Axial piston machine with fixed flange having fixed perforations arranged eccentrically

Abstract

The invention relates to a swash plate design axial piston machine (10) with a displacement volume that can be adjusted beyond zero, wherein the respective rocker can be deflected with an adjusting cylinder (30) arranged transversely to the rotation axis (11), wherein the axial piston machine (10) is equipped with a fixing flange (40) having four fixing perforations (41; 42; 43; 44), according to the invention the fixing flange (40) is integrally and without interruption turned into the adjusting cylinder (30), wherein in the respective transition region (14) no further fixing perforation is arranged through the fixing flange (40) in the direction along the rotation axis (11).

Description

Technical Field

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

[0002] A swashplate axial piston pump, described in the datasheet "Axial Piston-Regulating Pump A4VG Structure Series 60" (order number RD 92038; version 2024-10-15) from Bosch Rexroth AG, is an axial piston pump with a displacement volume adjustable over zero position, wherein the corresponding rocker arm is deflected by an adjusting cylinder arranged transversely to the axis of rotation. The axial piston pump is equipped with a fixed flange, which is constructed according to a variant of standard SAE J744 FEB2013 with two fixing perforations. This fixed flange is suitable for the relatively small structural dimensions of the axial piston pump. A key feature of the axial piston pump is its short structural length along the axis of rotation, particularly the fixed flange's very close proximity to the adjusting cylinder.

[0003] A similar axial piston press is known from the data page "Axial Piston Press - Regulating Pump A4VG Structure Series 35," which is not obviously optimized for a short structural length. For example, the rated size 71 is equipped with a so-called 6-hole flange, for which two and four fixed perforations, variants, are integrated into a single fixed flange according to SAE J744 FEB2013. It would be desirable to apply this fixed flange to the axial piston press explained above. However, due to the short structural length, there is insufficient structural space near the regulating cylinder for the fixed perforations to accommodate the screw heads or nuts of the fixing bolts. Summary of the Invention

[0004] The advantage of this invention is that it maintains the short structural length of the axial piston machine described above, wherein the axial piston machine still has a fixing flange that allows for rigid fixation. Particularly conceivable here is that two axial piston machines are mounted close to each other along the axis of rotation in a tandem assembly. The corresponding connection, especially in larger axial piston machines, must be rigidly constructed to prevent excessive vibration during operation caused by unavoidable pressure pulses within the axial piston machines.

[0005] According to the independent claim, the fixed flange is integrally and uninterruptedly, especially without recesses, inserted into the regulating cylinder, wherein no additional fixing perforations are arranged in the corresponding transition area through the fixed flange along the direction of rotation axis.

[0006] The direction of movement of the working piston is preferably parallel to or slightly inclined to the axis of rotation. The first to fourth fixed perforations can each be configured as circular perforations, wherein the fixed perforations are preferably configured as gaps opening radially outward with respect to the axis of rotation. The plane of symmetry preferably includes the axis of rotation. It is conceivable that the axis of rotation extends at intervals relative to the plane of symmetry, such that the combined hydraulic pressures acting in the axial piston mechanism apply torque to the rocker arm.

[0007] Advantageous extensions and improvements are described in the dependent claims.

[0008] It can be specified that the fixed flange forms a flat fixed surface oriented perpendicular to the axis of rotation, wherein the fixed surface is machined such that it creates a boundary line or boundary edge of a non-machined surface directly adjacent to the housing relative to the regulating cylinder, wherein the distance between the fixed plane defined by the fixed surface and the regulating axis is at most 60% of the maximum hydraulically effective diameter of the first or second regulating chamber. This makes it almost impossible to move the fixed surface closer to the regulating cylinder. It should be noted that the fixed surface often abuts against a flat surface of the upper structural assembly that must not collide with the regulating cylinder. Simultaneously, the fixed surface protrudes slightly beyond the non-machined surface to ensure that the upper structural assembly abuts only against the fixed surface. The hydraulically effective diameters of the first and second regulating chambers are preferably the same size.

[0009] It can be specified that the mentioned boundary line has a first section extending circularly in the region of the regulating cylinder, wherein the corresponding center of the circle coincides with the axis of rotation, and a second section extending straight out of the boundary line is directly tangentially adjacent to the two opposing ends of the first section. The boundary line preferably has the same shape as a two-hole flange according to standard SAE J744 FEB2013. Thus, the axial piston press according to the invention can be used in all places where fixed flanges conforming to standards are currently used.

[0010] It can be specified that the mentioned boundary line has a third segment in the region of the regulating cylinder, which protrudes and extends with two straight legs, wherein the two straight legs are arranged mirror-symmetrically about a plane of symmetry, wherein they extend with an inclination of up to 5° relative to the regulating axis, and wherein the mentioned third segment extends over at least 70% of the length of the regulating cylinder. With this shape of the boundary line, the highest possible rigidity of the fixed flange is achieved because the transition area is reduced to a small range, i.e., the angular radius. The mentioned inclination angle is preferably chosen in this way so that the casting blank of the housing can be easily removed from the corresponding mold. Also mentioned is the demolding ramp, which is initially arranged in the region of the regulating cylinder. However, the small distance between the fixed plane and the regulating axis, as explained above, causes the demolding ramp to also project onto the boundary line through the explained angular radius.

[0011] It can be specified that regulating valves are respectively assigned to the first and second regulating chambers. These regulating valves are constructed as insert valves, wherein they are directly mounted into the housing. The central axis of the regulating valve is arranged parallel to and spaced apart from the plane of symmetry, wherein the distance between the central axis and the regulating axis is at most 80% of the maximum hydraulically effective diameter of the first or second regulating chamber. The fixed flange and the regulating valve are respectively arranged on opposite sides of the regulating axis along the direction of rotation. Similar regulating valves are known from the axial piston mechanism explained at the beginning. The regulating valves are preferably directly mounted into the canister-shaped housing.

[0012] It can be specified that the angle between the central axis of the control valve and the reference plane is between 30° and 60°, wherein a lug-like protrusion is provided on the housing in the region of the control valve, wherein the lug-like protrusion extends around the control cylinder from the associated control valve to the fixed flange, wherein the lug-like protrusion is integrally connected with the control cylinder and the fixed flange, thereby causing reinforcement of the fixed flange. For the axial piston machine explained at the beginning, a lug-like protrusion has already been used in the region of the control valve, but this protrusion is not continuously guided to the fixed flange, thus failing to reinforce the fixed flange. More precisely, the path to the fixed flange is interrupted by the bolt heads or nut gaps there. With the lug-like protrusion according to the design of the present invention, a noteworthy reinforcement of the fixed flange can be achieved with minimal material overhead.

[0013] Recesses can be provided on the exterior of the housing in the areas of the third and fourth fixing perforations, respectively, wherein the recesses are arranged on the side of the fixing flange where the cylinder is located. The recesses should provide space for the bolt heads or nuts of the fixing bolts there. The recesses are preferably constructed directly into the can-shaped housing part.

[0014] It can be specified that the housing includes a can-shaped housing component integrally formed therein, wherein it completely forms a fixed flange, which is part of the regulating cylinder, such that the fixed flange integrally and uninterruptedly rotates into the regulating cylinder within the region of the can-shaped housing component, wherein a rocker arm is arranged inside the can-shaped housing component. The corresponding fixed flange is particularly rigid, allowing the axial piston mechanism to be manufactured at particularly low cost.

[0015] It can be specified that the lug-shaped protrusions are integrally set on the can-shaped housing. The corresponding fixing flange is particularly rigid, and the axial piston mechanism can be manufactured at a particularly low cost.

[0016] It goes without saying that the features mentioned above and explained below can be used not only in the combinations described, but also in other combinations or individually, without departing from the scope of the invention. Attached Figure Description

[0017] The invention will now be explained in more detail with the aid of the accompanying drawings. Wherein: Figure 1 A longitudinal section of an axial piston machine according to the invention is shown; Figure 2 It shows according to Figure 1 A local cross-section in the regulating cylinder area of ​​an axial piston machine; Figure 3 It shows according to Figure 1 A perspective view of an axial piston machine, showing the side of the fixed flange; Figure 4 It shows according to Figure 1 Another perspective view of an axial piston machine; and Figure 5 A perspective view of a can-shaped housing component according to a second embodiment of the invention is shown. Detailed Implementation

[0018] Figure 1 A longitudinal section of the axial piston mechanism 10 according to the invention is shown. The cutting plane includes a rotation axis 1, which is oriented perpendicular to a return axis 12. The axial piston mechanism 10 includes a housing 20, which is composed of a can-shaped housing member 21 and a plate-shaped housing member 27, wherein the aforementioned housing members 21 and 27 are integrally formed and manufactured by a casting process. Currently, an optional feed pump 15 is integrated into the plate-shaped housing member 27.

[0019] The housing 20 includes a plate-shaped fixed flange 40 oriented perpendicular to the axis of rotation 11. The fixed flange 40 is arranged at the end of the housing 20 pointing along the axis of rotation 11, where it is part of the can-shaped housing component 21. In the region of the fixed flange 40, a drive shaft 16 extends from the housing 20, and the drive shaft is preferably supported on the housing 20 by means of rolling bearings in a manner rotatable about the axis of rotation 11.

[0020] Inside the housing 20 is a cylinder 22, which is torsionally connected to the drive shaft 16 about the axis of rotation 11, for example by means of a splined shaft tooth. Along the axis of rotation 11, the cylinder 22 is preferably slidably supported on a plate-shaped housing member 27 by a separate distribution plate having two kidney-shaped control ports. Multiple, for example nine, working pistons 23 are arranged in the cylinder 22 in a linearly movable manner toward the rocker arm 25. The working pistons 23 are currently oriented slightly inclined relative to the axis of rotation 11, but can also be oriented parallel to the axis of rotation 11. Each working piston 23 is placed on the flat control surface of the rocker arm 25 by a slide connected to the associated working piston 23 via a ball joint. The rocker arm 25 is rotatably supported on the housing 20 about the axis of rotation 12, particularly on a can-shaped housing member 21, wherein the axis of rotation 12 is perpendicular to... Figure 1 Oriented by the drawing plane. Currently, the rotation axis 12 intersects the rotation axis 11. The displacement volume of the axial piston machine 10 can be continuously adjusted by deflecting the cradle 25. The displacement volume of the axial piston machine 10 can currently be adjusted past the zero position, so that the rotation direction of the drive shaft 16 can be reversed by adjusting the cradle 25 while keeping the flow direction of the axial piston machine 10 the same.

[0021] Figure 2 It shows according to Figure 1 A partial cross-section of the axial piston mechanism in the region of the adjusting cylinder 30. The corresponding cutting plane includes the adjusting axis 13, which extends perpendicular to the axis of rotation. The adjusting cylinder 30 is configured as a dual-function cylinder, comprising first and second adjusting chambers 31, 32, which are separated from each other by an adjusting piston 33. The first and second adjusting chambers 31, 32 are further defined by a housing 20, particularly by a canister-shaped housing member 21. Furthermore, the first adjusting chamber 31 is defined by a separate cover 38. The adjusting piston 30 is capable of linear movement along the direction of the adjusting axis 13, which forms the central axis of the adjusting piston 33 and the first and second adjusting chambers 31, 32. A return spring 36 is arranged inside the adjusting piston 33, which preloads the adjusting piston 33 into a position where the displacement volume of the axial piston mechanism is zero. The adjusting piston 33 is kinetically coupled 34 to the rocker arm 25. Currently, the rocker arm 25 has a pin arranged spaced apart from the axis of rotation, wherein the pin is inserted into a groove on the adjusting piston 33 that surrounds the adjusting axis 13.

[0022] It should also be pointed out that Figure 2The slewing bearing 37, visible in the image, supports the rocker arm 25 in a manner that allows rotation about the axis of rotation. The slewing bearing 37 is currently constructed as a rolling bearing, particularly as a cylindrical roller bearing, although it can also be constructed as a sliding bearing.

[0023] In addition, Figure 2 The diagram illustrates the maximum hydraulically functional diameter 35 of two regulating chambers 31 and 32, wherein the two regulating chambers 31 and 32 currently have the same hydraulically functional diameter.

[0024] Figure 3 It shows according to Figure 1 A perspective view of the axial piston mechanism 10, showing the side of the fixed flange 40. The fixed flange 40 forms a flat fixing surface 45, which points away from the adjusting cylinder 30. Furthermore, the fixed flange includes a cylindrical centering protrusion 46 about the axis of rotation 11. In particular, the diameter and length of this centering protrusion 46 are the subject of standard SAE J744FEB2013. This standard also defines the possible locations and sizes of the fixing perforations 41-44. A two-hole variant is provided, comprising first and second fixing perforations 41, 42. The first and second fixing perforations 41, 42 are arranged mirror-symmetrically to each other, wherein the corresponding plane of symmetry contains the axis of rotation 11, which is parallel to the axis of rotation (in...). Figure 1 The first and second fixing holes 41 and 42 are arranged in a reference plane that includes a rotation axis 11, which is arranged perpendicular to the aforementioned plane of symmetry. The first and second holes are preferably configured to be mirror-symmetrical about the aforementioned reference plane.

[0025] Furthermore, the mentioned standard describes a four-hole variant of the fixed flange, in which the third and fourth fixing holes 43 and 44 are arranged according to the four-hole variant, that is, they are spaced apart with respect to the mentioned reference plane and are also arranged mirror-symmetrically with respect to each other with respect to the mentioned plane of symmetry. The two additional fixing holes of the four-hole variant are omitted according to the invention. The reason for this is that the current axial piston mechanism 10 is made very short along the direction of the rotation axis 11. This is achieved in particular by moving the fixing surface 45 very close to the adjusting axis 13.

[0026] If multiple axial piston units 10 are assembled in series along the axis of rotation 11, then, for example, the aforementioned four-hole variant is required, wherein this series assembly is self-supportingly fixed to the upper-level structural assembly. The fixed flange 40 must then transmit a notable torque, borne by the fixing screws passing through the fixing holes 41-44. Even if, as an alternative, the first and second fixing holes 41, 42 of the two-hole variant are used, the elimination of the two fixing holes in the four-hole variant causes a loss of rigidity. To minimize this loss of rigidity, the fixed flange 40 is currently configured such that it is reinforced by the adjusting cylinder 30. Therefore, a plate is no longer involved, which extends as freely as possible radially outward from the housing about the axis of rotation 11. More precisely, a transition region 14 is provided between the fixed flange 40 and the adjusting cylinder 30, in which the fixed flange 40 integrally and uninterruptedly rotates into the adjusting cylinder 30. The fixed flange 40 and the regulating cylinder 30 are formed by an integrally constructed can-shaped housing 21.

[0027] In the can-shaped housing part 21 Figure 3 In the first embodiment shown, the boundary line 50 is made according to the aforementioned standard, based on the example for a two-hole flange. The boundary line 50 is the edge produced towards the regulating cylinder 30 when the blank of the can-shaped housing part 21, manufactured by a casting process, is machined at the fixed surface 45. The boundary line 50 includes a first section 51, which is circularly curved, with the corresponding center coinciding with the axis of rotation 11. A second section 52, which is straight, is directly and tangentially adjacent to the two opposing ends of the first section. The transition region 14 between the boundary line 50 and the regulating cylinder 30 has been filled with material on the casting blank so that there are no recesses there that extend beyond the unavoidable shoulder in the region of the boundary line 50. The transition region 14 is formed approximately flat, wherein it tangentially enters the regulating cylinder 30, which is formed approximately cylindrical, and wherein it is arranged parallel to the fixed surface 45. Deviations from the ideal shape explained above arise particularly from the preferred demolding ramps present on the casting blank.

[0028] The first to fourth fixing holes 41-44 pass through the fixing flange 40 along the direction of the rotation axis 11. The fixing holes are preferably configured as gaps that open radially outward about the rotation axis 11, so that fixing screws can be easily inserted into the assigned fixing gaps 41-44.

[0029] Figure 4 It shows according to Figure 1Another perspective view of the axial piston machine 10. Two regulating valves 60 are particularly visible, each assigned to a first or second regulating chamber. These regulating valves are made as insert valves, which can involve pressure reducing valves, pressure regulating valves, or 3 / 2-directional valves. The regulating valve 60 correspondingly has a central axis 60, which is currently oriented, for example, at a 45° angle relative to the reference plane explained above, wherein the regulating valve 60 is arranged on the side of the regulating cylinder 30 facing away from the fixed flange 40 along the axis of rotation 11, and furthermore, it is arranged on the same side of the reference plane as the regulating cylinder 30. To provide the structural space necessary to receive the regulating valve 60, the cylinder-shaped housing 21 is provided with a lug-like protrusion 62. This protrusion is guided around the regulating cylinder 30 all the way to the fixed flange 40 and integrally rotates into said fixed flange. This lug-like protrusion 62 causes significant reinforcement of the fixed flange 40, for which no noteworthy additional casting material is required relative to the lug-like protrusion, which is sufficient to receive the regulating valve 60.

[0030] In addition, Figure 4 As can be seen, a recess 47 is arranged on the can-shaped housing 21 in the area of ​​the third and fourth fixing perforations 44. The recess 47 is intended to provide structural space for the screw head or nut of the fixing screw (not shown) therein.

[0031] In addition, Figure 4 As can be seen, the open side of the plate-shaped housing member 27 and the can-shaped housing member 21 are closed by the plate-shaped housing member, thereby creating a closed internal space in which the cylinder and the rocker arm are received (in Figure 1 (See attached figures 22 and 25).

[0032] Figure 5 A perspective view of a can-shaped housing member 21' according to a second embodiment of the invention is shown. The view orientation corresponds to... Figure 3 The view direction. The second embodiment of the can-shaped housing 21' is constructed identically to the first embodiment, except for the differences explained below, and thus, in connection with this, refers to... Figures 1 to 4 The explanation.

[0033] In the second embodiment 21', the flat fixing surface 45 is enlarged such that the transition region 14 between the fixing flange 45 and the adjusting cylinder 30 is still formed solely by the corner radius. This creates a boundary line 50' in the region of the adjusting cylinder 30 with a third segment 53 extending slightly protrudingly from it by two straight legs 54. The two straight legs 54 are arranged mirror-symmetrically about a plane of symmetry, extending at an inclination of up to 5° relative to the adjusting axis 13. The third segment 53 extends, for example, over at least 80% of the length of the adjusting cylinder 30. This results in a particularly rigid fixing flange 40.

[0034] List of reference numerals in the attached diagram: 10 Axial Piston Press 11. Axis of rotation 12 Rotation axis 13 Adjusting the axis 14 Transition Zone 15 Feed pump 16 drive shafts 20. Housing 21. Can-shaped housing component (first embodiment) 21' Can-shaped housing component (second embodiment) 22 cylinder barrel 23 Working piston 24 Slides 25 Cradle 26. Non-machining surfaces of the housing 27. Plate-shaped housing components 30 Adjusting cylinder 31 First Adjustment Room 32 Second Adjustment Room 33 Adjusting piston 34. Kinematic coupling between the rocker arm and the adjusting piston 35. Maximum diameter that functions in hydraulic applications 36. Return spring 37 Slewing Bearing 38 lids 40 Fixed flange 41 First fixing hole 42 Second fixing hole 43 Third fixing hole 44 Fourth fixing hole 45 Fixed surface 46 Centering protrusion 47. Recess (for securing screws) 50 Boundary Line (First Implementation) 51' Boundary Line (Second Implementation) 51 First Section 52 Second Section 53 Third Section 54 Straight support legs 60 Control valve 61. Central axis of the regulating valve 62. Ear-shaped protrusions

Claims

1. An axial piston machine (10) having a housing (20) housing in which a cylinder (22) rotatable about a rotation axis (11) and a rocker arm (25) rotatable about a return axis (12) are received, wherein a plurality of working pistons (23) are received in the cylinder (22) in a manner linearly movable toward the rocker arm (25), wherein the working pistons (23) are supported on the rocker arm (25) such that the displacement volume of the axial piston machine (10) can be adjusted by deflection of the rocker arm (25). An adjusting cylinder (30) is provided, having an adjusting piston (33) that can move linearly along an adjusting axis (13). The adjusting piston (33) separates the first and second adjusting chambers (31, 32) from each other. The rotation axis (12) is oriented perpendicular to the rotation axis (11). The adjusting axis (13) forms the central axis of the adjusting piston (33). The adjusting axis is oriented perpendicular to both the rotation axis (11) and the rotation axis (12). The housing (20) is arranged separately from and separated from the axis of rotation (12), wherein the adjusting piston (33) is kinematically coupled (34) to the rocker arm (25), wherein the housing (20) includes a plate-shaped fixing flange (40) oriented perpendicular to the axis of rotation (11), wherein the fixing flange (40) is traversed along the axis of rotation (11) by first, second, third and fourth fixing perforations (41, 42, 43, 44) along the axis of rotation (11), wherein the plane of symmetry encompasses the axis of rotation (11), wherein the plane of symmetry extends parallel to the axis of rotation (12), wherein the reference plane is arranged perpendicular to the plane of symmetry, wherein the reference plane encompasses the axis of rotation (11), wherein the first and second fixing perforations (41, 42) are arranged in the region of the reference plane and are mirror-symmetrical about each other about the plane of symmetry, wherein the third and fourth fixing perforations (43, 44) are mirror-symmetrical about each other about the plane of symmetry, wherein the third and fourth fixing perforations are arranged on the side of the reference plane opposite to the adjusting axis (13). Its features are, The fixed flange (40) is integrally and uninterruptedly rotated into the regulating cylinder (30), wherein no additional fixing perforations are arranged in the corresponding transition area (14) through the fixed flange (40) along the direction of the rotation axis (11).

2. The axial piston machine (10) according to claim 1. The fixed flange (40) forms a flat fixed surface (45) oriented perpendicular to the axis of rotation (11), wherein the fixed surface (45) is machined such that a boundary line (50) is formed toward the regulating cylinder (30) relative to the housing (20) of a non-machined surface (26), wherein the distance between the fixed plane defined by the fixed surface (45) and the regulating axis (13) is at most 60% of the maximum hydraulically effective diameter (35) of the first or second regulating chamber (31, 32).

3. The axial piston machine (10) according to claim 2. The boundary line (50) mentioned therein has a first section (51) that extends in a circular shape in the region of the regulating cylinder (30), wherein the corresponding center of the circle coincides with the axis of rotation (11), wherein the second section (52) that extends in a straight shape from the boundary line (50) is directly tangential to the two opposite ends of the first section (51).

4. The axial piston machine (10) according to claim 2. The boundary line (50') mentioned therein has a third section (53) in the region of the regulating cylinder (30), the third section extending protrudingly with two straight legs (54), wherein the two straight legs (54) are arranged mirror-symmetrically about the plane of symmetry, wherein they extend in a manner inclined at most 5° relative to the regulating axis (13), wherein the third section (53) mentioned therein extends over at least 70% of the length of the regulating cylinder (30).

5. The axial piston machine (10) according to any one of the preceding claims. A regulating valve (60) is assigned to each of the first and second regulating chambers (31, 32), the regulating valve being configured as a receptacle valve, wherein it is directly mounted into the housing (20), wherein the central axis (61) of the regulating valve (60) is arranged parallel to and spaced apart from the plane of symmetry, wherein the distance between the central axis (61) and the regulating axis (13) is at most 80% of the maximum hydraulically effective diameter of the first or second regulating chamber (31, 32), wherein the fixed flange (40) and the regulating valve (60) are arranged on opposite sides of the regulating axis (13) along the direction of the rotation axis (11).

6. The axial piston machine (10) according to claim 5. The angle between the central axis (61) of the regulating valve and the reference plane is between 30° and 60°, wherein a lug-shaped protrusion (62) is provided on the housing (20) in the region of the regulating valve (60), wherein the lug-shaped protrusion extends around the regulating cylinder from the associated regulating valve (60) to the fixed flange (40), wherein the lug-shaped protrusion (62) is integrally connected with the regulating cylinder (30) and the fixed flange (40), thereby causing reinforcement of the fixed flange (40).

7. The axial piston machine (10) according to any one of the preceding claims. In the regions of the third and fourth fixing perforations (43, 44), recesses (47) are provided on the outer side of the housing, wherein the recesses (47) are arranged on the side of the fixing flange (40) where the cylinder (22) is located.

8. The axial piston machine (10) according to any one of the preceding claims. The housing (20) includes a can-shaped housing member (21) integrally formed therein, wherein it completely forms a fixed flange (40), which is part of the regulating cylinder (30), such that the fixed flange (40) is integrally and uninterruptedly rotated into the regulating cylinder (30) in the region of the can-shaped housing member (21), wherein the rocker arm (25) is arranged inside the can-shaped housing member (21).

9. The axial piston machine (10) according to claim 8, in the case of its retraction of claim 6, The lug-shaped protrusion (62) is integrally disposed on the can-shaped housing part (21).

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