WO2022112704A1

WO2022112704A1 - Flange and rotor for a rotary electrical machine

Info

Publication number: WO2022112704A1
Application number: PCT/FR2021/052069
Authority: WO
Inventors: Diana FANTUZ; Juan Wang; Ioan Deac; Gabriel MAUMON
Original assignee: Nidec Psa Emotors
Priority date: 2020-11-30
Filing date: 2021-11-23
Publication date: 2022-06-02
Also published as: FR3116964A1

Abstract

Disclosed is a flange (10) of a rotor (1) of a rotary electrical machine rotating about an axis of rotation X, comprising an inner face (101) turned towards a rotor body (3), an outer face (102) opposite the inner face (101), a radially external edge (103) extending between the inner face (101) and the outer face (102), and a central bore (104), the flange (10) comprising at least one supply duct (12) for a coolant, the supply duct having an inlet (12a) on the inner face (101) of the flange and an outlet (12b) on the edge and/or on the outer face of the flange, the outlet (12b) being closer to the edge than the central bore of the flange, the inlet (12a) of the supply duct being closer to the axis of rotation X than the outlet (12b), the supply duct (12) extending along a substantially straight elongation axis Y.

Description

Title: Flange and rotor of rotating electrical machine

The present invention claims the priority of French application 2012391 filed on November 30, 2020, the content of which (text, drawings and claims) is incorporated herein by reference.

The present invention relates to rotating electrical machines, and more particularly those cooled by a circulation of a cooling fluid, in particular a cooling liquid, for example oil, circulating at least partially in a rotor of the machine and the case possibly in a shaft of the machine and/or in a pack of rotor toroidal plates of the rotor. The invention relates more particularly to the rotors of such machines, and even more particularly to the flanges.

The invention relates more particularly 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.

Prior technique

It is known to cool the hot spots of a rotating electrical machine, in particular the winding heads of the stator, by a cooling liquid ejected by the rotor onto them during operation of the machine. Flanges are arranged at the ends of the rotor mass, and the cooling fluid is ejected through ducts made in these flanges.

In the applications US 2010/0194220, JP 2013-055799, JP 2006-025545, US 2010/0237725 for example, the machine comprises a flange in which is formed a conduit for supplying a cooling liquid which is not rectilinear in the flange, in particular these ducts have at least a right angle or a curvature.

Such flanges are of complex shape, which makes them difficult and expensive to manufacture. In particular, the presence of a duct with a substantially right angle in the flange implies the presence of hidden cavities, that is to say cavities which are not observable from the outside of the flange. To form such cavities, the flange must be manufactured by a complex process such as for example a process from a lost mould.

In application JP 2013-055775, the electric machine comprises a flange in which extends a conduit for supplying a cooling fluid which is inclined by approximately 45° with respect to the axis of rotation of the machine. The duct outlet is on one side of the flanges and is closer to the outer surface of the shaft than to the air gap of the machine. Such a conduit does not make it possible to target certain specific hot spots. In particular, it does not allow the cooling fluid to be ejected into the air gap, for example to cool the heads of the stator coils.

There is a need to simplify the manufacture of rotating electrical machine flanges. There is also a need to further improve the cooling of rotating electrical machines cooled by a circulation of cooling fluid.

Disclosure of Invention

The invention aims to meet this need and has as its object, according to a first of its aspects, an electrical machine rotor flange rotating around an axis of rotation X, comprising an inner face facing a rotor mass, a face outer face opposite the inner face, a radially outer edge extending between the inner face and the outer face, and a central bore, the flange comprising at least one conduit for supplying a cooling fluid, the supply conduit having an inlet on the inner face of the flange and an outlet on the edge and/or on the outer face of the flange, the outlet being closer to the edge than to the central bore of the flange, the inlet of the supply duct being closer to the X axis of rotation than the outlet, the supply duct extending along a substantially rectilinear Y axis of elongation.

The term “substantially rectilinear elongation axis” denotes an axis having no curvature or bend, in particular a bend at a substantially right angle.

In one embodiment, the elongation axis is straight.

The outlet of the supply duct can be located closer to the edge of the flange than to the outer surface of the shaft. The outlet of the supply duct can be located closer to the edge of the flange than to the axis of rotation X of the machine. The outlet of the supply duct can be arranged between the edge of the flange and the axis of rotation X of the machine electric, in the first half from the slice, better in the first third, better in the first quarter, even in the first fifth from the slice. The outlet of the duct can be arranged between the edge of the flange and the periphery of the central bore of the flange, in the second half from the central bore, better in the last third, better in the last quarter, even in the last fifth from center bore. The outlet of the duct can be arranged between the edge of the flange and the X axis of rotation of the electric machine in the second half from the X axis, better in the last third, better in the last quarter, even in the last fifth from the X axis.

The flange according to the invention has the advantage of allowing the hottest zones of the electric machine to be cooled, for example the heads of the stator coils. Such a flange also makes it possible to eject the cooling fluid against the internal wall of a casing of the machine. In contact with the internal wall of the casing, the cooling fluid can thus be cooled thanks to heat exchanges with the outside of the casing and in particular with a cooling liquid which can circulate outside the casing.

The supply duct is oriented so as to eject the cooling fluid towards an internal wall of the casing, in particular a cylindrical wall of revolution of the casing.

In one embodiment, the outlet of the supply duct can be arranged on the edge of the flange. It may then not lead to the outer face of the flange.

In another embodiment, the outlet of the supply duct can be arranged in a junction zone between the outer face and the edge of the flange.

The junction zone between the edge of the flange and the outer face can be a curved surface. When the flange is observed in a cross section containing the axis X of rotation of the electric machine, the junction zone can form an arc of a circle, for example a quarter circle.

As a variant, the junction zone between the edge of the flange and the external face can be an edge. The edge may be curved, in particular circular, when observed along the axis of rotation of the rotor.

When the flange is observed in a cross section containing the axis X of rotation of the electric machine, the supply ducts can be perpendicular or oblique with respect to the axis of rotation X of the machine. The supply duct or ducts can emerge facing the heads of the stator coils. The ends of the stator windings are the parts of the electrical conductors of the stator which protrude from the stator mass of the stator. Such an arrangement of the ducts makes it possible to eject cooling fluid into the air gap of the machine and thus improves the cooling of the coil heads.

Such a flange does not have complex shapes, such as hidden cavities, for example. Only simple shapes such as grooves, holes or chamfers are used. To manufacture a flange according to the invention, it is therefore not necessary to carry out a casting in sand or to use intermediate parts, such as for example stoppers during the foundry operation.

The flange may include cavities which are fully observable from the outside. These cavities may be close to the shaft. Thus, the circulation of the fluid in the ducts is improved.

The flange may be a casting, being in particular made of aluminum or aluminum alloy, in particular by die casting. The geometry of the flange according to the invention allows very simple manufacture without re-machining or drilling, or with re-machining and possible drilling, but easy to achieve. The flange can be made in a single piece made in one piece.

Materials other than aluminum can be used.

As a variant, the flange can be made by machining. As a further variant, it can be manufactured by a combination of machining and foundry steps.

The flange according to the invention therefore has the advantage of being able to be manufactured more simply and less expensively than the flanges of the prior art.

Such a flange makes it possible to effectively cool the electric machine and in particular certain hot spots such as the winding heads of the stator of the electric machine. In particular, the arrangement of the outlet of the supply duct at the level of the flange makes it possible to eject the cooling fluid as close as possible to the coil heads of the stator.

The cooling fluid can be a liquid, for example water or oil. As a variant, the cooling fluid can be a gas, for example air.

The supply ducts can be oriented radially. Each flange may comprise a single supply duct, or else between 1 and 8 supply ducts, for example 2, 4, 6 or 8. It may comprise for example an even number of supply ducts, or variant an odd number. The supply ducts of a flange can for example be evenly distributed around the flange, for example at 180° when the flange has two ducts, and at 90° when the flange has four ducts. The number of feed ducts may be dependent on the number of poles of the stator. For example, if the stator has N poles, each flange can have N/2 supply ducts. Such a link between the number of poles of the stator and the number of supply ducts of a flange makes it possible to ensure the symmetry of the electrical machine.

The flange may have a greater longitudinal dimension comprised between 5 mm and 20 mm, better still between 8 mm and 15 mm, being for example of the order of 12 mm.

The length D of the supply duct is measured along the elongation axis Y between the periphery of the central bore of the flange and the outlet. The length D of the supply duct can be between 20 mm and 100 mm, better still between 25 mm and 80 mm, being for example of the order of 33 mm. Such a length facilitates the production of the supply duct.

The angle a defined between the axis of elongation Y of the supply duct and a plane perpendicular to the axis X of rotation of the machine can be between 0 and 30°, preferably between 5 and 25°, better between 10 and 20°, for example of the order of 12°.

The angle a can be chosen so that the cooling fluid is projected onto a particular area of the electrical machine, such as the housing, the phase connectors or the winding heads of the stator.

For example, to spray the part of the coil ends closest to the stator, an angle α of between 8 and 12° is chosen. To spray the central part of the coil heads, an angle α of between 16 and 18° can be chosen. To spray the ends of the coil heads, an angle α of between 20 and 25° can be chosen.

The invention offers great flexibility in the choice of orientation of the flow of the cooling fluid, which makes it possible to simply target different zones of the machine in order to cool them.

Preferably, the angular distance between the elongation axis Y of the conduit and the inner face of the flange may be substantially equal to the thickness of the flange.

Preferably, a cross-section of the supply duct may be circular in shape over at least half, better still 2/3, better still 4/5 of its total length. Over the rest of the length of the supply duct, the cross-section of the duct may be rectangular, square, oval, half-moon or other, this list not being exhaustive. The cross-section of the supply duct can be of a given shape over part of its length and of a different shape over the rest of the length of the supply duct.

The cross section of the supply duct may be circular in shape over its total length.

When the cross section of the supply duct is circular, the diameter of the cross section of the supply duct may be between 0.5 and 10 mm, preferably between 1 mm and 8 mm, better still between 2 and 4 mm, for example of the order of 3 mm.

The diameter of the cross-section of the supply duct can be constant over the entire length of the supply duct. The supply duct is then generally cylindrical in shape.

Alternatively, the diameter of the conduit cross section may vary along the length of the supply conduit. The supply duct is then of generally frustoconical or conical shape. The diameter of the cross section at the inlet of the supply duct may be greater than that at the outlet. Alternatively, the diameter of the cross section at the inlet of the supply duct may be smaller than that at the outlet.

The cross-sectional area of the supply duct may be constant over at least half, better 2/3, better 4/5 of its total length.

Alternatively, the cross-sectional area is constant over the entire length of the supply conduit. The cross-sectional area of the supply duct may be between 1 mm ² and 300 mm ² , better still between 3 mm ² and 200 mm ² , better still between 12 mm ² and 50 mm ² , being for example of the order of 30 mm ² .

The supply ducts can be supplied with cooling fluid by the shaft or from the rotor mass.

Such a cooling fluid supply simplifies the design of the cooling circuit because fewer parts are to be passed through by the fluid. The circuit being thus shorter, the sizing is simplified.

The supply duct or ducts can be supplied with cooling fluid by the shaft only. As a variant, the supply ducts can be supplied with cooling fluid from the stack of sheets only. The inlets of the supply ducts may comprise an inlet portion widened in the direction of the axis of rotation of the rotor. The enlarged inlet portions may be located on the inner face of the flange. They can for example face a shaft of the machine. The different inlet portions of a flange may not be connected together at said flange.

The widened inlet portion can be truncated by the inner face of the flange, it then forms a notch in the flange. The inner face being intended to be attached to the rotor mass, the notch is then closed by the latter at the level of the truncated face of the outlet. When the enlarged inlet portions are not connected together at the level of the flange, they thus form cavities which are close to the axis of the rotor.

The volume of the cavity formed at the inlet of the coolant supply conduit may be between 10 and 1300 mm ³ , better still between 30 and 1000 mm ³ , better still between 50 and 800 mm ³ , better still between 80 and 400 mm ³ , being for example of the order of 98 mm ³ .

As a variant, the inlets of the supply ducts can be interconnected at a radially inner end by an annular recess. The widened inlet portions are then connected together at the flange and form the annular recess. The annular recess may be located on the inner face of the flange. The annular recess can for example face a shaft of the machine.

The annular recess can be used to collect the cooling fluid coming from the rotor, and to distribute it in the various supply ducts of the flange. Such a configuration makes it possible to promote a regular distribution. Moreover, such a configuration makes it possible to dispense with the need to index the flange.

In the case of an annular recess, the difference between the internal and external diameter of this recess can be between 1 mm and 6 mm, better still between 2 mm and 5 mm, being for example of the order of 3.5 mm . Preferably, the internal diameter of the recess may be substantially equal to the diameter of the shaft, for example it may be equal to the diameter of the shaft plus one millimeter. The outer diameter of the recess may be less than the distance between the periphery of the central bore and the housings of the magnets. The volume of the annular recess may be between 400 and 10200 mm ³ , better still between 800 and 8000 mm ³ , better still between 1000 and 6000 mm ³ , better still between 2000 and 5000 mm ³ , better still between 2500 and 4000 mm ³ , being for example of the order of 2800 mm ³ .

Preferably, the height of the cavities or of the annular recess, that is to say their dimension in a radial direction, may be less than the distance between the periphery of the central bore and the housings of the magnets. Such a height limitation makes it possible to reduce the risk of cooling fluid flowing into the magnet housings, which could cause the flange to become unbalanced.

The length of the widened inlet portions, that is to say the cavities or the annular recess, in the axial direction of the machine is less than the thickness of the flange, better still less than 2/3 of the thickness of the flange, better still less than half the thickness of the flange. Such a limitation of the length facilitates the filling of the cavities and of the annular recess by the cooling fluid and thus avoids the case where the cavity is only partially filled. Partial filling would cause the flange to become unbalanced. Moreover, with such a length of the inlet portions widened in the axial direction, the residual thickness of the flange at the level of the widened inlet portions is sufficient to ensure correct mechanical strength of the flange.

Preferably, the enlarged inlet portions are at least half filled, better still at least 2/3 full, even better completely filled. Complete filling of the enlarged inlet portions improves the cooling of the electrical machine. In particular, it makes it possible to have a good distribution of the coolant in the flanges, and thus not to generate any imbalance in the event that these inlet portions are not completely filled.

Preferably, the cavities and the annular recess are of a sufficiently small volume to allow easy filling with cooling fluid. Preferably, the volume of the cavities and of the annular recess is small enough to allow them to be filled regardless of the speed of rotation of the electrical machine.

Preferably, the volume of the cavities and of the annular recess is large enough for the pressure at the outlet of the duct not to be too high. This limitation of the outlet pressure makes it possible to limit the risk of deterioration of the electrical conductors of the stator, and in particular of their outer coating. The presence of enlarged inlet portions or an annular recess at the level of the inlets makes it possible to collect the cooling fluid from the shaft before it is ejected from the flange. This makes it possible, for example, to limit the intrusion of air into the cooling circuit. These shapes also make it possible to compensate for angular misalignment between the supply ducts of the flange and the shaft.

Preferably, the cavities formed by the enlarged inlet portions or the annular recess are formed close to the shaft of the rotor. These cavities and this recess allow the storage of the cooling fluid close to the shaft of the rotor and thus ensures the balancing of the flange. The risk of unbalance in the flange is thus reduced.

The outlets of the supply ducts can be cylindrical in shape.

Preferably, when the outlets of the supply ducts are cylindrical, they are arranged in the junction zone between the edge and the external face of the flange. Such outlets make it possible to obtain a better dispersion of the flow of cooling fluid.

Preferably, the diameter of the supply duct at the outlet may be greater than the diameter of the supply duct upstream of the outlet in the flange. This difference in diameter makes it possible to promote the dispersion of the flow of cooling fluid in the air gap and thus to better manage the distribution of the cooling fluid in the cooling circuit.

As a variant, the outlets of the supply ducts may include a flared portion. The supply ducts can become wider as one moves from the entrance to their exit. They may in particular be wider towards their outlet than towards their inlet.

The outlet comprising a flared portion can be arranged on the edge of the flange. As a variant, it can be arranged in the junction zone between the edge and the external face of the flange. The use of an outlet having a flared portion makes it possible to extend the zone over which the cooling fluid is projected. It also reduces the coolant pressure at the outlet. The jet of cooling fluid is thus not concentrated on a restricted area. Such a dispersion of the cooling fluid makes it possible to reduce the risk of erosion of the resin covering the winding of the stator of the machine and thus to limit the wear of the electric machine.

The flared portion can form a flare angle b in a plane perpendicular to the axis of rotation of the rotor. The flare angle b can be between 10° and 50°, better between 20° and 40°, being for example of the order of 30°. The flare angle b makes it possible to have a more or less wide area for sprinkling the cooling fluid on the coil heads.

The flange may comprise a supply duct, the inlet of which comprises a widened portion in the direction of the axis of rotation of the rotor and an outlet comprising a flared portion opening onto the edge of the flange. The flange may comprise a supply duct, the inlet of which comprises a widened portion in the direction of the axis of rotation of the rotor and an outlet comprising a flared portion opening out into the junction zone between the edge and the external face of the flange. The flange may comprise a supply duct, the inlet of which comprises a widened portion in the direction of the axis of rotation of the rotor and a cylindrical outlet opening out into the junction zone between the edge and the external face of the flange. The flange may comprise a supply duct, the inlet of which comprises a widened portion in the direction of the axis of rotation of the rotor and a cylindrical outlet opening onto the edge of the flange.

The flange may comprise an annular recess interconnecting the inlets of the supply ducts and at least one supply duct having an outlet comprising a flared portion opening onto the edge of the flange. The flange may comprise an annular recess interconnecting the inlets of the supply ducts and at least one supply duct having an outlet comprising a flared portion opening into the junction zone between the edge and the external face of the flange. The flange may comprise an annular recess interconnecting the inlets of the supply ducts and at least one supply duct having a cylindrical outlet opening out into the junction zone between the wafer and the external face of the flange. The flange may comprise an annular recess interconnecting the inlets of the supply ducts and at least one supply duct having a cylindrical outlet opening onto the edge of the flange.

Preferably, all the supply ducts of the same flange have the same type of inlet and outlet. As a variant, some supply ducts of the same flange have a flared outlet and the others have a straight outlet.

Rotor

Another subject of the invention, according to another of its aspects, is a rotor of a rotating electrical machine, comprising a rotor mass and at least one flange as defined above.

The rotor mass may comprise a stack of rotor laminations. The flange can be arranged at one end of the rotor mass.

In one embodiment, the subject of the invention is a rotor comprising a rotor mass and two flanges as defined above, each disposed at one end of the rotor mass.

At least one axial channel for distributing the cooling fluid to the flange(s) may be formed in the rotor mass or between the rotor mass and the shaft, along the shaft. This or these axial distribution channels can pass axially through at least part of the rotor mass.

As a variant, the shaft can be traversed over its entire length by an internal channel, supplying the cooling fluid. This channel can extend axially. This internal channel can supply radial channels, for example radial channels located at the ends of the rotor. The radial channels can thus supply the flanges of the rotor with cooling fluid.

The or each supply duct and/or the annular recess and/or the widened portion(s) of the inlets of the supply ducts can face at least one axial channel for distributing the rotor mass or a radial channel located at the end of the rotor.

The rotor may include permanent magnets inserted into the rotor mass. It may comprise permanent magnets, with in particular surface or buried magnets. The rotor can be flux concentrating. It can include one or more layers of magnets arranged in an I, U or V. The housings for the permanent magnets can be made entirely by cutting in the sheets. Each sheet of the stack of sheets can be monobloc.

The cooling fluid can flow axially in the housings of the permanent magnets and join the flanges.

Alternatively, it may be a wound or squirrel cage rotor, or a variable reluctance rotor.

The number of poles P at the rotor is for example between 4 and 48, being for example 4, 6, 8, 10 or 12.

The diameter of the rotor can be less than 400 mm, better still less than 300 mm, and greater than 50 mm, better still greater than 70 mm, being for example between 100 and 200 mm. Each sheet is for example cut from a sheet of magnetic steel or sheet containing magnetic steel, for example steel 0.1 to 1.5 mm thick. The sheets can be coated with an electrically insulating varnish on their opposite faces before they are assembled within the stack. Electrical insulation can also be obtained by heat treatment of the sheets, if necessary.

The shaft can be made of a magnetic material, which advantageously makes it possible to reduce the risk of saturation in the rotor mass and to improve the electromagnetic performance of the rotor.

As a variant, the rotor comprises a non-magnetic shaft on which the rotor mass is arranged. The shaft can be made at least in part from a material from the following list, which is not exhaustive: steel, stainless steel, titanium or any other non-magnetic material.

The rotor mass can in one embodiment be placed directly on the non-magnetic shaft, for example without an intermediate rim. As a variant, in particular in the case where the shaft is not non-magnetic, the rotor may comprise a rim surrounding the shaft of the rotor and coming to rest on the latter.

The rotor can be cantilevered or cantilevered from the bearings used to guide the shaft.

The rotor can be made in several sections aligned in the axial direction, for example at least two sections. Each of the sections can be offset angularly relative to the adjacent pieces (“step skew”).

The cooling fluid can circulate in the housings of the permanent magnets, or between the shaft and the stack of laminations. The cooling fluid can be in direct contact with the permanent magnets of the rotor on part of an outer surface of said permanent magnets, so as to have a capture of the calories to be evacuated in an optimal manner and thus protect the permanent magnets of the rotor. “Direct contact” means physical contact with the outer surface of the permanent magnets, which may be covered with a protective varnish.

machine and stator

Another subject of the invention is a rotating electrical machine, comprising a rotor as defined previously and a stator. The machine can be used as a motor or as a generator. The machine can be reluctance. It can be a driving force generator or alternatively 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 machine has a stator. The latter comprises teeth defining notches between them. The stator may comprise electrical conductors, at least some of the electrical conductors, or even a majority of the electrical conductors, which may be in the shape of a U-shaped or I-shaped hairpin.

The machine may comprise a shaft traversed over at least part of its length by an internal channel for supplying the cooling fluid. The shaft may not have a one-way coolant flow through its entire length. On the contrary, it can be traversed by a flow of cooling fluid over approximately half of its length. The internal channel of the shaft may comprise a first axial portion over half the length of the shaft, and a second radial portion configured to conduct the cooling fluid from the first portion towards the stack of laminations, and in particular towards the axial coolant distribution channel formed in the pack of rotor laminations or between the pack of rotor laminations and the shaft, along the latter.

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 the filling of 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” is meant that the notches have a continuous closed contour when viewed in cross section, taken perpendicular to the axis of rotation of the machine. You can go all the way around 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”, we mean 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 varnish, in order to limit the losses by induced currents.

The machine may comprise a shaft traversed over at least part of its length by an internal channel for supplying the cooling fluid.

Processes

A further subject of the invention, independently or in combination with the foregoing, is a process for manufacturing a flange as defined above, in which the flange is made by foundry.

The flange can be manufactured without re-machining. The method is thus simplified and the flange can be produced more economically.

The duct or ducts can be made using drawers arranged in the mold.

In another embodiment, the flange can be manufactured with re-machining, in particular with a step of drilling the supply duct.

Preferably, the method of manufacturing a flange according to the invention does not include a step of molding from a lost mould. The flange can be manufactured without the use of an intermediate part such as for example a stopper. The manufacturing method according to the invention is thus simpler and more economical to implement than the methods of the prior art.

The manufacturing method according to the invention makes it possible to manufacture a flange with a wide variety of cooling fluid supply ducts. Through this process, it is possible to vary the inclination, the width and/or the shape of the duct without complicating the manufacture of the flange.

A further subject of the invention, independently or in combination with the foregoing, is a method for cooling a rotating electrical machine as defined above, in which the cooling fluid is circulated in opposite directions within the rotor , then the cooling fluid is projected onto the coil heads of the electrical conductors of the stator.

Brief description of the drawings

[Fig 1] Figure 1 is a longitudinal sectional view, schematic and partial, of a rotor made in accordance with the invention,

[Fig 2] Figure 2 is a detail view of Figure 1 of one of the axial ends of the rotor,

[Fig 3] Figure 3 is a sectional view, schematic and partial, of a flange of the rotor of Figure 1,

[Fig 4a] Figure 4a is a perspective view of a flange of the rotor of Figure

1,

[Fig 4b] Figure 4b is a sectional view, schematic and partial, of the flange of Figure 4a,

[Fig 5a] Figure 5a is a view similar to Figure 4a of an alternative embodiment,

[Fig 5b] Figure 5b is a view similar to Figure 4b of an alternative embodiment,

[Fig 6a] Figure 6a is a view similar to Figure 4a of an alternative embodiment,

[Fig 6b] Figure 6b is a view similar to Figure 4b of an alternative embodiment,

[Fig 7a] Figure 7a is a view similar to Figure 4a of an alternative embodiment,

[Fig 7b] Figure 7b is a view similar to Figure 4b of an alternative embodiment, [Fig 8a] Figure 8a is a view similar to Figure 4a of an alternative embodiment, and

[Fig 8b] Figure 8b is a view similar to Figure 4b of an alternative embodiment.

detailed description

There is illustrated in Figures 1 and 2 an inner rotor 1 of a rotating electrical machine, also comprising an outer stator 2. The stator 2 makes it possible to generate a rotating magnetic field for driving the rotor 1 in rotation, within the framework of a motor synchronous, and in the case of an alternator, the rotation of the rotor induces an electromotive force in the electrical conductors 4 of the stator 2.

The rotor 1 represented in FIG. 1 comprises a magnetic rotor mass 3 extending axially along the axis of rotation X of the rotor, this rotor mass being formed by a stack of magnetic toric laminations 8 stacked along the axis X, the plates being for example identical and superimposed exactly. The magnetic laminations are preferably made of magnetic steel. All grades of magnetic steel can be used.

The rotor mass 3 has a central opening for mounting on a shaft 5. The shaft can, in the example considered, be made of a non-magnetic material, for example non-magnetic stainless steel or aluminum, or on the contrary be magnetic.

In accordance with the invention, the rotor 1 comprises two flanges 10 each disposed at one end of the pack of rotor laminations 8. Each flange has an inner face 101 facing the pack of rotor laminations 8 and an opposite outer face 102. A radially outer edge 103 extends between the inner face and the outer face of the flange. Each flange also has a central bore 104 for mounting it on the shaft 5 of the machine.

In the embodiment of FIG. 1, each of the flanges 10 comprises four supply conduits 12 for a cooling fluid, both supplied from the shaft of the rotor 5. These two supply conduits 12 are arranged at 180 °, as visible in Figure 1, and they are fed by radial distribution channels 13 of the cooling fluid to the flange which are formed in the shaft 5. These radial distribution channels 13 are fed by a central channel 51 of tree 5, which communicates with them. As illustrated in Figures 2 and 3, the conduit 12 extends along an axis of elongation Y. The axis of elongation Y is inclined at an angle a with respect to a plane P perpendicular to the axis X of the rotor . In the example represented, the angle a is of the order of 12°. Such an angle a makes it possible in particular to spray the heads of the coils of the electrical conductors 4 of the stator 2.

Each supply duct 12 has an inlet 12a on the side of the axis of rotation X of the rotor 1 and an outlet 12b opposite the electrical conductors 4 of the stator 2. The inlet 12a is closer to the central bore 104 of the flange 10 than output 12b. The outlet 12b is closer to the edge 103 of the flange than to the central bore 104. The outlet 12b is arranged between the edge of the flange and the axis of rotation X, in the first half from the edge. In the example shown, the elongation axis Y of conduit 12 is straight between inlet 12a and outlet 12b.

In the embodiment illustrated in Figures 1 to 3, the length D of the duct, measured along the elongation axis Y between the periphery of the central bore 104 of the flange and the outlet 12b is of the order of 33 mm, and each flange has four supply ducts 12.

The various possible embodiments for the inputs 12a and the outputs 12b are described below with reference to FIGS. 4a to 8b.

In the embodiment of FIGS. 4a and 4b, the inlets 12a are not interconnected, and each supply conduit comprises an inlet portion 12a widened in the direction of the axis of rotation of the rotor. The widened portion of the outlet is truncated by the inner face of the flange, it then constitutes a notch in the flange. When the flange is attached to the pack of rotor laminations 3, as illustrated in FIGS. 1 and 2, the notch is closed at the truncated portion. The outlet 12a thus forms a cavity which is close to the axis of the rotor. Such inlets 12a can serve to collect the cooling fluid from the rotor. The volume of the cavity formed at the level of the inlet 12a of the duct is of the order of 98 mm ³ .

In the embodiment of FIGS. 5a and 5b, the inlets 12a of the supply ducts 12 of the flanges 10 are interconnected at a radially inner end by an annular recess 14. The annular recess 14 serves to collect the cooling fluid coming from the shaft of the rotor, and to distribute it in the four ducts supply of the flange. The difference between the internal and external diameter of this recess is in the example described of the order of 3.5 mm.

In the embodiment of Figures 6a and 6b. The outlets 12b are arranged in the junction zone between the radially outer edge 103 of the flange and the outer face 102 of the flange. They are oriented radially outwards, which allows the projection of the cooling fluid on the stator. Outlets 12b are cylindrical in shape and circular in cross section. In the example shown, the circular cross section has a diameter of the order of 3 cm. The cylindrical outlet can be truncated by the plane containing the outer face of the flange to improve the dispersion of the cooling fluid towards the stator. In addition, such a truncated shape makes it possible to limit the presence of cooling fluid in the air gap and promote its projection towards the electrical conductors of the machine. Such a shape also makes it possible to limit the pressure of the cooling fluid. It also allows for wider watering. In the example described, each flange has four outputs 12b, distributed around the flange at 90°.

In the embodiment illustrated in Figures 7a and 7b, the outputs 12b are arranged on the radially outer edge of the flange. In this embodiment, the outputs have a flared-shaped portion towards the electrical conductors 4 of the stator 2. The flared-shaped portion forms a flare angle b in the median plane of the flange, a plane which is perpendicular to the axis rotation and rotor. The flare angle b is here of the order of 30°.

In the embodiment illustrated in FIGS. 8a and 8b, the outlets 12b are arranged in the junction zone between the radially outer edge of the flange and the outer face of the flange. In this embodiment, the outputs have a flared-shaped portion towards the electrical conductors 4 of the stator 2. The flared-shaped portion forms a flare angle b in the median plane of the flange, a plane which is perpendicular to the axis rotation of the rotor. The flare angle b is here of the order of 30°.

Of course, the invention is not limited to the examples which have just been described.

For example, the rotor can be made with other coolant passages, for example oriented radially at approximately mid-length of the package or in contact with the magnets.

Claims

1. flange (10) of the rotor (1) of an electrical machine rotating around an axis of rotation X, comprising an inner face (101) facing a rotor mass (3), an outer face (102) opposite the face (101), a radially outer edge (103) extending between the inner face (101) and the outer face (102), and a central bore (104), the flange (10) comprising at least one supply (12) of a cooling fluid, the supply conduit having an inlet (12a) on the inner face (101) of the flange and an outlet (12b) on the edge and/or on the outer face of the flange, the outlet (12b) being closer to the edge than to the central bore of the flange, the inlet (12a) of the supply duct being closer to the axis of rotation X than the outlet (12b), the duct feed (12) extending along a substantially rectilinear axis of elongation Y, the feed ducts being supplied with cooling fluid by the shaft of the rotor of the electrical machine ctric.

2. Flange according to the preceding claim, the angle a defines between the axis of elongation Y of the supply duct (12) and a plane perpendicular to the axis of rotation X being between 0 and 30°, preferably between 5 and 25°, better still between 10 and 20°, for example of the order of 12°.

3. flange (10) of the rotor (1) of an electric machine rotating around an axis of rotation X, comprising an inner face (101) facing a rotor mass (3), an outer face (102) opposite the face (101), a radially outer edge (103) extending between the inner face (101) and the outer face (102), and a central bore (104), the flange (10) comprising at least one supply (12) of a cooling fluid, the supply conduit having an inlet (12a) on the inner face (101) of the flange and an outlet (12b) on the edge and/or on the outer face of the flange, the outlet (12b) being closer to the edge than to the central bore of the flange, the inlet (12a) of the supply duct being closer to the axis of rotation X than the outlet (12b), the duct (12) extending along a substantially rectilinear axis of elongation Y, the angle a defines between the axis of elongation Y of the inlet duct (12) and a plane perpendicular to the axis of rotation X being between 0 and 30°, preferably between 5 and 25°, better still between 10 and 20°, for example of the order of 12°.

4. Flange according to any one of the preceding claims, the outlet (12b) of the supply duct (12) being arranged between the edge (103) of the flange and the axis of rotation X of the electric machine, in the first half from the slice, better in the first third, better in the first quarter, even in the first fifth from the slice.

5. Flange according to any one of the preceding claims, the outlet (12b) of the supply duct (12) being arranged on the edge (103) of the flange or on a junction zone between the outer face (102) and the edge (103) of the flange.

6. Flange according to any one of the preceding claims, a cross section of the supply duct (12) being of circular shape over at least half, better 2/3, better 4/5 of its total length.

7. Flange according to the preceding claim, the diameter of the cross section of the supply duct (12) being between 0.5 and 10 mm, preferably between 1 mm and 8 mm, better still between 2 and 4 mm, for example of the order of 3 mm.

8. Flange according to any one of the preceding claims, a surface of the cross section of the supply duct (12) being constant over at least half, better 2/3, better 4/5 of its total length.

9. Flange according to any one of the preceding claims, the inlets (12a) of the supply ducts (12) comprising an inlet portion widened in the direction of the axis of rotation (X) of the rotor.

10. Flange according to any one of the preceding claims, the inlets (12a) of the supply ducts being interconnected at a radially inner end by an annular recess (14).

11. Flange according to any one of the preceding claims, the outlets (12b) of the supply ducts (12) being of cylindrical shape.

12. Flange according to any one of claims 1 to 9, the outlets (12b) of the supply ducts (12) comprising a flared portion.

13. Rotor of a rotating electrical machine, comprising a rotor mass (8) and at least one flange (10) according to any one of the preceding claims.

14. Rotary electrical machine comprising a rotor (1) according to the preceding claim and a stator (2).

15. Machine according to the preceding claim, comprising a shaft (5) traversed over its entire length by an internal channel (51) for supplying the cooling fluid.

16. A method of manufacturing a flange (10) according to any one of claims 1 to 11, wherein the flange is made by casting.