CN110912288A

CN110912288A - Single-phase permanent magnet synchronous motor and dust collector with same

Info

Publication number: CN110912288A
Application number: CN201911252260.7A
Authority: CN
Inventors: 陈彬; 胡余生; 肖勇; 张志东; 史进飞; 肖胜宇; 李霞; 唐林; 朱绍轩; 桂鹏千; 孙辉; 丁佳婷
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2019-12-09
Filing date: 2019-12-09
Publication date: 2020-03-24

Abstract

The invention provides a single-phase permanent magnet synchronous motor and a dust collector with the same. Single-phase permanent magnet synchronous motor includes multiclass stator tooth, and multiclass stator tooth includes: a first type of stator teeth; the first type of stator teeth and the second type of stator teeth are encircled to form an annular working cavity for accommodating the rotor part; and a uniform air gap radial thickness g1 is formed between the first type of stator teeth and the rotor part, a uniform air gap radial thickness g2 is formed between the second type of stator teeth and the rotor part, and g1 is not equal to g 2. The motor is arranged to have an arrangement comprising a plurality of types of stator tooth structures, and the radial thickness of the uniform air gap formed between the two types of tooth structures and the rotor portion is arranged to be different. The uniform equal air gap stator teeth can effectively reduce motor torque pulsation and improve output torque, and meanwhile, the uniform equal air gap structure can reduce manufacturing difficulty and improve manufacturing precision.

Description

Single-phase permanent magnet synchronous motor and dust collector with same

Technical Field

The invention relates to the technical field of motor equipment, in particular to a single-phase permanent magnet synchronous motor and a dust collector with the same.

Background

The single-phase motor is a single-phase winding, the number of switching devices required for driving the main circuit is small, and the hardware cost of the control system is low. However, the magnetic field in the single-phase motor is a pulse vibration magnetic field, and the electromagnetic torque of the motor exists in the position of 0 point. If a specific structure is not adopted, the stopping position of the motor (the point of the cogging torque is 0) is superposed with the point of the electromagnetic torque is 0, and at the moment, the motor cannot be started no matter any current is applied, so that the problem of starting dead points exists.

Usually, a single-phase permanent magnet motor can solve the problem of starting dead points by adopting unequal air gaps (namely, uniform air gap radial thickness change under the same stator tooth). However, the unequal air gap structure can increase the cogging torque, further leading to the increase of the output torque pulsation of the motor, and meanwhile, the unequal air gap structure can increase the average air gap length of the motor, thus reducing the output torque density of the motor.

Disclosure of Invention

The invention mainly aims to provide a single-phase permanent magnet synchronous motor and a dust collector with the same, and aims to solve the problem that the motor in the prior art has a starting dead point.

In order to achieve the above object, according to one aspect of the present invention, there is provided a single-phase permanent magnet synchronous motor including a plurality of types of stator teeth, the plurality of types of stator teeth including: a first type of stator teeth; the first type of stator teeth and the second type of stator teeth are encircled to form an annular working cavity for accommodating the rotor part; and a uniform air gap radial thickness g1 is formed between the first type of stator teeth and the rotor part, a uniform air gap radial thickness g2 is formed between the second type of stator teeth and the rotor part, and g1 is not equal to g 2.

Further, a first contour line of an end surface of the first type of stator tooth facing the rotor portion has a central angle γ 1, and a second contour line of an end surface of the second type of stator tooth facing the rotor portion has a central angle γ 2, where γ 1 > γ 2 and g1 < g 2.

Further, the first type of stator teeth are multiple, the second type of stator teeth are multiple, and the multiple first type of stator teeth and the multiple second type of stator teeth are alternately arranged along the circumferential direction of the rotor part.

Further, along the rotation direction of the rotor part, the second type of stator teeth are taken as a reference starting point, a central angle formed by a connecting line of the geometric center of the second contour line of the second type of stator teeth and the geometric center of the rotor part and a connecting line of the first contour line center of the adjacent first type of stator teeth and the geometric center of the rotor part is gamma, wherein gamma is not equal to 2 pi/s, and s is the number of slots of the motor.

Furthermore, along the rotation direction of the rotor part, the second type of stator teeth are taken as a reference starting point, and the included angle of the circle centers formed by the geometric centers of the second contour line, the geometric center of the first contour line and the geometric center of the rotor part is gamma 3, wherein gamma 3 is less than 2 pi/s.

Further, the single-phase permanent magnet synchronous motor further includes: the stator comprises a rotor part, a first type of stator teeth, a second type of stator teeth and a third type of stator teeth, wherein the first type of stator teeth, the second type of stator teeth and the third type of stator teeth are sequentially and alternately arranged along the circumferential direction of the rotor part; and gradually changed uniform air gap radial thickness is formed between the third type of stator teeth and the rotor part.

Further, the uniform air gap formed between the third type of stator teeth and the rotor portion is arranged with a radial thickness gradually decreasing along the rotation direction of the rotor portion.

Furthermore, a chamfer structure is arranged at the rear end of at least one of the first type of stator teeth and the second type of stator teeth and on the side facing the rotor part, and the chamfer structure is an inclined plane or an arc surface.

Furthermore, at least one of the first type of stator teeth and the second type of stator teeth is provided with a rectangular groove on the end surface facing to the rotor part, and the rectangular groove is arranged on one side of the geometric center line of the first type of stator teeth or the geometric center line of the second type of stator teeth.

Furthermore, the rear end of the second type of stator teeth is provided with a rectangular groove.

According to another aspect of the invention, a vacuum cleaner is provided, which comprises a single-phase permanent magnet synchronous motor, wherein the single-phase permanent magnet synchronous motor is the single-phase permanent magnet synchronous motor.

By applying the technical scheme of the invention, the motor is arranged in an arrangement mode comprising a plurality of types of stator tooth structures, and uniform breath formed between the two types of tooth structures and the rotor part is radially arranged to be different. The uniform equal air gap stator teeth can effectively reduce motor torque pulsation and improve output torque, and meanwhile, the uniform equal air gap structure can reduce manufacturing difficulty and improve manufacturing precision.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 shows a schematic structural view of a first embodiment of a single-phase permanent-magnet synchronous machine according to the invention;

fig. 2 shows a schematic structural view of a second embodiment of a single-phase permanent-magnet synchronous machine according to the invention;

fig. 3 shows a schematic structural view of a third embodiment of a single-phase permanent-magnet synchronous machine according to the invention;

fig. 4 shows a schematic structural view of a third embodiment of a single-phase permanent magnet synchronous machine according to the invention.

Wherein the figures include the following reference numerals:

10. a first type of stator teeth;

20. a second type of stator teeth;

30. a rotor portion;

40. a third type of stator teeth;

50. a beveling structure;

60. a rectangular groove.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Exemplary embodiments according to the present application will now be described in more detail with reference to the accompanying drawings. These exemplary embodiments may, however, be embodied in many different forms and should not be construed as limited to only the embodiments set forth herein. It is to be understood that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art, in the drawings, it is possible to enlarge the thicknesses of layers and regions for clarity, and the same devices are denoted by the same reference numerals, and thus the description thereof will be omitted.

The single-phase permanent magnet synchronous motor comprises at least two types of stator teeth with different structures, wherein the different structures mean that the air gap structures formed between the stator teeth with different types and a rotor part are different. Wherein, at least 2 air gaps in the air gap structure formed by each stator tooth and the rotor part of the motor are uniform air gaps, the uniform air gaps refer to the air gaps which are formed by the contour line of a single stator tooth and the rotor part and have uniform radial thickness, and the thicknesses of the 2 uniform air gap structures are different. In particular, when the machine comprises only two types of stator teeth, the two types of stator teeth comprise a first type of stator teeth and a second type of stator teeth, which enclose an annular working chamber for accommodating the rotor portion. And a uniform air gap radial thickness g1 is formed between the first type of stator teeth and the rotor part, a uniform air gap radial thickness g2 is formed between the second type of stator teeth and the rotor part, and g1 is not equal to g 2.

Referring to fig. 1 to 4, according to an embodiment of the present application, a single-phase permanent magnet synchronous motor is provided.

Specifically, the single-phase permanent magnet synchronous motor (hereinafter referred to as a motor) includes a plurality of types of stator teeth, including 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 enclose an annular working chamber for accommodating the rotor portion 30. The uniform air gap radial thickness g1 is formed between the first type of stator teeth 10 and the rotor part 30, the uniform air gap radial thickness g2 is formed between the second type of stator teeth 20 and the rotor part 30, and g1 is not equal to g 2.

In this embodiment, the motor is configured to have an arrangement including a plurality of types of stator tooth structures, and the uniform radial thickness of breath formed between the two types of tooth structures and the rotor portion is configured to be different. The uniform equal air gap stator teeth can effectively reduce motor torque pulsation and improve output torque, and meanwhile, the uniform equal air gap structure can reduce manufacturing difficulty and improve manufacturing precision.

The central angle corresponding to the first contour line of the end surface of the first type of stator tooth 10 facing the rotor portion 30 is γ 1, and the central angle corresponding to the second contour line of the end surface of the second type of stator tooth 20 facing the rotor portion 30 is γ 2, where γ 1 > γ 2, and g1 < g 2. The rotor portion 30 includes a rotor, a rotating shaft, and the like, and the center of the central angle referred to in this application refers to the geometric center of the rotor portion. The first type of stator teeth 10 are plural, the second type of stator teeth 20 are plural, and the plural first type of stator teeth 10 and the plural second type of stator teeth 20 are alternately arranged. The arrangement can effectively eliminate the problem of dead points existing in the starting of the single-phase motor. In the figure, F is the rotation direction of the rotor portion.

In the adjacent first type of stator teeth 10 and second type of stator teeth 20, along the rotation direction of the rotor portion 30, with the second type of stator teeth 20 as a reference starting point, a central angle formed by a connecting line of the geometric center of the second contour line of the second type of stator teeth 20 and the geometric center of the rotor portion 30 and a connecting line of the geometric center of the first contour line of the adjacent first type of stator teeth 10 and the geometric center of the rotor portion 30 is γ, wherein γ ≠ 2 π/s, and s is the number of slots of the motor. In order to optimize the performance of the motor, the second type of stator teeth 20 are used as a reference starting point along the rotation direction of the rotor part 30, and a circle center included angle formed by connecting the geometric center of the second contour line, the geometric center of the first contour line and the geometric center of the rotor part 30 is gamma 3, wherein gamma 3 is less than 2 pi/s.

According to another embodiment of the present application, the single phase permanent magnet synchronous machine further comprises a third type of stator teeth 40. The number of the third type of stator teeth 40 is multiple, and the plurality of first type of stator teeth 10, the plurality of second type of stator teeth 20, and the plurality of third type of stator teeth 40 are alternately arranged in sequence along the circumferential direction of the rotor portion 30. Wherein a gradual uniform air gap radial thickness is formed between the third type of stator teeth 40 and the rotor portion 30.

As shown in fig. 4, the uniform air gap formed between the third type of stator teeth 40 and the rotor portion 30 is gradually reduced in radial thickness in the rotational direction of the rotor portion 30. This arrangement can reduce motor torque ripple.

As shown in fig. 2, a chamfer structure 50 is provided at a rear end of at least one of the first type stator teeth 10 and the second type stator teeth 20 and on a side facing the rotor portion 30, and the chamfer structure 50 is a slope or an arc surface. Namely, the chamfered structure 50 is provided at the tooth shoe on the opposite side of the first type stator teeth 10 and the second type stator teeth 20 to the motor rotation direction. This arrangement is advantageous for improving the starting torque of the motor. The front end and the rear end in the application are determined relative to the rotation direction of the rotor part, and along the rotation direction of the rotor part, the front end is turned into the preset point firstly, and the rear end is turned into the preset point later.

As shown in fig. 3, according to another embodiment of the present application, a rectangular groove 60 is opened on an end surface of at least one of the first type stator tooth 10 and the second type stator tooth 20 facing the rotor portion 30, and the rectangular groove 60 is disposed on one side of a geometric centerline of the first type stator tooth 10 or a geometric centerline of the second type stator tooth 20. This arrangement facilitates attenuating the magnitude of cogging torque and output torque.

Preferably, as shown in fig. 3, the rear end of the second type stator teeth 20 is opened with a rectangular groove 60. The stator teeth are modified in a rectangular slotting mode for the stator teeth with smaller central angles, when the rotation direction of the motor is anticlockwise, the slotting position is located on the right side of the central line of the small teeth, the distance between the central line of the rectangular slot and the central line of the small teeth is L, the height of the rectangular slot is H, and the width of the rectangular slot is D. That is, the rectangular slot 60 is located at one side of the center of the contour line of the first type or the second type of stator tooth, which is deviated to the opposite direction of the motor rotation direction.

The second contour line center of the second type of stator tooth 20 is deviated to the side of the reverse direction of the motor rotation direction, and a rectangular groove 60 is formed in the side of the second contour line center deviated to the clockwise direction.

Specifically, the motor adopting the structure can solve the problem of starting dead points of a single-phase motor, improve starting torque, reduce torque pulsation and improve output torque; the problem of dead points existing in the starting of the single-phase motor is solved. And a single tooth of the motor is of an equal air gap structure, so that the manufacturing difficulty is reduced, and the manufacturing precision is improved.

The motor is provided with at least two different types of stator teeth, and the stator teeth with different structures correspond to different air gaps. The stator teeth comprise two types of stator teeth, the radial thickness of the uniform air gap corresponding to the same stator tooth is not changed, but the radial thickness of the uniform air gap of the stator teeth of the two types of structures is different.

The two types of stator teeth are alternately distributed, but are not uniformly distributed, namely, the intervals among the teeth are different. And the circle center angles of the air gaps corresponding to the two stator teeth are different, namely the air gap belts of the two stator teeth are different in length. And the tooth with the smaller circle center angle is taken as a reference, and the circle center angle between the center lines of two stator teeth is smaller than 2 pi/s.

The motor can further comprise another structure, and the corresponding air gap of the structure is a graded air gap structure, namely, the thickness of the air gap under the same tooth is changed. The gradual change type air gap is arranged along the rotation direction of the motor, and the radial thickness of the uniform air gap of the motor is gradually reduced.

The problem of the starting dead point of the single-phase permanent magnet motor can be solved through stator tooth deviation, the staggered angle of two torques is enlarged through setting different uniform air gap radial thicknesses under different teeth, and the starting torque is improved. The single-phase permanent magnet motor has only one phase of armature current, the magnetic field generated by the armature winding is a pulse vibration magnetic field, and the electromagnetic torque of the motor has 0 point. If the single-phase permanent magnet motor does not adopt a specific structure, the stop position of the motor (the point of the cogging torque being 0) is superposed with the point of the electromagnetic torque being 0, no matter the stator winding of the motor is electrified in any form, the single-phase motor cannot generate tangential torque, and the single-phase motor cannot be started at the moment, so that the single-phase motor has the problem of starting dead points.

The starting problem is usually solved by adopting a method of a graded air gap structure, but the graded air gap has the problems of reducing output torque and higher difficulty in motor assembly. In order to solve the problem of starting dead points, reduce the influence on the output torque of the motor and reduce the installation difficulty of a rotor, each tooth is set to be a stator structure with a uniform air gap.

As shown in fig. 1, the motor includes at least two different air gap configurations. Both air gaps are uniform air gaps, namely the radial thickness of the uniform air gap of the motor under the same tooth is unchanged. However, the thickness of the two air gaps is different, i.e. g1 ≠ g 2. The radial thickness of the uniform air gap has little influence on the output torque of the motor, and the motor is simple to assemble and install.

The angles of the central angles corresponding to the two air gaps are different, wherein gamma 1 is not equal to gamma 2, namely the radians of the stator teeth corresponding to the two air gaps are not equal. Wherein the air gap with large central angle and the uniform air gap with smaller radial thickness are g1 < g 2. The air gap with a large central angle can generate deviation between the cogging torque and the electromagnetic torque and generate phase difference, and the air gap corresponding to the teeth with the large central angle is smaller in order to enlarge the phase difference between the two torques.

Only these two air gaps are included in the machine and the two air gaps 1 are arranged alternately to 1. Because the two tooth structures are different, if the two tooth structures are asymmetrically arranged, asymmetric magnetic pull force can be generated, so that the problems of torque pulsation, high noise and the like are caused, and the two tooth structures need to be alternately arranged.

The small teeth and the large teeth adjacent to each other along the rotation direction of the motor have a central angle of 2 pi/s corresponding to the center of the contour line between the small teeth and the large teeth. Since the electromagnetic torque offset amount of the motor is larger than the cogging torque offset amount, in order to obtain a positive starting torque, the electromagnetic torque offset direction needs to be opposite to the motor rotation direction.

Further, the motor can also comprise another air gap structure different from the former two air gap structures. In order to further improve the starting capability of the motor, a graded air gap structure is added on the basis of the embodiment. The gradual change type air gap structure can also generate positive starting torque, and the two structures are combined, so that the single-phase permanent magnet motor can obtain larger starting torque, and the motor has better starting capability.

Because both the graded air gap cogging torque and the electromagnetic torque are offset in the direction of the stator air gap being small and the cogging torque is offset by a larger angle. In order to obtain a larger starting angle and reduce the starting difficulty, the radial thickness of the uniform air gap of the gradual change type air gap along the rotating direction of the motor is gradually reduced, as shown in figure 4.

For the stator teeth with two structures of the motor, at least one stator tooth can be further designed into a shape that a single-side tooth shoe is warped outwards. The single-side tooth shoe outward warping structure can also eliminate the starting dead point of the single-phase motor, and the stator tooth structure with the single-side tooth shoe outward warping structure can greatly improve the starting torque and further reduce the starting current of the motor.

When the rotation direction of the motor is anticlockwise, in order to obtain positive starting torque, the linear cutting part is positioned at the right side tooth shoe of the large tooth, and the linear cutting uses the upper vertex angle M of the tooth shoe as a positioning point to form a datum line with an angle phi from a horizontal line. Of course, the cutting line may be translated downward from the reference line by a distance d. Meanwhile, in order to reduce torque ripple and noise in the running process of the motor, an arc transition mode is further adopted for obtuse angles and sharp angles generated by linear cutting, and the radius of an arc section is preferably the same order of magnitude according to the size of the stator tooth shoe, as shown in fig. 2.

For the stator teeth with two structures of the motor, at least one stator tooth can be further designed into a unilateral rectangular slotted structure. The stator tooth single-side rectangular slotting structure can also eliminate the starting dead point of the single-phase motor, can reduce the cogging torque and the output torque pulsation of the motor, and can obtain smaller torque pulsation and larger starting torque by overlapping the single-side rectangular slotting stator tooth structure. When the rotation direction of the motor is anticlockwise, the slotting part is positioned at the right side of the central line of the small tooth, namely the rear end of the stator tooth, the distance between the central line of the rectangular groove and the central line of the small tooth is L, the height of the rectangular groove is H, and the width of the rectangular groove is D, as shown in figure 3.

The single-phase permanent magnet synchronous motor in the above embodiments can also be used in the technical field of dust collector equipment, that is, according to another aspect of the present invention, a dust collector is provided, which includes a single-phase permanent magnet synchronous motor, and the single-phase permanent magnet synchronous motor is the single-phase permanent magnet synchronous motor in the above embodiments.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition to the foregoing, it should be noted that reference throughout this specification to "one embodiment," "another embodiment," "an embodiment," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment described generally throughout this application. The appearances of the same phrase in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the scope of the invention to effect such feature, structure, or characteristic in connection with other embodiments.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A single-phase permanent magnet synchronous motor, comprising a plurality of types of stator teeth, the plurality of types of stator teeth comprising:

a first type of stator teeth (10);

a second type of stator teeth (20), wherein the first type of stator teeth (10) and the second type of stator teeth (20) are enclosed to form an annular working cavity for accommodating a rotor part (30);

wherein a uniform air gap radial thickness g1 is formed between the first type of stator teeth (10) and the rotor portion (30), a uniform air gap radial thickness g2 is formed between the second type of stator teeth (20) and the rotor portion (30), and g1 ≠ g 2.

2. The single-phase permanent magnet synchronous motor according to claim 1, wherein a first contour line of an end surface of the first type of stator tooth (10) facing the rotor portion (30) has a central angle γ 1, and a second contour line of an end surface of the second type of stator tooth (20) facing the rotor portion (30) has a central angle γ 2, wherein γ 1 > γ 2, and g1 < g 2.

3. The single-phase permanent magnet synchronous motor according to claim 1, wherein the first type of stator teeth (10) is plural, the second type of stator teeth (20) is plural, and the plural first type of stator teeth (10) and the plural second type of stator teeth (20) are alternately arranged in a circumferential direction of the rotor portion (30).

4. The single-phase permanent magnet synchronous motor according to claim 1, wherein a central angle γ formed by a connecting line of a geometric center of a second contour line of the second type of stator teeth (20) and a geometric center of the rotor portion (30), and a connecting line of a geometric center of a first contour line of an adjacent first type of stator teeth (20) and a geometric center of the rotor portion (30) is defined as a reference starting point of the second type of stator teeth (20) in a rotation direction of the rotor portion (30), wherein γ ≠ 2 π/s, s is a number of motor slots.

5. According to claim4The single-phase permanent magnet synchronous motor is characterized in that along the rotation direction of the rotor part (30), the second type of stator teeth (20) are taken as a reference starting point, and a circle center included angle formed by a connecting line of the geometric center of the second contour line, the geometric center of the first contour line and the geometric center of the rotor part (30) is gamma 3, wherein gamma 3 is less than 2 pi/s.

6. The single-phase permanent magnet synchronous motor of claim 1, further comprising:

a plurality of third type stator teeth (40), wherein the plurality of third type stator teeth (40) are alternately arranged along the circumferential direction of the rotor part (30) in sequence, and the plurality of first type stator teeth (10), the plurality of second type stator teeth (20) and the plurality of third type stator teeth (40) are alternately arranged in sequence;

wherein a gradual uniform air gap radial thickness is formed between the third type of stator teeth (40) and the rotor part (30).

7. Single-phase permanent-magnet synchronous machine according to claim 6, characterized in that the uniform air gap formed between the stator teeth (40) of the third type and the rotor part (30) is arranged with decreasing radial thickness in the direction of rotation of the rotor part (30).

8. The single-phase permanent magnet synchronous machine according to claim 1, characterized in that a chamfered structure (50) is provided at a rear end of at least one of the stator teeth (10) of the first kind and the stator teeth (20) of the second kind and on a side facing the rotor portion (30), the chamfered structure (50) being a bevel or a cambered surface.

9. The single-phase permanent magnet synchronous motor according to claim 1, wherein a rectangular groove (60) is opened on an end surface of at least one of the first type of stator teeth (10) and the second type of stator teeth (20) facing a side of the rotor portion (30), and the rectangular groove (60) is disposed on one side of a geometric centerline of the first type of stator teeth (10) or a geometric centerline of the second type of stator teeth (20).

10. The single-phase permanent-magnet synchronous machine according to claim 9, characterized in that the rear ends of the stator teeth (20) of the second type are provided with said rectangular slots (60).

11. A vacuum cleaner comprising a single-phase permanent magnet synchronous motor, characterized in that the single-phase permanent magnet synchronous motor is according to any one of claims 1 to 10.