Secondary device for an inductive transmission device

Abstract

The invention relates to a secondary device (1) for an inductive transmission device for an electric machine, in particular an externally excited electric machine for a motor vehicle, the secondary device comprising a secondary ferrite core (2) and a control device (3) which is arranged at least in part on a cooling device (6) and is designed at least to rectify an electrical signal transmitted to the secondary device (1), wherein an intermediate element (10) is arranged between the secondary ferrite core (2) and the cooling device (6), the intermediate element connecting the secondary ferrite core (2) to the heat sink (7), wherein the longitudinal axis of the heat sink (7) extends along the rotational axis (8) of the secondary device (1).

Description

[0001] Secondary device for an inductive transmission device

[0002] The invention relates to a secondary device for an inductive transmission device, in particular a separately excited electric machine for a motor vehicle, comprising a secondary ferrite core and a control device arranged at least partially on a cooling device, which is designed at least for rectifying an electrical signal transmitted to the secondary device.

[0003] Secondary devices designed for inductive transmission in inductive excitation devices for separately excited electrical machines, particularly in applications as drive units for motor vehicles, are generally known from the prior art. Such secondary devices are known to include a control device configured to rectify the electrical signal transmitted to the secondary device via the inductive excitation device, i.e., transmitted from the primary to the secondary side, in order to subsequently supply it to the rotor windings of the electrical machine.

[0004] In the operation of such secondary equipment, it is further known that heat is generated, for example, due to electrical losses in the control unit. This generated heat must be dissipated from the electronic components of the secondary equipment to ensure continuous operation at a defined power output. It is known, for example, that the control unit can be arranged on a cooling unit in such a way that the cooling unit can conduct heat into the rotor shaft in a defined manner. For example, a circuit board of the cooling unit is circular and arranged perpendicular to the axis of rotation of the secondary equipment or the rotor shaft, within the rotor shaft.

[0005] Depending on the available installation space, for example the diameter of the rotor shaft, and depending on which electronic components of the control device are to be provided, for example a number of rectifier diodes, the design of a protection circuit and the like, such an arrangement is not possible or only possible with difficulty, since the diameter of the cooling device is limited, so that the diameter of the rotor shaft cannot be arbitrarily set below a minimum dimension or not arbitrary rectifier devices can be used in the control device.

[0006] The invention is based on the objective of providing an improved secondary device for an inductive excitation device for a separately excited electric machine, in which the design freedom with regard to the dimensions of the secondary device, in particular adapted to a rotor shaft, and / or the design of the control device is improved.

[0007] The problem is solved by a secondary device having the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0008] As described, the invention relates to a secondary device for an inductive transmission device for an electric machine. The inductive transmission device, or the secondary device, is specifically intended for a separately excited electric machine, which may be a component of a motor vehicle.

[0009] The separately excited electric machine is designed, in particular, as a drive unit for motor vehicles. The secondary unit comprises a secondary ferrite core and a control device arranged, at least partially, on a cooling unit. The control device is designed, at least, to rectify an electrical signal transmitted to the secondary unit.

[0010] The invention is based on the finding that an intermediate element is arranged between the secondary ferrite core and the cooling device, connecting the secondary ferrite core to the heat sink, the heat sink extending with its longitudinal axis along the axis of rotation of the secondary device. The described configuration can therefore also be understood as a "horizontal heat sink" or as an axially oriented heat sink. In contrast to the previously described arrangements in which the control device or the circuit board on which the rectifier elements are arranged extends radially or is arranged in a plane perpendicular to the axis of rotation, it is proposed here to arrange the cooling device along the axis of rotation of the secondary device or the rotor shaft in which the secondary device is mounted. This makes the cooling device more scalable, as it is not limited to the inner diameter of the rotor shaft.

[0011] The intermediate element represents the interface, connection, or transition between the secondary ferrite core and the described heat sink, or more generally, the cooling device and thus also the control device arranged on the cooling device. As further described below, the intermediate element has one or more functions, for example, regarding the positioning of the secondary ferrite core and heat sink, or the arrangement of electrical conductors, and the like.

[0012] The described secondary device can be provided with an intermediate element that has at least two, and in particular exactly three, axially projecting contact sections from an end face of the intermediate element, through which the intermediate element rests axially against the secondary ferrite core, the contact sections defining a gap between the end face of the intermediate element and the secondary ferrite core. The provision of the described contact sections allows, for example, the defined formation of a gap between the intermediate element and the ferrite core in the axial direction.

[0013] Since the secondary ferrite core is generally made of a relatively brittle material, bonding it to the core is preferred. Firstly, the intermediate element with its contact sections ensures axial positioning between the intermediate element and the secondary ferrite core. Secondly, a defined gap is created in which, for example, an adhesive can be applied to secure the intermediate element to the secondary ferrite core, or vice versa. Furthermore, the design of the contact sections improves positional accuracy, as such a system, implemented via individual points or sections—specifically a three-point system—can be executed more precisely than a surface-level system across the entire axial area, such as the end face of the intermediate element.

[0014] Furthermore, in this embodiment, the intermediate element can have a larger diameter than the secondary ferrite core, allowing the secondary ferrite core to be centered on the intermediate element with respect to the axis of rotation. This results in a defined air gap around the secondary ferrite core, which can be determined by adjusting the diameter of the intermediate element.

[0015] The intermediate element, after further development of the secondary device, can have a through-opening through which at least one connecting line is routed, electrically connecting a secondary coil to the control device. The through-opening thus allows the connecting line, in particular an electrical connecting line, to be routed axially from the secondary coil of the secondary device through the intermediate element, thereby connecting the secondary coil to the control device, especially the rectifier elements or rectifier diodes. The described through-opening thus represents an axial "window" through which the connecting line can be routed. The intermediate element therefore also serves to arrange or align the connecting line.

[0016] In the described embodiment, it can be provided, in particular, that a deflecting device connected to the through-opening, and especially recessed axially into the intermediate element, is provided. This deflecting device is designed to guide the at least one connecting line, especially along a curved path, from an outer radial position of the through-opening to an inner radial position. In other words, the connecting line, which is guided axially through the intermediate element via the through-opening, is guided by the deflecting device from the outer radial position, where the connecting line passes through the intermediate element, along the deflecting device to the inner radial position. The deflecting device can have at least one path or path section that is curved in the axial direction.This means that the connecting pipe guided by the deflection device changes both its radial and axial positions. The curvature can be particularly pronounced in the axial direction. In cross-section, the deflection device can, for example, be S-shaped or described as a "chute" and be shaped accordingly.

[0017] By recessing the deflection device axially into the intermediate element, a groove can be formed in the axial direction. This groove is recessed relative to the base surface of the intermediate element or lies closer to the secondary ferrite than the base surface. The groove, in which the connecting line is received, can be filled with a potting compound to secure the connecting line. In principle, the deflection device is thus designed to guide at least one connecting line from the connection area of ​​the through-opening in the direction of the axis of rotation, specifically in the direction of the control device. This control device, as described, is arranged at least partially on the cooling device, which is located near the axis of rotation or extends axially along its longitudinal axis.

[0018] The described secondary device may further include at least one support device designed to support the at least one connecting line in the radial direction, in particular radially outwards with respect to an axis of rotation of the secondary device. The support device may, for example, be designed as a web extending axially from the previously described base surface.

[0019] The support device thus forms a step or platform against which the connecting line can rest in the radial direction. Even under rotational speed and corresponding forces acting on the connecting line, the connecting line cannot move radially because it is supported by the support device. This ensures that the support device secures the connecting line, preventing excessive deformation that could damage the connecting line or its connections, such as soldered joints. The previously described deflection device can be combined with the support device, meaning the support device can be integrated into the deflection device, or vice versa.

[0020] The described secondary device can be further developed such that the intermediate element has at least one contact element, in particular a receiving socket, configured to receive a connection element, in particular one connected to a rotor winding, in the axial direction, wherein the at least one contact element is supported in the axial direction on a support surface of the intermediate element, and / or that the intermediate element has at least one reference geometry configured to define an orientation of the contact element in the circumferential direction. The intermediate element can, in principle, be cylindrical or disc-shaped, regardless of the specific embodiment. Here, a base surface or end surface of the intermediate element can be aligned with or coincide with the axis of rotation of the secondary device with its surface normal. The base surface can also be configured as a support surface.serve as a support surface and, within the framework of the embodiment described above, accommodate or support at least one contact element.

[0021] A receiving socket, for example, is referred to as a contact element. The contact element, or the two contact elements arranged on the intermediate element, are fundamentally designed to each receive a connecting element in the axial direction. The connecting element can, for example, be designed as a contact pin or contact blade and project into the rotor shaft in such a way that the connecting element, or an end section of the connecting element, is aligned in the axial direction. When the secondary device is inserted into the hollow rotor shaft, the connecting element can thus engage with the contact element, or the contact element and connecting element can be connected to each other. Support forces generated during this process can be absorbed by the support surface, so that the contact element is also supported in the axial direction when contacted by the connecting element.Furthermore, the intermediate element can have at least one reference geometry designed to define the circumferential orientation of the contact element. For example, an arrangement device can be used to determine the positioning of the contact elements on the intermediate element. For instance, the contact elements can be inserted into openings in the intermediate element using press-fit pins and / or bonded there.

[0022] Until the adhesive bond is established, the assembly device can, for example, be aligned with the reference geometry to ensure the correct positioning of the contact elements. The assembly device can include a reference bar that engages with the contact elements. Furthermore, the assembly device has at least one contact section that is aligned with the reference geometry. Thus, the orientation of the reference geometry of the intermediate element can be transferred to the orientation of the contact elements by means of the assembly device. Once the adhesive has cured, the assembly device can be removed.

[0023] As previously described, the intermediate element can be larger in the radial direction than, for example, the secondary ferrite core. In other words, the diameter of the intermediate element can be larger than the diameter of the secondary ferrite core in order to position the secondary ferrite core within the rotor shaft. Specifically, the secondary ferrite core should be arranged on the intermediate element in such a way that a defined air gap is formed between the secondary ferrite core and the inner wall of the rotor shaft. To achieve this, the intermediate element rests, at least partially, against the inner wall of the rotor shaft, thus securing and positioning the secondary ferrite core within the rotor shaft and also the cooling device.In a further embodiment of the secondary device, the intermediate element may have at least two, and in particular three, circumferentially arranged contact ribs designed to contact an inner wall of the rotor shaft when the secondary device is mounted in the rotor shaft. The gap defined in this way between the secondary ferrite core and the inner wall of the rotor shaft is particularly important when the secondary ferrite core is bonded into the rotor shaft and a uniform and defined bonding gap is required for this purpose.

[0024] In the described embodiment, the intermediate element should not be in contact with the inner wall of the rotor shaft with its entire outer circumference or surface. This would necessitate comparatively high assembly forces. Since the defined contact between the contact element and the connecting element is to be established and monitored, it is desirable that the insertion force or assembly force for the intermediate element into the rotor shaft be sufficiently low to allow for the application of the necessary force between the connecting element and the contact element.

[0025] This is achieved in particular by forming defined contact ribs, specifically exactly three contact ribs, on an outer circumferential surface of the intermediate element. When the intermediate element is inserted into the rotor shaft, it is only in contact with the inner wall of the rotor shaft via these contact ribs. This makes it possible to create a defined transition fit or press fit between the intermediate element and the rotor shaft, while keeping the assembly force sufficiently low to ensure proper joining between the connecting element and the contact element.

[0026] Furthermore, the intermediate element is positioned radially within the rotor shaft by the mounting ribs. Since the secondary ferrite core and the cooling device are arranged on the intermediate element, they are also positioned within the rotor shaft by the intermediate element. The primary device can also be accommodated in a recess in the intermediate element, such that the primary device is spaced apart from the secondary device. This prevents contact between the primary and secondary sides. According to a further embodiment of the secondary device, the intermediate element of the secondary device can have a frame projecting axially from a base surface of the intermediate element and extending over a defined circumferential segment, in particular at least 90°. The frame thus projects axially beyond the base surface of the intermediate element. The frame is, for example, C-shaped.Specifically, the frame is formed in the area of ​​the previously described through-opening or at its circumferential position. For example, the center point of the frame can be located in the same circumferential position as the center point of the through-opening relative to the axis of rotation of the secondary device. This ensures, in particular, clearances and creepage distances between the rotor shaft and the connecting line that passes through the through-opening. By forming the frame over the defined circumferential segment, for example, <270°, specifically 180°, and therefore not entirely on the intermediate element, it can be ensured, for example, that a defined mounting of the heat sink on the intermediate element is possible. For example, the heat sink can be positively coupled to the intermediate element, in particular by being slid radially onto a guide on the intermediate element from the direction opposite the frame.

[0027] The secondary device can further be configured to include an intermediate element with at least one connection point for a protective circuit, particularly for a varistor. The described configuration allows a protective circuit, which can also be associated with the control device, to be arranged on the intermediate element. For example, the protective circuit can comprise a varistor mounted on the intermediate element, thus spatially separated from the control device. This enables spatial separation between the protective circuit and the rectifier circuit, offering, for instance, greater flexibility in the use of available space.

[0028] As a measure to protect against voltage spikes, it may be necessary to connect electronic components such as a varistor in parallel with the rotor winding. From a space-saving perspective, integrating these components into the intermediate element is a cost-effective solution. This is especially true if the component is a relatively large through-hole (THT) part, which, unlike a more compact surface-mount (SMD) component, cannot simply be placed on one of the existing circuit boards. A recess can be machined on the back of the intermediate element, deep enough to accommodate a varistor.

[0029] The legs of the varistor, for example, protrude through bores to the opposite side of the intermediate element, where they are guided onto or through an intermediate circuit board attached to the intermediate element and thus soldered in place. In general, the intermediate element can have at least one cavity or at least one recess that accommodates at least one electronic component. The component is held securely in place by the shape of the recess.

[0030] Furthermore, the secondary device may include an anti-rotation device arranged on the intermediate element. This anti-rotation device forms an insertion section that is open in the axial direction, for example, in a V-shape or Y-shape. The insertion section is designed to receive and guide the connecting elements that engage with the rotor shaft when the secondary device is inserted into the rotor shaft.

[0031] For example, curved contact edges can be formed on the insertion section, against which the connecting element can rest or slide when the secondary device is inserted, thus enabling the insertion section to position the intermediate element circumferentially. This ensures that subsequent rotation of the intermediate element is prevented when the connecting elements engage with their respective insertion sections. Furthermore, the blind contact can be improved, as even in the event of a positional deviation, the contact edges still make contact with the connecting element or with the insulation of the connecting element, thus guiding the intermediate element into the correct circumferential position.

[0032] In addition to the secondary device described above, the invention relates to an inductive transformer device comprising a secondary device described above. Furthermore, the invention relates to an electric machine comprising a secondary device described above and / or a secondary device described above. Finally, the invention relates to a motor vehicle comprising such an electric machine and / or a secondary device described above and / or a secondary device described above.

[0033] All the advantages, details and features described in relation to the secondary device are fully transferable to the inductive transformer device, the electric machine and the motor vehicle.

[0034] The invention is explained below with reference to exemplary embodiments and the figures. The figures are schematic representations and show:

[0035] Fig. 1 shows a schematic representation of a secondary device for an inductive transformer device for a separately excited electrical machine;

[0036] Fig. 2 shows a detail of an intermediate element of the secondary device of Fig. 1 according to a first embodiment in a first view;

[0037] Fig. 3 shows a detail of an intermediate element of the secondary device of Fig. 1 according to a second embodiment in a second view;

[0038] Fig. 4 shows a schematic representation of a secondary device according to a third embodiment;

[0039] Fig. 5 shows a partially separated representation of the secondary device from Fig. 4;

[0040] Fig. 6 is a perspective view of the secondary device of Figs. 4, 5;

[0041] Fig. 7 shows a schematic representation of a secondary device according to a fourth embodiment in an assembled state;

[0042] Fig. 8 shows the secondary device of Fig. 7 in an assembled state. Fig. 1 shows a secondary device 1 for an inductive transmission device (not shown in detail). The inductive transmission device can have a primary device in addition to the secondary device 1, which is shown in Figs. 1-3. According to the known operation of the inductive transmission device, an electrical signal, in particular an electric current, can be inductively transmitted from the primary device to the secondary device 1. For example, the secondary device 1 can be connected to a rotor winding of a rotor of the electric machine in order to energize the rotor. The following description is therefore also applicable to an inductive transmission device, an electric machine, and a motor vehicle that have a described secondary device 1.

[0043] The secondary device 1 has a secondary ferrite core 2, which is coupled, for example, to a secondary coil (not shown in detail). Corresponding electrical signals can be received by the secondary device 1 through inductive interaction with a primary coil. The secondary device 1 also has a control device 3, which, by way of example, includes four rectifier elements 4, specifically rectifier diodes, and an optional protection circuit 5. The control device 3 is arranged, at least partially, on a cooling device 6, which has a heat sink 7 extending with its longitudinal axis in the axial direction with respect to a rotational axis 8 of the secondary device 1. The rotational axis 8 of the secondary device 1 can, for example, coincide with the rotational axis of a rotor shaft in which the secondary device 1 can be arranged or is arranged.

[0044] The control device 3 is connected to the secondary coil (not shown) via connecting lines 11, 12. In other words, the electrical signal, in particular the electrical current, received by the secondary coil is supplied to the control device 3 and rectified by means of the rectifier elements 4. The rectified electrical signal can then be directed to contact elements 9, which, in the assembled state of the secondary device 1, are connected to terminal elements connected to the rotor winding. The contact elements 9 are arranged on the secondary device 1 such that the secondary device 1 is designed for blind mounting, as described below.

[0045] Figures 1-3 show an intermediate element 10, which is arranged axially with respect to the axis of rotation 8 between the secondary ferrite core 2 and the control device 3 or the cooling device 6. The intermediate element 10 therefore connects the secondary ferrite core 2 with the cooling device 6, or, more specifically, positions the secondary ferrite core 2 and the cooling device 6, for example with respect to the axis of rotation 8, specifically within the rotor shaft of the electric machine when the secondary device 1 is installed.

[0046] The intermediate element 10 is shown in isolation in various embodiments in Figures 2 and 3. As described, the secondary coil is connected to the control device 3 via the connecting lines 11 and 12. The intermediate element 10 guides the connecting lines 11 and 12 from a common or separate through-opening 13, located at an outer radial position, along a deflecting device 14 to an inner radial position, as illustrated by way of example in Figure 1. In other words, each connecting line 11 and 12 passes axially through the intermediate element 10 via the through-opening 13 and is then deflected radially inward by the deflecting device 14 so that the connecting lines 11 and 12 can be connected to the control device 3 there. The deflecting device 14 optionally has a curved track 15, which can also be called a "chute" and is, for example, S-shaped.

[0047] In the illustrated embodiment, the deflection device 14 or the track 15 is received in a channel 16. The connecting lines 11, 12 can be potted within the channel 16 in the assembled state, thus securing them in the deflection device 14. Furthermore, the intermediate element 10 has a support device 17 for each connecting line 11, 12, which is designed to support the connecting lines 11, 12 in the radial direction, for example, when a centrifugal force acts on the connecting lines 11, 12. Figures 2 and 3 also show two windows 18 in which the contact elements 9 can be received. The windows 18 can also be considered or designed as recesses. For example, the contact elements 9 can be designed as press-fit pins and received in the windows 18.so that a connecting element which engages in a contact element 9 can be guided through the window 18.

[0048] As described, connecting elements can engage radially within the rotor shaft, aligned in the axial direction. When the secondary device 1 is inserted into the rotor shaft, the connecting elements are inserted into the contact elements 9 to connect the control device 3 to the rotor winding. This allows the secondary device 1 to be blindly mounted within the rotor shaft, so that the rotor of the electric machine can be completely manufactured, in particular the rotor laminations can be joined to the rotor shaft and the rotor winding can be potted, before the secondary device 1 is mounted. This prevents the electronic components of the secondary device 1 from being exposed to high temperatures or temperature fluctuations.

[0049] The intermediate element 10 has a frame 19 which, in the illustrated embodiments, is C-shaped, i.e., extends over a defined circumferential segment of the intermediate element 10. The center point of the frame 19 is clearly coincident with the center point of the through-opening 13 when viewed circumferentially with respect to the axis of rotation 8. This increases the clearance and creepage distance between the connecting lines 11, 12, the contact elements 9, and a rotor shaft in which the intermediate element 10 is housed.

[0050] Furthermore, the frame 19 has a reference geometry 20 in which the previously described connection elements can be received in the axial direction. The reference geometry 20 can also serve to position the contact elements 9. For example, an arrangement device can engage the contact elements 9 with a reference beam such that a contact section of the arrangement device rests against the reference geometry 20. This allows for relative positioning of the contact elements 9 with respect to the reference geometry 20.

[0051] Fig. 2 also shows a positive locking device 21, which is designed to connect the heat sink 7 to the intermediate element 10. By way of example, the positive locking device 21 is T-shaped in cross-section, so that a correspondingly shaped counterpart of the heat sink 7 can be slid onto the positive locking device 21 in the radial direction – opposite the frame 19. The exact design of the positive locking device 21 can be modified as desired and is to be understood as merely an example.

[0052] Fig. 3 shows the intermediate element 10 according to a further embodiment. In the embodiment shown, a single through-opening 13 is provided for the connecting lines 11, 12. Furthermore, a recess 22 for receiving a primary device is provided in the intermediate element 10. The intermediate element 10 also has contact ribs 23, which are arranged, for example, circumferentially distributed on the outer surface of the intermediate element 10. Purely by way of example, exactly three contact ribs 23 can be provided.

[0053] The contact ribs 23 enable the intermediate element 10 to be supported and positioned against an inner wall of the rotor shaft. If, for example, the secondary ferrite core 2 is smaller than the intermediate element 10, particularly if it has a smaller diameter, the secondary ferrite core 2 can be centered on the intermediate element 10, allowing it to be positioned with a defined air gap relative to the inner wall of the rotor shaft. The contact ribs 23 ensure that the assembly forces required for the intermediate element 10 remain comparatively low, especially compared to full-surface contact across the entire outer surface of the intermediate element 10 against the inner wall of the rotor shaft. In other words, a transition fit or press fit is possible without requiring an unnecessarily high assembly force. The intermediate element 10 in Fig.3 also has contact sections 24 through which contact with the secondary ferrite core 2 is possible. The contact sections 24 project axially from an end surface 25 of the intermediate element 10 towards the secondary ferrite core 2. This creates a defined gap space which can be used, for example, for the axial positioning of the secondary ferrite core 2 and for forming an adhesive gap.

[0054] Figures 4-6 show a secondary device 1 according to a further embodiment. The intermediate element 10 has an intermediate circuit board 32, or an intermediate circuit board 32 is connected to the intermediate element 10, which has connection points 26 for a protection circuit 5, in particular for a varistor. The protection circuit 5 can thus be provided in addition to or as an alternative to the protection circuit 5 described above. The described embodiment allows the protection circuit 5, which can also be assigned to the control device 3, to be arranged on the intermediate element 10. For example, the protection circuit 5 can comprise a varistor that is arranged on the intermediate element 10 and can thus be spatially separated from the rest of the control device 5, in particular from the rectifier elements 4.This allows for a spatial separation between the protection circuit 5 and the rectifier elements 4, thus enabling, for example, greater flexibility in the use of installation space.

[0055] As a measure to protect against voltage spikes, it may be necessary to connect electronic components such as a varistor in parallel with the rotor winding. From a space-saving perspective, integrating these components into the intermediate element 10 is a cost-effective solution. This is especially true if the component is a relatively large through-hole (THT) part, which, unlike a more compact surface-mount (SMD) component, cannot simply be placed on one of the existing circuit boards. A recess 27 on the back of the intermediate element 10 can be made deep enough to accommodate a varistor.

[0056] The legs of the varistor, for example, extend through bores to the opposite side of the intermediate element 10, where they are guided onto or through an intermediate circuit board 32, which is arranged on the intermediate element 10, and thus soldered in place. In general, the intermediate element 10 can have at least one cavity or at least one recess 27 that accommodates at least one electronic component. The component is held in a form-fitting manner by the shape of the recess 27.

[0057] Furthermore, the secondary device 1, as shown in Figures 7 and 8, can be provided with an anti-rotation device 28, which is arranged on the intermediate element 10. The anti-rotation device 28 forms an insertion section 29, which is open in the axial direction, for example in a V-shape or Y-shape. The insertion section 29 is designed to receive and guide the connecting elements 30 that engage in the rotor shaft when the secondary device 1 is inserted into the rotor shaft.

[0058] For example, curved contact edges 31 can be formed on the insertion section 29, against which the connecting element 30 can rest or slide when the secondary device 1 is inserted, so that the insertion section 29 can position the intermediate element 10 circumferentially. This ensures that subsequent rotation of the intermediate element 10 is prevented when the connecting elements 30 engage with their respective insertion sections 29. Furthermore, the blind contact is improved, since even in the event of a positional deviation, the contact edges 31 come into contact with the connecting element 30 or with insulation of the connecting element 30, thus guiding the intermediate element 10 into the correct circumferential position.

[0059] The advantages, details, and features shown in the individual embodiments can be combined, interchanged, and transferred to one another as desired. (Reference symbol)

[0060] Secondary facility

[0061] Secondary ferrite core

[0062] Control device

[0063] rectifier element

[0064] Protection circuit

[0065] Cooling device

[0066] heat sink

[0067] axis of rotation

[0068] Contact element

[0069] Intermediate element, 12 connecting lines

[0070] Passage opening

[0071] Deflection device

[0072] Train

[0073] gutter

[0074] Support device

[0075] Window

[0076] Frame

[0077] Reference geometry

[0078] Positive locking device

[0079] Exclusion

[0080] Attachment ribs

[0081] Plant section

[0082] End surface

[0083] Connection point

[0084] in-depth

[0085] Anti-rotation device

[0086] Insertion section

[0087] Connection element

[0088] Installation edge

[0089] Intermediate board

Claims

Patent claims 1. Secondary device (1) for an inductive transmission device for an electric machine, in particular a separately excited electric machine for a motor vehicle, comprising a secondary ferrite core (2) and a control device (3) arranged at least partially on a cooling device (6), which is designed at least for rectifying an electrical signal transmitted to the secondary device (1), characterized in that an intermediate element (10) is arranged between the secondary ferrite core (2) and the cooling device (6), which connects the secondary ferrite core (2) to the heat sink (7), wherein the heat sink (7) extends with a longitudinal axis along the axis of rotation (8) of the secondary device (1).

2. Secondary device (1) according to claim 1, characterized in that the intermediate element (10) has at least two, in particular exactly three, axially projecting contact sections (24) from an end surface of the intermediate element (10), through which the intermediate element (10) abuts the secondary ferrite core (2) in the axial direction, wherein the contact sections (24) define a gap between the end surface (25) of the intermediate element (10) and the secondary ferrite core (2).

3. Secondary device (1 ) according to claim 1 or 2, characterized in that the intermediate element (10) has a through-opening (13) through which at least one connecting line (11 , 12) is guided, which electrically connects a secondary coil to the control device (3).

4. Secondary device (1 ) according to claim 3, characterized in that a deflecting device (14) is provided, connected to the through-opening (13), in particular recessed in the intermediate element (10) in the axial direction, which is designed to guide the at least one connecting line (11 , 12), in particular on a curved path (15), from an outer radial position of the through-opening (13) to an inner radial position.

5. Secondary device (1 ) according to one of the preceding claims, characterized in that at least one support device (17) is provided which is designed to support the at least one connecting line (11 , 12) in the radial direction, in particular radially outwards with respect to an axis of rotation (8) of the secondary device (1 ).

6. Secondary device (1) according to one of the preceding claims, characterized in that the intermediate element (10) has at least one contact element (9), in particular a receiving socket, which is configured to receive a connection element, in particular one connected to a rotor winding, in the axial direction, wherein the at least one contact element (9) is supported on a support surface of the intermediate element (10) in the axial direction and / or that the intermediate element (10) has at least one reference geometry (20) which is configured to define an orientation of the contact element (9) in the circumferential direction.

7. Secondary device (1 ) according to one of the preceding claims, characterized in that the intermediate element (10) has at least two, in particular three, contact ribs (23) arranged circumferentially on the intermediate element (10), which are designed to contact an inner wall of the rotor shaft in a state of the secondary device (1 ) mounted in a rotor shaft.

8. Secondary device (1 ) according to one of the preceding claims, characterized in that the intermediate element (10) has a frame (19) projecting axially from a base surface of the intermediate element (10) and extending over a defined circumferential segment, in particular at least 90°.

9. Inductive transformer device comprising a secondary device (1) according to any of the preceding claims.

10. Electrical machine comprising an inductive transformer device according to the preceding claim and / or a secondary device (1 ) according to any one of claims 1 to 8.

11. Motor vehicle comprising an inductive transformer device according to claim 9 and / or an electric machine according to the preceding claim, a secondary device (1) according to any one of claims 1 to 8.

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