Improvements in Rotary Engines, Pumps, and Blowers.
Year: 1886

page_text: Date of Application, 9th Oct., 1886.
Complete Left, 7th July, 1887.
Complete Accepted, 12th Aug., 1887.
PROVISIONAL SPECIFICATION.
Improvements in Rotary Engines, Pumps, and Blowers.
We, LUDWIG ZECHMEISTER of Münich and PHILIPP JACOB WEBER of Neuötting
in the Regency of Bavaria, Engineers, do hereby declare the nature of this invention
to be as follows:-
This invention comprises a rotary engine which is adapted for motor pump, fan or
the like and consists of a cylinder, in which rotate concentrically three or more
pistons following behind each other each fixed to a shaft. The shafts of these pistons
are centrally introduced into each other and impart the motion of the pistons either to
the outside if the engine serves as a motor, or from outside to the pistons, if it serves
as a pump, fan or the like. The transmission is effected through the concentric shafts
to a three- or more-cranked axle, which is excentrically journalled with regard to the
cylinder of the engine.
The engine is composed as follows:
Three or more plates forming pistons are arranged to rotate in a cylinder; the first
is connected for a third (or less) of its length with a hollow shaft journalled in a
sleeve, fixed to or formed with the cylinder. The second piston is connected to a
second hollow shaft which slides in the first and so on until the last piston is fixed to
a solid shaft passing concentrically through the hollow shafts. The ends of the shafts
within the cylinder are enlarged so that their respective surfaces in the cylinder all
lie at the same level.
To the outer ends of each of the shafts respectively are fixed cranks which are
connected by rods with pins arranged along the periphery of a fly wheel which is
caused to rotate.
The usual known elastic beads are arranged round the edges of the pistons. To
allow these heads to be fitted with the greatest possible exactness, each piston consists
of three parts viz. one part fixed to the axle and having a rectangular cross section
and of two wedge shaped surface plates whose surfaces are placed radially to the axis
TD 017

page_text: of the cylinder so as to complete the sector. The beads, when passing the inlet, are
pressed down by the steam (or other fluid) and come out of action. This incon-
venience is removed by the use of a wedge or prism arranged in the piston wall,
which is pressed by the steam against the cylinder wall, so that a tight closing is
ensured, especially between inlet and outlet; a washer is also arranged in the end of
the cylinder, and of equal diameter to the shafts.
The inlet consists of a series of separate pipes, of which more or less may be covered
by the slide, so that the following piston may stop the inlet of steam to the preceding
piston, after the latter has travelled a greater or less distance, so that the most suitable
amount of steam required for efficient expansion may be supplied to each cylinder.
Dated this 9th day of October 1886.
HERBERT & Co.,
67, Strand,
Agents.
Improvements in Rotary Engines, Pumps, and Blowers.
We, LUDWIG ZECHMEISTER of Munich, and PHILIPP JACOB WEBER of Neuötting
in the Regency of Bavaria, Engineers, 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 comprises a rotary engine which is adapted for motor, pump, fan or
the like, and consists of a cylinder in which rotate concentrically three or more pistons
following behind each other, each fixed to a shaft. The shafts of these pistons are
centrally introduced into each other and impart the motion of the pistons either to the
outside, if the engine serves as a motor, or serve to transmit motion to the pistons,
if the machine serves as a pump, fan, or the like.
The transmission is effected through the concentric shafts to a three- or more-
cranked axle, which is eccentrically journalled with regard to the cylinder of the
engine, the pivots of the piston cranks describing a much smaller or a much larger
circle than that described by the pivots of the cranks of the driving axle.,
In the present rotary engine three or more pistons are arranged. Dead point is
thereby removed, the work increased and a manner of action is produced as found in
compound engines or in Woolf's engines. Here at least one piston is always in
action, as shown by piston a, Fig. 1, even, when the two other pistons and c are
in an alternate position.

page_text: The engine is composed as follows:
Referring to the drawings annexed,
Fig. 1 is a vertical section through the cylinder.
Fig. 2 a longitudinal section of the same showing the eccentrically lodged driving
shaft with connecting links a¹ b' c¹.
Fig. 3 is a diagram illustrating the relative position of the crank pins of the main
driving shaft and the pistons upon the system shown in Fig. 1.
Figs. 4 and 5 are cross sections illustrating a modification in the connection of the
piston shafts with the main driving shaft.
Figs. 6, 7, 8, 9, 10 illustrate other modifications.
Three or more plates forming pistons are arranged to rotate in a cylinder; the first
is connected for a third (or less) of its length with a hollow shaft a journalled in a
sleeve fixed to or formed with the cylinder. The second piston is connected to
a second hollow shaft which slides in the first, and so on according to the number
of pistons, until the last piston is fixed to a solid shaft o passing eccentrically through
the hollow shafts a b.
The ends of the shafts within the cylinder may be enlarged so that their respective
surfaces in the cylinder all lie at the same level.
To the outer ends of each of the shafts respectively are fixed cranks a b c which
are connected in the manner hereafter described with pins arranged along the
periphery of a fly-wheel or equivalent which is caused to rotate.
The details are so constructed that the pivots of the piston cranks describe a circle,
which is much smaller, or much larger than that described by the pivots of the
driving-shaft fly wheel or cranks. Preferable is the former case as shown by Fig. 3
(diagram). In this figure the circle marked outside with Roman ciphers, shows the
circle of the crank pivots of the main-driving shaft.
Each piston is situated on a nave which occupies, according to the mumber of
pistons one third or less of the length of the cylinder; the piston however must
occupy, the whole length of the cylinder; therefore a piston must always cover the
two naves of the other pistons. As in Fig. 2 the piston c covers the naves of a and b,
vice versa the piston a must cover the naves of b and c, while the centre-piston b
covers on one side the nave a, on the other side the nave c. The friction walls are
tightened by the usual elastic beads, arranged round the edges of the pistons. To
allow these beads to be fitted with the greatest possible exactness, each piston consists
of three parts, viz., one part fixed to the axle and having a rectangular cross section,
and of two wedge shaped surface plates m m, whose surfaces are placed radially to the
axis of the cylinder so as to complete the sector.-Since the beads when passing the
inlet port, are generally pressed down by the steam (or other fluid) so as to be
rendered temporarily useless, a wedge or prism is arranged in the piston wall b
(Fig. 1), which is pressed by the steam against the cylinder wall, so that a tight
closing is ensured, especially between inlet and outlet p and v. A washere is also
arranged in the end of the cylinder, and of equal diameter to the piston naves. This
washer is tightly lodged and secured in the cover of the cylinder. The leaf springs f
press the washer against the front surface of the piston naves so as to ensure their
closing against each other and against the ends of the cylinder.
The inlet p consists of a series of separate pipes, of which more or less may be
covered by the slide h, so that the following piston may stop the inlet of steam to the
preceding piston, after the latter has travelled a greater or less distance so that the
most suitable amount of steam required for efficient expansion may be supplied.
In Fig. 1 the piston bis on the point of stopping the steam inlet to the piston a;
after a slight advanced motion, also the piston 6 comes into action with full steam,
while the piston a is driven by expansion, a proportion also governing the spaces, as
takes place between the two cylinders of a compound-or Woolf's engine.
For the application as a pumping engine, the inlet is to be arranged from p to the
dotted line, ending with the flange i (Fig. 1).

page_text: The outlet may likewise be increased to the dotted line 7 (Fig. 1) especially if the
pump is intended to work in the contrary direction.
x
The shaft which may be called the main driving shaft is journalled eccentrically
as regards the cylinder and shaft O. It is provided at the end with cranks, one for
each piston, or with the equivalent of said cranks, namely a fly-wheel. The manner
of connecting the cranks a b c¹ to the fly wheel varies, and may be performed as
shown in Fig. 1. Around the periphery of the fly-wheel, equidistant or otherwise
from each other and from the centre of the shaft r, are arranged pins connected to
the ends of the cranks a b c respectively, by connecting links a¹ b c¹.
The transmission of motion may also be effected by aid of cranks without
connecting links in the following manner. (Figs. IV and V).
The cranks a b c secured to the shafts of the pistons have straight (radial or
inclined) or curved slits z, in which slide the pins rst of the cranks or fly wheel of
the eccentric shaft.
The lastmentioned pins may also be provided with slits in which slide the straight
or bent piston cranks.
In lieu of each single pin there may be placed a pair of pins at a relative distance
apart sufficient to admit of the straight or curved piston cranks moving and sliding to
and fro between the two pins.
The curving or inclining of the slits or of the piston cranks has for its purpose, and
is regulated according to, the acceleration or decrease of the rate of travel during
part of the stroke of the respective parts, that is to say of the pistons.
The piston cranks may also be so constructed as to be shortened and extended as
required according to the eccentric position of the pins of the driving shaft cranks,
one part of the crank sliding on or in the other (or by parallelograms of connecting
rods). By the insertion of springs into the transmission devices, any shocks in the
motion of the respective parts are diminished or neutralised.
The transmission of motion is here effected as follows:
The slits 2 of the piston cranks a receive into them the pins of the
cranks stor of a corresponding fly-wheel or disc fixed onto the driving shaft. The
pins slide in the slits of the cranks a b c and thus the peculiar movement of the
pistons is produced.
Or the pins have slits, in which slide the cranks a¹ bc, or each two pins are
provided with rolls between which the cranks slide. Or the cranks may be adapted to
be shortened or extended; they have then an ear that receives the corresponding
pins.
A further modification has for its purpose to remove the tensions produced by the
crank apparatus especially with an eccentric position of the impulsion shaft.
The main driving shaft is here entirely dispensed with, while the cylinder-pistons
and their cranks etc. remain unaltered. A drum serving as strap-pulley is placed
loosely on the extended shaft of the innermost piston. The three slide rods A B C
(Fig. VI) oscillate upon pivots held in eyes cast onto the inner rim of this drum or
pulley. These slide rods are in two parts as shown in Fig. VII, the fore shank A
being connected with the rear shank A' through the part A² rigidly securing them
together. The rear shanks A¹ B¹ C₁ are connected by connecting links A³ B³ C³ with
the corresponding piston cranks, but the longer fore shanks A B°C are provided with
slits embracing the fixed pivot Z correspondingly stationary on the engine. Owing to
the eccentric position of the pivot Z, which can be displaced within the radius of the
piston-cranks and even a little beyond the same, the slide rods give the pistons by
their joints or hinges A³ ³ (3 the same rotary motion as with the crank apparatus
beforementioned with the advantageous difference that the angle of the links with
regard to the cranks varies only slightly, in consequence of which the pistons play
freely, and the tension or the friction produced by the beforementioned,constructions is
removed.
In Figs. VI and VII the links A³ B³ ³ are so connected with the slide-rods, that
this connecting point coincides with the crank circle, when the pivot z is in the outer
extremity of the slit in the sliding rod. This connecting point may however also be

page_text: placed at the extreme end of the slide rods, diametrically opposite to the position
Fig. VI VII, so that this connecting point lies behind the pivot Z. Then the rear
shanks must naturally be extended and so bent as not to come in contact by their
oscillations with the piston or main-shaft; or these rear shanks may be given a
bow-shaped recess M (Fig. X) to cause them to pass about the shaft; by this means
however the construction would become too complicated for three pistons, while, for
two pistons this construction affords important advantages, as the angle-difference of
the two pistons is considerable and allows of pistons of only 45° so that with but one
revolution a working capacity of 14 cylinder-filling is produced. With regard how-
ever to the circumstance, that at the same time two cranks or pistons can be held at
one and the same slide rod, it is advisable for the sake of simplicity to arrange with
two pistons (Fig. VIII and IX) only one slide rod. The manner of working is then
the same as with all hitherto mentioned constructions. Only the removal of the dead
point is then dispensed with. In Figs. VIII and IX the slide rod A is equal to that
of Figs. VI and VII; only at the outer part is placed the bow A' with its bolt, for
receiving the link A5, which then actuates the second piston. The approaching angle
of the two pistons is here 90° so that on one revolution a complete filling of the
cylinder is effected; this angle however can be diminished to 60°, whereby one
revolution causes 1 cylinder-filling, a working capacity, not heretofore attained with
rotary engines with pistons.
In case it becomes necessary to place a particular journal-bearing before the
impulsion drum, therefore also before the pivot Z, the slide rods must be given the
shape shown in Fig. X. The bow M in the longitudinal slits allows, notwithstanding
their oscillations, the shaft of the drum to pass unimpededly. Instead of the friction
rolls upon the pivot Z a guide block N must then be employed, journalled upon Z, in
order that by the guiding of the block N the pivot Z is retained in the longitudinal
slits of the slide rods. It is also possible to couple two or more cylinders to one and
the same axle by the application of the abovementioned slide rods; the driving wheels
are then fixed on the shaft, and the innermost piston of each set of pistons must like-
wise be fastened to a tube (as heretofore to a shaft) to allow the main shaft to pass
through.
Having now particularly described and ascertained the nature of this invention, and
in what manner the same is to be performed, we declare that, what we claim is :
In rotary engines.
1) A series of pistons connected one on each, to a series of concentric shafts with
crank arms on said shafts in combination with a main shaft journalled at a point
eccentric with regard to the common axis of the said concentric shafts, and having a
series of cranks or the equivalent thereof operated by the cranks of the aforesaid
concentric shafts.
2) The combination of a series of concentrically revolvable cranks and a shaft
journalled at a point eccentric with regard to said cranks, and having a series of fixed
cranks or their equivalent; with links connecting said cranks, the radius of the points
of connection of the links with the first series of cranks being greater or less than
the radius of the points of connection of the links with the second series of cranks or
their equivalent.
3) The manner of connecting said series of cranks
a) By providing the piston cranks with slits and causing the pins of the main
shaft cranks to engage and slide in said slits.
6) By providing the main shaft cranks with slitted pins or equivalent devices, and
causing the piston cranks to engage and slide therein.
c) Consisting in connecting the piston cranks direct to the main shaft crank pins,
the piston cranks being capable of extension and contraction.
4) An inlet port composed of separate channels arranged each with a greater
inclination to the cylinder than the preceding, substantially as and for the purpose set
forth.

page_text: 5) The combination in a piston of a rectangular base, two face plates m m and
wedge or prism & substantially as set forth.
6) The combination with the cylinder and piston shafts terminating therein, of a
disc e adapted to be pressed against the end of said piston shaft, substantially as and
for the purpose set forth.
7) The combination of the piston-cranks with a drum or equivalent revolving con-
centrically with said cranks, the double connecting rods A B C pivoted in the
periphery of said drum and connected by links A³ ³ ³ with said cranks, together
with the eccentrically placed and stationary pivot Z substantially as and for the
purpose set forth.
8) The combination of two piston-cranks by links A3 A5 with one double rod A
pivoted in drum or equivalent, and pivot Z substantially as and for the purpose set
forth.
9) The combination of double rod A having enlargement M with guide block N
upon pivot Z substantially as and for the purpose set forth.
10) The combination with the above-mentioned gear or gears, of springs inserted at
suitable places to lessen or neutralise shocks in the movement of the parts.
L. ZECHMEISTER.
P. J. WEBER.
By Herbert & Co.,
67, Strand, W.C., London,
Agents to Applicants.