Axial piston machine

Abstract

The invention relates to an axial piston machine (2), comprising: a housing (4); a cylinder barrel (26) which is accommodated in the housing (4) so as to be rotatable about an axis of rotation (24) and in which a plurality of pistons (36) are accommodated so as to be linearly displaceable, in such a way that the pistons (36) together with the cylinder barrel (26) define cylinder chambers (38), each leading with an inlet opening (40) to a cylinder barrel control surface (58); a distribution plate (56), which has a distribution plate control surface (57) against which the cylinder control surface is slidably displaceable; wherein the distribution plate control surface (57) has a first control opening (66) and a second control opening (68).

Description

TECHNICAL FIELD

[0001] The invention relates to an axial piston machine according to the preamble of claim 1. BACKGROUND

[0002] Axial piston machines of swash plate design or of swash block design are known from the prior art. Both design forms have a cylinder barrel which is rotatable about an axis of rotation, in which a plurality of pistons are accommodated in linearly movable manner. The cylinder barrel has a cylinder barrel control face (first control face) which is directed in the direction of the axis of rotation, each cylinder chamber being directed to the cylinder barrel control face with an assigned intake opening. The cylinder barrel control face is in slidable manner abutted against a distribution plate control face (second control face), wherein the distribution plate control face is arranged at least torsionally about the axis of rotation. On the distribution plate control face there are arranged first and second control openings which are each kidney-shaped configured, wherein they are each in fluid connection with an assigned first or second working port. By rotation of the cylinder barrel, it is possible for each intake opening to either coincide with the first control opening or with the second control opening, so that a fluid exchange is possible.

[0003] In the circumferential direction, the first and second control openings are spaced apart from one another, so that first and second commutation regions are produced which are arranged diametrically opposite about the axis of rotation. By suitable design of the commutation regions, it is possible to reduce the pressure pulsations of the axial piston machine to a minimum.

[0004] Therefore, axial piston machines such as disclosed in DE 10 2021 203 902 A1 have at least one initial up-tune opening in the first and / or second commutation region, which is respectively connected to an assigned pre-compression chamber. The fluid connection thus produced between the two assigned pre-compression chambers has a high flow resistance, so that the effect of the pre-compression chambers is only slightly reduced. The mentioned flow resistance is preferably designed in such a way that small pressure pulsations are produced in the case of high rotational speeds.

[0005] Furthermore, DE 10 2022 200 140 A1 also describes an axial piston machine which has at least one initial up-tune opening in the first and / or second commutation region. The initial up-tune opening is here permanently connected to a pre-compression chamber in order to reduce the pressure pulsations. SUMMARY

[0006] It is the task of the invention to provide an axial piston machine which ensures operation in the case of high rotational speeds and at the same time enables a further reduction of the pressure pulsations in the case of such high rotational speeds.

[0007] This task is solved by an axial piston machine having the features of claim 1 and by an axial piston machine having the features of claim 6.

[0008] The task is thus solved by an axial piston machine for which the pressure equalization volume is less than three times the maximum volume of the cylinder chamber.

[0009] The task is thus solved by an axial piston machine for which the pressure equalization volume is less than three times the maximum volume of the cylinder chamber.

[0010] Thereby, sufficient volume can be provided early and quickly for the initial pressure formation in the cylinder chamber to be accelerated as such, which is very slow in conventional axial piston machines. In other words, the axial piston machine can be brought to the initial pressure quickly, which requires a high upstroke volume flow in the case of atmospheric underpressure, since the effective compression modulus is initially very low.

[0011] Advantageous refinements of the application are specified in the respective dependent claims.

[0012] According to the disclosure, the pressure equalization volume can be less than twice the maximum individual compression chamber volume over the entire stroke of the axial piston machine (hydrostatic machine). Here, each compression chamber volume is defined by one of the plurality of cylinder chambers. Thus, the pressure equalization volume is preferably less than twice the volume defined by one of the plurality of cylinder chambers. In other words, the pressure equalization volume can be less than twice the maximum volume of one cylinder chamber. Thereby, the axial piston machine can also be brought to the initial pressure more quickly.

[0013] It is particularly preferred that the pressure equalization volume can be less than half the maximum individual compression chamber volume over the entire stroke of the axial piston machine. Most preferably, the pressure equalization volume can be less than one third of the maximum individual compression chamber volume over the entire stroke of the axial piston machine.

[0014] In an advantageous embodiment, the pressure equalization volume can be a pre-compression chamber, to which the initial upstroke opening is permanently fluidically connected. Furthermore, it can be advantageous here that the initial upstroke volume defined by the pre-compression chamber connected to the initial upstroke opening essentially corresponds to the magnitude of the dead volume of the drive chamber to be commutated in the zero stroke. The comparatively high volume of the pre-compression chamber thus allows the pressure built up previously in the range of the initial compression of the compression chamber to be reduced quickly to the compression chamber pressure.

[0015] It can be expedient here for the pre-compression chamber to be arranged in the second housing part between the first working connection and the second working connection. Advantageously, the pre-compression chamber can be embodied here by means of a blind-hole thread hole, which can be closed with a blocking screw, preferably oriented perpendicular to the rotational axis.

[0016] According to a particularly preferred refinement, the initial upstroke cross section defined by the at least one initial upstroke opening can be greater than the upstroke cross section defined by the upstroke opening. In other words, the area defined by the at least one initial upstroke opening or the plurality of initial upstroke openings, if present, can be greater according to the application than the area defined by the upstroke opening.

[0017] Thereby, sufficient cross section can be provided early and quickly in order to thus accelerate the initial pressure build-up of the compression chamber, which is very slow in conventional axial piston machines. In other words, the axial piston machine can be brought quickly to an initial pressure, which requires a high upstroke volume flow in the case of atmospheric underpressure, since the effective compression modulus is initially very low.

[0018] The initial upstroke cross section can preferably be at least 20% greater, particularly preferably at least 40% greater, particularly preferably at least 60% greater than the upstroke cross section.

[0019] According to another particularly preferred design, a plurality of initial upstroke openings can be provided. It can be expedient here for the initial upstroke cross section to be the sum of the cross sections defined by the plurality of initial upstroke openings. Furthermore, it can be advantageous here for the initial upstroke cross section to be at least a factor of 2 greater, preferably a factor of 1.8 greater than the upstroke cross section. In combination therewith, the initial upstroke volume can be further reduced, which has a very advantageous effect in terms of installation space and production costs.

[0020] According to an advantageous refinement, blind-hole boreholes which are not necessarily closed again can also be envisaged here. In relation to the volume of the compression chamber (in the maximum displacement volume), the blind-hole boreholes have a size of 0.29 (in the machine observed), which corresponds to 0.43 in relation to the dead volume (in the zero stroke).

[0021] According to an advantageous refinement, the axial piston machine can also have a cradle which is deflectable by the adjustment piston about the pivot axis for setting a specific, for example maximum, displacement volume of the axial piston machine. It is particularly advantageous here for the sign of the torque which the piston exerts on the cradle to remain the same, so that the cradle continuously presses against the adjustment piston. Damage to the adjustment system can thus be avoided.

[0022] The inlet faces or the inlet openings are preferably identically configured to one another, wherein they are arranged uniformly distributed around the axis of rotation. The first and / or the second control openings can be configured as continuous faces. However, it is also conceivable that they consist of a plurality of discontinuous sub-faces which are separated from one another by a reinforcing web along a circumferential direction with respect to the axis of rotation, such that the reinforcing web is inside the profile of the kidney. The last-mentioned variant is chosen for increasing the pressure strength. With respect to the principle of action of the present application, the two variants are equivalent.

[0023] The first and the second end side of the inlet openings or the inlet faces are preferably implemented mirror-symmetrically to one another, wherein the respective axis of symmetry intersects the axis of rotation. Thereby, the axial piston machine exhibits the same performance as possible for both possible directions of rotation. The axial piston machine according to the present application preferably has a 4-quadrant capability, that is to say, it can be operated not only as a pump but also as a motor for both possible directions of rotation of the cylinder.

[0024] The axial piston machine can be implemented in a swash plate configuration or in a swash axle configuration. For the preferred swash plate configuration, the second control face is preferably arranged substantially position-fixed with respect to the housing. The radially inner side and / or the radially outer side of the inlet face is preferably respectively configured circularly with respect to the axis of rotation.

[0025] It can be provided that in the first and / or the second commutation region at least one up-regulation opening or at least one down-regulation opening is respectively arranged, wherein the at least one up-regulation opening is respectively arranged adjacent to the first control opening and can be permanently fluidically connected with the first working connection. Furthermore, the at least one down-regulation opening is respectively arranged adjacent to the second control opening, wherein the at least one down-regulation opening can be permanently fluidically connected with the second working connection. Thereby, the pressure in the cylinder chamber from high-pressure operation to low-pressure operation can be reduced by means of the third or the fourth control opening towards the respective control connection which guides the low pressure. Thus, the pressure pulsation is reduced to a minimum. The small area of the up-regulation opening or the down-regulation opening leads to a throttling of the respective volume flow, such that the pressure reduction does not take place abruptly, but rather gently. For the cylinder chamber from low-pressure operation to high-pressure operation, the opposite case occurs, in that this cylinder chamber is connected by means of the up-regulation opening or the down-regulation opening with the working connection which guides the high pressure, such that the pressure in the cylinder chamber is not formed abruptly, but rather gently. It is to be considered here that the mentioned processes take place in the course of short time intervals due to the desired high rotational speed. The duration of the pressure reduction or the pressure formation can be adjusted by means of the spacing between the up-regulation opening or the down-regulation opening and the assigned first or second control opening along the circumferential direction.

[0026] Furthermore, it is conceivable that each of the merging openings in its first and second zero position coincides or touches with its border with at least one of the upper and lower tuning openings, respectively. Thus, in the mentioned zero positions, a fluid connection between the first and second control openings and thus a fluid connection between the first and second working connections exists. However, the flow resistance of the fluid connection is high due to the small coincidence. The flow resistance is preferably designed such that particularly low pressure pulsations occur in the case of high rotational speeds.

[0027] It is particularly preferred that exactly one upper tuning opening is arranged in the first commutation region and exactly one lower tuning opening is arranged in the second commutation region. Thereby, the position required along the circumferential direction for the upper and lower tuning openings is small, wherein the volume flow necessary for the minimization of the pressure pulsations can flow through the mentioned control openings despite this. BRIEF DESCRIPTION OF DRAWINGS

[0028] An embodiment of an axial piston machine according to the application is explained in detail below in the drawings.

[0029] Figure 1 A longitudinal sectional view of an axial piston machine according to the application is shown;

[0030] Figure 2 A schematic plan view of the contact area between the cylinder control surface and the distribution plate control surface of an axial piston machine according to the application in a first embodiment is shown;

[0031] Figure 3 and 4 A sectional view of the second housing part of an axial piston machine according to the first embodiment is shown for two advantageous modifications;

[0032] Figure 5 A schematic plan view of the contact area between the cylinder control surface and the distribution plate control surface of an axial piston machine according to the application in a second embodiment is shown;

[0033] Figure 6 A schematic plan view of the contact area between the cylinder control surface and the distribution plate control surface of an axial piston machine according to the application in a third embodiment is shown; and

[0034] Figure 7 A rocker torque-rotation angle-diagram for a conventional and an axial piston machine according to the application is shown. DETAILED DESCRIPTION

[0035] Figure 1A longitudinal section through an axial piston machine 2 according to the present disclosure is shown. The axial piston machine 2 comprises a housing 4 which is composed of a first housing part 6 and a separate second housing part 8. The first housing part 6 is basin-shaped in such a way that it has a housing opening 10 which in Figure 1 the middle points to the right. This housing opening 10 is completely covered by the second housing part 8. The first housing part 6 and the second housing part 8 abut against each other at a flat sealing face 12. The housing 4 is sealed or fluid-tightly closed by a seal 14 which is embodied for example as an O-ring or a flat seal.

[0036] On the bottom 16 of the first housing part 6 a first rotary bearing 18 is accommodated. In the second housing part 8 a second rotary bearing 20 is accommodated. The rotary bearings 18, 20 are currently preferably embodied as conical roller bearings which are mounted in an X arrangement. The rotary bearings 18, 20 support a drive shaft 22 in a rotatable manner about a rotary axis 24 on the housing 4. The drive shaft 22 is surrounded by separate cylinder barrels 26. The drive shaft 22 and the cylinder barrels 26 are in a rotary drive connection by means of a splined shaft toothing 28.

[0037] The drive shaft 22 currently projects with a drive shaft journal 30 out of the housing 4 on the first housing part 6. As an alternative to the embodiment shown in Figure 1 the middle, it is also possible to provide a drive shaft journal or similar drive means on both axial end sides of the housing 4 or only on opposite sides of the housing 4.

[0038] In the cylinder barrels 26 a plurality of, for example seven or nine, cylinder bores 32 are arranged in a uniformly distributed manner about the rotary axis 24. Slips 34 can be fixedly mounted into the cylinder bores 32. In the cylinder bores 32 or, if present, in the slips 34, respectively, pistons 36 of the preferably solid piston type are accommodated in a linearly movable manner, so that cylinder chambers 38 with a variable volume are produced. In other words, the pistons 36 together with the cylinder barrels 26 define respectively assigned cylinder chambers 38 whose volume changes periodically when the cylinder barrels 26 are rotated about the rotary axis 24. Through a merging opening 40 each cylinder chamber 38 can be brought or placed into fluid exchange connection with a first working channel 42 or a second working channel 44 depending on the rotational position of the cylinder barrels 26.

[0039] The end of each piston 36 which projects out of the cylinder barrel 26 is connected by means of a ball-and-socket joint 46 with a separate slide 48 which is supported on a flat control face 50 of a rocker or swash plate 52 in such a way that the piston 36 with the slide 48 forms together with the rocker 52 a hydrostatic slide bearing.

[0040] The rocker 52 is pivotable about a pivot axis 53. The pivot axis 53 is currently arranged next to the rotation axis 24, so that in operation a restoring torque acts on the rocker 52, which is oriented counter to the force of the adjustment piston 54, which is set for displacing or deflecting the rocker 52. If no pressure is applied in the adjustment chamber, the axial piston machine 2 is pivoted into a position in which it has the greatest displacement volume, with the adjustment piston 54 being in the end position displaced in. In contrast thereto, a position with the adjustment piston 54 being in the end position displaced out is shown in Figure 1 The rocker 52 is pivotable about a pivot axis 53. The pivot axis 53 is currently arranged next to the rotation axis 24, so that in operation a restoring torque acts on the rocker 52, which is oriented counter to the force of the adjustment piston 54, which is set for displacing or deflecting the rocker 52. If no pressure is applied in the adjustment chamber, the axial piston machine 2 is pivoted into a position in which it has the greatest displacement volume, with the adjustment piston 54 being in the end position displaced in. In contrast thereto, a position with the adjustment piston 54 being in the end position displaced out is shown in

[0041] The base body of the rocker 52 and the first and second housing parts 6, 8 are made of cast iron. The adjustment piston 54 is integrally composed of steel, wherein it is preferably at least on its surface hardened. The adjustment piston 54 is thus significantly harder than the first housing part 6, in which the adjustment bore is arranged directly. For cost reasons, no sliding sleeve 34 composed of brass or a similar sliding bearing material is provided. Likewise, no usual adjustment piston composed of brass is provided. The resulting sliding pairing cast iron steel is susceptible to wear in this way. In this respect, it is particularly critical that forces oriented perpendicularly to the adjustment axis act on the adjustment piston 54 in the touching contact with the rocker 52. Such forces cause local load peaks in the guiding contact between the adjustment piston 54 and the adjustment bore, wherein the wear is particularly high at these locations.

[0042] A separate distribution or control plate 56 is arranged between the cylinder barrel 26 and the second housing part 8 in the axial direction. Thereby, the distribution plate 56 is spaced apart from the second rotation bearing 20 in the axial direction. The distribution plate 56 has a distribution plate control face 57, which is slidably movable against a cylinder barrel control face 58 of the cylinder barrel 26, in order to allow a relative movement between the cylinder barrel 26 and the distribution plate 56. The distribution plate control face 57 and the cylinder barrel control face 58 are pressed towards each other in operation by the hydrostatic forces and / or by springs abutting against the cylinder barrel 26 on the end side. The distribution plate control face 57 and the cylinder barrel control face 58 are arranged rotationally symmetrical about the rotation axis 24, wherein they fluid-tightly match each other. Currently, the distribution plate control face 57 and the cylinder barrel control face 58 are composed spherically. However, they can also be composed flatly. The distribution plate 56 is arranged position-fixed relative to the housing 4.

[0043] The first and second working channels 42, 44 in the second housing part 8 adjoin the distribution plate 56, wherein the first and second working channels lead out of the housing 4 to the first and second working connections 60, 62. The working connections 60, 62 point away from one another, that is to say are arranged on opposite sides of the second housing part 8. Each cylinder chamber 38 of the cylinder barrel 26 leads with its respective assigned intake opening 40 to a cylinder barrel control face 58. The intake openings 40 are each connected to the cylinder chamber 38 by means of an associated intake channel 64. The intake channels 64 extend obliquely and radially out of the cylinder chamber 38, that is to say, with respect to the rotational axis 24, obliquely in a gentle slope, so that the flow is only minimally diverted and at the same time the intake openings 40 are arranged far inwards, that is to say as close as possible to the rotational axis 24. This is achieved, inter alia, in that no spring is arranged radially between the cylinder barrel 26 and the drive shaft 22. By being as close as possible to the rotational axis 24 in the intake openings 40, a smaller centrifugal force acts on the pressure fluid, such as hydraulic oil. The cylinder barrel 26 can thus be operated at high rotational speeds without cavitation occurring on the suction side of the axial piston machine 2. The intake openings 40 currently preferably have a different cross section than the substantially cylindrical cylinders 32 or cylinder chambers 38.

[0044] Figure 2 A schematic plan view of the contact area between the cylinder barrel control face 58 and the distribution plate control face 57 is shown. Here, the intake openings 40 configured on the cylinder barrel control face 58 are shown in broken lines and the openings configured on the distribution plate control face 57 are shown in solid lines.

[0045] It can be seen here that the distribution plate control face 57 has a first (high-pressure) control opening 66 and a second (low-pressure) control opening 68. The first control opening 66 is fluidically connected here to the first working connection 60, while the second control opening 68 is fluidically connected to the second working connection 62. The first and second control openings 66, 68 are configured kidney-shaped, wherein the first control opening 66 is divided in the first embodiment into a plurality of kidney-shaped and circumferentially uniformly distributed control openings 66a to 66e. As already mentioned, by means of the rotation of the cylinder barrel 26 it is possible for each intake opening 40 to either coincide with the first control opening 66 or with the second control opening 68, in order thus to ensure fluid exchange.

[0046] The first and second control openings 66, 68 are spaced apart from one another along the circumferential direction by means of a first and second commutation region 70, 72, as shown in Figure 2 With respect to the rotational axis 24, the first and second commutation regions 70, 72 are directly opposite one another.

[0047] As shown in Figure 2As shown in Fig. 1, an upstroke opening 74 is provided in the first commutation region 70 and a pressure reduction hole 76 is configured in the second commutation region 72. The upstroke opening 74 is arranged here adjacent to the first control opening 66 and permanently fluidically connected to the first working port 60. The pressure reduction hole 76 is arranged adjacent to the second control opening 68 and permanently fluidically connected to the housing pressure. Thereby, the pressure in the cylinder chamber, which is running from high pressure to low pressure, can be reduced by the upstroke opening 74 towards the respective working port 60, 62, which is guided at low pressure. Thus, the pressure pulsation is reduced to a minimum.

[0048] In Figure 2 In the first embodiment shown in Fig. 1, an initial upstroke opening 78 is also provided in the first commutation region 70. This initial upstroke opening is preferably arranged adjacent to the first control opening 66. The initial upstroke opening 78 is configured here such that each of the merging openings 40 coincides in its first zero position with the initial upstroke opening 78 provided in the first commutation region 70.

[0049] According to the first embodiment, the initial upstroke opening 78 is permanently fluidically connected to an assigned pre-compression chamber (initial upstroke volume) 80. The assigned pre-compression chamber 80 is preferably configured in the second housing part 8 here. The second housing part 8 can also be referred to as a connection plate or as a connection body.

[0050] As mentioned before, the second housing part 8 has the assigned pre-compression chamber 80, which is preferably a closed cavity with a constant volume. The pre-compression chamber 80 currently has a volume which is relatively small, in the range between 3 ccmm and 20 ccmm, preferably between 5 ccmm and 10 ccmm, particularly preferably approximately 7 ccmm. In particular, the volume of the pre-compression chamber 80 corresponds to the dead volume of the drive chamber to be commutated in the zero stroke. The pre-compression chamber 80 is here an example of a pressure equalization volume according to the application.

[0051] In Figure 2 As can be seen in Fig. 1, the initial upstroke cross section defined by the initial upstroke opening 78 is larger than the upstroke cross section determined by the upstroke opening 74. The initial upstroke cross section is several times larger than the upstroke cross section, which is here in the range between 5 and 20, preferably between 10 and 15, particularly preferably approximately 12. In other words, the initial upstroke cross section is at least 5 times larger, preferably 10 times larger, particularly preferably 12 times larger than the upstroke cross section.

[0052] Thereby, in combination with the pre-compression chamber 80 as pressure equalization volume, a reduction of pressure pulsations can be induced. Here, the initially up-regulated cross section has the function early on and provides the cross section quickly, and in contrast thereto the pre-compression chamber 80 as pressure equalization volume has the function to quickly reduce the pressure, which was previously built up due to the relatively small volume, to the pressure of the compression chamber in the range of the initial compression of the compression chamber. The up-regulated main pressure stroke is realized by the further switching geometry. Thereby, it is achieved that only the slow initial pressure formation of the compression chamber is accelerated, but the further pressure formation can be carried out slowly.

[0053] Figure 3 A preferred design of the initially up-regulated opening 78 and the pre-compression chamber 80 is shown in a top view on the cylinder side. Here, on the left side in Figure 3 a second switching region 72 is arranged and is represented here, for example in a very simple embodiment, by a bore hole in the direction of the housing 4. In Figure 3 the right side in is shown the initially up-regulated opening 78 and the pre-compression chamber 80 as well as the up-regulated opening 74. As already described, the initially up-regulated opening 78 is hydraulically connected with the pre-compression chamber 80.

[0054] Figure 3 In the design shown in Figure 4 the pre-compression chamber 80 is constructed in the connecting plate, that is to say in the second housing part 8. Here, the pre-compression chamber 80 is realized by means of a blind hole thread hole 82, which is axially oriented with respect to the rotation axis 24, which is closed by a blocking bolt 84. A connecting channel 86 for connecting the pre-compression chamber 80 to the initially up-regulated opening 78 is realized by a simple through hole 88. In an alternative design, the pre-compression chamber 80 is also embodied substantially radially with respect to the rotation axis 24 between the first working channel 42 and the second working channel 44 in the second housing part 8 as shown in

[0055] Figure 5 A second embodiment of the axial piston machine 2 according to the application is shown. In the following, here only the differences to the first embodiment described above are discussed.

[0056] Here, as in Figure 5As shown, the initial upward adjustment opening 78 is fluidly connected to the first working channel 42 via a connecting channel 90. A pre-tightened check valve 92 is provided in the connecting channel 90, which, due to pre-stress, maintains the connection between the first working channel 42 and the initial upward adjustment opening 78 until the ultimate pressure is reached. In other words, the check valve 92 automatically closes when the ultimate pressure is reached, thus fluidly separating the initial upward adjustment opening 78 from the first working channel 42. The pre-tightening force of the check valve 92 here corresponds to at most two-thirds of the pressure present in the first working channel 42. In other words, the check valve 92 closes when two-thirds of the pressure present in the first working channel 42 is reached. Because the supply pressure remains almost constant here, rapid initial pressure formation is possible. Therefore, the first working channel 42 is an example of a pressure balancing volume.

[0057] Figure 7 A third embodiment of the axial piston mechanism 2 according to the present invention is shown. The differences from the first embodiment described above will be discussed here only.

[0058] As in Figure 7 As can be seen, a plurality of initial upward adjustment openings 78 are constructed in the first reversing region 70. In a third embodiment, three initial upward adjustment openings 78 are specifically constructed. Each of the initial upward adjustment openings 78 is connected here to the pre-compression chamber 80, which serves as the initial upward adjustment volume.

[0059] The initial upward adjustment openings 78 each have an initial upward adjustment cross-section smaller than that of the axial piston machine 2 according to the first embodiment. The sum of the cross-sections defined by the initial upward adjustment openings 78, that is, the total cross-section or total area, is greater than the upward adjustment cross-section defined by the upward adjustment openings 74 according to the present invention. Preferably, the initial upward adjustment cross-section is here a multiple of 1.8 larger than the overall upward adjustment cross-section.

[0060] As explained above, the axial piston mechanism 2 has a rocker arm 52. The choice of material is particularly crucial here, as a force oriented perpendicular to the adjusting axis acts on the adjusting piston 54 during contact with the rocker arm 52. Figure 7 In this respect, the rocker torque of the rocker 52 is recorded by the rotation angle of the cylinder 26. Here, the rocker torque of a conventional axial piston machine from the prior art, such as DE 10 2021 203 902A1, is shown by dashed lines, while the rocker torque in the axial piston machine 2 according to the present invention is shown by solid lines.

[0061] Compared to conventional axial piston presses, the rocker torque in the axial piston press 2 according to the present invention does not change in sign. That is, as in Figure 7It can be seen that the rocker torque is continuously negative in the axial piston machine 2 according to the application. In other words, the sign of the torques exerted by all pistons on the rocker 52 as a whole always remains the same, so that the rocker 52 is always pressed onto the adjusting piston 54 and cannot be lifted off the adjusting piston. Damage to the adjusting system can thus be effectively avoided.

[0062] List of reference signs

[0063] 2 axial piston machine

[0064] 4 housing

[0065] 6 first housing part

[0066] 8 second housing part

[0067] 10 housing opening

[0068] 12 sealing surface

[0069] 14 seal

[0070] 16 bottom

[0071] 18 first rotary bearing

[0072] 20 second rotary bearing

[0073] 22 drive shaft

[0074] 24 rotary axis

[0075] 26 cylinder barrel

[0076] 28 spline shaft toothing

[0077] 30 drive journal

[0078] 32 cylinder bore

[0079] 34 slide

[0080] 36 piston

[0081] 38 cylinder chamber

[0082] 40 run-in opening

[0083] 42 first working channel

[0084] 44 second working channel

[0085] 46 ball-and-socket joint

[0086] 48 slide

[0087] 50 control surface

[0088] 52 rocker

[0089] 53 pivot axis

[0090] 54 adjustment piston

[0091] 56 distribution plate

[0092] 57 distribution plate control surface

[0093] 58 cylinder control surface

[0094] 60 first working port

[0095] 62 second working port

[0096] 64 infeed passage

[0097] 66 first control opening

[0098] 68 second control opening

[0099] 70 first reversing region

[0100] 72 second reversing region

[0101] 74 upstroke opening

[0102] 76 pressure reduction hole

[0103] 78 initial upstroke opening

[0104] 80 pre-compression chamber

[0105] 82 blind threaded hole

[0106] 84 latching bolt

[0107] 86 connecting passage

[0108] 88 through hole

[0109] 90 connecting passage

[0110] 92 check valve

Claims

1. An axial piston machine (2) having: a housing (4) comprising a first housing part (6) and a second housing part (8); a cylinder barrel (26) accommodated in the housing (4) in a rotatable manner about an axis of rotation (24) and having a plurality of pistons (36) accommodated in a linearly movable manner therein, such that the pistons (36) together with the cylinder barrel (26) define cylinder chambers (38) which are each directed with a merging opening (40) to a cylinder barrel control face (58); a distribution plate (56) arranged preferably fixedly in position on a second axial end of the second housing part (8), having a distribution plate control face (57) against which the cylinder barrel control face (58) is in slidable movement; wherein the distribution plate control face (57) has a first control opening (66) which is in fluid connection with a first working port (60) and a second control opening (68) which is in fluid connection with a second working port (62), the first control opening and the second control opening being separated from one another along a circumferential direction by a first commutation region (70) and a second commutation region (72), wherein at least one upshift opening (74) or upshift slot or upshift recess is provided in the first commutation region (70) and / or second commutation region (72), and wherein at least one initial upshift opening (78) is provided in the first commutation region (70) and / or second commutation region (72), which is in fluid connection or can be brought into fluid connection with a pressure equalization volume (80); characterized in that the pressure equalization volume (80) is less than three times the maximum volume of a cylinder chamber (38).

2. The axial piston machine (2) as claimed in claim 1, characterized in that The pressure equalization volume is a pre-compression chamber (80), the initial upshift opening (78) being permanently fluidically connected to the pre-compression chamber.

3. Axial piston machine (2) according to claim 2, characterized in that The pre-compression chamber (80) is arranged in the second housing part (8) between the first working port (60) and the second working port (62).

4. Axial piston machine (2) according to claim 2 or 3, characterized in that The pre-compression chamber (80) is implemented by means of a blind hole threaded hole (82) which is preferably oriented perpendicular to the axis of rotation (24) and which can be closed with a latching bolt (84).

5. The axial piston machine (2) as claimed in claim 2, characterized in that The pre-compression chamber (80) is a blind hole bore, the initial upshift opening (78) being permanently fluidically connected to the blind hole bore and / or the blind hole bore taking the initial upshift cross section as a starting point.

6. An axial piston machine (2) having: a housing (4) comprising a first housing part (6) and a second housing part (8); a cylinder barrel (26) accommodated in the housing (4) in a rotatable manner about an axis of rotation (24) and having a plurality of pistons (36) accommodated in a linearly movable manner therein, such that the pistons (36) together with the cylinder barrel (26) define cylinder chambers (38) which are each directed with a merging opening (40) to a cylinder barrel control face (58); a distribution plate (56) is preferably arranged fixed in position on a second axial end of the second housing part (8), the distribution plate having a distribution plate control face (57) against which the cylinder control face (58) is slidably movable; wherein the distribution plate control face (57) has a first control opening (66) which is fluidically connected to a first working port (60) and a second control opening (68) which is fluidically connected to a second working port (62), the first control opening and the second control opening being separated from one another in a circumferential direction by a first commutation region (70) and a second commutation region (72), wherein at least one upshift opening (74) or upshift slot or upshift recess is provided in the first commutation region (70) and / or second commutation region (72), and wherein at least one initial upshift opening (78) is provided in the first commutation region (70) and / or second commutation region (72), the at least one initial upshift opening being fluidically connected or connectable to a pressure equalization volume; characterized in that the pressure equalization volume is a pressure channel, in particular a first working channel (42), which is fluidically connected to the first working port (60), the initial upshift opening (78) being fluidically connected to the pressure channel by means of a connecting channel (90), and a pre-tensioned non-return valve (92) being arranged in the connecting channel (90).

7. Axial piston machine (2) according to any of the preceding claims, characterized in that An initial upshift cross section defined by means of the at least one initial upshift opening (78) is greater than an upshift cross section defined by means of the upshift opening (74).

8. Axial piston machine (2) according to claim 7, characterized in that The initial upshift cross section is at least 20%, preferably 40%, in particular 60% greater than the upshift cross section.

9. Axial piston machine (2) according to claim 7 or 8, characterized in that A plurality of initial upshift openings is provided, and the initial upshift cross section is the sum of the cross sections defined by means of the plurality of initial upshift openings.

10. Axial piston machine (2) according to any one of the preceding claims, further having a cradle (52) which is deflectable by means of an adjustment piston (54) about a pivot axis (53), the cradle serving to set a specific displacement volume of the axial piston machine (2).

11. Axial piston machine (2) according to claim 10, characterized in that The sign of the torque which the piston (36) exerts on the cradle (52) is kept the same, so that the cradle (52) permanently presses against the adjustment piston (54).

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