US3584648A - Hydrostatic machine - Google Patents

Hydrostatic machine Download PDF

Info

Publication number
US3584648A
US3584648A US863871A US3584648DA US3584648A US 3584648 A US3584648 A US 3584648A US 863871 A US863871 A US 863871A US 3584648D A US3584648D A US 3584648DA US 3584648 A US3584648 A US 3584648A
Authority
US
United States
Prior art keywords
combination
eccentric
housing
chamber
rings
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US863871A
Other languages
English (en)
Inventor
Walter Lubos
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
G Duesterloh GmbH
Original Assignee
G Duesterloh GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE19681801541 external-priority patent/DE1801541C/de
Application filed by G Duesterloh GmbH filed Critical G Duesterloh GmbH
Application granted granted Critical
Publication of US3584648A publication Critical patent/US3584648A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03C—POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
    • F03C1/00—Reciprocating-piston liquid engines
    • F03C1/02—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders
    • F03C1/04—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinders in star or fan arrangement
    • F03C1/0403—Details, component parts specially adapted of such engines
    • F03C1/0435—Particularities relating to the distribution members
    • F03C1/0444—Particularities relating to the distribution members to plate-like distribution members
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
    • F01B3/00—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis
    • F01B3/0002—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having stationary cylinders
    • F01B3/0008—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having stationary cylinders having self-acting distribution members, e.g. actuated by working fluid
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/86493—Multi-way valve unit
    • Y10T137/86574—Supply and exhaust
    • Y10T137/86638—Rotary valve

Definitions

  • valve plate of a reversible hydrostatic axial or radial piston machine surrounds an eccentric of the shaft and comprises two rings which are sealingly telescoped into loykps'rglc MAPmE each other and are biased apart so that each thereof engages alms rawmg lgs' an inner face of the housing.
  • a rst chamber of the housing U.S.
  • valve plate which surrounds the valve plate communicates with one ofthe 418/61 ports and a second chamber, dened by the valve plate, comllnt. Cl .Flk ll/02, municates with the other port.
  • the valve plate alternately con- 1 ⁇ 04c 17/02 nects the fluid pressurizing spaces of the machine with the first Field of Search 137/625.21 and second chambers when the eccentric rotates with the 625.24; 251/175, 185, 281, 283; 123/8, l2; 91/56; shaft or when the housing rotates with reference to the eccen- 103/130; 230/145; 418/61 tric.
  • the present invention relates to hydrostatic machines in general, particularly to hydraulically operated radial or axial piston pumps or motors. Still more particularly, the invention relates to improvements in pumps or motors of the type wherein the shaft or housing is preferably rotatable in two directions so that the suction port constitutes the discharge port and vice versa when the direction of rotation is changed.
  • the invention relates mainly to improvements in control members, known as valve plates, which are used in such machines to regulate the flow of fluid from the suction port into the pressurizing space or spaces and from the pressurizing space or spaces to the outlet port.
  • valve plate In hydrostatic machines wherein the valve plate is pressed against the control face of the housing by hydraulic fluid and wherein each revolution of the rotary part causes a complete forward and return stroke of rotary or axial pistons, one end face of the valve plate is subjected to pressure of hydraulic fluid along a circle whose center is located on the axis of rotation.
  • the reaction field in the valve plate is eccentric due to the provision of fluid-conveying channels. Consequently, at least some overdimensioning of the valve plate is desirable and normally necessary in order to insure that the eccentric reaction forces cannot tilt the valve plate; such tilting would permit direct flow of fluid between the inlet port and the outlet port. Overdimensioning of the valve plate produces excessive friction, increased wear and a reduction in output.
  • a hydraulically held valve plate acts not unlike a disc brake which is very undesirable in hydraulic motors with a high rate of fluid throughput as well as in motors which produce relatively little torque.
  • the mass of revolving parts is often excessive so that the time required for acceleration and deceleration of such parts is too long.
  • An object of the invention is to provide a hydrostatic machine, particularly a hydraulic axial or radial piston pump or motor, wherein the valve plate is constructed, assembled and mounted in a novel and improved way.
  • Another object of the invention is to provide a hydrostatic machine wherein the wear on the entire valve plate is uniform and wherein such wear is less pronounced than in presently known machines.
  • a further object of the invention is to provide a hydrostatic machine wherein the valve plate is in proper sealing engagement with adjoining parts even if it is subjected to lesser mechanical and/or hydraulic stresses than in presently known machines, and wherein the sealing action between the valve plate and the adjoining parts is not affected by wear on the faces which move with reference to each other.
  • a concomitant object of the invention is to provide a hydrostatic machine wherein the valve plate can be placed into requisite sealing engagement with the adjoining parts of the machine even if the end faces of the valve plate and/or the complementary faces of the adjoining parts are not exactly parallel to each other.
  • Still another object of the invention is to provide a hydrostatic machine wherein the high-pressure and low-pressure chambers are sealed from each other in a novel and improved way, and wherein such sealing is achieved without adding to the bulk and/or weight ofthe machine.
  • the invention is embodied in a hydrostatic machine which may constitute an axial or radial piston motor or pump and comprises first and second units one of which is rotatable with reference to the other unit in at least one direction, preferably in two directions.
  • the first unit includes a housing defining a first annular chamber and having a pair of parallel internal faces flanking the ends of the chamber, and the second unit includes a shaft mounted in the housing and an eccentric provided on the shaft in the chamber.
  • the machine further comprises a novel annular control member or valve plate which rotatably surrounds the eccentric in the first chamber and defines a second annular chamber which is sealed from the first chamber.
  • the control member comprises a pair of rings movable axially of each other and each having an annular end face, and means for biasing the rings axially apart so that each end face bears against a face of the housing.
  • the other unit i.e., the one which does not rotate
  • the other unit is provided with fluid-admitting and discharging ports each communicating with one of the chambers and the housing is formed with at least one fluidpressurizing space terminating in one face of the housing and alternately communicating with the first and second chambers in response to relative movement between the housing and the control member on rotation of the one unit.
  • the means for biasing the rings of the control member axially apart may include mechanical and/or fluid-operated biasing means. ln accordance with a feature or the invention, all points of the end faces on the rings of the control member perform substantially translatory movements relative to the corresponding faces of the housing in response to rotation of the one unit, and the extent of such translatory movement equals the radius of eccentricity of the eccentric.
  • One of the two rings is preferably sealingly telescoped into the other ring and friction-reducing means (e.g., a needle bearing or a ball or roller bearing) is preferably interposed between the eccentric and the adjoining ring of the control member.
  • FIG. 1 is a fragmentary axial sectional view of a rotary piston machine which embodies one form of the invention and wherein the eccentric is integral with a rotary shaft;
  • FIG. 2 is a similar fragmentary axial sectional view of a second rotary piston machine wherein the eccentric is movable axially of and rotates with the shaft;
  • FIG. 3 is a fragmentary axial sectional view of a third machine constituting a modification of the machine shown in FIG. 2;
  • FIG. 4l is a fragmentary axial sectional view of a fourth machine wherein the housing rotates with reference to the eccentric.
  • FIG. 1 illustrates a portion of a radial piston machine having a housing including an end wall or cover 1 provided with ports 2, 3 one of which is the inlet or suction port and the other of which is the outlet or discharge port, depending on the direction of rotation of the shaft 6.
  • the housing further includes a cylindrical wall or shell l which is sealingly connected with the cover ll.
  • the shaft 6 has an integral eccentric end portion which moves a valve plate, here shown as a ring-shaped control disc 7, by way of a needle bearing S.
  • the periphery of the control disc 7 is surrounded by a ring-shaped chamber 26 of the cover 1.
  • the control disc comprises a substantially ringshaped inner portion 9 (hereinafter called inner ring) and a ring-shaped outer portion 10 (hereinafter called outer ring).
  • the inner ring is sealingly telescoped into the outer ring in such a way that the two rings are movable axially relative to each other.
  • the outer ring 10 has an annular end face Il which bears against the adjacent inner face 12 of the cover 1.
  • An annular end face 13 of the inner ring 9 bears against the adjacent outer face or control face 141 of the shell 4.
  • the end face 13 is formed with an endless circular groove or chamber 15 and the inner ring 9 is further provided with a second endless circular groove 16 which communicates with the groove or chamber 15 by way of circumferentially spaced axially parallel apertures or bores 17.
  • An elastically deformable ring-shaped sealing element 18 is interposed between the rings 9, 10 to prevent leakage of fluid between the groove 16 and the chamber 26.
  • the sealing element 18 also serves as a means for biasing the rings 9, 10 axially and away from each other.
  • the inner ring 9 is provided with two ring-shaped surfaces 20, 21 located opposite similar ring-shaped surfaces 22, 23 of the outer ring 10.
  • the surfaces 2li-23 are located in planes extending at right angles to the axis of the shaft 6. Fluid which exerts pressure against the surfaces -23 tends to bias the rings 9, 10 axially and away from each other.
  • the shell 4 of the housing is provided with axially parallel fluid-pressurizing spaces or channels 25 having end portions 24 machined into the end face 14.
  • the cover 1 is provided with a compartment 19 communicating with the groove 16 and port 2; this compartment is located substantially behind the control disc 7.
  • This compartment is located substantially behind the control disc 7.
  • FIG. 2 illustrates a portion of a second radial piston machine. All such parts of this machine which are clearly analogous to the corresponding parts of the machine shown in FIG. l are denoted by similar reference characters.
  • the onepiece sealing element 18 of FIG. l is replaced by a ring-shaped sealing element 28 which is recessed into the inner ring 9 and performs only a sealing function, and a package of dished springs 27 interposed between the surfaces 20, 22 and tending to move the rings 9, 10 axially and away from each other.
  • the eccentric 5 of FIG. 2 rotates with but is separably mounted on a polygonal end portion or stub 29 of the shaft 6. The stub 29 permits axial movements of the eccentric 5 with reference to the shaft 6.
  • a helical spring 30 reacts against a ring-shaped retainer 31 mounted on a cylindrical extension 32 of the stub 29 and bears against an internal shoulder of the eccentric 5 to bias the inner end face 33 of the eccentric against the outer face 14 of the shell 4.
  • a cap 34 which is threaded onto the eccentric 5 extends into the compartment 19 and acts not unlike a plunger to assist the spring 30 in maintaining the faces 33, 14
  • a suitable seal is interposed between the cap 34 and eccentric 5 to seal the compartment 19 from the space surrounding the extension 32. Fluid filling the compartment 19 exerts pressure against the end face of the cap 34 to thereby urge the end face 33 against the outer face 14.
  • the inner ring 9 of the control disc 7 in the machine of FIG. 2 constitutes the outer race of an antifriction bearing which further includes an annulus of circumferentially spaced rolling elements in the form of balls 35 received in a cage 36 and running in a circumferential groove of the eccentric 5.
  • the latter constitutes the inner race of the antifriction bearing.
  • the gaps between the balls 35 constitute apertures performing the function of bores 17 shown in FIG. 1.
  • the groove 16 of FIG. l is replaced by the space 16a within the outer ring 10.
  • each fluid-pressurizing space 25 communicates once with the outer chamber 26 (i.e., with the port 3) and once with the inner chamber 15 or 15a (i.e., with the port 2). Since all points on the end faces 11 and 13 cover equal distances when the shaft 6 rotates, the wear on such end faces and on the adjoining faces 12, 14 is uniform so that all of these faces remain flat even after prolonged use of the machine. The wear is less than in conventional machines because the extent of relative movement is less than in machines where the valve plate performs exclusively a rotary movement.
  • All of the faces 11-14 are lubricated either by the fluid in the chamber 26 or by lubricant in the lubricating groove so that the lubrication is simpler and more thorough than in known machines. This also results in reduced wear on the control member and housing.
  • control member 7 comprises two rings which are biased axially apart insures that the end faces 1 1, 13 are in requisite sealing engagement with the faces 12, 14 even if such faces undergo considerable wear and even if the faces 12, 14 are not exactly parallel to each other.
  • the mechanical biasing action of the sealing element 18 or of the springs 27 is assisted by the fluid which exerts pressure against the surfaces 20, 22 or 21, 23, depending on the direction of rotation of the shaft 6, i.e., depending upon whether the pressurized fluid fills the chamber 15 (or 15a) or the chamber 26. It was found that the combined mechanical and hydraulic biasing means which tend to move the rings 9, l0 axially apart prevent appreciable leakage between the ports 2, 3 even after the faces 11-14 have undergone considerable wear.
  • the eccentric 5 imparts to the control member 7 a wobbling or translatory movement (not unlike a wedge or cam) whereby the stroke of the control member need not exceed between 0.5 and 1.5 times the diameter of a space 25.
  • Those parts of the control member which are adjacent to the shaft 6 can or could perform a rotary movement celeration and deceleration characteristics because the mass of moving parts is relatively small.
  • the main purpose of the elastic sealing element 18 and of the springs 27 is to insure that the end faces 11, 13 remain in requisite sealing engagement with the faces l2, 14 when the shaft 6 is idle. Once the shaft rotates to cause the flow of fluid from the port 2 to the pressurizing spaces 25 and from such spaces to the port 3, or vice versa, pressure of fluid on the surfaces 20, 22 or 2l, 23 insures that the end faces of the rings 9, remain in satisfactory sealing engagement with the faces 14 and 12.
  • An advantage of the axially movable eccentric 5 shown in FIG. 2 is that its end face 33 prevents fluid from entering the bore for the shaft 6.
  • the spring 30 insures that the bore for the shaft 6 is sealed from the inner chamber 15a when the shaft is idle. Once the shaft rotates and the pressure of fluid in the machine rises, the end face 33 is held in requisite sealing engagement with the face 14 mainly by fluid pressure.
  • Another advantage of the structure shown in FIG. 2 is that the apertures for the passage of fluid from the chamber a to the port 2 or vice versa are provided between the rolling elements 35.
  • the improved control member can be used in hydrostatic machines with radially or axially movable pistons.
  • the shaft 6 extends through and beyond the eccentric 5 and cover l.
  • a package of dished springs 37 is interposed between the eccentric S and a sleeve 38 to bias the end face 33 against the outer face 14.
  • the compartment 19 is replaced by an annular groove 39 machined into the cover l and communicating with the port 2. Otherwise, the construction and mode of operation of the machine shown in FIG. 3 are identical with those of the machine shown in FIG. 2.
  • FIG. 4 there is shown a further fluid displacing machine which includes a stationary shaft 6 and a rotary unit including the housing (cover l and shell 4).
  • the eccentric 5 is keyed to the fixed shaft 6, as at 40, and is not intended to move in axial direction of the shaft.
  • the end faces of the eccentric are formed with substantially circular recesses 41, 42 for supporting ring-s 43, 44 which are biased by helical springs 47, 43 reacting against internal annular surfaces 45, 46 in the recesses 41, 42.
  • the springs 47, 48 respectively bias the supporting rings 43, 44 against the faces 12 and 14.
  • the nonoccupied portions 49, 50 of the recesses 4l, 42 constitute annular compartments through which the fluid flows when the machine is in operation.
  • the ports 2, 3 are provided in the exposed end portion of the fixed shaft 6 and are respectively connected with the compartments 50, 49 by bores orchannels 57, 55 machined into the shaft 6.
  • the compartment 49 further communicates with the chamber 26 by way of bores 54 machined into the cover l, concentric grooves 5l, 53 in the supporting ring 41, and axially parallel ducts 52 which connect the groove 5l with the groove 53.
  • the compartment 50 connects the port 2 with the inner chamber 15a through the intermediary of one or more radial channels or bores 56 in the eccentric 5.
  • the springs 47, 48 in the recesses 4l, 42 serve to insure requisite sealing engagement between the supporting rings 43, 44 and the faces l2, 14 when the housing is idle. Once the housing rotates so that the pressure of fluid in the compartment 49 and/or S0 rises, the supporting rings are biased against the housing mainly by fluid pressure.
  • the supporting rings 43, 44 surround sealing elements which are recessed into the periphery of the shaft 6. These supporting rings invariably prevent leakage of fluid along the shaft t5, not only outwardly toward the ports 2, 3 but also inwardly into the bore which accommodates the larger diameter portion of the shaft.
  • a combination comprising first and second units one of which is rotatable relative to the other in at least one direction, said first unit including a housing defining a first annular chamber and having a pair of parallel faces flanking the ends of said chamber, said second unit including a shaft mounted in said housing and an eccentric provided on said shaft in said chamber; and an annular control member rotatably surrounding said eccentric in said chamber and defining a second annular chamber sealed from said first chamber, said control member comprising a pair of rings movable axially of each other and each having an annular end face, and means for biasing said rings axially apart so that each of said end faces bears ⁇ against a different face of said housing, said other unit having fluid-admitting and discharging ports each communicating with a different one of said chambers and said housing further having at least one fluid-pressurizing space terminating in one of said faces thereof .and alternately communicating with said first and second chambers in response to relative movement between said housing and said control
  • said means for biasing said rings axially apart includes adjacent but spaced surfaces provided on said rings in at least one of said chambers so that the fluid in said one chamber acts against such surfaces to urge the rings against the corresponding faces of said housing.
  • a combination as defined in claim l further comprising friction-reducing means interposed between said eccentric and said control member.
  • said means for biasing said rings axially apart comprises spring means interposed between said rings.
  • a combination as defined in claim 9, wherein the means for biasing said eccentric comprises a plunger located in the path of pressurized fluid.
  • said antifriction bearing means comprises an annulus of rolling elements surrounding said eccentric and defining a plurality of apertures.
  • a combination as defined in claim l wherein said eccentric is provided with a pair of concentric circular recesses each adjacent to one face of said housing and further comprising a pair of annular supporting members each received in one of said recesses and means for biasing said supporting members against the respective faces of said housing.
  • portions of said recesses constitute compartments each connecting one of said chambers with the respective port.
  • one of said supporting members ismprovided with a pair of axially spaced concentric grooves and ducts connecting said grooves, said grooves and ducts connecting said first chamber with the respective compartment.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Reciprocating Pumps (AREA)
  • Hydraulic Motors (AREA)
US863871A 1968-10-05 1969-10-06 Hydrostatic machine Expired - Lifetime US3584648A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19681801541 DE1801541C (de) 1968-10-05 Steuereinrichtung für reversierbare hydrostatische Axial- oder Radialkolbenmaschinen

Publications (1)

Publication Number Publication Date
US3584648A true US3584648A (en) 1971-06-15

Family

ID=5709802

Family Applications (1)

Application Number Title Priority Date Filing Date
US863871A Expired - Lifetime US3584648A (en) 1968-10-05 1969-10-06 Hydrostatic machine

Country Status (4)

Country Link
US (1) US3584648A (fr)
FR (1) FR2019982A1 (fr)
GB (1) GB1287011A (fr)
SE (1) SE359619B (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3767165A (en) * 1972-07-05 1973-10-23 Trw Inc Shaft retaining means for hydrostatic steering devices
US4112973A (en) * 1976-07-08 1978-09-12 G. Duesterloh Gmbh Control arrangement for a hydrostatic axial or radial piston machine
US6200109B1 (en) * 1996-08-17 2001-03-13 Continental Teves Ag & Co., Ohg Electromotor/pump assembly
US20170107789A1 (en) * 2015-10-19 2017-04-20 Baker Hughes Incorporated High temperature, bi-directional shear seal and related methods

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4405802C2 (de) * 1994-02-23 1996-06-27 Duesterloh Gmbh Steuereinrichtung für eine hydrostatische Arbeitsmaschine
CN102011758B (zh) * 2009-09-04 2013-01-02 佛山市顺德区中意液压有限公司 一种双列径向十柱塞马达用配油装置
FR3005485B1 (fr) * 2013-05-13 2015-05-29 Exoes Systeme d'admission ameliore pour une machine de detente axiale

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2969810A (en) * 1955-12-27 1961-01-31 Edward C Dudley Wobble plate pump
US3034484A (en) * 1961-02-02 1962-05-15 Stefancin Carl Rotary engine
US3174403A (en) * 1959-10-26 1965-03-23 Young Spring & Wire Corp Hydraulic servo control mechanism
US3316814A (en) * 1965-04-22 1967-05-02 Germane Corp Rotary fluid pressure device
US3370611A (en) * 1964-11-21 1968-02-27 Dowty Hydraulic Units Ltd Slide valves

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2969810A (en) * 1955-12-27 1961-01-31 Edward C Dudley Wobble plate pump
US3174403A (en) * 1959-10-26 1965-03-23 Young Spring & Wire Corp Hydraulic servo control mechanism
US3034484A (en) * 1961-02-02 1962-05-15 Stefancin Carl Rotary engine
US3370611A (en) * 1964-11-21 1968-02-27 Dowty Hydraulic Units Ltd Slide valves
US3316814A (en) * 1965-04-22 1967-05-02 Germane Corp Rotary fluid pressure device

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3767165A (en) * 1972-07-05 1973-10-23 Trw Inc Shaft retaining means for hydrostatic steering devices
US4112973A (en) * 1976-07-08 1978-09-12 G. Duesterloh Gmbh Control arrangement for a hydrostatic axial or radial piston machine
US6200109B1 (en) * 1996-08-17 2001-03-13 Continental Teves Ag & Co., Ohg Electromotor/pump assembly
US20170107789A1 (en) * 2015-10-19 2017-04-20 Baker Hughes Incorporated High temperature, bi-directional shear seal and related methods
US10100607B2 (en) * 2015-10-19 2018-10-16 Baker Hughes, A Ge Company, Llc High temperature, bi-directional shear seal and related methods

Also Published As

Publication number Publication date
GB1287011A (en) 1972-08-31
DE1801541A1 (de) 1970-06-25
FR2019982A1 (fr) 1970-07-10
SE359619B (fr) 1973-09-03

Similar Documents

Publication Publication Date Title
US3223046A (en) Rotary radial piston machines
US3124079A (en) Jxanjacquxs j joyer
GB1236400A (en) Hydraulic rotary motors and pumps
US3721161A (en) Axial piston hydraulic apparatus
US4813340A (en) Rotary fluid energy translating device
US3654761A (en) Fluid handling device with radially variable working chambers
US3584648A (en) Hydrostatic machine
US2862455A (en) Hydrodynamic machine
US3892503A (en) Apparatus and method for multiple mode motor
US3356037A (en) Reciprocating pistons for pumps and motors
US4738185A (en) Swash plate-type pump-motor
US3433124A (en) Hydraulic motor
US3163121A (en) Piston pumps
US3468263A (en) Power transmission
US3522759A (en) Pump or motor device
US3656407A (en) Radial piston pump
US3858487A (en) Radial piston type hydraulic pump or motor
US3304883A (en) Piston shoes and guide means in radial piston machines
US3890882A (en) Fluid device having plastic housing and means for mounting a cylinder barrel
US1998984A (en) Pump or motor
US3884124A (en) Hydraulic device
US3006284A (en) Swash-plate pump
US3280757A (en) Rotary machine
US3844685A (en) Vane machine with pressure bias and balancing means for the rotary control port member
US3885457A (en) Radial piston machine