An Improved Rotary Engine.
Year: 1891

page_text: Date of Application, 5th Mar., 1891
Complete Specification Left, 4th Dec., 1891-Accepted, 9th Jan., 1892
PROVISIONAL SPECIFICATION.
An Improved Rotary Engine.
I, EDWARD FUHRMANN CLARKE, of Four Oaks, Sutton Coldfield, in the County
of Warwick, Mechanical Engineer do hereby declare the nature of this inven-
tion to be as follows
My invention relates to an improved rotary engine.
My improved engine comprises a cylinder provided with radial pistons which
revolve about the axis of the said cylinder and which extend through suitable
guides in the periphery of a rotary cylinder or drum of considerably less diameter
than the aforesaid cylinder and arranged excentrically therein so that one part of
its periphery is in contact with the inner circumference or wall of the outer
cylinder.
The admission and exhaust ports are so arranged that the steam or other fluid
will act successively upon the said pistons, and cause them to revolve about their
common axis and thus rotate the inner cylinder or drum about its axis.
I so
An important feature of my said invention is the provision which I make for
effectually utilizing the expansion of the steam or other fluid. For this purpose,
construct my rotary engine that, by the time the steam or other fluid
admitted to the cylinder has, by its action upon one or other of the pistons, moved
the said piston through a certain angle, the next succeeding piston will have been
moved past the admission-port, and a quantity of the steam or other fluid will thus
be enclosed or imprisoned in the space between these pistons, and will, by its
expansion, assist in the continued movement of the pistons about their common
axis, the area of surface of the piston exposed to the action of the fluid increasing
as the steam expands and its pressure diminishes; and the steam or other fluid
entering through the admission-port will, meanwhile, act upon the piston which
has just moved past it.
I can construct my engine to operate with different degrees of expansion by
increasing or diminishing the capacity of the crescent-shaped space between the
outer cylinder and the inner cylinder or drum, that is to say, by varying the
relative diameters of the inner and outer cylinders; or by enlarging or diminishing
the number of pistons, and consequently reducing or increasing the quantity of
steam admitted between each piston and the next succeeding piston.
A driving-shaft is firmly secured to one end of the inner cylinder or drum and
extends through a suitable stuffing-box in the cover of the outer cylinder. This
shaft is supported in one or more bearings and is provided with a driving-pulley
or other convenient means for communicating motion to the shaft or machine to
be driven.
The end of the inner cylinder or drum in which the said shaft is fixed, is closed,
and is fitted in a circular recess or cavity in the corresponding end of the outer
cylinder. The other end of the said inner cylinder or drum bears against a plane
surface of the corresponding end of the outer cylinder.
I provide an adjusting screw or other suitable device whereby the said inner
cylinder or drum may be kept in close contact with the said surface of the outer
cylinder so as to form a fluid-tight or approximately fluid-tight joint therewith.
The aforesaid guides are, moreover, so fitted to the pistons and to their seats in
he said inner cylinder or drum as to prevent leakage of the fluid between these
parts. Each of these guides is preferably formed of two parts which are of such
form in transverse section that, together with the portion of the piston between
hem, they form a cylinder, which works in a corresponding seat in the periphery
f the inner cylinder or drum.

page_text: The pistons are so arranged that they can move at different relative velocities
as required by the excentricity of the inner cylinder or drum.
I mount the said pistons upon an overhanging shaft, that is to say, a shaft firmly
fixed at one end in the corresponding end of the outer cylinder, but unsupported
at its other end. This form of construction is importaut, as it enables me to
dispense with stuffing-boxes for preventing leakage around the said shaft. In this
manner I can greatly reduce the friction.
To prevent any tendency to the compression of the fluid by the action of the
pistons while moving through the inoperative angle or portion of their revolution,
1 form in the wall of the outer cylinder a recess or cavity extending from the
exhaust port to or nearly to the part of the said wall which is in contact with the
inner cylinder or drum; this recess or cavity may, if desired, form a part of
the exhaust-port. I thus provide a passage for the flow of the fluid between the
wall of the outer cylinder and the pistons while the latter are moving from the
exhaust-port to the admission-port on the inoperative side of the outer cylinder,
except at that part of the wall of the said cylinder with which the inner cylinder
or drum is in contact, where a fluid-tight joint should be formed between the said
part of the wall and the pistons as they successively move past the same.
I find it advantageous to construct my improved engine with six pistons, but I
do not limit myself to any particular number thereof.
Dated this 5th day of March 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Rotary Engine.
I, EDWARD FUHRMANN CLARKE, of Four Oaks, Sutton Coldfield in the
County of Warwick, Mechanical Engineer, 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 :-
My invention relates to an improved rotary engine which may be constructed to
be driven either by steam or compressed air, or water. In the drawings attached
hereto I have shown a motor suitable for being driven by steam.
My improved engine comprises a cylinder provided with radial vanes or pistons
hereinafter called pistons which revolve about the axis of the said cylinder and
which extend through suitable guides in the periphery of a rotary cylinder hercin-
after termed a drum. The said drum is of less diameter than the cylinder and is
arranged eccentrically with respect to the latter in such a manner that one part
of its periphery is in contact with the inner circumference or wall of the cylinder.
The parts are so arranged that the steam will act successively upon the said
pistons and cause them to revolve about their common axis and thus rotate the
inner cylinder or drum about its axis.
An important feature of my said invention is the provision which I make for
effectually utilizing the expansion of the steam. For this purpose I so construct
my rotary engine that, by the time the steam admitted through an admission port
to the cylinder has by its action upon one or other of the pistons, moved the said
piston through a certain angle, the next succeeding piston will have been moved
past the admission port, and a quantity of the steam will thus be enclosed or
imprisoned in the space between these pistons.
As the pistons continue their rotary movement the said space between the pistons
increases in volume and the steam therein is thus allowed to expand. The arrange-
ment of the parts is such that during the expansion period the motive fluid continues
to assist in driving the pistons about their common axis.
The degree of expansion will to a great extent depend upon the actual positions

page_text: of the inlet and exit ports with respect to the centres round which the pistons and
the drum revolve, it also depends to some extent upon the number of pistons which
may be used, as will be readily understood by reference to Figure 2 where the
parts are so placed as to give a very high degree of expansion. If water is to be
used as the motive fluid the ports must be so arranged that the chamber containing
the water shall at the moment when the exhaust commences be practically of the
same volume as it was at the moment of cut off.
A driving shaft is firmly secured to oue end of the drum and extends through a
stuffing-box in one of the cylinder covers and on this shaft a pulley is fixed for the
transmission of the power.
In the accompanying drawings I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a partial longitudinal central section and partial side elevation, of
one form of my improved engine.
Figure 2 is a section on the tine, a Figure 1.
Figure 3 is a longitudinal central section of a portion of another engine made
according to my invention as hereinafter described and constructed so that it can
be driven in either direction, and
Figure 4 is a half end elevation of the said reversible engine and half section
on the line ¹¹ Figure 3.
Like letters of reference indicate corresponding parts throughout the drawings.
A is the cylinder which is provided with suitable covers A', A' and with an
admission port A³ and an exhaust port A' for the steam or other working
fluid.
B, B are radial pistons which are mounted upon a shaft or spindle C so as to be
free to revolve thereon in the cylinder A, the said pistons being formed with
hollow bosses or hinges through which the said shaft or spindle passes. These
pistons extend through and work in suitable guides D fitted in corresponding seats
in the periphery of a rotary drum E, which is arranged eccentrically within and is
of considerably smaller diameter than the cylinder A. C₁ is a loose gun-metal or
other suitable sleeve, which is placed upon the spindle C, and which serves as a
liner between the same and the bosses or hinges of the pistons, and diminishes the
wear of the parts in frictional contact.
I firmly fix the shaft or spindle C, at one end only in the cover A' of the
cylinder A, leaving it unsupported at its other end as shown in Figure 1. This
form of construction is very important insomuch as it enables me to close one end
of the drum E thereby avoiding the necessity for a trunnion bearing for the said
drum which bearing would be required if the shaft or spindle C passed completely
through the drum and was supported at both ends. I thus greatly reduce the
friction. This construction is more especially important because in consequence of
the shaft C not requiring to be supported by the cover A² I am able to support the
revolving drum E in any convenient manner so that it may be made to revolve
with the least amount of friction.
The guides D slide freely upon the pistons B, while the latter revolve about
their common axis. Each of the said guides D is preferably formed of two parts
which are of such shape in transverse section that, together with the portion of the
piston between them, they fill up and work in cylindrical openings or seats E' in
the periphery of the drum E. By this construction I obviate the necessity for
forming slots in solid cylindrical guides and fitting the pistons accurately in such
slots, and I am enabled to very readily fit the guides D to the pistons B, and to
the seats E' in the said drum E, in such a manner as to prevent leakage of the
fluid between these parts. The said pistons are mounted separately upon the
spindle C, so that they are free to move at different relative velocities as necessitated
by their passing through the periphery of the drum E.
The drum E is so arranged that its periphery is in contact
circumference or wall of the cylinder A on one side of its axis.
pistons move in contact with the interior surface of the cylinder
with the interior
The edges of the
A except where

page_text: "
the drum E is in contact with the interior surface of the cylinder A where it is
slightly recessed to fit the drum E, and consequently form fluid-tight or approxi-
mately fluid-tight joints therewith. The closed end of the drum E works in a
cylindrical recess A° formed in the cover A. The other end of the said drum E
which is open, bears against the inner surface of the cover A¹; I provide suitable
means hereinafter described for enabling the said drum to be set up or adjusted so
as to keep it in close contact with the surface of the cover A' and thus form a fluid-
tight or approximately fluid-tight joint therewith.
The steam under pressure entering the cylinder A through the steam port A³
will act successively upon each of the pistons B and will continue to act thereon
from the time when the said piston passes the admission port A³ until the time it
passes the exhaust port A' at which time the working fluid is allowed to escape
through the said exhaust port. All the pistons B will therefore, be caused to
continuously revolve about their common axis and thus rotate the drum E about
its axis.
In the closed end of the drum E a driving shaft F is secured which passes out
of the cylinder through a stuffing box A. G is a bed plate on which the engine
is mounted. His a bearing for supporting and steadying the outer end of the
driving shaft and I is a pulley by which the power is transmitted as required.
To keep the drum E in close contact with the surface of the cylinder cover A¹
so as to form a fluid-tight, or approximately fluid-tight joint therewith, I provide a
nut which works on a screw threaded part F2 provided on the driving shaft in
such a position that the said nut can be screwed against the bearing H and so
force the drum E against the cover A¹ The said nut is formed with a plain
or unthreaded portion which fits the shaft F and through this part of the nut
are passed one or more set screws F³ to lock the nut F and prevent its working
loose.
In the drawing I have shown an engine having six pistons but this number may
be increased or diminished as desired. The exhaust port A is carried about half
way round the cylinder that is preferably from a point in the inner circumference
of the cylinder A. which is in a line with the centres of the cylinder A and the
drum E to the exhaust opening A' in the base so that the pistons are only subject
to the propelling force of the steam during about half of each revolution that is
from the time the piston has passed the lip of the steam port until it reaches
the exhaust opening. The position of the cut off is so arranged as to suit the
degree of expansion required and may be carlier or later than is shown in the
drawing.
For preventing leakage between the drum E and cylinder A 1 provide an
L-shaped packing piece J see Figure 2 which is placed in a recess A formed in
the cylinder and is pressed against the drum E and against the side of the
recess A by a spring J. The piece J is made to accurately fit the periphery of
the drum E and the side of the recess A and is thus very effective in preventing
leakage. I moreover prefer to hollow out that part of the cylinder wall which is
between the two ports A', A' so as to make it have the same. curvature as the
periphery of the drum E; I thus obtain contact over a considerable surface instead
of along a line only and thereby aid the piece J in preventing leakage. If found
necessary or advisable I may pack the ends or sides or both ends and sides of
the pistons by applying thereto in any suitable manner loose pieces with or without
springs for forcing the said loose pieces outward against the walls of the cylinder.
My said engine is provided with any suitable governor which may be conveniently
mounted on the bed G and driven by spur gear from the end of the shaft F.
The mode of working of my improved engine is as follows:-Steam having
been admitted into the cylinder A through the admission port A³ it at once acts
upon whichever of the pistons happens to be next the said port on the driving side
and forces the said piston to revolve round its axis C, at the same time rotating
the drum E and thereby causing all the pistons to revolve round their common
axis.

page_text: As soon as the next piston passes the admission port the steam or other fluid
between the said two pistons is isolated or imprisoned and is carried round with
the said pistons. This imprisoned fluid has not however completed its work because
the area of the forward piston exposed to the pressure of the said fluid is greater
than that of the rear piston and the leverage also of the said forward piston is
greater and therefore the fluid continues to aid in forcing the pistons round. It is
further obvious that the space between the pistons increases in volume as the
rotation continues and the working fluid is thus allowed to expand, the pressure
being thus gradually reduced as its volume increases. This expansion continues
until the forward piston reaches the lip of the exhaust port, at which point the
working fluid is allowed to escape. It is obvious that I may arrange to work with
as low a terminal pressure as is consistent with securing a free exhaust.
In Figures 3 and 4 I have shown a modification of my engine which will run in
either direction. In this engine the exhaust port is continued all round the
cylinder except at that part where the cylinder and drum meet. In the said port I
place a shell K which constitutes part of a cylinder and is formed with or attached
to a disc K¹.
A
The said disc forms an inner lining for the cover A¹ and it is provided with a
neck K which passes out through a stuffing box A provided in the said cover. To
this neck is securely attached the spindle C on which the pistons revolve.
handle L is also fixed on the said neck K' whereby the shell K can be moved in
the cylinder and caused to occupy a position on either side thereof. On whichever
side of the cylinder the said shell is placed, the circular exhaust port on that side
the cylinder is completely filled up by the said shell so that the steam may be
admitted on that side the cylinder and exhausted on the other. By turning the
shell around to the other side of the cylinder, the conditions are reversed, and the
steam must now be admitted at and exhausted from the ports which before served
the reverse purpose.
For reversing the inlet and outlet ports I provide as follows that is to say, I form
in the cylinder three passages, a central one N which always acts as an exhaust
passage, and two outside passages N' which act as exhaust or admission passages
according to the direction in which the engine is intended to run. O is a box
forming a valve chest, closed by a lid O' and fed by a pipe O Figure 4, and
having formed therein a valve seat O' on which works an ordinary D slide-valve P.
The said valve is formed with cars P1 which engage with a short lever secured
on a spindle Q' that passes out of the valve chest through a stuffing box O and is
coupled by a lever Q to the aforesaid handle L. The lever Q' is formed with a
long slot Qin which works a pin L' that connects the two levers Q and L. By
this arrangement, when the handle L is operated to move the shell K to one side
or the cther, the D-valve P is also moved at the same time to cause one passage N'
to communicate with the exhaust passage N and the other with the valve chest.
When the shell K is reversed, the D-valve is also reversed at the same time and
the steam is thus admitted at and exhausted from the reverse sides and the engine
caused to turn in the reverse direction. I may or may not use a packing piece for
preventing leakage across the bridge between the steam and exhaust ports, as
may be found necessary. Owing to the peculiar arrangement of levers above
described the handle Ĺ can be moved some little distance without materially
shifting the D-valve, and consequently I am enabled to vary the cut off and point
of release.
I have described my invention hitherto when used as a steam motor, but it will
be quite obvious that if desired it may be used to work with compressed air, or by
suitably altering the arrangement of ports as previously indicated it may be driven
by water.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that I make
no general claim to rotary motors in which a series of pistons are made to revolve

page_text: within a cylinder and to slide through a surrounding drum placed eccentrically
within the said cylinder as I am aware that such construction is not new, but what
I claim is :-
First. A rotary motor consisting of the parts constructed and combined substan-
tially as described with reference to the accompanying drawings and operating as
and for the purpose specified.
Second. The means of reversing a motor such as that described and claimed by
means of the shell K and slide valve P substantially as described and illustrated in
Figures 3 and 4.
Third. Supporting the shaft or spindle C of a motor upon which the pistons are
mounted at one end only as and for the purposes above specified.
Fourth. Constructing the cover A of the said motor with a recess as shown in
Figure at A so that the drum may revolve in the recess and be pressed forward
when desired so as to be kept in close contact with the cover A' for the purpose
specified.
Fifth. In motors constructed as above described and claimed the use of the
loose sleeve or bush C¹ placed upon the shaft or spindle C substantially as and for
the purposes above specified.
Dated this 4th day of December 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.