KR20160131946A - Single-phase outer-rotor motor and electric apparatus having the same - Google Patents

Abstract

A single-phase outer rotor motor comprise: a stator; and a rotor. The stator includes a stator core in which a coil is wound above the stator. The stator core includes: a yoke; and a plurality of teeth of which each includes a tooth main body, and a tooth tip. The rotor includes a permanent magnet forming a plurality of magnetic poles facing a rotor yoke and the tooth tip of the stator core. The permanent magnet and the tooth tip define a gap therebetween. When the motor is disconnected from current, the rotor can be positioned at an initial position by a leakage magnetic field generated by the permanent magnet operating with the tooth tip of the stator core.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a single-phase external-rotor motor,

The present invention relates to a motor, and more particularly to a single phase external rotor permanent magnet motor having a small cogging torque and a device employing a single phase external rotor permanent magnet motor.

Single phase external rotor brushless motors typically include a stator and a rotor rotatable about the stator. The stator has a stator core and a plurality of teeth extending from the stator core. The top of the tweed is wound with a winding. When energized, the winding generates an alternating magnetic field. The rotor is disposed about the stator and generally includes a rotor shaft, a rotor yoke fixedly mounted to the rotor shaft, and a plurality of permanent magnets fixed to the rotor yoke to form a rotor magnetic field. The interaction between the rotor magnetic field and the stator alternating magnetic field causes the rotor to rotate. In order to prevent the rotor from staying at a dead-point, the outer surface of the tooth of the stator core generally adopts an asymmetric structure. A motor of such a construction generally has a large cogging torque, which affects the smooth rotation of the motor, thus producing velocity ripple, vibration and noise.

Therefore, there is a need for a device employing a single-phase motor and a single-phase external-rotor brushless motor with reduced cogging torque.

In one aspect, a single phase external rotor brushless motor is provided, which includes a stator and a rotor. The stator includes a stator core and windings wound around the stator core. The stator core includes a plurality of teeth extending radially outwardly from the yoke and the yoke. Each typing body including a tooth tip extending circumferentially from a distal end of the tooth body. The rotor includes a rotor yoke disposed around the stator core and a permanent magnet disposed on an inner wall surface of the rotor yoke to form a plurality of magnetic poles. The inner surface of the permanent magnet and the outer surface of the tooth tip are opposed to each other, defining a gap therebetween such that the rotor rotates relative to the stator. When the motor is de-energized, the rotor may be placed in an initial position by a leakage magnetic field generated by at least one permanent magnet that cooperates with the 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 radial width of the gap. More preferably, the circumferential width of the slot opening is less than or equal to three times the minimum radiation width of the gap.

Preferably, the gap is a uneven gap, and the radial width of the gap associated with each stimulus gradually increases from the center of the magnetic pole toward the circumferential end of the magnetic pole.

Preferably, the ratio of the maximum radial width to the minimum radial width of the gap is greater than 1.5.

Preferably, the radial width of the gap associated with each stimulus is symmetrical about the median line of the stimulus along the circumferential direction.

Preferably, the outer surfaces of the tooth tip are located on the same cylindrical surface, and the central axis of the cylindrical surface coincides with the central axis of the rotor.

Preferably, the inner surface of the magnetic pole is a flat surface or an arc surface, and the pole arc coefficient is greater than 0.75.

Preferably, the stator includes an insulation bracket attached around the stator core and a winding wound around the insulation bracket. The insulating bracket includes an upper bracket portion and a lower bracket portion. The upper bracket portion and the lower bracket portion cover the stator core from their opposite axial ends. Each of the upper bracket portion and the lower bracket portion includes a ring portion attached around the yoke of the stator core, a sleeve portion attached to the periphery of the tooth main body, and a counter portion opposing the inner surface of the tooth tip.

Preferably, a vent plate is disposed at the axial end of the counterpart, at least partially covering the end face of the axial end of the tooth tip.

Advantageously, a slit is formed in at least one connecting corner region between the tooth tip and the thread body.

Preferably, the teeth of the stator core are individually formed and interconnected to form the stator core.

Advantageously, at least one throw of the stator core is formed individually and connected to the yoke.

Advantageously, the rotor comprises a plurality of permanent magnets, and the permanent magnets are plastic-packaged in the entire body.

In another aspect, a single phase permanent magnet motor is provided. Wherein the motor comprises a core and an armature including windings wound around the core, the core comprising an annular portion and a plurality of teeth extending outwardly from the annular portion, each distal end of the threaded body and the distal end And a slot opening is formed between each two adjacent tooth tips; And at least one permanent magnet disposed on an inner surface of the rotor yoke to form a plurality of magnetic poles and a yoke surrounding the armature, the inner surface of the pole facing the outer surface of the tooth tip, . The circumferential width of the slot opening is less than or equal to five times the minimum radial width of the gap. The radial width of the gap corresponding to each magnetic pole gradually increases from the middle portion of the magnetic pole toward the circumferential end.

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

Preferably, the ratio of the maximum radial width to the minimum radial width of the gap is greater than 1.5.

Preferably, the radial width of the gap corresponding to each magnetic pole is symmetrical with respect to the middle line of the magnetic poles extending along the radial direction of the rotor.

Preferably, the tooth tip of the tooth is symmetrical about the radius of the motor through the center of the tooth main body of the tooth.

Preferably, the teeth of the stator core are individually formed and interconnected to form the stator core.

Advantageously, said at least one throw of said stator core is individually formed and connected to said annular portion.

Advantageously, the rotor comprises a plurality of permanent magnets, and the permanent magnets are plastic-packaged in the entire body.

In another aspect, a single-phase outer-rotor brushless motor is provided that includes 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 the yoke. Each threaded body including a threaded tip extending circumferentially from a distal end of the threaded body. The rotor includes a rotor yoke disposed around the stator core, and a permanent magnet disposed on an inner wall surface of the rotor yoke to form a plurality of magnetic poles. The inner surface of the permanent magnet and the outer surface of the tooth tip are opposed to each other and define a gap therebetween so that the rotor rotates relative to the stator. When the motor is de-energized, the rotor stops in its initial position, where the middle line of the tooth tip of the stator is closer to the middle line of the neutral region between two adjacent magnetic poles than the middle line of two adjacent poles.

An electric device employing the single-phase external rotor motor is also provided. The electric device includes an impeller or a reduction device driven by the motor.

In the single phase motor, magnetic bridges or small / narrow slot openings are defined between adjacent teeth of the stator core, the outer surface of the tooth tip of the stator and the inner surface of the permanent magnet define a gap therebetween , The circumferential width of the slot opening is less than or equal to five times the minimum radial width of the gap, and the ratio of the maximum radial width to the minimum radial width of the gap is greater than 1.5. Therefore, the rotor can be positioned at an initial position deviating from the dead-point position by the leakage magnetic field generated by the rotor magnetic pole, and the cogging torque can be effectively suppressed.

In the following, the invention is further illustrated with reference to the drawings and examples.

1 illustrates a single-phase external-rotor brushless motor in accordance with an embodiment of the present invention.
Fig. 2 is a radial cross-sectional view of the single-phase external-rotor brushless motor of Fig. 1;
3 is a cross-sectional view of the single-phase external-rotor brushless motor of Fig. 1 cut in the axial direction.
4 is an enlarged view of a portion surrounded by a dotted box in Fig.
Figure 5 shows the stator core of the single-phase external-rotor brushless motor of Figure 1;
1 shows the insulation bracket of the single-phase external-rotor brushless motor of Fig.
Fig. 7 is an assembled view of the stator core of Fig. 5 and the insulation bracket of Fig.
Figure 8 shows the rotor in the dead-point position when the single-phase external-rotor brushless motor is not energized.
Fig. 9 shows the rotor in the initial position when the single-phase external-rotor brushless motor is not energized.
10 shows a stator core of a motor according to a second embodiment of the present invention.
11 shows a stator core of a motor according to a third embodiment of the present invention.
12 and 13 show the rotor of a motor according to another embodiment of the present invention.
14 shows a rotor according to another embodiment of the present invention.
Figure 15 shows a rotor according to another alternative embodiment of the present invention.
16 shows a motor according to another embodiment of the present invention.
17 shows an embodiment of a fan employing the motor of the present invention.
18 shows an electric device using the motor of the present invention.

Embodiments of the present invention are described by way of example only with reference to the accompanying drawings. In the drawings, the same structures, elements and portions appearing in the drawings are designated by the same reference numerals throughout the drawings. The dimensions of the components and features shown in the figures are generally selected for convenience and are not necessarily drawn to scale.

1, 2 and 3, a single-phase permanent magnet motor according to an embodiment of the present invention includes a stator 10 and a rotor 20 surrounding the stator 10. As shown in Fig. Preferably, the single-phase permanent magnet motor is a single-phase permanent magnet brushless motor.

The stator 10 includes a stator core 11 made of a magnetic conductive material, an insulation bracket 13 attached on the stator core 11 and a winding 15 wound around the insulation bracket 13.

2, 4 and 5, the stator core 11 includes a plurality of annular portions 110 disposed at the center of the stator core 11, that is, a plurality of radially outward portions extending from the stator yoke and the annular portion 110 Includes four teeth. A winding slot is formed between each two adjacent teeth. Each threaded body 112 and a tooth tip 114 extending from the distal end of the threaded body 112 along the circumferential direction of the stator. Each of the two adjacent tooth tips 114 defines a slot opening 115 in communication with a corresponding winding slot therebetween. Preferably, each slot opening 115 has the same width in the circumferential direction. That is, the tooth tips are uniformly arranged along the circumferential direction. Preferably, each penetration is symmetrical about the radius of the motor through the center of the tooth body of the tooth. Preferably, the tooth tips have the same circumferential width. Alternatively, the tooth tips may have different circumferential widths, and each tooth may be asymmetrical to the radius of the motor through the center of the tooth body of the tooth.

The annular portion 110 is generally in the shape of a pupil cylinder. The through-hole 111 is defined to penetrate the central portion of the annular portion 110 along the axial direction. As shown in Figures 1, 2 and 3, the stator 10 further includes a base 16 and a bearing holder 17 formed on the base 16. The base 16 is generally a circular disc-shaped. The bearing holder 17 extends vertically from the center of the base 16 for fixing the stator core 11 thereon. Specifically, the bearing holder 17 is inserted through the through hole 111 of the annular portion 110 of the stator core 11. The bearing holder 17 defines therein a through hole for rotatably mounting the rotary shaft 21 of the rotor 20 therein.

The tooth body 112 extends radially from the outer wall surface of the annular portion 110 and the tooth body 112 is uniformly disposed along the circumferential direction of the annular portion 110. Each tooth body 112 has a tooth tip 114 formed at its radially distal end. Preferably, the tooth tip 114 is symmetrical about the radius of the motor passing through the center of the tooth body 112. 4, the outer surface 117 of the tooth tip 114, that is, the surface that is enlarged from the annular portion 110, is an arc surface. Preferably, the outer surface 117 of the tooth tip 114 is located on the same cylindrical surface having a central axis coinciding with the central axis of the rotating shaft 21. [ The inner surface 118 of the tooth tip 114, i.e., the surface facing the annular portion 110, is generally a flat surface.

In some embodiments, a slit 116 is formed in the connecting corner region between the tooth tip 114 and the tooth body 112. The provision of the slit 116 prevents crease during the process of bending the tooth tip 114 of the stator core 11 relative to the tooth body 112. Specifically, the two parts / wings of the tooth tip 114 on the opposite side of the tooth body 112 extend radially outwardly in the initial state such that the width of the winding slot and the slot opening 115 is greater than the width of the winding 15 In order to facilitate. After winding is completed, the two portions of the tooth tip 114 are bent inwardly into the final position around the slit 116 by using a tool. It should be appreciated that in some embodiments, the slit 116 may be formed only in the connecting corner region between the tooth body 112 and the portion of the tooth tip 114 on a single side of the tooth body 112.

6 and 7, the insulating bracket 13 includes an upper bracket portion 131 and a lower bracket portion 133. The upper bracket portion 131 and the lower bracket portion 133 cover the stator core 11 from the opposite shaft thereof.

The upper bracket portion 131 and the lower bracket portion 133 have substantially the same shape and structure and are disposed opposite to each other. Each of the upper bracket portion 131 and the lower bracket portion 133 includes a ring portion 130 attached around the annular portion 110 of the stator core 11, a sleeve portion 132 attached around the tooth body 112, And an opposing portion 134 that opposes the inner surface of the tooth tip 114. The ring portion 130 is generally in the shape of a circular tube, which surrounds the outer wall portion of the annular portion 110 of the stator core. The annular end flange 136 extends inwardly from the axially upper end of the ring portion 130. The end flange 136 covers the upper end surface of the annular portion 110 of the stator core. The side wall of the ring portion 130 defines a plurality of openings (not numbered) in which the sleeve portion 132 is disposed. The opening allows the tooth body 112 to pass therethrough. The sleeve portion 132 also has an end face and a side face corresponding to the end face and the side face of the tooth body 112. The sleeve portion 132 covers the end surface and both sides of the tooth body 112. As described herein, the end surface of the tooth body 112 refers to the upper and lower surfaces in the axial direction of the motor of the tooth body 112, and the side surface of the tooth body 112 has two surfaces parallel to the radial direction It is called. The sleeve portion 132 of the upper bracket portion 131 covers the upper surface and the two sides of the tooth body 112 and the sleeve portion 132 of the lower bracket portion 133 covers the lower surface of the tooth body 112 It should be understood that it covers two sides. The upper bracket portion 131 and the lower bracket portion 133 substantially cover the entire side and end surfaces of the tooth body 112 so as to insulate the stator core 11 from the winding 15.

The counterpart 134 is formed by circumferentially bending the radially distal end of the sleeve portion 132 against the inner surface 118 of one corresponding tooth tip 114.

In addition, vent plates 135 and 137 are disposed at the axial ends of the counterparts 134. Vent plates 135, 137 at least partially cover the end face of the axial end of the tooth tip 114. In particular, the vent plate 135 is disposed at the axially upper end of the opposing portion 134 of the upper bracket portion 131, at least partially covering the axially upper end surface of the corresponding one tooth tip 114; The vent plate 137 is disposed at the axially lower end of the opposing portion 134 of the lower bracket portion 133 and at least partially covers the axially lower end surface of the corresponding one of the tooth tips 114.

1 to 3, the rotor 20 includes a rotating shaft 21 passing through the annular portion 110, a rotor yoke 22 fixedly connected to the rotating shaft 21, a plurality of permanent magnet poles And a permanent magnet (24) disposed on the inner wall surface of the rotor yoke (22) to form a permanent magnet (24). In this embodiment, the permanent magnets 24 include a plurality of division magnets, each of which forms the permanent magnet poles 24. In an alternative embodiment, the permanent magnet may be formed of an integral ring magnet as shown in Fig. The ring magnet includes a plurality of sections, each section forming a permanent magnet pole (24). Preferably, the inner surface 241 of the permanent magnet 24 is a flat surface, so that the manufacture of the permanent magnet 24 can be simplified. However, it should also be understood that the inner surface of the permanent magnet may be an arc surface. Preferably, the pole-arc coefficient of the permanent magnet 24, that is, the ratio of the quotient of 360 angles divided by the actual angle of the permanent magnet 24 along the circumferential direction to the number of rotor poles is 0.75 Which improves the cogging torque characteristics and increases the efficiency of the motor.

3, the rotor shaft 21 is rotatably disposed in the through-hole of the bearing holder 17. As shown in Fig. For example, the rotary shaft 21 is rotatably supported in the bearing holder 17 by a bearing. The rotor yoke 22 is generally cylindrical in shape to cover the stator core 11. The rotor yoke 22 includes an end plate 221 fixedly connected to the rotating shaft 21 and an annular side wall 222 extending from the end plate 221. The end plate 221 is disposed opposite the base 16 and a gap is formed between the axial end of the side wall 222 and the base 16. The end plate 221 forms a plurality of windows therein for allowing outside air to enter and for cooling the interior of the motor. During operation of the motor, the rotor yoke 22 and the permanent magnets 24 rotate relative to the stator under the interaction between the permanent magnets 24 and the magnetic fields of the stator.

In some embodiments, the number of permanent magnet poles 24 may be the same or multiple relative to the number of teeth. For example, the number of teeth is two or three times the number of permanent magnet poles. In this embodiment, the rotor 20 comprises eight permanent magnets forming eight permanent magnet poles, the stator 10 comprising eight stator teeth, and a total of eight winding slots between adjacent teeth To form an 8-pole 8-slot motor. Preferably, the stator winding is electrically connected to the single-phase direct current electricity by a single-phase brushless direct-current motor driver and is supplied thereto to form a single-phase direct current brushless motor. It should be understood that the present invention can be used as a single phase permanent magnet synchronous motor in which the stator windings are connected to a single phase AC power source.

The inner surface 241 of the permanent magnet pole 24 faces the outer surface 117 of the tooth tip 114 and an air gap 119 is formed therebetween. The radial width of the gap 119 varies along the circumferential direction of the permanent magnet poles 24, forming a non-uniform gap. The radial width of the gap 119 progressively increases from the circumferential center toward the opposite circumferential end of the inner surface 117 of the permanent magnet pole 24. [ The radial distance between the circumferential center point of the inner surface of the permanent magnet pole 24 and the cylindrical surface on which the outer surface of the tooth tip 114 is located is the minimum radial width G1 of the gap 119 and the permanent magnet pole 24 and the cylindrical surface on which the outer surface of the tooth tip 114 is located is the maximum radial width G2 of the gap 119. The radial distance between the inner circumferential end point of the gap 119 and the cylindrical surface, Preferably, the ratio of the maximum radial width to the minimum radial width of the gap 119 is greater than 1.5, more preferably greater than 2, i.e., G2: G1 > 2.

The width D of the slot opening 115 (generally referred to as the minimum width of the slot opening 115 in the circumferential direction) is greater than or equal to zero but less than or equal to five times the minimum radial width of the gap 119 That is, 0 < Preferably, the width D of the slot opening 115 is greater than or equal to the minimum radial width of the gap 119, but less than or equal to three times the minimum radial width of the gap 119, that is, G1 &lt; to be. Alternatively, the adjacent tooth tips 114 may be connected together by a narrow bridge 115a having a large magnetoresistance as shown in FIG.

8 and 9, when the motor is not energized, the permanent magnet 24 of the rotor 20 generates attractive force to attract the tooth of the stator 10. Figures 8 and 9 show the rotor 20 in a different position. Specifically, FIG. 8 shows the rotor 20 in the dead-point position (i.e., the center of the magnetic pole of the rotor is aligned with the center of the tooth tip of the stator). Fig. 9 shows the rotor 20 in the initial position (i.e., the stop position of the rotor when the motor is not energized or powered off). 8 and 9, the magnetic flux of the magnetic field generated by the magnetic pole of the rotor 20 passing through the stator 10 is? 1 when the rotor 20 is at the dead-point position, The magnetic flux of the magnetic field generated by the magnetic pole of the rotor 20 passing through the rotor 20 is Φ2 when the rotor 20 is at the initial position and Φ2> Φ1 and the path of Φ2 is shorter than the path of Φ1 , The magnetic resistance of the magnetic circuit? 2 is therefore less than that of? 1. Therefore, the rotor 20 can be placed in the initial position when the motor is not energized, thereby preventing stopping at the dead-point position and thus preventing start failure of the rotor when the motor is energized . In this embodiment, the rotor 20 stops at the initial position shown in Fig. 9 when the motor is not energized or is powered off. In this initial position, the middle line of the tooth tip 114 of the stator core is preferably aligned with the middle line of the neutral region between the two adjacent rotor poles 24. [ This position is farthest away from the dead-point position, which can effectively prevent the start-up failure of the rotor when the motor is energized. In fact, due to other factors such as friction, the midline of the tooth tip 114 of the stator core is between 0 and 30 electrical degrees from the midline of the neutral region between the two adjacent rotor poles 24, But the stop position is still far away from the dead-point position. That is, when the motor is not energized, the rotor rotates at an initial position where the middle line of the tooth tip of the stator core is closer to the middle line of the neutral region between two adjacent poles than the middle line of two adjacent poles 24 Stop.

In the above-described embodiment of the present invention, the rotor may be located at an initial position deviating from the dead-point position by a leakage magnetic field generated by the rotor pole 24 itself pulling on the tooth tip of the stator core 11 . Leakage magnetic circuits generated by the rotor poles 24 do not penetrate the tooth body and the windings. The cogging torque of the thus configured single-phase permanent magnet brushless motor can be effectively suppressed, so that the motor has increased efficiency and performance. In the experiment, the peak of the cogging torque (rated torque of 1 Nm, rated rotation speed of 1000 rpm, and stator core stack height of 30 mm) of the single-phase external-rotor brushless DC motor is less than 80 mNm. The motor of the present invention can be designed to have bi-directional starting capability as needed. For example, bidirectional rotation can be achieved using two position sensors, such as Hall sensors, and associated controllers. Also, it can be designed to start in a single direction, in which case only one position sensor is needed.

Figure 10 shows a stator core 40 of a motor according to another embodiment of the present invention. The stator core 40 is different from the stator core 11 of the embodiment in that the stator core 40 of the present invention includes a plurality of individual tooth sections 41 connected to each other. Each tooth section 41 includes a yoke section 410, a tooth body 412 extending radially outward from the yoke section 410 and a tooth tip 414 extending circumferentially from the distal end of the tooth body 412 ). The tooth sections 41 are arranged circumferentially to collectively form the stator core 40. The yoke section 410 of the tooth section 41 collectively forms an annular yoke. The yoke sections 410 can be engaged with each other by a convex-concave fastening structure therebetween. In this embodiment, projections 415 are formed in the circumferential side of each yoke section 410, and a recess 417 is formed in the other circumferential side of each yoke section 410. The protrusions 415 of each yoke section 410 are snap-fitted to the recesses 417 of the other adjacent yoke sections 410 and the recesses 417 of each yoke section 410 are snap- 410, so that the entire tooth section 41 is connected as a whole. Alternatively, the yoke section 410 may have a planar contact surface fixed to each other by a user. Since the stator core 40 can be formed by interconnecting the individual tooth sections 41, the windings can be performed before connecting the toothed section 41 as a whole. Therefore, the slot opening between the tooth tips 414 can have a reduced size without affecting the winding process.

11 shows a stator core 50 according to another embodiment of the present invention. The stator core 50 is similar to the stator core 50 of the first embodiment in that the stator core 50 of the present embodiment includes a first tooth 51 formed integrally with the yoke 510 and a second tooth 52 formed separately. (11). The second tooth 52 is snap-fitted to the yoke 510, and the first tooth 51 and the second tooth 52 are also arranged in the circumferential direction. Preferably, the second tooth 52 is inserted into the yoke portion 510. The yoke portion 510 has a plurality of insertion slots 511. The radially inner end of the second tooth 52 has an insertion portion 522 coinciding with the insertion slot 511 in the shape surface. Preferably, the insertion slot 511 is a swallowtail-shaped slot. The stator core 50 of this embodiment includes a separate second tooth 52 that can be inserted into the yoke 510 after winding is completed. Therefore, the slot opening between the tooth tips can be reduced in size without affecting the winding process.

12 and 13 illustrate a rotor 60 according to another embodiment of the present invention. The rotor 60 is different from the rotor 20 of the first embodiment in that the rotor 60 further includes a packaging portion 65. [ Specifically, the rotor 60 is packaged by placing the rotor yoke 62 and the permanent magnet 64 in the mold cavity and injecting the plastic into the mold cavity.

16 shows a motor according to another embodiment of the present invention. In this embodiment, the rotor 70 includes a permanent magnet 26 and a magnet member 24 disposed alternately at intervals in the circumferential direction. The permanent magnets 26 are magnetized in the circumferential direction of the rotor. The adjacent permanent magnets 26 have opposite polarities. The magnet member 24 may be made of a hard magnetic material such as a ferromagnetic material or a soft magnetic material such as iron. The magnet member 24 has a thickness that gradually decreases from the circumferential center to two circumferential sides. The minimum thickness of the magnet member 24, i.e., its thickness on the circumferential side surface thereof, is substantially equal to the thickness of the permanent magnet 26. [ The inner circumferential surface of the magnet member 24 facing the stator is a flat surface extending parallel to the tangential direction of the outer surface of the stator. Thus, the circumferentially inner surface of the permanent magnet and the circumferentially inner surface of the magnet member collectively form the inner surface of the rotor, which is a symmetrical polygon in the radial section of the rotor (70). The inner surface of the permanent magnet and the inner surface of the magnet member collectively form the polygonal inner surface of the rotor (70). The stator 10 and the rotor 70 form a symmetrical non-uniform gap therebetween, the gap having a size gradually decreasing along two circumferential sides at the circumferential center of the magnet member 24, And reaches the maximum width Gmax at the position corresponding to the magnet 26. [ When the motor is de-energized, the rotor 70 can be placed in an initial position by a leakage magnetic field generated by the permanent magnet 26 passing through the magnet member 24 and the corresponding tooth tip of the stator.

The motor of the present invention is particularly suitable for fans such as range hood fans, vehicle cooling fans, ventilation fans, and the like. 17 shows a motor 1 of the present invention employed in a fan 2 according to one embodiment. The fan (2) includes an impeller (3) connected to and driven by the motor (1) to generate an air flow.

Fig. 18 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, vehicle or air conditioner including the fan 2 of Fig. The electric device 4 may also be a washing or drying device including a speed reducing device 3 driven by a motor 1. [

It should be appreciated that the single-phase permanent magnet motor may be a single-phase permanent magnet brush motor comprising a yoke having a core and a winding wound on the core, and a yoke having a permanent magnet fixed on the inner surface of the yoke.

In the detailed description and the claims of this application, the verbs "comprise", "include", "contain", and "have" And are not intended to identify the presence of the foregoing items, nor to exclude the presence of additional items or features.

While the present invention has been described with reference to one or more preferred embodiments, those skilled in the art will appreciate that various modifications are possible. For example, the rotor stimulus may be integral rather than divisible as described in the above embodiments, and the number of slots and poles may vary from 2 poles 2 slots to N poles N slots without departing from the scope of the present invention . The scope of the invention is, therefore, determined with reference to the following claims.

Claims (34)

As a single phase outer-rotor motor:
A stator comprising a stator core and windings wound about the stator core, the stator core comprising a plurality of teeth extending outwardly from the yoke and the yoke, each of the plurality of teeth extending from a distal end of the respective tuft body and the toothed body in a circumferential direction A tooth tip extending into the body; And
A rotor yoke disposed about the stator core and a rotor including at least one permanent magnet disposed on an inner surface of the rotor yoke to form a plurality of magnetic poles, the inner surface of the magnetic pole having an outer surface A gap is formed therebetween to allow the rotor to be rotated relative to the stator,
Wherein the rotor is capable of being positioned in an initial position by a leakage magnetic field generated by at least one permanent magnet operating in conjunction with the tooth tip of the stator core when the motor is de-energized, Rotor motors. The single-phase external-rotor motor of claim 1, 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 spin width of the gap. The single-phase external-rotor motor of claim 1, 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 three times the minimum spin width of the gap. The rotor of claim 1, wherein the gap is a uneven gap, and the radial width of the gap corresponding to each pole gradually increases from the center of the pole toward the circumferential end of the pole. motor. 5. The single-phase external-rotor motor according to claim 4, wherein the ratio of the maximum radial width to the minimum radial width of the gap is greater than 1.5. 5. The single-phase external-rotor motor according to claim 4, wherein the radial width of the gap corresponding to each magnetic pole is symmetrical with respect to an intermediate line of the magnetic pole extending along the radial direction of the rotor. 7. The single-phase external-rotor motor according to any one of claims 1 to 6, wherein the outer surfaces of the tooth tip are located on the same cylindrical surface, and the central axis of the cylindrical surface coincides with the central axis of the rotor. 7. The single-phase external-rotor motor according to any one of claims 1 to 6, wherein the inner surface of the magnetic poles is a flat surface or a circular arc surface, and the pole arc coefficient is greater than 0.75. The stator of claim 1, wherein the stator includes an insulation bracket attached around the stator core and a winding wound around the insulation bracket, wherein the insulation bracket includes an upper bracket portion and a lower bracket portion, The bracket portion covers the stator core from their opposite axial ends, each of the upper bracket portion and the lower bracket portion having a ring portion attached around the yoke of the stator core, a sleeve portion attached around the tooth body, Gt; rotor &lt; / RTI &gt; The single-phase external-rotor motor according to claim 9, wherein a vent plate is disposed at the axial end of the counterpart, at least partially covering an end face of the axial end of the tooth tip. The single-phase external-rotor motor according to claim 1, wherein a slit is formed in at least one connecting corner region between the tooth tip and the thread body. The single-phase external-rotor motor of claim 1, wherein the teeth of the stator core are individually formed and interconnected to form the stator core. The single-phase external-rotor motor of claim 1, wherein at least one throw of the stator core is formed separately and is connected to the yoke. The single-phase external-rotor motor according to claim 1, wherein the rotor comprises a plurality of permanent magnets forming the magnetic poles, and the permanent magnets are plastic-packaged in the entire body. As a single phase permanent magnet motor:
CLAIMS What is claimed is: 1. An armature comprising a core and a winding wound about the core, the core comprising an annular portion and a plurality of teeth extending outwardly from the annular portion, wherein each threaded body and a plurality of teeth extending from a distal end of the tooth body in a circumferential direction Wherein a slot opening is formed between each two adjacent tooth tips; And
A yoke surrounding the armature and at least one permanent magnet disposed on the inner surface of the rotor yoke to form a plurality of magnetic poles, the inner surface of the pole facing the outer surface of the tooth tip, and a gap being formed therebetween Including,
Wherein the width of the slot opening in the circumferential direction is less than or equal to five times the minimum radial width of the gap and the radial width of the gap corresponding to each magnetic pole progressively increases from the middle portion of the magnetic pole toward the circumferential end, Single phase permanent magnet motor. 16. The method of claim 15, wherein when the motor is de-energized, the yoke and the poles can be placed in an initial position by a leakage magnetic field generated by at least one permanent magnet that cooperates with the tooth tip of the armature, Wherein the initial position deviates from a dead-point position of the motor. 16. The single-phase permanent magnet motor of claim 15 wherein the circumferential width of the slot opening is less than or equal to three times the minimum radial width of the gap. The single-phase permanent magnet motor according to any one of claims 15 to 17, wherein the ratio of the maximum radial width to the minimum radial width of the gap is greater than 1.5. The single-phase permanent magnet motor according to any one of claims 15 to 17, wherein the radial width of the gap corresponding to each magnetic pole is symmetrical with respect to the middle line of the magnetic poles extending along the radial direction of the rotor. The single-phase permanent magnet motor according to any one of claims 15 to 17, wherein the tooth tip of the tooth is symmetrical about the radius of the motor through the center of the tooth main body of the tooth. As a single phase outer-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 the yoke and the yoke, each of the plurality of teeth extending from a distal end of the toothed body to a circumferential A tooth tip extending in a direction parallel to an axis of rotation; And
A rotor including a rotor yoke disposed about the stator core and a permanent magnet disposed on an inner wall surface of the rotor yoke to form a plurality of magnetic poles, the inner surface of the permanent magnet and the outer surface of the tooth tip And defining a gap therebetween to allow the rotor to rotate relative to the stator,
Wherein when the motor is de-energized, the rotor is stopped at an initial position, wherein the midline of the tooth tip of the stator has an intermediate line of neutral areas between two adjacent magnetic poles, To a single-phase external rotor motor. 22. The single-phase external rotor motor of claim 21, 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 spin width of the gap. 22. The single-phase external rotor motor of claim 21, 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 three times the minimum radial width of the gap. 23. The method of at least one of claims 21 to 23, wherein the gap is a non-uniform gap, the radial width of the gap corresponding to each magnetic pole gradually increasing from the central portion of the magnetic pole toward the circumferential end, . 25. The single-phase external rotor motor of claim 24, wherein the ratio of the maximum radial width to the minimum radial width of the gap is greater than 1.5. 25. The single-phase external rotor motor according to claim 24, wherein the radial width of the gap corresponding to each magnetic pole is symmetrical to the middle line of the magnetic poles extending along the radial direction of the rotor. 22. The single-phase external rotor motor of claim 21, wherein the outer surfaces of the tooth tip are located on the same cylindrical surface, and the central axis of the cylindrical surface coincides with the central axis of the rotor. 1. A fan comprising a motor and an impeller driven by the motor, the motor being a single-phase external rotor motor:
A stator comprising a stator core and windings wound around the stator core, the stator core comprising a plurality of teeth extending radially outwardly from the yoke and the yoke, each of the plurality of teeth extending from the distal end of the toothed body and the distal end A tooth tip extending in a circumferential direction; And
A rotor including a rotor yoke disposed about the stator core and a permanent magnet disposed on an inner wall surface of the rotor yoke to form a plurality of magnetic poles, the inner surface of the permanent magnet and the outer surface of the tooth tip And defining a gap therebetween to allow the rotor to rotate relative to the stator,
Wherein a magnetic flux of a magnetic field generated by the rotor and passing through the stator is varied in accordance with a different position of the rotor with respect to the stator when the motor is de-energized, The rotor is located at an initial position when the motor is not energized and the magnetic flux reaches a maximum value when the rotor is in the initial position, And the initial position deviates from the dead-point position. An electric device comprising a single-phase permanent magnet motor,
A stator core having a plurality of teeth and a stator comprising the tooth wound winding, each tooth tip body including a tooth tip extending circumferentially from a distal end of the tooth body; And
A yoke surrounding the stator and a rotor including at least one permanent magnet disposed on the inner surface of the yoke to form a plurality of poles, the inner surface of the pole facing the outer surface of the tooth tip, Gap is formed -
Wherein the rotor can be positioned in an initial position by a leakage magnetic field generated by at least one permanent magnet operating in conjunction with the tooth tip of the stator when the motor is de-energized. 29. The rotor of claim 29, wherein a bridge or narrow slot opening is formed between adjacent tooth tips, the distance between the midpoint of the inner surface of the pole and the center of the rotor is less than the circumferential end point of the inner surface of the pole, Wherein the distance between the centers is less than the distance between the centers. 32. The electrical device of claim 29 or 30, 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 radial width of the gap. 29. The method of claim 29 or 30, wherein when the rotor is in its initial position, the midline of the tooth tip of the stator core is further coupled to an intermediate line of a neutral region between two adjacent magnetic poles, Close, electrical device. 31. The electrical device of claim 29, wherein the electrical device further comprises an impeller driven by the rotor, the microwave oven being a range hood, air conditioner, vehicle or ventilation fan. 30. The electrical device of claim 29, wherein the electrical device is a washing machine or dryer, further comprising a reduction device driven by the rotor.

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