Patent Publication Number: US-8985979-B2

Title: Positive displacement rotary machine

Description:
This application is the United States national phase application of International Application PCT/RU2011/000158 filed Mar. 15, 2011, which claims the benefit of Russian Patent application No. RU 2010109516 FILED, Mar. 16, 2010, the entire disclosure of which is incorporated herein by reference. 
     The invention pertains to machine-building, specifically to rotary positive-displacement machines, which can be used as pumps, hydraulic drives, including controllable ones. 
     STATE OF THE ART 
     A positive-displacement rotary machine (PDRM) is known (U.S. Pat. No. 2,708,413 E. Loewen FIG. 18), containing a housing with a sphere-like inner working surface a rotor with a working surface of revolution mounted in the housing with the capability of rotation, a separator made in the form of a flat ring mounted with the capability of turning around an axis which is perpendicular to the axis of the rotor and the separator divides the working cavity into two parts, in addition at the working surface of the rotor two grooves are made along its axis of rotation, in each groove one piston in the form of half a ring is mounted with the capability of closing of the working cavity and the capability of rotary oscillations around its axis intersecting rotor axis. For interaction of the pistons with the separator a sealing element is used made in the form of a flat ring with sections of cylindrical surfaces on one side of the ring with their axes in the plane of the ring. The mating cylindrical areas made on pistons interact with the cylindrical surfaces. Due to the sphere-like form of the working cavity and the use of sealing elements the mating surfaces between working members are areas (not lines) what reduces internal back flows of the working fluid. 
     However, PDRM is not widely used. The cause is in not reliable mesh of the rotating sealing element with the piston, since all normal lines to cylindrical areas served for meshing (especially areas on pistons) are directed mainly across the separator. As a result, friction force decelerating the sealing element and directed along the separator makes a small angle to the support areas, which produces conditions for jamming. It seems impossible to extend the angular length of the cylindrical areas on the piston and on the both sealing elements to have normal lines oriented mainly along the separator, because of the position and the separator between them and the need to variate the angle between the piston and the separator during the rotor rotation. 
     A drawback also is the existence of two pairs of inlet openings and outlet openings for working fluid on the housing of each stage and their angular sizes which are not big enough. The last statement deals with the fact that in order to maintain the pressure with one stage of PDRM the length of the inlet openings/outlet openings should not extend the thickness of the piston. 
     A positive-displacement rotary machine is known (RU 2202695), containing a stator; working chambers; a rotor mounted with the capability of rotation; a separator mounted with the capability of rotation, in which the axes of rotation of the rotor and separator intersect at an acute angle; inlet openings and outlet openings of the working fluid; in which the separator meshes with the rotor through the sealing synchronizing element (SSE) having a through slot through which the rotor passes. 
     The drawback of the PDRM is in fact that for the SSE fastening its axle should be placed in outer part of the separator which increases the thickness of the separator outer part and consequently its moment of inertia. Since the rotation of the separator is not uniform, the increase of its moment of inertia limits maximal linear velocity at which the PDRM can operate. Besides the main SSE support working against friction force between the separator and the housing is located inside the outer part of the separator while the load application point by friction force is found in the separator recess, so the arm of the SSE support forces is shorter then the arm of load forces. Consequently the load of friction pair SSE axle—separator is increasing and life time is shortening. Another drawback is also that the loaded areas of the SSE prevail over not loaded areas. It makes complicated heat removal and makes the SSE the most vulnerable member of the PDRM in operation with a liquid near oiling point or with temporally leaks of liquid (for example, “dry” start, gaslocks in working fluid flow). 
     Another drawback is the existence of two pairs of inlet openings and outlet openings for working fluid on the housing of each stage. To connect inlet openings/outlet openings with each other we have to go around the groove of big diameter made for the separator mounting in the housing. It increases the mass and complexity of the housing, decreases the specific parameters of the PDRM. Especially if two stages are used and we have to connect eight inlet/outlet openings. Another drawback is the existence of a flat section of the rotor, which goes through a recess in the sealing synchronizing element. It does not allow to make ducts for working fluid through the rotor, limits maximal working pressure and maximal torque that can be transferred to the next hydraulically parallel stage of the PDRM needed to get more uniform feed. 
     A positive-displacement rotary machine is known (RU 2376478), containing a housing, the working surface of which is designed in the form of part of a spherical segment, a rotor with a working surface of revolution mounted in the housing with the capability of rotation, an annular concentric working cavity, formed by the housing and rotor, a separator, designed in the form of an inclined washer, set fixed in the housing at an angle to the axis of rotation of the rotor and dividing the working cavity into two parts, at least one groove being made on the working surface of the rotor along its axis of rotation, a piston is mounted in the rotor capability of closing off (sealing) the working cavity and executing rotary oscillations around its axis, which intersects the axis of the rotor, the piston being designed at least in the form of a part of a disk, and there is at least one sealed groove in each piston for passage of the separator. 
     By using of the sealing synchronizing element (SSE) which axis of rotational oscillations intersects the axis of the piston and axis of the rotor the PDRM has reliable synchronization and boundaries of volumes with different pressures are presented by areas, that reduces internal back flows. Friction pairs in the PDRM also interact by areas and it reduces their load and increases lifetime. Other types of the SSE do not give such advantages. Though for the SSE fastening its axle should go through the piston which leads to increase of thickness of the piston and as consequence to increase of its moment inertia. The latter limits the maximal linear velocity of the piston whereby the PDRM can operate. Besides the main SSE support place, working against the stage pressure difference forces and friction forces between the SSE and separator directed across the piston, is located inside a part of the piston residing inside the rotor, while the point of these forces application is beyond the rotor, that is why the arm of the support forces is shorter than the arm of load forces. As a consequence the maximal pressure withstanding by one stage and lifetime are limited by wear resistance of the friction pair SSE axle—piston. Another drawback is that the loaded areas of the SSE substantial prevail over not loaded areas. It makes complicated heat removal and makes the SSE the most vulnerable member in operation with a liquid near boiling point or with temporally leaks of liquid (for example, “dry” start, gaslocks in working fluid flow). Another drawback is the existence of two pairs of inlet openings and outlet openings for working fluid on the housing of each stage which are to connect by ducts for working fluid around the working cavity. 
     This PDRM is closest prior air. 
     The task of the invention is to design the reliable, able to withstand short-time pressure overloads, thermal overloads, compact PDRM with high specific power and long lifetime. A result from this is the need to exclude high loaded friction pairs from the PDRM design. 
     The PDRM satisfying to those conditions is designed on the basis of the PDRM with sphere-like working cavity. 
     The task of the invention is achieved in that the positive-displacement rotary machine comprising a housing, a rotor, at least one piston, at least one separator, a sphere-like working cavity formed around the rotor, inlet openings and outlet openings for working fluid, least a part of the piston is mounted with the capability of accomplishing rotary oscillations relative to the rotor in a plane positioned mainly along a rotor axis and at least a part of the separator is mounted with the capability of rotation around the rotor, and the piston or a part of the piston is hinge joint with the separator or with a part of the separator. 
     The hinge joint of the piston with the rotated separator can be made reliable and all members have enough spaces for heat removal from friction pairs. The most loaded in the prior art friction pairs—SSE axle are not present in this design. In addition the reliability is increased due to excluding of small members—the SSE. 
     The task of the invention is achieved in that hinge joints on the piston and on the separator are made in the form of combination of a cylindrical thickening and a slot with coaxial to the thickening concave cylindrical areas. 
     The task of the invention is also achieved in that hinge joints on the piston is made in the form at an arc-shaped bent and on the separator is made in the form of an arc-shaped slot. 
     The task of the invention is also achieved in that hinge joints on the piston is made in the form of an arc-shaped slot and on the separator is made in the form of arc-shaped bent. 
     The task of the invention is achieved in that inside rotor ducts for working fluid which are leading from one side to the other side of the separator to make it possible to supply and/or discharge the working fluid to/from the working cameras only from one side of the separator. 
     The task of the invention is achieved in that the separator is mounted with the possibility of variation of its inclination angle to rotation of the rotor to control the machine feed. 
     The task of the invention is achieved in that there is a ball-shaped part positioned concentrically in the sphere-like cavity, and the inlet opening and the outlet opening are made at the ball-shaped part at the different sides of the piston. 
     The task of the invention is achieved in that the separator except a rotating around the rotor part has a static part that reducing the load on the rotating part. 
     The task of the invention is achieved in that there is an additional piston and for interaction with it the separator contains movable to one another parts. 
    
    
     
       The invention is explained by means of drawings. 
       All figures contain isometric projections. 
         FIG. 1  shows a two-staged positive-displacement rotary machine (PDRM). The nearest housing part is removed. 
         FIG. 2  shows the housing part which is present at  FIG. 1 . 
         FIG. 3  shows the housing part that is absent at  FIG. 1 . 
         FIG. 4  shows an external appearance of the PDRM. 
         FIG. 5  shows the rotor of the PDRM. 
         FIG. 6  shows a system of ducts inside the rotor of PDRM. 
         FIG. 7  shows a separator. 
         FIG. 8  shows a piston. 
         FIG. 9  shows a hinge joint between the piston and the separator. 
         FIG. 10  shows inserts of the rotor. 
         FIG. 11  shows the rotor with ½ cut off. 
         FIG. 12  shows a piston with asymmetric hinge joint. 
         FIG. 13  shows a separator with asymmetric hinge joint. 
         FIG. 14  shows an enforced embodiment of the piston. 
         FIG. 15  shows a separator with a mate joint between its two “C”-shaped parts, the joint coincide with its hinge joint. 
         FIG. 16  shows a piston with inserts. 
         FIG. 17  shows a piston having movable and static parts. ¼ cut off is made in the movable part. 
         FIG. 18  shows a separator having movable and static parts. ¼ cut off is made in the movable part. 
         FIG. 19  shows an assembly of the PDRM consisting of the piston, separator and turnable shaft for usage in the PDRM with controlled feed. 
         FIG. 20  shows a turnable shaft. 
         FIG. 21  shows a housing part of the PDRM with controlled feed. 
         FIG. 22  shows a movable part of the separator with a protrusion for connection with the movable part of the separator. 
         FIG. 23  shows the static part of the separator with a slot for connection with the movable part of the separator. 
         FIG. 24  shows a piston with a hinge joint in the form of an arc-shaped bent. 
         FIG. 25  shows a separator with a hinge joint in the form of an arc-shaped slot. 
         FIG. 26  shows a hinge interaction of the piston according to  FIG. 24  and the separator according to  FIG. 25 . 
         FIG. 27  shows the PDRM with the flow of working fluid along the rotor trough ducts made inside the rotor. 
         FIG. 28  shows a housing part of the PDRM according to  FIG. 27 . 
         FIG. 29  shows the rotor of the PDRM according to  FIG. 27  with ½ cut off of one of the stages. 
         FIG. 30  shows the piston of the PDRM according to  FIG. 27 . 
         FIG. 31  shows the separator of the PDRM according to  FIG. 27 . 
         FIG. 32  shows the piston with holes and with hinge joints of different types according to  FIG. 27 . 
         FIG. 33  shows the separator with hinge joints of different types according to  FIG. 27 . 
         FIG. 34  shows the PDRM with a uniform feed in one stage. 
         FIG. 35  shows a housing part of PDRM according to  FIG. 34 . 
         FIG. 36  shows a rotor of PDRM according to  FIG. 34 . 
         FIG. 37  shows a piston of PDRM according to  FIG. 34 . 
         FIG. 38  shows the main part of the separator of the PDRM according to  FIG. 34 . 
         FIG. 39  shows the movable (relatively tot he main part of the separator) part of the separator of PDRM according to  FIG. 34 . 
         FIG. 40  shows the interaction of the pistons, the main part of the separator and movable part of the separator of PDRM according to  FIG. 34 . 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     To simplify the description we will introduce some definitions. 
     Sphere-like surface is understood to mean a surface similar to a sphere or part of a sphere, permitting slight deviations from an ideal sphere, related to imprecision of manufacture, the need to ensure working gaps, with the design of seals, gaps to reduce viscous friction, etc. 
     Sphere-like cavity is understood to mean a cavity in which at least one of the surfaces bounding it is a sphere-like surface. 
     Ball-shaped part is understood to mean a part similar to a ball or part of a ball permitting slight deviations from an ideal ball, related to impression of manufacture, the need to ensure working gaps, with the design of seals, gaps to reduce viscous friction, etc. 
     Passages of various shape for the working fluid made within or along the surface of a part, for example, holes, grooves, cavities obtained by casting or other methods in which no working member moves, will be called ducts. 
     One or more surface sections of one part with a working gap from which during operation there is a constant or periodic possibility of presence the surface of the second part will be called a region of interaction of two parts. 
     The gap between two parts in which they have the capability of relative movement but leaks of the working fluid through it are absent or within permissible limits for the given device owing to the smallness of the gap or owing to positioning of sealing elements in it will be called working gap. 
     We will state that two parts interact with each other, if they have a region of interaction in them. 
     A piston is a member of the PDRM which separates cameras with different pressures and transmits the main torque and energy between the rotor or shaft of the rotor and working fluid. 
     A separator is a member of the PDRM which separates cameras with different pressures and does not transmit the main torque and energy between the rotor or shaft of the rotor and working fluid. The separator via the piston or the working fluid receives from the rotor (interchanges with the rotor) the torque needed to compensate the friction forces and not uniform rotation. The separator can comprise movable parts with respect to each other. 
     With identical numbers can designate functionally similar elements in the description. 
     The positive-displacement rotary machine (PDRM) ( FIG. 1 ) can be used as a pump or a hydraulic drive. It consists of two stages  1  and  2 . Stages  1  and  2  have common housing  3  and common rotor  4  mounted in the housing  3  with the capability of rotation. Axis of the rotor  4  rotation is the axis of the PDRM. In each stage the piston  6  is mounted with capability of performing rotational oscillations relative to the rotor  4  in a plane oriented mainly along axis  5  of the rotor  4 , and the separator  7  is mounted with the capability of rotation around the rotor  4 . 
     To be definite, we will describe tile PDRM operation by using it as a pump on the assumption with that if the rotor  4  is shown at the figures than as direction of rotation is counterclockwise while looking from the left. 
     The housing  3  of the PDRM is made from the two almost (up to fastening elements and grooves for sealing) mirror symmetric parts  8  and  9  ( FIG. 3 ,  4 ). Mating plane  10  between them contains axis  5  of rotor  4  rotation. There are two sphere-like cavities  11  (one cavity per one stage) in the housing  3  with their centers at the axis  5 . (Coaxial to the axis  5  through the cavities  11  is made a cylindrical hole for the rotor  4 . The cavities  11  divide it into three sections: middle section  12  between the cavities  11 , and two end sections  13  and  14  outstanding beyond the cavities  11  in the opposite directions. 
     Around each sphere-like cavity  11  there is a circular slot  15  of larger outer diameter than the diameter of the cavity  11  symmetrically located there and opened inside the cavity  11 . I.e. the slot  15  is made in the surface of the cavity  11 . Slot  15  is bounded by side sphere-like surface  16  ( FIG. 2 ,  3 ) which center coincides with the center of the cavity  11  and with two end faces  17  in the form of the symmetrically situated parallel flat rings. Symmetry axis  18  (slot  15  generatrix rotation axis) oriented in this embodiment at an angle of 25 degrees to axis  5  and lies in the mating plane  10 . 
     At the middle section  12  of the cylindrical hole symmetrically between the cavities  11  and symmetrically to a plane coincident with axis  5  and perpendicular to plane  10  an inlet of the opening  20  for working fluid is located ( FIG. 2 ) at one part  8  (not shown at  FIG. 1 ) of housing  3 . The inlet opening  20  has rectangular outlines with rounded corners. It has angular length more than turn ¼ turn around axis  5  (106 degrees in this embodiment). The inlet opening  20  transforms into the inlet cylindrical branch pipe  21  of the working fluid inlet with the thread  22  at the end  FIG. 4 ) for connection to supply pipes. At the second part  9  of the housing  3  symmetrically to mating plane  10  there is tie similar outlet openings  23  for working fluid ( FIG. 3 ) transforming into similar outlet branch pipe  24  with the thread  25  at the end ( FIG. 4 ) for connection to discharge pipes. 
     Sections  13  and  14  of cylindrical hole serve as slide bearings for the rotor  4 . On their surfaces in the first part  8  of the housing  3  there are unloading grooves  26  ( FIG. 2 ) in the form of rectangular (in cylindrical coordinates system) closed contours with rounded corners. In terms of an angular length around axis  5  at outer border they are equal to angular length of the inlet opening  20 . In terms of a length along axis  5  each contour is approximately equal to one half of analogues size of the inlet opening  20 . The grooves  26  of the both contours are connected by pipes of small diameter (not shown) that are laying along outer surface of the housing  3  with outlet opening  23  on the second part  9  of the housing  3  ( FIG. 3 ). Symmetrically at the second part  9  of the housing  3  on surfaces of the sections  13  and  14  are similar grooves  26  in the form of closed contours connected by pipes to inlet opening  20  at limiting of rotor  4  shift in axial direction. 
     On the end face  27  from the cylindrical section  13  there is the coaxial to axis  5  outlet hole  29  of smaller diameter. There is the annular groove  30  in it used for discharge of leakages from the high pressure area to the low (inlet) pressure area connected by pipes of small diameter (not shown) through cheek valves to the inlet opening  20  and outlet opening  23 . Further from the cavity  11  in the hole  29  there is a annular groove  32  for collecting of leakages from the low pressure area(from groove  30 ) that get through the sealing elements. It is needed in order to operate the PDRM in a closed contour with increased inlet pressure. The analogous outlet hole  29  with the similar grooves  30 ,  31 ,  32  is on the end surface  28 . There is the flange  33  on the mating perimeter of the housing  3  on the both its parts  8  and  9  to connect them with each other. On the flange  33  the grooves also are made (not shown) for sealing of the fixed mating, which are bordering on the perimeter of the inner cavity of the housing  3 . 
     The outer surface of housing  3  ( FIG. 4 ) with a shift approximately repeats the form of its inner cavity. The lobe  35  is formed around the groove  15 . 
     Manufacturing of the housing parts for the PDRM of high pressure by casting with the following finishing by electroerosion method. 
     Stages  1  and  2  of rotor  4  ( FIG. 5 ) are made on one cylindrical axle. They divide it in three sections: middle section  36  and two end sections  37  and  38 , which are in the outward directions from the stages  1  and  2 . Each stage of the rotor  4  has central ball-shaped part  39  with the center on axis  5  with the diameter which is close to the axle diameter. Side walls  40  are located from the opposite along axis  5  sides made as truncated cones, which are coaxial to the axis  5  and symmetrical rested against the ball-shaped part  39  with their smaller base stands. The side walls  40  are connected to the sections  36  and  37  on the stage  1  and sections  36  and  38  on stage  2  with transition sections  41  that have sphere-like surfaces which diameter larger than the axle diameter and their centers coincide with the centers of the corresponding central ball-shaped parts  39 . There is opened ring cavity  42  to outside between two side walls  40  of each stage, and its bottom is the ball-shaped surface of the part  39 . Along the axis  5  through the side walls  40 , transition sections  41  on the ball-shaped part  39  the groove  43  is made for piston  6 . The groove  43  gets in for a not large depth in the ball-shaped part  39  as ring groove and its geometrical center coincides with the center of the ball-shaped part  39 . For convenience of manufacturing of the grooves  43  touch the sections  36 ,  37 ,  38 . The groove  43  looks like as symmetrical through rectangular groove through the rotor  4  except the cylinder  47  that is remained in the ball-shaped part  39 . The end face surfaces  44  of the groove  43  are flat and parallel to the axis  5 . The grooves  43  divide the ring cavity  42  into two parts  46 . The stage  2  is turned regarding to stage  1  on ¼ of revolution around the axis  5 . Symmetrically regarding to the groove  43  through the side walls  40  surface the outlets  48  of the duct to working fluid passing into the rotor go out. There are two symmetrical screw-shaped (screw-like) ducts  49  ( FIG. 6 ) of double thread type with large thread pitch inside the central ball-shaped part  39  and each of them connects two ducts  48  located in the different side walls  40  ad going out to the different parts  46  ( FIG. 1 ) of the ring cavity  42 . The duct  50  in passing out from each screw duct  49  on the surface of section  36 , which outlet has the form close to rectangle or trapezoid (in cylindrical coordinates system), turned by the larger base stand to its stage ½ with round corners. We will call such outlets from stage  1  openings  51  and openings  52  from the stage  2 . The openings  51  and  52  have an angular length around the axis  5  less than ¼ revolution and going out approximately to one and the same area of the section  36  aligned with the position of the openings  20  and  23  along the axis  5  on the housing  3 . Symmetrically regarding to axis  5  two openings  51  are located and with turn by ¼ of revolution symmetrically located two opening  52 . The ducts  49  have a sectional view in the form of miner part of the circle out off by chord with rounded corners. According to function of the ducts  49  it is more correct to state that each duct  49  is transferring the working fluid from one side from the ball-shaped part  39  to the opposite side (or to its center) and further it is passing into the duct  50  which leads to the inlet openings  20 /outlet openings  23  of the working fluid, Meanwhile on their way (in the mating area or somewhere else) one more duct  48  is connecting on the opposite from the first duct  48  side relating to the center of ball-shaped part  39  (also on the opposite side of the groove  43 ). The duct outlets  48  have large enough angular length (in this embodiment more than 90 degrees) and that is why the strengthening ribs  53  ( FIG. 5 ) are left in them. The grooves  54  in fours are made in the form of rectangular (in cylindrical coordinates system) with rounded corners outlines, which have angular length around the axis  5  equal to angular length of the openings  51  and  52  and the length along the axis  5  that is equal approximately half of the corresponding length of the openings  51  and  52  on the surfaces of the sections  37  and  38 . Their position along axis  5  coincides with the position of grooves  26  on the housing  3  and the angular position coincides with the position of the openings  51  and  52 . They serve as a simulator of the openings  51  and  52  and together with grooves  26  make the hydraulic unloading of the rotor  4 . 
     The end faces  55  and  56  of sections  37  and  38  correspondingly serve as axial hearing for limiting of the rotor  4  movement in the axle direction. The output shafts  58  are extending from the end faces  55 ,  56 . One of them is used for connection with the drive and the other for connection of any add-on equipment. On the output shafts  58  the flats (splines)  59  are made. 
     It is supposed the manufacturing of rotor  4  by casting with the following finishing by electroerosion method. To simplify the manufacturing of the ducts inside rotor  4 , the holes can be made in the central part of the end faces  55 ,  56  which are coaxial to axis  5  and regarding to depth reach the screw ducts  49 . Then the output shafts  58 , which are produced separately, are pressing-in into these holes. 
     The separator  7  ( FIG. 7 ) has the form of the body of revolution—symmetrical ring, Conventionally one can mark its inner part  60  (i.e. the nearest to its centre axis) and outer (i.e. the farthest from its centre) part  61 . On the figures they are separated by a line-and-dash circle. The outer part  61  in the assembled PDRM is located in the groove  15  and the inner part  60  is located in the cavity  11 . The axis  62  is the axis of the ring geneatrix revolution. The central hole  63  in the ring is limited by sphere-like surface and it has a diameter close to the diameter of the ball-shaped part  39  of the rotor  4  of the separator  7  for mounting on it with the minimal gape that allows them their relative rotation. The outer side face  64  of the ring is limited by sphere-like surface that is concentric to the central hole  63  which diameter is close to the diameter at the sphere-like surface  16  of housing  3 . The end faces  66  of the separator  7  are flat. The outside part  63  serves to interact with the groove  15  of housing  3  and on the inside part  60  two coaxial hinge joints  65  are made. The hinged joint  65  is made as a blind hole that is going through the surface of the hole  63  from the separator  7  centre which axis  67  is laying in the separator  7  plane. The hole diameter is lager than thickness of separator  7  that is why the hole on the separator  7  is forming a through she  68  limited by two cylindrical areas  69  which are produced from the hole and bottom of the hole. There is a local thickening  70  of the same diameter coaxial to it at the end of the hole. The cylindrical thickening  70  means two projections in the different sides (end faces  66 ) of the separator  7  coaxial convex cylindrical areas. The bottom of the hole is flat. It is an end face  71  of the thickening  70 . On the end face  71  of the thickening  70  there is closed coaxial to the thickening  70  hole  72  of smaller diameter. The other end face  73  of the cylindrical thickening  70  is concentric to the hole  63  sphere-like surface going alone the border lines of the inner part  60  and outer part  61 . The basic meaning of the thickening  70  is that it makes cylindrical convex areas working as friction pair with the piston  6 . The separator  7  is central symmetrical. 
     The piston  6  ( FIG. 8 ) is made as a flat ring. The end faces  74  of the ring are flat, the outer side face  75  is limited by sphere-like surface with diameter that is close to the diameter of the cavity  11  for the capability of rotation in latter without large gapes. The surface of the hole  76  is cylindrical. The piton  6  conventionally can be divided on inner (the nearest to the ring axis) part  77  and outer (peripheral) part  78 . The inner part  77  does not extend from the groove  43 . On the outer part  78  symmetrically made two coaxial hinge joints  79 . The hinge joint  79  is made as blind hole which is going through the side face  75  in the direction to the center of piston  6  which axis  80  is laying in the plane of the piston  6 . The diameter of the hole is larger than the thickness of the piston  6 , therefore the hole on the piston  6  is forming the through slot  81  limited by two cylindrical areas  82  left from the hole, and bottom of the hole. At the end of the hole there is coaxial cylindrical thickening  83  of the same diameter. The thickening  83  consists of two projection in the different directions (end faces  74 ) from the piston  6  coaxial to cylindrical areas which axis is directed to the center of the piston  6 . The flat bottom of the hole is to end face  84  of the thickening  83 . On the end face  84  of the thickening  83  there is the blind hole  85  coaxial to it of smaller diameter from which the pressed-in axle  86  projects. It is using for increasing of supporting surfaces of the hinge joints  79 . The other end face  87  of the cylindrical thickening  83  is the concentric to the side face  75  concave sphere-like surface which is going along border lines of the inner part  77  and outer part  78  of the piston  6 . The basic meaning of the thickening  83  is that it creates cylindrical convex areas working as friction pair with the separator  7 . The piston  6  is central symmetrical. 
     Assembled the thickening  83  of the piston  6  enters into slot  68  of the separator  7  ( FIG. 9 ) and the thickening  70  of the separator  7  enters into slot  81  of the piston  6 . The axis  80  enters into the hole  72 . Cylindrical areas  82  of the slot  81  of the piston  6  are working as friction pair against cylindrical thickening  70  of the separator  7  taking over mainly the loads acting in the plane of the piston  6  perpendicular to the axis  88  of the hinge joint  89 . The cylindrical areas  69  of slot  68  of the piston  7  are working as friction pair against cylindrical thickening  83  of the piston  6  taking over mainly the loads acting in the plane of separator  7  perpendicular to the axis  88  of the hinge joint  89 . The loads acting along the axis  88  is taking up by the friction pair the end face  84  of thickening  83  of piston  6 —the end face  71  of thickening  70  of the separator.  7 . The friction pairs piston  6 —rotor  4  and housing,  3 —separator  7  take op all other loads. 
     For capability of the piston  6  mounting into the rotor  4  the rotor  4  is made assembled. As separate parts—inserts  90  ( FIG. 10 ) is separated a cylinder  47  with connected to it cylindrical bulges  91 , which axis  92  is perpendicular to the axis  93  of the cylinder  47  and go through its center. The insert  90  is a half of the cylinder  47  with its part of bulge  91 . The separation is going in the plane which is parallel to the end faces  94  of the cylinder  47 . The bulge  91  is extending beyond the diameter of cylinder  47  and its end face  95  has a section (part) of the ball-shaped part  39  surface. The ducts sections  49  passing through the cylinder  47  also fall into the inserts  90 . The through slot  96  ( FIG. 11 ) is forming in the rotor  4  on the position of the groove  43  as a combination of symmetrically positioned rectangle and hole. 
     During assembly the inserts  90  are inserting into the hole  76  of the piston  6  from both sides, their bulges  91  are mounting parallel to the thickenings  83  of piston  6  and all together are mounting into the slot  96  of rotor  4 . The piston  6  is coming at that into the slot  90  with sliding fit and inserts  90  are pressing-in. 
     For capability of mounting of the separator  7  on the rotor  4 , the separator  7  ( FIG. 7 ) is made from two c-shaped parts, the joint  97  between which is made according to type “bulge into groove”. On the diametrically opposite areas of one part there are bulges  98  and on the other part are grooves  99 . There is a v-shaped groove  100  outlines of the bulge  98  and along the groove  99  outline the chamfers are made. The bulge  98  can in the groove  99  only in one direction—along the axis  67  of the hinge joint  65 . During assembly for complete fixing of the separator  7  parts the pins  100  are mounting into the holes at the boundary line the bulge  98 —groove  99 . 
     For simplification of manufacturing ( FIG. 12 ) the thickenings  83  on the piston  6  can be moved to one side of the piston  6  and the slots  81  to the other side of the piston  6 . Instead of thickenings  83  and slot  81  from one side of the piston  6  it will be longer thickening  83 , and from the other side of the piston  6  instead of the thickening  83  and slot  81  will be the longer slot  81 . Thereby analogous changes also take place on the separator  7  ( FIG. 13 ). Instead of the thickening  70  and slot  68  from one side of the separator  7  the longer thickening  70  is manufacturing and from the other side of separator  7  instead of the thickening  70  and slot  68  the longer slot  68  is manufacturing. Since the piston  6  and the separator  7  are holding from movements by other friction pairs (piston  6 —rotor  4 , separator  7 —housing  3 ) then for transferring them the torque relative to their rotation axes it is sufficient of the cylindrical areas  69  from one side of the piston  6  and the cylindrical areas  82  from one side of the separator  7 . One hinge joint  89  with thickening  70  and slot  81  controls the rotation at the piston  6  and the other hinge joint  89  with thickening  83  and slot  68  controls the rotation of the separator  7 . Thereby the insert  90  is made in the form of the cylinder  47  without bulges  91 . 
     For strengthening of the piston  6  and for increasing its bearing area on the rotor  4 , piston  6  ( FIG. 14 ) is made as a disk (not a ring). I.e. the cylinder  47  is a part of the piston  6  but not the rotor  4 . Meanwhile sections of ducts  49  are also relocated to the piston  6 . When the piston  6  turns around the ducts  49  are closed partially by the piston  6  but area of passage is decreasing proportionally to reducing of the working fluid flow through them. In order to reduce the resistance to the working fluid, on the piston  6  between sections of ducts  49  additionally separate holes  102  for passage of the working fluid passing through the ducts  49  are made. When the piston  6  turns around the holes  102  change each other passing the working fluid, but their total area changes slightly. For more strengthening of the piston  6  the large holes on the piston which are corresponding to sections ducts  49  can be changed by the set of smaller holes  102 . In the center of the piston  6  the hole  103  is made for the axis of the piston  6 . 
     For assembly simplification the joint  97  between the parts of the separator  7  according to  FIG. 7  is passing through the hinge joint  65  ( FIG. 15 ). The separator  7  consists of two approximately similar e-shaped parts of the ring, at the ends of each part there are cylindrical rings  104 , which are he parts of the thickenings  70  which are shared between the parts of the separator  7 . On one c-shaped part of the separator  7  fall the distant from its center parts of the thickenings  70  and on the other c-shaped part the nearest to the center parts of the thickenings  70 . The plane which separates them is parallel to the end faces  71 . 
     Thereby for assembly simplification and increasing of bearing surface the cylindrical areas  82  on the piston  6  ( FIG. 16 ) are made on the inserts  105  and increased in angular dimensions. The sectional view of the insert  105  is a combination of a circle sector with a small circle which is positioned symmetrically from outer side of the circle sector. I.e. the insert  105  is shaping as an arc with the coaxial to it cylindrical bulge  106  from the outer side. 
     For the inserts  105  on the piston  6  similar slots  81  will be made but of slightly larger size, on which cylindrical areas  82  the coaxial to them cylindrical grooves  107  are made for the cylindrical bulge  106 . 
     During assembly the piston  6  is placing into the rotor  4  at first and then the c-shaped parts of the separator  7  are joining around it, the axis  86  is placed into the holes  72  of the rings  104 , the axis connecting them and after that the inserts  105  are place. Besides the axis  86  passing two rings  104  and the hole  85  of the piston  6  is pressing-in only into one of the rings  104  (preferable the second one) or only into the hole  85  of the piston  6 . The other ring  104  can rotate on the axle  86 . A movable jointing of the two parts of the separator  7  decreasing the load on it in the most vulnerable place—in the place of the joint position. The axis  86  takes up the centrifugal forces acting on the parts of the separator  7  in order for they do not act upon the friction pairs. The PDRM do not loose the operability also by wearing process or absence of the axis  86 . I.e. for manufacturing simplification the parts of the separator  7  can be not secured to each other and the joint  97  between them can be made otherwise. 
     For increasing of bearing area of the cylindrical areas  69  of the separator  7  the inserts can not be used which are similar to the inserts  105 . 
     It is possible to decrease the forces acting from the working fluid on the piston  6  and on the separator  7  and also to increase their bearing surface by the separation of the piston  6 /separator  7  in two parts movable relatively to each another. The ring groove  108  is made on the surface of the hole  76  in the piston  6  ( FIG. 17 ), the groove  108  along the diameter do not cross the slots  81  of the piston  6 . From the insert  90  side the ring bulge  109  made on it enters the groove. Since the bulge  109  can extend into the working cavity  150  it can take up a part of the load acting on the piston  6  including the torque and energy which are transferring between the rotor  4  and working fluid. That is why from functional point of view the bulge  109  is an immobile part of the piston  6  fixed to the rotor  4 . The presence of the groove  43  on the ball-shaped part  39  of the rotor  4  is not obligatory also in other modifications of the piston  6  but the presence of the bulge  109  additionally decreases the need in it. 
     Similarly on the separator  7  ( FIG. 18 ) the ring groove  110  can be made on the outer side face  64  that does not cross the slots  68  of the separator  7 . To the housing  3  is fastened a ring  111  with the ring bulge  112  on the inner surface. The bulge  112  extending into the working cavity  150  is positioned in the groove  110  of the separator  7  and can take up a part of the load of the separator  7 . That is why from functional point of view the bulge  112  and the ring  111  are a static part of the separator  7  fixed to the housing  3 . Thereby the groove  15  on the housing  3  can be absent. I.e. the static part of the separator  7  can be fastened to the housing  3  with the assistance of the groove  15  or without it. Since the bulge  112  is located in the groove  110  of the separator  7  then the load by pressure difference is transferring on it to due to flows of the working fluid between end faces of the groove  110  and the bulge  112  or through the lubricant grooves (they are shown). For increasing of the proportion that is taking up the load by the static part of the separator  7  (i.e. for taking up the load from the rotating part of the separator  7 ) the holes which are leading into the groove  110  can be made at the end faces  66  of the movable part of the separator  7 . 
     For possibility of assembly of the piston  6  ( FIG. 17 ) with the ring groove  108  and insert  90  with the ring bulge  109  the piston  6  is made from two symmetrical parts. The boundary into  113  is passing along the plane of the piston  6  through its center. The parts are fixed to each other with the assistance of the rivets  114  or any other method. 
     The manufacturing of the separator  7  consisting of the movable relative to each other parts simplifies the creating of a PDRM with regulated feed on the basis of the PDRM according to  FIG. 1 . For that the static (i.e. not involved in the rotation of the rotor but having possibility to change its position relative to the housing  3 ) part of the separator  7  ( FIG. 19 ) is provided with the turnable shaft  115 . To increase the rigidity of the separator  7  the turnable shaft  115  ( FIG. 20 ) is made as a cylinder  116  with a concave sphere-like head  117 . The diameter of the concave surface coincides with the diameter of the cavity  11 . At the center of the head  117  there is a blind hole  118  coaxial to the cylinder  116 . Symmetrically closer to the ends of the heed  117  there are the grooves  119  for fastening of the static part of the separator  7 . On the static part of the separator  7  there are the cylindrical bulges  120  ( FIG. 19 ) in two its diametrically opposite places extending in radial direction. At a distance from the cylindrical bulges  120  there are fixing bulges  121  entering the grooves  119 . For possibility of assembly the static part of the separator  7  is made from two half-rings  122 , the joint between which is passing through the cylindrical  120 . 
     In the housing  3  ( FIG. 21 ) instead of the groove  15  the recesses  123  are made for the heads  117  and holes  124  for outlet of the cylinder  116  of the turnable shaft  115 . The axis  125  of the holes  124  is passing through the center of the cavity  11  perpendicular to the mating plane  10 . 
     During assembly the half-rings  122  enter into the groove  110  of the separator  7 , their cylindrical bulge  120  is pressing-in into the hole  118  of the turnable shaft  115 , ties them up together, and the fixing bulges  121  enter into the grooves  119  of the head. Further the turnable shafts  115  enter the holes  124  when the rotor  4  enters the housing  3 . 
     The rotor  4  of the machine does not differ principally from the rotor  4  according to  FIG. 5 . 
     It is possible to increase the rigidity of the static part of the separator  7  if the positions of the bulge  112  and groove  110  will be interchanged. I.e. the bulge  112  is made on the movable part of the separator  7  ( FIG. 22 ) and the groove  110  is done on the static part of the separator  7  ( FIG. 23 ). Thereby the fixing area of the thickening  70  to the separator  7  is constrainedly decreasing and its cylindrical areas are extending from the main body of the separator  7 . 
     It is possible to increase the bearing area of the separator  7  and/or piston  6  using several parallel bulges  112  and grooves  110  on their movable parts and several bulges  112 / 109  and grooves  110 / 108  on their static parts. This is a combination of the previously given examples. 
     Instead of the engagement of the type the bulge—groove between the rotor  4  or static part of the rotor  6  and movable part of the piston and/or between the movable and static part of the separator  7  or the housing  3  the ball bearing can be applied. To do this it is enough to make grooves, which serve as pats of the ball bearing on the corresponding parts and place between them balls with a separator. 
     The other design of the joint  89  also has high-reliability. the piston  6  ( FIG. 24 ) is made as a flat ring. The end faces  74  of the ring are flat, the outer side  75  is limited by sphere-like surface with the diameter which is close to the diameter of the cavity  11  for the possibility to rotate in the cavity without large gaps. The surface of the hole  76  is cylindrical. the piston  6  can be conventionally divide in the inner (the nearest to the axis of the ring) part  77  and outer (periphery) part  78 . The inner part  77  does not extend from the groove  43 . On the outer part  78  the two coaxial hinge joints  127  are made central symmetrically. The joint  127  is made as a local arc-shaped bent  128  of the piston  6  which axis  80  is passing through the center of the piston  6 . The bent  128  is passing completely through the outer part  7  of the piston  6 . There is a sector of the ring on the local sectional view of the bent  128 . In the present example its (ring sector) angle dimensions are: 250 degrees per inner bent and 130 degrees per outer bent. 
     The separator  7  ( FIG. 25 ) has the form of a body of revolution—symmetrical ring. Conventionally one can mark on it (ring) the inner (the nearest to its center, axis) part  60  and other (i.e. farther from its center) part  61 . On the figure they are separated by line-and-dash circle. The outer part  61  in the assembled PDRM is located in the groove  15  and the inner part  60  is located in the cavity  11 . The axis  62  is the ring generatrix axis of revolution. The central hole  63  in the ring is limited by the sphere-like surface having the diameter close to the diameter of the ball-shaped part  39  of the rotor  4  in order to be able to mount the separator  7  on it with minimal gap allowing their relative rotation. The outer side face  64  of the ring is limited by the sphere-like surface that is concentric to the central hole  63  which diameter is close to the diameter of the sphere-like surface  16  of the groove  15 . The end faces  66  of the separator  7  are flat. The outer part  61  serves for interaction with the groove  15  of the housing  3 , and on the inner part  60  central symmetrically two coaxial hinge joints  129  are made. The hinge joint  129  is made as the through arc-shaped slot  130 , which axis  67  is passing through the center of the separator  7 . The slot  130  is passing from the hole  63  till outer part  61 . The slot  130  is limited from side by the concave cylindrical area  69  that is similar to the area  69  of the separator  7  according to  FIG. 7 , from the other side by sector (part) of the cylinder  131  with angle dimension example of 300 degrees. 
     The sector diameter of the cylinder  131  can be not only smaller or equal but also can be larger than the thickness of the separator  7 . I.e. in this place can be a thickening of the separator  7 . 
     The friction pair is the concave cylindrical area  69 —the outer side of the bent  128  of the piston  6  is similar to the friction pair the area  69 —thickening  70 . Therefore for increasing of bearing area on the place of the areas  69  the inserts  105  can he used. 
     In other embodiment one or both bents  128  can be made on the separator  7  and one or two slots  130  on the piston  6 . 
     The hinge joints  79 / 65  on the piston  6  and/or on the separator  7  can be used by other embodiments of the PDRM with the sphere-like working cavity  11  increasing their reliability. For example, it can be used in the PDRM with the passage of the working fluid through the rotor  4  along the axis  5  of the rotor  4  ( FIG. 27 ). In this example two stages  1  and  2  were used to show how the stages mate each other. On their position can be any quantity of stages. 
     The housing  3  ( FIG. 28 ) of the PDRM is similar in many details to the housing of the PDRM according to  FIG. 1 . There are differences in inlet and outlet of the working fluid. The housing  3  of the PDRM is made from the two practically (within the consideration of fastener elements, grooves for sealing elements and branch pipes of the inlet  21  and outlet  24  of the working fluid) mirror symmetric parts  8  and  9  ( FIG. 29 ). The part  8  is not shown because it is similar to the part  9 . The mating plane  10  between them is passing through the axis  5  of the rotor rotation  4 . There are two sphere-like cavities  11  (one per a stage) in the housing  3 , which centers are laying on the axis  5 . Coaxial to the axis  5  the cylindrical hole for the rotor  4  is passing through the cavities  11 . The cavities  11  divide it in three areas: middle  12 , being between the cavities  11  and two outer  13  and  14  extending beyond the cavities  11  to the opposite directions. 
     Around each sphere-like cavity  11  the ring groove  15  of lager outer diameter than the diameter of the cavity  11  is symmetrically located in it and opened into the cavity. I.e. it is made on the surface of the cavity  11 . The groove  15  is limited by the sphere-like surface  16  which center coincides with the center of the cavity  11  and two end faces  17  in the form of the symmetrically located parallel flat rings. The axis of symmetry  18  (the groove  15  generatrix revolution axis) of the groove  15  is located in this example at the angle 25 degrees to the axis  5  and is laying in the mating plane  10 . 
     On the outer area  13  of the cylindrical hole, on the housing  3  there is a ring groove  132  for inlet to the rotor of the working fluid. At the one part  9  there is a branch pipe  21  of the inlet of the working fluid leading to the groove  132 . There is a thread tor connection of supply main pipes at the end of the branch pipe  21 . Analogous, at the outer area  14  of the cylindrical hole, on the housing there is a ring groove  113  for outlet of the working fluid from the rotor  4 . On the same part  9  there is the branch pipe  24  of outlet of the working fluid leading to the groove  133 . There is a thread for connection of supply main pipes at the end of the branch pipe  24 . The end faces  27  and  28  of the sections  13  and  14  correspondingly serve as axial bearings in order to limit the motion of the rotor in the axle direction. 
     On the end faces  27 ,  28  from the cylindrical section  13  there are coaxial to the axis  5  outlet holes  29  of smaller diameter. At the mating perimeter of the housing  3  on its both parts  8  and  9  there is a flange  33  for their connection to each other. There are holes  34  for pin-bolts on the end face  33 . On the end face  33  grooves (not shown) for sealing of the immobile mating along the perimeter of the inner cavity of the housing  3  are also made. 
     Stages  1  and  2  of the rotor  4  ( FIG. 29 ) are made on one cylindrical shaft. They divide it in three sections: middle  36  and two outer  37  and  38  extending in outer directions from the stages  1  and  2 . each stage of the rotor  4  has the central ball-shaped part  39  with the center on the axis  5  and with the diameter close to the diameter of the shaft. From the opposite sides along the axis  5  two side walls  40  made in the form of truncated cone which are coaxial to the axis  5  and symmetrically rested with the smaller base stands on the bal-shaped part  39  are located. The side walls  40  are connected with the sections  36  and  37  on the stage  1  and sections  36  and  38  on the stage  2  by the transitions  41  having sphere-like surfaces which diameter larger than the diameter of the shaft and the centers coincide with the centers of the corresponding central ball-shaped parts  39 . Between the two side walls  40  of each stage the opened outward ring cavity  42  is formed which bottom is the surface of the ball-shaped part  39 . From one side of the rotor  4  along the axis  5  the groove  43  for the piston  6  is passing through the side walls  40 , transitions  41  and ball-shaped part  39 . The groove  43  is getting in the ball-shaped part  39  deeper then its center. For convenience of manufacturing the grooves  43  are touching the sections  36 ,  37 ,  38 . The end face surfaces  44  of the groove  43  are flat and parallel to the axis  5 . At places of the groove  43  outlets to the side walk  40  there are the hollows  45  on the surface of the wall  40  from one side of the  43 . The duct  42  crosses the groove  43  in one place. 
     Two straight ducts  134  for passage of the working fluid are made through all stages inside the rotor  4 . Their sectional views have a form of circle section (a little bit smaller than a half) cut off be chord. Its corners are rounded. The stubs  135  are left at the beginning of the duct  134 , between all stages  1 ,  2  and at the end of the duct  134 , interchangeability in the ducts  134 . I.e. in one duct  134  is the partition  135  left before the first stage  1 , in the second duct before the second stage  2  and etc. After the last stage in the next duct  134  the stubs  135  is also installed. The groove  43  is passing on the wall  136  dividing the ducts  134 . 
     From one side of the groove  43  on the surface of the ball-shaped pat  39  the inlet opening  137  for the working fluid is made leading to the duct  134  and not divided by the stubs  135  before this stage. The opening is similar to an equilateral trapezium with rounded corners (on the sphere) oriented by the larger base to the groove  43  and is bordering to it. From the other side of the groove  43  through the surface of the ball-shaped part  39  the outlet opening  138  is made leading to the other duct  134  divided by the stub  135  at the entrance of the stage. Since each next stage of the rotor  4  is turned relatively to the previous stage around the axis  5  half-around so one duct  134  is connecting the outlet opening  138  of the stage  1  with the inlet opening  137  of the next stage  2 . In the ball-shaped part  39  and in the wall  136  there is a hole  139  which axis is passing through the center of the ball-shaped part  39  perpendicularly to the wall  136 . The hole  139  serves for the mounting of the axis of the piston  6 . At the outer section  13  there are the holes  140  connecting the not divided duct  134  with the groove  132 . The similar holes  140  at the outer section  14  connect not divided there the duct  134  with the groove  133 . 
     At the ends of the rotor  4  for connection with the drive and next sections of the PDRM there are output half shafts  58  of smaller diameter than the diameter of the sections  36 ,  37 ,  38 . 
     The piston  6  ( FIG. 30 ) looks like the part of the piston  6  according to  FIG. 24  with one hinge joint  79  but without the hole  76 . The piston  6  is made in the form of a symmetrical part of the disk with the flat (except the hinge joint  127 ) end faces  74 . In this embodiment, the disk part comprises the sector of 70 degrees and the cylinder with the diameter a little hit smaller than the diameter of the ball-shaped part  39 . It is limited by the sphere-like side face  75  which diameter is close to the diameter of the cavity  11 , concentric to it section of the cylindrical surface  141  and two flat areas connecting them. Conventionally on the piston  6  can be marked the inner part  77 —the part that does not extend beyond the ball-shaped part  39  and outer part  78 —farther part from the center of the end face side  75 . Symmetrically through the outer part  78  of the piston  6  the hinge joint  127  is passing. It is made as local arc-shaped bent  128  of the piston  6  which axis  80  is passing through the axis of rotary oscillations of the piston  6 . In local sectional view of the bent  128  there is the sector of the ring. In the present embodiment its angle dimension are: 250 degrees per inner curve and 130 degrees per outer curve. In the piston  6  there is a coaxial to the axis of the of rotary oscillations of the piston  6  hole  143  for installing an axle in it. 
     The separator  7  ( FIG. 31  ) is similar to the separator  7  according to  FIG. 25 , except that there is only one hinge joint  129  on it. 
     For synchronization strengthening of the piston  6  and the separator  7  the piston  6  ( FIG. 32 ) in the present PDRM can be made in the form of a whole disk as the piston  6  according to  FIG. 24 . For that the groove  43  is making as open-ended. It is preferably to make the second hinge joint  129  on the piston  6  for convenience of mounting into the rotor  4  as an arc-shaped slot  130  with the cylinder sector  131  and the second hinge joint  129  on the separator  7  ( FIG. 33 ) as an arc-shaped bent  128 . Such location of the hinge joints  127 ,  129  makes this PDRM more leak-tight i.e. pressure difference is falling on the side of the piston without holes  142  and on the opposite to it side of the separator  7  where the hinge joints  127  without slots  30  are used. The added part of the piston  6  in comparison with  FIG. 30  has not to create any blocks to the working fluid during its passage through the working cavity that is why in the its extending into the working cavity part the holes  142  are made. 
     In the PDRM according to  FIG. 37-33  the passage of the working fluid from stage to stage is realized through the ducts  134  passing inside the rotor  4 . The PDRM can consist of great number of stages. 
     The ducts of sufficient cross section passing inside of the rotor  4  in PDRM of such embodiment were succeeded to manufacture due to small thickness of the piston  6  which is possible when using the separator  7  at least one part which is rotating. 
     For unloading the rotor  4  from axial force, the stage  1 ,  2  of the PDRM can pump through the working fluid in opposite to each other directions. For this purpose the ducts  132  and  133  are replaced from the sections  13  and  14  to the section  12  (not shown). The branch pipes  21  and  24  can be located as on one part  8  or  9  so on the others. Thereby the leading to them duct are passing along the axis  5  to the section  12  but not to the sections  13 / 14 . 
     For producing of feed which is close to uniform by one stage (in one cavity  11 ) in one stage several pistons  6  ( FIG. 34 ) can be mounted. By using of one stage it is convenience to divide the housing  3  on the central symmetrical parts  8  and  9  by the planes  10  which are passing along the end faces  17  of the groove  15 . Thereby there is a flange  33  at the boundary as a ring with the holes  34  for connection of the parts  8  and  9  by the pin-bolts. Thereby a spacer plate  145  is presenting as a flat ring with extension of the holes  34  between the parts  8  and  9 . The side face  16  of the groove  15  is relocated to the spacer plate  145  as the surface of its hole. Within the part  8 / 9  there is the section  37 / 38  of the hole and a little bit smaller than a half of sphere-like cavity  11  which center is laying on the axis  5  of the hole. The cavity  11  is limited by the inclined to the axis  5  plane which is passing through the mating plane  10 . On the surface of the cavity  11  closer to the section the hole  37 / 38  symmetrically to the axis  5  the inlet opening  20  and the outlet opening  23  of the working fluid are located. The angular length of the opening  20 / 23  around the axis  5  in this embodiment is 90 degrees. The openings  20 / 23  are located in the interaction area of the surface  41  of the rotor  4  with the housing  3 . The inlet opening  20  is leading into the branch pipe  21  of the inlet  21  that has the thread  22  for connection of supply pipes. The outlet opening  23  is passing into the branch pipe of the outlet  24  having the thread  25  for connection of discharge pipes. 
     The rotor  4  ( FIG. 36 ) is made on the one cylindrical shaft. The rotor  4  has the central ball-shaped part  39  with the center on the axis  5  and diameter close to the shaft diameter. The two side walls  40  are located from the opposite directions from it along the axis  5 , the side walls  40  are manufactured as truncated cones which are coaxial to the axis  5  and symmetrically rested by their smaller base standings to the ball-shaped part  39 . The side walls  40  are connected with the sections  37  and  38  of the cylindrical shaft by the transitions  41  having sphere-like surfaces the diameter of which is lager than the shaft diameter, and the centers coincide with the center of the ball-shaped part  39 . Between two side walls  40  opened outwards the ring cavity  42  is formed, which bottom is the surface of the ball-shaped part  39 . Along the axis  5  through the side walls  40 , through transition sections  41 , over the ball-shaped part  39  the two symmetrical c-shaped open-ended and turned by 180 degrees in its plane and by ¼ revolution relative to the axis  5  grooves  43  for the pistons  6  are passing. The groove  43  gets in the not large depth into the ball-shaped part  39  as a ring groove center of which is coinciding with the center of the ball-shaped part  39 , is passing through the truncated cone of one of the side walls  40 , is touching a little bit the truncated cone of the other side wall  40  (for mounting of the piston  6 ). The end faces  44  of the groove  43  are flat and parallel to the axis  5 . Each groove  43  divides the side wall  40  on two equal parts, through which symmetrically relative to the groove  43 , over the surface of the side walls  40  and transition surfaces  41  over the surface of the rotor  4  the ducts  48  for the working fluid are passing. We will call the outlines of the ducts  48  on one of the surfaces  41  the openings  51  and on the other surface  41  —the openings  52 . The openings  51  and  52  have the angular length around the axis  5  less than ¼ of revolution and their sizes are approximately equal to the sizes of the openings  20  and  23  on the housing  3 . The two openings  51  are located symmetrically relative to the axis  5  and tow openings  52  are located symmetrically with the turn by ¼ resolution. 
     The end faces  55  and  56  of the sections  37  and  38  serve correspondingly as axial bearings limiting the rotor  4  movements in the axial direction. The output shafts  58  are extending from the end faces  55 ,  56 . One of them is working for connection with the drive and the other for connection of auxiliary equipment. The flats (splines)  59  are made on the output shafts  58 . 
     The piston  6  ( FIG. 37 ) is made as a part (a little bit smaller than a half) of a flat ring. The end faces  74  of the ring are flat, the outer side  75  is limited by the sphere-like surface with the diameter close to the diameter of the cavity  11  for possibility of rotating of the latter without large gaps. The surface of the ring hole  76  is cylindrical. The piston  26  can be divided conventionally on the inner (the nearest to the ring axis) part  77  and outer (peripheral) part  78 . The inner part  77  does not get out of the groove  43 . The two coaxial hinge joint  129  are made symmetrically on the outer part  78 . The hinge joint  129  is made as the through arc-shaped slot  130  which axis  67  is passing through the center (the axis of rotary oscillations) of the piston  6 . The slot  130  is passing front the inner part  77  up to the side face  75 . The slot  130  is limited from one side by the concave cylindrical area  69  that is similar to the area  69  of the separator according to  FIG. 7 , from the other side by sector (part) of the cylinder  131  the angular dimension in the embodiment of 300 degrees. 
     The diameter of the sector (part) of the cylinder  131  is equal in this embodiment to the thickness of the piston  6 . The chamfers  147  are made on the corners of the surface of the hole  76  (ring sector) to simplify the mounting into the groove  43  during assembly. 
     The separator  7  ( FIG. 38 ) has the form of the body of revolution—symmetrical ring. Conventionally one can mark on it the inner (i.e. closer from its center) part  60  and outer (i.e. farther from its center) part  61 . They are separated on the figure by line-and-dash circle. The outer part  61  in the assembles PDRM is located in the groove  15 , and the inner part  60  is located in the cavity  11 . The axis  62  is the axis of revolution of generatrix of the ring. The central hole  63  in the ring is limited by the sphere-like surface having the diameter close to he diameter of the ball-shaped part  39  of the rotor  4  to mount the separator  7  on it with minimal gap what allows their relative rotation. The outer side face  64  of the ring is limited by the sphere-like surface concentric to the central hole  63  which diameter is close to the diameter of the sphere-like surface  16  of the groove  15 . The end faces  66  of the separator  7  are flat. The outer part  61  serves for interaction with the groove  15  of housing  3  and the two coaxial hinge joints  127  are made axis-symmetrically on the inner part  60 . The hinge joint  127  is made as the local arc-shaped bent  128  of the separator  7  which axis is passing through the center of the separator  7 . The bent  128  is passing through the whole inner part  60  of the separator  7 . There is the sector of the ring on the local sectional view  128 . Its angular dimensions in this embodiment are: 250 degrees at inner curve and 130 degrees at outer curve. Two through grooves  148  are performed symmetrically to the axis of the hinge joint  127  through the whole inner part  60  of the separator  7 . The groove  148  is limited by the sphere-like surface concentric to the hole  63  and by the two flat almost radical area. The grooves are served for the mounting into them of the movable relative to the main separator  7  parts  146  of the separator  7 . 
     The movable part  146  of the separator ( FIG. 39 ) has the form of a small sector of the ring. The axis  62  is the axis of revolution of its generatrix. The central hole  63  in the ring is limited by the sphere-like surface having the diameter close to the diameter of the ball-shaped part  39  of the rotor  4 . The outer side face  64  of the ring sector is limited by the sphere-like surface concentric to the central hole  63  which diameter is close to the diameter of the sphere-like cavity  11 . The end faces  66  are flat. The hinge joint  127  is performed symmetrically on the part  146  in the form of a local arc-shaped bent  128  which axis  80  is passing through the center of the part  146 . The thickness of the part  146  is lager than the thickness of the separator  7 . The rectangular grooves  149  are made at its ends for mating with the main separator  7 . The grooves  149  let the turn of the movable part  146  of the separator relative to the main separator  7  at a small angle (±3 degrees in this embodiment) around the axis  42  for compensation of the angle changing between the axis  80  of the different pistons  6  by rotating of the rotor  4 . 
     An additional separator  7  (as on the  FIG. 38 ) can be used instead of the movable parts  146  of the separator  7  instead of the through groove  148  so the part  146  will not fulfill the described function of the separator and can be called according to the vocabulary from the analogy as sealing forced element (SFE). Thus for mounting of several pistons around one ball-shaped part of the rotor  4  the combination for using as the hinge joints  89  between the piston  6  and separator  7  so the using of SFE are allowed. 
     The machine according to the  FIG. 34  is similar to the machine according to the  FIG. 1  in operating principle, therefore it can be made controllable by the angle variation of the separator  7 , similarly to the machine according to  FIG. 27 . 
     The reliable synchronization of the piston  6  was appeared in the machine according to the  FIG. 34  in comparison with the analog (U.S. Pat. No. 2,708,413) due to the hinge joint  89  and the possibility was appeared to increase the inlet openings  20  and the outlet openings  23  due to their connection with the working chambers not directly but through the ducts  48 . 
     The represented two types of the hinge joint  127 - 129  and  65 - 79  are interchangeable in the most cases and can be used in all represented machines. 
     In the machines according to the  FIG. 1  and the  FIG. 19-21  similar to the machine according to the  FIG. 34  it can be no ducts  49  inside the rotor  4 . But the passage of the working fluid inside the ball-shaped part  39  increases considerably (by approx. 3 times) the specific parameters of the PDRM. I.e. the considerable result is achieved due to the fact that the working fluid is passing inside the rotor through the existing there ducts  49 / 134 . 
     In the machines according to the  FIG. 1 ,  FIG. 19-21  and  FIG. 34  the side walls  40  of the rotor  4  and end faces  66  of the separator  7  do not interact with each other (in contrast to the outwardly similar analogous machine RU 2006119356) and do not have any strict limitations for the form. The convenient forms for manufacturing are chosen for them. The forms of the ducts for passage of the working fluid do not have also any strict limitations. 
     The form of the outer side face  64  and side surface  16  of the groove  15  should not be obligatory sphere-like. They can have the form of another surface of revolution, for example, cylindrical or not be the surface of revolution, i.e. the gape (spaces) between them can be large enough to exclude their interaction. It increases the possibilities of groove  15  manufacturing. The separator  7  is fitted in the required place in the cavity  11  due to interaction with the ball-shaped part  39  of the rotor  4 . The present of the gape between them allows to simplify their manufacture. 
     The sphere-like transition surface  41  on the rotor  4  can be replaced by any other surface of revolution and can disappear due to increasing of the diameter of the sections  36 ,  37 ,  38 . 
     With the sufficient safety factor of the rotor  4  the side walls  40  can have cylindrical surface which is an extension of the shaft areas  36 ,  37 ,  38  surfaces. I.e. geometrically (visually) two elements can be excluded—the side walls  40  and the transition surface  41 . 
     To increase the reliability and strength all immobile joints  97 ,  113  can be replaced by permanent, for example, welding joints. 
     The PDRM by  FIG. 1  as a pump works in the following way. Around the sphere-like part  39  of the rotor  4  of each of the stages  1 ,  2  in the cavities  11  of housing  3  from the opened ring cavity  42  formed a ring working cavity  143 , which the separator  7  divides into two parts  144  of variable cross section. The piston  6  divides each part  144  into two working chambers  152  and  153 . Rotation of the piston  6  with the rotor  4  via hinge  89  between the piston  6  and the separator  7  draw into rotation the separator  7 . During rotation of the rotor  4  the working chambers  152 ,  153  change their volume because of the separator  7  inclination. Two central symmetrically located relatively to sphere-like part  39  chambers  152  are increasing their volume, at the same time as two other central symmetric chambers  152  are decreasing their volume. Chambers  152 / 153  situated on the other from the area  36  side of the separator  7  due to the screw ducts  49  inside the sphere-like part  39  together with the chambers  152 / 153  located from the side of area  36  are connected by ducts  50  with the opening  51  and  52  situated at the area  36  of the rotor  4  between the stages  1  and  2 . At this place at the housing  3  the inlet opening  20  and axis symmetrically to it regarding axis  5  of rotor  4  rotation the outlet opening  23  of working fluid are located. Outlets of the ducts  50  to the rotor  4  surfacing coming from increasing their volume chambers  152  overlap with opening  20 , and outlets of the ducts  50  to the rotor  4  surface coming from decreasing their volume chambers  153  overlap with opening  20 . Due to decrease of the chambers  153  volume, the working fluid from them have to go out through ducts  49 ,  50  to outlet opening  23  and further to the outlet branch pipe  24 . Due to increase of the other chambers  152  volume, a new portion of working fluid enters them through  50 ,  49  through inlet opening  20  and from the inlet branch pipe  21 . 
     When the volume of chambers  153  of one of the stages  1 / 2  reaches the minimum, and the volume of other chambers  152  reaches the maximum, the outlets  51 / 52  of the ducts  50  due to the rotor rotation comes out of overlapping with the outlet opening  23  and with the inlet opening  20  respectively and start to enter in overlapping with the opposite openings—the inlet opening  20  and outlet opening  23  respectively. Pairs of the chambers  152  and  146  change each other. The process is repeated. Due to the shift in faze in ¼ of revolution between the stages  1  and  2 , the total supply becomes closer to uniform (non pulsating). 
     The separator  7  is subjected to periodic axis symmetric load from the working fluid on its inner part  60 , which its outer part  61  transfers to the end faces  17  of the groove  15 . Since the direction of this force is perpendicular to the velocity of the separator  7 , it does not transfer the torque and energy between the rotor  4  and the working fluid. 
     The piston  6  is subjected to the periodic central symmetric load from the working fluid on its outer part  78 , which it transfers to the end faces  44  of the groove  15 . Via the piston  6  the energy and torque transition between the rotor  4  and the working fluid occurs. 
     The piston  6  via hinge joint  89  transfers a part of energy of the rotor  4  to the separator  7  to compensate the friction forces acting on the separator  7  (mainly in the groove  15 ). 
     Besides because of rotational oscillations of the piston  6 , it is subjected to inertial forces proportional to the integral of piston  6  masses multiplied by squared distances from them to axis  86  along the piston  6  plane. They are transferred via areas  82  to the thickening  70  of the separator  7 , i.e. via hinge joint between the piston  6  and separator  7 . 
     Because of small unsteadiness rotation of the separator  7 , it is subjected to inertial forces which are proportional to its moment of inertia in its plane. They are transferred via areas  69  of the separator  7  to the thickenings  83  of the piston  6 , i.e. via hinge joint between the separator  7  and piston  6 . 
     Areas  82  and areas  69  are almost perpendicular to the transferred by them forces. 
     Rotor  4  is balanced regarding to radial forces acting on it from the working fluid. Not balanced moment of forces significantly decreased due to the distance between areas  37  and  38  playing the role of bearings. 
     The PDRM by  FIG. 19-21  works in the similar with PDRM by  FIG. 1  way. Additionally it gains the ability to vary its feed from the maximal feed in one direction to the same feed in the opposite direction while the rpm of the rotor is constant. It takes place when simultaneously the turnable shafts of both stages are turning on by an external control drive in the range of angles from −25 to +25 degrees around the axes  125 . 
     The PDRM by  FIG. 27  as a pump works in the following way. Around the sphere-like part  39  of the rotor  4  of each of the stages  1 ,  2  in the cavities  11  of housing  3  from the opened ring cavity  42  formed a ring working cavity  150 , which the separator  7  divides into two parts  151  of variable cross section. In the narrow place the cross section is equal to zero. I.e. the part  151  is c-shaped (does not form a ring). The piston  6  divides each part  144  into two working chambers  152  and  153 . Rotation of the piston  6  with the rotor  4  via hinge joint  89  between the piston  6  and the separator  7  draw into rotation the separator  7 . But the rotation of the separator  7  does not move the parts  151  relatively to the housing  3 . During rotation of the rotor  4  one part of the piston moves in one part  151  dividing it into chambers  152  and  153 . The chambers  152  are situated behind (along the direction of rotor  4  rotation) the piston  6  and increasing their volume, and chambers  153  are situated beforehand the piston  6  and decreasing their volume. The working fluid from ducts  134  inside the rotor  4  through inlet opening  137  on rotor  4  located behind the piston  6  passes into the chambers  152 . And from the chambers  153  the working fluid passes out through opening  138  located before the piston  6  to the other duct  134 . When the piston  6  reaches the minimal cross section of the one of the parts  151  after passing it the piston  6  enters into the same part  151  but from the other side. The process is repeated. The ducts  134  pass the working fluid between the outlet opening  138  of one stage  1  and the inlet opening  137  of the other stage  2  or between the inlet branch pipe  21 /outlet branch pipe  24  and inlet opening  20  of the stage  1 /outlet opening  23  of the stage  2  through openings  140 . The feed of the PDRM is close to uniform. 
     The separator  7  is subjected to the periodic circular moving pulsating load from the working fluid on its inner part  60  which its outer part  61  transfers to the end faces  17  of the groove  15 . Since the direction of that force is perpendicular to the velocity of the separator  7 , it does not transfer the torque and energy between the rotor  4  and the working fluid. Excluding the stage pressure drop acting on the cross section of the separator  7  and pushing it in the direction of its rotation. 
     The piston  6  is subjected to periodic central symmetric load from the working fluid on its outer part  78  which it transfers to end face  44  of the groove  43 . via the piston  6  the energy and torque transfer between the rotor  4  and the working fluid is done. The piston  6  via the hinge joint  89  transfer a part of rotor  4  energy to the separator  7  for a compensation of friction forces acting on the separator  7  (mainly in the groove  15 ). 
     Besides because of rotational oscillations of the piston  6  it is subjected to inertial forces proportional to the integral of piston  6  masses multiplied by their squared distance to the axis  86  along the piston  6  plane. They are transferred via the bent  128  on the piston  6  to the cylinder sector  131  of the separator  7 , i.e. via hinge joint  89  between the piston  6  and separator  7 . 
     Because of small non uniformity of the separator  7  rotation it is subjected to the inertia forces proportional to its inertia moment taken in its plane they are transferred via areas  69  of the separator  7  to the bent  128  of the piston  6 , i.e. via hinge joint  89  between the separator  7  and piston  6 . On the hinge joints  89  there are areas practically perpendicular to the forces transferred through them. 
     The PDRM by  FIG. 34  as a pump works in the similar with the PDRM by  FIG. 1  way. Around the sphere-like part  39  of the rotor  4  in the cavities  11  of housing  3  from the opened ring cavity  42  a ring working cavity  150  is formed, which the separator  7  along with the movable parts  146  of the separator  7  divides into two parts  151  of variable cross section. Each piston  6  divides each part  151  into working chambers  153  and  153 . Rotation of the piston  6  with the rotor  4  via hinge  89  between the piston  6  and the separator  7  draw into rotation the separator  7 . Rotation of the other piston  6  with the rotor  4  via hinge joints  89  between the piston  6  and movable parts  146  of the separator  7  draw the latter into rotation. During rotation of the rotor  4  the working chambers  151 .  153  change their volume due to the separator  7  inclination. One chamber  152  is increasing its volume, at the same time as the chamber  153  located from the other side of the piston  6  is decreasing its volume. Chambers  152 / 153  situated on the other from the separator  7  side and separated by the other piston  6  due to the turning angle of ¼ revolution around  5  between pistons  6  are shifted in faze at 90 degrees. 
     When the volume of the chamber  151  is increasing it is connected by duct  48  with the inlet opening  20  of the working fluid, and from the inlet branch pipe  21  through openings  20  and  50 / 51  the working fluid is coming into it. When the volume of the chamber  152  is decreasing it is connected by duct  48  with the outlet opening  23  of the working fluid, and the working fluid is coming out from it to the outlet branch pipe  24  through the openings  23  and  51 / 52 . When the minimal or the maximal volume is reached by the chambers  152 / 153  the switch in their commutation occurs. The process is repeated for the other chambers  152 / 153 . Due to the shift in faze between the pares of chambers  152 / 153 , the feed of the PDRM is closer to uniform.