Improvements in Rotary Engines.
Year: 1897

page_text: Date of Application, 27th May, 1897
Improvements in Rotary Engines.
I, AUGUSTE BOURAINE, of 240, Rue de Rivoli, Paris, in the Republic of France,
Engineer, do hereby declare the nature of this invention to be as follows:-
The present invention relates to an improved rotary steam engine, the principal
advantage of which consists in the method of distribution employed, and the sim-
licity of the parts composing it.
The improved engine is one in which the distribution and expansion are variable;
the reversing may take place at high or low pressures; the exhaust is free; and
the condensing either of simple, double, triple, or quadruple effect. It may be
used for all kinds of industries, as a locomotive engine, for railway and tramway
purposes, and also as a marine engine, for torpedo boats, or other kinds of vessels,
for which it is admirably adapted.
The machine consists of a foundation plate upon which are mounted two
cylinders through which the same shaft passes. Each of these cylinders has a
jacket into which the steam passes before and after distribution. In each of them
is placed a reciprocating slide, which works in a guide, and a rotary cam piston
keyed upon the shaft.
The movable slide is actuated by one or more springs, or by the pressure of steam
entering by a cock. The edge of the slide just rests upon the piston, and forms a
point d'appui or abutment for the steam, which compels this piston to move.
Grooves are made in the slides and the pistons, to receive pieces which completely
prevent the steam from passing. These pistons are duplicated in reversing engines,
and are used singly for non-reversing engines.
The motor shaft passes through the centre of the, cylinders, pistons being
mounted thereon, and through the covers of the cylinders and stuffing boxes. The
ends of the shaft are held in bronze bushes or bearings. Upon the shaft, and out-
side the cylinders, are fixed two excentrics, actuating the distribution movement,
which will now be described.
Upon each of the motor cylinders is a small cylinder serving for the distribution
of the steam. Each of these cylinders is composed of two slightly conical shells of
bronze, arranged one within the other, like the plug of a tap. The outer shell
serves to reverse the engine, and two recesses are made in this shell for the free
passage of the exhaust steam at all times during the working of the engine.
A passage gives access to the steam to the inner shell: A port in the outer shell
forms the admission and the variable expansion for one motor cylinder. This
shell is actuated by hand by means of a simple lever, which will impart thereto
a slight axial movement in either direction, as required. According to the direc-
tion of this movement, the port will come opposite one of two passages, providing
for the admission of steam first to one side, then to the other, to reverse the
direction. During the movements of the outer shell, one of the recesses comes
opposite one of the passages, and so puts these passages in communication with
the exhaust.

page_text: The system of reversing is of the simplest; the parts composing it are subject to
no strain, and wear and tear is completely avoided. The reversing is effected
completely by hand, and does not lessen the power of the motor.
The operating lever, which is fixed to the outer shell, works over a graduated
sector, giving the degrees of expansion and also the rotation to right or left. The
teeth formed upon the sector allow of the lever being fixed in any desired position.
This construction is applicable to coupled cylinder engines. For engines having
several cylinders, and working at double, triple, or quadruple expansion, the lever
is fixed upon a small shaft communicating the movement to all the reversing shells
by a toothed sector, keyed in front of each shell on the special shaft. This sector
engages with its corresponding shell, which, to this end, also carries a toothed
sector. For high power engines, where the action of a lever would be insufficient
to reverse, an appropriate gear is employed, such, for instance, as a worm gear.
The inner shell, which works as the slide valve, has two ports, and is actuated by
the excentric, which is keyed upon the motor shaft. This excentric governs the
shell by an arm mounted on the upper shaft, which is itself connected to the shell
by means of two squares. One of these squares forms a shoulder against which
abuts a spring situated in the interior of the shell. This spring, pressing against
the shell, makes it fit perfectly.
The excentric imparts to the shell a reciprocating axial motion, to effect the
necessary distribution.
A cover is provided for the distribution cylinders, a good joint with the outer
shell being made by means of a piece of felt so placed as to stop all leakage. The
small cylinders may be arranged in various positions, the parts requiring a slight
modification in arrangement according to the altered circumstances. Thus, the
cylinders may be placed in connection with the abutment slides, or they may be
placed on the sides of the motor cylinder, and these different positions of the small
cylinders may be employed according to the circumstances and space at disposal.
* From the foregoing it will be seen that the improved engine presents numerous
advantages over those at present in use, arising from its simplicity of construction,
its variable expansion, its reversing arrangement, as well as the economical use of
steam.
It may be here remarked, that the characteristic principle of the improved engine
consists in distributing and reversing by means of the two shells carried the one
upon the other.
I, AUGUSTE BOURAINE, of, 240, Rue de Rivoli, Paris, in the Republic of France,
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:-
The present improvement relates to an improved rotary engine, the principal
advantages of which consists in the method of distribution employed, and the sim-
plicity of the parts composing it.
The improved engine is one in which the distribution and expansion are variable;
it is a reversing engine, it can work at high or low pressures. It may be used for
all kinds of industries, as a locomotive engine for railway or tramway purposes,

page_text: and also as a marine engine for torpedo boats or other kinds of vessels, for which
it is admirably adapted.
In order to render the following explanation as clear as possible, I have shewn,
by way of example, in the accompanying drawings, my improved rotary engine.
Figure 1 is an elevation, partly in section, of the engine.
Figure 2 is a transverse section, shewing the internal construction of a cylinder,
and the distribution.
Figure 3 is an end view.
Figures 4, 5, 6, 7, 8, 9, 10, 11, and 12, relate to certain details of the engine
which will be more particularly referred to hereafter.
A is the foundation plate upon which are mounted two cylinders B B', through
which the same shaft C passes. In each of these cylinders is placed
(1.) A reciprocating slide D (Figure 2), which works in a guide E (Figures 2
& 4);
(2.) A rotary cam piston keyed upon the shaft C (Figures 1 & 2) by means of
keys or feathers a a¹.
The slide D is actuated by one or more springs H (Figure 4), or by the pressure
of steam entering by a cock I. In the example shewn on the drawing, I have
combined the two means, spring and steam, in such manner, that should an accident
occur and a spring break, the cock may be immediately opened to let in steam, so
that the action of the engine need not be stopped. The edge of the slide D just
rests upon the piston F, and forms a "point d'appui" or abutment for the steam
which compels this piston to move. Grooves are made in the slides D and the
pistons F to receive pieces JJ, which completely prevent the steam from passing.
As will be seen, the piston F is an advantageous substitute for crank-pins or
cranks; also for connecting rods and piston rods; and it also does away with these
four parts, thereby considerably diminishing friction and wear and tear, and
facilitating repairs. These pistons are duplicated in reversing engines, and are
used singly for non-reversing engines.
The motor shaft C passes through the centre of the cylinders (the pistons being
mounted thereon), and through the covers of the cylinders K K¹ and the stuffing
boxes L. The ends of the shaft Care held in bronze bushes or bearings M M¹.
Upon the shaft, and outside the cylinders, are fixed two excentrics bb (Figures 1
& 11), actuating the distribution movement which will now be described.
For engines with cylinders arranged in pairs, it is evident that a single excentric
suffices.
Upon each of the motor cylinders B B is a small cylinder 00', serving for the
distribution of the steam. Each of these cylinders contains two slightly conical
shells P and Q of bronze (Figures 1 & 2), arranged one within the other, like the
plugs of a tap. The shell P serves to reverse the engine, and two recesses R and R¹
are made in this shell for the free passage of the exhaust steam at all times during
the working of the engine.
A passage S gives access for the steam to the inner shell Q. A port T in the oute:
shell P forms the admission and the variable expansion for the motor cylinder B.
This shell P is actuated by hand by means of a simple lever, which will impart
thereto a slight axial movement in either direction, as required. According to the
direction of this movement, the port T will come opposite one of two passages V
or V1, providing for the admission of steam, first to one side, then to the other, to
reverse the direction. During the movements of the outer shell P, one of the
recesses R or R¹ comes opposite one of the passages V, VI, and so puts these passages
in communication with the exhaust. Thus, if the port T of admission is opposite
the passage VI, the recess R is opposite the passage V. The motor then turns in a
certain direction. If, on the contrary, the port T is brought opposite the pas-
sage V, the recess R¹ comes opposite the passage V₁, and the movement is in the
contrary direction. By these same movements of the shell P, the variable expan-

page_text: sion is also effected, by reducing the admission according to the degree of expansion
it is desired to obtain.
The system of reversing is of the simplest; the parts composing it are subject
to no strain; and wear and tear is completely avoided. The reversing is effected
completely by hand, and does not lessen the power of the motor.
The operating lever which is fixed to the outer shell P works over a graduated
sector G, giving the degrees of expansion, and also the rotation to right or left.
The teeth formed upon the sector allow of the lever being fixed in any desired
position.
This construction is applicable to engines with cylinders arranged in pairs.
For engines having several cylinders, and working at double, triple, or quadruple
expansion, the lever is fixed upon a small shaft 7 (Figures 1 and 9), communicating
the movement to all the reversing shells by a toothed sector h (Figures 1 & 10),
keyed in front of each shell on the special shaft Z. This sector h engages with its
corresponding shell P, which, to this end, as seen in Figure 10, also carries a
toothed sector. For high power engines, where the action of a lever would be
insufficient to reverse, an appropriate gear is employed, such, for instance, as a
worm gear.
The inner shell Q, which works as the slide valve, has two ports e e¹, Figure 2,
and is actuated by the excentric b, which is keyed upon the motor shaft C. This
excentric governs the shell by the armi f, mounted on the upper shaft c, which is
itself connected to the shell Q by means of two squares, placed at nn. One of
these squares forms a shoulder, against which abuts a spring situated in the
interior of the shell Q. This spring, pressing against the shell, makes it fit
perfectly.
The excentric b imparts to the shell Q a reciprocating axial motion, to effect the
necessary distribution.
According as the port T of the shell P is opposite the passage V or V¹ of the
cylinder, the port e or el of the shell effects the distribution.
It is to be understood that whatever be the direction of rotation of the engine,
the movement of the shell remains always the same.
The shafts cc', which operate the shells Q Q¹, pass through stuffing boxes U, the
arrangement of which is shewn in Figure 1. The tightening up of these stuffing
boxes is effected by the two nuts 7 and q, the first of which screws upon the shell P,
and the second on a bronze ring.
The ends of the small shafts cc rest in standards or supports N N¹ fixed on the
frame, and which support also the end of the shaft Z at the same time.
Covers mm (Figures 1 and 3) are provided for the distribution cylinders 0, 0¹,
a good joint with the outer shell P being made by means of a piece of felt so
placed as to stop all leakage. The small cylinders 0, 0, may be arranged in
various positions, first of all, as shewn in the drawings, on top of the cylinders B
and B¹; they may be also placed over the movable slides. In this second combina-
tion, the guide E is vertical, and the springs pressing on the slide D are done away
with, the duty of these latter being performed partly by the weight of the slide,
and partly by the steam.
The two steam ports are then arranged one on each side of the guide E, in order
to avoid the casting of the cylinder with its jacket, and yet allow the steam to be
used more directly, and under the best conditions.
A third arrangement consists in placing the small cylinders 0, 0¹, on the sides
of the motor cylinder.
These different positions of the small cylinders may be employed according to
the circumstances and space at disposal. It is manifest that, for non-reversing
engines, the shell P may be dispensed with. In the latter case, the shell Q will
have a single admission port e; the exhaust will be independent of the distributing
cylinder; and will remain always open. In this latter case, the cylinder need not
be cast with the jacket.

page_text: From the foregoing it will be seen that the improved engine presents numerous
advantages over those at present in use, arising from its simplicity of construction,
its variable expansion, and its reversing arrangement, as well as the economical use
of steam.
It may be here remarked that the characteristic principle of the improved engine
consists in distributing and reversing by means of the two shells P and Q, carried
the one upon the other.
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 what I
claim is:-