Improvements in Rotary Engines, applicable also to Rotary Motors, Pumps, Blowers, and Meters.
Year: 1890

page_text: Date of Application, 29th May, 1890
Complete Specification Left, 2nd Mar., 1891-Accepted. 25th Apr., 1891
PROVISIONAĻ SPECIFICATION.
Improvements in Rotary Engines, applicable also to Rotary Motors,
Pumps, Blowers, and Meters.
I, THOMAS ANDREW MCKEE, of Wesley College, Stephen's Green, Dublin,
Bachelor of Arts, do hereby declare the nature of this invention to be as
follows:-
This invention relates to improvements in that class of rotary engines wherein
is employed a revolving piston provided with sliding vanes which are caused to
alternately project into and withdraw from the steam space as the piston rotates.
My invention may also be applied to rotary motors, pumps, blowers, and meters.
The chief objects of my invention, are, to procure a perfectly uniform motion, to
reduce friction, to provide means whereby any wear of the principal working parts
may be automatically taken up or compensated for, to keep the engine steam tight,
and generally, to produce a compact, simple, and efficient engine, without either
cranks or fly wheels, which will be economical to construct, and easy to repair and
clean.
According to my invention,-the-revolving piston, (the axis of which rotates in
bearings carried by the cylinder ends,) is formed with a peripheral groove, giving
to it the form of a pulley wheel.
The space between the sides of this peripheral groove and the inner periphery of
the cylinder forms the steam space, into and from which the vanes hereinafter
described project and withdraw. I render this space steam tight by means of
packing rings disposed within grooves around the piston on either side of the said
steam space, and automatically take up or compensate for any wear of these packing
rings by the following arrangement :-
Each packing ring is made in several segments, connected by tongued and grooved,
rabbeted, or other expansible and steam tight joints, and each segment is acted upon
by a convenient spring, the pressure of the several springs tending to expand the
packing rings which the segments compose, and force them against the inner
periphery of the cylinder.
Extending from the periphery towards the centre of the piston are radial transverse
slots within each of which a sliding vane is disposed. As the piston rotates these
sliding vanes are caused, by means hereinafter described, to alternately project into
and withdraw from the steam space. When fully withdrawn into the piston, the
outer edges of the vanes should be just below the bottom of the peripheral piston
groove or steam space. I effect the alternate projection into and withdrawal from
the steam space of these vanes, by means of camshaped guide grooves at each end
of the cylinder, into which fit accurately yet freely friction wheels mounted upon
axes or spindles passing through the sliding vanes in a direction parallel with the
piston axis, each vane having its own spindle and friction wheels.
I provide for the automatic taking up of any wear between the edges of the vanes
and the inner periphery of the cylinder, and ensure constant steam tight contact
between the same at the point where such steam tight contact should exist, by the
following arrangement:-
The aperture in each vane through which its friction wheel axis or spindle passes,
is so constructed, (by making it of ovál section for example,) as to permit the vane
to have a slight amount of play upon such spindle in a radial direction as regards
the piston; springs contained within recesses in the vanes bear upon the said axes
or spindles in such manner, as to tend to force the vanes towards the periphery of

page_text: the cylinder, and as the interior of the cylinder or edges of the vanes wears, such
wear is compensated for by means of the said springs.
Projecting internally into the cylinder in a radial direction is a stationary "butt"
or steam stop, which fits accurately within the before mentioned peripheral piston
groove or steam space. This butt" is divided transversely at right angles to the
axis of the piston, the two portions being connected by a tongued and grooved,
rabbeted, or other expansible and steam tight joint, and containing within a
suitable recess a convenient spring, which tends to force them apart against the
sides of the peripheral piston groove, a constant steam tight fit between the sides of
the butt and the sides of the said groove is thus automatically maintained.
15
To keep the edge of the "butt" and the bottom of said groove in steam tight
contact, mount the "butt" within suitable guides on the cylinder, so that it may
have a certain amount of play in a radial direction as regards the piston, and
dispose a second spring in such manner as to exert its pressure in forcing the "butt"
down into the said piston groove.
The cam shaped guiding grooves, which receive the friction wheels carried by
the spindles which pass through the vanes, are so constructed and arranged as to
withdraw the vanes below the peripheral piston groove or steam space just clear of
the butt," as they approach such butt during the rotation of the piston, and to
project them gradually until they come into steam tight contact, with the inner.
periphery of the cylinder after. passing such "butt." I prefer that each vane
should come into contact with the inner periphery of the cylinder the instant before
the vane in front commences to leave such inner periphery.
".
Steam enters the steam space through a port in the cylinder situate close to and
upon one side of the stationary "butt: as it enters, it meets such stationary" butt
in one direction, and in the other direction the vanes of the rotating piston, it
accordingly acts upon and propels whichever vane is. in contact with the inner.
periphery of the cylinder until such vane commences to withdraw therefrom, by
which time the next succeeding vane will be in contact with the cylinder, and be acted
upon and propelled in turn. The exhaust steam escapes by a second port in the
cylinder, situate upon the other side of the "butt" to the inlet port. All steam
pressure upon the vane as it commences to be withdrawn froin the cylinder may be
removed, by forming a small recess or depression in the cylinder, just at that part
of its inner periphery. where the vanes cominence to leave it, this recess or.
depression allowing the steam to escape over the edge of the vanes as they arrive
thercat, which will instantly, relieve all pressure upon the vanes at that point.
If desired, the waste steam may pass from the outlet port into a condensing
chamber, the interior of which is occupied by a coil or worm through which cold
water flows. This chamber is provided with a cock having grooves, or depressions.
on opposite sides and actuated from the engine, which cock may be caused to make
a half turn at suitable intervals and permit the water of condensation to escape
whilst preventing the entrance of air.
The engine may be reversed by changing the steam entrance from one port to the
other, and there being no fly wheel it can be started and stopped almost instan-
taneously, and almost without loss of power from impetus or inertia.
If desired, two stationary "butts” may be employed, the number of vanes
increased; and the engine rendered double acting, the sliding vanes. being by
suitable modifications of the guide groove each projected and withdrawn twice at
each revolution of the piston.
1
1000

page_text: COMPLETE SPECIFICATION..
Improvements in Rotary Engines, applicable also to Rotary Motors,
Pumps, Blowers, and Meters.
1, THOMAS ANDREW MCKEE, of Wesley College,. Stephen's Green, Dublin,
Bachelor of Arts, do hereby declare the nature of this invention, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
This invention relates to improvements in that class of rotary engines wherein
is employed a revolving piston provided with sliding vanes, which are caused to
alternately project into and withdraw from the steam space as the piston rotates.
My invention may also be applied to rotary motors, pumps, blowers, and meters.
The chief objects of my invention are to procure a perfectly uniform motion, to
reduce friction, to provide means whereby any wear of the principal working parts
may be automatically taken up or compensated for, to keep the engine steam tight,
and generally to produce a compact simple and efficient engine, without either
cranks or
ffy wheels, which will be economical to construct and easy to repair
and clean.
According to my invention, the revolving piston is formed with a peripheral
groove, giving to it the form of a pulley wheel. The space between the sides of
this peripheral groove and the inner periphery of the cylinder forms the steam
space, into and from which the vanes hereinafter described project and withdraw.
I render this space steam tight by means of packing rings disposed around the
piston on either side of the said steam space, and automatically take up or
compensate for any wear of these packing rings by the following arrangement.
Each packing ring is made in several segments, connected by tongued and
grooved rabbeted or other expansible and steam tight joints, and each sigment is
acted upon by a convenient spring or springs the pressure of the several springs
tending to expand the segmental packing rings and force them against the inner
periphery of the cylinder.
Extending from the. periphery towards the centre of the piston are radial
transverse slots, within each of which a sliding vane is disposed. As the piston
rotates, these sliding vanes are caused, by means hereinafter described, to
alternately project into and withdraw from the steam space.
When fully
withdrawn into the piston, the outer edges of the vanes should be just below the
bottom of the peripheral piston groove or steam space.
I effect the alternate projection into and withdrawal from the steam space of
these vanes by means of cam shaped guide grooves at each end of the cylinder,
into which guide grooves fit accurately yet freely friction wheels mounted upon
axes or spindles passing through the sliding vanes in a direction parallel with
the piston axis, cach vane having its own spindle and friction wheels.
I provide for the automatic taking up of any wear between the edges of the
vanes and the inner periphery of the cylinder, and ensure constant steam tight con-
tact between the same at the points where such steam tight contact should exist.
by the following arrangement:-
-
The aperture in cach vane through which its friction wheel axes or spindle passes
is so constructed, (by making it of oval transverse section for example,) as to
permit the vane to have a slight amount of play upon its spindle in a radial
direction as regards the piston; springs contained within recesses in the vanes
bear upon the said axes or spindles in such manner as to tend to force the vanes
towards the periphery of the cylinder, and as the interior of the cylinder, or edges
of the vanes, wears, such wear is compensated for by means of the said springs.
Projecting internally into the cylinder in a radial direction is a stationary
or steam stop, which fits accurately within the
peripheral piston groove or steam space. This butt" is preferably divided
"butt
22
before mentioned

page_text: transversely at right angles to the axis of the piston, the divided portions being
connected by a tongued and grooved, rabbeted, or other expansible and steam
tight joint, and containing within a suitable recess a convenient spring which tends
to force them apart against the sides of the peripheral piston groove, a constant
steam tight fit between the sides of the butt and the sides of the said groove
may thus automatically be maintained. To keep the edge of the "but" and the
bottom of said groove in steam tight contact, I may mount the "butt" between
suitable guides on the cylinder so that it may have a certain amount of play in a
radial direction as regards the piston, and may dispose a second spring in such
manner as to exert its pressure in forcing the "butt down into the said peripheral
piston groove. I do not however confine myself to this arrangement as other means
of keeping the "butt" and piston groove in steam tight contact may be found
preferable.
27
The camshaped guiding grooves which receive the before mentioned friction
wheels, are so shaped and arranged, as to withdraw the vanes below the peripheral
piston groove or steam space, just clear of the "butt," as they approach it during
the rotation of the piston, and to project them gradually until they come into
steam tight contact with the inner periphery of the cylinder after passing such
"butt."
22
Steam enters the steam space through a port in the cylinder situate close to and
upon one side of the stationary "butt; as it enters it meets such stationary butt
in one direction, and in the other direction the vanes of the revolving piston, it
accordingly acts upon and propels whichever vane is in contact with the inner
periphery of the cylinder, until such vane commences to withdraw therefrom,
by which time the next succeeding vane will be in contact with the cylinder and be
acted upon and propelled in turn. The exhaust steam escapes by a second port in
to the inlet port.
the cylinder, situate upon the other side of the "butt
pressure upon the vane as it commences to be withdrawn from the cylinder may be
removed by forming a small recess or depression in the cylinder, just at that part
of its inner periphery where the vanes commence to leave it, this recess or
depression allowing the steam to escape over the edges of the vanes as they arrive
thereat, which will instantly relieve all pressure upon the vanes' at that point.
All steam
If desired the waste steam may pass from the outlet port into a condensing
chamber, the interior of which is occupied by a coil or worm through which cold
water flows. This chamber may be provided with a cock having grooves on
opposite sides and actuated from the engine, which cock may be caused to make
a half turn at suitable intervals and permit the water of condensation to escape,
whilst preventing the entrance of air.
The engine may be reversed by changing the steam inlet from one port to the
other, and there being no fly wheel it can be started and stopped almost instan-
taneously and almost without loss of power from impetus or inertia.
If desired, two stationary butts" may be employed, the number of vanes
increased, and the engine rendered double acting, the sliding vanes being each, (by
suitable modifications of the guide grooves) projected and withdrawn twice at cach
revolution of the piston.
In the accompanying drawings in which similar letters refer to corresponding
parts in all the figures,
Fig. is a side elevation of the engine complete.
Fig. 2 is an edge view of the same.
Fig. 3 is a vertical transverse section on line 1-2 Fig. 1.
Fig. 4 is a detached view of the revolving piston in partly sectional side
elevation.
Fig. 5 is an edge view of Fig. 4.
Figs. 6 and 7 are detached views of one of the vanes in sectional side elevation
and partly sectional end view.
Fig. 8 is a side elevation and Fig 9 a plan of the underside of the stationary
* butt."

page_text: Fig. 10 is a plan of the same looking from the top, shewing the manner in
which it is mounted in the cylinder.
Fig. 11 is an elevation of the inner side of one of the end plates of the
cylinder, shewing the camshaped guide groove carried thereby.
Fig. 12 is a vertical section of the condenser I prefer to employ.
Fig. 13 is a vertical longitudinal section of a modified arrangement of rotary
engine embodying my improvements.
the same.
Fig. 14 is a partly sectional side elevation of one of the sliding vanes thereof.
a is the cylinder of the engine closed at each end by the plates b. These end plates b
carry the bearings which support the axis d of the revolving piston e. is
a groove formed around the periphery of the piston e imparting a pulley shape to
The space bounded by the sides of the said groove fand the inner
surface of the cylinder a forms the steam space and is rendered steam tight by
means of the packing rings g disposed within grooves which surround the piston e
upon either side. In the drawings these grooves are shewn as produced by flanges h
formed around the peripheries of plates i secured one upon either side of the piston e.
Upon referring to Figs. 4 and 5 it will be seen that the packing rings g are com-
posed of several segments connected by expansible steam tight joints at gl. g² are
convenient springs which maintain each segment in constant steam tight contact
with the inner face of the cylinder a notwithstanding any wear that may take
place. kk are radial transverse slots in the piston e within which are disposed
the sliding vanes 1. The pulley shape of the piston e ensures that the vanes 7 will
be at all times, whether projecting into or withdrawn from the steam space,
supported for the whole length of their sides. The protrusion and withdrawal
of the vanes into and from the steam space as the piston e rotates is-effected by
means of camshaped guide grooves m carried one by each end plate of the
cylinder a, which guide grooves receive friction rollers n carried by spindles o
passing through apertures p in the vanes 1. When fully withdrawn into the piston e
is
22
the edges of the vanes should be just below the bottom of the groove f
the stationary "butt or steam stop which accurately fits the peripheral groove f
of the piston e, and may, if desired, be constructed and arranged as hereinafter
described so that any wear of the same or of the groove f may be compensated
for. The guide grooves me should be so shaped and arranged, as shewn, as to with-
draw the vanes just clear of the lower edge of the "butt 7 as theya pproach
the same during the rotation of the piston, and to project them gradually until
they come into steam tight contact with the inner periphery of the cylinder a
after passing the "butt" % I prefer that each vane should be brought into
contact with the inner periphery of the cylinder a the instant before the vane
in front commences to withdraw therefrom. are slots in the plates i for the
passage of the spindles o.
I will now describe the arrangement I employ for taking up or compensating for
any wear that may take place between the edges of the vanes and the interior
of the cylinder, and by which ensure constant steam tight contact between the
same at the points where such steam tight contact should exist.
The apertures p in the vanes through which the spindles o pass are so constructed
(by making them of oval shape for example, as shewn in Fig. 7) as to permit the
vanes to have a slight amount of play upon the spindles o in a radial direction as
regards the piston. Convenient springs contained within recesses in the vanes
bear upon the spindles o in such manner as to tend to force the vanes towards the
inner surface of the cylinder, and any wear that may occur is thus compensated for,
whilst at the same time the edges of the vanes will accomodate themselves to any
inaccuracies that may occur in the interior of the cylinder.
When it is desired to compensate for any wear that may take place between
the stationary "butt" and the peripheral piston groove f, the said "butt"
may be constructed and arranged in the following manner as shewn in the
drawings:
-
The upper portion of the "butt" passes through an aperture in the cylinder

page_text: and is embraced upon either side by the bars on the exterior of the cylinder,
between which bars it is free to move in a vertical direction. A spring held down
by the rod tends to force the "butt" towards the interior of the cylinder
and maintains the lower edge thereof in constant contact with the bottom of the
piston groove. It will be seen upon referring to Figs. 8 and 9 that the "butt "
વ્
is made in two portions connected by an expansible steam tight joint q². A spring
contained within a recess in the "butt" tends to force these portions apart and
consequently to maintain the side edges of the "butt" in constant contact with the
sides of the peripheral piston groove f. In order to permit this lateral expansion
of the butt," should wear take place between the side edges thereof and the sides
of the said groove, it is of course necessary that the slot in the cylinder a through
which the butt passes should be slightly longer than the width of the "butt"
and in order to prevent the escape of steam I secure to the side edges of the "butt
where they pass through such slot, some suitable clastic or yielding packing g¹
(Figs. 3, 8, 9, and 10).
:
The action of the apparatus is as follows:-
.
Steam enters the cylinder a by a port u as it enters it meets in one direction
the stationary butt" and in the other direction the vanes of the revolving
piston e. It accordingly acts upon and propels whichever of the vanes is in
contact with the inner periphery of the cylinder a until such vane commences to
withdraw therefrom, by which time the next succeeding vane will be in contact
with the cylinder, and be acted upon and propelled in its turn. All steam pressure
upon the vanes as they commence to be withdrawn from the cylinder may be
removed by forming a small recess or depression (Fig. 13) in the inner
periphery of the cylinder, just at that point where the vanes commence to
withdraw, which recess permits the steam to escape over the top edge of the
vane. The exhaust steam escapes by an outlet port w situate upon the opposite
side of the stationary "butt y to the inlet port, and may pass from thence
into a condensing chamber a, (Fig. 12), by the pipe
represent the
ends of a
worm (not shewn in the drawings) which fills the interior of the
chamber and through which cold water circulates. The condensed steam collects as
water at the lower part of the chamber, and is allowed to escape by causing
the cock to occasionally make a half turn, such movement of the cock y being
automatically effected by the engine.
In the modification (Fig. 13) it will be seen that the steam space is considerably
'reduced in size at the point where the steam enters through the port u, and
gradually enlarges from thence. This is effected by a curved rib a', secured to the
interior of the cylinder a, which projects into the steam space and accurately fits
from side to side the peripheral piston groove. Only two vancs are preferably
employed, and the guide grooves m, by means of which they are projected into and
withdraw from the steam space are so constructed and arranged, (as shewn in dotted
lines) as to cause them to come into contact with the interior of the cylinder at
approximately the point and to commence to withdraw from the saine at the
point. When one vane has reached point the other vane will have arrived at
the point .
This modified arrangement permits the expansive force of the steam
to be more effectively utilized. At the moment one of the vanes arrives at the
point, the steam enters at boiler pressure by the inlet port u, and immediately it
has filled the space between such vane and the "buit" is automatically cut off by
any suitable arrangement of valve worked from the engine, the expansive force of
the admitted steam then propels the vane until it arrives at its point of withdrawal
by which time the other vane will be at point 2 and steam will again be automatically
admitted.
Since in this modification the curve of the rib a¹ is not concentric with the axis
of rotation of the piston e, I provide the outer edges of the vanes with the self
adjusting bearing parts, which fit freely and are capable of turning slightly within
longitudinal semicircular grooves in said outer edges, and may be kept in position
therein by springs Contained within recesses in the vanes l.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I would observe in conclusion
that I am aware that rotary engines having a revolving piston provided with sliding
vanes which are projected into and withdrawn from the steam space as the piston
rotates have long been known and used, and therefore I do not claim the same
broadly as constituting my invention, but I declare that what I claim is :-
1. A rotary engine of the class set forth, wherein the revolving piston is con-
structed with a peripheral groove, which forms, in conjunction with the interior of
the cylinder, the steam space, whereby the sliding vanes are supported for the whole
length of their sides, whether projecting into or withdrawn from the steam space,.
substantially as described and illustrated.
2. A rotary engine of the class set forth, wherein the steam space is maintained
steam tight by segmental packing rings surrounding the revolving piston upon either
side combined with springs whereby such segmental packing rings are maintained
in constant contact with the interior of the cylinder, substantially as described.
3. A rotary engine of the class set forth, wherein the sliding vanes are projected
into and withdrawn from the steam space as the piston rotates by means of guide
grooves, substantially as described.
4. In a rotary engine of the class set forth, the combination with the sliding
vanes 1, of friction wheels mounted upon the spindles », and guide grooves m,
substantially as and for the purpose described and illustrated.
5. In a rotary engine of the class set forth, the herein described method of taking
up or compensating for any wear that may occur between the edges of the sliding
vanes and the interior of the cylinder, substantially as described and illustrated in
Figs. 6 and 7 of the drawings.
6. The herein described method of taking up or compensating for any wear that
may occur between the edges of the butt" and the peripheral piston groove,
substantially as described and illustrated in Figs. 8, 9 and 10 of the drawings.
7. In a rotary steam engine of the class set forth, the herein described method of
relieving the pressure upon the vanes at the moment they commence to withdraw
from the cylinder, consisting of depressions » formed in the cylinder at that point
where the vanes commence to withdraw, which depressions permit the steam to
escape over the edges of the vanes, substantially as described.
8. The general combination and arrangement of parts constituting a rotary engine
substantially as herein described and illustrated.
Dated this 2nd day of March 1891.
E. P. ALEXANDER & SON, Fels. Inst. P.A.,
19, Southampton Buildings, London, W.C., Agents.