The outer housing is called the rotor housing. Yes the seals are
located at the three
corners of the rotor. Hence they are called the apex seals. The dish
out of the face of the
rotor forms the combustion chamber. The depth of the dish controls the
compression
ratio. The rotor orbits around the center of the eccentric output
shaft. The time
of the orbit is the same as the eccentric shaft takes to make one
revolution.
As the rotor is orbiting around the center of the e-shaft is is
revolving only
1/3 as fast as the e-shaft. The combustion chamber actually moves
around inside
the rotor housing. For these reasons the engines is sometimes called a
rotary
combustion engine or a planetary engine.

Yes there are lots of formula. The formulas are available in several
books.
I don't have the formulas scanned in but if you can't find any of
these books
let me know and I will scan them in for you.

* The definitive book on the rotary is simply called "ROTARY ENGINE"
by Kenichi Yamamoto published by Toyo Kogyo Co. Ltd. (Mazda) in
1969. This is a highly technical book chronicling the development of
the wankel by Mazda. Kenichi is an engineer and has risen to  CEO of
Mazda.

* This book on the rotary is also  called "ROTARY ENGINE"
by Kenichi Yamamoto published by Sankaido Co. Ltd.
Second edition published in 1981. This is an updated version of
the first "ROTARY ENGINE" book. Confusing eh what? This book
has a much greater emphasis on emmisions.

* Another technical book on the Wankle rotary engine is; "The Wankel
RC Engine Design and Performance" by R.F.Ansdale Published by A.S.
Barnes & Company Lib of Cong 69-18692

* The Wankel engine Design Development Application by Jan P. Norbye.
Chilton Book Company. ISBN 0-8019-5591-2 Published in 1971. A little
history and results of the Wankel engine development by NSU,
Mercedes, Mazda and others and some results of work by
Curtiss-Wright.  Also some history on all rotary engines. Not as
technical as I would like but not bad.



Paul Lamar

by Paul Lamar

The wankel rotary consists of a three sided rotor moving in a
modified oval
chamber or rotor housing. There are at least two holes in the walls of
one
side of the rotor housing. In the other side of the rotor housing
there is
at least one spark plug. One hole is used as an intake port and the
other as
an exhaust port. Just like a one cylinder two cycle piston engine. The
rotor
rotates around the center of the output shaft while at the same time
rotating around its own axis. This is very similar to the way the earth
rotates around the sun while rotating around its own axis. The rotor
rotates
one third as fast about its own axis as it does around the center of
the
output shaft. Actually what is happening is the center or CG of the
rotor is
moving in a circle around the center of the output shaft while the
output
shaft rotates. Very very clever on the part of Felix Wankel to invent
and
engine that uses this motion.

As this motion is taking place the tips of the triangular shaped
rotor are
passing the ports in the housing. As one tip, call it tip A, passes the
intake port in the rotor housing the face behind tip A starts to draw
in the
fuel air mixture. Call it face or chamber number 1.  When the next tip
call
it tip B passes the intake port the mixture is captured and starts to
compress. As the chamber continues around the housing it encounters the
spark plug and the mixture inside it is fully compressed.  The spark
plug
fires and the chamber starts to expand imparting the pressure energy
in the
burning mixture to the output shaft. As the rotor continues on around
tip A
passes the exhaust port and the burnt mixture starts to leave chamber
1.
This completes the four cycles for chamber one. In the mean time
chamber two
and chamber three are completing various cycles of this same sequence
simultaneously.

This three chamber simultaneous action  is the reason the wankel
engine is
so light and compact for the power it is able to generate. Furthermore
the
forces in each chamber due to the pressure in each chamber are
completely
contained in the one piece cast iron rotor. In a four cycle piston
engine
this is not the case. The compression force must pass down a
connecting rod,
into the crankshaft and up another connecting rod into another chamber
that
is expanding and extracting power from the burning mixture. This makes
piston engine force paths and consequent stresses far far more
complicated
than the wankel engine.

Although the wankle has similarities with a two cycle engine,
particularly
in regard with the way the porting mechanism works, it is in no way a
two
cycle engine. All four cycles are continuously taking place
simultaneously
and those are intake, compression expansion and exhaust.

An animated picture is worth many words:
http://www.rotaryengineillustrated.com/
Hans

Quick time does not work with either browser I have.

Here are the math scans Eric. From the Ansdale book.


Paul Lamar
 
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