PORT PLATE WITH INCREASED RIGIDNESS AND METHOD FOR PRODUCING SUCH PORT PLATE

Abstract

The invention relates to a port plate 10, 11 that is used as a valve plate or a bearing plate. The port plate 10, 11 comprises a fluid blocking surface section 15 and a fluid passage surface section 13, 14 that is arranged within said at least one fluid blocking surface section 15. Structural reinforcement elements 12, 19 are arranged within the fluid passage orifice of the fluid passage surface section 13, 14.

Claims

1. A port plate for a fluid throughput regulating device, comprising at least one fluid blocking surface section and at least one fluid passage surface section that is arranged within said at least one fluid blocking surface section, wherein at least one structural reinforcement element is arranged within the fluid passage orifice of said at least one fluid passage surface section.

2. The port plate according to claim 1, wherein it is designed and arranged as a valve plate and/or as a bearing plate for a fluid working machine, preferably for a high pressure fluid working machine, more preferred for a hydraulic fluid working machine, even more preferred for a high-pressure hydraulic fluid working machine.

3. The port plate according to claim 1, wherein a plurality of structural reinforcing elements is provided in the fluid passage orifice of said at least one fluid passage surface section, where said plurality of structural reinforcing elements is preferably at least in part interconnected with each other, more preferably at least partially forming a truss-like design and/or a honeycomb-like design.

4. The port plate according to claim 3, wherein said at least one structural reinforcement element is designed in a way that it shows fluid flow enhancing properties.

5. The port plate according to claim 3, wherein said at least one structural reinforcement element is connected to said at least fluid blocking surface section along a circumferential part of the respective fluid passage surface section.

6. The port plate according to claim 3, wherein said at least one structural reinforcing element and/or said at least one fluid blocking surface section is/are designed at least in part as a single piece.

7. The port plate according to claim 1, wherein essentially no structural reinforcement element protrudes at least one surface side that is formed by at least one fluid blockage surface section and/or in that said port plate forms essentially a planar contour on at least one surface side.

8. The port plate according to claim 1, wherein at least one of said at least one fluid passage surface sections has a kidney like shape and/or in that said at least one of said at least one fluid passage surface section is used for alternately enabling and blocking/hindering a fluid flow through said fluid passage surface section in combination with an additional device.

9. The port plate according to claim 1, wherein it is at least partially manufactured using at least one manufacturing technique, taken from the group comprising material removal techniques, additive manufacturing techniques, 3-D printing techniques, moulding techniques, sintering techniques, material connection techniques, soldering techniques, welding techniques and pressure welding techniques.

10. A fluid valve unit, comprising at least two elements that can be moved relative to each other, in particular that can be rotated relative to each other, wherein at least one said at least two elements is designed at least in part as a port plate according to claim 1.

11. The fluid working device, comprising at least one fluid valve unit according to claim 10 and/or at least one port plate.

12. A method for producing a port plate according to claim 1, for producing a fluid valve unit according to claim 10 and/or for producing a fluid working device wherein at least in part at least a manufacturing technique is used, that is taken from the group comprising material removal techniques, additive manufacturing techniques, 3-D printing techniques, moulding techniques, sintering techniques, material connection techniques, soldering techniques, welding techniques, and pressure welding techniques.

13. The fluid valve unit according to claim 10, wherein at least a first one of said at least two elements that can be moved relative to each other shows at least a structural reinforcement element that forms at least partly an essentially planar contour of the element on at least the surface side that is neighbouring at least a second one of said at least two elements.

14. The port plate according to claim 2, wherein a plurality of structural reinforcing elements is provided in the fluid passage orifice of said at least one fluid passage surface section, where said plurality of structural reinforcing elements is preferably at least in part interconnected with each other, more preferably at least partially forming a truss-like design and/or a honeycomb-like design.

15. The port plate according to claim 1, wherein said at least one structural reinforcement element is designed in a way that it shows fluid flow enhancing properties.

16. The port plate according to claim 2, wherein said at least one structural reinforcement element is designed in a way that it shows fluid flow enhancing properties.

17. The port plate according to claim 1, wherein said at least one structural reinforcement element is connected to said at least fluid blocking surface section along a circumferential part of the respective fluid passage surface section.

18. The port plate according to claim 2, wherein said at least one structural reinforcement element is connected to said at least fluid blocking surface section along a circumferential part of the respective fluid passage surface section.

19. The port plate according to claim 4, wherein said at least one structural reinforcement element is connected to said at least fluid blocking surface section along a circumferential part of the respective fluid passage surface section.

20. The port plate according to claim 4, wherein said at least one structural reinforcing element and/or said at least one fluid blocking surface section is/are designed at least in part as a single piece.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Further advantages, features, and objects of the invention will be apparent from the following detailed description of the invention in conjunction with the associated drawings, wherein the drawings show:

[0028] FIG. 1: a possible design of a bent axis hydraulic pump, comprising a valve plate and a bearing plate as a valve device for the pumping chambers in a schematic cross section;

[0029] FIG. 2: a possible embodiment of a valve plate and of a bearing plate in a schematic top view;

[0030] FIG. 3: two possible embodiments for reinforcing structures in a schematic top view;

[0031] FIG. 4: a schematic cross section through the walls of the reinforcing structure according to different embodiments.

DETAILED DESCRIPTION

[0032] In FIG. 1 a possible embodiment for a so-called bent axis hydraulic pump 1 is shown in a schematic cross section. The basic design of a bent axis hydraulic pump 1 as shown in FIG. 1 is known in the state of the art. The presently shown embodiment is a variant of a pumping device. Other exemplary embodiments are a variable swash plate displacement type, a variable wobble plate displacement type and/or a fixed displacement type.

[0033] In the presently shown embodiment, a drum 2 with a plurality of cylindrical cavities 3 is rotated (indicated by an arrow near the lower-left side of drum 2 in FIG. 1). The rotation of drum 2 is introduced by a rotating shaft 25 (indicated by a rotating arrow around rotating shaft 25 in FIG. 1) via swash plate 4. The rotational movement can be introduced by any kind of device, like a combustion engine, an electric motor and so on (not shown). For transferring the rotational movement from the rotating shaft 25 to the drum 2, the swash plate 4 and the rotating drum 2 are connected to each other in a torque-proof manner. For this, the pistons 5 that are slidably contained in the cylindrical cavities' 3 of the drum 2 (in which they move back-and-forth under the rotating movement of drum 2 and swash plate 4) are placed with their piston feet 6 in retaining supports 26 that are arranged on the surface side of swash plate 4 that faces the drum 2. The connection between the piston feet 6 and the respective retaining supports 26 is established using a positive form-fitting interconnection, so that the two parts (pistons 5 and swash plate 4) can be rotated with respect to each other, but no translational movement can occur. Therefore, the piston feet 6 cannot lift off the surface of the swash plate 4. Therefore, a back-and-forth movement of the pistons 5 in their respective cylindrical cavities 3 can be ensured. The back-and-forth movement of the pistons 5 in their respective cylindrical cavities 3 results in a cyclically varying volume of the cylindrical cavities 3, so that a pumping action for fluid can be performed.

[0034] As indicated in FIG. 1, the longitudinal axis 27 of drum 2 (and therefore the longitudinal axis of the pistons 5/the cylindrical cavities 3 for retaining the pistons 5) are arranged at an angle to the surface normal 28 of the swash plate's 4 surface. This angle is not necessarily fixed (depending on the design of the bent axis hydraulic pump 1). In the presently shown embodiment, a moving rod 29 that can be moved back-and-forth (as indicated by a double arrow in FIG. 1) can be set to an appropriate position by a suitable actuator (not shown). The different positions translate into different angles between the longitudinal axis 27 of drum 2 and the surface normal 28 of swash plate 4. Depending on the angle , the overall length of the back-and-forth movement of the pistons 5 in their respective cylindrical cavities 3 can be varied.

[0035] In the presently shown embodiment, the valve plate 10 is attached to the housing via fluid line connecting plate 30 in a way that no rotating movement of the valve plate 10 with respect to the housing of bent axis hydraulic pump 1 occurs. However, a tilting movement of drum 2 is possible by a movement of moving rod 29. The bearing plate 11, however, is rotating together with rotating drum 2.

[0036] It is to be noted that a variation of angle between the longitudinal axis 27 of drum 2 and the surface normal 28 of swash plate 4 will change the overall length of the movement of a piston 5 in its cylindrical cavity 3 during a 360 turn of the drum 2. This way, the amount of fluid that is pumped can varied so that the bent axis hydraulic pump 1 can be adapted to different pumping requirements.

[0037] In principle, a valve plate arrangement 9 according to the state of the art provides the required valve functionality, using a reliable design that is simple to manufacture. However, the valve plate arrangement 9 design becomes increasingly problematic with larger pressures.

[0038] It is to be understood that both plates 10, 11 of the valve plate arrangement 9 are subject to strongly varying pressures, where the pressure load is loading different parts of the two plates 10, 11 to a different extent at different times. This is problematic, since the pressure load will lead to some deformation of the valve plate 10 and the bearing plate 11, not only with respect to other parts of the bent axis hydraulic pump 1, but also with respect to each other. Therefore, an increased mechanical pressure between the two plates can occur easily, resulting in increased mechanical wear. On the other hand, during certain times of the actuation cycle of the bent axis hydraulic pump 1, the loading pressure can be distributed in a way that the valve plate 10 and the bearing plate 11 are not sufficiently pressed together, so that they can get out of contact to a certain extent. Therefore, a small gap might develop, which can lead to a significant loss of hydraulic oil, reducing the efficiency of the bent axis hydraulic pump 1.

[0039] Therefore, it is strongly desired to employ a design for the plates 10, 11 of the valve plate arrangement 9 that results in more rigid plates, i.e. plates 10, 11 that are less prone to deformations and elongations under the hydraulic fluid pressure loads that will occur during standard operating conditions of the bent axis hydraulic pump 1.

[0040] The idea is to provide a structural reinforcement element 12 within a fluid throughput orifice 13, 14 instead of the standard design for orifices of the valve plate 10 and that of the bearing plate 11. As it is not unusual for bent axis hydraulic pumps 1, the standard orifices of the valve plate 10 presently do show a kidney-shaped slit 13, while the orifice of the bearing plate 11 shows a circular 14 shape. Presently, two kidney-shaped slits 13 are arranged on the disc 15 of the valve plate 10 that is shown in FIG. 2a, where the respective kidney-shaped slits 13 show a structural reinforcement 12, respectively. In case of the bearing plate 11, two circular bores 14 are provided on the disc 15 of the bearing plate 11 (see FIG. 2b). Similar to the valve plate 10, the circular bores 14 comprise structural reinforcement elements 12.

[0041] The height of the structural reinforcement element 12 is essentially equivalent to the thickness of the port plate 10, 11 in the vicinity of this structural reinforcement element 12. Put in other words, the respective port plate 10, 11, including the structural reinforcement element 12, forms an essentially planar contour on both surfaces sides of the port plate 10, 11.

[0042] In FIG. 3, possible embodiments for a structural reinforcement 12 are shown in subfigures a and b. Both structural reinforcements 12 can be used for either valve plate 10 and/or bearing plate 11 according to FIG. 2, as well as for completely different designs.

[0043] In FIG. 3a, a honeycomb pattern 16 is shown, that serves as a structural reinforcement for an orifice (like a kidney-shaped slit 13 or circular bore 14). In the honeycomb pattern 16, a plurality of hexagons 17 is arranged side-by-side along different lines 18a, 18b, 18c. Two neighbouring lines 18a, 18b or 18b, 18c (and so on) are offset by half the distance between two neighbouring hexagons 17 within the same line 18a, 18b, 18c. Using this offset, upper and lower corners of the hexagons 17 in the neighbouring lines 18 can be arranged in an interleaved pattern.

[0044] The bordering walls 19 between two hexagons 17 can have a varying thickness depending on the requirements of the detailed embodiment. Typically, they have a thickness of some 0.5 mm. Certainly, the bordering walls 19 are an obstacle to a fluid flow through the reinforced 12 orifices 13, 14, since fluid may only pass through the hexagons 17. This is particularly true when (as it is preferred) the honeycomb pattern 16 is essentially planar to the surface side of the respective plate 10, 11 that contacts the respective other plate 10, 11 of a plate arrangement, in which the two plates can be moved relative to each other (for example the valve plate 10 and the bearing plate 11 of a valve plate arrangement). Certainly, the last statement is also valid for other designs of structural reinforcement elements. The bordering walls 19 can show a different cross-sectional shape, which can be chosen according to mechanical requirements as well as according to fluid flow requirements. As an example, the bordering walls 19 can show an essentially rectangular cross-section 19, where the corners are somewhat rounded. This is shown in FIG. 4a.

[0045] Furthermore, in FIG. 4a, the longitudinal axis 20 of the channels 21 that are formed between the bordering walls 19 may be arranged perpendicular to the surface of the disc 15. However, this is not a mandatory requirement. Instead, it is also possible to arrange the longitudinal axes of the channels 21 between two neighbouring was 19 in a way that an angle, deviating from 90 is formed between the longitudinal axes 20 and the surface of the plate 15. Is to be noted that the angle does not necessarily has to be the same over the complete area of an orifice 13, 14. Instead, the angle might vary and be chosen locally in order to be optimised for the current phase of the pumping cycle of the respective piston 5 in its respective cavity 3.

[0046] Furthermore, in FIG. 4c it is shown that the bordering walls 19 can also have a shape that is significantly different from a rectangular design (with or without rounded corners). As an example, the neighbouring walls 19 can show an elliptical cross-section. Such a cross-section usually has a comparatively low fluid flow resistance. To even further reduce the fluid flow resistance, a drop like shape can be chosen as well. A drop-like shape is known to show a very low fluid flow resistance, so this might be a preferred design.

[0047] Coming back to FIG. 3a and the honeycomb pattern 16 shown therein, additional attention is drawn to the contour line 22 of the fluid flow orifice 13, 14 that would define the orifice's wall in case there would be no structural reinforcement 12 present. This contour line 22 is shown in FIG. 3a. To follow this contour line 22 as close as possible with the honeycomb pattern 16, in the vicinity of the contour lines 22 a plurality of partial hexagons 23 is/are provided. These partial hexagons 23 are shaped in a way that they essentially follow the contour line 22 on one side, while they follow the shape of the neighbouring full hexagon 17 on the other side. In case the partial hexagons 23 would become too small, they are simply omitted.

[0048] However, the structural reinforcement 12 does not necessarily has to show a honeycomb pattern 16 design. Instead, any kind of a truss-like arrangement 24 of bordering walls 19 (that includes geometrical shapes of the same and/or different type, size, angular arrangement, number and so on) can be used as well, as it is shown in FIG. 3b. The truss-like arrangement 24 is connected along the contour line 22 of the respective orifice 13, 14 (differently shaped orifice) to the remaining disc 15 of the respective plate 10, 11.

[0049] The bordering walls 19 of the truss-like arrangement 24 can show a similar variety of cross sections, just like the honeycomb structure 16 that is shown in FIG. 3a. Reference is made to FIG. 4, showing different possible embodiments for the cross sections of such bordering walls 19.

[0050] While the present disclosure has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this disclosure may be made without departing from the spirit and scope of the present disclosure.