on them now.
>

Richard said during his presentation that aluminum housings would not be
appropriate for a dual rotor.  There just isn't enough material to
stabilize the stationary gear was how I understood the explanation
(someone please correct me if I got that wrong).  It may be that Racing
Beat has had their production schedule held up by the laws of physics.

It's a real shame, though.  Aluminum housing could push the installed
rotary's power to weight ratio into the vicinity of .75.   At that
point, builder's would be falling over themselves to convert, and my own
CG concerns would disappear.

I've researched and designed a aluminium rear housings ( our front) and I
didn't find any problems with sufficient material to hold the stationary
gear, in fact there's plenty - in my approach.
If it's in a single and the front ( our rear) the stationary does NO work
other than to be the bearing.
Unless your driving from the front ( our rear), which I think Richard is.
To be fair to Richard, I haven't researched that yet as I came across other
difficulties in the rear housing, which isn't so bad in the front.

My main concern were oil passages and oil drain back passages. One can
barrel drill the passages, as in the Mazda engines, but the sharp corners
are a bit of a problem for good oil flow. I would prefer a much less
restrictive approach, and I have made a suggestion to Richard. The other
problem of drain back (not a problem in the Front - Our back) requires a
much larger passage, which is cast into the Mazda housing. There are other
issues!

The sealing issues I had overcome ( to a degree) however one must remember
that the rotary uses most of it's available space for water cooling, oil
cooling and oil return - there isn't a lot of room to modify these things.

Personally I agree with PL in that the best possible solution is to have an
all aluminium housings with the same wear surface as the Rotary housings.
That mega-bucks of development, not to mention sourcing the technology.

I have spoken to Francois at Mistral about this and it's a major problem to
overcome.
George ( down under)


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