Single-phase permanent magnet synchronous motor and vacuum cleaner having the same

Abstract

The present invention provides a single-phase permanent magnet synchronous motor and a vacuum cleaner having the same. The single-phase permanent magnet synchronous motor includes multiple types of stator teeth, and the multiple types of stator teeth include at least first-type stator teeth; second-type stator teeth, and the first-type stator teeth and the second-type stator teeth are arranged to form an annular working chamber for accommodating a rotor part; wherein the angle of the center angle corresponding to the first contour line of the end face of the first-type stator tooth facing the rotor part side is different from the angle of the center angle corresponding to the second contour line of the end face of the second-type stator tooth facing the rotor part side. Compared with ordinary single-phase permanent magnet motors, the tooth slot torque of the motor provided in the present application is greatly reduced, the torque pulsation is greatly reduced, and the output torque of the motor is also significantly improved. The single-phase permanent magnet synchronous motor using the present application has a small size, light weight, simple structure, easy large-scale manufacturing and low manufacturing cost.

Description

Technical Field

[0001] The present invention relates to the technical field of motor equipment, and in particular to a single-phase permanent magnet synchronous motor and a vacuum cleaner having the same. Background Art

[0002] Single-phase motors have single-phase windings, and require fewer switching devices to drive the main circuit, so the hardware cost of the control system is low. However, the magnetic field inside a single-phase motor is a pulsating magnetic field, and the electromagnetic torque of the motor has a zero point position. If a specific structure is not adopted, the motor parking position (the point where the cogging torque is 0) coincides with the point where the electromagnetic torque is 0. At this time, no matter what current is passed, the motor cannot start, so there is a problem of starting dead point.

[0003] Usually, single-phase permanent magnet motors use unequal air gaps (i.e., the thickness of the air gap under the same stator tooth varies) to solve the problem of starting dead point, such as a gradient air gap structure. In the prior art, single-phase motors all use uniform air gaps and gradient air gap structures (unequal air gaps). While solving the problem of motor starting dead point, this structure will increase the cogging torque of the motor, resulting in increased motor output torque pulsation and increased motor noise. At the same time, the unequal air gap structure will increase the average air gap length of the motor, causing the output torque density of the motor to decrease. Summary of the invention

[0004] The main purpose of the present invention is to provide a single-phase permanent magnet synchronous motor and a vacuum cleaner having the same, so as to solve the problem of a starting dead point when the motor is started in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a single-phase permanent magnet synchronous motor is provided, the single-phase permanent magnet synchronous motor comprises multiple types of stator teeth, the multiple types of stator teeth at least comprise: first type of stator teeth; second type of stator teeth, the first type of stator teeth and the second type of stator teeth are arranged to form an annular working chamber for accommodating a rotor part; wherein an angle of a center angle corresponding to a first contour line of an end face of the first type of stator teeth facing the rotor part side is different from an angle of a center angle corresponding to a second contour line of an end face of the second type of stator teeth facing the rotor part side.

[0006] Furthermore, in adjacent first-class stator teeth and second-class stator teeth, a geometric center line of a first contour line along a radial direction of the rotor portion intersects with a geometric center line of a second contour line along a radial direction of the rotor portion and forms an angle γ, wherein γ≠2π / s, and s is the total number of first-class stator teeth and second-class stator teeth.

[0007] Further, s=2n, the number of first-type stator teeth is n, the number of first-type stator teeth and the number of second-type stator teeth is n, and n is an integer greater than or equal to 1.

[0008] Further, there are a plurality of first-type stator teeth and a plurality of second-type stator teeth, and the plurality of first-type stator teeth and the second-type stator teeth are alternately arranged along the circumferential direction of the rotor part.

[0009] Furthermore, along the rotation direction of the rotor part, the angle of the central angle corresponding to the first contour line is greater than the angle of the central angle corresponding to the second contour line, wherein, with the second type of stator tooth as a reference starting point, along the rotation direction of the rotor part, the central angle between the geometric center lines of the contour lines of the end surface of the first type of stator tooth adjacent to the second type of stator tooth facing the rotor part is less than 2π / s.

[0010] Furthermore, the geometric center line of the first contour line along the radial direction of the rotor part is used as the reference line, and the angle of 2π / s along the rotation direction of the rotor part is the offset baseline of the first type of stator teeth. An offset angle θ is formed between the geometric center line of the first contour line along the radial direction of the rotor part and the offset baseline, wherein θ=ab, 0<θ<π / 2-α, α is the center angle formed by a line connecting the two ends of the first contour line and the geometric center of the rotor part, b is the center angle formed by a line connecting the offset baseline, the front end of the first contour line, and the geometric center of the rotor part, and a is the center angle formed by a line connecting the offset baseline of the first type of stator teeth, the rear end of the first contour line, and the geometric center of the rotor part.

[0011] Further, a uniform air gap thickness g2 is formed between the second type of stator teeth and the rotor portion, and a uniform air gap thickness g1 is formed between the first type of stator teeth and the rotor portion, wherein g1=g2.

[0012] Furthermore, g1<g2.

[0013] Furthermore, the thickness of the air gap formed between the second type of stator teeth and the rotor part is gradually increased or gradually decreased along the circumferential direction of the rotor part, and / or the thickness of the air gap formed between the first type of stator teeth and the rotor part is gradually increased or gradually decreased along the circumferential direction of the rotor part.

[0014] Further, there are multiple first-class stator teeth and multiple second-class stator teeth, the multiple first-class stator teeth and the multiple second-class stator teeth are arranged to form an annular working chamber, the multiple first-class stator teeth include at least two first-class stator teeth arranged adjacent to each other, and / or the multiple second-class stator teeth include at least two first-class stator teeth arranged adjacent to each other.

[0015] Furthermore, the single-phase permanent magnet synchronous motor includes: a first stator body, a plurality of first-type stator teeth are connected to the first stator body; a second stator body, the second stator body is arranged opposite to the first stator body, and a plurality of second-type stator teeth are connected to the second stator body.

[0016] Further, the central angle formed by the line connecting the geometric center of the first contour line formed by adjacent first-type stator teeth and the geometric center of the rotor part is γ1, where γ1=2π / s, and / or the central angle formed by the line connecting the geometric center of the second contour line formed by adjacent second stator bodies and the geometric center of the rotor part is also γ1.

[0017] Furthermore, with the first type of stator teeth as the reference starting point, the central angle formed by the line connecting the geometric center of the first contour line, the second contour center and the geometric center of the rotor part of the second type of stator teeth adjacent to each other along the rotation direction of the rotor part is γ3, where γ3>2π / s.

[0018] Further, there are a plurality of first-type stator teeth, and a plurality of second-type stator teeth, and the number of the first-type stator teeth is different from the number of the second-type stator teeth.

[0019] Further, the structure of at least one first-type stator tooth among the plurality of first-type stator teeth is different from the structures of the remaining first-type stator teeth and the second-type stator teeth.

[0020] Furthermore, the first stator body and the second stator body are integrally formed, and the cross-sections of the first stator body and the second stator body are annular or square.

[0021] Further, the first stator body and the second stator body are arranged at a distance, and a recessed portion is arranged on the adjacent surfaces of the first stator body and the second stator body.

[0022] Furthermore, taking the second type of stator teeth as a reference starting point, a central angle formed by a line connecting the geometric centers of the first contour line and the second contour of the first type of stator teeth adjacent to each other in the rotation direction of the rotor part and the geometric center of the rotor part is γ2, wherein γ2<2π / s.

[0023] According to another aspect of the present invention, there is provided a vacuum cleaner, comprising a single-phase permanent magnet synchronous motor, wherein the single-phase permanent magnet synchronous motor is the above-mentioned single-phase permanent magnet synchronous motor.

[0024] By applying the technical solution of the present invention, by setting the stator teeth of the motor into various types of tooth structures, and setting the center angles corresponding to the contour lines of different tooth structures in different ways, that is, by offsetting a part of the stator teeth of the motor, the starting dead point of the motor is eliminated, and the output torque of the motor can be improved. Compared with ordinary single-phase permanent magnet motors, the tooth slot torque of the motor provided by the present application is greatly reduced, the torque pulsation is greatly reduced, and the output torque of the motor is also significantly improved. The single-phase permanent magnet synchronous motor using the present application has a small size, light weight, simple structure, easy large-scale manufacturing and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 A schematic structural diagram of a first embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0027] Figure 2 A schematic structural diagram of a second embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0028] Figure 3 A schematic structural diagram of a third embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0029] Figure 4 A schematic structural diagram of a fourth embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0030] Figure 5 A schematic structural diagram of a fifth embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0031] Figure 6 A schematic structural diagram of a sixth embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0032] Figure 7 A schematic structural diagram of a seventh embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0033] Figure 8 A schematic structural diagram of an eighth embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0034] Fig. 9 A schematic diagram of the rotor position at time 0s of the single-phase permanent magnet synchronous motor according to the present invention is shown;

[0035] Fig.10 A schematic diagram of the rotor position of a single-phase permanent magnet synchronous motor at zero cogging torque according to the present invention is shown;

[0036] Fig.11 A schematic diagram of cogging torque corresponding to different rotor positions of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0037] Fig.12 A schematic diagram showing the starting torque of a single-phase permanent magnet synchronous motor at different rotor positions under the same current according to the present invention is shown;

[0038] Fig.13A schematic diagram of output torque of a single-phase permanent magnet synchronous motor according to the present invention at the same current and with different stator tooth structures under the same average air gap thickness is shown.

[0039] The above drawings include the following reference numerals:

[0040] 10. First class stator teeth;

[0041] 20. Second type of stator teeth;

[0042] 30. Rotor unit;

[0043] 40. The first stator body;

[0044] 50. A second stator body;

[0045] 60. Depression. DETAILED DESCRIPTION

[0046] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0047] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0048] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0049] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in a variety of different forms and should not be construed as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of the layers and regions may be enlarged, and the same reference numerals are used to represent the same devices, and thus their descriptions will be omitted.

[0050] Combination Figures 1 to 13 As shown, according to a specific embodiment of the present application, a single-phase permanent magnet synchronous motor is provided.

[0051] Specifically, Figure 1 As shown, the single-phase permanent magnet synchronous motor includes a first type of stator teeth 10 and a second type of stator teeth 20. The first type of stator teeth 10 and the second type of stator teeth 20 are arranged to form an annular working chamber for accommodating the rotor part 30. The angle of the center angle corresponding to the first contour line of the end face of the first type of stator teeth 10 facing the rotor part 30 is different from the angle of the center angle corresponding to the second contour line of the end face of the second type of stator teeth 20 facing the rotor part 30.

[0052] In this embodiment, by setting the stator teeth of the motor into various types of tooth structures, and setting the center angles corresponding to the contour lines of different tooth structures in different ways, that is, by offsetting a part of the stator teeth of the motor, the starting dead point of the motor is eliminated, and the output torque of the motor can be improved. Compared with ordinary single-phase permanent magnet motors, the tooth slot torque of the motor provided by the present application is greatly reduced, the torque pulsation is greatly reduced, and the output torque of the motor is also significantly improved. The single-phase permanent magnet synchronous motor using the present application has a small size, light weight, simple structure, easy large-scale manufacturing and low manufacturing cost.

[0053] The motor has at least two types of stator teeth, and the central angles of the contour lines of the end faces of different types of stator teeth facing the rotor part are different, and each stator tooth is arranged to form an annular working chamber for accommodating the rotor part. On the stator teeth of the motor, among all two adjacent stator teeth, there is at least one set of adjacent stator teeth, and the central angle between the center lines of the contour lines of the end faces of the two teeth facing the rotor part is not equal to 2π / s, where s is the number of stator teeth contained in the motor. In particular, when there are only two types of stator teeth, they are defined as the first type of stator teeth and the second type of stator teeth.

[0054] Among the adjacent first-type stator teeth 10 and second-type stator teeth 20, the geometric center line of the first contour line along the radial direction of the rotor part 30 intersects with the geometric center line of the second contour line along the radial direction of the rotor part 30 and forms an angle γ, wherein γ≠2π / s, and s is the total number of the first-type stator teeth 10 and the second-type stator teeth 20. Figure 1 to Figure 2 As shown, F is the rotation direction of the rotor part, A is the geometric center line of the first contour line, B is the geometric center line of the second contour line, and C is the offset baseline. s=2n, the number of the first type of stator teeth 10 is n, the number of the first type of stator teeth 10 and the second type of stator teeth 20 is n, and n is an integer greater than or equal to 1.

[0055] In this embodiment, there are a plurality of first-class stator teeth 10 and a plurality of second-class stator teeth 20. A plurality of first-class stator teeth 10 and a plurality of second-class stator teeth 20 are alternately arranged along the circumference of the rotor portion 30. Stator teeth of the same type are obtained by a single stator tooth passing through a circular array around the geometric center of the rotor. Along the rotation direction of the rotor portion 30, the angle of the center angle corresponding to the first contour line is greater than the angle of the center angle corresponding to the second contour line, wherein, with the second-class stator tooth 20 as the reference starting point, along the rotation direction of the rotor portion 30, the center angle between the geometric center lines of the contour lines of the end faces of the first-class stator teeth 10 adjacent to the second-class stator teeth 20 facing the rotor portion is less than 2π / s. Such an arrangement can improve the performance of the motor.

[0056] like Figure 2 As shown, the geometric center line of the second contour line along the radial direction of the rotor part 30 is used as the reference line, and the angle of 2π / s along the rotation direction of the rotor part 30 is the offset baseline of the first type of stator tooth 10. The geometric center line of the first contour line along the radial direction of the rotor part 30 and the offset baseline form an offset angle θ, wherein θ=ab, 0<θ<π / 2-α, α is the center angle formed by the line connecting the two ends of the second contour line and the geometric center of the rotor part 30, and b is the center angle formed by the line connecting the offset baseline, the front end of the first contour line (that is, the front end of the stator tooth, along the rotation direction of the rotor part, the end that first turns into the preset point is the front end, and vice versa, the end that later turns into the preset point is the rear end), and the geometric center of the rotor part 30. a is the center angle formed by the offset baseline of the first type of stator tooth 10, the rear end of the first contour line, and the geometric center of the rotor part 30. Wherein, as Figure 2 As shown, the rotation direction of the rotor part 30 is counterclockwise, then the front end of the first type of stator tooth 10 is the end that rotates to the predetermined point first, and the rear end of the first type of stator tooth 10 is the end that rotates to the predetermined point later, and the front end and rear end of the second type of stator tooth are determined in the same way. Preferably, 0<θ≤π / 4-α / 2.

[0057] like Figure 4As shown, a uniform air gap thickness g2 is formed between the second type of stator teeth 20 and the rotor part 30, and a uniform air gap thickness g1 is formed between the first type of stator teeth 10 and the rotor part 30, wherein g1=g2. The corresponding air gap thicknesses under the stator teeth of the motor are uniformly distributed, and the stator teeth of two different structures have the same air gap thickness, wherein the air gap thickness refers to the radial air gap thickness. Preferably, g1<g2. Among them, the air gap thicknesses of g1 and g2 are uniform air gap radial equal thickness structures, and such a setting reduces the manufacturing difficulty and improves the manufacturing accuracy. That is, the air gap formed between the end of a single stator tooth on the motor and the rotor part 30 is a uniform air gap with equal thickness, wherein the air gap thickness refers to the radial air gap thickness.

[0058] Among them, under the two different structures of the stator teeth of the motor, at least one type of stator teeth, i.e., the corresponding air gap under the structure of one type of stator teeth is a gradual air gap. That is, in this embodiment, the thickness of the air gap formed between the second type of stator teeth 20 and the rotor part 30 is gradually increased or gradually decreased along the circumference of the rotor part 30. The thickness of the air gap formed between the first type of stator teeth 10 and the rotor part 30 is gradually increased or gradually decreased along the circumference of the rotor part 30. Figure 5 As shown, under the same tooth of the gradient stator, along the rotation direction of the motor, that is, the rotation direction of the rotor part, the air gap thickness gradually decreases, wherein the maximum air gap thickness is g3 and the minimum air gap thickness is g4.

[0059] Further, the structure of at least one of the plurality of first-class stator teeth 10 is different from the structures of the remaining first-class stator teeth 10 and second-class stator teeth 20. That is, in addition to the first-class and second-class stator teeth, the motor also has a third-class stator tooth or more stator teeth, and the contour lines of the end faces of different classes of stator teeth facing the rotor part have different central angles, and when the motor includes an odd number of stator teeth, the number s of stator teeth included in the motor is an even number.

[0060] According to another embodiment of the present application, regarding the arrangement of different types of stator teeth, one is that the stator teeth are not interspersed with each other, and the motor stator teeth as a whole include two large stator tooth sets, that is, each stator tooth set only includes the same type of stator teeth. Another arrangement is that the stator teeth are interspersed and there are also stator tooth sets, each stator tooth set only includes the same type of stator teeth, and the number of stator teeth in the stator tooth set is greater than or equal to 2. Specifically, there are multiple first-class stator teeth 10, and there are multiple second-class stator teeth 20. The multiple first-class stator teeth 10 and the multiple second-class stator teeth 20 are arranged to form an annular working chamber, and the multiple first-class stator teeth 10 include at least two first-class stator teeth 10 arranged adjacent to each other. Alternatively, the multiple second-class stator teeth 20 include at least two first-class stator teeth 10 arranged adjacent to each other.

[0061] like Figure 1 and Figure 3 As shown, the single-phase permanent magnet synchronous motor includes a first stator body 40 and a second stator body 50. A plurality of first-type stator teeth 10 are connected to the first stator body 40. The second stator body 50 is arranged opposite to the first stator body 40, and a plurality of second-type stator teeth 20 are connected to the second stator body 50. Such an arrangement can facilitate the installation of the motor and improve the reliability of the motor.

[0062] In another embodiment of the present application, the first stator body 40 and the second stator body 50 are integrally formed, and the cross-sections of the first stator body 40 and the second stator body 50 are annular or square. That is, the motor stator structure can be divided into two identical and independent parts, namely the first stator body 40 and the second stator body 50, similar to a C-shaped or U-shaped stator. Or the stator is an integral part, and the overall shape can be circular or square.

[0063] like Figure 6 As shown, in this embodiment, the central angle between the geometric center lines of the contour lines of two adjacent stator teeth of the same structure is 2π / s. Specifically, the central angle formed by the line connecting the geometric center of the first contour line formed by adjacent first-type stator teeth 10 and the geometric center of the rotor part 30 is γ1, where γ1=2π / s. The central angle formed by the line connecting the geometric center of the second contour line formed by the adjacent second stator body 50 and the geometric center of the rotor part 30 is also γ1. Further, taking the first-type stator tooth 10 as the reference starting point, the second-type stator teeth 20 adjacent to each other along the rotation direction of the rotor part 30, the central angle formed by the line connecting the geometric center of the first contour line, the second contour center and the geometric center of the rotor part 30 is γ3, where γ3>2π / s. Such an arrangement can effectively improve the performance of the motor.

[0064] Wherein, with the second type of stator teeth 20 as the reference starting point, the central angle formed by the geometric center of the first contour line and the second contour of the first type of stator teeth 10 adjacent to each other along the rotation direction of the rotor part 30 and the line connecting the geometric center of the rotor part 30 is γ2, wherein γ2<2π / s. Such a setting can effectively improve the performance of the motor.

[0065] Furthermore, with the first type of stator teeth 10 as a reference starting point, along the rotation direction of the rotor part 30 , a central angle formed by a line connecting the geometric center of the first contour line of adjacent first type of stator teeth 10 , the geometric center of the second contour and the geometric center of the rotor part 30 is less than 2π / s.

[0066] In this embodiment, the total number of teeth of the two types of stator teeth of the motor is 2n, where n is an integer greater than or equal to 1, and the number of the two types of stator teeth is not equal, that is, the number of teeth of one type of stator teeth is greater than that of the other type of stator teeth. And when the motor includes an odd number (3, 5, 7...) of stator tooth structures, the number of stator teeth contained in the motor is a multiple of 2. Specifically, there are a plurality of first-type stator teeth 10, and a plurality of second-type stator teeth 20, and the number of the first-type stator teeth 10 is different from the number of the second-type stator teeth 20. Among them, the structure of at least one first-type stator tooth 10 among the plurality of first-type stator teeth 10 is different from the structures of the remaining first-type stator teeth 10 and second-type stator teeth 20.

[0067] like Figure 1 , Figure 7 , Figure 8 As shown, the first stator body 40 and the second stator body 50 are integrally formed. The cross-sections of the first stator body 40 and the second stator body 50 are arranged in an annular structure or a square structure, such as a C-shape and a U-shape. Figures 2 to 5 As shown, the first stator body 40 and the second stator body 50 may also be arranged in a distance arrangement. Figure 3 As shown, a recessed portion 60 is provided on the surface adjacent to the first stator body 40 and the second stator body 50. The recessed portion 60 is used to be nested with the structure related to the motor housing to fix the stator core.

[0068] The single-phase permanent magnet synchronous motor in the above embodiment can also be used in the technical field of vacuum cleaner equipment. That is, according to another aspect of the present invention, a vacuum cleaner is provided, including a single-phase permanent magnet synchronous motor, which is the single-phase permanent magnet synchronous motor in the above embodiment.

[0069] Specifically, the motor structure of the present application effectively solves the problem of the starting dead point of the single-phase motor, reduces the torque pulsation of the motor, improves the output torque of the motor structure, eliminates the starting dead point of the single-phase motor, reduces the manufacturing difficulty, and improves the manufacturing accuracy.

[0070] In the present application, the stator core of the motor includes at least two different stator tooth structures, wherein the rotor part includes components such as a rotor and a rotating shaft. Taking the geometric center of the rotor as the center of the circle, the stator teeth of different structures have different sizes of the center angles corresponding to the outline of the rotor part. On the stator teeth of the motor, among all two adjacent stator teeth, there is at least one group of adjacent stator teeth, and the center angle between the center lines of the two adjacent rotor part outlines is not equal to 2π / s, where s is the number of stator teeth.

[0071] The motor has two stator teeth with different profile lengths, each with 2 stator teeth. The two stator teeth are arranged alternately in a 1-to-1 manner, which can eliminate the unbalanced magnetic pull caused by different tooth structures. The same stator teeth are obtained by a single stator tooth passing through a circular array around the center of the rotor. The teeth with a larger central angle corresponding to the stator tooth profile are called large teeth, and the teeth with a smaller central angle are called small teeth. Taking the small teeth of the stator core as a reference, the center angle between the contour center of the adjacent large teeth along the rotation direction and the contour center of the small teeth is γ, γ < 2π / s, where s is the number of stator teeth.

[0072] Taking the center line of the small tooth profile as a reference, the straight line with a 2π / s degree angle with the center line of the small tooth profile is the tooth offset baseline of the large tooth, and the offset angle of the motor large tooth θ=ab. The value range of θ is 0<θ<π / 2-α, and α is the central angle of the motor small tooth profile. If the offset angle is too small, the starting torque generated is small, and if the offset angle is too large, the leakage magnetic field between the adjacent stator teeth will increase.

[0073] The motors have stator teeth with two different profile lengths. The two stator tooth arrangements also include:

[0074] 1. The two types of stator teeth are not arranged interlaced with each other. The motor stator teeth as a whole include two large stator tooth sets, that is, each stator tooth set only contains the same type of stator teeth.

[0075] 2. Two types of stator teeth are arranged in an interlaced manner and there are also stator tooth sets. Each stator tooth set contains only the same type of stator teeth, and the number of stator teeth in the stator tooth set is greater than or equal to 2.

[0076] The relationship between the stator teeth under the two additional stator tooth arrangements is as follows: the center angle between the contour center lines of two adjacent stator teeth of the same structure is 2π / s. Taking the contour center line of the small tooth (the tooth with the smaller center angle) as the reference, the center angle between the contour center line of the adjacent large tooth (the tooth with the larger center angle) in the direction of motor rotation and the small tooth contour center line is less than 2π / s. Taking the contour center line of the large tooth as the reference, the center angle between the contour center line of the adjacent small tooth in the direction of motor rotation and the large tooth contour center line is greater than 2*π / s.

[0077] In the present application, an asymmetric stator tooth structure is provided to solve the problem of the starting dead point of the single-phase permanent magnet motor, increase the starting torque of the single-phase permanent magnet motor, increase the output torque, and reduce the torque pulsation.

[0078] Since the armature current of a single-phase permanent magnet motor is only one phase, the magnetic field generated by the armature winding is a pulsating magnetic field, and the motor electromagnetic torque has a 0 point. Single-phase permanent magnet motors do not use a specific structure, and the motor parking position (the point where the cogging torque is 0) coincides with the point where the electromagnetic torque is 0. Regardless of what form of current is passed through the motor stator winding, the single-phase motor cannot generate tangential torque, and the single-phase motor cannot start at this time, so the single-phase motor has a starting dead point problem. The usual solution is to set an asymmetric tooth structure to offset the motor's cogging torque and electromagnetic torque, so that the 0 point positions of the two torques are staggered. When the motor stops, it stays at the point where the cogging torque is 0. As long as the motor electromagnetic torque is not 0 at this time, the motor can start normally.

[0079] like Figure 1 As shown, by setting different center angles of the contour lines of the end faces of the stator teeth, the 0 point of the motor's tooth slot torque is offset from the 0 point of the electromagnetic torque, thereby eliminating the problem of the starting dead point. Specifically, the motor stator core includes at least two different stator tooth structures. The stator teeth of different structures have different sizes of center angles corresponding to the contour lines facing the rotor part. On the stator teeth of the motor, among all two adjacent stator teeth, there is at least one group of adjacent stator teeth, and the center angle between the center lines of the contour lines of the two facing the rotor part is not equal to 2π / s, where s is the number of stator teeth. The structural characteristics of different stator cores are analyzed in detail by setting the number of types of motor stator teeth and the number of stator teeth.

[0080] In another embodiment of the present application, the motor has two stator teeth with different structures, and the number of stator teeth is 4, and the number of teeth of each of the two stator teeth is 2. The two stator tooth structures are arranged in a 1 to 1 alternating arrangement along the rotation direction of the motor (1212... structure, 1 and 2 represent two different stator teeth), and the same stator teeth are obtained by rotating a single stator tooth around the center of the circle. Alternating placement can eliminate the unbalanced magnetic pull caused by different tooth structures.

[0081] Taking one of the small teeth as a reference, the center angle between the contour line center of the adjacent large tooth in the motor rotation direction and the contour line center of the small tooth is less than 2π / s. Due to this tooth structure, the phase angle of the electromagnetic torque offset is greater than the cogging torque. Therefore, in order to generate a positive starting torque and make the motor starting angle larger, the tooth offset direction needs to be set opposite to the motor rotation direction.

[0082] Taking the geometric center line of the small tooth contour as a reference, the straight line with an angle of 2π / s with the geometric center line of the small tooth contour is the tooth offset baseline of the large tooth. The offset angle of the motor large tooth is θ = ab, as shown in Figure 2As shown, the value range of θ is 0<θ<π / 2-α, and α is the central angle spanned by the contour line of the motor's small tooth. A suitable θ value can effectively improve the starting torque of the motor without affecting the output torque of the motor. If the θ value is too large, leakage magnetic flux will be generated between two adjacent stator teeth. If the θ value is too small, the starting ability of the motor will be poor and the starting current of the motor will be large. The air gaps under all the stator teeth of the motor are uniform air gap structures, that is, the air gap thickness under one tooth remains unchanged, such as Figure 2 shown.

[0083] The above-mentioned large and small tooth structure can eliminate the starting dead point of the motor, so the air gap thickness of all motors can be set to be the same. The use of uniform air gap can reduce the average air gap thickness of the motor, reduce torque pulsation, and increase output torque. Figure 2 On the basis of the structure, a concave structure is formed on the upper and lower sides of the overall iron core by removing part of the stator tooth body iron core, such as Figure 3 As shown, it is used for embedding with the structure related to the motor casing to fix the stator core.

[0084] In order to further enhance the motor starting capability, the air gap thickness under different teeth can be set to be different, that is, the air gap thickness under the same stator tooth of the motor is evenly distributed, but the air gap thicknesses corresponding to two different teeth are different. The air gap thickness corresponding to the large tooth is smaller than the air gap thickness corresponding to the small tooth, that is, g1<g2, such as Figure 4 Two different stator teeth with uniform air gaps of different thicknesses can further enhance the effect of asymmetric teeth, increase starting torque, and reduce starting current.

[0085] The stator teeth of the motor have two structures, and at least one structure of the stator teeth has a corresponding air gap of a gradual air gap, such as Figure 5 As shown. The gradual air gap can also eliminate the motor starting dead point. The two structures are used simultaneously to greatly increase the starting torque and reduce the starting current. In order to obtain the positive starting torque, along the direction of motor rotation, the motor air gap gradually decreases for the same stator tooth, where the maximum air gap thickness is g3 and the minimum air gap thickness is g4, that is, g3>g4.

[0086] The arrangement of the stator teeth of the motor can be set as follows: for 4 or more stator teeth, the two types of stator teeth are not interlaced with each other, and the motor stator teeth as a whole include two stator tooth sets, that is, each stator tooth set only includes the same type of stator teeth (1...1122...2 structure, 1 and 2 represent two different stator teeth), such as Figure 6 As shown in FIG. 1 , the central angle γ1=2π / s is included between the geometric center lines of the contours of two adjacent stator teeth of the same structure.

[0087] Taking the center line of the small tooth profile as the reference, the center line of the profile of the adjacent large teeth in the direction of motor rotation and the center line of the small tooth profile have an angle γ2<2π / s. Taking the geometric center line of the large tooth profile as the reference, the geometric center line of the profile of the adjacent small teeth in the direction of motor rotation and the center line of the large tooth profile have an angle γ3>2π / s. Although there will be a certain unbalanced magnetic pull when using the 1...1122...2 structure arrangement, it still has certain advantages over the gradient air gap structure, with smaller tooth slot torque fluctuation and larger starting torque, which can reduce the starting current.

[0088] In another embodiment of the present application, two types of stator teeth are arranged alternately and there are also stator tooth sets, each stator tooth set contains only the same type of stator teeth, and the number of stator teeth in the stator tooth set is greater than or equal to 2, such as Figure 7 shown.

[0089] The above description of the motor stator core only limits the stator tooth structure. The yoke of the motor stator core may include a closed ring, a closed frame or an open frame, such as a C-shaped and a U-shaped, etc. The closed frame yoke of the stator teeth with two different structures of two teeth is as follows: Figure 8 shown.

[0090] Fig. 9 and Fig.10 The rotor position of the motor at 0s and 0 cogging torque (b) is shown, corresponding to Fig.11 and Fig.12 Point a and point b in. Fig.12 It can be seen that the motor starting torque is greater than 0 at the moment of 0 cogging torque, so that the motor can start automatically after the winding is energized when stationary, solving the problem of the starting dead point of the single-phase motor. Fig.13 It is shown that under the condition of the same average air gap thickness, the motor with a tooth offset structure has a larger output torque and smaller torque fluctuation than the motor with the commonly used unequal air gap (gradient air gap) structure, which is beneficial to reducing the motor operation noise and has a better application effect.

[0091] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0092] In addition to the above, it should be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present invention.

[0093] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A single-phase permanent magnet synchronous motor, characterized in that: The single-phase permanent magnet synchronous motor includes multiple types of stator teeth, and the multiple types of stator teeth at least include: A first type of stator teeth (10); Second-type stator teeth (20), wherein the first-type stator teeth (10) and the second-type stator teeth (20) are arranged to form an annular working chamber for accommodating a rotor part (30); wherein the angle of the center angle of a first contour line of the end surface of the first type of stator tooth (10) facing the rotor part (30) is different from the angle of the center angle of a second contour line of the end surface of the second type of stator tooth (20) facing the rotor part (30); In adjacent first-type stator teeth (10) and second-type stator teeth (20), a geometric center line of the first contour line along the radial direction of the rotor part (30) intersects with a geometric center line of the second contour line along the radial direction of the rotor part (30) and forms an angle γ, wherein γ≠2π / s, and s is the total number of the first-type stator teeth (10) and the second-type stator teeth (20).

2. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: s=2n, the number of the first type of stator teeth (10) is n, the number of the first type of stator teeth (10) and the number of the second type of stator teeth (20) is n, and n is an integer greater than or equal to 1.

3. The single-phase permanent magnet synchronous motor according to claim 2, characterized in that: There are a plurality of first-type stator teeth (10) and a plurality of second-type stator teeth (20), and the plurality of first-type stator teeth (10) and the plurality of second-type stator teeth (20) are alternately arranged along the circumferential direction of the rotor part (30).

4. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: Along the rotation direction of the rotor part (30), the angle of the center angle corresponding to the first contour line is greater than the angle of the center angle corresponding to the second contour line, wherein, taking the second-type stator tooth (20) as a reference starting point, along the rotation direction of the rotor part (30), the center angle between the geometric center lines of the contour lines of the end surface of the first-type stator tooth (10) adjacent to the second-type stator tooth (20) facing the rotor part is less than 2π / s.

5. The single-phase permanent magnet synchronous motor according to claim 4, characterized in that: The geometric center line of the second contour line in the radial direction of the rotor part (30) is used as a reference line, and the angle of 2π / s along the rotation direction of the rotor part (30) is the offset baseline of the first type of stator tooth (10). An offset angle θ is formed between the geometric center line of the first contour line in the radial direction of the rotor part (30) and the offset baseline, wherein θ=ab, 0<θ<π / 2-α, α is the center angle formed by a line connecting the two ends of the second contour line and the geometric center of the rotor part (30), b is the center angle formed by a line connecting the offset baseline, the front end of the first contour line and the geometric center of the rotor part (30), and a is the center angle formed by a line connecting the offset baseline of the first type of stator tooth (10), the rear end of the first contour line and the geometric center of the rotor part (30).

6. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: A uniform air gap thickness g2 is formed between the second type of stator teeth (20) and the rotor part (30), and a uniform air gap thickness g1 is formed between the first type of stator teeth (10) and the rotor part (30), wherein g1=g2.

7. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: g1<g2.

8. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: The thickness of the air gap formed between the second type of stator teeth (20) and the rotor part (30) is gradually increased or gradually decreased along the circumferential direction of the rotor part (30), and / or the thickness of the air gap formed between the first type of stator teeth (10) and the rotor part (30) is gradually increased or gradually decreased along the circumferential direction of the rotor part (30).

9. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: There are a plurality of first-type stator teeth (10), and a plurality of second-type stator teeth (20); the plurality of first-type stator teeth (10) and the plurality of second-type stator teeth (20) are arranged to form the annular working chamber; at least two of the plurality of first-type stator teeth (10) are arranged adjacent to each other, and / or at least two of the plurality of second-type stator teeth (20) are arranged adjacent to each other.

10. The single-phase permanent magnet synchronous motor according to claim 9, characterized in that: The single-phase permanent magnet synchronous motor comprises: A first stator body (40), a plurality of the first-type stator teeth (10) being connected to the first stator body (40); A second stator body (50), wherein the second stator body (50) is arranged opposite to the first stator body (40), and a plurality of the second-type stator teeth (20) are connected to the second stator body (50).

11. The single-phase permanent magnet synchronous motor according to claim 10, characterized in that: The central angle formed by the line connecting the geometric center of the first contour line formed by adjacent first-type stator teeth (10) and the geometric center of the rotor part (30) is γ1, wherein γ1=2π / s, and / or the central angle formed by the line connecting the geometric center of the second contour line of the adjacent second stator body (50) and the geometric center of the rotor part (30) is also γ1.

12. The single-phase permanent magnet synchronous motor according to claim 11, characterized in that: Taking the first type of stator teeth (10) as a reference starting point, the second type of stator teeth (20) adjacent to the rotation direction of the rotor part (30), the central angle formed by the line connecting the geometric center of the first contour line, the second contour center and the geometric center of the rotor part (30) is γ3, where γ3>2π / s.

13. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: There are a plurality of first-type stator teeth (10), and a plurality of second-type stator teeth (20), and the number of the first-type stator teeth (10) is different from the number of the second-type stator teeth (20).

14. The single-phase permanent magnet synchronous motor according to claim 13, characterized in that: The structure of at least one of the plurality of first-type stator teeth (10) is different from the structures of the remaining first-type stator teeth (10) and the second-type stator teeth (20).

15. The single-phase permanent magnet synchronous motor according to claim 10, characterized in that: The first stator body (40) and the second stator body (50) are integrally formed, and the cross-sections of the first stator body (40) and the second stator body (50) are annular or square.

16. The single-phase permanent magnet synchronous motor according to claim 10, characterized in that: The first stator body (40) and the second stator body (50) are arranged at a distance from each other, and a recessed portion (60) is arranged on the surface adjacent to the first stator body (40) and the second stator body (50).

17. The single-phase permanent magnet synchronous motor according to claim 11, characterized in that: Taking the second type of stator teeth (20) as a reference starting point, a central angle formed by a line connecting the geometric centers of the first contour line and the second contour of the first type of stator teeth (10) adjacent to the rotation direction of the rotor part (30) and the geometric center of the rotor part (30) is γ2, where γ2<2π / s.

18. A vacuum cleaner, comprising a single-phase permanent magnet synchronous motor, characterized in that: The single-phase permanent magnet synchronous motor is the single-phase permanent magnet synchronous motor according to any one of claims 1 to 17.

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