Hi Group:

Is it possible to quantify the diminished smoothness of
the single rotor engine over the std. 2 rotor engine.
One of our helicycle builders group had some concern
that the power pulses of the single rotor could in time
degrade the transmission gears.  BTW, the transmission
is of very high quality and there would be a 6 vee belt
link between the engine and trans.

TIA

Ed Angell

The dotted line is the torque fluctuations of the one rotor.
Very severe to say the least.

Paul Lamar

The torque pulses of a single rotor Wankel are the same as a 3

cylinder

4 stroke engine, and a bit more severe than a 2 cylinder 2 stroke.

The

multi Vee belt will go a long way toward protecting the trans, and
I would expect it to be OK - Vance

Are you sure that is not a two cylinder four stroke Vance with one

torque

pulse

per revolution? The two rotor is the same as a four cylinder four

stroke

with

two torque pulses per revolution.  The one rotor is the same as a one

cylinder

two stroke engine with one torque pulse per revolution.
I think you still have not figured out the wankel :-)>

Paul Lamar

No! Paul! You are confusing your self by using the rotation of the

output

shaft, which does not have a one to one relationship with the

thermodynamic

cycle.

The PSRU does not give a damn about the thermodynamic cycle or what you

claim

the thermodynamic cycle is. All the PSRU cares about and all the PSRU sees
is the torque pulse coming out of the output shaft.

One rotation of the rotor takes each face through all four "strokes "
of the Otto cycle - ie equivalent two two revoloutions of the classic
crankshaft engine, thus the shape, and duration of the torque pulses are
idistinguishible from a 3 cylinder, even firing 4 stroke engine, when
plotted on an equivalent time base. - Vance

Not true. We don't take power from the rotor. You seem confused about

that.

If we did try to take power from the rotor the size and weight advantages
of the wankel rotary would be totally destroyed. Perhaps then it might be

comparable

to your beloved Rube Goldberg piston engine :-)>

Paul Lamar

Paul - Surely you jest. The only place the power comes from is the
pressure/area term
acting on the surface of the rotor during the expansion of the combustion
products.
the stationary gear acts as a moving leverage pivot point, while the
pressure on
the rotor flank pushes down on the eccentric (crank pin) and drives it
around
(remarkedly similar to the action of a piston acting on the crankshaft thru
the
rod). About 2/3rd of the pumped volume displacement of the Wankel comes from
the relative "stroke" of the eccentric, and the other third from the
changing shape
of the wall as the rotates relative to the housing.  The Wankel is an
excellent
engine but not magic - it does not cunjure magic rotation into the output
shaft..
I am sure that I have a better understanding of all heat engines than the
average
engineer, including the Wankel - Vance

Of course I jest. But the PSRU still does not care about all this.
All it cares about is the torque pulse. One per e-shaft rotation
for a one rotor just like a two cycle one cylinder piston engine.
Two pulses per rotation just like a two cylinder two cycle piston
engine and a four cylinder four cycle piston engine.

Paul Lamar
 
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