WO1989006750A1

WO1989006750A1 - Hydrostatic axial piston engine, in particular for a motor vehicle gearbox with power split

Info

Publication number: WO1989006750A1
Application number: PCT/DE1989/000017
Authority: WO
Inventors: Michael Meyerle
Original assignee: Michael Meyerle
Priority date: 1988-01-16
Filing date: 1989-01-16
Publication date: 1989-07-27
Also published as: EP0357698B1; ATE124498T1; DE58909319D1; EP0357698A1

Abstract

A hydrostatic axial piston engine, in particular for a motor vehicle gearbox with power split, comprises a preferably interlocking holding device (40; 75) and a spring-loaded stabilizing device for the cylinder block (2) which is actuated by springs (24). The holding device (40; 75) has an accessory device for hydraulic and/or spring-assisted reinforcement of the holding forces. The stabilizing device for the cylinder block (2) has an additional hydraulic device for additional reinforcement of the stabilizing forces. The holding and stabilizing forces are automatically adapted to the various operating and load conditions with a view to improving the efficiency. An automatic adjustment device for the valve plate (31) ensures automatic adjustment of the valve plate (31) independent of the load or adapted to the operating conditions, also with a view to improving the efficiency and reducing engine noise.

Description

Hydrostatic axial piston machine, in particular for a motor vehicle transmission with power split.

The invention relates to a hydrostatic axial piston machine, in particular for motor vehicle transmissions with power split according to the preamble of claim 1.

Hydrostatic axial piston machines of this type are widely known for their predominant use in construction machine gearboxes. These well-known hydrostatic transmissions are almost unsuitable for demanding use in gearboxes for passenger vehicles due to their unfavorable efficiency and the excessive noise level.

The object of the invention is to develop a hydrostatic axial piston machine, in particular for use in power split transmissions for cars or bus transmissions, in which the efficiency is improved and, moreover, the noise level is reduced.

The object is achieved by the features listed in the main claims 1, 2, 16, 17 and 22. Further advantageous refinements emerge from the subclaims and the description.

The invention is explained using exemplary embodiments with reference to drawings. Show it Eigur 1 shows a longitudinal section of the hydrostatic axial piston machine according to the invention with positive and non-positive hold-down device and a device with spring force pressure and hydraulic pressure of the cylinder block on its valve plate.

Eigur 2 a partial section of the positive and non-positive hold-down of the pistons 3

Own 2a shows a partial section of a hydraulic hold-down device

3 shows a partial section "X" according to Eigur 2, in which the spring element is shown as an elastomer

Own 3a shows a partial section "Y" according to Eigur 3 in the installed state

Eigur 4 Representation of the Eeder element as a stamped and 4a embossed flax coil spring

Eigur 5 partial section of the positive and non-positive hold-down and 5a bracket with a spring element designed as an O-ring or Eormring

FIG. 6 partial section of a piston for axially pressing the cylinder block onto the control surface with a special "molded sealing ring with a sealing lip

7 shows an adjustable control disk according to section "Z" FIG. 8

8 shows a longitudinal section of the hydrostatic axial piston machine according to the invention similar to FIG. 1, but with an additional hydraulic hold-down device

9 shows a longitudinal section as in FIG. 8 with two internal springs for the hold-down device

The unfavorable hydraulic efficiency in the known hydrostatic axial piston machines is to a large extent also due to the fact that the form-fitting hold-down device is associated with a sealing problem, which is due to the fact that the sliding shoes 4 are not full enough of their counter sliding surface in all operating states Apply swash plate 11, which with the Hydrostatic circuit-related high-pressure oil of the hydrostatic sliding bearing between the sliding shoes 4 and the swash plate is lost to an increased extent, which leads to relatively high and uncontrollable leakage losses. In order to eliminate this, the invention has a hydraulic hold-down device 75 according to the invention, FIG. 2a, as a separate or additional hold-down device or / and a spring-elastic hold-down device in order to ensure the leakage oil losses between the sliding shoes 4 and the sliding plane for all operating states to reduce the inclined surface or pressure plate 11 to a minimum.

The known hydrostatic axial piston machines have, for the axial pressing of the cylinder block against its control disc, depending on the embodiment, internal springs which have a sufficiently high spring force for the entire speed range. The spring force depends on the maximum permissible speed and is adjusted with a correspondingly high value. This means that the spring force is unnecessarily high for lower engine speeds, which are approximately one third of the maximum engine speed in the main operating area, for example. The consequence of this is that unnecessarily high friction losses or power losses occur in the main operating area. In order to achieve a targeted adaptation to the respective operating conditions with the lowest possible friction losses, the invention provides an adaptation of the pressing forces of the cylinder block to its control disk which is specific to the operating conditions, in that the cylinder block 2 has a spring 24 with a for a low speed constant spring force and an additional variable hydraulic contact pressure is specifically pressed onto its control surface 37. The variable hydraulic contact force is essentially dependent on the size of the speed of the drive motor. In special cases, it is possible to modulate or correct this pressure as a function of the hydrostatic pressure or the tensile force using a corresponding control device. An annular piston 20, which is supported against the drive shaft 10 and contains a sealing ring 21 or 28 for sealing against the cylinder block, which sits in a corresponding groove of the annular piston, is used for the hydraulic cylinder block pressure. On the opposite side, another annular piston 22 is provided, which is connected to the cylinder block 2 and via a fuse. ring 27 is axially fixed. This annular piston 22 has a sealing ring, which is expediently directed inwards to the shaft 10 and is designed as an O-ring 23 or as a shaped ring 28 with a radially elastic sealing lip 29 or as a piston ring with radial play to the groove base. With regard to a torque-dependent deflection of the shaft 10, which can lead to a corresponding radial displacement of the cylinder block 2, the sealing ring 28 according to FIG. 6 is designed as a special shaped ring with an elastic sealing lip 29, which has a corresponding radial, largely free of lateral forces Allows displacement of the cylinder block 2. This also applies to the ring pistons

The hydraulic oil pressure is expediently supplied to the piston chamber 25 centrally through a shaft 55 or 10 via a bore 26.

This device causes a specifically metered pressing of the cylinder block 2 against its control surface 37 and thus an optimization of the efficiency within this functional range.

The hydraulic hold-down device 75, FIG. 2a, provides hydraulic pressing of the perforated disk 6 against the sliding shoes 4-. According to the invention, this hold-down device 75 is equipped with a hold-down ring 7, which is non-rotatably but axially movable against the perforated disk 6 in the inclined body or in the swash plate 5. The hold-down ring 7 is supported against a retaining ring 8 and possibly a washer 76, which serves as a one-piece washer. A spring element 77 is located between the locking ring or disk 76 and the hold-down ring 7 arranged. This spring element 77 is preferably formed element or elastomer element as Gummi¬, the ^'nut in a ring of the retaining ring is inserted. 7 In the axial direction, the spring element 77 acts against the hold-down ring 7 with a certain spring force. The pressure oil required for generating the hydraulic contact pressure is led into the hold-down ring 7 via oil lines 79, the oil pressure against the sealing and Spring element 77 acts. Depending on the oil pressure and the effective area on the sealing or spring element 77, an axial force is exerted on the holding-down ring 7 against the perforated disk 6. Depending on the operating state, a specific oil pressure is generated, which is dependent, for example, on a speed signal or / and a load-dependent signal and / or a feed or supply pressure for the hydrostatic transmission and the control and regulating device. The required contact forces are usually dependent on the speed. In accordance with this requirement, a targeted contact pressure can be generated with this device via a speed-dependent pressure, which is present in this way in the automatic car transmission of this type. The hold-down forces are thus relatively low in the main operating area, for example in the case of a passenger car, as a result of which the friction losses between the perforated disk 6 and the hold-down ring 7 can be substantially reduced. According to the invention, the holding-down ring 7 has additional recesses on the sliding surface opposite the perforated disk 6, for example in the form of an annular groove 80 and a transverse groove 81, which are connected together with the hydraulic system of the hydraulic holding-down device and for lubricating the sliding surfaces between the holding-down ring 7 ^• and serve the perforated disc 6. The amount of lubricating oil can be metered through a throttle bore 84 in the inflow to the lubrication system.

The sealing and spring element 77, when used in the hydraulic hold-down device 75, is expediently designed as a rubber element or elastomer element which, as shown, has one or two sealing lips projecting in the axial direction to support the axial spring force and at the same time seal tion of the hydraulic oil. A circumferential oil space is created between the two sealing lips, which ensures a uniform hydraulic pressure.

The hydraulic hold-down device 75, in the form shown, can be produced relatively inexpensively, since no high manufacturing accuracy of the height dimensions for the hold-down ring 7 and the perforated disk 6 is required, since even larger dimensional deviations can be compensated for by the sealing or spring element 77 . In addition, a relatively simple dimension setting by means of the disk 76, which is designed as an insert disk in various thickness dimensions, can also be implemented very economically, even for very high production quantities. This also applies to the form-fitting, spring-loaded hold-down device 40 in connection with this adjusting disk 76, which is not shown in the drawings.

The oil feed pipe 78 for the hydraulic hold down bracket 75 is connected to ^'the hold-down ring 7 and serves gleich¬ time to prevent rotation relative to the helical body bzw.- pivot body. 5

With this hold-down device 75 with simultaneous lubrication of the rotating perforated disc 6, there is no need to fill the hydrostatic transmission space with oil. The hydrostat components can work in the oil-free space, which eliminates the splashing losses and thus significantly improves the efficiency. The low friction forces also reduce the friction temperature and wear in favor of greater stability of the corresponding components.

The form-fitting hold-down device 40 essentially consists of a perforated disk 6 which is held in place via the hold-down ring 7 and a locking ring 8 with little axial play "B". The perforated disc 6 rotates with the cylinder block 2 and the piston 3, the holding-down ring 7 being mounted in the inclined or swiveling body 5 so as to prevent rotation. To prevent rotation, protruding drivers 14, which engage in recesses 15 of the inclined body 5, serve on the holding-down ring 7. The swash plate or pressure plate 11 likewise has drivers 12 which engage in recesses in the swivel body 5 for securing against rotation. These recesses 13 and 15 for securing the pressure plate 11 or the hold-down ring 7 against rotation are cast into the swivel body 5, preferably in a cost-saving manner. A spring element 9 or 46, 41 is, as shown in Figure 3, 3a, formed as an elastomer in the form that inwardly directed resilient segments 41 with the dimension "F" are connected to a closed ring 46 as possible, the engage in recesses 43 of the hold-down ring 7 and are resiliently supported against the retaining ring 8 and the hold-down ring 7. These resilient sub-segments 41 have a special profile 52 which is designed such that, at a relatively high spring rate, a fairly exact axial force is generated on the hold-down ring 7 of the perforated disc 6 and the sliding shoes 4 against the slant plate or pressure plate 11 becomes. As shown in FIG. 3a, the spring profile 52 is comb-shaped, the spring rate depending on the comb shape and the degree of softness of the elastomer. The recesses 43 for the spring segment 41 can be cut inexpensively without cutting, for example when using the sintering or die-casting technique for the hold-down ring 7 or it can also be milled, all recesses being able to be produced very efficiently in one operation. When using milling technology, however, it is advisable to design the spring segment 41 in a radius-like manner, as in FIG. 4, and to adapt the recess 19 accordingly. In the segment areas "G", the hold-down ring 7 has a U leading edge 47 which lies in the diameter area of the inner diameter 48 for the locking ring 8 or is only slightly smaller. Since the supporting edge diameter 47 of the Niderhalteringes 7 and 48 for the locking ring 8 have almost the same diameter, it is prevented that an axial force-dependent tilting moment the locking ring 8 is prevented in order to ensure that the locking ring, which is open at one point, is securely seated in all operating situations. The spring element according to FIG. 4 is made in the form of a flat spring or from flat material and has inwardly directed spring parts 16 with projecting resilient tongues 17 which engage in recesses 19 of the hold-down ring 7 and against the hold-down ring 7 and the Support circlip 8. The spring parts 16 can be connected to one another via a circumferential ring 18 and thus be formed in one piece or can be inserted loosely in the recesses 19 as separate individual members (FIGS. 4, 4a).

5 and 5a show a form-fitting hold-down device with a spring element, which is designed as an elastomer in the form of an O-ring or profile ring 72 and lies in an annular groove 44 or 73 of the hold-down ring 7. The profile ring 72, such as the Federelemerite 9; 6, 17 have the advantage of higher spring elasticity compared to the O-ring 45. and a lower spring force-related tilting moment on the locking ring 8 .. Instead of the O-ring 45 or profile ring 72 there is also a steel spring made of flat material or. Steel wire with a cylindrical or square cross section, as not shown in the drawings, can be used. .

In order to further improve the efficiency, the invention provides for the cylinder block 2 to be formed with cast-in sleeves 35 and for the end face 54 of the cylinder block 2 to be conical with an angle oL which approximately corresponds to the maximum swivel angle, the piston running surface 57 with the conical end face 54 of the cylinder block 2 is flush. It is thereby achieved that a longer effective piston guidance is achieved with the same overall length of the axial piston machine compared to the prior art, whereby the lateral force-related frictional forces of the piston 3 are reduced in favor of a further improvement in efficiency.

In this embodiment, the cylinder base 36 of the cylinder block 2, like the piston sleeve 35, is also metallically connected to the cylinder block structure ^' off, that is, it is cast together and consists of a special, low-friction and very resistant alloy known per se, which which has special emergency running properties. This special sliding layer on the cylinder base 36 and on the piston running surface 35 can also be applied in a metal-bonding manner by other methods, for example by a spraying process.

A further improvement in efficiency and, above all, a reduction in noise as a result of targeted adaptation is achieved in that the control disk 31 is not. as is known, is fixedly arranged, but can be rotated automatically as a function of specific operating values. For this purpose, the valve disk 31 is connected to an adjusting piston 32 which, depending on the speed of the drive motor or / and depending on the laser state or the hydrostatic pressure, can be rotated to a limited extent within an angular range. The control disk 31 is provided with kidney-shaped recesses 38 for the two high-pressure lines and additional damping slots 34. Depending on the operating state, the control disk 31 is rotated with regard to noise optimization. In known axial piston machines, there is the disadvantage that these noise damping slots 34 are localized, which means that, with a noise-optimized design, increased leakage oil loss occurs in many operating states, as is generally known to those skilled in the art. As mentioned, the adjustment of the valve disk 31 is triggered by a speed signal and / or a pressure signal of the working pressure or by an electrical signal. The connection of the swivel disk 31 to the adjusting piston 32 takes place via a driver 59 of the control disk which bears against the piston 32 against a spring force. The piston 32 is activated when an adjustment signal is initiated. nals adjusted against the pressure of a spring 33 in the corresponding direction, the control disk via a centering 60; 61 is held in the central position. The adjusting forces are relatively low because the control disk 31 is hydrostatically supported axially on both pressure sides. With regard to the cost optimization, the control disk 31 is inexpensively designed as a sheet metal body, the kidney-shaped recesses 38 and the damping slots 34 being stamped.

FIG. 8 shows an axial piston machine which has a hydraulically effective hold-down device or hold-down device 71 for the piston sliding shoes 4. This hold-down device 71 can be used as an alternative or in addition to the hold-down devices 40 described so far. It is characterized in that the perforated disk 68, which presses down the sliding shoes 40 of the pistons 3, is pressed axially against the sliding shoes 40 by a hydraulic force on the inside diameter. This hold-down device 71 consists of a spherical cap 66 which is pressed axially with its spherical outer surface 67 onto the likewise spherical surface of a perforated disk 68. The axial contact force is generated by a pressure medium in the piston chamber 70, which acts on an axially displaceable piston 64. This axial force is transmitted from the annular piston 64 to the spherical cap 66 by intermediate members - preferably bolts 65 - which are loosely supported in corresponding recesses in the cylinder block 2. As in the embodiment according to FIG. 1, a spring 24 for generating a constant axial force of the cylinder block 2 on the control surface or control disk 31; 37 proposed see, which is fixed axially against the drive shaft 10 via a support ring 62 and on the other side via a support ring or piston ring 22 against the cylinder block 2. A, preferably speed-dependent, pressure is generated in the piston chamber 25 or 70 via the oil line 26, which on one side presses the cylinder block 2 against the control surface 37 or 31, depending on the speed, in addition to the spring force of the spring 24 and on the other side Presses the perforated disk 68 against the sliding shoes 4 of the pistons 3 via the annular piston 64 and the intermediate members — bolts 65, spherical cap 66.

In a further embodiment, not shown, the piston ring 64 is additionally subjected to the spring force of the spring 24, the support ring 62 being omitted and the spring 24 _' and the piston 64 being adapted accordingly. In this embodiment, the spring force of the spring 24 acts with the same spring force on the cylinder block 2, and the hold-down device 71 via the calotte 66. The spring 24 can be designed for a relatively low spring force in favor of lower frictional forces between the piston crown 36 and the Control surface 37 or 31 and in favor of correspondingly low frictional forces in the hold-down device 71. The higher contact forces required for higher speeds are generated by the speed pressure in the piston chamber 70, 25, which is supplied via the oil line 26. The contact pressure for the holding-down device 71, as well as the stabilizing force for the cylinder block 2, is automatically modulated depending on the operating speed, which means in particular that the frictional losses in all operating states are reduced to one The minimum dimension is reduced, and the leakage-related losses on the slide shoes 4 and on the control surface 37 are also minimized to an optimal degree.

The hold-down 71 with hydraulic pressure in the various execution forms, as described and partly not shown in the drawings, can also be used very effectively as an independent hold-down device. The prerequisite for this is that the calotte 66 is additionally spring-loaded, e.g. by a separate spring in the piston chamber 70 or by direct support of the spring 24 on the annular piston 64, the support ring 62 being omitted, or by a spring between the cylinder block 2 and the calotte 66. The perforated disk 68 is made correspondingly thicker.

Another embodiment shown in FIG. 9, similar to the embodiment according to FIG. 8, sees two piston surfaces of different sizes, e.g. an annular piston 64 with a small piston surface and an annular piston 22 with a large piston surface, the hydraulic pressing force of the cylinder block 2 against the control surface 37 and the hydraulic pressing force against the lower bracket 71 being of different sizes. The outer diameter 69 of the annular piston 64 and its inner diameter 86 and the pressing of the cylinder block 2 in the opposite direction of the outer diameter 69 are decisive for the effective hydraulic forces for holding down the sliding shoes 4 of the inner ring piston 64 and the inner diameter 87 of the outer ring piston 22. This allows an optimal adaptation to different conditions or conditions.

In all of the embodiments, the cylinder block 2 is rotatably connected to the drive shaft 10 and axially free.

In the case of inclined axis hydrostatic units, details of the invention can be used to a limited extent. In the sense of rational mass production, one of the components - perforated disk 6, hold-down ring 7 or securing ring 8 - is designed as a dimension compensation element according to the system of a sorting method. This means that, with a view to efficient, economical assembly of the hold-down device, for example the locking ring 8, it is manufactured as a compensating member in various thicknesses with the setting dimension "E". During assembly, depending on requirements or given dimension "A" between the contact surface of the pressure plate 11 and the contact surface of the annular groove 49 in the inclined body 5 and the given overall dimension "C" between the contact of the pressure plate 11 and the final dimension of the hold-down device 7 the locking ring 8 is selected with the appropriate setting dimension "Ξ". The determination of the given dimensions "A" and "C" and the setting of the setting dimension "E" can be carried out electronically very efficiently for mass production. The. Axial play "B" is almost "zero" when new, so free of play.

For demanding use, particularly in cars and generally in road vehicles, the use of the known axial piston units is almost impossible due to their unfavorable efficiency. Even when used in a power split transmission, which only load the hydrostatic transmission with a partial output, the efficiency is often unsatisfactory. The details of the invention allow a significant improvement in the overall efficiency of the hydrostatic axial piston machine despite the applicability of rational and cost-effective production methods. According to the invention, the individual components are designed in such a way that they enable economical, modern production for mass production; this is an essential aim of the invention. ezugzecen

A setting dimension

B axial play

C overall dimension

D

E distance

F dimension

G measure

78 Oil supply

79 oil drilling

80 ring groove

81 lubrication groove

82 ring groove

83 spring

84 throttle bore

85 holding-down device

86 diameter

87 diameter

88 stabilizing device

89 Stabilizing device

90 stabilizing device

91 end housing

Claims

Patent claims

1. -Hydrostatic axial piston machine, in particular for a motor vehicle transmission with power split, with a cylinder block, in which pistons (3) movable in the axial direction work with sliding shoes (4), which are held by a hold-down device (40; 75) on a pivotable or not - Swiveling slant disc are guided, the hold-down device preferably being of a positive fit, characterized in that a) the hold-down device (75; 71, 85) is designed as a hydraulic hold-down device, a hydraulic force being exerted on an inclined body or swivel body (5) rotationally fixed hold-down ring (7) and a perforated disc (6) rotating with the cylinder block (2) acts in such a way that the sliding shoes (4) of the pistons (3) counter to an inclined surface (pressure plate 11) be pressed; b) and / or a spring device (9; 41; 72; 16, 17; 46; 45; 77) - is provided, which the pistons (3) via their sliding shoes (4), a perforated disc (6) and one Hold-down body (hold-down ring 7) resiliently presses against an inclined surface (pressure plate 11), the spring device being accommodated in the inclined or swivel body (5) within a preferably form-fitting hold-down and preferably combined with a hydraulic hold-down f75 is.

2. Hydrostatic axial piston machine according to the Oberbegri f of claim 1, characterized in that the cylinder block (2) via a spring element (spring 24) plus a hydraulic force, which results from a speed signal and / or a pressure signal of the hydrostatic pressure and / or a feed pressure, pressed against a thrust surface or control surface (37) in the axial direction , the hydraulic force being generated in a piston pressure chamber (25) within the cylinder block (2).

3. Axial piston machine according to claim 1, characterized in that the Feder¬ element for the hold-down (40; 75) as an elastomer (9; 46; 41; 45; 46; 72; 77) is designed differently and loose in recesses of the hold-down plate (7) is inserted.

4. Axial piston machine according to claim 1, that the spring element (77; 46) is at the same time designed as a sealing element for sealing the pressure oil for generating the hydraulic hold-down pressure (FIG. 2a).

5. Axial piston machine according to claim 1, 3 and 4, characterized in that the Nieder¬ holder (75) as a hydraulic hold-down device has a hydraulic system with oil guides (79) with Ausneh¬ measures (80, 81) of the hold-down ring (7th ) are connected and additionally serve as a lubrication device between the hold-down ring (7) and the perforated disk (6), a throttle bore preferably metering the inflow for lubrication (FIG. 2a).

6. Axial piston machine according to claim 1 and 3 to 5 d a d u r c h g e k e n n z e i c h n e t that the oil supply element (oil supply 78) for the hydraulic hold-down is simultaneously designed as an anti-rotation element for the hold-down ring (7) (Figure 2a).

7. Axial piston machine according to claim 1 and 3 to 6, characterized in that for the Downholder (75) is provided a disc (76). as

Serves washer and as a washer for the spring element (77) and is supported against a locking ring (8), the washer (76) is formed in two parts or is cut radially at one point as a one-piece version for installation for insertion into an annular groove (82 ) (Figure 2a). or as a normal disc (as shown).

8. Axial piston machine according to several of claims 1 to 7, characterized in that the Federele¬ element for the hold-down (40; 75) as an elastomer (9; 46; 41; 45; 72; 77) is designed differently and in Ausnehmun¬ gene of the hold-down plate (7) is loosely inserted.

9. Axial piston machine according to several of claims 1 to 8, characterized in that the Feάerele- element is designed as a metal spring in the form of a flat spring element (18, 16, 17) and in recesses (19) of the holding plate or in recesses of the holding plate and Ausneh ¬ mounts of the inclined or swivel body (5) are mounted, preferably with resilient partial elements (16, 17, 41) are connected to each other by partial areas (spring collar 18) and thus the spring can preferably be made in one piece (FIG 3 and 4).

10. Axial piston machine according to several of claims 1 to 9 d a d u r c h g e k e n n z e i c h n e t that the positive hold-down device (40; 75) one in the inclined or swivel body (5) non-rotatable

Has hold-down plate (7) which is fixed against a retaining ring (8) seated in an annular groove (49) of the oblique or »swivel body (5) and that the hold-down plate (7) is non-resilient at least in a partial area (42; G) Supporting edges (47) with an effective diameter which lie in the diameter range of the supporting edges (48) of the inclined or swivel body (5), so that the retraction forces of the pistons (3), in particular Especially at high speeds, no or only insignificant tilting moment can affect the retaining ring (8) (FIG. 3).

11. Axial piston machine according to several of claims 1 to 10, characterized in that the Feder¬ element (9, 46, 41) is integrally formed ^' and resilient with one another via a ring (46) connected partial areas (41; 52) with a dimension " F "and in this area the resilient element is designed with a special spring profile (52, 53) (FIGS. 3, 3a).

12. Axial piston machine according to several of claims 1 to 11, characterized in that the Feder¬ element is designed as a flat spring (16, 17, 18) which in some areas have spring bodies (16) with resilient partial elements (spring tongues 17) which in recesses (19th ) of the hold-down ring (7) engage and are resiliently supported against the retaining ring (8) and the hold-down ring (7).

13. Axial piston machine according to several of claims 1 to 12 d a d u r c h g e k e n n z e i c h n e t that the Feder¬ element as an elastomer in the form of a closed ring, e.g. is designed as an O-ring (45) or as a profile ring (72) and is arranged in an annular groove (44; 73) of the hold-down ring (7) (FIG. 5).

14. Axial piston machine according to several of claims 1 to 13 d a d u r c h g e k e n n z e i c h n e t that the spring

(24) for axially pressing the cylinder block (2) against the control surface (37) on the drive shaft (10) in the central bore of the cylinder block (2), as is known per se, and that annular piston (20, 22) as Support rings for the spring force and as a pressure piston for generating additional force are designed as hydraulic force against the drive shaft (10) and against the cylinder block (2) and that in the piston pressure chamber

(25) the spring (24) is arranged.

15. Axial piston machine according to several of claims 1 to 14, characterized in that the Kolben¬ space (25) via an annular piston (20) with a sealing ring (21) which is supported against the shaft (10) and a second ring piston (22) with a sealing ring (23) in the cylinder block

^' (2) is fixed, is formed and that the sealing rings as an elastomer in the form of an O-ring (21, 23) or a shaped ring (28) with radially elastic sealing lips (29) or as a piston ring in a known form, for example are made of gray cast iron or plastic with radial play in the annular groove (Figures 1 and 6).

16. Axial piston machine according to the preamble of claim 1, characterized in that the Kolben¬ running sleeve (35) for the piston (3) is a known, in the Zy¬ cylinder block (2) cast sleeve, which consists of special sliding material and that the piston tread one has an inclined entry at an angle C corresponding to the conical contour (54) of the cylinder block and that the angle approximately corresponds to the maximum swivel angle of the swivel body (5) or the swash plate (11) (FIG. 1).

17. Axial piston machine according to the preamble of claim 1, characterized in that the Zylin¬ derblock (2) runs against a control disc (31), the kidney-shaped openings (38) with damping slots (34) and that this control disc (31) automatically an angle about its central axis depending on a speed signal and / or a pressure signal can be rotated (Figure 7).

18. Axial piston machine according to claim 17, characterized in that the control disc (31) is operatively connected to a piston (32) which is hydraulically or electrically adjustable against the pressure of a spring (33) (Figures 7 and 8).

19. Axialkolbenmasehine according to claim 17 and 18, characterized in that the automatically adjustable control disc (31) as a sheet metal body with punched kidney-shaped openings (38) and punched _. Damping slots (34) is formed.

20. Axialkolbenmasehine according to several of claims 1 to 19, characterized in that with a conical end face (54) formed cylinder block (2) cast or metallically connected piston sleeves (35) and a cast or sprayed or metallically connected barrel smile layer on Has cylinder bottom (36).

21. Axialkolbenmasehine according to several of claims 1 to 20, characterized in that a link (11; 6; 7; 8), preferably the locking ring (8), the positive and non-positive hold-down (40) is made as an adjusting member with different thicknesses with respect to one rational assembly process (Figure 2).

22. Axialkolbenmasehine according to the preamble of claim 1, characterized in that a Nieder¬ holder (71) for the sliding shoes (4) is provided, in the form that an axially displaceable on an oil pressure inside lying pressure element (calotte 66) on of the drive shaft (10) is pressed against a perforated disk (68) which interacts with the sliding shoes (4), the perforated disk being pressed on from the inside (FIGS. 8, 9).

23. Axialkolbenmasehine according to claim 22, characterized in that the Nieder¬ holder (71) consists of a spherical cap (66) with a spherical An¬ pressing surface (67) which presses against a corresponding Kugel¬ surface of a perforated disc (68), and that an under Oil ^• pressure axially displaceable piston (64) presses axially against the calotte (66) via intermediate members (pin 65) (FIG. 8).

24. Axialkolbenmasehine according to several of claims 1 to 23, characterized in that the hydrau¬ lische and / or spring-loaded inner Nieder¬ holder (71) with a positive or / and a positive plus spring-loaded outer lower holder (40) or / and an outer hydraulic hold-down device (75) is combined (FIGS. 8, 9, 2a).

25. Axialkolbenmasehine according to claim 22 to 24, characterized in that an axially displaceable against the spherical cap (66) piston (64) can be acted upon hydraulically and via a spring (83), a stronger spring (24) being accommodated in a piston chamber (25) , which is supported against the cylinder block (2) axially in the direction of the control surface (37) and in the other axial direction against the drive shaft (10), and a weaker spring (83) which bears against the perforated disc (68) Intermediate links (64, 65, 66) and. In the other direction against the stronger spring (62) or a link (support ring 62) of the drive shaft (10) supports (Pig.9) l

26. Axialkolbenmasehine according to claim 22 to 25, characterized in that a spring (24) via intermediate members (64, 65, 66) is supported against a perforated plate (68) of the hold-down device on one side and on the other side is supported on the cylinder block (2) via a corresponding intermediate member (22), so that the cylinder block (2) is pressed resiliently against its control surface (31; 37) and the sliding shoes ^" (4) are applied via the same spring forces. the piston (3) is held down and that the hold-down and pressing forces are additionally increased by a speed-dependent and / or load-dependent pressure in the piston chamber (25; 70) (similar to FIG. 8, but without a support disc (62)), wherein spring (24) abuts piston (64).

27. Axialkolbenmasehine according to several of claims 22 to 26, characterized in that at least Two annular pistons (22, 64) are provided between the drive shaft (10) and the cylinder block (2) with two differently sized, effective piston surfaces in order to simultaneously exert equally large hydraulic contact forces on the holding-down device (71) of the slide shoe (4 ) and to produce the cylinder block (2) against the control disc (37; 31).

28 «Axialkolbenmasehine according to several of claims 1 to 27, characterized in that the hydraulic pressure for the hold-down devices (40; 75; 71) and / or the devices for pressing the cylinder block (2) against the control disk (37) is a speed-dependent Pressure or / and a load-dependent pressure or / and a pressure from the supply and feed pressure for the hydrostatic or for the control / regulation.

29. Axialkolbenmasehine according to several of claims 1 to 28, characterized in that the hydraulic hold-down devices (75, 71, 85) for the sliding shoes (4) and the .hydraulic device for the stabilizing device (88; 89; 90) simultaneously with the same hydraulic pressures are controlled, for example is a speed-dependent pressure and / or a load-dependent pressure.

30. axial piston machine according to several of claims 1 to 29, that the control disc (31) has a basic classification under the criterion of low noise behavior and is dependent on the load and / or speed, e.g. can be changed within the adjustment range angle / b by appropriate control pressure.