Phase connector for rotating electric machine stator

Abstract

Phase connector for rotating electrical machine stator. Phase connector (10) for the stator (3) of a rotating electrical machine (1), comprising: - a winding connector (14) connected to the stator (3), having phase output lugs (42), - connection elements (16) to an inverter, - phase junction pieces (18) connecting the phase output lugs of the winding connector to the connection elements (16), the phase junction pieces (18) being flexible in a plane of flexibility (P). Figure for the abbreviation: Fig. 1a

Description

Title of the invention: Phase connector for a rotating electrical machine stator technical field

[0001] The present invention relates to rotating electrical machines and more particularly to machines comprising a phase connector. The invention is particularly concerned with reducing vibrations in such a machine, especially in the phase connector.

[0002] The invention relates to synchronous or asynchronous machines, operating on alternating current. It relates in particular to traction or propulsion machines for electric (Battery Electric Vehicle) and / or hybrid (Hybrid Electric Vehicle - Plug-in Hybrid Electric Vehicle) motor vehicles, such as passenger cars, vans, trucks, or buses. The invention also applies to rotating electrical machines for industrial and / or power generation applications, particularly in the marine, aeronautical, or wind power sectors.

[0003] The invention relates more particularly to phase connectors used to connect the winding conductors of a stator to an inverter comprising a stator power supply bus. Previous technique

[0004] It is known to use connectors to enable the connection of the windings of an electric machine stator to an inverter.

[0005] A rotating electrical machine comprising a connecting piece linking the inputs and outputs of each phase of the machine's stator to an inverter is known in particular from international application WO 2023 / 153002. This connecting piece has a circular cross-section and comprises a braided connection that can deform in all directions.

[0006] There is a need for a phase connector that can be simply attached to the stator, allowing for a flexible assembly between the stator and the inverter, while ensuring good mechanical support.

[0007] There is still a need to reduce the vibrational stresses exerted on the electrical machine.

[0008] There is also a need for a phase connector that is economical and simple to produce. Description of the invention

[0009] The invention aims to meet all or part of these needs and achieves this, according to one of its aspects, by means of a phase connector for a rotating electrical machine stator, comprising: - a winding connector connected to the stator, including phase output lugs, - connection components for an inverter, - phase junction pieces, connecting the phase output lugs of the winding connector to the connection elements, the phase junction pieces being flexible in a plane of flexibility.

[0010] The flexible phase connection pieces allow for flexible assembly between the stator and the inverter. Thus, the phase connector makes it possible to link the phase outputs of the stator to the inverter while compensating for any assembly play.

[0011] The winding connector can be mechanically held to the stator, and the connecting elements can be mechanically held to a machine housing. The invention facilitates assembly by compensating for play between the stator winding and the housing, and reduces rigidity stresses between the stator and the housing thanks to flexible phase connection pieces.

[0012] Furthermore, the phase connector is configured to also provide a sealing function between the cavity containing the stator and the inverter itself. In the case of a stator cooled by a cooling fluid, for example oil, the phase connector withstands internal pressure and a splash bath, in addition to providing the connection to the inverter.

[0013] The winding connector may include a set of electrical conductors having phase output lugs connected to stator winding conductors and / or to a stator power bus.

[0014] The flexibility provided by the phase junction pieces makes it possible to achieve vibration decoupling between the stator and the housing. The assembly makes it possible to decouple the natural vibration modes of the stator on the one hand and of the housing on the other, and to reduce parasitic effects.

[0015] There is no phase connector in the assembly screwed between the stator and the inverter.

[0016] The term "winding conductor" refers to the electrical conductors forming the stator winding. These winding conductors may be hairpin-shaped, in particular U-shaped or I-shaped. Summary of the invention

[0017] The flexible phase connection pieces are arranged between the winding connector and the inverter connection elements. They are not located at the phase connector output, and in particular not between the phase connector and the inverter. They allow for compensating for play during assembly and filtering vibrations.

[0018] The phase junction pieces can be rigid in a direction perpendicular to their plane of flexibility. They may not be configured to deform outside the plane of flexibility. The junction piece is rigid in one lateral dimension, which ensures that the support for the connection elements to the inverter remains secure.

[0019] By 'flexibility plane', we mean a plane in which the corresponding connecting piece can deform. The flexibility plane may be parallel to a major axis of the corresponding connecting piece.

[0020] The phase connector may include, in particular, three phase junction pieces, especially in the case of a three-phase winding, in particular one per phase.

[0021] The phase junction pieces may be identical to each other. In one embodiment, the phase connector may comprise three identical phase junction pieces.

[0022] A phase junction piece, in particular each phase junction piece, may not include a braided flexible wire.

[0023] A phase junction piece can be laminated, in particular each phase junction piece can be laminated. Phase junction pieces can comprise a plurality of sheets of electrically conductive material, in particular copper, for example between 10 and 100 sheets, or even between 20 and 50 sheets, for example about 31 sheets. This can be referred to as multi-laminated. A sheet can have a thickness of between 0.05 and 1 mm, or even between 0.06 and 0.8 mm, or even between 0.07 and 0.6 mm, in particular between 0.08 and 0.4 mm, being for example about 0.1 mm.

[0024] The lamination allows for flexibility in the phase junction piece. Each phase junction piece can thus have a certain degree of flexibility, allowing functional play in the phase connector, facilitating its assembly and the operation of the stator.

[0025] A phase junction piece, in particular each phase junction piece, can be formed from a block of electrically conductive material in the shape of a rectangular prism, in particular a rectangular prism or block. Such a shape provides a flat surface for assembly, in particular brazing. The prism is deformed to form the phase junction piece, so as to provide a vertical connection portion and a horizontal connection portion.

[0026] A phase junction piece, in particular each phase junction piece, may have a rectangular cross-section.

[0027] In cross-section, it can have a width 1 between 1 and 30 mm, or even between 5 and 15 mm, or even between 7 and 10 mm, being for example about 8 mm.

[0028] In cross-section, it can have a thickness e of between 1 and 15 mm, or even between 2 and 10 mm, or even between 2.5 and 6 mm, being for example about 3 mm.

[0029] The bar can have a developed length L between 25 and 200 mm, or even between 30 and 100 mm, or even between 40 and 60 mm, being for example about 46 to 47 mm.

[0030] A phase junction piece, in particular each phase junction piece, may have two connection portions configured to make a brazed connection, in particular each disposed at one end of the bar.

[0031] The phase junction piece, in particular each phase junction piece, may include two flattened connection portions, in particular each disposed at one end of the bar.

[0032] The bar can be deformed so that the phase connecting piece has a shape that can accommodate the different positions of the different phase connecting pieces, these being all identical to each other in shape. Advantageously, only one type of phase connecting piece is used.

[0033] A phase junction piece can be configured to form a curve, particularly in its central, sufficiently large portion, in order to provide greater flexibility. The radius of curvature can, for example, be approximately 2.5 mm. The phase junction piece may thus not form a right angle.

[0034] In addition, a phase junction piece can be configured to have a substantially vertical connection and another substantially horizontal connection.

[0035] The phase junction piece, in particular each phase junction piece, may have two connection portions inclined at an angle α to each other, the angle α being between 75° and 115°, or even between 80° and 105°, or even between 85° and 95°, being for example about 90°.

[0036] The bar from which the connecting piece is formed can be deformed so that the two connecting portions are inclined at an angle to each other. The deformation can, in particular, take a shape substantially L-shaped. Such a shape allows for the absorption of tolerances related to the stator winding. These tolerances can include manufacturing tolerances and possible positional variations, for example, from 0 to 4 mm, which can be very significant.

[0037] The phase junction piece, in particular each phase junction piece, may have two ends separated by a minimum distance d greater than 30 mm, or even greater than 32 mm, being for example approximately 34 mm. The minimum distance d The distance between two ends of the phase junction piece is measured between the free ends of its two connecting portions.

[0038] A minimum distance D between two consecutive phase junction pieces can be greater than 7 mm, or even greater than 9 mm, or even greater than 10 mm, being for example approximately 11 mm. By 'minimum distance' is meant the smallest distance between the two closest points of each of the two consecutive phase junction pieces.

[0039] Sufficient spacing facilitates manufacturing, particularly the passage of necessary tools, such as soldering pliers. Sufficient spacing also ensures adequate insulation distance between phases. Connection elements

[0040] The connecting elements can be made of an electrically conductive material, for example copper.

[0041] The phase connector may include, in particular, three connection elements to an inverter, especially in the case of a three-phase winding, in particular one per phase.

[0042] The inverter connection elements can each have a male shape, for example, being substantially cylindrical with a rounded top. In this case, the inverter can have a female connector, which advantageously minimizes its size. Furthermore, this can facilitate the assembly of the inverter onto the phase connector.

[0043] Alternatively, the inverter connection elements may each have a female shape.

[0044] The connecting elements may include at least one flat surface, in particular two flat surfaces, especially those arranged symmetrically with respect to each other. The flat surface(s) provide indexing and anti-rotation functions, particularly when the connecting element is inserted into its support.

[0045] The connecting elements may include a reduced-thickness portion for connection to a phase junction piece. This reduced-thickness portion may be machined. It may include a flat-shaped machined area, particularly for brazing with the phase junction pieces. This provides a portion where heating can be limited during the brazing required for the electrical connection.

[0046] The reduced thickness portion can be provided on the side opposite the connection to the inverter, i.e., on the stator side. It includes a machined, flat area allowing for a brazed connection with the flexible phase connecting pieces. Insulating support

[0047] The inverter connection elements may be at least partially surrounded by one or more insulating supports. In one embodiment, the phase connector may comprise a single insulating support surrounding all the inverter connection elements.

[0048] The phase junction pieces ensure a flexible connection with the insulating support so as not to constrain it and to avoid deformations.

[0049] The insulating support can be in the shape of an arc, for example, a kidney bean. This shape allows it to be contained within the overall dimensions of the stator and to avoid hindering the insertion of the rotor into the stator during assembly. The insulating support can also be configured to ensure sufficient distance between the phase connector and the housing to promote air insulation and assembly.

[0050] The insulating support may have several windows for the passage of the connecting elements, in particular one window per connecting element, for example three windows.

[0051] The insulating support may include one or more bathtubs arranged or integrated into the insulating support around one or more windows. In one embodiment, the insulating support may include one bathtub per window, in particular three bathtubs.

[0052] The phase connector may include a layer of resin or silicone in the corresponding potting, particularly around the corresponding connection element. This layer of resin or silicone can provide a seal around the windows at the bottom of the potting. The potting allows the resin or silicone, inserted in liquid form, to circulate around the connection element. The resin or silicone may be deposited in the potting in liquid form, and then the resin or silicone hardens.

[0053] The insulating support may have a peripheral groove for receiving a gasket, particularly on one face of the insulating support intended to face a housing. The gasket may be designed to be compressed against the housing when the housing is in place on the phase connector and the stator. The insulating support is then fixed against the housing.

[0054] Such a seal ensures a tight seal at one or more windows in the housing designed to allow the passage of the inverter connection elements, and thus improves the stator's sealing, which is particularly advantageous for a stator cooled by a cooling fluid. Such a configuration with good sealing allows the cooling fluid, for example oil, to cool the stator output phases as well as the components of the stator winding connector.

[0055] The insulating support may include fixing barrels to allow attachment to the housing. The insulating support may include several fixing barrels, for example two. Each mounting sleeve can be configured to receive a threaded insert, typically made of metal such as brass, for mechanically securing screws. Each mounting sleeve can be opened on the housing side and closed on the stator side. The retaining screws are designed to be inserted from the side opposite the stator. The mounting sleeves are not used for electrical contact but solely to ensure proper mechanical connection between the parts.

[0056] The fixing barrels are positioned between bathtubs in order to contain the size of the insulating support and increase its rigidity.

[0057] In one embodiment, the insulating support may include two inserts arranged alternately with three tubs.

[0058] In one embodiment, the insulating support may include four inserts to receive four screws, which are arranged alternately with three recesses. In this embodiment, two screws are positioned at the ends of the insulating support to reinforce the mechanical support of the assembly.

[0059] The insulating support may have ribs around the fixing shafts. Such ribs stiffen the insulating support and form the tubs. The ribs may be arranged in a cross shape around a fixing shaft. Winding connector

[0060] The winding connector may for example be as described in international applications WO 2022 / 214749 or WO 2023 / 198968. Rotating electric machine

[0061] The invention also relates to a rotating electrical machine, in particular comprising a phase connector as described above.

[0062] The machine may include a stator comprising stator winding electrical conductors. The machine may also include a housing and an inverter. The stator may be arranged in the housing, in particular by shrink fitting.

[0063] The electric machine can retain enough flexibility so that the assembly is not brittle.

[0064] The machine can be used as a motor or as a generator. The machine can be a reluctance machine. It can be a synchronous motor or, alternatively, a synchronous generator. Alternatively, it can be an asynchronous machine. The electrical machine may not be an alternator.

[0065] The maximum rotational speed of the machine can be high, for example, exceeding 10,000 rpm, or even exceeding 12,000 rpm, for example, in the range of 14,000 to 15,000 rpm, or even 20,000, 24,000, or 25,000 rpm. The maximum rotational speed of the machine can be less than 100,000 rpm, or even 60,000 rpm, or even less than 40,000 rpm, better still less than 30,000 rpm.

[0066] The invention may be particularly suitable for high-power machines. The electric machine may have a power of at least 10 kW, better at least 15 kW, better at least 20 kW, for example in the order of 25 kW or 157 kW or 180 kW.

[0067] The machine may comprise a single inner rotor or, alternatively, an inner rotor and an outer rotor, arranged radially on either side of the stator and coupled in rotation.

[0068] The invention also relates, according to another of its aspects, independently or in combination with the above, to a vehicle comprising an electric machine as described above.

[0069] The vehicle may be a hybrid. For example, the vehicle may include, in addition to the electric motor, a combustion engine, such as a gasoline engine. An electric motor in a hybrid vehicle exhibits significant vibrational stress because it combines thermal and electrical vibrations. The electric motor according to the invention makes it possible to simultaneously reduce these two types of vibrations.

[0070] Alternatively, the vehicle may be electric. It may then consist solely of an electric machine. Brief description of the drawings

[0071] The invention will be better understood upon reading the following description, non-limiting examples of its implementation, and upon examination of the accompanying drawings, in which:

[0072] [Fig. la] The [Fig. la] is a perspective view of a rotating electrical machine according to the invention.

[0073] [Fig. 1b] The [Fig. 1b] is another perspective view of the rotating electrical machine of the [Fig.1a].

[0074] [Fig.2a] The [Fig.2a] is a schematic and partial perspective view of the phase connector of the rotating electrical machine of the [Fig.la].

[0075] [Fig.2b] The [Fig.2b] is another schematic and partial front view of the phase connector of the rotating electrical machine of the [Fig.la].

[0076] [Fig.3] Fig.3 represents respectively side, front and other side views of a phase junction piece.

[0077] [Fig.4] The [Fig.4] is a schematic and partial cross-sectional view of the phase junction piece.

[0078] [Fig.5] The [Fig.5] is a schematic and partial perspective view of the insulating support from below with the connecting elements.

[0079] [Fig.6] The [Fig.6] is a cross-sectional view along AA of the insulating support with the connecting elements, and a top view.

[0080] [Fig.7] The [Fig.7] is a cross-sectional view along BB of the insulating support with the connecting elements, and a top view.

[0081] [Fig.8a] The [Fig.8a] is a schematic and partial perspective view of a variant embodiment of a phase connector.

[0082] [Fig.8b] The [Fig.8b] is another schematic and partial perspective view of the variant embodiment of the [Fig.8a]. Detailed description

[0083] In the figures and in the rest of the description, the same references represent identical or similar elements.

[0084] Figures 1a and 1b illustrate a rotating electrical machine 1 comprising a stator 3 and a phase connector 10. The stator 3 has winding electrical conductors that form coil heads 30. The stator 3 and the phase connector 10 are coaxial. The stator also has channels 5 for the circulation of a cooling fluid.

[0085] The phase connector 10 includes a winding connector 14 connected to the stator 3. It includes an insulating support 40 carrying phase connector electrical conductors having connection tabs to the stator winding conductors 41 and phase output tabs 42.

[0086] The winding connector 14 is fixed to the stator coil heads 30 by welds between the connection tabs to the stator winding conductors 41 and the winding electrical conductors. The winding connector 14 is thus mechanically held to the stator.

[0087] The phase connector 10 also includes three connection elements 16 to an inverter not shown, as well as three phase junction pieces 18, connecting the phase output lugs 42 of the winding connector 14 to the connection elements 16, as illustrated in Figures 2a and 2b. The phase junction pieces 18 are arranged between the winding connector 14 and the connection elements 16 to the inverter.

[0088] The phase connecting pieces 18 are flexible in a flexibility plane P, which is the plane of [Fig. 2b]. The phase connecting pieces 18 can be rigid in a direction perpendicular to their flexibility plane P, i.e., outside the plane of [Fig. 2b]. In this example, they are configured so as not to deform outside the flexibility plane P.

[0089] The three phase junction pieces 18 are identical to each other. Each phase junction piece 18 is laminated, comprising a plurality of sheets of electrically conductive material, in particular copper, for example approximately 31 sheets. This can be described as multi-laminated. A sheet may have a thickness of, for example, approximately 0.1 mm.

[0090] Each phase junction piece 18 is in this example formed from a rectangular prism-shaped bar of electrically conductive material. Each phase junction piece 18 has a rectangular cross-section. Its cross-section may have a width 1, for example, of approximately 8 mm. Its cross-section may have a thickness e, for example, of approximately 3 mm. The bar may have a developed length L, for example, of approximately 46 to 47 mm.

[0091] The block is deformed to form the phase connecting piece 18, so as to provide a vertical connection portion 18a and a horizontal connection portion 18b. The two connection portions 18a and 18b are configured to allow a brazed connection, each located at one end of the bar. Both connection portions 18a and 18b are flattened in shape.

[0092] The bar is deformed so that the phase connecting piece 18 has a shape that can accommodate the different positions of the different phase connecting pieces, all of which are identical. As illustrated in Figures 3 and 4, each phase connecting piece 18 is configured to form a curve, particularly in its central part, which is quite large, in order to provide greater flexibility. The radius of curvature R is, for example, approximately 2.5 mm.

[0093] The bar from which the connecting piece 18 is formed is deformed so that the two connecting portions 18a and 18b are inclined at an angle α to each other. The deformation may, in particular, take a shape substantially L-shaped. The two connecting portions 18a and 18b are thus inclined at an angle α to each other, the angle α being, for example, approximately 90°.

[0094] Furthermore, each phase junction piece has two ends separated by a minimum distance d, for example, of approximately 34 mm. The minimum distance d between two ends of the phase junction piece is measured between the free ends of its two connecting portions 18a and 18b.

[0095] Finally, a minimum distance D between two consecutive phase junction pieces is, for example, approximately 11 mm, as illustrated in [Fig. 2a]. The minimum distance D is the smallest distance between the two closest points of each of the two consecutive phase junction pieces 18.

[0096] The phase connector comprises three connection elements 16 to an inverter, which are mechanically held to a machine housing. They have in The example describes each a male form, being substantially cylindrical with a rounded apex, as illustrated in figures 5 and 6.

[0097] The connecting elements 16 also include two flats 17, arranged symmetrically with respect to each other. The flats 17 provide an anti-rotation function, particularly when inserting the connecting element into its support 20. The connecting elements 16 also include a reduced-thickness portion 19 for connection to the corresponding phase junction piece 18.

[0098] The reduced thickness portion 19 is provided on the side opposite the connection to the inverter, i.e. on the stator side.

[0099] The connection elements to the inverter 19 are supported by a single insulating support 20 surrounding all the connection elements 19. The insulating support 20 is in the shape of an arc, resembling a kidney bean. The insulating support 20 has three openings for the passage of the connection elements 19. In addition, it has three recesses 21 formed in the insulating support around the openings.

[0100] The phase connector has a resin layer 22 in the corresponding tub, around the corresponding connecting element 16. The resin layer 22 ensures a seal around the windows, in the bottom of the tubs 21.

[0101] The insulating support 20 also has a peripheral groove 24 intended to receive a seal 25, on a face of the insulating support 20 intended to face a housing.

[0102] Finally, the insulating support 20 includes mounting bushings 26 for attachment to the housing. The insulating support may include two mounting bushings 26, as illustrated in the example in Figures 5 to 7. Each mounting bushing 26 is configured to receive a threaded insert 27, intended to receive mechanical retaining screws. Each mounting bushing 26 is open on the housing side, as seen in [Fig. 7] (b), and closed on the stator side.

[0103] The insulating support 20 also has ribs 28 around the fixing shafts 26. Such ribs 28 make the insulating support 20 more rigid. The ribs 28 are arranged in a cross around a fixing shaft 26.

[0104] In the embodiment illustrated in figures 1a to 7, the insulating support comprises two inserts 27 arranged alternately with three tubs 21.

[0105] In an alternative embodiment illustrated in figures 8a and 8b, the insulating support comprises four fixing shafts 26 and four inserts 27 to receive four screws, which are arranged alternately with three tubs 21.

Claims

Demands

1. Phase connector (10) for stator (3) of rotating electrical machine (1), comprising: - a winding connector (14) connected to the stator (3), having phase output lugs (42), - connection elements (16) to an inverter, - phase junction pieces (18), connecting the phase output lugs of the winding connector to the connection elements (16), the phase junction pieces (18) being flexible in a flexibility plane (P).

2. Phase connector according to the preceding claim, the phase junction pieces (18) being identical to each other.

3. Phase connector according to any one of the preceding claims, a phase junction piece (18) being laminated, in particular each phase junction piece (18) being laminated.

4. Phase connector according to any one of the preceding claims, a phase junction piece (18), in particular each phase junction piece (18), being formed from a bar of electrically conductive material in the shape of a block, in particular a straight block.

5. Phase connector according to the preceding claim, the phase junction piece (18), in particular each phase junction piece (18), comprising two flattened connection portions (18a, 18b), in particular each disposed at one end of the bar.

6. Phase connector according to any one of the preceding claims, the phase junction piece (18), in particular each phase junction piece (18), comprising two connection portions (18a, 18b) inclined at an angle α to each other, the angle α being between 75° and 115°, or even between 80° and 105°, or even between 85° and 95°, being for example about 90°.

7. Phase connector according to any one of the preceding claims, the phase junction piece (18), in particular each phase junction piece (18), having two ends separated by a minimum distance (d) greater than 30 mm, or even greater than 32 mm, being for example about 34 mm.

8. Phase connector according to any one of the preceding claims, a minimum distance (D) between two connecting pieces of phase (18) consecutive being greater than 7 mm, or even greater than 9 mm, or even greater than 10 mm, being for example about 11 mm.

9. Phase connector according to any one of the preceding claims, the connection elements (16) to the inverter having a reduced thickness portion (19) for connection to a phase junction piece (18).

10. Phase connector according to any one of the preceding claims, the connection elements (16) to the inverter being surrounded at least partially by one or more insulating supports (20).

11. Phase connector according to the preceding claim, the insulating support (20) having several windows for the passage of the connection elements (16), in particular one window per connection element.

12. Phase connector according to the preceding claim, the insulating support (20) comprising one or more tubs (21) provided in the insulating support (20) around one or more windows.

13. Phase connector according to any one of the three preceding claims, the insulating support (20) having a peripheral groove (24) intended to receive a seal (25), in particular on a face of the insulating support (20) intended to face a housing.

14. Phase connector according to any one of the four preceding claims, the insulating support (20) having fixing barrels (26) to allow fixing to the housing.

15. Phase connector according to the preceding claim, the insulating support (20) having ribs (28) around the fixing shafts (26).

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