Secondary device for an inductive excitation apparatus for an externally excited electric machine

Abstract

A secondary device (1) for an inductive excitation apparatus for an externally excited electric machine, in particular for a motor vehicle, wherein the secondary device (1) has a control device (2), in particular a rectifier device (3), which is designed to rectify an electrical signal transmitted to the secondary device (1), and a cooling device (7) associated with the control device (2), said control device (2) being at least partially located on a rectifier circuit board (5) on the cooling device (7), and said rectifier circuit board (5) being electrically connected to an intermediate circuit board (10) that is mechanically separate from the rectifier circuit board (5).

Description

[0001] Secondary device for an inductive excitation device for a separately excited electric machine

[0002] The invention relates to a secondary device for an inductive excitation device for a separately excited electric machine, in particular for a motor vehicle, wherein the secondary device comprises a control device designed for rectifying an electrical signal transmitted to the secondary device, in particular a rectifier device, and a cooling device associated with the control 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., from the primary to the secondary side, in order to subsequently supply it to the rotor windings of the electrical machine.

[0004] It is further known that heat is generated in the operation of such secondary equipment, 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.

[0005] For example, the control unit may include a rectifier that generates heat during operation. In this case, it is possible to mechanically connect the rectifier, i.e., the rectifier board, to the contact elements, which then establish an electrical connection to the rotor windings via electrical contact with terminals in the rotor shaft. For example, the contact elements described may be attached to or integrated into the rectifier board. However, this means that forces acting on the heat sink and the rectifier board are also transmitted to the contact elements and the electrical connection between the contact elements and the rectifier board, and vice versa. Over the lifespan of the device, this poses a risk to the electrical connection, such as the solder joints, which could be damaged.

[0006] The invention is based on the objective of providing an improved secondary device for an inductive excitation device for a separately excited electrical machine, in which, in particular, the connection between the rectifier board and the contact elements 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 excitation device for a separately excited electric machine. The secondary device includes a control device configured at least for rectifying the electrical signal transmitted to the secondary device during operation of the inductive excitation device. The electrical signal, for example, the electric current, is transmitted from the primary side to the secondary side or from a primary device to the secondary device during operation of the inductive excitation device and is rectified by the control device. The control device can, for example, be configured as a rectifier device or include a rectifier device. Such a rectifier device can, for example, comprise at least two rectifier diodes.

[0009] The invention is based on the finding that the control device is at least partially arranged on a rectifier board on the cooling device, wherein the rectifier board is electrically connected to an intermediate board that is mechanically separated from the rectifier board. In other words, a mechanical separation between the rectifier board and the intermediate board is proposed, while the rectifier board and the intermediate board are electrically connected to each other. Within the scope of this application, the electrical connection is therefore not considered a mechanical connection, since it merely serves the purpose of electrical contact between the intermediate board and the rectifier board. In other words, the electrical connection between the intermediate board and the rectifier board is not suitable for mechanically connecting the rectifier board and the intermediate board to each other, in particular for rigidly coupling them together.The electrical connection between the rectifier board and the intermediate board does not define a spatial relationship between them. Conversely, the electrical connection explicitly allows for relative movement between the rectifier board and the intermediate board.

[0010] Accordingly, the cooling device on which the rectifier board is mounted allows for the dissipation of heat generated during the operation of the rectifier. The control unit includes the rectifier board for the rectifier assembly or rectifier elements of the rectifier assembly. This board is positioned on the cooling device in such a way that heat generated during operation can be dissipated from the rectifier board via the cooling device. The intermediate board is specifically used to support the contact elements that ultimately establish the electrical connection to the rotor winding of the electric machine.This results in a mechanical decoupling of the contact elements from the rectifier board, so that forces, accelerations and the like acting on the rectifier board cannot be mechanically transmitted to the intermediate board, since it is mechanically separated from the rectifier board and only electrically connected to it.

[0011] The contact elements can be arranged on the surface of the intermediate board that faces the cooling device in the axial direction, or on the opposite side, facing the intermediate contact element or the secondary ferrite core. If an intermediate contact element is used, the intermediate contact element can have at least one receiving space in which the contact elements arranged on the intermediate board are accommodated. As previously described, the intermediate board should generally be mechanically separated from the rectifier board, but electrically connected to it. In principle, any electrical connection element that does not require a rigid mechanical coupling between the rectifier board and the intermediate board can be used for this purpose.In one embodiment of the secondary device, the intermediate board can be connected to the rectifier board by means of at least one flexible connecting element, in particular a flexible conductor and / or a round conductor, and in particular connected exclusively electrically. A ribbon cable, for example, can be understood as a flexible conductor.

[0012] In this context, the term "exclusively electrical" means, in particular, that an electrical contact is established between the intermediate board and the rectifier board, but this contact does not create a rigid mechanical coupling between the two. In other words, relative movements between the intermediate board and the rectifier board are possible via the flexible connecting element, and these movements are not blocked or restricted by the flexible connecting element. The flexible connecting element therefore establishes the electrical connection between the intermediate board and the rectifier board, but does not rigidly couple them together.

[0013] If the intermediate board is moved relative to the rectifier board, or vice versa, the flexible electrical connector is deformed. Therefore, accelerations or forces acting on the rectifier board are not transmitted to the intermediate board, as the flexible connector does not transmit them, or at least not significantly.

[0014] The described secondary device can further comprise an intermediate contact element arranged axially between a secondary ferrite core of the secondary device and the cooling element of the secondary device, with the intermediate plate being arranged on an axial mounting surface of the intermediate contact element. The intermediate contact element can thus receive or support the intermediate plate in the axial direction. In principle, the intermediate contact element can therefore provide the axial mounting surface on which the intermediate plate is mounted.

[0015] The intermediate plate's base can be arranged axially on the mounting surface or aligned parallel to the mounting surface of the intermediate contact element. As previously described, the intermediate plate is primarily intended to accommodate or provide the contact elements for connection to the rotor winding. During assembly, the connection elements, such as contact blades or contact pins, which are connected to the rotor winding, are thus made contact with the contact elements. This is achieved, in particular, by inserting the secondary assembly into the hollow rotor shaft, into which the described connection elements project radially.

[0016] Assembly forces occurring during contact between contact elements and connection elements are therefore transferred from the intermediate circuit board to the intermediate contact element and supported there. Consequently, such assembly forces are not transmitted via the connecting element and thus not transferred to the rectifier circuit board.

[0017] The secondary device may further provide that the described intermediate contact element has at least one recess for at least one contact element, in particular a receiving socket, which is arranged on the intermediate circuit board and / or for at least one connecting element received in the contact element and extending axially through the contact element. The recess may, for example, be designed as a window or a depression. The contact element may be inserted into the recess. The contact element may, for example, be designed as a receiving socket, in particular as a receiving socket with spring tongues. The connecting element described above may engage in the contact element or extend axially through the contact element. This allows for defined positional compensation, for example, to compensate for manufacturing or assembly tolerances.In a further embodiment of the secondary device, the intermediate board may have two contact elements and be formed in one piece, in particular in a U-shape with a connecting web, or it may have two separate sub-boards. In the first described embodiment, the intermediate board is formed in one piece. Here, the intermediate board may have two legs arranged in a U-shape, for example, connected to each other by a connecting web.

[0018] Each leg of the intermediate board can have a contact element. Alternatively, the intermediate board can also be provided by two spatially separated sub-boards. For example, each sub-board can form a leg, but they are not connected in a U-shape, but rather separated from each other. Specifically, the one-piece design of the intermediate board offers the advantage of simplified handling and assembly. The separate design with two sub-boards offers the advantage of greater flexibility. In any case, the legs of the intermediate board can deform or move relative to each other in a defined manner to compensate for tolerances, for example, by deforming the connecting web. The recess or free space between the two legs of the intermediate board...The space between the two sub-boards can be used in particular for routing the connecting cables through which the secondary coil is connected to the control unit.

[0019] According to a further embodiment of the secondary device, the intermediate circuit board can be positioned on the intermediate contact element by means of a positioning device, particularly in an assembly state. The positioning device has a positioning bar that can be brought into engagement with the contact elements and / or the positioning device has at least two contact sections designed to position the intermediate circuit board on the intermediate contact element by contacting the contact sections in reference geometries. The assembly state relates to a process step in an assembly or manufacturing process in which the intermediate circuit board is arranged on the intermediate contact element, for example, by being glued in place. In other words, the embodiment also relates to a method for manufacturing the secondary device.

[0020] In the described assembly state, a positioning device can be used that has a positioning bar which engages with the contact elements arranged on the intermediate plate. For example, the positioning bar is inserted into the contact elements, thus positioning them, particularly with respect to the axis of rotation of the secondary device. The contact elements are thereby aligned circumferentially by adjusting the positioning device. Once contact is established between the positioning bar and the contact elements, the positioning device can be brought into contact with the reference geometries on the intermediate contact element, thereby aligning the contact elements with the intermediate contact element. This alignment, in turn, positions the intermediate plate relative to the intermediate contact element due to the arrangement of the contact elements on the intermediate plate.In this position, the intermediate circuit board can be attached to the intermediate contact element, for example by gluing. Once the connection is established, the positioning device can be removed, for example, the positioning bar can be taken out of the contact elements.

[0021] According to a further embodiment, the intermediate board of the secondary device can have at least one bore for receiving at least one contact element and / or a connection surface, in particular a solder pad, for at least one connecting element, particularly overlapping the at least one bore. For example, the contact element(s) can be designed as a press-fit socket and inserted into the bore in the intermediate board. Furthermore, the intermediate board has the connection surface on which the previously described connecting elements, or each previously described connecting element, in particular a flexible connecting element, can be electrically contacted. The bore and the connection surface are particularly partially overlapping in the circumferential or radial direction of the secondary device.The secondary device may also be provided with an intermediate board that has at least one connection point for a protection circuit, in particular for a varistor and / or a diode. The described configuration allows a protection circuit, which can also be associated with the control device, to be located on the intermediate board. For example, the protection circuit can include a varistor that is mounted on the intermediate board and thus spatially separated from the rectifier board. This enables a spatial separation between the protection circuit and the rectifier circuit, which, for example, offers greater flexibility in the use of available space.

[0022] 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 contact 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 contact element, deep enough to accommodate a varistor.

[0023] The legs of the varistor, for example, protrude through bores to the opposite side of the intermediate contact element, where they are guided onto or through the intermediate circuit board and thus soldered in place. In general, the intermediate contact 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.

[0024] In addition to the secondary device, the invention relates to an inductive excitation device comprising a primary device and a previously described secondary device. Furthermore, the invention relates to a drive arrangement comprising such an inductive excitation device and / or a previously described secondary device. Finally, the invention relates to a motor vehicle comprising a previously described drive arrangement and / or a previously described inductive excitation device and / or a described secondary device. All advantages, details, and features described with respect to the secondary device are fully transferable to the inductive excitation device, the drive arrangement, and the motor vehicle.

[0025] The invention is explained below with reference to exemplary embodiments and the figures. The figures are schematic representations and show:

[0026] Fig. 1 shows a secondary device according to a first embodiment;

[0027] Fig. 2 shows a partially separated representation of the secondary device of Fig. 1;

[0028] Fig. 3 shows a partially separated representation of the secondary device from Fig. 1, 2;

[0029] Fig. 4 shows an intermediate board of the secondary device of Fig. 1-3;

[0030] Fig. 5 shows the intermediate circuit board of Fig. 4 with hidden contact elements;

[0031] Fig. 6 shows an intermediate circuit board for a secondary device according to a second embodiment;

[0032] Fig. 7 shows a section of a secondary device according to a third embodiment; and

[0033] Fig. 8 shows a perspective view of the secondary device from Fig. 7.

[0034] Figures 1-3 show a secondary device 1 for an inductive excitation device for a separately excited electric machine (not shown in detail), for example, a drive unit for a motor vehicle drive system. The secondary device 1 includes a control unit 2, which comprises a rectifier unit 3 and optionally a protective circuit 4. The rectifier unit 3 is arranged on a rectifier board 5, which is attached to a heat sink 6 of a cooling device 7. The rectifier unit 3 has, for example, four rectifier elements, in particular rectifier diodes. These can generate heat during operation of the secondary device 1, which can be dissipated via the heat sink 6. The heat sink 6 can, for example, be in contact with an inner wall of the rotor shaft when the secondary device 1 is mounted, thus transferring heat to or from the rotor shaft via the heat sink 6.

[0035] The rectifier board 5 is connected via connecting leads 8 to a secondary coil (not shown) of the secondary device 1. At the output side, the rectifier board 5 is electrically connected to contact elements 9. The contact elements 9 are arranged on an intermediate board 10, which is axially mounted on an intermediate contact element 11 with respect to a rotational axis of the secondary device 1. In particular, the intermediate board 10 is arranged on an axial mounting surface 12 of the intermediate contact element 11.

[0036] The intermediate contact element 11, for example, has means for guiding the connecting leads 8 from radially outside to radially inside, so that they can contact the rectifier board 5. To ensure that no accelerations or forces can be transmitted between the contact elements 9, which are designed to receive and electrically contact connecting elements 20 (see Figs. 7, 8) that are in turn connected to the rotor winding of the electric machine, and the rectifier board 5, the intermediate board 10 is mechanically separated from the rectifier board 5. This means that, for example, assembly forces that may occur when inserting the connecting elements into the contact elements 9 during the insertion of the secondary device 1 into the rotor shaft do not act on the rectifier board 5. Conversely, accelerations or forces are not transmitted between the intermediate board 10 and the rectifier board 5.Forces acting on the rectifier board 5 do not mechanically affect the intermediate board 10, as the latter is mechanically decoupled from the rectifier board 5.

[0037] The intermediate board 10 is connected to the rectifier board via connecting elements 13.

[0038] The rectifier board 5 is electrically connected but mechanically decoupled from the rectifier board 5. For example, Figures 4 and 5 show that the connecting elements 13 can be designed as flexible conductors, such as ribbon cables, which allow relative movement or mechanical decoupling between the rectifier board 5 and the intermediate board 10. Figure 6 shows, for example, that the connecting elements 13 can be designed as round conductors. In principle, the design of the connecting elements 13 is arbitrary, as long as it is ensured that they establish an electrical connection between the intermediate board 10 and the rectifier board 5 and do not create a mechanical coupling that rigidly connects the intermediate board 10 to the rectifier board 5.

[0039] Figures 4 and 5 show exemplary bores 14 through which contact elements 9 can be arranged on the intermediate circuit board 10. A connection surface 15 is also shown, through which the connecting elements 13 can be contacted or electrically connected to the intermediate circuit board 10. In the embodiment shown in Figures 4 and 5, there is an overlap in the radial and circumferential directions in which the bores 14 and the connection surfaces 15 overlap.

[0040] In the embodiments of the intermediate circuit board 10 according to Figs. 4-6, it is shown that the contact elements 9 are arranged on legs 16, 17 of the intermediate circuit board 10. The legs 16, 17 are connected to each other via a connecting web 18.

[0041] This allows, as described below, for tolerance compensation or positional compensation in the arrangement of the intermediate plate 10 on the intermediate contact element 11, particularly through deformation of the connecting web 18. Alternatively to the one-piece design, the intermediate plate 10 can also be made in two parts, for example by separating the connecting web 18. The preceding description applies accordingly.

[0042] To position the intermediate board 10 on the intermediate contact element 11, it can be glued to the intermediate contact element 11. A positioning device can be used to ensure the correct positioning between the intermediate board 10 and the intermediate contact element 11. The positioning device can, for example, have a positioning bar that engages with the contact elements 9. The positioning device has, for example, two contact sections that are brought into contact with reference geometries 19 (see Fig. 1-3), thus ensuring the circumferential positioning of the intermediate board 10. In this position, the intermediate board 10 can be attached to the intermediate contact element 11, for example, by gluing. The positioning device can then be removed.This ensures that the contact elements 9 are correctly positioned in the circumferential direction so that they can correctly receive the connecting elements 20 when the secondary device 1 is inserted into the rotor shaft.

[0043] Figures 7 and 8 show another embodiment of a secondary device 1, which also has an intermediate circuit board 10 and an intermediate contact element 11. In the embodiment shown, unlike the previously described arrangements of the contact elements 9, the contact elements 9 are arranged on the axially opposite side of the intermediate circuit board 10, i.e., between the intermediate circuit board 10 and the intermediate contact element 11. This means that the connecting elements 20, for example, the contact blades or contact pins, extend through the intermediate circuit board 10 and engage with the contact elements 9 behind the intermediate circuit board 10.

[0044] This allows the connecting elements 20 to essentially insert into the contact elements 9 from the rear, for which purpose the intermediate board 9 has a cutout or opening, specifically a slot, in this area. Advantageously, the contact elements 9 in this design can compensate for larger tolerances. This is further supported, for example, by the fact that the connecting elements 20 can be made longer in the axial direction, so that their connection can be made more flexible and thus more tolerant of misalignment.

[0045] In order to accommodate the contact elements 9 on the side of the intermediate contact element 11, the intermediate contact element 11 has a receiving space 21 for each contact element 9. As shown, for example, in Figs. 7 and 8, the contact element 9 is received in the receiving space 21, or the receiving space 21 in the intermediate contact element 11 provides space in which the contact element 9 can be received when the intermediate board 10 is arranged on the intermediate contact element 11.

[0046] The advantages, details and features described in relation to the individual embodiments can be combined, interchanged and transferred to one another as desired.

[0047] Reference mark

[0048] Secondary facility

[0049] Control unit

[0050] rectifier device

[0051] Protection circuit

[0052] rectifier board

[0053] heat sink

[0054] Cooling device

[0055] Connection cable

[0056] Contact element

[0057] Intermediate board

[0058] Intermediate contact element

[0059] Mounting surface

[0060] Connecting element

[0061] Drilling

[0062] Connection surface, 17 legs

[0063] Connecting bridge

[0064] Reference geometry

[0065] Connection element

[0066] Recording room

Claims

Patent claims 1. Secondary device (1) for an inductive excitation device for a separately excited electric machine, in particular for a motor vehicle, wherein the secondary device (1) comprises a control device (2) designed for rectifying an electrical signal transmitted to the secondary device (1), in particular a rectifier device (3), and a cooling device (7) associated with the control device (2), characterized in that the control device (2) is at least partially arranged on a rectifier board (5) on the cooling device (7), wherein the rectifier board (5) is electrically connected to an intermediate board (10) which is mechanically separated from the rectifier board (5).

2. Secondary device (1) according to claim 1, characterized in that the intermediate board (10) is connected to the rectifier board (5) by means of at least one flexible connecting element (13), in particular a flexible conductor track and / or a round conductor, and in particular is connected exclusively electrically.

3. Secondary device (1 ) according to claim 1 or 2, characterized in that the secondary device (1 ) has an intermediate contact element (11 ) which is arranged in the axial direction between a secondary ferrite core and the cooling device (7), wherein the intermediate plate (10) is arranged on an axial mounting surface (12) of the intermediate contact element (11 ).

4. Secondary device (1 ) according to claim 3, characterized in that the intermediate contact element (11 ) has at least one recess for at least one contact element (9), in particular a receiving socket, which is arranged on the intermediate board (10) and / or for at least one connecting element received in the contact element (9) and extending axially through the contact element (9).

5. Secondary device (1) according to one of the preceding claims, characterized in that the intermediate board (10) has two contact elements (9) has and is formed in one piece, in particular in a U-shape with a connecting web (18) or has two separate sub-plates.

6. Secondary device (1) according to one of the preceding claims, characterized in that the intermediate board (10), in particular in an assembly state, can be positioned on the intermediate contact element (11) by means of a positioning device, wherein the positioning device has a positioning bar which can be brought into engagement with the contact elements (9) and / or the positioning device has at least two contact sections which are designed to position the intermediate board (10) by contacting the contact sections in reference geometries (19) on the intermediate contact element (11).

7. Secondary device (1) according to one of the preceding claims, characterized in that the intermediate board (10) has at least one bore (14) for receiving at least one contact element (9) and / or a connection surface (15), in particular a solder pad, for at least one connecting element (13), in particular in overlap with the at least one bore.

8. Secondary device (1 ) according to one of the preceding claims, characterized in that the intermediate board (10) has at least one connection point for a protection circuit, in particular a varistor.

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

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

1. Motor vehicle comprising a drive arrangement according to the preceding Claim and / or an inductive excitation device according to claim 9 and / or a secondary device (1 ) according to any one of claims 1 to 8.

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