EP2585718A1

EP2585718A1 - Axial piston machine

Info

Publication number: EP2585718A1
Application number: EP11727173.4A
Authority: EP
Inventors: Clemens Krebs
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2010-06-23
Filing date: 2011-06-22
Publication date: 2013-05-01
Also published as: CN102947587A; WO2011161178A1; CN102947587B; DE102011051257A1; US9447686B2; US20130199363A1; JP2013533418A

Abstract

The invention relates to an axial piston machine, comprising a housing the casting of which is optimized in respect to casting and in the bottom of which an insert ring is formed which is optimized with respect to the pressure load. The invention further relates to an insert ring for such an axial piston machine.

Description

description

Axial piston machine The invention relates to an axial piston machine according to the preamble of

Claim 1 and a suitable for such an axial piston insert ring.

Such an axial piston machine is known, for example, from DE 10 2006 062 065 A1 and the data sheet RDE 93220-04-R / 02.08 by Bosch Rexroth AG and can be designed, for example, as a single or double axial piston machine. In these known solutions, the axial piston machine is designed with a housing in which at least one cylinder drum is rotatably mounted with a plurality of each defining a working space piston. These pistons are each supported via a piston foot on a swash plate whose angle of attack determines the piston stroke.

Each limited by a piston working chamber is connected via an end face arranged in the housing control disc alternately with a high pressure and a low pressure channel. The cylinder drum is rotatably connected to a drive shaft, which acts depending on the type of machine (motor, pump) either as an output shaft or drive shaft.

In the known solutions, the housing of the axial piston machine is approximately cup-shaped, wherein in a bottom of the cup-shaped housing, the high-pressure and low-pressure channels are formed, which are connected via the reference to the rotating cylinder drum fixed control disc successively with the working spaces of the cylinder drum. In this control disk a plurality of lying on a common pitch circle, relatively small pressure kidneys are formed, between each of which a pressure ridge is arranged. On the low pressure side, each control disk is designed with a suction kidney, which extends over a larger circumferential angle range compared to the small pressure kidneys. The high-pressure channels are subjected to comparatively high pressures in the region of the pressure kidneys and the pressure webs adjoining them during operation of the axial piston machine. The problem here is that usually the cup-shaped housing is made of nodular cast iron, and that in the transition region of the peripheral wall of the housing to the bottom area a problematic in terms of casting front course zone exists in which during the solidification voids can occur. At high loads due to high hydraulic pressure, damage or deformation of the housing may then occur in the area of these voids, so that the running time of the axial piston machine is reduced. These problems are reinforced in Doppelaxialkolbenmaschinen before, because the casting problems are even more difficult to master due to the double-cup housing.

In DE 195 36 997 C1 a Doppelaxialkolbenpumpe is shown in swash plate design, in which the actual pump housing is designed with an approximately disc-shaped central part, in which the two drive shafts of the unit are rotatably connected to each other. In this area, an impeller of a charge pump is mounted, via which the pressure medium on the low pressure side can be acted upon by a boost pressure. To install this impeller, the middle part is designed with an insert, which is used after mounted impeller in the middle part. In this insert part of the cylinder drums associated high-pressure and low-pressure passage sections of a pump unit are executed. In the second pump unit, these high-pressure and low-pressure channel sections are formed in the wall of the central part, so that the same problems as in the initially described prior art can occur in this area.

A corresponding double-axial piston pump is also described in the data sheet RDE 93220-04-R / 02.08 of Bosch Rexroth AG. In contrast, the invention has for its object to provide an axial piston machine in which the risk of damage due to compressive stress is reduced. This object is achieved by an axial piston machine with the features of claim 1. The invention is further solved by an insert ring according to the independent claim 14. Advantageous developments of the invention are the subject of the dependent claims.

The axial piston machine according to the invention is designed with a housing in which a cylinder drum is rotatably mounted with a plurality of each defining a working space piston. These are supported by piston feet on a swash plate. The work spaces delimited by the pistons can be connected alternately to a low pressure and a high pressure passage via an end face in the housing arranged control disc. In the axial piston machine, the cylinder drum is rotatably connected to a drive shaft. According to the invention, the housing is approximately pot-shaped with a cup base penetrated by the drive shaft, this floor being formed in sections by an insert ring. This insert ring has a multiple function, since it serves one for storing the drive shaft and on the other hand has a high-pressure channel section, the control wheel side has an axial mouth region and high pressure channel side has a radial or axial mouth region. Here is the material, the construction and the manufacturing process of

Insert ring optimized with regard to the pressure load.

The insert ring according to the invention is designed accordingly.

According to the inventive concept thus determines the housing no longer the pressure resistance of the pump, since the high-load areas are designed around the high-pressure connection in the material-optimized insert ring, the casting technology is much better to control. This design makes it possible to carry out the housing comparatively thin-walled, while the housing bottom is formed in the region of the pressure-loaded zones through the insert ring. In this way, the housing, in particular the core of the casting tool over which the interior of the housing is formed, be optimized by casting and the space, especially the length of the entire unit, compared to the conventional solutions be shortened because they require very voluminous housing to provide the required pressure resistance.

In addition, the housing according to the invention can be produced due to its simple structure with significantly lower manufacturing costs.

The reduced production costs result in particular from the fact that the core forming the interior of the housing can be formed significantly more solid than in the prior art. In addition, due to the insert ring, the housing can be designed with lower material accumulations and thus lower stresses during the casting process.

The insert ring is used in a variant in a receptacle of the housing, wherein the diameter of the receptacle and thus the outer diameter of the insert ring is significantly larger than the outer diameter of the drive shaft. The housing upper part is then pierced in the region of the pot bottom with a large diameter, so that the casting core, which forms the housing cavity, can be made very stable and can not deform or break during casting. Furthermore, material accumulation and the associated problems are avoided in the difficult solidification range.

This receptacle can be designed for axial guidance and for axial force absorption with a stepped bore, which receives a circumferential shoulder of the insert ring.

In principle, it is also possible, instead of the conventionally used spheroidal casting, to produce the housing from a different material, for example from light metal or gray cast iron. In one embodiment of the invention, the insert ring is designed as a casting, wherein preferably the proven ductile iron is used. Alternatively, nitrided cast steel can be used for production. The insert ring can also be made as a forged part or a solid part by cutting. So can For example, at high pressure loads the insert ring made of steel (forged or solid material) are produced, in which case the channels are formed by machining. In a particularly compact solution, a low-pressure channel section with a radial and an axial or radial mouth region is also embodied in the insert ring.

The construction of the axial piston machine can be simplified if a mating surface for a pressure bushing inserted into the housing is made on the high-pressure-side opening area.

In a variant of the invention, a pressure bush is designed as a stepped bushing, wherein a pressure force resulting from the pressure bush in the direction of the mating surface acts inwardly.

In such a variant, it is particularly advantageous if the pressure bush with respect to an angular position acts as a positional securing of the insert ring. The axial piston machine can be made adjustable.

According to the invention it is preferred if the insert ring has a receptacle for a shaft bearing of the drive shaft. In one embodiment of the invention, the axial piston machine is designed with a charge pump, via which the low-pressure side inflowing pressure medium can be acted upon with a boost pressure.

An impeller wheel of a charge pump can be guided on the drive shaft and taken away by it.

A variant of the invention provides that the impeller wheel, at least in sections, forms a sealing gap with at least one insert ring. In one embodiment of the invention, the axial piston machine is designed as a double axial piston machine, wherein in a common housing two cylinder drums is designed with facing floors, each of these floors is designed with an insert ring in the sense of the above.

In the area between the cylinder drums, a charge pump can be arranged, via which the pressure medium can be acted upon by a charge pressure on the low-pressure side. The execution of an axial piston machine with a charge pump is particularly advantageous at high speeds, even with a single axial piston machine.

In a Doppelaxialkolbenmaschine each cylinder drum may be associated with a drive shaft, which are connected via a coupling socket. The insert ring according to the invention has a high-pressure channel section which has a frontal and a radial or axial mouth section. Furthermore, this insert ring is optimized with respect to the manufacturing process, the design or the choice of material to the pressure conditions and preferably made of ductile iron. In principle, high-strength and ductile special castings can also be used. The insert ring can - as stated above - be designed as a forged or made of a solid part by machining.

The compressive strength of the insert ring can be increased by suitable heat treatment, for example by tempering, nitriding or gas hydro carbonation.

Preferred embodiments of the invention are explained in more detail below with reference to schematic drawings. Show it:

Figure 1 shows a longitudinal section through a single axial piston machine;

FIG. 2 shows a longitudinal section through a double axial piston machine;

Figure 3 is a detail view of the axial piston machine of Figure 2; FIG. 4 shows a detailed illustration of the axial piston machine according to FIG. 3 in a further enlargement; Figures 5 and 6 are views of a first insert ring of the double axial piston machine of Figure 1;

Figures 7 and 8 are corresponding views of another insert ring of Doppelaxialkolbenmaschine according to Figure 2 and

FIG. 9 shows a variant of the embodiment according to FIG. 1.

In the following the invention will be explained with reference to two embodiments, wherein Figure 1 show a Einfachaxialkolbenpumpe and Figures 2 to 8 show a Doppelaxial- piston machine. Since the basic structure of such axial piston machines from the prior art is well known, only the components essential for understanding the invention will be explained below.

The single-axial-piston pump 1 according to FIG. 1 has a pump housing 2 in which a drive shaft 4 is mounted, whose left end section protrudes out of the pump housing 2 in FIG. 1 and is provided with an external toothing 6 via which a drive can be coupled. In the central region, the drive shaft 4 has a further external toothing 8, which meshes with a corresponding internal toothing of a cylindrical drum 10. This has a multiplicity of cylinder bores 12 lying on a common pitch, in each of which a piston 14 is guided. This limits together with the cylinder bore 12 a working space 16 whose volume is dependent on the piston stroke. A remote from the working space 16 Kolbenfuß 18 each piston 14 is pivotally connected to a shoe 20. This is located on a rotatably mounted in the pump housing 2 swash plate 22, wherein the angle of attack of a contact surface 24, on which the sliding shoes 20 slide, determines the piston stroke. Depending on the configuration of the axial piston this pitch can be made adjustable or invariable. The cylindrical drum has on its right in Figure 1 end face an end wall 26 in which a plurality of lying on a common pitch channels 27 are formed, which open on the one hand in the working space 16 and on the other hand in the outer end face 28 of the end wall 26. This is executed concave spherical and is slidably mounted on a housing fixedly mounted control disc 30, in which in a conventional manner pressure kidney 32 and a comparatively large suction kidney 34 are formed. The basic structure of such kidneys will be explained below with reference to FIGS. 5 to 8. The pump housing 2 is designed in several parts and has a frontal

Lid 36 which is placed on an approximately pot-shaped housing 38. The drive shaft 4 is mounted on roller bearings in the pump housing 2, wherein a rolling bearing 40 is received in the housing 38 in the region of the cover 36 and another rolling bearing or a rolling bearing assembly 42. The pot-shaped housing 38 has a pot bottom 44, which forms in the figure 1 to the right side of the end face of the pump housing 2. In the illustrated embodiment, a pressure port P and a suction port T are formed radially in this pot bottom 44 and are connected via a pressure channel 46 or a suction channel 48 to the above-mentioned pressure kidneys 32 and the suction kidney 34.

According to the invention an insert ring 50 is inserted into the bottom of the pot 44, which is formed of a comparatively high-strength material, such as nodular cast iron with additional heat treatment, while the housing 38 may be made of a material with comparatively lower compressive strength, for example, cast iron or light metal casting or the like. In the insert ring 50, an HD channel portion 52 and an ND channel portion 54 are formed, which are each designed as an angular channel. An axial mouth region 56 or 58 overlaps the pressure kidneys 32 and the suction kidney 34, respectively. A mouth region which opens in the radial direction then opens into the respectively adjacent pressure channel 46 or suction channel 48.

The insert ring 50 explained in greater detail below is inserted into a receptacle of the pot bottom 44, which is designed as a stepped bore 59. This is in the Representation of Figure 1 to the left in the radial direction extended, so that a radially projecting shoulder 140 of the insert ring 50 (see also Figure 5) is supported in the axial direction on a shoulder of the stepped bore 59. The radial guidance takes place along the outer peripheral surface 170 (see FIG. 6) of the shoulder 140 and the outer circumferential surface of a ring section 142 of the insert ring 50 explained in more detail with reference to FIGS. 5 and 6, which are supported in the radial direction on the peripheral surfaces of the stepped bore 59.

As can be seen further from FIG. 1, an end section of the drive shaft 4 passing through the insert ring 50 is designed with a shaft toothing 61 so that a through drive option, for example for a double pump, can be realized. In the embodiment shown in Figure 1, the stepped bore 59 of the pot bottom 44 expands to the right, so that a receptacle 63 for the bottom of the pot 44 end capping closure 65 is formed. This is accepted for versions with Durchtriebsoption.

As can be seen in FIG. 1, the inner diameter of the stepped bore 59 and the outer diameter of the correspondingly stepped insert ring 50 are significantly larger than the diameter of the drive shaft 4, so that a comparatively large opening is formed in the pot bottom 44, which is much easier to control by casting, since on the one hand the core can be made more massive and the other

Material accumulations, such as occur in the prior art can be avoided.

As shown in Figure 1, the roller bearing 42 is inserted into a receiving space 60 of the insert ring 50, wherein an axial support also takes place via the control disk 30, so that the roller bearing 42 is fixed by the insert ring 50 and the control disk 30 in the axial direction. Further details of this insert ring 50 will be explained below. In the region of the pressure port P is a pressure bushing 62 in the pressure channel

46 used. As will be explained in more detail below with reference to FIG 4, this pressure bushing 62 is formed stepwise and so acted upon by high pressure or housing pressure, that is a radially inwardly acting Druckkraftsultierende established. The lower end portion of the pressure bush in FIG. 1 lies snugly against a mating surface of the insert ring 50, so that it is fixed in position via the pressure bushing 62. Further details of the pressure bushing 62 will be explained below with reference to FIG.

As already mentioned, the pump housing 2 or, more precisely, the pot-shaped housing 38 is subjected to considerable pressure forces during operation of the axial piston pump, in particular in the region of the pot bottom 44 adjoining the control disk 30. These are inventively absorbed by the insert ring 50, which is tuned to this pressure load in terms of its geometry and the choice of material. This makes it possible to design the pot-shaped housing 38 with a comparatively simple structure, which is easy to control by casting technology. In the embodiment of a double-axial piston machine described below, this concept is adopted accordingly. In principle, in such a double-axial piston machine, the unit according to FIG. 1 is mirrored about an axis of symmetry located in the bottom of the pot so that a central housing 38 (for the sake of simplicity, the same reference numerals are used below for the sake of simplicity) is shown in FIG , which has a central part 64, in which two pressure ports P1, P2 and two in this illustration dashed lines indicated tank ports T1, T2 are formed, which are each associated with a unit 66, 68 of the Doppelaxialkolbenpumpe 1.

The housing 38 of this double unit is then designed correspondingly "double-cup shaped", wherein the middle part 64 forms the bottom of the pot 44 of both units 66, 68. To this middle part 64 are each cylindrical housing walls 70, 72 attached, which together with the outer covers 36, 74 form a receiving space for the cylinder drums 10, 76 of the unit 66, 68. The basic structure of each of these units 66, 68 corresponds in principle to that of the single-axial piston machine described above, so that detailed explanations with reference to the relevant explanations are dispensable. Accordingly, each unit 66, 68 has a drive shaft 4 or 78, wherein the drive shaft 78 assigned to the second unit 68 does not project out of the cover 74 but is connected in a rotationally fixed manner to the drive shaft 4 via a coupling bush 80 explained in more detail below. As described for example in DE 195 36 997 C1, such Doppelaxialkolbenmaschinen can be designed with a charge pump 82. In the concrete solution, this charge pump 82 is formed by an impeller, which is rotatably connected to the drive shaft 4 and via which the insert rings 50, 86 are acted upon suction side with a boost pressure. In the illustrated solution, an impeller 84 is axially guided on the drive shaft 4 and supported and sealed relative to the respective insert ring 50, 86 with a minimum gap. Further details of this arrangement will be explained with reference to the following figures.

FIG. 3 shows an enlarged view of the central part 64 of the double axial piston machine 1 according to FIG. 2. It can be seen that in each case a pressure bush 62, 88 is inserted in the region of the two pressure ports P1, P2, each serving as an axial securing device for the associated insert ring 50, 86 serves. The HD pressure medium flow path is - in accordance with the embodiment described above - formed with a pressure channel 46, 90. This each passes into an HD channel section 52 or 92 of the insert ring 50 and the insert ring 86. At these two insert rings 50, 86 each end face a control disk 30, 94, in the pressure kidney 32, 96 and the suction kidney 34, 98 are formed.

As explained above, the pressure kidneys 32, 96 and the suction kidneys 34, 98 during the rotation of the cylinder drums 10, 76 are alternately in fluid communication with the working spaces 16. In the illustration according to FIG. 3, the impeller wheel 84, which is mounted on the drive shaft 4 with an axially projecting hub 100, can be clearly seen, wherein internal teeth are formed in the hub 100, which meshes with an external toothing 102 formed on the end section of the drive shaft 4 , Via the impeller wheel 84 pressure medium is sucked from a suction chamber T and conveyed into a charge pressure chamber 104. The charge pressure chamber 104 connected to the connections T1, T2 is connected to the suction kidneys 34, 98 via suction-side LP channel sections 54, 105. As already mentioned, the two drive shafts 4, 76 are non-rotatable via a

Coupling sleeve 80 is connected, which meshes on the one hand with the external teeth 102 of the drive shaft 4 and on the other hand with a corresponding external toothing 106 of the drive shaft 78. Figure 4 shows a further enlarged partial view of the central portion 64 in the region of the two pressure bushes 62, 88. It can be seen a part of the impeller 84 with the hub 100, which is rotatably connected to the drive shaft 4. According to this representation, the insert ring 50 has an end face to the Impellerrad 84 projecting circumferential sealing collar 108 which engages around the outer periphery of the impeller 84 sections, so that it is sealed in the radial direction with minimal gap. The radial seal against the insert ring 86 takes place accordingly.

As is also illustrated in FIG. 4, a gap 107, 109 exists in the axial direction between face surfaces 101 and 103 of the impeller wheel 84 and the adjacent end face portions of the insert ring 50, 86, respectively. The hub 100 dips into a stepped position, towards the left (Figure 4) expanding axial bore 1 10 of the insert ring 50 and is guided in this area with a small gap and thus also sealed in the radial direction. This axial bore 1 10 is - as already explained with reference to Figure 1 - tert to a receiving area 60 for the rolling bearing 42 tert. This receiving space 60 is supplemented with a front recess 1 12 of the control disk 30 to a receptacle for the rolling bearing 42, so that it is supported in the axial direction. An outer ring of the rolling bearing 42 serves to center the control disk 30. The inner peripheral surface of the hub 100 is on the one hand in the axial direction a shaft stage 1 1 1 supported and guided over a fit 1 13 on the outer circumference of the drive shaft 4 in the radial direction. The axial fixation of the Impellerrads 84 takes place by a retaining ring 1 15. For axial support of the insert rings 50, 86 are on the central part 64 support shoulders

1 17, 1 19 formed on which corresponding annular end faces of the insert ring 50 and 86 abut.

The construction of the two identical pressure sockets 62, 88 is shown in FIG. 4. Accordingly, each pressure bush 62, 88 has an inclined radial shoulder 14, so that the insert-ring-side end section has a smaller diameter than the connection-side end section of the pressure bushing 62. At the latter part of the pressure bushing 62 above (Figure 4) of the radial shoulder 1 14 an annular groove with a sealing ring 1 16 is formed, which bears sealingly against a peripheral wall of the pressure channel 46, in which the pressure bushing 62 is inserted. The connection-side end portion of the pressure bushing 62 is slightly radially reset, so that an annular gap 1 18 formed between said peripheral wall of the pressure channel 46 and the outer periphery of the pressure bushing 62. This annular gap 1 18 ends at a distance from the sealing ring 1 16 and is extended in this area to an annular groove 120 which are acted upon via one or more radial bores 122 of the pressure bushing 62 with the pressure at the pressure port P. Thus, this pressure acts on the larger annular end face 124 of this pressure bushing 62. The smaller ring end face 126, which is located at the bottom in FIG. 4, is also subjected to the pressure in the pressure channel 46 or in the HD channel section 92. The inclined radial shoulder 1 14 is acted upon via an annular gap 128 between the outer periphery of the smaller end portion of the pressure sleeve 62 and the peripheral wall of the pressure channel 46 with the housing pressure, which corresponds approximately to the tank pressure and thus substantially lower than the pressure at the high pressure port P. is. Accordingly, the pressure bushing 62 is acted upon along one of the surface of the radial shoulder 1 14 corresponding surface difference radially inwardly with the high pressure, so that the pressure bushes 62, 88 are always acted upon in the direction of the associated insert ring 50, 86. The end section of the pressure bush 62 designed with the annular end face 126 dips into a corresponding radial mating receptacle 130 of the insert ring 50 so that it is fixed in the circumferential direction is. The insert ring 86 is formed accordingly and is thus fixed in position via the sealing bushing 88. The radial centering of the insert rings 50, 86 takes place in each case via their stepped peripheral surfaces, which are encompassed by correspondingly stepped centering webs 132, 134 or 136, 138 of the middle part 64.

Details of the two insert rings 50 and 86 will be explained with reference to Figures 5 to 8. 5 and 6 show the insert ring 50 in a three-dimensional representation (FIG. 5) and in a diagonal section (FIG. 6). The illustration according to FIG. 5 shows the gradation of the insert ring

50 of the control-disc-side shoulder 140 and an opposite annular portion 142, which is radially set back relative to the control-disk-side end portion 140. A step surface 141 is used for axial support on the explained on the basis of Figure 4 housing-side support shoulder 1 17 and absorbs all engine forces. In the ring section 142 or over both sections, the fitting receptacle 130 is formed for the pressure bushing 62. According to the geometry of this control disk 30, in the end section 140 of the insert ring 50, the low-pressure-side orifice region 58 already explained with reference to FIG. 1 and the high-pressure-side orifice regions 56 are shown in the end section 140 of the insert ring 50 the HD / ND channel sections 52, 54 formed in the insert ring 50 are provided. Thus, in the concrete exemplary embodiment, three approximately kidney-shaped high-pressure-side mouth regions 56 and a comparatively large kidney-shaped low-pressure side mouth region 58 are formed whose geometry is designed in accordance with the suction / compression kidneys of the control disk 30. Furthermore, a fixing bore 146, into which a corresponding projection of the control disk 30 is inserted, also opens into the support surface 144, so that these two components are positioned at right angles. As explained above, the axial centering of the control disk 30 takes place via the outer ring of the rolling bearing 42 (see FIG. 4).

The course of the channel sections 52, 54 can be clearly seen from FIG. 6. Accordingly, both channel sections 52, 54 have an angular configuration, wherein the mouth regions 56, 58 each extend in the axial direction in the bearing surface 144 of the control element. the disc-side end portion 140 open. In this embodiment, the channel sections are formed angular, since the axial piston pump 1 has lateral P and T ports. In the case of rear connections of a single pump, the channel sections 52, 54 could also be designed to be straight through.

The mouth regions oriented towards the pressure connection P or the suction connection T open radially in the circumferential wall in the transition region between the control-side end section 140 and the ring section 142 which is radially recessed.

As already explained, the axial bore 1 10 of the insert ring 50 is on the one hand expanded to a receiving region 60 for the rolling bearing 42. The adjoining part of the axial bore 1 10 (left in Figure 6) is set back radially and forms a shoulder 148 for the axial limitation of the installation space for the outer ring of the rolling bearing 42, which is formed on the drive shaft 4 as a floating bearing. In the region of the end face of the ring section 142, in the case of an impeller design, the sealing collar 108 already explained in FIG. 4 is formed, which surrounds the impeller 84 in sections in the circumferential direction. As mentioned above, such an impeller can be designed both in a single pump and in a double pump. In principle, however, both pump constructions can also be realized without an impeller. In a single pump without charge pump, the insert ring 50 may be performed without the sealing collar 108.

The hub 100 of the Impellerrads 84 is, as already mentioned above, executed in the radial direction with respect to the insert ring 50 with play and thus guided only on the drive shaft 4.

FIG. 7 shows the insert ring 86 of the unit 68, which in principle has a similar design. This has a control-disk-side end section 150 with the three kidney-shaped, pressure-side mouth regions 56 and the comparatively large low-pressure-side orifice region 58 and the fixing bore 146. In the illustration according to FIG Further, the mating receptacle 152 for the pressure bushing 88 of the unit 68. This mating receptacle 152 terminates in the transitional rich between the ring portion 154 and the end portion 150 of the insert ring 86, which is reset in the radial direction. The thus formed step 163 is used, as already explained, for the axial fixation of the insert ring 86 on the support shoulder 1 19 shown in Figure 4 and thus for supporting the axial engine forces. The step 163 limits the installation space for the rolling bearing 40.

In the illustration according to FIG. 7, a recess 156 is also visible, which opens towards the suction chamber T, so that the pressure medium can flow via this recess 156 to the impeller wheel 84.

According to the sectional view in FIG. 8, in the end face of the annular section 154, the impeller wheel side again has a front recess whose peripheral walls form a sealing collar 158 which surrounds a section of the impeller wheel 84 with a sealing gap so that it separates the boost pressure region from the suction pressure region. An axial bore 160 of the insert ring 86 is extended in the region of the control disk-side end portion 150 to a receptacle 162 for the right in Figure 2 bearings 164. The adjoining to the left region of the axial bore 160 is contrast radially reset. As can be seen in FIG. 4, the two outer circumferential surfaces 166, 168 of FIG

Ring portion 154 and the end portion 150 of the insert ring 86 to the associated ring lands 136, 138 at. In the same way, the above-described insert ring 50 is centered with its outer peripheral surfaces 170, 172 via the centering webs 132, 134. The support shoulders 1 17, 1 19 each serve for axial force absorption.

In approximately the same manner as in the insert ring 50, the high-pressure side channel portion 52 of the insert ring 86 is designed as an angular channel and opens via the ren renal estuaries 56 in the end face 144 of the end portion 150, while the connection-side mouth area in the peripheral wall of the insert ring 86 opens. In this transition region (154-150), also the fitting receptacle 152 for the pressure bushing 88, which is already designated with reference to FIG. 7, is formed. The low-pressure-side channel section 54 terminates in the kidney-shaped mouth region 58 on the face side and in the radial direction in the circumferential region of the insert ring 86. FIG. 9 shows the pot bottom side region of a variant of the exemplary embodiment according to FIG. 1. In this embodiment, the channel sections 52, 54 are designed to be angular and lead to the corresponding terminals P, T out in the peripheral region of the insert ring 50, so that correspondingly the housing-side terminals P, T are also arranged in the radial direction. In the variant according to FIG. 9, the ND-channel section 54 and the HD-channel section 52 extend approximately parallel to the axis of the shaft 4, so that they are removed from the control disk 30

End portions of the channel sections 52, 54 in the right in Figure 9 end face 176 of the insert ring 50 open. Such insert ring 50 is likely to be easier to produce due to the approximately coaxial channel guide as an insert ring with a radial mouth area.

In the embodiments described above, the insert rings 50, 86 and the associated control discs 174 (see Figures 2 and 4) are designed as separate components. In a variant of the invention, the control discs 30, 174 and the associated insert rings 50, 86 can also be made in one piece. This development has the advantage that the relatively production-intensive machining of the contact areas between these two components can be omitted. This variant has the further advantage that the machining of the spherical reversing surface, along which the control disk 30, 174 rests against the correspondingly concave end face of the respective cylinder drum 10, 76, takes place on a comparatively compact and thus better workable component. Disclosed is an axial piston machine with a casting-optimized housing, in the bottom of which is formed with respect to the pressure load optimized insert ring. Further disclosed is an insert ring for such an axial piston machine. LIST OF REFERENCE NUMBERS

1 axial piston machine

2 pump housings

4 drive shaft

6 external toothing

8 more external teeth

10 cylinder drum

12 cylinder bore

14 pistons

16 workspace

18 piston foot

20 shoe

22 swash plate

24 contact surface

26 end wall

27 channel

28 face

30 control disk

32 print kidney

34 suckling kidneys

36 lids

38 housing

40 rolling bearings

42 rolling bearings

44 pot bottom

46 pressure channel

48 suction channel

50 insert ring

52 HD channel section

54 ND channel section

56 mouth area

58 mouth area 59 stepped bore

60 recording area

61 shaft toothing

62 pressure bush

63 recording

64 middle section

65 cap

66 unit

68 unit

70 housing wall

72 housing wall

74 Lid

76 cylinder drum

78 drive shaft

80 coupling socket

82 charge pump

84 impeller wheel

86 insert ring

88 pressure bush

90 pressure channel

92 HD channel section

94 control disk

96 pressure kidneys

98 suckling kidney

100 hub

101 plane surface

102 external toothing

103 plane surface

104 Booster pressure chamber 05 ND duct section

106 external toothing

107 gap

108 sealing collar 109 gap

1 10 axial bore

1 1 1 shaft level

1 12 frontal extension

1 13 fit

1 14 radial shoulder

1 15 Circlip

1 16 sealing ring

1 17 Support shoulder

1 18 annular gap

1 19 Support shoulder

120 ring groove

22 radial bore

124 ring end face

126 ring end face

128 gap

130 registration

132 centering bar

134 centering bar

136 Centering bar

138 Centering bar

140 steering-wheel-side shoulder

141 step surface

142 ring section

144 bearing surface

146 Fixing hole

148 shoulder

150 control-side end portion

152 registration

154 ring section

156 recess

158 sealing collar

160 axial bore admission

step

roller bearing

Outer circumferential surface

control disc

face

Claims

claims

Axial piston machine with a pump housing (2) in which a cylinder drum (10, 76) is mounted with a plurality of a respective working space (16) defining piston (14) which are supported on a preferably adjustable swash plate (22), wherein the working space (16) via a front side in the pump housing (2) arranged control disc (30, 174) is alternately connectable to a low pressure and a high pressure channel and wherein the cylinder drum (10, 76) rotatably connected to a drive shaft (4, 78), characterized characterized in that the housing (2, 38) is approximately pot-shaped with a pot bottom (44) which is partially formed by an insert ring (50, 86) on which the drive shaft (4, 78) is mounted and in which a HD Channel section (52) is formed which preferably has an axial control-disk-side orifice region (56) and preferably a radial or axial HD-channel-side orifice region, wherein the insert ring (50, FIG. 86) is optimized by design, material selection or manufacturing process with respect to the pressure load.

Axial piston machine according to claim 1, wherein the insert ring (50, 86) in a housing-side receptacle (63) is inserted, whose diameter is significantly greater than the diameter of the drive shaft (4, 78).

Axial piston machine according to claim 1 or 2, wherein the insert ring (50, 86) is a casting, preferably a nitrided cast steel part, a heat treated spheroidal cast iron part or a forged part or from a solid part

Machining is made.

Axial piston machine according to claim 1, 2 or 3, wherein in the insert ring (50, 86) an LP channel portion (54) is formed with a radial and / or an axial mouth region (58).

Axial piston machine according to one of the preceding claims, wherein in the radial mouth region of the HD channel section (52) has a fitting receptacle (130, 152) for a pressure bushing (62, 88) is formed.

6. Axial piston machine according to claim 5, wherein the pressure bush (62, 88) is stepped, so that a pressure force resulting in the direction of the fitting receptacle (130, 152) is effective.

7. Axial piston machine according to claim 5 or 6, wherein the pressure bush (62, 88) forms a position assurance of the associated insert ring (50, 86).

8. Axial piston machine according to one of the preceding claims, wherein the control disc (30, 174) and the insert ring (50, 86) are made in one piece.

9 axial piston machine according to one of the preceding claims, wherein the insert ring (50, 86) has a receptacle (60, 162) for a shaft bearing (42, 164).

10. Axial piston machine according to one of the preceding claims, with a charge pump (82) via which the low-pressure side inflowing pressure medium can be acted upon with a boost pressure.

1 1. Axial piston machine according to claim 10, wherein an impeller (84) on the drive shaft (4) is guided.

12. axial piston machine according to claim 10 or 1 1, wherein an impeller (84) of the charge pump (82) at least partially with one or both

Insert rings (50, 86) forms a sealing gap.

13. Axial piston machine according to one of the preceding claims, wherein this is designed as a double axial piston machine with two in a housing aufgenomme- nen cylinder drums (10, 76), which at least one drive shaft

(4, 78), wherein each unit (66, 68) of the double axial piston machine is associated with an insert part (50, 86) in the sense of at least one of the preceding claims. Axial piston machine according to claim 13, with two drive shafts (4, 78), which are connected to each other via a coupling bushing (80).

Insertion ring for an axial piston machine according to one of the preceding claims, comprising an HD channel section (52) having a frontal and an axial or radial mouth region (56), wherein the insert ring (50, 86) is made as a cast or forged part or by machining ,

Insertion ring according to claim 15, wherein its compressive strength is increased by heat treatment.