Single-phase permanent magnet motor and electric equipment comprising same

Abstract

The invention discloses a single-phase permanent magnet motor and electric equipment comprising the same, the single-phase permanent magnet motor comprises a stator part and a rotor part, the stator part comprises a plurality of tooth parts, the rotor part is provided with permanent magnets and ferromagnetic poles, and the corresponding magnetic pole numbers of the permanent magnets and the ferromagnetic poles on the rotor part are equal. The number of the tooth parts is twice that of the corresponding magnetic poles of the permanent magnets on the rotor part, and the corresponding magnetic poles of the permanent magnets and the ferromagnetic poles on the rotor part are sequentially and alternately arranged in the circumferential direction of the rotor part; when the geometric axes of the permanent magnets are aligned with the central axes of the corresponding tooth parts, air gaps formed between the surfaces of the ferromagnetic poles and the corresponding tooth parts are asymmetrically arranged by taking the central axes of the corresponding tooth parts as the axes, the magnetic field axes of the permanent magnets deviate from the central axes of the corresponding tooth parts by a certain angle, and the rotor rotates by a certain angle until the rotor is static under the action of cogging torque. When current passes through the winding, the torque synthesized by the electromagnetic torque and the cogging torque is a positive value, so that the motor has the self-starting capability.

Description

Technical Field

[0001] The present invention relates to the field of motors, and in particular to a single-phase permanent magnet motor and an electric device comprising the same. Background Art

[0002] Single-phase permanent magnet motors are widely used in the field of low-power household appliances due to their advantages such as simple motor structure and control circuit, and low cost. The stator part of the existing single-phase permanent magnet motor generally adopts an integral structure, that is, the ring part and the tooth part of the stator part are integrally formed, the tooth part includes a tooth body and a tooth tip, the winding is wound on the tooth body, the tooth tip is symmetrically arranged along the central axis of the tooth body, and the stator surface corresponding to the tooth tip is an arc surface with the center of the rotor as the origin. The rotor can be arranged in a circular area surrounded by multiple tooth tips, or it can be arranged around the periphery of multiple tooth tips.

[0003] Permanent magnets are generally provided on the rotor. When the geometric axis of the permanent magnet is aligned with the central axis of the stator tooth, the single-phase permanent magnet motor is at a dead point. At this position, the zero crossing point of the back electromotive force and the zero crossing point of the cogging torque coincide. The problem is that even if current is passed through the winding, the electromagnetic torque generated by the current and the back electromotive force is zero. At the same time, when the cogging torque is also zero, the output torque of the motor is zero. If the motor has been started and operated, the problem caused by the dead point will be overcome by relying on the inertia torque of the motor. However, when the motor winding is not passed through current, the motor is at a dead point in a stationary state. No matter what current is passed through the winding, the motor does not have the ability to self-start. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defect in the prior art that the single-phase permanent magnet motor is at a dead point position when stationary, resulting in the motor having no self-starting capability, and to provide a single-phase permanent magnet motor and an electric device comprising the same.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] A single-phase permanent magnet motor comprises a stator part and a rotor part, wherein the stator part comprises a plurality of teeth parts, and is characterized in that:

[0007] The rotor part is provided with permanent magnets and ferromagnetic poles, the number of magnetic poles corresponding to the permanent magnets and the ferromagnetic poles on the rotor part is equal, and the number of the teeth is twice the number of magnetic poles corresponding to the permanent magnets on the rotor part, and the magnetic poles corresponding to the permanent magnets and the ferromagnetic poles on the rotor part are alternately arranged in sequence along the circumferential direction of the rotor part;

[0008] When the geometric axis of the permanent magnet is aligned with the central axis of the corresponding tooth portion, the air gap formed between the surface of the ferromagnetic pole and the corresponding tooth portion is configured such that the air gap is asymmetrically configured with respect to the central axis of the corresponding tooth portion.

[0009] In this solution, by arranging permanent magnets and ferromagnetic poles on the rotor part, the number of N-polarity (or S-polarity) permanent magnets can be reduced by half compared with the traditional single-phase permanent magnet motor, the utilization rate of the permanent magnet becomes higher, and the cost of the motor is lower; further, when the geometric axis of the permanent magnet is aligned with the center axis of the tooth part, the air gap formed by the surface of the ferromagnetic pole and the corresponding tooth part is asymmetrically arranged with the center axis of the corresponding tooth part, at this time, the magnetic field axis of the permanent magnet will deviate from the center axis of the corresponding tooth part by a certain angle, and the cogging torque on the rotor is not zero. Under the action of the cogging torque, the rotor will rotate a certain angle until it stops, and the corresponding cogging torque is zero and the back electromotive force is not zero in the stationary state. When the winding passes current, the electromagnetic torque formed by the current and the back electromotive force and the torque synthesized by the cogging torque is a positive value, so that the motor has the ability to self-start.

[0010] Furthermore, the gap formed between the surface of the permanent magnet and the corresponding tooth portion is symmetrically arranged with respect to the central axis of the corresponding tooth portion.

[0011] In this solution, when the geometric axis of the permanent magnet is aligned with the central axis of the corresponding tooth portion, a symmetrical gap and an asymmetrical air gap are respectively formed between the rotor portion and the tooth portion, making it easier to achieve that the magnetic field axis of the permanent magnet deviates from the central axis of the corresponding tooth portion by a certain angle, thereby improving the self-starting ability of the motor.

[0012] Furthermore, the radial thickness dimension of the air gap is arranged to change continuously along the circumferential direction of the rotor part.

[0013] In the present scheme, through this arrangement, it is easier to make the air gap formed between the surface of the ferromagnetic pole and the corresponding tooth portion asymmetrically arranged with the center axis of the corresponding tooth portion, further ensuring that when no current is passed through the winding, the magnetic field axis of the permanent magnet deviates from the center axis of the tooth portion by a certain angle, and compared with other arrangements, the above arrangement is more convenient for processing the ferromagnetic pole, and is also simpler and more reasonable in structure.

[0014] Furthermore, a plurality of the teeth are arranged to form a circular curved surface, and the central axis of the circular curved surface coincides with the central axis of the rotor portion;

[0015] The distance from the surface of the ferromagnetic pole to the central axis of the rotor part gradually changes along the circumferential direction of the rotor part.

[0016] In this scheme, the distance from the center axis of the rotor part to the circular curved surface is equal by setting the circular curved surface and its positional relationship with the rotor part; on this basis, the radial thickness dimension of the air gap is set by adjusting the distance from the surface of the ferromagnetic pole to the center axis of the rotor part. Compared with changing the structure of the stator part to overcome the dead point position of the motor, it can avoid the reduction of the mechanical strength of the tooth part and the local saturation of the tooth tip due to processing, which affects the performance of the motor. At the same time, since the price of the ferromagnetic pole is lower than that of the permanent magnet and it is easy to process, this setting only needs to process the surface of the ferromagnetic pole so that the distance dimension from the center axis of the rotor part gradually changes along the circumferential direction of the rotor part, which is more convenient and more cost-effective in processing.

[0017] Furthermore, the stator part is arranged around the periphery of the rotor part, and the distance from the surface of the ferromagnetic pole to the central axis of the rotor part gradually decreases along the circumferential rotation direction of the rotor part.

[0018] In the present embodiment, the stator part is arranged around the periphery of the rotor part, that is, the single-phase permanent magnet motor is an inner rotor structure, and the annular surface formed by the several teeth of the stator part is the inner annular surface. The permanent magnets and the ferromagnetic poles are both outwardly facing the corresponding teeth along the radial direction of the rotor part. At this time, the distance from the surface of the ferromagnetic pole to the central axis of the rotor part gradually decreases along the circumferential rotation direction of the rotor part, that is, the air gap formed by the surface of the ferromagnetic pole and the corresponding tooth part gradually increases along the circumferential rotation direction of the rotor part, which is more conducive to the starting rotation of the motor.

[0019] Furthermore, the rotor part is arranged around the periphery of the stator part, and the distance from the surface of the ferromagnetic pole to the central axis of the rotor part gradually increases along the circumferential rotation direction of the rotor part.

[0020] In the present embodiment, the rotor part is arranged around the periphery of the stator part, that is, the single-phase permanent magnet motor is an outer rotor structure, and the annular curved surface formed by the several teeth of the stator part is the outer annular curved surface. The permanent magnets and the ferromagnetic poles are both inwardly facing the corresponding teeth along the radial direction of the rotor part. At this time, the distance from the surface of the ferromagnetic pole to the central axis of the rotor part gradually increases along the circumferential rotation direction of the rotor part, that is, the air gap formed by the surface of the ferromagnetic pole and the corresponding tooth part also gradually increases along the circumferential rotation direction of the rotor part, which is also beneficial to the starting rotation of the motor.

[0021] Furthermore, the surface of the ferromagnetic pole is a smooth curved surface, and the distance from the smooth curved surface to the central axis of the rotor part gradually changes along the circumferential direction of the rotor part.

[0022] In this solution, by setting the surface of the ferromagnetic pole to a smooth curved surface, the surface of the ferromagnetic pole can smoothly transition along the circumferential direction of the rotor part, and the radial thickness dimension of the corresponding air gap can also smoothly increase or decrease along the circumferential direction of the rotor part, so that the operation of the motor is smoother.

[0023] Furthermore, the surface of the ferromagnetic pole is a stepped curved surface, which is composed of multiple sections of curved surfaces. The distance between each section of the curved surface and the central axis of the rotor part is the same, and the distance between the multiple sections of the curved surface and the central axis of the rotor part gradually changes along the circumferential direction of the rotor part.

[0024] In this solution, compared with other settings, the surface of the ferromagnetic pole is set to a stepped surface formed by splicing multiple curved surfaces, which is beneficial to the processing of the ferromagnetic pole.

[0025] Furthermore, the distances from the surface of the permanent magnet to the center axis of the rotor part are the same, and the distances from the surface of the permanent magnet to the center axis of the rotor part are the same as the maximum distances from the surface of the ferromagnetic pole to the center axis of the rotor part.

[0026] In the present solution, through this arrangement, the permanent magnets and the ferromagnetic poles can smoothly transition on the surface of the rotor part, making the structure of the rotor part more reasonable and also facilitating the operation of the motor.

[0027] Furthermore, the ferromagnetic poles and the rotor part are integrally formed.

[0028] In this solution, a part of the structure of the rotor part is directly used as the ferromagnetic pole, and the permanent magnets are arranged at intervals on the surface of the rotor part, which is more convenient and simple in processing and manufacturing.

[0029] Furthermore, the rotor part is provided with a limiting groove between adjacent ferromagnetic poles, and the permanent magnet is cooperatively arranged in the limiting groove.

[0030] In this solution, when the ferromagnetic poles are integrally arranged with the rotor part, the permanent magnet is arranged in a limiting groove opened between adjacent ferromagnetic poles, so that the permanent magnet is more stable relative to the rotor part.

[0031] An electric device is characterized in that the electric device comprises the single-phase permanent magnet motor as described above.

[0032] In this solution, the single-phase permanent magnet motor as described above is applied to the electric device, which effectively avoids the problem that the single-phase permanent magnet motor in the electric device cannot start automatically.

[0033] The positive and progressive effects of the present invention are:

[0034] In this solution, by arranging permanent magnets and ferromagnetic poles on the rotor part, the number of N-polarity (or S-polarity) permanent magnets can be reduced by half compared with the traditional single-phase permanent magnet motor, the utilization rate of the permanent magnet becomes higher, and the cost of the motor is lower; further, when the geometric axis of the permanent magnet is aligned with the center axis of the tooth part, the air gap formed by the surface of the ferromagnetic pole and the corresponding tooth part is asymmetrically arranged with the center axis of the corresponding tooth part, at this time, the magnetic field axis of the permanent magnet will deviate from the center axis of the corresponding tooth part by a certain angle, and the cogging torque on the rotor is not zero. Under the action of the cogging torque, the rotor will rotate a certain angle until it stops, and the corresponding cogging torque is zero and the back electromotive force is not zero in the stationary state. When the winding passes current, the electromagnetic torque formed by the current and the back electromotive force and the torque synthesized by the cogging torque is a positive value, so that the motor has the ability to self-start. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the structure of a single-phase permanent magnet motor in Example 1 of the present invention.

[0036] Figure 2 It is a schematic structural diagram of the stator part in Example 1 of the present invention.

[0037] Figure 3 Schematic diagram of the structure of the rotor part in Example 1 of the present invention.

[0038] Figure 4 Schematic diagram of the structure of a single-phase permanent magnet motor in Example 2 of the present invention.

[0039] Figure 5 Schematic diagram of the structure of the rotor part in Example 2 of the present invention.

[0040] Figure 6 Schematic diagram of the structure of a single-phase permanent magnet motor in Example 3 of the present invention.

[0041] Figure 7 Schematic diagram of the structure of a single-phase permanent magnet motor in Example 4 of the present invention.

[0042] Figure 8 Schematic diagram of the structure of a single-phase permanent magnet motor in Example 5 of the present invention.

[0043] Description of reference numerals:

[0044] Stator part 10

[0045] Outer ring 100

[0046] Tooth 200

[0047] Tooth body 210

[0048] Tooth tip 220

[0049] Central Axis 211

[0050] Torus 230

[0051] Permanent magnet 300

[0052] Geometric axis 310

[0053] Ferromagnetic Pole 400

[0054] Air Gap 410

[0055] Rotor core 500

[0056] Winding 20 DETAILED DESCRIPTION

[0057] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but are not to be construed as limiting the present invention. All other embodiments obtained by ordinary technicians in the field without creative work based on the embodiments of the present invention are within the scope of protection of the present invention.

[0058] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “circumferential”, “radial”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0059] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0060] Example 1

[0061] This embodiment provides a single-phase permanent magnet motor, such as Figure 1 As shown, the single-phase permanent magnet motor includes a stator part 10 and a rotor part, the rotor part includes a permanent magnet 300, a ferromagnetic pole 400 and a rotor core 500, and the stator part 10 is arranged on the periphery of the rotor part, that is, the single-phase permanent magnet motor is an inner rotor structure. Figure 2 As shown, the stator part 10 is an integral structure consisting of an outer ring part 100 and a tooth part 200. The outer ring part 100 has an outer shape similar to a circular cylindrical structure. Six tooth parts 200 are formed on the inner wall surface of the outer ring part 100 extending inwardly along its radial direction. Each tooth part 200 includes a tooth body 210 and a tooth tip 220. The tooth body 210 is connected to the inner wall surface of the outer ring part 100. The tooth tip 220 is arranged at one end of the tooth body 210 away from the outer ring part 100 and extends to both ends along the circumferential direction of the stator, that is, the tooth tip 220 is symmetrically arranged along the central axis 211 of the tooth part 200. It should be noted that Figure 2 It can be known that the central axis 211 of each tooth portion 200 is the central axis 211 of the tooth body 210 . The description of the central axis 211 in this embodiment represents the central axis 211 of the tooth portion 200 .

[0062] like Figure 1 As shown, the winding 20 of the single-phase permanent magnet motor is wound on the tooth body 210 of the tooth portion 200, and the rotor portion includes a rotor core 500, a permanent magnet 300 and a ferromagnetic pole 400, wherein the overall structure of the rotor core 500 is a circular cylindrical structure, and a rotating shaft can be arranged inside the rotor core 500, the rotating shaft passes through the inside of the rotor core 500 and is fixed to the rotor core 500, and the rotating shaft is used to drive the rotor core 500 to rotate, so that the rotor portion rotates relative to the stator portion 10. On the outer surface of the rotor core 500, a unipolar permanent magnet 300 and a unipolar ferromagnetic pole 400 are arranged, and the number of the permanent magnet 300 and the number of the ferromagnetic pole 400 are both three, so that the number of magnetic poles corresponding to the permanent magnet 300 and the ferromagnetic pole 400 on the rotor part can correspond to the number of the teeth 200 of the stator, and on the outer surface of the rotor core 500, the magnetic poles corresponding to the permanent magnet 300 and the ferromagnetic pole 400 on the rotor part are arranged alternately in sequence along the circumferential direction of the rotor part. Through this arrangement, compared with the traditional single-phase permanent magnet motor, the number of N-polarity (or S-polarity) permanent magnets 300 can be reduced by half, the utilization rate of the permanent magnet 300 becomes higher, and the cost of the motor is lower.

[0063] Further, such as Figure 1As shown, each permanent magnet 300 is arranged on the surface of the rotor core 500, and has a geometric axis 310 pointing to the center of the rotor part, and the permanent magnet 300 is symmetrically arranged with respect to the geometric axis 310. The description of the geometric axis 310 in this embodiment is expressed as the geometric axis 310 of the permanent magnet 300. When the geometric axis 310 of the permanent magnet 300 is aligned with the central axis 211 of the corresponding tooth part 200, the air gap 410 formed between the outer surface of the ferromagnetic pole 400 and the corresponding tooth part 200 is asymmetrically arranged with respect to the central axis 211 of the corresponding tooth part 200, at this time, the magnetic field axis of the permanent magnet 300 will deviate from the central axis 211 of the corresponding tooth part 200 by a certain angle, and at this time, the cogging torque on the rotor part is not zero. Under the action of the cogging torque, the rotor part will rotate by a certain angle until it is stationary, and the corresponding cogging torque is zero and the back electromotive force is not zero in the stationary state. When current flows through the winding 20, the torque synthesized by the electromagnetic torque formed by the current and the back electromotive force and the cogging torque is positive, so that the motor has the ability of self-starting.

[0064] Further, such as Figure 1 As shown, the gap formed between the surface of the permanent magnet 300 and the corresponding tooth portion 200 is symmetrically arranged with the central axis 211 of the corresponding tooth portion 200, so that when the geometric axis 310 of the permanent magnet 300 is aligned with the central axis 211 of the corresponding tooth portion 200, a symmetrical gap and an asymmetrical air gap 410 are respectively formed between the rotor portion and the tooth portion 200, which makes it easier to achieve that the magnetic field axis of the permanent magnet 300 deviates from the central axis 211 of the corresponding tooth portion 200 by a certain angle, thereby improving the self-starting ability of the motor.

[0065] Further, combined with Figure 3 As shown, the surfaces of the tooth tips 220 of the six tooth portions 200 are arranged to form a circular curved surface 230. It should be noted that, Figure 3 It is only a schematic diagram of the circular curved surface 230, corresponding to Figure 1 There are certain slots between the tooth tips 220 of the adjacent tooth portions 200, and the specific circumferential dimensions of the slots can be adjusted as needed. Figure 3 For example, the central axis of the rotor portion coincides with the central axis of the annular curved surface 230. Figure 3 In the figure, the rotor part is arranged concentrically with the annular curved surface, the distance from the central axis of the rotor part to the annular curved surface 230 is equal, and the distance from the outer surface of each ferromagnetic pole 400 to the central axis of the rotor part gradually changes along the circumferential direction of the rotor part.

[0066] Through the above arrangement, the distance from the outer surface of the ferromagnetic pole 400 to the central axis of the rotor part is adjusted to achieve the radial thickness size change of the air gap 410, and the radial thickness size gradually changes along the circumferential direction of the rotor part, making it easier to make the air gap 410 formed between the surface of the ferromagnetic pole 400 and the corresponding tooth part 200 be asymmetrically arranged with the central axis 211 of the corresponding tooth part 200, further ensuring that when the winding 20 is not energized, the magnetic field axis of the permanent magnet 300 deviates from the central axis of the tooth part 200 by a certain angle, and compared with other arrangement methods, the above arrangement method is more convenient for processing the ferromagnetic pole 400, and the structure is also simpler and more reasonable. At the same time, since the price of the ferromagnetic pole 400 is lower than that of the permanent magnet 300 and it is easy to process, this arrangement only needs to process the surface of the ferromagnetic pole 400 so that the distance size to the central axis of the rotor part gradually changes along the circumferential direction of the rotor part, which is more convenient and more cost-saving in processing.

[0067] like Figure 1 and Figure 3 As shown, in this embodiment, the rotor part is arranged inside the stator part 10, that is, the single-phase permanent magnet motor is an inner rotor structure, and the annular surface formed by the six teeth 200 of the stator part 10 is an inner annular surface. The permanent magnet 300 and the ferromagnetic pole 400 are both outwardly toward the corresponding tooth part 200 along the radial direction of the rotor part. At this time, the distance dimension from the surface of the ferromagnetic pole 400 to the central axis of the rotor part gradually decreases along the circumferential rotation direction of the rotor part, that is, the radial thickness dimension of the air gap 410 formed by the surface of the ferromagnetic pole 400 and the corresponding tooth part 200 gradually increases along the circumferential rotation direction of the rotor part, which can increase the time difference (that is, the rotor electrical angle difference) between the no-load back electromotive force zero crossing point and the tooth slot torque zero crossing point, so that the no-load back electromotive force has a larger value at the tooth slot torque zero crossing point. When current is passed, the electromagnetic torque of the motor is larger, and then the output torque of the motor is larger, which is more conducive to the starting rotation of the motor. For example, when the circumferential rotation direction of the rotor part is clockwise, the distance dimension from the surface of the ferromagnetic pole 400 to the central axis of the rotor part gradually decreases in the clockwise direction, and the radial thickness dimension of the air gap 410 formed by the surface of the ferromagnetic pole 400 and the corresponding tooth part 200 gradually increases in the clockwise direction; and the same is true for the counterclockwise direction.

[0068] like Figure 1 and Figure 3As shown, the surface of the ferromagnetic pole 400 is specifically a stepped surface, which is composed of two sections of curved surfaces spliced ​​together. The distance between each section of the curved surface and the central axis of the rotor part is the same, and the distance between the two sections of the curved surface and the central axis of the rotor part gradually changes along the circumferential direction of the rotor part. Compared with other settings, by setting the surface of the ferromagnetic pole 400 as a stepped surface formed by splicing two sections of curved surfaces, it is beneficial to the processing of the ferromagnetic pole 400. Specifically, the surface of each ferromagnetic pole 400 includes two curved surfaces, which are arranged in a stepped shape. The distances between the two curved surfaces and the annular curved surface 230 are δ1 and δ2, respectively. The distance between the outer surface of the permanent magnet 300 and the annular curved surface 230 is δ, and the inner diameter of the annular curved surface 230 is 27.5 mm. The values ​​of δ, δ1 and δ2 are 0.6 mm, 0.6 mm and 1.85 mm, respectively. The corresponding distance from the outer surface of the permanent magnet 300 to the central axis of the rotor part is 26.9 mm, and the distances from the two curved surfaces on the ferromagnetic pole 400 to the central axis of the rotor part are 26.9 mm and 25.65 mm, respectively. Of course, in other embodiments, the outer surface of the ferromagnetic pole 400 can also be set as a plurality of curved surfaces as needed, as long as the distances from the plurality of curved surfaces to the central axis of the rotor part gradually change along the circumferential direction of the rotor part.

[0069] As described above, the distance size from the outer surface of each permanent magnet 300 to the central axis of the rotor part is the same, so that the gap formed between the outer surface of the permanent magnet 300 and the corresponding tooth part 200 is more uniform. Further, the distance size from the outer surface of the permanent magnet 300 to the central axis of the rotor part is the same as the maximum distance size from the outer surface of the ferromagnetic pole 400 to the central axis of the rotor part, so that a smooth transition can be made between adjacent permanent magnets 300 and ferromagnetic poles 400 on the rotor part, and the structure of the single-phase permanent magnet motor on the rotor side is more reasonable, which is more conducive to the operation of the motor. Of course, in other embodiments, adjacent permanent magnets 300 and ferromagnetic poles 400 can be set to have a non-smooth transition.

[0070] Further, such as Figure 1 and Figure 3 As shown, the corresponding pole pitch range angles of each permanent magnet 300 and ferromagnetic pole 400 on the rotor part are the same, that is, the corresponding pole pitch range central angles of the permanent magnet 300 and the ferromagnetic pole 400 on the rotor part are both 60 degrees. Of course, in other embodiments, the corresponding pole pitch range angles of the permanent magnet 300 and the ferromagnetic pole 400 on the rotor part may also be different, and can be adjusted according to actual needs as long as it does not affect the operation of the motor.

[0071] like Figure 1As shown, the ferromagnetic pole 400 is arranged on the surface of the rotor core 500, and the ferromagnetic pole 400 and the rotor core 500 are separated by a dotted line, indicating that the ferromagnetic pole 400 can be formed integrally with the rotor core 500, or can be separately formed. When the ferromagnetic pole 400 and the rotor core 500 are formed integrally, the materials used by the two can be the same. In this case, the permanent magnet 300 can be directly arranged on the surface of the rotor core 500 at intervals, which is more convenient and simple in processing and manufacturing. At the same time, when the ferromagnetic pole 400 and the rotor core 500 are formed integrally, the rotor part is provided with a limiting groove between adjacent ferromagnetic poles 400, and the permanent magnet 300 can be directly arranged in the limiting groove. On the one hand, a smooth transition can be made between the adjacent permanent magnets 300 and the ferromagnetic poles 400; on the other hand, the permanent magnet 300 can be made more stable relative to the entire rotor part.

[0072] This embodiment also provides an electric device including a single-phase permanent magnet motor. The single-phase permanent magnet motor pole adopts the single-phase permanent magnet motor as described above, which can effectively avoid the problem that the single-phase permanent magnet motor in the electric device cannot start automatically.

[0073] Example 2

[0074] This embodiment also provides a single-phase permanent magnet motor and an electric device including the same. The single-phase permanent magnet motor is basically similar to the single-phase permanent magnet motor in Embodiment 1 in structure and principle.

[0075] The difference is that, Figure 4 and Figure 5 As shown, in this embodiment, the surface of each ferromagnetic pole 400 is a smooth curved surface, and the distance dimension from the smooth curved surface to the central axis of the rotor part gradually changes along the circumferential direction of the rotor part. Through this arrangement, the surface of the ferromagnetic pole 400 can be smoothly transitioned along the circumferential direction of the rotor part, and the radial thickness dimension of the corresponding air gap 410 can also be smoothly increased or decreased along the circumferential direction of the rotor part, so that the operation of the motor is smoother. Specifically, the distance from the outer surface of the permanent magnet 300 to the annular surface 230 is δ, the minimum distance and the maximum distance from the outer surface of the ferromagnetic pole 400 to the annular surface 230 are δ1 and δ2 respectively, the inner diameter of the annular surface 230 is 27.5 mm, the values ​​of δ, δ1 and δ2 are 0.6 mm, 0.6 mm and 1.66 mm respectively, then the corresponding distance from the outer surface of the permanent magnet 300 to the central axis of the rotor part is 26.9 mm, then the corresponding maximum distance and the minimum distance from the outer surface of the permanent magnet 300 to the central axis of the rotor part are 26.9 mm and 25.84 mm respectively.

[0076] Example 3

[0077] This embodiment also provides a single-phase permanent magnet motor and an electric device including the same. The single-phase permanent magnet motor is basically similar to the single-phase permanent magnet motors in Embodiments 1 and 2 in structure and principle.

[0078] The difference is that, Figure 6 As shown, the rotor part of the unidirectional permanent magnet motor includes a permanent magnet 300, a ferromagnetic pole 400 and a rotor core 500, wherein the ferromagnetic pole 400 and the rotor core 500 are integrally formed. There are six permanent magnets 300, and the six permanent magnets 300 are arranged in pairs on the surface of the rotor core 500. Three pairs of permanent magnets 300 are in a V-shaped structure on the surface of the rotor core 500. One pair of permanent magnets 300 corresponds to one magnetic pole on the rotor part, that is, the number of magnetic poles corresponding to the six permanent magnets 300 on the rotor part is still three, and correspondingly, the number of magnetic poles corresponding to the ferromagnetic pole 400 on the rotor part is also three, and the number of teeth 200 in the stator part is six, and the magnetic poles corresponding to the permanent magnets 300 and the ferromagnetic pole 400 on the rotor part are also alternately arranged along the circumferential direction of the rotor part.

[0079] Through this arrangement, a pair of permanent magnets 300 are used as a whole, and when the geometric axis 310 of the whole is aligned with the central axis 211 of the corresponding tooth portion 200, the air gap 410 formed between the surface of the ferromagnetic pole 400 and the corresponding tooth portion 200 is set to: the air gap 410 is set asymmetrically with the central axis 211 of the corresponding tooth portion 200. Similarly, the magnetic field axis of the permanent magnet 300 can be deviated from the central axis 211 of the corresponding tooth portion 200 by a certain angle, and the cogging torque on the rotor portion is not zero. Under the action of the cogging torque, the rotor portion will rotate a certain angle until it stops, and the corresponding cogging torque is zero and the back electromotive force is not zero in the stationary state. When the winding passes current, the electromagnetic torque formed by the current and the back electromotive force and the torque synthesized by the cogging torque is a positive value, so that the motor has the ability to start by itself. In addition, in this embodiment, three pairs of permanent magnets 300 are arranged in a V-shaped structure on the surface of the rotor core 500. This structure has a magnetic concentration effect, which can make the no-load back electromotive force of the motor larger. Then, at the dead point of the motor, when current is passed through the winding, the electromagnetic torque is larger, that is, the output torque of the motor is larger, which can further improve the self-starting ability of the motor.

[0080] Example 4

[0081] This embodiment also provides a single-phase permanent magnet motor and an electric device including the same. The single-phase permanent magnet motor is basically similar to the single-phase permanent magnet motor in Embodiment 3 in structure and principle.

[0082] The difference is that, Figure 7As shown, in this embodiment, the structure of the permanent magnet 300 on the surface of the rotor core 500 is similar to an arch bridge shape, that is, the permanent magnet 300 is closest to the tooth portion 200 at the position of its geometric axis 310, and the permanent magnet 300 is farthest from the tooth portion 200 at both ends of the permanent magnet 300 in the circumferential direction of the rotor portion, but the permanent magnet 300 is still symmetrically arranged about its geometric axis 310. This arrangement improves the air gap magnetic field distribution by changing the shape of the permanent magnet 300, so that the air gap magnetic field is close to the required shape, thereby reducing the magnetic field harmonics.

[0083] Example 5

[0084] This embodiment also provides a single-phase permanent magnet motor and an electric device including the same. The single-phase permanent magnet motor is basically similar to the single-phase permanent magnet motors in Embodiments 1 and 2 in structure and principle.

[0085] The difference is that, Figure 8 As shown, the rotor part of the unidirectional permanent magnet motor includes a permanent magnet 300, a ferromagnetic pole 400 and a rotor core 500, wherein the ferromagnetic pole 400 and the rotor core 500 are integrally formed. The number of permanent magnets 300 is three, and in the circumferential direction of the rotor part, the permanent magnets 300 and the ferromagnetic poles 400 are alternately arranged in sequence, and the magnetic poles corresponding to the permanent magnets 300 and the ferromagnetic poles 400 on the rotor part are also alternately arranged in sequence. However, in this embodiment, the pole pitch range angles corresponding to the adjacent permanent magnets 300 and the ferromagnetic poles 400 on the rotor part are different, and the pole pitch range angle corresponding to each permanent magnet 300 is 80 degrees, and the pole pitch range angle corresponding to each ferromagnetic pole 400 is 40 degrees. In addition, the larger the pole pitch range angle corresponding to the permanent magnet 300, the greater the no-load back electromotive force of the motor, and then at the dead point position of the motor, after the winding is connected to the current, the electromagnetic torque is greater, that is, the output torque of the motor is greater, so that the self-starting ability of the motor can be further improved.

[0086] Example 6

[0087] This embodiment also provides a single-phase permanent magnet motor and an electric device including the same. The single-phase permanent magnet motor is basically similar to the single-phase permanent magnet motors in Embodiments 1 and 2 in structure and principle.

[0088] The difference is that in this embodiment, the rotor part is arranged around the periphery of the stator part, that is, the single-phase permanent magnet motor is an outer rotor structure, and the annular surface formed by the tooth tips of the six teeth of the stator part is an outer annular surface, and the permanent magnets and ferromagnetic poles are both inward along the radial direction of the rotor part toward the corresponding teeth.

[0089] At this time, the distance from the surface of the ferromagnetic pole to the central axis of the rotor part gradually increases along the circumferential rotation direction of the rotor part, that is, the air gap formed by the surface of the ferromagnetic pole and the corresponding tooth part also gradually increases along the circumferential rotation direction of the rotor part, which is also beneficial to the starting rotation of the motor.

[0090] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A single-phase permanent magnet motor, comprising a stator portion and a rotor portion, wherein the stator portion comprises a plurality of teeth, characterized in that: The rotor part is provided with permanent magnets and ferromagnetic poles, the number of magnetic poles corresponding to the permanent magnets and the ferromagnetic poles on the rotor part is the same, and the number of the teeth is twice the number of magnetic poles corresponding to the permanent magnets on the rotor part, and the magnetic poles corresponding to the permanent magnets and the ferromagnetic poles on the rotor part are alternately arranged in sequence along the circumferential direction of the rotor part; When the geometric axis of the permanent magnet is aligned with the central axis of the corresponding tooth portion, the air gap formed between the surface of the ferromagnetic pole and the corresponding tooth portion is configured such that the air gap is asymmetrically configured with respect to the central axis of the corresponding tooth portion.

2. The single-phase permanent magnet motor according to claim 1, characterized in that: The gap formed between the surface of the permanent magnet and the corresponding tooth portion is symmetrically arranged with respect to the central axis of the corresponding tooth portion.

3. The single-phase permanent magnet motor according to claim 1, characterized in that: The radial thickness dimension of the air gap is arranged to continuously change along the circumferential direction of the rotor part.

4. The single-phase permanent magnet motor according to claim 3, characterized in that: A plurality of the teeth are arranged to form a circular curved surface, and the central axis of the circular curved surface coincides with the central axis of the rotor portion; The distance from the surface of the ferromagnetic pole to the central axis of the rotor part gradually changes along the circumferential direction of the rotor part.

5. The single-phase permanent magnet motor according to claim 4, characterized in that: The stator part is arranged around the outer periphery of the rotor part, and the distance between the surface of the ferromagnetic pole and the central axis of the rotor part gradually decreases along the circumferential rotation direction of the rotor part.

6. The single-phase permanent magnet motor according to claim 4, characterized in that: The rotor part is arranged around the periphery of the stator part, and the distance between the surface of the ferromagnetic pole and the central axis of the rotor part gradually increases along the circumferential rotation direction of the rotor part.

7. The single-phase permanent magnet motor according to claim 4, characterized in that: The surface of the ferromagnetic pole is a smooth curved surface, and the distance from the smooth curved surface to the central axis of the rotor part gradually changes along the circumferential direction of the rotor part.

8. The single-phase permanent magnet motor according to claim 4, characterized in that: The surface of the ferromagnetic pole is a stepped curved surface, which is composed of multiple segments of curved surfaces. The distance between each segment of the curved surface and the central axis of the rotor part is the same, and the distance between the multiple segments of the curved surface and the central axis of the rotor part gradually changes along the circumferential direction of the rotor part.

9. The single-phase permanent magnet motor according to any one of claims 4 to 8, characterized in that: The distances from the surface of the permanent magnet to the central axis of the rotor part are the same, and the distance from the surface of the permanent magnet to the central axis of the rotor part is the same as the maximum distance from the surface of the ferromagnetic pole to the central axis of the rotor part.

10. The single-phase permanent magnet motor according to any one of claims 1 to 8, characterized in that: The ferromagnetic poles and the rotor part are integrally formed.

11. The single-phase permanent magnet motor according to claim 10, characterized in that: The rotor part is provided with a limiting groove between adjacent ferromagnetic poles, and the permanent magnet is cooperatively arranged in the limiting groove.

12. An electric device, characterized in that: The electric device includes a single-phase permanent magnet motor as described in any one of claims 1-11.

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