The Washington times., 1917-09-08
M0NAHAN BUILDS
SUCCESSFUL TYPE
OF ROTARY ENGINE
ny BURTON 5. BROWN.

ny BURTON 8. BR0wN.- -
For years engineers have been dis
couraged In their efforts to produce, q
satisfactory rotary, Easolene engine
because of the mechanical obstAcles'tc
be overcome and have pointed to the
various failures involved In the an
nuiar cylinder. flying piston, turbine
and other rotaries as almost conclu
siye evidence that q true and efficient
gasolene engine was impossible.
The satisfaction of engineers who
witnessed q demonstration OF this en-.
CINE at the Bell Automobile Corpora
tIon's office in New York recently, was
evident and they; voiced the opinion
that the Monahan rotary tube engine
has opened up a new neld in gasolene
engine developments.
Has Applied New Principles
After seeing this engine perform
last week the writer Is convinced that
the inventor and builder has done q
great piece Of work. The application
Of new principles has brought sue
cess. &c
The new engine is very simple, com.
pact and powerful and exceedingly
light. gf
The IDEAL engine IL one utilizing
most effectively the expansive foree
due to combustion, one free from vi
bration and one in which the friction
losses have been reduced to q mini
mum. The Monahan rotary engine
possesses these most desirable fea-
lures:
/. The effect Of reeiprocating mo
lions has been eliminated entirely, 1.
e., the piston continues in its travel
at q uniform rate of speed. The wear,
tear, and pounding effect as produced
on most pin and crank pin bearings in
the reciprocating type of engine also
have been eliminated.
The previous undesirable and neces.
sary stopping and starting OF q piston
1000 times per minute per single
cylinder, or 120.0o times per minute
for a slx-cylInder motor operating at
ZOO r. D. m. has been eliminated and
replaced by q continuous uniform rate
i
consequently reduces the friction and
power losses and IL smoother and
freef from the previous vibration.
ExDansion TyDe Approaches IDEAL.
?. The complete expansion type OF
engine approaches. the ideal engine In
the matter of the utilization Of the
explosive force of the Easolens due to
combustion. The operating condition
of the present-day motor IL such. that
the pressure exertsd upon the head Of
the cylinder II the same as that ex-
erted upon the piston. In other
words. with q motor Of say q four
inch bore and consequent piston area
of 1857 square inches and assuming
an explosive pressure Of 400 pounds,
the force exertsd upon the piston
would be 5000 pounds, and . similar
force would be exerted upon the cyl
inder head. This force tends to tear
the cylinder from the base. causes an
elongation OF the cylin-
der walls. and requires q bed heavy
and strong enough first TO permit the
cylinder to be properly and Adequate
ly held down, and secondly to absorb
this vibratory stress. In consequence
expansion types of engines.
(. e., engines with two pistons, one
replacing the cylinder head and each
one-half the stroke and in
opposite directions. have been built
and are in successful operation today.
But this construction Is limited.
In the Monahan rotary engine,
which Is In reality q double piston
engine, the force exerted upon the
cylinder head is utilized as might be
the recoil OF a gun. The frame Is
not submitted to the present day
stresses and vibration is most, ma
terially reduced. As in the complete
expansion type OF engine both cylin-
der head and piston transmit and
utilize the explosive force. All the ad-
OF the, complete expansion
type OF engine. such as freedom from
greater velocity OF expan-
sion and consequently greater speed.
the piston being required to travel
only one-half the stroke, and lessen
ed liability OF cylinder or head frac-
turs are maintained. And there have
been eliminated all the disadvantage
of the former double piston complete
expansion engine such as awkward
and heavy connecting rod, the fric-
ton losses and the lubricating diff
culties OF the double pistons.
Side Thrust Eliminated.
s. The third inherent quality OF this
principle OF engine operation is the
OF the side thrust on the
piston. The force exerted upon the
piston in power transmission must be
transmitted to the crank pin and
to the crank by means
of the connecting rod, which has q
variable degree of angularity. This
is due to the rotation OF the crank
shaft Because of this angularity OF
force transmission a considerable side
thrust is exerted upon the piston,
which means friction and loss OF
power. This condition necessitates a
piston of bell shaped design or SINH
lar, construction sufficiently long to
distribute this tremendous
strain and most efficient fabrication
of the pistons under most unfavor-
able conditions.
The elimination of side thrust as &C
in the Monahan engine has
the following advantages:
F,N Ill he