JP2008199801A - Fan system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fan system which can secure an axial ventilating path in an axial blower and also meet the downsizing and cost reduction of a motor. <P>SOLUTION: In an axial flow system which rotatably holds an axial flow blower that has a rotating shaft 8a at the center and besides has a cylindrical rotating vane 8, via a bearing, in a roughly square housing 9 which is equipped, at its center, with a bearing holder 12 capable of rotatably holding the vane 8, a sheet-shaped magnet 7 is arranged annularly around the vane 8 as the rotor of the motor which serves as a drive source for driving the vane 8. The magnet 7 is of such structure that it has an even number of poles in its circumferential direction, with N poles and S poles arranged alternately in its rotational direction. Furthermore, armature magnetic poles (that is, stators 6), which have two or more phases of coils, are arranged at two points of corners out of four points of the roughly square housing 9, to the rotor of this magnet 7. Accordingly, the rotor and the stator of the motor cease to exist in the vane 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fan system for blowing air having a motor and blades.

  Fan systems for blowing are roughly classified into three types: axial blowers, centrifugal blowers, and mixed flow blowers. In particular, fan systems used for industrial and home appliances operate in terms of air volume, noise, and wind pressure. Considering the conditions are used. The axial blower has a feature that the shape of the blades is a propeller fan, the direction of the blow is parallel to the rotation axis, the air volume is large, and the noise is relatively small. Centrifugal blowers are used for applications that require high wind pressure, and the direction of air blowing is a centrifugal direction perpendicular to the axis. The mixed flow blower has intermediate characteristics between the axial flow blower and the centrifugal blower.

  Usually, in these blowers (fan systems), a motor rotates a blade. That is, the output shaft of the motor is coupled to the central axis of the blade, and the blade is driven to rotate by the rotational force of the motor. At this time, since the fan system is composed of a motor and blades, the output capacity and the size of the motor vary depending on the size and rotational speed of the blades that are rotationally driven. Therefore, when the motor becomes large, some of the air passages of the blades are blocked by the motor. Therefore, in order to satisfy the overall fan system characteristics, it is best to match the shape of the motor with the shape of the blades. Since it is designed, the design freedom of each of the motor and the blade is limited.

Therefore, for example, a technique such as Patent Document 1 is disclosed in order to satisfy the demands corresponding to the thinning of the fan unit constituting the fan system. According to this technique, the height of the motor can be kept low by configuring the stator in which a plurality of coils are annularly arranged with respect to the annular magnet (magnet). As a result, the motor, which is the driving element of the blades, can be made as thin as possible to reduce the thickness of the entire fan unit.
Japanese Patent Laying-Open No. 2005-133710 (see paragraph numbers 0048 to 0050 and FIG. 2)

  However, the technique according to Patent Document 1 is effective only in a fan system such as a centrifugal blower in which air flow flows in a direction perpendicular to the shaft. This is because, by using a thin motor as the blade drive source, the radial dimension of the motor inevitably increases, and therefore, it cannot be applied to an axial blower having an air passage in the axial direction. Furthermore, if the fan unit is to be thinned by the technique disclosed in Patent Document 1, a motor magnet that can increase the energy density is required. As a result, problems such as an increase in the cost of the fan system from the viewpoint of manufacturing also occur.

  This invention is made | formed in view of the above problems, and makes it a subject to provide the fan system which can ensure the ventilation path of an axial direction.

  In order to solve the above-described problems, a fan system according to the present invention is a fan system that rotates blades with a rotational driving force of a motor, and includes a housing that houses the blades and includes corner portions, and a corner of the housing. And a stator of the motor disposed in the section.

  According to this, since the stator is provided at the corner of the casing, the motor does not block the ventilation path of the blades. This stator is preferably provided at two or four corners on the diagonal of the housing. The rotor is formed by arranging a plurality of magnetic poles in an annular shape on the outer periphery of the blade. Each stator is formed such that the magnetic resistances of the tooth portion, the yoke portion, the body portion connecting them and the magnetic gap between the tooth portions are substantially equal between the phases.

  According to the present invention, an axial ventilation path can be secured.

<< First Embodiment >>
Hereinafter, the fan system which is 1st Embodiment which concerns on this invention is demonstrated.
In the component exploded view of FIG. 1, the fan system 11 includes a blade 8, a magnet 7 in which a plurality of magnet sheets are annularly disposed on the outer periphery of the blade 8, and a recess for housing the blade 8 and the magnet 7. A housing 9 made of resin and a stator 6 housed in two opposing corners of the housing 9 having a substantially square end surface are provided.

  Therefore, in the fan system 11 of FIG. 1, the magnet 7 has an even number of magnet sheets formed in an annular shape and bonded to the outer periphery of the blades 8 so that N poles and S poles are alternately arranged. The motor for rotating the blades 8 is constituted by a rotor of the magnet 7 and a stator 6 housed in two corners.

  That is, the fan system 11 of FIG. 1 effectively uses most surfaces of the rotating blade 8 as an air passage, and the stator 6 is disposed in a corner portion that is a space other than the blade 8 of the housing 9. The air volume from 8 is utilized to the maximum. Thereby, the motor which becomes the rotational drive source of the blade | wing 8 is arrange | positioned so that the ventilation area | region of the blade | wing 8 may not be covered.

  In more detail, the stator 6 has the X-axis direction and the Y-axis by positioning functions such as the key grooves 1a and 1b formed on the stator 6 and the projections 10a and 10b on the housing 9 side (the projection 10a is not shown in FIG. 1). Axial direction is positioned and arranged at two opposing corners of the substantially square housing 9. A bearing holding portion 12 is disposed at the center of the housing 9, and the rotary shaft 8a at the center of the blade 8 can be rotated and held on the bearing holding portion 12 via a bearing (not shown). .

  FIG. 2 is a perspective view of the assembled fan system 11. In the fan system 11, blades 8 are arranged inside a substantially square housing 9 and are housed in a substantially square housing 9 having a slightly longer side than the diameter of the blades 8. The stators 6 are arranged at two opposite corners of the housing 9, and these stators 6 serve as a stator and an annular magnet 7 serves as a rotor to form a motor, and the blades 8 are driven to rotate.

  FIG. 3 is a perspective view showing a configuration in which a large number of fan systems 11 are arranged. As shown in FIG. 3, since the diameter of the effective blade 8 is increased and the housing 9 is substantially square, the area utilization factor of the fan system in which a large number of fan systems 11 are arranged in series is extremely high.

  FIG. 4 is a perspective view showing the structure of the three-phase stator 6 used in the fan system 11. The yoke portion 1 of the stator 6 has a shape that can be disposed at the corner of a substantially square housing 9 (FIG. 1). The yoke portion 1 is provided with a positioning fitting portion capable of restraining the position in at least two directions. As the fitting portion, the stator 6 has two pieces of the yoke portion 1 configured at right angles. Key grooves 1a and 1b having a substantially rectangular shape are provided on both sides of the main body.

  One key groove (for example, key groove 1a) of the yoke portion 1 is engaged with a projection on the housing side (not shown), thereby restraining in one direction (for example, the X axis). In addition, the restriction in the direction perpendicular to the direction (that is, the direction of the Y axis that is a perpendicular axis to the X axis) is restricted by a key groove 1b provided in the other piece of the yoke portion 1 in a housing not shown. By engaging with the other projection on the side, the restraining function is satisfied. Thereby, the position (namely, the position of an X-axis and a Y-axis direction) of the yoke part 1 in the plane direction can be determined uniquely. The positioning of the yoke part 1 in the Z-axis direction (that is, the depth direction) can be realized by bringing the lower end surface of the yoke part 1 into contact with the bottom of the housing 9 shown in FIG.

  Further, the yoke portion 1 is provided with a plurality of phases (magnetic poles) 2a, 2b, 2c in the circumferential direction of the inner surface, and a trunk portion (see FIG. 2) connecting the teeth 2a, 2b, 2c and the yoke portion 1 to each other. A coil 3a, 3b, 3c (the coil 3a is not shown in FIG. 4) is wound around the outer periphery of the coil (not shown). That is, the coils 3a, 3b, 3c are inserted between the teeth 2a, 2b, 2c and the yoke part 1, respectively.

  FIG. 5 is an exploded view of the three-phase stator 6 shown in FIG. In FIG. 5, in order to simplify the drawing, only one pole of the teeth 2a, 2b, 2c and the coils 3a, 3b, 3c shown in FIG. ing.

  In FIG. 5, the yoke portion 1 of the stator 6 has three holes 23 a, 23 b, and 23 c that fit into the body portion 21 of the teeth 2 (that is, the teeth 2 a, 2 b, and 2 c shown in FIG. 4). Is provided. For example, the body 21 of the tooth 2 that fits into the hole 23 b of the yoke portion 1 is provided with the coil 3 having an inner diameter that fits to the outer diameter of the body 21, and the joint 21 with the body 21 of the tooth 2. The hole portion 23b of the iron portion 1 is structured to be coupled by a method such as press fitting or gap fitting and adhesion with the coil 3 interposed. The center points of the holes 23a, 23b, and 23c are arranged so as to form a substantially equilateral triangle.

  Thus, as shown in FIG. 4, the coil 3 a (not shown) is inserted between the tooth 2 a and the yoke portion 1, and the coil 3 b is inserted between the tooth 2 b and the yoke portion 1. The coil 3c is inserted between the tooth 2c and the yoke part 1 after being inserted. Therefore, the magnetic flux passing through the coils 3a, 3b, 3c passes through the vertices of a substantially equilateral triangle.

  In addition, since the yoke part 1 and the teeth 2 are provided with all directional components in the X, Y, and Z directions, it is desirable that the yoke part 1 and the teeth 2 are configured by a powder magnetic core having magnetic three-dimensional isotropic properties. Such a dust core can be realized by compression-molding insulation-coated iron powder or by integrally molding the insulation-coated iron powder and magnetic powder.

  The integral molding of the iron powder and the magnetic powder is performed by first temporarily molding a magnetic powder such as iron powder at a pressure lower than the main molding pressure, and then filling the same cavity with the insulating powder and magnetic material. The powder temporary compact and the insulating powder are simultaneously molded and integrated. The powder magnetic core formed in this way maintains the shape of the bonding interface clearly, and integrally forms a magnetic powder having poor compressibility together with a sticky insulating powder from the state of the powder. It is possible to avoid a decrease in the density.

  Here, the reason why it is possible to improve the rotational torque of the motor by making the magnetic flux flow uniform by using the structure of the stator 6 as shown in FIG. 4 will be described in comparison with a comparative example. FIG. 6 is a conceptual diagram showing the flow of magnetic flux in the stator of the comparative example. FIG. 7 is a conceptual diagram showing the flow of magnetic flux in the stator according to the present embodiment.

  As shown in FIG. 6, the stator 60 of the comparative example is formed by integrally punching the yoke portion 61 and the teeth 62a, 62b, and 62c using a thin plate such as an electromagnetic steel plate and laminating them. . When the rotor of the magnet (not shown) is rotated inside the teeth 62a, 2b, 62c of the stator 60 having the minimum configuration as shown in FIG. 6, the phase between the phases generated by the teeth 62a, 62b, 62c The flow of magnetic flux is as shown in the figure. That is, the magnetic path of the magnetic flux flowing between the a phase of the teeth 62a and the b phase of the teeth 62b is 65ab, and the magnetic path of the magnetic flux flowing between the b phase of the teeth 62b and the c phase of the teeth 62c is 65bc. On the other hand, since only the a phase of the teeth 62a and the c phase of the teeth 62c are in a distant positional relationship, the magnetic path 65ac of the magnetic flux flowing between the a phase of the teeth 62a and the c phase of the teeth 62c is magnetic. The road length becomes longer. As a result, an unbalance occurs in the magnetic path length between either the magnetic path 65ab or the magnetic path 65bc and the magnetic path 65ac.

  On the other hand, the stator 6 of this embodiment is configured as shown in FIG. That is, each hole part 23a, 23b, 23c (FIG. 5) fitted to each trunk | drum (not shown) of each teeth 2a, 2b, 2c arrange | positioned at the yoke part 1 of the stator 6 is 3 The structure is arranged in a substantially equilateral triangle dimensionally. Therefore, by arranging the coils 3a, 3b, 3c (however, the coil 3a is not shown in FIG. 7) in a substantially equilateral triangular positional relationship, the balance of magnetic flux between the phases is improved. That is, as shown in FIG. 7, the magnetic paths 5ab, 5bc, 5ac between the teeth 2a, 2b, 2c correspond to the sides of a substantially equilateral triangle, and the magnetic path lengths between the phases are the same. Three-phase magnetic flux balances.

  Further, by appropriately varying the cross-sectional area of the body portion 21 (FIG. 5) between the phases, the tooth portion 22 (FIG. 5), the yoke portion 1, the magnetic gap between the body portion 21 and the tooth portion 22 connecting them, and Can be made equal between the phases.

  The magnet 7 has an even number of magnet sheets arranged in an annular shape so that S poles and N poles are alternately arranged. However, the magnet 7 has two mechanical angles occupied by the three teeth 2a, 2b, 2c. Preferably, pole or quadrupole magnet sheets are arranged.

  8 is a diagram showing the induced electromotive force generated in the stator having the structure shown in FIGS. 6 and 7, and FIG. 8A shows the induced electromotive force of the coil by the stator 60 of the comparative example. (B) has shown the induced electromotive force of the coil 3 by the stator 6 of this embodiment.

  As shown in FIG. 8A, in the stator 60 shown in FIG. 6, the b-phase stator (that is, the teeth 62 b) is arranged at the center. 100% is obtained by balance with the phases (the teeth 62a and the teeth 62c), but the magnetic path length is long in the a-phase stator (the teeth 62a) and the c-phase stator (the teeth 62c) at both ends. Therefore, it can be seen that the induced electromotive force is reduced by about 20% and only about 80% is obtained. As a result, in the stator 60, problems such as a decrease in the rotational torque of the motor and an increase in torque ripple occur.

  On the other hand, in the stator 6 of this embodiment as shown in FIG. 7, the magnetic path length between the phases (that is, the magnetic path length between the teeth 2a, 2b, 2c) is the same, and the three-phase magnetic fluxes are balanced. Therefore, as shown in FIG. 8B, the induced electromotive force of 100% can be obtained without reducing the induced electromotive force in all of the a phase, the b phase, and the c phase. As a result, a motor with good torque balance can be obtained without reducing the rotational torque of the motor.

  FIG. 9 is a conceptual diagram in which the stators 6 are arranged at two locations on the circumference (two diagonal positions of the housing 9) in the fan system according to the first embodiment. If only one stator 6 is arranged with respect to the annular magnet 7, stress is always applied to one side due to the attractive force of the magnet 7 and the core of the stator 6, and uneven rotation torque (unbalance). Occurs. Therefore, in order to improve such a problem, as shown in FIG. 9, by providing the stator 6 having the same configuration at the diagonal position of the housing, the attractive force of the magnet 7 and the core of the stator 6 is balanced. Can be structured. As a result, a motor with good torque balance can be realized.

  Here, the advantages and disadvantages resulting from the structure of the fan system of the comparative example and the fan system of the present embodiment will be compared. FIG. 10 is a sectional view showing the structure and blowing direction of the fan system 66 of the comparative example, and FIG. 11 is a sectional view showing the structure and blowing direction of the fan system 11 of the present embodiment.

  As shown in the comparative example of FIG. 10, the blades 63 are coupled to the rotation shaft of the motor 64 disposed at the center of the fan system 66 and rotate. Therefore, the motor 64 is desired to be as small as possible in order to be disposed at the center of the blade 63. However, since the magnetic gap radius between the rotor (not shown) and the stator (not shown) of the motor 64 is small, a magnet used as the rotor is a rare earth magnet having a large energy product in order to obtain a large rotational torque. Etc. need to be used. In addition, it is necessary to increase the volume of the magnet or to pass a large current through the coil, which increases the size of the entire motor. Moreover, since the motor 64 exists in the center part of the blade | wing 63, the part in which the motor 64 exists becomes a structure which cannot be used as a ventilation path, and worsens the ventilation efficiency of a fan system. Furthermore, in order to mount the motor 64 and the blades 63, the axial length H1 of the entire fan system needs to be larger than the axial length of the blades, which hinders downsizing and high efficiency of the fan system. There are many factors.

  On the other hand, in the fan system 11 of the present embodiment, as shown in FIG. 11, since the motor is not present in the central portion of the blade 8, the blade 8 can be configured up to the central portion of the fan system 11. Therefore, the fan system 11 can also use the center part of the blade | wing 8 as a ventilation path. Moreover, since it is not necessary to consider the axial length of the motor, the axial length H2 of the entire fan system 11 is equivalent to the axial length of the blades 8. As a result, the fan system 11 of this embodiment is compared with the comparison shown in FIG. Thinning can be realized as compared with the fan system 66 of the example.

  Furthermore, in the fan system 11 of this embodiment, since the outer diameter of the magnet 7 (FIG. 9) is substantially equal to the outer diameter of the blade 8, a large rotational torque can be transmitted to the blade 8. Further, since the area of the output gap portion of the motor can be increased, the energy product required for the magnet can be reduced, and as a result, the cost of the entire fan system 11 can be reduced.

  Further, in the fan system 66 of the comparative example, electric charges are accumulated through the bearing portion of the bearing, and there is a possibility that electric corrosion occurs in the bearing portion or the like. However, in the fan system 11 of the present embodiment, such electric current is generated. Erosion is less likely to occur. That is, in the fan system 11 of the present embodiment, since the portion that is configured as an annular motor and generates magnetic flux and the bearing portion of the bearing can be configured as separate bodies, charges are accumulated in the stator 6. However, since the electric charge does not flow through the bearing portion of the bearing, there is no possibility that electric corrosion occurs in the bearing portion or the like. If an electrical insulator such as a ceramic ball bearing is used for the bearing portion, the electrolytic corrosion problem is completely avoided.

  As described above, the fan system 11 of the present embodiment can be configured without the motor blocking the axial ventilation path even in the axial blower, so the shape of the blade 8 is designed regardless of the arrangement of the motor. It becomes possible to obtain a degree of freedom. As a result, since the optimum design can be performed with a single blade, the air volume can be maximized with a limited size. Further, the stator 6 for rotationally driving the blades drives the magnet 7 in the outer diameter portion of the rotating blades (FIG. 1), so that the motor 64 of the comparative example configured as a rotor with a small outer diameter (FIG. 10). ), A large rotational torque can be obtained with a small input power. In other words, the fan system 11 can obtain a large rotational torque even with the magnet 7 having a small energy product (1/2 · BHmax). Furthermore, it becomes possible to reduce the noise which becomes a problem as a fan system by reducing the energy product of the magnet and reducing the magnetic flux density of the torque output unit. In addition, since there is no motor in the axial direction of the blade 8, it is possible to achieve a significant reduction in thickness and size as a whole fan unit. As a result, the cost of the fan system can be reduced.

<< Second Embodiment >>
In the fan system of the first embodiment, as shown in FIG. 9, stators 6 are arranged at two opposite corners of a substantially square housing to balance the suction force (that is, rotational torque). Although an example is shown, similarly, it is possible to take measures so that stress is always applied in one direction due to suction force by arranging the stators at equal pitch intervals on the circumference. For example, when the stators are arranged at four or more positions on the circumference, a plurality of pairs of stators may be arranged with two stators facing each other at 180 degrees as a pair.

  FIG. 12 is a conceptual diagram in which the stator 6 is arranged at each of four corners of a substantially square housing in the fan system according to the second embodiment. As shown in FIG. 12, it is ideal to arrange the stators 6 at four locations by using the respective corner portions of the substantially square housing region in view of effective use of the housing region and balance of rotational torque. It can be said that this is the arrangement of the stators.

<< Third Embodiment >>
FIG. 13 is a perspective view of a stator applied to a single-phase motor in a fan system according to a third embodiment of the present invention. In the structural diagram of FIG. 13, the yoke portion 31 of the stator 36 has a shape that can be arranged at a right-angled corner such that it can be arranged at the corner of a substantially square housing (housing 9 in FIG. 1). ing. The yoke portion 31 is shown with an example in which key grooves 31a and 31b having a substantially rectangular shape are provided as positioning fitting portions capable of restraining positions in at least two directions.

  One key groove (for example, key groove 31a) of the yoke part 31 is engaged with a projection on the housing side (not shown), thereby restraining in one direction (for example, the X axis). Further, the restriction in the direction perpendicular to the direction (that is, the direction of the Y axis that is a perpendicular axis to the X axis) is constrained by a key groove 31b provided in the other piece of the yoke portion 31 in a housing (not shown). By engaging with the other projection on the side, the restraining function is satisfied. Thereby, the position (namely, the position of a X-axis direction and a Y-axis direction) of the plane direction of the yoke part 31 can be determined uniquely. The positioning of the yoke portion 31 in the Z-axis direction (that is, the depth direction) can be realized by bringing the lower end surface of the yoke portion 31 into contact with the bottom portion of the housing 9 shown in FIG.

  Further, a single-phase tooth 32 is provided in the inner portion of the yoke portion 31, and a coil 33 is wound around a body portion (not shown) connecting the teeth 32 and the yoke portion 31. ing. That is, the coil 33 is inserted between the tooth 32 and the yoke portion 31. By using a single-phase stator having such a structure, a large rotational torque can be obtained in a single-phase motor.

It is a component exploded view showing the assembly structure of the fan system of the present invention. It is the perspective view which completed the assembly of the fan system which concerns on this invention. It is a perspective view which shows the structure which has arrange | positioned many fan systems of this invention. It is a perspective view which shows the structure of the three-phase stator of the motor which has a stator only for a part of circumferential direction used for the fan system of this invention. FIG. 5 is an exploded view of the stator shown in FIG. 4. It is a conceptual diagram which shows the flow of the magnetic flux in the stator structure of the conventional motor. It is a conceptual diagram which shows the flow of the magnetic flux in the stator structure of the motor which concerns on this invention. FIGS. 8A and 8B are diagrams showing induced electromotive force generated in the stator having the structure shown in FIGS. 6 and 7, where FIG. Indicates power. In the fan system which concerns on 1st Embodiment of this invention, it is the conceptual diagram which has arrange | positioned the stator in two places on the circumference. It is sectional drawing which shows the structural drawing and ventilation direction of the conventional fan system. It is sectional drawing which shows the structure and ventilation direction of the fan system of this invention. In the fan system which concerns on 2nd Embodiment of this invention, it is the conceptual diagram which has each arrange | positioned the stator to four corners of a substantially square housing. It is a perspective view which shows the structure of the stator of the single phase motor which has a stator only in a part of the circumferential direction used for the fan system which concerns on 3rd Embodiment of this invention.

Explanation of symbols

1,31,61 yoke portion 1a, 1b, 31a, 31b keyway 2, 2a, 2b, 2c, 32, 62a, 62b, 62c teeth 3, 3a, 3b, 3c, 33 coil 4, 34 mounting hole 5ab, 5bc, 5ac, 65ab, 65bc, 65ac Magnetic path 6, 36, 60 Stator 7 Magnet 8, 63 Blade 8a Rotating shaft 9 Housing 10a, 10b Protrusion 11, 66 Fan system 12 Bearing holding portion 21 Body portion 22 Tooth portion 23a, 23b, 23c hole

Claims (14)

A fan system that rotates blades with the rotational driving force of a motor,
A housing that houses the blades and includes corners;
A fan system comprising: a stator of the motor arranged at a corner of the housing.   2. The fan system according to claim 1, wherein a shape of the housing is a substantially square shape with one side having a minimum dimension capable of accommodating the blades.   3. The fan system according to claim 1, wherein the rotor of the motor is formed by arranging a magnetic pole in an annular shape on an outer periphery of the blade. 4.   3. The fan system according to claim 1, wherein the stator of the motor is disposed at two opposite corners of the casing. 4.   The fan system according to claim 1 or 2, wherein the stator of the motor is arranged at four corners of the casing.   3. The fan system according to claim 1, wherein the motor is a single-phase motor, and the stator includes a yoke portion, one coil, and one tooth. .   3. The fan system according to claim 1, wherein the motor is a three-phase motor, and the stator includes a yoke portion, three coils, and three teeth. .   Each of the three coils is wound around a body portion protruding from each of the three teeth and interposed between the teeth and the yoke portion, and each of the body portions has a substantially equilateral triangle shape. The fan system according to claim 7, wherein the fan system is arranged to be a vertex.   9. The fan system according to claim 8, wherein the body portion is coupled to a hole portion provided in the yoke portion by press-fitting or gap fitting, and is fixed by adhesion or welding.   The said housing | casing and the said stator are provided with the processus | protrusion for positioning and a keyway so that positioning of at least 2 axes orthogonal to each other is uniquely determined. Fan system.   The fan system according to claim 1 or 2, wherein the yoke part and the teeth are configured by a dust core. A fan system comprising a plurality of blades that rotate with a rotational driving force of a three-phase motor, a housing that houses the blades, and a plurality of stators of the three-phase motor disposed in the housing,
The fan system, wherein the stator is formed such that magnetic resistances of a tooth portion, a yoke portion, a body portion connecting them and a magnetic gap between the tooth portions are substantially equal between phases.   13. The fan system according to claim 12, wherein the stator has a substantially equal cross-sectional area of the body portion, and the body portion is arranged in a substantially equilateral triangle.   The fan system according to claim 12, wherein the rotor of the three-phase motor is formed by arranging a plurality of magnetic poles in an annular shape on an outer periphery of the blade.

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