Pivot angle measuring device on variable displacement hydrostatic axial piston machine

Abstract

A translational pivot angle measuring device (100; 200); 300); 400, 400; 500); 600) and a pivot angle measuring device (100; 600) having such a pivot angle measuring device (100; 200); 300); 400, 400; 500); the invention relates to a hydrostatic axial piston machine (1) having a pivot angle measuring device (2, 600), which is designed and designed to indirectly detect a pivot angle of a swash plate or cylinder barrel (2) of the axial piston machine (1). The pivot angle can be adjusted by means of an adjusting piston (18) guided in an adjusting cylinder (20), wherein the pivot angle measuring device (100; 200); 300); 400, 400; 500); 600) has a movable transmitter and a receiver (30) fastened to the housing. The transmitter consists of two permanent magnets (26; 126), which can be linearly and translatably driven by the adjusting piston (18) in the direction of movement (24) of the adjusting piston and which have a distance (MLS) from each other.

Description

Technical Field

[0001] This invention relates to the detection of the pivot angle of an axial piston machine with adjustable displacement hydrostatic force, using either a swashplate or swashplate configuration. Background Technology

[0002] An axial piston press with adjustable displacement hydrostatic design, known from the prior art, has its working piston coupled to a swashplate mounted on a pivot support. The pivot support is pivotally supported within the housing of the axial piston press to allow for displacement adjustment.

[0003] DE 102017213457 A1 illustrates an axial piston machine in which a pivot support is coupled to an adjusting piston of a hydrostatic regulating device via a journal integrally constructed with the pivot support and via a slider rotatably supported thereon. The regulating device has an adjusting cylinder designed as a screw-in insert sleeve, in which the adjusting piston is partially housed. The adjusting piston serves a dual purpose. The regulating pressure medium is supplied here from an external source of regulating pressure medium.

[0004] In such an axial piston machine, it is important for control and regulation tasks to detect the pivot angle of the pivot support or cylinder.

[0005] Rotary pivot angle measuring devices are known from existing technologies.

[0006] DE 102014200566 A1 discloses a rotary pivot angle measuring device positioned on the (non-physical) pivot axis of a pivot support. Therefore, the pivot angle is detected directly and without change (without acceleration or deceleration). The pivot angle measuring device has a shaft coupled to the pivot support via a rotary coupling device and a pivot support journal. The coupling device is a leaf spring made of spring steel. A disadvantage of such a pivot angle measuring device is the structural space requirement.

[0007] DE 102010045540 A1 discloses an axial piston machine with an adjusting device having an adjusting piston to which a rotary pivot angle measuring device is coupled. The pivot angle measuring device has a permanent magnet that moves along a circular track beside a pivot angle receiver having a Hall sensor, using a return rod. The return rod, with its (free) end section, is embedded in a receiving portion of the adjusting piston.

[0008] Furthermore, as is known from existing technology, for the aforementioned axial piston machine with an adjusting piston and a rotary pivot angle measuring device, the (free) end section of the return rod is embedded in the circumferential groove of the adjusting piston, where the lever of the pivot support is also embedded. The pivot angle measuring device is installed in the through-hole of the housing, thereby sealing the internal space of the axial piston machine, in which tank pressure exists.

[0009] The disadvantage of the two last-mentioned rotary pivot angle measuring devices and their linear / translational conversion of the adjusting piston movement to the rotary transmitter movement is that the (free) end section of the return rod must always be moved in and out radially relative to the clearance of the adjusting piston. Furthermore, at the end region of the adjusting piston stroke, only a relatively large movement of the adjusting piston (with an increasing tendency) can be converted into a small rotational movement of the transmitter, which correspondingly increases the risk of clamping. In addition, it is disadvantageous that the support of the return rod and the clamping of the transmitter magnet require increased structural space along the axial direction of the bearing structure.

[0010] An axial piston machine with a slanted shaft structure is also known from existing internal technology. Its adjusting cylinder is constructed as a differential cylinder, and a journal extending transversely to the direction of movement of the adjusting piston is fixed on the piston rod of the differential cylinder. This journal drives the control lentil body. The end section of the piston rod extends into the measuring chamber and has a slanted groove through which the pivot angle of rotation is detected.

[0011] Furthermore, prior art disclosed internally provides a translational pivot angle measuring device with a rod-shaped magnet, which is driven by an adjusting piston of an axial piston machine in a swashplate configuration. Summary of the Invention

[0012] The objective of this invention is to avoid the drawbacks of rotary pivot angle detection and, in addition, to update the prior art with translational pivot angle measuring devices mentioned in the last supplementary disclosure, in which the measurement range of the pivot angle measuring device should be expanded.

[0013] This task is accomplished by a pivot angle measuring device having the features of claim 1 and by an axial piston machine having the features of claim 8.

[0014] The claimed pivot angle measuring device is designed and configured for the indirect detection of the pivot angle of the swashplate or cylinder of a hydrostatic axial piston machine. The pivot angle can be adjusted by means of an adjusting piston guided in an adjusting cylinder, at which the pivot angle is indirectly detected. For this purpose, the claimed pivot angle measuring device has a transmitter movable with the adjusting piston and a receiver, particularly a Hall sensor, fixed to a housing. The pivot angle measuring device is translational. According to the invention, the transmitter is directly or indirectly coupled to the adjusting piston and can be translated along its direction of movement. The transmitter is formed by two preferably rod-shaped permanent magnets spaced apart from each other.

[0015] This avoids the radial movement of the return rod into and out of the adjusting piston's clearance / groove, which is necessary for existing rotary pivot angle measuring devices, in the (free) end section. In particular, it allows for the conversion of the larger movement of the adjusting piston at the end region of the adjusting piston's stroke into a large, unreduced translational or linear movement of the transmitter, minimizing the risk of clamping. The measuring range can also be expanded, for example, by 60 mm.

[0016] In the first principle of the pivot angle measuring device according to the invention, the transmitter is quadrupole. For this purpose, the two north poles and two south poles of the two permanent magnets are arranged in an alternating sequence along the direction of movement of the adjusting piston. More precisely, either the north pole of the first permanent magnet is arranged first, then the south pole, and then correspondingly the north pole of the second permanent magnet is arranged first, then the south pole, and then the north pole, and correspondingly the south pole of the second permanent magnet is arranged first, then the north pole, and then correspondingly the south pole of the second permanent magnet is arranged first, then the north pole.

[0017] In the second principle of the pivot angle measuring device according to the invention, the transmitter is tripolar. For this purpose, either the two north poles or the two south poles of the two permanent magnets point towards each other along the direction of movement of the adjusting piston. More precisely, along the direction of movement of the adjusting piston, either the north pole of the first permanent magnet is first arranged followed by its south pole, and then the south pole of the second permanent magnet is first arranged followed by its north pole, or the south pole of the first permanent magnet is first arranged followed by its north pole, and then the north pole of the second permanent magnet is first arranged followed by its south pole.

[0018] Each permanent magnet has a main axis that extends through the south and north poles of the corresponding permanent magnet. In a third principle of the pivot angle measuring device according to the invention, the two main axes of the two permanent magnets are arranged perpendicular to the direction of movement of the adjusting piston. Here, the north pole of the first permanent magnet and the south pole of the second permanent magnet face the receiver, while the south pole of the first permanent magnet and the north pole of the second permanent magnet face away from the receiver. Alternatively, the south pole of the first permanent magnet and the north pole of the second permanent magnet face the receiver, while the north pole of the first permanent magnet and the south pole of the second permanent magnet face away from the receiver.

[0019] In a particularly flexible improvement to the pivot angle measuring device according to the invention, the receiver is capable of detecting all possible directions of motion of the permanent magnet in adjacent planes of motion. The receiver is referred to as a 3D sensor.

[0020] Here, the receiver has an electronic sensor component that is stationary, fixed to the housing, adjacent to a permanently moving, translationally movable magnet. The sensor component has a longitudinal axis that defines the receiver's main axis. Therefore, this main axis of the receiver can be arranged laterally or longitudinally to the direction of movement of the adjusting piston when using the aforementioned 3D sensor.

[0021] An air gap is provided between the permanent magnet and the connector. The ratio of the air gap to the distance between the two permanent magnets is preferably between 0.295 and 0.558, and particularly 0.426. Therefore, for example, in a specific application, the air gap can be 4.35 mm, and the distance between the two permanent magnets relative to each other is 10.2 mm.

[0022] The disclosed hydrostatic axial piston mechanism is constructed in a swashplate or swashplate configuration and therefore has a swashplate or cylinder, the pivot angle of which can be adjusted by means of an adjusting piston guided in an adjusting cylinder. The pivot angle measuring device described above is operatively connected to the adjusting piston.

[0023] In one improved embodiment, the regulating cylinder is a differential cylinder, wherein the regulating piston has a piston rod to which a transverse journal is fixed. Two permanent magnets are then indirectly or directly fixed to an end section of the piston rod opposite to the piston. This end section is movable within the measuring housing, into which the connector is inserted (e.g., into a through-hole).

[0024] Preferably, two permanent magnets are indirectly fixed to the end section of the piston rod by a support member extending along the direction of motion. The support member, when viewed in a cross-section transverse to the direction of motion of the adjusting piston, can be U-shaped. The support member can be a bent sheet metal component.

[0025] Two permanent magnets can be housed in a magnet housing, which is then fixed to a support member. Attached Figure Description

[0026] The principles and embodiments of this disclosure are described below with reference to the accompanying drawings.

[0027] Figure 1 An embodiment of an axial piston machine according to the invention, having a pivot angle measuring device according to the invention, is shown;

[0028] Figure 2 It shows Figure 1 The cutting portion of the axial piston machine, the axial piston machine having Figure 1 Pivot angle measuring device in the middle;

[0029] Figure 3 It shows Figure 1 The cut-off portion of the axial piston machine, wherein the axial piston machine has a second embodiment of the pivot angle measuring device according to the invention;

[0030] Figure 4 It shows Figure 1 The cut-off portion of the axial piston machine, the axial piston machine having a third embodiment of the pivot angle measuring device according to the invention;

[0031] Figure 5 A fourth embodiment of the pivot angle measuring device according to the invention is shown;

[0032] Figure 6 A fifth embodiment of the pivot angle measuring device according to the invention is shown; and

[0033] Figure 7 A sixth embodiment of the pivot angle measuring device according to the present invention is shown. Detailed Implementation

[0034] Figure 1 An embodiment of the axial piston machine 1 according to the invention is shown in longitudinal section. The axial piston machine has an annular cylinder 2, on which a plurality of cylinders 4 are formed, and pistons 6 are arranged in each of these cylinders. The piston bottom 8 of the piston 6 is hingedly coupled to the flange 10 of the drive shaft 12. According to the structural principle of the skew-shaft machine, the central axis of the cylinder 2 is obliquely positioned relative to the central axis of the drive shaft 12.

[0035] In order to change the relative tilt position of the two central axes and thus change the pivot angle of cylinder 2, the cylinder has a recessed abutment surface that is tensioned against a corresponding convex abutment surface of the control lentil body 14. A transverse journal 16 is centrally embedded in the control lentil body 14 and is radially inserted into an adjusting piston 18. The adjusting piston 18 is guided along the direction of motion 24 in the adjusting cylinder 20 of the adjusting device. The adjusting cylinder 20 is made as a differential cylinder with a dual function. Correspondingly, the adjusting piston 18 consists of a piston section 21 and a piston rod 22, from which the transverse journal 16 extends radially toward the control lentil body 14.

[0036] The central axis 24 of the piston rod 22, and consequently the central axis of the adjusting cylinder 20, defines the direction of motion 24, wherein... Figure 1 The movement to the left corresponds to a decrease in the pivot angle and thus to a decrease in the displacement of the axial piston machine 1, while the movement to the right corresponds to an increase in the pivot angle and thus to an increase in the displacement of the axial piston machine 1.

[0037] A first embodiment of the pivot angle measuring device 100 according to the invention is arranged on the free end section 22a of the piston rod 22. It has a U-shaped support member 25 made of sheet metal, which extends parallel to the central axis 24 into the measuring housing 23. The support member 25 is fixed to the free end section 22a of the piston rod 22 by means of two pins and screws. It possesses two rod-shaped permanent magnets 26. More precisely, the two permanent magnets 26 are inserted or injected into a groove-shaped magnet housing 28, which is fixed to the central bottom side of the U-shaped support member 25. Two legs (in...) Figure 1 (From the center downwards) extending out from the permanent magnet 26 and its magnet housing 28, in the two legs due to Figure 1 The cross-section only shows one leg.

[0038] As already explained, the support member 25 extends into the stationary measuring housing 23, where a magnet housing 28 is fixed thereon and two permanent magnets 26 housed therein. For the axial piston machine 1... Figure 1 For the maximum pivot angle shown, only the first permanent magnet 26 and a portion of the second permanent magnet 26 are arranged in the measuring housing 23. For the minimum pivot angle, both permanent magnets 26 are fully arranged in the measuring housing 23.

[0039] A receiver 30, designed as a Hall sensor, is arranged in a through-hole in a stationary measuring housing 23. The receiver has a socket that can be accessed on the outer surface of the measuring housing 23.

[0040] Figures 2 to 4 The same cut-off portions of the measuring housing 23 are shown, which have three different embodiments of the pivot angle measuring device 100; 200; 300 according to the invention.

[0041] The electronic sensor component is housed in the receiver 30, which extends into the measuring housing 23 facing the permanent magnet 26. Figures 2 to 4 In the lower end section of the receiver 30, the sensor component is covered and therefore not visible. The axis of this sensor component, and consequently the main axis 30b of the end section of the receiver 30, is... Figures 2 to 4 In the embodiment shown, it is arranged perpendicular to the drawing plane and thus transverse to the direction of movement 24 of the adjusting piston 18.

[0042] In accordance with Figure 1 and 2 In one embodiment, the rod-shaped permanent magnets 26 are arranged such that the south pole S of the first permanent magnet 26, the north pole N of the first permanent magnet 26, the south pole S of the second permanent magnet 26, and finally the north pole N of the second permanent magnet 26 are arranged in a row along the direction of movement 24. Thus, a four-pole arrangement consisting of two permanent magnets 26 is formed.

[0043] In accordance with Figure 3 In this embodiment, the two rod-shaped permanent magnets 26 are arranged such that the north pole N of the first permanent magnet 26, the south pole S of the first permanent magnet 26, the south pole S of the second permanent magnet 26, and finally the north pole N of the second permanent magnet 26 are arranged in a row along the direction of movement 24. Thus, a tripolar arrangement consisting of the two permanent magnets 26 is formed.

[0044] In accordance with Figure 4 In this embodiment, the permanent magnet 126 is configured such that it has two poles, N and S, on its long sides facing each other. Here, the first permanent magnet 126 has its north pole N on the side facing the receiver 30, while its south pole S faces the support member 25. Conversely, the second permanent magnet 126 has its south pole S on the side facing the receiver 30, while its north pole N faces the support member 25.

[0045] Figures 5 to 7 Another embodiment of the pivot angle measuring device 200; 300; 400 according to the present invention is shown respectively.

[0046] If you have already referred Figures 1 to 4 As explained, in the receiver 30 facing the permanent magnet 26 (in Figures 5 to 7 The lower end section houses an electronic sensor component. The axis of this sensor component, and consequently the main axis 30b of the end section of the receiver 30, is... Figures 5 to 7In the embodiment shown, it is arranged parallel to the drawing plane and thus parallel to the direction of motion 24.

[0047] In accordance with Figure 5 In one embodiment, the rod-shaped permanent magnets 26 are arranged such that the south pole S of the first permanent magnet 26, the north pole N of the first permanent magnet 26, the south pole S of the second permanent magnet 26, and finally the north pole N of the second permanent magnet 26 are arranged in a row along the direction of movement 24. Thus, a four-pole arrangement consisting of two permanent magnets 26 is formed.

[0048] In accordance with Figure 6 In one embodiment, the rod-shaped permanent magnets 26 are arranged such that the north pole N of the first permanent magnet 26, the south pole S of the first permanent magnet 26, the south pole S of the second permanent magnet 26, and finally the north pole N of the second permanent magnet 26 are arranged in a row along the direction of movement 24. Thus, a tripolar arrangement consisting of two permanent magnets 26 is formed.

[0049] In accordance with Figure 7 In this embodiment, the permanent magnet 126 is configured such that it has two poles, N and S, on its long sides facing each other. The first permanent magnet 126 has its south pole S on the side facing the receiver 30, while its north pole N faces the support member 25. Conversely, the second permanent magnet 126 has its north pole N on the side facing the receiver 30, while its south pole N faces the support member 25.

[0050] The distance MLS between the two permanent magnets 26 relative to each other can be 10.2 mm. The air gap LS between the end section of the receiver 30, which is configured as a Hall sensor, and the permanent magnets 26 can be 4.35 mm + / - 1.34 mm.

[0051] The two permanent magnets 26 and 126 can be arranged so that they are spaced apart from each other and the receiver 30 can be arranged so that the detectable range of movement of the adjusting piston 18 is 60 mm.

[0052] exist Figure 1 and Figures 2 to 4 In the attached figures, relative to Figures 5 to 7 The diagram, rotated 90°, shows the arrangement of sensor 30 relative to the two magnets 26. The spatial mounting position between sensor 30 and magnets 26 can be arbitrary, as long as magnets 26 can perform a defined reciprocating motion along the main axis. In other words, the spatial mounting position between sensor 30 and magnets 26 can be arbitrary, as long as magnets 26 can perform a defined reciprocating motion relative to the main axis 30b of sensor 30 along their direction of motion 24 (central axis 24).

[0053] List of reference numerals in the attached diagram:

[0054] 1. Axial piston machine

[0055] 2 cylinders

[0056] 4 cylinders

[0057] 6 Pistons

[0058] 8 Piston bottom

[0059] 10 Flange

[0060] 12 drive shafts

[0061] 14. Controlling lentil body

[0062] 16 transverse journals

[0063] 18 Adjusting the piston

[0064] 20 Adjusting cylinder

[0065] 21 Piston Section

[0066] 22 Piston rod

[0067] 22a Free end section

[0068] 23 Measuring housing

[0069] 24. Central axis / direction of movement

[0070] 25 Support components

[0071] 26 permanent magnet

[0072] 28. Magnet casing

[0073] 30 receivers

[0074] 30b main axis

[0075] 100° Pivot Angle Measuring Device

[0076] 126 permanent magnet

[0077] 200° Pivot Angle Measuring Device

[0078] 300° Pivot Angle Measuring Device

[0079] 400° Pivot Angle Measuring Device

[0080] 500° Pivot Angle Measuring Device

[0081] 600° Pivot Angle Measuring Device

[0082] LS air gap

[0083] MLS Spacing

Claims

1. A pivot angle measuring device (100; 200; 300; 400; 500; 600), said pivot angle measuring device being designed and configured for indirectly detecting the pivot angle of the swashplate or cylinder (2) of a hydrostatic axial piston machine (1), wherein, The pivot angle can be adjusted by means of an adjusting piston (18) guided in an adjusting cylinder (20), wherein the pivot angle measuring device (100; 200; 300; 400; 500; 600) has a movable transmitter and a receiver (30) fixed on the housing, characterized in that the pivot angle measuring device (100; 200; 300; 400; 500; 600) is translational, and the transmitter is formed by two permanent magnets (26; 126) which can be linearly and translationally driven by the adjusting piston (18) along the direction of movement (24) of the adjusting piston, and the two permanent magnets have a distance (MLS) relative to each other.

2. The pivot angle measuring device (100; 400) according to claim 1, wherein the two north poles (N) and two south poles (S) of the two permanent magnets (26) are arranged in an alternating sequence along the direction of movement (24) of the adjusting piston (18).

3. The pivot angle measuring device (200; 500) according to claim 1, wherein either the north pole (N) or the south pole (S) of the two permanent magnets (26) point to each other along the direction of movement (24) of the adjusting piston (18).

4. The pivot angle measuring device (300; 600) according to claim 1, wherein each permanent magnet (126) has a main axis extending through the South Pole (S) and the North Pole (N), characterized in that, The two permanent magnets (126) are arranged with their two main axes perpendicular to the direction of movement (24) of the adjusting piston (18). The north pole (N) of the first permanent magnet (126) and the south pole (S) of the second permanent magnet (126) face the receiver (30), while the south pole (S) of the first permanent magnet (126) and the north pole (N) of the second permanent magnet (126) face away from the receiver (30). Alternatively, the south pole (S) of the first permanent magnet (126) and the north pole (N) of the second permanent magnet (126) face the receiver (30), while the north pole (N) of the first permanent magnet (126) and the south pole (S) of the second permanent magnet (126) face away from the receiver (30).

5. The pivot angle measuring device (100; 200; 300; 400; 500; 600) according to any one of the preceding claims, wherein the receiver (30) is capable of detecting all possible directions of motion of the permanent magnet (26; 126) in the plane of motion.

6. The pivot angle measuring device (100; 200; 300; 400; 500; 600) according to claim 5, wherein the receiver (30) has an electronic sensor component having a longitudinal axis that defines the main axis (30b) of the receiver (30), characterized in that, The main axis (30b) of the receiver (30) is arranged transversely or longitudinally to the direction of movement (24) of the adjusting piston (18).

7. The pivot angle measuring device (100; 200; 300; 400; 500; 600) according to any one of the preceding claims, wherein an air gap (LS) is provided between the permanent magnet (26; 126) and the connector (30), characterized in that, The ratio of the air gap (LS) to the distance (MLS) between the two permanent magnets (26; 126) is between 0.295 and 0.558, preferably 0.

426.

8. A hydrostatic axial piston machine (1) with a swashplate structure or a swashplate shaft structure, wherein, The pivot angle of the swashplate or cylinder (2) can be adjusted by means of an adjusting piston (18) guided in the adjusting cylinder (20), wherein a pivot angle measuring device (100; 200; 300; 400; 500; 600) according to any of the preceding claims is provided.

9. The hydrostatic axial piston machine (1) according to claim 8, wherein the adjusting cylinder (20) is a differential cylinder, and wherein the adjusting piston (18) has a piston rod (22) to which a transverse journal (16) is fixed, characterized in that, The two permanent magnets (26; 126) are indirectly or directly fixed to the end section (22a) of the piston rod (22).

10. The hydrostatic axial piston machine (1) according to claim 9, characterized in that, The two permanent magnets (26; 126) are indirectly fixed to the end section (22a) of the piston rod (22) by a support member (25) extending along the direction of motion (24).

11. The hydrostatic axial piston machine (1) according to claim 10, characterized in that, The support member (25) is U-shaped when viewed in a cross-section arranged transversely to the direction of movement (24) of the adjusting piston (18).

12. The hydrostatic axial piston machine (1) according to claim 10 or 11, characterized in that, The two permanent magnets (26; 126) are housed in a magnet housing (28), which is fixed to a support member (25).

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