Inductive angle measuring mechanism

Abstract

To provide a comparatively accurately operating, compact, and inexpensively producible scanning element for an inductive angle measuring mechanism.SOLUTION: An inductive angle measuring mechanism includes a scale element rotatable relatively to a scanning element. In a first receiving track, the scanning element includes a first receiving conductive path and a second receiving conductive path, by which a first signal and a second signal can be generated. The first and second signals have a first phase offset relative to each other. The scanning element further includes fifth, sixth, seventh and eighth receiving conductive paths. The fifth and sixth receiving conductive paths are connected in series with each other, so that a first overall signal can be generated by the fifth and sixth receiving conductive paths. The seventh and eighth receiving conductive paths are connected in series with each other, so that a second overall signal can be generated by the seventh and eighth receiving conductive paths. The first overall signal and the second overall signal have a second phase offset relative to each other.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The invention relates to an inductive angle measuring arrangement according to claim 1. Inductive angle measuring mechanisms are used to determine the angular position of machine parts that can rotate relative to one another. In inductive position measuring mechanisms, an excitation track and a receiving track are often implemented, for example in the form of conductor tracks, on a common, usually multi-layer, printed circuit board, which is fixedly connected, for example, to a stator of the position measuring mechanism. Opposite this printed circuit board is a scale element, on which a graduation structure is implemented and which is fixedly connected to a movable part of the position measuring mechanism. When a time-alternating excitation current is applied to the excitation track, a position-dependent signal is generated in the receiving track during the relative movement of the scale element and the scanning element. This signal is then further processed in the evaluation electronics. [Background technology]

[0002] From EP 1 715 298 B1, an inductive angle measuring instrument is known which has an inner and an outer graduation track which have a different number of signal periods and which, in cooperation with an associated scanning element, allows the angular position to be determined in an absolute manner. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] EP1715298B1 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem on which the invention is based is to provide a scanning element for an inductive angle measuring mechanism which is relatively accurate, compact and inexpensive to manufacture. [Means for solving the problem]

[0005] This problem is solved according to the invention by the features of claim 1. The inductive angle measuring mechanism therefore comprises a scanning element and a scale element which is rotatable about an axis relative to the scanning element. The scale element has a first graduation track with first graduation structures which are arranged periodically around the axis along the circumferential direction and a second graduation track with second graduation structures which are also arranged periodically along the circumferential direction. The scanning element has an excitation track as well as a first receiving track and a second receiving track. The first receiving track comprises a first receiving conductor and a second receiving conductor. The first and second receiving conductors run periodically along a first circumferential line having a first radius, in particular with a constant first period length. The first and second receiving conductors are arranged circumferentially offset relative to each other, so that a first signal can be generated by the first receiving conductor and a second signal can be generated by the second receiving conductor. The first and second signals have a first phase offset relative to each other. The second receiving track includes a fifth receiving conductor, a sixth receiving conductor, a seventh receiving conductor and an eighth receiving conductor. The fifth, sixth, seventh and eighth receiving conductors each run periodically along a second circumferential line having a second radius, in particular with a constant second periodic length. The fifth, sixth, seventh and eighth receiving conductors run along the circumferential direction and are each arranged circumferentially offset with respect to one another. The fifth and sixth receiving conductors are connected to one another in series, so that a first overall signal can be generated by the fifth and sixth receiving conductors. The seventh and eighth receiving conductors are also connected to one another in series, so that a second overall signal can be generated by the seventh and eighth receiving conductors. The first overall signal and the second overall signal have a second phase offset with respect to one another.

[0006] The scanning element is used in an angle measurement mechanism to determine its angular position relative to a scale element, which is arranged rotatably about an axis relative to the scanning element, such that the measurement direction is circumferential to the axis.

[0007] It is advantageous for the second period length to be greater than the first period length. Thus, the second reception track provides angular position information at a relatively low resolution and is therefore often referred to as a coarse track. Correspondingly, the first reception track can also be referred to as a fine track since higher-resolution angular position information is generated thereby.

[0008] In a further form of the invention, the first phase shift PH1 is a quarter of the first constant period length λ1 (PH1 = 1 / 4·λ1). Similarly, the second phase shift PH2 can be a quarter of the second constant period length λ2 (PH2 = 1 / 4·λ2). The period lengths λ1, λ2 are presented here in degrees or radians and relate to the central angle around the axis A. Therefore, the first phase shift PH1 and the second phase shift PH2 are related to the respective period lengths λ1, λ2 and can thus be expressed as a part of the period lengths λ1, λ2.

[0009] In a further form of the invention, the first reception track has a first number n1 of reception conductor paths and the second reception track has a second number n2 of reception conductor paths. In this regard, the first number n1 is smaller than the second number n2 (n1 < n2).

[0010] The second number n2 is at least twice as large as the first number n1 (n2 > 2·n1), and in particular it is advantageous for the second number n2 to be exactly twice as large as the first number n1 (n2 = 2·n1). In particular, the first radius R1 of the first circumferential line and the second radius R2 of the second circumferential line are of different sizes. It is advantageous for the second radius R2 to be smaller than the first radius R1 (R2 < R1).

[0011] In a further form of the invention, the scanning element includes a first excitation track and a second excitation track. The first reception track is surrounded by the first excitation track on the radially outer side and by the second excitation track on the radially inner side. In contrast, the second reception track is surrounded by the second excitation track only on one side.

[0012] The scanning element is advantageously formed in such a way that the fifth and sixth receiving conductors run periodically with a constant second periodic length λ2 and are additionally arranged with an angular offset φ2 relative to one another along the circumferential direction, which angular offset φ2 is at most 1 / 16 of the second periodic length (φ2 < 1 / 16·λ2).

[0013] Advantageously, the seventh and eighth receiving conductors run periodically with a constant second periodic length λ2 and are arranged with an angular offset φ2 with respect to one another along the circumferential direction. The angular offset φ2 between the seventh and eighth receiving conductors is also advantageously at most 1 / 16 of the second periodic length λ2, so that φ2 < It is 1 / 16·λ2.

[0014] In a further embodiment of the invention, the scanning element is formed as a printed circuit board, and the excitation track, the first receiving track and the second receiving track run in less than four conductive layers, i.e. in less than four planes. The conductive layers are structured such that receiving conductor paths are formed therefrom. In addition, the excitation conductors of the excitation track are generated by structuring the conductive layers. The scanning element may in particular be formed as a printed circuit board, in which the excitation track, the first receiving track and the second receiving track run in exactly two conductive layers.

[0015] Advantageously, the scanning element is formed such that the first and / or second receiving track extends over the entire circumference around the axis, i.e. over 360° there is always at least one receiving conductor of the receiving track, so that every radial line emanating from a central point on the axis intersects at least one receiving conductor, so that the first and / or second receiving track do not have gaps over the entire circumference.

[0016] Advantageous configurations of the invention can be seen from the dependent claims. Further details and advantages of the scanning element according to the invention become apparent from the following description of exemplary embodiments based on the attached drawings. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a perspective view of an angle measurement mechanism including a scanning element and a scale element. [Diagram 2] FIG. 2 is a plan view of a scale element. [Diagram 3] FIG. 2 is a plan view of one side of the scanning element. [Figure 4] FIG. 2 is a plan view of a portion of a scanning element. [Diagram 5] FIG. 2 is a plan view of a portion of a scanning element, in particular with a number of receiving conductors removed; [Figure 6] 4 shows a schematic, unfolded representation of the receiving conductors of the first receiving track; FIG. [Figure 7] 4 shows a schematic, unfolded representation of the receiving conductors of the second receiving track; FIG. [Figure 8] 4 is a graph showing a signal on a reception conductor of a first reception track. [Figure 9] 4 is a graph showing a signal on a reception conductor of a second reception track. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The angle measurement mechanism of the presented exemplary embodiment, based on Fig. 1, comprises a scanning element 1 which is used to capture the angular position of a scale element 2. The scale element 2 is arranged rotatably relative to the scanning element 1 about an axis A. Such an angle measurement mechanism can be used, for example, in a drive mechanism, where the scale element 2 is non-rotatably coupled to, for example, a drive shaft of a motor.

[0019] In Fig. 2, the scale element 2 is shown in plan view. The scale element 2 has a ring-like or toric shape. In the illustrated exemplary embodiment, the scale element 2 consists of a base 2.3, which is made of epoxy resin, on which two graduation tracks 2.1, 2.2 are arranged. The graduation tracks 2.1, 2.2 are formed in the shape of a ring and are arranged on the base 2.3 concentrically and at different radii with respect to the axis A or to a scale center point M2 lying on the axis A, so that the first graduation track 2.1 runs along a first graduation circumference line and the second graduation track 2.2 runs along a second graduation circumference line. The graduation tracks 2.1, 2.2 each comprise a graduation structure consisting of a periodic sequence of conductive graduation areas 2.11, 2.21 and non-conductive graduation areas 2.12, 2.22 arranged alternately along the circumferential direction x, the conductive graduation areas 2.11, 2.21 each being formed from a layer of conductive material. In the example shown, the conductive graduation areas 2.11, 2.21 are made of copper, which is applied to the base 2.3. In contrast, the base 2.3 is not coated in the non-conductive graduation areas 2.12, 2.22. In contrast to Fig. 1, the conductive graduation areas 2.11, 2.21 are represented in Fig. 2 by being filled with black.

[0020] Due to the arrangement with two graduation tracks 2.1, 2.2 each, the angular position of the scale element 2 can be determined in an absolute manner. The outer first graduation track 2.1 of the scale element 2 has a greater number of respective graduation areas 2.11, 2.12 along the circumferential direction x, so that a higher resolution for measuring the angular position can be achieved by the graduation areas 2.11, 2.12. In the presented exemplary embodiment, the first (outer) graduation track 2.1 has 32 respective graduation areas 2.11, 2.12 along the circumferential direction x. The first graduation track 2.1 therefore has a first period length λ1 of 360° / 32=11.25°.

[0021] In contrast to this, the second (inner) graduation track 2.2 has only 15 respective graduation fields 2.21, 2.22 and therefore the second graduation track 2.2 has a second period length λ2 of 360° / 15=24°.

[0022] The period lengths λ1, λ2 are presented here in degrees and relate to the central angles about the axis A or scale centre point M2. The scanning element 1 is formed as a printed circuit board having several layers and electronic components 1.5 mounted on the scanning element 1.

[0023] As also shown in figure 3, the scanning element 1 has a circular ring shape. In the presented exemplary embodiment, the electronic components 1.5 are only attached to one side of the printed circuit board, in particular the side facing away from the scale element 2. However, alternatively or additionally, both sides of the printed circuit board could also be provided with the electronic components 1.5.

[0024] 3, the scanning element 1 has a first receiving track 1.1 and a second receiving track 1.2 for determining angular information. The receiving tracks 1.1, 1.2 each have a ring shape, in which it applies for both receiving tracks 1.1, 1.2 that their center point M1 lies on the axis A. The receiving tracks 1.1, 1.2 are therefore arranged approximately concentrically with respect to the center point M1.

[0025] The first receiving track 1.1 in the presented exemplary embodiment comprises a first receiving conductor 1.11, a second receiving conductor 1.12, a third receiving conductor 1.13 and a fourth receiving conductor 1.14. The first receiving track 1.1 therefore has a first number n1=4 receiving conductors 1.11, 1.12, 1.13, 1.14.

[0026] The receiving conductors 1.11, 1.12, 1.13, 1.14 of the first receiving track 1.1 are arranged offset relative to one another in the circumferential direction x, and these receiving conductors 1.11, 1.12, 1.13, 1.14 run along a first circumferential line K1 with a first radius R1 (FIG. 5). The receiving conductors 1.11, 1.12, 1.13, 1.14 of the first receiving track 1.1 have a spatially periodic path that is substantially sinusoidally or sinusoidally shaped. The receiving conductors 1.11, 1.12, 1.13, 1.14 of the first receiving track 1.1 additionally have a constant first period length λ1=11.25° over their path, which can also be found in the first graduation track 2.1 (FIG. 5). That is to say, the first period length λ1 extends over a central angle of 11.25° around the central point M1.

[0027] In Fig. 5, only the first receiving conductor 1.11 and the second receiving conductor 1.12 are shown for the first receiving track 1.1. The third receiving conductor 1.13 and the fourth receiving conductor 1.14 arranged between them are erased for clarity. The following discussion is based on this representation of the first receiving conductor 1.11 and the second receiving conductor 1.12, the situation also applies to the correspondingly phase-shifted third and fourth receiving conductors 1.13, 1.14 which are part of each other. In the presented exemplary embodiment, the first receiving conductor 1.11 and the second receiving conductor 1.12 are arranged relative to each other along the circumferential direction x with a first angular offset φ1, which here corresponds to ¼ of the complete first period length λ1. Within the first receiving track 1.1, directly adjacent receiving conductors 1.11, 1.12, 1.13, 1.14 are therefore arranged offset in the circumferential direction x by half the first angular offset φ1.

[0028] Since φ1=1 / 4·λ1, the first angular shift φ1 is 1 / 4·11.25°=2.81° in the presented exemplary embodiment. The second receiving track 1.2 in the presented exemplary embodiment includes, according to FIG. 4, the fifth receiving conductor 1.21, the sixth receiving conductor 1.22, the seventh receiving conductor 1.23, the eighth receiving conductor 1.24, the ninth receiving conductor 1.25, the tenth receiving conductor 1.26, the eleventh receiving conductor 1.27 and the twelfth receiving conductor 1.28. The second receiving track 1.2 thus has a second number n2=8 receiving conductors 1.21-1.28. The receiving conductors 1.21-1.28 of the second receiving track 1.2 are also arranged offset relative to one another in the circumferential direction x. These receiving conductors 1.21-1.28 run along a second circumferential line K2 (FIG. 5) with a second radius R2. The receiving conductors 1.21-1.28 of the second receiving track 1.2 have a constant second periodic length λ2 over their path, which here differs from an ideal sinusoidal shape. The receiving conductors 1.21-1.28 of the second receiving track 1.2 also have a periodic path. In the presented exemplary embodiment, the second periodic length λ2=360° / 15=24°.

[0029] Hence, here the second period length λ2 is greater than the first period length λ1. λ2>λ1 The receiving conductors 1.21-1.28 of the second receiving track 1.2 run along a second circumferential line K2 having a second radius R2, which is smaller than the first radius R1, and thus R2 <R1 It is.

[0030] Both circumferences K1, K2 have the same centre point M1. In addition to this, the first number n1=4 receiving conductors 1.11, 1.12, 1.13, 1.14 of the first receiving track 1.1 is less than the second number n2=8 receiving conductors 1.21-1.28 of the second receiving track 1.2.

[0031] n1 <n2 Therefore, in the presented exemplary embodiment, the second number n2 is also twice as large as the first number n1.

[0032] n2=2·n1 In FIG. 5, only the fifth and sixth receiving conductors 1.21 and 1.22 are shown for the second receiving track 1.2. The following discussion is based on this representation of the fifth and sixth receiving conductors 1.21 and 1.22, and the situation also applies to the correspondingly mutually phase-shifted receiving conductors 1.23, 1.24, 1.25, 1.26, 1.27, 1.28. In the presented exemplary embodiment, adjacent receiving conductors 1.21-1.28 in the second receiving track 1.2 are arranged in relation to one another along the circumferential direction x with a second angular offset φ2, which corresponds to 1 / 16 of the complete second periodic length λ2 (φ2=24° / 16=1.5°). In the second receiving track 1.2, two mutually adjacent receiving conductors 1.21-1.28 are connected to one another in series. In particular, the fifth and sixth receiving conductors 1.21, 1.22, the seventh and eighth receiving conductors 1.23, 1.24, the ninth and tenth receiving conductors 1.25, 1.26 and the eleventh and twelfth receiving conductors 1.27, 1.28 are connected to one another in series.

[0033] The scanning element 1 further comprises a first excitation track 1.3 and a second excitation track 1.4. In the presented exemplary embodiment, the excitation tracks 1.3, 1.4 comprise a plurality of excitation conductors, but may also each be formed as only one excitation conductor. The first receiving track 1.1 runs radially inside the first excitation track 1.3 and radially outside the second excitation track 1.4. The second excitation track 1.4 additionally runs radially outside the second receiving track 1.2. Both the excitation tracks 1.3, 1.4 and the receiving tracks 1.1, 1.2 run along the circumferential direction x.

[0034] Both the receiving conductors 1.11, 1.12, 1.13, 1.14 of the first receiving track 1.1 as well as the receiving conductors 1.21-1.28 of the second receiving track 1.2 run in different layers of the printed circuit board, joining them with vias V (figures 6 and 7), so that undesired short circuits are avoided at the intersections. Although strictly speaking each of the receiving conductors 1.11-1.14; 1.21-1.28 consists of a number of conductor pieces arranged side by side and respectively distributed over two planes or layers, such structures are referred to collectively here as one receiving conductor 1.11-1.14, 1.21-1.28.

[0035] In FIG. 6, the paths of the first and second receiving conductors 1.11, 1.12 are shown diagrammatically, and for the sake of clarity, the first and second receiving conductors 1.11, 1.12 are shown as straight lines, whereas in reality they are completely round. In addition, in FIG. 6, the first and second receiving conductors 1.11, 1.12, which are actually overlapping, are shown shortened and offset from one another in order to better show the respective paths of the receiving conductors 1.11, 1.12. Accordingly, the circumferential direction x, i.e. the measuring direction, is shown here as straight. As already mentioned above, the first and second receiving conductors 1.11, 1.12 each have a sinusoidal path. The ends shown in FIG. 6 are electrically connected to one another at point U.

[0036] In Fig. 7, the fifth and sixth receiving conductors 1.21, 1.22 and the seventh and eighth receiving conductors 1.23, 1.24 are shown separately and diagrammatically, in a straight line. The simplified representation in Fig. 7 is to be understood as the left and right ends of the receiving conductors 1.21, 1.22, 1.23, 1.24 coming together again, i.e. there are also closed conductors, and the fifth and sixth receiving conductors 1.21, 1.22 as well as the seventh and eighth receiving conductors 1.23, 1.24 are connected to each other in series. Accordingly, the ends U shown in Fig. 7 of the receiving conductors 1.21, 1.22, 1.23, 1.24, which together form a whole, are electrically connected to each other at point U. Between the points U in FIG. 7, the receiving conductors 1.21, 1.22, 1.23, 1.24 run overlapping in two planes, i.e. from the upper left to the lower right or from the upper right to the lower left. The receiving conductors 1.21, 1.22, 1.23, 1.24 have broadly straight paths in the representation of FIG. 7, so that they each enclose a diamond-shaped face. This geometry allows a relatively dense or narrow arrangement of the receiving conductors 1.21-1.28 on the substrate. If the receiving conductors 1.21-1.28 of the real arrangement are correspondingly curved, the receiving conductors 1.21-1.28 of the second receiving track 1.2 have curved paths with a relatively large radius between the cusps. For space reasons, the vias V are here shifted outwards, in which respect the vias V located radially inwards are each radially offset (see also FIGS. 3-5).

[0037] In the assembled state, the scanning element 1 and the scale element 2 face each other with an axial distance or gap between them, so that when the scale element 2 and the scanning element 1 rotate relative to each other, signals that depend on the respective angular position can be generated by inductive effects in the receiving conductors 1.11-1.14, 1.21-1.28. A prerequisite for the generation of corresponding signals is that the excitation tracks 1.3, 1.4 generate an electromagnetic excitation field that alternates over time in the region of the respective scanned graduation structure. In the illustrated exemplary embodiment, the excitation tracks 1.3, 1.4 are designed as a number of single conductors that are pierced by a current in parallel planes.

[0038] When the excitation tracks 1.3, 1.4 are energized, a tubular or cylindrically oriented electromagnetic field is generated around the excitation tracks 1.3, 1.4. The field lines of this resulting electromagnetic field run around the excitation tracks 1.3, 1.4, and their direction depends, as is known, on the current direction in the excitation tracks 1.3, 1.4. Eddy currents are induced in the region of the conductive graduation areas 2.11, 2.21, whereby a field modulation depending on the angular position is achieved. Correspondingly, the relative angular position can be measured by the receiving tracks 1.1, 1.2, respectively.

[0039] In particular, at the junction C (see for example FIG. 6), the first signal S1.11 generated or received by the first receiving conductor 1.11 and the second signal S1.12 generated or received by the second receiving conductor 1.12 can be taken off. In FIG. 8, the trajectories or envelopes of the first signal S1.11 and the second signal S1.12 are shown depending on the respective angular position between the scanning element 1 and the scale element 2. The first signal S1.11 and the second signal S1.12 have a first phase shift PH1 relative to each other, which is π / 2 in the presented exemplary embodiment, and the complete period of the first signal S1.11 and the second signal S1.12 is by definition 2π. That is to say, the first receiving conductor 1.11 and the second receiving conductor 1.12 provide signals at 0° and 90°.

[0040] The period of the first signal S1.11 and the second signal S1.12 results from the geometry of the first receiving conductor 1.11 and the second receiving conductor 1.12 in conjunction with the geometry of the first graduation track 2.1. The first receiving conductor 1.11 and the second receiving conductor 1.12 have a geometric first period length λ1 according to FIG. 5 and are arranged with respect to one another in the circumferential direction x with an angular offset φ1 (=1 / 4·λ1). Accordingly, the first signal S1.11 and the second signal S1.12 have a period that corresponds to the first period length λ1. Furthermore, the amount of the first phase offset PH1 can also be expressed as 1 / 4·λ1.

[0041] PH1=1 / 4·λ1 The third and fourth receiving conductors 1.13, 1.14 are arranged offset with respect to the first and second receiving conductors 1.11, 1.12, so that the third receiving conductor 1.13 provides a third signal that is phase-shifted by π / 4 with respect to the first signal S1.11 of the first receiving conductor 1.11. Similarly, the fourth signal of the fourth receiving conductor 1.14 is phase-shifted by π / 4 with respect to the second signal S1.12. The third and fourth signals are used for redundant position value acquisition, in particular for safety-relevant applications.

[0042] The fifth and sixth receiving conductors 1.21, 1.22 generate a fifth signal S1.21 and a sixth signal S1.22, respectively, according to Fig. 9. The fifth signal S1.21 and the sixth signal S1.22 here have a phase shift ph of π / 8 (22.5°). The fifth and sixth receiving conductors 1.21, 1.22 are connected to each other in series, so that a first overall signal SU1 is generated by these receiving conductors.

[0043] Similarly, the seventh and eighth receiving conductors 1.23 and 1.24 generate the seventh and eighth signals S1.23 and S1.24, respectively. The seventh and eighth signals S1.23 and S1.24 have the same phase shift ph of π / 8 with respect to each other as the fifth and sixth signals S1.21 and S1.22. The seventh and eighth receiving conductors 1.23 and 1.24 are also connected in series with each other. As a result, the seventh and eighth receiving conductors 1.23 and 1.24 generate a second overall signal SU2.

[0044] The amounts of phase shift ph of π / 8 and the second phase shift PH2 of π / 2 can be read from the context of the definitions, based on which the complete period of the fifth, sixth, seventh and eighth signals S1.21, S1.22, S1.23, S1.24 as well as the second overall signal SU2 is 2π.

[0045] The fifth, sixth, seventh and eighth signals S1.21, S1.22, S1.23, S1.24 as well as the first and second overall signals SU1 and SU2 each have a period with a second period length λ2 of equal magnitude. This period results from the geometry of the fifth and sixth receiving conductors 1.21 and 1.22 in conjunction with the geometry of the second graduation track 2.2. The receiving conductors 1.21, 1.22 have the geometric second period length λ2 according to FIG. 5 and are arranged with a second angular offset φ2 (=1 / 16·λ2) relative to one another in the circumferential direction x. As a result, the fifth and sixth signals S1.21 and S1.22 have a period that corresponds to the second period length λ2. The magnitude of the phase shift ph between the fifth signal S1.21 and the sixth signal S1.22 or between the seventh signal S1.23 and the eighth signal S1.24 can therefore also be presented as 1 / 16·λ2.

[0046] ph=1 / 16·λ2 Furthermore, the first overall signal SU1 and the second overall signal SU2 have a second phase shift PH2 relative to one another, which in the presented exemplary embodiment corresponds to π / 2, the complete period of the first overall signal SU1 and the second overall signal SU2 being, by definition, 2π. The second phase shift PH2 is therefore ¼ λ2, i.e. PH2=1 / 4·λ2 It is.

[0047] The first overall signal SU1 and the second overall signal SU2 can thus be used as 0° and 90° signals. By means of the ninth to twelfth receiving conductors 1.25 to 1.28, further pairs of overall signals offset by 90° with respect to one another (45° and 135° signals) can be formed, so that redundant position value acquisition is also achieved here.

[0048] The scanning element 1 has an electronic circuit with electronic components 1.5 electrically connected to one another. This electronic circuit may, for example, also include an ASIC chip. The signals generated by the receiving tracks 1.1, 1.2 are further processed by some of the electronic components 1.5 that constitute the evaluation circuit. In particular, in the present configuration with two graduation tracks 2.1, 2.2 and two receiving tracks 1.1, 1.2, the absolute position can be calculated by the evaluation ASIC. This electronic circuit of the scanning element 1 serves not only as an evaluation element but also as an excitation control element, under the control of which an excitation current is generated or created, which then flows through the excitation tracks 1.3, 1.4. The excitation tracks 1.3, 1.4 are thus energized by one and the same excitation control element.

[0049] The first receiving track 1.1 is surrounded radially outwardly by the first excitation track 1.3 and at the same time radially inwardly by the second excitation track 1.4. In contrast to this, the second receiving track 1.2 is surrounded only on one side by the second excitation track 1.4. By the one-sided application of the excitation field to the second receiving track 1.2, an extremely space-saving construction of the scanning element 1 can be achieved. In this case, due to the special configuration of the receiving tracks 1.1, 1.2, especially the second receiving track 1.2, sufficiently large first signals S1.11 and second signals S1.12 can be generated. In addition to this, the one-sided application of the excitation field is to the second receiving track 1.2, since the second period length λ2 of the second receiving track 1.2 is greater than the first period length λ1 of the first receiving track 1.1, the one-sided application of the excitation field is to the (second) receiving track 1.2 with a coarser resolution. [Explanation of symbols]

[0050] 1 Scanning Element 1.1 First Received Track 1.11 First receiving conductor 1.12 Second receiving conductor 1.2 Second receiving track 1.21 Fifth receiving conductor 1.22 Sixth receiving conductor 1.23 Seventh receiving conductor 1.24 Eighth receiving conductor 1.3 First excitation track 1.4 Second excitation track 2 Scale elements 2.1 First scale track 2.11, 2.12 First scale structure 2.2 Secondary scale track 2.21, 2.22 Second scale structure K1 First Circular Line K2 Second Circular Line PH1 First phase shift PH2 Second phase shift R1 First radius R2 Second radius S1.11 First signal S1.12 Second signal SU1 First overall signal SU2 Second overall signal x circumferential direction λ1 First period length λ2 Second period length

Claims

1. An inductive angle measurement mechanism comprising a scanning element (1) and a scale element (2) rotatable relative to the scanning element (1), the scale element (2) has a first graduation track (2.1) with first graduation structures (2.11, 2.12) arranged periodically and a second graduation track (2.2) with second graduation structures (2.21, 2.22) arranged periodically, the scanning element (1) has an excitation track (1.3, 1.4) and a first receiving track (1.1) and a second receiving track (1.2), the first receiving track (1.1) comprises a first receiving conductor (1.11) and a second receiving conductor (1.12), the first and second receiving conductors (1.11, 1.12) running periodically along a first circumferential line (K1) having a first radius (R1), the first and second receiving conductors (1.11, 1.12) being arranged offset relative to one another in the circumferential direction (x), such that a first signal (S1.11) can be generated by the first receiving conductor (1.11) and a second signal (S1.12) can be generated by the second receiving conductor (1.12), the first signal (S1.11) and the second signal (S1.12) having a first phase offset (PH1) relative to one another, the second receiving track (1.2) comprises a fifth receiving conductor (1.21), a sixth receiving conductor (1.22), a seventh receiving conductor (1.23) and an eighth receiving conductor (1.24), the fifth, sixth, seventh and eighth receiving conductors (1.21, 1.22, 1.23, 1.24) each running periodically along a second circumferential line (K2) having a second radius (R2) and each being arranged offset in the circumferential direction (x) with respect to one another, the fifth and sixth receiving conductors (1.21, 1.22) are connected to each other in series, so that a first overall signal (SU1) can be generated by the fifth and sixth receiving conductors (1.21, 1.22); and the seventh and eighth receiving conductors (1.23, 1.24) are also connected in series with each other, so that a second overall signal (SU2) can be generated by the seventh and eighth receiving conductors (1.23, 1.24), An inductive angle measurement arrangement, wherein the first overall signal (SU1) and the second overall signal (SU2) have a second phase shift (PH2) relative to each other.

2. 2. An inductive angle measurement arrangement according to claim 1, wherein the first and second receiving conductors (1.11, 1.12) run periodically with a constant first periodic length (λ1).

3. 3. An inductive angle measuring arrangement according to claim 1 or 2, wherein the fifth, sixth, seventh and eighth receiving conductors (1.21, 1.22, 1.23, 1.24) run periodically with a constant second periodic length (λ2).

4. 4. An inductive angle measurement arrangement according to claim 2, wherein the second periodic length (.lambda.2) is greater than the first periodic length (.lambda.1).

5. 5. An inductive angle measurement arrangement according to claim 1, wherein the first and second receiving conductor paths (1.11, 1.12) run periodically with a constant first periodic length (λ1) and the first phase shift (PH1) is a quarter of the first periodic length (λ1).

6. 6. An inductive angle measurement arrangement according to claim 1, wherein the fifth, sixth, seventh and eighth receiving conductors (1.21, 1.22, 1.23, 1.24) run periodically with a constant second periodic length (λ2), and the second phase shift (PH2) is a quarter of the second periodic length (λ2).

7. 7. An inductive angle measuring arrangement according to claim 1, wherein the first receiving track (1.1) has a first number n1 of receiving conductors (1.11, 1.12, 1.13, 1.14) and the second receiving track (1.2) has a second number n2 of receiving conductors (1.21 to 1.28), in which n1 is smaller than n2.

8. 8. The inductive angle measurement arrangement of claim 7, wherein the second number n2 is at least twice as large as the first number n1, i.e. n2>2·n1.

9. 9. An inductive angle measurement arrangement according to any one of claims 1 to 8, wherein the second radius (R2) is smaller than the first radius (R1).

10. 10. An inductive angle measurement mechanism according to claim 1, wherein the scanning element (1) comprises a first excitation track (1.3) and a second excitation track (1.4), the first receiving track (1.1) being surrounded on the radially outer side by the first excitation track (1.3) and on the radially inner side by the second excitation track (1.4), while the second receiving track (1.2) being surrounded on only one side by the second excitation track (1.4).

11. 11. The inductive angle measuring arrangement according to claim 1, wherein the fifth and sixth receiving conductors (1.21, 1.22) run periodically with a constant second periodic length (λ2) and are arranged with an angular offset (φ2) relative to one another along the circumferential direction (x), the angular offset (φ2) being at most 1 / 16 of the second periodic length (λ2), such that φ2<1 / 16·λ2.

12. 12. The inductive angle measuring arrangement according to claim 1, wherein the seventh and eighth receiving conductors (1.23, 1.24) run periodically with a constant second periodic length (λ2) and are arranged with an angular offset (φ2) relative to one another along the circumferential direction (x), the angular offset (φ2) being at most 1 / 16 of the second periodic length (λ2), such that φ2<1 / 16·λ2.

13. 13. An inductive angle measurement arrangement according to claim 1, wherein the scanning element (1) is formed as a printed circuit board and the excitation track (1.3, 1.4), the first receiving track (1.1) and the second receiving track (1.2) run in less than four conductive layers.

14. 14. An inductive angle measurement arrangement according to any one of the preceding claims, wherein the first receiving track (1.1) and / or the second receiving track (1.2) extend over the entire circumference.

15. 15. An inductive angle measurement arrangement according to claim 1, wherein the scanning element (1) is formed as a printed circuit board and the excitation track (1.3, 1.4), the first receiving track (1.1) and the second receiving track (1.2) run in exactly two conductive layers.

Images