Sandwich-type connection device for connecting the hollow conductors of an internally cooled electric machine and electric machine comprising a connection device of this type

Abstract

The invention relates to a connection device (1) for electrically and hydraulically connecting electrical hollow conductors (17) of an internally cooled electric machine (23), comprising an electrically conductive connection part (2) with one or more hollow conductor connections (6), a side part (24) arranged on one side of the connection part (2), and a seal (5) arranged between the connection part (2) and the side part (24). According to the invention, at least two coolant channels (16) are integrated in the stack, via which a coolant can be fed into the hollow conductor (17) or coolant flowing out of the hollow conductors (17) can be collected.

Description

[0001] Connection device in sandwich technology for connecting waveguides of an internally cooled electrical machine and electrical machine with such a connection device

[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] Various designs of internally cooled electrical 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 electrical machine during operation.

[0005] The winding of conventional electrical machines typically consists of a thin hollow wire wound into coils. In other designs, the winding comprises rigid waveguides in the form of hairpins or pins. The pins or hairpins are rigid winding pieces, usually made of copper, which are inserted into slots in the stator of the electrical machine and generate the required magnetic field during operation of the electrical machine.

[0006] The waveguides have open ends through which a coolant can be fed into or exited from the waveguides. These waveguides are coated 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 connector, in which the galvanic isolation is achieved by means of a ceramic ball, is described, for example, in EP 3 357 143 A2. Another waveguide connector, which comprises several components assembled into a stack with an integrated coolant channel, is known from WO 2015 / 150 556 A1. OBJECT OF THE INVENTION

[0008] It is an object of the present invention to provide a connecting device for electrically and hydraulically connecting a plurality of electrical waveguides of an internally cooled electrical machine, which is of simple construction and can be manufactured quickly and inexpensively.

[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] According to the invention, a connection device for electrically and hydraulically connecting the electrical waveguides of an internally cooled electrical machine is proposed, which comprises at least the following:

[0011] - an electrically conductive connecting part with one or more waveguide connections, to each of which a waveguide is electrically and hydraulically connected;

[0012] - a side part arranged on one side of the connecting part; wherein the connecting part and the side part are separate components which are assembled into a stack;

[0013] - an internal coolant channel which runs through the connecting part, the coolant channel being hydraulically connected to the waveguide(s) so that a coolant emerging from the waveguide(s) can be collected in the coolant channel or a coolant present in the coolant channel can be fed into the waveguide(s).

[0014] Due to its modularity, the connection device can be easily adapted to specific requirements and configured with more or fewer electrical connection components, depending on the number of electrical phases of the machine. The individual components required for this purpose (connectors, seals, insulators) simply need to be integrated into the stackable structure.

[0015] A "side piece" can, in principle, be any component located on one side of the connecting piece and forming part of the stacked structure. Accordingly, a side piece can be an insulator, a seal, or another component. Additional components, such as an insulator and / or another seal, can be arranged between the connecting piece and the side piece.

[0016] The connecting part is preferably made of a metallic material, such as copper. The internal coolant channel preferably runs within the metallic material.

[0017] The seal is preferably designed as a flat seal.

[0018] In a specific embodiment of the invention, the connecting device is formed as a stacked arrangement, each of which is closed off at its end faces by an electrically insulating side part. Preferably, at least one of the end faces has a central coolant connection through which a coolant can be fed into the coolant channel or through which coolant exiting the coolant channel can be drained.

[0019] The direction in which the individual components of the connecting device are stacked essentially runs along a straight line. Using wedge-shaped components, a curved, e.g., ring-shaped, or other geometry of the stacking arrangement could also be created.

[0020] The individual components of the connecting device, namely at least the connecting part and the side part, are preferably designed in the form of a plate.

[0021] The waveguide(s) connected to the connecting part preferably point in the region of their connection in a direction that is substantially transverse to a direction in which the connecting part and the side part are stacked (stacking direction). The waveguide connections are preferably all arranged on the same side of the stacking arrangement.

[0022] In a specific embodiment, the connection device comprises at least one electrically conductive connection part and a seal. In this case, the aforementioned internal coolant channel preferably runs through the connection part and the seal. In the case of a multi-phase embodiment of the connection device, this correspondingly comprises a plurality of adjacently arranged connection parts, with at least one seal or an insulator being arranged between each of the two adjacently arranged connection parts. In a specific embodiment of the invention, for example, at least one seal and an insulator can be arranged between two adjacently arranged connection parts. A multi-phase embodiment of the connection device therefore has a plurality of adjacently arranged connection parts, a plurality of seals, and optionally a plurality of side parts.

[0023] The said connecting part preferably has a device for connecting an electrical phase (U, V, W), such as a terminal, a cable lug or the like.

[0024] In a special embodiment, the connecting device has at least two integrated coolant channels through which a coolant can be fed into the waveguides or coolant escaping from the waveguides can be collected.

[0025] The connecting device can further comprise a clamping device with which the connecting part, the side part, and optionally other components of the stacking arrangement are clamped against one another. In one embodiment of the invention, the clamping device can comprise one or more clamping bolts extending through the connecting device. Alternatively, the clamping device can also encompass the stacking arrangement like a clamp.

[0026] The individual components of the connecting device that are stacked on top of each other can also be glued together.

[0027] The present invention further relates to an electrical machine with a waveguide winding and a connecting device designed using stacking or sandwich technology for electrically and hydraulically connecting the electrical waveguides.

[0028] BRIEF DESCRIPTION OF THE DRAWINGS The invention is explained in more detail below with reference to the accompanying drawings. They show:

[0029] Fig. 1 is a schematic view of a prior art three-phase electrical machine with hollow wire windings;

[0030] Fig. 2 shows an embodiment of an electrical / hydraulic connection device for a three-phase electrical machine with star connection;

[0031] Fig. 3 is a side view of part of the electrical / hydraulic connection device of Fig. 2;

[0032] Fig. 4 is a sectional view of an electrical / hydraulic connecting device along a longitudinal axis of the connecting device;

[0033] Fig. 5 shows an embodiment of an electrical / hydraulic connection device for a three-phase electrical machine with a star connection, in which a part designed for the flow and a part designed for the return of the cooling circuit are arranged spatially separated from one another;

[0034] Fig. 6 shows an embodiment of an electrical / hydraulic connection device for a three-phase electrical machine with a star connection, in which a part designed for the supply and a part designed for the return of the cooling circuit are combined in one unit.

[0035] EMBODIMENTS OF THE INVENTION

[0036] Fig. 1 shows a schematic view of a known three-phase synchronous machine 25 with an internal stator 24 and an external rotor (not shown). The electrical phases are designated L1, L2, and L3, respectively, and are connected in a star configuration.

[0037] The stator 24 comprises six teeth 20 on which the individual windings 18 are arranged. The windings 18 each consist of a hollow wire 17 through which a coolant flows to cool the electric motor 25 during operation. In the illustrated embodiment, coolant is supplied to the waveguide ends of the individual windings 18 and to the star point 0 and is discharged again via internal, T-shaped connectors 26.

[0038] The synchronous machine shown in Fig. 1 further comprises a cooling system with a coolant pump 21 and a heat exchanger 22. The pump 21 pumps coolant through various coolant lines 19 to the phase-side ends of the windings 18, as well as to the star point 0, where the coolant enters the respective waveguides 17. The coolant then flows through the waveguides 17 and via the T-shaped connectors 26 back toward the heat exchanger 22, where it is cooled and flows on to the pump 21.

[0039] The electrical and hydraulic connection of the individual waveguides 17 in this electrical machine is relatively complex. Therefore, an alternative connection device with a sandwich-like structure is proposed, as illustrated by way of example in the following figures. The connection device according to the invention can, in principle, be used on all internally cooled electrical machines with one or more phases, as well as on other internally cooled devices, such as electromagnets, valves, etc.

[0040] Fig. 2 shows an electrical / hydraulic connection device 1 for the waveguides 17 of an internally cooled electrical machine 25 according to a first embodiment of the invention. In this embodiment, the connection device 1 comprises four adjacently arranged connection parts 2 - one each for phase II, V, W and one for the star point * - made of an electrically conductive material, such as Cu, to which the associated waveguides 17 are electrically and hydraulically connected. For this purpose, each connection part 2 comprises a plurality of waveguide connections 6, to each of which a waveguide end is connected. The waveguide ends can, for example, be soldered or welded or otherwise mounted on the connection part 2. In addition, the connection parts 2 each comprise a terminal 3, to which one of the electrical phases (II, V, W or *) can be connected via a cable lug.

[0041] Between each two adjacent connecting parts 2, a first seal 5, an insulator 4, and a further seal 5 are arranged. The seals 5 are preferably designed as flat seals. At each of the two front ends of the connecting device 1 (left and right in the image) there is an electrically insulating side part 24, which forms the end of the arrangement. The overall result is a stacked or sandwich-like structure.

[0042] In the embodiment shown here, the individual components 2, 4, 5, 24 of the stacked arrangement are clamped by means of a clamping device 11. This presses the individual components 2, 4, 5, 24 against one another, which simultaneously seals the coolant channels 16 running inside. Such a connection device 1 can be easily assembled and, depending on the number of electrical phases or the serial connections of the machine 25 to be contacted, can be configured with more or fewer connection parts 2. In addition to connecting the phases, a connection part 2 can also be used to implement the electrical wiring according to a specific winding pattern. In order to reduce the hydraulic pressure required for the flow through a coil, it is also possible to separate a coil and electrically connect the coil parts in the connection part 2.The individual parts of the coil are then electrically connected in series, but can be supplied with coolant in parallel, which reduces the pressure required for flow.

[0043] The internal structure of the connecting device 1 and the clamping device 11 are shown in more detail in the following Figures 3 and 4. Fig. 3 shows a side view of part of the electrical / hydraulic connecting device 1 from Fig. 2, and Fig. 4 shows a sectional view of the connecting device 1 along a longitudinal axis of the connecting device. As can be seen in Figures 3 and 4, a first coolant channel 16 runs through the left part of the sandwich-like structure and is hydraulically connected to the waveguide connections 6 of the connecting parts 2 for phases U, V, W. In the right part of the connecting device 1 there runs another coolant channel 16 which is hydraulically connected to the waveguide connections 6 of the connecting part 2 for the star point *.The side parts 24 arranged at the ends each comprise a central coolant connection 8, via which coolant can be fed into the coolant channels 16 or coolant emerging from the coolant channels 16 can be discharged (see arrows VL, RL).

[0044] In the cooling circuit operating mode illustrated here, the left coolant connection 8 shown in Fig. 4 serves as the coolant inlet (supply line) and the right coolant connection 8 serves as the coolant outlet (return line). The left coolant channel 16 is accordingly a distribution channel 9, through which the coolant is fed into the individual waveguides 17 (see the outward-pointing arrows at the waveguide ends 17). The right coolant channel 16 is accordingly a collection channel 10, in which the coolant escaping from the individual waveguides 17 is collected (see the inward-pointing arrows at the waveguide ends of the star point).

[0045] In this embodiment, the clamping device 11 comprises three clamping bolts 12 or threaded bolts that extend through the entire connecting device 2. Nuts 13 are arranged at the protruding ends of the clamping bolts 12, with which the device is clamped.

[0046] Fig. 5 shows an embodiment of an electrical / hydraulic connection device 1 for a three-phase electrical machine 25 with a star connection, in which a part of the connection device 1 designed for the supply and a part designed for the return of the cooling circuit are arranged spatially separate from each other. In this case, the left part comprises connection parts 2 for all three phases II, V, W, and the right part only one connection part 2 for the star point. The division of the connection device can also be designed differently.

[0047] Fig. 6 again shows an embodiment of an electrical / hydraulic connection device 1 for a three-phase electrical machine 25 with a star connection, in which a part designed for the forward flow and a part designed for the return flow of the cooling circuit are combined in a single unit.

Claims

5 AMENDED CLAIMS received by the International Bureau on 28 March 2024 (28.03.2024) 1. Connection device (1) for the electrical and hydraulic connection of electrical waveguides (17) of an internally cooled electrical device, 10 in particular an electrical machine (23), comprising: - at least one electrically conductive connecting part (2) with one or more waveguide connections (6) for connecting the end(s) of one or more waveguides (17); - at least one arranged on one side of the connecting part (2) 15 electrically insulating side part (24); wherein the at least one connection part (2) and the at least one side part (24) are arranged as a stack; characterized in that at least two coolant channels (16) are integrated in the stack, via which 20 a coolant can be fed into the waveguides (17) or coolant emerging from the waveguides (17) can be collected, wherein the coolant channels (16) extend substantially in a direction in which the connecting part (2) and the side part (24) are stacked. 25 2. Connecting device (1) according to claim 1, characterized in that the waveguide or waveguides (17) are connected to the connecting part (2) in a direction which is substantially transverse to a direction in which the connecting part (2) and the side part (24) are stacked. 30 3. Connecting device (1) according to claim 1, characterized in that it comprises a plurality of connecting parts (2) arranged next to one another, wherein at least one seal (5) is arranged between each two connecting parts (2) arranged next to one another. AMENDED SHEET (ARTICLE 19) 5 4. Connecting device (1) according to claim 1, characterized in that it is formed as a stack arrangement which extends substantially along a straight axis.

5. Connection device (1) according to claim 1, characterized in that 10 it is formed as a stack arrangement which is closed at its front ends by an electrically insulating side part (24).

6. Connection device (1) according to claim 5, characterized in that at least one of the side parts (24) has a central coolant connection (8) 15, via which a coolant can be fed into the coolant channel (16) or coolant emerging from the coolant channel (16) can be discharged.

7. Connection device (1) according to claim 1, characterized in that 20 a clamping device (11) is provided with which the connecting part (2) and the side part (24) and optionally further components of the stacking arrangement are clamped against one another.

8. Connection device (1) according to claim 1, characterized in that 25 the connecting part (2) has a device (3) for connecting an electrical phase (U, V, W).

9. Connecting device (1) according to claim 7, characterized in that the clamping device (11) comprises a clamping bolt (12) which extends through 30 the connecting device (2) extends through.

10. Internally cooled electrical device, in particular an electrical machine, with a waveguide winding (18) and a connecting device (1) for electrically and hydraulically connecting the electrical waveguides (17) 35 according to one of the preceding claims. AMENDED SHEET (ARTICLE 19)

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