Connection plate for electrically and hydraulically connecting the hollow conductors of an internally cooled electric machine and electric machine comprising a connection plate of this type

Abstract

The invention relates to an electric machine (1) comprising a winding formed of hollow conductors (5), wherein the hollow conductors (5) each have open ends (12), via which a coolant can be fed into the hollow conductors (5) or can exit the hollow conductors (5). The electric machine (1) comprises a connection unit (3) for electrically and hydraulically connecting the hollow conductors (5) to a connection plate (6), in which multiple electrical conductor paths (11) are integrated, wherein the connection plate (6) has multiple through-openings (15) in which the ends (12) of the hollow conductors (5) are arranged.

Description

[0001] Connection plate for the electrical and hydraulic connection of the waveguides of an internally cooled electrical machine and electrical machine with such a connection plate

[0002] The invention relates to an internally cooled electrical machine with a waveguide winding and a connection plate for the electrical and hydraulic connection of the waveguides.

[0003] BACKGROUND OF THE INVENTION

[0004] Internally cooled electric machines with a waveguide winding 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] DE 10 2018 218 668 A1 discloses an electrical machine with a winding formed from waveguides, wherein the waveguides each have open ends through which a coolant can be fed into the waveguides or exited from the waveguides, and with a connection unit for electrically and hydraulically connecting the waveguides, comprising a connection plate in which several electrical conductor tracks are integrated, wherein the connection plate has several through-openings in which the ends of the waveguides are arranged. Another electrical machine with a waveguide winding is known from DE 10 2018 129 230 A1.

[0008] In internally cooled electrical machines with waveguide windings, the electrical and hydraulic connection of the individual waveguides represents a technical challenge.

[0009] OBJECT OF THE INVENTION

[0010] It is an object of the present invention to provide an electrical machine with a winding formed from waveguides, which comprises a connection unit which makes it possible to connect the ends of the individual waveguides easily and quickly electrically and hydraulically.

[0011] This object is achieved according to the invention by the features specified in claim 1. Further embodiments of the invention emerge from the subclaims.

[0012] According to the invention, an internally cooled electrical machine with a winding formed from waveguides is proposed, in which the waveguides each have open ends through which a coolant can be fed into the waveguides or exited from the waveguides. The electrical machine according to the invention comprises a connection unit for electrically and hydraulically connecting the waveguides, which comprises a connection plate in which several electrical conductor tracks are integrated, wherein the plate further has a plurality of through openings in which the ends of the waveguides are arranged. The waveguide ends are in electrical contact with at least one of the conductor tracks integrated in the plate.

[0013] In principle, the conductor tracks can run in one plane or on different planes within the board. The connection board preferably comprises one or more subsurface (embedded) conductor tracks.

[0014] In a specific embodiment of the invention, the connection plate can be formed as a sandwich construction consisting of several superimposed plates or layers. Each layer can be made of an insulating material and optionally comprise one or more conductor tracks. The individual layers can, for example, be glued together, overmolded with plastic, bonded with resin, welded, or otherwise connected to one another. The layers or plates are preferably arranged one above the other in an axial direction of the electrical machine.

[0015] According to a special embodiment of the invention, the connecting plate (which may consist of individual layers) has a recess in its surface in the area of ​​at least one of the through-holes, which allows a waveguide end located in the respective through-hole to be electrically contacted with a conductor track located below the surface. In this case, the recess extends from the surface of the connecting plate to the depth of the conductor track and provides sufficient space for a soldering or welding process.

[0016] The connecting plate is preferably ring-shaped or can also be designed in the form of a circular segment.

[0017] The ends of the waveguides are preferably inserted through the through holes provided in the connecting plate and protrude above the surface on the other side. The waveguide ends can also be flush with the surface of the connecting plate.

[0018] The connection unit or its connection plate is preferably mounted on the stator of the electric machine or on the waveguide ends and has a side facing the winding and a side facing away from the winding. The aforementioned recesses are preferably provided in the side of the connection plate facing away from the winding.

[0019] In addition to the connection plate, the aforementioned connection unit preferably comprises a second component or a second section. The second component can have at least one channel integrated therein, which is fluidically connected to several waveguide ends and through which the coolant can be fed into the waveguides or coolant escaping from the waveguides can be collected. The connection unit can also comprise two or more integrated channels. The second component is preferably a separate component that is placed on the connection plate and tightly connected to the connection plate.

[0020] A ring seal can be provided between the connecting plate and the second component. Alternatively or additionally, the two parts can also be glued, welded, or otherwise tightly connected.

[0021] The second component can be made of plastic or metal, for example.

[0022] The connecting plate or its layers can be made of an insulating material, such as fiberglass, aramid, ceramic, or plastic. Alternatively, the connecting plate or individual layers can also be made of metal, provided that electrical insulation from the waveguide ends is ensured.

[0023] The present invention also relates to a connection unit for the electrical and hydraulic connection of waveguides of a winding of an electrical machine. The connection unit comprises a connection plate made of an electrically insulating material, in which a plurality of electrical conductor tracks extending at different levels within the connection plate are integrated. The connection plate has a plurality of through-openings for connecting the ends of the waveguides.

[0024] The connection unit can comprise a single or multiple coolant channels. The coolant channel(s) can be provided optionally in the connection plate, the second component, or in both elements. According to a preferred embodiment of the invention, the channel(s) is / are provided in the form of grooves.

[0025] The connection plate or the entire connection unit can be made of multiple parts or a single piece. It can be manufactured, for example, using an additive manufacturing process or an injection molding process.

[0026] BRIEF DESCRIPTION OF THE DRAWINGS The invention is explained in more detail below with reference to the accompanying drawings. They show:

[0027] Fig. 1 is a sectional view of an electrical machine with a waveguide winding formed from individual pins and two connection units for electrically and hydraulically connecting the individual pins;

[0028] Fig. 2 is a perspective view of a layer of one of the connection units of Fig. 1;

[0029] Fig. 3 is an enlarged sectional view of one of the connection units of Fig. 1;

[0030] Fig. 4 is an enlarged view of the surface of a layer of one of the connection units;

[0031] Fig. 5 a connection unit with two integrated coolant channels.

[0032] EMBODIMENTS OF THE INVENTION

[0033] Fig. 1 shows a sectional view of an electrical machine 1 with a stator 2 and a waveguide winding formed from individual pins. The pins are each designed as a waveguide 5 and comprise a continuous channel through which a coolant is conducted to cool the electrical machine 1 during operation.

[0034] On both sides of the stator 2 (top and bottom in the image), a connection unit 3 is provided, with which the waveguides 5 are both electrically contacted and hydraulically integrated into the cooling circuit. Each connection unit 3 comprises a connection plate 6 made of an electrically insulating material, in which a plurality of electrical conductor tracks 11 running one above the other at different levels are integrated. The connection plate 6 furthermore has a plurality of through-openings 15, in each of which an end 12 of the waveguides 5 is arranged, so that the waveguide ends 12 are in electrical contact with at least one of the conductor tracks 11 integrated in the connection plate 6. The connection unit 3 furthermore comprises a coolant channel 8, via which a coolant can be fed into the waveguides 5 or via which coolant escaping from the waveguides 5 can be collected.In the illustrated embodiment, all waveguides 5 are hydraulically connected in parallel. In this case, the coolant is fed from the outside into the connection unit 3 shown in the image above via a central coolant connection 4 (supply line) (see arrow A). It then enters the coolant channel 8 and flows from there through the individual waveguides 5, all of which are hydraulically connected in parallel, into the connection unit 3 shown in the image below. There, the coolant is collected in channel 8 and discharged to the outside via a central coolant connection (return line) (see arrows B).

[0035] The channels 8 contained in the connection units 3 are each formed in a second part 7 or section. The second part 7 is placed on the connection plate 6 and tightly connected to it. An annular seal 14 is provided between the second part 7 and the connection plate 6. Alternatively or additionally, the two parts 6, 7 can also be glued together or otherwise tightly connected. The second part 7 can be made of plastic or metal, for example.

[0036] In the illustrated embodiment, the connection plates 6 are each formed as a sandwich construction consisting of several superimposed plates or layers 6a-6d, which are arranged one above the other in an axial direction of the electrical machine. Each layer 6a-6d is made of an insulating material and can optionally comprise one or more conductor tracks. The individual layers 6a-6d are preferably glued to one another or can be connected to one another in some other way.

[0037] Fig. 2 shows the surface of a layer 6b of the annular connecting plate 6.

[0038] Layer 6b is made of an electrically insulating material with a plurality of conductor tracks 11 embedded in its surface. Waveguides 5 arranged within the same conductor track 11 are electrically connected to one another via the conductor track 11.

[0039] The electrical machine 1 shown in Fig. 1 is a three-phase device and accordingly has three external phase connections to which the electrical phases U, V, and W are connected. The layer 6b shown in Fig. 2 provides electrical connections for all three phases U, V, and W. The individual waveguides 5 can be electrically connected via the conductor tracks 11, for example, such that several waveguides 5 are connected in series to form a coil. Several such coils belonging to the same electrical phase II, V, W can be connected in parallel.

[0040] Fig. 3 shows a sectional view of a connection unit 3, in which the integrated coolant channel 8 is clearly visible. The connection unit 3 comprises a connection plate 6 formed from several layers 6a-6d, on which the second part 7 with the coolant channel 8 is arranged. The two parts are screwed together by means of screws 9.

[0041] Fig. 4 shows an enlarged view of the surface of a layer 6b, in which a recess 13 provided in the surface of the connecting plate 6 is clearly visible. The recess 13 serves to contact, in particular to solder or weld, a waveguide end 12 located in the through-opening 15 to a conductor track 11 located below the surface. As can be seen, the recess 13 extends from the surface of the connecting plate 6 into the depth of the conductor track 11 and offers sufficient space for a soldering or welding process.

[0042] The connection unit 3 or its connection plate 6 is preferably mounted on the stator 2 of the electric machine 1 and has a side facing the winding and a side facing away from the winding. The aforementioned recesses 13 are preferably provided in the side of the connection plate 6 facing away from the winding. However, they could also be provided on the other side.

[0043] The connecting plate 6 or its layers 6a-6d can be made of an insulating material, such as fiberglass, aramid, ceramic, or plastic. Alternatively, the connecting plate or individual layers could also be made of metal.

[0044] Finally, Fig. 5 shows a variant of a connection unit 3 in which two coolant channels 8 for the supply and return lines are integrated. This variant accordingly comprises a hydraulic connection 4 for the supply line and a second connection 4 for the return line.

Claims

Claims: An electric machine (1) with a winding formed from waveguides (5), wherein the waveguides (5) each have open ends (12) through which a coolant can be fed into or exit the waveguides (5), and with a connection unit (3) for electrically and hydraulically connecting the waveguides (5), comprising a connection plate (6) in which several electrical conductor tracks (11) are integrated, wherein the connection plate (6) has several through-openings (15) in which the ends (12) of the waveguides (5) are arranged; characterized in that the connection plate (6) has a recess (13) on its surface in the area of ​​at least one of the through-openings (15) which makes it possible to electrically contact a waveguide end (12) located in the respective through-opening (15) with a lower-lying conductor track (11).An electrical machine (1) according to claim 1, characterized in that the conductor tracks (11) run on different levels within the terminal plate (6). An electrical machine (1) according to claim 1, characterized in that the terminal plate (6) is a sandwich construction of several superimposed plates (6a-6d). An electrical machine (1) according to claim 3, characterized in that the plates (6a-6d) are made of an insulating material in which one or more electrical conductor tracks (11) are integrated. An electrical machine (1) according to any one of the preceding claims, characterized in that the terminal unit (3) further comprises a second component (7) with a channel (8) which is connected to several waveguide ends. (12) is connected and through which the coolant can be fed into the waveguides (5) or coolant escaping from the waveguides (5) can be collected.

6. Electric machine (1) according to claim 1 , characterized in that the connection plate (6) and / or a second component (7) has at least one groove in a surface opposite the respective other part (6, 7) which is in contact with several waveguide ends (12) and through which the coolant can be fed into the waveguides (5) or coolant exiting from the waveguides (5) can be collected.

7. Electric machine (1) according to claim 5 or 6, characterized in that the second component (7) is placed on the connection plate (6) and is tightly connected to the connection plate (6).

8. Electric machine (1) according to claim 1 , characterized in that the connection plate (6) and / or the second component (7) is designed in a ring shape.

9. Electric machine (1) according to claim 5, characterized in that the second component (7) is made of plastic or metal.

10. Electric machine (1) according to one of the preceding claims, characterized in that the connection plate (6) is made of an insulating material, such as GRP, aramid, or a plastic, or of metal, such as aluminium, with integrated conductor tracks (11).

11. Connection unit (3) for connecting waveguides (5) of a winding of an electrical machine (5), comprising a connection plate (6) in which several electrical conductors (11) are integrated, wherein the The connection plate (6) has a plurality of through-holes (15) for connecting ends (12) of the waveguides (5); characterized in that the connection plate (6) has a recess (13) on its surface in the area of ​​at least one of the through-holes (15) which makes it possible to electrically contact a waveguide end (12) located in the respective through-hole (15) with a lower-lying conductor track (11).

Images