Electric machine, fan and electric appliance

Abstract

The application discloses a motor, a fan and an electric appliance. The motor comprises a stator assembly and a rotor assembly. The rotor assembly comprises a rotor core and a plurality of permanent magnets. The rotor core comprises a plurality of core units arranged at intervals in the circumferential direction. The number of the permanent magnets is N, and N is an even number. The minimum distance between two permanent magnets which are symmetrically arranged about the central axis of the rotor core is D2. The maximum length of the permanent magnet is a. The maximum thickness of the permanent magnet is b. A coefficient K satisfies: D2 / K < a < D2, and b < a / 2. The motor of the application can increase the output torque, improve the no-load back electromotive force, reduce the loss and improve the operating efficiency under the premise of adapting to various diameters of the rotating shaft.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a motor, a fan, and electrical equipment. Background Technology

[0002] As the performance of electrical equipment improves, the performance requirements for the motors within these devices also increase. To provide versatility, the motor rotor needs to be compatible with shafts of various diameters; that is, the rotor's shaft hole needs to be compatible with shafts of larger diameters. However, a shaft hole with a larger inner diameter will reduce the cross-sectional area of ​​the permanent magnet, resulting in a decrease in the motor's output torque and a reduction in efficiency at the same output torque. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a motor that, while adapting to shafts of various diameters, can increase output torque, improve no-load back EMF, reduce losses, and improve operating efficiency.

[0004] The present invention also provides a fan and electrical equipment having the above-mentioned motor.

[0005] According to a first aspect of the present invention, an electric motor includes a stator assembly comprising a stator core and a plurality of windings. The stator core is annular and has an inner hole. The stator core includes a stator yoke and a plurality of stator teeth. The plurality of stator teeth are connected to the inner peripheral wall of the stator yoke and are spaced apart along the circumferential direction of the stator core. The plurality of windings are respectively wound around the plurality of stator teeth. A rotor assembly is rotatably disposed in the inner hole. The rotor assembly includes a rotor core and a plurality of permanent magnets. The rotor core includes a plurality of core units spaced apart along the circumferential direction. A mounting slot is defined between two adjacent core units. The plurality of permanent magnets are correspondingly mounted in the plurality of mounting slots. The number of permanent magnets is N, and N is an even number. The minimum distance between two permanent magnets arranged symmetrically about the central axis of the rotor core is D2. The maximum radial length of the permanent magnet along the rotor core is a. The maximum circumferential thickness of the permanent magnet is b. A coefficient K satisfies: ,in, , .

[0006] According to the first aspect of the present invention, the motor has at least the following beneficial effects: by optimizing the minimum distance D2 between two permanent magnets arranged symmetrically about the central axis of the rotor core, the maximum radial length a of the permanent magnets, and the maximum circumferential thickness b of the permanent magnets, the following advantages are achieved: ,in, , N represents the number of permanent magnets. Under the premise of adapting to various diameter shafts, i.e., the value of D2 is relatively large, by optimizing the maximum radial length a and the maximum circumferential thickness b of the permanent magnets, the cross-sectional area of ​​the core unit, the cross-sectional area of ​​the permanent magnets, and the ratio between the two are adjusted. This increases the magnetic field of the permanent magnets, while reducing the magnetic flux saturation of the rotor core, improving the utilization rate of the permanent magnets and the rotor core, thereby increasing the output torque of the motor. At the same time, it increases the no-load back EMF, thereby reducing losses and improving the operating efficiency of the motor.

[0007] According to some embodiments of the present invention, the maximum thickness b of the permanent magnet along the circumferential direction satisfies: 5.5mm≤b≤9.5mm; and / or, the minimum distance D2 between two permanent magnets arranged symmetrically about the central axis of the rotor core satisfies: 24mm≤D2≤33mm.

[0008] According to some embodiments of the present invention, the maximum outer diameter of the rotor core is D1, the outer end of the mounting groove is provided with a slot and the minimum width of the slot is W1, satisfying: 0.25≤N*W1 / (π*D1)≤0.4.

[0009] According to some embodiments of the present invention, the maximum outer diameter of the rotor core is D1, and the minimum outer diameter of the stator core is D3, satisfying: 0.65≤D1 / D3≤0.75.

[0010] According to some embodiments of the present invention, the stator tooth includes a tooth portion and a tooth shoe. The tooth portion is connected to the inner peripheral wall of the stator yoke and extends toward the center of the stator core. The tooth shoe is connected to one end of the tooth portion away from the stator yoke and protrudes toward both sides of the tooth portion in the circumferential direction. The minimum tooth width of the tooth portion is W2, which satisfies: 0.33≤2*W2 / (D3-D1)≤0.47.

[0011] According to some embodiments of the present invention, the stator tooth includes a tooth portion and a tooth shoe. The tooth portion is connected to the inner peripheral wall of the stator yoke and extends toward the center of the stator core. The tooth shoe is connected to one end of the tooth portion away from the stator yoke and protrudes toward both sides of the tooth portion along the circumferential direction. The maximum distance between the two ends of the tooth shoe that are opposite to each other along the circumferential direction is W3, and the maximum distance between the two ends of the core unit that are opposite to each other along the circumferential direction is W4, satisfying: 1.1≤W3 / W4≤1.3.

[0012] According to some embodiments of the present invention, the stator yoke includes a plurality of yoke units arranged sequentially along the circumference, at least one of the two adjacent yoke units is provided with a splicing structure, and the remaining two adjacent yoke units are connected by a bending portion, and the plurality of stator teeth are respectively connected to the plurality of yoke units.

[0013] According to some embodiments of the present invention, the rotor assembly further includes an inner core disposed within a space surrounded by a plurality of core units, the inner core being disconnected from the plurality of core units; and / or, adjacent two core units being disconnected from each other.

[0014] According to a second aspect of the present invention, a wind turbine includes a wind turbine and a motor according to a first aspect of the present invention, wherein the rotor assembly includes a rotating shaft connected to the rotor core, and the wind turbine is mounted on the rotating shaft.

[0015] According to the second aspect of the present invention, the fan has at least the following beneficial effects: Because the fan uses the aforementioned motor, by optimizing the minimum distance D2 between two permanent magnets arranged symmetrically about the central axis of the rotor core, the maximum radial length a of the permanent magnets, and the maximum circumferential thickness b of the permanent magnets, the fan satisfies… ,in, , N represents the number of permanent magnets. Under the premise of adapting to various diameter shafts, i.e., the value of D2 is relatively large, by optimizing the maximum radial length a and the maximum circumferential thickness b of the permanent magnets, the cross-sectional area of ​​the core unit, the cross-sectional area of ​​the permanent magnets, and the ratio between the two are adjusted. This increases the magnetic field of the permanent magnets, while reducing the magnetic flux saturation of the rotor core, improving the utilization rate of the permanent magnets and the rotor core, thereby increasing the output torque of the motor. At the same time, it increases the no-load back EMF, thereby reducing losses and improving the operating efficiency of the motor.

[0016] An electrical device according to a third aspect of the present invention includes a fan according to a second aspect of the present invention.

[0017] The electrical device according to the third aspect of the present invention has at least the following beneficial effects: Because the electrical device uses the aforementioned fan, by optimizing the minimum distance D2 between two permanent magnets arranged symmetrically about the central axis of the rotor core, the maximum radial length a of the permanent magnets, and the maximum circumferential thickness b of the permanent magnets, the following advantages are achieved: ,in, , N represents the number of permanent magnets. Under the premise of adapting to various diameter shafts, i.e., the value of D2 is relatively large, by optimizing the maximum radial length a and the maximum circumferential thickness b of the permanent magnets, the cross-sectional area of ​​the core unit, the cross-sectional area of ​​the permanent magnets, and the ratio between the two are adjusted. This increases the magnetic field of the permanent magnets, while reducing the magnetic flux saturation of the rotor core, improving the utilization rate of the permanent magnets and the rotor core, thereby increasing the output torque of the motor. At the same time, it increases the no-load back EMF, thereby reducing losses and improving the operating efficiency of the motor.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a cross-sectional view of the motor in an embodiment of the present invention (with one of the permanent magnets hidden); Figure 2 This is a partial cross-sectional view of the rotor assembly in an embodiment of the present invention; Figure 3 This is a partial cross-sectional view of the stator core and core unit assembly in an embodiment of the present invention; Figure 4 This is a cross-sectional view of the permanent magnet in an embodiment of the present invention; Figure 5 This is a graph showing the per-unit value of the no-load back EMF as a function of the value of K and the operating efficiency of the motor as a function of the value of K in an embodiment of the present invention. Figure 6 This is a graph showing the per-unit value of the no-load back EMF as a function of the value of N*W1 / (π*D1) in an embodiment of the present invention. Figure 7 This is a surface plot showing how the efficiency of the motor varies with the values ​​of D1 / D3 and 2*W2 / (D3-D1) in an embodiment of the present invention. Figure 8 This is a comparison graph showing the curves of the output torque of the motor in this embodiment of the invention and the output torque of the motor in the prior art solution as a function of input current.

[0020] Figure label: Stator assembly 100; stator core 110; stator yoke 111; yoke unit 1111; splicing structure 1112; bending part 1113; stator tooth 112; tooth part 1121; tooth shoe 1122; winding groove 113; Rotor assembly 200; rotor core 210; core unit 211; outer magnetic bridge 2111; inner magnetic bridge 2112; mounting slot 212; permanent magnet 220; first end face 221; second end face 222; inner core 230; air gap 240. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0022] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0023] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0024] In the description of this invention, unless otherwise explicitly defined, terms such as setting, installing, connecting, assembling, and cooperating should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0025] Reference Figures 1 to 8 As shown, a first aspect embodiment of the present invention provides a motor for use in electrical equipment, such as an air conditioner or a fresh air system. For example, the motor is used in the fan of an air conditioner as a power source to enable the fan to deliver air. The following is a detailed description of the structure and components of the motor.

[0026] Reference Figure 1 As shown, the motor includes a stator assembly 100 and a rotor assembly 200. Both the stator assembly 100 and the rotor assembly 200 are annular, with the stator assembly 100 arranged around the outer periphery of the rotor assembly 200. The inner peripheral wall of the stator assembly 100 and the outer peripheral wall of the rotor assembly 200 are spaced apart and form an air gap 240. In other words, the motor has an inner rotor structure.

[0027] Reference Figure 1As shown, the stator assembly 100 includes a stator core 110 and multiple windings. The stator core 110 is generally annular and typically consists of multiple stator laminations stacked along its central axis. The stator core 110 includes a stator yoke 111 and multiple stator teeth 112. The stator yoke 111 is annular, and the multiple stator teeth 112 are connected to the inner circumferential wall of the stator yoke 111 and extend radially toward the central axis of the stator core 110. The multiple stator teeth 112 are evenly spaced circumferentially around the stator core 110. Thus, the space located on the side of the multiple stator teeth 112 closest to the central axis of the stator core 110 forms the inner hole of the stator core 110. It is easy to understand that the direction of the central axis of the stator core 110 is the axial direction of the stator core 110, the direction around the central axis of the stator core 110 is the circumferential direction of the stator core 110, and the direction perpendicular to the central axis of the stator core 110 and pointing outward from the central axis of the stator core 110, and its reverse direction, are the radial directions of the stator core 110. Along the radial direction of the stator core 110, the side closer to the central axis of the stator core 110 is the inner side, and the side farther away from the central axis of the stator core 110 is the outer side.

[0028] Reference Figure 1 As shown, it can be understood that a winding slot 113 is defined between two adjacent stator teeth 112, and the number of winding slots 113 is equal to the number of stator teeth 112. Furthermore, the number of winding slots 113 and the number of stator teeth 112 are both equal to the number of windings. Multiple windings are respectively wound around multiple stator teeth 112, and each winding is accommodated within the winding slots 113 located on both sides of the corresponding stator tooth 112.

[0029] Reference Figure 1 As shown, it can be understood that the stator assembly 100 is arranged around the outer periphery of the rotor assembly 200, that is, the rotor assembly 200 is located in the inner hole of the stator core, and the rotor assembly 200 can rotate relative to the stator assembly 100. Specifically, the rotor assembly 200 includes a rotor core 210 and a plurality of permanent magnets 220. The rotor core 210 is composed of a plurality of core units 211. The outer contour of the core unit 211 is roughly fan-shaped, and the smaller end of the fan-shaped core unit 211 is closer to the central axis of the stator core 110 than the larger end. The plurality of core units 211 are arranged at equal intervals along the circumference of the stator core 110. A mounting slot 212 is defined between two adjacent core units 211. The number of mounting slots 212 is equal to the number of core units 211, and the number of mounting slots 212 and the number of core units 211 are equal to the number of permanent magnets 220. Multiple permanent magnets 220 are respectively installed in multiple mounting slots 212.

[0030] Reference Figure 1As shown, it can be understood that in this example, the motor is a twelve-slot, ten-pole motor, that is, there are twelve winding slots 113 and ten permanent magnets 220.

[0031] Of course, the number of slots and poles of a motor is not limited to twelve slots and ten poles; other combinations of slots and poles are also possible, which will not be elaborated here.

[0032] Reference Figure 1 As shown, the number of permanent magnets 220 is defined as N, and N is an even number. Multiple permanent magnets 220 are arranged at equal intervals along the circumference of the rotor core 210. Therefore, there exist two permanent magnets 220 that are centrally symmetrically arranged about the central axis of the rotor core 210, that is, these two permanent magnets 220 are arranged radially opposite each other along the rotor core 210.

[0033] The minimum distance D2 between two permanent magnets 220 arranged symmetrically about the central axis of the rotor core 210 is defined. D2 can be measured directly by measuring the minimum distance between the two end faces of the two symmetrically arranged permanent magnets 220 facing the central axis of the rotor core 210. Typically, these two end faces are parallel. It is easy to understand that D2, to a certain extent, reflects the size of the space surrounded by multiple core units 211, that is, the diameter of the shaft that can be installed. The larger D2 is, the larger the diameter of the shaft that can be installed, and vice versa.

[0034] Reference Figure 4 As shown, the maximum radial length of the permanent magnet 220 along the rotor core 210 is defined as 'a', which is the maximum distance between two opposing walls of the permanent magnet 220 along the radial direction of the rotor core 210. The maximum circumferential thickness of the permanent magnet 220 along the rotor core 210 is defined as 'b', which is the maximum distance between two opposing walls of the permanent magnet 220 along the circumferential direction of the rotor core 210. Generally, on the projection plane perpendicular to the central axis of the rotor core 210, the projection of the permanent magnet 220 is rectangular, that is, the length of the projection of the permanent magnet 220 is 'a', and the width of the projection of the permanent magnet 220 is 'b'.

[0035] Reference Figure 1 and Figure 4 As shown, it can be understood that the number N of permanent magnets 220, the minimum distance D2 between two permanent magnets 220 arranged symmetrically about the central axis of the rotor core 210, the maximum radial length a of the permanent magnets 220 along the rotor core 210, the maximum circumferential thickness b of the permanent magnets 220 along the rotor core 210, and the coefficient K satisfy the following: ,in, , .

[0036] Reference Figure 2As shown, it can be understood that the two end faces of the permanent magnet 220 that are radially opposite to each other along the rotor core 210 are defined as the first end face 221 and the second end face 222, wherein the first end face 221 is closer to the central axis of the rotor core 210 than the second end face 222. The core unit 211 is defined to have a first center line Z1 that intersects with and is perpendicular to the central axis of the rotor core 210, and the permanent magnet 220 has a second center line Z2 that intersects with and is perpendicular to the central axis of the rotor core 210, the second center line Z2 being perpendicular to the first end face 221 and the second end face 222.

[0037] Reference Figure 2 As shown, it can be understood that on the projection plane perpendicular to the central axis of the rotor core 210, among the adjacent core units 211 and permanent magnets 220, the angle between the line connecting the end of the second end face 222 closest to the first center line Z1 and the projection of the central axis of the rotor core 210 and the second center line Z2 is defined as θ1, and the vertical distance from the end of the second end face 222 closest to the first center line Z1 to the first center line Z1 is defined as L1. Similarly, the angle between the line connecting the end of the first end face 221 closest to the first center line Z1 and the projection of the central axis of the rotor core 210 and the second center line Z2 is defined as θ2, and the vertical distance from the end of the first end face 221 closest to the first center line Z1 to the first center line Z1 is defined as L2.

[0038] It is easy to understand that, generally speaking, the end of the projection of the second end face 222 closest to the first center line Z1 is located on the projection of the wall of the core unit 211 facing the permanent magnet 220. Similarly, the end of the projection of the first end face 221 closest to the first center line Z1 is located on the projection of the wall of the core unit 211 facing the permanent magnet 220. Therefore, L1 reflects, to some extent, the circumferential dimension of the outer end of the core unit 211 in the rotor core 210, and L2 reflects, to some extent, the circumferential dimension of the inner end of the core unit 211 in the rotor core 210.

[0039] Reference Figure 2 As shown, according to the Pythagorean theorem, we can obtain... ,in, .

[0040] Similarly, ,in, .

[0041] therefore, .

[0042] In other words, 9.5 ≤ K = L1 / L2 ≤ 22. Therefore, the coefficient K reflects, to some extent, the ratio of the outer and inner dimensions of the core unit 211 in the circumferential direction of the rotor core 210. Generally speaking, L2 is small, and the value of L2 can be regarded as a fixed value. The coefficient K thus reflects, to some extent, the space occupied by the core unit 211 in the circumferential direction of the rotor core 210 or the amount of material used in the core unit 211.

[0043] It is easy to understand that the space in the circumferential direction of the rotor core 210 of the rotor assembly 200 is occupied by the core unit 211 and the permanent magnet 220. Given a fixed maximum outer diameter and minimum inner diameter of the rotor core 210, a larger space occupied by the core unit 211 in the circumferential direction (i.e., a larger quantity of core units 211) results in a smaller space occupied by the permanent magnet 220 in the circumferential direction (i.e., a smaller quantity of permanent magnets 220). Conversely, a smaller space occupied by the core unit 211 in the circumferential direction results in a larger space occupied by the permanent magnet 220 in the circumferential direction.

[0044] It is easy to understand that the no-load back EMF is positively correlated with the product of the number of turns of the winding and the magnetic flux of the permanent magnet 220.

[0045] When K < 9.5, under the premise that the value of L2 is constant and the maximum outer diameter of the rotor core 210 remains unchanged, L1 is too small, that is, the outer end of the core unit 211 is too small in the circumferential direction of the rotor core 210. The cross-sectional area and quantity of the core unit 211 decrease, and the magnetic flux of the core unit 211 is easy to saturate. Although the cross-sectional area and quantity of the permanent magnet 220 increase, the utilization rate decreases.

[0046] When K > 22, under the premise that the value of L2 is constant and the maximum outer diameter of the rotor core 210 remains unchanged, L1 is too large, that is, the outer end of the core unit 211 has too large a dimension in the circumferential direction of the rotor core 210, which leads to a reduction in the cross-sectional area and quantity of the permanent magnet 220, a decrease in the output torque of the motor, and a decrease in the no-load back EMF. Although the cross-sectional area and quantity of the core unit 211 increase, the utilization rate decreases and the iron loss increases.

[0047] Therefore, by ensuring that 9.5 ≤ K ≤ 22, for example, K can be 9.5, 11, 13.4, 14, 15.6, 17.1, 18, 19, 21.5, or 22, even with a large D2, the maximum length a and maximum thickness b of the permanent magnet 220 are optimized to adjust the amount of the core unit 211. Simultaneously, the amount of the permanent magnet 220 and the ratio of the amount of the core unit 211 to the amount of the permanent magnet 220 are adjusted to keep the amounts of the core unit 211 and the permanent magnet 220 within a suitable range. This increases the magnetic field of the permanent magnet 220 while reducing the magnetic flux saturation of the core unit 211, and improves the utilization rate of the permanent magnet 220 and the rotor core 210. This, in turn, increases the output torque of the motor, increases the no-load back EMF by approximately 32%, reduces losses, and improves the operating efficiency of the motor.

[0048] It is easy to understand that the output torque of a motor is positively correlated with the product of the no-load back EMF and the input current.

[0049] Given a fixed output torque, increasing the no-load back EMF reduces the input current, thereby lowering losses and further improving the motor's operating efficiency, ultimately enhancing its output performance.

[0050] Reference Figure 5 As shown in the figure, the per-unit value of the no-load back EMF varies with the value of K, and the operating efficiency of the motor varies with the value of K. The per-unit value of the no-load back EMF is a relative value based on a no-load back EMF of 1 in the prior art. From the two curves in the figure, it can be seen that as the value of K increases, both the per-unit value of the no-load back EMF and the operating efficiency of the motor first increase and then decrease, reaching their maximum values ​​when K is around 17.5. When 9.5 ≤ K ≤ 22, both the per-unit value of the no-load back EMF and the operating efficiency of the motor are relatively large, with the per-unit value of the no-load back EMF being approximately 1.05–1.3 and the operating efficiency of the motor being approximately 68%–73.5%. In other words, 9.5 ≤ K ≤ 22 can effectively improve the no-load back EMF and operating efficiency of the motor.

[0051] Reference Figure 1 As shown, it can be understood that the minimum distance D2 between the two permanent magnets 220 arranged symmetrically about the central axis of the rotor core 210 satisfies: 24mm ≤ D2 ≤ 33mm. For example, D2 can be 24mm, 26mm, 29mm, 30.5mm, 31mm, 32.7mm, or 33mm, etc. Under the premise that the maximum outer diameter of the rotor core 210 is fixed, making D2 larger allows for an increase in the shaft hole of the rotor assembly 200, thereby enabling it to accommodate shafts of various diameters, improving versatility, and helping to reduce development costs.

[0052] Reference Figure 4 As shown, it can be understood that the maximum thickness b of the permanent magnet 220 along the circumference of the rotor core 210 satisfies: 5.5mm ≤ b ≤ 9.5mm. For example, b can be 5.5mm, 6mm, 6.8mm, 7.2mm, 8mm, 8.9mm, or 9.5mm, etc., making the maximum thickness of the permanent magnet 220 larger, thereby increasing the magnetic field of the permanent magnet 220, which is beneficial to improving the output torque of the motor and increasing the no-load back EMF.

[0053] In this embodiment, the requirements of 24mm≤D2≤33mm and 5.5mm≤b≤9.5mm are simultaneously met. Under the premise of adapting to shafts of various diameters, the amount of permanent magnet 220 can be increased, the magnetic field of permanent magnet 220 can be increased, thereby effectively ensuring the output torque of the motor and increasing the no-load back EMF, thus improving the output performance of the motor.

[0054] It is easy to understand that, due to the increased amount of permanent magnet 220, the magnetic field stability of permanent magnet 220 is high and the anti-demagnetization ability is enhanced, which makes the demagnetizing current required for permanent magnet 220 to demagnetize larger, achieving a demagnetizing current increase of about 30%, which is beneficial to improving the demagnetizing performance of the motor.

[0055] Reference Figure 1 As shown, it is understandable that the disconnection between two adjacent core units 211 helps to reduce magnetic leakage and improve the utilization rate of the permanent magnet 220.

[0056] Reference Figure 1 As shown, it can be understood that a mounting groove 212 is defined between two adjacent core units 211. The outer end of the mounting groove 212 (i.e. the end away from the rotor core 210) is provided with a slot. The minimum width of the slot is defined as W1. The minimum width of the slot W1 is the minimum distance between the outer ends of the two opposite sides of the two core units 211 located on both sides of the circumference of the rotor core 210 along the mounting groove 212.

[0057] Reference Figure 1 As shown, in this embodiment, the core unit 211 includes two outer magnetic bridges 2111 and two inner magnetic bridges 2112. The two outer magnetic bridges 2111 are located on both sides of the outer end of the core unit 211 along the circumference of the rotor core 210, and the two inner magnetic bridges 2112 are located on both sides of the inner end of the core unit 211 along the circumference of the rotor core 210. The outer magnetic bridges 2111 and inner magnetic bridges 2112 respectively abut against the two ends of the permanent magnet 220 in the radial direction to achieve positioning of the permanent magnet 220. The minimum width W1 of the slot is the minimum distance between the two outer magnetic bridges 2111 located at the outer end of the mounting slot 212 and arranged opposite each other in the circumference of the rotor core 210.

[0058] Reference Figure 1As shown, the maximum outer diameter of the rotor core 210 is defined as D1. In this embodiment, the number of core units 211 is even. On the projection plane perpendicular to the central axis of the rotor core 210, the maximum outer diameter D1 of the rotor core 210 is the maximum distance of the line segment passing through the center of the rotor core 210 (i.e., the projection of the central axis) and extending to the projection of the outer wall surfaces of two core units 211 arranged symmetrically about the central axis of the rotor core 210. In other words, the maximum outer diameter D1 of the rotor core 210 is the maximum value of the outer diameter at all points on the rotor core 210.

[0059] Reference Figure 1 As shown, it can be understood that the minimum width W1 of the slot and the maximum outer diameter D1 of the rotor core 210 satisfy: 0.25≤N*W1 / (π*D1)≤0.4. Given a fixed size for the outer magnetic bridge 2111, W1 reflects, to some extent, the width of the mounting slot 212 along the circumference of the rotor core 210, and the width of the mounting slot 212 matches the maximum thickness b of the permanent magnet 220. That is, W1 reflects, to some extent, the space occupied by the permanent magnet 220 in the circumference of the rotor core 210. The larger W1 is, the larger the space occupied by the permanent magnet 220 in the circumference of the rotor core 210, and the greater the number of permanent magnets 220 used. Correspondingly, the smaller the space occupied by the core unit 211 in the circumference of the rotor core 210, meaning a smaller number of core units 211 are used. N*W1, to some extent, reflects the space occupied by N permanent magnets 220 in the circumference of the rotor core 210.

[0060] π*D1 is the circumference of the circle with the maximum outer diameter of the rotor core 210 as its diameter. Generally speaking, after the minimum inner diameter of the stator core 110 is determined and the distance of the air gap 240 in the radial direction of the stator core 110 is determined, the maximum outer diameter D1 of the rotor core 210 can be determined, that is, the space of the rotor assembly 200 in the circumferential direction of the rotor core 210 can be determined.

[0061] When N*W1 / (π*D1) < 0.25, based on D2 and with the maximum outer diameter D1 of the rotor core 210 determined, the minimum width of the slot is too small, the maximum thickness of the permanent magnet 220 is too small, the amount of permanent magnet 220 used decreases, the magnetic field of the permanent magnet 220 weakens, resulting in a decrease in the output torque of the motor and a decrease in the no-load back EMF. Meanwhile, the amount of core unit 211 used increases. Due to the limitation of the magnetic field of the permanent magnet 220, the utilization rate of core unit 211 decreases, iron loss increases, and the operating efficiency of the motor decreases.

[0062] When N*W1 / (π*D1)>0.4, based on D2 and the maximum outer diameter D1 of the rotor core 210 is determined, the minimum width of the slot is too large and the maximum thickness of the permanent magnet 220 is too large. Although the amount of permanent magnet 220 increases and the magnetic field of permanent magnet 220 is enhanced, the amount of core unit 211 decreases and the magnetic flux of core unit 211 is easily saturated, resulting in a decrease in the utilization rate of permanent magnet 220. This will also lead to a decrease in the output torque of the motor, a decrease in the no-load back EMF, and a decrease in operating efficiency.

[0063] Therefore, by ensuring that 0.25≤N*W1 / (π*D1)≤0.4, for example, the value of N*W1 / (π*D1) is 0.25, 0.28, 0.31, 0.36, 0.39, or 0.4, etc., based on the determination of D2 and the maximum outer diameter D1 of the rotor core 210, the amount of permanent magnet 220 and core unit 211 is optimized by optimizing the minimum width of the slot, thereby enhancing the magnetic field of permanent magnet 220, increasing the no-load back EMF, reducing the magnetic flux saturation of core unit 211, and improving the utilization rate of core unit 211 and permanent magnet 220, reducing iron loss, and thus improving the output torque and operating efficiency of the motor.

[0064] Reference Figure 6 As shown in the figure, the per-unit value of the no-load back EMF varies with the value of N*W1 / (π*D1). The curve shows that as the value of N*W1 / (π*D1) increases, the per-unit value of the no-load back EMF first increases and then decreases. The per-unit value of the no-load back EMF is largest, approximately 1.2, when the value of N*W1 / (π*D1) is approximately 0.325. It is easy to understand that when 0.25 ≤ N*W1 / (π*D1) ≤ 0.4, the per-unit value of the no-load back EMF ranges from approximately 1.05 to 1.2. Therefore, maintaining 0.25 ≤ N*W1 / (π*D1) ≤ 0.4 can effectively increase the no-load back EMF, thereby improving the operating efficiency of the motor.

[0065] Reference Figure 1 As shown, the minimum outer diameter of the stator core 110 is defined as D3. In this embodiment, the outer contour of the stator core 110 is a regular polygon with the same number of sides as the number of winding slots 113, and both are even. On the projection plane perpendicular to the central axis of the stator core 110, the minimum outer diameter D3 of the stator core 110 is the distance between two line segments symmetrically arranged about the central axis of the stator core 110 in its outer contour. In other words, the minimum outer diameter D3 of the stator core 110 is the minimum value of the outer diameter at all points on the stator core 110.

[0066] Reference Figure 1As shown, it can be understood that the maximum outer diameter D1 of the rotor core 210 and the minimum outer diameter D3 of the stator core 110 satisfy: 0.65≤D1 / D3≤0.75.

[0067] It is easy to understand that, given a fixed distance of the air gap 240 along the radial direction of the stator core 110, It reflects, to some extent, the radial thickness of the stator core 110.

[0068] When D1 / D3 < 0.65, the value of D3-D1 is too large, increasing the radial thickness of the stator core 110, the amount of stator core 110 used, and the number of winding turns, thus increasing the cost. Under the premise that the minimum outer diameter of the stator core 110 is fixed, the space of the rotor core 210 will be compressed, reducing the radial thickness of the rotor core 210, and decreasing the amount of rotor core 210 used and the amount of permanent magnet 220 used. The magnetic flux of the rotor core 210 is prone to saturation, and the magnetic flux of the permanent magnet 220 is too small. Although the number of winding turns increases, the utilization rate of the winding and the stator core 110 decreases, and the iron loss and copper loss increase, resulting in a small no-load back EMF of the motor, a decrease in the output torque of the motor, and a reduction in efficiency.

[0069] When D1 / D3 > 0.75, the value of D3-D1 is too small, the radial thickness of the stator core 110 decreases, the amount of stator core 110 used and the number of turns in the winding decrease, and the magnetic flux of the stator core 110 is prone to saturation. Under the premise that the minimum outer diameter of the stator core 110 is fixed, the radial thickness of the rotor core 210 increases, the amount of rotor core 210 used and the amount of permanent magnet 220 used increases, the cost increases. Although the magnetic flux of permanent magnet 220 increases, the utilization rate of permanent magnet 220 and rotor core 210 decreases, iron loss and copper loss increase, resulting in a small no-load back EMF of the motor, a decrease in the output torque of the motor, and a decrease in efficiency.

[0070] Therefore, by ensuring that 0.65≤D1 / D3≤0.75, for example, the value of D1 / D3 is 0.65, 0.68, 0.69, 0.72, 0.73, or 0.75, the maximum outer diameter D1 of the rotor core 210 and the minimum outer diameter D3 of the stator core 110 are optimized and adjusted. This keeps the radial thickness of the stator core 110 and the rotor core 210, the number of turns in the winding, and the amount of permanent magnet 220 within a reasonable range. This reduces the magnetic flux saturation of the stator core 110 and the rotor core 210, improves the utilization rate of the winding and permanent magnet 220, and reduces iron and copper losses. Thus, while ensuring the output torque of the motor, the no-load back EMF of the motor is increased, while reducing material usage and lowering costs by about 20%, and effectively improving the operating efficiency of the motor.

[0071] Reference Figure 3 As shown, it can be understood that the stator tooth 112 includes a tooth portion 1121 and a tooth shoe 1122. The tooth portion 1121 is connected to the inner peripheral wall of the stator yoke portion 111 and extends radially toward the center of the stator core 110. The tooth shoe 1122 is connected to one end of the tooth portion 1121 away from the stator yoke portion 111, and the tooth shoe 1122 protrudes circumferentially toward both sides of the tooth portion 1121 along the stator core 110.

[0072] Reference Figure 3 As shown, it can be understood that the minimum tooth width of tooth 1121 is defined as W2. W2 is the minimum distance between two opposing walls of tooth 1121 along the circumference of stator core 110. Generally speaking, the two opposing walls of tooth 1121 along the circumference of stator core 110 are parallel.

[0073] Reference Figure 1 and Figure 3 As shown, it can be understood that the minimum tooth width W2 of the tooth portion 1121, the maximum outer diameter D1 of the rotor core 210, and the minimum outer diameter D3 of the stator core 110 satisfy: 0.33≤2*W2 / (D3-D1)≤0.47. That is, the ratio of the minimum tooth width of the tooth portion 1121 to the radial thickness of the stator core 110 is limited.

[0074] Under the premise that 0.65≤D1 / D3≤0.75, the value of D3-D1 can be considered as determined. When 2*W2 / (D3-D1)<0.33, the minimum tooth width of tooth 1121 is too small, and the magnetic flux of tooth 1121 is prone to saturation, resulting in a decrease in the utilization rate of the magnetic field, and a decrease in the output torque and operating efficiency of the motor. When 2*W2 / (D3-D1)>0.47, the minimum tooth width of tooth 1121 is too large, the cross-sectional area of ​​winding slot 113 is reduced, resulting in a decrease in the number of turns of the winding, which will also lead to a decrease in the output torque of the motor, and a decrease in the no-load back EMF and efficiency.

[0075] Therefore, by ensuring that 0.33≤2*W2 / (D3-D1)≤0.47, for example, the value of 2*W2 / (D3-D1) is 0.33, 0.38, 0.4, 0.42, 0.45, or 0.47, the minimum tooth width of the tooth section 1121 can be further optimized to reduce the magnetic flux saturation of the tooth section 1121 and ensure the number of turns of the winding, thereby ensuring the output torque of the motor and improving the no-load back EMF and the operating efficiency of the motor.

[0076] Reference Figure 7As shown in the figure, the graph displays the surface plot of the motor efficiency as a function of the values ​​of D1 / D3 and 2*W2 / (D3-D1). The graph shows that when the value of D1 / D3 is constant, the motor efficiency first increases and then decreases as the value of 2*W2 / (D3-D1) increases. Similarly, when the value of 2*W2 / (D3-D1) is constant, the motor efficiency first increases and then decreases as the value of D1 / D3 increases. Furthermore, the motor efficiency is at its maximum, approximately 73%, when the values ​​of D1 / D3 are approximately 0.72 and 2*W2 / (D3-D1) are approximately 0.43. When 0.65 ≤ D1 / D3 ≤ 0.75 and 0.33 ≤ 2*W2 / (D3-D1) ≤ 0.47, the motor efficiency remains above approximately 66.5%. Therefore, it can be seen that when 0.65≤D1 / D3≤0.75 and 0.33≤2*W2 / (D3-D1)≤0.47, the efficiency of the motor can be effectively improved.

[0077] Reference Figure 3 As shown, it can be understood that the maximum distance between the two opposite ends of the stator core 110 along the circumference of the toothed shoe 1122 is defined as W3, and the maximum distance between the two opposite ends of the rotor core 211 along the circumference of the core unit 211 is defined as W4. In this embodiment, the maximum distance W4 between the two opposite ends of the rotor core 210 along the circumference of the core unit 211 is the same as the maximum distance between the two opposite ends of the rotor core 210 along the circumference of the two external magnetic bridges 2111.

[0078] In other embodiments, with the core units 211 disconnected from each other, and no external magnetic bridges 2111 on either side of the outer end of the core unit 211 along the circumference of the rotor core 210, the maximum distance W4 between the two opposite ends of the core unit 211 along the circumference of the rotor core 210 is the maximum distance between the two opposite walls of the core unit 211 along the circumference of the rotor core 210. Alternatively, if an external magnetic bridge 2111 is provided on only one side, the maximum distance W4 between the two opposite ends of the core unit 211 along the circumference of the rotor core 210 is the maximum distance between the external magnetic bridge 2111 and other walls.

[0079] Reference Figure 3 As shown, it can be understood that the maximum distance W3 between the two ends of the toothed shoe 1122 along the circumference of the stator core 110 and the maximum distance W4 between the two ends of the core unit 211 along the circumference of the rotor core 210 satisfy: 1.1≤W3 / W4≤1.3.

[0080] It is easy to understand that the magnetic field lines between the stator assembly 100 and the rotor assembly 200 are mainly conducted through the toothed shoe 1122 and the core unit 211. The maximum distance W3 between the two opposite ends of the toothed shoe 1122 along the circumference of the stator core 110 reflects, to some extent, the ability of the toothed shoe 1122 to receive or emit magnetic field lines. The larger the value of W3, the better the ability of the toothed shoe 1122 to receive or emit magnetic field lines, and the lower the magnetic flux saturation of the toothed shoe 1122 under the premise of a constant magnetic field strength. Similarly, the maximum distance W4 between the two opposite ends of the core unit 211 along the circumference of the rotor core 210 reflects, to some extent, the ability of the core unit 211 to receive or emit magnetic field lines. The larger the value of W4, the better the ability of the core unit 211 to receive or emit magnetic field lines, and the lower the magnetic flux saturation of the core unit 211 under the premise of a constant magnetic field strength.

[0081] When W3 / W4 < 1.1, the maximum distance W3 between the two opposite ends of the stator core 110 along the circumference of the toothed shoe 1122 is too small, the magnetic flux of the toothed shoe 1122 is easily saturated, the utilization rate of the magnetic field decreases, and the output torque of the motor decreases; while the maximum distance W4 between the two opposite ends of the rotor core 210 along the circumference of the core unit 211 is too large. Limited by the toothed shoe 1122, the utilization rate of the core unit 211 decreases, the iron loss increases, and the cost increases.

[0082] When W3 / W4 > 1.3, the maximum distance W4 between the two opposite ends of the core unit 211 along the circumference of the rotor core 210 is too small, the magnetic flux of the core unit 211 is easily saturated, the utilization rate of the magnetic field decreases, and the output torque of the motor decreases; while the maximum distance W3 between the two opposite ends of the toothed shoe 1122 along the circumference of the stator core 110 is too large. Limited by the core unit 211, the utilization rate of the toothed shoe 1122 decreases, the iron loss increases, and the cost increases.

[0083] It is easy to understand that a permanent magnet 220 is installed between two adjacent core units 211. The permanent magnet 220 has a certain thickness along the circumference of the rotor core 210, and to reduce magnetic leakage, the two adjacent core units 211 are disconnected from each other and the distance between them is as large as possible (less than the thickness of the permanent magnet 220). A slot of winding groove 113 is formed between two adjacent tooth shoes 1122. If the slot of winding groove 113 is too large, it will lead to an increase in cogging torque and a deterioration in vibration and noise. Although the number of tooth shoes 1122 is greater than the number of core units 211, in this embodiment there are twelve tooth shoes 1122 and ten core units 211. Due to the limitation of installing permanent magnets 220, in order to reduce magnetic leakage and reduce cogging torque, generally speaking, W3 > W4, and W3 / W4 ≥ 1.1.

[0084] Therefore, by making 1.1≤W3 / W4≤1.3, for example, the value of W3 / W4 is 1.1, 1.15, 1.2, 1.28 or 1.3, the maximum distance W3 between the two opposite ends of the toothed shoe 1122 along the circumference of the stator core 110 and the maximum distance W4 between the two opposite ends of the core unit 211 along the circumference of the rotor core 210 are optimized. At the same time, the magnetic flux saturation of the toothed shoe 1122 and the core unit 211 is reduced, the utilization rate of the magnetic field is improved, the iron loss is reduced, thereby improving the output torque and operating efficiency of the motor and reducing the cost.

[0085] In other embodiments, the outer contour of the stator core 110 may also be a polygonal shape (with a recess in the outer contour), a circle, or a closed loop formed by connecting multiple arc segments.

[0086] Understandably, the stator laminations that make up the stator core 110 are formed by stamping from sheet metal such as silicon steel plates. The shape of the stamped stator laminations can be ring-shaped; simply stacking multiple ring-shaped stator laminations in corresponding positions along the thickness direction yields the ring-shaped stator core 110. Alternatively, the shape of the stamped stator laminations can be chain-shaped; stacking multiple chain-shaped stator laminations in corresponding positions along the thickness direction yields a chain structure, which is then bent into a ring shape using a bending process and joined end to end to obtain the ring-shaped stator core 110.

[0087] Reference Figure 1 As shown, it can be understood that in this embodiment, the stator laminations obtained by punching are in a chain shape. Therefore, during material layout, the chain-shaped stator laminations are arranged in a straight line on the silicon steel sheet and other plates. This optimizes the layout, reduces waste, improves the material utilization rate of the plates, and thus reduces material costs.

[0088] Continue to refer to Figure 1 Specifically, in the stator core 110 composed of chain-like stator laminations, the stator yoke 111 includes multiple yoke units 1111, the number of which is equal to the number of stator teeth 112. The multiple yoke units 1111 are arranged sequentially along the circumference of the stator core 110 and form a ring. The multiple stator teeth 112 are respectively connected to the wall surface of the multiple yoke units 1111 on the side facing the central axis of the stator core 110.

[0089] Reference Figure 1 and Figure 3It is understood that at least one adjacent pair of yoke units 1111 is provided with a splicing structure 1112, and each other adjacent pair of yoke units 1111 is connected by a bending portion 1113. Specifically, in this embodiment, the stator core 110 is composed of a chain-like structure. After the chain-like structure is assembled into a ring, the first and last two yoke units 1111 are joined together by the splicing structure 1112. The splicing structure 1112 can be a dovetail groove structure, a concave-convex fit structure, etc. Each other adjacent pair of yoke units 1111 is connected by a bending portion 1113. The bending portion 1113 allows the adjacent pair of yoke units 1111 to be bent relative to each other in a direction perpendicular to the central axis of the stator core, so that the chain-like structure can be bent into a ring-shaped stator core 110, which is convenient for production.

[0090] Of course, the stator core 110 is composed of multiple chain-like structures spliced ​​together in sequence to form a ring. Adjacent chain-like structures are connected by splicing structure 1112. In each chain-like structure, a bending part 1113 is connected between every two adjacent yoke units 1111, which will not be described in detail here.

[0091] Reference Figure 1 As shown, it can be understood that in this embodiment, the rotor assembly 200 also includes an inner core 230, which is disposed within the space surrounded by multiple core units 211. Typically, the inner core 230 has a shaft hole in its center for the shaft to pass through, and the shaft is fixedly connected to the inner core 230. The inner core 230 is disconnected from the multiple core units 211, which helps to further reduce magnetic leakage and improve the utilization rate of the permanent magnets 220. It is readily understood that the spaces between the multiple core units 211, the multiple permanent magnets 220, the inner core 230, and the shaft are filled with injection-molded material to achieve interconnection and fixation, thereby improving the structural stability of the rotor assembly 200.

[0092] Reference Figure 8 As shown, the figure compares the output torque of the motor in this embodiment with that of the motor in the prior art, showing the changes in input current. From the two curves in the figure, it can be seen that under light load conditions, i.e., when the input current is small (specifically, within the range of 0A to 0.6A), the two curves essentially overlap. Under heavy load conditions, i.e., when the input current is small (specifically, within the range of 0.6A to 1.6A), the curve of this embodiment is above the curve of the prior art. In other words, under light load conditions, the output torque of the motor in this embodiment is essentially equal to that of the motor in the prior art, while under heavy load conditions, the output torque of the motor in this embodiment is greater than that of the motor in the prior art. The motor in this embodiment possesses good heavy load capacity and improves overload capacity to a certain extent.

[0093] The fan of the second aspect of the present invention includes a wind turbine and a motor of the first aspect of the present invention, wherein the wind turbine is fixedly connected to the rotating shaft.

[0094] Since the fan adopts all the technical solutions of the motor in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments.

[0095] The electrical equipment according to the third aspect of the present invention includes the fan according to the second aspect of the present invention. The electrical equipment may be an air conditioner, a fresh air unit, etc.

[0096] Since the electrical equipment adopts all the technical solutions of the fan in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments.

[0097] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An electric motor, characterized in that, include: A stator assembly includes a stator core and multiple windings. The stator core is annular and has an inner hole. The stator core includes a stator yoke and multiple stator teeth. The multiple stator teeth are connected to the inner peripheral wall of the stator yoke and are arranged at intervals along the circumference of the stator core. The multiple windings are respectively wound on the multiple stator teeth. A rotor assembly is rotatably disposed in the inner hole. The rotor assembly includes a rotor core and a plurality of permanent magnets. The rotor core includes a plurality of core units arranged at intervals along the circumference. A mounting slot is defined between two adjacent core units. The plurality of permanent magnets are correspondingly mounted in the plurality of mounting slots. Wherein, the number of permanent magnets is N, and N is an even number; the minimum distance between two permanent magnets arranged symmetrically about the central axis of the rotor core is D2; the maximum radial length of the permanent magnet along the rotor core is a; the maximum circumferential thickness of the permanent magnet is b; and the coefficient K satisfies: ,in, , .

2. The motor according to claim 1, characterized in that: The maximum thickness b of the permanent magnet along the circumferential direction satisfies: 5.5mm≤b≤9.5mm; and / or, the minimum distance D2 between two permanent magnets arranged symmetrically about the central axis of the rotor core satisfies: 24mm≤D2≤33mm.

3. The motor according to claim 1, characterized in that: The maximum outer diameter of the rotor core is D1, and the outer end of the mounting slot is provided with a slot opening with a minimum width of W1, satisfying: 0.25≤N*W1 / (π*D1)≤0.

4.

4. The motor according to claim 1, characterized in that: The maximum outer diameter of the rotor core is D1, and the minimum outer diameter of the stator core is D3, satisfying: 0.65≤D1 / D3≤0.

75.

5. The motor according to claim 4, characterized in that: The stator tooth includes a tooth portion and a tooth shoe. The tooth portion is connected to the inner peripheral wall of the stator yoke and extends toward the center of the stator core. The tooth shoe is connected to one end of the tooth portion away from the stator yoke and protrudes toward both sides of the tooth portion along the circumferential direction. The minimum tooth width of the tooth portion is W2, which satisfies: 0.33≤2*W2 / (D3-D1)≤0.

47.

6. The motor according to claim 1, characterized in that: The stator tooth includes a tooth portion and a tooth shoe. The tooth portion is connected to the inner peripheral wall of the stator yoke and extends toward the center of the stator core. The tooth shoe is connected to one end of the tooth portion away from the stator yoke and protrudes toward both sides of the tooth portion along the circumferential direction. The maximum distance between the two ends of the tooth shoe that are opposite each other along the circumferential direction is W3, and the maximum distance between the two ends of the core unit that are opposite each other along the circumferential direction is W4, satisfying: 1.1≤W3 / W4≤1.

3.

7. The motor according to claim 1, characterized in that: The stator yoke includes a plurality of yoke units arranged sequentially along the circumference. At least one of the adjacent two yoke units is provided with a splicing structure, and each of the other adjacent two yoke units is connected by a bend. The plurality of stator teeth are respectively connected to the plurality of yoke units.

8. The motor according to claim 1, characterized in that: The rotor assembly further includes an inner core disposed within a space surrounded by a plurality of core units, wherein the inner core is disconnected from the plurality of core units; and / or, adjacent core units are disconnected from each other.

9. A fan, characterized in that, The rotor assembly includes a wind turbine and an electric motor as described in any one of claims 1 to 8, wherein the rotor assembly includes a shaft connected to the rotor core, and the wind turbine is mounted on the shaft.

10. Electrical equipment, characterized in that, Includes the fan as described in claim 9.

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