Centering of housing part of axial piston machine

Abstract

The invention relates to a hydrostatic axial piston machine, in the housing of which a drive shaft is rotatably mounted about an axis of rotation, the housing having a pot-shaped housing part with a first abutment and a cover-shaped housing part with a second abutment. The two abutment portions are tightly clamped relative to each other in a sealing manner. The first mating pin is inserted in the first mating recess of the first abutment on the one hand and in the second mating recess of the second abutment on the other hand. On the opposite side with respect to the axis of rotation, a second mating pin is provided, which is inserted in the third mating recess of the first abutment on the one hand and in the fourth mating recess of the second abutment on the other hand. The second mating recess has a radial expansion with respect to the axis of rotation, wherein the second mating recess is a slotted hole and / or a mating groove.

Description

Technical Field

[0001] The invention relates to the centering and positioning of two housing parts, preferably to the centering and positioning of two single housing parts of an axial piston machine of swash plate design. Background Art

[0002] In the case of an axial piston machine of swash plate design, the cylinder barrel rotating with the drive shaft is arranged in an at least two-part housing. The first housing part is often designed in the shape of a pot, while the second housing part is designed in the shape of a cover. The drive shaft is supported on the one hand in the first housing part and on the other hand in the second housing part. If the two working connections of the axial piston machine are formed in the cover-shaped housing part, this housing part is also called a connecting plate.

[0003] Prior art

[0004] DE 102015212731 A1 describes an axial piston machine in which a pot-shaped housing part is composed of a tubular wall section and a flange, so that a three-part housing is produced overall. The tubular wall section is fastened to a connecting plate, which is called a housing cover. On the wall section and on the housing cover, circumferential contact surfaces are respectively formed; these contact surfaces must be pressed against each other in a sealing manner.

[0005] DE 10 2018 205 884 A1 discloses the above-mentioned widely used two-part housing construction, which has a pot-shaped housing part and a cover-shaped housing part.

[0006] Since the rotating cylinder accommodated in the pot-shaped housing part is pressed against the stationary manifold plate, which is supported on the cover-shaped housing part, a high degree of dimensional stability is required when positioning the two housing parts relative to one another.

[0007] For this purpose, DE 102018205884 A1 discloses a cylindrical centering or orientation flange that surrounds a cover-shaped housing part, and the centering or orientation flange is precisely inserted into the cylindrical inner peripheral section of the pot-shaped housing part. This ensures that the two housing parts are concentric with each other. The correct rotational position of the two housing parts relative to each other is achieved by two centering pins, which are respectively inserted into two pin holes. The two pin holes of the cover-shaped housing part are arranged outside the cylindrical centering or orientation flange and are arranged opposite to each other with respect to the drive shaft of the axial piston machine, while the two pin holes of the pot-shaped housing part are arranged at corresponding positions outside the cylindrical inner peripheral section.

[0008] However, it has been found that such a centering of the two housing parts relative to one another can lead to tensile stresses. Summary of the invention

[0009] The object of the invention is to enable simple centering and positioning of two housing parts of an axial piston machine relative to one another, while avoiding tensile stresses.

[0010] This object is achieved by the feature combination of claim 1 .

[0011] The hydrostatic axial piston machine according to the present disclosure has a housing in which a drive shaft and a cylinder coupled to the drive shaft in a torsionally rigid manner are supported in a manner that allows rotation around an axis of rotation. The housing is at least two-piece and has a pot-shaped housing part with a first abutment portion and a cover-shaped housing part with a second abutment portion. The pot-shaped housing part (itself) can also be multi-piece, which then produces a housing larger than a two-piece. The two abutments are clamped to each other in a sealing manner, for example with a flat seal located between them. According to the present invention, a first mating pin (centering pin, orientation pin) is provided, which is inserted into a first mating gap of the first abutment portion on the one hand and inserted into a second mating gap of the second abutment portion on the other hand with precise matching in the radial direction and in the circumferential direction of the axis of rotation, respectively. A second matching pin (centering pin, orientation pin) is provided on the side radially opposite to the rotation axis, and the second matching pin is inserted into the third matching gap of the first abutment portion with precise matching in the radial direction and in the circumferential direction of the rotation axis, and the second matching pin is inserted into the fourth matching gap of the second abutment portion. The second matching gap has an expansion portion in the radial direction with respect to the rotation axis, so that the second matching gap is a long hole and / or a matching groove. In the circumferential direction, the second matching gap has no expansion portion, but is dimensioned with precise matching like the first matching gap and preferably also like the third and fourth matching gaps of the second matching pin.

[0012] The term “exact fit” means all-round with respect to the cylindrical locating pin and the cylindrical locating recess.

[0013] As a result, the cylindrical centering or orientation flange of the cover-shaped housing part according to the prior art and the edge of the main opening of the pot-shaped housing part that fits exactly therewith can be omitted. As a result, the main housing opening can be enlarged compared to the prior art and deviations from the circular shape of the main housing opening of the pot-shaped housing part are possible. As a result, costs are saved when manufacturing and relatively easily assembling the cradle, including the opening spring underneath the cradle.

[0014] In other words: In the prior art, the individual pin holes extend through the flange section of the cover-shaped housing part. The pin holes in the two housing parts can therefore be (supplementarily) drilled, reamed and pinned together after assembly by means of two cylindrical pins. Due to the tolerance conditions of the two pin holes in the respective housing parts, tension stresses can occur during assembly and the housing parts must be positioned (mounted) relative to each other with great effort during assembly. This process is precisely what is to be avoided with the present invention (cylindrical pin and elongated hole or matching groove in one of the housing parts), so that the two housing parts can be manufactured independently of each other, wherein nonetheless no tension stresses are generated on the two cylindrical pins.

[0015] The radial expansion of the fourth engagement recess is preferably dimensioned only so small that tolerance-induced tensioning of the two housing parts in the radial direction of the rotational axis is avoided, so that the radial expansion is not necessarily visible to the naked eye.

[0016] In one exemplary embodiment, the radial extent of the fourth seating recess is therefore only a maximum of 7% greater than the extent of the fourth seating recess in the circumferential direction.

[0017] Preferably, all four engagement recesses are designed as corresponding blind holes.

[0018] If the two working connections of the axial piston machine are also formed in the cover-shaped housing part and if the second contact of the cover-shaped housing part is circumferential and arranged in one plane, this housing part is also referred to as a connecting plate.

[0019] If the two abutments (of the two housing parts) are in their own plane and are completely circumferential, and if a flat seal is arranged between the two abutments, this flat seal can have two through-gaps through which the dowel pins extend. The through-gaps for the first dowel pin then preferably (also) have a radial expansion with respect to the axis of rotation, whereby the through-gaps are (also) elongated holes. As a result, the spacing tolerances of the two dowel pins do not cause deformations of the flat seal, wherein the flat seal is nevertheless precisely oriented. In addition, incorrect installation of the flat seal relative to the two housing parts is prevented thereby. This applies in particular if the radial expansion of the fourth dowel gap and the radial expansion of the through-gaps of the flat seal are dimensioned in such a way that they are visible to the installer.

[0020] The two housing parts can be fastened to each other in a manner known per se by means of a plurality of, for example, four, screws. The preferably pot-shaped housing part then has blind-hole-like threaded holes for the screws. This results in a closed outer surface of the cast pot-shaped housing part in this area.

[0021] A distributor plate with two kidney-shaped control openings, of which one acts as a high-pressure kidney and the other acts as a low-pressure kidney during operation of the axial piston machine, can be clamped against the cover-shaped housing part in a manner known per se. If the drive shaft is supported in the cover-shaped housing part by means of rolling bearings (e.g. tapered roller bearings), the stationary distributor plate preferably has a central recess with an inner edge, by means of which the distributor plate is centered and positioned on the stationary outer ring of the rolling bearing.

[0022] From DE 10 2018 205 884 A1 it is known to provide milled radial grooves in the contact region of a cover-shaped housing part against which the distributor plate is clamped, which connect the peripheral region of the distributor plate and thus the interior of the axial piston machine to the outer ring of the rolling bearing.

[0023] In contrast, according to the disclosure, at least one (for example two) groove-shaped cast radial recesses are provided in the contact region of the cover-shaped housing part (to which the distributor plate is clamped), and the radial recesses extend in the radial direction. Such recesses are expanded by the distributor plate into radial channel sections, which connect the outer peripheral region of the distributor plate and thus the interior of the housing to the outer ring of the rolling bearing. This eliminates the need for milling for forming the radial recesses.

[0024] In the distribution plate - viewed in the direction of rotation of the cylinder barrel, not far before the low-pressure kidney - a control opening (especially a control hole or a control slit) can be provided, which is fluidically connected to the cast radial gap. This fluid connection is achieved, for example, by a control groove constructed in one side of the distribution plate that abuts against the abutment area of ​​the cover-shaped housing part. A relief flow path is then generated from the cylinder loaded with high pressure through its orifice or opening provided in the cylinder barrel through the control opening of the distribution plate along the control groove and via a radial channel section to the interior space of the housing. This relief flow path itself is known from the prior art. This relief flow path is advantageous when the axial piston machine is operated as a pump with a small or minimum rotation angle for compensating leakage only in a circuit with a hydraulic load under load.

[0025] According to the disclosure, it is particularly preferred in this case that the radially outer end section of the groove bottom of the cast radial recess (in the region of the outer peripheral edge or outer edge of the distributor plate) is inclined or has a bevel. This bevel can also be referred to as a guide surface or guide ramp for the pressure medium. As a result, the pressure medium flowing via this relief flow path can be diverted away from the flat seal in order not to wear it out.

[0026] In one embodiment of the ramp, the ramp extends in its radially inner (end) section all the way to below the outer edge of the distributor plate. When looking at the desired control outflow direction of the pressure medium from the radial inner side to the radial outer side, the ramp thus already begins radially inside the outer edge of the distributor plate.

[0027] The chamfer can also start behind the outer edge of the distributor plate or outside the outer edge. This can be advantageous because otherwise a cross-sectional narrowing of the relief flow path can occur below the outer edge of the distributor plate.

[0028] Preferably, a cast space is formed in the cover-shaped housing part on the side of the rolling bearing opposite the distributor plate, axially adjacent to the rolling bearing (viewed along the axis of rotation). The end section of the drive shaft extends into this space. At least one (for example two) groove-shaped cast axial recesses are formed in the inner shell section of the cover-shaped housing part, against which the outer ring of the rolling bearing rests. The axial recess extends in the axial direction (for example parallel to the axis of rotation) and is expanded by the outer ring of the rolling bearing into an axial channel section, which connects the first-mentioned radial channel section to the cast space. As a result, the outer ring of the rolling bearing does not hinder the pressure balance between the interior of the housing and the cast space.

[0029] An additional stress-relieving flow path can then also be produced from the cylinder subjected to high pressure via its bore or opening provided in the cylinder barrel through the control opening along the control groove and then via the axial channel section to the casting space.

[0030] In order to fix the rotational position of the distributor plate, in particular in cooperation with an inner shell of the distributor plate held on the outer ring of the rolling bearing, an orientation pin is preferably provided which is inserted on the one hand into an orientation recess of the cover-shaped housing part and on the other hand into an orientation recess of the distributor plate.

[0031] In the case of a cast-in radial recess, the orientation recess of the cover-shaped housing part can be arranged at the radially outer end of the cast-in radial recess.

[0032] In DE 102018205884 A1, burrs may be formed when drilling the orientation gap, which must be removed with great difficulty because the orientation gap intersects the annularly surrounding groove. In contrast, according to the present disclosure, it is preferred that the transverse dimension of the gap in the region of the orientation pin (in the circumferential direction of the rotation axis) is enlarged relative to the radially inner transverse dimension so that the orientation pin is surrounded by the radial gap over its entire periphery. With this improvement, fewer burrs are generated, which can also be removed relatively easily for this purpose.

[0033] In order to avoid mechanical weakening of the cover-shaped housing part, it is preferred that the alignment recesses of the cover-shaped housing part are arranged outside the radial recesses.

[0034] In this case, the orientation recess can be arranged between the two arms of the cast radial recess, or the orientation recess can be arranged next to the cast radial recess.

[0035] The two working connections of an axial piston machine are usually formed on a cover-shaped housing part.

[0036] According to a first preferred development of the cover-shaped housing part, a flattened portion and / or a recess is formed on the outer side of the cover-shaped housing part between the two working connections, which is set back along the axis of rotation. This serves to save material.

[0037] Preferably, the flattened portion and / or the recess extends transversely to the axis of rotation up to the edge of the cover-shaped housing part and up to the working connection. In this way, the cover-shaped housing part has the necessary rigidity, wherein in particular the maximum deflection of the cover-shaped housing part under load is small, so that the flat seal seals in accordance with the specification.

[0038] According to a second preferred improvement of the cover-shaped housing part, the pre-compression space is integrated in the cover-shaped housing part between the two working joints. The pre-compression space is constructed as a substantially cylindrical blind hole, wherein the axis intersects the rotation axis at right angles, wherein the two working joints are directed perpendicularly away from the central axis. The blind hole can be potted, wherein it is drilled in any case in a cutting process. The open side of the blind hole is closed fluid-tightly with a separate locking screw (with a sealing ring). A channel (preferably a straight bore) is provided inside the cover-shaped housing part, which connects the pre-compression space to the distribution plate. A small bore is provided in the distribution plate along the circumferential direction between the two kidney-shaped control openings, so that the cylinder of the cylinder barrel is fluidically connected to the pre-compression space when it is between the kidney-shaped control openings or moves between the kidney-shaped control openings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In the attached figure:

[0040] Figure 1 An axial piston machine according to a first embodiment of the present disclosure is shown in longitudinal section;

[0041] Figure 2 Shows Figure 1 A perspective view of a pot-shaped housing member of an axial piston machine in FIG.

[0042] Figure 3 The case with rolling bearings and distributor plate is shown Figure 1 A perspective view of a cover-shaped housing part of an axial piston machine in FIG.

[0043] Figure 4 Shown without rolling bearings and distributor plate Figure 3 Another perspective view of the cover-shaped housing member in FIG.

[0044] Figure 5 Shows Figure 1 A perspective view of a flat seal of an axial piston machine in FIG.

[0045] Figure 6 Shows Figure 1 Another perspective view of a cover-shaped housing part of the axial piston machine in FIG.

[0046] Figure 7 perspective views showing different embodiments of cover-shaped housing parts;

[0047] Figure 8 Shown for Figure 1 A perspective view of another example of a cover-shaped housing part of an axial piston machine in FIG.

[0048] Fig. 9 Shown for Figure 1 A perspective view of another example of a cover-shaped housing part of an axial piston machine in FIG.

[0049] Fig.10 Shown for Figure 1 A perspective view of a section of another example of a cover-shaped housing part of an axial piston machine in FIG. 1 ; and

[0050] Fig.11 Shows Fig.10 Cross-sectional view of the cover-shaped housing part in FIG. DETAILED DESCRIPTION

[0051] Two embodiments of the present disclosure are described below based on the drawings.

[0052] Figure 1 A hydrostatic axial piston machine according to a first embodiment of the present disclosure is shown in longitudinal section. The axial piston machine can be operated as a pump or as a motor, wherein its displacement can be adjusted by means of a deflectable swash plate 1. For this purpose, an adjusting device 2 is provided, by means of which the swash plate 1 can be deflected in the direction of increasing the rotation angle and thus the displacement against the force of a return spring or an opening spring 3. A plurality of pistons 4 are distributed on the circumference of the cylinder 1 and are arranged approximately parallel to the drive shaft 6 and are coupled to the swash plate 1. The drive shaft 6 is connected to the cylinder 5 in a rotationally fixed manner, but the cylinder 5 can be axially moved relative to the drive shaft 6. The cylinder 5 is held in place by means of a compression spring 8 (at Figure 1 The cylinder opening 10 is clamped in the center (to the right) so that the corresponding circumferential cylinder opening 10 is pressed against the stationary distribution plate 12.

[0053] Figure 3 A disk-shaped distributor plate 12 with two kidney-shaped control openings is shown, wherein the control opening permanently provided for high pressure is stabilized by three webs, so that four partial openings are produced there, while the control opening provided for low pressure is continuous.

[0054] Also refer to Figure 1 It can be seen that the axial piston machine has a two-part housing, which consists of a pot-shaped housing part 14 (in Figure 1 on the left) and the cover-shaped housing member 16 (on the Figure 1 The drive shaft 6 is supported in the cover-shaped housing part 16 by means of a rolling bearing 18 designed as a tapered roller bearing and in the pot-shaped housing part 14 by means of another tapered roller bearing.

[0055] Figure 2 Shows Figure 1 1 is a perspective view of a pot-shaped housing part 14 of an axial piston machine in FIG. It can be seen that this housing part 14 has a first flat surface-shaped abutment portion 20, in which four blind-hole-shaped threaded holes for screws (not shown) are formed, with which this housing part 14 is clamped tightly against the cover-shaped housing part 16. In addition, a first fitting recess 21 and a third fitting recess 23 are arranged on the area of ​​the first abutment portion 20 that is radially opposite to the rotation axis 7, which are also configured as blind holes. Fitting pins 31, 32 are respectively inserted into the two fitting recesses.

[0056] Figure 3 Shows Figure 1 1 is a perspective view of the cover-shaped housing part 16 of the axial piston machine in FIG. It can be seen that this housing part 16 also has a circumferential flat surface-shaped second abutment portion 26, in which four through-holes for screws (not shown) are formed, with which this housing part 16 is clamped sealingly against the pot-shaped housing part 14. In addition, a second fitting gap 22 and a fourth fitting gap 24 are arranged in the area of ​​the second abutment portion 26 radially opposite the rotation axis 7, which are also constructed as blind holes. In the two fitting gaps 22, 24, a second mating gap 22 and a fourth mating gap 24 are respectively inserted (in Figure 2 One of the mating pins 31, 32 shown in FIG.

[0057] In the embodiment shown, the two fitting pins 31, 32 are cylindrical and can therefore also be referred to as cylindrical pins. The first and third and fourth fitting recesses 21, 23, 24 are also cylindrical and fit precisely. In contrast, the second fitting recess 22 has a radial expansion with respect to the rotation axis 7, while it has no expansion in the circumferential direction around the rotation axis 7. Thus, the second fitting recess 22 is a long hole and / or a fitting groove. Since the expansion is so small that the radial extension is less than 107% of the extension in the circumferential direction, the expansion is Figure 3 This is of course barely visible in the illustration in FIG. Thus, tensioning stresses of the two housing parts 14 , 16 during assembly and screw connection are avoided.

[0058] Depend on Figure 2 It appears that an advantageous enlargement of the main housing opening and a deviation from the circular shape of the main housing opening of the pot-shaped housing part 14 is achieved compared to the prior art.

[0059] Also refer to Figure 3 , showing a rolling bearing 18 for the drive shaft 6 which is installed in a cover-shaped housing part 16 (see Figure 1 ) and the distributor plate 12 resting on the cover-shaped housing part 16. The stationary distributor plate 12 is centered by the stationary outer ring of the rolling bearing 18. The correct rotational position of the distributor plate 12 is ensured by an orientation pin 34, which is inserted into an orientation recess 35 of the cover-shaped housing part 16 on the one hand and into an orientation recess 36 of the distributor plate 12 on the other hand. The orientation recess 36 of the distributor plate 12 is arranged directly adjacent to the outer edge 12c of the distributor plate 12 and extends in the radial direction up to this outer edge 12c.

[0060] A control opening 12a is provided in the distributor plate 12 along the circumferential direction of the cylinder 5, not far before the low-pressure kidney. Fig.11 Let me explain in detail.

[0061] Figure 4 Shows Figure 3 16, but without the distributor plate 12 and the rolling bearing 18. From this, the inner shell section 38 for the outer ring of the rolling bearing 18 and the contact area 39 for the distributor plate 12 can be seen.

[0062] When viewed along the axis of rotation 7, a cast space 48 is formed in the cover-shaped housing part 16 axially adjacent to the rolling bearing 18, into which the end section of the drive shaft 6 extends. The space 48 is connected to the interior of the housing via two channels that are opposite to each other with respect to the axis of rotation 7, so that pressure compensation can take place there. The outer ring of the rolling bearing 18 therefore does not hinder pressure compensation with the space 48.

[0063] For this pressure compensation, two groove-shaped cast recesses 44 extending in the radial direction are provided in the contact area 39 for the distributor plate 12. These recesses 44 are each expanded by the distributor plate 12 into radial channel sections, which connect the outer peripheral area of ​​the distributor plate 12 and thus the interior of the housing to the outer ring of the rolling bearing 18.

[0064] In the inner shell section 38 of the cover-shaped housing part 16, on which the outer ring of the rolling bearing 18 rests, two groove-shaped cast axial recesses 38 are formed, in which the outer ring of the rolling bearing 18 is provided. Figure 4 Only one axial gap can be seen in FIG. These gaps 38 extend approximately parallel to the axis of rotation 7 and are each expanded into an axial channel section by the outer ring of the rolling bearing 18. Finally, two further cast groove-shaped gaps 47 or radial channel sections are provided, in which the outer ring of the rolling bearing 18 is provided. Figure 4 Only one channel section can be seen in FIG. 4 , and this channel section finally opens into the casting space 48 .

[0065] In the embodiment shown, an orientation recess 35 for an orientation pin 34 is arranged in one of the two first-mentioned groove-shaped recesses 44. Here, the relevant groove-shaped recess 44 is widened radially outwardly in the region of the orientation pin 34 along the circumferential direction relative to the radially inner transverse dimension so that the orientation pin 34 is surrounded by the groove-shaped recess 44 over its entire circumference.

[0066] Figure 5 Shows Figure 1 The flat seal 50 of the axial piston machine in FIG. 1 is clamped between two housing parts 14, 16, more precisely between their two abutment parts 20, 26. The flat seal 50 has two through-slots 41, 42, through which two dowel pins 31, 32 extend.

[0067] The second through-opening 42 of the flat seal 50, through which the second dowel pin 32 extends, has the shape of an oblong hole and corresponds to the shape of the oblong hole of the second dowel pin 22. This ensures that the first dowel pin 31, even if it is in its extreme position due to tolerances or manufacturing inaccuracies, does not affect the correct position of the flat seal 50 and thus its function.

[0068] The opening 52 of the flat seal 50 seals the fluid passage from the high-pressure connection A to the adjusting device 2 on the pot-shaped housing part 14 .

[0069] The flat seal 50 thus has two functions: sealing the housing and sealing the channel (control oil bore) for reporting high pressure.

[0070] Figure 6 Shows Figure 1 , 3 4 and 5 , a perspective exterior view of the cover-shaped housing part 16 . The two working connections A, B of the axial piston machine are formed on opposite sides of the cover-shaped housing part 16 .

[0071] In this case, an outer flattened portion 54 of the cover-shaped housing part 16 is formed between the two working connections A, B, which outer flattened portion is recessed along the axis of rotation 7 . This serves to save material.

[0072] The flattened portion 54 extends transversely to the rotation axis 7 up to the edge of the cover-shaped housing part 16 and up to the working connections A, B. In this way, the cover-shaped housing part 16 has the necessary rigidity, wherein in particular the maximum deflection of the housing part 16 under load is small, so that the flat seal 50 (see Figure 5 ) shall be sealed in accordance with the specifications.

[0073] Figure 7 The perspective exterior views of various embodiments of a cover-shaped housing part 116 are shown, wherein a pre-compression space 118 is arranged between two working connections A, B. The pre-compression space 118 is designed as a substantially cylindrical blind hole, wherein the axis intersects the axis of rotation 7 at right angles, wherein the two working connections A, B are directed perpendicularly away from the central axis. The blind hole is precast and drilled in a cutting process. The open side of the blind hole is closed in a fluid-tight manner with a locking screw (not shown) with a sealing ring.

[0074] A channel in the form of a straight bore (not visible) is provided inside the cover-shaped housing part 116, which connects the pre-compression space 118 to the distributor plate 12. In the distributor plate 12, small bores are provided in the circumferential direction between the two kidney-shaped control openings, so that the cylinder of the cylinder barrel 5 can be moved through its cylinder opening 10 (see Figure 1 ) is fluidly connected to the pre-compression space 118.

[0075] Figure 8 A cover-shaped housing part 216 is shown, which can be placed in place of the cover-shaped housing part 16. Figure 1 On the pot-shaped housing member 14 of the axial piston machine in FIG. Figure 8 2 and 3. The two radial gaps 244 are not widened in the circumferential direction at their outer end sections, but are divided into two parts. For the two radial gaps 244, a shape with a constant cross section, for example a Y-shape, is created. More precisely, in the illustrated embodiment of the two gaps 244, a radially inner straight section and a radially outer arc-shaped section are respectively provided.

[0076] Used for (in Figure 1 The orientation gap 35 of the orientation pin 34 is arranged in one of the (shown in Figure 8 Between the two end sections of the radially outer arc-shaped section of the radial gap 244 (on the left in the figure).

[0077] Fig. 9 A cover-shaped housing part 316 is shown, which can be placed on the housing instead of the cover-shaped housing part 16. Figure 1 14 of an axial piston machine in the pot shape. Different shapes of two radial gaps 344 cast opposite to each other with respect to the rotation axis 7 are shown. The two radial gaps 344 are bent. Each radial gap 344 has a radially oriented inner section and an oblique outer end section. Both oblique outer end sections face the high-pressure kidney.

[0078] Used for (in Figure 1 The orientation gap 35 of the orientation pin 34 shown in Fig. 9 The end sections of the radial recess 344 (on the right in the middle) are arranged adjacent to each other.

[0079] for Figure 8 and 9For the two cover-like housing parts 216, 316, the radial recesses 244, 344 (shown on the right) are extended in a stepped manner up to the cast space 48, so that the cast space is also pressure-balanced with the (other) interior of the housing. For this purpose, cast axial recesses 246, 346 are provided, which together with the outer ring of the rolling bearing 18 form an axial channel.

[0080] use Figure 8 and 9 The two cover-like housing parts 216 , 316 produce a mechanical reinforcement of the cover-like housing parts 216 , 316 .

[0081] Fig.10 A cutaway perspective detail of another exemplary embodiment of a cover-shaped housing part 416 is shown with Figure 1 Further components of the axial piston machine.

[0082] In the distribution plate 12, a short distance before the low-pressure kidney is provided along the circumferential direction of the cylinder 5. Figure 3 The control hole 12a shown in FIG. 1 is fluidically connected to the cast radial recess 444. This fluid connection is achieved by a relatively short control groove 12b extending in the circumferential direction, which is formed in the side of the distributor plate 12 that abuts against the abutment area 39 of the cover-shaped housing part 416. In this control groove 12b, Fig.10 Only one end section with a small cross section is shown in section. This results in a relief flow path from the cylinders subjected to high pressure via their openings 10 provided in the cylinder barrel 5 through the control bore 12a along the control groove 12b and via the radial cast grooves or recesses 444 to the interior of the housing. This relief flow path is advantageous when the axial piston machine is operated as a pump with a minimum swivel angle only for compensating leakage in a circuit with a hydraulic load under load.

[0083] According to the present disclosure, radial casting grooves or gaps 444 are largely related to Fig. 9 The radial casting gap 344 in is similar. Fig. 9 Unlike the recess 344 in the groove, a chamfer 445 is formed in the radially outer end section of the groove bottom of the recess 444 in the region of the outer peripheral region of the distributor plate 12. Fig.10 Only the (radially outer) part of the bevel can be seen in FIG. This bevel 445 can also be referred to as a guide surface or guide ramp for the pressure medium and is cast together with the cover-shaped housing part 416. The pressure medium, which is also referred to as control oil in the case of oil and flows through this relief flow path, is deflected from the flat seal 450 according to the arrow and flows to the inner wall of the pot-shaped housing part via the bevel 445 and flows.

[0084] Fig.11 Shows Fig.10 4. It is conceivable that the inclined surface 445 extends at its radially inner (end) section all the way to below the outer edge 12c of the distribution plate 12. As a result, the inclined surface 445 starts further inward than the outer edge 12c of the distribution plate 12 when observing the flow direction of the pressure medium from the radial inner side to the radial outer side. In other words, the deflection of the pressure medium already begins below the outer edge 12c of the distribution plate 12.

[0085] If there is space, as an alternative, the beginning of the bevel 445 can also be arranged outside the outer edge 12c of the distributor plate 12, so that the cross section of the cast groove is reduced only after the outer edge 12c of the distributor plate 12, thereby avoiding a narrowing of the relief flow path. Since the beginning of the bevel 445 outside the outer edge 12c is already in the interior of the housing, the narrowing has a smaller negative effect here than if the bevel 445 already starts inside the outer edge 12c. For a compact design of the interior of the housing, it is possible that the bevel 445 must then be steeper.

[0086] The relieved pressure medium (control oil) can now not directly impact the flat seal 450, which would then be subjected to unfavorable loads. Dirt particles or metal particles (due to cavitation) are also present in the relieved pressure medium (control oil), which are thus also not directly thrown onto the flat seal 450. This prevents the flat seal 450 from becoming leaky. This reduces the risk to people and the environment.

[0087] List of reference numerals:

[0088] 1 Swash plate

[0089] 2 Adjustment device

[0090] 3 Open spring

[0091] 4 Piston

[0092] 5 Cylinder

[0093] 6 Drive shaft

[0094] 7 Axis of rotation

[0095] 8 Compression spring

[0096] 10 Cylinder opening

[0097] 12 Distribution board

[0098] 12a Control opening / control hole

[0099] 12b Control slot

[0100] 12c Outer edge

[0101] 14 Pot-shaped housing part

[0102] 16 Cover-shaped housing member

[0103] 18 Rolling bearings

[0104] 20 First abutment portion

[0105] 21 First fit clearance

[0106] 22 Second matching gap (long hole)

[0107] 23 Third fit clearance

[0108] 24 Fourth matching gap

[0109] 26 Second abutment

[0110] 31 First matching pin

[0111] 32 Second matching pin

[0112] 34 Orientation pin

[0113] 35 Directional Gap

[0114] 36 Directional gap

[0115] 38 Inner shell segment

[0116] 41 through-gap (long hole) for first mating pin

[0117] 42 through-gap for second mating pin

[0118] 44 Casting radial clearance

[0119] 46 Axial gap of casting

[0120] 47 Another radial gap of the casting

[0121] 48 Casting Space

[0122] 50 Flat seal

[0123] 52 Piercing

[0124] 54 Flattening

[0125] 116 Cover-shaped housing member

[0126] 118 Pre-compression space

[0127] 216 Cover-shaped housing member

[0128] 244 Casting radial clearance

[0129] 246 Axial gap in casting

[0130] 316 Cover-shaped housing member

[0131] 344 Casting radial clearance

[0132] 346 Axial gap of casting

[0133] 416 Cover-shaped housing part

[0134] 444 Casting radial clearance

[0135] 445 bevel

[0136] 450 flat seal

[0137] A Working connector / high pressure connector

[0138] B working connector / low pressure connector

Claims

1. A hydrostatic axial piston machine, in whose housing a drive shaft (6) is supported in a manner rotatable about an axis of rotation (7), wherein the housing comprises a pot-shaped housing part (14) with a first abutment part (20) and a cover-shaped housing part (16; 116; 216; 316; 416) with a second abutment part (26), wherein the two abutment parts (20, 26) abut against each other in a sealing manner, characterized in that A first mating pin (31) is provided, which is inserted into the first mating gap (21) of the first abutment portion (20) with a precise fit on the one hand and into the second mating gap (22) of the second abutment portion (26) with a precise fit on the other hand, wherein a second mating pin (32) is provided on the side opposite to the rotation axis (7), which is inserted into the third mating gap (23) of the first abutment portion (20) with a precise fit on the one hand and into the fourth mating gap (24) of the second abutment portion (26) with a precise fit on the other hand, wherein the second mating gap (22) has a radial expansion portion with respect to the rotation axis (7), whereby the second mating gap (22) is a long hole and / or a mating groove.

2. The axial piston machine according to claim 1, characterized in that The radial extent of the second engagement recess (22) is only a maximum of 7% greater than the extent of the second engagement recess (22) in the circumferential direction.

3. Axial piston machine according to any one of the preceding claims, characterized in that All four engagement recesses ( 21 , 22 , 23 , 24 ) are designed as corresponding blind holes.

4. Axial piston machine according to any one of the preceding claims, characterized in that The two abutment parts (20, 26) of the two housing parts (14, 16; 116; 216; 316; 416) are located in respective planes and are completely circumferential, and a flat seal (50; 450) is arranged between the two abutment parts (20, 26), the flat seal having two through-gaps (41, 42), through which two mating pins (31, 32) extend.

5. The axial piston machine according to claim 4, characterized in that The through-opening (41) for the first dowel pin (31) has a radial expansion with respect to the axis of rotation (7), so that the through-opening (41) is a slotted hole.

6. Axial piston machine according to any of the preceding claims, wherein the two housing parts (14, 16; 116; 216; 316; 416) are fastened to one another by means of a plurality of screws, characterized in that The pot-shaped housing part (14) has a blind-hole-like threaded hole for a screw.

7. An axial piston machine according to any one of the preceding claims, wherein a distribution plate (12) having two kidney-shaped control openings is clamped against a cover-shaped housing part (16; 116; 216; 316; 416), in which during operation of the axial piston machine one of the control openings acts as a high-pressure kidney and the other acts as a low-pressure kidney, and wherein the drive shaft (6) is supported in the cover-shaped housing part (16; 116; 216; 316; 416) by means of a rolling bearing (18), characterized in that The distributor plate (12) has a central recess with an inner edge, by means of which the distributor plate (12) is held on the outer ring of the rolling bearing (18).

8. The axial piston machine according to claim 7, characterized in that At least one cast radial recess (44; 244; 344; 444), the distribution plate (12) is clamped toward the abutment area, the radial gap extends in the radial direction, and the radial gap is expanded into a radial channel section through the distribution plate (12), and the radial channel section connects the outer peripheral area of ​​the distribution plate (12) and thus the internal space of the housing with the outer ring of the rolling bearing (18).

9. The axial piston machine according to claim 8, wherein a control opening (12a) is provided in the distribution plate (12), which is fluidically connected to the cast radial recess (444), characterized in that A radially outer end section of the groove bottom of the cast radial recess (444) has a chamfer (445) in the region of the outer edge (12c) of the distributor plate (12).

10. Axial piston machine according to any one of claims 8 to 9, characterized in that A cast space (48) is provided in a cover-shaped housing part (16; 116; 216; 316; 416) on the side of the rolling bearing (18) opposite the distribution plate (12) when viewed along the rotation axis (7) and axially adjacent to the rolling bearing (18), wherein at least one cast axial gap (46; 246; 346) is formed in an inner shell section (38) of the cover-shaped housing part (16; 116; 216; 316; 416), against which the outer ring of the rolling bearing (18) abuts, the axial gap extending in the axial direction and expanding through the outer ring into an axial channel, which connects the radial channel with the cast space (48).

11. Axial piston machine according to any one of claims 7 to 10, characterised in that An orientation pin (34) is inserted, on the one hand, into an orientation recess (35) of a cover-shaped housing part (16; 116; 216; 316; 416) and, on the other hand, into an orientation recess (36) of a distributor plate (12).

12. Axial piston machine according to any one of claims 8 to 10 and according to claim 11, characterised in that The alignment recess (35) of the cover-shaped housing part (16; 116) is arranged in the cast radial recess (44).

13. Axial piston machine according to any one of claims 8 to 10 and according to claim 11, characterised in that The orientation recess (35) of the cover-shaped housing part (216) is arranged between two arms of the cast radial recess (244).

14. Axial piston machine according to any one of claims 8 to 10 and according to claim 11, characterised in that The alignment recess (35) of the cover-shaped housing part (316; 416) is arranged adjacent to the cast radial recess (344; 444).

15. An axial piston machine according to any one of the preceding claims, wherein Two working connections (A, B) of an axial piston machine are formed on the cover-shaped housing part (216), characterized in that a flattened portion (54) and / or a recess of the cover-shaped housing part (216) is formed on the outer side of the cover-shaped housing part (16) between the two working connections (A, B), which is recessed along the axis of rotation (7).

16. An axial piston machine according to any one of claims 1 to 14, wherein Two working connections (A, B) of an axial piston machine are formed in the cover-shaped housing part (116), characterized in that a pre-compression space (118) is arranged in the cover-shaped housing part (16) between the two working connections (A, B).

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