Magnet module for rotor of electric machine

Abstract

The invention describes a magnet module (130) for a rotor (110) of an electric machine (100), in particular a wind turbine generator, comprising a base member (132) extending in a width direction (103), in particular a circumferential direction, in a length direction (101), in particular an axial direction, and in a thickness direction (102), in particular a radial direction, and the base member has a rotor housing mounting surface (133) and a magnet mounting surface (134) at opposite sides, both of which extend in a width direction (102) and a length direction (101); the invention relates to a rotor (100) comprising a base member (132) having a rotor housing mounting surface (133), a magnet (135) mounted at the magnet mounting surface (134) of the base member (132), the base member (132) having at least one first base member groove (137) at the rotor housing mounting surface (133), the first base member groove extending in a length direction (101).

Description

Technical Field

[0001] The present invention relates to a magnet module for a rotor of an electric machine, to a rotor for an electric machine, and also to an electric machine, in particular to a wind turbine generator. Background Art

[0002] For permanent magnet generators, particularly relatively large generators, the permanent magnets mounted on the rotor are housed in magnet modules. The magnet modules can be mounted to the rotor housing, for example, using a "T-track" retention system. Thus, radial and circumferential or tangential movement of the magnet modules can be constrained, for example, by structural features machined onto or into the rotor housing.

[0003] However, conventionally, due to the manufacturing and assembly processes, there are dimensional tolerances and a certain degree of "play" may exist between the base plate of the magnet module and the retention system, thereby preventing the magnet module from being rigidly mounted to the rotor housing.

[0004] The following forces may act on the module: a) Due to the permanent magnets, there may be high radial magnetic forces acting on the magnet modules, which pull them onto the rotor housing, due to the fact that the magnetic air gap between the rotor housing and the base plate is significantly smaller (less than 0.2 mm when taking into account any coatings on the components or due to surface flatness) compared to the large main working electromagnetic air gap of the generator (typically between 3 and 8 mm).

[0005] b) For wind turbine generator applications, the motor may only operate in one quadrant of the power-speed plane, with only one direction of rotation and torque (and thereby reacting force to the rotor housing and generating torque).

[0006] c) Under open circuit or no-load conditions when there is no stator current and no load torque, there may be no high circumferential net force producing a net torque, and the tangential force may swing around zero (but at a significantly lower amplitude) due to interaction with the salient pole stator structure. However, in this mode, the tangential force is typically lower than the friction force generated by the high radial force pulling the magnets into the rotor housing and the surface friction coefficient, and the module may not slip within the T-track.

[0007] Furthermore, generators with multiple stator sections powering parallel converters may, under certain operating conditions, such as reduced converter operation (RCO), activate or operate only selected sections of the stator. As the magnet modules transition from active to inactive sections / sectors of the stator, the forces acting on the modules can result in more complex transient module torques and forces. These forces or torques can overcome friction and allow the magnet modules to move (slide or lift) within the rotor housing's retention system. This can traditionally result in so-called "module rattle," which can be annoyingly noisy but, more importantly, can also lead to fatigue issues with the retention structure due to the modules repeatedly impacting the rotor housing structure. In the past, these traditionally observed magnet module movements may have limited the operating envelope to modes where only limited sections of the stator are activated.

[0008] Therefore, there may be a need for a magnet module for a rotor of an electric machine, there may be a need for a rotor for an electric machine, and there may be a need for an electric machine in which some of the above-mentioned disadvantages are reduced or even overcome. Further, there may be a need for an improved method for securely mounting a magnet module to a rotor in which undesirable motion and noise can be reduced or even avoided while having limited negative impact on the main rotor torque. Summary of the Invention

[0009] This need may be met by the subject matter according to the independent claims. Advantageous embodiments of the invention are described by the dependent claims.

[0010] According to an embodiment of the present invention, a magnet module for a rotor of an electric motor is provided, wherein the electric motor is particularly a wind turbine generator, and the magnet module comprises: a base member extending in a width direction, particularly a circumferential direction, in a length direction, particularly an axial direction, and in a thickness direction, particularly a radial direction, and the base member has a rotor shell contact / mounting surface and a magnet contact / mounting surface located at opposite sides, both of which extend in the width direction and the length direction; a magnet, wherein the magnet is mounted at the magnet mounting surface of the base member, wherein the base member has at least one first base member groove at the rotor shell mounting surface, and the first base member groove extends in the length direction.

[0011] In addition to the base member and the magnet, the magnet module may further include a cover member that covers the magnet and can be welded to the base member. The cover member can protect the magnet from damage and / or corrosion.

[0012] The base member may be configured substantially as a rectangular plate, and the magnet may also have a rectangular cross-section (when viewed in the width direction or radial direction).

[0013] The width, length, and thickness directions can be associated with or attributed to the magnet module itself. When the magnet module is mounted on a rotor, the circumferential, axial, and radial directions become corresponding directions, and the rotation axis extending along the axial direction can be attributed to the rotor. The circumferential and radial directions can further be attributed to the rotor and, in particular, to the entire assembled electric machine. In the conventional sense, both directions are perpendicular to the axial direction.

[0014] The rotor housing mounting surface may be a substantially planar surface, in particular having a rectangular shape, and / or the magnet mounting surface may be a substantially planar surface, in particular having a rectangular shape. The respective mounting surfaces may be machined surfaces. When the magnet module is mounted to the rotor and the magnet is mounted to the base member, in particular to the magnet mounting surface of the base member, there may or may not be any material between or overlying the rotor housing mounting surface and / or the magnet mounting surface.

[0015] The interface between the magnet and the base member may, for example, consist of or include an adhesive layer or adhesive line.

[0016] Any gap between the rotor housing and the rotor housing mounting surface of the magnet module may be minimized or may be kept below a given threshold.The same applies to any gap between the magnet mounting surface of the magnet module and the mounting surface of the magnets.

[0017] For mounting requirements, the magnet may include a base member mounting surface, which may also be a substantially flat planar surface, in particular a machined surface.

[0018] The (first) base member groove may also be referred to as a base member slot or a base plate slot. The first / second base member groove may extend substantially or primarily along a length direction of the magnet module, the length direction corresponding to the axial direction (of the rotor or motor) in the assembled state.

[0019] The first / second base member grooves can act as magnetic flux barriers, thereby deforming magnetic flux lines and directing them around the first / second base member grooves. Thus, the radial force pulling the magnet module toward the rotor housing can be increased, thereby achieving improved stability of the magnet module when the magnet module is assembled or mounted to the rotor housing.

[0020] The positioning along the width direction of the first / second base member recess can be determined or defined based on a specific application, in particular including simulation of the resulting magnetic flux or force and / or torque acting on the magnet module when the magnet module is placed or arranged at the rotor housing, in particular at the mounting area or at a specific mounting area. The base member recess can also be considered as a base member cavity.

[0021] The base member recess may be open to or towards the rotor housing mounting surface.The recess may or may not contain a non-magnetic and / or non-conductive medium, such as air or any other suitable fluid or solid material.

[0022] Introducing at least a first base member groove (and in particular, a second base member groove) into the base member can enhance the performance of the resulting or assembled electric machine or assembled rotor, as the retention or attraction force of the magnet module mounted to the rotor can be improved. Further, in particular, the addition of the first and / or second base member grooves can further improve the performance or effectiveness of any potentially existing rotor housing grooves or slots.

[0023] The magnet module may consist of a permanent magnet bonded to a ferromagnetic base plate, which may have a thickness of, for example, between 3 mm and 7 mm, in particular of approximately 5 mm.

[0024] The magnets may be covered by a metal cover that may be positioned over the magnets and may be welded to the base plate to fully encapsulate the magnets and, for example, to protect against corrosion and damage. The base plate, or base member in general, may typically have a machined surface or surfaces to better control the size of the "protrusion" within the rotor housing retention system and to ensure the flatness of the base plate to minimize "parasitic" air gaps between the base plate and the rotor housing in the primary magnetic flux path or magnetic circuit of the magnets.

[0025] According to an embodiment of the present invention, the first base member groove opens toward the rotor housing mounting surface, and / or wherein the magnet protrudes from the base member in a thickness direction or a radial direction; and / or wherein the base member is configured as a base plate.

[0026] When the first and / or second base member grooves are open toward the rotor housing mounting surface, manufacturing the first and / or second base member grooves may be simplified, and magnetic flux lines may be deformed to improve attraction.

[0027] One or more base member grooves can be manufactured, for example, by milling or machining or grinding processes or EDM erosion processes. In other embodiments, the base member including the first and / or second base member grooves can be a casting or can be produced by casting or, for example, by additive manufacturing.

[0028] According to an embodiment of the present invention, the base member has a second base member groove at the rotor housing mounting surface, the second base member groove is spaced apart from the first base member groove in the width direction, and the second base member groove extends in the length direction, in particular, extends parallel to the first base member groove.

[0029] When the magnet module is assembled to the rotor for increased mounting fixation or attachment, the presence of the second base member groove can further increase radial forces, in particular, acting on the magnet module. This can reduce unwanted movement and / or noise caused by the magnet module. The first and / or second base member grooves can be substantially parallel to the length of the magnet module, or can be parallel to the axial direction of the assembled rotor or assembled motor. This can also simplify manufacturing.

[0030] According to an embodiment of the present invention, the base member comprises an edge extending in the length direction at the widthwise end portions, in particular at the circumferential end portions, the edge being provided to engage with a retaining structure at the rotor housing, and / or wherein the first and / or second base member grooves extend at least partially parallel to the edge.

[0031] The edge can be used to engage with a conventionally known retaining structure, in particular a rail structure. The edge can, for example, comprise a cross-sectional shape that is complementary to one half of a T-shape when the retaining structure is equipped with a T-shaped rail extending in the axial direction. Thus, a conventionally available rotor can be used to mount the magnet module on the rotor.

[0032] According to an embodiment of the present invention, the base member groove has an axial extension or extension in the length direction, and the extension or extension is 50% to 100% of the extension of the base member in the length direction; and / or wherein the base member groove has a circumferential extension or extension in the width direction, and the extension or extension is 1% to 10% or 15% of the extension of the base member in the width direction; and / or wherein the base member groove has a radial extension or extension in the thickness direction, and the extension or extension is 10% to 100%, in particular 40% to 80%, of the extension of the base member in the thickness direction.

[0033] This provides great flexibility and allows the selection or determination of corresponding dimensions or extensions based on the specific application. These dimensions can be derived, for example, from simulations of magnetic flux and / or forces and / or torques and simulations regarding the structural stability of the component.

[0034] According to an embodiment of the invention, the base member groove is formed by several base member groove portions which are separated from each other along the length direction, the base member groove portions having the same or different shapes and / or extensions.

[0035] When the plurality of base member groove portions are provided that are separated from each other, the portion therebetween can be used to increase the mechanical rigidity or stability of the base member, thereby preventing the base member from bending or reducing the bending.

[0036] According to an embodiment of the present invention, a rotor for an electric motor is provided, wherein the electric motor is particularly a wind turbine generator, and the rotor comprises: at least one magnet module according to any one of the aforementioned embodiments; a rotor shell, wherein the rotor shell has a rotation axis along an axial direction and has a plurality of magnet module mounting areas, the magnet module mounting areas are spaced apart in a circumferential direction and extend in the axial direction and the circumferential direction, and the rotor shell has a rotor shell groove at at least one of the magnet module mounting areas, wherein the magnet module is arranged at the at least one of the magnet module mounting areas having the rotor shell groove.

[0037] The rotor may be an external rotor or an internal rotor. The rotor housing may have substantially cylindrical symmetry, with the axis of symmetry being parallel to or coinciding with the axial direction. The rotor housing recess may also be referred to as a rotor housing slot or rotor housing cutout. The rotor housing recess may open toward a magnet module mounting region, and in particular, a magnet module including at least the first and / or second base member recess may be mounted in the magnet module mounting region.

[0038] The presence of the first and / or second base member grooves may advantageously deform the magnetic flux lines (around the respective grooves), thereby potentially or advantageously leading to higher radial forces pulling or pushing the magnet modules towards the rotor housing.

[0039] In particular, the presence of the rotor housing grooves in combination with the presence of the first base member grooves and / or the second base member grooves can advantageously deform the magnetic flux lines (around the respective grooves), thereby potentially or advantageously leading to higher radial forces pulling or pushing the magnet modules toward the rotor housing. As a result, any movement or "rattle" of the magnet modules attached to the rotor housing can be reduced or even avoided, thereby improving performance.

[0040] A rotor housing groove can be thought of as a cutout machined into the rotor housing. A rotor housing groove or cutout can function in the following ways: 1) Reducing the cross-sectional area of ​​contact between the base member and the rotor housing relative to the cross-sectional area of ​​the magnet module can increase the magnetic flux density in the gap between the base member and the rotor housing. Simply put, since the same magnetic flux travels through a smaller area, the magnetic flux will tend to travel through the small air gap between the base member and the rotor housing steel, rather than through the larger gap introduced by the rotor housing grooves or rotor housing cutouts. The radial force acting on this surface of the magnet module can then be increased, as the force is proportional to the square of the radial magnetic flux density (Fr = (Br² – Bt²)•A / 2µ0).

[0041] 2) The cutouts or rotor housing grooves may also tend to generate localized high flux density areas at corners due to flux concentration, again promoting higher forces in defined locations. The dimensions of the rotor housing grooves, particularly their width and circumferential offset relative to the center of the retaining track (particularly the T-track), can be carefully optimized to generate the required force (without significant loss of main rotor torque). For example, the circumferential movement can be used to generate a torque about the point about which the magnet module may pivot (derived from the engagement of the base plate protrusion with the rotor housing T-track). This can offset or reduce any torque from the interaction of the magnet module with the stator windings or teeth that attempts to lift the magnet module.

[0042] According to an embodiment of the present invention, the rotor housing includes a plurality of retaining rails, in particular retaining rails providing insertion slots, which are spaced apart in the circumferential direction and extend in the axial direction, wherein the magnet module mounting areas are respectively provided between two adjacent retaining rails, wherein two edges of the base member of the magnet module extending in the length direction are inserted between the two adjacent retaining rails, wherein the retaining rails in particular have a T-shape.

[0043] The retaining rails can essentially have a "T"-shaped cross-section. An insertion slot can be provided between two adjacent retaining rails in each pair, into which one or more magnet modules can be inserted in the axial direction. The rotor can, for example, accommodate five to ten magnet modules between each pair of retaining rails. Conventional mounting systems for mounting magnet modules can thus be utilized.

[0044] According to an embodiment of the invention, the rotor housing groove of the rotor housing is arranged circumferentially between a first base member groove and a second base member groove of the base member, and / or wherein the circumferential spacing between the first and / or second base member groove and the rotor housing groove is 1% to 5% of the width extension of the base member.

[0045] When the rotor housing groove is arranged circumferentially between the first base member groove and the second base member groove, the magnetic flux lines can be advantageously concentrated in the area between the rotor housing groove and the first / second base member grooves to increase the magnetic flux density and thus increase the radial force pulling the magnet module toward the rotor housing. The precise relative positioning of the first / second base member grooves and the rotor housing groove can be determined from simulations.

[0046] According to an embodiment of the invention, the rotor housing groove has an axial extension, which corresponds to the total axial extension of a plurality of magnet modules arranged between two adjacent retaining rails, the magnet modules being arranged axially one behind the other or spaced apart, wherein the rotor housing groove has a circumferential extension, which is 10% to 40% of the width extension of the base member, and / or wherein the rotor housing groove has a radial extension, which is 5% to 40% of the radial extension of the rotor housing.

[0047] Other values ​​are possible and may be determined based on structural simulations and / or magnetic simulations.

[0048] According to an embodiment of the present invention, the rotor housing groove has a cross-sectional area size taken perpendicularly to the axial direction, which is 5 to 20 times the cross-sectional area size of the first and / or second base member grooves.

[0049] Thus, the rotor housing recess may be significantly larger in cross-sectional area than either of the first and / or second base member recesses. The relatively larger area of ​​the rotor housing recess is possible due to the relatively greater extension of the rotor housing wall thickness relative to the thickness of the base member of the magnet module into which the rotor housing recess may be provided or machined.

[0050] According to an embodiment of the present invention, the base member groove and / or the rotor housing groove at least partially has a rectangular shape in a cross section perpendicular to the axial direction, in particular a rectangle with sharp angles or rounded corners or chamfered corners, a triangular shape, a V-shape or a U-shape, and / or wherein the rotor housing groove and / or the first and / or second base member grooves are filled with air or an adhesive or an epoxy resin or other non-magnetic filler, such as a plastic or a composite material.

[0051] Different cross-sectional shapes can provide different effects that may be related to performance and / or stability and can be selected based on the specific application. This provides great flexibility. The corresponding shape can also be selected based on available manufacturing technology or manufacturing simplicity.

[0052] According to an embodiment of the present invention, an electrical machine is provided, in particular a wind turbine generator, comprising: a stator having a stator winding; and a rotor according to one of the preceding embodiments, the rotor being rotatably supported relative to the stator.

[0053] The stator can be, for example, a segmented stator or a non-segmented stator. In particular, the stator can be a segmented stator comprising a plurality of stator segments, each segment providing a circumferential annular portion spanning, for example, 30°, 45°, 60°, 90°, 120°, or another value. Each stator segment can be equipped with a separate (multi-phase) stator winding set, which can be connected to an associated converter. The electric machine can include multiple converters, to which the respective stator windings of the different stator segments are connected.

[0054] The electric machine can, for example, also be configured to operate in a reduced converter operating mode, in which one or more stator windings of one or more stator segments are inoperable and the connected converter is also inoperable. In particular, in this operating mode, embodiments of the present invention can provide significant advantages with respect to unwanted rattling of the magnet modules or movement of the magnet modules.

[0055] According to an embodiment of the present invention, during the rotation of the rotor according to the rotation direction: one of the two edges extending in the axial direction is the leading edge of the base member relative to the rotation direction, and the other of the two edges extending in the axial direction is the trailing edge of the base member relative to the rotation direction, wherein the first and / or second base member grooves are located at a position closer to the leading edge than the trailing edge in the width direction or the circumferential direction, wherein in particular, the pivot point or pivot axis is located at the trailing edge, wherein the motor is in particular one of the following: an integer-slot distributed winding permanent magnet synchronous motor, or a fractional-slot concentrated winding permanent magnet synchronous motor.

[0056] Therefore, the first and second base member grooves may not be provided in a central area between two edges extending in the axial direction, for example, but may be moved or offset toward one side or one circumferential side or one side in the width direction of the magnet module. During operation, conventionally, the magnet module may pivot or rotate or make a clicking sound around a pivot point or pivot axis, which is located at a circumferential end (particularly an edge) and into which the magnet module is pushed due to rotation. According to embodiments of the present invention, the pivoting or clicking sound around or about this pivot point can be reduced.

[0057] It should be understood that the features disclosed, explained, provided or adopted for the magnet module for the rotor of an electric motor, either alone or in any combination, may also be provided, alone or in any combination, to the rotor of an electric motor and / or the electric motor and / or the method for manufacturing a magnet module for the rotor of an electric motor according to an embodiment of the present invention, and vice versa.

[0058] According to an embodiment, a method for manufacturing a magnet module for a rotor of an electric motor is provided, wherein the electric motor is particularly a wind turbine generator, the method comprising: providing a base member extending in width, length and thickness directions, the base member having a rotor shell contact / mounting surface and a magnet contact / mounting surface located at opposite sides, both surfaces extending in width and length directions; mounting a magnet at the magnet mounting surface of the base member, and providing at least one first base member groove at the rotor shell mounting surface of the base member.

[0059] The aspects defined above and further aspects of the invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to the examples of embodiment.The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Embodiments of the present invention will now be described with reference to the accompanying drawings. The present invention is not limited to the illustrated or described embodiments.

[0061] Figure 1 schematically illustrates a portion of an electric machine according to an embodiment of the present invention in a cross-sectional view; Figure 2 A three-dimensional diagram schematically illustrates a base member of a magnet module according to an embodiment of the present invention; Figure 3 and Figure 4 illustrate simulation results of magnetic flux in a conventional motor and in a motor according to an embodiment of the present invention; Figure 5 schematically illustrating geometric details of parts of an electric machine according to an embodiment of the present invention; Figure 6 and Figure 7 A three-dimensional diagram schematically illustrates a base plate of a magnet module according to an embodiment of the present invention; Figure 8 schematically illustrates a cross-sectional view of a magnet module according to an embodiment of the present invention; Figure 9 Another example of a portion of a motor according to an embodiment of the present invention is illustrated in cross-sectional view; and Figure 10 、 11, 12, and 13 schematically illustrate examples of a base member of a magnet module according to an embodiment of the present invention in cross-sectional views. DETAILED DESCRIPTION

[0062] The illustrations in the drawings are schematic. It should be noted that in different figures, elements that are similar or identical in structure and / or function are provided with the same reference numerals or with reference numerals that differ only within the first digit. The description of an element not described in one embodiment can be taken from the description of this element in relation to another embodiment.

[0063] Figure 1 The portion of the electric machine schematically illustrated in a cross-sectional view along an axial direction 101 (which is perpendicular to a radial direction 102 and also perpendicular to a circumferential direction 103) comprises a stator 104 having stator windings 105 arranged between teeth 106. Further, the electric machine 100 comprises a rotor 110 according to an embodiment of the invention.

[0064] It should be understood that features shown in the figures for the respective electric machine or for the rotor may also be applied to the magnet module alone or to the rotor alone, without the stator of the electric machine.

[0065] The rotor 110 includes at least one magnet module 130 according to an embodiment of the present invention. The rotor 110 further includes a rotor housing 111 having a rotation axis 112 (at Figure 1 The rotation axis 112 is illustrated in the figure but is actually located at the center of the rotor, which is moved vertically downward away from the rotor housing 111). The rotation axis 112 is along the axial direction 101.

[0066] The rotor housing has a plurality of magnet module mounting areas 113a, 113b, 113c. Figure 1 Only one of the mounting areas 113a is fully shown in the figure. The different magnet module mounting areas 113a, 113b, 113c are spaced apart in the circumferential direction 103 and extend in the axial direction 101 as well as in the circumferential direction 103. The respective magnet module mounting areas 113a, 113b, 113c each include a respective mounting surface 114a, 114b, 114c, in particular providing a contact surface for the magnet module to be mounted.

[0067] As from Figure 1 As can be understood, the rotor housing 111 has a rotor housing groove 115 at at least one magnet module installation area 113a. At the at least one magnet module installation area 113a, a magnet module 130 according to an embodiment of the present invention is arranged. An example of an embodiment of the magnet module 130 will be explained with reference to the following drawings.

[0068] exist Figure 1 In the embodiment illustrated in FIG, the rotor housing 111 comprises a plurality of retaining rails 116 providing insertion slots therebetween, wherein the retaining rails 116 are spaced apart in the circumferential direction 103 and extend in the axial direction 101. Figure 1 It can be understood that the magnet module mounting areas 113 a , 113 b , 113 c are provided between two adjacent holding rails 116 , respectively.

[0069] Two edges 131 of the base member 132 of the magnet module 130 extending in the length direction (parallel to the axial direction 101) are inserted between two adjacent holding rails 116. Figure 1 It can be appreciated that the retaining rail 116 has a “T” shape.

[0070] The magnet module 130 is an example of a magnet module for a rotor of an electric machine according to an embodiment of the present invention. The magnet module 130 includes a base member 132 that extends in a width direction corresponding to the circumferential direction 103. The base member 132 also extends in a length direction corresponding to the axial direction 101 and in a thickness direction corresponding to the radial direction 102. The base member 132 has a rotor housing mounting surface 133 and a magnet mounting surface 134 on the opposite side, wherein both mounting surfaces 133 and 134 extend in the width direction 103 and in the length direction 101.

[0071] A magnet 135 is mounted at a magnet mounting surface 134 of the base member 132. The magnet 135 is covered by a protective cover 136, which is optional.

[0072] The base member 132 has at least one first base member groove 137 at the rotor housing mounting surface 133. The first base member groove 137 mainly extends along a length direction corresponding to the axial direction 101. Figure 1 It can be understood that the first base member groove 137 opens toward the rotor housing mounting surface 133 of the base member 132 .

[0073] The magnets 135 extend / protrude from the base member 132 in a thickness direction or radial direction (corresponding to the radial direction 102 ). In the illustrated embodiment, the base member 132 is configured as a base plate.

[0074] exist Figure 1In the embodiment of the magnet module 130 illustrated in FIG, the base member 132 includes a second base member groove 138 (which is optional) at the rotor housing mounting surface 133, the second base member groove 138 being spaced apart from the first base member groove 137 along the width direction 103. The second base member groove 138 also extends along the length direction 101.

[0075] Further, in Figure 1 In the illustrated embodiment, the base member 132 comprises edges 131 extending in the length direction 101 at widthwise ends, in particular circumferential ends, wherein the edges 131 are provided to engage with the retaining structure 116 at the rotor housing 111 .

[0076] Likewise, as Figure 1 It can be understood that the rotor housing groove 115 of the rotor housing 111 is arranged circumferentially (ie, along the circumferential direction 103 ) between the first base member groove 137 and the second base member groove 138 of the base member 132 .

[0077] Furthermore, Figure 1 The cross-sectional view also illustrates that the rotor housing groove 115 has a cross-sectional area dimension taken perpendicular to the axial direction 101 that is 5 to 20 times the cross-sectional area dimension of the first and / or second base member grooves 137, 138. Figure 1 In the embodiment illustrated in FIG, the base member recesses 137, 138 and the rotor housing recess 115 have a rectangular shape with relatively sharp edges. In other embodiments, other shapes may be provided, such as Figures 10 to 13 The shapes explained in .

[0078] Figure 2 The base member 232 of a magnet module according to an embodiment of the present invention is illustrated in a schematic three-dimensional view, in particular when viewed from above on the side in contact with the rotor housing. The base member 232 includes a rotor housing mounting surface 233, at which a first and a second base member groove 237, 238 are provided. In the illustrated embodiment, the base member grooves 237, 238 extend along the entire axial length 'al' of the base member 232. Therefore, the corresponding grooves can be formed by cutting or machining, which starts at the axial end face of the module and axially advances along the entire length of the magnet module or the entire length of the base member 232 in the axial direction 201. Figure 1 The illustrated magnet module base member 132 may be configured, for example, as follows Figure 2 As explained.

[0079] Figure 3 and Figure 4The magnetic flux lines in the comparative example and the magnetic flux lines in the embodiment of the motor according to the embodiment of the present invention are explained respectively. Figure 4 It can be understood that the magnetic flux obtained by simulation increases locally at the area marked with reference numeral 440. The increased magnetic flux density results in an increased radial force that pulls the corresponding magnet module 430 toward the rotor housing 411. The increased magnetic flux density is due to both the base member grooves 437, 438 and the rotor housing groove 415.

[0080] Figure 5 Another embodiment of an electric machine 500 according to an embodiment of the present invention is illustrated in a geometric or cross-sectional view. A first base member recess 537 has an extension ce in a widthwise or circumferential direction 503 and an extension re in a radial direction 502. The first base member recess 537 is separated from the second base member recess 538 by a separation distance rs. The first and second base member recesses 537, 538 are separated from the centerline cl of the rotor housing recess 515 by an amount rc. A separation width sw exists between the first base member recess 537 and the rotor housing recess 515 in the circumferential direction. The specific dimensions rc, rs, cl, ce, re, and sw can be determined or selected based on the specific application, for example, based on simulations.

[0081] Figure 6 A base member 632 of a magnet module according to another embodiment of the present invention is illustrated. The corresponding magnet module can be used, for example, in a rotor and / or motor according to an embodiment of the present invention. Figure 6 In the embodiment illustrated in FIG, the respective first and second base member recesses 637, 638 do not extend along the entire axial length al of the base member 632, but are provided only in a central portion that extends approximately 80% to 95% of the axial length al of the base member 632. This can have the advantage of reducing the effect of the base member recesses on the base member stiffness. This can also potentially allow for a reduction in the thickness of the remaining "bridge," which allows for improved magnetic saturation, which improves the effect of the base member recesses on the module forces. The respective base member recesses 637, 638 can either extend completely through the entire base member 632, or can extend only partially through the base member 632 along the thickness direction 602 corresponding to the radial direction.

[0082] exist Figure 7In the embodiment of the base member 732 illustrated in FIG, the corresponding base member groove is formed by a plurality of base member groove portions 737a, 737b and 738a, 738b, which are separated from each other along the length direction 701. Thus, the rigidity of the base member 732 can be further improved. This base member 732 can also be adopted for any magnet module according to embodiments of the present invention.

[0083] Figure 8 The magnet module 830 according to an embodiment of the present invention, illustrated in cross-section in FIG, also includes a first base member recess 837 and a second base member recess 838 in the base member 832. In this embodiment, the respective recesses 837, 838 extend through the entire depth of the base member, i.e., have a radial extension in the radial direction 802 or width direction that is 100% of the radial extension 839 of the base member 832.

[0084] Figure 9 A portion of an electric machine 900 according to an embodiment of the present invention is schematically illustrated in cross-sectional view. In the illustrated embodiment, the base member 932 of the magnet module 930 includes a first base member recess 937 and a second base member recess 938, which have different circumferential spacings 940, 941 relative to the rotor housing recess 915. Thus, the spacing relative to the rotor housing recess 915 is asymmetric relative to the width direction 903 or the circumferential direction. The different spacings 940, 941 can be derived, for example, based on magnetic flux simulations. Different recesses in the base member 932 can have different widths and / or depths.

[0085] Figures 10 to 13 The embodiments illustrating a base member 1032 , 1132 , 1232 , 1332 of a magnet module according to embodiments of the present invention may, for example, be provided in one or more or all of the previously illustrated embodiments of a rotor or motor according to embodiments of the present invention.

[0086] exist Figure 10 In the embodiment illustrated in FIG, the first and second base member recesses 1037, 1038 have a rectangular shape in cross section. Figure 11 Has a rectangular shape with rounded or chamfered corners. Figure 12 In the embodiment, the grooves 1237, 1238 have chamfered or angled inner corners, and Figure 13 The shape of the base member grooves 1337, 1338 illustrated in FIG. 1 has a triangular shape or a V-shape.

[0087] According to the embodiments previously illustrated or described, Figures 10 to 13Thereby, for example, the mechanical strength can be improved, or stress concentration can be avoided, and further manufacturing can be simplified.

[0088] According to an embodiment of the invention, two slots are introduced in the base plate of the magnet module, said slots being separated to be larger than the width of the rotor housing groove or rotor housing slot, said rotor housing groove or rotor housing slot being preferably located as shown in FIG. Figure 1 The additional slots 137, 138 may act to enhance the magnetic flux concentration caused by the accompanying rotor housing slot 115 and may generate a magnetic field such as Figure 4 Thereby, the module radial force can be enhanced and a torque can be generated about the module pivot point 151 (see Figure 1 , where the direction of rotor rotation during normal operation is to the left). The slots 137, 138 in the base member 132 do not have to extend the full depth of the base plate or base member 132 so that the base plate or base member maintains its structural integrity and required rigidity (e.g., they can be 3 mm deep within a 5 mm base plate thickness). The base plate slots can typically be 1 mm to 6 mm wide, for example, with a depth of 3 mm. The resulting overlap ( Figure 5 The amount sw) region / zone explained in can be controlled by the spacing of the base plate slot relative to the rotor housing slot width. The overlap ( Figure 5 The sw shown in FIG may for example amount to about 6 mm. The overlap may be dimensioned such that the force is insensitive to any circumferential movement of the base plate within the T-track, which movement would result in an asymmetric overlap.

[0089] According to embodiments of the present invention, only one base member groove, such as groove 137 or groove 138, may be provided, rather than two base member grooves. Thus, the second base member groove is an optional feature according to embodiments of the present invention. Embodiments of the present invention also provide for enhanced fatigue life of the adhesive used to secure the magnet to the base plate or base member.

[0090] According to the embodiments of the present invention, the following advantages can be achieved: 1) Simple additional machined features applied to the base plate that significantly improve the performance of the proposed rotor housing slots without changing the entire proven retention system.

[0091] 2) Guide the magnetic flux and generate locally high flux density to achieve the required force without significantly reducing the overall performance of the permanent magnet motor.

[0092] 3) It is an enabling technology to allow the use of magnets that do not have parallel magnetisation directions or flux focusing magnets and therefore allow for possible benefits in terms of increased flux torque and energy production.

[0093] 4) It is an enabling technology to provide a more reliable solution for fixing magnet segments on base plates for concentrated winding topologies (adhesive life).

[0094] It should be noted that the term "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. Furthermore, elements described in connection with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

1. A magnet module (130) for a rotor (110) of an electric machine (100), in particular a wind turbine generator, the magnet module comprising: a base member (132), the base member extending in a width direction (103), in particular in a circumferential direction, in a length direction (101), in particular in an axial direction, and in a thickness direction (102), in particular in a radial direction, and having a rotor housing mounting surface (133) and a magnet mounting surface (134) located at opposite sides, the rotor housing mounting surface and the magnet mounting surface both extending in the width direction (102) and the length direction (101); a magnet (135) mounted at a magnet mounting surface (134) of the base member (132), The base member (132) has at least one first base member groove (137) at the rotor housing mounting surface (133), and the first base member groove extends along the length direction (101).

2. The magnet module according to claim 1, in, The first base member groove (137) opens toward the rotor housing mounting surface (133); and / or wherein the magnet (135) protrudes from the base member in a width direction (102); and / or Wherein, the base member (132) is configured as a base plate.

3. A magnet module according to any one of the preceding claims, wherein The base member (132) has a second base member groove (138) at the rotor housing mounting surface (133), the second base member groove being spaced apart from the first base member groove (137) in the width direction (103), and the second base member groove extending in the length direction, in particular extending parallel to the first base member groove.

4. A magnet module according to any one of the preceding claims, wherein The base member (132) comprises an edge (131) extending in the length direction (101) at a widthwise end, in particular at a circumferential end, the edge (131) being provided to engage with a retaining structure (116) at the rotor housing (111); and / or Wherein, the first and / or second base member groove (137, 138) extends at least partially parallel to the edge (131).

5. The magnet module according to any one of the preceding claims, in, The first and / or second base member grooves (137, 138) have an axial extension or amount in the length direction, the extension or amount being 50% to 100% of the extension of the base member (132) in the length direction; and / or wherein the first and / or second base member grooves (137, 138) have a circumferential extension or extension in the width direction, the extension or extension being 1% to 15% of the extension of the base member (132) in the width direction; and / or The first and / or second base member grooves (137, 138) have a radial extension or extension in the thickness direction, which is 10% to 100%, in particular 40% to 80%, of the extension of the base member (132) in the thickness direction.

6. A magnet module according to any one of the preceding claims, wherein The first and / or second base member groove (137, 138) is formed by a plurality of base member groove portions (737a, 737b, 738a, 738b) which are separated from each other along the length direction, the base member groove portions having the same or different shapes and / or extensions.

7. A rotor (110) for an electric machine (100), in particular a wind turbine generator, comprising: at least one magnet module (130) according to any one of the preceding claims; A rotor housing (111), the rotor housing having a rotation axis (112) along an axial direction (101) and having a plurality of magnet module mounting areas (113a, 113b, 113c), the magnet module mounting areas being spaced apart in a circumferential direction and extending in the axial and circumferential directions, the rotor housing (111) having a rotor housing groove (115) at at least one (113a) of the magnet module mounting areas, The magnet module (130) is arranged at the at least one (113a) magnet module installation region having a rotor housing groove (115).

8. A rotor according to the preceding claim, wherein: The rotor housing (111) comprises a plurality of retaining rails (116), in particular retaining rails providing insertion slots, the retaining rails being spaced apart in the circumferential direction and extending in the axial direction, The magnet module installation areas (113a, 113b, 113c) are respectively provided between two adjacent holding rails (116). wherein two edges (131) of the base member of the magnet module extending in the length direction are inserted between two adjacent holding rails (116), In this case, the retaining rail has, in particular, a T-shape.

9. A rotor according to any one of the preceding claims 7 or 8, in, The rotor housing groove (115) of the rotor housing is arranged circumferentially between the first base member groove (137) and the second base member groove (138) of the base member (132); and / or The circumferential spacing (sw) between the first and / or second base member grooves (137, 138) and the rotor housing groove (115) is 1% to 15% of the width extension (we) of the base member (132).

10. A rotor according to any one of the preceding claims 7 to 9, in, The rotor housing groove (115) has an axial extension corresponding to the total axial extension of a plurality of magnet modules arranged between two adjacent holding rails, the plurality of magnet modules being arranged axially behind or spaced apart from each other, wherein the rotor housing groove (115) has a circumferential extension that is 10% to 40% of the width extension of the base member, and / or The rotor housing groove (115) has a radial extension which is 5% to 40% of the radial extension of the rotor housing.

11. A rotor according to any one of the preceding claims 7 to 10, in, The rotor housing groove (115) has a cross-sectional area dimension taken perpendicularly to the axial direction, which is 5 to 20 times the cross-sectional area dimension of the first and / or second base member grooves (137, 138).

12. A rotor according to any one of the preceding claims 7 to 11, in, The first and / or second base member recess (137, 138) and / or the rotor housing recess (115) at least partially has a rectangular shape in a cross section perpendicular to the axial direction, in particular a rectangular shape with sharp or rounded or chamfered corners, a triangular shape, a V-shape or a U-shape, and / or The rotor housing groove (115) and / or the first and / or second base member grooves (137, 138) are filled with air or adhesive, or epoxy resin or other non-magnetic fillers, such as plastic.

13. An electric machine (100), in particular a wind turbine generator, comprising: a stator (104), the stator having a stator winding (105); A rotor (110) according to any one of the preceding claims 7 to 12, wherein the rotor is rotatably supported relative to the stator.

14. An electric machine according to the preceding claim, wherein During rotation of the rotor according to the direction of rotation: One of the two edges (131a, 131b) extending in the axial direction serves as a leading edge (131a) of the base member relative to the rotation direction, The other of the two edges extending in the axial direction serves as a trailing edge (131b) of the base member relative to the rotation direction, wherein the first and / or second base member recess is located closer to the leading edge (131a) than to the trailing edge (131b) in the width direction or the circumferential direction, wherein in particular the pivot point (151) or the pivot axis is located at the trailing edge, wherein the motor is in particular one of the following: Integer-slot distributed winding permanent magnet synchronous motor; or Fractional-slot concentrated winding permanent magnet synchronous motor.

15. A method for manufacturing a magnet module (130) for a rotor (110) of an electric machine (100), in particular a wind turbine generator, the method comprising: Providing a base member (132) extending in a width direction, in a length direction, and in a thickness direction, the base member having a rotor housing mounting surface (133) and a magnet mounting surface (134) located at opposite sides, the rotor housing mounting surface and the magnet mounting surface both extending in the width direction and in the length direction; Mounting the magnet (135) on the magnet mounting surface (134) of the base member; At least one first base member groove (137) is provided at a rotor housing mounting surface (133) of the base member.

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