Rotation angle measuring device on hydrostatic axial piston machine with variable piston displacement

Abstract

A translational rotation angle measuring device (100; 200); 300); 400, 400; 500); 600), 700) and a method for measuring the angle of revolution (100; 200); 300); 400, 400; 500); 600), 700) for a hydrostatic axial piston machine (1), which is designed and designed to indirectly detect the angle of revolution of a swash plate or cylinder (2) of the axial piston machine (1). The rotation angle can be adjusted by means of an adjusting piston (18) guided in an adjusting cylinder (20), wherein the rotation angle measuring device (100; 200); 300); 400, 400; 500); 600), 700) has a movable transmitter and a receiver (30) fastened to the housing. The transmitter is formed by, for example, two permanent magnets (26; 126), which can be driven linearly and translatably by the adjusting piston (18) in the direction of movement (24) thereof.

Description

TECHNICAL FIELD

[0001] The present application relates to the detection of the swivel angle of a fluidstatic axial piston machine of swash plate design or swash shaft design, which is adjustable in terms of its piston displacement. BACKGROUND

[0002] From the prior art, fluidstatic axial piston machines of swash plate design are known, whose working pistons are coupled to a swash plate constructed on a rocker. In order to be able to adjust the piston displacement of the axial piston machine, the rocker is swivelably supported in the housing of the axial piston machine.

[0003] DE 102017213457 A1 describes an axial piston machine whose rocker is coupled to the adjustment piston of a fluidstatic adjustment device via a journal formed integrally with the rocker and via a slide rotatably supported on the journal. The adjustment device has an adjustment cylinder constructed as a screwable plug-in sleeve, in which the adjustment piston is partially received. The adjustment piston serves a dual purpose. The adjustment pressure medium is provided here by an external adjustment pressure medium source.

[0004] In such axial piston machines, it is important for the control and adjustment tasks that the swivel angle of the rocker or cylinder barrel is detected.

[0005] From the prior art, rotary swivel angle measuring devices are known.

[0006] DE 102014200566 A1 discloses a rotary swivel angle measuring device, which is positioned on the (non-physical) swivel axis of the rocker. The swivel angle is thus detected directly and without conversion (without an increase or decrease in scaling). The swivel angle measuring device has a shaft, which is coupled to the rocker via a rotary coupling and the rocker journal. The coupling is a leaf spring made of spring steel. A disadvantage of such a swivel angle measuring device is the structural space requirement.

[0007] DE 102010045540 A1 discloses an axial piston machine whose adjustment device has an adjustment piston, to which a rotary swivel angle measuring device is coupled. The swivel angle measuring device has a permanent magnet, which moves on a circular track next to a swivel angle receiver with a Hall sensor using a return lever. The return lever is inserted with its (free) end section into a receiving portion of the adjustment piston.

[0008] Furthermore, it is known from the prior art that, for the aforementioned axial piston machines with a control piston and with a rotary swivel angle measuring device, the (free) end section of the return lever is inserted into the surrounding groove of the control piston, into which the lever of the yoke is also inserted. The swivel angle measuring device is accommodated in a through-clearance of the housing and thereby seals off the interior space of the axial piston machine, in which the tank pressure prevails.

[0009] The disadvantage of the two last-mentioned rotary swivel angle measuring devices and their linear or translatory control piston movement into a rotary transmitter movement is that the insertion and removal of the (free) end section of the return lever must also always be carried out radially with respect to the clearance of the control piston. In addition, only a transmission of the large-amplitude movement of the control piston into a small rotary movement of the transmitter can be carried out at the end region of the control piston stroke with increasing tendency, in which there is always an increased risk of jamming. Furthermore, it is disadvantageous that an increased structural space requirement is required for the bearing of the return lever and for the clamping of the transmitter magnet along the axial direction of the bearing structure.

[0010] It is also known from the prior art that axial piston machines of the inclined shaft design have a control cylinder which is configured as a differential cylinder, on the piston rod of which a journal is fixed which extends transversely to the movement direction of the control piston and which carries a control lens. The end section of the piston rod extends into the interior of the measuring chamber and has a slanted groove through which a rotary swivel angle detection is carried out.

[0011] Furthermore, it is known from the prior art that an additional disclosure has a translatory swivel angle measuring device with a rod-shaped magnet which is carried by the control piston of an axial piston machine of the swash plate design. SUMMARY

[0012] The task of the present invention is to avoid the disadvantages of the rotary swivel angle detection and to update the last-mentioned additional disclosure of the prior art with a translatory swivel angle measuring device, in that the measurement range of the swivel angle measuring device should be enlarged. Here, the structural length of the swivel angle measuring device along the movement direction of the control piston should be reduced to a minimum.

[0013] The task is solved by a swivel angle measuring device with the features of claim 1 and by an axial piston machine with the features of claim 8.

[0014] The claimed swivel angle measuring device is designed and set up for indirect detection of the swivel angle of a swash plate or cylinder of a hydrostatic axial piston machine. The swivel angle can be adjusted by means of an adjusting piston which is guided in an adjusting cylinder, at which the swivel angle is indirectly detected. To this end, the claimed swivel angle measuring device has a transmitter which can move together with the adjusting piston and a receiver, in particular a Hall sensor, which is fixed on a housing. According to the invention, the swivel angle measuring device is translatory. To this end, the transmitter is directly or indirectly coupled to the adjusting piston and can be moved translatory along its movement direction. The transmitter is formed by two or more preferably rod-shaped permanent magnets.

[0015] Thereby, the displacement of the (free) end section of the return lever into and out of the gap / slot of the adjusting piston, which is necessary for the prior art rotary swivel angle measuring devices, is avoided. In particular, the transmission of the large amplitude movement of the adjusting piston can be converted into a less reduced large amplitude translatory or linear movement of the transmitter at the end region of the adjusting piston stroke, wherein the risk of jamming remains small. By means of the two or more permanent magnets, an overall optimum of high measuring accuracy and long adjusting piston stroke can be achieved.

[0016] In the end position of the adjusting piston, in which the return spring of the adjusting piston is most relaxed and thereby has its greatest length, at least one of the permanent magnets according to the invention is arranged at least partially inside the return spring. Thereby, at least two permanent magnets and the return spring overlap in the end position of the adjusting piston. Thereby, the construction length or construction space of the swivel angle measuring device according to the invention in the movement direction is reduced to a minimum.

[0017] In a specific design concept which saves position space, nevertheless with high measuring accuracy in a measuring range of for example 60 mm in the movement direction, two permanent magnets are provided. Particularly position space-saving is that one of the two permanent magnets is arranged completely inside the return spring of the adjusting piston in the end position of the adjusting piston. Further position space-saving is that the other one of the two permanent magnets is additionally arranged partially inside the return spring of the adjusting piston.

[0018] In a first principle of the rotary angle measuring device according to the application, the north poles and the south poles of the permanent magnets are arranged in an alternating sequence along the movement direction of the adjustment piston. In the case of two permanent magnets, the transmitter is thus four-pole. To this end, the two north poles and the two south poles of the two permanent magnets are arranged in an alternating sequence along the movement direction of the adjustment piston. More precisely, either the north pole of the first permanent magnet and then the south pole of the first permanent magnet and then, respectively, the north pole of the second permanent magnet and then the south pole of the second permanent magnet are arranged one after the other, or the south pole of the first permanent magnet and then the north pole of the first permanent magnet and then, respectively, the south pole of the second permanent magnet and then the north pole of the second permanent magnet are arranged one after the other.

[0019] In a second principle of the rotary angle measuring device according to the application, either the respective north poles of the permanent magnets or the respective south poles of the permanent magnets are directed at one another along the movement direction of the adjustment piston. In the case of two permanent magnets, the transmitter is thus three-pole. To this end, either the two north poles of the two permanent magnets or the two south poles of the two permanent magnets are directed at one another along the movement direction of the adjustment piston. More precisely, along the movement direction of the adjustment piston either the north pole of the first permanent magnet is arranged first and then the south pole of the first permanent magnet and then, respectively, the south pole of the second permanent magnet is arranged first and then the north pole of the second permanent magnet is arranged, or the south pole of the first permanent magnet is arranged first and then the north pole of the first permanent magnet is arranged and then, respectively, the north pole of the second permanent magnet is arranged first and then the south pole of the second permanent magnet is arranged.

[0020] Each permanent magnet has a main axis which extends through the south pole and the north pole. In a third principle of the rotary angle measuring device according to the application, the main axes of the permanent magnets are arranged perpendicular to the movement direction of the adjustment piston. In the case of two permanent magnets, it is shown that either 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, or that either 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.

[0021] In a particularly structurally flexible refinement of the rotary angle measuring device according to the application, the receiver is able to detect all possible movement directions of the permanent magnets in adjacent movement planes. This receiver is also referred to as a 3D sensor.

[0022] The receiver has here an electronic sensor member which is stationary in a housing-secured manner adjacent to the translationally moving permanent magnet. The sensor member has a longitudinal axis which defines a main axis of the receiver. This main axis can thus be arranged, in particular, transversely or longitudinally to the movement direction of the adjusting piston when using the 3D sensor mentioned above. However, this main axis of the receiver can also assume all angles deviating from the movement direction of the adjusting piston when using the 3D sensor mentioned above.

[0023] A gap is provided between the permanent magnet and the receiver. A spacing is preferably also provided between the permanent magnets. In the case of two permanent magnets, the ratio of the gap to the spacing of the two permanent magnets is preferably between 0.295 and 0.558, in particular 0.426. Thus, for example, in a specific application case, the gap can be 4.35 mm, while the spacing of the two permanent magnets relative to one another is 10.2 mm.

[0024] The fluid-static axial piston machine disclosed is made in a swash plate design or in a swash axle design and thus has a swash plate or a cylinder barrel whose swivel angle can be adjusted by means of an adjusting piston which is guided in an adjusting cylinder. The swivel angle measuring device described above according to the disclosure document is in operative connection with the adjusting piston.

[0025] In a particularly preferred refinement, the adjusting cylinder is a differential cylinder, wherein the adjusting piston has a piston rod, a lateral journal being secured to the piston rod. The permanent magnet is then secured indirectly or directly on an end section of the piston rod which is opposite the piston. This end section can be moved in a measuring housing in which the receiver is accommodated, for example in a through gap.

[0026] If the housing-secured spring abutment of the return spring, viewed in the movement direction of the adjusting piston, is arranged directly adjacent to the receiver and / or to the through gap of the measuring housing, a particularly large structural length of the adjusting piston in the movement direction is saved.

[0027] According to a first securing scheme, the permanent magnet is secured indirectly on the end section of the piston rod extending in the movement direction by means of a carrier member.

[0028] The carrier member can be u-shaped in a cross section arranged transversely to the movement direction of the adjusting piston. The carrier member can be a bent plate part.

[0029] The carrier member can be secured at the end section or the slot-shaped gap of the end section by means of one screw and two centering journals or centering bushings.

[0030] The permanent magnet is preferably received in a magnet housing. The magnet housing can be fixed on the support member by means of a screw journal which is preferably cast into the magnet housing and two centering journals which are cast integrally on the magnet housing, for example.

[0031] According to a second fixing variant, a flattened portion is formed on the end section of the piston rod, which flattened portion extends parallel to the movement direction and which flattened portion is formed by milling or milling away. The permanent magnet is then fixed on the flattened portion of the piston rod.

[0032] In the second fixing variant, it is also preferred that the permanent magnet is received in a magnet housing, which magnet housing is fixed on the flattened portion and thus on the end section of the piston rod by means of a screw connection and two centering journals, for example. BRIEF DESCRIPTION OF DRAWINGS

[0033] The principles and embodiments of the present disclosure are described below on the basis of the drawings.

[0034] Figure 1 An embodiment of an axial piston machine according to the application is shown, which has an angle of rotation measuring device according to the application;

[0035] Figure 2 An embodiment of an axial piston machine according to the application is shown, which has an angle of rotation measuring device according to the application; Figure 1 An axial piston machine according to the application is shown, which has a second embodiment of an angle of rotation measuring device according to the application; Figure 1 An axial piston machine according to the application is shown, which has a third embodiment of an angle of rotation measuring device according to the application;

[0036] Figure 3 An axial piston machine according to the application is shown, which has a third embodiment of an angle of rotation measuring device according to the application; Figure 1 An axial piston machine according to the application is shown, which has a second embodiment of an angle of rotation measuring device according to the application;

[0037] Figure 4 An axial piston machine according to the application is shown, which has a third embodiment of an angle of rotation measuring device according to the application; Figure 1 An axial piston machine according to the application is shown, which has a third embodiment of an angle of rotation measuring device according to the application;

[0038] Figure 5 A fourth embodiment of an angle of rotation measuring device according to the application is shown;

[0039] Figure 6 A fifth embodiment of an angle of rotation measuring device according to the application is shown;

[0040] Figure 7 A sixth embodiment of an angle of rotation measuring device according to the application is shown;

[0041] Figure 8 An axial piston machine according to the application is shown, which has a third embodiment of an angle of rotation measuring device according to the application; Figures 1 to 7 An axial piston machine according to the application is shown, which has a third embodiment of an angle of rotation measuring device according to the application;

[0042] Figure 9 a cross section of an axial piston machine in Figure 1 with a seventh embodiment of an angle of rotation measuring device according to the application is shown; and

[0043] Figure 10 a cross section of an angle of rotation measuring device in Figure 9 is shown. DETAILED DESCRIPTION

[0044] Figure 1 An embodiment of an axial piston machine 1 according to the application is shown in longitudinal section. It has a rotating cylinder barrel 2, on the circumference of which a plurality of cylinders 4 are formed, in which respectively a piston 6 is arranged. The piston base 8 of the piston 6 is coupled in articulated fashion to a flange 10 of a drive shaft 12. According to the construction principle of a slanting shaft machine, the centre axis of the cylinder barrel 2 is arranged obliquely relative to the centre axis of the drive shaft 12.

[0045] In order to be able to change the oblique position of the two centre axes relative to one another and thereby the angle of rotation of the cylinder barrel 2, this cylinder barrel has a concave abutment face, which is clamped against a corresponding convex abutment face of a control lens 14. A lateral journal 16 is embedded in the control lens 14, which is radially built into an adjusting piston 18. The adjusting piston 18 is guided in the adjusting cylinder 20 of the adjusting device along a movement direction 24. The adjusting cylinder 20 is produced as a double-acting differential cylinder. In correspondence therewith, the adjusting piston 18 is composed of a piston section 21 and a piston rod 22, from which the lateral journal 16 radially projects in the direction of the control lens 14.

[0046] The centre axis 24 of the piston rod 22 and thereby of the adjusting cylinder 20 defines the movement direction 24, in which a movement to the left in Figure 1 corresponds to a reduction of the angle of rotation and thereby to a reduction of the piston displacement of the axial piston machine 1, while a movement to the right corresponds to an expansion of the angle of rotation and thereby to an expansion of the piston displacement of the axial piston machine 1.

[0047] In Figure 1 is shown the case in which the adjusting piston 18 is in an end position, in which it is clamped by a return spring 17, which is shown more clearly in Figure 1 to the right. Figures 2 to 4

[0048] ​On the free end section 22a of the piston rod 22 is arranged a first embodiment of the rotational angle measuring device 100 according to the invention. It has a U-shaped support member 25 made of sheet metal, which extends parallel to the central axis 24 into the interior of 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 a screw. It has two rod-shaped permanent magnets 26. More precisely, the two permanent magnets 26 are inserted or sprayed into a slot-shaped magnet housing 28, which is fixed on the bottom surface in the middle of the U-shaped support member 25. Two legs (downwards in Figure 1 ) extend from the permanent magnets 26 and their magnet housings 28, in which legs only one leg is shown due to the sectional plane in Figure 1 .

[0049] As already explained, the support member 25 extends with the magnet housings 28 fixed thereon and the two permanent magnets 26 received therein into the interior of the stationary measuring housing 23. For the maximum rotational angle of the axial piston machine 1 shown in Figure 1 , only the first permanent magnet 26 and a part of the second permanent magnet 26 are arranged in this measuring housing 23. For the minimum rotational angle, both permanent magnets 26 are completely arranged in this measuring housing 23.

[0050] In the through-going gap of the stationary measuring housing 23 is arranged a receiver 30 configured as a Hall sensor, which has a socket accessible on the outside of the measuring housing 23.

[0051] Figures 2 to 4 Identical cutouts of the measuring housing 23 are shown, which have three different embodiments of the rotational angle measuring device 100, 200, 300 according to the invention.

[0052] An electronic sensor member is received in the end section of the receiver 30 facing the permanent magnets 26, which projects into the measuring housing 23 (below in Figures 2 to 4 ), which sensor member is covered in this end section of the receiver 30 and thus not visible. The axis of this sensor member and thus the main axis 30b of the end section of the receiver 30 is arranged perpendicular to the drawing plane and thus transversely to the direction of movement 24 of the adjusting piston 18 in the embodiment shown in Figures 2 to 4 .

[0053] In accordance with Figure 1 and 2In an embodiment according to Fig. 1 1, the rod-shaped permanent magnets 26 are arranged such that first a south pole S of the first permanent magnet 26, then a north pole N of the first permanent magnet, then a south pole S of the second permanent magnet 26 and finally a north pole N of the second permanent magnet are lined up along the movement direction 24. Thereby, a quadrupole arrangement consisting of two permanent magnets 26 is formed.

[0054] In an embodiment according to Fig. 1 1, the rod-shaped permanent magnets 26 are arranged such that first a south pole S of the first permanent magnet 26, then a north pole N of the first permanent magnet, then a south pole S of the second permanent magnet 26 and finally a north pole N of the second permanent magnet are lined up along the movement direction 24. Thereby, a quadrupole arrangement consisting of two permanent magnets 26 is formed. Figure 3

[0055] In an embodiment according to Fig. 1 1, the rod-shaped permanent magnets 26 are arranged such that first a south pole S of the first permanent magnet 26, then a north pole N of the first permanent magnet, then a south pole S of the second permanent magnet 26 and finally a north pole N of the second permanent magnet are lined up along the movement direction 24. Thereby, a quadrupole arrangement consisting of two permanent magnets 26 is formed. Figure 4

[0056] In Figures 2 to 4 the end position (maximally to the right), the piston rod 22 of the adjustment piston 18 is clamped into said end position by means of the return spring 17. In this end position, the free end section 22a of the piston rod 22 and a large part of the bearing member 25 are arranged inside the return spring 17. Furthermore, in the end position, the permanent magnet 26 (to the right in Figures 2 to 4 Fig. 1 1 ) near the end section 22a is arranged completely inside the return spring 17 and away from the permanent magnet 26 (to the left in Figures 2 to 4 Fig. 1 1 ) near the end section 22a is arranged partially inside the return spring 17.

[0057] Figures 5 to 7 Another embodiment of a rotary angle measuring device 200, 300, 400 according to the application is shown respectively.

[0058] As already explained with reference to Figures 1 to 4 Fig. 1 1, an electronic sensor member is received in the end section of the receiver 30 facing the permanent magnet 26 (below in Figures 5 to 7 Fig. 1 1 ). The axis of this sensor member and thereby the main axis 30b of the end section of the receiver 30 is arranged parallel to the drawing plane and thereby parallel to the movement direction 24 in the embodiment shown in Figures 5 to 7 Fig. 1 1.

[0059] In an embodiment according to Fig. 1 1, the rod-shaped permanent magnets 26 are arranged such that first a south pole S of the first permanent magnet 26, then a north pole N of the first permanent magnet, then a south pole S of the second permanent magnet 26 and finally a north pole N of the second permanent magnet are lined up along the movement direction 24. Thereby, a quadrupole arrangement consisting of two permanent magnets 26 is formed. Figure 5 ​​In an embodiment according to Fig. 1 1, the rod-shaped permanent magnets 26 are arranged such that first the south pole S of the first permanent magnet 26, then the north pole N of the first permanent magnet, then the south pole S of the second permanent magnet 26 and finally the north pole N of the second permanent magnet are lined up along the movement direction 24. Thereby, a quadrupole arrangement consisting of two permanent magnets 26 is formed.

[0060] In an embodiment according to Fig. 1 1, the rod-shaped permanent magnets 26 are arranged such that first the south pole S of the first permanent magnet 26, then the north pole N of the first permanent magnet, then the south pole S of the second permanent magnet 26 and finally the north pole N of the second permanent magnet are lined up along the movement direction 24. Thereby, a quadrupole arrangement consisting of two permanent magnets 26 is formed. Figure 6

[0061] In an embodiment according to Fig. 1 1, the rod-shaped permanent magnets 26 are arranged such that first the south pole S of the first permanent magnet 26, then the north pole N of the first permanent magnet, then the south pole S of the second permanent magnet 26 and finally the north pole N of the second permanent magnet are lined up along the movement direction 24. Thereby, a quadrupole arrangement consisting of two permanent magnets 26 is formed. Figure 7

[0062] The distance MLS of 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 configured as a Hall sensor and the permanent magnets 26 can be 4.35 mm + / - 1.34 mm.

[0063] The two permanent magnets 26, 126 can be arranged spaced apart relative to each other and the receiver 30 can be arranged such that the detectable movement range of the adjusting piston 18 is 60 mm.

[0064] Figure 8 Fig. 1 1 shows a cutout of a rotary angle measuring device according to different embodiments. The illustration includes all different design variants and orientations of the permanent magnets 26, 126 according to Figures 1 to 7 Figures 1 to 7

[0065] In Figure 8 it is indicated that the support member 25 has a bottom surface and two legs therein, wherein in Figure 8 only half of the bottom surface and one of the two legs can be seen. The support member 25 is fixed on the end section 22a of the piston rod 22 on one side by means of a screw 32. The screw 32 is inserted through a through-clearance of the bottom surface of the support member 25 and is screwed into a threaded hole of the end section 22a.

[0066] The orientation of the support member 25 along the movement direction 24 (see Figures 1 to 7 ​​​​) by two centring bushes 34, which are inserted into through recesses in the bottom face of the bearing member 25 before and after the screw 32 in the direction of movement 24 and into blind hole drillings in the end section 22a of the piston rod 22, respectively.

[0067] The magnet housing 28 has two slot-like recesses for the two permanent magnets 26, 126, between which a web is arranged, into which a screw journal 36 is cast. This screw journal 36 is inserted through a through recess in the bottom face of the bearing member 25 and screwed with a nut.

[0068] The nut of the screw journal 36 and the screw head of the screw 32 are received in the interior of the u-shaped in cross section bearing member 25 so as not to hook together with the return spring 17 (see Figures 2 to 4 ).

[0069] Figure 9 A cross section of the axial piston machine 1 in Figure 1 is shown, which has a seventh embodiment of the rotational angle measuring device 700 according to the application. The rotational angle measuring device 700 has a flattened portion 725 at the end section 722a of the piston rod 722, which extends parallel to the direction of movement 24 (see Figure 1 ) and which is produced by milling off approximately half of the cross section of the end section 722a of the piston rod 722.

[0070] In Figure 9 is shown the case that the piston rod 722 of the adjusting piston 18 is in an end position (maximally to the right), into which it is clamped by the maximally relaxed return spring 17. In this end position, the free end section 722a of the piston rod 722 and a large part of the flattened portion 725 are arranged inside the return spring 17. Furthermore, in the end position, the permanent magnet 26, 126 (to the right in Figure 9 ) near the end section 722a is arranged completely inside the return spring 17 and the permanent magnet 26, 126 (to the left in Figure 9 ) remote from the end section 722a is arranged partially inside the return spring.

[0071] Figure 10 A cross section of the axial piston machine 1 in Figure 9cut-out of the rotary angle measuring device 700 in the middle. It can be seen that the magnet housing 28, which has the two permanent magnets 26, 126, is fixed on the flattened portion 725. For this purpose, the magnet housing 28 has two slot-like recesses for the permanent magnets 26, 126, between which a partition is arranged. Through the recess in the partition, a screw of a screw connection 736 is inserted, the nut of which is arranged on the outer circumference of the end section 722a of the piston rod 722. More precisely, the nut is received in a recess on the outer circumference of the end section 722a so as not to hook together with the return spring 17 (see Figure 9 ).

[0072] On both end sections of the magnet housing 28, which are spaced apart along the movement direction 24, a respective centring journal 738 is cast, which extends into the respective blind hole drilling of the flattened portion 725.

[0073] Figures 2 to 4 and Figure 9 It is shown that on the inner wall of the measuring housing 23, a spring abutment 19 for the return spring 17 is arranged, which is fixed on the housing by a radial shoulder. This spring abutment 19 is arranged in the immediate proximity of the recess of the receiver 30. Thereby, the constructional length of the rotary angle measuring device 100, 200, 300, 400, 500, 600, 700 in the movement direction 24 is reduced to a minimum.

[0074] In Figure 1 and in Figures 2 to 4 and in Figure 9 the arrangement of the receiver 30 relative to the two permanent magnets 26 is shown in an orientation rotated by 90° relative to Figures 5 to 7 The installation position in space between the receiver 30 and the permanent magnets 26 can be arbitrary, as long as the permanent magnets 26 perform a reciprocating defined movement along their movement direction 24 (central axis 24) relative to the main axis 30b of the receiver 30.

[0075] List of reference signs:

[0076] 1 axial piston machine

[0077] 2 cylinder barrel

[0078] 4 cylinder

[0079] 6 piston

[0080] 8 piston bottom

[0081] 10 flange

[0082] 12 drive shaft

[0083] 14 control lens

[0084] 16 transverse journal

[0085] 17 return spring

[0086] 18 adjustment piston

[0087] 19 spring abutment

[0088] 20 adjustment cylinder

[0089] 21 piston section

[0090] 22; 722 piston rod

[0091] 22a; 722a free end section

[0092] 23 measuring housing

[0093] 24 center axis / movement direction

[0094] 25 bearing member

[0095] 26 permanent magnet

[0096] 28; 728 magnet housing

[0097] 30 receiver

[0098] 30b main axis

[0099] 32 screw

[0100] 34 centering bushing

[0101] 36 screw journal

[0102] 100 rotary angle measuring device

[0103] 126 permanent magnet

[0104] 200 rotary angle measuring device

[0105] 300 rotary angle measuring device

[0106] 400 rotary angle measuring device

[0107] 500 rotary angle measuring device

[0108] 600 rotary angle measuring device

[0109] 700 rotary angle measuring device

[0110] 725 flattening

[0111] 736 screw connection

[0112] 738 centering journal

[0113] LS air gap

[0114] MLS pitch

Claims

1. A swivel angle measuring device (100; 200; 300; 400; 500; 600; 700) designed and set up for indirectly detecting the swivel angle of a swash plate or cylinder barrel (2) of a hydrostatic axial piston machine (1), wherein the swivel angle can be adjusted by means of an adjusting piston (18) guided in an adjusting cylinder (20), and wherein the swivel angle measuring device (100; 200; 300; 400; 500; 600; 700) has a movable transmitter and a receiver (30) fixed on a housing, characterized in that, The rotary angle measuring device (100; 200; 300; 400; 500; 600; 700) is translatory and the transmitter is formed by a plurality of permanent magnets (26; 126) which can be driven linearly and translatory by the adjusting piston (18) along its movement direction (24), wherein at least one of the permanent magnets (26; 126) is at least partially arranged inside a return spring (17) of the adjusting piston (18) in the end position of the adjusting piston (18).

2. Rotary angle measuring device (100; 200; 300; 400; 500; 600; 700) according to claim 1, having two permanent magnets (26; 126), wherein one of the two permanent magnets (26; 126) is completely arranged inside the return spring (17) in the end position of the adjusting piston (18).

3. Rotary angle measuring device (100; 200; 300; 400; 500; 600; 700) according to claim 1, having two permanent magnets (26; 126), wherein one of the two permanent magnets (26; 126) is completely arranged inside the return spring (17) in the end position of the adjusting piston (18), while the other one of the two permanent magnets (26; 126) is partially arranged inside the return spring (17).

4. Rotary angle measuring device (100; 200; 400; 600) according to any one of the preceding claims, wherein the north poles (N) and the south poles (S) of the permanent magnets (26) are arranged in an alternating order along the movement direction (24) of the adjusting piston (18), or wherein either the respective north poles (N) or the respective south poles (S) of the permanent magnets (26) are pointing towards each other along the movement direction (24) of the adjusting piston (18).

5. The turn angle measuring device (300; 600) according to any one of claims 1 to 3, wherein each permanent magnet (126) has a main axis extending through the south pole (S) and the north pole (N), characterized in that, The main axis of the permanent magnets (126) is arranged perpendicular to the movement direction (24) of the adjusting piston (18).

6. Rotary angle measuring device (100; 200; 300; 400; 500; 600; 700) according to any one of the preceding claims, wherein the receiver (30) is able to detect all possible movement directions of the permanent magnets (26; 126) in the movement plane.

7. The turning angle measuring device (100; 200; 300; 400; 500; 600; 700) according to claim 6, wherein the receiver (30) has an electronic sensor member, the sensor member having a longitudinal axis, the longitudinal axis defining a 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 movement direction (24) of the adjusting piston (18).

8. A fluid-static axial piston machine (1) of swash plate design or swash shaft design, wherein the swivel angle of the swash plate or the cylinder barrel (2) can be adjusted by means of an adjusting piston (18) which is guided in an adjusting cylinder (20), characterized in that Rotary angle measuring device (100; 200; 300; 400; 500; 600; 700) according to any one of the preceding claims.

9. The hydrostatic axial piston machine (1) of claim 8, wherein the adjusting cylinder (20) is a differential cylinder, and wherein the adjusting piston (18) has a piston rod (22), on which a lateral journal (16) is fixed, characterized in that The permanent magnets (26; 126) are indirectly fixed on the end section (22a) of the piston rod (22) by means of a bearing member (25), wherein the bearing member (25) extends along the movement direction (24).

10. The hydrostatic axial piston machine (1 ) according to claim 9, characterized in that The bearing member (25) is fixed on the end section (22a) by means of one screw (32) and two centering journals or centering bushes (34).

11. The hydrostatic axial piston machine (1) as claimed in claim 9 or 10, characterized in that The permanent magnet (26; 126) is received in a magnet housing (28) which is fixed on the carrier member (25) by means of a screw journal (36) and preferably two centering journals which are preferably cast into the magnet housing (28).

12. The hydrostatic axial piston machine (1) of claim 8, wherein the adjusting cylinder (20) is a differential cylinder and wherein the adjusting piston (18) has a piston rod (722), on which a lateral journal (16) is fixed, wherein on an end section (722a) of the piston rod (722) a flattening (725) is formed, which extends parallel to the direction of movement (24), characterized in that The permanent magnet (26; 126) is fixed on the flattened portion (725).

13. The hydrostatic axial piston machine (1) of claim 12, wherein the permanent magnet (26; 126) is received in a magnet housing (28) which is then fixed on the end section (722a) and / or on the flattened portion (725) by means of a screw connection (736) and two centering journals (738).

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