KR20160131945A - Single-phase outer-rotor motor and rotor thereof - Google Patents

Abstract

A single-phase outer-rotor motor comprises: a stator; and a rotor surrounding the stator. The stator includes: a stator core; and windings wound around the stator core. The stator core includes: a yoke; and a plurality of teeth. Each of the teeth includes a tooth tip and a distal end. A slot opening is formed between two adjacent tooth tips. The rotor includes: a housing; and a permanent magnet fixed to the inside of the housing. The permanent magnet forms a closed ring in the circumferential direction. The permanent magnet forms a plurality of magnetic poles in the circumferential direction. A symmetrical uneven gap is defined between the outer surface of the stator and the inner surface of the permanent magnet. The circumferential width of the slot opening is five times less than or equal to the minimum width of the gap. The single-phase outer-rotor motor according to the present invention can efficiently avoid the dead point position of the rotor.

Description

[0001] SINGLE-PHASE OUTER-ROTOR MOTOR AND ROTOR THEREOF [0002]

The present invention relates to a single-phase motor, and more particularly to a single-phase external rotor motor.

Single phase motors are commonly used in small household appliances such as washing machines, dishwashers, refrigerators, air conditioners, and the like. In terms of the relative positions of the stator and rotor, the single-phase motors are classified as internal rotor motors and external rotor motors. As the term implies, in a single phase outer rotor motor, the stator is disposed internally, the rotor surrounds the stator, and the load can be embedded directly in the rotor. For single-phase external rotor motors, there is a need to reduce the cogging torque of the motor and to avoid dead spots when the rotor is stopped.

Therefore, there is a need for an external rotor motor and its rotor that can effectively avoid the dead point position of the rotor.

SUMMARY OF THE INVENTION In one aspect, And a permanent magnet attached to the inside of the housing. The permanent magnet is a circumferential closed ring and includes a plurality of sections along the circumferential direction. Each section forms a stimulus. The adjacent sections of the permanent magnets have different polarities. Each of the sections of the permanent magnets has a symmetrical structure, and the distance between the inner surface of each section of the permanent magnet and the central axis of the rotor gradually changes from two circumferential side surfaces of the inner surface toward the center.

Preferably, the distance between the inner surface of each section of the permanent magnet and the central axis of the rotor gradually decreases from the two circumferential side surfaces of the inner wall surface toward the center.

Preferably, the inner surface of each section of the permanent magnet is a flat surface.

Preferably, the inner surface of the permanent magnet collectively forms a regular polygon.

In another aspect, the present invention provides a single-phase external rotor motor comprising a stator and a rotor. The stator includes a stator core and windings wound around the stator core. The stator core includes a yoke and a plurality of teeth extending outwardly from an outer edge of the yoke, each tooth comprising a tooth body connected to the yoke and a tooth tip formed at a distal end of the tooth body. The rotor comprising: a housing; And at least one permanent magnet attached to the interior of the housing to form a plurality of magnetic poles. The inner surface of the magnetic pole of the rotor and the outer surface of the tooth tip of the stator define a non-uniform gap therebetween. When the motor is not energized, the rotor may be placed in an initial position by a leakage magnetic field generated by at least one permanent magnet operating with a tooth tip of the stator core.

Preferably, a slot opening is formed between each two adjacent tooth tips, and the circumferential width of the slot opening is less than or equal to five times the minimum gap between the stator and the rotor.

Preferably, the circumferential width of the slot opening is less than or equal to three times the minimum gap between the stator and the rotor.

Advantageously, said tooth tip has a width greater than that of said tooth body. Two circumferential sides of the tooth tip extend beyond the tooth body to form two wings, respectively. The adjacent wing portion of each of the two adjacent tooth tips defines one of the slot openings. At least one of the two wing portions adjacent to each slot opening is tilted out before the winding is wound and the tilted wing is deformed to bend inward after the winding is wound.

Preferably, the tilted wing portion is formed with a cutting groove, and after the winding is wound, the tilted wing portion is deformed to bend inward to reduce or remove the cutting groove.

In another aspect, the present invention provides a single-phase external rotor motor comprising a stator and a rotor surrounding the stator. The stator includes a stator core and windings wound around the stator core. The stator core includes a yoke and a plurality of teeth extending integrally and radially outwardly from an outer edge of the yoke. Each tooth forms a tooth tip at its distal end. A slot opening is formed between each two adjacent tooth tips. The rotor includes a housing and a permanent magnet attached to the interior of the housing. The permanent magnets form a closed ring in the circumferential direction. The permanent magnets form a plurality of magnetic poles along the circumferential direction. A symmetric non-uniform gap is defined between the outer surface of the stator and the inner surface of the permanent magnet. The circumferential width of the slot opening is less than or equal to 5 times the minimum width of the gap.

Preferably, the outer surface of the tooth tip of the stator is located on a common cylindrical surface, and the inner surface of the permanent magnet of the rotor forms a regular polygon.

Preferably, the circumferential width of the slot opening is less than or equal to three times the minimum width of the gap.

Preferably, the ratio of the maximum width to the minimum width of the gap is greater than two.

In another aspect, the present invention provides an electric device including a single-phase motor. The motor includes a stator and a rotor surrounding the stator. The rotor comprising: a housing; And a ring permanent magnet attached to the inside of the housing. Wherein the ring permanent magnet comprises a plurality of sections along a circumferential direction, each section forming a permanent pole, the adjacent sections of the permanent magnet having different polarities, each section of the permanent magnet having a symmetrical structure . The distance between the inner surface of each section of the permanent magnet and the central axis of the rotor gradually increases from the center toward the two circumferential sides of the inner surface.

A non-uniform gap is defined between the outer surface of the tooth tip of the stator of the motor and the inner surface of the magnetic pole of the rotor, as compared to the prior art outer rotor motor, which prevents the rotor from stopping at the dead point, Ensuring a successful start of the rotor when supplied with energy. In addition, the circumferential width of the slot opening is less than or equal to five times the minimum width of the gap, which can effectively reduce the cogging torque.

1 shows a stator of an external rotor motor according to an embodiment of the present invention.
Fig. 2 is a top view of Fig. 1; Fig.
Figure 3 shows the stator core of the stator of Figure 1;
Fig. 4 is a top view of Fig. 3; Fig.
Fig. 5 shows the state before the formation of the stator core of Fig.
Fig. 6 is a top view of Fig. 5. Fig.
7 shows the stator core of the stator according to the second embodiment.
Fig. 8 shows the state before the formation of the stator core of Fig.
9 shows the stator core of the stator according to the third embodiment.
Fig. 10 shows the state before the formation of the stator core of Fig.
11 shows the stator core of the stator according to the fourth embodiment.
Fig. 12 shows the state before the formation of the stator core of Fig.
13 shows the stator core of the stator according to the fifth embodiment.
Fig. 14 shows the state before the formation of the stator core of Fig.
Fig. 15 shows a stator core of the stator according to the sixth embodiment.
16 shows the stator core of the stator according to the seventh embodiment.
17 shows the stator core of the stator according to the eighth embodiment.
18 shows the stator core of the stator according to the ninth embodiment.
19 shows a rotor of an external rotor motor according to an embodiment of the present invention.
Fig. 20 shows a rotor according to the second embodiment.
Fig. 21 shows the rotor according to the third embodiment.
Fig. 22 shows a rotor according to the fourth embodiment.
Fig. 23 shows a rotor according to a fifth embodiment.
Fig. 24 shows the motor formed by the stator of Figs. 1 to 4 and the rotor of Fig. 18;
Fig. 25 is an enlarged view of box X of Fig. 24 with the magnetic lines removed for clarity.
Fig. 26 shows the positional relationship when the motor of Fig. 24 is at the dead point position.
Fig. 27 shows a motor formed by the stator of Figs. 1 to 4 and the rotor of Fig.
Figure 28 shows the motor formed by the stator of Figures 9 and 10 and the rotor of Figure 20;
Fig. 29 shows a motor formed by the stator of Figs. 9 and 10 and the rotor of Fig. 23. Fig.
Figure 30 shows a motor formed by the stator of Figure 18 and the rotor of Figure 19;
Fig. 31 shows a motor formed by the stator of Fig. 17 and the rotor of Fig. 18;
Fig. 32 shows the motor 1 of the present invention employed in the electric device.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the technical solution and results of the present invention, a preferred embodiment of the invention will be described with reference to the accompanying drawings.

A single phase outer rotor motor includes a stator and a rotor surrounding the stator. The stator and rotor can have a variety of different configurations, and different stator and rotor can be combined to be motors having different characteristics. Figs. 1 to 16 show various embodiments of the stator, Figs. 17 to 21 show various embodiments of the rotor, Figs. 22 to 28 show several motors formed by the stator and rotor, Are illustrated by way of example. The drawings are to be understood as merely for purposes of illustration and description. The stator and rotor of the present invention are not intended to be limited to the embodiment shown in the drawings, and the motor formed by the stator and rotor is also not intended to be limited to the embodiment as shown.

1 to 4 show the stator 10 according to the first embodiment. In this embodiment, the stator 10 includes a stator core 12, an insulation bracket 14 surrounding the stator core 12, and windings 16 wound around the insulation bracket 14. [

The stator core 12 is fabricated by laminating self-conducting materials such as silicon steel sheets. The stator core 12 includes an annular yoke 18 and a plurality of teeth 20 extending integrally and radially outwardly from the outer edge of the yoke 18. [ The teeth 20 are uniformly arranged along the circumferential direction of the yoke 18. [ Each tooth 20 includes a tooth body 22 connected to the yoke 18 and a tooth tip 24 formed at the distal end of the tooth body 22. The tooth body 22 extends along a straight line. Preferably, the tooth body 22 extends along the radial direction of the annular yoke 18. A winding slot 26 is formed between each two adjacent tooth bodies 22. The winding slot 26 is generally a sector shape with a gradually increasing width from the yoke 18 in the radially outward direction. The tooth tip 24 is generally arc-shaped, generally extending along its circumferential direction, and generally symmetrical with respect to the tooth main body 22. Preferably, each tooth tip 24 is symmetrical about the radius of the motor passing through the center of the tooth body 22 of tooth 20. In the circumferential direction, the tooth tip 24 has a width greater than the width of the tooth body 22 and the two circumferential sides of the tooth tip 24 extend beyond the tooth body 22, Thereby forming the wing portion 28. In this embodiment, a narrow slot opening 30 is formed between the wing portions 28 of the adjacent tooth tip 24.

Each tooth tip 24 includes an inner surface 32 facing the tooth body 22 and an outer surface 34 facing the rotor 50. Preferably, the outer surface 34 is an arc surface. The outer surface 34 of the tooth tip 24 functions as the outer surface of the stator 10 and is generally located on the same cylindrical surface and is coaxial with the yoke 18 of the stator 10. A cutting groove 36 is formed in the inner surface 32 of the tooth tip 24. In this embodiment, there are two cutting grooves 36 disposed symmetrically to two wing portions 28 proximate and separate from the tooth body 22. Each cutting groove 36 extends in the radial direction, i. E., Along the thickness direction of the tooth tip 24, to the inner surface 32 of the tooth tip 24. The cutting groove 36 generally has a depth that is half the thickness of the tooth tip 24 in the cutting groove 36 so that the cutting groove 36 does not significantly affect the magnetic path.

The winding 16 is wound around the tooth body 22 and positioned on the inner side of the tooth tip 24. The winding 16, the tooth body 22, and the inner surface 32 of the tooth tip 24 are separated by an insulating bracket 14. The insulating bracket 14 is generally made of a plastic material to prevent a short circuit of the winding 16. 5 and 6, a portion of the tooth tip 24 outside of the cutting groove 36 is tilted outwardly prior to winding around the stator core 12, So that the winding 16 can be easily wound around the tooth main body 22. After the winding is completed, the outer surface 34 of the tooth tip 24 is pushed inward and the tooth tip 24 is deformed to bend toward the tooth body 22 to form the arc outer surface 34. During this process the distance between the tooth tips 24 is reduced to narrow the slot opening 30 to form a narrow slot opening 30 and the cutting groove 36 to be narrowed or even slit shaped. Preferably, the angle between the portion of the tooth tip 24 outside the cutting groove 36 before deformation and the portion after deformation, that is, the deformation angle is in the range of 15 to 60 degrees. More preferably, the deformation angle of the portion of the tooth tip 24 outside the cutting groove 36 is in the range of 20 to 45 degrees.

In the stator of the same size, the tooth tip 24 of the stator core 12 of the stator 10 is tilted outwardly prior to winding of the winding to facilitate winding of the winding. After the winding process is completed, the tooth tip 24 is deformed to bend inward. Compared to prior art stator core structures formed by laminating silicon steel sheets formed by single step punching, the tooth tips 24 have a greater width in the circumferential direction, and the slots 24 between the tooth tips 24 The width of the opening 30 is significantly and preferably reduced to half or even less than the width of the slot opening 30 of the prior art stator core structure, effectively reducing the cogging torque. The cutting groove 36 is formed to facilitate the internal bending deformation of the tooth tip 24 but in some embodiments the cutting groove 36 may be formed when the material itself of the tooth tip 24 has a certain degree of deformation capability. Can be omitted.

7 shows the stator core 12 of the stator 10 according to the second embodiment because each tooth tip 24 of the present embodiment has a cutting groove 36 of the stator core. As an example of the orientation shown in the figures, each cutting groove 36 is formed in the wing portion 28 on the counter clockwise side of the corresponding tooth body 22. As shown in FIG. 8, prior to forming the stator core 12, only the wing portion 28 of the tooth tip 24 on the counterclockwise side of the tooth body 22 is tilted outwardly. Since each wing portion 28 on the same side of the tooth tip 24 is tilted outwardly, each tilted wing portion 28 and wing portion 28 of the untilted adjacent tooth tip 24 are offset from each other in the circumferential direction So that the adjacent wing portions 28 can still form a large distance therebetween to facilitate winding. After the winding process is completed, the tilted wing portion 28 bends inward, which reduces the distance between adjacent wing portions 28 to form a narrow slot opening 30, thereby reducing the cogging torque.

9 shows the stator core 12 of the stator 10 according to the third embodiment. The stator core 12 of the third embodiment is formed such that the cutting groove 36 is formed in the connecting region of the wing portion 28 and the tooth body 22 and only one of the two wing portions 28 Is tilted to the outside before winding as shown in Fig. Thus, the cutting groove 36 can have a large depth, the tooth tip 24 can have a larger tilting angle, and the tooth tip 24 can have a large distance therebetween prior to the formation of the stator core So that winding can be performed more easily. It should also be appreciated that the connecting region of the wing portion 28 and the tooth body 22 can form the cutting groove 36 and the two wing portions 28 are tilted out before they are wound.

11-14 illustrate the stator core 12 of the stator 10 according to two other embodiments in that some of the tooth tips 24 form the cutting grooves 36 and the other part is the cutting groove 36 are not formed. The tooth tips 24 having the cutting grooves are alternately aligned with the tooth groove tips 24 without cutting grooves. Preferably, the cutting grooves 36 of the tooth tips 24 having the cutting grooves 36 are each formed in the two wing portions 28. Prior to the formation of the stator core, both wing portions 28 are tilted outwardly, which creates a greater distance for adjacent tooth tips without cutting grooves 36, thereby facilitating winding. The cutting grooves 36 may be formed in the connecting region of the wing portion 28 and the tooth body 22, as shown in Figs. 11 and 12, respectively. Alternatively, the cutting groove 36 may be formed spaced apart from the tooth body 22 in the middle of the wing portion 28 as shown in Figs. 13 and 14.

In the above-described embodiment, the wing portion 28 of the tooth tip 24 of the stator core 12 is tilted outwardly before winding, and is deformed to bend inward after winding. Thus, winding of the winding 16 is facilitated, and after the final formation of the stator core, the tooth tip has a large circumferential width to form a small slot opening 30, thus reducing the cogging torque. One or both of the two wings of each tooth tip 24 of the same stator core 12 can be tilted outward as long as one of the wing portions 28 is tilted outwardly on the opposite side of each slot opening 30. [ Or both wings may not be tilted to the outside. The above-mentioned object can be achieved by combining the tilted wing and the un-tilted winding in various suitable patterns, which is not limited to the embodiment shown in the drawings. In the various embodiments shown, the tooth tips 24 of the stator core 12 are discontinuous along the circumferential direction, which forms a narrow slot opening 30 therebetween. In some other embodiments, the tooth tips 24 may be connected to one another along the circumferential direction, thereby minimizing cogging torque.

15 and 16 show the stator core 12 of the stator 10 according to two other embodiments. In these two embodiments, a magnetic bridge 38 is formed between adjacent tooth tips 24. The magnetic bridge 38 is integrally connected to the tooth tip 24 to form a collectively closed annular edge. Preferably, the closed annular edge has a minimum radial thickness at the location of the magnetic bridge 38. More preferably, at least one axial extending groove 40 is formed in the inner surface of the magnetic bridge 38. [ As shown, each magnetic bridge 38 forms a plurality of grooves 40 uniformly disposed along the circumferential direction. To allow wrapping to be performed, the tooth tips can be separated from the tooth body 22 (shown in FIG. 15) in the area of connection between them. Thus, after the winding process is completed, the annular edge formed collectively by the tooth tip 24 is again connected around the tooth body 22 along the axial direction to form the stator core 12. [ 16, the tooth body 22 is separated from the yoke 18 at the connection area therebetween and the yoke 18 is assembled in the tooth body 22 after the winding is done Thereby forming the stator core 12.

17 and 18 show the stator core 12 according to two other embodiments. The structure of the stator core 12 of these two embodiments is generally the same as the embodiment of Figures 15 and 16 respectively except that the circumferential outer surface 34 of the tooth tip 24 is disposed in the wing portion 28, 24 so that the tooth tip 24 is asymmetric about the radius of the motor passing through the center of the tooth body 22 of tooth 20.

Figures 19-23 illustrate a rotor 50 in accordance with various embodiments of the present invention. The rotor 50 is an outer rotor that includes a housing 52 and one or more permanent magnets 54 attached to the interior of the housing 52. The circumferential outer surface of the permanent magnet 54 is attached to the housing 52, which can be integrally connected and positioned using an adhesive or by insert molding. The inner surface (56) of the permanent magnet (54) defines a space for mounting the stator (10) therein. The space is slightly larger in magnitude than the stator 10, so that the stator 10 and the rotor 50 define a gap therebetween.

19 shows the rotor 50 according to the first embodiment. In this embodiment, the permanent magnet 54 includes a plurality of spirit magnets uniformly disposed along the circumferential direction of the housing 52, and a gap is formed between each two adjacent permanent magnets 54. Each of the permanent magnets 54 serves as one permanent magnet of the rotor 50, and the adjacent permanent magnets 54 have opposite polarities. In this embodiment, each of the permanent magnets 54 is part of a circular ring, and the inner surface 56 of the permanent magnet 54 facing the stator 10 is an arc surface. The inner surface 56 of the entire permanent magnet 54 forms the inner surface of the rotor 50, which is located on the same cylindrical surface coaxial with the rotor 50. The radial direction between the outer surface of the tooth tip 24 of the stator 10 and the inner surface 56 of the permanent magnet 54 of the rotor 50 when any one of the stator described above is mounted in the rotor 50 The distance is constant along the circumferential direction, so that the stator and rotor (10, 50) define a substantially uniform gap therebetween.

Preferably, the ratio of the pole-arc coefficient of each permanent magnet 54, that is, the ratio of the span angle? Of the permanent magnet 54 to the 360-degree divided by the number N of rotor poles, N is greater than 0.7, which can improve the torque characteristics of the motor and enhance motor efficiency. The number of permanent magnets 54 is the same as the number of teeth 20 in the various embodiments of the stator 10 and the rotor 50 of the motor, Are the same. As shown, there are eight permanent magnets 54 and eight tees 20, and eight magnets 54 form eight poles of the rotor 50, To define eight winding slots 26 to form an eight-pole eight slot motor in cooperation. In another embodiment, the number of teeth 20 of the stator 10 may have a multiple relationship with the number of permanent magnets 54 of the rotor 50. For example, the number of teeth 20 is two or three times the number of permanent magnetic poles 54. Preferably, the windings 16 of the stator 10 are electrically connected and single-phase DC brushless DC motor drivers supply single-phase DC electricity to form a single-phase DC brushless motor. In another embodiment, the design of the present invention is equally applicable to single phase permanent magnet synchronous motors.

20 to 23 illustrate a rotor 50 according to several different embodiments. In this embodiment, the circumferential inner surface 56 of the magnet 54 is not a cylindrical arc surface. After the stator 10 is mounted, the stator 10 and the rotor 50 define a non-uniform gap therebetween do. These embodiments are described in detail below.

20 shows the rotor 50 according to the second embodiment. In the second embodiment, the permanent magnets 54 are symmetrical with respect to the middle line extending along the thickness direction of the magnets 54. The permanent magnet 54 has a gradually decreasing thickness from the circumferential center of the permanent magnet 54 to two circumferential sides. The inner surface 56 of each permanent magnet 54 facing the stator 10 is a flat surface extending in parallel with the tangential direction of the radially outer surface of the stator. Each permanent magnet 54 forms a permanent magnetic pole. In the radial cross section as shown in Fig. 20, the inner surfaces of the permanent magnets 54 are each positioned on the side of the regular polygon. Therefore, the gap formed between the permanent magnet 54 and the stator 10 is a symmetric nonuniform gap. The size of the gap has a minimum value at a position corresponding to the center of the circumference of the permanent magnet 54 and gradually increases from the position of the minimum value toward the two circumferential sides of the permanent magnet 54. [ The provision of a symmetrical non-uniform gap facilitates positioning of the rotor 50 at a position deviating from the dead point position when the motor is powered off, so that the rotor 50 is capable of successfully Can be started.

Fig. 21 shows the rotor 50 according to the third embodiment, which is different from the embodiment of Fig. 20 mainly in that the permanent magnet 54 is a circumferentially closed ring-shaped integral structure. The ring-shaped permanent magnet 54 includes a plurality of sections in the circumferential direction. Each section functions as one pole of the rotor 50, and adjacent sections have different polarities. Similar to each permanent magnet 54 of the rotor 50 of FIG. 20, each section of the permanent magnet 54 has a gradually decreasing thickness from the circumferential center to two circumferential sides. The inner surface 56 of each section facing the stator 10 is a flat surface. 21, the entire section of the permanent magnet 54 cooperates to form a regular polygonal inner surface of the rotor 50. As shown in Fig. 20, the gap formed between each magnetic pole of the permanent magnet 54 and the outer surface of the stator 10 is a symmetric non-uniform gap.

22 shows a rotor 50 according to a fourth embodiment, which is similar to the embodiment of Fig. 20, in which the rotor 50 comprises a plurality of permanent magnets 54 arranged circumferentially spaced apart And each permanent magnet 54 has a flat circumferential inner surface 56. The permanent magnets 54 are asymmetrical in structure, gradually increasing from one circumferential side toward the other circumferential side, and gradually decreasing from a position adjacent to the other circumferential side. The permanent magnets 54 have a maximum thickness at a position deviating from the center of the circumference of the permanent magnet 54, and the two circumferential sides of the permanent magnet 54 have different thicknesses. The connecting line between the two end sides of the inner surface 56 of the permanent magnet 54 and the center of the rotor 50 forms a non-isosceles triangle. Therefore, after assembly with the stator 10, the stator 10 and the rotor 50 define a non-uniform asymmetry gap therebetween. The provision of an asymmetric non-uniform gap facilitates positioning the rotor 50 in a position deviating from the dead point position when the motor is powered off, so that the rotor 50 is started successfully when the motor is energized .

Fig. 23 shows the rotor 50 according to the fifth embodiment. In this embodiment, the rotor 50 includes a housing 52 and a plurality of permanent magnets 54 and a magnetic body 58 attached to the inner surface of the housing 52. The magnetic body 58 may be made of a hard magnetic material such as a ferromagnetic or rare earth magnet or a soft magnetic material such as iron. The permanent magnets 54 and the magnetic bodies 58 are arranged in a circumferentially alternating spacing manner so that one magnetic body 58 is inserted between each two adjacent permanent magnets 54. [ In this embodiment, the permanent magnets 54 are generally columnar with a square cross-section. Each of the two adjacent permanent magnets 54 defines a large space therebetween having a circumferential width that is much larger than the permanent magnets 54. Thus, the magnetic body 58 has a circumferential width larger than that of the permanent magnet 54, and the width can be several times the width of the permanent magnet 54. [

The magnetic body 58 is symmetrical with respect to the radius of the rotor passing through the center of the magnetic body 58. The magnetic body 58 has a gradually decreasing thickness to two circumferential sides at the center / center of the circumference. The minimum thickness of the magnetic substance 58, that is, the thickness at the circumferential side surface, is substantially the same as that of the permanent magnet 54. [ The circumferential inner surface 60 of the magnetic body 58 facing the stator 10 is a flat surface extending parallel to the tangential direction of the outer surface of the stator 10. The circumferential inner surface 56 of the permanent magnet 54 and the circumferential inner surface 60 of the magnetic body 58 collectively form the inner surface of the rotor 50 which is a polygonal symmetric to the radiating end face of the rotor 50 . After the rotor 50 is assembled with the stator 10, the gap formed between the stator 10 and the rotor 50 is a symmetric uneven gap. Preferably, the permanent magnets 54 are magnetized along the circumferential direction, that is, the circumferential sides of the permanent magnets 54 are polarized to have corresponding polarities. The two adjacent permanent magnets 54 have opposite polarity directions. That is, the two adjacent faces of the two adjacent permanent magnets 54 facing each other have the same polarity. Thus, the magnetic body 58 between the two adjacent permanent magnets 54 is polarized with the corresponding magnetic polarity, and the two adjacent magnetic bodies 58 have different polarities.

A motor with different characteristics can be obtained from different combinations of stator 10 and rotor 50 described above, some of which are illustrated below.

Fig. 24 shows a motor formed by the stator 10 of the first embodiment shown in Figs. 1 to 4 and the rotor 50 shown in Fig. The tooth tips 24 of the stator 10 are circumferentially spaced apart to form a slot opening 30 and the outer surface 34 of the tooth tip 24 is located on the same cylindrical surface so that the entirety of the stator 10 The outer surface is circular. The permanent magnet 54 of the rotor 50 is circumferentially spaced apart and the inner surface 56 of the permanent magnet 54 facing the stator 10 is planar so that the entire inner surface of the rotor 50 is a regular polygon Shape. The outer surface 34 of the stator 10 and the inner surface 56 of the rotor 50 are spaced apart radially to form a gap 62. The gap 62 has a radial width that varies along the circumference of the permanent magnet 54, which is a symmetric non-uniform gap 62 that is symmetrical about the midline of the permanent magnet 54. The radial width of the gap 62 gradually increases from the circumferential center toward the two circumferential sides of the inner surface 56 of the permanent magnet 54. [

25, the radial distance between the circumferential center of the inner surface 56 of the permanent magnet 54 and the outer surface 34 of the tooth tip 24 is the minimum width Gmin of the gap 62, The radial distance between the circumferential side of the inner surface 56 of the tooth tip 24 and the outer surface 34 of the tooth tip 24 is the maximum width Gmax of the gap 62. Preferably, the ratio of the maximum width Gmax to the minimum width Gmin of the gap is greater than 1.5, that is, Gmax: Gmin> 1.5. More preferably, Gmax: Gmin> 2. Preferably, the width D of the slot opening 30 is not greater than five times the minimum width Gmin of the gap 62, i.e., D < = 5Gmin. Preferably the width D of the slot opening 30 is greater than or equal to the minimum width Gmin of the gap 62 but less than or equal to three times the minimum width Gmin of the gap 62, ? D? 3Gmin.

24 and 26, when the motor is not energized, the permanent magnets 54 of the rotor 50 generate attractive forces to attract the teeth 20 of the stator 10. 24 and 26 show the rotor 50 at different positions. Specifically, Fig. 26 shows the rotor 50 at the dead point position (i.e., the center of the magnetic pole of the rotor 50 is aligned with the center of the tooth tip 24 of the stator 10). Fig. 24 shows the rotor 50 at the initial position (i.e., the stop position of the rotor 50 when the motor is not energized or is powered off). 24 and 26, the magnetic flux of the magnetic field generated by the magnetic pole of the rotor 50 passing through the stator 10 when the rotor 50 is at the dead point position is? 1, and the rotor 50 is in the initial position, the magnetic flux of the magnetic field generated by the magnetic pole of the rotor 50 passing through the stator 10 is? 2. Since the path of? 2 is shorter than the path of? 1 and the magnetoresistance of? 2 is less than the magnetoresistance of? 1, the rotor 50 can be placed in the initial position when the motor is not energized , It is possible to prevent the rotor 50 from stopping at the dead point position shown in Fig. 24, thereby preventing the start failure of the rotor 50 when the motor is energized.

24, in the initial position, the midline of the tooth tip of the stator is closer to the midline of the neutral region between the two adjacent magnetic poles 54 than the midline of the two adjacent magnetic poles 54. Preferably, the midline of the tooth tip 24 of the tooth 20 of the stator 10 is aligned with the midline of the neutral region between the two adjacent permanent magnetic poles 54. This position is farthest away from the dead point position, which can effectively prevent rotor starting failure when the motor is energized. Due to other factors such as actual friction, the midline of the tooth tip 24 at the initial position is offset from the midline of the neutral region between the two adjacent permanent magnetic poles 54 by an angle of, for example, 0 to 30 degrees But the initial position is still far from the dead point position. In the above-described embodiment of the present invention, the rotor 50 has an initial position deviating from the dead point by a leakage magnetic field generated by the permanent magnet 54 of the rotor 50, which cooperates with the tooth tip 24 of the stator As shown in FIG. The leakage magnetic flux generated by the permanent magnet 54 does not pass through the tooth body 22 and the winding 16. The cogging torque of the thus configured single-phase permanent magnet brushless motor can be effectively suppressed, so that the motor can enhance efficiency and performance. The peak value of the cogging torque of the single-phase external rotor brushless direct-current motor is shown to be less than 80 mNm (the rated torque is 1 Nm, the rated rotational speed is 1000 rpm, and the stator core stack height is 30 mm).

Fig. 27 shows a motor formed by the stator 10 of the first embodiment shown in Figs. 1 to 4 and the rotor 50 of the third embodiment shown in Fig. The tooth tip 24 of the stator 10 is circumferentially spaced to form a slot opening 30 and the outer surface 34 of the tooth tip 24 is positioned on the same cylindrical surface. The permanent magnet 54 of the rotor 50 includes a plurality of sections circumferentially connected to each other and each section serves as one pole of the rotor 50 and the circumferential inner surface 56 of the pole is flat The inner surface of the entire rotor 50 is a regular polygonal shape. The stator 10 and the rotor 50 form a symmetrical non-uniform gap 62 therebetween, the width of the gap 62 gradually increasing from the two circumferential sides toward the circumferential center of each pole, (Gmax) at the center of the circumference of the stimulus and a minimum width (Gmin) at the side of the circumference. When the rotor 50 is stopped, the center of each tooth tip 24 aligns with the joining of the two corresponding sections of the permanent magnet 54, which avoids the dead point position, .

Fig. 28 shows a motor formed by the stator 10 of the third embodiment shown in Figs. 9 and 10 and the rotor 50 of the fourth embodiment shown in Fig. The tooth tip 24 of the stator 10 is circumferentially spaced to form a slot opening 30 and the circumferential outer surface 34 of the tooth tip 24 is positioned on the same cylindrical surface. The permanent magnet of the rotor 50 is an asymmetric structure having a non-uniform thickness along the circumferential direction. The circumferential inner surface 56 of the permanent magnet 54 of the rotor 50 is inclined at an angle with respect to the tangential direction of the circumferential outer surface 34 of the tooth tip 24 and the circumferential inner surface 56 of the permanent magnet 54 And the circumferential outer surface 34 of the tooth tip 24 define an asymmetric non-uniformity gap 62 therebetween. The width of the gap 62 gradually decreases from one circumferential side toward the other circumferential side of the permanent magnet 54, and then gradually increases. The gap 62 has a maximum width Gmax at the clockwise side of the permanent magnet 54 and the minimum width Gmin of the gap 62 is equal to half the width of the permanent magnet 54 It is adjacent to the clockwise side but deviates from it.

Fig. 29 shows a motor formed by the stator 10 of the third embodiment shown in Figs. 9 and 10 and the rotor 50 of the fifth embodiment shown in Fig. The tooth tip 24 of the stator 10 is circumferentially spaced to form a slot opening 30 and the outer surface 34 of the tooth tip 24 is positioned on the same cylindrical surface. The rotor 50 includes a permanent magnet 54 and a magnetic body 58 which are circumferentially spaced and arranged alternately. The inner surface 56 of the permanent magnet 54 and the outer surface 60 of the magnetic body 58 form a polygonal inner surface of the rotor 50 collectively. The stator 10 and the rotor 50 form a symmetrical non-uniform gap 62 therebetween which has a size gradually decreasing from the circumferential center to the two circumferential sides of the magnetic body 58, Reaches a maximum width Gmax at a position corresponding to the maximum width Gmax. The rotor 50 may be positioned in an initial position by a leakage flux circuit, each of which passes through a permanent magnet 54, two adjacent magnetic bodies 58 and a corresponding tooth tip 24. In the initial position, the center of the permanent magnet 54 is radially aligned with the tooth tip 24 such that the permanent magnet 54 exerts a circumferential force on the stator 10, Facilitates start-up.

Fig. 30 shows a motor formed by the stator 10 shown in Fig. 17 and the rotor 50 shown in Fig. The tooth tips 24 of the stator 10 are connected to each other in the circumferential direction and the entire outer surface of the stator 10, i.e., the outer surface 34 of the tooth tip 24, is a cylindrical surface. The inner surface of the rotor 50, that is, the circumferential inner surface 56 of the permanent magnet 54, is located on a cylindrical surface coaxial with the circumferential outer surface 34 of the stator 10. The circumferential outer surface 34 of the stator 10 and the circumferential inner surface 56 of the rotor 50 define a uniform gap 62. The circumferential outer surface 34 of the tooth tip 24 has a locating groove 42 that allows the tooth tip 24 to have an asymmetric structure so that when the rotor 50 is stationary, Ensures that the centerline of the area between adjacent permanent magnets 54 deflects at an angle to the centerline of the tooth tip 24 of tooth 20 of stator 10. Preferably, when the stator stops, the locating slots 42 of the stator 10 align with the centerlines of the two adjacent permanent magnets 54 of the rotor 50, Enabling the rotor 50 to start successfully. As can be appreciated, in this embodiment, the tooth tips 24 of the stator 10 can be separated from one another through narrow slot openings in the circumferential direction.

Fig. 31 shows a motor formed by the stator 10 of the sixth embodiment shown in Fig. 15 and the rotor 50 of the second embodiment shown in Fig. The tooth tips 24 of the stator 10 are connected to each other in the circumferential direction, and the entire outer surface of the stator 10 is a cylindrical surface. The circumferential inner surface 56 of the permanent magnet 54 of the rotor 50 is a flat surface extending parallel to the tangential direction of the outer surface of the stator 10. The circumferential inner surface 56 of the permanent magnet 54 and the circumferential outer surface 34 of the tooth tip 24 form a symmetrical nonuniform gap 62 therebetween. The width of the gap 62 gradually decreases from the circumferential center to the two circumferential sides of the permanent magnet 54 and decreases from the minimum width Gmin in the circumferential center of the permanent magnet 54 to the maximum width in the two circumferential sides Width Gmax.

32 shows the motor 1 of the present invention employed in the electric device 4 according to another embodiment. The electric device 4 may be a range hood, ventilation fan, or air conditioner including an impeller 3 driven by the rotor shaft 21 of the motor. The electric device 4 may also be a washer or dryer comprising a speed reducing device 3 driven by the rotor 50 of the motor.

The stator 10 of Figs. 1-11 generally has the same structure and features, and may form a narrow slot opening or even have no slot opening, which can be replaced to implement the same function when combined with the rotor 50 have. In addition, depending on the different gaps formed between the stator and the rotor, and depending on the symmetry and asymmetry of the stator and rotor structure, it is also possible to provide a suitable means for enabling the rotor 50 to start successfully when the motor is energized The circuit can be designed. It should be understood that the combination of the stator 10 and the rotor 50 is not limited to the embodiments described above. Various modifications that do not depart from the spirit of the present invention are within the scope of the present invention. The scope of the invention will, therefore, be determined with reference to the following claims.

Claims (19)

As a rotor for a single-phase external rotor motor:
housing; And
And a permanent magnet attached to the inside of the housing,
Wherein the permanent magnet is a circumferential closed ring comprising a plurality of sections along a circumferential direction, each section forming a magnetic pole, the adjacent sections of the permanent magnet having different polarities, each section of the permanent magnet And the distance between the inner surface of each section of the permanent magnet and the central axis of the rotor gradually changes from two circumferential side surfaces of the inner surface toward the center thereof, . The rotor according to claim 1, wherein the distance between the inner surface of each section of the permanent magnet and the central axis of the rotor gradually decreases from two circumferential side surfaces of the inner wall surface toward the center thereof, . The rotor for a single-phase external rotor motor according to claim 1, wherein the inner surface of each section of the permanent magnet is a flat surface. The rotor of claim 1, wherein the inner surfaces of the permanent magnets collectively form a regular polygon. As a single phase external rotor motor:
A stator comprising a stator core and a winding wound around the stator core, the stator core comprising a plurality of teeth extending outwardly from an outer edge of the yoke and the yoke, each tooth having a tooth body connected to the yoke, A tooth tip formed at a distal end of the tooth body, the winding wound around the tooth body; And
A rotor surrounding the stator, the rotor
housing; And
And at least one permanent magnet attached to the interior of the housing to form a plurality of magnetic poles,
Wherein an inner surface of the poles of the rotor and an outer surface of the tooth tip of the stator define a non-uniform gap therebetween, and when the motor is not energized, the rotor rotates with the tooth tip of the stator core Phase magnetic field generated by at least one permanent magnet which makes at least one magnetic field. 7. The rotor of claim 5, wherein a slot opening is formed between each two adjacent tooth tips, the circumferential width of the slot opening being less than or equal to five times the minimum gap between the stator and the rotor, motor. 7. The single-phase external rotor motor of claim 6 wherein the circumferential width of the slot opening is less than or equal to three times the minimum gap between the stator and the rotor. 7. The method of claim 6, wherein the tooth tip has a width greater than that of the tooth body, two circumferential sides of the tooth tip extending beyond the tooth body to form two wings each, Adjacent wing portions of the tooth tips define one of the slot openings and at least one of the two wing portions adjacent to each slot opening is tilted out before the winding is wound and the tilted wing is bent inward after the winding is wound Single - phase external rotor motor. The single-phase external rotor motor according to claim 8, wherein the tilted wing portion is formed with a cutting groove, and after the winding is wound, the tilted wing portion is deformed to bend inward to reduce or remove the cutting groove. 10. A permanent magnet according to any one of claims 5 to 9, wherein the plurality of permanent magnets are made of a ring permanent magnet comprising a plurality of sections along the circumferential direction, each section forming a magnetic pole, Wherein a distance between the inner wall surface of each section of the permanent magnet and the central axis of the rotor is set so as to extend from two circumferential sides of the inner wall surface toward the center Phase external rotor motors that gradually change as the motor rotates. As a single phase external rotor motor:
A stator comprising a stator core and a winding wound about the stator core, the stator core comprising a plurality of teeth extending integrally and radially outwardly from the outer edge of the yoke and the yoke, each ti- Forming a tooth tip, wherein a slot opening is formed between each two adjacent tooth tips;
A rotor surrounding the stator, the rotor comprising a housing and a permanent magnet attached to the interior of the housing, the permanent magnet forming a circumferentially closed ring, the permanent magnet having a plurality of magnetic poles Wherein the outer surface of the stator and the inner surface of the permanent magnet define a symmetrical nonuniform gap therebetween and the circumferential width of the slot opening is less than or equal to five times the minimum width of the gap, Electronic motor. 12. The single-phase external rotor motor according to claim 11, wherein the outer surface of the tooth tip of the stator is located on a common cylindrical surface, and the inner surface of the permanent magnet of the rotor forms a regular polygon. 12. The single-phase external rotor motor of claim 11, wherein the circumferential width of the slot opening is less than or equal to three times the minimum width of the gap. The single-phase external rotor motor according to any one of claims 11 to 13, wherein the ratio of the maximum width to the minimum width of the gap is greater than two. An electric device comprising a single-phase motor, the motor comprising:
Stator; And
And a rotor surrounding the stator, the rotor comprising:
housing; And
A ring permanent magnet attached to the interior of the housing, the ring permanent magnet comprising a plurality of sections along a circumferential direction, each section forming a permanent pole, adjacent sections of the permanent magnet having different polarities, Each of the sections of the permanent magnet having a symmetrical structure,
Wherein the distance between the inner surface of each section of the permanent magnet and the central axis of the rotor gradually increases from the center of the inner surface toward two circumferential sides. 16. The stator of claim 15, wherein the stator comprises a stator core and a winding around the stator core, the stator core including a plurality of teeth extending outwardly from an outer edge of the yoke and the yoke, And a tooth tip formed at a distal end of the tooth body, wherein a symmetrical non-uniform gap is formed between an inner surface of the permanent magnet of the rotor and an outer surface of the tooth tip of the stator. 17. The method of claim 16, wherein a winding slot is formed between each two adjacent tooth tips, the winding wound about the tooth body, a slot opening being formed between each two adjacent tooth tips, The width in the circumferential direction being less than or equal to five times the minimum gap between the stator and the rotor. 16. The electrical device of claim 15, wherein the electrical device is a range hood, air conditioner, or ventilation fan further comprising an impeller driven by the motor. 16. The electrical device of claim 15, wherein the electrical device further comprises a speed reducing device driven by the motor.

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