Improvements in Rotary Motors.
Year: 1899

page_text: Date of Application, 9th Aug., 1899-Accepted, 7th Oct.,
1899
Improvements in Rotary Motors.
We, CARL ALRIK HULT, of Flemminggatan 48, Engineer, and OSCAR WALFRID
HULT, of Handtverkaregatan 30, Engineer, both in Stockholm, in the Kingdom
of Sweden, 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 rotary motors and especially to such rotary motors,
in which the casing, containing the piston of the motor, is caused to rotate by
the said piston. The invention has for object the construction of motors, which
are very effective relatively to their size and in which the condensation is highly
reduced of the motive fluid if it has a tendency to condense in the working
chamber as in the case of steam which is the most commonly used fluid. More-
over, the loss of work caused by the friction is very small relatively to the total
amount of the work developed. These advantages are obtained by the employ-
ment of influx and efflux passages or recesses for the motive fluid, which passages
or recesses are arranged in a special manner, in combination with the employment
of two or more wings or sliding plates or blocks (hereinafter called slides),
mounted in the same piston and serving to take up and to transmit the pressure
of the motive fluid.
The invention also relates to an arrangement used in connection with the said
passages or recesses, when these are employed for controlling the efflux of the
steam, and which arrangement has for object to control the influx of said fluid.
In the accompanying drawings:
Figure 1 is a vertical longitudinal section of a rotary motor constructed
according to our invention; and
Figure 2 is a cross section on the crooked line 2-2 Figure 1;
Figure 3 is a vertical longitudinal section of a modification of the motor shown
in Figures 1 and 2; and
Figure 4 is a cross section of the same taken on the crooked line 4-4
Figure 3;
Figures 5 to 7 illustrate another modification; Figure 5 being a vertical
longitudinal section and Figures 6 and 7 cross sections taken on the lines G-G
and 7-7 respectively of Figure 5.
The motors have a cylindrical piston 10, provided with two sliding plates or
blocks or the like which I term slides 11 and 12 (the number of which may exceed
two) and eccentrically located in a casing 13, which, as has heretofore been the
case, is rotatably mounted, so that it can be rotated by the piston, being in
contact with the same along the line 14. To this end the casing 13 is by means
of elastic rings 31, journalled in a frame 15, forming a steamproof house or
casing round the casing 13, (in the description which follows the motive fluid is
supposed to be steam), as the space between the casing 13 and the frame 15

page_text: serves as a passage for the steam, the frame 15 having a tube 16 for the inlet
of fresh steam or for the discharge of expanded steam.
The numerals 1 to 6 indicate the different positions of the sectional lines of
the periphery of the piston and those surfaces of the slides 11 and 12 which are
exposed to the pressure of the steam (the working surfaces of the slides).
In the motor shown in Figures 1 and 2 the fresh steam enters the motor
through the hollow shaft 17, which is concentric with the piston 10, and thence
it passes alternately through the passages 18 and 19 made in the piston into the
working chamber between the piston 10 and the casing 13. The flow of the steam
into the said chamber is controlled by a mechanism arranged in the manner
hereinafter described.
Each of the inlet passages 18 and 19 opens into the working chamber near the
corresponding slide 11 or 12 (it is evident that the number of passages is similar
to that of the slides), and on the other side of the slide is the mouth of an
outlet passage 20 or 21. These latter passages, which are also arranged in the
piston 10, extend to recesses or steam ports 22 and 23 in one or both sides of the
piston 10, the ports being preferably arranged in both sides of the piston, other-
wise the outlet for the expanded steam would hardly be sufficient.
The steam ports 22 and 23 have such a position in the sides of the piston that,
on the rotation of the piston, they are alternately covered and uncovered by the
side pieces 131 of the casing 13, which side pieces have central openings.
Figure 2, in which the arrows indicate the direction of rotation of the piston 10
and the casing 13, shows the ports 22 about to be uncovered, so that the steam
can begin to flow away from the working chamber behind the slide 12, in which
chamber the expansion is ended, when the slide is at 3. The expansion com-
menced in the same working chamber, when the slide 12 was at 2.
At the same
time that the ports 22 are uncovered the ports 23 are covered by the side pieces 13¹,
so that the chamber in front of the slide 12 is closed by degrees and is completely
closed, when the slide 12 is at 5 (the slide 11 being then at 4). The exhaust
steam passes from the ports 22 and 23 respectively through the projections or
necks 132, which serve as paths for the rings 31 supporting the casing 13, and
then through and between the rings 31, through the space between the casing 13
and the frame 15 and through the tube 16 into the atmosphere or into a con-
denser.
In the modification shown in Figures 3 and 4, there are also recesses or ports
22 and 231 in the sides of the piston. but these recesses or ports do not com-
municate with the outlet passages 20 and 21, as in the motor previously described,
but with the inlet passages 18 and 19. The influx of the steam is consequently
controlled by the side pieces 131 of the casing 13, as the ports also in this case
are so located that they are alternately covered and uncovered by the said side
pieces. The passage of the steam through the motor is in this case contrary to
that of the steam in the motor previously described, as the fresh steam enters
through the tube 16, passes through the space between the casing 13 and the
frame 15, through and between the rings 31 and through the necks 132 into the
casing 13, and leaves the motor through the hollow shaft 17, which contains an
arrangement for controlling the outflow of the waste steam. This arrangement
consists of a sleeve 24. inserted in the shaft and firmly connected to the same,
the said sleeve being closed at one end and provided with apertures 25. forming
extensions of the outlet passages 20 and 21. Against the inner side of the
sleeve 24 rests another sleeve 26, which is fixed, that is to say, it does not partake
in the rotation of the shaft, a part of the said sleeve 26 being cut away at the
apertures 25 so as to form, at the said apertures, a tongue 26' which covers only.
a part of the inside of the sleeve 24 rotating with the shaft. The outflow of the
expanded steam is consequently controlled by the movable apertures 25 being
alternately covered and uncovered by the fixed tongue 26¹.
In the position of the parts of the motor shown in Figure 4 the ports 221 are
just about to be uncovered by the side pieces 131 so that the fresh steam can

page_text: begin to flow into the working chamber behind the slide 11. The outflow of
the waste steam from the chamber in front of the slide 12 takes place through the
passage 21.
Figures 5 to 7 illustrate a modification of the motor shown in Figures 3 and 4:
In this modification there are no recesses or ports in the sides of the piston, the
influx as well as the efflux of the steam to and from the working chamber taking
place respectively through passages 181, 19¹ and 20¹, 21', connecting the work-
ing chamber with the interior of the hollow shaft 17. The influx of the steam is
controlled by an arrangement, such as is used for the same purpose in the motor
shown in Figures 1 and 2 and which is described in the following part of this
specification, while the efflux is controlled by an arrangement, similar to the
arrangement controlling the efflux of the steam from the motor shown in
Figures 3 and 4, namely, a sleeve 24, rotating with the shaft 17 and provided
with apertures 25, which form extensions of the outlet passages 20 and 21, and
a fixed sleeve 26, inserted in the sleeve 24 and partially cut away near one end
so as to form a part or tongue 261, which alternately covers and uncovers the
apertures 25. The sleeves 24 and 26 also belong to the arrangement for con-
trolling the influx of the steam.
The waste steam, having entered the sleeve 24 through the outlet passages 201
and 211, moves through apertures 27 made in the said sleeve and through
apertures 28 made in the motor shaft 17 to the space within one of the necks 133
and thence through and between the rings 31 and through the space between the
casing 13 and the frame 15 to the tube 16.
In the motors shown in Figures 1 and 2 and 5 to 7 respectively that is to say,
in cases where the efflux of the motive fluid takes place through the recesses or
ports in the sides of the piston or through the hollow motor shaft, the influx
of the steam is controlled by a special arrangement which is constructed as
follows. As above stated the motor shaft contains a sleeve 24, closely resting
against the inside of the shaft and firmly connected to the same, and another
sleeve 26 closely resting against the inside of the sleeve 24 and connected to the
fixed portions of the motor in such a manner that it cannot rotate. Inside the
sleeve 26 there is a third sleeve 34 resting against the wall of the said sleeve 20
and firmly united to the sleeve 24 by means of a screw connection or in any
other suitable manner, and finally there is in the sleeve 34, closely surrounded
by the same, a governing or controlling device, consisting of a sleeve or, as shown
in the drawing, of a valve body 35, the cross section of which is Z-shaped and
which is connected, by means of a bar 30, to a governor (not shown in the
drawing), located in the fly wheel 29 of the motor, the said wheel having the
form of a house or casing. The sleeve or the Z-shaped valve body consequently
rotates with the motor shaft or with the sleeves 24 and 34, but it also turns in
one direction or the other when acted upon by the governor, thereby governing
or regulating the speed of the motor.
The sleeves 24 and 34 which are firmly connected to one another and which partake
in the rotation of the shaft 17 and therefore in that of the piston 10, are pro-
vided with apertures 36, 37 and 38, 39 respectively, which are situated in the
extensions of the inlet passages 18 and 19 (Figures 1 and 2) or 181 and 191
(Figures 5 and 6).
The fixed sleeve 26 is provided with an aperture 40, whose position and exten-
sion along the circumference of the sleeve (together with the circumferential
extension of the apertures in the sleeves 24 and 34) determine the moment of
the commencement and the end of the influx, as this commences when those
edges of the apertures 36, 38 and 37, 39 respectively which move in advance of
the others, pass one edge (the rear edge) of the aperture 40, and finishes, when
the succeeding edges of the apertures 36, 38 and 37, 39 pass the other (the fore)
edge of the aperture 40. The sleeve 26 and its aperture 40 consequently deter
mine the distribution of the motive fluid (the steam) into the motor, and therefore
the said sleeve may be called the distribution sleeve. This sleeve is preferably

page_text: arranged in such a manner that it can be turned or adjusted into different posi-
tions, whereby the periods of influx and expansion can be altered.
The speed of the motor is controlled, as above stated, by means of a sleeve,
introduced into the sleeve 34 (the controlling sleeve) and provided with aper-
tures, corresponding to the apertures 38 and 39 of the last mentioned sleeve, the
steam entering through the hollow motor shaft of the motors in question. As
shown in the drawings the controlling device may, however, consist of a valve
body 35, the cross section of which is Z- (or I-) shaped, the flanges of the said
valve body resting closely against the inside of the sleeve 34. The portion of
the valve body connecting the said flanges is perforated, in order that the steam
may flow from both sides of the same to one or the other of the inlet passages.
The valve body 35 (or the sleeve) is connected, as above stated, to the governor,
located in the fly wheel 29 of the motor, and it has such a position in the
sleeve 34, that one of the edges of the flanges (or one of the edges of the apertures
in the sleeve if such is used) at the normal speed of the motor are close to the
rear edges of the apertures 38 and 39 of the sleeve 34. When the speed of the
motor increases for some reason or other, the valve body 35 is by means of the
governor turned forwards in relation to the sleeve 34, the apertures of which are
consequently closed or reduced in a degree corresponding to the increase of speed
of the motor, whereby the influx of the steam is reduced, so that the motor is
caused to return to its normal speed, the valve body then being caused to return
to its normal position in relation to the sleeve 34.
In order that the speed controlling device may cut off the influx of steam at
the proper moment, the above mentioned edges of the same should reach to the
sleeve 26, and they are therefore provided with projections 351 passing through
the apertures 38 and 39 of the sleeve 34. By this arrangement the end of the
influx period 'becomes immediately dependent on the position of the speed
controlling device relatively to the fixed sleeve 26.
It is evident, that the sleeve 24 is not indispensable in the described arrange-
ment for controlling the influx of the steam (nor in the above mentioned arrange-
ment for controlling the efflux of the steam). The purpose of the same is only
to avoid friction between two different metals, viz., the iron of the rotating
motor shaft 17 and the brass (or other suitable metal) of the fixed sleeve 24. In
case of the sleeve 24 being omitted, the sleeve 34 is directly connected to the
shaft 17.
The described arrangements (the sleeves, the valve body and the tongue) for
controlling the influx and the efflux of the motive fluid, which arrangements are
located in the hollow motor shaft, may be employed independently of one another
(as will be seen by reference to Figures 1 to 4) as well as in other rotary motors
than those referred to.
As mentioned above the necks form the paths of the rings 31 by means of
which the casing 13 is journalled in the frame 15. The motor shaft 17 carries
annular pieces 32, serving as the paths of rings 33 for holding the shaft rotatably
mounted in the end pieces of the frame.
In all the motors the influx of the fresh steam into the working chamber
commences, when either of the slides is at the point 1 and continues until the
slide has reached the point 2, when the expansion commences.
The expansion
takes place, while the slide moves to the point 3, and is succeeded by the efflux
which continues, until the slide is at the point 5 (the slide, which at that moment
is exposed to the pressure of the fresh steam is then at the point 4).
The object of the described arrangements for controlling the flow of the steam
through the motor is in the first place to facilitate the employment in rotary
motors having a piston casing which is caused to rotate by the piston of two or
more plates, blocks or slides, serving to transmit the pressure of the steam (or
other motive fluid) to the shafts, which slides etc., are mounted in the same
piston and move in the same space or chamber viz., the crescent-shaped chamber
between the casing 13 and the piston 10. If, when employing two or more slides,

page_text: the system of the steam passages were arranged in the ordinary manner, that is
to say, having the outlet passages in direct communication with the atmosphere
(or a condenser) the efflux would commence immediately after or even before the
end of the influx, or in other words, there would be a very slight expansion or
an intermediate efflux of the fresh steam which in either case would occasion
great loss of power. This circumstance, which will easily be understood by
reference to Figures 2, 4, 6 and 7, would arise from an outlet passage, for instance
the passage 21, beginning to let out the steam, as soon as it began to pass the
point of contact between the casing and the piston. The point 6 in Figures 2, 4
and 6 indicates the position of the slides, in which the steam would begin to
flow away in the supposed case. In the motors described above the efflux is
delayed until the slides have reached the point 3.
The advantages of employing two or more wings or slides in the same piston
are very great. The motors are much more effective relatively to their size than
other motors having only one slide, and the condensation of the steam on account
of the contact with the walls of the working chamber is considerably reduced,
all this depending on the fact, that during each revolution there are two or
more periods of influx (which are succeeded by complete periods of expansion
and efiux), according as there are two or more slides. The loss of work caused
by the friction is nearly as small as when a single slide is used, and consequently
it is very small in comparison with the whole amount of the work developed.
Though especially adapted for rotary motors having a piston casing caused to
rotate by the piston this invention can also be applied to motors with a fixed
piston casing.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. In rotary motors and especially in rotary motors having a piston casing
caused to rotate by the piston the arrangement in the sides of the piston, which
sides are in contact with the open side pieces of the said casing, of recesses
(ports 22 and 23, Figures 1 and 2 and 22 and 231, Figures 3 and 4), which com-
municate either with the outlet passages (20 and 21), made in the piston, or
with the inlet passages (18 and 19), also made in the piston, to the end that the
efflux of the motive fluid from, or the influx of the same into, the working
chamber of the motor may be controlled by the passing of the recesses (22, 25
or 22, 23) before the openings of the side pieces, substantially as set forth.
2. In motors of the kind characterized in Claim 1, a fixed part or tongue (261)
arranged in the hollow shaft serving as a conduit for leading away the expanded
motive fluid at a point where the outlet passages open into the hollow shaft (when
the recesses (22 and 23) in the sides of the piston communicate with the inlet
passages, made in the piston), the said tongue resting against the inside of the
shaft or of a sleeve (24) mounted in the said shaft, to the end that the efflux of
the expanded motive fluid may be controlled by the tongue (26), which alter-
nately covers and uncovers the outlet passages, substantially as set forth.
3. The modification of the arrangement described in Claim 1 in which the
arrangement for controlling the efflux of the motive fluid is the same whilst the
arrangement for controlling the influx of the said Huid consists of the ordinary
passages, extending from the circumference of the piston to the interior of the
hollow shaft and of devices located in the said shaft and controlling the influx of
the motive fluid, substantially as set forth.
4. In rotary motors, and especially in rotary motors such as are referred to in
Claims 1 and 3 an arrangement for controlling the influx of the motive fluid into
the motor through the hollow motor shaft, which serves as a conduit for the said
fluid, the said arrangement being characterized by a fixed and, if desired, adjust-
able sleeve (26), provided with an aperture (40), whose position and extension
along the periphery of the sleeve determine the commencement and the end of the

page_text: influx period and another sleeve (34), inserted in the sleeve (26) and resting
against the inside of the same, the said sleeve (34) being firmly connected to
the motor shaft, thus partaking in the movement of the same, and being pro-
vided with two apertures (38 and 39), which are situated in the extensions of the
inlet passages (18 and 19, Figures 1 and 2 or 18 and 191, Figures 5 and 6), made
in the piston and running to the first mentioned sleeve (26), so that the influx
through one or the other of the said passages begins, when the foremost edge of
the corresponding aperture (38 or 39) passes one edge (the rear) of the aperture
(40) of the sleeve (26), and ends, when the rear edge of the aperture (38 or 39)
passes the other (the fore) edge of the aperture (40) substantially as set forth.
5. In arrangements such as are characterized in Claim 4 the arrangement of
a sleeve inserted in the sleeve (34), resting closely against the inside of the
said sleeve (34) and provided with apertures corresponding to the apertures (38
and 39) of the sleeve (34), or of a valve body (35), having a Z- or I-shaped cross
section and the flanges of which rest closely against the inside of the sleeve (34)
the said sleeve or valve body rotating at the same speed as the motor shaft and
being connected to the governor of the motor, whereby the wall of the sleeve or
the Hanges of the valve body is or are caused to cover, more or less, the aper-
tures (38 and 39) of the sleeve (34), thus controlling the speed of the motor,
substantially as set forth.
6. In arrangements such as are referred to in Claim 5 providing the controlling
device (the sleeve or the valve body) near the edges controlling the influx of the
motive fluid, with projections (35), which pass through the apertures (38 and 39)
of the sleeve (34) to the fixed sleeve (26), so that the controlling device can cut
off the influx at the proper moment, substantially as set forth.
Dated the 0th day of August 1800
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.