Connection device for electrical and hydraulic connection of hollow conductors in internally cooled electric motors

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 electric 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 mounting the ends of the electrical hollow conductors (4), a hollow inner cavity (15) connected to the hollow conductors (4) and an electrical connection point (9) for connecting the hollow conductors (4) to an electrical potential. According to the invention, an electrically insulating pipeline (7) is also provided, which is directly or via an adapter (6) connected to the connection piece (2) and is hydraulically connected to the hollow conductors (4).

Description

Technical Field

[0001] The present invention relates to a connection device for electrically and hydraulically connecting a plurality of electrical hollow conductors of an internally cooled electrical machine. Background Art

[0002] Internally cooled electric machines with windings consisting of hollow conductors are known in the prior art. The hollow conductors have through-going channels through which a coolant passes in order to cool the electric machine during operation.

[0003] Hollow conductors known in the prior art are generally in the shape of a hairpin or a pin. The pin or hairpin is usually a rigid winding made of copper, which is inserted into the slots of the motor stator and generates the required magnetic field during the operation of the motor. Another embodiment of an internally cooled motor includes a winding consisting of a thin hollow metal wire that is wound into a coil.

[0004] The hollow conductor has an open end through which a coolant can be fed into the hollow conductor or flow out of the hollow conductor. Known hollow conductors are generally provided with an electrical insulation layer on their outer surface.

[0005] In internally cooled electric machines with hollow conductor windings, the electrical isolation of the hydraulic connection from the supply potential is a technical challenge. For example, EP 3 357 143 A2 describes a known design of a hollow conductor connection in which the electrical isolation is performed by means of ceramic balls. Summary of the invention

[0006] The object of the invention is to provide a connecting device for the electrical and hydraulic connection of a plurality of electrical hollow conductors of an internally cooled electric machine, which allows simple electrical isolation of the hollow conductors from the coolant connection.

[0007] According to the invention, this object is achieved by means of a feature according to claim 1. Further embodiments of the invention are presented in the dependent claims.

[0008] A connection device for electrically and hydraulically connecting an electrical hollow conductor of an internally cooled electric machine is provided, wherein the electrical isolation of the hollow conductor 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 tube, or the like.

[0009] According to one embodiment of the present invention, the connection device comprises a connection piece, by means of which the hollow conductor can be electrically and hydraulically connected, wherein the connection piece has:

[0010] ° one or more interfaces for receiving at least one electrical hollow conductor;

[0011] ° a hollow inner cavity in communication with the hollow conductor; and

[0012] °An electrical connection, especially a terminal, used to connect a hollow conductor to an electrical potential.

[0013] The connection device according to the present invention further comprises an electrically insulating pipeline hydraulically connected to the connection piece and the hollow conductor.

[0014] The pipeline is preferably designed to withstand an internal pressure of at least 60 bar, 80 bar or 100 bar.

[0015] The electrically insulating pipeline can be connected to the hollow conductor connecting piece directly or by means of an adapter. In the embodiment using the adapter, it preferably has a first connection connected to the connecting piece and a second connection connected to the pipeline.

[0016] The adapter can be designed in a tubular shape, for example. The adapter can be made of an electrically insulating material (such as plastic).

[0017] In a variant of the invention, the connection piece can include a section designed as a socket. The electrically insulating line can, for example, be connected directly to the socket of the connection piece. In another embodiment using an additional adapter, the connection piece is detachably mounted to the adapter. The adapter can in this case have an opening in which the socket of the connection piece is mounted.

[0018] The connector can, for example, have a section with one or more interfaces, in particular openings, for connecting the ends of the hollow conductors. The openings are preferably sized such that the ends of the hollow conductors can be inserted into the openings and connected therein in a pressure-resistant and sealed manner, for example by soldering or welding.

[0019] According to a variant, the hollow conductor interface of the connecting piece can be designed as a separate plate-shaped piece which is integrated into the connecting piece in a pressure-resistant and leak-tight manner, for example by soldering or welding.

[0020] The connection device according to the invention, including the electrically insulating line, is preferably accommodated in a connection box. The connection box can have one or more electrical connections and one or more coolant connections. In order to improve mechanical stability, sealing, etc., the connection device can be partially or completely encapsulated with a synthetic resin. The invention also relates to such a connection box.

[0021] The connectors may be made of conductive materials (such as copper), insulating materials (such as plastic), or a combination of conductive and non-conductive materials.

[0022] The connecting piece or the adapter piece (if any) may have an external thread, on which one or more nuts are arranged, by means of which the relevant components can be fixed in or on the housing of the connection box.

[0023] The electrical connection element may, for example, comprise a cable lug to which the electrical phases (U, V, W) can be connected. In principle, any other known type of terminal block may also be used. The electrical connector and the connection element are preferably connected by material joining, for example by soldering.

[0024] The invention also relates to an internally cooled electric machine having a hollow conductor winding and a connecting device with a line made of an electrically insulating material which electrically isolates the hollow conductor from a central coolant connection.

[0025] In the case of a multi-phase electric machine, preferably a separate connection device is provided for each phase. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be explained in detail below with reference to the accompanying drawings, in which:

[0027] Figure 1 A cross-sectional view showing a connecting device for a hollow conductor of an internally cooled electric motor according to a first embodiment of the present invention;

[0028] Figure 2 A cross-sectional view showing a connecting device for a hollow conductor of an internally cooled electric motor according to a second embodiment of the present invention;

[0029] Figure 3 A perspective view showing a connection arrangement for multiple phases of an internally cooled electric machine; and

[0030] Figure 4 An exemplary illustration of a connection box for connecting the hollow conductors of an internally cooled electric machine to the different phases U, V, W and to the coolant circuit is shown. DETAILED DESCRIPTION

[0031] Figure 1 1 shows a cross-sectional view of a connection device 1 for an internally cooled motor winding hollow conductor 4 according to a first embodiment of the present invention. The connection device 1 is mainly used to connect the electrical hollow conductor 4 to the corresponding electrical phases U, V, W and also to connect it hydraulically to the coolant connection 13 (see Figure 3 and Figure 4 ).

[0032] The connection device 1 comprises a connection piece 2 made of a conductive material (e.g. copper), to which a hollow conductor 4 is electrically connected, and an electrically insulating pipe 7 connected to the other side of the connection piece 2. A joint for the pipe 7 is denoted by reference numeral 17, and a corresponding union nut is denoted by reference numeral 10.

[0033] The electrically insulating line 7 is designed as a plastic hose and serves to provide the necessary electrical isolation of the hollow conductor 4 from the hydraulic coolant connection 13. The connecting piece 2 has a hollow interior 15 to which the hollow conductor 4 and the electrically insulating line 7 are hydraulically connected.

[0034] In the embodiment shown, the connection element 2 comprises a terminal block 3 designed as a separate component, which has a plurality of interfaces 14 in the form of openings for receiving the ends of the hollow conductors. Instead of a separate terminal block 3, the connection element 2 can also directly have a fixing part with a plurality of openings for the ends of the hollow conductors. The connection element 2 also comprises an electrical connection 9 or a terminal for connecting a supply potential (e.g. phases U, V, W of a three-phase motor). The terminal can be designed, for example, as a cable lug.

[0035] The connecting member 2 further has an external thread 19 , on which a plurality of nuts 11 are arranged, and the connecting member 2 can be fixed to the housing of the connecting box 12 by means of the nuts.

[0036] The connection device 1 shown provides a very simple and cost-effective way of connecting a plurality of hollow conductors 4 of an internally cooled electric machine to the corresponding electrical phases U, V, W and also connecting them hydraulically to the coolant connection 13 .

[0037] Figure 2 A cross-sectional view of a connection device 1 for an internally cooled motor hollow conductor 4 according to a second embodiment of the present invention is shown, wherein, unlike the first embodiment, an electrically insulating pipe 7 is connected to the connection piece 2 via an additional adapter 6. The adapter 6 accordingly comprises a first joint 16 for connecting to the connection piece 2 and a second joint 17 connected to the pipe 7. The two joints 16, 17 are designed to ensure a tight connection under high pressure. The joints 16, 17 can be designed, for example, as a crimp connection, in particular a cutting ring connection.

[0038] The connection piece 2 has a section designed as a pipe socket 5, to which the electrically insulating line 7 is connected. In the region of the first connection 16, a nut 10 is provided, which produces a crimp connection between the adapter piece 6 and the connection piece 2. A corresponding nut 10 is also provided at the second connection 17 in order to connect the plastic hose 7 to the adapter piece 6. In the case of a softer plastic hose, the end of the hose is stabilized by a pipe insert 8 arranged in the plastic hose 7. In the case of a hard plastic hose, a pipe insert may not be necessary.

[0039] The adapter 6 itself can be made of plastic or metal. An external thread 19 can be provided on the circumference of the adapter 6, and a plurality of nuts 11 are provided on the external thread 19, by means of which the connecting device 1 can be fixed on the housing of the connecting box 12.

[0040] The connection device 1 can be partially or completely encapsulated with synthetic resin. In this case, it is not necessary to mount the connection device 1 to the housing.

[0041] Figure 3 A connection device 1 for multiple phases U, V, W of an internally cooled electric machine is shown, wherein the hollow conductors 4 assigned to a phase are respectively electrically and hydraulically connected to the corresponding connection piece 2. Each of the connection pieces 2 has an electrical connection terminal 9 for the voltage supply of the phase. The electrical connection terminal 9 is omitted for the connection piece 2a of the neutral point.

[0042] The hollow conductors 4 of the individual phases U, V, W are each connected to one of the two hydraulic connections 13 via a separate plastic hose. Figure 3 The hollow conductor 4 of the lower connector is connected to another hydraulic connector 13 through another plastic hose. One of the two hydraulic connectors 13 serves as the inlet of the cooling circuit, and the other serves as its return. The distributor 18 connects one of the hydraulic connectors 13 to the respective connectors 2 of the three phases U, V, and W.

[0043] at last, Figure 4 Also shown is an exemplary illustration of a connection box 12 for the electrical and hydraulic connection of the hollow conductors 4 of the internally cooled electric machine. Figure 2 The connection device 1 shown is located in a connection box 12 and is mounted to the housing of the connection box 12 by means of a nut 11 .

[0044] The connections for the hollow conductors 4 of the phases U, V, W and the corresponding phase terminals are located on the right side of the connection box 12 in the figure (top of the figure). In addition, the connection for the star point can be seen at the bottom right in the figure. The inlet and return connections 13 of the hydraulic cooling circuit are located on the left side of the connection box 12.

Claims

1. A connection device (1) for electrically and hydraulically connecting a plurality of electrical hollow conductors (4) of an internally cooled electric machine, comprising a connection piece (2), by means of which the hollow conductors (4) can be electrically and hydraulically connected, wherein: The connecting member (2) has: o one or more interfaces (14) for mounting the ends of the electrical hollow conductors (4); o a hollow inner cavity (15) in communication with the hollow conductor (4); and o an electrical connection (9) for connecting the hollow conductor (4) to an electrical potential, Its characteristics are: An electrically insulating pipeline (7) is provided which is hydraulically connected to the connecting piece (2) and the hollow conductor (4).

2. The connection device (1) according to claim 1, characterized in that: The electrically insulating pipeline (7) is connected to the connecting piece (2) via an adapter (6), wherein the adapter (6) has a first joint (16) connected to the connecting piece (2) and a second joint (17) connected to the pipeline (7).

3. The connection device (1) according to claim 1, characterized in that: The pipeline (7) is designed as an electrically insulating hose.

4. The connection device (1) according to claim 1, characterized in that: The connecting piece (2) comprises a section which is designed as a pipe base (5), and the electrically insulating pipe (7) or the adapter (6) is connected to the section.

5. The connection device (1) according to claim 3, characterized in that: The hose is a Teflon hose or a PEEK capillary tube.

6. The 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 the ends of the hollow conductor (4), or The connecting piece has an additional plate-shaped piece (3) having one or more openings (14) for connecting the ends of the hollow conductor (4).

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

8. An internally cooled electric machine having a hollow conductor winding and a connecting device (1) for the electrical and hydraulic connection of an electrical hollow conductor (4) according to one of the preceding claims.

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