JP2019106798A - Magnet motor and washing machine provided with magnet motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a washing machine provided with a magnet motor and a magnet motor having high torque, low noise and good productivity. SOLUTION: The magnet motor of the present invention includes a stator 12 and a rotor 31, and the stator 12 has a slot 124 and a teeth 13 into which a plurality of armature windings 11 are wound, and the rotor 31 has a rotor 31. It has a magnet 21 magnetized so that one surface is all N poles and the other surface on the opposite side is all S poles when viewed from the direction of the rotation axis, and a tooth portion 232 and a core back portion 231 and 242. The core back portions 231 and 242 have a ring-shaped rotor core 22, and the outer peripheral surface of the core back portions 231 and 242 is formed with an uneven shape 241 when viewed from the rotation axis direction. Is larger than the thickness T of the teeth portion 232, and the teeth portion 232 is arranged on an extension line in the rotation axis direction of the convex portion 241 in the concave-convex shape. [Selection diagram] FIG. 5A

Description

  The present invention relates to a magnet motor and a washing machine provided with the magnet motor.

  In recent years, in particular, washing machines have been required to increase the capacity of laundry, to reduce noise, and to reduce costs. With regard to noise, in addition to the sound of the washing machine body, there are motor operation sounds (hereinafter referred to as motor sounds). The motor noise is caused by an electromagnetic excitation force caused by the rotational force of the motor. Therefore, it is effective to reduce the torque pulsation due to the fluctuation of the electromagnetic force as a countermeasure for the motor noise.

  Patent Document 1 describes a technique for increasing the torque and reducing noise of a washing machine motor in order to meet the above-mentioned requirements.

  Patent Document 2 describes a technique for sandwiching a magnet provided with a single-pole magnetic pole from the front and back sides by a member molded of a soft magnetic material as an efficient motor-driven wheel drive device having a small number of parts.

  Patent Document 3 describes a technique using a member (dust magnetic core) obtained by compression molding of magnetic powder for a so-called claw pole type stator core.

Japanese Patent Application Laid-Open No. 9-131037 JP, 2013-9541, A Unexamined-Japanese-Patent No. 2007-209198

  By the way, in the technology described in Patent Document 1, the motor for washing machine is multipolarized (56 poles and 42 slots), and a core of 56 complex shapes and a magnet which are molded in advance are combined and molded with resin to obtain high torque. And motor technology that results in low noise. However, there is no description on the productivity and cost required for the washing machine. In other words, the manufacturing method in which a large number of magnets are fitted to the rotor core to manufacture the rotor increases the processing cost even if the material cost is reduced using low cost ferrite magnets, resulting in an expensive motor. .

The technique described in Patent Document 2 merely reduces the number of parts, and there is no mention of motor characteristics. The motor required for the washing machine is required to have a high torque and a low cogging torque for suppressing noise. However, simply reducing the number of parts can not satisfy high torque and low cogging torque.
Also, there is no stator for the thickness of the magnet. That is, there is an unnecessary portion (dead space) which does not affect the magnetic circuit equivalent to the thickness of the magnet in the thickness direction of the motor. Therefore, diversion to a washing machine motor which needs to be miniaturized is difficult.

  The technology described in Patent Document 3 is an example in which a tooth shape is devised using a dust core for a small motor with a diameter of 60 mm and a torque of 4 N · m, but the manufacturable range is limited. The reason is that the diameter and thickness of the core shape and the height and width of the teeth shape are restricted from the fluidity of the magnetic powder and the poor formability. For example, the tooth shape can only be processed to be thinner and thinner at the tip.

  In the case of a drum-type washer / dryer with a washing capacity of 12 kg, the motor torque is required to be about 40 N · m, and the required torque is 10 times greater, so the technology of Patent Document 3 can not be diverted. In the first place, it is difficult to achieve high torque, which requires high magnetic flux, by using a powder magnetic core having a lower saturation magnetic flux density than electromagnetic steel sheets or cold rolled steel sheets. Furthermore, the molding of the powder magnetic core requires a dedicated mold and a large-sized press machine, and when applied to a large amount of products such as a washing machine, it requires huge capital investment, which is economically uneconomical. .

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a magnet motor having high torque and low noise and good productivity, and a washing machine provided with the magnet motor.

  In order to solve the above problems, a magnet motor according to a first aspect of the present invention includes a stator and a rotor, the stator having slots and teeth in which a plurality of armature windings are wound, and the rotation The ring has a magnet magnetized so that one side is all N poles and the other side is all S poles when viewed from the rotation axis direction, and a ring having teeth and a core back portion The core back portion has a concavo-convex shape on the outer peripheral surface as viewed from the rotational axis direction, and the radial depth of the concavo-convex shape and the height in the rotational axis direction are greater than the thickness of the teeth portion The teeth portion is disposed on an extension of the convex portion in the convex-concave shape in the direction of the rotation axis.

  A magnet motor according to a second aspect of the present invention includes a stator and a rotor, and the stator has slots and teeth in which a plurality of armature windings are wound, and the rotor has its rotational axis direction In addition to having a magnet magnetized so that one side is all N poles and the other side is all S poles as viewed from the point of view, it has a ring-shaped rotor core with teeth and a core back portion, In the core back portion, the outer peripheral surface is formed in a concavo-convex shape as viewed from the rotation axis direction, and the teeth portion is disposed on an extension of the convex portion in the concavo-convex shape in the rotation axis direction.

  A washing machine according to a third aspect of the present invention includes a washing tub for containing clothes, an outer tub containing the washing layer, a drive mechanism for rotating the washing tub, and a magnet motor according to the first or second aspect of the present invention. Is equipped.

  According to the present invention, it is possible to provide a magnet motor and a washing machine provided with the magnet motor, which have high torque and low noise and high productivity.

The perspective view of the main parts which constitute the magnetic circuit of a magnet motor. The disassembled perspective view which shows the structure of a rotor. The I section enlarged view of FIG. 2A. The perspective view which shows the material of 1st yoke. The perspective view which shows the manufactured 1st yoke. The perspective view which shows the material of 2nd yoke. The perspective view which shows the manufactured 2nd yoke. The disassembled perspective view which shows the structure of a rotor. The figure which shows the convex part of a rotor, and the thickness of teeth. Sectional drawing which shows the flow of the magnetic flux of the annular part of 1st yoke of a comparative example, and teeth. Sectional drawing which shows the flow of the magnetic flux in the annular part of 1st yoke of 1st Embodiment, teeth, and the convex part of 2nd yoke. The arrangement | positioning figure of the magnetic pole of the rotor seen from the stator. 7B is an enlarged view of a part II. Radial direction sectional drawing of a magnet motor. The III section enlarged view of FIG. The figure which shows the case where the internal peripheral surface of the teeth part of the stator of a comparative example is not made non-concentric shape. The perspective view of a washing machine provided with a magnet motor. The longitudinal cross-sectional view of a washing machine provided with a magnet motor. The perspective view of the magnetic pole of the rotor seen from the stator of 2nd Embodiment. The side view of the magnetic pole of the rotor seen from the stator of 2nd Embodiment. The perspective view which shows the structure of the rotor of 3rd Embodiment. The IV enlarged view of FIG. 13A. The figure which shows the torque waveform of the magnet motor of 1st * 2nd * 3rd embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The present invention relates to a magnet motor and a washing machine using the same.
In the following embodiments, as an example, a configuration in which the washing machine W (see FIG. 10) is operated by the magnet motor 1 (see FIG. 1) will be described.

First Embodiment
FIG. 1 is a perspective view of main parts constituting a magnetic circuit of the magnet motor 1.
As shown in FIG. 1, the XYZ axes are defined with the Z axis as the rotation axis of the motor.
The magnet motor 1 includes a stator 12 and a rotor 31.

The stator 12 is provided with a plurality of armature windings 11 for forming a magnetic field. The rotor 31 has a magnet 21 and a rotor core 22 forming a magnetic circuit by the magnet 21.
In the magnet motor 1, the rotor 31 is rotated around the Z-axis direction by the magnetic attraction between the stator 12 and the N and S poles between the rotor 31 and the repulsive force of the same pole of NN or SS. Make a rotational movement. In addition, FIG. 1 abbreviate | omits and shows a rotation support mechanism including a shaft and a bearing, and shows the state which decomposed | disassembled the rotor 31 and the stator 12. FIG.

The stator 12 has a core 10 formed by laminating and fixing press-formed electromagnetic steel plates in the axial direction, and the armature winding 11 is wound around a slot 124 (see FIG. 8) of the core 10. A plurality of thin long teeth 13 of the stator 12 are formed to face the plurality of rotors 31.
The symbols “N” and “S” described in FIG. 1 indicate the magnetic poles of the rotor core 22.

<Rotor 31>
FIG. 2A is an exploded perspective view showing the structure of the rotor 31. As shown in FIG. FIG. 2B is an enlarged view of a portion I of FIG. 2A.
The rotor 31 has a magnet 21 and a pair of rotor cores 22 sandwiching the magnet 21. The magnet 21 has a flat annular shape, and viewed in the Z-axis direction, one surface is all N pole, and the other opposite surface is all S poles. In FIG. 2A, the Z-axis positive direction (upper direction in FIG. 2A) is N pole, and the negative direction (lower direction in FIG. 2A) is S pole.

The magnet 21 has, for example, a donut shape (ring shape) having an outer diameter of 205 mm, an inner diameter of 180 mm, and a thickness of 9 mm. It is desirable to use a samarium-iron-nitrogen permanent magnet as the magnet 21, but it is not particularly limited.
The specific proportion (weight%) of the raw material of the magnet 21 is, for example, about 73% of iron, about 24% of samarium, and about 3% of nitrogen. Among the above-described raw materials, the rare earth element is samarium. Samarium is about 1/5 the price of neodymium, a rare earth element used in conventional neodymium magnets.

On the other hand, in the conventional neodymium magnet, iron: about 65%, neodymium: about 28%, dysprosium: about 5%, and boron: about 2% in proportion are often used. Among the above-mentioned raw materials, rare earth elements are neodymium and dysprosium. Therefore, the samarium-iron-nitrogen permanent magnet has a smaller proportion of rare earth elements (samarium) than conventional neodymium magnets. Specifically, while the samarium of the rare earth element of the samarium-iron-nitrogen permanent magnet is about 24%, the rare earth element of the conventional neodymium magnet is about 33% (neodymium: about 28%, dysprosium: about 5%) is there.
Therefore, the samarium-iron-nitrogen permanent magnet 21 has the advantage of being less susceptible to market trends and leading to improved productivity.

  Furthermore, unlike a conventional neodymium magnet or a sintered magnet of a ferrite magnet, a samarium-iron-nitrogen permanent magnet can be easily molded into a desired shape by molding into a resin by kneading into a resin. Therefore, samarium-iron-nitrogen based permanent magnets can be easily molded because they can be molded like plastic. In addition, even if a waste portion of the raw material remains in molding, the raw material loss can be reduced because the raw material can be reused. On the other hand, conventional neodymium magnets and ferrite magnets are compacted at high pressure, temporarily molded, and sintered at high temperature. Since it sinter-shrinks and is finally machined to the desired shape by cutting etc., it takes time to manufacture. Moreover, although raw material loss generate | occur | produces by cutting, since it is sintering, it can not reuse as it is but processes, such as regrind, are needed. Therefore, the samarium-iron-nitrogen permanent magnet 21 can improve the processing accuracy of the magnet at a lower cost than before and can reduce the variation in size.

  The magnetic energy of the rotor 31 of the present embodiment enters and exits from the upper and lower surfaces of the doughnut-shaped Z-axis direction of the magnet 21 shown in FIG. 2A. Specifically, magnetic flux is emitted from the N pole (see FIG. 2A) of the magnet 21 and passes near the magnet 21 to enter the S pole (see FIG. 2A).

Therefore, in order to increase the effective magnetic pole area with the same amount of magnet, the flat motor is more preferable in consideration of the fact that the torque of the magnet motor 1 can be increased. In addition, it is desirable that the magnet motor 1 be a flat motor also in that the depth dimension L1 of the washing machine W (see FIG. 11) can be shortened.
From the above, it is desirable for the magnet 21 to be a motor whose radial dimension is larger than the thickness dimension. Thereby, the depth dimension is short and the high torque magnet motor 1 is obtained.

<Rotor core 22 of rotor 31>
Next, the rotor core 22 constituting the rotor 31 will be described.
The rotor core 22 shown in FIG. 2A has a configuration in which the annular magnet 21 is sandwiched between the first yoke 23 and the second yoke 24 (see FIG. 2B), and each has one on each side. Further, the number of teeth 232 of the first yoke 23 and the number of convex portions 241 of the second yoke 24 are the same.
The first yoke 23 has a flat plate-like annular portion 231 extending in the XY plane and a plurality of piece-like teeth 232 formed by being bent from the outer peripheral edge of the annular portion 231 in the Z-axis direction.

The second yoke 24 has an annular portion 242 in an annular shape as viewed in the Z-axis direction, and a plurality of convex portions 241 having a convex shape in a radially outward direction from the outer peripheral surface of the annular portion 242. Further, the number of teeth 232 of the first yoke 23 and the number of convex portions 241 of the second yoke 24 are the same.
Further, the teeth 232 of the first yoke 23 and the convex portion 241 of the second yoke 24 are disposed at substantially the same position in the circumferential direction. That is, as shown in FIG. 1, the teeth 232 of the first yoke 23 and the convex portion 241 of the second yoke 24 are arranged to overlap in the Z-axis direction.

<First Yoke 23 of Rotor Core 22>
3A and 3B are perspective views showing the process of manufacturing the first yoke 23. As shown in FIG. FIG. 3A shows the material of the first yoke 23, and FIG. 3B shows the first yoke 23 manufactured. 3A and 3B show the dimensions in an exaggerated manner.
The 1st yoke 23 shown to FIG. 3B is shape | molded by draw-pressing the steel plate of 1 sheet shown to FIG. 3A. Here, 3.2 mm of the cold-rolled steel plate SPCC material of JIS standard was used as a material. That is, if it is a steel plate conforming to the JIS standard, it is possible to carry out molding at low cost without requiring a special die or press. Therefore, the thickness of the annular portion 231 of the first yoke 23 and the thickness of the plurality of piece-like teeth 232 formed by bending the outer edge of the annular portion 231 are substantially constant.

  In this embodiment, a 3.2 mm thick steel plate of SPCC material is used as a material of the first yoke 23. However, a JIS standard electromagnetic steel plate 100A600 material (plate thickness 1.0 mm) may be used, or a molded article The first yoke 23 may be formed by stacking three pieces. The configuration of the first yoke 23 can be changed in consideration of the required specifications of the motor and the productivity. That is, the first yoke 23 may be manufactured by drawing and pressing a single steel plate, or may be formed by stacking a plurality of pieces formed by drawing and pressing. In this case, the thickness of the first yoke 23 can be arbitrarily selected.

<Second Yoke 24 of Rotor Core 22>
4A and 4B are perspective views showing the process of manufacturing the second yoke 24. As shown in FIG. FIG. 4A shows the material of the second yoke 24, and FIG. 4B shows the manufactured second yoke 24. 4A and 4B show the dimensions in an exaggerated manner.
The second yoke 24 is manufactured as follows.
Prepare electromagnetic steel sheet 50A1000 material (plate thickness 0.50 mm) (see FIG. 4A) of JIS standard. And between the convex part 241 and center part are cut by shear processing so that the outer peripheral side of the annular part 242 may become uneven | corrugated shape, and a cast is manufactured.
As shown in FIG. 4B, a plurality of, for example, 42, pieces of the produced molded product are stacked and fixed by caulking or the like to form a second yoke 24 (see FIG. 2A).

The two first yokes 23 and the two second yokes 24 manufactured as described above are combined symmetrically on one side with respect to the magnet 21 on one side.
FIG. 5A is an exploded perspective view showing the structure of the rotor 31, and FIG. 5B is a view showing the thickness of the convex portion 241 of the rotor 31 and the teeth 232.

  As shown in FIG. 5A, the teeth 232 of the first yoke 23 are fitted to the outer peripheral portion of the annular magnet 21 so that the teeth 232 of the first first yoke 23 face in the Z-axis negative direction from the positive direction of the Z axis. The projections 241 of the second yoke 24 are fitted so as to coincide with the teeth 232 of the first first yoke 23.

  Next, the first one of the first first yokes 23 is fitted first (from the positive direction of the Z axis) so that the teeth 232 of the second first yoke 23 face the positive direction of the Z axis from the negative direction of the Z axis. The outer circumferential portion of the magnet 21 is fitted so as to be shifted by 1⁄2 pitch in the circumferential direction with respect to the teeth 232 of the 1 yoke 23. As described above, the teeth 232 of the second first yoke 23 and the teeth 232 of the first first yoke 23 are shifted by 1⁄2 pitch in the circumferential direction, whereby periodic N poles and S poles are obtained. It can be made.

  Further, the protrusion 241 of the second second yoke 24 is fitted so as to face the positive direction of the Z axis so as to coincide with the teeth 232 of the second first yoke 23.

  As shown in FIG. 5B, the height H (21 mm (0.50 mm × 42 sheets)) of the convex portion 241 of the second yoke 24 is the thickness T of the teeth 232 of the first yoke 23 when viewed from the Z-axis direction. Larger than (3.2 mm). The depth D of the convex portion 241 is 10 mm, which is larger than the thickness T (3.2 mm) of the teeth 232 of the first yoke 23.

  Thereby, in the first first yoke 23 and the second yoke 24 (left side in FIG. 5A) fitted from the Z-axis positive direction, the magnetic fluxes from the N pole of the magnet 21 are the teeth 232 of the first yoke 23 and Since it passes through the convex portion 241 of the second yoke 24, it becomes magnetically N pole (see FIG. 2A).

  In the other pair of the first yoke 23 and the second yoke 24 (right side in FIG. 5A) fitted in the Z-axis negative direction, the magnetic flux entering the S pole of the magnet 21 is the same as that of the first yoke 23. Since it passes through the teeth 232 and the projection 241 of the second yoke 24, it becomes magnetically a south pole (see FIG. 2A).

  In this manner, the multipolar rotor core 22 can be easily produced from five parts, that is, 21 × 1 magnets, 1 × 23 first yokes, and 2 × 24 second yokes. Therefore, it is possible to supply the low-noise magnet motor 1 with high torque and low cogging torque at low cost.

<Roles of first yoke 23 and second yoke 24>
Here, the roles of the first yoke 23 and the second yoke 24 will be described.
FIG. 6A is a cross-sectional view showing the flow of the magnetic flux of the annular portion 931 and the teeth 932 of the first yoke 93 of the comparative example.
FIG. 6B is a cross-sectional view showing the flow of magnetic flux in the annular portion 231 and the teeth 232 of the first yoke 23 and the convex portion 241 of the second yoke 24 according to the first embodiment. Arrows in FIGS. 6A and 6B indicate the flow of magnetic flux (magnetic lines of force).

When a similar magnet motor was produced only with the first yoke 93 of the comparative example, magnetic saturation occurred at the root 930 of the teeth 932 as shown in FIG. 6A, and the desired motor characteristics were not obtained. In order to solve this magnetic saturation, it is effective to increase the thickness near the root of the teeth 232. However, merely increasing the plate thickness impairs the squeeze-press formability and requires a large-sized press.
Further, the maximum thickness of the cold rolled steel sheet defined in the JIS standard is 3.2 mm, and if it is intended to secure a thickness greater than this, it becomes not a general cold rolled steel sheet but a custom-made steel sheet, and the material cost increases.

As a result of intensive investigations, it has been found that if a member to be a bypass of the magnetic path is disposed near the root of the first yoke 23 where magnetic saturation occurs to solve the problem, the magnetic flux density is reduced and magnetic saturation does not occur. The bypass portion of this magnetic path is a convex portion 241 located on the outer peripheral surface of the annular portion 242 of the second yoke 24. As shown in FIG. 6B, by superimposing the teeth 232 of the first yoke 23 and the projections 241 of the second yoke 24, magnetic saturation does not occur.
Therefore, the first yoke 23 and the second yoke 24 are fitted so that the teeth 232 of the first yoke 23 and the convex portions 241 of the outer peripheral surface of the annular portion 242 of the second yoke 24 coincide with each other.

  Furthermore, as shown in FIG. 5B, since the unevenness depth D of the outer peripheral portion of the second yoke 24, that is, the depth D of the convex portion 241 is larger than the thickness T of the teeth 232 of the first yoke 23, the rotation is The teeth 31 of the first yoke 23 and the outer diameter of the magnet 21 do not contact in the radial direction. Here, the outer diameter of the magnet 21 is substantially the same as the outer diameter of the annular portion 242 excluding the convex portion 241 of the second yoke 24.

  In this embodiment, there is a gap of 6.8 mm (D (10 mm) -T (3.2 mm)). This gap is established as a motor. Without this gap, the N pole and the S pole are short-circuited through the outer peripheral surface of the magnet 21 and can not be realized as a motor. Further, if the gap is narrow, the leakage flux from the teeth 232 of the first yoke 23 increases, the effective flux decreases, and the average torque decreases. Therefore, the gap between the magnet 21 and the teeth 232 of the first yoke 23 is appropriately set, the leakage flux is suppressed, and the average torque is held.

FIG. 7A is a layout view of the magnetic poles of the rotor 31 as viewed from the stator 12. FIG. 7B is an enlarged view of a part II of FIG. 7A.
As shown in FIG. 7B, the N pole and the S pole are arranged with a gap in the Z axis direction and the circumferential direction, and are not in contact with each other. In particular, if the gap in the Z-axis direction is too narrow, leakage flux increases and the strength of the magnetic flux decreases. Therefore, the average torque which depends on the strength of the magnetic flux is reduced. That is, the length s1 of the teeth 232 of the rotor 31 is shorter than the thickness t1 of the magnet 21. By optimizing the length s1 of the teeth 232 of the rotor 31 to be shorter than the thickness t1 of the magnet 21, the leakage flux is suppressed and the decrease in average torque is suppressed.

<Stator 12 of Magnet Motor 1>
FIG. 8 is a radial sectional view of the magnet motor 1.
The stator 12 includes a stator core 123 having a core back 121 and teeth 13 of the stator. The armature winding 11 is wound in each slot 124 between the plurality of teeth 13 formed in the stator core 123.

  FIG. 9A is an enlarged view of the teeth 13 of the stator of the magnet motor 1, and is an enlarged view of a portion III in FIG. FIG. 9B shows the case where the inner circumferential surface 913 n of the tooth portion 913 of the stator of the comparative example is not in a non-concentric shape. The two-dot chain line in FIG. 9B is a case where the inner circumferential surface 913 n of the tooth portion 913 has a non-concentric shape.

  As shown in FIG. 9A, the shape of the inner peripheral surface 13n of the tooth portion 13 of the stator 12 is a nonconcentric shape convex toward the rotor 31 (see FIG. 8), and the end 13e of the tooth 13 of the stator 12 is Beveling is applied. Both the non-concentric shape of the inner peripheral surface 13n of the tooth portion 13 and the beveling of the end 13e of the tooth 13 make the change in magnetic flux smooth and reduce torque pulsation, which is effective in reducing noise.

If the non-concentric shape of the inner circumferential surface 13n of the teeth portion 13 is increased, torque pulsation can be reduced, but the average torque is also reduced. Therefore, we aim to improve the average torque by combining the beveling, and perform balance design of the average torque and the torque pulsation. Assuming that the tooth pitch of the pitch between the teeth 13 is θ ₁ , the beveling angle is θ ₂ , and the beveling range is variously studied, the average torque and torque pulsation are balanced in the range of 1.4 ≦ θ1 / θ2 ≦ 2.0. It turned out that it can design. In the range of 1.4> θ1 / θ2 or θ1 / θ2> 2.0, the average torque is decreased or the torque pulsation is increased, so that the desired result is not obtained.

  Among them, the most effective θ1 / θ2 = 1.57 or around 1.57 is adopted as an example. The reduction of the torque pulsation leads to the reduction of the electromagnetic excitation force, and the noise at the time of motor operation is reduced. The beveling product was able to reduce the noise by 3 dB in overall value compared to the case without beveling processing (two-dot chain line) in FIG. 9B. This configuration can provide a quiet motor, a quiet washing machine, in other words, a low noise motor and a low noise washing machine.

FIG. 10 is a perspective view of the washing machine W including the magnet motor 1. FIG. 11 is a longitudinal sectional view of the washing machine W including the magnet motor 1.
As shown in FIG. 11, the magnet motor 1 is installed inside the washing machine W, so the magnet motor 1 is not shown in FIG.
The washing machine W is a drum-type washing machine in which the washing tub 35 rotates around an axis of rotation close to horizontal. The washing machine W also has a function of drying the clothes.
The washing machine W includes the magnet motor 1 (see FIG. 1), a base 31, a housing 32, a door 33, an operation / display panel 34, and a drainage hose h.

The base 31 supports the housing 32.
The housing 32 forms an outer shell of the washing machine W. The housing 32 includes left and right side plates 32a and 32a, a front cover 32b, a rear cover 32c (see FIG. 11), and an upper surface cover 32d. In the vicinity of the center of the front cover 32b, a circular insertion port h1 (see FIG. 11) for taking in and out the clothes is formed.
The door 33 is an openable / closable lid provided at the above-mentioned inlet h1. The door 33 is opened and closed when loading and unloading laundry.

The operation / display panel 34 shown in FIG. 10 is a panel provided with an electric switch, an operation switch, a display, and the like, and is installed on the upper surface cover 32 d. The user operates the washing machine W by operating while viewing the operation / display panel 34.
The drainage hose h is a hose for discharging the washing water of the outer tank 37 (see FIG. 11), and is connected to the outer tank 37. From the drainage hose h, drainage after washing, drainage after rinsing, drainage at the time of dehydration are drained.

The washing machine W additionally includes a washing tub 35, a lifter 36, an outer tub 37, a magnet motor 1, and a blower unit 39, as shown in FIG.
The washing tub 35 has a bottomed cylindrical shape. Clothes are stored in the washing tub 35 at the time of washing, rinsing and the like. The washing tub 35 is contained in the outer tub 37 and is rotatably supported coaxially with the outer tub 37. A large number of through holes (not shown) are provided in the peripheral wall and the bottom wall of the washing tub 35 for water flow at the time of dewatering and ventilation at the time of drying. Further, the opening h2 of the washing tub 35 and the opening h3 of the outer tub 37 face the door 33 in the closed state.

In the example shown in FIG. 11, the rotation center axis of the washing tub 35 is inclined so that the sides of the openings h2 and h3 are high, but the invention is not limited thereto. That is, the central axis of rotation of the washing tub 35 may be horizontal or may be vertical to the vertical washing machine.
The lifter 36 is installed on the inner circumferential wall of the washing tub 35. The lifter 36 lifts and drops the clothes during washing and drying to promote washing and drying.

  The outer tank 37 is for storing wash water and the like, and has a bottomed cylindrical shape. As shown in FIG. 11, the outer tub 37 encloses the washing tub 35. A damper (suspension) 100 and a spring 101 for damping the vibration of the outer tub 37 and the washing tub 35 are respectively installed on the left and right of the outer tub 37.

  A drainage hole (not shown) is provided at the lowermost part of the bottom wall of the outer tank 37, and a drainage hose h is connected to the drainage hole. Then, the washing water is stored in the outer tub 37 in a state where the drainage valve (not shown) provided to the drainage hose h is closed. Then, the wash water is discharged by opening the drain valve.

  As shown in FIG. 11, the magnet motor 1 is a mechanism for rotating the washing tub 35, and is installed outside the bottom wall 37 s of the outer tub 37. The rotation shaft 1 j of the magnet motor 1 penetrates the bottom wall 37 s of the outer tub 37 and is connected to the bottom wall 35 s of the washing tub 35.

  The blower unit 39 sends hot air to the washing tub 35 and is disposed above the washing tub 35. The blower unit 39 includes a heater (not shown) and a fan (not shown). Then, the air heated by the heater is fed to the washing tub 35 housed in the outer tub 37 by the fan. By this, the clothes containing moisture are gradually dried in the washing tub 35.

  According to the above-described configuration, the stator 12 includes the stator 12 and the rotor 31. The stator 12 includes the slot portion 124 and the teeth 13 in which the plurality of armature windings 11 are wound. It has a magnet 21 magnetized so that one side is all N pole and all the other side is S pole when viewed from the rotation axis direction, teeth 232 and a core back portion (231, 242) A ring-shaped rotor core 22 is provided, and the core back portion has a convex portion 241 whose outer peripheral surface has a concavo-convex shape when viewed from the rotational axis direction, and the teeth 232 are on the extension of the convex portion 241 in the rotational axis direction. It is arranged.

The thickness T of the tooth 232 is substantially constant from the tip to the root, and the radial depth D and the axial height H of the convex portion 241 are larger than the thickness T of the tooth 232. Since the thickness T of the teeth 232 is substantially constant from the tip to the root, the magnetic lines of force are aligned smoothly, and the motor efficiency is improved.
In addition, the multipolar magnet motor 1 can be manufactured with a simple structure. Therefore, the magnet motor 1 can be provided which is easy to manufacture and low in cost. Furthermore, cogging and noise of the magnet motor 1 are suppressed.
Therefore, the magnet motor 1 can be effectively applied as a motor for a washing machine.

  Further, the rotor core 22 of the magnet motor 1 has a first yoke 23 having substantially the same thickness as the annular portion 231 and the teeth 232, and a second yoke 24 having a concavo-convex shape (convex portion 241) on the outer peripheral surface of the annular portion 242. doing. Therefore, since the first yoke 23 and the second yoke 24 can be press-formed using commercially available steel plates, the manufacturing cost of the magnet motor 1 is low.

From the above, the high torque and low noise magnet motor 1 can be provided with high production efficiency.
By applying the above-described magnet motor 1 to the washing machine W, it is possible to realize the washing machine W having the above-described effects.

Second Embodiment
12A is a perspective view of the magnetic poles of the rotor 31 viewed from the stator of the second embodiment, and FIG. 12B is a side view of the magnetic poles of the rotor 31 viewed from the stator of the second embodiment.
The second embodiment is different from the first embodiment in that the width b1 of the teeth 332 of the first yoke 33 and the width b2 in the circumferential direction of the convex portion 341 of the second yoke 34 are different.
The other configurations (the configurations of the stator 12 and the washing machine W, etc.) are the same as in the first embodiment. Therefore, parts different from the first embodiment will be described, and descriptions of overlapping parts will be omitted.

In the second embodiment, the width b2 of the convex portion 341 of the second yoke 34 in the circumferential direction is different from the width b1 of the teeth 332 of the first yoke 33, and the width b2 of the convex portion 341 of the second yoke 324 is different. Is getting narrower.
This is because the phase and displacement amount of the torque pulsation waveform generated in the first yoke 33 and the phase and displacement amount of the torque pulsation waveform generated in the second yoke 34 mutually cancel each other. A width b1 of 332 and a width b2 of the convex portion 341 of the second yoke 34 in the circumferential direction are determined to form a so-called stagger structure.

  Further, depending on the case, the length s4 (see FIG. 12B) of the teeth 332 of the first yoke 33 and the thickness s5 (see FIG. 12B) of the second yoke 34 are also changed to obtain a flat torque waveform as much as possible. It should be designed as

  According to the above configuration, cogging is smoothed and torque pulsation can be suppressed.

Third Embodiment
13A is a perspective view showing a configuration of a rotor 31 according to a third embodiment, and FIG. 13B is an enlarged view of IV in FIG. 13A.
The third embodiment is different from the second embodiment in that the shape of the teeth 432 of the first yoke 43 is different. The other configurations of the stator 12 and the washing machine W are the same as those in the second embodiment. Therefore, only the portions different from the first embodiment will be described, and the description of the overlapping portions will be omitted.

The shape of the teeth 432 of the first yoke 43 is a pentagon. That is, the teeth 432 of the rotor 31 are skewed to reduce torque pulsation.
Here, the case where the teeth 432 are pentagonal is shown, but a skew effect can be expected if the shape has periodicity even if it is a triangle, a tetragon, a polygon, an arc, a wave, or a shape including curves. it can. Therefore, the shape of the teeth 432 is arbitrary as long as the teeth 432 have a periodicity.
Moreover, although the case where this 3rd Embodiment was given to 2nd Embodiment was shown, it is possible also with the combination with 1st Embodiment.

<Effect>
In FIG. 14, torque waveforms of the magnet motor 1 of the first, second, and third embodiments are indicated by thin solid lines (first embodiment), broken lines (second embodiment), and thick solid lines (third embodiment), respectively. Show. The torque waveform (two-dot chain line) of the magnet motor 1 of only the first yoke 23 described in paragraph 0025 as a comparative example is also described. The electrical angle (deg) is taken on the horizontal axis of FIG. 14, and the torque (Nm) is taken on the vertical axis of FIG.

  From FIG. 14, in order to satisfy the average torque of 40 N · m required for the washing machine, the structure of only the first yoke 23 of the comparative example (two-dot chain line) does not reach the torque of 40 N · m. The configuration (thin solid line) in which the second yoke 24 having the convex portion 241 (see FIG. 2B) on the outer peripheral surface as viewed from the axial direction of the first embodiment is thin exceeds 40 Nm on average. It turns out that it is.

Further, in the configuration in which the width b1 of the teeth 332 and the width b2 in the circumferential direction of the convex portion 341 in the second embodiment shown in FIG. 12A are changed, torque pulsation (broken line) can be reduced as compared with the first embodiment.
Further, the configuration (thick solid line) in which the shape of the teeth 432 of the first yoke 43 of the third embodiment shown in FIGS. 13A and 13B is pentagonal (thick solid line) can further reduce torque pulsation compared to the second embodiment.

  In this embodiment, the rotor 31 of the magnet motor 1 according to the first embodiment, the second embodiment, and the third embodiment includes the first yoke 23 (33, 43) and the second yoke 24 (34). Although the method is described separately, it may be integrally molded by devising the processing method. The point is that low-cost materials can be used with low cost processing methods, and can be configured to have high torque and low torque pulsation.

«Other Embodiments»
1. Although each said embodiment demonstrated the structure which drive | operates a washing machine by the magnet motor 1, it does not restrict to this. For example, in addition to home appliances such as air conditioners and refrigerators, the embodiments can be applied to industrial motors such as pumps, automobiles and railways.

2. In addition, the above embodiments are described in detail for easy understanding of the present invention, and the present invention is not necessarily limited to those having all the configurations described. In addition to the configuration of the embodiment, it is possible to add, delete, and replace other configurations.

3. Further, the mechanisms and configurations described above indicate what is considered to be necessary for the description, and not all the mechanisms and configurations of the product are necessarily shown.

1 Magnet motor (drive mechanism)
Reference Signs List 2 rotor core 11 armature winding 12 stator 121 core back 13 stator teeth 123 stator core 124 slot 21 magnet 22 rotor core 23 first yoke 231 annular portion (core back portion, first annular portion)
232 Tees (Tees Department)
24 second yoke 241, 341 convex (concave and convex)
242 Annular part (Core back part, 2nd annular part)
31 Rotor D Concave and convex depth (radial depth of concave and convex shape)
T thickness of teeth (thickness of teeth)
H Height of convex part (radial depth of concavo-convex shape and height in rotation axis direction)
b1 Teeth width (circumferential width of teeth)
b2 circumferential width of convex part s1 tooth length (teeth length)
t1 Magnet thickness 35 Washing tank 37 Outer tank 1j Rotation shaft (drive mechanism)
W Washing machine

Claims (12)

It has a stator and a rotor,
The stator has slots and teeth in which a plurality of armature windings are wound,
The rotor is
A ring-shaped rotor core having a magnet magnetized so that one surface has all N poles and the other surface has all S poles when viewed from the rotation axis direction, and has teeth and a core back portion Have
An outer peripheral surface of the core back portion is formed in a concavo-convex shape when viewed from the rotation axis direction,
The radial depth of the uneven shape and the height in the rotational axis direction are larger than the thickness of the tooth portion, and the tooth portion is disposed on an extension of the convex portion in the uneven shape in the rotational axis direction. Magnet motor characterized by. In the magnet motor according to claim 1,
The thickness of the teeth portion is substantially constant from the tip to the root. In the magnet motor according to claim 1,
The rotor core is
A first yoke having a first annular portion and teeth portions having substantially the same thickness as the first annular portion;
A magnet motor comprising: a second annular portion; and a second yoke having the concavo-convex shape provided on an outer peripheral surface of the second annular portion. In the magnet motor according to claim 1,
A circumferential width of the teeth portion of the rotor core;
A magnet motor characterized in that the core back portion is viewed from the rotation axis direction and the circumferential width of the convex portion of the uneven shape on the outer peripheral surface is different. In the magnet motor according to claim 1,
A magnet motor characterized in that the shape of the teeth portion of the rotor core is a repetition of a shape including a wave shape, a triangle, a tetragon, a pentagon, a polygon or a curve when viewed in the radial direction. In the magnet motor according to claim 1,
In the rotor core, the teeth portions are offset by a half pitch from each other. In the magnet motor according to claim 1,
In the rotor core, the teeth portion extends in the radial direction of the magnet, and the length of the teeth portion is shorter than the thickness of the magnet. In the magnet motor according to claim 1,
The magnet motor is characterized in that the width of its diameter is larger than its thickness. In the magnet motor according to claim 1,
A magnet motor characterized in that the magnet is a samarium-iron-nitrogen permanent magnet. In the magnet motor according to claim 1,
A magnet motor characterized in that the teeth of the stator have a convex non-concentric shape on the side of the rotor, and beveling is applied in the circumferential direction of the non-concentric shape. It has a stator and a rotor,
The stator has slots and teeth in which a plurality of armature windings are wound,
The rotor is
A ring-shaped rotor core having a magnet magnetized so that one surface has all N poles and the other surface has all S poles when viewed from the rotation axis direction, and has teeth and a core back portion Have
An outer peripheral surface of the core back portion is formed in a concavo-convex shape when viewed from the rotation axis direction,
A magnet motor characterized in that the teeth portion is disposed on an extension of the convex portion in the convex-concave shape in the rotation axis direction. A washing tub for containing clothes,
An outer tub containing the washing tub;
A drive mechanism for rotating the washing tub;
A washing machine comprising the magnet motor according to any one of claims 1 to 11.

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