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 a stator part, the stator part is provided with a plurality of stator teeth, the plurality of stator teeth are arranged to form a working chamber for accommodating a rotor part, and a tooth shoe of at least one of the plurality of stator teeth is provided with a beveled structure, the beveled structure is arranged toward the rotor part, and an air gap thickness is formed between the beveled structure and the rotor part. The structural design of the outward warping of the end of the stator tooth shoe makes the corresponding asymmetric air gap further enlarge the deviation angle between the center line of the rotor magnetic pole and the center line of the stator tooth relative to the gradual air gap structure, significantly improves the starting torque of the motor, can be applied to occasions with high requirements for the starting torque of the motor, and increases the use range of the motor. On the other hand, the starting torque of the motor is large, and the time for the motor to accelerate from a standstill to a synchronous speed is further shortened. The problem of zero point at the start of the motor is effectively avoided.

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] For a single-phase permanent magnet synchronous motor with uniform air gap, the number of stator and rotor pole pairs corresponds. Under the action of the magnetic field generated by the rotor permanent magnet and the stator salient pole, a periodically changing cogging torque will be generated. Affected by the cogging torque, the motor will be stationary at a position where the cogging torque is zero, that is, the position where the center line of the rotor magnetic pole coincides with the center line of the stator tooth. However, since the electromagnetic torque generated at this position is also zero after power is turned on, the motor will not be able to start successfully. This rotor position is called the starting dead point. When the motor rotates normally, the rotor can pass through the starting dead point smoothly through its own inertia.

[0003] The starting dead point problem is the primary problem that restricts the widespread application of single-phase permanent magnet synchronous motors. The most common solution is to change the magnetic permeability distribution of the magnetic circuit so that the center line of the rotor pole deviates from the center line of the stator tooth by a suitable angle, so that the electromagnetic torque after the motor is powered on can overcome the cogging torque and start the motor smoothly. At present, the solutions to the starting dead point at home and abroad are mainly based on optimizing the motor structure.

[0004] In the prior art, there is a method of adding auxiliary magnetic poles. The magnetic poles of soft magnetic materials are placed in the gaps between the stator teeth, thereby changing the position of the maximum magnetic permeability from the position of the stator tooth axis to a certain angle toward the auxiliary magnetic poles, so that the electromagnetic torque at startup is not zero. However, since the motor has additional auxiliary magnetic poles, the difficulty of motor manufacturing is increased in production, and the material cost of the motor is also increased.

[0005] Another method is to use an asymmetric air gap structure, which is generally achieved by changing the shape of the stator pole shoe. Since the magnetic circuits with different air gap lengths have different magnetic permeabilities, the shorter the air gap length, the greater the magnetic circuit permeability. By changing the air gap length, the spatial air gap permeability distribution can be changed to obtain an asymmetric air gap structure, so that the motor rotor pole axis and the stator tooth axis deviate by a certain angle, so that the electromagnetic torque at startup is not zero. Among the most commonly used asymmetric air gap structures, the gradual air gap structure minimizes the tooth torque while solving the problem of starting difficulties. However, the torque generated by the gradual air gap structure is limited, the motor starting torque is small, and the time to accelerate to the synchronous speed is long, which limits its scope of use. Summary of the invention

[0006] 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 dead point in motor starting in the prior art.

[0007] To achieve the above object, according to one aspect of the present invention, there is provided a single-phase permanent magnet synchronous motor, comprising: a stator part, the stator part is provided with a plurality of stator teeth, and the plurality of stator teeth surround a working cavity for accommodating a rotor part. At least one stator tooth of the plurality of stator teeth is provided with a chamfering structure at the tooth shoe, the chamfering structure faces the rotor part, and an air gap thickness is formed between the chamfering structure and the rotor part. Among them, the plurality of stator teeth include a first type of stator teeth and a second type of stator teeth. The tooth shoes of the first type of stator teeth and the tooth shoes of the second type of stator teeth are both provided with chamfering structures. The air gap thickness formed between the first type of stator teeth and the rotor part is g1, and the air gap thickness formed between the second type of stator teeth and the rotor part is g2, where g1≠g2.

[0008] Further, along the rotation direction of the rotor part, the chamfering structure is arranged on the end face at the rear end of the tooth shoe, and the air gap thickness formed between the chamfering structure and the rotor part is arranged to gradually decrease along the rotation direction of the rotor part.

[0009] Further, the chamfering structure is an arc surface structure or a plane structure.

[0010] Further, the chamfering structure is a plane structure. The plane where the chamfering structure is located and the plane where the tooth bottom surface of the tooth shoe is located have an included angle Φ. The connection line between the midpoint of the end face profile line of the tooth shoe and the vertex of the included angle Φ is W. The straight line W and the tooth bottom surface of the tooth shoe have an included angle α, where 1.2α<Φ<2α.

[0011] Further, there is a distance d between the plane where the chamfering structure is located and the tooth bottom surface of the tooth shoe, where 0.1M<d<0.7M, and M is the width of the tooth shoe.

[0012] Further, a uniform air gap thickness is formed between the first type of stator teeth and the rotor part, and a uniform air gap thickness is formed between the second type of stator teeth and the rotor part.

[0013] Further, a uniform air gap thickness is formed between the first type of stator teeth and the rotor part. Along the rotation direction of the rotor part, the air gap thickness formed between the second type of stator teeth and the rotor part is arranged to gradually decrease.

[0014] Further, there are a plurality of the first type of stator teeth and a plurality of the second type of stator teeth, and the plurality of the first type of stator teeth and the plurality of the second type of stator teeth are arranged alternately.

[0015] Further, the profile line of the end face of the first type of stator teeth on the side facing the rotor part is the first contour line, and the profile line of the end face of the second type of stator teeth on the side facing the rotor part is the second contour line. Among them, the central angle formed by the connection line between the first contour line and the geometric center of the rotor part is smaller than the central angle formed by the connection line between the second contour line and the geometric center of the rotor part.

[0016] Furthermore, a central angle formed by a line connecting the geometric center line of the first contour line, the geometric center line of the second contour line and the geometric center of the rotor part is γ, wherein γ<2π / s, and s is the number of stator slots.

[0017] 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 used as the offset baseline. An offset angle θ is formed between the geometric center line of the second contour line along the radial direction of the rotor part and the offset baseline, wherein θ=ab, 0.1π / p<θ<0.3π / p, p is the number of pole pairs of the motor, b is the center angle formed by a line connecting the offset baseline, the end of the second contour line through which the offset baseline passes, and the geometric center of the rotor part, and a is the center angle formed by a line connecting the rear end of the stator tooth where the offset baseline is located and the offset baseline and the geometric center of the rotor part.

[0018] Furthermore, along the rotation direction of the rotor part, grooves are provided on the end surfaces of the rear ends of the plurality of stator teeth facing the rotor part.

[0019] Further, a cross section of the groove along the radial direction of the rotor part is rectangular.

[0020] 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.

[0021] The technical solution of the present invention is applied, by setting a trimming structure at the tooth shoe of the stator tooth, and forming the air gap thickness of the motor between the trimming structure and the rotor part, the end of the stator tooth forms a structure that tilts outward due to the trimming structure, and the magnetic permeance at the end of the tooth shoe becomes smaller, thereby changing the spatial air gap magnetic permeance distribution, so that the single-phase permanent magnet synchronous motor has an asymmetric air gap structure, and the closed magnetic flux of the rotor is offset when the motor stops, and at the same time, the rotor magnetic pole axis no longer coincides with the stator tooth axis, and deviates by a certain angle in the direction away from the end of the outward-tilted tooth shoe. At this position, the electromagnetic torque of the motor after the current is connected is not zero, and it has self-starting capability. At the same time, the structural design of the outward tilt of the end of the stator tooth shoe makes the corresponding asymmetric air gap further expand the deviation angle between the rotor magnetic pole center line and the stator tooth center line relative to the gradual air gap structure, significantly improves the starting torque of the motor, can be used in occasions where the motor starting torque is high, and increases the use range of the motor. On the other hand, the motor starting torque is large, and the time for the motor to accelerate from static to synchronous speed is further shortened. The problem of zero point when the motor starts is effectively avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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:

[0023] 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;

[0024] Figure 2 Shows Figure 1 A is an enlarged structural diagram;

[0025] Figure 3 A schematic structural diagram of a second embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0026] Figure 4 Shows Figure 3 The enlarged structural diagram at B in FIG.

[0027] Figure 5 A schematic structural diagram of a third embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0028] Figure 6 Shows Figure 5 The enlarged structural diagram at C in FIG.

[0029] Figure 7 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 8 A schematic structural diagram of a fifth embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0031] Fig. 9 A schematic structural diagram of a sixth embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown;

[0032] Fig.10 A structural schematic diagram of a seventh embodiment of a single-phase permanent magnet synchronous motor according to the present invention is shown.

[0033] The above drawings include the following reference numerals:

[0034] 1. Arc transition of tooth shoe tip angle; 2. Cutting straight edge; 3. Arc transition of obtuse angle of stator tooth bottom; 4. Arc transition of obtuse angle of tooth shoe; 5. Rotor magnetic pole axis; 6. Stator magnetic pole axis; 7. Arc segment cutting;

[0035] 10. stator teeth; 11. tooth boots; 12. first-class stator teeth; 13. second-class stator teeth;

[0036] 20. Rotor unit;

[0037] 30. Bevel structure;

[0038] 40. Groove. DETAILED DESCRIPTION

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] Combination Figures 1 to 10 As shown, according to a specific embodiment of the present application, a single-phase permanent magnet synchronous motor is provided.

[0044] Specifically, Figure 1 As shown, the single-phase permanent magnet synchronous motor includes a stator part. The stator part is provided with a plurality of stator teeth 10, and the plurality of stator teeth 10 are arranged to form a working cavity for accommodating a rotor part 20. A beveled structure 30 is provided at a tooth shoe 11 of at least one stator tooth 10 among the plurality of stator teeth 10, and the beveled structure 30 is arranged toward the rotor part 20, and an air gap thickness is formed between the beveled structure 30 and the rotor part 20.

[0045] In this embodiment, a trimming structure is provided at the tooth collar of the stator tooth, and the formed trimming structure and the rotor part form the air-gap thickness of the motor. Since the trimming structure is provided, the end of the stator tooth forms a structure that warps outwards, and the magnetic conductance at the end of the tooth collar becomes smaller, thereby changing the spatial air-gap magnetic conductance distribution, enabling the single-phase permanent magnet synchronous motor to have an asymmetric air-gap structure, causing the closed magnetic chain of the rotor to shift when the motor stops, and at the same time, the rotor magnetic pole axis no longer coincides with the stator tooth axis and deviates by a certain angle in the direction away from the end warped tooth collar. At this position, the electromagnetic torque after the motor is connected to the current is not zero, and the motor has self-starting ability. At the same time, the structural design of the warped end of the stator tooth collar further enlarges the deviation angle between the center line of the rotor magnetic pole and the center line of the stator tooth with respect to the gradient air-gap structure, significantly improving the starting torque of the motor, which can be applied to occasions with high requirements for the starting torque of the motor, increasing the application range of the motor. On the other hand, the starting torque of the motor is large, and the time for the motor to accelerate from rest to the synchronous speed is further shortened. Effectively avoiding the problem of the existence of a zero point in the starting of this motor.

[0046] As Figure 1 shown in F in Figure 2 , along the rotation direction of the rotor part 20, the chamfering structure 30 is arranged on the end face at the rear end of the tooth collar 11, and the chamfering structure 30 and the rotor part 20 are arranged such that the air-gap thickness gradually decreases along the rotation direction of the rotor part 20. Such an arrangement can improve the starting ability of the motor. Among them, the chamfering structure 30 is an arc surface structure or a plane structure. Among them, as Figure 5 shown, 1 is the arc transition of the tooth collar sharp angle, 2 is the cut straight edge, and 3 is the arc transition at the obtuse angle at the bottom of the stator tooth. As Figure 6 shown, 5 is the rotor magnetic pole axis, and 6 is the stator magnetic pole axis. As

[0047] In this embodiment, as Figure 2 shown, the chamfering structure 30 is a plane structure, the plane where the chamfering structure 30 is located and the plane where the tooth bottom surface of the tooth collar 11 is located have an included angle Φ, the connection line between the midpoint of the end face profile line of the tooth collar 11 and the vertex of the included angle Φ is W, and the straight line W and the tooth bottom surface of the tooth collar 11 have an included angle α. Figure 2 In Figure 4 , V is the vertex angle of the included angle formed by the tooth bottom surface and the chamfering structure. Among them, 1.2α < Φ < 2α. As Figure 7 shown, the plane where the chamfering structure 30 is located and the tooth bottom surface of the tooth collar 11 have a distance d, where 0.1M < d < 0.7M, and M is the width of the tooth collar 11. As

[0048] Specifically, the plurality of stator teeth 10 include first-class stator teeth 12 and second-class stator teeth 13. The tooth boots 11 of the first-class stator teeth 12 and the tooth boots 11 of the second-class stator teeth 13 are both provided with a chamfered structure 30, the air gap thickness formed between the first-class stator teeth 12 and the rotor part 20 is g1, and the air gap thickness formed between the second-class stator teeth 13 and the rotor part 20 is g2, wherein g1≠g2. Such a configuration can improve the output torque of the motor rotor.

[0049] Preferably, a uniform air gap thickness is formed between the first type of stator teeth 12 and the rotor portion 20, and a uniform air gap thickness is formed between the second type of stator teeth 13 and the rotor portion 20. Figure 8 As shown, a uniform air gap thickness may be formed between the first type of stator teeth 12 and the rotor part 20, and the air gap thickness formed between the second type of stator teeth 13 and the rotor part 20 may be gradually reduced along the rotation direction of the rotor part 20. Such an arrangement can further improve the output torque of the motor rotor. In this embodiment, a plurality of first type of stator teeth 12 and a plurality of second type of stator teeth 13 may be alternately arranged.

[0050] Furthermore, if Fig. 9 As shown, the profile of the end surface of the first type of stator tooth 12 facing the rotor part 20 is the first contour line, and the profile of the end surface of the second type of stator tooth 13 facing the rotor part 20 is the second contour line, wherein the center angle formed by the line connecting the first contour line and the geometric center of the rotor part 20 is smaller than the center angle formed by the line connecting the second contour line and the geometric center of the rotor part 20. The center angle formed by the line connecting the geometric center line of the first contour line, the geometric center line of the second contour line and the geometric center of the rotor part 20 is γ, wherein γ<2π / s, and s is the number of stator slots. The geometric center line of the first contour line along the radial direction of the rotor part 20 is used as the reference line, and the angle of 2π / s along the rotation direction of the rotor part 20 is used as the offset baseline. The geometric center line of the second contour line along the radial direction of the rotor part 20 and the offset baseline form an offset angle θ, wherein θ=ab, 0.1π / p<θ<0.3π / p, p is the number of pole pairs of the motor, b is the center angle formed by the line connecting the offset baseline, the end of the second contour line through which the offset baseline passes, and the geometric center of the rotor part 20, and a is the center angle formed by the line connecting the rear end of the stator tooth where the offset baseline is located and the offset baseline and the geometric center of the rotor part 20. This arrangement significantly improves the starting torque of the motor, can be used in occasions where the motor starting torque is high, and increases the scope of use of the motor.

[0051] According to another embodiment of the present application, along the rotation direction of the rotor part 20, grooves 40 are formed on the end faces of the rear ends of the plurality of stator teeth 10 facing the rotor part 20. The cross-section of the groove 40 in the radial direction of the rotor part 20 is rectangular. Such a setting can also improve the output torque of the motor and eliminate the problem of dead points in the motor startup.

[0052] 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, and the single-phase permanent magnet synchronous motor is the single-phase permanent magnet synchronous motor in the above embodiment.

[0053] Specifically, adopting the motor structure of the present application, the present application solves the problem of difficult startup of the single-phase permanent magnet synchronous motor by modifying the end of the stator single-sided tooth boot to be outwardly warped, and the actual tooth boot forms an asymmetric air gap structure. At the same time, the single-phase permanent magnet synchronous motor with this stator tooth structure has a larger electromagnetic starting torque compared with the gradually changing air gap stator tooth structure, and the acceleration time to reach the synchronous speed is shortened.

[0054] The outwardly warped shape of the end of the stator tooth boot is realized by cutting off a single-sided part of the tooth boot of the stator tooth. The cutting forms include cutting a part of the tooth boot based on the upper vertex angle of the tooth boot in a straight line and cutting a part of the tooth boot based on the arc of the side of the tooth boot and the bottom of the stator tooth. Both the cutting form and the size of the cutting part area will affect the size of the starting angle, thereby affecting the size of the motor starting torque.

[0055] For straight-line cutting, the cutting part starts from the upper vertex angle V of the tooth boot and is cut at a ray angle of Φ. The angle Φ is the included angle between the cutting straight line and the upper edge of the tooth boot, so as to realize the structural design of the outwardly warped tooth boot. At the same time, the cutting line can be moved downward in parallel, and the moving distance is d. By setting an appropriate translation distance, an appropriate cutting part can be selected.

[0056] By determining the angle Φ and the translation distance d, the cutting part can be jointly determined. Among them, the angle Φ needs to satisfy: 1.3α < Φ < 1.5α, and when the translation distance d satisfies 0.3M < d < 0.5M, the area of the cutting part by line cutting is appropriate, so that the motor has a larger starting electromagnetic torque. The value of α varies with different sizes of the stator and is defined as the included angle between the straight line determined by the upper vertex angle of the tooth boot to the midpoint of the bottom of the stator tooth and the upper edge of the tooth boot, where M is the width of the tooth boot. For the arc cutting method, the specific cutting part of the arc cutting is obtained by the arc transition between the stator tooth top and the side of the tooth boot. The radius of the arc segment is preferably the size of the same number of poles according to the size of the stator tooth boot.

[0057] According to one embodiment of the present application, the stator is carried out on a structure of a stator tooth shoe with a uniform air gap. When the motor rotates counterclockwise, in order to obtain a positive starting torque, the outer warped tooth shoe needs to be located at the right tooth shoe of the stator tooth. After the stator tooth shoe is cut, an obtuse angle of the tooth bottom will be generated at the bottom of the stator tooth. In order to reduce the torque ripple and noise during the operation of the motor, the existence of the bottom obtuse angle should be avoided. The arc segment transition is used to replace the tooth bottom obtuse angle. The radius of the arc segment is preferably the same order of magnitude according to the size of the stator tooth shoe. When the downward distance of the cutting line is zero, a tooth shoe tip angle will be generated on the upper side of the tooth shoe after the cutting. In order to avoid the existence of the tooth shoe tip angle after the tooth shoe is cut, the magnetic circuit distribution of the motor is improved, and the tooth shoe tip angle is replaced by the arc segment transition. The radius of the arc segment is preferably a size that is smaller by one number of poles according to the size of the stator tooth shoe. When the downward distance is not zero, the tooth shoe cutting will generate a certain tooth shoe obtuse angle. The tooth shoe obtuse angle is replaced by the arc segment transition. The radius of the arc segment is preferably a size that is smaller by one number of poles according to the size of the stator tooth shoe.

[0058] In another embodiment of the present application, the cutting form that constitutes the stator tooth shoe warping is not limited to straight line cutting, but can also be a circular arc segment cutting form, and the specific arc cutting position is obtained by utilizing the arc transition between the stator tooth top and the tooth shoe side, wherein the arc segment radius is preferably the size of the same number of poles according to the stator tooth shoe size. At the same time, there is no need to deal with the sharp corners existing in similar straight line cutting, and the circular arc line cutting can also be moved downward in parallel to modify the cutting area without affecting the effect of the technical solution.

[0059] According to an embodiment provided by the present application, based on the uniform air gap structure formed by the stator, two different stator tooth structures are further improved and set, and the two tooth structures correspond to different air gap structures, specifically: both air gap structures are structures of uniform air gap (the thickness of the air gap under the same stator tooth remains unchanged), but the thickness of the two air gaps is different, that is, g1≠g2, and the two different uniform air gaps are alternately distributed in a 1-to-1 form. While maintaining the structure of the unilateral tooth boot outward warping, the uniform air gaps of different thicknesses are set under the two different stator teeth, which can further increase the deviation angle between the motor rotor magnetic pole axis and the stator winding magnetic pole, improve the starting torque, and reduce the starting current.

[0060] Based on the uniform air gap structure, two different stator tooth structures are set up, namely the gradient air gap structure and the basic uniform air gap structure, and the gradient air gap and the uniform air gap are alternately distributed in a 1:1 form. In order to obtain a positive starting torque, the thickness of the gradient air gap gradually decreases along the rotation direction of the motor, that is, g11 <g12.

[0061] The use of a gradient air gap can also solve the starting problem of a single-phase motor. At the same time, it can also further increase the counterclockwise deviation angle of the motor rotor pole centerline and improve the motor starting torque. Replacing part of the basic uniform air gap structure with a gradient air gap structure and combining it with a single-sided tooth boot outward warping structure can increase the starting torque of the motor and thereby reduce the starting current.

[0062] In another embodiment of the present application, the center angles of two different stator tooth structures corresponding to the contours of the rotor parts are different, which leads to different contour lengths of the stator teeth, wherein the large tooth has a larger center angle, and the small tooth has a smaller center angle. The large and small tooth structures are alternately distributed in a 1-to-1 form, and the center angle between the center of the large tooth contour and the center of the small tooth contour is γ, γ<2π / s, where s is the number of stator slots. At the same time, with the geometric center line of the small tooth contour as a reference, the straight line with a 2π / s degree angle to the geometric center line of the small tooth contour is the tooth offset baseline of the large tooth, and the offset angle θ=ab of the motor large tooth is set. Among them, the value range of θ is 0.1π / p<θ<0.3π / p, and p is the number of motor pole pairs. If the offset angle is too small, the starting torque generated is small, and if the offset angle is too large, the leakage magnetic flux between adjacent stator teeth will increase. The large and small tooth offset structure can also solve the problem of the starting dead point of a single-phase motor, and at the same time make the motor rotor magnetic pole axis and the stator winding magnetic pole axis deviate clockwise from the center of the stator tooth yoke by a certain angle, but the stator winding magnetic pole axis deviates at a greater angle, thereby increasing the starting angle of the motor. Combining the large and small tooth structure with the single-sided tooth boot outward warping structure can increase the starting torque of the motor and reduce the starting current.

[0063] Furthermore, if Fig.10 As shown, the rectangular slotting method is specifically configured as follows: a groove 40 is provided on the end surface of the rear end of the four stator teeth 10 facing the rotor part 20, the slotting portion and the tooth boot outward warping portion are located on the same single side of the stator tooth, the distance between the center line of the rectangular slot and the center line of the stator tooth is L, the height of the rectangular slot is H, and the slot width is D. The front end and rear end of the stator tooth in this application refer to the end of the stator tooth that first turns into the preset point along the rotation direction of the rotor part as the front end, and the end that turns into the preset point later as the rear end. The stator tooth slotting structure can also solve the problem of the starting dead point of a single-phase motor. Combining the single-sided tooth boot outward warping structure with the rectangular slotting structure can allow the motor rotor magnetic pole axis to continue to offset counterclockwise by a certain angle, which can increase the starting torque of the motor and reduce the starting current.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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: Including: A stator part, where a plurality of stator teeth (10) are provided on the stator part. The plurality of stator teeth (10) surround a working cavity for accommodating a rotor part (20). A chamfering structure (30) is provided at the tooth shoe (11) of at least one of the plurality of stator teeth (10). The chamfering structure (30) faces the rotor part (20), and an air gap thickness is formed between the chamfering structure (30) and the rotor part (20). Along the rotation direction of the rotor part (20), the chamfering structure (30) is provided on the end face at the rear end of the tooth shoe (11), and the air gap thickness formed between the chamfering structure (30) and the rotor part (20) is arranged to gradually decrease along the rotation direction of the rotor part (20). Along the rotation direction of the rotor part (20), grooves (40) are formed on the end faces of the rear ends of the plurality of stator teeth (10) on the side facing the rotor part (20). Among them, the plurality of stator teeth (10) include a first type of stator teeth (12) and a second type of stator teeth (13). The chamfering structure (30) is provided on the tooth shoes (11) of both the first type of stator teeth (12) and the second type of stator teeth (13). The air gap thickness formed between the first type of stator teeth (12) and the rotor part (20) is g1, and the air gap thickness formed between the second type of stator teeth (13) and the rotor part (20) is g2, where g1≠g2. There are a plurality of the first type of stator teeth (12) and a plurality of the second type of stator teeth (13), and the plurality of the first type of stator teeth (12) and the plurality of the second type of stator teeth (13) are arranged alternately.

2. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: The chamfering structure (30) is an arc surface structure or a plane structure.

3. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: The chamfering structure (30) is a plane structure. The plane where the chamfering structure (30) is located and the plane where the tooth bottom surface of the tooth shoe (11) is located have an included angle Φ. The connection line between the midpoint of the end face profile of the tooth shoe (11) and the vertex of the included angle Φ is W. The straight line W and the tooth bottom surface of the tooth shoe (11) have an included angle α, where 1.2α<Φ<2α.

4. The single-phase permanent magnet synchronous motor according to claim 3, characterized in that: The plane where the chamfering structure (30) is located and the tooth bottom surface of the tooth shoe (11) have a distance d, where 0.1M<d<0.7M, and M is the width of the tooth shoe (11).

5. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: A uniform air gap thickness is formed between the first type of stator teeth (12) and the rotor part (20), and a uniform air gap thickness is formed between the second type of stator teeth (13) and the rotor part (20).

6. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: A uniform air gap thickness is formed between the first type of stator teeth (12) and the rotor part (20). Along the rotation direction of the rotor part (20), the air gap thickness formed between the second type of stator teeth (13) and the rotor part (20) is arranged to gradually decrease.

7. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: The profile line of the end surface of the first type of stator tooth (12) facing the rotor part (20) is a first contour line, and the profile line of the end surface of the second type of stator tooth (13) facing the rotor part (20) is a second contour line, wherein the center angle formed by the line connecting the first contour line and the geometric center of the rotor part (20) is smaller than the center angle formed by the line connecting the second contour line and the geometric center of the rotor part (20).

8. The single-phase permanent magnet synchronous motor according to claim 7, characterized in that: The central angle formed by the line connecting the geometric center line of the first contour line, the geometric center line of the second contour line and the geometric center of the rotor part (20) is γ, wherein γ<2π / s, and s is the number of stator slots.

9. The single-phase permanent magnet synchronous motor according to claim 7, characterized in that: The geometric center line of the first contour line along the radial direction of the rotor part (20) is used as a reference line, and the angle of 2π / s along the rotation direction of the rotor part (20) is used as a deviation baseline. The geometric center line of the second contour line along the radial direction of the rotor part (20) and the deviation baseline form a deviation angle θ, wherein θ=ab, 0.1π / p<θ<0.3π / p, p is the number of pole pairs of the motor, b is the center angle formed by a line connecting the deviation baseline, the end of the second contour line through which the deviation baseline passes, and the geometric center of the rotor part (20), and a is the center angle formed by a line connecting the rear end of the stator tooth where the deviation baseline is located and the deviation baseline and the geometric center of the rotor part (20).

10. The single-phase permanent magnet synchronous motor according to claim 1, characterized in that: The groove (40) has a rectangular cross section along the radial direction of the rotor part (20).

11. 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 10.

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