US 3810721 A
A housing accommodates a system of chambers which are angularly spaced about an axis about which they also rotate. Each of the chambers has a first center line intersecting the axis of rotation and side walls which extend in parallelism with its center line. A system of pistons is also rotatable in the housing about a second axis and has a plurality of angularly spaced piston members each of which has a portion located on an imaginary circle concentric with the axis of rotation of the piston system and intersecting the axis of rotation of the chamber system. Ths piston members each have a longitudinal second center line which intersects the circle and the axis of rotation of the respective pistons enter into and exit from the respective chambers in longitudinal direction of the first center lines of the chambers.
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O Unlted States Patent [1 1 1111 3,810,721 Eyer 1 May 14, 1974  ROTARY PISTON MACHINE WITH BYPASS 3,515,496 6/1970 Eddy 417/440 EGULATION 2,948,229 8/1960 Brundage 417/440 3,120,814 2/1964 Mueller 417/310 Inventorr Charles y -s -F t 3,272,128 9/1966 Brundage 417/440 France  Assignee: Consulta-Treuhand GmbH, 'f' 'f f Stuttgart Germany Assistant Exammer-John J. Vrabhk Attorney, Agent, or Firm-Michael S. Str1ker  Filed; Aug. 10, 1972  Appl. No.: 279,671  ABSTRACT A housing accommodates a system of chambers which 30 Foreign A fi fi p i i Data are angularly spaced about an axis about which they A also rotate. Each of the chambers has a first center ug. 16, 1971 Germany 2140970 A r 28 1972 German 2220943 lme intersecting the axis of rotat1on and side walls p y which extend in parallelism with its center line. A sys- 521 US. (:1 417/440, 91/197, 91/491, is p musing a second was and has a plurality of angularly spaced pis- 418/165, 418/169, 418/170, 418/3 b h f h h I d 51 1111. (:1 F04b 23/00, F04b 41/00, F010 1/10 f w 9? 58 Field of Search 418/166, 170, 168, 169; wmnmc. t 9 am 9"" t1on of the piston system and lntersectmg the axis of 417/440, 310
rotatlon of the chamber system. Ths p1ston members 961 2. .2.911:1:92:111112212292111?11::i:- UNITED STATES PATENTS spective pistons enter into and exit from the respective 726,896 5/ 1903 Franzen 413/167 chambers in longitudinal direction of the first center 2,979,036 4/1961 Noren 418/169 lines f h chambers 3,241,745 3/1966 Williams... 418/170 3,548,789 12/1970 Creek 418/170 9 Claims, 14 Drawing Figures MTENTEUMY 14 m SHEET 02 0F 12 PATENTEDIAYMIQN sum oaur12 PATENTEDIAYM m4 3310.721
sum on or 12 PATENTEUIAY 14 m4 sum as or 12 PATENTEDIAY 14 m4 131310.721 sum 07 0F 12 p TEnm 1 4 I971. 3310.721
saw 11 or 12 .aza
ae/z 365 FIG.
ROTARY PISTON MACHINE WITH BYIASS REGULATION BACKGROUND OF THE INVENTION The present invention relates generally to fluid machines, and more particularly to fluid machines which can be utilized as pressure or suction pumps or else as fluid motors.
Fluid machines as a general device, used either for conveying or pumping of liquid or gaseous medium or else used as motors, are not novel per se. in fact, a rather large number of different types of such machines is known from the art. However, many of these which utilize rotating chamber systems are so constructed that the rotating masses are not balanced, meaning that a quite substantial stress'occurs upon the journals for these masses and that special requirements must be met in terms of the mechanical strength of the various components involved. Other fluid machines known from the art utilize a component which acts as a piston and which displaces the medium to be conveyed, in tangential direction and over relatively long distances whereby large frictional losses are caused. In particular, the type of prior-art machine here under consideration has been found to cause difficulties if the necessary sealing effect is intended to. be obtained with relatively simple means, which heretofore has been impossible of achievement.
SUMMARY OF THE INVENTION It is accordingly a general object of the present invention to provide an improved fluid machine which avoids the disadvantages of the prior art.
Another object of the invention is to provide such an improved fluid machine which can be either utilized as a pump or as a motor, as desired.
A further object of the present inventionis to provide such an improved fluid machine which is rather simple in its construction and highly reliable in its operation.
In persuance of these objects, and of others which will become apparent hereafter, one feature of the invention resides in a fluid machine, and more particularly in a combination which briefly stated comprises housing means, wall means and piston means. The wall means is rotatable in the housing means about a first axis and defines a plurality of chambers which are angularly spaced about the same. These chambers each have a first center line intersecting the first axis and respective side walls which extend in parallelism with the first center line. Piston means is rotatable in the housing means about a second axis and comprises a plurality of angularly spaced piston members having a portion located on an imaginary surface .concentric with the second axis and intersecting the first axis. The piston members each have a longitudinal second center line which intersects the second axis and the circle and they are so arranged that the aforementioned portions enter into and exit from the respective chambers in longitudinal direction of the respective first center line.
According to the invention at least those surface portions of the piston portions which enter into and exit from the chambers, and which move along and slide on the side walls of the chambers, can be arcuately curved either in part-spherical or part-cylindrical manner, with the centers of curvature coinciding with that point which determines the movement of the respective piston portion, that is the point at which the intersection of the longitudinal second center line of the associated piston member with the imaginary circle occurs. However, the axis of curvature can also be considered as extending normal to the respective longitudinal second center line. With such a construction particularly advantageous sealing effects are obtained, because the sealing line continuously shifts on the curved surface portion during the movement of the respective piston portion, so that an absolute minimum of wear will occur.
It is evident that within the general ambients of the present invention, as more particularly outlined in the appended claims, various embodiments of the fluid machine are possible. One such embodiment can utilize a hollow-cylindrical housing having opposite open ends which are closed by appropriate plates or end walls. The journals for the rotating components as well as the inlet and outlet openings for the medium to be conveyed, can be provided in these end walls. Located in the housing is a stationary central core which is rigidly A the chamber system whose axis'of rotation coincides with the central axis of hollow cylindrical housing. The stationary central core may be provided with at least one recess in which the piston system may be located. In such an arrangement the pistons will engage into the respective chambers in the manner of the engagement of the gear teeth with the recesses between the teeth of another gear, and because of this it is sufficient to have the shaft constituting the axis about which the piston system rotates, extend outwardly of the housing and to connect it with a suitable drive component. As soon as the axis and thereby the piston system are caused to rotate, the individual pistons take along the chamber system which is annularly arranged.
Depending upon the construction of the piston and chamber systems, the supply and removal of medium can take place laterally of the respective chamber which for this purpose may be laterally open or may be connected with the inlet and outlet openings by the provision of appropriate bores. No space exists between the inner surfaces of the end walls and the side faces of the chamber and piston systems, and because of this the relative position of the inlet and outlet openings on or in the housing assures without any difficulties an automatic control of the supply and ejection of medium. Of course, other possibilities for arranging the inlet and outlet openings exist also.
The chambers may be of various cross-sectional configurations. They may be constructed as cylindrical bores, that is they may have a circular cross-section. in such a case it is advantageous if the portions of the pistons which engage into the chambers are wholly or in part of spherical configuration, the part having such configuration than being connected rigidly by an appropriate piston rod or portion with the hub-like body constituting the carrier of the piston system for all of the pistons.
However, the chambers may also be of rectangular cross-section in tangential direction of the rotation of the chamber system. In this case the pistons, or rather the portions of the pistons which enter into the chambers, must naturally similarly be of rectangular outline. However, it is advantageous that they be further so configurated that those walls of the pistons which extend normal or substantially normal to the direction of rotation of the piston system be configurated as portions of a cylinder in the region where they adjoin the bottom wall of the piston, with these part-cylindrical surface portions having a cylinder axis which is common to them and which extends at right angles to the longitudinal axis of the housing. These cylinder surfaces then merge in planar surfaces or in surfaces which are arcuately curved in the opposite sense and which bound the foot of the respective piston.
One of the end walls of the housing may also be provided with an appropriate recess, in which case the piston system may utilize a disk of circular outline which rotatably mounted in this recess and whose diameter corresponds to the outer diameter of the entire piston system. Plate portions are then mounted on this disk extending in parallelism with the axis of rotation of the latter and extending laterally into the chambers of the rotating chamber system, which chambers are open laterally for this purpose at the side facing towards the plate or disk and which plate portions may be of oval or wing-shaped profile.
It is further advantageous, according to another concept of the invention, to provide the novel fluid machine with a regulating arrangement which permits a continuous variation of the flow of medium through the machine, that is of the medium which is pumped by the machine per unit of time. This is particularly advantageous in the case of the use of the machine as a liquid pump and the control should be continuously variable from zero to maximum flow. This arrangement is particularly suitable in the case ofa fluid machine so constructed as a pump that the chambers are of rectangular cross section and the inlet or outlet opening for the medium is provided at the flat sides of the rotating chamber system. The regulating arrangement can be relatively simple, in that intermediate the supply opening provided in an end wall of the housing and the rotating chamber system there is located a plate, preferably circular or having the configuration of a sector of a circle, which is pivotable through a certain angle. This plate has an opening which connects the inlet opening in the end wall of the housing either exclusively with the suction side of the pump or in a continuously variable degree with the pressure side of the chamber system as well as with the suction side. The opening provided for this purpose in this pivotable plate is so configurated that its inner edge, that is the radial inner edge which is closer to the axis of rotation of the chamber system, will in any possible possible of the plate leave free the inlets of the chambers which are located opposite the opening, with respect to the suction side of the machine, whereas the outer edges of the opening, that is the radially outer edge which faces away from the axis of rotation of a chamber system and towards the circumferential wall of the hollowcylindrical housing, will be so configurated that the point at which intersects that wall of the same chamber which in the direction of rotation of the chamber system is the forward or leading wall, will be displaced in radial direction during pivoting of the plate whereby the working stroke of the piston entering into the chamber is varied. This can be achieved, for instance, in that the plate of circular cross-section is turnable about the central axis of the rotating chamber system and that the inner edge of the opening in this plate is configurated arcuately, with the diameter of the circle of which the inner edge forms a part corresponding approximately to that of the stationary core. The outer edge of the opening in the circular plate has an arcuate portion which extends in parallelism with the inner edge and is a portion of a circle whose diameter corresponds at least to the maximum possible distance between the bottom walls of the pistons and the axis of rotation of the chamber system. The outer edge merges towards the pressure side of the machine gradually (until it reaches the inner edge) into a curved portion or into a straight edge portion. This means that the width of the opening in direction towards the suction side is initially constant and will then decrease to zero in direction towards the pressure side. The end portion of this opening which faces away from the pressure side can be bounded by an edge portion of any desired configuration, for instance of semi-circular outline.
The regulating arrangement just described has certain important advantages. The spirally contoured edge portion of the outer edge of the opening assures that when the plate having the edge is turned or pivoted, that portion of the chamber into which the piston enters will be in communication with the inlet side up to the point at which the outer edge moves over and overlaps the open side of the chamber so that the quantity of medium filling this portion of the chamber is pressed towards the suction side by the piston. However, as soon as the bottom of the piston passes the aforementioned point, the regulating opening is closed by the piston wall and the remainder of the medium, which is now trapped in the closed portion of the chamber, is conveyed under pressure to the outlet opening. This means that the above-described concept permits a continuous variation inthe quantity of medium which is pumped per unit of time, without having to fear that a pressure loss occurs at the pressure side of the pump.
The arrangement for regulating purposes as outlined above, can be employed in any type of rotating displacement pumps, for instance gear pumps or the like.
The capacity of the pump of the motor, depending upon whether the novel fluid machine is used as a pump or as a motor, can be increased by using not a single piston system but two of these. In this case the diameter of the piston systems can be so selected that the points determining the movement of the pistons, which will be explained in more detail later, will be located at the periphery of the respective piston systems.
The operation of the machine can be further improved by providing an additional chamber system and an additional piston system, with the control of these systems being effected from one of the points which determine the movement of the pistons in the first piston systems. It is also possible to so construct the machine that the aforementioned points governing the movement of the pistons are not located in the pistons themselves, but control the pistons via a suitable linkage.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a partially sectioned view illustrating one embodiment of the invention;
FIG. 2 is a view similar to FIG. 1 but illustrating a further embodiment of the invention;
FIG. 3 is a view similar to FIG. 1 illustrating an additional embodiment of the invention;
FIG. 4 is a section taken on line IVIV of FIG. 3;
FIG. 5 is a diagrammatic view of the regulating arrangement employed in FIGS. 3 and 4, illustrated as a development of the two rotating systems;
FIG. 6 is a view similar to FIG. 1 illustrating an additional embodiment of the invention;
FIG. 7 is a view similar to FIG. 6 illustrating still a further embodiment of the invention;
FIG. 8 is a section through FIG. 7, with parts omitted for the sake of clarity;
FIGS. 9a -9c are diagrammatic views illustrating the operation of the embodiment in FIGS. 7 and 8;
FIG. 10 is an axial section of a further embodiment of the invention;
FIG. 11 is a view similar to FIG. 10 illustrating another embodiment of the invention; and
FIG. 12 is a section through FIG. 11, with the housing removed, in a plane normal to the axis of rotation in FIG. 11.
DESCRIPTION OF THE PREFERRED EMBODIMENTS,
Before discussing the drawing in detail I wish to point out that all Figures are essentially diagrammatic in nature. All components or elements which are not essential for an understanding of the invention, have been omitted for the sake of clarity.
With this in mind, and discussing firstly the embodiment in FIG. 1, it will be seen that the fluid machine illustrated in that Figure utilizes a stationary housing 1 having a circumferential hollow-cylindrical wall the opposite open ends of which are closed by two end walls or end plates. Neither of these is visible in the drawing, one being concealed behind the contents of the housing and the other having been removed to show the contents, but they are analogous to the arrangement as illustrated in FIG. 4 to which reference may be had if desired.
Located in the interior of the housing is a stationary central core 4 which may be of one piece with one of the end plates, or which may be secured rigidly in appropriate manner by suitable means with one of the end plates or with both. The diameter d of the central core 4 is so selected that an annular space having the radial width b exists between the outer circumferential surface of the core 4 and the inner circumferential surface of the housing 1. A recess 41 is provided in the core 4, accommodating the piston system 3 which rotates about an axis of rotation designated B. In radial direction the recess 41 is bound by a cylindrical surface 41a the radius of which corresponds'to the largest radius of the piston system and whose axis coincides with the axis B about which the piston system 3 rotates.
The rotatable chamber system 2 is accommodated in the annular clearance 5. It is in form ofa ring or annulus which can turn about the axis of rotation A but which in itself is not journalled. Rather, it is maintained and guided by the core 4 and the wall 1. In FIG. 1 the ring in which the chamber system is constituted is sectioned in a plane normal to its axis of rotation A. It will be seen that the ring is provided with the individual chambers 21 which here are in form of cylindrical bores the bottom portion of which, that is the radial outermost portion facing away from the axis of rotation A, is bounded by a semi-spherical surface 22. The center lines 21a, that is the axis of the cylindrical bores, extend radially and intersect the axis of rotation A. The side walls 21b bounding the chambers 21 extend in parallelism with the respective center line 21a and in the region of the surfaces 22 each of the chambers 21 is provided with a bore which intersects it in substantial parallelism with the axis A and extends from one to the opposite axial end of the ring or chamber system 2.
Although this is not illustrated in FIG. 1, the openings for entry and exit of medium to be conveyed are provided in the end walls of the housing. They are so dimensioned and arranged that the bores 23 which are open at opposite axial ends of the ring 2, will automatically be connected during the suction phase of operation of the inlet opening of the housing 1, and during the pressure face with the outlet opening. This can be achieved in a simple manner by having the bores 23 constructed as outlined above, so that they extend from one to the opposite axial end of the ring 2, and the inlet and outlet openings located in the end walls of the opposite axial ends of the housing I are so offset with reference to one another that the bores 23 are either completely closed by the respective end walls or, depending upon the position of the respective chamber 21, will be in communication with the inlet opening for the fluid or the outlet opening for the pressurized fluid.
In the embodiment of FIG. 1 the piston system 3 has a hub 36 which is provided on the shaft 37, either by being of one piece with it or by being secured thereon with the use of a woodruff key or analogous connecting means. The shaft 37 is journalled in one of the end walls of the housing and serves as the drive shaft. The pistons 31 are fixedly connected with the hub by solid cross section piston rods 33. It may also be considered that the rods 33 are piston members and that the components 31 are piston portions, the latter being the portions which actually enter into and are withdrawn from the chambers 21 as a glance at FIG. 1 will establish.
The walls or surfaces bounding the portions or pistons 31 are of part-spherical configuration, the configuration being so selected that the surface portions which slide along the side walls of the chambers 21 will be part-spherical in configuration. The center point C of the respective piston 31, that is of the sphere from which the respective piston 31 is formed, is located on the center line 33a of the rods 33 which extends radially with respect to the axis of rotation B. The distance between point C, which latter governs the movement of the respective pistons 31, and the axis of rotation B is so selected that the path in which each point C will move during rotation of the piston system about the axis B, will be caused to pass through the axis of rotation A of the chamber system 2. In other words, the points C are located on an imaginary circle whose center coincides with the axis of rotation B and which intersects the axis of rotation A. The bottom of each piston 31, that is the surface facing radially outwardly away from the axis of rotation B, may either be constituted by a surface located in a plane normal to the center line 33a, or as illustrated by the broken lines 32 in FIG. 1, it may be provided with a concave depression.
It will be appreciated that when the machine in FIG. 1, illustrated as a pump, is placed into operation, it is first necessary to drive the shaft 37, for instance in the direction of the arrow p. This causes the piston system to rotate about the axis B. As this takes place, those pistons 31 which are located in respective ones of the chambers 21 take along the chamber system 2, so that the latter rotates in the direction of the arrow q about the axis A, and with reference to the stationary central core 4. With respect to the illustration in FIG. 2, the inlet opening will be located in such instance of rotation at the right-hand side and the outlet opening for the medium at the left-hand side of the machine. For instance, the inlet opening may be located in the end wall of the housing which is at the far side of the plane of FIG. 1, and the outlet opening may be located in the end wall of the housing which has been removed in FIG. 1 for purposes of clarity. These openings are so arranged that the inlet opening will always be in communication with the bore 23 of a respective chamber 21 as soon as the piston 31 located in that chamber begins to move out of the latter. This communication remains established until the piston 31 leaves the chamber at the location v. Conversely, the connection between the outlet opening at the pressure side and the bore 23 of a chamber is established at the moment at which the piston begins at the location s to enter into the respective chamber 21; this communication remains established until the piston has reached its radially outermost position with respect to the chamber 21. Care must be taken that the inlet and outlet openings do not so overlap that at the moment of the movement of the chamber or the piston from a pressure operation to suction operation, that is during passage through the axis x, a communication will be established via the respective bore 23 between the suction side and pressure side of the pump. This means that the inlet and outlet opening should be terminated at a distance from the axis x which corresponds to half the diameter of the bore 23, but at most they should terminate at the axis x itself. Both the inlet and the outlet opening can be configurated as channels extending along the edge of the inner cylindrical surface of the housing 1 in the respective end wall thereof, with the suction and pressure conduits communicating with these channels.
Coming to FIG. 2 it will be seen that here there is illustrated a further embodiment of the present invention. In this instance the end wall of the housing facing towards the viewer is again removed for purposes of clarity, and the other end wall which is spaced from the view and located behind the general plane of FIG. 2 is not visible. It is further to be understood that the machine in FIG. 2 is sectioned along the line D-A-E which is illustrated in chain lines. The outlet opening is here provided on the machine in a tubular bend 6 which is appropriately located on the upper side of the hollowcylindrical housing 1. Like reference numerals identify like components as in FIG. 1, and it should be understood that this is true throughout the drawing.
In FIG. 2 the chambers 121 are of rectangular cross section and the outlet openings 123 of the chambers are configurated in that the planar chamber walls 124 extend to the edge of the disk so that the Chambers 121 are open in radially outward direction. The piston system here utilizes a circular plate 136 which is provided at a side facing towards the plate and is located in an appropriate recess provided for this purpose in the endwall of the housing which is concealed in FIG. 2. Thus, the plate 136 will be located outside the confines of the walls 124 of the chamber.
The diameter of the plate 136 and the spacing of its axis of rotation 13 from the axis of rotation A of the chamber system are so selected that the edge of the plate 136 intersects the axis A. The pistons 131 are here provided in the form of wing-shaped elements of plate-like configuration which are carried by the plate 136 extending normal to the general plane thereof, so that they enter into the chambers 121 from the open side thereof. The bottom surface of the respective pistons is identified with reference numeral 131a and configurated in form of a segment of a cylinder whose axis coincides with the axis of rotation B of the system 3. The piston wall portions 131b and 131b' which slide along the planar side walls bounding the chambers 121 are configurated as cylinder segments the axis C of which extends normal to the plate 136 at the point of intersection of the symmetry axis of the piston 131 which extends radially to the axis B, with the arcuate edge of the plate 136. These cylinder segment surfaces terminate in the direction towards the axis of rotation B at the location where the portion of the piston walls sliding along the chamber walls ends, and'from there they are connected by a surface 1310 of any desired configuration with the respectively opposite piston wall 131b or l3lb. The axis C corresponds to the point C determining the movement of the pistons, extending normal to the longitudinal center line of the pistons which extends radially from the axis of rotation B to the center of the piston bottom surface 1310.
In FIG. 2 the medium to be pumped is supplied through the drive shaft 137 which is a hollow shaft and serves to drive the piston system 3. In order to permit a communication between the chambers 121 in the space 138 during the suction phase of the operation, the pistons 131 are provided with overflow channels 132 which are formed (for instance by milling) in that side of the pistons 131 facing towards the axis of rotation B, in such a manner that they extend from the end 131' of the wall 13lb facing in the direction of rotation p to the oppositely facing edge 131" which is defined by the wall 13117 and the bottom wall 131a.
The embodiment of FIG. 2 is particularly suitable as a pump. It operates by a combination of principles which dictate the operation of centrifugal pumps and displacement pumps. In particular, the shaft 137 serves to supply the'medium which is to be pumped. Furthermore, it has motion imparted to it in a sense causing the piston system 3 to rotate in the direction of the axis p. The pistons 131 which thereby enter into the chambers 121 cause the chamber system 2 to rotate in the direction of the arrow q. Because the chamber outlets 123 are adjacent the chambers in radial direction and take up the entire cross-section of the chambers, the high speed of rotation causes the chamber walls 124 to act in the same manner as the blades of a centrifugal pump, that is the medium in the chambers is pushed outwardly by centrifugal force. As soon as the piston 131 enters into one of the chambers 121, this centrifugal force is reinforced, that is the compressive force exerted by the piston is superimposed upon it. Thus, the advantages of a pump of the type operating as a centrifugal pump are combined with the advantages of a piston or displacement pump.
In operation the space 138 will be filled with the medium which is to be pumped. As soon as the piston system 3 has turned to such an extent that the edge 131" of that piston which is at dead position passes through the point C, the medium can fall from the space 138 into the chamber 131 due to the vacuum which develops in the chamber via the overflow channel 132 which is now no longer closed off by the chamber wall 124. During continued rotation of the machine the chamber 121 fills further via the overflow channel with the medium which continues to flow in through the hollow shaft 137, and after the piston is retracted from the chamber the latter remains filled during the further rotation so that the medium is always transported in the chambers to the opposite side of the machine. During such transportation the centrifugal force will always cause the medium to exert a pressure against the cylindrical inner wall of the housing 1. As soon as the opening 123 moves into communication with the interior of the outlet opening, that is in FIG. 2 with the outlet bend 6, the medium is ejected into the outlet bend 6, to leave the same in the direction of the arrow p, under the influence of the combined centrifugal force and the pressure exerted by the piston.
Calculations and tests have shown that pumps operating according to the principle outlined above, are capable of achieving a highly advantageous degree of output. In particular, the quantity of liquid which can be conveyed with such a pump per unit of time, and given the same energy requirement for rotating the pump, corresponds to that quantity which is normally achieved only with a multistage centrifugal pump.
Coming now to FIG. 3 it will be seen that this shows another embodiment of the novel fluid machine, advantageously also utilized as a pump. Here, the interengaging rotating bodies are each configurated as a piston and as a chamber system, and for purposes of clarity in discussion these systems will hereafter be designated as rotating systems. The drawing shows that there are different size dimensions of these systems and hence the systems will be designated as the small and the large rotating system.
With the above explanation in mind it will be seen that here again there is provided a stationary core 4, surrounded by an annular large rotating system 220 which has chambers 221 of rectangular cross section. At opposite axial ends these chambers are open to the respective end walls of the housing and they are closed only by planar walls 22! extending normal to the tangential direction of rotation. In axial direction they are closed by bottom walls 221". The transition between the walls 221 and the bottom wall 221" is so rounded that it corresponds to the form of the pistons 231 of the small rotating system 230. Separating walls 224 located between two successive chambers 221 have approximately the same width as the chambers themselves and serve as pistons for the chamber spaces 239 provided in the small rotating system 230 intermediate the respective pistons acting upon the large chamber system.
FIGS. 3 and 4 clearly show that the small rotating system 230 has a central portion 236 which is driven in a manner analogous to FIG. 1 by a shaft which is journalled in one of the end walls of the housing and extended tothe exterior thereof for engagement by a suitable drive. The shaft is designated with reference numeral 237. The pistons 231 are provided at the periph cry of the central portion 236 and have a rectangular cross section in correspondence with the configuration of the chambers 221 with which they are to cooperate. The portions 231' of the pistons 231, which slide along the planar walls of the chambers 221 in the large rotating system, are configurated as sections of a cylindrical surface whose center axis C determines the piston movement and is spaced from the axis of rotation B of the small rotating system to such an extent that during rotation the respective axis C pass through the axis of rotation A.
The operation of the embodiment illustrated in FIGS. 3 and 4 corresponds essentially to that illustrated in FIG. 1. However, the individual chambers open directly to the respective inlet and outlet openings, rather than requiring the bores 23 of the embodiment in FIG. 1 because laterally the chambers are closed only by the inner surface of the endwalls of the housing. In this embodiment, however, the walls 224 between the chambers 221 of the large rotating system 220 act not only as divider walls but also as pistons themselves, in that they enter into the spaces or chambers 239 between the pistons 231 of the small rotating system and displace mediumlocated therein or cause as a result of the vacuum established thereby, the inflow of additional medium. Because of this dual interaction, a substantial increase of the quantity of liquid or medium which can be pumped during a single rotation is observed. Of course, the inlet and outlet openings must be so dimensioned that not only the chambers of the large rotating system but also the chambers of the small rotating system will move into communication with the inlet and outlet openings at the appropriate position of the small rotating systems.
FIGS. 3 and 4 further show a regulating arrangement for permitting a continuous regulation of the flow through quantity of medium. In the illustrated embodiment this arrangement utilizes a circular plate 300 which is particularly clearly shown in FIG. 4 and which is located between the large rotating system and the endwall 8' at the inlet side (see FIG. 4). The diameter of the plate 300 corresponds to the inner diameter of the cylindrical housing 1 and by means of a control shaft 306 the plate 300 can be turned about the axis A. In axial direction the plate 300 is so dimensioned (so thick) that an opening 302 provided in it has a sufficient cross section to serve for supplying the machine in tangential direction in form of a supply channel. The opening may be so configurated at its inner edge, that is the edge facing towards the axis of rotation A, will have an arcuate contour and surround this axis A, with the arcuate contour corresponding in diameter of the arc to the inner diameter of the large rotating system 220. The outer edge of the opening 302 extends in the portion facing towards the inlet opening 301, that is in the direction of rotation of the two rotating systems, in parallelism with the inner edge of the opening 302 with the diameter of the outer edge being somewhat larger than the diameter of a circle which delimits the chamher 221 in outward direction. The outer edge then merges into a curve which continuously approaches the inner edge and joins with the same under an acute angle.
By the use of the control shaft 306 the plate 300 can be turned in the direction toward the inlet opening to such an extent that the end of the opening 302 located at the pressure side and forming the aforementioned acute angle will be displaced towards the pressure side in the terminal position of the plate 300 by a certain angle, for instance by approximately 20 in the illustrated embodiment, with reference to a straight line passing through the axis A and B. The opposite end position of the plate 300 in turn corresponds to a rotation of the plate by approximately 90 in direction opposite to the direction of rotation q of the large rotating system 200. The here discussed end positions of the regulating movement for the plate 300 are based upon the structural relationships chosen for the embodiment in FIGS. 3 and 4. Evidently, they will differ with different structural relationships and will be determined from case to case upon the number of chambers and pistons, and by the contour of the outer edge bounding the opening 302.
The inlet opening 301 is provided in the endwall 8 and the outlet opening 303 is provided in the endwall 8' of the housing. It will be appreciated that the length of the opening 302 must be so selected that its inlet end will assure in the pressure-side terminal position of the opening 302 a sufficient communication with the inlet opening 301, that is a communication which assures that the entire medium quantity can be supplied to the suction side. The edge of the opening 302 which faces in the direction of rotation q of the chamber system 220 may have any desired configuration, for instance a semi-circular contour.
FIG. 5 shows diagrammatically how the regulating arrangement of FIGS. 3 and 4 operates. In FIG. 5 a portion of the rotating systems 220 and 230 has been shown for purposes of orientation in developed form. The explanation of the operation of the regulating arrangement can be understood by considering only the chambers 221 of the large rotating system 220 and the pistons 231 of the small rotating systems 230. With this in mind it will be seen that the opening 302 of the plate 300 is shown in the two end positions 302a and 3020 as well as in an intermediate position 302b. During the operation of the machine the opening 302 remains in its selected position without movement, whereas the two systems rotate in the direction of the arrow q, with the individual pistons moving from the position 231' via the position 231a to the position 231b, the dead position, into the chambers 221 as indicated by the arrows fand d which show the direction of movement relative to the large rotating system 220; subsequently the pistons are retracted from the chambers again in the direction of the arrow 2.
In FIG.'5 the inlet opening is designated with reference numeral 301 and identified by a broken line, whereas the outlet opening 303 is shown by a dotted line. In the starting position, that is in the inlet side end position 302a which is shown in dot-dash lines, the arrangement is such that no communication exists between the outlet or pressure side and the inlet or suction side as the chambers pass. During the entry of the piston 231 the same presses the entire content of the chamber into the outlet opening 303. As the piston passes the dead or center position 23lb it will be given its suction stroke. To prevent the development of a vacuum a portion 303 of the outlet opening extends far enough past the dead center position so that from the pressure side a portion of the medium can continue to flow in until the piston reaches the opening 302 and the chamber 221 is connected via the same with the inlet opening 301.
Assuming, now, that the plate 300 is turned in the direction counter to the direction of rotation q of the large rotary system 220, until it reaches any arbitrarily assumed intermediate position 30% of the regulating opening, which position is shown in a line wherein dashes alternate with double dots, then the regulating opening will free a portion of the side of the chamber 221 which moves along the plate 300, already while the piston 231 enters into the chamber. This means that this portion of the chamber is in communication with the suction side and that the entering piston presses the medium in the chamber back to the suction side. However, as soon as the piston moves past the point of intersection of the line bounding the opening with the chamber wall, for instance the point Y, this connection is interrupted and the piston now exerts its full pressure upon that amount of medium which is still contained in the residual part of the chamber. It must be pointed out for the sake of clarity that in the example illustrated in FIG. 5 this is not the point Y, but that due to the simultaneous movement of the piston and chamber the point in question is farther toward the right in FIG. 5. In their pressure side end position 3026, illustrated by a line using alternating double dashes and double dots, the chambers are in communication with the suction side during the entire inward movement 'of the piston and no portion of the medium is yielded up to the pressure side.
For purposes of orientation the three regulating positions of the opening 302 have been shown in FIG. 3 with the same types of lines as have been used in FIG. 5. In a similar manner the relative positions of the inlet opening 302 and the outlet opening 303 have been shown.
Component 305 or flange 305' is shown in FIG. 4 as being provided on the end wall 8'; it serves to connect the conduit through which medium is supplied. The outlet opening 303 is configurated as a channel 304 which extends along the edge of the housing, is relatively wide and becomes still wider in direction oppositely to the rotation q of the large rotary system. This channel 304 is provided in the endwall 8 and terminates in a non-illustrated connection for the pressure conduit.
The plate 300 is relatively thick, that is it is of relatively substantial dimension in its axial direction. It can however be replaced by a thinner plate in which case the supply of the medium is effected via a channel provided in the endwall 8' analogous to the outlet opening 303 and 304 in FIG. 4. In such a manner this channel extends and is dimensioned to such an extent as is necessary in order to obtain an unimpeded supply of medium to the machine under all regulating conditions.
The drive of the embodiment in FIGS. 3-5 is advantageously effected via the shaft 237 which constitutes and defines the axis of rotation of the small rotating system 230, with the individual systems 231 engaging and effecting rotation of the large rotating system 220. Each individual point of the piston walls will then move, with reference to the large rotating system 220, along a straight line. If the diameter of the circle on which the points C designating the movement of the pistons are located, is identified with reference character Q, then the length of the straight line on which the individual points C move, will equal 20. The driving force for the large rotating system 220 is transmitted to the latter from the small rotating system 230, via the engagement of the piston at the side of the respective engaged chamber 221 of the large rotating system which faces in the direction p, it is advantageous -in order to reduce or avoid wear-- to maintain the friction between the two engaged surfaces as long as possible. It has been found that if the radius of curvature of the curved piston surface, which engages the chamber surface during transmission of rotary force thereto, is so selected that it has with respect to the diameter Q of the circle on which the points C determining the movement of the individual pistons are located, is as lz'rr, then the piston wall will be configurated as a section from the circumferential surface cylinder whose total circumference would equal the total length 2Q of the straight line along which the respective point C moves to and fro during a complete revolution. In this manner it is achieved that that portion of the piston wall which presses against the chamber wall will perform during the engagement of the piston with the chamber, and with reference to the chamber, only a rolling movement without any gliding along the chamber wall. Such a possibility is particularly advantageous if the machine is for instance utilized as a pump for conveying a liquid which contains a hard particle, for instance water containing sand.
FIG. 6 illustrates a somewhat modified version of embodiment in FIGS. 3 and 4. The embodiment in FIG. 6 permits a further increase in the throughput capacity of the machine, utilizing not a single but two piston systems. It will be appreciated that in the embodiment of FIG. 6 the outer diameter N of the two piston systems 430 and 430" which rotate about the axis B and B" respectively, can be no greater than half the diameter M of the chamber system 420, as related to the bottom surfaces 42 of the chambers. It is desired, as has already been indicated, to have the point C or the axis C be so located that they will be positioned on an imaginary circle passing through the axis of rotation A of the chamber system 420; for this reason it is advantageous, although not mandatory, to choose the diameter relationship N:M 1:2 in order to obtain the most advantageous stroke. However, in special constructions it may be advantageous to give one or two of the two piston systems a diameter which is smaller than half the diameter M of the chamber system. This is definitely possible, always assuming that the earlier outlined requirement concerning the curvature of the lateral piston surfaces has been met, that is that the center of curvature for the axis of curvature is located at the point C or passes through the same.
In FlG. 6 the chambers of the chamber system 420 are designated with reference numeral 421, and the intermediate walls between these chambers with reference numeral 424. The two piston systems 430' and 430" have their pistons identified with reference numerals 431' and 431", respectively. The hubs of the piston systems are designated with reference numeral 436' and 436" and their associated shafts with 437 and 437 The recesses between the individual pistons have reference numerals 439 and 439" in the two piston systems.
In the illustrated embodiment of FIG. 6 a substantial increase in the quantity of medium which can be conveyed per unit of time if the machine is used as a pump, is obtained as compared for instance to the embodiment of FIGS. 3 and 4. Conversely, if the embodiment of FIG. 6 is used as a fluid motor, a corresponding increase of the torque at identical numbers of revolutions per minute is obtained. The diameters of the two piston systems 430 and 430" are identical in the embodiment of FIG. 6, but they are in each case smaller by a certain amount than half the diameter of the chamber system, as related to the base surfaces 429 of the chambers. Thus, M is M/2. The axis C and C" of the cylinder surfaces constituting the side walls of the pistons 431 and 431" move on imaginary circles T and T" illustrated in broken lines, in accordance with what has been explained above. These circles pass through the axis of rotation A of the chamber system 420 and in part coincide with the walls of the recesses provided in the core 4 for accommodating the piston systems 430' and 430".
Analogous to the embodiment described with respect to FIGS. 3-5, the embodiment in FIG. 6 is so constructed that due to the dimensioning of the pistons 431 and 431" and the spaces 439 and 439" on the one hand, and on the chambers 421 and the intermediate wall 424 on the other hand, the possibility exists to use the spaces 439 and 439 also as chambers, and to have the walls 424 act as pistons, to thereby obtain a further improvement in the capacity of the embodiment.
If the embodiment in FIG. 6 is used as a pump, it can be driven by driving an appropriate shaft, for instance shaft 437'. Of course, both the shafts 437 and 437" can be driven. Conversely, if the embodiment of FIG. 6 is used as a fluid motor, then it is possible for instance to have both shafts 437' and 437" drive an output shaft by having them act upon the latter via appropriate gears. On the other hand, the output shaft could be directly connected with the chamber system 420 and the piston systems 430 and 430 would simply be iournalled for rotation.
Still another increase in the volumetric capacity, and thereby in the fluid-moving capacity per unit of time, can be obtained by connecting an auxiliary chamber of rectangular or circular cross section fixedly with the rotating chamber system, and to have it perform a rotating movement together with the rotating chamber system about the axis of rotation of the latter. In such a case the longitudinal axis of this auxiliary chamber extends in parallelism with the longitudinal axis of one of the chambers of the rotating chamber system, and the auxiliary chamber accommodates a piston of appropriate cross section. On the flat end face of one of the pistons of the piston system an entraining pin can then be provided which extends through a slot formed in the wall separating the rotating chamber system and the auxiliary chamber, engaging the additional piston and causing the latter to perform movements. The pin is then so arranged that its longitudinal axis which extends normal to the direction of movement of the rotating piston system, passes through the point which determines the piston movements, that is the pin is located on the circumferential surface of an imaginary cylinder whose central axis coincides with the axis of rotation of the rotating piston system and whose imaginary circumferential surface contains the ideal axis of rotation of the rotating chamber system. The axis of the pin thus passes during each rotation of the piston sys-
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