Hydrostatic axial piston machine with swash plate arrangement

Abstract

Axial piston machine of the type having a swash plate arrangement An axial piston machine in order to make the adjusting device easily and cost-effectively producible and to require less structural space provides that the joint between the adjusting piston and the swash plate is a movable rotary joint, which rotary joint comprises a joint body receptacle on one of the two components adjusting piston and swash plate and a joint body on the other of the two components piston and swash plate, and which joint body is guided snugly in the joint body receptacle in the direction of the movement direction of the adjusting piston, can be twisted about a rotary axis running parallel to the axis of rotation and can be moved with a directional component perpendicular to the movement direction of the adjusting piston and perpendicular to the rotary axis.

Description

Technical Field

[0001] This invention relates to a hydrostatic axial piston machine, particularly an axial piston pump, employing a swashplate structure. The axial piston machine comprises: a housing; a drive shaft rotatably supported within the housing; a cylinder with a displacer piston, torsionally connected to the drive shaft; and a swashplate with a working surface supported within the housing, the displacer piston being supported on the working surface, and the angular position of the working surface relative to the rotational axes of the drive shaft and cylinder being changeable by deflection of the swashplate about its rotational axis to adjust the displacement. An adjustment device is provided for deflecting the swashplate, the device having an adjustment cylinder and a dual-function adjustment piston capable of longitudinal movement within the cylinder, wherein the adjustment cylinder extends longitudinally substantially along the rotational axis of the drive shaft and is located on one side of the drive shaft and cylinder, and wherein the adjustment piston comprises a piston and a piston rod fixedly connected to the piston, the piston rod being guided in a guide hole connected to the adjustment cylinder and hinged to the swashplate. Background Technology

[0002] An axial piston pump is known from DE 10 2014 211 965 A1. For this pump, two single-acting regulating pistons are used to adjust the swashplate to both larger and smaller rotation angles. A larger, first regulating piston is adjacent to a regulating chamber, to which the inflow and outflow of pressurized fluid is controlled by a regulating valve. A smaller, also referred to as a mating piston, is adjacent to a second regulating chamber, which is permanently connected to the high-pressure side of the axial piston pump, where high pressure is thus permanently present during operation. The longitudinal axes of the two regulating pistons extend parallel to the axis of the drive shaft of the axial piston pump. The regulating pistons rest with their working surfaces against slides, which are supported in a fully rotatable manner on ball bearing journals fitted into the swashplate. During swashplate adjustment, movement is generated between the working surfaces of the regulating pistons and their respective slides in a plane perpendicular to the axis of the drive shaft.

[0003] For a hydrostatic axial piston pump known from DE 103 514 73 A1, the swashplate is capable of deflecting about an axis of rotation that is spaced apart from the rotational axes of the drive shaft and cylinder. The swashplate can be deflected in one direction by a single-acting adjusting piston and in the opposite direction by a transmission force and a helical pressure spring. While the axial piston pump here possesses a relatively inexpensive adjusting mechanism, it appears to have some drawbacks, such as the limited level of adjustable force and the limited continuous rotational capability of the swashplate due to its zero position.

[0004] A hydrostatic axial piston pump employing a swashplate structure is known from DE 19 08 234 A. For this hydrostatic axial piston pump, the swashplate is deflected by a dual-function regulating piston to adjust the displacement. The regulating piston is adjacent to a first regulating chamber, to which the inflow and outflow of pressurized fluid are controlled by a regulating valve. The regulating piston is also adjacent to a smaller annular regulating chamber in cross-section, in which high pressure is persistently present. The piston of the regulating piston can only move linearly and cannot tilt. It is kinematically coupled to the swashplate via a coupling rod, which is connected to the piston via a first rotary joint and to the swashplate via a second rotary joint.

[0005] A hydrostatic axial piston machine employing a swashplate structure is known from DE 37 14 888 C2. This hydrostatic axial piston machine has a dual-functioning, annular adjusting piston surrounding a cylinder. The adjusting piston originates from a cylindrical bushing—guided at both ends along the axis of rotation of the drive shaft—and has an external ring that divides the annular space between the housing and the bushing into two adjusting chambers. The bushing of the adjusting piston is kinematically coupled to the swashplate via a ball-and-socket joint and a sliding joint. The sliding joint is constructed between a synchronizing journal on the swashplate and a spherical bushing, which is movable along the axial direction of the synchronizing journal. The ball-and-socket joint is constructed between the spherical bushing and a retaining ring, internally spherically shaped and housed within the adjusting piston bushing, which receives the spherical bushing. Therefore, the aim is to achieve a planar contact state between the spherical bushing and the retaining ring, and thus with the adjusting piston. Summary of the Invention

[0006] The objective of this invention is to further improve a hydrostatic axial piston machine of the type indicated at the beginning, such that the regulating device can be easily and cost-effectively manufactured and requires less structural space.

[0007] This task is solved for a hydrostatic axial piston machine of the type described at the beginning by the following method: the joint between the adjusting piston and the swashplate is a movable rotary joint, comprising a joint body receiving portion on one of the components (adjusting piston and swashplate) and a joint body on the other component (adjusting piston and swashplate). The joint body is guided in close contact with the joint body receiving portion along the direction of movement of the adjusting piston, is capable of twisting about a rotational axis extending parallel to the axis of rotation, and is capable of moving in a directional component perpendicular to both the direction of movement of the adjusting piston and the rotational axis. According to the invention, only a linear contact is provided between the joint body and the joint body receiving portion. There are no components with cylindrical or spherically curved inner surfaces, and the joint body rests against these inner surfaces in a planar manner. This allows for easy design and cost-effective establishment of an articulated connection between the adjusting piston and the swashplate. Assembly is also easy because the joint body can be easily pushed into the joint body receiving portion when the swashplate is installed, with the adjusting piston already installed.

[0008] The hydrostatic axial piston machine according to the invention can be improved in an advantageous manner.

[0009] Preferably, the joint body receiving portion is located within the adjusting piston, and the joint body is positioned on the swashplate. The adjusting piston, which has a joint body receiving portion—that is, a clearance portion—can be easily pushed into the adjusting cylinder. Afterward, no further operation on the adjusting piston is required. The swashplate can be easily mounted using the forward-protruding joint body.

[0010] Even if the adjusting cylinder and adjusting piston are arranged such that the adjusting piston can move not parallel to, but slightly oblique to, the axis of rotation of the drive shaft, it is preferable that the joint body receiving portion within the adjusting piston extends perpendicular to the direction of movement of the adjusting piston, thereby allowing the joint body to move perpendicular to the direction of movement of the adjusting piston within the joint body receiving portion. The force required to adjust the swashplate is therefore applied to the adjusting piston along its longitudinal direction.

[0011] It is conceivable that the joint body is a roller that enters into a slightly elongated joint body receiving portion. However, it is preferable that the joint body has a spherical surface. The joint body receiving portion is a receiving hole, the diameter of which is slightly larger than the diameter of the spherical surface according to a clearance fit, and the joint body enters into the receiving hole with its spherical surface.

[0012] The joint body can be a ball journal, which is specifically fixed, pressed in, or screwed into the swashplate. Alternatively, the ball can be machined directly onto the swashplate.

[0013] The joint body can also be a spherical cap bearing, that is, a bushing with a spherical outer surface, which is held on the journal of the swashplate.

[0014] The receiving hole for the spherical joint body is preferably constructed as a blind hole, thereby ensuring sufficient stability of the adjusting piston in the region of the receiving hole. To prevent overpressure or negative pressure from forming between the joint body with the spherical surface and the bottom of the receiving hole during joint body movement, the region of the receiving hole prior to the joint body is fluidly connected to the interior of the housing.

[0015] Specifically, an unloading hole extends outward from the material of the adjusting piston through the receiving hole in the region prior to the joint body. The diameter of this unloading hole is much smaller than that of the receiving hole. Therefore, a groove is not required in the surface of the joint body to unload the aforementioned area.

[0016] The receiving hole is preferably located in an axial plane extending through the longitudinal axis of the adjusting piston, the axis of which intersects the longitudinal axis of the adjusting piston. The spherical surface of the joint body is then advantageously arranged away from the axis of rotation of the swashplate at a distance such that the longitudinal axis of the adjusting piston extends at a certain distance beyond the following arc, on which the center of the spherical surface of the joint body moves as the swashplate deflects. This can also be ensured for adjusting pistons arranged obliquely to the axis of rotation of the drive shaft, if the joint body is arranged on the swashplate such that the distance between the center of the spherical surface of the joint body and the central axis of the adjusting piston first decreases and then increases as the swashplate deflects from the first extreme position to the second extreme position.

[0017] The piston rod is not guided by a guide hole at every position along its entire length, as the overhead of creating a straight guide hole increases with its length. Preferably, the guide hole is only long enough that the piston rod still protrudes beyond the guide hole when fully inserted, thus the length of the piston rod's guide in the guide hole is independent of the position of the adjusting piston. However, it is advantageous that the length of the piston rod's guide in the guide hole is greater on the side farther from the cylinder than on the side closer to the cylinder. Therefore, the guide hole terminates at a different distance from the adjusting cylinder at its end farther from the cylinder. This effectively traps the tilting torque acting on the adjusting piston. The following consideration forms the basis for this: the pressure in the fluid chamber at the piston section of the adjusting piston decreases to the housing pressure within the gap between the guide hole and the piston rod. The longer the gap, the greater the force generated by the pressure in the gap. Therefore, by varying the guide length and thus by varying the gap length, a lateral force acting on the adjusting piston can be generated.

[0018] The piston of the adjusting piston can have an annular groove on the outside, and the piston ring abutting against the wall of the adjusting cylinder is located in the annular groove. Therefore, the guidance of the adjusting piston is achieved solely by the piston rod on a single diameter, thus preventing any stiffness in movement.

[0019] If the axial piston press according to the invention is operated as an axial piston pump, it is preferable to have at least one return spring configured as a helical pressure spring, which is arranged in the receiving portion of the housing before the piston rod and is tightened between the housing and the piston rod of the adjusting piston, with the axis of the return spring coinciding with the axis of the adjusting piston. Therefore, the return spring is subjected to a purely linear load. Its two ends are supported on mutually parallel surfaces. The return spring is used to position the swashplate in a preferred position, preferably a fully outwardly rotated position, when the axial piston press is stopped. At the start of operation, the axial piston press immediately begins delivery, thereby generating pressure. Attached Figure Description

[0020] Two embodiments of the axial piston machine employing a swashplate structure according to the present invention are shown in the accompanying drawings. The invention will now be explained in detail with the aid of the illustrations in these drawings.

[0021] in:

[0022] Figure 1 A longitudinal section of the first embodiment is shown, wherein the joint body is a spherical bushing held on a swashplate; and

[0023] Figure 2 A longitudinal section is shown of a second embodiment equipped only with components important for the explanation of the invention, wherein the joint body is a ball journal pressed into a swashplate. Detailed Implementation

[0024] Here, firstly, according to... Figure 1 The embodiments will be described below. The following discussion will primarily focus on the differences between the second and first embodiments.

[0025] according to Figure 1 The hydrostatic axial piston machine is configured to operate as either a pump or a motor. The axial piston machine has a two-component housing 10, which includes a housing tank 11 and a connecting plate 12 that closes the open side of the housing tank. A pressure fitting and a reservoir fitting are constructed on the connecting plate in a manner not shown in detail. Channels, not shown in detail, extend from both the pressure fitting and the reservoir fitting, converging in a kidney-shaped opening on the inner surface of the connecting plate 12.

[0026] The axial piston mechanism has a drive shaft 15, which is supported in a rotatable manner about a rotation axis 18 by a first tapered roller bearing 16 housed in the bottom 17 of the housing 11 and a second tapered roller bearing (not shown) received by the connecting plate 12. A cylinder 19 is connected to the drive shaft 15 in a torsion-resistant but axially movable manner and has an odd number, for example nine, piston bores 20 arranged at equal angular intervals on a pitch circle and oriented parallel to the rotation axis 18. These piston bores open their entire cross-section toward the end of the cylinder 19 away from the connecting plate 12, and converge at the end of the cylinder toward the connecting plate 12 in an arc-shaped confluence slot 21 on the same pitch circle.

[0027] A distribution plate 25 is arranged between the cylinder 19 and the connecting plate 12. This distribution plate remains in a non-rotatable state relative to the connecting plate 12 and has two [parts] arranged according to [the specified parameters]. Figure 1 The cross-section does not show the arc-shaped control kidney-shaped components, which are located on the same pitch circle as the manifold 21. One of the control kidney-shaped components coincides with the kidney-shaped opening in the connecting plate 12 and is thus fluidly connected to the pressure connector, while the other kidney-shaped component coincides with the opening of another kidney-shaped component in the connecting plate and is thus fluidly connected to the reservoir connector of the axial piston mechanism. Thus, as the cylinder 19 rotates with the drive shaft 15, the piston bore 20 alternately connects to the pressure connector and the reservoir connector through its manifold 21.

[0028] Each piston bore 20 receives a displacement piston 26, which has a fully movable slide 27 on its piston head located outside the piston bore 20. Each displacement piston 26 rests against the working surface 34 of a swashplate 35 via its slide, the swashplate being supported in two bearings housed within the housing 11 in a manner that allows it to deflect about an axis of rotation 36. The axis of rotation 36 intersects the axis of rotation 18 of the drive shaft 15 at a right angle and is perpendicular to the axis of rotation 18 of the drive shaft 15. Figure 1 The drawing plane is extended. The cylinder on which the bearing bush and swashplate 35 are supported is in Figure 1 The swashplate 35 is outlined by a dotted circle 37. At its center, the swashplate 35 has a large opening 38 for the drive shaft 15 to pass through.

[0029] To ensure that the expulsion piston 26, after the expulsion stroke—during which the expulsion piston is pushed into the piston bore 20—can reliably remain on the working surface 34 of the swashplate 35 and move out of the piston bore during the suction stroke, a return plate 40 is mounted on the shoulder of the slide block 27. The return plate, with its central rolled edge 41, abuts against a return ball 42 constructed according to a spherical layer pattern. This return ball is coupled to the drive shaft 15 in a torsion-resistant but axially movable manner. A [missing information - likely a device or structure] is placed in the annular gap 43 between the drive shaft 15 and the cylinder 19. Figure 1 The helical pressure spring, omitted in the text, is supported on the cylinder 19 by a safety ring and on the return ball by a support washer and a pressure rod extending along the teeth between the drive shaft 15 and the cylinder 19. Thus, the helical pressure spring presses the cylinder 19 against the distribution plate 25 and the distribution plate against the connecting plate 12, while the return ball 42 and the return plate 40 press the slide 27 against the swashplate 35, thereby pulling the expulsion piston 26 out of the piston bore 20 during the suction stroke.

[0030] To change the angular position of the swashplate 35, the axial piston mechanism has an adjustment device 45, which includes a dual-function adjusting piston 46. This adjusting piston is configured as a differential piston with two unequal working surfaces, the larger of which is called the adjusting surface 47 and the smaller of which is called the mating surface 48. The adjusting piston 46 has a piston section 49 and a piston rod 50, wherein the working surface is formed on the piston section 49 and the piston rod 50 extends from the piston section 49 on one side. The piston section 49 and piston rod 50 of the adjusting piston 46 are capable of linear longitudinal movement within a graded housing bore 51 that extends slightly obliquely to the rotation axis 18 of the drive shaft 15. The piston section 49 is located in a bore section 52 of the housing bore 51, which has a larger diameter and forms an adjusting cylinder, while the piston rod 50 is guided longitudinally in a bore section 53 with a smaller diameter. The central axis 54 of the housing bore 51 and the adjusting piston 46 is... Figure 1 The center line is drawn as a dashed line. The movement of the adjusting piston 46 occurs along this central axis 54.

[0031] The orifice section 53 is of such length that, even when fully inserted, the piston rod 50 extends a certain distance beyond the orifice section 53 and into the section 55 of the housing orifice 51, in which the diameter is slightly larger than that in the orifice section 53. Therefore, the piston rod 50 is always guided along the same length regardless of the position of the adjusting piston.

[0032] The piston section 49 of the adjusting piston 46 divides the bore section 52 of the housing bore 51 into an adjusting chamber 56 and a mating chamber 57, wherein the cross-section of the adjusting chamber corresponds to the adjusting surface 47 and the bore section 52 of the adjusting piston 46, and wherein the mating chamber has an annular cross-section, the outer diameter of which is equal to the diameter of the bore section 52 and the inner diameter of which is equal to the outer diameter of the piston rod 50, and the annular cross-section corresponds to the mating surface 48 of the adjusting piston 46. The adjusting surface 47 is approximately three times larger than the mating surface 48. The mating chamber 57 is permanently fluidly connected to the pressure joint of the axial piston mechanism. Therefore, high pressure exists in the mating chamber 57. This high pressure generates a force on the annular mating surface 48 of the adjusting piston 46, which acts in the direction of the piston rod 50's movement. To seal the adjusting chamber 56 and the mating chamber 57 relative to each other, piston rings 58 are inserted into an annular groove surrounding the piston section 49.

[0033] The guide length, and thus the gap length between the bore section 53 and the piston rod 50, is also greater on the outer surface of the bore section 53 than on the inner surface facing the interior of the housing 10. Correspondingly, the gap length is greater on the outer surface than on the inner surface, and within the range of this gap length, the pressure present in the mating chamber 57 decreases until it reaches the housing pressure. Figure 1 The inclined direction of the end 59 of the orifice section 53 away from the mating chamber is outlined by a dashed line. The decrease in pressure present in the mating chamber 57 at different gap lengths within the circumference of the orifice section 53 causes a lateral force acting on the adjusting piston. This lateral force acts in opposition to the tilting torque generated by the force acting on the adjusting piston through the spherical bushing, so that the adjusting piston moves without tilting.

[0034] The housing hole 51 is closed outward by a spiral plug 60.

[0035] The regulating chamber 56 can be controlled by one or more regulating valves that connect the regulating chamber to a pressure fluid source or a reservoir, or isolate the regulating chamber from both a pressure fluid source (which can also be formed via a pressure connector on the machine) and a reservoir. If the regulating chamber 56 is connected to a pressure fluid source, pressure fluid flows into the regulating chamber and the piston rod 50 moves out. If the regulating chamber 56 is connected to a reservoir, pressure fluid can be expelled from the regulating chamber, and the piston rod 50 moves in. If the regulating chamber 56 is isolated, the piston rod remains stationary.

[0036] Near the free end, a blind hole 65 extending perpendicularly to the central axis 54 is cut into the piston rod 50 of the adjusting piston 46, and a smaller drill hole 66 extends outward from the blind hole into the section 55 of the housing hole 51.

[0037] A journal 67 is integrally constructed on the swashplate 35, and a spherical sleeve 68 is inserted into the journal 67 up to a shoulder and held on the shoulder by a safety ring. The diameter of the spherical surface of the spherical sleeve 68 is equal to the diameter of the blind bore 65. The journal 67 and the spherical sleeve 68 pass through a slightly elongated opening 69 in section 55, along the central axis 54 of the adjusting piston 46 and the housing bore 51, into the blind bore 65 of the adjusting piston 46. If the clearance necessary for the movement of the spherical sleeve in the blind bore is ignored, the contact line between the spherical sleeve 68 and the wall of the blind bore (i.e., the adjusting piston 46) is a circle.

[0038] If the adjusting piston 46 moves now, the spherical sleeve 68 is driven in two directions, thereby deflecting the swashplate 35. Here, the depth of the spherical sleeve 68 into the blind hole 65 and the position of the contact line between the spherical sleeve and the adjusting piston along the blind hole also change. Simultaneously, the spherical sleeve 68 rotates relative to the adjusting piston 46 about a rotation axis that extends parallel to the axis of rotation 36 and moves with the depth of insertion. The joint between the adjusting piston 46 and the swashplate 35 is thus a movable rotary joint, particularly a movable ball-and-socket joint, having a spherical sleeve 68 held on the swashplate 35 as the joint body and a blind hole 65 on the adjusting piston 46 as a receiving portion of the joint body.

[0039] exist Figure 1 A circle 70 is drawn with dashed lines. The center of this circle lies on the axis of rotation 36 of the swashplate 35, and the circle lies in a plane perpendicular to the axis of rotation 35. When adjusting the swashplate 35, the center of the spherical surface of the spherical bushing 68 moves along a portion of this circle 70. Figure 1 The swashplate 35 is shown in a position where it is deflected to its maximum extent in one direction relative to the zero position, in which the working surface 34 is perpendicular to the axis of rotation 18 of the drive shaft 15. The journal 67 and the spherical bushing are located at one end of the housing 10 with a slightly elongated opening 69. There is a first maximum distance between the center of the spherical surface of the spherical bushing 68 and the central axis 54. If the swashplate is now moved from its position by adjusting the piston 46... Figure 1 Starting from the position shown in the middle, according to Figure 1 In the view, if the swashplate is deflected counterclockwise, the distance between the center and the central axis first decreases and then increases, reaching its maximum after the swashplate has deflected from zero to its maximum deflection in the other direction. Therefore, the center of the spherical surface of the spherical bushing 68 does not fall on the central axis 54 of the adjusting piston at any angular position of the swashplate 35. If this were the case, the adjusting piston 46 could rotate about its central axis 54, provided the journal 67 allows it. The distance between the center and the central axis is always greater than zero, thereby preventing torsion of the adjusting piston.

[0040] In the position of the swashplate 35 between the zero position and the maximum deflection position, the axial piston mechanism operates as a pump. In the position of the swashplate 35 between the zero position and another maximum deflection position, the axial piston mechanism operates as a motor in the same direction of rotation and without switching between the working joint and the reservoir joint.

[0041] Furthermore, the adjusting device 45 includes two adjusting springs 75 and 76 arranged concentrically, configured as helical compression springs and tightened between the adjusting piston and the bottom of the housing bore 51. Therefore, the adjusting springs are loaded along their longitudinal axis and act in the direction of the movement of the adjusting piston 46. Thus, when there is no pressure in the adjusting chamber and in the mating chamber, the swashplate 35 occupies a position... Figure 1 The position shown is the maximum outward rotation in one direction. This ensures that the machine begins delivery immediately upon startup of the pump, without requiring an external pressure source to supply pressurized fluid to the regulating device.

[0042] exist Figure 2 In the illustrated embodiment, only the housing 10, swashplate 35, adjusting piston 46, and two adjusting springs 75 and 76 are shown.

[0043] Unlike in the first embodiment, in the second embodiment, the ball journal 80 is pressed into the bore 79 of the swashplate 35, the ball journal 80 with its ball head 81 enters the blind hole 65 of the adjusting piston 46, and the adjusting piston 46 can deflect the swashplate 35 through the ball journal.

[0044] Unlike in the first embodiment, the orifice section 53—in which the piston rod 50 of the adjusting piston 46 is guided—extends all the way to the bottom of the housing orifice 51, such that the piston rod is always guided within its length outside the orifice section 52 regardless of the position of the adjusting piston 46 and is located between the housing orifice 51 and the interior of the housing 10 except for the area of ​​the opening 69, and the gap length between the piston rod 50 and the orifice section 53 depends on the position of the adjusting piston 46.

[0045] In the second embodiment, the unloading hole 66 for the blind hole 65 extends into the blind hole 65 along the axial direction of the adjusting piston 46, because pressure compensation cannot be performed radially outside the piston rod 50 due to the narrow gap, at least not rapidly.

[0046] List of reference numerals in the attached diagram:

[0047] 10. Dual-component shell

[0048] 11 10 shell tank

[0049] 12 10 connecting plate

[0050] 15 drive shafts

[0051] 16 Tapered Roller Bearings

[0052] 17 11 bottom

[0053] 18 15 axis of rotation

[0054] 19 Cylinder

[0055] 20 Piston bore

[0056] 21 20 junction gap

[0057] 25 Distribution Board

[0058] 26 Displacement Piston

[0059] 27 Slide

[0060] Working face on 34 35

[0061] 35 swashplate

[0062] 36 35 axis of rotation

[0063] 37 Circumference

[0064] The center hole in 38 35

[0065] 40 Return Plate

[0066] Center curl on 41 40

[0067] 42 Return Ball

[0068] 43. Annular gap

[0069] 45 Adjustment device

[0070] 46 Adjusting the piston

[0071] 47 Adjustment surface

[0072] 48 Pairing Faces

[0073] Piston section 49 46

[0074] 50 Piston Rod

[0075] 51. Casing Hole

[0076] Hole section 52 51

[0077] Section 53

[0078] The central axis of 54 46

[0079] Section 55 51

[0080] 56. Adjustment Room

[0081] 57 Pairing Room

[0082] 58 Piston Rings

[0083] 59 53 end side

[0084] 60 screw plug

[0085] 65 Blind Hole

[0086] 66 Drilling

[0087] Journals on 67 35

[0088] 68 spherical bushing

[0089] Opening 69 in 55

[0090] 70 circumference

[0091] 75 Adjusting spring

[0092] 76 Adjusting spring

[0093] Drilling in 79 35

[0094] 80 spherical journal

[0095] 81 80 ball head

Claims

1. A hydrostatic axial piston machine employing a swashplate structure, comprising: a housing (10); a drive shaft (15) rotatably supported within the housing (10); a cylinder (19) with a displacement piston (26) to which the drive shaft (15) is torsionally connected; and a swashplate (35) supported within the housing (10), the swashplate having a working surface (34) on which the displacement piston (26) is supported, and the angular position of the working surface (34) relative to the axis of rotation (18) of the drive shaft (15) and the cylinder (19) is adjustable for displacement via the swashplate (35) about the axis of rotation (36). The device is deflected to change the position; and an adjustment device (45) having an adjustment cylinder (52) and a dual-function adjustment piston (46) that can move longitudinally within the adjustment cylinder (52), wherein the adjustment cylinder (52) extends longitudinally obliquely to the axis of rotation (18) of the drive shaft (15) and is located on one side of the drive shaft (15) and the cylinder (19), and wherein the adjustment piston (46) includes a piston section (49) and a piston rod (50) fixedly connected to the piston section (49), the piston rod being guided in a guide hole (53) connected to the adjustment cylinder (52) and the piston rod being hinged to the swashplate (35). characterized in that The joint between the adjusting piston (46) and the swashplate (35) is a movable rotary joint, which includes a joint body (68, 80) on the swashplate (35) and a joint body receiving portion (65) on the adjusting piston (46). The joint body (68, 80) is guided in close contact with the joint body receiving portion (65) along the direction of movement of the adjusting piston (46), can be twisted about a rotation axis extending parallel to the rotation axis (36), and can move in a directional component perpendicular to the direction of movement of the adjusting piston (46) and perpendicular to the rotation axis. The joint body (68, 80) has a spherical surface, and the receiving portion of the joint body is a receiving hole (65) with a diameter slightly larger than the diameter of the spherical surface, and the joint body (68, 80) enters the receiving hole (65) with the spherical surface. The receiving hole (65) is located in an axial plane extending through the longitudinal axis of the adjusting piston (46), and the spherical surface of the joint body (68, 80) is arranged away from the axis of rotation (36) of the swashplate (35) at such a distance that the longitudinal axis (54) of the adjusting piston (46) extends at a certain distance beyond the following arc (70), on which the center of the spherical surface of the joint body (68, 80) moves when the swashplate (35) deflects.

2. The hydrostatic axial piston machine according to claim 1, wherein the joint body receiving portion (65) extends perpendicular to the moving direction of the adjusting piston (46), such that the joint body (68, 80) can move in the joint body receiving portion (65) perpendicular to the moving direction of the adjusting piston (46).

3. The hydrostatic axial piston machine according to claim 1, wherein the joint body is a ball journal (80) which is fixed at the swashplate (35).

4. The hydrostatic axial piston machine according to claim 1, wherein the joint body is a spherical bushing (68) held on the journal (67) of the swashplate (35).

5. The hydrostatic axial piston machine according to claim 1, wherein the receiving hole (65) is a blind hole, and a compensation hole (66) extends outward from the region of the blind hole in front of the joint body (68, 80), the diameter of the compensation hole being smaller than the diameter of the receiving hole (65).

6. The hydrostatic axial piston machine according to claim 1, wherein as the swashplate (35) deflects from the first extreme position to the second extreme position, the distance between the center of the spherical surface of the joint body (68, 80) and the central axis (54) of the adjusting piston (46) first decreases and then increases.

7. The hydrostatic axial piston machine according to claim 1, wherein the guide length of the piston rod (50) in the guide hole (53) is greater on the side away from the cylinder (19) than on the side closer to the cylinder (19).

8. The hydrostatic axial piston machine according to claim 1, wherein the piston section (47) of the adjusting piston (46) has an annular groove on the outside, and the piston ring (58) abutting against the wall of the adjusting cylinder (52) is located in the annular groove.

9. The hydrostatic axial piston machine according to claim 1, wherein at least one adjusting spring (75, 76) configured as a helical pressure spring and tightened between the housing (10) and the piston rod (50) of the adjusting piston (46) is arranged in the receiving portion (51) of the housing (10) before the piston rod (50), the axis of the adjusting spring coinciding with the central axis (54) of the adjusting piston (46) and the adjusting spring subjected to a linear load.

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