Inclined axis type axial plunger machine with pre-compression volume

Abstract

The invention relates to an oblique-axis axial piston machine (10) with a constant displacement. According to the invention, drainage openings are arranged in the first reversing region (43), each of which can establish a fluid exchange connection with one of the outlet openings (66) by rotation of the cylinder barrel (60), said drainage openings being permanently connected to the pre-compression chamber (33) via a connecting channel (70) extending completely within the housing (20), the pre-compression chamber (33) is closed except for the connecting channel (70), and the pre-compression chamber is completely arranged in the housing (20).

Description

Technical Field

[0001] The present invention relates to an axial plunger machine according to the preamble of claim 1. Background Technology

[0002] A slant-shaft axial piston machine with a constant displacement is known from DE102019202483A1. This type of machine typically operates as a motor, for example, a vehicle wheel or rope reel driven directly by the axial piston machine. Therefore, the operating speed is relatively low. The housing comprises first and second housing sections, which are each integrally formed canister-like structures.

[0003] Another type of axial piston machine with constant displacement is known from US4382399A. The housing includes a tubular housing section, which is closed at its two opposite ends by plate-shaped covers.

[0004] A swashplate axial piston machine with an externally added pre-compression volume is known from DE102022202520A1. Swashplate machines are often operated as pumps, employing high speeds to achieve large flow rates with a small machine. As the speed increases, pressure pulsation intensifies, resulting in noise and vibration. This effect can be counteracted by the pre-compression volume. Summary of the Invention

[0005] The objective of this invention is to provide a swashplate axial piston compressor with a constant displacement, which should primarily operate as a pump. This axial piston compressor should be driveable by a variable-speed electric motor to achieve volumetric flow rate regulation. The axial piston compressor should operate quietly even at high drive speeds. The axial piston compressor should have a compact structure and low manufacturing cost. The axial piston compressor should have self-priming capability even at high speeds or high flow rates.

[0006] According to claim 1, a drainage opening is proposed to be arranged in the first reversing zone. By rotating the cylinder, the drain opening can connect with the outlet opening respectively. One of them establishes a fluid exchange connection, wherein the drainage opening is permanently connected to the pre-compression chamber through a connection channel extending entirely within the housing, wherein the pre-compression chamber is constructed to be closed except for the connection channel and is arranged entirely within the housing.

[0007] The first and second rotation axes preferably intersect, but they may also intersect at a small interval. The control surface and the reverse control surface are preferably spherical, with the reverse control surface most preferably concave and the control surface convex. The working plunger is preferably linearly parallel to the second rotation axis, and the direction of movement may also be slightly inclined to the second rotation axis, particularly at an angle less than 15°. The inclination angle is preferably between 20° and 30°, particularly 25°. It is conceivable that when the axial plunger machine is used as a motor in a conventional manner, the aforementioned inclination angle is approximately 40°. Nine working plungers are preferably provided. The axial plunger machine is preferably operated by a pressurized fluid, most preferably a pressurized liquid, particularly hydraulic oil.

[0008] Advantageous improvements and modifications to the invention are given in the dependent claims.

[0009] It can be specified that the pre-compression chamber extends along the extension axis with a constant cross-sectional shape, wherein the inclination angle of the extension axis relative to the second rotation axis is at most 15°, and the pre-compression chamber is arranged transversely to the second rotation axis next to the cylinder. Therefore, the main dimensions of the axial piston machine according to the invention are substantially no larger than those of known axial piston machines. The extension axis and the second rotation axis are preferably parallel to each other. The cross-sectional shape is preferably constructed to be circular. In the direction of the second rotation axis, the pre-compression chamber preferably extends beyond the cylinder, most preferably extending to two opposite sides of the cylinder.

[0010] It can be specified that the housing includes first and second housing portions, each can-shaped and integrally formed, which are fitted together with their open sides to enclose an internal space in which a drive shaft, cylinder, and working plunger are arranged. The drive shaft is rotatably supported only on the first housing portion, and a pre-compression chamber is located away from the first housing portion and is at least segmentally defined by the second housing portion. In particular, the second housing portion with the pre-compression chamber can be manufactured material-savingly and is easy to process. The first and second working interfaces are preferably arranged on the second housing portion.

[0011] It can be specified that the can-shaped, one-piece molded second housing portion includes an annular section and a bottom section, wherein at least 50% of the pre-compression chamber volume is arranged in the annular section. Thus, the second housing portion requires particularly little material while still possessing high rigidity. The first and second working interfaces are preferably arranged on the bottom section.

[0012] It can be specified that the pre-compression chamber is directly constructed as a borehole in the second housing portion, the borehole being sealed with a first sealing screw, wherein the first sealing screw is screwed into the second housing portion in the bottom section. The borehole is easy to machine, particularly as it can be drilled together with the first and second working interfaces in a single setup. The borehole is preferably designed to be open on one side.

[0013] It can be specified that the second rotation axis and the extension axis form an intermediate plane, and the first and second control kidney-shaped grooves are respectively arranged completely on opposite sides of the intermediate plane, such that the intermediate plane intersects with the first and second reversing regions. These features, in particular, determine the position of the pre-compression chamber on the circumference of the second housing portion. This proposed arrangement results in a particularly compact axial piston machine.

[0014] It can be specified that the first reversing region with the drainage opening and the pre-compression chamber are arranged on the same side of the second rotation axis. At the location of the drainage opening, a particularly high pressure is generated in the pressure field between the control surface and the reverse control surface. With the proposed arrangement, the corresponding pressure acts approximately at the center of the sealing surface between the first and second housing parts, so there is no need to worry about the sealing contact loosening on one side (Aufklaffen).

[0015] It can be specified that the control surface is arranged on a separate control plate, which is fixedly positioned on the rest of the housing, wherein a first section of the connecting channel passes through the control plate parallel to the second axis of rotation. The separate control plate is preferably made of a non-ferrous metal, particularly brass or bronze, to minimize wear.

[0016] It can be specified that the connection channels, located away from the control panel, are only directly arranged in the second housing section. This allows for the provision of the second and third sections of the connection channels at a low cost and in a space-saving manner.

[0017] It can be specified that the connecting channel in the second housing portion includes second and third sections, which extend straight and are directly adjacent to each other. The second section extends parallel to the second rotation axis from the control plate, and the third section extends transversely to the second rotation axis to the pre-compression chamber. Thus, the second and third sections of the connecting channel can be easily and cost-effectively machined as straight drill holes. The third section preferably extends perpendicular to the second rotation axis. The third section preferably opens on the inner circumferential surface of the pre-compression chamber.

[0018] It can be stipulated that the first, second, and third sections of the connecting channel are arranged parallel to the intermediate plane. Depending on the desired location of the drainage opening in the first reversing area, the intermediate plane can intersect with the connecting channel, or it can be arranged at a certain distance from the connecting channel.

[0019] It can be specified that the first and second housing parts are tightened together by an odd number of connecting screws, wherein the connecting screws are arranged mirror-symmetrically about a central plane, with one of the connecting screws located in a region of the central plane and on the side of the second axis of rotation opposite to the pre-compression chamber. Without the central connecting screw, the sealing gap between the first and second housing parts may loosen slightly due to the hydraulic pressure in the axial plunger, which is concerning. This could potentially lead to increased structural noise emissions. This can be avoided by using the central connecting screw.

[0020] It goes without saying that the features described above and below can be used not only in the combinations given therefor, but also in other combinations or individually, without departing from the scope of the invention. Attached Figure Description

[0021] The invention will now be described in more detail with reference to the accompanying drawings. In the drawings:

[0022] Figure 1 A perspective view of the axial piston machine according to the present invention;

[0023] Figure 2 for Figure 1 The longitudinal sectional view of the axial piston machine shown; and

[0024] Figure 3 for Figure 1 A perspective view of the control panel of the axial piston machine shown. Detailed Implementation

[0025] Figure 1 A perspective view of an axial plunger machine 10 according to the present invention is shown. The axial plunger machine 10 includes a housing 20 defining a central plane 15. The housing 20 includes first and second housing portions 21 and 22, which are can-shaped and integrally formed, and are tightly abutted against each other with their open sides such that they enclose a closed internal space. Figure 2 (Number 28 in the text). The corresponding sealing surface 23 is constructed as a plane, which is perpendicular to the first axis of rotation ( Figure 2 Orientation (number 11 in the text).

[0026] The second housing portion 22 is provided with first and second working interfaces 26 and 27, which in this embodiment are arranged on the end side of the housing 20. The first and / or second working interfaces 26 and 27 may also be arranged on the side of the housing 20, or a hybrid arrangement is also conceivable. The diameter of the first working interface 26 is larger than the diameter of the second working interface 27. Therefore, during pump operation, the first working interface 26 is preferably used as a suction interface, and the second working interface 27 is used as a pressure interface.

[0027] In this embodiment, the first and second housing portions 21 and 22 are fastened together by five connecting screws 30, which are arranged symmetrically about the intermediate plane 15. Therefore, the intermediate connecting screw 34 is arranged in the region of the intermediate plane 15.

[0028] The first housing portion 21 includes a fastening flange 80. This fastening flange 80 can be designed according to a desired standard form. In this embodiment, a form including two fastening through holes 82 is selected, these fastening through holes being arranged mirror-symmetrically about the intermediate plane 15 and parallel to the first axis of rotation. Figure 2 Number 11) passes through fastening flange 80.

[0029] The connecting screws 30 are screwed into the corresponding ribs 81 of the first housing portion 21, and the ribs extend to the fastening flanges 80. As a result, the housing 20 has high rigidity.

[0030] It should also be mentioned that the first sealing screw 31 in the second housing part 22, the pre-compression chamber ( Figure 2 Number 33) is sealed on the end side by the first sealing screw.

[0031] Figure 2 It shows Figure 1 The diagram shows a longitudinal sectional view of the axial plunger machine 10. In the canister-shaped first housing portion 21, a drive shaft 50 is rotatably supported about a first axis of rotation 11. Two corresponding rotary bearings 51 are designed as rolling bearings, particularly tapered roller bearings. The drive shaft 50 extends out of the housing 20 by a drive pin 52, allowing the drive shaft to be rotary driven, for example, by an electric motor (not shown). On the side of the rotary bearing 51 opposite to the drive pin 52, the drive shaft 50 has a flange 53. There, working plungers 62 are kinematically coupled to the drive shaft 50 via corresponding ball joints 16. The ball joints 16 of the working plungers 62 are arranged at a constant radius spaced apart from the first and second axes of rotation 11, 12. Another ball joint 16 is located precisely at the intersection of the first and second axes of rotation 11, 12. This ball joint 16 is associated with a guide plunger 63, whose central axis coincides with the second axis of rotation 12.

[0032] The cylinder 60 is rotatable about the second rotation axis 12. Working plungers 62 are linearly and movably housed within the cylinder 60 along the direction of the second rotation axis 12, thereby defining working chambers 65 with respect to the cylinder 60. As the cylinder 60 rotates about the second rotation axis 12, the volume of the working chamber changes because the tilt angle 14 between the first and second rotation axes 11, 12 is not zero, and in this embodiment is 25°. In this embodiment, nine working plungers 62 are provided.

[0033] The aforementioned tilt angle 14 is fixed in this embodiment because the separate control plate 40 is fixedly housed within the second housing portion 22. Within the scope of this application, the control plate 40 is considered a component of the housing 20. It forms a control surface 46, which can also be directly disposed on the second housing portion 22. To minimize wear, a separate control plate 40 is provided, made of a non-ferrous metal (particularly brass or bronze), wherein the first and / or second housing portions 21, 22 are made of cast iron or aluminum. The control plate 40 is housed in a cylindrical fitting recess about the second axis of rotation 12 within the second housing portion 22. An anti-torsion device 47 for the control plate 40 is implemented by means of a cylindrical pin that engages with fitting holes in the control plate 40 and the second housing portion 22.

[0034] The control surface 46 is non-planar and designed to be rotationally symmetrical about the second axis of rotation 12. The cylinder 60 slidably rests against the control surface 46 with a matching reverse control surface 61, thereby defining the position of the second axis of rotation 12. The guide plunger 63 and the spring 64 therein ensure that the cylinder 60 remains concentric about the second axis of rotation 12 even under no-pressure conditions. The control surface 46 and the reverse control surface 61 are preferably spherical, with the control surface 46 most preferably convex and the reverse control surface 61 concave. Each working chamber 65 opens with a corresponding outlet opening 66 on the reverse control surface 61.

[0035] The second housing portion 22 includes an annular section 24 and a bottom section 25. A pre-compression cavity 33 is formed by a single-sided open borehole extending along the extension axis 13 with a constant (circular in this embodiment) cross-sectional shape. It is conceivable that the pre-compression cavity 33 is formed by a core during the casting of the second housing portion. In this case, it may be necessary to hold the core at its two opposite ends in the direction of the extension axis 13; therefore, another (not shown) sealing screw is required for holding the through-hole (not shown) in the second housing portion 22. In this embodiment, the extension axis 13 is arranged parallel to the second rotation axis 12, or it may be slightly inclined to the second rotation axis 12. The pre-compression cavity 33 extends beyond the cylinder 60 along the extension axis 13 and extends to both ends of the cylinder 60 to obtain a larger volume of pre-compression cavity 33. Therefore, at least 50% of its volume is arranged in the annular section 24 of the second housing portion 22, and the remainder of the pre-compression cavity 33 is arranged in the bottom section 25. A one-sided opening of the pre-compression chamber 33 is also arranged there, which is fluid-tightly closed with a separate first sealing screw 31.

[0036] The second rotation axis 12 is inclined away from the pre-compression chamber 33 relative to the first rotation axis 11. The intermediate connecting screw 34 and the pre-compression chamber 33 are arranged on opposite sides of the second rotation axis 12.

[0037] The connecting channel 70 from the control surface 46 to the pre-compression chamber 33 includes first, second, and third sections 71, 72, and 73. The first section 71 passes through the control plate 40 parallel to the second axis of rotation 12, defining a drainage opening. Figure 3 (Number 45 in the text). The second section 72 extends directly into the second housing portion 22, aligned with the first section 71 and extending parallel to the second axis of rotation 12. The third section 73 extends transversely to the second axis of rotation 12 in a straight line, and in particular perpendicular to the second axis of rotation 12. The third section 73 leads directly into the pre-compression chamber 33, therefore, the drainage opening ( Figure 3 A permanent fluid exchange connection exists between section 45 and pre-compression chamber 33. Section 73 is preferably drilled into the second housing portion 22 from the outside, and the corresponding opening is fluid-tightly sealed with a second sealing screw 32. The entire connection channel 70 is preferably parallel to the intermediate plane (…). Figure 1 Arranged as number 15 in the middle, in this embodiment, its arrangement is about the middle plane ( Figure 1 (Item 15) is arranged in a mirror-symmetric manner. The intermediate plane is a plane that includes the first and second rotation axes 11 and 12 and the extension axis 33, i.e. Figure 2 The drawing plane. Based on the drainage opening ( Figure 3 The desired position of the connecting channel 70 (number 45) can be arranged with a smaller spacing from the intermediate plane.

[0038] exist Figure 2 The planar sealing surface 23 can be seen, and the first and second housing portions 21 and 22 are tightly abutted against each other at this sealing surface, where a sealing ring 83 is arranged. In this embodiment, the sealing surface 23 is oriented perpendicular to the first axis of rotation 11.

[0039] Figure 3 It shows Figure 1 The diagram shows a perspective view of the control plate 40 of the axial piston machine. The control plate 40 forms a spherical control surface 46, which is convexly curved, with the center of the sphere located on the second axis of rotation. Figure 2 On (number 12) of the control surface 46. The radially inner and radially outer sides of the control surface 46 are defined by the vacancy 49, each forming about the second rotation axis ( Figure 2 The boundary line (numbered 12) is rotationally symmetric. First and second control kidney-shaped grooves 41 and 42 are arranged within the control surface 46, respectively along the second rotation axis (…). Figure 2 The direction of number 12) passes through control plate 40. They are each designed as curved elongated holes with a constant width, defining a common diameter that corresponds to the outlet opening ( Figure 2The diameter of the outlet opening (numbered 66) is the same. As the cylinder 60 rotates, each outlet opening alternately establishes a fluid exchange connection with the first and second control kidney-shaped grooves 41, 42. In the circumferential direction, the first and second control kidney-shaped grooves 41, 42 are spaced apart from each other by the first and second reversing regions 43, 44, each reversing region being designed to be wide in the circumferential direction such that the outlet opening at any position in the cylinder does not form a low-resistance hydraulic short circuit between the first and second control kidney-shaped grooves 41, 42.

[0040] A drainage opening 45 is arranged in the first reversing area 43, the drainage opening being formed by the first section of the connecting channel ( Figure 1 The part number 71 is formed. Its exact position and diameter are preferably optimized through testing so that the axial piston machine can operate at the highest possible speed without producing excessive pressure pulsation. Figure 3 The proportions shown should be understood as preliminary designs that have not yet been optimized.

[0041] It should also be mentioned that there are two recesses (Kerbens) 48, which are associated with the first and second control kidney-shaped grooves 41 and 42, respectively. This further minimizes the pressure pulsation. This axial plunger machine is designed for a fixed preset direction of rotation; therefore, the two recesses 48 shown are sufficient. In cases where the direction of rotation is variable, four recesses are preferred.

[0042] List of reference numerals

[0043] 10-axis piston machine

[0044] 11 First axis of rotation

[0045] 12 Second axis of rotation

[0046] 13 Extended Axis

[0047] 14 tilt angle

[0048] 15. Intermediate Plane

[0049] 16 ball joints

[0050] 20 housing

[0051] 21 First shell section

[0052] 22 Second shell section

[0053] 23 Sealing surface

[0054] 24-ring section

[0055] 25 bottom section

[0056] 26 First Working Interface

[0057] 27 Second Working Interface

[0058] 28 interior spaces

[0059] 30 connecting screws

[0060] 31 First sealing screw

[0061] 32 Second sealing screw

[0062] 33 Pre-compression chamber

[0063] 34 connecting screws in the middle

[0064] 40 control board

[0065] 41 First control kidney-shaped slot

[0066] 42 Second control kidney-shaped groove

[0067] 43 First Reversing Area

[0068] 44 Second Reversing Area

[0069] 45 Drainage opening

[0070] 46 control surfaces

[0071] 47 Anti-torsion device

[0072] 48 grooves

[0073] 49 vacant departments

[0074] 50 drive shafts

[0075] 51 Rotary Bearing

[0076] 52 drive pin

[0077] 53 flange

[0078] 60 cylinders

[0079] 61 Reverse Control Surface

[0080] 62 working plunger

[0081] 63 Guide Piston

[0082] 64 springs

[0083] 65 working chamber

[0084] 66 Exit Opening

[0085] 70 connection channels

[0086] 71 Section 1

[0087] 72 Second Section

[0088] 73 Third Section

[0089] 80 Fastening Flange

[0090] 81 ribs

[0091] 82 Fastening Through Hole

[0092] 83 sealing ring

Claims

1. An axial piston machine (10) having a housing (20) in which a drive shaft (50) is rotatably supported about a first axis of rotation (11), wherein, A cylinder (60) is provided with a reverse control surface (61), wherein the reverse control surface (61) is slidably attached to a matching control surface (46), wherein the control surface (46) is fixedly arranged on the housing, wherein the control surface is non-planar and rotationally symmetrical about a second rotation axis (12), wherein the first and second rotation axes (11, 12) are arranged at a non-zero fixed tilt angle towards each other, wherein a plurality of working plungers (62) are linearly movably accommodated in the cylinder (60), such that the working plungers and the cylinder (60) respectively define a working chamber (65), wherein the working plungers (62) are respectively connected to the cylinder (60) via ball joints (16) arranged at intervals with respect to the first and second rotation axes (12). The drive shaft (50) is kinematically coupled, wherein first and second working interfaces (26, 27) are arranged on the housing (20), the first and second working interfaces being permanently fluidly connected to corresponding first or second control kidney-shaped grooves (41, 42) on the control surface (46), wherein each working chamber (65) is opened through an outlet opening (66) on the reverse control surface (61), wherein the outlet opening (66) can establish a fluid exchange connection with the first or second control kidney-shaped groove (41, 42) respectively by rotation of the cylinder (60), wherein the first and second control kidney-shaped grooves (41, 42) are spaced apart from each other by first and second reversing regions (43, 44) in the circumferential direction about the second rotation axis (12). The feature is that a drainage opening (45) is arranged in the first reversing region (43), and the drainage opening can establish a fluid exchange connection with one of the outlet openings (66) by the rotation of the cylinder (60). The drainage opening (45) is permanently connected to the pre-compression chamber (33) through a connecting channel (70) that extends completely in the housing (20). The pre-compression chamber (33) is closed except for the connecting channel (70). The pre-compression chamber is completely arranged in the housing (20).

2. The axial piston machine (10) according to claim 1, in, The pre-compression chamber (33) extends along the extension axis (13) with a constant cross-sectional shape, wherein the extension axis (13) has a maximum inclination angle of 15° relative to the second rotation axis (12), and wherein the pre-compression chamber (33) is arranged transversely to the second rotation axis (12) next to the cylinder (60).

3. The axial piston machine (10) according to any one of the preceding claims, in, The housing (20) includes first and second housing portions (21, 22), the first and second housing portions being can-shaped and integrally formed, wherein the first and second housing portions are fitted together with their open sides such that the first and second housing portions enclose an internal space (28), wherein the drive shaft (50), the cylinder (60) and the working plunger (62) are arranged in the internal space (28), wherein the drive shaft (50) is rotatably supported only on the first housing portion (21), wherein the pre-compression chamber (33) is arranged away from the first housing portion (21), wherein the pre-compression chamber is defined at least in sections by the second housing portion (22).

4. The axial piston machine (10) according to claim 3, in, The can-shaped and integrally formed second housing portion (22) includes an annular section (24) and a bottom section (25), wherein at least 50% of the volume of the pre-compression chamber (33) is arranged in the annular section (24).

5. The axial piston machine (10) according to claim 4, in, The pre-compression chamber (33) is directly constructed as a borehole in the second housing portion (22), wherein the borehole is sealed with a first sealing screw (31), wherein the first sealing screw (31) is screwed into the second housing portion (22) in the region of the bottom section (25).

6. The axial piston machine (10) according to any one of claims 2 to 5, in, The second rotation axis (12) and the extended axis (13) form an intermediate plane (15), wherein the first and second control kidney-shaped grooves (41, 42) are respectively arranged completely on opposite sides of the intermediate plane (15), such that the intermediate plane (15) intersects with the first and second reversing regions (43, 44).

7. The axial piston machine (10) according to claim 6, in, The first reversing region (43) with the drainage opening (45) and the pre-compression chamber (33) are arranged on the same side of the second rotation axis (12).

8. The axial piston machine (10) according to any one of the preceding claims, in, The control surface (46) is arranged on a separate control plate (40), which is fixedly arranged on the remaining housing (20), wherein a first section (71) of the connecting channel (70) passes through the control plate (40) parallel to the second rotation axis (12).

9. The axial piston machine (10) according to claim 8 of claim 3, in, The connection channel (70) that is away from the control panel (40) is arranged directly in the second housing portion (22).

10. The axial piston machine (10) according to claim 9, in, The connecting channel (70) in the second housing portion (22) includes second and third sections (72, 73), both of which extend in a straight line and are directly adjacent to each other. The second section (72) extends parallel to the second rotation axis (12) from the control plate (40), and the third section (73) extends laterally to the pre-compression chamber (33) along the second rotation axis (12).

11. The axial piston machine (10) according to claim 10 of claim 6, in, The first, second, and third sections (71, 72, 73) of the connecting channel (70) are arranged parallel to the intermediate plane (15).

12. The axial piston machine (10) according to any one of claims 6 to 11, in, The first and second housing portions (21, 22) are tightened together by an odd number of connecting screws (30), wherein the connecting screws (30) are arranged in a mirror symmetrical manner about the intermediate plane (15), wherein one of the connecting screws (34) is arranged in the region of the intermediate plane (15) and is located on the side of the second rotation axis (12) opposite to the pre-compression cavity (33).

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