US3722372A - Hydraulic axial piston machine of the bent-axis type - Google Patents

Hydraulic axial piston machine of the bent-axis type Download PDF

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Publication number
US3722372A
US3722372A US00128257A US3722372DA US3722372A US 3722372 A US3722372 A US 3722372A US 00128257 A US00128257 A US 00128257A US 3722372D A US3722372D A US 3722372DA US 3722372 A US3722372 A US 3722372A
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Prior art keywords
piston
cylinder
axis
pistons
units
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Expired - Lifetime
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US00128257A
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English (en)
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L Freese
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General Electric Co
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General Electric Co
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    • 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
    • F01B3/10—Control of working-fluid admission or discharge peculiar thereto
    • F01B3/103—Control of working-fluid admission or discharge peculiar thereto for machines with rotary cylinder block
    • F01B3/109—Control of working-fluid admission or discharge peculiar thereto for machines with rotary cylinder block by changing the inclination of the axis of the cylinder barrel relative to the swash plate
    • 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
    • F01B3/0032—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
    • 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
    • F01B3/0032—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
    • F01B3/0044—Component parts, details, e.g. valves, sealings, lubrication
    • F01B3/0052—Cylinder barrel
    • 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
    • F01B3/0082—Details
    • F01B3/0085—Pistons

Definitions

  • the support bodies or drive plates may also be made 2,146,133 2/1939 Tweedale ..91/505 adjustably slidable in a lateral direction so as to vary 2,967,491 1/1961 Wiggermann.... ..91/505 the bent-axis angle and thus the displacement of the 3,108,543 10/1963 Gregor ..9l/490 machine, 3,123,014 3/1964 Gregor Vietnamese ..91/490 1 3,220,353 11/1965 Gregor ..91 490 8 Claims, 4 Drawing Figures guy, "2 12 10 Y; 3 11; 21. 20 Q F 22 ⁇ i:
  • the present invention relates to hydraulic axial piston machines, and more specifically to the type designated bent-axis machines.
  • the invention also relates to machines of this type which work with gaseous media, such as pneumatic machines.
  • a common feature of the hydraulic axial piston machines is that they are provided with a number of pistons slidably accomodated in corresponding cylinders formed in a rotatably joumalled drum-like body and disposed in uniform spaced relationship arouiid and substantially parallel with the axis of rotation of the drum.
  • the pistons are either connected by means of piston rods with a drive plate on the drive shaft of the machine, or the free ends of the pistons are caused to abut, via a ball joint, against piston shoes which are capable of sliding against a non-rotatable camplate accomodated in the machine housing.
  • the former type is designated a bent-axis machine and the relative movement between pistons and cylinders in this type of machine is provided for by the fact that during rotation the center lines of the cylinder drum and the drive shaft form a specific angle with each other, while with the second type of machine, which is called an in-line machine, the aforementioned relative movement is provided for by the fact that the cam plate is positioned obliquely in relation to the cylinder drum, which is in this case coaxial with its drive shaft. Both of these machine types have characteristic advantagesand disadvantages.
  • FIG. 1 is a view of a central longitudinal section through a positive displacement hydraulic bent-axis piston machine according to the invention
  • FIG. 2 is a diagrammatic cross section of the ring of piston-cylinder assemblies incorporatediin the machine of FIG. 1 and is intended to illustrate an entraining driving function
  • FIG. 3 is a part sectional view'corresponding substantially to FIG. 1 but showing, somewhat diagrammatically, a variable displacement machine according to the invention
  • FIG. 4 is a sectional view taken along the line lV'--lV in FIG; 3.
  • each assembly includes a sleeve-shaped piston 12 which is slidably accomodated in a similarly sleeve-shaped cylinder 10, the two elements being mutually sealed by means of a sealing ring 13, Both piston and cylinder engage at their opposing outer ends spherical seating surfaces 24 and 22, v
  • the drive plate 44 may either by rotatably mounted in a cover portion 42b of the machine housing 42, by'means of a roller bearing 48 for example, or the radial forces acting on the drive plate may be taken up by a bearing 50 of the drive shaft 46.
  • the necessary relative movement between pistons and'cylinders upon rotation of the shaft is provided for by the fact that the axis of rotation 52 of the guide plate 40 forms a certain anglea with the axis of rotation 54 of the drive shaft.
  • the two axes of rotation intersect each other at or in the proximity of the centers of the spherical seating surfaces 22.
  • Working fluid is passed to and from the pistoncylinder assemblies through valve ports 56 and 56 arranged in the cover 42b of the machine housing.
  • the Ports 56 and 56 are so shaped (kidney shaped) that during rotation of the driving shaft the interior of the piston-cylinder assemblies is alternately placed in communication with, the supply and. return lines of the hydraulic system via connecting .passages 58 and 58,
  • An important feature of the bent-axis machine of the present'invention resides in a combined arrangement for driving the opposing guide plate 40 and for reducing the dead space or volume in the piston-cylinder assembly, i.e. the fluid accommodating volume of the assembly in excess of the stroke volume.
  • This'combined arrangement for driving the guide plate 40 and reducing dead space co-acts with the seating bodies 20 of the guide plate 40, since the seating bodies are provided with axial, cylindrical or conical extensions or pins 23 which occupy to the greatest possible extent the space in the interior of the piston-cylinder assemblies.
  • the pins 23 should be of such configuration that they do not prevent the pendulating movement relative to the seating surfaces 24 which the piston-cylinder assemblies must execute during rotation of the machine and which is caused by the kinematic conditions of the machine.
  • the pins 23 are so constructed that subsequent to permitting the necessary angular movement of the pistons 12 relative the seating surfaces 24 they make contact with the interior of the pistons and function as drive dogs.
  • FIG. 2 shows a cross section through the complete ring of piston-cylinder assemblies and the pins 23 extending thereinto.
  • the plate openings or recesses 74 which correspond in number, shape and position to the assembles so that the latter can pass through their respective openings in the plate.
  • the plate engages, at a non-fixed point on the edge of each opening, with a shoulder or flange 76 located on the outside of cylinder 10 passing through respective openings, so that an axial force directed towards the seating surfaces of the cylinders can be transmitted from the plate 72 to the cylinders to assist in holding the same against their respective seating surfaces.
  • the shape of the openings 74 is such that the openings permit certain mutual movement between the piston-cylinder assemblies and an oblique positioning of the assemblies relative the circular plate 72.
  • a second plate 78 engages shoulders or flanges located on the pistons 12 and subjects the pistons to an axial force, thereby holding the same against their respective seating surfaces 24. Owing to the fact that mutual relative movement of the pistons is slight, the plate 78 need not fully encircle the piston-cylinder assemblies, but need only be arranged to engage constantly respectively piston at practically one and the same point 82 located nearest the common axis of rotation 52 of the assemblies.
  • a coil spring 84 is conveniently arranged between the plates concentrical with the axis of rotation 52.
  • the spring is arranged so that one end thereof bears against the plate 78 (FIG. 1) while its other end bears against a spring seating 86 which is in the form of a sleeve slidably arranged on an extension of the journal pin 32.
  • the sleeve is provided with a curved surface 88 which when rolling along the plate 72 subjects the plate to a resilient force which is distributed on the cylinders 10 of the piston-cylinder assemblies, as clearly shown in FIG. 1.
  • the force system developed by the ringof piston-cylinder assemblies 12, 10 is primarily taken up, in one hand, by the drive plate 44, to the right, and, on the other, by the guide plate 40, to the left.
  • the drive plate 44 is balanced hydraulically by suitable dimensioning of the ports 56, 56' and the sealing gaps 55, 57 between the drive plate and the cover 42b of the housing in a manner whereby the axial forces exerted on this side by the working fluid on the drive plate 44 counteract and as near as possible coincide, with respect to their total magnitude with the axial forces from the piston-cylinder assemblies on the other side of the plate 44.
  • Hydraulic balancing can be accomplished in an analogous manner on the opposite side of the axial force system, at guide plate 40.
  • Pressure fluid can be passed through passages 21 in the seating bodies 20, with their extensions on pins 23, to cavities 70, located in the side of the guide plate 40 abutting the cover member 42a, the cavities being so dimensioned that axial hydraulic balance is obtained in relation to the forces exerted by the ring of piston-cylinder assemblies.
  • bent-axis machine of the present invention it is possible with the bent-axis machine of the present invention to provide in a simple manner hydraulic balance of the axial bearing forces on both sides of the load generating piston-cylinder system.
  • the axial reaction forces acting from the pistons on the drive plate can only be balanced hydraulically with great difficulty and must be provided with axial force absorbing roller bearings or the like, which results in increased weight and restricted useful life of the machine.
  • the contact surface between each cylinder and piston and its respective seat is preferably provided close to a great circle on. the seat, with the contact surface having a diameter of approximately the same magnitude as or slightly smaller than the maximum cross-sectional pressure area of the cylinder-piston unit.
  • FIGS. 3 and 4 illustrate an embodiment of a variable displacement hydraulic angle piston machine constructed in accordance with the invention, the pistoncylinder assemblies and surrounding components substantially coinciding with the corresponding components in the aforedescribed positive displacement machine.
  • the pistons 112 and cylinders 110 of the assembly engage spherical seating surfaces 124 and 122 resp. arranged on seating bodies associated with a guide plate 140 and a guide plate 144 resp.
  • the guide plate is fix-' edly attached to a central pin 132 which serves to suppin 132 is not journalled directly to the surrounding housing, but is journalled in a slide-like, movable body 160, hereinafter called the slide.
  • the side of the slide facing inwardly of the housing presents a planar surface which co-acts with the guide surface 140, while on its opposite side the slidehas a part cylindrical slide surface which co-acts with a complimentary shaped, concave cylindrical slide surface 162 located on the inside of the left end-wall portion 142 of the machine housing according to FIG. 3.
  • the planar form of the slide is rectangular or square and its mutually parallel planar side surfaces 164, 166 extending perpendicular to the axis of the cylindrical slide surface co-act when sliding, with opposing surfaces in the end portion 142 of the housing.
  • the slide can be likened to a very wide so-called Woodruff wedge accomodated in its cooperating groove.
  • the center of the slide surface 162 coincides with the intersecting point 153 between the axis of rotation 152 and 154 of the guide plate 140 and the drive plate 144, respectively. Consequently, if the slide is moved along the slide surface 162 in a-direction parallel with the plane of the drawing the anglea between the axis of rotation will be changed while retaining the positionof the intersection point 153,
  • Movement of the slide can be caused in a number of different ways, both purely manually and by means of hydraulic servo devices for example.
  • An example of hydraulic operation is illustrated in FIG. 4.
  • a pin 168 projects from one, 164, of the parallel planar sides of the slide 160 out through an opening 170 in the opposing wall of the housing.
  • the pin 160 engages in a groove in a servo-piston 172, which is slidably accomodated in a cylindrical bore 174 in the'housing parallel to the slide surface 162.
  • the piston By passing pressure fluid to and from the respective chambers 174'and 174 on opposite sides of the piston, the piston can be moved longitudinally, thereby moving the slide 160 to the desired position.
  • the servo-piston 170 may naturally be arranged in a different manner relative to the slide 160, and similarly several pistons may be used for operating the slide, for example in a manner whereby one servo device identical with that described above is also arranged on the opposite side of the slide parallel with its surface'166, so that the slide is actuated by symmetrically engaging operating forces.
  • Telescopic piston-cylinder assemblies of the type preferably used in the bent-axis piston machine of the present invention have a number of principle advantages compared with conventional piston arrangements, as described in more detail in the aforementioned patent.
  • force transmitting elements as piston rods or piston shoes are eliminated as is also the frictional losses which occur when transmitting the piston forces.
  • An important characteristic of the piston-cylinder assembly of the present invention is that no obliquely acting forces or tilting forces act between the pistons and cylinders, and that the common slide surface of the pistons and cylinders may be made short in relation to piston diameter and length of stroke, which enables shorter axial constructional lengths.
  • the mass forces caused by centrifugal forces have only a slight restricting effect on the speed of the machine, since the components of the rotary system most sensitive to these forces, namely the pistons and cylinders of the pistoncylinder assembly, are well supported at the ends of their seating bodies and-are capable of absorbing relatively large radial forces, and because of their sleeveshaped configuration are particularly light.
  • the interior of the sleeve-shaped pistons and cylinders is substantially filled by the pins serving as the combined drive means and dead-room filling means, which pins together with the seating bodies and the guide plate form a separate statically and dynamically balanced system.
  • the hydraulic machine of the present invention presents, if not a vhybn'de machine, nevertheless a hydraulic piston machine which constitutes an intermediate form of the two main types of known machines of the type in question, the inline machines and the bent-axis machine. It combines the compactness and structural favorability of the inline machine, particularly for providing variable displacement, and eliminates axial bearing forces, with the advantages of bent-axis-rnachine with respect to the function of the system with but small deviation between the directions of the primary hydraulic piston forces and the axis directions of the pistons, and the small dead space in the cylinders.
  • each piston-cylinder unit including a tubular cylinder having a tubular piston slideably disposed therein, a shaft rotatably supported on said housing and having it axis intersecting said central axis at an angle, first and second rotatable support bodies disposed adjacent the opposite axial ends of said'plurality of cylinder-piston units, said first support body being rotatably supported on said housing for rotation by said central axis, said second support body being coaxial with and connected to said shaft for rotation therewith, a plurality of pairs of first and second reaction-force absorbing seats mounted on said first and second support bodies respectively, said seats having a partial spherical convex surface thereon, each of said cylinder-piston units being movably and detachably positioned between a pair of
  • a machine further including slide means movably mounting said first support body on said housing for movement of said first support body relative to said housing along a path substantially parallel to a plane containing therein said central axis and the axis ofsaid shaft, the slide means being provided with a convex cylindrical slide surface thereon disposed in slidable engagement with a corresponding concave cylindrical slide surface formed on the housing, the center of rotation of the slide surfaces being located substantially at the intersection point between the central axis and the axis of the shaft, whereby movement of the slide means relative to the housing varies the angle between the axis of the shaft and the central axis.
  • the holding device includes a disc arranged substantially coaxially with the ring of piston-cylinder units and engaging the cylinders thereof, a retainer member positioned opposite said disc, said retainer member being substantially coaxial with the ring of piston-cylinder units and engaging the pistons thereof, and spring means positioned centrally of the ring of cylinder-piston units and between the disc and the retainer member to urge said disc and retainer member away from one another to maintain the cylinders and pistons in engagement with their respective seats.
  • the first rotatable support body has a central pin mounted thereon, said holding device including a seat member slideably supported on the central pin, and said spring means comprising a coil spring disposed in sliding relationship to the central pin and having one end thereof positioned in engagement with the seat member, the seat member being resiliently urged by the spring into engagement with one of the disc and retainer member and having a curved surface to permit said one of said disc and retainer member to rollingly bear thereagainst, the other end of the coil spring being cooperatively engaged with the other of the disc and retainer member.
  • a machine wherein the pistons are maintained in engagement with the seats secured to the first rotatable support body and the cylinders are maintained in engagement with the seats secured to the second rotatable support body, and the means for causing synchronous rotation of the first and second support bodies including extensions mounted on the seats secured to the first support body, said extensions being in the form of pins which project into the interior of the pistons and engage the inside surfaces of the pistons by means of a line-like contact during rotation of the machine so that the torque exerted on the first rotatable support body is transmitted through the cylinder-piston units to the second rotatable support body.
  • the holding device includes a disc arranged substantially coaxially with the ring of piston-cylinder units and engaging the cylinders thereof, a retainer member positioned o'pposite said disc, said retainer member being substantially coaxial with the ring of piston-cylinder units and engaging the pistons thereof, and spring means positioned centrally of the ring of cylinder-piston units and between the disc and the retainer member to urge said disc and retainer member away from one another to maintain the cylinders and pistons in engagement with their respective seats.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
  • Hydraulic Motors (AREA)
US00128257A 1970-04-03 1971-03-26 Hydraulic axial piston machine of the bent-axis type Expired - Lifetime US3722372A (en)

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SE04598/70A SE355640B (enrdf_load_stackoverflow) 1970-04-03 1970-04-03

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US (1) US3722372A (enrdf_load_stackoverflow)
JP (1) JPS5142763B1 (enrdf_load_stackoverflow)
GB (1) GB1297470A (enrdf_load_stackoverflow)
SE (1) SE355640B (enrdf_load_stackoverflow)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3796137A (en) * 1971-02-11 1974-03-12 Renzo Galdabin Rotary hydraulic machines
US4253381A (en) * 1978-06-02 1981-03-03 Centre Technique Des Industries Mechaniques Hydraulic machine of the multicylinder drum type
US6360647B1 (en) * 1998-04-17 2002-03-26 Parker Hannifin Ab Hydraulic rotating axial piston engine
US20060120881A1 (en) * 2002-12-18 2006-06-08 Bosch Rexroth Ag Axial piston engine
US20080250920A1 (en) * 2005-11-11 2008-10-16 Brueninghaus Hydromatik Gmbh Hydrostatic Piston Machine
US7966924B1 (en) 2008-09-11 2011-06-28 Sauer-Danfoss Inc. Non-linear feedback in a dual yoke hydromodule
DE102012222743A1 (de) 2011-12-15 2013-06-20 Robert Bosch Gmbh Axialkolbenmaschine in Schrägachsenbauweise
DE102012222850A1 (de) 2011-12-15 2013-06-20 Robert Bosch Gmbh Hydrostatische Axialkolbenmaschine
US20150078923A1 (en) * 2012-03-29 2015-03-19 Robert Bosch Gmbh Hydrostatic Axial Piston Machine

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2146133A (en) * 1936-06-01 1939-02-07 Waterbury Tool Co Power transmission
US2967491A (en) * 1953-01-24 1961-01-10 Wiggermann Georg Rotary piston pumps
US3108543A (en) * 1959-06-23 1963-10-29 Licentia Gmbh Fluid motor or pump
US3123014A (en) * 1964-03-03 Gregor
US3220353A (en) * 1962-09-05 1965-11-30 Licentia Gmbh Axial piston machines

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3123014A (en) * 1964-03-03 Gregor
US2146133A (en) * 1936-06-01 1939-02-07 Waterbury Tool Co Power transmission
US2967491A (en) * 1953-01-24 1961-01-10 Wiggermann Georg Rotary piston pumps
US3108543A (en) * 1959-06-23 1963-10-29 Licentia Gmbh Fluid motor or pump
US3220353A (en) * 1962-09-05 1965-11-30 Licentia Gmbh Axial piston machines

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3796137A (en) * 1971-02-11 1974-03-12 Renzo Galdabin Rotary hydraulic machines
US4253381A (en) * 1978-06-02 1981-03-03 Centre Technique Des Industries Mechaniques Hydraulic machine of the multicylinder drum type
US6360647B1 (en) * 1998-04-17 2002-03-26 Parker Hannifin Ab Hydraulic rotating axial piston engine
US20060120881A1 (en) * 2002-12-18 2006-06-08 Bosch Rexroth Ag Axial piston engine
US7470116B2 (en) * 2002-12-18 2008-12-30 Bosch Rexroth Ag Axial piston machine
US20080250920A1 (en) * 2005-11-11 2008-10-16 Brueninghaus Hydromatik Gmbh Hydrostatic Piston Machine
US7966924B1 (en) 2008-09-11 2011-06-28 Sauer-Danfoss Inc. Non-linear feedback in a dual yoke hydromodule
DE102012222743A1 (de) 2011-12-15 2013-06-20 Robert Bosch Gmbh Axialkolbenmaschine in Schrägachsenbauweise
DE102012222850A1 (de) 2011-12-15 2013-06-20 Robert Bosch Gmbh Hydrostatische Axialkolbenmaschine
WO2013087666A1 (de) 2011-12-15 2013-06-20 Robert Bosch Gmbh Hydrostatische axialkolbenmaschine
US20150078923A1 (en) * 2012-03-29 2015-03-19 Robert Bosch Gmbh Hydrostatic Axial Piston Machine
US9644617B2 (en) * 2012-03-29 2017-05-09 Robert Bosch Gmbh Hydrostatic axial piston machine

Also Published As

Publication number Publication date
GB1297470A (enrdf_load_stackoverflow) 1972-11-22
SE355640B (enrdf_load_stackoverflow) 1973-04-30
DE2116210B2 (de) 1975-10-30
DE2116210A1 (de) 1971-10-21
JPS5142763B1 (enrdf_load_stackoverflow) 1976-11-17

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