JP2016214071A - Single-phase outer-rotor motor and stator thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outer-rotor motor and a stator thereof which can effectively reduce the cogging torque.SOLUTION: A single-phase outer-rotor motor includes a stator and a rotor surrounding the stator. The stator and rotor define therebetween an even gap. The stator includes a stator core. The stator core includes a yoke and a plurality of teeth. Each tooth includes a tooth body and a tooth tip. A winding slot is formed between two adjacent tooth bodies. Windings are wound around the tooth bodies. The tooth tip forms an outer circumferential surface facing the rotor. The outer circumferential surfaces of all the tooth tips are connected to each other to collectively form a substantial cylindrical surface. The outer circumferential surface of the tooth tip is formed with a positioning groove deviating from a center of the outer circumferential surface of the tooth tip, which prevents the rotor from stopping at the dead-point position.SELECTED DRAWING: Figure 17

Description

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

  Usually, single-phase motors are used in small output household electrical appliances such as washing machines, dishwashers, refrigerators and air conditioners. From the viewpoint of the relative positions of the stator and the rotor, the single-phase motor is classified into an inner rotor type motor and an outer rotor type motor. In a single-phase outer rotor type motor, the stator is literally arranged on the inner side, the rotor surrounds the stator, and a load can be directly incorporated into the rotor. Since the number of magnetic poles of the rotor and the stator is the same for the single-phase motor, when the rotor is stopped, it is easy to stop at the dead center position where the center of the rotor magnetic pole is aligned in the radial direction with respect to the stator magnetic pole. This may cause the rotor to fail to start when the motor is energized. In order to solve this problem, conventionally, a non-uniform gap is formed between the magnetic poles of the stator and the rotor, and the gap gradually increases or decreases gradually from one side to the other side in the circumferential direction of the magnetic pole. As a result, the rotor is prevented from stopping at the dead center position. However, this solution results in a large cogging torque and thus a large motor vibration and noise.

  Therefore, there is a need for an outer rotor type motor and its stator that can effectively reduce the cogging torque.

  In one aspect, the present invention provides a stator for a single-phase outer rotor type motor, and includes a stator core and a winding wound around the stator core. The stator core includes a yoke and a plurality of teeth extending radially outward from an outer edge of the yoke. Each of the teeth includes a tooth body coupled to the yoke and a tooth tip formed at the distal end of the tooth body. A winding slot is formed between two adjacent tooth bodies. The winding is wound around the tooth body. The tooth tip forms an outer peripheral surface facing the rotor, and the outer peripheral surfaces of all the tooth tips are connected to each other and collectively form a substantially cylindrical surface. A positioning groove deviating from the center of the surface is formed.

  Preferably, the tooth tips have a closed ring shape connected circumferentially, and a magnetic bridge is formed between two adjacent tooth tips.

  Preferably, the inner surface of the magnetic bridge forms at least one groove.

  Preferably, the tooth tip has a width larger than the width of the tooth body, both circumferential sides of the tooth tip extend beyond the tooth body to form two wing parts, and the positioning groove is It arrange | positions at the wing part corresponding to the outer peripheral surface of a tooth | tip tip.

  Preferably, the radially inner end of the tooth body is detachably coupled to the yoke.

  Preferably, the radially outer end of the tooth body is detachably coupled to the tooth tip.

  In another aspect, the present invention provides a stator for a single-phase outer rotor type motor including the above-described stator and a rotor surrounding the stator. The rotor includes a plurality of magnetic poles. A substantially uniform gap is defined between the rotor and the stator.

  Preferably, when the rotor is stationary, the stator positioning grooves are aligned in the region between the two adjacent poles of the rotor.

  In yet another aspect, the present invention provides a single-phase outer rotor type motor comprising a stator and a rotor surrounding the stator. The rotor includes a housing and a permanent magnet attached to the inside of the housing, and forms a plurality of permanent magnetic poles. The magnetic pole has an inner peripheral surface facing the stator. The stator core includes a yoke and a plurality of teeth extending outwardly from the outer edge of the yoke. Each of the teeth includes a tooth tip formed at the distal end of the tooth body. The tooth tip has an outer peripheral surface facing the rotor. Preferably, a substantially uniform gap is formed between the inner peripheral surface of the magnetic pole and the outer peripheral surface of the tooth tip. A positioning groove deviating from the center of the outer peripheral surface of the tooth tip is formed on the outer peripheral surface of the tooth tip.

  Preferably, when the rotor is stationary, the stator positioning grooves are aligned in the region between the two adjacent poles of the rotor.

  Preferably, the tooth tips are connected to each other in the circumferential direction, and the outer peripheral surfaces of the tooth tips collectively form a substantially cylindrical surface.

  Preferably, a magnetic bridge is formed between two adjacent tooth tips, and the inner surface of the magnetic bridge facing the yoke forms at least one groove.

  Preferably, each of the teeth includes a tooth body coupled to the yoke, the tooth tip is disposed at a radially outer end of the tooth body, and the tooth body is detachably coupled to the tooth tip.

  Preferably, each of the teeth includes a tooth body coupled to the yoke, the tooth tip is disposed at a radially outer end of the tooth body, and the tooth body is detachably coupled to the yoke.

  In another aspect, the present invention provides an electrical device using the motor.

  Compared to conventional outer rotor type motors, the stator and rotor of the single phase outer rotor type motor of the present invention define a substantially uniform gap therebetween, which effectively reduces cogging torque. In addition, the outer peripheral surface of the tooth tip forms a positioning groove off the center of the tooth tip, which prevents the rotor from stopping at the dead center when the motor is de-energized, When energized, the motor rotor can be reliably started.

1 shows a stator of an outer rotor type motor according to one embodiment of the present invention. It is a top view of FIG. The stator core of the stator of FIG. 1 is shown. FIG. 4 is a plan view of FIG. 3. Fig. 4 shows the stator core of Fig. 3 before formation. FIG. 6 is a plan view of FIG. 5. The stator core of the stator by 2nd Embodiment is shown. Fig. 8 shows the stator core of Fig. 7 before formation. The stator core of the stator by 3rd Embodiment is shown. 10 shows the stator core of FIG. 9 before formation. The stator core of the stator by 4th Embodiment is shown. The stator core of FIG. 11 before formation is shown. 10 shows a stator core of a stator according to a fifth embodiment. Fig. 14 shows the stator core of Fig. 13 before formation. The stator core of the stator by 6th Embodiment is shown. The stator core of the stator by 7th Embodiment is shown. The stator core of the stator by 8th Embodiment is shown. 10 shows a stator core of a stator according to a ninth embodiment. 1 shows a rotor of an outer rotor type motor according to one embodiment of the present invention. 3 shows a rotor according to a second embodiment. 7 shows a rotor according to a third embodiment. 10 shows a rotor according to a fourth embodiment. 7 shows a rotor according to a fifth embodiment. FIG. 19 shows a 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 in FIG. 24 with the lines of magnetic force removed for clarity. The positional relationship when the motor of FIG. 24 exists in a dead center position is shown. FIG. 22 shows a motor formed by the stator of FIGS. 1 to 4 and the stator of FIG. 21. 21 shows a motor formed by the stator of FIGS. 9 to 10 and the rotor of FIG. FIG. 24 shows a motor formed by the stator of FIGS. 9 to 10 and the rotor of FIG. FIG. 20 shows a motor formed by the stator of FIG. 18 and the rotor of FIG. 18 shows a motor formed by the stator of FIG. 17 and the rotor of FIG. It is a figure which shows the motor 1 of this invention used with an electric equipment.

  In order to describe the technical solutions and results of the present invention in detail, preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  The single-phase outer rotor type motor includes a stator and a rotor surrounding the stator. The stator and rotor can have a variety of different structures, and when different stators and rotors are combined, motors with different characteristics can be obtained. 1 to 16 illustrate a plurality of embodiments of the stator, FIGS. 17 to 21 illustrate a plurality of embodiments of the rotor, and FIGS. 22 to 28 illustrate a plurality of stators and the rotor formed by the stator. These motors are exemplified. It should be understood that the drawings are for reference and illustration purposes only. The stator and the rotor of the present invention are not limited to the illustrated embodiment, and the motor formed by the stator and the rotor is not limited to the illustrated embodiment.

  1 to 4 show a stator 10 according to a first embodiment. In this embodiment, the stator 10 includes a stator core 12, an insulating bracket 14 disposed around the stator core 12, and a winding 16 wound around the insulating bracket 14.

  The stator core 12 is formed by stacking magnetic conductive materials such as silicon steel plates. The stator core 12 includes an annular yoke 18 and a plurality of teeth 20 that extend integrally outward in the radial direction from the outer end of the yoke 18. The teeth 20 are arranged at equal intervals along the circumferential direction of the yoke 18. Each tooth 20 includes a tooth body 22 coupled to the yoke 18 and a tooth tip 24 formed at the distal end of the tooth body 22. The tooth body 22 extends linearly. The tooth body 22 preferably extends along the radial direction of the annular yoke 18. A winding slot 26 is formed between two adjacent tooth bodies 22. The winding slot 26 is generally fan-shaped and has a width that gradually increases radially outward from the yoke 18. The tooth tip 24 is generally arcuate, extends generally along the circumferential direction, and is generally symmetric with respect to the tooth body 22. Each tooth tip 24 is preferably symmetric with respect to the radius of the motor passing through the center of the tooth body 22 of the tooth 20. In the circumferential direction, the width of the tooth tip 24 is larger than the width of the tooth body 22, and two wing portions 28 extending beyond the tooth body 22 are formed on both sides of the tooth tip 24 in the circumferential direction. In this embodiment, a narrow slot opening 30 is formed between the wings 28 of adjacent tooth tips 24.

  Each tooth tip 24 includes an inner surface 32 that faces the tooth body 22 and an outer surface 34 that faces the rotor 50. The outer side surface 34 is preferably an arc surface. The outer surface 34 of the tooth tip 24 functions as the outer surface of the stator 10, and is disposed on substantially the same cylindrical surface that is coaxial with the yoke 18 of the stator 10. A cut groove 36 is formed in the inner side surface 32 of the tooth tip 24. In this embodiment, there are two slits 36 that are symmetrically arranged in the two wings 28 that are adjacent to and spaced from the body 22. Each incision groove 36 extends along the radial direction, that is, along the thickness direction of the tooth tip 24, and extends to the inner surface 32 of the tooth tip 24. The depth of the cut groove 36 is substantially half of the thickness of the tooth tip 24 in the cut groove 36, and the cut groove 36 does not have a great influence on the magnetic path.

  The winding 16 is wound around the tooth body 22 and is located inside the tooth tip 24. The winding 16, the tooth body 22, and the inner surface 32 of the tooth tip 24 are separated separately by the insulating bracket 14. Usually, the insulating bracket 14 is made from a plastic material to prevent shorting of the windings 16. As shown in FIGS. 5 and 6, before winding the winding around the stator core 12, the outer portion of the cut groove 36 of the tooth tip 24 is inclined outward to increase the spacing between adjacent tooth tips 24. Thus, the winding 16 can be conveniently wound around the tooth body 22. After the end of winding, the outer surface 34 of the tooth tip 24 is pressed inward to deform the tooth tip 24 and bend toward the tooth body 22 to form an arcuate outer surface 34. During this process, the interval between the tooth tips 24 decreases, the slot opening 30 becomes narrower, the narrow slot opening 30 is formed, and the cut groove 36 becomes narrower or becomes a slit shape. There is also. Preferably, the angle of the portion of the tooth tip 24 outside the cut groove 36 before and after the deformation, that is, the angle of this portion after the deformation, that is, the deformation angle is in the range of 15 ° to 60 °. More preferably, the deformation angle of the outer portion of the cut groove 36 of the tooth tip 24 is in the range of 20 ° to 45 °.

  For stators of the same size, the tooth tips 24 of the stator core 12 of the stator 10 are tilted outward prior to winding of the winding, which facilitates winding of the winding. After completion of the winding process, the tooth tip 24 is deformed and bent inward. Compared with a conventional stator core structure formed by stacking silicon steel plates formed by one-stage punching, the circumferential width of the tooth tips 24 is larger, and the width of the slot opening 30 between the tooth tips 24 is very large. And preferably half or less than the width of the slot opening 30 of the conventional stator core structure, thereby effectively reducing the cogging torque. The cut groove 36 is formed to facilitate bending deformation inward of the tooth tip 24. In some embodiments, the cut groove 36 is formed when the material of the tooth tip 24 has a certain degree of deformability. It should be understood that 36 can be omitted.

  FIG. 7 shows the stator core 12 of the stator 10 according to the second embodiment, which is different from the stator core. Each tooth tip 24 of this embodiment has a cut groove 36 on only one of the wing portions 28. It is formed. Taking the orientation shown in each figure as an example, each cut groove 36 is formed in the wing portion 28 on the counterclockwise side of the corresponding tooth body 22. As shown in FIG. 8, only the wing portion 28 of the tooth tip 24 on the counterclockwise direction of the tooth body 22 is tilted to the outside of the stator core 12 before formation. Since all wings 28 on the same side of the tooth tip 24 are tilted, each tilted wing 28 and the non-tilted wing 28 of the adjacent tooth tip 24 are offset from each other in the circumferential direction, Similarly, there is a large gap between the adjacent wing portions 28, which facilitates winding. When the tilted wing portion 28 is bent inward after the winding process is finished, the interval between the adjacent wing portions 28 is reduced, narrow slot openings 30 are formed, and the cogging torque is reduced.

  FIG. 9 shows the stator core 12 of the stator 10 according to the third embodiment. Compared with the above embodiment, the stator core 12 of the third embodiment is cut into the connection region between the wing portion 28 and the tooth body 22. As shown in FIG. 10, only one of the two wing portions 28 is inclined outward before winding. Therefore, before the stator core is formed, the notch groove 36 has a large depth, the tooth tip 24 has a larger inclination angle, and the distance between the tooth tips 24 can be increased. Can be performed more conveniently. In addition, it should be understood that cut grooves 36 can be formed in both connection regions of the wing 28 and the tooth body 22 and that both wings 28 can be tilted outward prior to winding.

  FIGS. 11 to 14 show the stator core 12 of the stator 10 according to another two embodiments, in which a notch 36 is formed in some tooth tips 24, but not in other tooth tips. The difference is that the groove 36 is not formed. The tooth tips 24 with cut grooves are alternately arranged with the tooth tips 24 without the cut grooves. Preferably, the cutting groove 36 of the tooth tip 24 with the cutting groove 36 is formed in each of the two wing portions 28. If both wing portions 28 are tilted outward before the stator core is formed, the distance between adjacent tooth tips without the cut groove 36 is increased, and winding is facilitated. As shown in FIGS. 11 and 12, the cut groove 36 can be formed in each connection region between the wing portion 28 and the tooth body 22. Alternatively, as shown in FIGS. 13 and 14, the cut groove 36 may be formed in an intermediate portion of the wing portion 28 and separated from the tooth body 22.

  In the above embodiment, the wing portion 28 of the tooth tip 24 of the stator core 12 is tilted outward before winding, and is deformed and bent inward after winding. Therefore, winding of the winding 16 is facilitated, and after the stator core is finally formed, the circumferential width of the tooth tip can be increased to form a smaller slot opening 30, thereby reducing the cogging torque. Reduced. Indeed, as long as one of the wings 28 opposite each slot opening 30 is tilted outward, only one of the two wings at each tooth tip 24 of the same stator core 12 or both are tilted outward, or two It is possible not to tilt both wings outward. The above object can be realized by combining the tilted wing portion and the non-tilt wing portion in various appropriate patterns not limited to the illustrated embodiment. In the various embodiments described above, the tooth tips 24 of the stator core 12 are discontinuous along the circumferential direction, thereby forming a narrow slot opening 30 between each tooth tip. In other embodiments, the tooth tips 24 can be connected together along the circumferential direction, resulting in minimal 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 connects the tooth tips 24 together to form an annular profile that is collectively closed. Preferably, the closed annular profile has a minimum radial thickness at the location of the magnetic bridge 38. More preferably, one or more axially extending grooves 40 are formed on the inner surface of the magnetic bridge 38. As illustrated, each of the magnetic bridges 38 is formed with a plurality of grooves 40 arranged at equal intervals along the circumferential direction. To effect winding, the tooth tip can be separated at the connection area with the tooth body 22 (shown in FIG. 15). Therefore, after the end of the winding process, the annular contours collectively formed by the tooth tips 24 are connected again around the tooth body 22 along the axial direction to form the stator core 12. In the embodiment shown in FIG. 16, the tooth body 22 is separated at the connection region between the yoke 18, and after the winding process is finished, the yoke 18 is assembled inside the tooth body 22 to form the stator core 12. .

  17 and 18 show a 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 FIGS. 15 and 16, respectively, except that the outer peripheral surface 34 of the tooth tip 24 is disposed on the wing portion 28 and the center of the tooth tip 24. The tooth tip 24 is asymmetric with respect to the radius of the motor passing through the center of the tooth body 22 of the tooth 20.

  19-23 illustrate a rotor 50 according to 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 inside of the housing 52. The outer peripheral surface of the permanent magnet 54 is attached to the housing 52, which can be placed with an adhesive or joined together by insert molding. An inner side surface 56 of the permanent magnet 54 defines an interval for mounting the stator 10 therein. The size of this interval is slightly larger than that of the stator 10, and a gap is formed between the stator 10 and the rotor 50.

  FIG. 19 shows the rotor 50 according to the first embodiment. In this embodiment, the permanent magnet 54 includes a plurality of divided magnets arranged at equal intervals along the circumferential direction of the housing 52, and a gap is formed between each of the two adjacent permanent magnets 54. Each of the permanent magnets 54 functions as one permanent magnetic pole of the rotor 50, and adjacent magnetic poles have opposite polarities. In this embodiment, each of the permanent magnets 54 is a part of a ring, and the inner side surface 56 of the permanent magnet 54 facing the stator 10 is an arc surface. The inner surface 56 of all the permanent magnets 54 forms the inner surface of the rotor 50 and is disposed on the same cylindrical surface that is coaxial with the rotor 50. When any one of the above-described stators is attached to the rotor 50, the radial distance 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 is along the circumferential direction. As a result, a substantially uniform gap is formed between the stator 10 and the rotor 50.

  Preferably, the pole arc coefficient of each of the permanent magnets 54, that is, the ratio of the span angle α of the permanent magnetic pole 54 to the quotient obtained by dividing 360 degrees by the number N of rotor poles (ie, α: 360 / N) is 0.7. This can improve motor torque characteristics and improve motor efficiency. In various embodiments of the motor stator 10 and rotor 50, the number of permanent magnets 54 is the same as the number of teeth 20, that is, the magnetic poles of the stator 10 and rotor 50 are the same. As shown, there are eight permanent magnets 54 and eight teeth 20, which form the eight magnetic poles of the rotor 50, with the eight teeth 20 having eight windings therebetween. Slots 26 are defined to cooperatively form an 8-pole and 8-slot motor. In other embodiments, the number of teeth 20 of the stator 10 can be a multiple relationship with the number of permanent magnets 54 of the rotor 50. For example, the number of teeth 20 can be two or three times the number of permanent magnetic poles 54. Preferably, winding 16 of stator 10 is electrically connected and a single-phase DC current is supplied by a single-phase brushless DC motor driver to form a single-phase DC brushless motor. In another embodiment, the design of the present invention can also be applied to single phase permanent magnet synchronous motors.

  20-23 show a rotor 50 according to a number of other embodiments. In these embodiments, the inner peripheral surface 56 of the magnet 54 is not a cylindrical arc surface, and a non-uniform gap is formed between the stator 10 and the rotor 50 after the stator 10 is attached. These embodiments are described in detail below.

  FIG. 20 shows a rotor 50 according to the second embodiment. In the second embodiment, the permanent magnet 54 is symmetric with respect to a center line extending along the thickness direction. The thickness of the permanent magnet 54 gradually decreases from the circumferential center of the permanent magnet 54 to both sides in the circumferential direction. The inner side surface 56 of each permanent magnet 54 facing the stator 10 is a flat surface extending parallel to the tangential direction of the radially outer surface of the stator. Each of the permanent magnets 54 forms a permanent magnetic pole. In the radial cross section shown in FIG. 20, the inner surface of the permanent magnet 54 is positioned at each side of the regular polygon. Accordingly, the gap formed between the permanent magnetic pole 54 and the stator 10 is a symmetric and non-uniform gap. The size of the gap has a minimum value at a position corresponding to the circumferential central portion of the permanent magnet 54 and gradually increases from the position of the minimum value toward the two circumferential side portions of the permanent magnet 54. By providing a symmetric and non-uniform gap, when the motor is turned off, positioning of the rotor 50 at a position deviating from the dead center position is facilitated, and the rotor is started well when the motor 50 is started. Can be made.

  FIG. 21 shows the rotor 50 according to the third embodiment, which differs from the embodiment of FIG. 20 mainly in that the permanent magnet 54 has a ring-shaped integrated structure in which the permanent magnet 54 is closed in the circumferential direction. The ring-shaped permanent magnet 54 includes a plurality of sections in the circumferential direction. Each section functions as one magnetic pole of the rotor 50, and adjacent sections have different polarities. Like each permanent magnet 54 of the rotor 50 of FIG. 20, each section of the permanent magnet 54 gradually decreases in thickness from the circumferential center to both sides in the circumferential direction. The inner side surface 56 of each section facing the stator 10 is a flat surface. In the radial cross section shown in FIG. 21, all sections of the permanent magnet 54 cooperate to form the regular polygonal inner surface of the rotor 50. Similar to the embodiment of FIG. 20, the gaps formed between the magnetic poles of the permanent magnet 54 and the outer surface of the stator 10 are symmetrical and non-uniform gaps.

  FIG. 22 shows a rotor 50 according to a fourth embodiment similar to the embodiment of FIG. 20, which includes a plurality of circumferentially spaced permanent magnets 54, each permanent magnet 54. Has a flat inner peripheral surface 56. Unlike the above embodiment, in this embodiment, the permanent magnet 54 has an asymmetric structure, and the thickness gradually increases from one circumferential side to the other circumferential side, and the other circle. It gradually decreases from the position adjacent to the circumferential side. The thickness of the permanent magnet 54 becomes maximum at a position deviated from the center in the circumferential direction, and the thickness is different on both sides of the permanent magnet 54 in the circumferential direction. A line connecting the two end side surfaces of the inner surface 56 of the permanent magnet 54 and the center of the rotor 50 forms an isosceles triangle. Therefore, after combining with the stator 10, an asymmetric and non-uniform gap is formed between the stator 10 and the rotor 50. By providing an asymmetrical and non-uniform gap, when the motor is turned off, positioning of the rotor 50 at a position deviating from the dead center position is facilitated, and the rotor is started well when the motor 50 is started. Can be made.

  FIG. 23 shows a 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 member 58 attached to the inside of the housing 52. The magnetic member 58 can be made of a hard magnetic material such as a ferromagnetic material or a rare earth magnet, or a soft magnetic material such as iron. The permanent magnets 54 and the magnetic members 58 are alternately arranged at intervals in the circumferential direction, and one magnetic member 58 is inserted between two adjacent permanent magnets 54. In this embodiment, the permanent magnet 54 has a column shape having a substantially square cross section. A space having a circumferential width much larger than the width of the permanent magnet 54 is formed between two adjacent permanent magnets 54. Therefore, the magnetic member 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 member 58 is symmetric with respect to the rotor radius passing through its center. The thickness of the magnetic member 58 gradually decreases from the center / center in the circumferential direction to both sides in the circumferential direction. The minimum thickness of the magnetic member 58, that is, the thickness at the side in the circumferential direction is substantially the same as the thickness of the permanent magnet 54. The inner peripheral surface 60 of the magnet member 58 facing the stator 10 is a flat surface extending in parallel with the tangential direction of the outer surface of the stator 10. Accordingly, the inner peripheral surface 56 of the permanent magnet 54 and the inner peripheral surface 60 of the magnetic member 58 collectively form the inner surface of the rotor 50 that is a polygon that is symmetrical in the radial cross section of the rotor 50. After the rotor 50 is combined with the stator 10, the gap formed between the stator 10 and the rotor 50 is a symmetric and non-uniform gap. Preferably, the permanent magnet 54 is magnetized along the circumferential direction, i.e. polarized so that the circumferential sides of the permanent magnet 54 have a corresponding polarity. Two adjacent permanent magnets 54 have opposite polar directions. That is, two adjacent surfaces of two adjacent permanent magnets 54 facing each other have the same polarity. Accordingly, a polarity corresponding to the magnetic member 58 between the two adjacent permanent magnets 54 is given, and the two adjacent magnetic members 58 have different polarities.

  Motors having different characteristics can be obtained from different combinations of the stator 10 and the rotor 50, some of which are exemplified 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. Each tooth tip 24 of the stator 10 is circumferentially spaced to form a slot opening 30, the outer surface 34 of the tooth tip 24 is disposed on the same cylindrical surface, and the entire outer surface of the stator 10 is circular. The permanent magnets 54 of the rotor 50 are spaced apart from each other in the circumferential direction, the inner surface 56 of the permanent magnet 54 facing the stator 10 is a flat surface, and the entire inner surface of the rotor 50 is a regular polygon. The outer surface 34 of the stator 10 and the inner surface 56 of the rotor 50 are spaced apart in the radial direction to form a gap 62. The gap 62 is a symmetric and non-uniform gap whose radial width changes along the circumferential direction of the permanent magnetic pole 54, and is symmetric with respect to the center line of the permanent magnetic pole 54. The radial width of the gap 62 gradually increases from the circumferential center of the inner surface 56 of the permanent magnet 54 toward the circumferential side.

  Similarly, referring to FIG. 25, the radial distance between the center in the circumferential direction 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 portion of the inner surface 56 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 larger than 5 times the minimum width Gmin of the gap 62, that is, D ≦ 5 Gmin. More preferably, the width D of the slot opening 30 is equal to or larger than the minimum width Gmin of the gap 62, but less than or equal to three times the minimum width Gmin of the gap 62, that is, Gmin ≦ D ≦ 3Gmin. It is.

  Referring to FIGS. 24 and 26, when the motor is not energized, the permanent magnet 54 of the rotor 50 generates an attractive force that attracts the teeth 20 of the stator 10. 24 and 26 show the rotor 50 in different positions. Specifically, FIG. 26 shows the rotor 50 in the dead center position (that is, 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 in the initial position (that is, the stop position of the rotor 50 when the motor is not energized or when the power is shut off). As shown in FIGS. 24 and 26, when the rotor 50 is at the dead center position, the magnetic flux of the magnetic field generated by the magnetic poles of the rotor 50 passing through the stator 10 is Φ1, and when the rotor 50 is at the initial position, The magnetic flux generated by the magnetic poles of the rotor 50 passing through the stator 10 is Φ2. Since Φ2> Φ1, the path of Φ2 is shorter than the path of Φ1, the magnetic resistance of Φ2 is less than the magnetic resistance of Φ1, and the rotor 50 can be positioned at the initial position when the motor is de-energized. It is possible to avoid stopping at the dead center position shown in FIG. 26, and as a result, failure to start the rotor 50 when the motor is energized can be avoided.

  Referring to FIG. 24, in this initial position, the centerline of the stator tooth tip is closer to the centerline of the neutral region between the two adjacent magnetic poles 54 than the centerline of the two adjacent magnetic poles 54. Preferably, the centerline of the tooth tips 24 of the teeth 20 of the stator 10 is aligned with the centerline of the neutral region between two adjacent permanent magnetic poles 54. This position is farthest from the dead center position, and when the motor is energized, it is possible to effectively avoid the rotor starting failure. In the initial position, due to other factors such as actual friction, the center line of the tooth tip 24 can deviate from the center line of the neutral region between two adjacent permanent magnet columns 54 at an angle of, for example, 0 to 30 degrees. The initial position is still far from the dead center position. In the above embodiment of the present invention, the rotor 50 can be positioned in an initial position away from the dead center position by the leakage magnetic field provided by the permanent magnet 54 of the rotor 50 acting on the stator tooth tips 24. The leakage flux provided by the permanent magnet 54 does not pass through the tooth body 22 and the winding 16. The cogging torque of the single-phase permanent magnet brushless motor configured as described above can be effectively suppressed, and the efficiency and performance of the motor are improved. According to the experiment, it is found that the maximum value of the cogging torque of the single-phase permanent magnet brushless motor configured as described above is less than 80 mNm (the rated torque is 1 Nm, the rated rotation speed is 1000 rpm, and the stator core stacking 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. Each 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 disposed on the same cylindrical surface. The permanent magnet 54 of the rotor 50 includes a plurality of sections connected to each other in the circumferential direction. Each section functions as one magnetic pole of the rotor 50, and the inner peripheral surface 56 of the magnetic pole is a flat surface. The entire inner surface is a regular polygon. A symmetric and non-uniform gap 62 is formed between the stator 10 and the rotor 50, and the width of the gap 62 gradually increases from both sides in the circumferential direction of the magnetic pole toward the center in the circumferential direction. The maximum width Gmax is at the center in the direction, and the minimum width Gmin is at the circumferential side. When the rotor 50 is stationary, the center of each tooth end 24 is aligned with the junction of the two corresponding sections of the permanent magnet 54, thereby avoiding dead center locations and facilitating restart of the rotor 50. Become.

  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 tips 24 of the stator 10 are spaced apart in the circumferential direction to form slot openings 30, and the outer peripheral surface 34 of the tooth tips 24 is disposed on the same cylindrical surface. The permanent magnet of the rotor 50 has an asymmetric structure whose thickness is not uniform along the circumferential direction. The inner peripheral surface 56 of the permanent magnet 54 of the rotor 50 is inclined by a predetermined angle with respect to the tangential direction of the outer peripheral surface 34 of the tooth tip 24, and the inner peripheral surface 56 of the permanent magnet 54 and the outer peripheral surface 34 of the tooth tip 24. A non-uniform and asymmetric gap 62 is formed between them. The width of the gap 62 first gradually decreases from one circumferential side of the permanent magnet 54 toward the other circumferential side, and then gradually increases. Taking the illustrated orientation as an example, the gap 62 has a maximum width Gmax on the clockwise side of the permanent magnet 54, and the minimum width Gmin of the gap 62 is adjacent to the counterclockwise side of the permanent magnet 54, but from there. It is out of position.

  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 tips 24 of the stator 10 are spaced apart in the circumferential direction to form slot openings 30, and the outer surface 34 of the tooth tips 24 is disposed on the same cylindrical surface. The rotor 50 includes permanent magnets 54 and magnetic members 58 arranged alternately at intervals in the circumferential direction. The inner surface 56 of the permanent magnet 54 and the inner surface 60 of the magnetic member 58 collectively form the polygonal inner surface of the rotor 50. A symmetrical and non-uniform gap 62 is formed between the stator 10 and the rotor 50, and the size of the gap gradually decreases from the circumferential center of the magnetic member 58 to both sides in the circumferential direction, corresponding to the permanent magnet 54. Reaches the maximum width Gmax. The rotor 50 can be positioned in an initial position by a leakage flux circuit that passes through the permanent magnetic pole 54, two adjacent magnetic members 58, and the corresponding tooth tip 24, respectively. In the initial position, the center of the permanent magnet 54 is aligned with the center of the tooth tip 24 in the radial direction, and the permanent magnet 54 applies a circumferential force to the stator 10, so that the rotor 50 is easily activated.

  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, that is, the outer surface 34 of the tooth tip 24 is a cylindrical surface. The inner surface of the rotor 50, that is, the inner peripheral surface 56 of the permanent magnet 54 is disposed on a cylindrical surface coaxial with the outer peripheral surface 34 of the stator 10. The outer peripheral surface 34 of the stator 10 and the inner peripheral surface 56 of the rotor 50 define a uniform gap 62. The tooth tip 24 has an asymmetric structure having a positioning groove 42 on the outer peripheral surface 34. When the rotor 50 is stationary, the center line of the region between two adjacent permanent magnets 54 is the tooth of the tooth 20 of the stator 10. It is guaranteed that it is deviated by a predetermined angle with respect to the center line of the tip 24. Preferably, when the rotor is stationary, the positioning slot 42 of the stator 10 is aligned with the center line of two adjacent permanent magnets 54 of the rotor 50 and can be successfully activated each time the motor is energized. As can be seen, in this embodiment, the tooth tips 24 of the stator 10 can be spaced apart from one another in the circumferential direction by a narrow slot opening.

  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 inner peripheral surface 56 of the permanent magnet 54 of the rotor 50 is a flat surface that extends parallel to the tangential direction of the outer surface of the stator 10. A symmetrical and non-uniform gap 62 is formed between the inner peripheral surface 56 of the permanent magnet 54 and the outer peripheral surface 34 of the tooth tip 24. The width of the gap 62 gradually decreases from the circumferential center of the permanent magnet 54 toward both sides in the circumferential direction, and has a minimum width Gmin at the center in the circumferential direction of the permanent magnet 54 and is the largest at both sides in the circumferential direction. Significant Gmax.

  FIG. 32 shows the motor 1 of the present invention used in an electric device 4 according to another embodiment. The electric device 4 can be a range hood, a ventilation fan, or an air conditioner including the impeller 3 driven by the rotor shaft 21 of the motor. The electric device 4 includes the speed reduction device 3 driven by the rotor 50 of the motor, and can be a washing machine or a dryer.

  Each of the stators 10 of FIGS. 1 to 11 is substantially the same in structure and characteristics, may form a narrow slot opening or may not have a slot opening, and further has the same function when combined with the rotor 50. It should be understood that it can be replaced to bring about. In addition, depending on the various gaps formed between the stator and the rotor, and also according to the symmetry and asymmetry of the stator and rotor structure, an appropriate circuit can be designed to energize the motor when the motor is energized. 50 can be started successfully. It should be understood that the combination of the stator 10 and the rotor 50 is not limited to the above-described embodiment. Various modifications that do not depart from the spirit of the invention are within the scope of the invention. Accordingly, the scope of the invention is determined by reference to the claims that follow.

DESCRIPTION OF SYMBOLS 10 Stator 12 Stator core 16 Winding 18 Yoke 20 Tooth 22 Tooth main body 24 Tooth tip 26 Winding slot 28 Wing part 30 Slot opening part 32 Inner side surface 34 Outer side surface 42 Positioning groove 50 Rotor 52 Housing 54 Permanent magnet 56 Inner side surface

Claims (16)

A stator core including a yoke and a plurality of teeth extending radially outward from an outer edge of the yoke, each of the teeth being formed at a tooth body coupled to the yoke and a distal end of the tooth body A wound slot is formed between two adjacent tooth bodies, each of the tooth tips forming an outer peripheral surface facing the rotor, and all outer peripheral surfaces of the tooth tips are A stator core connected to each other and collectively forming a substantially cylindrical surface, wherein the outer peripheral surface of the tooth tip is formed with a positioning groove off the center of the outer peripheral surface of the tooth tip;
A winding wound around the tooth body;
A stator for a single-phase outer rotor type motor.   2. The stator for a single-phase outer rotor type motor according to claim 1, wherein the tooth tips have a ring shape connected in a circumferential direction and closed, and a magnetic bridge is formed between two adjacent tooth tips. .   The stator for a single-phase outer rotor type motor according to claim 2, wherein an inner surface of the magnetic bridge forms at least one groove.   The tooth tip has a width greater than the width of the tooth body, and both side portions of the tooth tip in the circumferential direction extend beyond the tooth body to form two wing portions, respectively, and the positioning groove Is a stator for a single-phase outer rotor type motor according to any one of claims 1 to 3, formed in the wing portion.   The stator for a single-phase outer rotor type motor according to any one of claims 1 to 4, wherein a radially inner end of the tooth body is detachably coupled to the yoke.   The stator for a single-phase outer rotor type motor according to any one of claims 1 to 4, wherein a radially outer end of the tooth body is detachably coupled to the tooth tip. A stator,
A rotor surrounding the stator;
A single-phase outer rotor type motor comprising:
The stator is a stator core including a yoke and a plurality of teeth extending outwardly from an outer edge of the yoke, each of the teeth including a tooth body coupled to the yoke and a distal end of the tooth body A winding slot is formed between two adjacent tooth bodies, and the tooth tip forms an outer peripheral surface facing the rotor, and the tooth tip has an outer peripheral surface. A stator core formed with a positioning groove off the center of the outer peripheral surface of the tooth tip, and a winding wound around the tooth body,
The rotor includes at least one permanent magnet that forms a plurality of magnetic poles, and the magnetic poles have an inner peripheral surface facing the stator.   The inner peripheral surface of the magnetic pole and the outer peripheral surface of the tooth tip are coaxial, and a substantially uniform gap is formed between the inner peripheral surface of the magnetic pole and the outer peripheral surface of the tooth tip. The single-phase outer rotor type motor according to claim 7.   The single-phase outer rotor type motor according to claim 7 or 8, wherein the positioning groove of the stator is aligned between two adjacent magnetic poles of the rotor when the motor is de-energized.   The single-phase outer rotor type motor according to any one of claims 7 to 9, wherein all of the outer peripheral surfaces of the tooth tips are connected to each other to collectively form a substantially cylindrical surface.   The single-phase outer rotor type motor according to claim 10, wherein a magnetic bridge is formed between two adjacent tooth tips, and a groove is formed on an inner peripheral surface of the magnetic bridge facing the yoke.   The single-phase outer rotor according to any one of claims 7 to 11, wherein the tooth tip is disposed at a radially outer end of the tooth body, and the tooth body is detachably coupled to the tooth tip. Type motor.   The single-phase outer rotor type according to any one of claims 7 to 11, wherein the tooth tip is disposed at a radially outer end of the tooth body, and the tooth body is detachably coupled to the yoke. motor.   An electric device comprising the single-phase outer rotor type motor according to any one of claims 7 to 13.   The electric device according to claim 14, wherein the electric device is a range hood, an air conditioner, or a ventilation fan further provided with an impeller driven by the motor. The electric device according to claim 14, wherein the electric device further includes a speed reducer driven by the motor.

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