KR101229464B1 - Rotor Having Polar Anisotropy Magnets of Ring Type and Motor Using the Same - Google Patents

Abstract

The present invention employs a magnet which is anisotropically magnetized a ferrite-based plastic magnet manufactured by mixing a ferrite powder and a resin and injection molding into a ring type as a magnet used in the rotor, thereby reducing noise and improving workability while eliminating a back yoke. It relates to a rotor having a ring-type polar anisotropic magnet and a motor using the same.
The present invention is a motor having a stator and a rotor, wherein the rotor is disposed at intervals facing the stator and spaced apart from the ring-type polar anisotropic magnet made of a plastic magnet; And a body coupled to the inner wall or the outer wall of the magnet.

Description

Rotor Having Polar Anisotropy Magnets of Ring Type and Motor Using the Same}

The present invention relates to a rotor having a ring-type polar anisotropic magnet and a motor using the same. In particular, the magnet used in the rotor is an anisotropic magnetized ferrite-based plastic magnet manufactured by injection molding into a ring type by mixing ferrite powder and resin. The present invention relates to a rotor having a ring-type polar anisotropic magnet that can reduce noise and improve workability by omitting a back yoke, and a motor using the same.

BLDC motors include an IPM type (Interior Permanent Magnet type) BLDC motor in which permanent magnets are inserted into the rotor, and a SPM type (DC surface type BLDC) motor in which permanent magnets are attached to the rotor surface. .

A typical SPM type (surface permanent magnet type) BLDC motor has an anisotropic N pole and S pole magnet 2a in the form of segments on the inner surface of the outer back yoke (rotor core) 1a, respectively, as shown in FIGS. 1 and 2. ) And a stator core 4 having a structure in which alternately arranged segments of anisotropic N-pole and S-pole magnets 2b are alternately arranged on the outer surface of the inner back yoke 1b. The bobbin (3) formed on the outer periphery of the coil (4a) is made of a stator (6) wound, the rotation shaft (7) is coupled to the center of the rotor (5).

The above SPM type BLDC motor attaches segmented ferrite magnets 2a, 2b to the surface of the back yokes 1a, 1b using an adhesive, and secondly joins a structure for preventing the magnets from falling off or insert molding. In this way, the magnet and the back yokes 1a and 1b are integrated with a resin to prevent the magnet from being detached due to the centrifugal force during the rotation of the rotor 5.

However, the SPM type BLDC motor using such a segment magnet has to have back yokes 1a and 1b which serve as a path for the magnetic flux emitted from the segment magnets 2a and 2b, thereby increasing the weight of the rotor. In addition, it was an obstacle to miniaturization and cost reduction of the motor.

In this case, since the magnet is a ferrite sintered magnet and is molded in a ring shape, there is a problem in that it is easily broken due to a large difference in shrinkage in the circumferential direction and the axial direction. . In particular, when used as a rotor of the drum / washing tank driving motor of the washing machine as shown in FIG.

The magnet used in the rotor of the motor is an oxide magnet produced by powder molding ferrite powder, a metal magnet produced by compression molding or casting, and a resin or synthetic rubber mixed with the magnetic powder, as described above. To bond magnets produced by compression or injection molding.

The ferrite sintered magnet has the disadvantage that the magnetic force is weak compared to the rare earth magnet (for example, Nd magnet), which is a kind of metal magnetic flux while having the lowest price, good corrosion resistance and excellent coercivity.

By the way, since the ferrite sintered magnet is a segment type, anisotropic treatment is possible at the time of molding, but polar anisotropy treatment is difficult. Since the ferrite magnet has a magnetic force distribution in which peaks occur at 1/4 and 3/4 points as shown in FIG. 3, it is required to process the ferrite magnet to have a sinusoidal curve for reducing noise. As a result, edge processing (shaping) of both sides (see FIG. 2) of each of the segment magnets 1a and 1b was performed to suppress the generation of noise by making the distribution of the magnetic force lines form a sinusoidal wave. There was a problem of ascension.

In addition, the rotor structure in which the anisotropic segment magnet is attached to the back yokes 1a and 1b has a neutral point between the N pole and the S pole magnets 2a and 2b, so that the skew is reduced to reduce noise due to torque ripple. In the case of magnetizing, the N pole and the S pole coexist in each segment magnet, and thus, the sinusoidal electromotive force (EMF) cannot be obtained.

Moreover, segment magnets use ferrite sintered magnets. In this case, because of the high ferrite brittleness, the machining dimensions are unstable, and there is a problem that the segment magnets are separated from the arrangement position or part easily broken by the pressure applied during insert molding.

In order to solve the above problems, the present invention employs a ring-type polar anisotropic magnet for injection molding a magnet used in the rotor by mixing ferrite powder and resin, so that the back yoke can be omitted and the rotor can be omitted. An object of the present invention is to provide a rotor having a ring-type polar anisotropic magnet and a motor using the same, which can improve workability with weight reduction effects.

Another object of the present invention is a ring type polar anisotropy that can maintain noise because the magnetic force line distribution of the magnet has a polar anisotropy showing a sinusoidal curve, and can have the same magnetic force as in the case of the back yoke. It is to provide a motor having a rotor having a magnet.

It is still another object of the present invention to provide a motor having a rotor having a ring type anisotropic magnet which achieves a simple and robust coupling between the ring type anisotropic magnet and the rotor body.

In order to achieve the above object, the present invention is a ring-type polar anisotropic magnet disposed at intervals facing the stator and made of a plastic magnet; And a body coupled to the inner wall or the outer wall of the magnet.

In addition, according to another feature of the invention, the present invention is a motor having a stator and a rotor, the rotor is disposed at intervals facing the stator spaced apart from the ring-type polar anisotropic magnet made of a plastic magnet; And a body coupled to the inner wall or the outer wall of the magnet.

The magnet is preferably a ferrite plastic magnet mixed with a ferrite powder and a resin.

In addition, the body has a stepped portion is formed to have a space portion on the inner wall or the outer wall to which the magnet is coupled, has a plurality of coupling holes on the inside of the stepped portion, the magnet is a plurality of coupling protrusions snap-coupled to the coupling hole of the body It is preferable to have a.

According to another feature of the invention, the present invention is a stator winding a coil in each of a plurality of split core; And a rotor having a rotating shaft coupled to the center and having an outer magnet and an inner magnet facing the inner and outer sides of the stator, wherein the outer magnet and the inner magnet are ring-type polar anisotropic magnets, respectively. to provide.

In this case, it is preferable that the outer magnet and the inner magnet are ferrite plastic magnets in which the ferrite powder and the resin are mixed and molded.

In addition, the rotor includes an outer magnet and an inner magnet made of a ring-type polar anisotropic magnet; A body having a trench groove in which the outer magnet and the inner magnet are coupled to the inner wall and the outer wall; And a support frame having an outer circumference portion connected to the inside of the body and having a rotation shaft coupled to the center portion, wherein the body is snap-coupled with the outer magnet and the inner magnet.

Furthermore, it is preferable that the outer magnet and the inner magnet are polar anisotropic magnets obtained by polar anisotropically magnetizing ferrite plastic magnets.

In addition, it is preferable that the opposing surface facing the stator of the outer magnet and the inner magnet is formed in a circle.

As described above, in the present invention, by employing a ring-type polar anisotropic magnet mixed with ferrite powder and nylon resin, there is an advantage that the same magnetic force can be realized without the back yoke while omitting the back yoke.

In addition, the present invention can reduce the weight of the rotor by omitting the back yoke, and also formed by a single ring-type magnet to omit the process of attaching and fixing a large number of segment magnets to the back yoke as in the prior art, greatly improving workability It can be improved.

Moreover, the present invention can be manufactured in a polar anisotropy showing the sinusoidal curve of the ring-type magnet to improve the noise without the edge process that is essential to the conventional segment magnet.

In addition, since the ring-type anisotropic magnet of the present invention is a plastic magnet produced by injection molding, the magnet is formed without a separate fixing means for fixing the outer magnet and the inner magnet to the body of the rotor as the coupling protrusion is easily integrally molded at the top. Can be firmly fixed to the body of the rotor.

1 is a cross-sectional view showing a motor having a conventional segment type magnet,
Plan view showing a rotor having a segment type anisotropic magnet shown in FIG. 2,
3 is a graph showing a magnetic force line distribution of a conventional segment type magnet;
4 is a cross-sectional view showing a motor having a rotor having a ring-type polar anisotropic magnet according to an embodiment of the present invention;
5 is a plan view showing a rotor having a ring-type polar anisotropic magnet shown in FIG.
6 is a cross-sectional view showing the rotor body shown in FIG.
7 is a graph showing a magnetic force line distribution (sine wave) of a ring-type polar anisotropic magnet according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described the configuration of a motor having a rotor having a ring-type polar anisotropic magnet according to an embodiment of the present invention.

In the present embodiment, a double rotor type is described as an example of the rotor. However, the rotor type is not limited thereto, and of course, the single-type rotor type can also employ a ring-type polar anisotropic magnet.

Referring to FIG. 4, the motor 100 having a rotor having a ring-type polar anisotropic magnet according to an embodiment of the present invention includes a reduced stator support 110, a rotation shaft 130, a stator 150, and a rotor ( 170).

This embodiment shows that the motor of the present invention is applied to, for example, a driving device for rotationally driving the washing tub of the fully automatic washing machine proposed in Patent No. 89891, and the motor of the present invention directly or indirectly drives the washing tub. Applicable to all drives.

The reduced stator support 110 has a power terminal 111 is installed on one side, a bearing (not shown) and a bearing housing (not shown) for supporting the rotating shaft 130 is installed inside. Since the stator support 110 is not a feature of the present invention, detailed description thereof will be omitted.

One end of the rotating shaft 130 is fixedly coupled to the center of the support frame 173 in the rotor 170. Accordingly, when the rotor 170 rotates by the rotating magnetic field of the stator 150, the rotating shaft 130 transmits the rotational force of the rotor 170 directly or indirectly to the washing tank of the washing machine.

The stator 150 is installed between the outer magnet 175 and the inner magnet 177, the coil wound on the bobbin 154 formed on the outer periphery of the plurality of split core 151 and the plurality of split core 151 153.

As shown in FIG. 5, the plurality of split cores 151 are radially arranged around the rotation shaft 130 and have outer and inner extensions 151a corresponding to the outer magnet 175 and the inner magnet 177, respectively. 151b) each has an " I " shape forming inward and outward curved surfaces with a predetermined curvature. In this case, since the roundness of the inner circumferential portion and the outer circumferential portion of the plurality of split cores 151 is increased, the air constant while being in close proximity between the outer magnet 175 and the inner magnet 177 positioned inside / outside the stator 150. Maintain a gap.

The rotor 170 is made of a thermosetting resin and forms a substantially annular body 171, a support frame 173 made of a metal body and fixed to the center of the body 171, and an outer circumference and an inner circumference of the body 171. And an outer magnet 175 and an inner magnet 177 that are respectively coupled together.

The body 171 is formed in an annular cross-section structure having a trench groove, serves to support the outer magnet 175 and the inner magnet 177, and the outer peripheral portion of the support frame 173 by an insert molding method The buried is formed to receive the rotational driving force of the rotary shaft 130.

In this case, the body 171 forms a rigid coupling with the outer periphery 173a of the support frame 173 through the extension portion 171a which is formed in the axial direction inside the injection molding, the coupling method is the body 171 When the injection molding of the is preferably formed integrally with the support frame 173 by insert molding.

In addition, as shown in FIG. 6, the body 171 includes a trench-shaped space S including the stator 150 along the annular body 171, and opposes the outer wall 171e and the inner wall 171d. ) Is provided with a stepped portion 171f so as to secure a space in which the outer magnet 175 and the inner magnet 177 are assembled. Furthermore, the stepped portion 171f has an outer magnet 175 and an inner magnet 177 assembled to the outer wall 171e and the inner wall 171d of the body 171 and then retained in an assembled state. And a plurality of coupling holes 171b and 171c in which a plurality of coupling protrusions 175a and 177a integrally formed at an upper end of the inner magnet 177 are fixedly coupled in a snap manner.

Unlike the conventional ferrite sintered magnets, the outer magnets 175 and the inner magnets 177 are bond magnets formed by mixing, for example, nylon resin with ferrite powder, that is, plastic magnets, and have no difficulty in molding. It is possible to process polar anisotropy magnetization in which all magnetic domains are set to 100% in the same direction. In this case, the external magnets 175 and the internal magnets 177 are alternately magnetized in a plurality of N poles and S poles in approximately the same areas.

The polar anisotropic outer magnet 175 and the inner magnet 177 do not generate peaks (refer to FIG. 3) in quarters and three quarters of the segment-type anisotropic magnet, and as shown in FIG. It has a magnetic force distribution curve, which eliminates the need for separate edge machining for each stimulus to reduce noise, thereby reducing processing costs and simplifying work.

Further, the outer magnet 175 and the inner magnet 177 are each formed of a ring-type single magnet so that efficiency reduction does not occur even when no back yoke is employed. As described above, the rotor 170 can have the same magnetic force as in the case of using the back yoke even if the back yoke is omitted, and it is possible to omit the work of attaching and fixing a plurality of magnets to the back yoke like a conventional segment type magnet. It is possible to improve the properties, it is possible to obtain a weight saving effect of the rotor 170.

Furthermore, the rotor 170 requires a number of split cores 151 to skew each stimulus, as in the prior art, for noise reduction, and also does not require edge machining (shaping) like conventional segment type magnets. The straight type can still improve noise. Therefore, it is preferable that the opposing surface of the outer magnet 175 and the inner magnet 177 facing the stator is formed in a circular shape.

In addition, as shown in Figure 5, the annular outer magnet 175 and the inner magnet 177 of the present invention is formed with a plurality of engaging projections (175a, 177a) on the top, respectively. As shown in FIGS. 4 and 6, the coupling protrusions 175a and 177a are coupled holes 171b and 171c formed in the stepped portion 171f of the inner wall 171d and the outer wall 171e of the body 171, respectively. Is snapped into). As described above, the external magnet 175 and the internal magnet 177 are snap-coupled to the body 171 through the coupling protrusions 175a and 177a, respectively, so that the assembly work is very easy.

As described above, the present invention employs a ring-type polar anisotropic magnet in which ferrite powder and nylon resin are mixed and molded as the outer magnet 175 and the inner magnet 177, thereby omitting the back yoke, but without the back yoke. Magnetic force can be implemented.

In addition, the present invention can reduce the weight of the rotor 170 in accordance with the omission of the back yoke, and also formed as a single magnet of the ring type as the outer magnet 175 and the inner magnet 177, a plurality of segment magnets as in the prior art Workability can be greatly improved by omitting the step of attaching and fixing the to the back yoke.

Furthermore, the present invention can improve the noise without the edge process that is essential for the conventional segment magnets by making the ring type magnets as the outer magnets 175 and the inner magnets 177 with the polar anisotropy showing the sinusoidal magnetic force distribution curve. .

In addition, since the outer magnet 175 and the inner magnet 177 of the present invention is a plastic magnet manufactured by an injection molding method as a ring-type polar anisotropic magnet, the coupling protrusions 175a and 177a can be easily integrally formed on the top. The magnet may be firmly fixed to the body 171 of the rotor without separate fixing means for fixing the external magnet 175 and the internal magnet 177 to the body 171 of the rotor 170.

In the above embodiment, the rotor of the present invention has been described by way of example a motor in which a plurality of split cores and a double rotor are combined, but the present invention includes a motor including a single rotor and a single stator or a double rotor and a double stator. It is also applicable to a motor.

For example, when the present invention is applied to a motor of a single rotor structure, a ring-shaped polar anisotropic magnet is assembled to an inner wall or an outer wall of an annular body made of a synthetic resin in which a single magnet is assembled, and the rotating shaft is coupled to a central portion of the body. It can have

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limited to the embodiments set forth herein. Various changes and modifications may be made by those skilled in the art.

The present invention employs a magnet which is anisotropically magnetized a ferrite-based plastic magnet manufactured by mixing a ferrite powder and a resin and injection molding into a ring type as a magnet used in the rotor, thereby reducing noise and improving workability while eliminating a back yoke. It can be applied to a rotor having a ring-type polar anisotropic magnet and a motor using the same.

110: stator support 130: rotation axis
150: stator 151: split core
153: coil 154: bobbin
170: rotor 171: body
171a: extension portions 171b and 171c: coupling holes
171d: inner wall 171e: outer wall
171f: step 173: support frame
173a: outer periphery 175: outer magnet
175a, 177a: engaging projection 177: internal magnet

Claims (12)

In a motor having a stator and a rotor,
The rotor is
A ring-type polar anisotropic magnet disposed at intervals facing the stator and formed of a plastic magnet;
The magnet includes a body coupled to the inner wall or the outer wall,
The body has a stepped portion formed to have a space portion on the inner wall or the outer wall to which the magnet is coupled, and has a plurality of coupling holes inside the stepped portion,
The magnet is characterized in that it has a plurality of engaging projections that are snap-coupled to the coupling hole of the body. The motor of claim 1, wherein the magnet is a ferrite plastic magnet mixed with a ferrite powder and a resin. delete A stator wound around a plurality of split cores, respectively; And
And a rotor having a rotating shaft coupled to a center thereof and having an outer magnet and an inner magnet facing the inner and outer sides of the stator.
The rotor is
An outer magnet and an inner magnet made of a ring-type polar anisotropic magnet;
A body having a trench groove in which the outer magnet and the inner magnet are coupled to the inner wall and the outer wall; And
An outer circumference portion includes a support frame coupled to an inner side of the body and coupled to a rotation shaft at a central portion thereof,
And the body snaps to the outer magnet and the inner magnet. 5. The motor of claim 4, wherein the outer magnet and the inner magnet are ferritic plastic magnets in which a ferrite powder and a resin are mixed and molded. delete The method of claim 4, wherein the outer magnet and the inner magnet is
A motor characterized in that it is a polar anisotropic magnet obtained by polarizing a ferrite plastic magnet. The method of claim 4, wherein the body has a stepped portion is formed so as to have a space on the inner wall and the outer wall to which the outer magnet and the inner magnet is coupled, and has a plurality of coupling holes inside the stepped portion,
The outer magnet and the inner magnet are each characterized in that it has a plurality of engaging projections that are snap coupled to the coupling hole of the body. 9. A motor according to any one of claims 4, 5, 7, and 8, wherein an opposing surface facing the stator of the outer magnet and the inner magnet is formed in a round shape. A ring-type polar anisotropic magnet disposed at intervals opposed to the stator and made of a plastic magnet;
The magnet includes a body coupled to the inner wall or the outer wall,
The body has a stepped portion formed to have a space portion on the inner wall or the outer wall to which the magnet is coupled, and has a plurality of coupling holes inside the stepped portion,
The magnet is characterized in that the rotor having a plurality of engaging projections that are snapped to the coupling hole of the body. 11. The rotor according to claim 10, wherein the magnet is a ferrite plastic magnet mixed with a ferrite powder and a resin. delete

Images