It occurred to me if you pump enough oil into the rotor roller
bearing it will cool it. Normally a roller bearing requires very
little oil and that is why they are used in charge cooled
engines.
The trouble is there is not enough oil flow to cool it at
high power
levels mixing small amounts of oil with the fuel.
The engine will also need a scavenge pump to get the hot oil
out and
through a oil cooler and back into an oil tank.
On the OMC all that is needed is one small hole in the back
side of
the eccentric lobe to feed high pressure cooling oil into the
rotor
roller bearing. High pressure cooling oil is fed into the
eccentric
shaft from one end or the other.
There will also be a hole in the case just beyond one or both
of the
main bearings to suck the excess cooling oil back out. Some
the of
the fuel mixture will be sucked out as well but the fuel will
go to
the bottom of the oil tank and can be recovered.
If the intake plumbing is changed so no mixture goes into the
main
bearings and through the rotor then no fuel will be sucked
out with
the cooling oil. In other words just a simple p-port is all
that is
required. In fact there will then be no mixture in the center
of the
engine at all.
Here is a scavenge pump on ebay for $219. One section can be
used as
the pressure pump.
This is A MAJOR DEVELOPMENT for charge cooled engine
including the
AIXRO if it works.
Paul Lamar
Paul, and Group, Roller, needle, and ball bearings have a
requirement for light lubrication. Rollers especially. If over
lubricated the rollers can hydroplane, or skip. The problem
is when
they touch back down. Think of a plane landing and how the tires
often chirp as they match speed. The same thing can happen to a
roller bearing with catastrophic results. The steel can weld
together
or chip causing bearing failure
Bill Jepson.
How does load and clearance factor in?
The load on the rotor roller bearing is quite complex due to
centrifugal force on the rollers varying as they make their way around
the center of the e-shaft.
It's a wonder they work at all. I think it is still worth a try.
Paul Lamar
Hi Paul,
How much was that guy wanting for one of those snowmobile
rotary engines, do you know ?
Cheers Chris.
I forgot but he is on here so he will let us know.
Paul Lamar
OMC ROTARY ENGINES
$795 for the 45 hp version, $695 for the 35 HP ones. Discount for
multiples engines.
A portion of each sale go to Paul & his efforts
ofrotaryeng@earthlink.net <mailto:ofrotaryeng@earthlink.net>
<
mailto:rotaryeng@earthlink.net <mailto:rotaryeng@earthlink.net>> to use
as he sees fit (this was unknown to him prior to my mentioning this),
whether as prize $$ for the Everett Hatch memorial fund for speed
records set using rotary engines, the TTC current efforts, the Compound
Turbo Rotary project, etc.
Kevin Richey
Gyrokevin (@) gmail.com
<http://gmail.com> <http://gmail.com>
Paul and group, while I truly like the idea of there being a number of
small rotary engines available, I must repeat the caution about needle
bearings. Flooding those could cause skating and spall. To answer Paul's
question higher load would be helpful here as it would keep the film
thin which should keep the bearings rotating. There are too many other
variables to be certain about how clearance would effect the bearings.
While at Kawasaki I wasn't responsible for engine design but I was able
to talk to those who were. If you see one of the connecting rods for two
strokes they used roller bearings. They were slotted on the big end. It
is not to let oil in as most think, it is to let it out! I did not
believe it when I was first told. It is counter intuitive. If converting
the charge cooled engines it would pay to do more research on this.
Bill Jepson
I don't think they rotate now all of the time anyway :-)
The load various widely with each revolution due to inertia forces.
It is not a simple shaft rotating around a fixed center.
I'll bet that is where the research was done you speak of :-)
I have SAE 730119 Titled Outboard Marine Corps Production
Rotary Combustion Snowmobile Engine.
They did mention bearing loads. It was not oil cooled because
it was more expensive. They probably saved a $100. They also
said it was less sensitive to exhaust back pressure than a 2 cycle
piston engine. It is a very interesting paper and I will scan it
soon and upload it. This was before synthetic oil so some what
more continuous power can be had as the rotor bearing temperature
is the limiting factor. Most oils break down at 250 F Mobile 1 keeps
going up to 500 F. Parts of the rotor are running at 691 F at 5500
RPM and WOT.
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 1998-2016 All world wide rights reserved.