Royce,
On the 2 rotor engines, the rotors are
cooled by spraying oil inside of
the rotor. Will there be a similar cooling
means for the single rotor and if
so how will it be done? If it is eliminated,
will this compromise the
reliability of the engine?
Thanks.
Wally
Wally the rotor cooling oil spray will still be
used. The jet will be relocated to
the e-shaft between the rear end housing and the
rotor. Remember the rotor is being
geared from the front stationary gear.
Royce
Francois St-Germain wrote:
There is no need for the oil jet spray on a single
rotor. The cooling oil comes from the rotor
and is evacuated by the main bearings drain.
On a 2 rotor the front and the end extremity are
cooled this way.
Frank
I am not so sure I agree with this Frank. The oil squirter actually
injects the proper amount of cooling oil into the rotor.
Eliminating the oil squirter will cause problems.
This is no different than a piston engine with an oil
squirter squirting oil into the bottom of a piston.
Paul Lamar
Frank, our study of the engine and the way it works, leads to a
conclusion that the mazda rotary does indeed use the oil sprayed into
the rotor to cool the rotor itself. We are going to use a jet on the
rear of the rotor to spray an oil stream directly into the openings of
the rotor. It appears that that is the reason for the chanells being
cast into the rotor so the oil can reach the inside of the rotor and
extract some of the heat of combustion from the rotor.
Some of the single rotor engines we have seen on the web say their rotor
is air cooled. (don't see any cooling fins on the mazda though. Maybe
they just let the air in the engine absorb the heat)
The rotor will have to be cooled some way, in order for it to remain
stable during operation. It will absorb a lot of the heat from
combustion, and there is no other way for it to leave the rotor except
in the oil. This is why the mazda rotary extracts such a high percentage
of it's rejected heat in the oil.
In our single rotor we are deviating from the mazda design in several
areas. However we are retaining all the features/design ideas that are
important for high power and longevity.
Paul says that mazda runs the coolant down the hot side to pick up heat.
and then down the cold side to warm the cold side to about the same temp
as the hot, side so the engine does not try to twist (go bananas :-). )
We have looked at that, and it is a good point. Even on the single
rotor where there won't be as much problem with that as a two rotor, we
still think it has some merit.
We do agree with Richard that the oil passages can be modified since
thay feed oil to the shaft and bearings either way.
We don't agree that the oil pressure regulator should be left out
though. Most oil pumps that we know about have a pressure relief in the
pump or at least the discharge passage. This prevents the pump from
developing excessive pressure and destroying something, as well as
relieving the engine of the extra load developed from unneccessarly high
oil pressure. It takes considerable force to turn a fully loaded pump
making 100 PSI. Try turnig one by hand even at a low pressure and you
can see that.
In order for the oil spray jet to be used on a single rotor the rear
bearing support (stationary gear) has to be modified.
There are only two ways to gear the rotor, either with the front gear,
or the rear gear. Richard brought up an excellent point on this. The
rear support is much larger and heavier than the front gear. The front
gear also controls shaft endplay. It just about has to be there. We
chose to use the front gear (support) in order to retain shaft endplay
control as designed, and to make the rear support from aluminum. It
looks and functions just as the cast one does, except for the gear
portion being missing. It sure does weight much less. We will also be
shortening it a little next to the rotor, in order to better accomodate
the oil spray jet.
The spray jet will also have a carb jet pressed into it to give better
oil control, and thereby eliminate the spring and check ball.
The angle of this jet is important so as to get the spray into the
rotor, and not on the edge of the bearing bore.
If anyone has a better idea on the spray jet, we would like to know
about it.
Royce
BTW Paul, welcome back you are missed, and so is the letter.
Thanks Royce. From personal experience if you block the output
of a positive displacement pump and you continue to over power it
you can indeed fail something. Probably the input shaft.
Paul Lamar
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