Allen Chan wrote:
What is wrong with a planetary gear box? They work
great and last forever.
In a purely practical sense, there is nothing wrong
with planetary gear box. It works and people are
happy with it.
However, if you can remove the planetary gear box by
"re-gearing" the crank shaft, you can gain some
mechanical advantages.
1. Remove the weight, of the planetary gb.
2. Remove the complexity( KISS principle) and
possiblity of failure in the planetary gb.
3. Remove the friction, heat, and vibration cause by
the planetary gb.
There are improvements is weight, reliablity, and fuel
efficiency.
Moot points all. ONE CANNOT CHANGE THE GEAR RATIO BETWEEN
ROTOR AND E-SHAFT AND STILL HAVE THE WANKEL THAT WE KNOW
AND LOVE AND HAVE NOW.
Designed right the gear box weight will get down to about
30 pounds. What vibration in the planetary? The vibration
in a two rotor wankel, what little there is of it, with gear box
comes from the fact it fires only twice per rev just like
a four cylinder.
Paul Lamar
The AirCraft Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/
Copyright 1998-2003 All world wide rights reserved.
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History of the invention of the rotary engine by Julian Marsh
1588 Ramelli, an Italian engineer invented a water pump which
continues to be used in oil pumps and compressors.
1636 Pappenheim, a German engineer invented the gear pump which
is still used to lubricate engines. This gear pump made it
possible to dispense with the reciprocating slide valves used by
Ramelli. [Fig 3]
Pappenheim drove his machine by an overshot water wheel set in
motion by a stream and was used to feedwater fountains. The
emperor Ferdinand II granted him a ?privilege? - the equivalent
of a patent in respect of this invention.
Even in the 17th century, engineers were trying to solve the
problem of ?leak-proofing? between moving parts and this problem
continues to be the Achilles heel of the rotary piston engine
although Mazda would seem to have reduced this problem to
manageable proportions.
1650 Otto von Guericke built a vacuum pump which employed
leather washers to prevent leakage between cylinder and piston.
1782 James Watt who invented the steam engine?s connecting rod
crank mechanism which made it possible to convert the piston?s
reciprocating motion into rotary motion designed an oscillating
piston machine in which a wing-shaped rotary blade performed an
almost complete revolution uncovering inlet ports in a chamber
separated off by a curved radial wall. [Fig 4]
1799 One of Watt?s co-workers, Murdock, adapted Pappenheim?s
gear pump to create a rotary piston steam engine. [Fig 5]
1846 Elijah Galloway built the first rotary piston engine with
inner epicycloid and enveloping outer line. [Fig 6]
1859 Jones, modified Pappenheim?s gear pump and produced a
double rotor with only two teeth per gear. Rootes compressors
and pumps employ this principle. [Fig 7]
1900 Alotham and Franchot designed a vane compressor comprising
a bust rotating inside a cycloidal housing. [Fig 8]
1901 The American, Cooley, lodged a patent for a rotary piston
engine with an internal epicycloid and enveloping outer chamber.
[Fig 9]
1908 The Englishman, Umpleby, transformed Cooley?s steam engine
into an internal combustion engine but experienced problems with
gas tightness. [Fig 10]
1923 A Swedish patent was granted to Wallinder and Skoog in
respect of a true rotary piston thermal engine with toothed
meshing, enveloping interior hypocycloid and internal five
pointed rotor with a 5:6 rotation ratio which could be used as
either a two or four stroke internal combustion engine.
[Fig 11]
1938 Sensaud and Lavaud, (the French engineers responsible for
the Traction Avant automatic gearbox which was a failure)
applied for a patent for a rotary piston engine with internally
meshing gears in a hypocycloid housing and a 5:6 reduction
ratio. Both Renault and Citroën, at the instigation of the
French Air Ministry provided backing for this project and a
number of engines were built at Batignolles. Unfortunately the
engine failed to live up to expectations and the project was
abandoned. [Fig 12]
1943 The Swiss manufacturer Bernard Maillard built an air
compressor based on a British patent for a rotary piston machine
with a 2:3 ratio and internal hypocycloid surfaced chambers.
Leakage under pressure made it impossible to use this design as
a thermal engine. [Fig 13]
What about the rest of the Figures? Rolf
Paul Lamar
That is not one one hundredth of the configurations Felix Wankel investigated.
In the summer of 1963 Felix presented a monumental 100 page technical paper
called Einteilung der Rotations- Kolbenmaschinen wherein every conceivable
configuration was categorized with hundreds of illustrations in color.
It really amounted to a book on the subject.
It was given to me by Eurgen Bax, president of Wankel GMBH
when I visited the factory in 1999.
It would take days to scan it in.
Paul Lamar
The AirCraft Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/
Copyright 1998-2003 All world wide rights reserved.
