Connecting device for a rotating structure assembly of a motor vehicle, and rotating structure

Abstract

The invention relates to a connecting device for a rotating structural assembly of a motor vehicle, comprising: a sleeve for arrangement in a radial guide passage of a wall of a hollow shaft; a linear conductor which is partially arranged in the sleeve, the conductor ends protruding on the edge of the sleeve forming a contact region for contacting the first and second electrical components; an electrically insulating sheath which surrounds the conductor at least in the sleeve and is arranged between an outer side of the conductor and an inner side of the sleeve, the conductor has a first side recess for forming a radial form-fitting connection between the conductor and the sheath, and the sheath has a second side recess for forming a radial form-fitting connection between the sheath and the sleeve. The invention also relates to a rotating structural assembly for a motor vehicle.

Description

Field of the Invention

[0001] The present invention relates to a connecting device for a rotating structural assembly of a motor vehicle, for electrically connecting a first electrical component disposed in a hollow shaft of the structural assembly to a second electrical component disposed outside the hollow shaft of the structural assembly. Furthermore, the present invention relates to a rotating structural assembly of a motor vehicle. Background Art

[0002] Current attention is focused on rotating structural assemblies for motor vehicles, such as rotors for electric drive motors. Such a rotating structural assembly may, for example, have a hollow shaft in which a first electrical component is disposed. In order to electrically connect this first electrical component to a second electrical component outside the rotor shaft, the hollow shaft is equipped with an electrical interface that must withstand loads caused by rotation, such as centrifugal forces. In the case of a rotor, the first electrical component may have a slip ring module disposed in the rotor shaft, as shown in DE 102021 123 305 A1, for energizing a second electrical component in the form of a rotor winding of the rotor. The rotor shaft may have wire openings through which connection wires are guided. These connection wires are, for example, contact-connected within the rotor shaft by fork-shaped contact elements. Summary of the Invention

[0003] The object of the present invention is to provide an electrically stable and mechanically simple electrical interface for a rotating structural assembly of a motor vehicle that can be easily fastened to a hollow shaft.

[0004] This object is solved according to the invention by a connecting device and a rotating structural assembly having the features of the respective independent claims. Advantageous embodiments of the present invention are the subject matter of the dependent claims, the description, and the drawings.

[0005] The connecting device for a rotating structural assembly for a motor vehicle according to the invention serves to electrically connect a first electrical component arranged in a hollow shaft of the structural assembly to a second electrical component arranged outside the hollow shaft of the structural assembly. The connecting device has a sleeve for arrangement in a radial lead-through of the wall of the hollow shaft and a linear conductor, with the conductor being arranged locally in the sleeve, wherein conductor ends protruding at the edge of the sleeve form contact areas for contacting the first and second electrical components. Furthermore, the connecting device has an electrically insulating jacket which surrounds the conductor at least within the sleeve and is arranged between the outer side of the conductor and the inner side of the sleeve. In order to subject the connecting element to the operating loads caused by rotation, the conductor has a first recess for forming a positive-locking connection between the conductor and the jacket, and the jacket has a second recess for forming a positive-locking connection between the jacket and the sleeve.

[0006] Furthermore, the invention relates to a rotating structural assembly for a motor vehicle, having: a hollow shaft including at least one radial lead-through; a first electrical component arranged within the hollow shaft; a second electrical component arranged outside the hollow shaft; and at least one connecting device according to the invention. Here, the sleeve of the connecting device is arranged in the lead-through, a first conductor end of the conductor arranged in the hollow shaft is electrically connected to the first component, and a second conductor end of the conductor arranged outside the hollow shaft is electrically connected to the second component. Preferably, the rotating structural assembly is configured as a rotor of a separately excited electric motor for a motor vehicle and additionally has a rotor core and an energizable rotor winding, with the hollow shaft being guided through the rotor core and the hollow shaft being non-rotatably connected to the rotor core, wherein the first electrical component at least partially includes a device for energizing the rotor winding of the rotor and the second electrical component includes the rotor winding. The separately excited electric motor can be, for example, a drive motor of a motor vehicle.

[0007] At high rotational speeds of the electric machine, the rotating structural assembly is subjected to high mechanical loads caused by centrifugal forces. In particular, the electrical interface between the inside and the outside of the hollow shaft must be particularly mechanically stable here, because in the event of a loss of electrical connection between the two components, the failure of the electric machine will occur. The electrical interface is formed by the at least one connecting device. The connecting device is a one-piece connecting piece having a sleeve, a conductor and a jacket. In particular, the structural assembly has two connecting devices, wherein the first connecting device connects the positive poles of the electrical components and the second connecting device connects the negative poles of the electrical components, and wherein the connecting devices are arranged symmetrically with respect to the axis of rotation of the hollow shaft. That is, two identically shaped connecting devices are arranged radially opposite each other at the same axial height of the hollow shaft. The hollow shaft has at least one radially oriented, i.e., perpendicular to the axis of rotation, passage. The passage can be configured, for example, as a hole or through-hole in the wall of the hollow shaft and has a circular cross-section.

[0008] The sleeve of the connecting device is arranged in the passage, wherein the sleeve is mechanically connected to the wall of the hollow shaft. The sleeve can be arranged, for example, press-fitted in the passage. Particularly preferably, the sleeve is screwed to the wall. For this purpose, the sleeve and the passage have corresponding threads. The sleeve is an elongated, for example, partially cylindrical hollow body and is made of a material with high strength, such as steel. For example, the sleeve can be configured as a hollow screw having a screw head including an external drive device that can be arranged outside the hollow shaft, and the external drive device is in particular a hexagon head for screwing the sleeve into the passage of the hollow shaft. To assemble the connecting device on the hollow shaft, the hollow screw is, for example, screwed into the passage from the outside and tightened by means of the screw head using a corresponding tool.

[0009] The sleeve encloses an electrical conductor, such as an electrical wire piece, here. The electrical wire piece can be made of copper, for example. The conductor projects from the sleeve on both sides, so that a first conductor end projecting on a first edge of the sleeve is arranged inside the hollow shaft and can be brought into electrical contact with a first electrical component there, and a second conductor end projecting on a second edge of the sleeve is arranged outside the rotor shaft and can be brought into electrical contact with a second electrical component there.

[0010] The conductor is hereby fastened in the sleeve by means of a sheath and is additionally electrically insulated with respect to the sleeve. The sheath can for example consist of an injectable plastic. The sheath is in particular formed by injection-molding the conductor in the sleeve, whereby an interlocking or material-locking connection is additionally formed between the conductor and the sleeve. The sheath can hereby also protrude at the edge of the sleeve and thus project locally from the sleeve, wherein the conductor ends project on both sides on the sheath in order to form contact areas. The protrusion of the insulator in the form of an insulating sheath can be adjusted arbitrarily in order to hereby provide a leakage path sufficient according to the rated voltage. When selecting a viscous injection material with small shrinkage characteristics, the connection can also be oil-sealed in order to prevent the cooling medium for cooling the rotating assembly from entering from the outside to the inside or from the inside to the outside. The mechanical connection between the conductor and the sleeve by means of the sheath is at least partially formed by undercuts. The conductor has a first undercut, which is for example formed by a tapered region of the conductor arranged in the sleeve. The conductor thus has a reduced cross-section in the tapered region. Around this tapered region, the injectable plastic can flow, harden and fix the conductor in the radial direction there. The conductor is hereby prevented from slipping out of the sheath due to centrifugal force by the first undercut.

[0011] Additionally, the sheath is positively connected to the sleeve by means of a second undercut in order to prevent the sheath and thus the conductor from slipping out of the sleeve due to centrifugal force. The second undercut can for example be configured as an overhanging region protruding beyond a first edge of the sleeve, which overhanging region covers the first edge of the sleeve. By means of this overhanging region, the first edge of the sleeve locks the relative movement between the sleeve and the sheath in the radial centrifugal force direction. The second undercut can be formed particularly simply when injection-molding the conductor in the sleeve.

[0012] The embodiments provided for the connecting device according to the invention and their advantages correspondingly apply to the rotating assembly according to the invention. Description of the Drawings

[0013] Other features of the invention result from the claims, the drawings and the description of the drawings. The features and feature combinations described above in the description and then described in the description of the drawings and / or shown individually in the drawings can not only be used in the combinations given respectively, but also in other combinations or individually.

[0014] The invention is now explained in detail with the aid of preferred embodiments and with reference to the drawings. In the drawings:

[0015] Figure 1 Schematic view showing a top view of an electrical connecting device for a rotating assembly;

[0016] Figure 2Schematic side view showing an electrical connection device; and

[0017] Figure 3 Schematic cross-sectional view showing the connection device provided in the wall of the hollow shaft of the rotating structural assembly. Detailed description of the invention

[0018] In the drawings, identical and functionally identical elements are provided with the same reference numerals.

[0019] Figure 1 and Figure 2 Schematic view showing an electrical connection device 1 of a rotating structural assembly for a motor vehicle, which can be provided in the wall 2 of a hollow shaft 3 as shown in Figure 3 . The hollow shaft 3 can be a rotor shaft, so that the rotating structural assembly is the rotor of an electric drive motor of a motor vehicle. A guiding passage 6 is provided in the hollow cylindrical wall 2 extending along the rotation axis 4 of the hollow shaft 3 and oriented in the radial direction 5 perpendicular to the rotation axis 4. A first electrical component, such as an energizing device (not shown here), can be provided in the hollow shaft 3, and the first electrical component is electrically connected to a second component outside the hollow shaft 3, such as a winding conductor of a rotor winding, through at least one connection device 1.

[0020] The connection device 1 has a sleeve 7, which is arranged in the guiding passage 6 and fastened there. The sleeve 7 can be, for example, a hexagonal hollow screw including a shaft 8 and a screw head 9. The shaft 8 can have an external thread 10 through which the sleeve 7 can be screwed into the guiding passage 6 from the outside. The screw head 9 is arranged outside the hollow shaft 3 and exposed on the wall 2. An electrical conductor 11, such as a copper wire, is guided through the sleeve 7 in the radial direction 5, wherein a first conductor end 12 protrudes on a first edge 13 of the sleeve 7 and extends into the interior 14 of the hollow shaft 3. The first conductor end 12 forms a first contact point for making contact with the first component. A second conductor end 15 protrudes on a second edge 16 of the sleeve 7 and thus extends into the environment 17 of the hollow shaft 3. The second conductor end 15 forms a second contact point for making contact with the second component.

[0021] The conductor 11 is mechanically connected to the sleeve 7 via the sheath 18. The sheath 18 is made of an electrically insulating material and electrically insulates the conductor 11 from the metallic sleeve 7. In particular, the sheath 18 is injected into the free space between the outer side of the conductor 11 and the inner side of the sleeve 7 and thus connects the sleeve 7 and the conductor 11 in a material-locking manner. Additionally, the sheath 18 and the conductor 11 as well as the sheath 18 and the sleeve 7 are form-fittingly connected in the radial direction 5 in order to prevent the sheath 18, the sleeve 7 and the conductor 11 from disengaging from one another due to centrifugal forces. For this purpose, the conductor 11 has a first undercut 19 in the form of a tapered region 20. The electrically insulating material flows around the tapered region 20 when being injected into the sleeve 7 and thus forms a form fit with the conductor 11. Furthermore, the sheath 18 has a second undercut 21 in the form of a projection 22. The projection 22 covers the first edge 13 of the sleeve 7 and thus remains in the sleeve 7 when centrifugal forces act on the sheath 18.

Claims

1. Connecting device (1) for a rotating structural assembly of a motor vehicle, for electrically connecting a first electrical component arranged in a hollow shaft (3) of the structural assembly to a second electrical component arranged outside the hollow shaft (3) of the structural assembly, the connecting device having: - a sleeve (7) for being arranged in a radial guide-through (6) of a wall (2) of the hollow shaft (3), - a linear conductor (11), which is locally arranged in the sleeve (7), wherein, conductor ends (12, 15) protruding at edges (13, 16) of the sleeve (7) form contact areas for making contact with the first electrical component and the second electrical component, - an electrically insulating jacket (18), which at least within the sleeve (7) surrounds the conductor (11) and is arranged between the outside of the conductor (11) and the inside of the sleeve (7), wherein, in order to enable the connecting element (1) to withstand the operating loads caused by rotation, the conductor (11) has a first undercut (19) for forming a positive-locking connection in the radial direction between the conductor (11) and the jacket (18), and the jacket (18) has a second undercut (21) for forming a positive-locking connection in the radial direction between the jacket (18) and the sleeve (7).

2. Connecting device (1) according to claim 1, characterized in that, the outside of the sleeve (7) has an external thread for screwing into the guide-through (6) of the hollow shaft (3).

3. Connecting device (1) according to claim 2, characterized in that, the sleeve (7) is configured as a hollow screw, in particular a hexagonal hollow screw, which has a screw head (9) that can be arranged outside the hollow shaft (3) for screwing the sleeve (7) into the guide-through (6) of the hollow shaft (3).

4. Connecting device (1) according to one of the preceding claims, characterized in that, the jacket (18) is formed by injection into the sleeve (7) and injection-molding around the conductor (11), thereby forming at least one material-locking connection between the conductor (11) and the sleeve (7).

5. Connecting device (1) according to one of the preceding claims, characterized in that, the second undercut (21) is configured as an overhanging region (22) protruding beyond an edge (13) of the sleeve (7) that can be arranged inside the hollow shaft (3), and the overhanging region covers this edge (13) of the sleeve (7).

6. Connecting device (1) according to one of the preceding claims, characterized in that, the first undercut (19) is formed by a tapered region of the conductor (11) arranged within the sleeve (7).

7. Rotating structural assembly for a motor vehicle, having: - a hollow shaft (3) including at least one radial guide-through (6), - a first electrical component arranged within the hollow shaft (3), - a second electrical component arranged outside the hollow shaft (3), and - at least one connecting device (1) according to one of the preceding claims, wherein, The sleeve (7) is arranged in the at least one lead-through portion (6), a first conductor end (12) of the conductor (11) arranged in the hollow shaft (3) is electrically connected to the first component, and a second conductor end (15) of the conductor (11) arranged outside the hollow shaft (3) is electrically connected to the second component.

8. The rotating structural assembly according to claim 7, characterized in that the structural assembly has two connecting devices (1), wherein the first connecting device (1) connects the positive poles of the respective electrical components and the second connecting device (1) connects the negative poles of the respective electrical components, and wherein the connecting devices (1) are arranged symmetrically with respect to the axis of rotation (4) of the hollow shaft (3).

9. The rotating structural assembly according to claim 7 or 8, characterized in that the at least one lead-through portion (6) in the hollow shaft (3) has an internal thread.

10. The rotating structural assembly according to any one of claims 7 to 9, characterized in that the rotating structural assembly is configured as a rotor of a separately excited electric motor for a motor vehicle and additionally has a rotor core and an energizable rotor winding, the hollow shaft (3) is guided through the rotor core, and the hollow shaft (3) is non-rotatably connected to the rotor core, wherein the first electrical component at least partially includes an energizing device for the rotor winding of the rotor and the second electrical component includes the rotor winding.

Images