Attempting to understand the Wankel engine
Is stationary gear in fact a rack? Is it just a circular toothed bar that
engages with a gear attached to the rotor one third larger that rolls around
it?
Ans: The stationary gear is just a spur gear. The gear attached to the rotor
is an internal spur gear. Check out:
http://www.keveney.com/Wankel.html
It appears that in one e-shaft revolution of the Mazda rotary engine that
the e-shaft lobe compels only 34 of the 51 internal gear teeth in the rotor
to engage with the stationary gear. Is the rotor in this instant compelled
to be held stationary for two thirds of a revolution?
Ans: No the rotor never stops turning.
In three e-shaft revolutions does the rotor only rotate twice?
Ans: The rotor turns only once. Check out:
http://www.rotaryeng.net/how-wank-works.jpg
Does the combustion against the rotor push the e-shaft the same as a piston
engine would push against a crankshaft with a .591" throw? Does the
subsequent turning of the e-shaft lobe force the rotor to revolve around the
stationary gear at two thirds the e-shaft travel and become out of phase one
third every revolution? With the rotor solidly linked to a stationary gear
is it possible for the combustion pressures to turn the rotor?
Ans: Yes but I don't know about the .591". It is small but finite.
You might say the rotor orbits around the e-shaft and is in turned
rotated by the stationary gear. That is the reason it is sometimes
called a planetary engine. Just like the earth rotates around its own
axis while it is rotating around the sun. Needless to say
there is no stationary gear to keep the two in exact sync.
Could the superior performance of the rotary engine be due only to the
superior length of the strokes? It appears that the Wankel engine completes
twelve strokes in 1080 degrees of e-shaft rotation. As three strokes take
place simultaneously in the Wankel engine, each stroke should have 270
degrees of duration. The one cylinder four stroke piston engines will rotate
six times or 2160 degrees to complete twelve strokes. Each stroke would have
a maximum of 180 degrees of duration. Would this duration also be deficient
due to the stop slow fast slow stop motion of the piston?
Ans: The 270 degrees has little to do with it. Better breathing and higher
RPM have the most to do with it. No poppet valves to get in the way of
the air going in and out. No starting and stopping pistons to cause high
mechanical stresses at RPM's in the range of 6000 to 10,000 RPM.
See:
http://www.rotaryeng.net/Bill-Marvin-timing-diag.gif
Years ago I made a prototype of the Wankel DKM 54 this engine has the
housing rotating over the rotor that is on a stationary bearing off set from
the housing center. In every rotation of the housing the rotor rotated at
two thirds the speed in the same direction. It took me a substantial period
of time to realize that the engine design is poor because it attempts to go
forward and backwards at the same time.
Ans: Not true.
Read
http://www.rotaryeng.net/
INTRODUCTION TO ROTARY ENGINE TECHNOLOGY
Has anyone put any thought into increasing the power and efficiency of the
Mazda rotary engine by changing the placement of the ports and reducing the
port sizes?
Ans: You really need to read the whole web site :)
http://www.rotaryeng.net/ The eff. gets better with larger ports
as the pumping losses are reduced.
Has anyone given any thought to have the combustion pressures actually turn
the rotor and subsequently the e-shaft?
Ans: See the above answers.
I think what you mean to say is: take power out of the rotor.
Yes, one of our subscribers actually suggested that and here
is his sketch of the mechanism. We call it Vance's (RIP) folly :)
Ken McKenzie
Paul Lamar ...No rotor no motor.
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