Connection device for electrically and hydraulically connecting hollow conductors of an internally cooled electrical machine

Abstract

The invention relates to a connection device (1) for electrically and hydraulically connecting a plurality of electrical hollow conductors (4) of an internally cooled electrical machine. The connection device (1) comprises a connection piece (2), by means of which the hollow conductors (4) can be electrically and hydraulically connected. The connection piece (2) has a plurality of connection points (14) for the attachment of ends of the electrical hollow conductors (4), a hollow interior (15), which is connected to the hollow conductors (4), and an electrical connection point (9) for connecting the hollow conductors (4) to an electric potential. According to the invention, an electrically insulating pipe (7) is also provided, which is connected to the connection piece (2) either directly or by means of an adapter element (6) and which is hydraulically connected to the hollow conductor or hollow conductors (4).

Description

[0001] Connection device for the electrical and hydraulic connection of waveguides of an internally cooled electrical machine

[0002] The invention relates to a connecting device for the electrical and hydraulic connection of several electrical waveguides of an internally cooled electrical machine.

[0003] BACKGROUND OF THE INVENTION

[0004] Internally cooled electric machines with a winding formed from waveguides are known from the prior art. The waveguides have a continuous channel through which a coolant is passed to cool the electric machine during operation.

[0005] Waveguides known from the prior art are generally in the form of hairpins or rods (pins). The pins or hairpins are usually rigid winding pieces made of copper that are inserted into slots in the stator of the electrical machine and generate the required magnetic field during operation. Another embodiment of internally cooled electrical machines comprises a winding made of thin hollow wire wound into coils.

[0006] The waveguides have open ends through which a coolant can be fed into or exited from the waveguides. These waveguides are usually provided with an electrically insulating layer on their outer surface.

[0007] In internally cooled electrical machines with waveguide windings, the galvanic isolation of the hydraulic connection from the electrical supply potential represents a particular technical challenge. A known design of a waveguide connection piece, in which the galvanic isolation is achieved by means of a ceramic ball, is described, for example, in EP 3 357 143 A2.

[0008] OBJECT OF THE INVENTION It is an object of the present invention to provide a connection device for the electrical and hydraulic connection of a plurality of electrical waveguides of an internally cooled electrical machine, which allows a simple galvanic isolation of the waveguides from a coolant connection.

[0009] This object is achieved according to the invention by the features specified in claim 1. Further embodiments of the invention emerge from the subclaims.

[0010] A connection device for the electrical and hydraulic connection of the electrical waveguides of an internally cooled electrical machine is proposed, in which the galvanic isolation of the waveguides from the coolant connection is achieved by a pipe made of an electrically insulating material. The electrically insulating pipe can be, for example, a plastic hose, in particular a Teflon hose, a PEEK capillary, or similar.

[0011] According to one embodiment of the invention, the connecting device comprises a connecting piece by means of which the waveguides can be connected electrically as well as hydraulically, wherein the connecting piece: o has one or more interfaces for attaching at least one electrical waveguide; o a hollow interior space which is in communication with the waveguides; and o an electrical connection, in particular a connection terminal, for connecting the waveguides to an electrical potential.

[0012] A connecting device according to the invention further comprises an electrically insulating pipe which is hydraulically connected to the connecting piece and the waveguide(s).

[0013] The pipeline is preferably designed to withstand an internal pressure of at least 60 bar, 80 bar or 100 bar.

[0014] The electrically insulating pipe can be connected to the waveguide connector either directly or via an adapter element. In the case of a design with an adapter element, the adapter element preferably has a first connection to which the connector is connected, and a second connection to which the pipe is connected.

[0015] The adapter element can, for example, be tubular. The adapter element can be made of an electrically insulating material, such as plastic.

[0016] In one variant of the invention, the connector can comprise a section designed as a pipe socket. The electrically insulating pipe can, for example, be connected directly to the pipe socket of the connector. In another embodiment with an additional adapter element, the connector is releasably attached to the adapter element. In this case, the adapter element can have an opening into which the pipe socket of the connector fits.

[0017] The connector can, for example, have a section with one or more interfaces, in particular openings, for connecting the waveguide ends. The openings are preferably dimensioned such that the waveguide ends can be inserted into the openings and connected there in a pressure-tight and leak-tight manner, e.g., by soldering or welding.

[0018] According to a variant, the waveguide interface of the connector can be designed as a separate, plate-shaped element that is integrated into the connector in a pressure-tight and leak-tight manner, e.g. by soldering or welding.

[0019] The connection device according to the invention, including the electrically insulating pipe, is preferably housed in a connection box. The connection box can have one or more electrical connections and one or more coolant connections. To improve mechanical stability, tightness, etc., the connection device can be partially or fully encapsulated with synthetic resin. The present invention also relates to such a connection box.

[0020] The connector can be made of an electrically conductive material, such as copper, an insulating material, such as plastic, or a combination of conductive and non-conductive materials. The connector or, if applicable, the adapter element can have an external thread on which one or more nuts are arranged, with the aid of which the respective component can be fastened in or to a housing of the junction box.

[0021] The electrical connector can, for example, comprise a cable lug to which an electrical phase (U, V, W) can be connected. In principle, any other known type of terminal can also be used. An electrical connection is preferably connected to the connector by a material bond, e.g., by soldering.

[0022] The invention also relates to an internally cooled electrical machine with a waveguide winding and a connecting device with a pipe made of an electrically insulating material, which galvanically separates the waveguides from a central coolant connection.

[0023] In a multi-phase electrical machine, a separate connection device is preferably provided for each phase.

[0024] BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The invention is explained in more detail below with reference to the accompanying drawings. They show:

[0026] Fig. 1 is a sectional view of a connection device for the waveguides of an internally cooled electrical machine according to a first embodiment of the invention;

[0027] Fig. 2 is a sectional view of a connecting device for the waveguides of an internally cooled electrical machine according to a second embodiment of the invention;

[0028] Fig. 3 is a perspective view of a connection device for several phases of an internally cooled electrical machine; and Fig. 4 is an exemplary representation of a connection box for connecting the waveguides of an internally cooled electrical machine to the various phases U, V, W and to a coolant circuit.

[0029] EMBODIMENTS OF THE INVENTION

[0030] Fig. 1 shows a sectional view of a connection device 1 for the waveguides 4 of a winding of an internally cooled electrical machine according to a first embodiment of the invention. The connection device 1 essentially serves to connect the electrical waveguides 4 to an associated electrical phase U, V, W and also to connect them to a coolant connection.

[0031] 13 (see Fig. 3, 4) to be connected hydraulically.

[0032] The connecting device 1 comprises a connecting piece 2 made of an electrically conductive material, such as copper, to which the waveguides 4 are electrically connected, as well as an electrically insulating conduit 7 connected on the other side of the connecting piece 2. The connection for the conduit 7 is designated by reference numeral 17, and an associated union nut by reference numeral 10.

[0033] The electrically insulating pipe 7 is designed as a plastic hose, which ensures the required galvanic isolation of the waveguides 4 from the hydraulic coolant connection 13. The connecting piece 2 has a hollow interior 15, which is hydraulically connected to the waveguides 4 and the electrically insulating pipe 7.

[0034] In the illustrated embodiment, the connecting piece 2 comprises a connection plate 3 designed as a separate component with several connections

[0035] 14 in the form of openings for fastening waveguide ends. Instead of a separate connection plate 3, the connection piece 2 could also simply have a fastening section with openings for the waveguide ends. The connection piece 2 further comprises an electrical connection 9 or a connection terminal for connecting an electrical supply potential (e.g., a phase U, V, W of a three-phase machine). The connection terminal can be designed, for example, as a cable lug. The connection piece 2 further has an external thread 19 on which several nuts 11 are arranged, with which the connection piece 2 can be fastened to the housing of a connection box 12.

[0036] The illustrated connecting device 1 offers a particularly simple and cost-effective way of connecting several waveguides 4 of an internally cooled electrical machine to an associated electrical phase U, V, W and also of hydraulically connecting them to a coolant connection 13.

[0037] Fig. 2 shows a sectional view of a connecting device 1 for the waveguides 4 of an internally cooled electrical machine according to a second embodiment of the invention, in which, in contrast to the first embodiment, the electrically insulating pipe 7 is connected to the connecting piece 2 via an additional adapter element 6. The adapter element 6 accordingly comprises a first connection 16 for connecting the connecting piece 2 and a second connection 17 to which the pipe 7 is connected. Both connections 16, 17 are designed to ensure a tight connection at high pressures. The connections 16, 17 can be designed, for example, as a crimp connection, in particular as a cutting ring connection.

[0038] The connector 2 has a section designed as a pipe socket 5, to which the electrically insulating pipe 7 is connected. A nut 10 is provided in the area of ​​the first connection 16, which creates a crimp connection between the adapter element 6 and the connector 2. A corresponding nut 10 is also provided at the second connection 17 to connect the plastic hose 7 to the adapter element 6. For softer plastic hoses, the hose end is stabilized there by a pipe insert 8, which is arranged in the plastic hose 7. For rigid plastic hoses, a pipe insert may not be required.

[0039] The adapter element 6 itself can be made of plastic or metal. An external thread 19 can be provided on the circumference of the adapter element 6, on which nuts 11 are arranged, with which the connection device 1 can be attached to the housing of a junction box 12. The connection device 1 can be partially or completely encapsulated with synthetic resin. In this case, attachment of the connection device 1 to the housing can be omitted.

[0040] Fig. 3 shows a connection device 1 for multiple phases U, V, W of an internally cooled electrical machine, in which the waveguides 4 assigned to a specific phase are each electrically and hydraulically connected to a corresponding connection piece 2. Each of the connection pieces 2 has an electrical connection terminal 9 for the voltage supply of a phase. The electrical connection terminal 9 is omitted for the connection piece 2a of the star point.

[0041] The waveguides 4 of the individual phases U, V, and W are each connected to one of the two hydraulic connections 13 via a separate plastic hose. The waveguides 4 assigned to the star point (see Fig. 3, lower connection) are connected to the other hydraulic connection 13 via another plastic hose. One of the two hydraulic connections 13 serves as the supply line, the other as the return line of the cooling circuit. A distributor 18 connects one of the hydraulic connections 13 to the individual connection pieces 2 of the three phases U, V, and W.

[0042] Finally, Fig. 4 shows an exemplary representation of a connection box 12 for the electrical and hydraulic connection of the waveguides 4 of an internally cooled electrical machine. The connection devices 1 shown in Fig. 2 are located within the connection box 12 and are fastened to the housing of the connection box 12 by means of nuts 11.

[0043] On the right side of the connection box 12 in the image are the connections for the waveguides 4 of phases U, V, and W and the corresponding phase terminals (top in the image). The connection for the star point can also be seen in the bottom right of the image. On the left side of the connection box 12 are the supply and return connections 13 of the hydraulic cooling circuit.

Claims

AMENDED CLAIMS received by the International Bureau on 11 December 2023 (11.12.2023) 1. A connecting device (1) for electrically and hydraulically connecting a plurality of electrical waveguides (4) of an internally cooled electrical machine, comprising a connecting piece (2) with which the waveguides (4) can be electrically and hydraulically connected, wherein the connecting piece (2): o one or more interfaces (14) for attaching ends of the electrical waveguides (4); o a hollow interior (15) which is connected to the waveguides (4); and o an electrical connection (9) for connecting the waveguides (4) to an electrical potential, characterized in that - an electrically insulating pipe (7) is provided which is hydraulically connected to the connecting piece (2) and the waveguide(s) (4); - the connecting piece (2) comprises a section designed as a pipe socket (5), - an adapter element (6) is provided which has a first connection (16) to which the pipe socket of the connecting piece (2) is connected, and a second connection (17) to which the electrically insulating pipe (7) is connected; - and that the first terminal (16) and the second terminal (17) are designed as a crimp connection.

2. Connecting device (1) according to claim 1, characterized in that the pipe (7) is designed as an electrically insulating hose.

3. Connecting device (1) according to claim 2, characterized in that the hose is a Teflon hose or a PEEK capillary.

4. Connecting device (1) according to one of the preceding claims, characterized in that the connecting piece (2) has one or more openings (14) for connecting ends of the waveguides (4) or an additional plate-shaped element (3) with one or more openings (14) for connecting ends of the waveguides (4).

5. Connecting device (1) according to one of the preceding claims, characterized in that the connecting piece (2) or the adapter element (6) has an external thread (19).

6. Internally cooled electrical machine with a waveguide winding and a connecting device (1) for electrically and hydraulically connecting the electrical waveguides (4) according to one of the preceding claims.

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