Rotor with simplified magnet holding

Abstract

The invention relates to an internal rotor comprising a yoke (10), magnets (50), a shaft (11) and one or two end plates (20, 30) at the axial end of the rotor. The inner surface (51) of each of the magnets is arranged against the periphery of the yoke. The or each end plate (20, 30) has, on its periphery, N claws (21, 31) projecting in the axial direction, which are formed by blades extending approximately perpendicular to the surface of the end plate. There is interference between the end plates (20, 30) and the assembly composed of the yoke (10) and the magnets (50). This interference increases as the end plates are axially fitted onto the assembly, such that the claws (21, 31) apply an increasing force on the magnets (50) during assembly. The magnets and claws are inscribed within the tubular casing (55) of the magnets, without penetrating into the air gap between the rotor and the stator.

Description

Simplified magnet holding rotor Field of invention

[0001] The present invention relates to the field of rotors, constituting the moving part, relative to the stator, of an electrical machine or an electromagnetic sensor. The rotor is in the form of a cylindrical sleeve driving or being driven by an axis linked to a yoke supporting permanent magnets which induce an electrical voltage in the windings of the stator of the generator / alternator separated from the circumferential surface of the rotor by an air gap.

[0002] The rotor can rotate at high speeds, resulting in a significant centrifugal force acting on the magnets attached to the periphery of the yoke. Typically, these magnets are glued to the surface of the yoke or held in place by a peripheral hoop. More recently, a solution has also been proposed where the permanent magnets are integrated into a rotor core called an "IPM" (interior permanent magnet) where the magnets are housed in cavities formed in the yoke, the peripheral projections of which form the magnetic poles. State of the art

[0003] Known in the prior art is patent application WO2022243411 describing a rotor designed for an electric motor, having a rotor body having a cylindrical rotor lamination pack and a number of surface magnets which are distributed on an outer surface of the rotor lamination pack as rotor poles, and which have a cross-sectional shape in the form of a loaf of bread having a convex curvature oriented towards the outer periphery, and a cuff-like protective sleeve which is arranged on the outer periphery of the rotor body, the protective sleeve having, at least on one end face, a turned-down collar which is formed by form-fitting and / or force-fitting in the radially inner regions between the curvatures of the tangentially adjacent surface magnets.

[0004] Patent application JP2003037954 describes a rotor comprising a non-magnetic magnet holder having a first arm portion and a circular tube-shaped non-magnetic rotor cover attached to cover the magnet holder and the magnet.

[0005] Patent application GB2559059 discloses a rotor, a rotating electrical machine, and a rotor manufacturing method in which the number of components is reduced, fixing is facilitated, and misalignment can be suppressed. The rotor comprises: a cylindrical rotor core in which a plurality of insertion holes are formed; and an annular detection magnet disposed coaxially with the rotor core. The detection magnet has a plurality of protruding portions protruding in the direction of the rotor core, said protruding portions being inserted into the insertion holes.

[0006] Patent application DE4331803 describes a rotor consisting of a carrier guided on the rotor shaft and magnet segments arranged on its peripheral face which, according to the invention, are held in contact with the carrier by retaining clips also guided on the rotor shaft. These retaining clips are designed in such a way that, when assembling the individual rotor elements, they take over the centering of the magnet segments during the assembly of the individual rotor parts and are only reinforced by compensation discs after complete assembly of all rotor elements, so that they keep the magnet segments pressed radially against the rotor magnet carrier.

[0007] Patent application US2020212739 describes a rotor having magnets located radially outside the rotor core and arranged along a circumferential direction, a holder comprising a support portion that supports the rotor core and the magnets from a first side in an axial direction, and a rotor cover comprising a cylindrical portion that surrounds the rotor core, the magnets and the holder from the outside in a radial direction and that opens towards the first side. The rotor cover comprises a lower portion that supports the rotor core from a second side of the rotor core in the axial direction. A portion of the radial outer edge of the support portion comprises a first portion and a second portion adjacent to the first portion in the circumferential direction. Disadvantages of the prior art

[0008] Prior art solutions have a first drawback which is the increase in the air gap. The magnet fixing parts form a crown or protuberances which locally increase the diameter and therefore lead to an increase in the air gap.

[0009] Compared to other documents, such as patent application WO2022243411 (interleaved document), the magnets are poorly held by a complementary means such as the addition of a peripheral metal hoop or plastic overmolding which also leads to an increase in the magnetic air gap, but also to greater losses when the hooping is carried out by an electrically conductive material. The rectangular-shaped tabs are not optimized for holding the magnets in operation, but only allow temporary holding during the assembly process before final securing by a complementary means.

[0010] In other solutions, the attachment causes magnetic leakage at the slots separating two consecutive magnets, which reduces performance.

[0011] In order to overcome the drawbacks of the prior art, the present invention relates, in its most general sense, to a rotor having the characteristics set out in claim 1 as well as in the independent claims.

[0012] The rotor comprises a yoke made of a ferromagnetic material and an axle, said yoke supporting N magnets,

[0013] said magnets being held on either side of their axial ends by at least one flange having at one of its peripheries N claws extending in the axial direction

[0014] • said magnets being magnetized radially or according to a rotating magnetization generating a radial main field, the width of the magnets being at least three times greater than the distance separating two adjacent magnets at the periphery of the rotor,

[0015] • the inner surface of each of said magnets being arranged against the periphery of said yoke,

[0016] • In a variant, the section of said magnets is curved, said tubular casing has a radius corresponding to the radius passing through the top of the curved part of the magnets, and said claws rest on two consecutive magnets, straddling the slot separating said two consecutive magnets.

[0017] As a possible alternative, the section of said magnets is rectangular, said tubular envelope has a radius corresponding to the radius passing through the outer edge of the magnets, and said claws rest on a middle zone of a magnet.

[0018] Additionally, in a variant, said claws are elastically deformable and configured to present, with the profile of said magnets, an increasing interference as a function of the axial engagement of the flange on said yoke.

[0019] In a variant:

[0020] - said cylinder head has trapezoidal section cavities with a large arched base

[0021] - said flanges have a peripheral ring formed of arcuate segments extending over an angular width of between 0.5 times and 2 times the angular width of a magnet, said arcuate segments connected by deformable segments, each of said arcuate segments having two claws resting on the outer surface of one or two magnets, fitting inside the tubular envelope of the magnetized structure,

[0022] - each arcuate segment is folded back on the side opposite the claw to form a wedge whose outer face is inclined, in the radial plane, to force the centripetal displacement of said arcuate segment by the force exerted on said wedge by the outer edge of the corresponding cavity, during the axial engagement of said flange on said cylinder head.

[0023] In particular for this variant, said magnets are curved and in that said claws come to bear on the external surface of two consecutive magnets, by fitting inside the tubular envelope of the magnetic structure, said wedges being positioned angularly between two consecutive claws.

[0024] Alternatively, said magnets are of rectangular section and in that said claws come to bear in the center of the external surface of a magnet, by fitting inside the tubular envelope of the magnetized structure, said wedges being angularly aligned with said claws.

[0025] In all compatible variants, an additional feature is that said magnets are of constant section along their entire length.

[0026] In all compatible variants, said claws are formed by blades extending perpendicular to the surface of said flange and have an end of decreasing width.

[0027] In particular, said flange has a radial rib at the level of the folding edge of each of said claws.

[0028] In all compatible variants, said magnets have a domed outer surface.

[0029] In one variant, said claws have a three-dimensional wedge shape capable of engaging in the space between the lateral flanks of two consecutive magnets.

[0030] The invention also relates to an electrical machine comprising a stator and a rotor having one or a combination of the characteristics described above.

[0031] In particular, the rotor is located inside the stator.

[0032] Alternatively, the rotor is located outside the stator.

[0033] The invention also relates to a magnetic sensor comprising a magnetosensitive probe and a rotor having one or a combination of the characteristics previously described.

[0034] The inner surface of the magnet is the surface in contact with the rotor yoke, the opposite surface being the outer surface of the magnet. Thus, a tubular envelope inscribing the magnets is a tube whose inner and outer cylindrical surfaces are sufficient to contain all of the magnets, i.e. no inner or outer surface of any of the magnets will pass through either of the cylindrical surfaces of the tubular envelope.

[0035] Detailed description of a non-limiting example of embodiment

[0036] The present invention will be better understood on reading the following description, concerning a non-limiting example of embodiment illustrated by the appended drawings where:

[0037] The figure represents an exploded view of a rotor corresponding to a first example of embodiment,

[0038] represents a perspective view of the rotor being assembled,

[0039] represents a sectional view of the rotor being assembled,

[0040] represents a perspective view of the rotor after assembly,

[0041] represents a sectional view of the rotor after assembly,

[0042] represents a perspective view of the rotor according to a first variant embodiment,

[0043] represents a perspective view of the rotor according to a second embodiment,

[0044] represents a detailed view in the axial direction of the rotor according to a third embodiment variant,

[0045] represents a perspective view of the rotor according to the third embodiment,

[0046] represents a detailed view in cross section, at the level of a pocket of the rotor according to the third embodiment variant before axial insertion of the flange,

[0047] represents the same detailed view of the third embodiment variant in the state after axial insertion of the flange,

[0048] represents a detailed view in the axial direction of the rotor according to a fourth embodiment variant having prismatic magnets,

[0049] represents a perspective view of an angular position sensor comprising a rotor corresponding to the present invention.

[0050] represents a sectional view of a rotor, intended for an external rotor motor, according to a fifth variant embodiment General principle

[0051] The rotor (1) according to the invention comprises a yoke (10) formed by a stack of stacked ferromagnetic sheets, or optionally, for applications to a sensor, or when magnetic losses are not a major concern, by a non-laminated ferromagnetic material.

[0052] This yoke (10) has a generally cylindrical shape, possibly hollowed out by pockets (17) to reduce its weight and its inertia. It is linked to an axis (11) supported by bearings (12, 13). The circumferential surface (14) of the yoke (10) has facets (15) of a shape complementary to the rear face (51) of the magnets (50). The rotor comprises N magnets (50) and the yoke (10) has N complementary facets (15).

[0053] Optionally, the yoke (10) has axial ribs (16) forming radial protuberances arranged between the consecutive facets (10) to facilitate the positioning of the magnets (50) which magnetically bond to the facets (15). The thickness of these axial ribs (16) is less than half the thickness of the magnets (50). Of course, in the case where the magnets are magnetized after their positioning on the rotor, the person skilled in the art would have no difficulty in finding a temporary solution for holding them in position before their final clamping.

[0054] The magnets (50) are surface magnets, formed by elements arranged tangentially on the circumferential surface of the yoke (10), and magnetized radially or with a rotating magnetization with a radial main component. The tangential dimension L of the magnets (50) is at least twice the radial dimension l of the magnet (50). Two consecutive magnets (50) are separated by an interval (52) corresponding to the width of the ribs (16). After assembly, the magnets (50) form an assembly resembling the ladyfingers of a strawberry charlotte, with a succession of magnets (50) whose outer surface defines a tubular envelope (55) interspersed with intervals of small width. Generally, the means for fixing the magnets (50) to the yoke (10) are completely inscribed in the tubular casing (55) of the magnets (50), without penetrating into the air gap between the rotor and the stator.

[0055] The outer surface (54) of the magnets (50) is optionally curved and convex, with a radius of curvature less than the radius of the tubular casing (55); it can also be flat.

[0056] More particularly, the invention relates to holding the magnets (50) on the yoke (10) using one or more flanges (20, 30) having claws (21, 31) extending in axial directions, substantially perpendicular to the plane of the disc area (22, 32) of the flanges (20, 30).

[0057] These flanges (20, 30) are axially engaged on the yoke (10), on either side of the yoke (10). The claws (21, 31) are folded with a re-entrant angle relative to the periphery of the disc zone (22, 32), less than or equal to 90° before assembly and engagement of the flanges (20, 30) on the magnets (50). These flanges have an interference with the assembly composed of the yoke (10) on which the magnets (50) are arranged, said interference increasing as the flanges are axially engaged, so that the claws (21, 31) exert an increasing force on the magnets (50) during this engagement.

[0058] Example of assembly and maintenance of the magnets (50) on the yoke (10)

[0059] The embodiments presented in figures 1 to 7 disclose a preferred embodiment of the connection between the magnets (50) and the yoke (10).

[0060] This connection is ensured by two flanges (20, 30) having claws (21, 31) extending in axial directions, substantially perpendicular to the plane of the disc zone (22, 32) of the flanges (20, 30).

[0061] These flanges (20, 30) are axially engaged on the yoke (10), on either side of the yoke (10). The claws (21, 31) are folded with a re-entrant angle relative to the periphery of the disc zone (22, 32), less than 90°, typically between 80° and 88° before assembly and engagement of the flanges (20, 30) on the magnets (50).

[0062] The claws (21, 31) have an end (23, 33) of decreasing width, defining two converging edges (26, 25; 35, 36).

[0063] When the claws (21, 31) engage on the outer surface (54) of the magnets, contact first occurs in a contact zone (28, 29; 38, 39) corresponding to the intersection of the inner face (27, 37) of the claw (21, 31) on the one hand, with the curved outer surfaces (54) of the two adjacent magnets. By exerting pressure on the flanges (20, 30) so as to bring them closer to the axial end of the magnets (50), the claws deform radially, the angle relative to the periphery of the disc area (22, 32) increasing, and the contact areas (28, 29; 38, 39) move along the two edges (26, 25; 35, 36), the contact areas (28, 29; 38, 39) then being optionally longer than during the initial contact when the profile of the ends (23, 33) is designed to be congruent with the landing surface on the outer surfaces of the adjacent magnets (54).We then speak of the existence of increasing interference between the claws (21, 31) and the magnets (54) when the flanges (20, 30) are engaged on the magnets (50) to hold them in place.

[0064] When this engagement position of the two flanges is reached, the magnets (50) are firmly held by the radial forces exerted by the elastic bending of the claws (21, 31), and the entire outer surface (24, 34) of the claws (21, 31) is completely inscribed in the tubular casing (55) of the magnets (50), without penetrating into the air gap between the rotor and the stator. The claws thus exert a radial force sufficient to withstand the centrifugal forces applied to the magnets when the motor is used at its maximum working speed. The bending angle of the claws does not exceed 90°. In this engagement position, the interference between the claws (21, 31) and the outer surfaces of the magnets (51) is maximum.

[0065] The disc area (22, 32) of the flange (20, 30) also has an annular protrusion (18, 19) for guidance on the axis (11) and for axial support and abutment for the bearings (12, 13).

[0066] Variant of realization to increase the stiffness of the claws (21, 31)

[0067] According to a first variant, illustrated by the, the folding zones (60) formed between the disc zone (22, 32) of the flange (20, 30) and the claws (21, 31) have a punching or a radial rib (61) increasing the stiffness of the claw (21, 31), which makes it possible to use thinner and therefore less expensive sheets.

[0068] According to a second variant, illustrated by the, the cylinder head (10) has radial protrusions (70) with a T-shaped section, in the median transverse plane of the cylinder head (10), and extending over at most a third of the axial height of the cylinder head (10).

[0069] The claws (21, 31) have a complementary notch (71) which engages on this radial protrusion (70) to form a radial stop for the end of the claw (21, 31) and prevent it from moving away unexpectedly. Production of the flanges

[0070] The flanges (20, 30) can be produced by cutting and stamping a metal sheet, preferably non-magnetic, for example a stainless steel or aluminum sheet.

[0071] The disc areas (22, 32) of the flanges (20, 30) are preferably solid to close the pockets (17) and reduce turbulence which is a source of air noise.

[0072] Incidentally, these flanges (20, 30) can receive an unbalance by brazing or by machining to achieve rotor balancing.

[0073] These two variants are particularly advantageous for high-speed motors.

[0074] Alternative embodiment with radially deformable flanges

[0075] In the variants described above, the claws (21, 31) are, at rest, slightly retracted relative to a flange (20, 30) whose external diameter corresponds to the diameter of the tubular casing in which the assembly of magnets (50) is located. The axial engagement of the flange causes centrifugal deformation of the end of the claws (21, 31), by increasing interference with the tubular surface of the magnets (50).

[0076] An alternative embodiment, as shown in figures 8 to 11 or 12, consists of providing a flange (20, 30) having, before assembly, a diameter slightly greater than the diameter of the tubular envelope in which the magnet assembly is inscribed, with deformable zones allowing a reduction in the diameter after assembly, down to a diameter corresponding to that of the tubular envelope of the magnet assembly.

[0077] For these embodiment variants where the flange (20, 30) is of variable diameter, the claws (21, 31) are pressed against the outer surface of the magnets (50) less by elastic deformation (they could even be rigid) but rather by the approach caused by the centripetal deformation of the flange (20, 30).

[0078] This deformation of the flange (20, 30) can be achieved by a cutting alternating arcuate annular segments (91) and deformable segments (92). These deformable segments (92) are for example formed by cutting out “S”-shaped strips making it possible to absorb a coming together of two consecutive arcuate annular segments (91). These arcuate annular segments (91) and these deformable segments (92) define a deformable ring whose diameter can be reduced. The arcuate annular segments (91) extend to a central zone for the passage of the axis (11), by points connected together by annular links (94).

[0079] The angular width of the arcuate annular segments (91) is between one and two times the angular width of a magnet (50), the deformable segments (92) occupying the complementary angular width. The deformation can be in the plane of the flange (20, 30), or in a perpendicular direction.

[0080] Each arcuate segment (91) has two claws (21) which rest on the outer surface (54) of one or two magnets, fitting inside the peripheral envelope of the magnetized structure.

[0081] The modification of the diameter of the flange (20, 30) results from the interaction with the yoke (10) during its axial engagement.

[0082] The yoke (10) has cavities (17) of trapezoidal section with a large arcuate-shaped base having an angular width less than the angular width of a magnet (50). The external arcuate surface constrains, when the flange (20, 30) is engaged on the yoke (10), the centripetal movement of a wedge (93) formed by folding the arcuate segment (91), on the side opposite the claw (21). This wedge (93), the outer face (95) of which is inclined, in the radial plane (i.e. the plane containing both the axis of rotation and a radius passing through the center of mass of a wedge), forces the centripetal displacement of said corresponding arcuate segment (91) by the force exerted on said wedge (93) by the outer edge (87) of the corresponding cavity (17), during the axial engagement of said flange on said cylinder head (10), and the crushing of the deformable sectors (92) located between two consecutive arcuate segments (91).This deformation mechanically ensures the bringing together of the claws (21, 31) against the surface of the magnets (50). Figures 10 and 11 show a detailed sectional view in a plane parallel to the radial plane, but slightly offset within a cavity (17), so as to be able to observe the insertion of a shim (93) within said cavity (17). L represents the state at the start of insertion for which a radial clearance is visible between the outer edge (87) of the cavity (17) and the inclined outer face (95) of the shim (93). L represents the state at the end of insertion for which this clearance has been absorbed and where the outer edge (87) and the inclined outer face (95) are in contact. The clearance between the magnet (50) and the claw (21) has been deliberately exaggerated to improve readability, but very slight deformations of the order of 1 or a few tenths of a mm, allow assembly to be ensured taking into account manufacturing variations, while guaranteeing good maintenance of the magnet.

[0083] It may be noted that when the flanges (20, 30) are fully engaged on the yoke (10) of the rotor (1), the stress exerted between the extensions (93) and the outer walls of the cavities (17) is maximum. This embodiment therefore comprises, like the previous embodiments, an increasing interference between the flanges (20, 30) and the yoke (10) of the rotor or the magnets (50), leading to an increase in the holding force of said magnets (50) as the flanges (20, 30) are axially inserted to reach their final assembly position.

[0084] In a first embodiment, represented by figures 8 to 11, the magnets (50) are curved and the claws (21, 31) come to bear on the external surface of two consecutive magnets (50), by fitting inside the peripheral envelope of the magnetized structure, said wedges (93) being positioned angularly between two consecutive claws (21, 31).

[0085] In a second embodiment, represented by the, the magnets (50) are of rectangular section and the claws (21, 31) come to bear at the center of the external surface of a magnet (50), by fitting inside the peripheral envelope of the magnetized structure, said wedges (93) being angularly aligned with said claws (21, 31). Cooling flask

[0086] Optionally and as more particularly visible in figures 9 and 10, the flange (20, 30) can be provided with fins (90) extending to the disc surface to ensure cooling. Application to the production of a sensor

[0087] The rotor described above, in its various intended variants, is applicable to the production of a sensor. Laen illustrates an example of production.

[0088] The particularity of the yoke (10) is that the shaft is hollow to allow coupling to the shaft of a driving member. The magnets (50) are generally more numerous, but thinner than in the application to a motor. A magnetosensitive probe (80) mounted on a printed circuit (81) is positioned opposite the enveloping surface (55) of the magnets (50). The outer surface of the magnets (50) is configured to produce a sinusoidal variation of the magnetic field during its displacement.

[0089] Compared to a rotor intended for a motor, the rotor of a sensor generally rotates at a lower angular speed, but has a larger diameter. Consequently, the peripheral speed can lead, as in “motor” applications, to relatively large centrifugal forces acting on the magnets (50), which justifies the use of a claw-type hold as proposed by the present invention. External rotor variant

[0090] Therepresents an alternative embodiment with an external rotor. This embodiment differs from the previous embodiment in that the rotor is designed to accommodate a stator within it. Thus, the magnets are arranged on the inner periphery of the yoke (10). The magnets are shown in thewith shaped poles, but the invention is compatible with parallelepiped magnets as shown in the case with an internal rotor.

Claims

- Rotor comprising a yoke (10) and an axis (11), said yoke (10) supporting N magnets (50) magnetized radially or according to a rotating magnetization generating a main radial field, the inner surface (51) of each of said magnets (50) being arranged against the periphery of said yoke (10), said magnets (50) being held on either side of their axial ends by at least one flange (20, 30) having at one of its peripheries N claws (21, 31) extending in the axial direction, said claws (21, 31) are formed by blades extending obliquely to the surface of said flange, characterized in that the flange(s) (20, 30) are configured to be axially engaged on the assembly consisting of the rotor yoke (10) on which are positioned the magnets (50), by presenting an increasing interference with said yoke (10) or said magnets (50), the peripheral envelope of said claws (21, 31) is inscribed, after assembly,in the tubular casing (55) inscribing said magnets (50), said claws (21, 31) coming into constrained contact with a part of the external surface (54) of the magnet (50)., - Rotor according to claim 1 characterized in that the section of said magnets (50) is curved, said tubular casing (55) having a radius corresponding to the radius passing through the top of the curved part of the magnets (50), and in that said claws (21, 31) come to bear on two consecutive magnets (50), straddling the slot separating said two consecutive magnets (50). - Rotor according to claim 1 characterized in that the section of said magnets (50) is rectangular, said tubular envelope (55) having a radius corresponding to the radius passing through the outer edge of the magnets (50), and in that said claws (21, 31) come to bear on a median zone of a magnet (50). - Rotor according to claim 1 characterized in that said claws are elastically deformable and configured to present, with the profile of said magnets, an increasing interference as a function of the axial engagement of the flange on said yoke (10). - Rotor according to claim 1 characterized in that: said yoke (10) has cavities (17) of trapezoidal section with a large base of arcuate shape said flanges (20, 30) have a peripheral ring formed of arcuate segments (91) extending over an angular width between 0.5 times and 2 times the angular width of a magnet (50), said arcuate segments (91) connected by deformable segments (92), each of said arcuate segments (91) having two claws (21) coming to bear on the external surface (54) of one or two magnets, by fitting inside the tubular casing (55) of the magnetized structure, each arcuate segment (91) is folded on the side opposite the claw (21) to form a wedge (93) whose external face is inclined, in the radial plane, to force the centripetal displacement of said arcuate segment (91) by the force exerted on said wedge (93) by the external edge of the corresponding cavity (17), during the axial engagement of said flange on said yoke (10). - Rotor according to claim 5 characterized in that said magnets (50) are curved and in that said claws (21, 31) come to bear on the external surface (54) of two consecutive magnets (50), by fitting inside the tubular casing (55) of the magnetized structure, said shims (93) being positioned angularly between two consecutive claws (21, 31). - Rotor according to claim 5 characterized in that said magnets (50) are of rectangular section and in that said claws (21, 31) come to bear in the center of the external surface (54) of a magnet (50), by being inscribed inside the tubular envelope (55) of the magnetized structure, said shims (93) being angularly aligned with said claws (21, 31). - Rotor according to claim 1 characterized in that said magnets (50) are of constant section over their entire length. - Rotor according to claim 1 characterized in that said claws (21, 31) are formed by blades extending in the axial direction forming an acute angle with the plane of the disc zone (22, 32) of said puddle (20, 30) and have an end (23, 33) of decreasing width. - Rotor according to the preceding claim, characterized in that said flange has a radial rib at the level of the folding edge of each of said claws. - Rotor according to claim 1 characterized in that said magnets (50) have a curved external surface (54). - Rotor according to claim 1 characterized in that said claws (21, 31) have a three-dimensional shape of corners capable of engaging in the space between the lateral flanks of two consecutive magnets. - Rotor according to claim 1 characterized in that all of the means for fixing the magnets (50) on the yoke (10) are located in the tubular casing (55) inscribing said magnets (50). - Electrical machine comprising a stator and a rotor characterized in that said rotor conforms to claim 1. - Electrical machine according to the preceding claim characterized in that the rotor is located inside the stator. - Electrical machine according to claim 14 characterized in that the rotor is located outside the stator. - Electromagnetic sensor comprising a magnetosensitive probe and a rotor characterized in that said rotor conforms to claim 1.

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