Motor, fan, and electrical device

Abstract

The present application discloses a motor, a fan, and an electrical device. The motor comprises a stator assembly (100) and a rotor assembly (200). The stator assembly (100) comprises a stator core (110), the stator core (110) comprising a stator yoke portion (111) and a plurality of stator teeth (112), and each stator tooth (112) comprising a tooth portion (1121) and a tooth shoe (1122); the rotor assembly (200) comprises a rotor core (210), the rotor core (210) comprising a plurality of core units (211) arranged in a spaced apart manner in a circumferential direction; a minimum outer diameter of the stator core (110) is D1, a minimum inner diameter of the stator core (110) is D2, a maximum outer diameter of the rotor core (210) is D3, a minimum inner diameter of the rotor core (210) is D4, a minimum tooth width of the tooth portion (1121) is W1, a maximum distance between two opposite ends of the core units (211) in the circumferential direction is W2, and a coefficient K satisfies: (formula).

Description

Motors, fans and electrical equipment

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese patent applications filed on January 24, 2025, with application number 202510121409.7 entitled "Electric Machines, Fans and Electrical Equipment" and application number 202520172291.6 entitled "Electric Machines, Fans and Electrical Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of motor technology, and in particular to a motor, a fan, and electrical equipment. Background Technology

[0004] As the performance of electrical equipment improves, the performance requirements for the motors within these devices also increase. For motors, the output performance is closely related to the magnetic flux saturation degree of the stator and rotor cores. Currently, existing motors have high magnetic flux saturation degrees in their stator and rotor cores, resulting in significant losses and reduced motor efficiency. Summary of the Invention

[0005] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a motor that can increase no-load back EMF, reduce losses, improve operating efficiency, and simultaneously reduce production costs.

[0006] This application also provides a fan and electrical equipment having the above-mentioned motor.

[0007] An electric motor according to a first aspect embodiment of this application 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 arranged at intervals along the circumference of the stator core. Each stator tooth includes a tooth portion and a tooth shoe. The tooth portion is connected to the inner circumferential 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 circumferentially toward both sides of the tooth portion. The plurality of windings are respectively wound around the plurality of tooth portions. A rotor assembly is also included. The rotor assembly, rotatably disposed within the inner hole, includes a rotor core and multiple permanent magnets. The rotor core comprises multiple core units spaced apart along the circumferential direction, with mounting slots defined between adjacent core units. The multiple permanent magnets are correspondingly mounted in the mounting slots. The minimum outer diameter of the stator core is D1, the minimum inner diameter of the stator core is D2, the maximum outer diameter of the rotor core is D3, the minimum inner diameter of the rotor core is D4, the minimum tooth width of the gear is W1, and the maximum distance between the two opposite ends of the core unit along the circumferential direction is W2. The coefficient K satisfies:

[0008] The motor according to the first aspect embodiment of this application has at least the following beneficial effects: by optimizing and adjusting the minimum outer diameter D1 of the stator core, the minimum inner diameter D2 of the stator core, the maximum outer diameter D3 of the rotor core, the minimum inner diameter D4 of the rotor core, the minimum tooth width W1 of the teeth, and the maximum distance W2 between the two circumferentially opposite ends of the core unit, the following advantages are achieved: In other words, by optimizing the thickness of the motor in the radial direction, and by adjusting the ratio between the minimum tooth width of the tooth section and the maximum distance between the two opposite ends of the core unit in the circumferential direction, the magnetic flux saturation of the stator core and rotor core is reduced, while the no-load back EMF is increased, thereby reducing losses and improving the operating efficiency of the motor.

[0009] According to some embodiments of this application, the minimum inner diameter D2 of the stator core satisfies: 58mm≤D2≤62mm.

[0010] According to some embodiments of this application, the minimum thickness of the stator yoke along the radial direction of the stator core is H, satisfying: 1.5≤W1 / H≤2.2.

[0011] According to some embodiments of this application, the minimum tooth width W1 of the tooth portion satisfies: 5.3mm≤W1≤7.2mm.

[0012] According to some embodiments of this application, the maximum distance between the two opposite ends of the toothed shoe along the circumferential direction is W3, which satisfies: 1.1≤W3 / W2≤1.4.

[0013] According to some embodiments of this application, the number of permanent magnets is N, and the maximum thickness of the permanent magnets along the circumferential direction is b, satisfying: 0.35≤N*b / (π*D2)≤0.54.

[0014] According to some embodiments of this application, the maximum radial length of the permanent magnet along the rotor core is a, satisfying: 1.4≤a / b≤2.15.

[0015] According to some embodiments of this application, 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.

[0016] According to some embodiments of this application, 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.

[0017] A wind turbine according to a second aspect of this application includes a wind turbine and a motor according to a first aspect of this application. The rotor assembly includes a rotating shaft fixedly connected to the rotor core, and the wind turbine is connected to the rotating shaft.

[0018] The fan according to the second aspect embodiment of this application has at least the following beneficial effects: Because the fan uses the aforementioned motor, by optimizing and adjusting the minimum outer diameter D1 of the stator core, the minimum inner diameter D2 of the stator core, the maximum outer diameter D3 of the rotor core, the minimum inner diameter D4 of the rotor core, the minimum tooth width W1 of the teeth, and the maximum distance W2 between the two circumferentially opposite ends of the core unit, it satisfies… In other words, by optimizing the thickness of the motor in the radial direction, and by adjusting the ratio between the minimum tooth width of the tooth section and the maximum distance between the two opposite ends of the core unit in the circumferential direction, the magnetic flux saturation of the stator core and rotor core is reduced, while the no-load back EMF is increased, thereby reducing losses and improving the operating efficiency of the motor.

[0019] The electrical equipment according to the third aspect of this application includes the fan according to the second aspect of this application.

[0020] The electrical equipment according to the third aspect of the present application has at least the following beneficial effects: Because the electrical equipment uses the aforementioned fan, by optimizing and adjusting the minimum outer diameter D1 of the stator core, the minimum inner diameter D2 of the stator core, the maximum outer diameter D3 of the rotor core, the minimum inner diameter D4 of the rotor core, the minimum tooth width W1 of the teeth, and the maximum distance W2 between the two circumferentially opposite ends of the core unit, it satisfies… In other words, by optimizing the thickness of the motor in the radial direction, and by adjusting the ratio between the minimum tooth width of the tooth section and the maximum distance between the two opposite ends of the core unit in the circumferential direction, the magnetic flux saturation of the stator core and rotor core is reduced, while the no-load back EMF is increased, thereby reducing losses and improving the operating efficiency of the motor.

[0021] Additional aspects and advantages of this application 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 this application. Attached Figure Description

[0022] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0023] Figure 1 is a cross-sectional view of the motor in an embodiment of this application (with one of the permanent magnets hidden);

[0024] Figure 2 is a partial cross-sectional view of the stator core and core unit assembly in an embodiment of this application;

[0025] Figure 3 is a cross-sectional view of the permanent magnet in an embodiment of this application;

[0026] Figure 4 is a surface plot showing the variation of the no-load back EMF with the values ​​of K and D2 in an embodiment of this application;

[0027] Figure 5 is a surface plot showing the variation of motor efficiency with the values ​​of N*b / (π*D2) and a / b in an embodiment of this application; and

[0028] Figure 6 is a comparison of the output torque of the motor in the embodiment of this application and the output torque of the motor in the prior art solution as a function of input current.

[0029] Reference numerals: 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 slot 113; Rotor assembly 200; Rotor core 210; Core unit 211; Outer magnetic bridge 2111; Inner magnetic bridge 2112; Mounting slot 212; Permanent magnet 220; Inner core 230; Air gap 240. Detailed Implementation

[0030] The embodiments of this application 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 this application, and should not be construed as limiting this application.

[0031] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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 limitations on this application.

[0032] In the description of this application, "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.

[0033] In the description of this application, unless otherwise expressly 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 application in conjunction with the specific content of the technical solution.

[0034] Referring to Figures 1 to 6, a first aspect embodiment of this application provides a motor used 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.

[0035] The following is a detailed description of the structure and components of the motor.

[0036] Referring to Figure 1, it can be understood that 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.

[0037] Referring to Figure 1, it can be understood that 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 the central axis of the stator core 110. 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 all connected to the inner peripheral 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.

[0038] Referring to FIG2, 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 along the circumference of the stator core 110 toward both sides of the tooth portion 1121.

[0039] Referring to Figure 1, it can be understood that a winding slot 113 is defined between two adjacent stator teeth 112. The number of winding slots 113 is equal to the number of stator teeth 112, and 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 on the tooth portions 1121 of multiple stator teeth 112, and each winding is accommodated in the winding slots 113 located on both sides of the corresponding stator tooth 112.

[0040] Referring to Figure 1, 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 110, 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 which is approximately 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, and 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.

[0041] Referring to Figure 1, it can be understood that the disconnection between two adjacent core units 211 helps to reduce magnetic leakage and improve the utilization rate of the permanent magnet 220.

[0042] Referring to Figure 1, 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.

[0043] 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.

[0044] Referring to Figure 1, the minimum outer diameter of the stator core 110 is defined as D1, and the minimum inner diameter of the stator core 110 is defined as D2. 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 numbers, meaning the number of stator teeth 112 is also even. The inner wall surface of the stator teeth 112 is an arc-shaped surface. On the projection plane perpendicular to the central axis of the stator core 110, the minimum outer diameter D1 of the stator core 110 is the distance between two line segments symmetrically arranged about the central axis of the stator core 110 in the outer contour of the stator core 110. The minimum inner diameter D2 of the stator core 110 is the minimum distance of the line segments passing through the center of the stator core 110 (i.e., the projection of the central axis) and extending to the projection of the inner wall surfaces of the two stator teeth 112 symmetrically arranged about the central axis of the stator core 110.

[0045] Referring to Figure 1, the maximum outer diameter of the rotor core 210 is defined as D3, and the minimum inner diameter of the rotor core 210 is defined as D4. 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 D3 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 the two core units 211 arranged symmetrically about the central axis of the rotor core 210. The minimum inner diameter D4 of the rotor core 210 is the minimum 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 inner wall surfaces of the two core units 211 arranged symmetrically about the central axis of the rotor core 210.

[0046] In other words, the minimum outer diameter D1 of the stator core 110 is the minimum value of the outer diameter at all points of the stator core 110, the minimum inner diameter D2 of the stator core 110 is the minimum value of the inner diameter at all points of the stator core 110, the maximum outer diameter D3 of the rotor core 210 is the maximum value of the outer diameter at all points of the rotor core 210, and the minimum inner diameter D4 of the rotor core 210 is the minimum value of the inner diameter at all points of the rotor core 210.

[0047] Referring to Figure 2, it can be understood that the minimum tooth width of the tooth 1121 is defined as W1, which is the minimum distance between two opposing walls of the tooth 1121 along the circumference of the stator core 110. Generally speaking, the two opposing walls of the tooth 1121 along the circumference of the stator core 110 are parallel.

[0048] Referring to Figure 2, it can be understood that the maximum distance W2 between the two opposite ends of the core unit 211 along the circumference of the rotor core 210 is defined. Typically, in this embodiment, adjacent core units 211 are disconnected. Each 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 position the permanent magnet 220. The maximum distance W2 between the two opposite ends of the core unit 211 along the circumference of the rotor core 210 is also the maximum distance between the two opposite ends of the two outer magnetic bridges 2111 along the circumference of the rotor core 210.

[0049] 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 W2 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 W2 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.

[0050] In other embodiments, if two adjacent core units 211 are connected, the maximum distance W2 between the two ends of the core unit 211 that are opposite to each other in the circumferential direction of the rotor core 210 is the maximum distance between the two walls of the core unit 211 that are opposite to each other in the circumferential direction of the rotor core 210. W2 does not include the dimensions of the structure that connects the two adjacent core units 211.

[0051] Referring to Figures 1 and 2, it can be understood that the coefficient K, the minimum outer diameter D1 of the stator core 110, the minimum inner diameter D2 of the stator core 110, the maximum outer diameter D3 of the rotor core 210, the minimum inner diameter D4 of the rotor core 210, the minimum tooth width W1 of the tooth portion 1121, and the maximum distance W2 between the two opposite ends of the core unit 211 along the circumference of the rotor core 210 satisfy the following:

[0052] It is easy to understand that,

[0053] It is understandable that W1 / W2 is the ratio of the minimum tooth width of the tooth 1121 to the maximum distance between the two ends of the core unit 211 that are opposite to each other in the circumferential direction along the rotor core 210, which reflects the dimensional relationship between the tooth 1121 and the core unit 211 in the circumferential direction.

[0054] It is understandable that the radial thickness of the motor is defined as the radial distance between the outer contour of the stator core 110 and the inner contour of the rotor core 210. The armature diameter of the motor is defined as the diameter of a circle with the projection of the central axis of the stator core 110 onto the axial direction as its center and the distance between the midpoint of the air gap 240 in the radial direction and the center of the circle as its radius. The value of the armature diameter is...

[0055] In other words, It is the ratio of half the armature diameter to the radial thickness of the motor. D2 / D1 is the split ratio. This reflects the radial dimensional relationship between the stator core 110 and the rotor core 210.

[0056] 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.

[0057] When K ≤ 0.19, on the one hand, given that the value of W1 / W2 is constant, The values ​​are too small, meaning the split ratio and armature diameter are too small, and the radial thickness of the motor is too large, resulting in an increase in the radial dimension of the stator core 110, an increase in the amount of stator core 110 used and the number of winding turns, and an increase in cost; while the radial dimension of the rotor core 210 is reduced, the amount of rotor core 210 used and the amount of permanent magnet 220 used are reduced, 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 too small no-load back EMF of the motor, a decrease in the output torque of the motor, and a decrease in efficiency; on the other hand, in Given a fixed value, if the value of W1 / W2 is too small, the minimum tooth width of the tooth 1121 is too small, and the maximum distance between the two ends of the iron core unit 211 that are opposite to each other in the circumferential direction of the rotor iron core 210 is too large, that is, the size of the tooth 1121 in the circumferential direction is too small and the size of the iron core unit 211 in the circumferential direction is too large, the magnetic flux of the stator iron core 110 is easily saturated, while the amount of rotor iron core 210 used increases, the cost increases, and the amount of permanent magnet 220 used decreases, the utilization rate of rotor iron core 210 decreases, the iron loss is large, which will also lead to the motor's no-load back EMF being too small, the motor's output torque decreasing, and the efficiency decreasing.

[0058] When K ≥ 0.4, on the one hand, given that the value of W1 / W2 is constant, The values ​​are too large, i.e., the split ratio and armature diameter are too large, and the radial thickness of the motor is too small, resulting in a reduction in the radial dimension of the stator core 110, a reduction in the amount of stator core 110 used and the number of turns in the winding, and an easy saturation of the magnetic flux of the stator core 110; while the radial dimension of the rotor core 210 increases, the amount of rotor core 210 used and the amount of permanent magnet 220 used increases, increasing costs. 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 too small no-load back EMF of the motor, a decrease in the output torque of the motor, and a decrease in efficiency; on the other hand, in Given a fixed value, if the value of W1 / W2 is too large, the minimum tooth width of the tooth 1121 is too large, and the maximum distance between the two ends of the core unit 211 that are opposite to each other along the circumference of the rotor core 210 is too small, that is, the circumferential dimension of the tooth 1121 is too large and the circumferential dimension of the core unit 211 is too small, the magnetic flux of the rotor core 210 is prone to saturation. Although the amount of permanent magnet 220 is increased, the utilization rate of permanent magnet 220 decreases. On the other hand, the amount of stator core 110 is increased, the cost increases, and the number of turns of the winding is reduced, the utilization rate of stator core 110 decreases, the iron loss is large, which will also lead to the motor's no-load back EMF being too small, the motor's output torque decreasing, and the efficiency decreasing.

[0059] Therefore, by ensuring 0.19 ≤ K ≤ 0.4, for example, K can be 0.19, 0.22, 0.25, 0.31, 0.35, 0.38, or 0.4, the minimum outer diameter D1 of the stator core 110, the minimum inner diameter D2 of the stator core 110, the maximum outer diameter D3 of the rotor core 210, the minimum inner diameter D4 of the rotor core 210, the minimum tooth width W1 of the tooth portion 1121, and the maximum distance W2 between the two opposite ends of the core unit 211 along the circumference of the rotor core 210 are adjusted and optimized. This allows for the radial dimensions of the stator core 110 and the rotor core 210 to be optimized. By keeping the radial dimensions, the circumferential dimensions of the tooth 1121, the circumferential dimensions of the core unit 211, the number of turns in the winding, and the amount of permanent magnet 220 within a reasonable range, the magnetic flux saturation of the stator core 110 and the rotor core 210 is reduced, and the utilization rate of the winding and permanent magnet 220 is improved, reducing iron loss and copper loss. Thus, while ensuring the output torque of the motor, the no-load back EMF of the motor is increased by about 32%, while reducing the amount of materials used and lowering the cost by about 20%, and effectively improving the operating efficiency of the motor.

[0060] 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.

[0061] Given a fixed output torque, increasing the no-load back EMF reduces the input current, thereby further reducing losses and improving the motor's operating efficiency, ultimately enhancing its output performance.

[0062] 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.

[0063] 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.

[0064] It is 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.

[0065] Referring to Figures 1 and 2, 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.

[0066] Referring again to Figures 1 and 2, it can be understood that at least one pair of adjacent yoke units 1111 is provided with a splicing structure 1112, and each other pair of adjacent 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 pair of adjacent yoke units 1111 is connected by a bending portion 1113. The bending portion 1113 allows the adjacent two yoke units 1111 to be bent relative to each other in a direction perpendicular to the central axis of the stator core 110, so that the chain-like structure can be bent into a ring-shaped stator core 110, which is convenient for production.

[0067] 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.

[0068] Referring to Figure 1, it can be understood that the minimum inner diameter D2 of the stator core 110 satisfies: 58mm ≤ D2 ≤ 62mm. For example, D2 can be 58mm, 59mm, 59.5mm, 61.3mm, or 62mm, etc. Given a fixed radial width of the air gap 240, a larger minimum inner diameter D2 of the stator core 110 results in a larger armature diameter for the motor, thereby increasing the radial thickness of the rotor core 210. By reducing the saturation level of the rotor core 210 and increasing the amount of permanent magnets 220, the output torque and no-load back EMF of the motor are increased, thereby improving the output performance of the motor.

[0069] 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.

[0070] Referring to Figure 4, the figure shows a surface plot of the motor's no-load back EMF as a function of the values ​​of K and D2. The figure shows that when D2 is constant, the motor's no-load back EMF first increases and then decreases as K increases. Similarly, when K is constant, the motor's no-load back EMF first increases and then decreases as D2 increases. Furthermore, the motor's no-load back EMF is at its maximum, approximately 73.5V, when K is approximately 0.3 and D2 is approximately 60. When 0.19 ≤ K ≤ 0.4 and 58mm ≤ D2 ≤ 62mm, the motor's no-load back EMF remains above approximately 72V. Therefore, setting 0.19 ≤ K ≤ 0.4 and 58mm ≤ D2 ≤ 62mm effectively improves the motor's no-load back EMF.

[0071] Referring to Figure 2, it can be understood that the minimum thickness of the stator yoke 111 along the radial direction of the stator core 110 is defined as H. H is the minimum thickness of the yoke unit 1111, which is also the minimum distance between two opposing walls of the yoke unit 1111 along the radial direction of the stator core 110. Generally speaking, the two opposing walls of the yoke unit 1111 along the radial direction of the stator core 110 are parallel.

[0072] Referring to Figure 2, it can be understood that the minimum tooth width W1 of the tooth portion 1121 and the minimum thickness H of the stator yoke 111 satisfy the following condition: 1.5 ≤ W1 / H ≤ 2.2. When W1 / H < 1.5, the minimum width W1 of the tooth portion 1121 is too small, and the magnetic flux of the tooth portion 1121 is prone to saturation, which will lead to a decrease in the output torque of the motor. The minimum thickness H of the stator yoke 111 is too large, which increases the material and cost. When W1 / H > 2.2, the minimum thickness H of the stator yoke 111 is too small, and the magnetic flux of the stator yoke 111 is prone to saturation, which will lead to a decrease in the output torque of the motor. The minimum tooth width W1 of the tooth portion 1121 is too large, which increases the material and cost.

[0073] Therefore, 1.5 ≤ W1 / H ≤ 2.2 is made, for example, the value of W1 / H is 1.5, 1.63, 1.78, 1.82, 1.95, 2.1 or 2.2, etc., to adjust the minimum tooth width of the tooth portion 1121 and the minimum thickness of the stator yoke portion 111, so that the ratio of the minimum tooth width W1 of the tooth portion 1121 to the minimum thickness H of the stator yoke portion 111 is within a suitable range, thereby reducing the magnetic flux saturation of the stator core 110, increasing the output torque of the motor, and reducing material costs.

[0074] Understandably, specifically, the minimum tooth width W1 of tooth 1121 satisfies: 5.3mm ≤ W1 ≤ 7.2mm. For example, W1 can be 5.3mm, 5.8mm, 6.1mm, 6.8mm, 7mm, or 7.2mm, etc., so that the minimum tooth width of tooth 1121 is set relatively large, thereby reducing the magnetic flux saturation of tooth 1121 and stator core 110, effectively improving the output torque and efficiency of the motor.

[0075] Referring to Figure 2, it can be understood that the maximum distance between the two opposite ends of the toothed shoe 1122 along the circumference of the stator core 110 is defined as W3. 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 W2 between the two opposite ends of the core unit 211 along the circumference of the rotor core 210 satisfy: 1.1≤W3 / W2≤1.4.

[0076] 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 W2 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 W2, 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.

[0077] When W3 / W2 < 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 W2 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.

[0078] When W3 / W2 > 1.4, the maximum distance W2 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.

[0079] 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 113 is formed between two adjacent toothed shoes 1122. If the slot is too large, it will lead to an increase in cogging torque and a deterioration in vibration and noise. Although the number of toothed shoes 1122 is greater than the number of core units 211, in this embodiment there are twelve toothed 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 > W2, and W3 / W2 ≥ 1.1.

[0080] Therefore, by making 1.1≤W3 / W2≤1.4, for example, the value of W3 / W2 is 1.1, 1.15, 1.2, 1.28, 1.31, 1.38 or 1.4, 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 W2 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.

[0081] Referring to Figure 3, it can be understood that the number of permanent magnets 220 is defined as N, the maximum radial length of the permanent magnet 220 along the rotor core 210 is 'a', where 'a' is the maximum distance between two opposing walls of the permanent magnet 220 along the radial direction of the rotor core 210, and the maximum circumferential thickness of the permanent magnet 220 along the rotor core 210 is 'b', where 'b' is the maximum distance between two opposing walls of the permanent magnet 220 along the circumferential direction of the rotor core 210. Generally, on a projection plane perpendicular to the central axis of the rotor core 210, the projection of the permanent magnet 220 is rectangular, meaning 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'.

[0082] Referring to Figures 1 and 3, it can be understood that the maximum thickness b of the permanent magnet 220 and the minimum inner diameter D2 of the stator core 110 satisfy the condition: 0.35 ≤ N*b / (π*D2) ≤ 0.54. Here, N*b reflects, to some extent, the space occupied by N permanent magnets 220 in the circumferential direction of the rotor core 210. It is easy to understand that the space of the rotor assembly 200 in the circumferential direction of the rotor core 210 is occupied by the core unit 211 and the permanent magnets 220. Given a fixed maximum outer diameter D3 and minimum inner diameter D4 of the rotor core 210, a larger space occupied by the permanent magnets 220 in the circumferential direction indicates a larger quantity of permanent magnets 220, while a smaller space occupied by the core unit 211 in the circumferential direction indicates a smaller quantity of core unit 211.

[0083] π*D2 is the circumference of the circle with the minimum inner diameter D2 of the stator core 110 as its diameter. Generally speaking, once the minimum inner diameter D2 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 space of the rotor assembly 200 in the circumferential direction of the rotor core 210 can be determined.

[0084] When N*b / (π*D2) < 0.35, given that the minimum inner diameter D2 of the stator core 110 is determined, the 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. Meanwhile, the amount of core unit 211 used increases, but due to the limitation of the magnetic field of the permanent magnet 220, the utilization rate of the core unit 211 decreases, iron loss increases, and the operating efficiency of the motor decreases.

[0085] When N*b / (π*D2)>0.54, given that the minimum inner diameter D2 of the stator core 110 is determined, the thickness of the permanent magnet 220 is too large. Although the amount of permanent magnet 220 increases and the magnetic field of the permanent magnet 220 is enhanced, the amount of core unit 211 decreases and the magnetic flux of the core unit 211 is easily saturated, resulting in a decrease in the utilization rate of the permanent magnet 220. This will also lead to a decrease in the output torque of the motor and a decrease in operating efficiency.

[0086] Therefore, by ensuring that 0.35≤N*b / (π*D2)≤0.54, for example, the value of N*b / (π*D2) is 0.35, 0.38, 0.41, 0.46, 0.51, or 0.54, and given that the minimum inner diameter D2 of the stator core 110 is determined, the amount of permanent magnet 220 and core unit 211 is optimized, the magnetic flux saturation of core unit 211 is reduced, and the utilization rate of core unit 211 and permanent magnet 220 is improved, thereby reducing iron loss and thus improving the output torque and operating efficiency of the motor.

[0087] Referring to Figure 3, it can be understood that the maximum length *a* and maximum thickness *b* of the permanent magnet 220 satisfy 1.4 ≤ a / b ≤ 2.15. Under the premise that the maximum thickness *b* of the permanent magnet 220 satisfies 0.35 ≤ N*b / (π*D²) ≤ 0.54, i.e., given a fixed maximum thickness *b*, making *a / b ≥ 1.4 increases the length of the permanent magnet 220, strengthens its magnetic field, and improves the utilization rate of the core unit 211, thereby increasing the motor's output torque and operating efficiency. Making *a / b ≤ 2.15 avoids the drawback of excessive magnetic flux saturation in the core unit 211 due to an excessively large magnetic field of the permanent magnet 220, reducing iron losses and thus ensuring the motor's output torque and operating efficiency.

[0088] Therefore, by making 1.4≤a / b≤2.15, for example, the value of a / b is 1.4, 1.52, 1.65, 1.89, 1.92, 1.98, 2.01, 2.11 or 2.15, the amount of permanent magnet 220 is further optimized to enhance the magnetic field and improve the utilization rate of the iron core unit 211, reduce iron loss, and thus improve the output torque and operating efficiency of the motor.

[0089] Referring to Figure 5, the graph shows the variation of motor efficiency with the values ​​of N*b / (π*D²) and a / b. The graph shows that, for a constant value of a / b, the motor efficiency first increases and then decreases as the value of N*b / (π*D²) increases; similarly, for a constant value of N*b / (π*D²), the motor efficiency first increases and then decreases as the value of a / b increases. Furthermore, the motor efficiency is at its maximum, approximately 73.5%, when the value of N*b / (π*D²) is approximately 0.45 and the value of a / b is approximately 1.8. When 0.35 ≤ N*b / (π*D²) ≤ 0.54 and 1.4 ≤ a / b ≤ 2.15, the motor efficiency remains above approximately 69%. Therefore, it is evident that 0.35 ≤ N*b / (π*D²) ≤ 0.54 and 1.4 ≤ a / b ≤ 2.15 can effectively improve motor efficiency.

[0090] Referring to Figure 1, 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 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.

[0091] Referring to Figure 6, it can be understood that the figure shows a comparison of the output torque curves of the motor in this embodiment and the motor in the prior art solution as a function of 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 basically 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 solution. In other words, under light load conditions, the output torque of the motor in this embodiment is basically equal to that of the motor in the prior art solution, 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 solution. The motor in this embodiment has good heavy load capacity and improves overload capacity to a certain extent.

[0092] The fan of the second aspect of this application includes a wind turbine and a motor of the first aspect of this application, wherein the wind turbine is fixedly connected to the rotating shaft.

[0093] 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.

[0094] The electrical equipment in the third aspect of this application includes the fan in the second aspect of this application. The electrical equipment may be an air conditioner, a fresh air unit, etc.

[0095] 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.

[0096] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application 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 this application.

Claims

1. An electric motor, including: 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 arranged at circumferential intervals along the stator core. Each stator tooth includes a tooth portion and a tooth shoe. The tooth portion is connected to the inner circumferential 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 circumferentially toward both sides of the tooth portion. The multiple windings are respectively wound around the multiple tooth portions. 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 minimum outer diameter of the stator core is D1, the minimum inner diameter of the stator core is D2, the maximum outer diameter of the rotor core is D3, the minimum inner diameter of the rotor core is D4, the minimum tooth width of the gear is W1, the maximum distance between the two opposite ends of the core unit along the circumferential direction is W2, and the coefficient K satisfies:

2. The motor according to claim 1, wherein, The minimum inner diameter D2 of the stator core satisfies: 58mm≤D2≤62mm.

3. The motor according to claim 1 or 2, wherein, Along the radial direction of the stator core, the minimum thickness of the stator yoke is H, which satisfies: 1.5≤W1 / H≤2.

2.

4. The motor according to claim 3, wherein, The minimum tooth width W1 of the toothed part satisfies: 5.3mm≤W1≤7.2mm.

5. The motor according to any one of claims 1 to 4, wherein, The maximum distance between the two opposite ends of the toothed shoe along the circumferential direction is W3, which satisfies: 1.1≤W3 / W2≤1.

4.

6. The motor according to any one of claims 1 to 5, wherein, The number of permanent magnets is N, and the maximum thickness of the permanent magnets along the circumferential direction is b, satisfying: 0.35≤N*b / (π*D2)≤0.

54.

7. The motor according to claim 6, wherein, The maximum radial length of the permanent magnet along the rotor core is a, which satisfies: 1.4≤a / b≤2.

15.

8. The motor according to any one of claims 1 to 7, wherein, 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.

9. The motor according to any one of claims 1 to 8, wherein, 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.

10. A fan, comprising a wind turbine and a motor as described in any one of claims 1 to 9, wherein, The rotor assembly includes a rotating shaft fixedly connected to the rotor core, and the impeller is connected to the rotating shaft.

11. Electrical equipment, including the fan as described in claim 10.

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