KR20200123386A - Motor and cleaner including same - Google Patents

Abstract

The present invention realizes a compact driving motor capable of both high output including high speed rotation and light weight. The compact driving motor is a driving motor (50) rotating in a predetermined direction. The driving motor (50) is provided with a rotor (52) which does not have a magnet and has a plurality of salient pole parts (52b). A stator core (60) has a plurality of element cores (61) and the plurality of magnets (62). A slit (52c, or a void (an example of a second air gap)) is formed in the salient pole parts (52b). The salient pole parts (52b) have a large magnetic circuit part (52d, a first magnetic circuit part) having a larger cross-sectional area in the front of the slit (52c) in a rotational direction, and a small magnetic circuit part (52e, a second magnetic circuit part) having a small cross-sectional area in the rear of the slit (52c) in the rotational direction.

Description

Drive motor and cleaner including same {Motor and cleaner including same}

The present invention relates to a drive motor that rotates in a predetermined direction in which a magnet is not used for a rotor, and a stick-type cleaner including the same, and more particularly, to a drive motor suitable for ultra-high rotation and a stick-type cleaner including the same.

Recently, a so-called stick-type vacuum cleaner in which a vacuum cleaner body, hose, and electric cord are omitted is attracting attention. The stick type vacuum cleaner needs to generate high suction power by rotating a small fan at high speed. Accordingly, there is a demand for a drive motor (mini fan motor) capable of realizing high-speed rotation of 50000 r/min or more and ultra-high rotation of 100000 r/min or more with small and light weight while securing a certain amount of torque.

In general, the allowable tensile stress of the magnet used in the rotor of the motor is low, and it is destroyed and scattered by the centrifugal force generated when it is rotated at ultra-high speed, so the surface of the rotor is protected by SUS tube, carbon fiber, or glass fiber. Was known. On the other hand, there is also a switched reluctance motor that does not use a magnet for the rotor and consists of only an electromagnetic steel plate that has an allowable tensile stress much higher than the allowable tensile stress of the magnet, and the rotor of this motor has an allowable tensile stress. Since it is composed of only this high electromagnetic steel plate, it has a robust structure, and, compared with a magnet type motor, there is little fear of damage even if the rotor is rotated at an ultra high speed. Therefore, it is suitable for mini fan motors.

On the other hand, the switched reluctance motor rotates only with the attraction force drawn by the iron rotor to the stator teeth excited by energizing the coil of the stator. In order to achieve high output, increase the number of coil turns or coil cross-sectional area. It is essential to increase the amount of copper and increase the amount of copper used. Therefore, compared with a magnet-type motor that rotates using magnetic attraction and repulsion, it is disadvantageous in terms of motor output, efficiency, and compact and lightweight.

Accordingly, a flux switching motor is provided in which a coil and a magnet are installed in the stator, and the rotor teeth excited by the magnetic flux flowing from the magnets arranged in the stator and the stator teeth excited by the coil attract each other to enhance the suction force. It has been proposed (eg, Patent Documents 1 and 2).

[Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2002-199679

[Patent Document 2] Japanese Patent No. 5791713

In general, iron materials are widely used for motors. Therefore, there is a problem that the motor is liable to become heavy. As the size of the motor decreases, the weight is reduced by that amount, but further reduction in weight (ultra-light weight) is required in the aforementioned mini fan motor or the like.

Accordingly, the main purpose of the disclosed technology is to realize a drive motor that can achieve both high output and weight reduction including high-speed rotation.

The disclosed technology relates to a drive motor rotating in a predetermined direction.

The drive motor includes a rotatable shaft, a rotor integrally provided with the shaft, and having a plurality of salient pole parts protruding radially without a magnet, and an air gap around the rotor. Equipped with a stator that is installed with an air gap in between.

The stator has a back yoke portion, a stator core having a plurality of teeth extending inward from the back yoke portion, and a plurality of coils installed around the teeth portion.

The stator core has a plurality of element cores and a plurality of magnets.

A void is formed in the protruding portion. In addition, the protrusion portion is a large-sized furnace portion (or a first magnetic passage portion, a first magnetic circuit part, a first magnetic circuit part) having a larger cross-sectional area extending forward in the rotational direction than the void, and a rear portion in the rotational direction than the void. It has an element path part (second magnetic path part, second magnetic circuit part) with a small cross-sectional area extending.

That is, in this drive motor, the rotor does not have a magnet. Therefore, since the rotor of the drive motor is composed only of an electromagnetic steel sheet having a high allowable tensile stress, it has a sturdy structure, and there is little risk of damage even if the rotor is rotated at high speed or ultra high speed.

In addition, this stator core has a plurality of element cores and a plurality of magnets, and corresponds to a so-called flux switching motor. Accordingly, the magnetic flux of the magnet flows from the protruding end of the protruding pole of the rotor through the air gap from the element core, and the magnetic flux flows out from the protruding end of the protruding part of the other protruding pole and passes through the air gap and the element core. In this way, a magnetic circuit rotating on another magnet is constructed, and the protruding portion is magnetized to an N-pole or S-pole according to the rotation angle of the rotor, so that magnetic attraction is strengthened, so that high-speed rotation can be stably performed with high output.

In addition, a void is formed in the protruding portion of the rotor. The rotor is heavy because it is a so-called metal mass. By forming voids in the plurality of protruding portions of the rotor, the rotor and further the drive motor can be significantly reduced in weight.

In addition, this protruding pole portion has a large furnace portion having a large cross-sectional area in the front of the rotation direction, and has an element furnace portion having a small cross-sectional area in the rear portion of the rotation direction.

The rotor rotates by a magnetic attraction force generated between the tooth portion and the protrusion portion. At this time, a large amount of magnetic flux is introduced from the magnet between the tooth part and the large furnace part, and a large suction force acts toward advancing the rotation direction. On the other hand, since the element path portion located at the rear of the rotation direction has a small cross-sectional area, only a small amount of magnetic flux flows in and out between the tooth portion and the element path portion compared to the large furnace portion. Has only a small attraction force.

Accordingly, it is possible to suppress the magnet torque generated in the direction opposite to the rotation direction of the rotor. As a result, it is possible to increase the motor torque required in the rotational direction of the rotor, so that a high output can be obtained even in a small size. Therefore, it is possible to achieve both weight reduction and high output.

In the driving motor, the air gap may be formed of a slit that penetrates in an axial direction and extends in a radial direction, and a thickness of the protrusion part may be greater toward a front part than a rear part in a rotation direction with respect to the slit.

These slits can be easily processed. It is possible to simply and precisely form the large furnace portion and the element furnace portion.

The driving motor may also have a pair of inclined side surfaces that are further away from each of the magnets toward the outside in a radial direction, and each of the side surfaces may be in surface contact with the tooth.

Then, since the surface area of the magnetic pole increases, high magnetic force can be obtained.

In addition, the motor may have an end surface positioned on an inner diameter side of each of the magnets on an outer diameter side of the motor than a protruding end of the tooth.

Then, since the amount of the magnet exposed to the leakage magnetic flux from the tooth is reduced, irreversible demagnetization, that is, a decrease in magnetic force can be suppressed, thereby stabilizing the motor output. In addition, since the eddy current generated when the leakage magnetic flux passes through the magnet can be similarly reduced, the motor can be highly efficient.

The drive motor may also be an anisotropic Sm-Fe-N bond magnet including 40% by volume or more of a resin component in each of the magnets.

When the resin component is 40% by volume or more, the magnet can be lightened. The weight can be further reduced by adopting a Sm-Fe-N bonded magnet, which has a smaller specific gravity than an Nd-Fe-B bonded magnet. Further, since the magnetic force can be strengthened by the adoption of an anisotropic magnet, a significant improvement in the power density of the motor can be realized. Further, since the eddy current loss generated by the magnet is reduced by the adoption of a magnet containing a large amount of a resin component as an insulator, high efficiency of the motor can be realized even if the amount of resin is increased.

The drive motor may further include an impeller mounted on the shaft and a shroud disposed to cover the impeller having a suction port at a central portion to configure a fan motor.

In the case of a fan motor, it is required to rotate at high speed in a predetermined direction. This drive motor is very effective in meeting this demand. In the case of an integrated fan motor in which an impeller is mounted on a shaft and a shroud is disposed to cover the impeller, a combination with a small drive motor is also good.

In this case, it is preferable to configure a mini fan motor having an outer diameter of 100 mm or less, a height of 50 mm or less, and a suction power of 250 W or more.

In the case of such a mini fan motor, it is suitable for a stick type vacuum cleaner and thus a cleaner with excellent convenience can be realized.

Further, in this case, the coil is formed to have a predetermined inner dimension by an edgewise winding bending a flat wire having a rectangular cross section from its short side, and each of the teeth is Each of the coils may be mounted on each of the teeth and have an outer dimension that is coupled to the inner dimension of.

Since the process of attaching the coil to the stator is simplified, it can be manufactured in an ultra-mini size. In addition, by setting it as an edge-wise winding, since the side area in which the square wire is exposed to the leakage magnetic flux in the tooth is small, it is possible to realize high efficiency by suppressing eddy current.

According to the disclosed technology, a drive motor capable of achieving both high output including high-speed rotation and weight reduction while securing practical torque can be realized.

1 is a schematic diagram showing an application example (stick type vacuum cleaner) of a mini fan motor comprising a drive motor according to an embodiment.
2 is a schematic perspective view of a mini fan motor configured as a driving motor according to an embodiment.
3 is an exploded view of the mini fan motor.
4 is a schematic perspective view showing a drive motor.
5 is a schematic diagram showing a stator (coil is omitted).
6 is a schematic diagram showing a stator core.
7 is a schematic perspective view showing a coil.
8 is a diagram for explaining a magnetic state when the drive motor rotates.
9 is a schematic perspective view showing a modified example of the drive motor.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The description of the following embodiments is essentially merely an illustration, and is not intended to limit the present invention, its applications, or its use.

The vertical direction used in the description follows the direction indicated by arrows in FIG. 2 for convenience. In addition, the axial direction means a direction in which the rotation axis P extends, the circumferential direction means a direction around the rotation axis P, and the radial direction means a radial or radial direction centered on the rotation axis P.

<Example of application of disclosed technology>

1 illustrates a stick type cleaner 1 suitable for the disclosed technology. This vacuum cleaner 1 is of a cordless type (wireless), and is configured to be driven by electric power from a built-in battery 8.

The vacuum cleaner 1 is equipped with a mini fan motor 2 to which the disclosed technology is applied. The vacuum cleaner 1 is composed of a suction part 3, a pipe part 4, a main body part 5, a dust case 6, a handle part 7 and the like.

The suction unit 3 has a suction port 3a on its lower surface, and is configured to be slidable along the floor by a rotatable roller 3b. The pipe part 4 is made of an elongated cylindrical member that can be stretched. The tube part 4 has its lower end connected to the suction part 3 and its upper end connected to the body part 5. The pipe portion 4 communicates the suction port 3a and the body portion 5.

The main body 5 is formed in a size slightly larger than that of the tube 4. The main body 5 accommodates a mini fan motor 2, a battery 8, a control unit 9, and the like. The control unit 9 controls the driving of the mini fan motor 2. The battery 8 is a rechargeable secondary battery and supplies electric power to the mini fan motor 2.

The handle portion 7 is a portion gripped by the user and is provided integrally with the body portion 5. The gripping portion is provided so as to protrude from the rear of the main body 5 to the rear. The vacuum cleaner 1 is configured so that the user can hold the gripping part with one hand.

A dust case 6 is provided below the gripping portion. The dust case 6 is configured to be detachable from the main body 5. The mini fan motor 2 is disposed adjacent to the dust case 6. The mini fan motor 2 is driven by power supplied from the battery 8 under the control of the controller 9. When the mini fan motor 2 is driven, a strong suction force is formed. Accordingly, the dust sucked from the suction port 3a is accumulated in the dust case 6 through the tube 4.

(Mini fan motor (2))

2 shows a mini fan motor 2. The mini fan motor 2 is a small device in which a fan and a motor are integrated. The fan is a so-called centrifugal fan. As the impeller 20 rotates around the rotation shaft P, air is sucked in from the inlet 31 and air is discharged outward in the radial direction.

The outer diameter (D) and height (H) of the mini fan motor 2 are designed to be very small so as to be accommodated in the main body 5. Specifically, the outer diameter (D) is preferably 100 mm or less, and the height (H) is preferably 50 mm or less. For example, in the case of the illustrated mini fan motor 2, the outer diameter D is approximately 70 mm, and the height H is approximately 40 mm (so-called palm size). Therefore, its weight is light and it is not difficult to put it on the palm of the hand.

In addition, it is configured to obtain high output with high efficiency so as to obtain sufficient performance as the vacuum cleaner 1 by using the power of the battery 8. In the case of the illustrated mini fan motor 2, it can be driven at a high speed rotation of 50000 r/min or more, further, ultra-high rotation of 100000 r/min or more with a power consumption of 600 W, and is configured to obtain a suction power ratio of 250 W or more.

Along with FIG. 2, as shown in FIG. 3, the mini fan motor 2 includes a housing 10, an impeller 20, a shroud 30, a substrate 40, and a drive motor 50. It is equipped with. Here, the disclosed technology is applied to the drive motor 50.

The housing 10 is configured by vertically combining the first housing 10a and the second housing 10b. The housing 10 has a pair of upper and lower annular frames, and a plurality of columnar frames connecting these annular frames, and is provided in a basket shape. The drive motor 50 is housed in the housing 10.

The impeller 20 has a substantially conical shape and is disposed on the upper side of the housing 10. A plurality of vanes 21 are provided on the outer peripheral surface of the impeller 20. The impeller 20 is installed at the tip end of the shaft 51 in a state in which rotation is not possible with respect to the shaft 51.

The shroud 30 is fixed on the upper side of the housing 10 so as to cover the impeller 20. In the central portion of the shroud 30, a suction port 31, which is an opening formed in a circular shape, is formed.

The substrate 40 is made of a disk-shaped member, and is installed under the housing 10. Electrical components such as a capacitor 41 and a semiconductor element 42 are provided on the upper and lower surfaces of the substrate 40.

(Drive motor (50))

The drive motor 50 has a shaft 51, a rotor 52, and a stator 53.

A magnet 62 is installed on the stator 53 of the drive motor 50, and the rotor 52 is composed of only a magnetic material, so that the magnet 62 is configured to magnetize the rotor 52. It is a so-called flux switching motor, and is configured to rotate in only one direction in the counterclockwise direction (CCW direction) using magnet torque.

(Shaft (51))

As shown in Fig. 4, the shaft 51 is made of a cylindrical member. The shaft center of the shaft 51 coincides with the rotation shaft P. As shown in FIG. 3, the shaft 51 has a base end 51a positioned inside the housing 10 and a tip end 51b protruding upward of the housing 10. A pair of bearings 54 and 54 are mounted at the top and bottom of the base end 51a, and the shaft 51 is axially supported by the housing 10 in a rotatable state through these bearings 54 and 54. . The rotor 52 is provided integrally with the shaft 51 (or the rotor 52 is fixedly coupled to the shaft 51) at an intermediate portion of the base end portion 51a.

(Rotor (52))

The rotor 52 has a cylindrical boss portion 52a and a plurality of (six in this embodiment) salient pole parts projecting radially from the outer circumferential surface of the boss portion 52a. 52b). The rotor 52 is not provided with a magnet. It is formed only of iron. Specifically, the rotor 52 is formed by stacking a plurality of iron plates (magnetic bodies) having a substantially star shape described above in the vertical direction.

The rotor 52 is fixed to the shaft 51 by pressing the base end 51a into the shaft hole formed in the center of the boss 52a. Each protruding pole portion 52b protrudes from the outer peripheral surface of the boss portion 52a toward the outside in the radial direction. Each of the protruding pole portions 52b is arranged at regular intervals in the circumferential direction.

Each protruding pole portion 52b has a pair of protruding side surfaces 521 and 523, and a protruding end face 522 leading to a protruding edge outside the motor radial direction of the protruding side surfaces 521 and 523. . The pair of protrusion side surfaces 521 and 523 are both flat, and extend substantially parallel to each other while facing in the circumferential direction. In addition, the protruding end surface 522 has a protruding end surface 525 connected to the protruding side 523 and a protruding end surface 524 connected to the protruding side 521. In addition, a slight curved portion is formed between the protruding end surface 524 and the protruding end surface 525 so that the protruding end surface 525 may be referred to as an air gap (G, hereinafter, a first air gap). Yes) is a little bigger. That is, each protruding pole portion 52b has a structure protruding in front of the protruding end face 525 with respect to the rotation direction (CCW direction) of the motor 50 (so-called asymmetric structure). In addition, a slit 52c is formed in each protruding electrode portion 52b, which will be described later.

(Stator (53))

As shown in Fig. 4, the stator 53 is constituted by a plurality of members in a substantially circular annular shape. The stator 53 is installed in the housing 10 with a predetermined air gap (G, hereinafter may be referred to as a first air gap) around the rotor 52 interposed therebetween. (The so-called inner rotor type). The stator 53 has a stator core 60, an insulator 70, and a coil 80.

5 shows the stator 53 with the coil 80 omitted. 6 shows the stator core 60 in a state in which the insulator 70 is further omitted.

The stator 53 (stator core 60) has a cylindrical back yoke portion 60a, and a plurality of (8 in this embodiment) tooth portions 60b extending radially inside from the back yoke portion 60a. Have. Each tooth portion 60b is arranged at equal intervals in the circumferential direction. A slot 60c for accommodating the coil 80 is formed between the two adjacent teeth 60b and 60b.

The width (the size in the circumferential direction) of the tooth portion 60b is formed to have almost the same size except for the protruding end portion (the width of the protruding end portion is narrow). The inner diameter of the stator 53 and the outer diameter of the rotor 52 are so that an air gap G of a predetermined size is formed between the protruding end of each tooth part 60b and the protruding end of the protruding end 52b of the rotor 52 It is designed.

As shown in Fig. 6, the stator core 60 has a plurality of (8 in this embodiment) element cores 61 having a substantially U shape when viewed from the top (meaning the case viewed from above), and a plurality (this embodiment In the example, 8) magnets 62 are used.

Each element core 61 is formed by stacking a plurality of iron plates (magnetic bodies) having a substantially U shape in the vertical direction (axial direction). Each element core 61 has a yoke element 61a having an arc shape as viewed from above, and a pair of tooth elements 61b and 61b extending and protruding in a shape opposite from both ends of the yoke element 61a. It is configured to have a constant thickness in the vertical direction relative to the direction. The yoke element 61a constitutes a part of the back yoke portion 60a, and each tooth element 61b constitutes a side portion of the tooth portion 60b.

Each magnet 62 contains 40 vol. It is formed in a substantially plate shape using an anisotropic Sm-Fe-N bond magnet containing% or more. By adopting the Sm-Fe-N bonded magnet, which has a smaller specific gravity than the Nd-Fe-B bonded magnet, the motor 50 can be lightened, and the magnetic force can be reinforced by the adoption of an anisotropic magnet, so the power density of the motor 50 Can be realized. In addition, 40 vol. By setting it as% or more, since the eddy current generated in the magnet decreases, the motor 50 can be made highly efficient even if the amount of resin is increased.

Each magnet 62 is specifically, a pair of inclined rectangular side surfaces 62a, 62a that are further away toward the outer side in the radial direction, a narrow rectangular inner end surface 62b, and a wide rectangular outer side It has an end surface 62c. One side of the side surface 62a constitutes an N-pole, and the other side surface 62a constitutes an S-pole.

Each magnet 62 is radially arranged in a state in which the same magnetic poles face each other in the circumferential direction in the stator core 60. And, the element core 61 and the magnet 62 are each circular in a state where one magnet 62 is sandwiched between the tooth elements 61b and 61b facing each other of the two adjacent element cores 61 and 61 Connected by the illusion of.

The side surfaces 62a of each magnet 62 are in surface contact with the tooth elements 61b and 61b facing each other of the two adjacent element cores 61 and 61, respectively. Since the side surface 62a of each magnet 62 is inclined, the surface area thereof is increased compared to the case where it is not inclined. Accordingly, since it is possible to generate a stronger magnetic force, it is possible to increase the output of the motor 50.

The inner end surface 62b of each magnet 62 is located farther away from the protruding end of each tooth element 61b (outside in the radial direction). When the drive motor 50 rotates, a magnetic path (flow path of magnetic flux) is formed between the protruding end of the tooth part 60b and the protruding end of the protruding electrode part 52b. At this time, compared to the inner end surface 62b of the magnet 62 By protruding the protruding end of each tooth element 61b to the air gap G, the amount of magnetic flux directed to the magnet 62, that is, the magnetic flux to which the magnet 62 is exposed can be suppressed. Accordingly, it is possible to have an action of suppressing irreversible demagnetization of the magnet 62 and generation of eddy currents.

As shown in Fig. 5, a plastic material (insulating material) insulator 70 is attached around the stator core 60 connected in a circular annular shape. Specifically, the upper surface of the tooth part 60b, a part of both sides of the tooth part 60b, a part of the back yoke part 60a (a part facing the slot 60c), etc. are covered by the insulator 70 . The stator core 60 positioned at the protruding end of the tooth portion 60b (a portion corresponding to the air gap G) is exposed from the insulator 70.

As shown in Fig. 4, a coil 80 is provided in a portion of each tooth portion 60b covered by the insulator 70. Since this drive motor 50 is used in the mini fan motor 2, its size is very small. The coil 80 also has a small size corresponding to this.

7 shows the coil 80. The coil 80 can generate a high magnetic force and is considered to be easy to assemble.

That is, each coil 80 is formed to have a predetermined inner dimension. Further, each tooth portion 60b has an outer dimension that is coupled to the inner dimension of the coil 80, and each tooth portion 60b is configured so that each coil 80 formed in a predetermined shape can be mounted.

Each coil 80 is formed by winding an electric wire formed by covering an electric conductor such as copper with an insulating film. A flat wire (80a) having a rectangular cross section is used for this electric wire. A coil 80 is formed by bending the flattened wire 80a toward the short side of this cross section (edge-wise winding).

In the case of the flat line 80a, since it can be wound without gaps, a higher dot area ratio can be obtained compared to the round line. In addition, in the case of an edge-wise winding, since the short side of the thinner thickness is wound, the size of the coil 80 in the winding direction (axial direction) can be reduced, and thus the motor 50 can be miniaturized. In addition, the circumferential side area of the flat angle line 80a can be reduced, so that the eddy current generated by the exposure of the flat angle line 80a to the fringing magnetic flux leaking from each tooth portion 60b can be suppressed. ) High efficiency is possible. Further, even if the short side is small, the cross-sectional area of the flattened wire 80a can be increased, that is, the electric wire can be made thick by increasing the long side. Therefore, high magnetic force can be generated because a large current can be passed.

The ends of each coil 80 mounted on each tooth portion 60b are connected to a predetermined terminal of the substrate 40 with the insulating film removed. Power is supplied from the battery 8 to the substrate 40. A plurality of switching elements for switching this power are provided on the substrate 40, and a predetermined current (alternating current) is supplied to each coil 80 by controlling such switching elements by the control unit 9.

In the case of the drive motor 50, two-phase different coil groups consisting of A-phase and B-phase are configured. As shown in FIG. 4 for each pattern, the A-phase and B-phase coil groups are arranged alternately in the circumferential direction. Two currents (alternating current) having different phases are supplied to the coil groups of each of these phases.

At this time, it has a structure (asymmetrical structure) in which each protruding pole part 52b protrudes by the protruding end face 525 with respect to the rotation direction of the motor 50 (CCW direction), so that it is a two-phase motor to ensure stability at the start. It achieves a uniform rotation direction in the CCW direction. Here, the protruding end surface 525 protruding in the rotation direction is unnecessary in the case of a three-phase motor.

The rotational position of the rotor 52 relative to the stator 53 is detected from a change in the induced voltage or the like, and control is performed to switch the energized state to each coil group based on the rotational position. Accordingly, a magnetic field (rotating magnetic field) for rotating the rotor 52 is formed in the stator 53. The rotor 52 rotates counterclockwise by this rotating magnetic field and a magnetic attraction force (magnet torque) between the protruding pole portions 52b magnetized by the respective magnets 62.

(Detailed structure of the rotor 52)

As described above, a slit 52c (an example of void, void, hereinafter may be referred to as a second air gap) is formed in each protruding portion 52b of the rotor 52. The slit 52c penetrates in the axial direction. The slit 52c also extends in a radial direction from the boundary portion with the boss portion 52a to the protruding end portion of the protruding electrode portion 52b in a linear shape.

The rotor 52 is a so-called iron mass. Therefore, although the rotor 52 is heavy, it is possible to significantly reduce the weight of the rotor 52 and further the drive motor 50 by forming the slit 52c in each of the protruding pole portions 52b.

In addition, as shown in Fig. 4, the front of the slit 52c of each protruding pole portion 52b (the forward side in the rotational direction, the CCW side in the case of the main drive motor 50) has a larger width (thickness). A portion (a large passage portion or a first magnetic passage portion 52d) extending in the direction is provided. In addition, a portion extending in the radial direction with a small width (thickness) in the rear (reverse side in the rotation direction, CW side in the case of the main drive motor 50) than the slit 52c of each protruding pole portion 52b ( An element path portion or a second magnetic path portion 52e is provided. (Road part, magnetic circuit part)

That is, the cross-sectional area of the large furnace portion 52d positioned in front of the rotational direction (the area of the cross-sectional area with respect to the protruding direction of each protruding portion) is larger than the cross-sectional area of the element path 52e located at the rear of the rotational direction have. Accordingly, a large amount of the magnetic flux of the magnet 62 flows in and out of the large furnace portion 52d, and conversely, the amount of the magnetic flux flowing in and out of the element passage portion 52e is reduced. Accordingly, the magnetic attraction force in the rotation direction of the motor 50 increases, and conversely, the magnetic attraction force in the reverse rotation direction of the motor 50 (in the case of the main motor 50, the CW direction) decreases. Therefore, since the motor 50 can achieve high torque, it is possible to achieve both high output and weight reduction.

8 schematically shows a predetermined magnetic state when the drive motor 50 rotates. The rotor 52 is rotating in a counterclockwise direction as indicated by an arrow R.

Since the large cross-sectional area of the large furnace portion 52d positioned in front of the rotational direction is large, an arrow Y1 indicates between the tooth portion 60b (the portion of the tooth element 61b) and the large furnace portion 52d. As such, since a large amount of magnetic flux flows in and out, a large attraction force acts toward advancing the rotation direction.

On the other hand, since the element path portion 52e located at the rear of the rotation direction has a small cross-sectional area, the tooth portion 60b (a portion of the tooth element 61b) and the element path portion 52e as indicated by the arrow Y2. ), only a small amount of magnetic flux flows in and out compared to the large furnace part, so only a small attraction force acts on the side that moves backward in the direction of rotation.

Accordingly, it is possible to suppress the magnet torque generated in the direction opposite to the rotation direction of the rotor 52. As a result, the torque of the motor 50 can be increased, a high output can be obtained even in a small size, and both high output and weight reduction can be achieved.

<Example of transformation>

9 shows a modified example of the drive motor 50. In the drive motor 50 according to the present modification, a rotor 52 having four protruding pole portions 52b is used. Although there are eight coils 80, in this drive motor 50, a single current (alternating current) is switched to form a rotating magnetic field (so-called single phase).

In the case of the mini fan motor 2, high-speed rotation of 50000 r/min or more, and ultra-high rotation of 100000 r/min or more is required. If there are many protruding pole portions 52b, the energization switching control performed during one rotation increases by that amount. Therefore, if the rotational speed is largely increased, there is a fear that the energization switching control becomes complicated and the control becomes unstable or uncontrollable. Therefore, the drive motor 50 according to the present modified example in which the protrusion portion 52b is small is advantageous for ultra-high speed rotation.

The driving motor according to the disclosed technology is not limited to the above-described embodiment, and includes various configurations other than that.

For example, in the above-described embodiment, an example of application of a stick-type cleaner has been illustrated, but the disclosed technology is not limited thereto. For example, it can be applied to driving other home appliances such as juice blenders or food processors, and robots.

The shape of the void is not limited to the slit. By forming a void in the protrusion portion, a magnetic path larger than the rear portion may be formed in the front portion in the rotation direction of the protrusion portion. For example, it may be a groove extending in the radial direction, or a space formed inside the protrusion part. The void may be divided into a plurality of small voids.

The slit shape is also an example. Depending on the specification, it may be slightly curved or wider, but may be smaller or obliquely extended. .

The wire of the coil 80 is preferably a flat wire, but is not limited thereto. It may be a normal round line.

In addition, the motor 50 is a so-called two-phase, eight-slot, six-pronged motor, and in a modified example, it operates as a so-called single-phase, eight-slot, four-pronged motor, but the motor according to the disclosed technology is the above-described constant. , The number of slots, various combinations other than the number of protrusions, for example, 3 phases, 12 slots and 10 protrusions may also be included.

1 cleaner
2 mini fan motor
10 housing
20 impeller
30 shroud
40 substrate
50 drive motor
51 shaft
52 rotor
52b protruding pole
52c slit (void), second air gap
52d large magnetic circuit part, the first magnetic circuit part
52e element path part, second magnetic path part
53 stator
60 stator core
60a back yoke part
60b Teeth
60c slot
61 element core
61a yoke element
61b tooth element
62 Magnet
70 insulator
80 coils
80a flat wire
P rotation axis
G air gap, first air gap
521 ~ 525 stone pole side

Claims (20)

Rotatable shaft;
A rotor fixedly coupled to the shaft, rotatable about the shaft, and including a plurality of salient pole parts protruding radially about the shaft; And
Includes; a stator that is disposed in the circumferential direction of the rotor while surrounding the rotor and a first air gap therebetween,
The stator is
A stator core having a back yoke portion and a plurality of teeth portions extending inwardly from the back yoke portion,
It includes a plurality of coils installed around each of the plurality of teeth,
The stator core includes a plurality of element cores and a plurality of magnets,
Each of the plurality of protruding pole portions,
A second air gap, a first magnetic circuit part and a second magnetic circuit part located on both sides of the second air gap magnetic circuit part),
The first magnetic path part is located on the forward side in the rotational direction of the rotor among both sides of the second air gap,
In a cross section of the protruding direction of each of the protruding pole portions, an area of the cross section of the first magnetic path portion is formed to be larger than an area of the cross section of the second magnetic path portion. The method of claim 1,
The second air gap is formed of a slit penetrating in an axial direction and extending in a radial direction, and a thickness of each of the plurality of protruding pole portions is formed to be thicker in a front portion than a rear portion in a rotation direction with respect to the slit. The method of claim 1,
The driving motor of each of the plurality of protruding pole portions has a front portion protruding radially toward the first air gap than a rear portion of the second air gap in a rotation direction. The method of claim 1,
Each of the plurality of element cores is formed by stacking a plurality of U-shaped iron plates, which are magnetic elements, including an arc-shaped yoke element and a pair of tooth elements extending in opposite shapes from both ends of the yoke element in the axial direction. And
The yoke element constitutes a part of the back yoke portion, and each of the pair of tooth elements constitutes a side portion of each of the plurality of teeth portions. The method of claim 4,
The plurality of magnets are disposed in a state in which the same magnetic poles are opposed in the circumferential direction, and each of the plurality of magnets is disposed between opposed tooth elements of two adjacent element cores,
A drive motor in which the plurality of element cores and the plurality of magnets are disposed in a circumferential direction, respectively, to have a circular annular shape. The method of claim 5,
Each of the plurality of magnets has a pair of inclined side surfaces that are further away toward the outside in a radial direction,
Each of the pair of inclined side surfaces is in surface contact with each of the plurality of teeth portions. The method of claim 5,
The drive motor protruding into the first air gap such that an end portion positioned in the radial direction of each of the plurality of magnets is closer to the shaft than an end portion positioned in the radial direction of each of the pair of tooth elements. The method of claim 5,
The plurality of coils are driving motors disposed so that two currents of different phases are supplied to each adjacent coil. The method of claim 1,
A resin component was added to each of the plurality of magnets by 40 vol. A drive motor in which anisotropic Sm-Fe-N bond magnets containing more than% are used. The method according to any one of claims 1 to 9,
An impeller mounted on the shaft,
A drive motor comprising a fan motor having a suction port in a central portion and further comprising a shroud disposed to cover the impeller. The method of claim 10,
A drive motor comprising a mini fan motor with an outer diameter of 100 mm or less, a height of 50 mm or less, and a suction power of 250 W or more. The method of claim 1,
Each of the plurality of coils is formed by an edgewise winding bending a flattened line having a rectangular cross section from its short side,
A drive motor in which each of the plurality of coils is mounted on each of the plurality of teeth portions. Rotatable shaft;
A rotor fixedly coupled to the shaft, rotatable around the shaft, and including a plurality of protruding poles protruding in a radial direction around the shaft; And
Includes; a stator that is disposed in the circumferential direction of the rotor while surrounding the rotor and a first air gap therebetween,
The stator is
A stator core having a back yoke portion and a plurality of teeth portions extending inwardly from the back yoke portion,
It includes a plurality of coils installed around each of the plurality of teeth,
The stator core includes a plurality of element cores and a plurality of magnets,
Each of the plurality of protruding pole portions,
A second air gap, a first magnetic circuit part and a second magnetic path part positioned on both sides of the second air gap,
The first magnetic path part is located on the forward side in the rotational direction of the rotor among both sides of the second air gap,
A vacuum cleaner comprising a driving motor formed to have a cross-section of the protruding direction of each of the protruding pole portions, wherein an area of the cross-section of the first magnetic path portion is larger than that of the cross-section of the second magnetic path portion. The method of claim 13,
The second air gap is formed of a slit penetrating in an axial direction and extending in a radial direction, and the thickness of each of the plurality of protruding pole portions is a driving motor having a front portion thicker than a rear portion in the rotation direction with respect to the slit. Cleaner to include. The method of claim 13,
Each of the plurality of protruding pole portions includes a driving motor in which a front portion of each of the plurality of protruding pole portions protrudes in a radial direction toward the first air gap than a rear portion of the second air gap in a rotation direction. The method of claim 13,
Each of the plurality of element cores is formed by stacking a plurality of U-shaped iron plates, which are magnetic elements, including an arc-shaped yoke element and a pair of tooth elements extending in opposite shapes from both ends of the yoke element in the axial direction. And
The yoke element constitutes a part of the back yoke portion, and each of the pair of tooth elements comprises a driving motor constituting a side portion of each of the plurality of teeth portions. The method of claim 16,
The plurality of magnets are disposed in a state in which the same magnetic poles are opposed in the circumferential direction, and each of the plurality of magnets is disposed between opposed tooth elements of two adjacent element cores,
The plurality of element cores and the plurality of magnets are each arranged in a circumferential direction to be provided in a circular annular shape,
Each of the plurality of magnets has a pair of inclined side surfaces that are further away toward the outer side in a radial direction, and the pair of inclined side surfaces each includes a drive motor provided to make surface contact with each of the plurality of teeth. . The method of claim 17,
And a driving motor protruding into the first air gap such that an end portion located in the radial direction of each of the plurality of magnets is closer to the shaft than an end portion located in the radial direction of each of the pair of tooth elements. The method of claim 17,
The plurality of coils are cleaners including a driving motor arranged to supply two currents of different phases to each of the adjacent coils. The method of claim 13,
A resin component was added to each of the plurality of magnets by 40 vol. A vacuum cleaner including a drive motor in which anisotropic Sm-Fe-N bond magnets containing% or more are used.

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