WO2022214749A1

WO2022214749A1 - Connector for rotary electric machine stator

Info

Publication number: WO2022214749A1
Application number: PCT/FR2022/050561
Authority: WO
Inventors: Cyril Moya; Olivier Blanc
Original assignee: Nidec Psa Emotors
Priority date: 2021-04-07
Filing date: 2022-03-25
Publication date: 2022-10-13
Also published as: FR3121801B1; EP4320711A1; FR3121801A1

Abstract

Connector for rotary electric machine stator, the connector comprising a set of electrical conductors having tabs for connecting to stator winding conductors and/or to a stator power supply bus, each electrical conductor being at least partially surrounded by one or more insulating supports, at least one insulating support bearing at least one anchoring finger projecting along an axis of elongation Y, the anchoring fingers being configured in such a way that it is possible to turn around them in a plane perpendicular to their axis of elongation Y.

Description

Title: Connector for rotating electrical machine stator

The present invention claims the priority of French application 2103539 filed on April 7, 2021, the content of which (text, drawings and claims) is incorporated herein by reference.

Technical area

The invention relates to synchronous or asynchronous alternating current machines. 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 individual cars, vans, trucks or buses. The invention also applies to rotating electrical machines for industrial and/or energy production applications, in particular naval, aeronautical or wind turbine applications.

The invention relates more particularly to the connectors used to connect the winding conductors of a stator to a supply bus thereof.

Prior technique

It is known to use connectors to allow the windings of an electric machine stator to be connected to a power supply bus.

Application WO 2019/174877 discloses a circuit for connecting pins of the winding of an electric stator to the power electronics. In addition, the circuit is encapsulated in an insulating unit. The insulating unit has spaces in which the pins are inserted. The tops of the pins are covered by the insulating unit.

Application WO 2017/032537 discloses a plastic cap for insulating the pins of the winding of a stator of a rotating electrical machine. Conductor bars for connection to an inverter can be slid into the cap. The tops of the pins are covered by the cap.

Application EP 3 758 196 discloses a connector whose coupling elements to the windings of the stator are insulated. Applications US 2010/0253175, US 2012/0194028, EP 3 079234 disclose insulating elements for the winding conductors of a stator which are not integrated into a connector.

There is a need to benefit from a connector that is economical and simple to make. There is also a need to benefit from a connector that can simply be attached to the stator.

Summary of the invention

Connector

The invention aims to meet this need and it achieves this, according to one of its aspects thanks to a connector for a stator of a rotating electrical machine, the connector comprising a set of electrical conductors having connection lugs to winding conductors stator and/or to a power supply bus of the stator, each electrical conductor being surrounded at least partially by one or more insulating supports, at least one insulating support carrying at least one anchor finger extending projecting along an axis d Y elongation, the anchoring fingers being configured in such a way that it is possible to go around them in a plane perpendicular to their Y elongation axis.

“Electrical conductor” means the electrical conductor or conductors of the connector for the stator.

The term "winding conductor" means the electrical conductors forming the winding of the stator. These winding conductors can be hairpin, in particular U-shaped or I-shaped.

An anchor pin can have a single free end. The other end of the anchor finger can be connected to the insulating support.

As a variant, the two ends of the anchor finger can be connected to one or more insulating supports.

The configuration of the anchor fingers is such that it is possible to circumnavigate them in a plane perpendicular to their elongation axis Y, i.e. the anchor fingers can be completely circumvented. They are only attached to the insulating support by their end opposite their free end or by their two ends.

The electrical conductors of the connector can be bent on edge or on flat. In one embodiment, they are curved on edge. Such a configuration makes it possible to limit loss of material during the cutting of the electrical conductors of the connector in the sheets. This configuration is particularly advantageous when the longitudinal axis Y of the anchoring fingers is contained in a perpendicular or oblique plane with respect to the axis of elongation X of the stator,

The electrical conductors may extend over an angular extent greater than 60°, better still greater than 100°, better still greater than 145°, better still greater than 180°, better still greater than 210°, better still greater than 270°, better still greater than 300 °, for example of the order of 360°.

The connector according to the invention may comprise at least one electrical conductor extending over more than 30°, better still over more than 60°, better still over more than 100°, better still over more than 140°, better still over more than 180°, better over 210°, better over 270°. The connector may comprise at least two electrical conductors each extending over more than 100°, better over more than 140°, better over more than 180°, better over more than 210°, even better over 270°. Preferably, the connector is generally substantially circular in shape. In one embodiment, the connector has an angular extent of the order of 360°.

The connector may include a neutral conductor. Alternatively, the connector does not include a neutral conductor.

The connector according to the invention may have a triangle configuration. Alternatively, the connector according to the invention may have a star configuration.

An electrical conductor may be surrounded at least partially by an insulating support only. As a variant, an electrical conductor can be surrounded at least partially by two insulating supports. As a further variant, an electrical conductor may be surrounded at least partially by more than two insulating supports.

In one embodiment, all the electrical conductors are not at least partially surrounded by the same number of insulating supports. For example, a connector may comprise electrical conductors surrounded at least partially by an insulating support and electrical conductors surrounded at least partially by two insulating supports. The same insulating support can surround more than one, in particular two or three, electrical conductors. The same insulating support can surround more than three electrical conductors, for example up to seven electrical conductors.

The anchor fingers may extend radially inward from the connector and/or radially outward from the connector. Alternatively, the anchor fingers may extend axially.

At least one axis of elongation Y of an anchor finger can be contained in a plane perpendicular, parallel, or oblique with respect to the axis of elongation X of the stator, better the axes of elongation Y of all the Anchoring fingers can be contained in a plane perpendicular, parallel, or oblique with respect to the axis of elongation X of the stator.

The anchor fingers are intended to be inserted between the winding conductors of the stator, in particular between the winding conductors of two adjacent slots.

The insulating support(s) can be made of thermoplastic material such as for example Polyamide 6 (PA6), Polyphenylene Sulfide (PPS), Polybutylene terephthalate (PBT), Polyphthalamide (PPA), this list not being exhaustive. The insulating supports can be made of thermosetting material such as, for example, polyimide.

The anchoring fingers can be made of thermoplastic material, such as Polyamide 6 (PA6), Polyphenylene Sulfide (PPS), Polybutylene terephthalate (PBT), Polyphthalamide (PPA), this list not being exhaustive. . The anchoring fingers can be made of thermosetting material such as polyimide for example.

The insulating support(s) can be made of the same material as the anchoring fingers. As a variant, the insulating support(s) can be made of a material other than that of the anchoring fingers. The use of thermoplastic material gives the connector insulating properties. In particular, it allows the stator winding conductors to be isolated from each other.

The anchoring fingers allow that after impregnation of the stator, the connector is integral with the winding of the stator. The vibration resistance of the stator assembly is thus improved. Friction is thus reduced. Thanks to the connector according to the invention, the phase input and output winding conductors no longer participate in the mechanical holding of the connector, and are therefore less stressed by the weight and movements of the connector. Their wear is thus reduced.

Thanks to the connector according to the invention, the following risks can be reduced:

- risk of tearing of the insulating part surrounding the winding conductors at the foot of the stator slots,

- risk of breakage of the impregnation varnish surrounding the phase input and output winding conductors, - risk of wear of the enamel of the phase input and output winding conductors, linked to the breakage of the varnish and friction due to vibrations,

- risk of short circuit,

- risk of fatigue of the welded connections between the winding conductors and the connector.

The connector according to the invention can also make it possible to reduce the size of the stator. The total height of the stator, including the height of the winding buns and the connector, is thus reduced. It is then possible to reduce the length of the housing and the rotor shaft. A reduction in the length of the rotor shaft improves the rigidity of the machine and reduces parasitic noise linked to vibrations as well as bearing resistance. Thanks to the connector according to the invention, the electrical machine can therefore be more compact and less heavy. Its manufacturing cost is therefore reduced since the quantity of material required is reduced. The reduced weight of the machine relieves the impact of the engine on other vehicle equipment.

The conductor according to the invention makes it possible to dispense with the use of holding means. In particular, the connector according to the invention may not come to rest on the stack of laminations of the stator. It therefore does not interfere with the impregnation step. There is also better control of the environment around the electric machine and in particular its proximity to other vehicle equipment.

Each electrical conductor may comprise at least one zone not at least partially surrounded by an insulating support.

When the electrical conductors of the connector are not surrounded at least partially by an insulating support, they are said to be bare.

Two insulating supports can be separated by a bare electrical conductor part. The distance between two insulating supports can be variable.

The distribution of the insulating supports on the circumference of the connector around the axis of elongation of the stator can be uniform.

Alternatively, the distribution of insulating supports on the circumference of the connector around the elongation axis of the stator may not be uniform

Two insulating supports can be separated by an angle of between 1 and 180°, better still between 5 and 120°, better still between 10 and 100°, for example of the order of 15° or 40°.

The connector according to the invention comprises bare zones, where the material constituting the electrical conductors, for example copper, is visible. The exchange coefficient the heat between the copper and the air is greater than that between the air and the insulating material of the supports. The movement of the air generated by the rotor of the machine cools the bare parts of the electrical conductors. These bare electrical conductor parts thus make it possible to improve the cooling of the connector.

The electrical conductors of the connector are better cooled, so they expand less under the effect of heat. The electrical conductors therefore exert less stress on the insulating supports. The risk of deterioration, and in particular of cracking, is thus reduced.

In addition, the connector according to the invention requires less insulating material, such as thermoplastic, than a fully overmolded connector. The cost of the connector is thus reduced.

The distance between the surfaces of the bases of two adjacent anchoring fingers carried by the same insulating support can be constant. The distance between the surfaces of the bases of two adjacent anchoring fingers carried by the same insulating support may depend on the number of anchoring fingers that the insulating support has. For example, the distance between the surfaces of the bases of two adjacent anchoring fingers carried by the same insulating support can be between 0.5 and 10 mm, better between 1 and 8 mm, better between 2 and 6 mm, better between 3 and 4 mm, for example of the order of 3.8 mm.

As a variant, the distance between the surfaces of the bases of two adjacent anchoring fingers carried by the same insulating support can be between 150 and 300 mm, for example can be of the order of 210 mm. This may in particular be the case when the support has few anchoring fingers, for example only three anchoring fingers.

The anchor fingers can be evenly distributed on the same insulating support. As a variant, the anchoring fingers may not be uniformly distributed on the same insulating support.

All insulating supports can have the same gap between two anchor fingers.

The insulating support(s) surrounding the electrical conductors may be of variable length in the circumferential direction. The number of anchoring fingers carried by an electrical conductor may depend on the length in the circumferential direction of the insulating support or supports which surround it. The number of anchoring fingers carried by an electrical conductor can vary from one electrical conductor to another. Fingers anchoring can be distributed so that the distribution of the anchoring fingers is substantially symmetrical with respect to a plane containing the axis of elongation of the stator. The angular spacing between the surfaces of the bases of two adjacent anchoring fingers carried by the same support can depend on the spacing between two adjacent notches of the stator. The angular spacing between the surfaces of the bases of two adjacent anchoring fingers carried by the same support can also depend on the number of anchoring fingers on each insulating support. The angular spacing between the surfaces of the bases of two adjacent anchoring fingers carried by the same support is between 2 and 180°, better between 3 and 120°, better between 4 and 100°, better between 5 and 90° by example of the order of 5.7°.

The distance between the surfaces of the bases of two adjacent anchoring fingers carried by the same insulating support can be substantially equal to the spacing between two teeth of the stator. The electrical conductors of the connector may be surrounded at least partially by an insulating support over an angular extent of at most 360°, better still at most 240°, better still at most 120°, for example of the order of 30 ° or 10°.

The circumference of the connector around the elongation axis of the stator is surrounded at least partially by the insulating supports over at most 100% of its circumference, better over at most 75%, even better over at most 50%.

The circumference of the connector around the elongation axis of the stator is surrounded at least partially by the insulating supports over at least 10% of its circumference, better over at least 25%, even better over at least 50%. Each insulating support can cover a given electrical conductor over an angular extent of at most 360°, better at most 180°, better at most 100°, better at most 60°, even better at most 10°.

Each insulating support can cover a given electrical conductor over an angular extent of at least 5°, better still at least 7°, even better still at least 10°.

Each insulating support can cover at most 100% of the circumference around the axis of elongation of the stator of the electrical conductor which carries it, better at most 75%, even better at most 66%, better still at most 50%.

Such coverage by the insulating supports makes it possible to provide sufficient anchoring fingers to hold the connector on the stator, while leaving sufficient portions of bare electrical conductors to allow good cooling of the electrical conductors. The connector according to the invention can be surrounded at least partially by an insulating support over only part of its circumference. As a variant, the connector according to the invention can be surrounded at least partially by an insulating support over its entire circumference.

The connector may be surrounded at least partially over at least 1/10, better still over at least 1/4, better still over at least 1/3 of its circumference by an insulating support bearing at least one anchoring finger and disposed at the level of the lugs for connection to a power supply bus of the stator, this insulating support preferably being substantially centered on the lugs for connection to a power supply bus of the stator.

The presence of an insulating support carrying anchoring fingers at the level of the connection lugs to a supply bus of the stator makes it possible to stiffen this part of the connector. This part is thus less sensitive to vibrations of the machine and to the tightening forces of the supply bus.

The insulating support or supports can be fixed to the electrical conductors by overmolding and/or by snap-fastening.

These two fixing methods have the advantage of simplifying the assembly of the connector on the stator. In the case where the insulating supports are snapped in, the electrical conductors can be slid into the insulating supports.

Preferably, the anchoring fingers can be integral with the insulating support that carries them. The insulating supports with the anchor fingers can for example be molded, machined or printed using a three-dimensional additive manufacturing technique.

The electrical conductors can be arranged at two or three different abscissae on the elongation axis of the stator. Preferably, the electrical conductors can be arranged at two different abscissae on the elongation axis of the stator.

As a variant, the electrical conductors can all be arranged at the same abscissa on the elongation axis of the stator.

The electrical conductors of the connector can be arranged edgewise or flat. The electrical conductors can be arranged at different radial distances from the axis of elongation of the stator. For example, at least two electrical conductors can be arranged at different radial distances from the axis of elongation of the stator. In a particular embodiment, the electrical conductors are arranged on edge and are arranged at different radial distances from the axis of elongation of the stator. In another mode of embodiment, the electrical conductors are arranged flat and are arranged at different radial distances from the axis of elongation of the stator.

The electrical conductors can be arranged above the stator winding electrical conductors and at different axial distances from the entry of the slots. For example, at least two electrical conductors can be arranged at axial distances from the axis of the different slots. In a particular embodiment, the electrical conductors are arranged on a flat surface, above the stator winding electrical conductors and are arranged at different axial distances from the entry of the slots. In another embodiment, the electrical conductors are placed on edge, above the stator winding electrical conductors and are placed at different axial distances from the entry of the slots.

As a variant, electrical conductors can be arranged at least two, in particular three, different abscissae on the elongation axis of the stator.

It is thus possible to use connectors with different levels, i.e. with different abscissas on the elongation axis of the stator. Preferably, a two-level connector is used. A two-level connector has the advantage of having reduced bulk in the axial direction.

The anchoring fingers can be of substantially frustoconical shapes.

The tapered shape of the anchoring fingers facilitates their demoulding and allows them to maintain sufficient rigidity. Such a shape of the anchor fingers is called "undercut".

The anchor fingers can be oblong in a plane perpendicular to their elongation axis Y. An "oblong" shape is a shape that is longer than it is wide and whose corners are rounded.

The oblong shape has a longer length and a shorter length. The longer length may be parallel to the elongation axis of the stator when viewed in cross section. The shorter length may be perpendicular to the stator elongation axis when viewed in cross section. The longer length may be perpendicular to the elongation axis of the stator when viewed in cross section. The shorter length may be parallel to the stator elongation axis when viewed in cross section.

The anchoring fingers can have, in a plane perpendicular to their axis of elongation Y, one of the following shapes: triangular, rectangular, trapezoidal, rhombus, elliptical, pentagonal, hexagonal, circular, U-shaped, V-shaped. Preferably the edges of these shapes are rounded. The demolding of the anchoring fingers is thus facilitated. The sides can be straight or curved.

All anchor fingers may have the same shape in a plane perpendicular to their Y elongation axis. Alternatively, the anchor fingers may have different shapes in a plane perpendicular to their Y elongation axis.

Each anchor finger may extend between a base and a free end.

The greatest length in the plane of the free end may be between 2 and 20 mm, better still between 4 and 15 mm, better still between 6 and 10 mm, for example of the order of 8 mm.

The shortest length in the plane of the free end may be between 1 and 10 mm, better still between 2 and 8 mm, better still between 3 and 5 mm, for example of the order of 3.7 mm.

The shortest length in the plane of the base may be between 1 and 15 mm, better still between 2 and 8 mm, better still between 3 and 5 mm, for example of the order of 4.7 mm.

The length of a finger in the radial direction can be between 2 and 20 mm, better between 3 and 15 mm, better between 4 and 10 mm, better between 6 and 8 mm, for example of the order of 6.9 mm.

The distance between the free ends of two adjacent anchoring fingers carried by the same insulating support can be constant. The distance between the free ends of two adjacent anchoring fingers carried by the same insulating support may be between 0.5 and 15 mm, better still between 1 and 10 mm, better still between 2 and 8 mm, better still between 3 and 5 mm , for example of the order of 4.3 mm. As a variant, the distance between the surfaces of the bases of two adjacent anchoring fingers carried by the same insulating support may be between 100 and 300 mm, better still between 150 and 240 mm, for example may be of the order of 210 mm . This may in particular be the case when the support has few anchoring fingers, for example only three anchoring fingers.

The anchoring fingers can be symmetrical with respect to a plane perpendicular to the axis of elongation of the stator and/or with respect to a plane parallel to the axis of elongation of the stator. In this case, the anchoring fingers may comprise tapers on both sides of the plane of symmetry. The anchoring fingers are thus more easily demolded. Alternatively, the anchor fingers can be asymmetrical. In this case, the anchor fingers can be tapered on one side only. Together

The invention also relates, according to another of its aspects, to an assembly comprising a connector as defined above and a stator of a rotating electrical machine. The stator may comprise a stator mass comprising notches provided between teeth, each notch receiving one or more winding conductors.

Each anchor finger can be located between the winding conductors of two adjacent slots.

The anchoring fingers are thus inserted between the winding conductors and allow the connector to be held in place. When the anchoring fingers are made of thermoplastic material, they can be used to insulate the winding conductors from each other.

Preferably, the upper parts of the winding conductors, that is to say the parts farthest from the stator mass, are not covered by the anchoring fingers. The anchor fingers may not cover the free ends of the winding conductors.

The anchoring fingers can be located on the side of the welding of the winding conductors or on the side of the buns of the winding.

The electrical conductors can be welded, in particular by laser, or brazed to the electrical conductors of the stator winding.

The angular extent of the connector is such that it can go all the way around the stator. The circumference of the connector is substantially equal to the circumference of the stator.

The connector may have a number of anchoring fingers less than the number of slots in the stator. For example, if the stator has 63 slots, the connector can have at most 57 anchoring fingers, better at most 40, better at most 35 anchoring fingers, better at most 25 anchoring fingers.

In another embodiment, with a limited number of anchoring fingers, the connector can comprise at most 10 anchoring fingers, better still at most 5 anchoring fingers, better still at most 3 anchoring fingers.

This number of anchoring fingers makes it possible to leave room for the belts of the connector. The anchoring fingers of the connector can be located at a non-zero distance from the winding conductors of the stator. Preferably, the anchoring fingers are not in contact with the winding conductors of the stator.

For example, the distance between a side and/or the lower surface of an anchor finger and an adjacent winding conductor may be between 0.2 and 2 mm, better between 0.3 and 1.5 mm, better between 0.4 and 1 mm, for example of the order of 0.5 mm. The distance between the inner diameter of the connector and the winding conductor furthest from the elongation axis of the stator in a slot may be between 0.2 and 6 mm, better between 0.4 and 3 mm, better between 0.8 and 1.5 mm, for example of the order of 0.9 mm.

Thus, the connector is not in direct contact with the winding conductors. The gaps between the connector and the winding conductors allow room for the impregnating resin to flow properly.

The assembly according to the invention can be impregnated with impregnating resin. The impregnating resin may be present in the space between the winding conductors and the anchoring fingers of the connector.

Preferably the resin is thermosetting. The term "thermosetting" means the fact that the resin polymerizes, for example under the effect of heat, to pass irreversibly to the solid state.

The resin may comprise at least one polyester, in particular a polyester-imide. Such a resin has the particular advantage of exhibiting good adhesion to bare copper, which facilitates its application to the ends of the winding conductors for the protection of electrical connections.

The resin may comprise one or more additives, for example to improve its crosslinking.

The resin may comprise at least one epoxy polymer. Alternatively, the resin may not include epoxy polymer.

Preferably, the resin used for the impregnation process according to the invention is single component. As a variant, it is two-component.

The impregnating resin binds the connector to the stator. The connector is thus integral with the stator and does not need to be fixed to the casing to be held in place.

Preferably, the bare parts of the connector are located at a non-zero distance from the internal wall of the casing. The distance between the lower surface of the anchoring fingers and the entrance to the slots of the stator may be less than the distance between the lower surface of the insulating support carrying the anchoring fingers and the entrance to the slots of the stator.

The term "lower surface" denotes the surface facing the stator mass.

The lower surface of the anchoring fingers can thus protrude from the insulating supports to which they are fixed. The connector therefore does not rest on the stator and does not mask the entry of the slots. The entrance to the notches is thus free, and it is easier to introduce the impregnating resin there.

In addition, the anchoring fingers extending beyond the insulating supports have the advantage of being able to descend closer to the notches of the stator without risking coming into contact with the oblique enamelled portions of the stator winding. The risk of collision between the connector and the winding conductors when positioning the connector is thus reduced.

The distance between the lower surface of the insulating supports and the plane perpendicular to the axis of elongation of the stator containing the entry of the slots can be between 0 and 80 mm, better between 5 and 60 mm, better between 7 and 50 mm, better between 10 and 30 mm, for example of the order of 20 mm.

The connector can be arranged radially inside and/or radially outside the winding conductors.

The connector according to the invention can therefore be used with different types of electrical machine, in particular with machines of different diameters.

If the connector is arranged radially inside the stator winding conductors, then the anchoring fingers can be oriented radially outwards. If the connector is arranged radially outside the stator winding conductors, then the anchor fingers can be oriented radially inward. These two configurations make it possible to reduce the bulk in the axial direction.

The connector may comprise at least one electrical conductor radially inside the winding conductors and at least one electrical conductor radially outside the winding conductors, the connector comprising at least one anchor finger comprising a first and a second radial end, the first end radial being fixed to an insulating support of the outer electrical conductor and the second radial end being fixed to an insulating support of the inner electrical connector. In this embodiment, the anchor fingers can extend radially above the space between two adjacent notches. The anchor fingers may extend radially above the stator teeth. Alternatively, the anchor fingers may extend above a notch. As a further variant, the anchoring fingers can extend between a notch and an adjacent tooth. In this embodiment, the anchoring fingers can pass through the winding of the stator.

The connector can be arranged above the winding conductors.

In this embodiment, the anchor fingers are directed axially downwards. This configuration has the advantage of being bulky in the radial direction.

Manufacturing process

The invention also relates, according to another of its aspects, to a method for manufacturing an assembly as defined above, comprising the following steps:

(a) lay the connector on the stator winding, and

(b) impregnate the assembly comprising the connector and the stator with an impregnating resin.

Preferably, step (b) of impregnation can be carried out by trickling, dipping or powder coating.

As a variant, step (b) of impregnation can take place by a rolled impregnation process (in English “rolling dipping”).

machine and stator

Another subject of the invention is a rotating electrical machine, comprising a connector as defined previously, a stator and a rotor. The machine can be used as a motor or as a generator. The machine can be reluctance. It can constitute a synchronous motor or, as a variant, a synchronous generator. As a further variant, it constitutes an asynchronous machine.

The maximum speed of rotation of the machine can be high, being for example greater than 10,000 rpm, better still greater than 12,000 rpm, being for example of the order of 14,000 rpm to 15,000 rpm , or even 20,000 rpm or 24,000 rpm or 25,000 rpm. The maximum speed of rotation of the machine may be less than 100,000 rpm, or even 60,000 rpm, or even even less than 40,000 rpm, better still less than 30,000 rpm. The invention may be particularly suitable for high-powered machines.

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

The machine can be inserted alone into a casing or inserted into a gearbox casing. In this case, it is inserted into a casing which also houses a gearbox. The notches can be at least partially closed. A partially closed notch makes it possible to create an opening at the level of the air gap, which can be used, for example, for the installation of electrical conductors for filling the notch. A partially closed notch is in particular made between two teeth which each have pole shoes at their free end, which close the notch at least in part.

Alternatively, the notches can be completely closed. By “fully closed notch”, is meant notches which are not open radially towards the air gap. In one embodiment, at least one notch, or even each notch, can be continuously closed on the side of the air gap by a bridge of material coming in one piece with the teeth defining the notch. All the notches can be closed on the air gap side by material bridges closing the notches. The material bridges may have come in one piece with the teeth defining the notch. The stator mass then has no cutout between the teeth and the bridges of material closing the slots, and the slots are then continuously closed on the side of the air gap by the bridges of material coming in one piece with the teeth defining the notch.

In addition, the notches can also be closed on the side opposite the air gap by an added yoke or in one piece with the teeth. The notches are then not open radially outwards. The stator mass may have no cutout between the teeth and the yoke.

In one embodiment, each of the notches has a continuously closed contour. By "continuously closed", it is meant that the notches have a continuous closed contour when observed in cross section, taken perpendicular to the axis of rotation of the machine. It is possible to make the complete turn of the notch without encountering a cutout in the stator mass. The stator may comprise coils arranged in a distributed manner in the slots, having in particular electrical conductors arranged in a row in the slots. By “distributed”, it is meant that at least one of the coils passes successively through two non-adjacent slots.

The electrical conductors may not be arranged in the notches loosely but in an orderly manner. They are stacked in the slots in a non-random manner, being for example arranged in rows of aligned electrical conductors. The stack of electrical conductors is for example a stack according to a hexagonal network in the case of electrical conductors of circular cross-section.

The stator may include electrical conductors housed in the slots. Electrical conductors at least, see a majority of electrical conductors, can be pin-shaped, U-shaped or I-shaped. The pin can be U-shaped ("U-pin" in English) or straight, being in form of I ("I-pin" in English).

The electrical conductors can thus form a distributed winding. The winding may not be concentrated or tooth wound.

In a variant embodiment, the stator has a concentrated winding. The stator may include teeth and coils disposed on the teeth. The stator can thus be wound on teeth, in other words with undistributed winding.

The stator teeth may include pole shoes. Alternatively, the stator teeth are devoid of pole shoes.

The stator may include an outer carcass surrounding the yoke.

The stator teeth can be made with a stack of magnetic laminations, each covered with an insulating resin, in order to limit the losses by induced currents.

Brief description of the drawings

The invention can be better understood on reading the following description, non-limiting examples of implementation thereof, and on examining the attached drawing, in which:

[Fig 1] Figure 1 is a perspective view of an assembly comprising a stator and a connector according to one embodiment of the invention,

[Fig 2] Figure 2 is a view of the connector of Figure 1 taken in isolation,

[Fig 2a] Figure 2a is a detail view of Figure 2, [Fig 3] Figure 3 is a view of a connector according to another embodiment of the invention,

[Fig 4a] Figure 4a is a view similar to Figure 3 of an alternative embodiment,

[Fig 4b] figure 4b is a view of the connector of figure 4a from another viewing angle,

[Fig 5] Figure 5 is a view similar to Figure 3 of a variant embodiment, [Fig 6a] Figure 6a is a view similar to Figure 3 of a variant embodiment,

[Fig 6b] figure 6b is a view of the connector of figure 6a from another viewing angle,

[Fig 7] Figure 7 is a partial front view of an insulating support of a connector according to the invention,

[Fig 8] Figure 8 is a partial top view of an insulating support of a connector according to the invention,

[Fig 9] Figure 9 is a partial perspective view of an insulating support of a connector according to the invention,

[Fig 10] Figure 10 is a partial perspective view from below of an assembly comprising a stator and a connector according to the invention,

[Fig 11] Figure 11 is a partial sectional view of an assembly comprising a stator and a connector according to the invention,

[Fig 12] Figure 12 is a partial perspective view of an assembly comprising a stator and a connector according to the invention,

[Fig 13] Figure 13 is a partial top view of an assembly comprising a stator and a connector according to the invention,

[Fig 14a] Figure 14a is a view similar to Figure 1 of an alternative embodiment,

[Fig 14b] figure 14b is a top diagram of the assembly of figure 14a, [Fig 15a] figure 15a is a sectional diagram of an assembly comprising a stator and a connector according to the invention, and

[Fig 15b] Figure 15b is a top diagram of the assembly of Figure 15a, Figures 16a to 16h are schematic and partial cross-sectional views of different variants of anchor fingers observed along their elongation axis.

detailed description

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

There is illustrated in Figure 1 a stator 2 of a rotating electrical machine 1 also comprising a rotor not shown. The stator makes it possible to generate a rotating magnetic field to drive the rotating rotor, in the context of a synchronous motor, and in the case of an alternator, the rotation of the rotor induces an electromotive force in the electrical conductors of the stator.

The examples illustrated below are schematic and the relative dimensions of the various constituent elements have not necessarily been respected.

The stator 2 comprises winding conductors 22, which are arranged in notches 21 made between teeth 23 of a stator mass 25. The notches 21 are closed.

The winding conductors 22 comprise strands 33. The strands 33 have a generally rectangular cross section, in particular with rounded corners. The strands 33 are in the example described superimposed radially in a single row.

The winding conductors 22 are for the most part shaped like pins, namely U or I, and extend axially into the slots. A first electrical conductor housed in a first notch is electrically connected to a second electric conductor housed in a second notch, at the outlet of said notches.

The stator 2 on which the connector 10 is arranged is preferably three-phase and external, but the invention is not limited to a particular number of phases.

The connector 10 is shown in isolation in Figure 2. The connector 10 comprises electrical conductors 11, insulating supports 13a, 13b and 13c and anchoring fingers 14. In the illustrated embodiment, the connector is of substantially general shape circular. A connector 10 is arranged radially outside the winding conductors of the stator 2. The circumference of the connector is substantially equal to the circumference of the stator. The connector 10 comprises four electrical conductors 11 of neutral and of phases W, V and U. The connector may also comprise connection elements 12 to an inverter. In the example of Figure 2, the connector comprises insulating supports 13a, 13b, 13c of variable angular extent. In this embodiment, the electrical conductors of the connectors are surrounded at least partially by the insulating supports over an angular extent of the order of 180°.

The connector comprises insulating supports 13a of small angular extent, supports 13b of medium angular extent and an insulating support 13c of large angular extent. Each insulating support 13a, 13b, 13c comprises at least one anchor finger 14 which extends radially inwards. The insulating supports 13a of small angular extent carry an anchor finger. The insulating supports 13b of medium angular extent carry four anchoring fingers 14. The insulating support of large angular extent carries about fifteen anchoring fingers. Preferably, the insulating support 13c of large angular extent is on the side of the connection elements 12 to an inverter, it is in particular substantially centered around these connection elements 12. The anchoring fingers 14 are uniformly distributed on each insulating support 13a , 13b and 13c.

The distribution of the anchoring fingers is substantially symmetrical with respect to the X axis of elongation of the stator. The insulating supports 13a, 13b and 13c are snapped onto the electrical conductors. The insulating supports 13a, 13b and 13c and the anchoring fingers 14 are made of thermoplastic or thermosetting material. In the embodiment of Figure 2, the electrical conductors 11 are arranged at two different heights on the axis X of elongation of the stator.

The insulating supports 13a, 13b and 13c can be separated or connected by bridges of material, in particular of thermoplastic material. For example, as seen in Figure 2a, the insulating support 13a is connected to the insulating support 13c by a bridge of material 135.

FIG. 3 represents another embodiment of a connector 10 according to the invention in which the connection elements 12 to an inverter do not extend at their base towards the inside of the connector. In this embodiment, the electrical conductors 11 are designed to be brazed or welded to the winding conductors 22.

Figures 4a and 4b show another embodiment of a connector 10 according to the invention in which the insulating supports 13a, 13b and 13c are molded over the electrical conductors 11. FIG. 5 represents another embodiment of a connector 10 according to the invention in which the insulating supports 13a, 13b and 13c are molded over the electrical conductors 11 and the connection elements 12 to an inverter extend below the connector 10. In this embodiment, the electrical conductors 11 are designed to be welded, in particular by laser, to the winding conductors 22.

Figures 6a and 6b illustrate another embodiment of a connector 10 according to the invention in which the insulating supports 13a, 13b and 13c are snapped onto the electrical conductors 11 and the electrical conductors 11 are arranged at three different heights on the X axis of stator elongation.

The anchoring fingers 14 are visible more particularly in Figures 7 to 9. The anchoring fingers of Figures 7 to 9 are those used in the connectors of Figures 1 to 6.

The anchoring fingers 14 are of substantially frustoconical shapes and of oblong shape in a plane perpendicular to their axis of elongation Y. Their axis of elongation Y extends radially.

The oblong shape has a greater length L and a smaller length 1, visible in Figure 9. In this embodiment, the greater length L is parallel to the axis of elongation X of the stator when observed in section transverse. The shortest length 1 is perpendicular to the elongation axis X of the stator when viewed in cross section. Each anchor finger can extend between a base 140 and a free end 141.

The greatest length L in the plane of the free end 141 is of the order of 8 mm. The smallest length 1 in the plane of the free end 141 is of the order of 3.7 mm. The smallest length 1 in the plane of the base 140 is of the order of 4.7 mm.

The length of the anchor fingers is around 6.9 mm.

The distance between the free ends 141 of two adjacent anchoring fingers 14 carried by the same insulating support is constant and is of the order of 4.3 mm. The distance between the surfaces of the bases 140 of two adjacent anchoring fingers carried by the same insulating support is constant and is of the order of 3.8 mm.

The anchoring fingers 14 are symmetrical with respect to a plane perpendicular to the elongation axis X of the stator and with respect to a plane parallel to the elongation axis X of the stator. Each long side of the oblong shape has two straight portions 142, 143 having opposite inclinations. These two straight portions can meet at the junction zone of the mould, a burr 144 is thus formed. As visible in FIG. 9, each anchoring finger 14 comprises a part 145 which protrudes from the connector 10. The protruding parts 145 face the stator mass, as illustrated in FIG. 10. Thus, the distance between the surface of the anchor fingers and stator slot entry is less than the distance between the bottom surface of the connector and the stator slot entry.

In the example of figures 10 and 11, the distance D between the lower surface of the insulating supports and the plane perpendicular to the axis of elongation of the stator containing the entrance to the slots is of the order of 20 mm. Thus, the connector does not mask the entry of the notches. During impregnation, the resin can thus flow more easily into the notches and the connector does not hinder the flow of the resin.

As illustrated in Figures 12 and 13, the anchoring fingers 14 are thus inserted between the winding conductors 22 and make it possible to hold the connector 10 in place and to isolate the winding conductors 22 from each other. In the embodiment shown, the anchoring fingers 14 are located on the side of the welds of the winding conductors 22.

The anchoring fingers 14 of the connector are located at a non-zero distance d1 from the winding connectors 22 of the stator. The distance dl between an anchor finger and an adjacent winding conductor 22 is of the order of 0.5 mm.

The distance d2 between the inside diameter of the connector and the winding conductor 22a located farthest from the elongation axis of the stator in a notch is of the order of 0.9 mm. Figures 14a and 14b illustrate another embodiment of an assembly comprising a stator and a connector 10 according to the invention. In this embodiment, the connector 10 is arranged above the winding conductors 22 of the stator. The anchor fingers 14 extend axially downward. The anchor fingers 14 are located above the teeth 23, between two consecutive notches 21. In the embodiment shown there may be as many anchoring fingers 14 as stator teeth 23. The anchor fingers isolate the winding conductors 22 in the circumferential direction. Thus the winding conductors 22 of a slot are insulated from the winding conductors 22 of the adjacent slots.

In the embodiment of FIGS. 15a and 15b, the connector 10 comprises an electrical conductor 11a radially exterior to the winding conductors 22 and an electrical conductor 11b radially interior to the winding conductors 22. The connector comprising anchoring fingers 14 comprising a first 14a and a second 14b radial end. The first end 14a is fixed to an insulating support 130 of the external electrical conductor 11a and the second end is fixed to an insulating support 131 of the internal electrical connector 11b. The anchoring fingers extend radially above the teeth 23 of the stator. Each slot can have two, four or six conductors, as illustrated by way of example. Of course, in the same embodiment, all the slots have the same number of conductors.

The anchoring fingers can have different shapes in a plane perpendicular to their elongation axis Y. They can be substantially trapezoidal (figures 16a and 16b). They can also be elliptical (Figure 16c). They can be hexagonal (FIG. 16d). They can be pentagonal (figure 16e). They may be diamond-shaped (Figure 16f). Finally, they can have a V-shape (FIG. 16g) or a U-shape (FIG. 16h). Of course, the invention is not limited to what has just been described. For example, the anchor fingers can have other shapes.

Claims

1. Connector for a rotating electrical machine stator, the connector (10) comprising a set of electrical conductors (11) having connection lugs (12) to stator winding conductors and/or to a stator power supply bus, each electrical conductor (11) being surrounded at least partially by one or more insulating supports (13a, 13b, 13c), at least one insulating support carrying at least one anchor finger (14) extending projecting along an axis d elongation Y, the anchoring fingers (14) being configured such that it is possible to circumnavigate them in a plane perpendicular to their axis of elongation Y, the anchoring fingers (14) being substantially frustoconical shapes and being oblong in a plane perpendicular to their elongation axis Y.

2. Connector according to the preceding claim, each electrical conductor (11) comprising at least one area not surrounded at least partially by an insulating support.

3. Connector according to one of the two preceding claims, at least one axis of elongation Y of an anchor finger (14) being contained in a plane perpendicular, parallel, or oblique with respect to the axis of elongation X of the stator, better the axes of elongation Y of all the anchoring fingers (14) being contained in a plane perpendicular, parallel, or oblique with respect to the axis of elongation X of the stator.

4. Connector according to any one of the preceding claims, the distance between the surfaces of the bases (140) of two adjacent anchoring fingers carried by the same insulating support (13a, 13b, 13c) being between 0.5 and 10 mm, better between 1 and 8 mm, better between 2 and 6 mm, better between 3 and 4 mm, for example of the order of 3.8 mm.

5. Connector according to any one of the preceding claims, the electrical conductors being surrounded at least partially by an insulating support (13a, 13b, 13c) over an angular extent of at most 360°, better still at most 240°, better of at most 120°, for example of the order of 30° or 10°.

6. Connector according to any one of the preceding claims, being surrounded at least partially over at least 1/10, better over at least 1/4, better over at least 1/3 of its circumference by an insulating support (13a, 13b , 13c) carrying at least one anchor finger (14) and arranged at the level of the connection lugs (12) to a bus supply of the stator, this insulating support (13a, 13b, 13c) being preferably substantially centered on the connection lugs (12) to a supply bus of the stator.

7. Connector according to any one of the preceding claims, the insulating support or supports (13a, 13b, 13c) being fixed to the electrical conductors (11) by overmolding and/or by snap-fastening.

8. Connector according to any one of the preceding claims, the electrical conductors (11) being arranged at two or three different abscissae, preferably at two different abscissae, on the elongation axis X of the stator.

9. An assembly comprising a connector (10) according to any one of the preceding claims and a stator (2) of a rotating electric machine, the stator comprising a stator mass (25) comprising notches (21) formed between teeth (23) , each slot receiving one or more winding conductors (22), each anchor finger (14) being located between the winding conductors of two adjacent slots.

10. Assembly according to the preceding claim, the anchoring fingers (14) of the connector (10) being located at a non-zero distance (dl) from the winding connectors (22) of the stator.

11. Assembly according to one of the two preceding claims, impregnated with impregnating resin, the impregnating resin being present in the space between the winding conductors (22) and the anchoring fingers (14) of the connector (10).

12. Assembly according to one of the three preceding claims, the distance between the lower surface of the anchoring fingers (14) and the entry of the notches (23) of the stator being less than the distance between the lower surface of the insulating support ( 13a, 13b, 13c) carrying the anchoring fingers and the entrance to the notches (23) of the stator.

13. Assembly according to any one of claims 9 to 12, the distance (D) between the lower surface of the insulating supports (13a, 13b, 13c) and the plane perpendicular to the axis of elongation X of the stator containing the entry of the notches being between 0 and 80 mm, better still between 5 and 60 mm, better still between 7 and 50 mm, better still between 10 and 30 mm, for example of the order of 20 mm.

14. Assembly according to any one of claims 9 to 13, the connector (10) being arranged radially inside and/or radially outside the winding conductors (22).

15. An assembly according to any one of claims 9 to 14, the connector (10) comprising at least one electrical conductor (11b) radially inside the winding conductors (22) and at least one electrical conductor (l ia) radially outside the winding conductors (22), the connector comprising at least one anchor finger (14) comprising a first and a second radial end (14a, 14b), the first radial end (14a) being fixed to an insulating support (130) of the outer electrical conductor (11a) and the second radial end (14b) being fixed to an insulating support (131) of the inner electrical conductor (11b).

16. Assembly according to any one of claims 9 to 15, the connector (10) being arranged above the winding conductors (22).

17. Assembly comprising a connector for a rotating electrical machine stator and a rotating electrical machine stator (2), the connector (10) comprising a set of electrical conductors (11) having connection lugs (12) to winding conductors stator and/or to a stator power supply bus, each electrical conductor (11) being surrounded at least partially by one or more insulating supports (13a, 13b, 13c), at least one insulating support carrying at least one finger anchor (14) extending projecting along an elongation axis Y, the anchoring fingers (14) being configured such that it is possible to go around them in a plane perpendicular to their axis of elongation Y, and the stator comprising a stator mass (25) comprising notches (21) formed between teeth (23), each notch receiving one or more winding conductors (22), each anchor finger (14) being located between the winding conductors of two adjacent slots ntes, the connector not resting on the stator and the angular extent of the connector being such that it goes all the way around the stator.

18. Assembly comprising a connector for a rotating electrical machine stator and a rotating electrical machine stator (2), the connector (10) comprising a set of electrical conductors (11) having connection lugs (12) to winding conductors stator and/or to a stator power supply bus, each electrical conductor (11) being surrounded at least partially by one or more insulating supports (13a, 13b, 13c), at least one insulating support carrying at least one finger anchor (14) projecting along an elongation axis Y, the anchor fingers (14) being configured in such a way that it is possible to circumnavigate them in a plane perpendicular to their axis of elongation Y, and the stator comprising a stator mass (25) comprising notches (21) arranged between teeth (23), each notch receiving one or more winding conductors (22), each anchor finger (14) being located between the winding conductors of two adjacent notches, the connector not resting on the stator and the axes of elongations Y being contained in a plane perpendicular to the elongation axis X of the stator.

19. A method of manufacturing an assembly according to any one of claims 9 to 18 comprising the following steps:

(a) placing the connector (10) on the stator winding, and

(b) impregnate the assembly comprising the connector (10) and the stator (2) with an impregnating resin.