improvements in Rotary Engines and Pumps.
Year: 1898

page_text: Date of Application in the United Kingdom, 17th May, 1898
Complete Specification Left, 17th May, 1898-Accepted, 19th Nov., 1898
improvements in Rotary Engines and Pumps.
I, LOUIS JULES JEAN BAPTISTE LE ROND, of 106, Miromesuil, Paris, in the
Republic of France, Civil 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:
This invention relates to a rotary engine which may be utilized either as a
motor or as a pump, and is an improvement on the invention described in the
Specification of former Application No. 10968 May 13th. 1898.
As a motor it may be operated by steam, compressed air, hot air, gas, petroleum,
water under pressure and, generally speaking, by any fluid capable of exerting
pressure upon a movable wall or partition or of expanding in a closed space of
variable capacity.
As a pump, the said machine being operated by a motor, it may be employed
for the suction or forcing of a liquid, or to compress a gas or a vapour, or finally
to produce a vacuum within a closed space or vessel.
In the accompanying drawing:
Figure 1 represents a partial longitudinal section through an engine or pump
provided with several rollers, in which neither expansion nor compression takes
place, but which is capable of operating in both directions.
Figure 2 is a cross section through the first roller shown in Figure 1.
Figure 3 is a cross section through the roller and cylinder of an engine adapted
to move in one direction only, shewing the four phases of the motion.
Figure 4 is a longitudinal section through a motor on the line V H Figure 5
adapted for motion in one direction, provided with two rollers and Woolf's
method of expansion, and on the other hand suitable for use as a pump for gas
and vapours and
Figure 5 is a cross-section of the same motor through the high pressure roller
taken on the line K K¹ Figure 4.
The sections or configurations of the grooves, the diaphragms or vanes and the
recesses are given by way of example only and as being advantageous arrangements
for ensuring tightness.
These examples are only intended to demonstrate that similar modifications
do not constitute different machines, but merely modifications in the accessory
arrangements of the improved engine or motor.
The machine consists of the following essential parts, as shown in the accom-
panying drawing:

page_text: (1) A fixed cylindrical envelope or casing A provided with recesses a which are
hereinafter referred to.
(2) A driving shaft & concentric with the cylinder A.
(3) A rotating cylinder B rigidly fixed upon the driving shaft b or forming
one piece with it; this rotating cylinder being concentric with the cylinder A
and rotating freely within the latter without friction but with as small an amount
of play as desired.
one or more annular
In the periphery of the cylinder B are formed
grooves C C C forming steam or other fluid spaces having the same axis of revo-
lution as the said cylinder.
(4) A series of discs or rollers D) DI ". . . passed either upon the same axis d
or upon different axes d₁ dą · which are either concentric or not but which
are in any case parallel one with the other and with the driving shaft b. These
and are
rollers correspond in number with the recesses or grooves C C₁ C.
spaced in precisely the same manner, in a direction parallel with the driving
shaft, and have, except for a small amount of play, the same section as the said
recesses or grooves. The shaft d or the shafts d₁ do. rest in hearings of any
suitable kind but which are so arranged that the rollers are constantly in engage-
ment within the recesses or grooves of the corresponding cylinder adapting them-
selves thereto exactly. Care being taken to allow for such engagement, the
section of the rollers may follow any desired line, broken or curved.
rollers D, I¹... are rigidly attached to their common shaft, or to their respective
shafts as the case may be, in any suitable manner, or form one piece with it (or
them) in such a manner as to rotate with the said shaft or shafts.
The
(5) A series of recesses a formed in the cylindrical casing A in order to enable
the rollers D, D¹, D¹¹. to enter the recesses or grooves C, C₁, C... contained
within the said casing A; these recesses having, allowing for a small amount of
play, the geometric form necessary for this purpose (that is to say, geometrically
speaking, the form of the teeth resulting from the penetration of the casing A
by the rollers D, D¹, D. . .).
E E
11
to
These
(6) A series of vanes or diaphragms E, E,
E₁"E"
the number of two at least for each of the grooves C, C₁, C₁ completely inter-
cepting these grooves which they divided into equal and isolated sectors.
vanes or diaphragms, which are precisely the same for the same groove, are
bounded on the one hand by the virtual surface of the cylinder B, on the other
hand by cylindrical surfaces of appropriate section the generating lines of which
are parallel with those of the cylinder B and consequently with the driving shaft b.
(7) A series of recesses F, F₂
F F
formed in the
periphery of the rollers D, D₁, Du and corresponding to the vanes or dia-
phragms E, E
EEE
.
E," E
11
1
F F¹
11
E," E¹¹
in such a manner that the
11
E¹ E₂¹
recesses C, C¹,
and the rollers 1), 11, Du having imparted to them
respectively uniform continuous movements of rotation, and a suitably calculated
relation existing between them, the recesses F₁ F, F, F, F, F.
are automatically presented to permit the passage of the vanes or diaphragms E,
The recesses F, F, . F, F, F F
which are precisely similar in the same roller are bounded by cylindrical surfaces
of appropriate section, the generating lines of which are parallel with the axis d
(or with the axes d₁ d) and consequently with the driving shaft b. The respective
sections of the vanes or diaphragms and of the recesses may be of any suitable
kind, provided that they correspond one with the other in such a manner that,
whatever may be the positions of the movable parts, there can under no circum-
stances exist any communication between the openings L, and L, which are
hereinafter referred to.
(8) A transmission mechanism of any suitable description (consisting of gear
wheels as shewn in Figure 1, for example) serving to impart to the shaft da
certain movement of rotation which may be either equal or proportional to that
of the shaft b according to circumstances, but in the opposite direction: the

page_text: purpose of this transmission mechanism being to absolutely ensure, during
the rotation, the synchronism of the passages of the recesses F, F, . . and of
the vanes or diaphragms E, E.
"
(9) Two series of apertures suitably arranged so as to serve either for the admis-
sion (or suction) or for the discharge (or forcing) of the fluid. These apertures
are formed in the fixed wall of the cylindrical casing A and open directly, without
the intervention of any distributing slide or valve, into the steam supply (or
suction) pipes and into the exhaust (or force) pipes respectively.
Under these conditions, the recesses C, C, C
the rollers D, D', D", the
movable vanes or diaphragms E, E.. E, EE," E" and (during one
phase of the motion, as will be apparent hereafter) the movable recesses F, F.
11
FF
regarded as a whole, constitute with the fixed casing A
a series of closed spaces of variable capacity reserved to the fluid, the tightness
of such spaces being very simply obtained, in principle, by the rapidity of the
rotation which either prevents entirely or reduces to a negligable quantity, any
leakage through the spaces, which may be as small as desired, existing between
the surfaces in motion.
1
2
"
1
be
Before passing to a consideration of the working of the apparatus, it may
pointed out that the parts above described may be modified or added to without
thereby altering either the principle or essence of the invention or the method
of action.
it
Thus, for example, the cylinder B may be made in one piece or
may consist
of annular parts passed upon the same shaft b or upon concentric shafts, and the
and to their axis dor
same remark applies to the rollers D, D', Du
axes d₁ d) with the reservation only that each assemblage of parts forming
a groove rotates with the shaft which carries it, and synchronously with the corre-
sponding roller.
The rollers D, D¹, D may also be capable of longitudinal motion upon
their axis (or axes) provided that they participate in the motion of rotation of
this (or these) latter, in order to ensure the aforesaid synchronous action.
.
The vanes or diaphragms should be of a section symmetrical with respect to a
meridian plane of the cylinder B, if the machine is intended to operate both
forwards and backwards indifferently; if, however, the machine is intended to
operate in one direction only they may be un-symmetrical in section.
Although the continuous flow of the fluid is not impeded by any distributing
slide or valve, there is no reason why the machine should not comprise slides or
valves for changing the direction of rotation.
i
The rollers D may be covered or cased, as indicated in Figure 5, for the purpose
of preventing loss of heat and of confining leakage within narrow limits.
The tightness of the movable joints communicating with the exterior like-
wise be increased if necessary by any suitable means, and other modifications or
additions of like character may be made.
may
In describing the operation of the machine when used as a motor I will assume,
for the sake of greater clearness, that a steam engine is under consideration, and
it is provided as represented in Figure 3, with a groove having two diaphragms
in which the steam enters at L, and issues at L₁.
The period of the motion is half a revolution and comprises four phases:
The first phase commences at the moment at which, the diametrical line joining
the rear faces of the vanes or diaphragms being in the position the vane or
diaphragm E, uncovers the aperture L. From this moment, the steam enters
behind the said vane or diaphragm and, owing to the connection between the two
vanes or diaphragms and to the difference of pressure upon the two extreme faces,
drives the diaphragm E, in the direction of the arrow after the manner of a piston,
whilst roller 1) acts as a tight or practically tight cylinder end as in an ordinary
5 steam engine.
The second phase commences at at the moment at which, the vane, or
diaphragm E uncovering the orifice L₂, the discharge of the fluid comprised

page_text: in E, M E, takes place. The motion continues in the same direction under the
influence of the difference of pressures exerted upon the two faces of the vanes
or diaphragms E₁.
The third phase commences at at the moment at which the vane or
diaphragm E clearing the recess F, the two faces situated at the left hand of
each diaphragm are exposed to the admission pressure, whilst the two right hand
faces are exposed to the discharge pressure. The resultant actions upon the two
diaphragms being equal and opposite in direction nullify each other. The recess
thus ceases to possess a motive action. On the other hand, the pressures upon the
two faces of the notch in the roller being unequal, and that exerted upon the left
hand half being the stronger, the roller in its turn assumes a motive action, in
the direction of the motion already commenced.
The fourth phase, which constitutes a dead angle, commences at at the
moment at which the roller ceases to possess a motive action; and it terminates
at the moment at which, the diaphragm E, uncovering in its turn the orifice L₁
owing to the speed acquired, a new period comprising the same phases commences.
If it is desired that the machine should be capable of operating backwards and
forwards, indifferently both the diaphragms and the recesses should be of sym-
metrical section with respect to a diameter.
If the fluid acts successively in different recesses the angles of keying or fixing
should be such that, in principle, the admission into the second recess coincides
with the escape from the first, and so on.
There is, however, a distinction to be made; if the fluid is not adapted for the
utilization of the force of expansion, owing to its low pressure or to its incom-
pressibility, the various recesses C C C
may be supplied directly from the
source of pressure.
On the other hand, if the fluid is adapted, as for example, steam, to the utiliza-
tion of the force of expansion, this fluid, flowing in a continuous manner at full
pressure into the first recess, will escape, after having performed a certain amount
of work, directly and without the intervention of a distributing valve, into a
second recess of greater capacity where the fluid will expand; then, if desired,
the fluid upon escaping from the second recess and without the intervention of
a distributing valve, will enter a third recess of still greater capacity where its
expansion will continue, and so on in succession.
In short, the method of expansion employed is the successive expansion of the
Woolf-type; and this machine is characterised by the fact that the fluid enters
it in the form of a continuous and uniform current, and that it likewise issues
therefrom, whether it be capable of expansion or not, in the form of a uniform
and continuous current but with the condition that in the case of a compressible
fluid the discharge pressure is not greater than that existing in the space into
which the discharge takes place.
The above explanations are respectively applicable to all fluids capable of
exerting pressure upon a movable wall or partition or of expanding in a closed
space of variable capacity. And the machine adapts itself in this way, by means
of a simple duplication of the constituent parts which only entails a prolongation
of the cyinders A and B in the direction of the axis of the driving shaft to the
complete utilisation of the pressure exerted by a fluid of any kind whether a
gas, vapour or liquid.
By way of example, the drawing represents a machine acting without expansion.
and operating in both directions (Figures 1 and 2) and a machine acting with
expansion (Figures 3, 4 and 5) operating in one direction only. In this latter
machine, the rollers are carried by distinct shafts, thereby enabling the length
of the conduit in the wall which connects the successive parts one with the other,
to be reduced. In the drawings, the movable cylinder and the rollers are of the
same diameter. All communication between the inlet and the outlet is absolutely
prevented in the following manner: The vanes or diaphragms bounded, upon one
face, by a diametrical plane, and upon the other by a cylinder the directrix of

page_text: which is the epicycloid arep traced in the diaphragm by the motion of the
edge m of the corresponding recess of the roller; whilst the said recess is bounded
by the following cylindrical surfaces: 1st, circular at t t 2nd, having for
directrices the epicycloid arcs m t and t¹s (inverse to 1p) traced respectively in
the roller by the motion of the points and of the diaphragm: 3rd, having for
directrix the arc m¹s of development generated in the same roller by the dia-
metrical face gr. The rollers are provided with casings or envelopes for the
prevention of radiation and leakage. This machine actuated by a motor would
act as either a compression or vacuum pump by successive steps.
The general explanations already given of the working of the machine as a
motor, also apply to its working as a pump; it is only necessary to substitute
the words suction" and forcing" respectively for the words admission
and "discharge.'
66
"
66
"
The advantages and the applications of the machine are the same as those of
the machine described in the said former specification but the first named has the
great advantage over the second that, owing to the continuity of the flow,
the improved machine is capable, both as motor and as pump, of greater speed,
and consequently of greater power, for a given capacity.
I may employ all the original arrangements contained in the above specification
and illustrated in the accompanying drawing, and which may be applicable to
other machines.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
The herein described improved rotary engine or pump comprising the following
characteristic parts.
(a) A fixed cylindrical casing.
(6) An internal cylinder rigidly fixed upon the driving shaft, rotating without
friction concentrically with the said casing and provided with annular
grooves or recesses to any desired number, which fulfil the office of the
cylinders of ordinary machines, and which are intercepted by vanes or dia-
phragms, to the number of at least two to each groove, these diaphragms
serving as pistons.
(c) A series of rollers equal in number to the recesses passed upon one or more
axes parallel with the driving shaft and actuated by it; the said rollers tra-
versing without friction the cylindrical casing, fitting exactly within the
grooves of the recesses, performing the office of cylinder ends and rotating
with a continuous motion mechanically controlled by the driving shaft,
in such a manner as to automatically present (in order to allow the passage
of the diaphragms) recesses with which they are provided for that purpose
which form a tight joint with the diaphragms and which themselves serve
as pistons at certain points during their rotation:
2. The improved rotary engine or pump arranged and operating substantially
as above described in detail, without the use or intervention of distributing slides
or valves as shown in the drawing.
T + 1741. dar of 1809
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.