WO2008071374A1

WO2008071374A1 - Axial piston machine and control plate for an axial piston machine

Info

Publication number: WO2008071374A1
Application number: PCT/EP2007/010759
Authority: WO
Inventors: Martin Zug
Original assignee: Robert Bosch Gmbh
Priority date: 2006-12-11
Filing date: 2007-12-10
Publication date: 2008-06-19
Also published as: EP2100039A1; DE102007024174A1; DE102007024174B4; US20090199705A1

Abstract

In a control plate for an axial piston machine having at least two control openings (31, 32), by means of which cylinder bores (9) of a cylinder drum (4) which is mounted rotatably in a housing (2) are connected alternately to a high pressure connection and a low pressure connection when the cylinder drum (4) is rotated, an extension surface (40) which extends to the outside is formed on a part region of the outer circumference of the control plate (20), which extension surface (40) is formed for defined contact with a holding element (52, 53) of the axial piston machine (1) in order to achieve an anti-rotation safeguard for the control plate (20).

Description

Axial piston machine and control plate for an axial piston machine

The present invention relates to a

Axial piston machine and a control plate for such axial piston machine.

In the case of axial piston machines, pistons which are arranged displaceably in longitudinal direction in cylinder bores of a cylinder drum execute a lifting movement during each revolution of the cylinder drum, which movement is composed of a suction stroke and a pressure stroke. In order to ensure a rotationally synchronized connection between the cylinder drum and the corresponding working line of the axial piston A, located on the front side of the cylinder drum, a so-called control plate in which usually kidney-shaped control openings for connecting the cylinder drum with a high pressure port and a low pressure port of the axial piston machine are formed ,

A classic control plate, as known from the prior art and described for example in a similar form in DE 102 51 552 B3, is in the

Figures 5 to 7 shown. The control plate 100 has an outer diameter which corresponds to the inner diameter of a corresponding housing part of the axial piston machine. In the direction of the βbgewandten from the cylinder drum side, the control plate 100 is supported on a housing cover, in which the high pressure port and the low pressure port of the axial piston machine are formed. The control plate 100 has distributed over its circumference a plurality of control openings 101 and 102, which are provided for connecting the cylinder drum to the low pressure port and the high pressure port. In addition to these control openings 101, 102, the so-called suction kidney and the so-called pressure kidney, the control plate 100 also has a central recess which from a shaft of the axial piston machine, which is non-rotatably connected to the cylinder drum, penetrated. At this central recess to join two lateral savings 103, which form a passage for Leckol. Furthermore, a groove 104, which can be removed in particular from the illustration in FIG. 7, is formed in the edge region, which allows a rotationally secure positioning of the control plate 100. As shown in Figure 6, this groove 104 cooperates with a mounted in the housing of the machine pin 110, so as to ensure that on the one hand, the plate 100 can not be installed rotated by 180 ° in the axial piston machine and on the other hand no rotation of the plate 100 occurs during operation.

Such control plates have often been preserved in the past, but must be prepared in a relatively laborious process, usually here the plates of bar sections or coarse stamped or forged parts machined, the corresponding parts are machined completely machined on all surfaces. In particular, the suction kidney 101, the pressure kidneys 102, the leaking passages 103 and the groove 104 for anti-twist protection are worked out in this operation.

The present invention is based on the object to provide a novel distributor or control plate for an axial piston machine, which is on the one hand at least equivalent to the known control plates in terms of their operating characteristics, on the other hand, however, can be made easier and cheaper.

The object is achieved according to the invention by a control plate for an axial piston machine having the features of claim 1 and an axial piston machine having the features of claim 11. Advantageous developments of the invention are the subject of the dependent claims. The solution according to the invention is based on the idea of configuring the control plate such that an outwardly extending extension surface is formed on a partial region of the outer circumference of the control plate, which is designed to achieve an anti-twist for the control plate such that it has a defined contact with a holding element allows the axial piston machine. For example, for this purpose, the extension surface have a straight edge region which is suitable for bearing against a flat wall of a corresponding holding element. Furthermore, an edge-side recess in the extension surface would also be conceivable or a protrusion, which, for example, with an oval or cylindrical shaped

Retaining element or can cooperate with a corresponding recess in the holding element.

According to the invention, a control plate for an axial piston machine is provided, which has at least two control openings, by means of which cylinder bores rotatably mounted in a housing cylinder drum are connected during rotation of the cylinder drum alternately with a high pressure port and a low pressure port, which is provided according to the invention that at a portion of the Outer circumference of the control plate an outwardly extending extension surface is formed, which is designed to achieve an anti-rotation for the control plate ^* for defined contact with a holding element of the axial piston machine.

The advantage of the solution according to the invention is that can be dispensed with to achieve the anti-rotation on the known pin-groove connection. In contrast to the groove shown in Figures 5 to 7 in the control panel according to the invention, the rotation is achieved by a special design of the outer periphery or the outer contour of the control plate, which brings with it the advantage that, for example, provided for this purpose continuous recesses throughout, ie can be performed over the entire thickness of the control plate. This in turn means that it is possible to produce the control plate according to the invention in a simple manner by a stamping process, in which case the outer contour, the inner contour and the kidney regions of the control plate are created directly. It is then only a post-processing of the two plan contact surfaces of the control plate required, which brings significant advantages in the production with it. Alternatively, the control plate could also be made by means of laser cutting, in which case a post-processing of the flat surfaces is eliminated, since a high-quality starting material with the required surface quality can be used. Both methods are only conditionally applicable to the control plate according to the prior art, since the preparation of the groove for the rotation can be created only by a machining of the plate.

Further developments of the inventive concept relate in particular measures by which the cost of materials and the space required by the control plate can be additionally reduced. In this case, it can be provided, for example, that the outer edge region of the plate is connected in the region of the at least one to the low-pressure connection

Control opening is reduced in the radial direction. Further, the radially inner edge of the control plate may be formed as a centering surface, which centers the control plate on a housing-side centering. This centering surface may consist of a plurality of partial surfaces, which are formed on radially inwardly extending into the passage opening segments of the inner edge of the control plate. The radial extent of the individual recesses is preferably so great that a gap arises in the region of the recesses between the control plate and the centering body, which gap is suitable for letting accumulated leakage fluid accumulate in the interior of the cylinder drum. According to the invention an axial piston machine is further proposed with a cylinder drum rotatably mounted in a housing, wherein in the cylinder drum cylinder bores are introduced, in which axially displaceable pistons are arranged, wherein the

Cylinder bores to an end face of the cylinder drum have openings that are alternately in connection with a high-pressure port and a low-pressure port with a rotation of the cylinder drum via at least two control ports of a control plate, wherein the control plate is formed according to the inventive idea described above. In advantageous whiteness, the machine is designed as a swash plate machine, in which case the holding element for the rotationally secure positioning of

Control plate may be formed by the actuating piston guide.

The invention will be explained in more detail with reference to the accompanying drawings. Show it:

Fig. 1 is a schematic representation of an inventively designed axial piston machine;

Fig. 2 is an illustration of a first

Embodiment of erfiπdungsgemäßen control plate;

Fig. 3 shows the arrangement of the invention

Control plate of Figure 2 in the axial piston machine;

Fig. 4 shows the arrangement of an alternative embodiment of an inventive

Control plate in an axial piston machine and Fig. 5 to 7, the embodiment and arrangement of a

Control plate of an axial piston machine according to the prior art.

The axial piston machine according to the invention shown in FIG. 1 and generally designated by the reference numeral 1 is largely identical to the axial piston machine known from DE 102 51 552 B3. Accordingly, the structure and function of the known components of the machine 1 will be briefly summarized below.

The axial piston machine 1 has a rotatably mounted in a housing 2 shaft 3, on which a cylinder drum 4 is arranged, wherein the

Cylinder drum 4 and the shaft 3 rotatably connected to each other. The shaft 3 penetrates the cylinder drum 4 and is supported on both sides of the cylinder drum 4 by means of a respective rolling bearing 5 and 6, wherein the lower roller bearing 6 in particular has an outer bearing ring 7 which is inserted into a corresponding recess of a housing cover 8 of the axial piston machine 1 ,

In the cylinder drum 4 distributed over the circumference a plurality of cylinder bores 9 are formed, wherein the central axes of the cylinder bores 9 extend parallel or inclined to the central axis of the shaft 3. In these holes 9 are axially displaceable piston 10 is used, which on the side facing away from the housing cover 8 side have a spherical head 11 which cooperates with a corresponding recess of a shoe 12 to a hinge connection. By means of the shoe 12, the piston 10 is supported on a chafing disk 13, so that upon rotation of the

Cylinder drum 4, the piston 10 accordingly perform an alternate stroke. The height of the stroke is determined here by the position of the chafing disk 13, which is a perpendicular to the longitudinal axis of the Shaft 3 extending tilting axis can be adjusted. For this purpose, an adjusting device 14 is provided with a piston 50, which cooperates with its two ends on the one hand with the swash plate 13 and on the other hand with a control piston guide 51. The configuration, in particular, of this cylinder-like or pot-type actuating piston guide 51 will be explained in more detail later.

The cylinder drum 4 has a central opening 15, in which a compression spring 16 is arranged, which is stretched between a first spring bearing 17 and a second spring bearing 18. The first spring bearing 17 is fixed by the shaft 3 in the axial direction, while the second spring bearing 18 by a in a groove of the

Cylinder drum 4 used Seeger ring is formed. By the force of the compression spring 16, the cylinder drum 4 is shifted in the axial direction so far that it rests sealingly with its end face 19 on the control plate 20.

The control openings 20 of the control plate 20, which are not visible in the sectional view according to FIG. 1, are in permanent contact with at least one high-pressure connection and a low-pressure connection of the axial piston machine 1 on each side remote from the cylinder drum. The cylinder bores 9 of the drum 4 are connected to the end face 19 via corresponding openings 21 the cylinder drum 4 open, these openings 21 sweep the control plate during rotation of the drum 4 and thereby alternately connected to the control ports for the high pressure or low pressure connection.

The determination of the position of the control plate 20 with respect to the shaft 3 is first carried out by a centering surface 29, the configuration will be explained in more detail below. A passage opening of the control plate 20 has for this purpose a radial extent, which with the outer radial extent of a Zentrierkorpers, which is connected to a Gehausebauteil corresponds. In the illustrated embodiment, the Zentrierkorper is formed by the outer bearing ring 7 of the rolling bearing 6. In the axial direction, the control plate 20 is supported on the housing cover 8, wherein to prevent leakage, the control plate 20 has a sealing environment 28 which is formed on the side remote from the cylinder drum 4 side of the control plate 20 and sealing with the surface of the housing cover 8 interacts.

For proper operation of the axial piston machine 1 in addition to a centered arrangement of the control plate 20 and a corresponding orientation is required, it must be ensured that even during the

Operation of the machine 1 no rotation of the control plate 20 takes place. While the above-described pin-groove connection is used in the prior art, it is now proposed according to the invention to design the control plate 20 in a special way, so turn a twist-proof arrangement is achieved, however, waives the pin-groove connection and accordingly the Production of the control plate 20 can be simplified. A first exemplary embodiment of a correspondingly designed control plate will now be explained with reference to FIGS. 2 and 3.

2, the control plate 20 with the central opening 30 and the control opening 31 for the low-pressure connection and three control openings 32 for the high-pressure connection can be seen. The central passage opening 30 in this case has a diameter which corresponds to the outer circumference of the bearing ring 7 of the rolling bearing 6. The inner edge 33 of the through-opening 30 accordingly forms the aforementioned centering surface 29. The passage opening 30 is further extended by two recesses 34 and 35, between which segments are formed, so that the centering surface 29 ultimately by the partial surfaces 29.1 and 29.2 to the Segments is formed. By the recesses 34 and 35, a gap 22 (see Figure 1) is partially formed on the circumference of the outer bearing ring 7, which is passable by a leakage fluid.

The special feature of the control disk 20 according to the invention consists in an extension surface 40 extending outward in the upper region of the outer circumference. This extension surface 40 is designed in a special manner in its edge region 41 in order to allow a defined abutment against a retaining element of the axial piston machine. In this way, despite dispensing with the pin-and-groove connection, a rotationally secure arrangement of the control disk 20 is made possible.

In the embodiment of Figures 2 and 3, the extension surface 40 has a straight edge portion 41, which can accordingly cooperate with a flat wall of a holding element. According to the illustration in FIG. 3, it is preferably provided for this purpose that as

Retaining element, the previously mentioned actuator piston guide 51 is used. This has a cylinder 52 which rests with its lower end on a pulley 53. In this case, this disk 53 is likewise cut straight in its edge region 54, so that the edge region 41 of the extension 40 of the control plate 20 can lie flush against the edge region of the disk 54, as shown in FIG. In this way, a rotation of the control disk 20 during the operation of the axial piston machine 1 is effectively prevented.

The advantage of the inventive design of the control disk 20 is that the corresponding configuration of the edge portion 41 of the extension 40 over the entire height or thickness of

Control disc 20 may extend. This makes it possible to produce the control disk 20 in a relatively simple and cost-effective manner. For example, a simple punching out of the control disk 20 would be conceivable, wherein At the same time the outer contour, the inner contour and the kidney areas could be created. In this case, only a post-processing on the two plan contact surfaces of the control disk 20 would be required. Alternatively, however, a correspondingly shaped blank could be processed by means of laser cutting, in which case a reworking of the flat surfaces is no longer necessary, since already a high-quality starting material with the necessary surface quality can be used. Both variants are much easier to carry out than previously required for the production of control discs machining machining of bar sections or coarse stamped or forged parts. At the same time, however, the functionality of the control disk is fully respected, as is still achieved by the appropriate design of the edge portion 41 of the extension 40, the desired rotation.

Figures 2 and 3, further measures for

Design of the control disk 20 are removed, through which the cost of materials and space requirements is further optimized. Thus, on the one hand it can be provided that the outer edge region 42 of the control plate is reduced in the radial direction in the region of the low-pressure control opening 31. As a result, on the one hand space requirements and on the other hand, the cost of materials is reduced. Furthermore, 20 openings can be formed by corresponding savings 43 and 44 in the edge region 41 of the expansion surface and / or in one of the extension surface 40 opposite edge region of the control plate, which serve for the lossless discharge of Pumplecköls.

Figure 4 shows an alternative embodiment of a control plate 20 according to the invention, which in the

Design of the edge region of the extension surface 40 different. In this case, the control piston guide 51 is formed only as upwardly extending cylinder 52, in which case the edge region 41 of Extension surface 40 has an edge-side recess 45 which cooperates with the cylindrical outer contour of the cylinder 52. Again, a rotation of the control disk 20 during operation of the axial piston machine is excluded by this configuration. Furthermore, it would be conceivable to design the extension surface in the edge region with a protrusion or a projection, which then interacts with a corresponding recess or recess in the holding element.

Overall, therefore, the present invention opens the possibility to produce control discs for axial piston machines easier and cheaper. At the same time, however, an exact arrangement and alignment of the control disk in the axial piston machine is still guaranteed.

Claims

claims

1. Control plate for an axial piston machine with at least two Steueroffnungen (31, 32), by means of which cylinder bores (9) rotatably mounted in a housing (2) mounted cylinder drum (4) during rotation of the cylinder drum (4) alternately connected to a high pressure port and a low pressure port characterized in that at an area of the outer circumference of the control plate (20) an outwardly extending extension surface (40) is formed, which for

Achieving an anti-rotation for the control plate (20) for defined contact with a holding element (52, 53) of the axial piston machine (1) is formed.

2. Control plate according to claim 1, characterized in that the expansion surface (40) has a straight edge region (41) for engagement with a flat wall of the holding element (52, 53).

3. Control plate according to claim 2, characterized in that the expansion surface (40) has an edge-side recess (45).

4. Control plate according to claim 3, characterized in that the recess (45) for cooperation with an oval or cylindrical holding element (52) is formed.

5. Control plate according to one of the preceding claims, characterized in that a recess (43, 44) is formed in the edge region of the extension surface (40) and / or in an edge region of the control plate (20) opposite the extension surface (40).

6. Control plate according to one of the preceding claims, characterized in that in the control plate (20) has a passage opening (30) is formed, wherein the radially inner edge (33) of the control plate (20) as a centering surface (29) is formed, which the Control plate (20) centered on a housing-side centering body (7).

7. Control plate according to claim 6, characterized in that the centering surface (29) consists of a plurality of partial surfaces (29.1, 29.2) which on radially inwardly into the passage opening (30) extending segments of the inner edge (30) of the control plate (20 ) are formed, which are separated by recesses (34, 35).

8. Control plate according to claim 7, characterized in that the radial extent of the individual recesses (34, 35) is so large that in the region of the recesses (34, 35) between the control plate (20) and the centering body (7) has a gap (22) arises.

9. Control plate according to one of the preceding claims, characterized in that the outer edge region (42) of the control plate (20) in the region of the at least one connected to the low-pressure connection control opening (31) is reduced in the radial direction.

10. Control plate according to one of the preceding claims, characterized in that this by a. Stamped part is formed.

11. Axial piston machine (1) with a rotatably mounted in a housing cylinder drum (4), in the cylinder bores (9) are introduced, in which axially displaceable piston (10) are arranged, wherein the cylinder bores (9) to a front side (19) of Cylinder drum (4) have openings (21) which are in rotation of the cylinder drum (4) via at least two control openings (31, 32) of a control plate (20) alternately in conjunction with a high pressure port and a low pressure port, characterized in that the control plate (20) is designed according to one of the preceding claims.

12. Axial piston machine according to claim 11, characterized in that the machine is designed as a swash plate machine, wherein the holding element (52, 53) by an actuating piston guide (14) is formed.

13. Axial piston machine according to claim 11 or 12, characterized in that in the Steuerplβtte (20) has a through hole (30) is formed, and that the cylinder drum (4) rotationally fixed on a shaft (3) is arranged, wherein the shaft (3) on the side of the control plate (20) in the housing (8) is mounted and the control plate (20) with a at the inner edge (33) of the control plate (20) formed centering surface (29) on an outer bearing ring (7) of a rolling bearing ( 6) is centered.