Permanent magnet DC motor stator assemblies with concave magnet configurations and conversion method

Abstract

The subject application presents permanent magnet DC motor stator assemblies utilizing concave magnet configurations to enhance magnetic flux concentration. The stator designs incorporate buried permanent magnets (111) arranged in specific geometric patterns, surrounded by soft magnetic elements (112). This arrangement creates focused magnetic flux paths while maintaining magnetic isolation between poles. The subject-application also provides a method for converting between radial and axial configurations, offering enhanced design flexibility and manufacturing efficiency. These innovations result in improved magnetic field distribution and motor performance.

Description

PERMANENT MAGNET DC MOTOR STATOR ASSEMBLIES WITH CONCAVE MAGNET CONFIGURATIONS AND CONVERSION METHOD

[0001] The subject application relates to the technical field of direct current (DC) motors, specifically concerning stator assemblies incorporating permanent magnets 111 for both radial and axial configurations.

[0002] This technology finds applications in electric motors requiring high efficiency and precise magnetic field control, particularly in brushed DC motors with specific magnetic flux requirements.

[0003] Conventional permanent magnet DC motor stators typically employ simple magnet arrangements which limit magnetic flux concentration capabilities.

[0004] These traditional designs often result in suboptimal magnetic field distribution and efficiency losses.

[0005] Current stator designs frequently struggle to maintain consistent magnetic field strength across the air gap.

[0006] Furthermore, standard configurations present limitations in converting between radial and axial architectures, restricting design flexibility and manufacturing efficiency.Summary of Subject application

[0007] The subject application provides stator assemblies incorporating permanent magnets 111 for both radial and axial configurations, as described in the accompanying claims.

[0008] Dependent claims describe specific embodiments of the subject application.

[0009] These and other aspects of the subject application will be apparent from an elucidated based on the embodiments described hereinafter.

[0010] Further details, aspects and embodiments of the subject application will be described, by way of example only, with reference to the drawings. In the drawings, like reference numbers are used to identify like or functionally similar elements. Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale.

[0011] shows two cross section of a first aspect of the subject application.

[0012] shows a cross section of magnetic poles of.

[0013] shows the cross sectionprojected onto the cross-section of the stator body a third aspect of the subject application.

[0014] shows a first schematic flow diagram according to the subject application.

[0015] shows a first cross section of a third aspect of the subject application.

[0016] shows a second cross section of a third aspect of the subject application.

[0017] shows a third cross section of a third aspect of the subject application.

[0018] shows a second schematic flow diagram according to the subject application.Preliminary Remarks

[0019] Because the illustrated embodiments of the subject application may, for the most part, be composed of components known to the skilled person, details will not be explained in any greater extent than that considered necessary for the understanding and appreciation of the underlying concepts of the subject application, in order not to obfuscate or distract from the teachings of the subject application.Objective of the subject application

[0020] A primary objective of the subject application is to enhance magnetic flux concentration and control in DC motor stator assemblies.

[0021] For this purpose, the inventors propose innovative stator assemblies featuring concave permanent magnet configurations and specialized soft magnetic element arrangements.

[0022] This solution implements buried permanent magnets in specific geometric patterns, combined with strategically positioned soft magnetic elements.

[0023] The design creates focused magnetic flux paths while ensuring magnetic isolation between poles, thereby improving overall motor performance and reducing operational noise through minimized magnetic interference.First aspect of the subject application

[0024] As described inand, a first aspect of the subject application relates to a permanent magnet DC motor stator assembly specifically designed for use in a radial brushed DC motor having a rotor.

[0025] The term 'permanent magnet DC motor stator assembly' refers to a stationary component of a direct current motor which incorporates permanent magnets 111 as its primary magnetic field source. As an example, this assembly may include a cylindrical stator structure with embedded permanent magnets 111, a disc-shaped stator with radially arranged magnetic poles 110, or a rectangular stator body with multiple magnetic pole 110 pairs.

[0026] The term 'radial brushed DC motor' designates an electric motor configuration where the magnetic flux paths are directed radially from the center to the periphery and remain within the section plane without axial components, with mechanical brushes providing electrical contact to the rotor. As an example, this may include traditional DC motors with copper brushes and a commutator, industrial motors with carbon brushes, or small appliance motors with precious metal brushes.

[0027] In particular, the stator assembly comprises an elongated stator body with a central longitudinal axis, a circumference and a cross-section.

[0028] By 'elongated stator body' is meant the main structural component of the stator which extends along its central axis and houses the magnetic components. As an example, this may take the form of a cylindrical steel housing, a hexagonal prismatic structure, or a rectangular cross-section body with rounded corners.

[0029] The term 'central longitudinal axis' refers to the primary reference line running through the center of the stator body along its length, which serves as the main axis of symmetry and rotation. As an example, this axis may serve as the reference for radial measurements, the centerline for magnetic flux paths, or the basis for angular position measurements.

[0030] Additionally, the cross-section has a perimeter line that delimits the contour of the stator assembly and exhibits an external circumferential dimension and a radial dimension perpendicular to the external circumferential dimension.

[0031] Furthermore, the elongated stator body cross-section includes multiple magnetic poles 110 formed within.

[0032] The term 'magnetic poles 110' designates the regions within the stator where magnetic flux emerges or enters, created by permanent magnets 111 and soft magnetic materials. As an example, these may include north-south pole pairs, multiple pole configurations with alternating polarities, or composite poles formed by multiple magnets.

[0033] Specifically, each magnetic pole 110 has a pole axis, P, and incorporates one or more permanent magnets 111 buried within the cross-section.

[0034] The term 'pole axis' refers to the reference line running through the center of each magnetic pole 110, which serves as the primary direction for magnetic flux concentration and magnet arrangement. As an example, this axis may serve as the alignment reference for permanent magnets 111, the direction of magnetic flux flow through the pole, or the centerline for determining the concave configuration of magnets.

[0035] Furthermore, these magnets are arranged to form a concave configuration when viewed from the central longitudinal axis.

[0036] By 'concave configuration' is meant an arrangement of permanent magnets 111 that curves outward when viewed from the central axis, creating a focused magnetic field. As an example, this may include C-shaped magnet arrangements, V-shaped configurations, or curved arrays of multiple magnets.

[0037] In particular, the concave configuration extends radially outward from the central longitudinal axis.

[0038] Moreover, this configuration has an apex, PX, located within a predetermined angular range with respect to the pole axis, P.

[0039] In an example, the predetermined angular range is within ±25°, preferably within ±20°, more preferably within ±15°, even more preferably within ±10°, particularly preferably within ±5°, more particularly preferably within ±3°, and most preferably within ±1°, with respect to the pole axis, P.

[0040] In particular, the apex, PX, corresponds to the point of maximum curvature of the concave configuration.

[0041] In addition, the radius of curvature at the apex, PX, is smaller than the inner radius defined by the perimeter line.

[0042] Also, the magnetic poles 110 include soft magnetic elements 112 made of soft-magnetic material.

[0043] The term 'soft magnetic elements 112' refers to materials with high magnetic permeability that can be easily magnetized and demagnetized, used to guide and shape magnetic flux paths. As an example, these may include silicon steel laminations, powdered iron cores, or ferrite components.

[0044] These soft magnetic elements 112 are arranged within the cross-section to surround the permanent magnets 111.

[0045] Finally, the permanent magnets 111 have magnetization directions that converge toward and define the pole axis, P, with such convergence creating a magnetic flux concentration effect along the pole axis, P.

[0046] By 'magnetic flux concentration effect' is meant the phenomenon where magnetic field lines are focused and intensified along specific paths due to the geometric arrangement of magnetic materials. As an example, this may occur through converging magnet orientations, shaped pole pieces, or strategic placement of flux guides.

[0047] First embodiment of the first aspect of the subject application

[0048] In a first embodiment of the first aspect of the subject application, the first permanent magnet DC motor stator assembly 100 includes permanent magnets 111 buried within the cross-section through a specific soft magnetic elements 112 arrangement.

[0049] By 'buried permanent magnets 111' is meant permanent magnets 111 which are completely enclosed within the cross-section of the stator body and surrounded by soft magnetic materials. As an example, this may include magnets embedded in machined cavities within the stator core, magnets inserted into pre-formed slots in the stator structure, or magnets encapsulated within a soft magnetic composite material.

[0050] In particular, the arrangement comprises inner soft magnetic elements 1121 positioned between the permanent magnets 111 and the central longitudinal axis.

[0051] The term 'inner soft magnetic elements 1121' refers to the soft magnetic components positioned between the permanent magnets 111 and the central longitudinal axis of the stator, which guide and shape the magnetic flux paths in the inner region. As an example, these elements may take the form of solid ferromagnetic segments, laminated steel structures which reduce eddy current losses, or powdered iron composite pieces which optimize the magnetic flux distribution.

[0052] Additionally, outer soft magnetic elements 1122 are positioned between the permanent magnets 111 and the perimeter line.

[0053] The term 'outer soft magnetic elements 1122' designates the soft magnetic components located between the permanent magnets 111 and the stator's outer perimeter, which complete the magnetic circuit and contain the magnetic flux. As an example, these may include continuous ring-shaped structures which provide a return path for magnetic flux, segmented elements which reduce magnetic losses, or shaped pieces which optimize the air gap flux density.

[0054] Furthermore, the inner soft magnetic elements 1121, permanent magnets 111, and outer soft magnetic elements 1122 form a radial sequence of alternating magnetic materials. This sequence extends from the central longitudinal axis to the perimeter line.

[0055] By 'radial sequence of alternating magnetic materials' is meant the specific arrangement of different magnetic materials along the radial direction, which creates an optimized magnetic circuit from the center to the periphery of the stator. As an example, this sequence may manifest as a soft magnetic core followed by permanent magnets 111 and an outer soft magnetic shell, a multi-layer arrangement with intermediate air gaps for flux concentration, or a composite structure with graduated magnetic properties along the radial direction.

[0056] Specifically, when moving from the central longitudinal axis outward, the radial sequence comprises soft magnetic material, then permanent magnet 111 material, followed by soft magnetic material.

[0057] Second embodiment of the first aspect of the subject application

[0058] In a second embodiment of the first aspect of the subject application, the first permanent magnet DC motor stator assembly 100 features permanent magnets 111 of each magnetic pole 110 that minimize magnetic flux cross-talk with permanent magnets 111 of adjacent magnetic poles 110.

[0059] By 'minimized magnetic flux cross-talk between permanent magnets 111 of adjacent poles' is meant an arrangement where the magnetic flux generated by the permanent magnets 111 of each pole primarily contributes to that specific pole's magnetic field, with minimal leakage or interference with the fields of neighboring poles. As an example, this minimization may be achieved through precise control of magnetization directions, strategic placement of the permanent magnets 111, or specialized magnetic circuit designs which contain and direct the magnetic flux generated by the permanent magnets 111. This principle applies even in cases where a single permanent magnet 111 111, such as a bipolar magnet, is used for two adjacent poles.

[0060] In particular, the minimization of magnetic flux cross-talk occurs through two specific mechanisms.

[0061] First, the permanent magnets 111 of each magnetic pole 110 contribute primarily to that pole's magnetic flux. In the case of a shared permanent magnet 111 between two adjacent poles, the magnetization within each pole section of the magnet is optimized to generate the flux concentration effect with minimal flux cross-talk.

[0062] The term 'primary magnetic flux contribution' refers to the characteristic where the magnetic field generated by each permanent magnet 111 mainly affects its associated pole's magnetic circuit with minimal influence on adjacent poles. This is achieved through precise orientation of magnetization directions, strategic placement of the permanent magnets 111, and optimized magnetic circuit geometries which confine the magnetic flux generated by the permanent magnets 111 to their respective poles.

[0063] Additionally, the soft magnetic elements 112 are arranged to form continuous magnetic paths between adjacent magnetic poles 110.

[0064] By 'continuous magnetic paths' is meant the uninterrupted routes through soft magnetic materials which guide and channel the complete magnetic flux of the motor between adjacent poles in a controlled manner. As an example, these paths may take the form of shaped ferromagnetic segments which direct flux around pole boundaries, laminated structures which provide low-reluctance paths for magnetic flux, or composite magnetic materials with specifically designed permeability distributions to optimize flux routing.

[0065] Third embodiment of the first aspect of the subject application

[0066] In a third embodiment of the first aspect of the subject application, the first permanent magnet DC motor stator assembly 100 features magnetic poles 110, each comprising a single permanent magnet 111 with a continuous curved shape to form the concave configuration.

[0067] By 'continuous curved shape' is meant a single, uninterrupted magnetic structure which follows a smooth curved profile without sharp corners or discontinuities in its geometry. As an example, this may include an arc-shaped magnet with uniform curvature, a smoothly bent magnetic structure with varying radius of curvature, or a curved profile with gradual transitions between different curvature sections.

[0068] Specifically, the continuous curved shape of each permanent magnet 111 includes at least one shape selected from three distinct options: C-shape, V-shape, or U-shape.

[0069] The term 'C-shape permanent magnet 111 111' refers to a magnetic element which forms a partial circular arc with open ends, resembling the letter C, which creates a focused magnetic field pattern. As an example, this configuration may manifest as a 180-degree curved magnet segment, a partially enclosed magnetic arc with specific angular span, or a curved magnetic structure with specialized end geometries for flux optimization.

[0070] The term 'V-shape permanent magnet 111 111' designates a magnetic element formed by two straight or slightly curved segments which meet at an angle, creating a pointed configuration similar to the letter V. As an example, this may include a symmetrical V-configuration with equal leg lengths, an asymmetric V-shape with different leg lengths for specialized flux patterns, or a modified V-shape with rounded vertex for manufacturing considerations.

[0071] The term 'U-shape permanent magnet 111 111' describes a magnetic element which forms a curved profile with parallel or nearly parallel ends, similar to the letter U. As an example, this may take the form of a symmetrical U-shaped magnet with uniform width, a modified U-shape with varying leg lengths for specific flux distributions, or a rounded U-configuration with optimized corner radii for magnetic performance.

[0072] Fourth embodiment of the first aspect of the subject application

[0073] In a fourth embodiment of the first aspect of the subject application, the first permanent magnet DC motor stator assembly 100 includes magnetic poles 110 with specific structural features.

[0074] In particular, each magnetic pole 110 comprises at least two permanent magnets 111, which can be either symmetrical or asymmetrical, having a polygonal shape to form the concave configuration.

[0075] The term 'symmetrical permanent magnets 111' refers to magnetic elements which possess identical geometric and magnetic properties when compared about a reference plane or axis within the magnetic pole 110 structure. On the other hand, 'asymmetrical permanent magnets 111' refers to magnetic elements which have different geometric or magnetic properties when compared about a reference plane or axis within the magnetic pole 110 structure. As an example, symmetrical arrangements may include pairs of identical pentagonal magnets arranged mirror-symmetrically, sets of trapezoidal magnets with matching dimensions and magnetization directions, or arrays of rectangular magnets positioned symmetrically about the pole axis, P. Asymmetrical arrangements may include magnets with different shapes, sizes, or magnetization directions on either side of the reference plane or axis.

[0076] By 'polygonal shape' is meant a geometric form bounded by straight lines which create a closed figure with specific angles and dimensions, with particular emphasis on pentagonal configurations in this context. As an example, this may manifest as regular pentagons with equal sides and angles, modified pentagons with optimized angles for magnetic flux direction, or irregular pentagonal shapes designed for specific flux concentration effects.

[0077] Specifically, the polygonal shape includes a pentagonal shape or a rectangular shape.

[0078] Additionally, the magnetic pole 110 structure incorporates air gaps located between adjacent permanent magnets 111.

[0079] The term 'air gaps between magnets' designates the non-magnetic spaces deliberately maintained between adjacent permanent magnets 111 within the same pole structure. As an example, these gaps may serve as flux barriers to control magnetic field distribution, as assembly clearances to facilitate manufacturing and installation, or as thermal expansion spaces to accommodate temperature variations during operation.

[0080] Furthermore, these air gaps include a specific air gap positioned at the pole axis, P.

[0081] By 'pole axis air gap' is meant a specific non-magnetic space located at the central axis of each magnetic pole 110 which influences the magnetic field distribution. As an example, this may include a central void which helps focus the magnetic flux, a shaped gap which optimizes the field pattern, or a controlled space which enhances the magnetic flux concentration effect.

[0082] First implementation of the fourth embodiment of the first aspect of the subject application

[0083] In a first implementation of the fourth embodiment of the first aspect of the subject application, the first permanent magnet DC motor stator assembly 100 features specific magnetic pole 110 configurations.

[0084] In particular, for each magnetic pole 110, the permanent magnets 111 have magnetization directions oriented at specific angles relative to each other and to the pole axis, P.

[0085] The term 'magnetization directions' refers to the vectors which indicate the alignment of magnetic domains within each permanent magnet 111 111, determining the path along which magnetic flux primarily flows. As an example, this may include axial magnetization parallel to the pole axis, P, radial magnetization perpendicular to the central axis, or angular magnetization at specific orientations relative to reference planes.

[0086] The specific angles between the magnetization directions are chosen to optimize the resulting magnetic field within each pole and to minimize flux cross-talk between adjacent poles. These angles may vary depending on the number of poles, the desired field characteristics, and the overall motor design.

[0087] Furthermore, the magnetization directions of these permanent magnets 111 generate a resulting magnetic field.

[0088] The term 'resulting magnetic field' designates the composite magnetic flux pattern which emerges from the combination of individual magnet contributions within a pole structure. As an example, this may appear as a concentrated flux pattern along the pole axis, P, a uniform field distribution in the air gap, or a shaped magnetic field optimized for specific motor performance characteristics.

[0089] In certain configurations, such as a 4-pole motor, this magnetic field may orient substantially at 45 degrees relative to the radial direction. However, the specific orientation of the resulting field may vary in other pole configurations to optimize motor performance.

[0090] In the 4-pole configuration,'45 degrees relative to the radial direction' refers to the specific angular orientation of the composite magnetic field which bisects the angle between the radial axis and the tangential direction. As an example, this orientation may serve to optimize torque production, enhance the interaction with armature windings, or create ideal flux paths through the magnetic circuit. In other configurations, the optimal field orientation may differ.

[0091] Second implementation of the fourth embodiment of the first aspect of the subject application

[0092] In a second implementation of the fourth embodiment of the first aspect of the subject application, the first permanent magnet DC motor stator assembly 100 incorporates a specific arrangement of permanent magnets 111.

[0093] Specifically, these permanent magnets 111 are arranged asymmetrically with respect to the pole axis, P.

[0094] By 'asymmetric arrangement' is meant the deliberate positioning of magnetic elements in a non-uniform pattern relative to a reference line or plane, despite the elements themselves being geometrically identical. As an example, this may include offset positioning of matching magnet pairs relative to the pole centerline, intentionally staggered placement of identical magnets to create specific flux patterns, or non-uniform spacing of symmetrical magnets to optimize magnetic field distribution.

[0095] The term 'pole axis arrangement' refers to the specific organizational pattern of magnetic components relative to the central reference line of each magnetic pole 110, which determines the magnetic field characteristics. As an example, this may manifest as deliberate displacement from the pole centerline to enhance flux concentration, strategic positioning to create controlled flux paths, or calculated offset placement to optimize the interaction with the motor's rotating components.

[0096] Fifth embodiment of the first aspect of the subject application

[0097] In a fifth embodiment of the first aspect of the subject application, the first permanent magnet DC motor stator assembly 100 features a specific arrangement of soft magnetic elements 112.

[0098] Specifically, these soft magnetic elements 112 are arranged asymmetrically with respect to the pole axis, P.

[0099] By 'asymmetric soft magnetic element arrangement' is meant the intentional non-uniform distribution of soft magnetic materials around the pole axis, P, which optimizes magnetic flux paths and field distribution. As an example, this may include varying thicknesses of soft magnetic sections around the pole, strategically placed flux concentrators with non-uniform dimensions, or graduated magnetic material distributions that create specific field patterns.

[0100] Furthermore, this asymmetric arrangement serves to form continuous magnetic paths between adjacent magnetic poles 110.

[0101] The term 'continuous magnetic paths' refers to uninterrupted routes through soft magnetic materials which guide magnetic flux between neighboring poles without significant discontinuities or air gaps. As an example, this may manifest as shaped bridge sections between poles, continuous ferromagnetic segments that link adjacent pole structures, or optimized flux channels that minimize magnetic reluctance between poles.

[0102] The term 'adjacent magnetic poles 110' designates neighboring pole structures within the stator assembly which interact magnetically through their shared soft magnetic elements 112. As an example, this may include successive north-south pole pairs connected by bridge sections, neighboring poles with complementary flux patterns, or consecutive pole structures linked by optimized magnetic circuits.

[0103] Sixth embodiment of the first aspect of the subject application

[0104] In a sixth embodiment of the first aspect of the subject application, the first permanent magnet DC motor stator assembly 100 features a plurality of magnetic poles 110 with a specific arrangement.

[0105] Specifically, multiple magnetic poles 110 are arranged circumferentially around the central longitudinal axis.

[0106] By 'circumferential arrangement' is meant the distribution of magnetic poles 110 in a circular pattern around the stator's central axis, which creates a symmetrical magnetic field distribution. As an example, this may include equally spaced poles around the periphery, strategically positioned pole pairs with specific angular separation, or optimized pole distributions for specific torque characteristics.

[0107] By 'central longitudinal axis arrangement' is meant the organization of magnetic components relative to the main rotational axis of the motor, which establishes the basic geometry of the magnetic circuit. As an example, this may include radial flux paths perpendicular to the axis, symmetric pole distributions around the axis, or optimized magnetic circuits that maintain consistent air gap flux density around the circumference.

[0108] Furthermore, these magnetic poles 110 alternate in polarity around the circumference.

[0109] The term 'alternating polarity' refers to the sequential arrangement of magnetic poles 110 where each pole has the opposite magnetic orientation to its adjacent neighbors, creating a repeating north-south pattern. As an example, this may manifest as consecutive north-south pole pairs, alternating magnetic field directions with uniform spacing, or complementary pole arrangements that optimize the magnetic circuit.Second aspect of the subject application

[0110] As described in, a second aspect of the subject application relates to a method 200 specifically intended for producing an axial permanent magnet DC motor stator assembly from a radial permanent magnet DC motor stator assembly.

[0111] The method 200 begins with providing 210 a stator body having a shape adapted to an axial flux configuration.

[0112] By 'shape adapted to an axial flux configuration' is meant a stator geometry which enables magnetic flux paths to flow parallel to the rotation axis. As an example, this may include a disc-shaped structure with axially-oriented magnetic circuits, a flat ring configuration with axially-arranged poles, or a cylindrical segment with axially-directed flux paths.

[0113] In particular, the stator body has a central rotation axis, an axial dimension, and a radial dimension perpendicular to the axial dimension.

[0114] Furthermore, the stator body has a cross-section in a plane containing the central rotation axis.

[0115] Additionally, this cross-section has a perimeter line delimiting its contour and exhibits the axial dimension and radial dimension of the stator body.

[0116] The method involves providing 220 a reference cross-section from the radial permanent magnet DC motor stator assembly according to the first aspect of the subject-application.

[0117] Subsequently, this reference cross-section is projected 230 onto the cross-section of the stator body, forming a projected pattern.

[0118] The projected pattern extends 240 along a circular cross-section of the stator body in a radial direction relative to the circular cross-section, forming an extended projected pattern.

[0119] Following this, cavities are created 250 within the cross-section according to the extended projected pattern.

[0120] Permanent magnets 111 are positioned 260 within the cavities with specific requirements.

[0121] The magnetization directions of the permanent magnets 111 are oriented to converge toward their respective pole axis, P.

[0122] As a result, the convergence of the magnetization directions creates the magnetic flux concentration effect along the pole axis, P.

[0123] The method involves forming 270 multiple magnetic poles within the cross-section.

[0124] Specifically, each magnetic pole comprises one or more permanent magnets 111 buried within the cross-section.

[0125] These magnets are arranged to form a concave configuration when viewed in the plane containing the central rotation axis.

[0126] The concave configuration extends axially outward from a radial plane perpendicular to the central rotation axis.

[0127] Moreover, the concave configuration has an apex, PX, located within a predetermined angular range with respect to the pole axis, P.

[0128] In an example, the predetermined angular range is within ±25°, preferably within ±20°, more preferably within ±15°, even more preferably within ±10°, particularly preferably within ±5°, more particularly preferably within ±3°, and most preferably within ±1°, with respect to the pole axis, P.

[0129] This apex, PX, corresponds to the point of maximum curvature of the concave configuration.

[0130] Additionally, the radius of curvature at the apex, PX, is smaller than the axial dimension defined by the perimeter line of the stator body.

[0131] Finally, each magnetic pole includes soft magnetic elements 112 made of soft-magnetic material arranged within the cross-section to surround the permanent magnets 111.Third aspect of the subject application

[0132] As described in,,and, a third aspect of the subject application relates to a second permanent magnet DC motor stator assembly 300 specifically designed for use in an axial brushed DC motor having a rotor.

[0133] In particular, the stator assembly comprises a stator body having a shape adapted to an axial flux configuration

[0134] In practice, the stator body has a central rotation axis, an axial dimension, and a radial dimension perpendicular to the axial dimension.

[0135] The term 'central rotation axis' refers to the primary reference line running through the center of the stator body, which serves as the main axis of symmetry and rotation. As an example, this axis may serve as the reference for radial and axial measurements, the alignment axis for magnetic pole arrangements, or the basis for defining the concave configuration of permanent magnets 111.

[0136] Additionally, the stator body has a cross-section in a plane containing the central rotation axis.

[0137] Furthermore, this cross-section has a perimeter line delimiting its contour and exhibits the radial dimension of the stator body.

[0138] In practice, the stator body cross-section includes multiple magnetic poles formed within.

[0139] Specifically, each magnetic pole has a pole axis, P, and incorporates one or more permanent magnets 111 buried within the cross-section. These magnets are arranged to form a concave configuration when viewed in the plane containing the central rotation axis.

[0140] The concave configuration extends axially outward from a radial plane perpendicular to the central rotation axis.

[0141] Moreover, this configuration has an apex, PX, located within a predetermined angular range with respect to the pole axis, P.

[0142] In an example, the predetermined angular range is within ±25°, preferably within ±20°, more preferably within ±15°, even more preferably within ±10°, particularly preferably within ±5°, more particularly preferably within ±3°, and most preferably within ±1°, with respect to the pole axis, P.

[0143] In particular, the apex, PX, corresponds to the point of maximum curvature of the concave configuration.

[0144] In addition, the radius of curvature at the apex, PX, is smaller than the axial dimension defined by the perimeter line of the stator body.

[0145] The magnetic poles also include soft magnetic elements 112 made of soft-magnetic material. These elements are arranged within the cross-section to surround the permanent magnets 111.

[0146] Finally, the permanent magnets 111 have magnetization directions that converge toward and define the pole axis, P, with such convergence creating a magnetic flux concentration effect along the pole axis, P.

[0147] First embodiment of the third aspect of the subject application

[0148] In a first embodiment of the third aspect of the subject application, the second permanent magnet DC motor stator assembly 300 includes permanent magnets 111 buried within the cross-section through a specific soft magnetic elements 112 arrangement.

[0149] The arrangement comprises inner soft magnetic elements 1121 positioned between the permanent magnets 111 and the radial plane perpendicular to the central rotation axis.

[0150] The term 'radial plane' refers to a geometric reference surface perpendicular to the central rotation axis which intersects the stator assembly at a specific position. As an example, this may include the mid-plane of the stator assembly, reference planes for magnetic component positioning, or datum surfaces for defining magnetic material sequences.

[0151] The term 'central rotation axis' designates the primary axis around which the motor's rotor revolves and which serves as the main reference for the stator's geometric and magnetic design. As an example, this may serve as the reference for axial measurements, the centerline for magnetic component alignment, or the basis for defining magnetic field symmetry.

[0152] Additionally, outer soft magnetic elements 1122 are positioned between the permanent magnets 111 and the perimeter line.

[0153] The inner soft magnetic elements 1121, permanent magnets 111, and outer soft magnetic elements 1122 form an axial sequence of alternating magnetic materials. This sequence extends from the radial plane perpendicular to the central rotation axis to the perimeter line.

[0154] By 'axial sequence of alternating magnetic materials' is meant the specific arrangement of different magnetic materials along the direction parallel to the rotation axis. As an example, this may manifest as layered structures of soft and hard magnetic materials, graduated sequences of materials with different magnetic properties, or optimized arrangements that enhance axial flux concentration.

[0155] Specifically, when moving axially outward, the axial sequence comprises soft magnetic material, then permanent magnet 111 material, followed by soft magnetic material.

[0156] Second embodiment of the third aspect of the subject application

[0157] In a second embodiment of the third aspect of the subject application, the second permanent magnet DC motor stator assembly 300 features permanent magnets 111 of each magnetic pole that minimize magnetic flux cross-talk with permanent magnets 111 of adjacent magnetic poles.

[0158] The minimization of magnetic flux cross-talk occurs through two specific mechanisms.

[0159] First, the permanent magnets 111 of each magnetic pole contribute primarily to that pole's magnetic flux.

[0160] Additionally, the soft magnetic elements 112 are arranged to form continuous magnetic paths between adjacent magnetic poles.

[0161] Third embodiment of the third aspect of the subject application

[0162] In a third embodiment of the third aspect of the subject application, the second permanent magnet DC motor stator assembly 300 features magnetic poles, each comprising a single permanent magnet 111 with a continuous curved shape to form the concave configuration.

[0163] Specifically, the continuous curved shape of each permanent magnet 111 includes at least one shape selected from three distinct options: C-shape, V-shape, or U-shape.

[0164] Fourth embodiment of the third aspect of the subject application

[0165] In a fourth embodiment of the third aspect of the subject application, the second permanent magnet DC motor stator assembly 300 includes magnetic poles with specific structural features.

[0166] Each magnetic pole comprises at least two permanent magnets 111, which can be either symmetrical or asymmetrical, having a polygonal shape to form the concave configuration.

[0167] Specifically, the polygonal shape includes a pentagonal shape or a rectangular shape.

[0168] Additionally, the magnetic pole structure incorporates air gaps located between adjacent permanent magnets 111.

[0169] Furthermore, these air gaps include a specific air gap positioned at the pole axis, P.

[0170] First implementation of the fourth embodiment of the third aspect of the subject application

[0171] In a first implementation of the fourth embodiment of the third aspect of the subject application, the second permanent magnet DC motor stator assembly 300 features specific magnetic pole configurations.

[0172] For each magnetic pole, the permanent magnets 111 have magnetization directions oriented at specific angles relative to each other and to the pole axis, P..

[0173] Furthermore, the magnetization directions of these permanent magnets 111 generate a resulting magnetic field.

[0174] In certain configurations, such as a 4-pole motor, this magnetic field may orient substantially at 45 degrees relative to the axial direction. However, the specific orientation of the resulting field may vary in other pole configurations to optimize motor performance.

[0175] In the context of the second permanent magnet DC motor stator assembly 300, the term 'axial direction' refers to the orientation parallel to the central rotation axis of the motor, which serves as a reference for magnetic field alignment in axial flux motors. As an example, this may include the direction of magnetic flux flow along the motor's length, the orientation of magnetic field components parallel to the shaft, or the reference direction for measuring magnetic field angles in axial flux motors.

[0176] Second implementation of the fourth embodiment of the third aspect of the subject application

[0177] In a second implementation of the fourth embodiment of the third aspect of the subject application, the second permanent magnet DC motor stator assembly 300 incorporates a specific arrangement of permanent magnets 111.

[0178] Specifically, these permanent magnets 111 are arranged asymmetrically with respect to the pole axis, P.

[0179] Fifth embodiment of the third aspect of the subject application

[0180] In a fifth embodiment of the third aspect of the subject application, the second permanent magnet DC motor stator assembly 300 features a specific arrangement of soft magnetic elements 112.

[0181] Specifically, these soft magnetic elements 112 are arranged asymmetrically with respect to the pole axis, P.

[0182] Furthermore, this asymmetric arrangement serves to form continuous magnetic paths between adjacent magnetic poles.

[0183] Sixth embodiment of the third aspect of the subject application

[0184] In a sixth embodiment of the third aspect of the subject application, the second permanent magnet DC motor stator assembly 300 features a plurality of magnetic poles with a specific arrangement.

[0185] Specifically, multiple magnetic poles are arranged circumferentially around the central rotation axis.

[0186] Furthermore, these magnetic poles alternate in polarity around the circumference.Fourth aspect of the subject application

[0187] As described in, a fourth aspect of the subject application relates to a second method 400 specifically intended for producing a radial permanent magnet DC motor stator assembly from an axial permanent magnet DC motor stator assembly.

[0188] The method begins with providing 410 an elongated stator body having a central longitudinal axis, a circumference and a cross-section.

[0189] Furthermore, the cross-section has a perimeter line delimiting its contour and exhibits an external circumferential dimension and a radial dimension perpendicular to the external circumferential dimension.

[0190] The method involves providing 420 a reference cross-section from the axial permanent magnet DC motor stator assembly according to the third aspect of the subject-application.

[0191] Subsequently, this reference cross-section is projected 430 onto the cross-section of the elongated stator body, forming a projected pattern.

[0192] The projected pattern extends 440 along a longitudinal cross-section of the elongated stator body in a direction parallel to the central longitudinal axis, forming an extended projected pattern.

[0193] Following this, cavities are created 450 within the cross-section according to the extended projected pattern.

[0194] Permanent magnets 111 are positioned 460 within the cavities with specific requirements.

[0195] The magnetization directions of the permanent magnets 111 are oriented to converge toward their respective pole axis, P.

[0196] As a result, the convergence of the magnetization directions creates the magnetic flux concentration effect along the pole axis, P.

[0197] The method involves forming 470 multiple magnetic poles 110 within the cross-section.

[0198] Specifically, each magnetic pole 110 comprises one or more permanent magnets 111 buried within the cross-section.

[0199] These magnets are arranged to form a concave configuration when viewed from the central longitudinal axis.

[0200] The concave configuration extends radially outward from the central longitudinal axis.

[0201] Moreover, the concave configuration has an apex, PX, located within a predetermined angular range with respect to the pole axis, P.

[0202] In an example, the predetermined angular range is within ±25°, preferably within ±20°, more preferably within ±15°, even more preferably within ±10°, particularly preferably within ±5°, more particularly preferably within ±3°, and most preferably within ±1°, with respect to the pole axis, P.

[0203] This apex, PX, corresponds to the point of maximum curvature of the concave configuration.

[0204] Additionally, the radius of curvature at the apex, PX, is smaller than the inner radius defined by the perimeter line.

[0205] Finally, each magnetic pole 110 includes soft magnetic elements 112 made of soft-magnetic material arranged within the cross-section to surround the permanent magnets 111.Conclusion

[0206] We have described and illustrated the subject-application. However, the subject-application does not limit itself to the embodiments we have presented. Indeed, numerous combinations of variants, alternatives, embodiments, and implementations can be considered without requiring substantial modifications to the subject-application. Thus, an expert in the field can deduce other variants, alternatives, embodiments, and implementations from reading the description and annexed figures and based on economic, ergonomic, and dimensional constraints to be respected.

[0207] Furthermore, when an expression uses the term "at least one", this means that the element or characteristic in question can be present in a single occurrence or in multiple occurrences, therefore including one, two, three, or more elements or characteristics, without a specified upper limit.

[0208] Moreover, when an element is "specifically designed" to fulfill a particular function, this means that this element is created specifically for the purpose of fulfilling this particular function.

[0209] However, depending on needs and available resources, one may consider using an existing element, which will be modified or adapted to fulfill this particular function, without requiring substantial modifications to the subject-application.

[0210] Regarding the expression "all or part", it indicates flexibility in the selection or use of the mentioned elements or data. This expression means that the described action or characteristic can apply to the complete set of elements or data in question, or only to a selected portion of them. The use of "all or part" thus encompasses a wide range of possibilities, from complete use to partial use, without specifying a precise lower or upper limit regarding the quantity or proportion concerned.

[0211] It should be noted that the examples provided throughout this description are presented for illustrative and non-limiting purposes. These examples aim to facilitate the understanding of the subject-application by the person skilled in the art by providing concrete illustrations of possible implementation.

[0212] However, the subject-application does not limit itself to these specific examples. The person skilled in the art will understand that these examples can be generalized, adapted, or modified according to specific needs, technological advances, or particular constraints, without departing from the spirit of the subject-application. Thus, whenever an example is given, it should be interpreted as encompassing not only the specific example mentioned but also all equivalent technical variants and alternatives that fulfill the same function or achieve the same objective in the context of the subject-application.

[0213] The subject-application can be subject to numerous variants and applications other than those described above. In particular, unless otherwise indicated, the various structural and functional characteristics of each particular implementation described above should not be considered as combined and / or closely and / or inextricably linked to each other, but, on the contrary, as simple juxtapositions. Furthermore, the structural and / or functional characteristics of the different embodiments described above can be subject in whole or in part to any different juxtaposition or any different combination.

Claims

A first permanent magnet DC motor stator assembly (100) specifically designed for use in aradialbrushed DC motor having a rotor, the first permanent magnet DC motor stator assembly (100) comprising,- an elongated stator body having a central longitudinal axis, a circumference and a cross-section,the cross-section of the elongated stator body having a perimeter line delimiting its contour and exhibiting an external circumferential dimension and a radial dimension perpendicular to the external circumferential dimension,the cross-section of the elongated stator body comprising,- a plurality of magnetic poles (110) formed within the cross-section, each magnetic pole (110) having a pole axis, P, and comprising,-- one or more permanent magnets (111) buried within the cross-section and arranged to form a concave configuration when viewed from the central longitudinal axis, wherein--- the concave configuration extends radially outward from the central longitudinal axis,--- the concave configuration has an apex, PX, located within a predetermined angular range with respect to the pole axis, P,--- the apex, PX, corresponds to the point of maximum curvature of the concave configuration, and--- the radius of curvature at the apex, PX, is smaller than the inner radius defined by the perimeter line,-- soft magnetic elements (112) made of soft-magnetic material that are arranged within the cross-section to surround the permanent magnets (111),wherein, the permanent magnets (111) have magnetization directions that converge toward and define the pole axis, P, such convergence creating a magnetic flux concentration effect along the pole axis, P.The first permanent magnet DC motor stator assembly (100) according to claim 1, wherein the permanent magnets (111) buried within the cross-section are implemented through a soft magnetic elements (112) arrangement comprising,- inner soft magnetic elements (1121) positioned between the permanent magnets (111) and the central longitudinal axis, and- outer soft magnetic elements (1122) positioned between the permanent magnets (111) and the perimeter line, wherein, the inner soft magnetic elements (1121), the permanent magnets (111), and the outer soft magnetic elements (1122) form a radial sequence of alternating magnetic materials extending from the central longitudinal axis to the perimeter line, the radial sequence specifically comprising soft magnetic material, then permanent magnet (111) material, then soft magnetic material when moving from the central longitudinal axis outward.The first permanent magnet DC motor stator assembly (100) of any one of claims 1 to 2, wherein the permanent magnets (111) of each magnetic pole (110) minimize magnetic flux cross-talk with permanent magnets (111) of adjacent magnetic poles (110), the minimization of magnetic flux cross-talk resulting from,- the permanent magnets (111) of each magnetic pole (110) contributing primarily to that pole's magnetic flux, and- the soft magnetic elements (112) being arranged to form continuous magnetic paths between adjacent magnetic poles (110).The first permanent magnet DC motor stator assembly (100) of any one of claims 1 to 3, wherein each magnetic pole (110) comprises a single permanent magnet (111) having a continuous curved shape to form the concave configuration, wherein the continuous curved shape includes at least one shape selected from C-shape, V-shape, and U-shape.The first permanent magnet DC motor stator assembly (100) of any one of claims 1 to 3, wherein each magnetic pole (110) comprises,- at least two permanent magnets (111), which can be either symmetrical or asymmetrical, having a polygonal shape to form the concave configuration, wherein the polygonal shape includes a pentagonal shape, and- air gaps located between adjacent permanent magnets (111), including an air gap at the pole axis, P.The first permanent magnet DC motor stator assembly (100) of claim 5, wherein for each magnetic pole (110),- the permanent magnets (111) have magnetization directions oriented at specific angles relative to each other and to the pole axis, P, wherein said angles are selected to optimize the resulting magnetic field within each pole and to minimize flux cross-talk between adjacent poles, and- the magnetization directions generate a resulting magnetic field oriented at an angle relative to the radial direction, wherein said angle is selected based on the number of poles to optimize motor performance, and wherein for a 4-pole configuration, said angle is substantially 45 degrees.The first permanent magnet DC motor stator assembly (100) of any one of claims 5 to 6, wherein the permanent magnets (111) are arranged asymmetrically with respect to the pole axis, P.The first permanent magnet DC motor stator assembly (100) of any one of claims 1 to 7, wherein the soft magnetic elements (112) are arranged asymmetrically with respect to the pole axis, P, to form continuous magnetic paths between adjacent magnetic poles (110).The first permanent magnet DC motor stator assembly (100) of any one of claims 1 to 8, wherein the plurality of magnetic poles (110) comprises multiple magnetic poles (110) arranged circumferentially around the central longitudinal axis with alternating polarities.A first method (200) specifically intended for producing anaxialpermanent magnet DC motor stator assembly from aradialpermanent magnet DC motor stator assembly, the method comprising,- providing (210) at least one stator body having a shape adapted to an axial flux configuration, the stator body having a central rotation axis, an axial dimension and a radial dimension perpendicular to the axial dimension, the stator body having a cross-section in a plane containing the central rotation axis, the cross-section having a perimeter line delimiting its contour and exhibiting the axial dimension and the radial dimension of the stator body,- providing (220) a reference cross-section from theradialpermanent magnet DC motor stator assembly according to claim 1,- projecting (230) the reference cross-section onto the cross-section of the stator body thereby forming a projected pattern,- extending (240) the projected pattern along a circular cross-section of the stator body in a direction that is radial relative to the circular cross-section thereby forming an extended projected pattern,- creating (250) cavities within the cross-section according to the extended projected pattern,- positioning (260) permanent magnets (111) within the cavities such that,-- the magnetization directions of the permanent magnets (111) are oriented to converge toward their respective pole axis, P, and-- the convergence of the magnetization directions creates the magnetic flux concentration effect along the pole axis, P,- forming (270) within the cross-section,-- a plurality of magnetic poles within the cross-section, each magnetic pole comprising,--- one or more permanent magnets (111) buried within the cross-section and arranged to form a concave configuration when viewed in the plane containing the central rotation axis, wherein---- the concave configuration extends axially outward from a radial plane perpendicular to the central rotation axis,---- the concave configuration has an apex, PX, located within a predetermined angular range with respect to the pole axis, P,the apex, PX, corresponds to the point of maximum curvature of the concave configuration, and---- the radius of curvature at the apex, PX, is smaller than the axial dimension defined by the perimeter line of the stator body,--- soft magnetic elements (112) made of soft-magnetic material arranged within the cross-section to surround the permanent magnets (111).A second permanent magnet DC motor stator assembly (300) specifically designed for use in anaxialbrushed DC motor having a rotor, the second permanent magnet DC motor stator assembly (300) comprising,- a stator body having a shape adapted to an axial flux configuration, the stator body having a central rotation axis, an axial dimension and a radial dimension perpendicular to the axial dimension, the stator body having a cross-section in a plane containing the central rotation axis, the cross-section having a perimeter line delimiting its contour and exhibiting the radial dimension of the stator body,the cross-section of the stator body comprising,- a plurality of magnetic poles formed within the cross-section, each magnetic pole having a pole axis, P, and comprising,-- one or more permanent magnets (111) buried within the cross-section and arranged to form a concave configuration when viewed in the plane containing the central rotation axis, wherein--- the concave configuration extends axially outward from a radial plane perpendicular to the central rotation axis,--- the concave configuration has an apex, PX, located within a predetermined angular range with respect to the pole axis, P,--- the apex, PX, corresponds to the point of maximum curvature of the concave configuration, and--- the radius of curvature at the apex, PX, is smaller than the axial dimension defined by the perimeter line of the stator body,-- soft magnetic elements (112) made of soft-magnetic material that are arranged within the cross-section to surround the permanent magnets (111),wherein, the permanent magnets (111) have magnetization directions that converge toward and define the pole axis, P, such convergence creating a magnetic flux concentration effect along the pole axis, P.The second permanent magnet DC motor stator assembly (300) according to claim 11, wherein the permanent magnets (111) buried within the cross-section are implemented through a soft magnetic elements (112) arrangement comprising,- inner soft magnetic elements (1121) positioned between the permanent magnets (111) and the radial plane perpendicular to the central rotation axis, and- outer soft magnetic elements (1122) positioned between the permanent magnets (111) and the perimeter line, wherein, the inner soft magnetic elements (1121), the permanent magnets (111), and the outer soft magnetic elements (1122) form an axial sequence of alternating magnetic materials extending from the radial plane perpendicular to the central rotation axis to the perimeter line, the axial sequence specifically comprising soft magnetic material, then permanent magnet (111) material, then soft magnetic material when moving axially outward.The second permanent magnet DC motor stator assembly (300) of any one of claims 11 to 12, wherein the permanent magnets (111) of each magnetic pole minimize magnetic flux cross-talk with permanent magnets (111) of adjacent magnetic poles, the minimization of magnetic flux cross-talk resulting from,- the permanent magnets (111) of each magnetic pole contributing primarily to that pole's magnetic flux, and- the soft magnetic elements (112) being arranged to form continuous magnetic paths between adjacent magnetic poles.The second permanent magnet DC motor stator assembly (300) of any one of claims 11 to 13, wherein each magnetic pole comprises a single permanent magnet (111) having a continuous curved shape to form the concave configuration, wherein the continuous curved shape includes at least one shape selected from C-shape, V-shape, and U-shape.The second permanent magnet DC motor stator assembly (300) of any one of claims 11 to 13, wherein each magnetic pole comprises,- at least two permanent magnets (111), which can be either symmetrical or asymmetrical, having a polygonal shape to form the concave configuration, wherein the polygonal shape includes a pentagonal shape, and- air gaps located between adjacent permanent magnets (111), including an air gap at the pole axis, P.The second permanent magnet DC motor stator assembly (300) of claim 15, wherein for each magnetic pole,- the permanent magnets (111) have magnetization directions oriented at specific angles relative to each other and to the pole axis, P, wherein said angles are selected to optimize the resulting magnetic field within each pole and to minimize flux cross-talk between adjacent poles, and- the magnetization directions generate a resulting magnetic field oriented at an angle relative to the axial direction, wherein said angle is selected based on the number of poles to optimize motor performance, and wherein for a 4-pole configuration, said angle is substantially 45 degrees.The second permanent magnet DC motor stator assembly (300) of any one of claims 15 to 16, wherein the permanent magnets (111) are arranged asymmetrically with respect to the pole axis, P.The second permanent magnet DC motor stator assembly (300) of any one of claims 11 to 17, wherein the soft magnetic elements (112) are arranged asymmetrically with respect to the pole axis, P, to form continuous magnetic paths between adjacent magnetic poles.The second permanent magnet DC motor stator assembly (300) of any one of claims 11 to 18, wherein the plurality of magnetic poles comprises multiple magnetic poles arranged circumferentially around the central rotation axis with alternating polarities.A second method (400) specifically intended for producing aradialpermanent magnet DC motor stator assembly from anaxialpermanent magnet DC motor stator assembly, the method comprising:- providing (410) at least one elongated stator body having a central longitudinal axis, a circumference and a cross-section, the cross-section having a perimeter line delimiting its contour and exhibiting an external circumferential dimension and a radial dimension perpendicular to the external circumferential dimension,- providing (420) a reference cross-section from theaxialpermanent magnet DC motor stator assembly according to claim 11,- projecting (430) the reference cross-section onto the cross-section of the elongated stator body thereby forming a projected pattern,- extending (440) the projected pattern along a longitudinal cross-section of the elongated stator body in a direction that is parallel to the central longitudinal axis thereby forming an extended projected pattern,- creating (450) cavities within the cross-section according to the extended projected pattern,- positioning (460) permanent magnets (111) within the cavities such that,-- the magnetization directions of the permanent magnets (111) are oriented to converge toward their respective pole axis, P, and-- the convergence of the magnetization directions creates the magnetic flux concentration effect along the pole axis, P,- forming (470) within the cross-section-- a plurality of magnetic poles (110) within the cross-section, each magnetic pole (110) comprising:--- one or more permanent magnets (111) buried within the cross-section and arranged to form a concave configuration when viewed from the central longitudinal axis, wherein---- the concave configuration extends radially outward from the central longitudinal axis,---- the concave configuration has an apex, PX, located within a predetermined angular range with respect to the pole axis, P,---- the apex, PX, corresponds to the point of maximum curvature of the concave configuration, and---- the radius of curvature at the apex, PX, is smaller than the inner radius defined by the perimeter line,--- soft magnetic elements (112) made of soft-magnetic material arranged within the cross-section to surround the permanent magnets (111).

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