EP4229739A1

EP4229739A1 - Rotor for a rotary electric machine

Info

Publication number: EP4229739A1
Application number: EP21785936.2A
Authority: EP
Inventors: Diana FANTUZ; Guillaume TARDY; Olivier Gas
Original assignee: Nidec PSA Emotors SAS
Current assignee: Nidec PSA Emotors SAS
Priority date: 2020-10-14
Filing date: 2021-09-13
Publication date: 2023-08-23
Also published as: FR3115167A1; WO2022079364A1; CN116325433A; US20230378830A1

Abstract

Rotor (30) for a rotary electric machine, comprising: - at least one permanent magnet (1) having, in cross-section, at least one long side (2a) and at least one short side (3a), - a rotor body (33) comprising stacked sheets, the rotor body (33) comprising at least one recess (4) receiving the permanent magnet (1), the recess (4) being delimited by at least one face (5a) opposite the large side (2a) of the permanent magnet (1), at least one sheet (6) comprising at least one deformable tongue (7) connecting to the face (5a) of the recess (4) and extending into the recess (4), the deformable tongue (7) being angled and comprising a foldable portion (8) configured to be pressed against the small side (3a) of the permanent magnet (1).

Description

Title: Rotor of rotating electric machine

The present invention claims the priority of French application 2010506 filed on October 14, 2020, the content of which (text, drawings and claims) is incorporated herein by reference.

Technical area

The present invention relates to rotating electrical machines and more particularly to the rotors of such machines. The invention relates to rotors with permanent magnets.

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

Permanent magnet rotors are generally composed of a toroidal mass and permanent magnets of various geometric shapes.

The rotor mass may comprise a stack of thin cut-out magnetic laminations. It can comprise one or more stacks of sheets stacked on top of each other.

The permanent magnets can be arranged on the surface, directly facing the air gap or, as a variant, be arranged inside the rotor mass, in housings of the latter, being then said to be “buried” or “embedded”.

In this case, it is necessary to ensure a radial and/or axial mechanical blocking of the magnets in their housing, this blocking having to be sufficient in order to avoid damage to the magnets and to allow the correct operation of the electric machine. rotating. Indeed, in the event of insufficient wedging, the magnets can be subjected to micro-movements, which can lead to the destruction of the magnets, to a degradation of the electrical and magnetic performance of the machine and to a lack of balance.

To fix the magnet in its housing, several techniques are applied today, such as the use of glue, of a specific form of magnet and corresponding housing, for example the use of magnets having a cross section trapezoidal, or the impregnation of the magnet in its housing after its installation.

However, these techniques have certain drawbacks. Their implementation can be delicate and expensive.

Bonding the magnets in their housings is a long process which generally requires a warm-up operation followed by a cooling operation. The sticking of the magnets can also cause runs, which affects the cleanliness of the parts and makes the manufacture of the machine more complex. In addition, the bonding of the magnets involves a risk of dispersion of positioning between the different magnets for the same sheet pack but also from one sheet pack to another if no pre-maintenance of the magnets is put in place before the bonding step. Finally, sticking can pose a problem of durability over time for the assembly for certain applications, and makes the recovery of the magnets practically impossible without deterioration.

As far as impregnation is concerned, it is a long, very expensive and cumbersome process in terms of implementation, given the need to use varnish tanks and ovens. Moreover, it imposes a thermal stress related to the demagnetization of the magnets and also makes the recovery of the magnets impossible without deterioration.

Finally, the use of magnets having a specific shape significantly increases the total manufacturing cost of the machine due to the high cost of these magnets. Furthermore, the specific shapes of these magnets can complicate the production of the magnetic sheet and its cutting.

In addition, in order to improve the cost and performance of electrical machines, it may be necessary to increase the quantity of magnets, especially when it is not possible to improve their quality, or to maintain the same performance with lower quality and less expensive magnets.

Optimal electromagnetic performance is obtained when a buried magnet - which has in cross-section two opposite short sides and two long sides opposite sides - is in perfect contact on each of its two long opposite sides with the stack of laminations in which it is buried, the passage of the magnetic flux from the magnets towards the stack of laminations being maximized.

However, there is generally a clearance between the magnets and their housings in the stack of laminations in which they are inserted, thus constituting an air gap from the magnetic point of view which necessarily induces losses in the electromagnetic performance of the machine. Such a clearance is linked to manufacturing constraints which do not allow, for reasonable costs, to respect very precise dimensions in the cutting of the sheets or in the design of the magnets. A backlash may also be due to the fact that, since the magnets are susceptible to corrosion, it may be necessary to cover them with a protective coating, also inducing uncertainty in their dimensions.

In addition, the assembly constraints require that a certain clearance be maintained between the magnets and the housings of the stack of laminations, so as to facilitate the insertion of the magnets into the latter, in particular when the stack of laminations is formed from a stack of thin magnetic sheets. Indeed, in this case, the walls of the stack of sheets may not be perfectly straight given the fact that they are made up of a stack of thin sheets, which may require an even greater assembly clearance.

If the machine has several magnets arranged in several rows per pole in the stack of laminations, the clearances of the magnets of the different rows add up and weaken the magnetic performance of the machine accordingly.

Application FR 3 069 115 relates to a rotor comprising a stack of laminations formed by a stack of identical laminations, each lamination comprising a deformable tongue to hold a permanent magnet in its housing. The deformable tongue is connected to the face of the housing located opposite the small side of the magnet.

Applications DE 10 2007 036315 and EP 2 115 855 describe tongues which deform in the plane of the sheet.

Applications DE 10 2011 078054 and DE 10 2016 204972 describe tongues which are connected to the face of the housing located opposite the small side of the magnet.

Applications US 2014/0077650 and US 2014/0000096 disclose holding the magnets by wedges.

There is a need to improve the magnetic performance and reduce the manufacturing and assembly costs of rotating electrical machines. Disclosure of Invention

Rotor

The invention aims to meet this need and thus has as its object, according to one of its aspects, a rotating electrical machine rotor, comprising:

- at least one permanent magnet having in cross section, in particular perpendicular to an axis of rotation of the rotor, at least one long side and at least one short side,

- a rotor mass comprising laminations stacked on top of each other, the rotor mass comprising at least one housing receiving the permanent magnet, the housing being delimited by at least one face facing the large side of the permanent magnet, at least a sheet comprising at least one deformable tongue being connected to said face of the housing and extending into the housing, the deformable tongue being bent and comprising a bendable portion configured to press against the small side of the permanent magnet.

The cross section of a permanent magnet is perpendicular to an axis of rotation of the rotor.

The rotor mass may comprise one or more stacks of laminations stacked on top of each other. Each stack of laminations can comprise at least one housing receiving the permanent magnet. In the case where the rotor mass comprises several stacks of laminations stacked on top of each other, the rotor mass may comprise, for a housing, a single or several permanent magnets, for example one permanent magnet per laminations package.

The deformable tongue can be provided in a metal sheet of the rotor mass. It can be in one piece with the rest of the sheet.

The deformable tab may comprise a bendable portion configured to be bent outside the plane of the sheet so as to press against the small side of the permanent magnet.

The surface condition of the deformable tongue can be identical to that of the rest of the sheet.

The deformable tongue may comprise a face having burrs resulting from the cutting of the deformable tongue in the sheet and a face without burrs. Preferably, the bendable portion of the deformable tongue is configured to press, via its face without burrs, against the small side of the permanent magnet. This makes it possible to leave the face without burrs on the side of the magnet, and thus to avoid the degradation of the permanent magnet during its introduction into the housing.

The deformable tongue can be configured to deform outside the plane of the sheet.

The bendable portion of the deformable tongue can be bent outside the plane of the sheet so as to press against the short side of the permanent magnet when the permanent magnet is in place in the housing. Once folded, the foldable portion preferably forms an angle substantially equal to 90° with respect to the rest of the deformable tab.

The bendable portion of the deformable tongue can be configured to bend so as to press against the small side of the permanent magnet following the deformation of the deformable tongue by the permanent magnet, in particular when the permanent magnet is introduced longitudinally in the housing, along the axis of rotation of the rotor.

The permanent magnet can be introduced magnetized or unmagnetized into the housing, along the axis of rotation of the rotor.

The deformable tongue can exert after deformation a thrust on the permanent magnet so as to maintain it in the housing.

The deformable tongue can make it possible to mechanically block the permanent magnet in the housing during its introduction into the housing and/or during operation of the machine when the permanent magnet is in place in the housing. The deformable tongue can thus make it possible to pre-position and/or maintain the permanent magnet in the housing, in particular during operation of the machine. The presence of the deformable tab eliminates the need for glue. It can make it possible to minimize, on the one hand, the micro-movements of the permanent magnet in the housing and therefore the risks of cracking of the permanent magnet, and on the other hand, the vibrations of the permanent magnet in the housing and so the noise.

The bendable portion of the deformable tongue can be configured to be pressed substantially in the middle of the small side of the permanent magnet.

The deformable tongue can be connected to the face of the housing which is opposite to the air gap, which is on the side of the axis of rotation of the rotor, and which is furthest from the axis of the pole to which the permanent magnet belongs considered. The permanent magnet may have in cross section a first short side and a second short side, opposite the first.

The bendable portion can be configured to press against the first short side of the permanent magnet.

For the same housing, the rotor may comprise deformable tabs whose bendable portion is configured to press against the first small side of the permanent magnet and other deformable tabs whose bendable portion is configured to press against the second small permanent magnet side

At least one sheet may include at least one stop facing the second short side of the permanent magnet. The face of the housing comprising the abutment may be the face of the housing to which the deformable tongue is connected or, as a variant, the opposite face.

The deformable tongue can be configured to exert a thrust on the permanent magnet so that the latter rests against the stop. The abutment may extend into a side portion of the housing, facing the second short side of the permanent magnet. This lateral portion of the housing can thus make it possible to provide a magnetic vacuum, useful for promoting the circulation of the magnetic flux in the rotor in an optimized manner.

At least one sheet may include at least one wedge facing the first short side of the permanent magnet. The face of the housing comprising the wedge may be the face of the housing to which the deformable tongue is connected or, as a variant, the opposite face.

The wedge may be located close to the deformable tongue, being for example placed between the deformable tongue and the permanent magnet when the latter is in place in the housing. As a variant, the sheets could be devoid of such a wedge.

The presence of a wedge facing the first short side of the permanent magnet and of a stop facing the second short side of the permanent magnet can allow better guidance of the permanent magnet when it is introduced longitudinally into the housing, along the axis of rotation of the rotor.

The deformable tongue may extend between a connection end to the face of the housing and a free end.

The width of the deformable tongue can decrease going from its connection end towards its free end. This makes it possible to have a high resistance of the tab at the level of its connection end. The narrowing of the tongue deformable from its connection end to its free end allows the deformable tab to deform on the side of its free end.

The width of the crushable tongue is measured transversely to the elongation axis of the crushable tongue.

The connection end can allow the connection of the deformable tab to the face of the housing facing the large side of the permanent magnet.

The deformable tongue can be bent between its connecting end and its free end. It may include a bend.

The elongation axis of the deformable tongue can be curved, following the bend of the deformable tongue.

The deformable tongue may comprise an axis of elongation comprising two rectilinear portions, namely a first rectilinear portion at the connection end of the deformable tongue, and a second rectilinear portion at the bendable portion of the deformable tongue.

An angle between the first and second rectilinear portions may be between 90° and 180°, better still between 100° and 170°, or even between 110° and 160°, in particular between 120° and 150°.

The elbow can interconnect the first and second rectilinear portions.

The deformable tongue may include a fold zone and be deformable, in particular plastically, by folding at the level of the fold zone so as to allow the foldable portion to be pressed against the small side of the permanent magnet.

The deformable tongue may have a restriction of its width. The presence of such a restriction can make it possible to obtain a zone at the level of which the width of the deformable tongue is reduced so as to facilitate the deformation of the deformable tongue, by bending of its foldable portion. The restriction thus makes it possible to define the zone at the level of which the tab is deformed by folding, i.e. the folding zone. The restriction can be located in the fold area.

The restriction can be made by cutting.

The cutout can have any shape, for example a rounded shape or not, a shape with angles, in particular a square, rectangular, triangular shape, or correspond to a longitudinal notch. The cutout can be made on a single side of the deformable tongue, either on the side of the inside of the elbow, or on the side of the outside of the elbow. Alternatively, the cutout is made on both sides of the deformable tab.

The deformable tab may include a folding axis extending in a plane parallel to the plane of the sheet. The deformable tab can thus be deformed, in particular plastically, by folding along this folding axis. The fold axis may extend in a direction parallel to the short side of the permanent magnet. The fold axis can be located in the fold area. The restriction can be located at the folding axis of the deformable tongue.

The first rectilinear portion may extend between the connection end and the elbow, with in particular a width which decreases towards the elbow.

The second rectilinear portion may extend between the elbow and the bend zone, with in particular a width which decreases towards the bend zone.

The foldable portion may extend between the fold zone and the free end of the deformable tab, with for example a constant width.

The folding zone can be located halfway between the elbow and the free end of the deformable tongue. Alternatively, the fold zone is located closer to the elbow than to the free end of the deformable tongue.

The thickness of the deformable tongue may be equal to that of the metal sheet of the rotor mass in which the deformable tongue is formed. The thickness of the sheet may be between 0.1 and 0.5 mm, in particular between 0.2 and 0.4 mm. For example, the thickness of the sheet is 0.27 mm or 0.35 mm.

The rotor mass may comprise at least two consecutive laminations, for example two or three, each with a deformable tab, the deformable tabs of two consecutive laminations overlapping. This can be particularly advantageous in the case where the sheets are not thick enough, for example when they have a thickness less than or equal to 0.4 mm, because in this case, the deformable tongues of each of the sheets taken in isolation do not do not have the required mechanical characteristics enabling them to maintain sufficient thrust on the permanent magnet after deformation. The length of the foldable portion may be at least equal to 1.5 times the thickness of the sheet, better between 2 and 15 times the thickness of the sheet, even better between 3 and 10 times the thickness of the sheet metal.

The length of the second portion can be at least equal to 1.5 times the thickness of the sheet, better between 2 and 4 times the thickness of the sheet.

The deformable tab may have at its free end a width of at least 1 mm, in particular between 2.5 and 4.5 mm.

The width of the deformable tab at its free end may be substantially equal to or slightly less than the width of the permanent magnet, that is to say the width of the small side of the permanent magnet. A free end of width slightly less than the width of the permanent magnet can make it possible to avoid, when the permanent magnet is introduced longitudinally into the housing, any friction of the foldable portion of the deformable tongue against a face of the housing located in view of a large side of the permanent magnet, which would interfere with the introduction of the permanent magnet into the housing.

The deformable tab may comprise or be constituted by a material chosen from steels M330-35, NO35-19, NO27-15, copper and mixtures thereof. Such materials can make it possible to obtain an optimal compromise between, on the one hand, flexibility and sufficient suppleness of the deformable tongue to allow, when the permanent magnet is introduced longitudinally into the housing, the deformation, in particular plastic, of the deformable tongue, while avoiding breakage of the deformable tongue, deformation of the rotor mass and/or damage to the permanent magnet, and on the other hand, an ability to maintain thrust on the permanent magnet after deformation of the deformable tongue.

The material constituting the deformable tab may or may not be identical to that of the rest of the sheet.

The housing may include a cutout made in the face of the housing to which the deformable tongue is connected. The cutout can be made in the face of the housing, between the deformable tongue and the permanent magnet. In the case where the rotor includes a wedge as described above, the cutout can be formed in the face of the housing, between the deformable tongue and the wedge. The presence of such a cutout makes it possible to increase the connection radius between the housing and the connection end of the deformable tongue to the face of the housing, and therefore to minimize the value of the radius or chamfer of the permanent magnet.

At least a portion of the permanent magnet may extend into the space formed in the housing by the cutout. The permanent magnet can thus at least partially cover the cutout. The circulation of the magnetic flux in the rotor can be improved.

In the case where the rotor comprises a shim as described above, the rotor mass may comprise at least one sheet comprising a shim as described above but devoid of a deformable tongue and a cutout as described above, and at least one sheet comprising at least one deformable tab and at least one cutout as described above but without a wedge.

The rotor may comprise at least two deformable tongues distributed along the rotor mass for the same housing, better still at least five, ten or twenty deformable tongues. For example, the rotor comprises five or six deformable tabs distributed along the rotor mass for the same housing.

In the case where the rotor mass comprises several packs of sheets stacked on top of each other, each pack of sheets may comprise at least two deformable tongues distributed along the pack of sheets for the same housing, better still at least five, ten or twenty deformable tabs. For example, each stack of sheets has five or six deformable tabs distributed along the stack of sheets for the same housing.

The greater the number of deformable tongues, the greater the thrust exerted by the deformable tongues after deformation on the permanent magnet. Thus, the greater the number of deformable tabs, the better the permanent magnet is mechanically locked in the housing.

The number of deformable tongues can be chosen so as to ensure sufficient mechanical blocking of the permanent magnet in the housing in order to avoid damage to the permanent magnets and allow the correct operation of the rotating electrical machine.

The deformable tabs can be distributed uniformly along the rotor mass, or not uniformly.

The spacing between two consecutive deformable tongues can be greater than or equal to the length of the foldable portion. It may in particular be greater than 0.675 mm, even greater than 0.81 mm. It can also be less than 4.32 mm, or even less than 2.97 mm. Such a spacing is necessary to allow the bendable portion of the deformable tab to be able to bend outside the plane of the sheets so as to press against the small side of the permanent magnet.

One and the same metal sheet of the rotor mass can comprise several deformable tabs, each deformable tab being formed in particular in said sheet and being in particular integral with the rest of said sheet. Said sheet may comprise several housings and one deformable tongue per housing. The rotor mass can then comprise, on the one hand, laminations comprising several housings and one deformable tab per housing, and, on the other hand, laminations without a deformable tab. For example, the rotor mass can comprise a sheet comprising several housings and a deformable tab per housing every N sheets, N being an integer between 2 and 20, better still between 4 and 15. There is then the presence of a sheet comprising several housings and one deformable tongue per housing then several sheets without a deformable tongue and so on. All the laminations of the rotor mass may therefore not be identical.

As a variant, all the laminations of the rotor mass can be identical. For example, each sheet may comprise several housings and a deformable tongue for one of these housings. The rotor mass then comprises a stack of said sheets, each sheet being angularly offset relative to the axis of rotation of the rotor so as to have deformable tongues for each housing.

The rotor mass may comprise at one of its ends sheets without a deformable tongue.

Similarly, in the case where the rotor mass comprises several stacks of laminations stacked on top of each other, each stack may comprise at one of its ends laminations without a deformable tongue.

This makes it possible to avoid having laminations whose deformable tabs protrude outside the rotor mass or the stack of laminations after deformation by the longitudinal introduction of the permanent magnet into the housing. This can thus allow the stacking of stacks of sheets on top of each other.

The rotor mass or each stack of laminations may comprise at one of its ends several laminations provided with deformable tongues configured so as not to bend during the longitudinal introduction of the permanent magnet into the housing. These sheets are preferably identical, which makes it possible to stiffen the deformable tongues and thus prevent their deformation during the longitudinal introduction of the permanent magnet into the housing.

Such tabs can then serve as a stop and define the bottom of the housing. These tabs thus make it possible to stop the longitudinal movement of the permanent magnet in the housing when it reaches the bottom of the housing, that is to say when it is completely introduced into the housing.

The housing may be delimited by at least one face facing a large side of the permanent magnet, said face comprising at least one convex deformation towards the inside of the housing, better still at least two convex deformations towards the inside of the housing . By "convex deformation towards the inside of the housing", we mean a local deformation of the sheet oriented in the housing. We can also talk about punching.

The deformation or deformations can make it possible to maintain the permanent magnet against the opposite face of the housing.

The face of the housing comprising the deformation(s) may be the face of the housing to which the deformable tongue is connected, or alternatively the opposite face.

When the face of the housing has a convex deformation towards the interior of the housing, the deformation can be positioned on the face of the housing so as to be opposite the center of the large side of the magnet.

When the face of the housing has two deformations that are convex towards the inside of the housing, the deformations can be positioned on the face of the housing so as to face respectively the first and second thirds of the long side of the magnet.

The housing may be delimited by at least one face facing a large side of the permanent magnet, said face comprising at least one deformable lug extending into the housing. The deformable lug may include a free end configured to press against the large side of the permanent magnet and hold the permanent magnet against the opposite face of the housing.

The deformable tab can be configured to deform outside the plane of the sheets. The face of the housing comprising the deformable tab can be the face of the housing to which the deformable tab is connected or, as a variant, the opposite face. The housing may have a major axis and a minor axis in cross section.

The presence of the deformable tongue can make it possible to mechanically lock the position of the permanent magnet in the housing along the major axis of the housing. This can allow the permanent magnet to be pre-positioned in the housing.

The additional presence of the deformation(s) and/or of the deformable tab makes it possible to mechanically block the position of the permanent magnet in the housing along the minor axis of the housing, so that it can no longer move. Its position in the housing is then locked. This minimizes the risk of magnetic losses at the interface between a permanent magnet and its housing, in particular at the level of the faces of the housing and the long sides of the permanent magnet.

A further subject of the invention, independently or in combination with the foregoing, is a rotor of a rotating electrical machine, comprising a rotor mass comprising laminations stacked on top of each other, the rotor mass comprising at least one permanent magnet having in section transverse, in particular perpendicular to an axis of rotation of the rotor, at least one long side and at least one short side, and at least one housing receiving the permanent magnet, the housing being delimited by:

- at least one face comprising at least one deformable tab extending into the housing, the deformable tab comprising a free end configured to press against the small side of the permanent magnet, and

- at least one face facing the large side of the permanent magnet comprising at least one convex deformation towards the interior of the housing, better still at least two convex deformations towards the interior of the housing, making it possible to hold the permanent magnet against the opposite side of the housing.

The deformable tongue can be bent. It may comprise a bendable portion configured to press against the small side of the permanent magnet.

The deformable tongue can be configured to deform outside the plane of the sheet and have a free end configured to press against the short side of the permanent magnet.

The presence of the deformable tab and the deformation(s) make it possible to mechanically block the position of the permanent magnet in the housing respectively along the major and minor axis of the housing so that it can no longer move. Its position in the housing is then locked. This minimizes the risks of magnetic losses at the interface between a permanent magnet and its housing, in particular at the faces of the housing and the long sides of the permanent magnet.

The face of the housing comprising the deformable tongue and that comprising the deformation(s) may be the same face. As a variant, the face of the housing comprising the deformable tongue is different from that comprising the deformation(s). For example, the face of the housing comprising the deformable tongue can be located opposite the small side of the permanent magnet or be opposite to that comprising the deformation(s).

machine and rotor

Another object of the invention is a rotating electrical machine comprising a stator and a rotor as defined above.

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. min, 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 include electrical conductors, at least a portion electrical conductors, or even a majority of electrical conductors, which can be in the shape of a U-shaped or I-shaped hairpin.

Manufacturing processes

Another subject of the invention is a method for manufacturing a rotor of a rotating electrical machine as defined above.

The method may include the step of introducing longitudinally, along the axis of rotation of the rotor, at least one permanent magnet into the housing.

A further subject of the invention, independently or in combination with the foregoing, is a method for manufacturing a rotor of a rotating electrical machine, in which a rotor mass comprising laminations stacked on top of each other is provided, the rotor mass comprising at least one housing configured to receive at least one permanent magnet having in cross section, in particular perpendicular to an axis of rotation of the rotor, at least one long side and at least one short side, the housing being delimited by at least one face in view of the long side of the permanent magnet, at least one sheet comprising at least one deformable tab connecting to said face of the housing and extending into the housing, the deformable tab being bent and comprising a bendable portion configured to press against the small side of the permanent magnet, the method comprising the step of introducing longitudinally, along the axis of rotation of the rotor, at least one a permanent magnet in the housing.

In the case where the rotor mass comprises several stacks of laminations stacked on top of each other, the method may first comprise the step consisting in introducing longitudinally at least one permanent magnet into the housing of each stack of laminations, then the step consisting of stacking the stacks of sheets on top of each other, with the permanent magnets in the housings.

The introduction of the permanent magnet into the housing can lead to deformation, in particular plastic deformation, of the deformable tongue by bending of so as to allow the bendable portion to press against the small side of the permanent magnet.

The deformable tongue can deform outside the plane of the sheet.

The permanent magnet may have in cross section a first small side and a second small side, opposite the first. The bendable portion can be configured to press against the first short side of the permanent magnet. At least one sheet may include at least one stop facing the second short side of the permanent magnet.

The deformable tongue can exert, after deformation, a thrust on the permanent magnet so as to hold it in the housing, in particular against the abutment.

The deformable tongue can thus make it possible to maintain the permanent magnet in the housing, in particular against the stop, during its introduction into the housing.

The methods may also include the step of performing at least one convex deformation towards the interior of the housing, better still at least two convex deformations towards the interior of the housing, on at least one face of the housing facing a large side of the permanent magnet.

The deformation(s) can be produced after the introduction of the permanent magnet into the housing. This facilitates the realization of the deformation(s) because the permanent magnet is then already held in the housing by the deformable tongue. The deformation or deformations can for example be carried out on a workstation different from that on which the introduction of the permanent magnet into the housing is carried out, and this without risk of losing the permanent magnet since the latter is retained in the housing by the deformable tongue.

The presence of the deformable tongue and the deformation(s) make it possible to mechanically block the position of the permanent magnet in the housing respectively along the major and minor axis of the housing so that it can no longer move. Thus, once the deformation(s) have been performed, the positioning of the permanent magnet in the housing is locked.

The deformation or deformations can be made on the face of the housing to which the deformable tab is connected or, as a variant, on the opposite face. Brief description of the drawings

[Fig 1] Figure 1 is a schematic and partial view, in perspective, of an example of a rotating electrical machine rotor according to the invention,

[Fig 2] Figure 2 is a schematic and partial front view of an example of sheet metal that can be used to form an alternative rotor embodiment according to the invention,

[Fig 3] Figure 3 is a view similar to Figure 2 without the permanent magnet, [Fig 4] Figure 4 shows a detail of the sheet metal of Figure 2, [Fig 5] Figure 5 is a view similar to Figure 4 of an alternative embodiment without the permanent magnet,

[Fig 6] Figure 6 is a view similar to Figure 2 of an alternative embodiment, and

[Fig 7] Figure 7 is a view similar to Figure 6 of an alternative embodiment.

detailed description

There is illustrated in Figure 1 an example of rotor 30 of a rotating electrical machine according to the invention, comprising a rotor mass 33 in which housings 4 are formed. Permanent magnets 1 are inserted into each of the housings 4.

The magnets 1 are in this example of generally rectangular shape in cross section as illustrated in the embodiments of Figures 2 and 6. Each magnet 1 has, in cross section, on the one hand, a first large side 2a and a second large side 2b, opposite the first, and on the other hand, a first short side 3a and a second short side 3b, opposite the first. Each housing 4 is delimited by two faces 5a, 5b respectively facing the first long side 2a and the second long side 2b of the magnet 1.

The housings 4 include deformable tongues 7 which are each connected to the face 5a of the corresponding housing 4 located opposite the first long side 2a of the corresponding magnet 1.

In a variant not shown, the deformable tongues 7 are each connected to the face 5b of the corresponding housing 4 located opposite the second long side 2b of the corresponding magnet 1.

The deformable tabs 7 each extend into the corresponding housing 4. A single housing 4 may comprise several deformable tongues 7 distributed along the rotor mass 33, as illustrated in FIG. 1. Each deformable tongue 7 comprises a bendable portion 8 which is bent so as to be pressed against the first short side 3a of the corresponding magnet 1.

The bendable portion 8 of the deformable tongue 7 is bent outside the plane of the sheets, along an axis 17 of folding of the deformable tongue 7 extending in a plane parallel to the plane of the sheet.

Each housing 4 has a stop 9 opposite the second small side 3b of the corresponding magnet 1, the stop 9 being connected to the face 5a of the corresponding housing 4. Each stop 9 extends in a side portion 21 of the corresponding housing 4, facing the second short side 3b of the corresponding magnet 1. This lateral portion 21 makes it possible to provide a magnetic vacuum, useful for promoting the circulation of the magnetic flux in the rotor 30 in an optimized manner.

The stop 9 can be formed in a sheet and be integral with the rest of the sheet. The same sheet may include the deformable tab 7 and the stop 9, as shown in Figures 1, 2, 3 and 6.

When its bendable portion 8 is bent so as to be pressed against the first small side 3a of the corresponding magnet 1, each deformable tongue 7 exerts a thrust on the corresponding magnet 1 according to the arrows indicated in FIG. 1, so as to maintain it in its housing 4 against the corresponding stop 9. Thus, the presence of the deformable tab 7 makes it possible to mechanically block the position of the magnet 1 in its housing 4 along the major axis 31 of the housing 4.

In the example of Figure 1, each housing 4 includes a wedge 10 facing the first short side 3a of the corresponding magnet 1, the wedge 10 being connected to the face 5a of the corresponding housing 4. Each wedge 10 is placed between the deformable tongue 7 and the magnet 1.

As a variant, the housings 4 can be devoid of wedges 10.

In the example of Figure 1, each housing 4 has two convex deformations 19 towards the inside of the housing on the face 5a of the housing 4, so as to hold the magnet 1 against the opposite face 5b of the housing 4. These deformations 19 can be made by punching the rotor mass 33, for example using a punch of generally spherical, cylindrical shape with or without radius, or pointed. A cylindrical punch with a radius has rounded edges between the bases and the side face of the cylinder, while a cylindrical punch without a radius has sharp edges, ie at sharp angles. Alternatively or additionally, the deformations 19 may be present on the face 5b of the housing 4 so as to hold the magnet 1 against the opposite face 5a of the housing 4.

Alternatively, each housing 4 has on its face 5a, a deformable tab 20 which extends into the housing 4, as shown in Figure 6. Each deformable tab 20 may have a free end which is pressed against the first long side 2a of the magnet 1 so as to hold it against the opposite face 5b of the housing 4. Each deformable lug 20 is deformed outside the plane of the sheets when the magnet 1 is in place in the housing 4. Alternatively or additionally, each housing 4 may include on its face 5b the deformable lug 20 which extends into the housing 4 and which has a free end which presses against the second large side 2b of the magnet 1 so as to hold it against the face 5a opposite of slot 4.

The presence of the deformation or deformations 19 and/or of the deformable tab 20 makes it possible to mechanically block the position of the magnet 1 in its housing 4 along the minor axis 32 of the housing 4. Thus, the position of the magnet 1 in the housing 4 is locked because blocked, on the one hand, by the deformable tab(s) along the major axis 31, and on the other hand, by the deformation(s) 19 and/or the deformable tab 20 along the minor axis 32.

There is illustrated in Figure 2 an example of sheet 6 that can be used to form the rotor according to the invention. Magnet 1, seen in cross section, is inserted into housing 4.

The foldable portion 8 of the deformable tongue 7 which is folded so as to be pressed against the first small side 3a of the magnet 1 is represented in FIG. 2 by the portion 8 of the deformable tongue 7 which extends beyond of the first short side 3a of the magnet 1.

The deformable tongue 7 is formed in the sheet 6. As illustrated in Figure 2, the deformable tongue 7 is integral with the rest of the sheet 6.

As illustrated in Figures 2 to 6, the housing 4 has a cutout 18 formed in the face 5a of the housing 4 to which the deformable tongue 7 is connected.

As illustrated in Figures 2, 4 and 6, the cutout 18 is formed in the face 5a of the housing 4, between the deformable tongue 7 and the magnet 1. A part of the magnet 1 extends into the space 43 formed in housing 4 by cutout 18. Magnet 1 thus at least partially covers cutout 18. As illustrated in Figure 3, the deformable tongue 7 extends between a connection end 11 allowing the connection of the deformable tongue 7 to the face 5a of the housing 4 and a free end 12. The width of the deformable tongue 7 decreases going from its connection end 11 towards its free end 12. For example, the deformable tab 7 has at its connection end 11 a width of 2.5 mm and at its free end 12 a width of 1.5 mm.

As illustrated in Figure 4, the deformable tab 7 is bent along its axis of elongation. It comprises an elbow 15 which connects together two rectilinear portions of the deformable tongue 7, namely a first portion 13 rectilinear and a second portion 14 rectilinear.

The first rectilinear portion 13 extends between the connection end 11 and the elbow 15 of the deformable tongue 7. In this example, the first rectilinear portion 13 has a length of 1.35 mm.

The second rectilinear portion 14 extends between the elbow 15 and the axis 17 of folding 17 of the deformable tongue 7. In this example, the second rectilinear portion 14 has a length of 2.1 mm.

The bendable portion 8 extends between the folding axis 17 and the free end 12 of the deformable tongue 7. In this example, the bendable portion 8 has a length of 2.5 mm.

In the example of Figure 4, the angle a between the first 13 and second 14 rectilinear portions is approximately 135°.

As illustrated in Figure 5, the deformable tab 7 may have a restriction 16 of its width at its axis 17 of folding. This restriction 16 can facilitate the deformation of the deformable tab 7 by folding its foldable portion 8.

As a variant, the deformable tongue 7 does not present any restriction 16 of its width at the level of its folding axis 17.

As illustrated in Figure 7, the deformable tab 7 can, in addition to being connected to the face 5a of the corresponding housing 4 located opposite the first large side 2a of the corresponding magnet 1, also be connected to the face 5b of the housing 4 located opposite the second large side 2b of the corresponding magnet 1. There is then a bridge 40 connecting the faces 5a and 5b of the housing 4. During the longitudinal introduction of the permanent magnet 1 in the housing 4, the bridge 40 can deform in addition to the deformable tongue 7. It can for example undergo a twist deformation.

Of course, the invention is not limited to the embodiments which have just been described. The rotor mass 33 may have other arrangements of the housings intended to receive the magnets, within the rotor mass.

The housings 4 and the magnets 1 can have other geometric shapes.

The housings can each extend along a longitudinal axis which can be straight or curved.

Claims

1. Rotor (30) of a rotating electric machine, comprising:

- at least one permanent magnet (1) having in cross section, perpendicular to an axis of rotation of the rotor, at least one long side (2a) and at least one short side (3a),

- a rotor mass (33) comprising laminations stacked on top of each other, the rotor mass (33) comprising at least one housing (4) receiving the permanent magnet (1), the housing (4) being delimited by at least a face (5a) facing the large side (2a) of the permanent magnet (1), at least one sheet (6) comprising at least one deformable tongue (7) being connected to said face (5a) of the housing (4 ) and extending into the housing (4), the deformable tab (7) being bent and comprising a bendable portion (8) configured to be bent outside the plane of the sheet so as to press against the small side (3a ) of the permanent magnet (1).

2. Rotor according to the preceding claim, the permanent magnet (1) having in cross section a first short side (3a) and a second short side (3b), opposite the first, the bendable portion (8) being configured to be pressed against the first short side (3a) of the permanent magnet (1), at least one plate comprising at least one stop (9) opposite the second short side (3b) of the permanent magnet (1).

3. Rotor according to one of the two preceding claims, the permanent magnet (1) having in cross section a first short side (3a) and a second short side (3b), opposite the first, the bendable portion (8) being configured to press against the first short side (3a) of the permanent magnet (1), at least one plate comprising at least one wedge (10) facing the first short side (3a) of the permanent magnet (1) .

4. Rotor according to any one of the preceding claims, the deformable tongue (7) extending between a connection end (11) to the face (5a) of the housing (4) and a free end (12), the width of the deformable tongue (7) which can in particular decrease going from its connection end (11) towards its free end (12).

5. Rotor according to any one of the preceding claims, the deformable tongue (7) comprising an elongation axis comprising two rectilinear portions, namely a first portion (13) rectilinear at the connection end (11) of the deformable tongue (7), and a second straight portion (14) at the bendable portion (8) of the deformable tongue (7).

6. Rotor according to any one of the preceding claims, the deformable tongue (7) having a restriction (16) of its width.

7. Rotor according to any one of the preceding claims, the deformable tab (7) comprising a folding axis (17) extending in a plane parallel to the plane of the sheet.

8. Rotor according to any one of the preceding claims, the housing (4) comprising a cutout (18) made in the face (5a) of the housing (4) to which the deformable tab (7) is connected.

9. Rotor according to any one of the preceding claims, comprising at least two deformable tongues (7) distributed along the rotor mass (33) for the same housing (4), better still at least five, ten or twenty deformable tongues ( 7).

10. Rotor according to any one of the preceding claims, the housing (4) being delimited by at least one face (5a, 5b) facing a long side (2a, 2b) of the permanent magnet (1), said face (5a, 5b) comprising at least one deformation (19) convex towards the interior of the housing (4), better still at least two deformations (19) convex towards the interior of the housing (4).

11. Rotor according to any one of the preceding claims, the housing (4) being delimited by at least one face (5a, 5b) facing a long side (2a, 2b) of the permanent magnet (1), said face (5a, 5b) comprising at least one deformable lug (20) extending into the housing (4), the deformable lug (20) comprising a free end configured to be pressed against the long side (2a, 2b) of the permanent magnet (1) and hold the permanent magnet (1) against the opposite face of the housing (5a, 5b).

12. Rotor of a rotating electrical machine, comprising a rotor mass (33) comprising laminations stacked on top of each other, the rotor mass (33) comprising at least one permanent magnet (1) having in cross section, perpendicular to an axis of rotation of the rotor, at least one long side (5a) and at least one short side (3a), and at least one housing (4) receiving the permanent magnet (1), the housing (4) being delimited by:

- at least one face comprising at least one deformable tongue (7) extending into the housing (4), the deformable tongue (7) being configured to deform outside the plane of the sheet and comprising a free end configured to lean against the small side (3a) of the permanent magnet (1), and

- at least one face (5a) facing the large side (2a) of the permanent magnet (1) comprising at least one deformation (19) convex towards the inside of the housing (4), better still at least two deformations (19 ) convex towards the inside of the housing (4), making it possible to hold the permanent magnet (1) against an opposite face (5b) of the housing (4).

13. Rotating electrical machine, comprising a stator and a rotor (30) as defined according to any one of the preceding claims.

14. A method of manufacturing a rotor (30) of a rotating electrical machine, in which a rotor mass (33) comprising laminations stacked on top of each other is provided, the rotor mass (33) comprising at least one housing (4 ) configured to receive at least one permanent magnet (1) having in cross section, perpendicular to an axis of rotation of the rotor, at least one long side (2a) and at least one short side (3a), the housing (4) being delimited by at least one face (5a) facing the large side (2a) of the permanent magnet (1), at least one sheet (6) comprising at least one deformable tab

(7) joining said face (5a) of the housing (4) and extending into the housing (4), the deformable tab (7) being angled and comprising a bendable portion (8) configured to be bent outside the plane of the sheet so as to press against the small side (3a) of the permanent magnet (1), the method comprising the step consisting in introducing longitudinally, along the axis of rotation of the rotor (30), at least one permanent magnet (1) in the housing (4).

15. Method according to the preceding claim, the introduction of the permanent magnet (1) into the housing (4) causing the deformation, in particular the plastic deformation, of the deformable tab (7) by bending so as to allow the portion foldable

(8) to press against the small side (3a) of the permanent magnet (1).