Star disk for rotor of current-excited electric machine, rotor, motor vehicle, and method for producing star disk

Abstract

The invention relates to a star-shaped disc (10) for a rotor of a current-excited electric machine, comprising a separately produced connection ring (18), which comprises a plurality of contact elements (12, 14, 16) embedded in a first plastic material (20), which contact elements are provided for connection to a respective rotor winding of the rotor or to a slip ring of the current-excited electric machine, the connection ring is held on the main body (22) of the star-shaped disc (10) by means of injection-molding by means of a second plastic material (26). The invention also relates to a rotor, to a motor vehicle having an electric traction motor, and to a method for producing a star-shaped disc for a rotor.

Description

Technical Field

[0001] The present invention relates to a star disk for a rotor of a current-excited motor, a rotor, a motor vehicle having an electric traction motor, and a method for manufacturing a star disk for a rotor. Background Technology

[0002] A star disk for a rotor of a separately excited synchronous motor is known from DE 102021122066 A1. At least the surface of the star disk is made of plastic, and busbars are embedded in the plastic, each busbar electrically connecting one pole shoe or slot of the star disk to an adjacent pole shoe or slot, and each busbar has a contact element at each end for receiving winding wires, the contact element protruding from the surface of the star disk. Summary of the Invention

[0003] The objective of this invention is to provide a solution that enables the corresponding contact elements of the rotor to be arranged, in a particularly simple and precise manner, relative to the rotor windings of the rotor to be in contact with the contact elements.

[0004] According to the present invention, this task is accomplished by the technical solution of the independent claim. Other possible designs of the invention are disclosed in the dependent claims, the specification, and the drawings. Features, advantages, and possible designs set forth within the scope of the specification for one of the technical solutions of the independent claim can be at least similarly regarded as features, advantages, and possible designs of corresponding technical solutions of other independent claims and any possible combinations thereof, and, if necessary, in combination with one or more dependent claims.

[0005] This invention relates to a star disk for the rotor of a current-excited motor. Current-excited motors are particularly useful as traction motors for motor vehicles. Traction motors are configured to drive motor vehicles by means of electrical energy. Current-excited motors can also be called separately excited motors. Current-excited motors are particularly useful as current-excited synchronous motors. The rotor of a current-excited motor typically comprises a rotor body with multiple pole shoes. Multiple rotor windings are wound around these pole shoes of the rotor body. To enable the rotor windings to be rotated for winding in a particularly simple and precise manner on the respective end faces of the rotor body, it is generally stipulated in current-excited motors that a star disk is arranged on each of the respective end faces of the rotor body. This star disk is designed to be particularly robust and, in particular, has rounded edges, thereby allowing the rotor windings to be rotated particularly easily around the star disk during winding.

[0006] Furthermore, current-excited motors typically include corresponding contact elements by which the rotor windings of the rotor can be interconnected and conductive contact between the rotor windings and the power source can be established (usually via slip rings). To enable particularly simple, reliable, and precise positioning of the contact elements relative to the rotor windings to be connected to the contact elements, it is specified that the star disk has separately manufactured terminal rings comprising multiple contact elements embedded in a first plastic material. These contact elements are configured for connection with the corresponding rotor windings of the rotor or with the slip rings of the current-excited motor. For example, crimp forks and / or solder tabs can be embedded in the first plastic material as contact elements. Crimp forks are configured for connection to the corresponding rotor windings of the rotor via crimping. Solder tabs are configured for conductive connection to the slip rings via welding. Alternatively, the corresponding contact elements can be configured for connection to the rotor windings or slip rings via threaded connections and / or plug-in connections. The terminal rings can be manufactured separately, for example, as so-called pre-molded parts. The terminal block may include wires embedded in a first plastic material, by means of which at least some of the contact elements of the terminal block are electrically connected to each other for interconnection of rotor windings.

[0007] Furthermore, the terminal rings in the star-shaped disk are specified to be held in place on the base of the star-shaped disk by injection molding encapsulation using a second plastic material. Therefore, separately manufactured terminal rings can be integrated into or fixed to the base of the star-shaped disk by injection molding encapsulation using the second plastic material. Since the contact elements are already fixed relative to each other in the separately manufactured terminal rings, it is possible to ensure that even when the terminal rings and the base are fixedly connected by injection molding encapsulation using the second plastic material, the contact elements integrated into the star-shaped disk remain precisely positioned relative to each other and fixedly held on the star-shaped disk. This effectively avoids the risk of relative movement of the contact elements relative to the base of the star-shaped disk in the motor, especially during operation. If the contact elements are directly embedded into the second plastic material during the manufacture of the star-shaped disk without being embedded in the first plastic material, the contact elements may tilt or move relative to each other during the casting encapsulation using the second plastic material, thus the contact elements are no longer precisely oriented relative to each other. Because the terminal rings are manufactured separately, the manufacturing method can be tailored to ensure that the contact elements remain precisely oriented relative to each other when embedded in the first plastic material, without tilting or moving relative to each other. When encapsulating the terminal rings thus manufactured using a second plastic material via injection molding, the subsequent process can be tailored to optimize the manufacturing of the star disk, particularly the manufacturing of the substrate or the casting encapsulation of the substrate using the second plastic material. In this step-manufactured star disk, the risk of movement of the contact elements relative to each other or relative to the substrate of the star disk is particularly low, resulting in particularly precise orientation of the contact elements relative to each other within the star disk. Because the contact elements are oriented particularly precisely relative to each other and relative to the substrate of the star disk, the contact elements can be connected and electrically contacted with the correspondingly assigned rotor windings particularly easily. The first plastic material can be different from the second plastic material, or the same plastic material can be used as both the first and second plastic material. The first and / or second plastic materials are, in particular, thermosetting or thermoplastic plastics.

[0008] In one possible extension of the invention, the base of the star-shaped disk and the terminal ring are injection-molded or cast together using a second plastic material. For example, the base of the star-shaped disk can be a steel base. This steel base can be manufactured, for example, as a forging. Therefore, the terminal ring and the base of the star-shaped disk can be injection-molded or cast together using a second plastic material. Thus, the base and the terminal ring are held together by means of the second plastic material. Alternatively, the terminal ring may rest directly against the base, and the base and the terminal ring are at least partially encapsulated by the second plastic material, thereby holding the terminal ring on the base of the star-shaped disk. Since the base and the terminal ring are manufactured separately, by at least partially encapsulating the base and the terminal ring with the second plastic material, the base and the terminal ring can then be precisely oriented relative to each other and fixed relative to each other in that precisely oriented position. Therefore, it can be ensured that the terminal ring is held particularly reliably on the base of the star-shaped disk.

[0009] Instead of a star-shaped disk being designed to include a separately manufactured substrate, which is injection-molded or cast onto the terminal ring using a second plastic material, the substrate of the star-shaped disk can be manufactured by injection molding or casting onto the terminal ring. Therefore, the corresponding pole shoes of the star-shaped disk can be injection-molded or cast onto the terminal ring using the second plastic material. Furthermore, the yoke of the star-shaped disk substrate can also be injection-molded or cast onto the terminal ring. This means that the substrate can be made entirely of the second plastic material by placing the terminal ring in an injection mold or casting mold and injection-molding or casting the substrate onto the terminal ring using the second plastic material.

[0010] The invention also relates to a rotor comprising a rotor base and at least one star disk, as described in conjunction with the star disk according to the invention, arranged at one end of the rotor base. Specifically, the rotor has a star disk on each end face of the rotor base. The rotor base can be configured as a lamination assembly. The rotor windings of the rotor, wound around the rotor base, rotate around the respective star disks. Furthermore, it is specified that the respective rotor windings of the rotor are connected to and thereby electrically contacted with contact elements embedded in the terminal rings, thus electrically interconnecting the rotor windings with each other. Because the contact elements are oriented and positioned with particular precision relative to the base of the star disks, the rotor windings can be connected to the contact elements particularly easily. Because the terminal rings are precisely oriented relative to the base of the star disks, the terminal rings have a precise orientation relative to the rotor windings of the rotor. This ensures that the rotor windings are electrically interconnected with each other via the terminal rings according to a predetermined interconnection.

[0011] The present invention also relates to a motor vehicle having an electric traction motor, particularly a current-excited synchronous motor, the synchronous motor comprising a stator and a rotor rotatable relative to the stator about a rotation axis, wherein the rotor is constructed according to the rotor configuration described herein. Because the rotor includes the star-shaped disk described herein, the risk of relative movement of the rotor's connecting rings relative to the base of the star-shaped disk is particularly low, thereby ensuring reliable interconnection of the rotor windings of the electric traction motor rotor by means of the connecting rings.

[0012] The present invention also relates to a method for manufacturing a star-shaped disk for use in rotors, particularly electric traction motors for motor vehicles. In this method, a terminal ring is manufactured by embedding corresponding contact elements into a first plastic material. Here, the contact elements are embedded into the first plastic material by injection molding or casting. Subsequently, the terminal ring thus manufactured is fixed to the base of the star-shaped disk by injection molding using a second plastic material. This integration of the terminal ring into the star-shaped disk minimizes the risk of relative movement of the corresponding contact elements relative to each other and relative to the base of the star-shaped disk. Therefore, the star-shaped disk is manufactured in a two-stage plastic casting or injection molding process.

[0013] In one possible extension of the invention, it is specified that, in order to manufacture the connector ring, contact elements are positioned relative to each other in a mold by means of at least one clamping device, while the contact elements are encapsulated or injection molded using a first plastic material. The at least one clamping device allows for particularly precise orientation of the contact elements relative to each other and prevents movement or tilting of the contact elements relative to each other during injection molding encapsulation using the first plastic material. After the contact elements are fixed relative to each other by means of the first plastic material, the at least one clamping device can be released, and if necessary, the connector ring opening held open by the clamping device can be closed, for example, by casting using the first plastic material.

[0014] In another possible design of the invention, the connector ring is disposed on the base of the star-shaped disk and is pressure-molded or cast together with the star-shaped disk using a second plastic material. The base of the star-shaped disk may be made of, for example, a metal material. Therefore, in order to secure the connector ring to the base of the star-shaped disk, the base of the star-shaped disk and the connector ring are at least partially injection-molded or cast together using the second plastic material, thereby holding the connector ring on the base of the star-shaped disk by means of the second plastic material after the second plastic material has hardened.

[0015] Based on the casting and encapsulation of the connector ring and the substrate by means of a second plastic material, the second plastic material can form a side recess, through which the substrate of the star disk and the connector ring are fixed in their positions relative to each other.

[0016] In this case, in another design of the invention, the base of the star-shaped disk may have a central opening into which the axially projecting flange of the connector ring is inserted. Thus, the connector ring can be radially centered relative to the base. The axially projecting flange can therefore be positioned, with its radially outer surface, on, particularly circumferentially, the inner wall of the base defining the radially inward opening of the star-shaped disk. Therefore, the connector ring is oriented with particular precision relative to the base and can subsequently be held in this position on the base by injection molding or casting encapsulation using a second plastic material. Inserting the flanged connector ring into the opening of the base ensures that the connector ring is precisely positioned relative to the base before being fixed to the base by casting or injection molding encapsulation using a second plastic material.

[0017] In another possible embodiment of the invention, the base of the star-shaped disk is forged from a metallic material, particularly steel. Forging the base allows for the particularly simple and rapid manufacture of a base with precise contours.

[0018] Further features of the invention can be derived from the claims, drawings, and description of the drawings. The features and combinations thereof mentioned above in the specification, as well as the features and combinations thereof shown separately in the description of the drawings and / or the drawings below, may be used not only in the given combinations, but also in other combinations or individually, without departing from the scope of the invention. Attached Figure Description

[0019] The attached image is as follows:

[0020] Figure 1 A schematic perspective view of the wiring ring is shown;

[0021] Figure 2 A schematic top view of a connector ring is shown, which is mounted on the base of a star-shaped disk; and

[0022] Figure 3 A schematic top view of the base of the junction box and the star disk is shown, which are encapsulated together by injection molding or casting with plastic material.

[0023] In the accompanying drawings, identical and functionally identical elements are given the same reference numerals. Detailed Implementation

[0024] Figure 3 The star-shaped disk 10 of the rotor of a current-excited motor for motor vehicles is shown. Figure 1 and Figure 2The diagram shows the corresponding intermediate stages in the manufacture of the star disk 10. The star disk 10 is provided for mounting onto the end face of the rotor base of the rotor. Thus, the corresponding rotor windings of the rotor, wound around the corresponding pole shoes of the rotor base, can rotate around the star disk 10 arranged on the end side of the rotor base for winding. The corresponding rotor windings of the rotor are electrically interconnected with each other and make electrical contact with the slip rings of the motor for energizing the corresponding rotor windings. For this purpose, the star disk 10 has a plurality of contact elements 12, some of which are currently configured as crimp forks 14 and others as solder tabs 16. The crimp forks 14 are provided for crimping with the corresponding rotor windings of the rotor, thereby interconnecting the rotor windings with each other. In particular, the crimp forks 14 are connected to each other by means of corresponding conductive connections for interconnecting the rotor windings. The crimp forks 14 can be configured to be tin-plated. The solder tabs 16 are provided for electrical contact with the slip rings of the rotor. The solder tabs 16 can be provided as small pieces made of solder, especially hard solder or soft solder.

[0025] To manufacture the star-shaped disk 10, it is stipulated that the first step is to manufacture... Figure 1 The terminal ring 18 is shown in the figure. To manufacture the terminal ring 18, the contact elements 12 are oriented relative to each other, for example, by means of at least one clamping device, and then the contact elements 12 are partially embedded in a first plastic material 20. For this purpose, the contact elements 12 can be encapsulated by casting or injection molding using the first plastic material 20. The terminal ring 18 thus manufactured (which is a pre-injection molded part) is then placed onto the base 22 of the star disk 10, as shown. Figure 2 As shown. In the current specification, the base 22 is manufactured as a forging made of metallic material. The base 22 has a central annular opening 24, into which a flange projecting axially from the connector 18 is at least partially inserted. Thus, by having the outer surface of the radially outwardly defining flange of the connector 18 abut against the inner wall of the radially inwardly defining opening 24 of the base 22 over its entire circumference, the connector 18 is radially centered relative to the base 22. Subsequently, the connector 18 and the base 22 are injection-molded or cast together using a second plastic material 26, thereby manufacturing as... Figure 3The star disk 10 is shown. Specifically, in the current specification, the base 22 of the star disk 10 is completely surrounded by a terminal ring 18 and a second plastic material 26. At least the contact elements 12 of the terminal ring 18 are at least partially free of plastic material, enabling particularly simple and reliable electrical contact between the contact elements 12 and the rotor windings or slip rings. The star disk 10 thus comprises a base 22 and a terminal ring 18 manufactured separately from the base 22, the base and the terminal ring being together encapsulated by casting or injection molding with the second plastic material 26, thereby holding the terminal ring 18 on the base 22 and fixing it in its relative position to the base 22 after the second plastic material 26 has hardened. The star disk 10 is configured to allow the poles of the rotor to contact each other and, via the terminal rings 18, the slip rings.

[0026] If the terminal ring 18 is not held to the base 22 of the star disk 10 by the second plastic material 26, the mobility of the terminal ring 18 relative to the star disk, which is constructed separately from the terminal ring 18, may result in high positional tolerances at the contacts of the crimp fork and the rotor winding, as well as between the solder tab 16 and the slip ring, which is detrimental to high process reliability at contact. If the contact elements 12 are to be directly integrated into the insulation of the star disk and thus into the second plastic material 26, these contact elements 12 may not be able to be held in place during injection molding, or may only be held in place at very high technical cost. The risk during injection molding is that the contact elements 12 may drift due to the injection pressure and may not be able to maintain a minimum distance from the base 22, which is critical for electrical breakdown strength. To overcome these disadvantages, in the star disk 10 shown in the figure, it is specified that the contact elements 12 (which are specifically constructed as copper contact bridges) are integrated into a pre-molded part, which is the terminal ring 18. The terminal ring 18, together with the base 22 of the star disk 10, is injection molded and encapsulated using an electrically insulating second plastic material 26. By manufacturing the star disk 10 in such a step-by-step manner, movement of the contact element 12 is avoided during the injection molding of the terminal ring 18 using the second plastic material 26. Nevertheless, the anti-rotational and fixed positioning of the contact element 12 relative to the rotor winding is still ensured. This results in particularly high process reliability when the crimp fork 14 is connected to the rotor winding.

[0027] In summary, the present invention demonstrates how a star disk 10 with a fixed injection terminal ring 18 can be provided.

[0028] List of reference numerals

[0029] 10 star-shaped disks

[0030] 12 contact elements

[0031] 14 crimp fork

[0032] 16 solder sheets

[0033] 18 connectors

[0034] 20 First Plastic Materials

[0035] 22-star disk base

[0036] 24 openings

[0037] 26 Second Plastic Material

Claims

1. Star disc (10) for a rotor of a current excited electric machine, the star disc having a separately manufactured connection ring (18) which comprises a plurality of contact elements (12, 14, 16) embedded in a first plastics material (20), which are provided for connection with corresponding rotor windings of the rotor or with a slip ring of the current excited electric machine, and which are held on a base body (22) of the star disc (10) by injection-moulding encapsulation by means of a second plastics material (26).

2. Star wheel (10) according to claim 1, characterized in that The base body (22) of the star disc (10) and the connection ring (18) are together injection-moulding encapsulated or cast encapsulated by means of the second plastics material (26).

3. Rotor comprising a rotor base body and at least one star disc (10) according to one of the preceding claims, which is arranged on an end side of the rotor base body, the rotor windings of the rotor wound around the rotor base body being diverted around the star disc.

4. Motor vehicle having an electric traction electric machine, the traction electric machine comprising a stator and a rotor according to claim 3, which is rotatable relative to the stator around an axis of rotation.

5. Method for manufacturing a spider (10) for a rotor, wherein The connection ring (18) is manufactured by embedding the corresponding contact elements (12, 14, 16) in a first plastics material (20) and subsequently fixing the connection ring (18) on a base body (22) of the star disc (10) by injection-moulding encapsulation by means of a second plastics material (26).

6. The method of claim 5, wherein, For manufacturing the connection ring (18), the contact elements (12, 14, 16) are positioned relative to one another in a mould by means of at least one pressing device, while the contact elements (12, 14, 16) are cast encapsulated or injection-moulding encapsulated by means of the first plastics material (20).

7. The method according to claim 5 or 6, characterized in that, The connection ring (18) is placed on the base body (22) of the star disc (10) and is injection-moulding encapsulated or cast encapsulated by the second plastics material (26) together with the star disc (10).

8. The method of claim 7, wherein, The base body (22) of the star disc (10) has a central opening (24) into which an axially protruding flange of the connection ring (18) is inserted, whereby the connection ring (18) is centred radially relative to the base body (22).

9. The method according to claim 7 or 8, characterized in that, The base body (22) of the star disc (10) is forged from a metallic material. The base body (22) of the star disc (10) is forged from a metallic material.

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