Electrical rotary converter for inductive energy transfer

Abstract

The invention relates to an electric rotary transformer (1) for inductive energy transmission. The rotary transformer (1) comprises a rotary transformer stator (2) having a primary winding (20). The rotary transformer (1) further comprises a rotary transformer rotor (3) which is designed to be rotatable relative to the rotary transformer stator (2) about an axis of rotation (D) and has a secondary winding (21), wherein the secondary winding (21) is inductively coupled or can be inductively coupled to the primary winding (20). The rotary transformer (1) further comprises a capacitive coupling device (4) for capacitive electrical signal transmission between the rotary transformer stator (2) and the rotary transformer rotor (3).

Description

TECHNICAL FIELD

[0001] The present invention relates to an electrical rotary transducer for inductive energy transfer and to a separately excited synchronous electrical machine comprising such a rotary transducer. BACKGROUND

[0002] So-called separately excited synchronous electrical machines require a DC voltage in their rotary transducer rotor in order to generate a rotor magnetic field. This process is referred to as "rotor excitation".

[0003] The electrical energy transfer on the rotating rotary transducer rotor takes place in an inductive manner and is therefore wireless. As part of a separately excited synchronous electrical machine, this component is referred to as "rotary transducer" or "rotary planar transducer".

[0004] The working principle of the inductive energy transfer is based on an electrical transducer, wherein the primary winding or primary coil of the transducer is arranged on the rotary transducer stator of the rotary transducer or the synchronous electrical machine and the secondary winding or secondary coil is provided on the rotating rotary transducer rotor. Since an alternating voltage is always generated in the secondary coil during inductive energy transfer, this alternating voltage needs to be converted into a direct voltage in order to power the electrical rotor.

[0005] For the operation of the electrical rotary transducer or the separately excited synchronous electrical machine configured with the rotary transducer, it is often necessary to transmit data, or at least signals, from the primary side, thus from the stator, to the secondary side, thus to the rotor, or in the reverse direction from the rotor to the stator, or in both directions.

[0006] In view of the above, EP 0 073 903 B1 discloses a rotary transducer comprising a rotary transducer stator and a rotary transducer rotor, which further comprises a capacitive coupling device for capacitive signal transmission between the rotary transducer stator and the rotary transducer rotor. To this end, the capacitive coupling device comprises a plate capacitor, which is arranged on the rotary transducer stator and on the rotary transducer rotor.

[0007] EP 2 933 655 A1 discloses a rotary transducer comprising a stator printed circuit board with windings and capacitor plates, and a rotor printed circuit board with windings and capacitor plates.

[0008] To reduce the weight, the publication "RAMINOSOA TSARAFIDY ET AL: Novel Rotary Transformer Topology with Improved Power Transfer Capability for High-Speed Applications", IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, IEEE SERVICE CENTER, PISCATAWAY, NJ, US, volume 56, No. 1, 21. November 2019 (2019-11-21), pages 277-286" proposes a rotor which is arranged centrally between two stator coils. SUMMARY

[0009] It is an object of the present application to show a new way in the development of rotary transformers. In particular, an improved embodiment for such a rotary transformer is created which provides a simple and efficient signal or data transmission between the primary side and the secondary side, thus between the stator and the rotor.

[0010] This object is solved by the subject matter of the independent claims. Preferred embodiments are subject matter of the dependent claims.

[0011] The basic idea of the present application is thus to equip an electrical rotary transformer with a capacitive coupling device by means of which a contactless signal transmission between a stator and a rotor which can be rotated relative to the stator can be realized. This allows the desired signal or data transmission between the stationary primary side and the rotatable secondary side of the rotary transformer. Since the signal or data transmission takes place electrically isolated from the inductive energy transmission, interference of the capacitive signal transmission by electromagnetic influences is excluded. In the case of a suitable configuration of the coupling device, the transmission in capacitive fashion further enables a high data transmission rate. Finally, such a capacitive coupling device requires only little installation space and has proven itself to be resistant to interference and thus reliable even during long-term operation.

[0012] The electrical rotary transformer for inductive energy transmission according to the application, in particular for a vehicle traction motor, comprises a rotary transformer stator having a primary coil. The rotary transformer further comprises a rotary transformer rotor which is formed so as to be able to rotate relative to the rotary transformer stator about an axis of rotation and which has a secondary coil. The secondary coil is inductively coupled or can be inductively coupled to the primary coil. According to the application, the rotary transformer additionally comprises a capacitive coupling device for capacitive signal transmission between the rotary transformer stator and the rotary transformer rotor. The capacitive coupling device is formed partly on the rotary transformer stator and partly on the rotary transformer rotor.

[0013] For generating and receiving electrical signals, the rotary transformer can comprise electrical transmitting and receiving units arranged on the rotary transformer stator. For generating and receiving electrical signals, the rotary transformer can also have electrical transmitting and receiving units arranged on the rotary transformer rotor. For signal transmission between the transmitting units and the receiving units, the rotary transformer can be extended by a first and a second electrically conductive path, which are electrically separated from each other and electrically connected in parallel to each other, thereby electrically connecting the two transmitting units and the receiving units to each other.

[0014] According to the invention, the capacitive coupling device comprises a first plate capacitor and a second plate capacitor. Each of the two plate capacitors comprises a first plate element and a second plate element, the second plate element being arranged spaced apart from the first plate element, thereby forming an intermediate space. The air in the intermediate space can act as a dielectric. In the case of this embodiment, the two first plate elements are arranged on the stator and the two second plate elements are arranged on the rotary transformer rotor. The second plate elements are thus formed so as to be rotatable and are also electrically isolated from them, unlike the first plate elements.

[0015] For capacitive coupling, the first plate elements and the second plate elements are thus respectively opposite each other, preferably axially. Each of the two first plate elements can thus be arranged at a very small distance from the corresponding second plate element in the axial direction. In this way, the capacitance of the plate capacitors also increases. Furthermore, the capacitive coupling device requires only a small installation space, in particular in the axial direction.

[0016] According to the invention, the first plate elements and the second plate elements of at least one plate capacitor, preferably of both plate capacitors, can thus each have a ring-shaped geometry. As mentioned above, it can thus be ensured that the function of the plate capacitors in terms of electrical signal transmission is not impaired during the rotational movement of the rotor.

[0017] According to the invention, the first plate elements and the second plate elements are arranged coaxially with respect to each other about the axis of rotation. This measure also ensures that the function of the plate capacitors is not impaired during the rotational movement of the rotor.

[0018] According to the invention, a transformer core made of a magnetic core material, preferably a ferrite material, is arranged on the rotary transformer stator. The course of the magnetic field lines can be improved by the transformer core and, as a result, the efficiency of the rotary transformer can be increased during the energy transfer from the primary side to the secondary side.

[0019] According to the invention, the transformer core surrounds a coil accommodation space in which the primary coil and the secondary coil arranged on the printed circuit board are arranged. The arrangement of both coils in the coil accommodation space makes it possible for the primary coil and the secondary coil to be inductively coupled to each other in a particularly efficient manner.

[0020] According to the application, the transformer core is formed in a ring shape and arranged coaxially to the axis of rotation. The installation space required is particularly small as a result.

[0021] According to the application, the transformer core has a recess on its inner circumference, which opens radially inwards, and a radially outer printed circuit board portion of the secondary coil printed circuit board is arranged in the recess. The radially outer printed circuit board portion with the secondary coil is surrounded in this way by the transformer core.

[0022] According to the application, the recess can have an axial recess, in which the primary coil is received. The primary coil is also completely surrounded in this way by the transformer coil.

[0023] Since the magnetic material of the transformer coil cannot have a beneficial effect on the capacitive coupling device, according to the application the capacitive coupling device is correspondingly arranged outside the transformer core or coil accommodation space. Since material of the transformer coil is saved in this way, significant cost advantages can be achieved.

[0024] According to the application, the primary coil and the secondary coil are arranged at a greater radial distance from the axis of rotation than the capacitive coupling device. This makes it possible to provide the transformer coil on the radially outer side and to fasten it to the stationary, thus non-rotating stator of the electric machine.

[0025] According to one preferred embodiment, the rotating transformer rotor has a secondary coil printed circuit board, which can be rotated relative to the rotating transformer stator about the axis of rotation. The secondary coil is arranged on the secondary coil printed circuit board - axially facing the primary coil. The secondary coil is thus formed by at least one conductor track arranged on the secondary coil printed circuit board. With regard to the application, "arranged on the secondary coil printed circuit board" means that the at least one conductor track forming the secondary coil is arranged - in particular visibly - on the surface of the printed circuit board or is surrounded - in particular invisibly - by the material of the secondary coil printed circuit board. Combinations of these two variants, in particular as can be applied in the case of a multilayer secondary coil printed circuit board, are also included in the above statement.

[0026] Both second plate elements are formed by at least one conductor track made of metal, preferably copper, formed on the secondary coil printed circuit board. With regard to the application as a whole, "arranged on the printed circuit board" means that the conductor track forming the plate element is arranged - in particular visibly - on the surface of the printed circuit board or is surrounded - in particular invisibly - by the material of the printed circuit board. Combinations of these two variants, in particular as can be applied in the case of a multilayer printed circuit board, are also included in the above statement.

[0027] In another preferred embodiment, however, the second plate element can also be arranged on a separate printed circuit board, thus not on a common printed circuit board with the secondary winding. In a further alternative embodiment, if no secondary winding printed circuit board is provided, the structure of the first plate element or / and the second plate element is formed as a ring element made of metal or as a copper-plated plastic on the rotor, and the first plate element or / and the second plate element surrounds the rotor shaft.

[0028] The two second plate elements can preferably be arranged radially on the inside of the secondary winding printed circuit board, and the secondary winding is arranged radially on the outside of the secondary winding printed circuit board, or vice versa. This variant can be particularly easy to implement, thus being low in production costs, since the secondary winding of the rotary transducer and the rotatable part of the two plate capacitors in the form of the second plate elements are formed on the same printed circuit board. Furthermore, the structure of this embodiment is particularly compact.

[0029] According to an advantageous further embodiment, the two plate capacitors are arranged spaced apart from one another along a radial extending away from the rotation axis. This variant requires particularly little installation space in the axial direction.

[0030] According to a further advantageous further embodiment, the two first plate elements are arranged on at least one additional printed circuit board, which is arranged spaced apart axially from the secondary winding printed circuit board. This additional printed circuit board can be produced relatively easily in terms of technology, thus being cost-effective in production. The secondary winding printed circuit board and the additional printed circuit board can also be arranged axially close to one another. This makes the installation space further saved in the axial direction. In this way, the capacity of the two plate capacitors can additionally be increased. With regard to the invention as a whole, "arranged on an additional printed circuit board" means that the conductor tracks forming the plate elements are arranged - particularly visibly - on the surface of the printed circuit board or are enclosed - particularly invisibly - by the printed circuit board material. A combination of these two variants, particularly in the case of a multilayer printed circuit board, is also included in the above expression.

[0031] It is particularly advantageous if the two first plate elements can each be formed by a conductor track made of metal, preferably of copper, which is formed on the additional printed circuit board. This variant can also be produced particularly easily.

[0032] According to another preferred embodiment, the two plate capacitors are arranged next to one another in the axial direction extending along the rotation axis. This variant embodiment is particularly compact in the radial direction. In a further variant, the two plate capacitors can be arranged next to one another axially and offset radially from one another.

[0033] According to an advantageous further embodiment, the two first plate elements are arranged on two different additional printed circuit boards. In the case of a further embodiment, the secondary coil printed circuit board is arranged axially between the two additional printed circuit boards.

[0034] According to a further advantageous further embodiment, the two second plate elements are arranged on axially opposite sides of the secondary coil printed circuit board. One of the two second plate elements thus axially faces the first plate element arranged on the first additional printed circuit board. The other of the two second plate elements axially faces the first plate element arranged on the second additional printed circuit board. This further solution also has a particularly compact axial structure and is also characterized by a low electrical / electronic susceptibility to interference.

[0035] The two first plate elements and the second plate elements can each be formed rotationally symmetrical with respect to the axis of rotation. In this way, at each rotational position of the rotary transformer rotor relative to the rotary transformer stator, a function of the plate capacitor in terms of electrical signal transmission during the rotary movement of the rotary transformer rotor is ensured.

[0036] The invention also relates to a separately excited synchronous electric machine, in particular for a traction electric machine of a vehicle. The synchronous electric machine comprises a synchronous electric machine stator which can be supplied with electrical power for generating a stator magnetic field. The machine further comprises a synchronous electric machine rotor which can be supplied with electrical power and which can be rotated relative to the synchronous electric machine stator for generating a rotor magnetic field, the synchronous electric machine rotor having a synchronous electric machine rotor shaft. The synchronous electric machine further comprises a rotary transformer according to the invention as introduced above, which is connected in a non-rotatable manner to the synchronous electric machine rotor shaft. The above-mentioned advantages of the rotary transformer according to the invention thus also apply to the separately excited synchronous electric machine according to the invention.

[0037] The synchronous electric machine can in particular be used in a motor vehicle comprising a battery as an energy source. The synchronous electric machine is thus in particular used for driving the motor vehicle and is thus in particular formed as a traction electric machine. The traction electric machine according to the invention preferably has an output or drive power of 100 kW to 240 kW, in particular 140 kW.

[0038] Further important features and advantages of the invention result from the dependent claims, the figures and the corresponding figure description based on the figures.

[0039] It goes without saying that the features mentioned above and those to be described hereinafter can be used not only in the combinations indicated, but also in other combinations or alone, without departing from the scope of the present invention.

[0040] Preferred exemplary embodiments of the present application are shown in the drawings and will be described in greater detail below, in which identical reference signs refer to identical or similar or functionally identical parts. BRIEF DESCRIPTION OF DRAWINGS

[0041] The drawings show schematically:

[0042] Figure 1 The electrical wiring of an electrical rotary transformer according to the present application is shown in the form of a circuit diagram,

[0043] Figure 2 is a schematic diagram showing the functional structure of the capacitive coupling device necessary for the present application,

[0044] Figure 3 is a mechanical structure of a first example of a rotary transformer according to the present application, in the case of which the plate-type capacitors of the capacitive coupling device are arranged radially adjacent to one another in a longitudinal section,

[0045] Figure 4 is a schematic diagram showing the functional structure of the capacitive coupling device necessary for the present application, Figure 3 is a plan view of the rotary transformer of

[0046] Figure 5 is a mechanical structure of a further example of a rotary transformer according to the present application, in the case of which the plate-type capacitors of the capacitive coupling device are arranged axially adjacent to one another in a longitudinal section,

[0047] Figure 6 is a plan view of the rotary transformer of Figure 5 DETAILED DESCRIPTION

[0048] Figure 1 The electrical wiring of an electrical rotary transformer 1 for inductive energy transmission according to the present application is shown in the form of a circuit diagram. The rotary transformer 1 can be used in a separately excited synchronous electric machine, in particular in a vehicle traction electric machine. On the primary side, the rotary transformer 1 comprises a rotary transformer stator 2 with a primary coil 20. On the secondary side, the rotary transformer 1 further comprises a rotary transformer rotor 3 formed so as to be rotatable relative to the rotary transformer stator 2 about a rotation axis D (not shown in the middle) and having a secondary coil 21. The secondary coil 21 is inductively coupled with the primary coil 20. Figure 1

[0049] ​​For the transfer of electrical energy from the primary coil 20 to the secondary coil 21, an alternating current needs to be generated in the primary coil 20. The alternating voltage required for this can be generated by means of a transistor circuit 22, which is arranged on the primary side and is electrically connected to the primary coil 20. The transistor circuit 22 can comprise four power transistors 23a, 23b, 23c, 23d, which in this embodiment are controlled by means of a control device 24 comprising two integrated circuits 25a, 25b. In the case of a supply of the primary coil 20 with an alternating current, an alternating voltage is also induced in the secondary coil 21. The secondary coil 21 is electrically connected to a rectifier circuit 26, which in this embodiment comprises four rectifier elements 27a, 27b, 27c, 27d, and by means of which the induced alternating voltage can be converted into a direct voltage. The four rectifier elements 27a-27d can be formed by rectifier diodes 28a-28d, respectively. The direct current generated in this way serves to supply the synchronous electric machine rotor with electrical power, in the case of a synchronous electric machine, as will be explained in more detail below. Figure 1 In the case of a synchronous electric machine, the synchronous electric machine rotor is schematically represented by means of an inductor identified by reference numeral 29 and an ohmic resistor identified by reference numeral 38.

[0050] For the transmission of signals or data between the primary side and the secondary side, and thus between the rotary transformer stator 2 and the rotatable rotary transformer rotor 3, the rotary transformer 1 comprises a capacitive coupling device 4. The structure of the capacitive coupling device 4 is shown in a circuit diagram-like manner in Figure 2 For the transmission of signals or data between the primary side and the secondary side, and thus between the rotary transformer stator 2 and the rotatable rotary transformer rotor 3, the rotary transformer 1 comprises a capacitive coupling device 4. The structure of the capacitive coupling device 4 is shown in a circuit diagram-like manner in

[0051] The first plate capacitor 5 comprises a first plate element 5.1 and a second plate element 5.2. The second plate capacitor 6 comprises a second plate element 6.1 and a second plate element 6.2. The two first plate elements 5.1, 6.1 are arranged spaced apart from the respective corresponding second plate elements 5.2, 6.2, thereby forming an intermediate space. The air in the intermediate space acts as a dielectric of the respective plate capacitor 5, 6.

[0052] In addition, as shown in Figure 2 , the electrical filter means 42, 43 are used to filter disturbances from the electrical signals transmitted through the two conductive paths 30a, 30b, which can be respectively arranged in the conductive paths 30a, 30b between the sending and receiving unit 40 and the two plate capacitors 5, 6 and in the conductive paths 30a, 30b between the sending and receiving means 41 and the two plate capacitors 5 and 6.

[0053] Figure 3 The mechanical structure of the rotary transducer 1 in the transition area of the stator 2 to the rotor 3 is illustrated in a highly simplified schematic view. In contrast to the rotary transducer stator 2, the rotary transducer rotor 3 is formed to be rotatable. The rotary transducer rotor 3 comprises a rotor shaft 9, which can be rotated about a rotation axis D. The central longitudinal axis M of the rotor shaft 9 is identical to the rotation axis D. The axial direction A extends along the central longitudinal axis M and thus also along the rotation axis D. The radial direction R extends perpendicular to the axial direction A away from the central longitudinal axis or the rotation axis D. The circumferential direction U extends perpendicular to the axial direction A and also perpendicular to the radial direction R and around the central longitudinal axis M or around the rotation axis D.

[0054] In contrast to the rotary transducer stator 2, the rotary transducer rotor 3 comprises a secondary coil printed circuit board 7, which is rotatable about the rotation axis D and is connected to the rotor shaft 9 in a non-rotatable manner. The conductor tracks 36 forming the secondary coil 21 are arranged on the secondary coil printed circuit board 7. The secondary coil 21 or the conductor tracks 36 are electrically connected to the rectifier circuit 26, which has already been described on the basis of Figure 1 and is likewise arranged on the secondary coil printed circuit board 7 (not shown in Figure 3 ). In the context of the present application, "arranged on the secondary coil printed circuit board 7" means that at least one conductor track forming the secondary coil 21 is arranged - in particular visibly - on the surface of the secondary coil printed circuit board 7 or is surrounded - in particular invisibly - by the material of the secondary coil printed circuit board 7. A combination of both variants, in particular in the case of a multilayer secondary coil printed circuit board 7, is also included in the above expression.

[0055] A transformer coil 31 made of a magnetic core material, preferably a ferrite material, is arranged on the rotary transformer stator 2. The transformer coil 31 preferably surrounds a coil accommodation space 15 in which the primary coil and the secondary coil 21 arranged on the secondary coil printed circuit board 7 are arranged. The transformer coil 31 of the rotary transformer stator 2 can be formed in an annular fashion and can be arranged coaxially to the rotation axis D. In Figure 3 the embodiment shown, the transformer coil 31 has a recess 33 on its inner circumference 32, which is open radially inwards. A radially outer printed circuit board portion 34 of the secondary coil printed circuit board 7 is arranged in the recess 33, on which the secondary coil 21 is arranged. As shown in Figure 3 the recess 33 can also have an axial recess 35 radially outward, in which the primary coil 20 of the rotary transformer stator 2 is arranged. The primary coil 20 is arranged in the recess 33 in a fixed manner with respect to the transformer core 31, such that the primary coil 20 and the secondary coil 21 are positioned opposite each other at a distance from each other along the axial direction A. In the case of a supply of the primary coil 20 with alternating current, an alternating voltage is induced in the secondary coil 21. The primary coil 20 can be formed by a coil winding 37 made of a conductive winding wire.

[0056] In the exemplary scenario, the primary coil 20 and the secondary coil 21 are arranged at a greater radial distance from the rotation axis D than the capacitive coupling device 4. Two plate capacitors 5, 6 are additionally arranged outside the transformer core 31 or outside the coil accommodation space 15, respectively.

[0057] As shown in Figure 3 two first plate elements 5.1, 6.1 of the two plate elements 5, 6 are arranged on the rotary transformer stator 2. Two second plate elements 5.2, 6.2 are arranged on the rotary transformer rotor 3. Thus, the two second plate elements 5.2, 6.2 are formed to be adjustable in rotation about the rotation axis D with respect to the two first plate elements 5.1, 6.1. In Figure 3In the embodiment shown, the two plate capacitors 5, 6 are additionally arranged spaced apart from each other in the radial direction R. Two first plate elements 5.1, 6.1 of the two plate capacitors 5, 6 are arranged on the rotary transformer stator 2. For capacitive coupling, the first plate element and the second plate element 5.1, 5.2 of the first plate capacitor 5 are arranged axially opposite and spaced apart from each other. For capacitive coupling, the first plate element and the second plate element 6.1, 6.2 of the second plate capacitor 6 are likewise arranged axially opposite and spaced apart from each other. Air is provided as dielectric in an axial intermediate space 12a of the first plate capacitor 5, which is formed between the first plate element 5.1 and the second plate element 5.2 of the first plate capacitor 5. Correspondingly, air is likewise provided as dielectric in an axial intermediate space 12b of the second plate capacitor 6, which is formed between the first plate element 6.1 and the second plate element 6.2 of the second plate capacitor 6.

[0058] Figure 4 An axial top view of the rotary transformer 1 is shown Figure 3 in the direction of the secondary winding printed circuit board 7. The conductor tracks 36 forming the secondary winding 21 can be clearly seen. The conductor tracks 36 extend in the circumferential direction U around the rotor shaft 9. As can be seen from the figure, Figure 4 The two second plate elements 5.2, 6.2 are each formed by a conductor track 10a, 10b, which is made of metal, for example copper, and is arranged on the secondary winding printed circuit board 7. In the context of the present application, "arranged on the secondary winding printed circuit board 7" means that the conductor track 10a, 10b forming the plate element 5.2, 6.2 is arranged, in particular visibly, on the surface of the printed circuit board, or is surrounded, in particular invisibly, by the printed circuit board material. Combinations of these two variants, in particular in the case of a multi-layer printed circuit board, are also included in the above expression.

[0059] In Figure 4In the embodiment, the two plate capacitors 5 and 6 are radially arranged on the inner side of the secondary coil printed circuit board 7, while the secondary coil 21 is radially arranged on the outer side of the secondary coil printed circuit board 7. The two second plate elements 5.2 and 6.2 are further formed to be rotationally symmetrical with respect to the rotation axis D. The two second plate elements 5.2 and 6.2 also have an annular or circular geometry and extend along the circumferential direction U. In addition, the second plate elements 5.2 and 6.2 are arranged coaxially with each other with respect to the rotation axis D. The radius R1 of the second plate element 5.2 of the first plate capacitor 5 from the rotation axis D is greater than the radius R2 of the second plate element 6.2 of the second plate capacitor 6.2. The above description of the geometric characteristics of the two second plate elements 5.2 and 6.2 is also applicable to the two first plate elements 5.1 and 6.1 of the first plate capacitor or the second plate capacitor 5 and 6, respectively, after adaptive modification. Figure 4 Not shown.

[0060] like Figure 3 As shown, the two first plate elements 5.1, 6.1 can be arranged on an additional printed circuit board 8, which, as part of the rotary transformer stator 2, is spaced apart from the secondary coil printed circuit board 7 in the axial direction A. The two first plate elements 5.1, 6.1 are also each formed by a conductor track 11a, 11b made of metal, preferably copper, which is formed on the additional printed circuit board 8. For the purposes of the present invention as a whole, "arranged on the additional printed circuit board" means that the conductor tracks forming the plate elements are arranged—particularly visibly—on the surface of the printed circuit board 8, or are surrounded—particularly invisibly—by the material of the printed circuit board 8. A combination of these two variants, which can be used in particular in the case of a multilayer printed circuit board 8, is also included in the above description.

[0061] Figure 5 Shows Figure 3 A variation of the example. Figure 5 In the case of a so-called "coplanar" arrangement, the two plate-type capacitors 5, 6 are arranged adjacent to each other along the axial direction A and at the same radial distance R1, R2 from the rotation axis D. Figure 5In the example shown, the two first plate elements 5.1 and 6.1 of the two plate-type capacitors 5 and 6 are arranged on two different additional printed circuit boards 8a and 8b of the stator 2, respectively. Thus, the secondary coil printed circuit board 7 is arranged between the two additional printed circuit boards 8a and 8b in the axial direction A. Furthermore, the two second plate elements 5.2 and 6.2 are arranged on axially opposite sides 13 and 14 of the secondary coil printed circuit board 7. Thus, the second plate element 5.2 of the first plate-type capacitor 5 is arranged on the first side 13 of the secondary coil printed circuit board 7. The second plate element 6.2 of the second plate-type capacitor 6 is arranged on the second side 14 of the secondary coil printed circuit board 7, axially opposite the first side 13. Thus, the second plate element 5.2 of the first plate-type capacitor 5 axially faces the first plate element 5.1 arranged on the first additional printed circuit board 8a, and they are axially opposite each other. The second plate element 6.2 of the second plate-type capacitor 6 axially faces the first plate element 6.1 arranged axially on the second additional printed circuit board 8b, and they are opposite each other in the axial direction A.

[0062] and Figure 4 similar, Figure 6 Shows Figure 5 Axial top view of the rotary converter when viewed toward the side 14 of the secondary coil printed circuit board 7. Accordingly, the secondary coil 21 is formed by a conductor track 36 provided on the secondary coil printed circuit board 7, which extends in a circumferential direction U around the rotor shaft 9. Figure 6 As shown, the two second plate elements 5.2, 6.2 are respectively formed by conductor tracks 10a, 10b arranged on the secondary coil printed circuit board 7, the conductor tracks being formed of metal, for example copper, wherein Figure 6 Only the second plate element 6.2 of the second plate-type capacitor 6 can be seen. The two first plate elements 5.1, 6.1 can also be formed by conductor tracks 11a, 11b made of metal, for example copper, which are arranged on the first additional printed circuit board 8a or the second additional printed circuit board 8b (see Figure 5 ).

[0063] exist Figure 5 and Figure 6 In the example of , the two first plate elements and the two second plate elements 5.1, 5.2, 6.1, 6.2 are also each formed rotationally symmetrically with respect to the rotation axis D. The first and second plate elements 5.1, 5.2, 6.1, 6.2 also each have an annular or circular geometry and extend in the circumferential direction U. In addition, the first and second plate elements 5.1, 5.2, 6.1, 6.2 are arranged coaxially with respect to the rotation axis D. Figure 5 or Figure 6In the example of Fig. 1, the first plate element and the second plate element 5.1, 5.2 of the first plate-type capacitor 5 are arranged at a radius R1 from the rotation axis D which is equal to the radius R2 at which the first plate element and the second plate element 6.1, 6.2 of the second plate-type capacitor 6 are arranged from the rotation axis D. In Figure 6 In the example of Fig. 1, the two plate-type capacitors 5, 6 are arranged radially on the inner side of the secondary coil printed circuit board 7, while the secondary coil 21 is arranged radially on the outer side of the secondary coil printed circuit board 7, which is similar to the embodiment of Fig. 2. Figure 4 In the example of Fig. 1, the two plate-type capacitors 5, 6 are arranged radially on the inner side of the secondary coil printed circuit board 7, while the secondary coil 21 is arranged radially on the outer side of the secondary coil printed circuit board 7, which is similar to the embodiment of Fig. 2.

Claims

1. An electrorotation converter (1) for inductive energy transfer, comprising: A rotary transformer stator (2) having a primary coil (20), A rotary converter rotor (3) is formed to be rotatable relative to the rotary converter stator (2) about a rotation axis (D) and has a secondary coil (21), wherein the secondary coil (21) is inductively coupled or can be inductively coupled to the primary coil (20), a capacitive coupling device (4) for capacitive signal transmission between the rotary converter stator (2) and the rotary converter rotor (3), the capacitive coupling device being formed partially on the rotary converter stator (2) and partially on the rotary converter rotor (3), The capacitive coupling device (4) comprises a first plate capacitor (5) and a second plate capacitor (6), each plate capacitor comprising a first plate element (5.1, 6.1) and a second plate element (5.2, 6.2), wherein two of the first plate elements (5.1, 6.1) are arranged on the rotary converter stator (2) and two of the second plate elements (5.2, 6.2) are arranged on the rotary converter rotor (3), wherein the first plate elements (5.1, 6.1) and the corresponding second plate elements (5.2, 6.2) are arranged opposite each other for capacitive coupling, The rotary converter rotor (3) comprises a secondary coil printed circuit board (7) rotatable about a rotation axis (D) relative to the rotary converter stator (2), and the secondary coil (21) is arranged on the secondary coil printed circuit board, wherein the secondary coil (21) is formed by at least one conductor track provided on the secondary coil printed circuit board (7), The two second plate elements (5.2, 6.2) are each formed by at least one conductor track made of metal, which is formed on the secondary coil printed circuit board (7). wherein the first plate element (5.1, 6.1) and the second plate element (5.2, 6.2) each have an annular geometry, wherein the first plate element (5.1, 6.1) and the second plate element (5.2, 6.2) are arranged coaxially with each other, wherein a transformer core (31) made of a magnetic core material is arranged on the rotary transformer stator (2), The transformer core (31) surrounds a coil accommodating space (15), the primary coil (20) and the secondary coil (21) of the secondary coil printed circuit board (7) are arranged in the coil accommodating space (15), wherein the transformer core (31) is formed in a ring shape and is coaxial with the rotation axis (D), The transformer core has a recess (33) on its inner circumference (32), the recess being radially inwardly open, and a radially outer printed circuit board portion (34) of the secondary coil printed circuit board (7) being arranged in the recess, the secondary coil (21) being arranged on the radially outer printed circuit board portion, wherein the recess (33) has an axial recess (35) for receiving the primary coil (20), wherein the capacitive coupling device (4) is arranged outside the transformer core (31) or the coil accommodating space (15), The primary coil (20) and the secondary coil (21) are arranged at a radial distance farther from the rotation axis than the capacitive coupling device (4).

2. The electrorotation converter according to claim 1, It is characterized by Two plate-type capacitors (5, 6) are arranged to be spaced apart along a radial direction (R) extending away from each other perpendicularly to the rotation axis (D).

3. The electrorotation converter according to claim 1 or 2, It is characterized by The two first plate elements (5.1, 6.1) are arranged on an additional printed circuit board (8; 8a, 8b), which is arranged axially spaced apart from the secondary coil printed circuit board (7).

4. The electrorotation converter according to claim 3, It is characterized by The two first board elements (5.1, 6.1) are each formed by a conductor track made of metal, which is arranged on an additional printed circuit board (8; 8a, 8b).

5. The electrorotation converter according to claim 1 or 2, It is characterized by The two first board elements (5.1, 6.1) are arranged on two different additional printed circuit boards (8a, 8b), The secondary coil printed circuit board (7) is arranged axially between two additional printed circuit boards (8a, 8b).

6. The electrorotation converter according to claim 5, It is characterized by The two second plate elements (5.2, 6.2) are arranged on axially opposite sides (13, 14) of the secondary coil printed circuit board (7), so that one of the two second plate elements (5.2) axially faces the first plate element (5.1) arranged on the first additional printed circuit board (8a), and the other of the two second plate elements (6.2) axially faces the first plate element (6.1) arranged on the second additional printed circuit board (8b).

7. The electrorotation converter according to any one of claims 1, 2, 4 and 6, It is characterized by Two plate-type capacitors (5, 6) are arranged adjacent to each other along an axial direction (A) extending along a rotation axis (D).

8. The electrorotation converter according to any one of claims 1, 2, 4 and 6, It is characterized by The two first plate elements (5.1, 6.1) and the two second plate elements (5.2, 6.2) are each formed rotationally symmetrically with respect to the axis of rotation (D).

9. The electrorotation converter according to any one of claims 1, 2, 4 and 6, It is characterized by The electric rotary converter (1) is used in a traction motor.

10. The electrorotation converter according to any one of claims 1, 2, 4 and 6, It is characterized by The first plate element (5.1, 6.1) and the corresponding second plate element (5.2, 6.2) are arranged axially opposite each other.

11. The electrorotation converter according to any one of claims 1, 2, 4 and 6, It is characterized by Both second plate elements (5.2, 6.2) are formed by at least one conductor track made of copper.

12. The electrorotation converter according to any one of claims 1, 2, 4 and 6, It is characterized by The transformer core (31) is made of ferrite material.

13. The electrorotation converter according to any one of claims 1, 2, 4 and 6, It is characterized by Two plate-type capacitors (5, 6) are arranged outside the converter core (31) or the coil accommodating space (15), respectively.

14. The electrorotation converter according to claim 4, It is characterized by The conductor tracks are made of copper.

15. A separately excited synchronous electric machine comprising: A synchronous electric machine stator capable of being supplied with power for generating a stator magnetic field, a synchronous motor rotor capable of being powered and rotatable relative to the synchronous motor stator for generating a rotor magnetic field, the synchronous motor rotor having a synchronous motor rotor shaft, and The electrorotary converter (1) according to one of the preceding claims, which is connected to the synchronous electric machine rotor shaft in a rotationally fixed manner.

16. The separately excited synchronous electric machine according to claim 15, characterized in that: The separately excited synchronous electric machine is a traction motor for a vehicle.

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