Motor, method for separating motor magnets, and method for reusing motor magnets

Abstract

To provide a motor in which the magnets can be easily separated. [Solution] An SPM motor having a stator, a rotor having an iron core disposed inside the stator, and a shaft disposed at the center of the rotor, with permanent magnets disposed on the surface of the iron core, wherein the iron core is provided with permanent magnet opposing holes that face the permanent magnets.

Description

Technical Field

[0001] The present invention relates to a motor, a method for separating magnets of a motor, and a method for recycling magnets of a motor.

Background Art

[0002] Motors are widely used as indispensable devices in modern society. Various structures are known. Among them, there is a structure called a PM (Permanent_Magnet) motor in which a permanent magnet is provided on a rotor. An example of a PM motor is disclosed in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, it is disclosed that a permanent magnet 13 is embedded in a rotor, and a cooling gas passage 9 is provided between the shaft 4 and the permanent magnet 13 in the rotor.

[0005] Here, since motors are widely used as indispensable devices in modern society, the number of motors discarded after use is extremely large. From the viewpoints of environmental protection in recent years and the availability of rare earth elements used in magnets, it has become important to facilitate the disassembly of motors. In particular, a motor structure in which magnets can be easily separated and a method for separating magnets of a motor considering the recycling of magnets are desired.

[0006] In the motor disclosed in Patent Document 1, such considerations have not been made.

[0007] Therefore, the object of this application is to provide a motor in which the magnets can be easily separated, a method for separating the magnets of a motor, and a method for reusing the magnets of a motor. [Means for solving the problem]

[0008] An SPM motor having a stator, a rotor having an iron core disposed inside the stator, and a shaft disposed at the center of the rotor, with permanent magnets disposed on the surface of the iron core, wherein the iron core is provided with permanent magnet opposing holes that face the permanent magnets. [Effects of the Invention]

[0009] The configuration of the present invention makes it possible to realize a motor in which the magnets can be easily separated. Furthermore, it provides a highly efficient method for separating the magnets of a motor and a method for reusing the magnets of a motor.

[0010] Further means and effects of the present invention will become apparent throughout the entire specification below. [Brief explanation of the drawing]

[0011] [Figure 1] This is a conceptual diagram of an SPM motor. [Figure 2] This is a schematic cross-sectional structure of an example of a rotor. [Figure 3] This is a schematic cross-sectional structure of an example of a rotor. [Figure 4] This is a schematic cross-sectional structure of an example of a rotor. [Figure 5] This is an explanatory diagram showing the magnetic circuit of the rotor. [Figure 6A] This is a conceptual diagram of a wedge jig. [Figure 6B] This is an explanatory diagram of the initial state using a wedge jig. [Figure 6C] This is an explanatory diagram of the intermediate state using a wedge jig. [Figure 6D] This is an explanatory diagram showing the finished state using a wedge jig. [Figure 7] This is an explanatory diagram of the rotor's cut section. [Figure 8A]It is a schematic cross-sectional view of an example of a core plate material. [Figure 8B] It is a schematic cross-sectional view showing the structure during lamination of an example of a core plate material. [Figure 8C] It is a schematic front view of an example of a core plate material. [Figure 8D] It is a schematic front view of an example of a core plate material. [Figure 8E] It is a schematic front view of an example of a core plate material. [Figure 9] It is a flowchart related to the separation of the magnets of the motor.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Examples

[0013] Figure 1 is a conceptual diagram of a PM (Permanent_Magnet) motor. Inside the stator 1, the rotor 2 is arranged. At the center of the rotor 2, there is a shaft 5 that serves as the rotation axis. Although not shown, there is a gap between the stator 1 and the rotor 2 to enable rotation. Also, inside the stator 1 in the inner direction, a coil that forms an electromagnet is provided. Since this is the structure of a normal SPM motor, the illustration is omitted.

[0014] Figure 2 is a schematic cross-sectional structure of an example of the rotor. Using Figure 2, the structure of the rotor 2 will be described. One of the features of the present invention lies in the structure of this rotor 2. The permanent magnet 20A of one pole and the permanent magnet 20B of the other pole are sequentially arranged on the surface of the rotor 2. It may also be referred to as the surface of the rotor core 10. Either one of the poles of one pole and the other pole is the S pole, and the other is the N pole.

[0015] In this way, the permanent magnets are attached to the surface of the rotor. A motor having this attachment or surface arrangement is called an SPM (Surface_Permanent_Magnet) motor.

[0016] A key feature of the SPM motor in this embodiment is that it has permanent magnet opposing holes 30.

[0017] The permanent magnet opposing holes 30 are shaped such that the direction in which the hole narrows faces the permanent magnet, with respect to the permanent magnet 20A at one pole and the permanent magnet 20B at the other pole. One example is a triangular shape. Note that even if the vertices are acute angles, this also includes cases where the hole has curvature, roundness, or a curve. Furthermore, any shape other than a triangle in which the hole narrows toward the permanent magnet is included in the category of permanent magnet opposing holes 30. The name "permanent magnet opposing holes" is established based on this aspect of the hole narrowing toward the permanent magnet.

[0018] The permanent magnet opposing hole 30 may be triangular in shape, or it may be an inverted teardrop shape that tapers towards the end, an arc shape that tapers towards the end, or a triangular shape with rounded ends. In all cases, the direction in which the hole narrows faces the side of the permanent magnet.

[0019] Furthermore, Patent Document 1 also discloses a cooling gas passage 9, which is a hole. However, this hole has approximately the same width or size on both the permanent magnet side and the opposite side. In other words, such a hole is not included in the permanent magnet opposing holes.

[0020] Figure 2 discloses a configuration in which there are three permanent magnets 20A for one pole and three permanent magnets 20B for the other pole, for a total of six poles. However, the number of poles is not particularly limited as long as it is an even number. When driving a motor, increasing the number of poles makes the rotation smoother, but the phase of the drive waveform supplied to the stator coil side becomes multiphase, which increases costs. Therefore, the number of poles is appropriately selected and designed according to the intended use of the motor and the allowable cost.

[0021] Figure 3 shows a schematic cross-sectional structure of an example rotor. The main difference from Figure 2 is the shape of the iron core 10. In Figure 2, it was circular, but in Figure 3, it is rectangular. The rectangular shape varies depending on the number of poles of the permanent magnet. For example, in the case of 4 poles, it will be quadrangular, and in the case of 6 poles, it will be hexagonal. As with Figure 2, there is no particular limit on the number of poles, but it is necessary to have at least 4 poles. For the purpose of simplifying the illustrations in the explanation, the following explanation will use the case of 4 poles or a quadrangular iron core 10 as an example.

[0022] The difference between Figure 4 and Figure 3 is that the outer shapes of the permanent magnets 20A on one pole and 20B on the other pole are arc-shaped. This allows for the placement of larger permanent magnets when housing the rotor 2 in the stator 1, improving the efficiency of space utilization.

[0023] Both Figure 3 and Figure 4, like Figure 2, are characterized by having permanent magnet opposing holes 30.

[0024] Figure 5 is an explanatory diagram showing the magnetic circuit of the rotor. For illustrative purposes, it is shown as a representative example in the lower right of Figure 3.

[0025] Magnetic field lines 50 are formed between one pole permanent magnet 20A located on the lower side of the rotor 2 and the other pole permanent magnet 20B located on the right side of the rotor 2, via the iron core 10. These magnetic field lines generate a rotational driving force in relation to the electromagnets formed by the coils of the stator 1.

[0026] Here, as shown in Figure 5, the magnetic field lines 50 are formed in a way that is less susceptible to interference from the permanent magnet opposing holes 30. This shape of magnetic field lines is achieved, firstly, by positioning the permanent magnet opposing holes 30 in the center of the direction of extension of the permanent magnet. Secondly, it is achieved by having a structure in which the shape of the permanent magnet opposing holes 30 becomes smaller on the side facing the permanent magnet. Figure 5 shows that the shape and position of the permanent magnet opposing holes 30 are set to have both of these structures. This makes it possible to avoid or suppress the influence on the magnetic circuit even when the permanent magnet opposing holes 30 are present.

[0027] Next, we will explain how to use the permanent magnet opposing holes 30, as described in Figures 2 to 5.

[0028] Figure 6A is a conceptual diagram of the wedge jig. The wedge jig 70 is configured such that its upper surface 70B is larger than its lower surface 70A. Its shape is such that, in each cross-section, it is similar to, for example, the shape of the permanent magnet opposing hole 30.

[0029] Next, the separation of permanent magnets using a wedge jig will be explained with reference to Figures 6B to 6D.

[0030] Figure 6B is an explanatory diagram of the initial state when using a wedge jig. The example shown is when it is applied to the lower part of Figure 4. The wedge jig 70 is inserted into the permanent magnet opposing hole 30 from the lower surface 70A of the wedge jig.

[0031] Next, the wedge jig 70 is pressed down from above in the diagram and pushed into the permanent magnet opposing hole 30. Figure 6C is an explanatory diagram of the intermediate state when the wedge jig is used. The pushed-in wedge jig 70 applies pressure or force that causes the permanent magnet opposing hole 30 to spread outwards from the surrounding iron core 10. As a result, deformation or cracks 71 occur.

[0032] Furthermore, the wedge jig 70 is pressed down from above in the diagram and pushed into the permanent magnet opposing hole 30. Deformation and cracking 71 progress. Figure 6D is an explanatory diagram of the final state when the wedge jig is used. As a result of pressing down from above in the diagram and pushing the wedge jig 70 into the permanent magnet opposing hole 30, the iron core 10 ultimately deforms in the deformed part 72 so that it spreads outwards. This deformation results in the permanent magnet being pulled away from the iron core 10.

[0033] The wedge jig 70 can also be simply called a jig. However, if the jig has a shape similar to or comparable to the shape of the permanent magnet opposing hole 30, and is larger from the bottom to the top, then simply pushing it in will apply a force to expand the permanent magnet opposing hole 30. Therefore, this is a desirable shape in practical terms.

[0034] However, this also includes cases in which a jig with a shape that is not similar or analogous is inserted into the permanent magnet opposing hole 30, and pressure is applied to the permanent magnet opposing hole 30 on the permanent magnet side by the jig using the principle of leverage, thereby deforming the permanent magnet opposing hole 30.

[0035] In this way, the SPM motor makes it possible to separate the permanent magnet from the iron core in a simple and highly productive manner by simply pressing the wedge jig 70 into the permanent magnet opposing hole 30.

[0036] Furthermore, this is not solely due to the effect of pressing, but also largely due to the shape of the permanent magnet opposing hole 30. Specifically, the permanent magnet opposing hole 30 is shaped so that the permanent magnet side is smaller, making it possible to concentrate the stress from the wedge jig 70 on the permanent magnet side. This makes the iron core 10 more easily deformable on the permanent magnet side.

[0037] Furthermore, it is desirable that the wedge jig 70 be made of a material with a higher hardness than the iron core 10. This is to concentrate the deformation on the iron core 10 side.

[0038] As described above, by providing permanent magnet opposing holes 30 in the iron core 10 of the rotor 2, an SPM motor that allows for easy separation of permanent magnets can be realized. Furthermore, by pressurizing and inserting a wedge jig 70 into the permanent magnet opposing holes 30, a method for separating the magnets of a motor that allows for easy separation of permanent magnets can be provided.

[0039] Furthermore, for the purpose of inducing deformation early, it is desirable that the distance between the end of the permanent magnet-facing hole 30 and the permanent magnet is 1 / 4 or less of the distance from the center of the iron core to the permanent magnet.

[0040] However, if the end of the permanent magnet-facing hole 30 on the permanent magnet side is too close to the permanent magnet, it becomes difficult to secure a sufficient amount of deformation of the iron core for separating the permanent magnet. For this reason, it is desirable that the distance between the end of the permanent magnet-facing hole 30 on the permanent magnet side and the permanent magnet is 1 / 50 or more of the distance from the center of the iron core to the permanent magnet. [Examples]

[0041] This embodiment is basically the same as Embodiment 1. The difference is that this embodiment has a notch or a micro-hole in a portion of the iron core from the end of the permanent magnet opposing hole 30 to the permanent magnet.

[0042] Figure 7 is an explanatory diagram of the notched section of the rotor.

[0043] The notch 90 is provided in a portion of the iron core from the end of the permanent magnet opposing hole 30 to the permanent magnet. The notch 90 has one or more micro-holes 91. These micro-holes 91 are provided to enable faster deformation of the iron core 10. Therefore, it is desirable that the notch 90 or the micro-holes 91 be arranged to extend linearly from the end of the permanent magnet opposing hole 30. If there are multiple micro-holes 91, it is also desirable that they be arranged linearly.

[0044] An example of a specific method for constructing the notch 90 or the micro-hole 91 will be explained using Figures 8A to 8E.

[0045] Figure 8A is a schematic cross-sectional view of an example of a core plate material. A small hole 101 is provided in a part of the core plate material 100, where the thickness is reduced midway. The core plate material 100 retains its thickness while the small hole 101 is provided. In the figure, the small hole 101 is V-shaped so that its tip faces the permanent magnet side. This ensures that at the cut portion 90, its tip faces the permanent magnet side.

[0046] Figure 8B is a schematic cross-sectional view showing the structure of a laminated iron core plate material, as in one example. By laminating the iron core plate material 100 shown in Figure 8A, a large number of micro-holes 101 are constructed to overlap.

[0047] Figure 8C is a schematic front view of an example of a sheet metal core. It is a view of Figure 8A or Figure 8B from the front.

[0048] Furthermore, the notched portion 90 or the minute hole portion 91 can have various shapes.

[0049] Figure 8D is a schematic front view of an example of a sheet metal core. The micro-holes 101 are configured as completely through holes. Instead, in order to maintain the function of the core, the sheet metal 100 of the core remains intact between adjacent micro-holes 101 in the vertical direction shown in the figure. In other words, the holes do not penetrate vertically, but are configured discontinuously or intermittently.

[0050] Figure 8E is a modified version of Figure 8D, in which the minute hole portion 101 is rectangular in Figure 8D, whereas in Figure 8E it is circular.

[0051] By stacking multiple iron core plate materials 100 as shown in Figures 8C to 8E in the direction of extension of the shaft 5, the notches 90 and minute holes 91 shown in Figure 7 can be easily formed.

[0052] As described above, by providing a notch or a micro-hole in a portion of the iron core from the end of the permanent magnet opposing hole 30 to the permanent magnet, in addition to the effects of Example 1, it is possible to further facilitate the separation of the magnet from the rotor. [Examples]

[0053] This embodiment is a flowchart illustrating the process of separating the permanent magnets from the rotor, based on the rotor structure of either Embodiment 1 or Embodiment 2. Figure 9 shows a flowchart related to the separation of the motor magnets.

[0054] In step S1, a wedge jig is inserted into the hole opposite the permanent magnet. In step S2, the wedge jig is pushed in and lowered. In step S3, as a result of the rotor deformation, the permanent magnet detaches and separates.

[0055] At this stage, the permanent magnet has been forcibly detached. Therefore, some adhesive used to bond the permanent magnet to the rotor's iron core may remain on it.

[0056] Therefore, if necessary, the adhesive is cleaned and removed in step S4.

[0057] If the sole purpose is the separation and recovery of the permanent magnet, the process can be terminated at step S4.

[0058] However, if the separated permanent magnets are to be attached to a new rotor and reused, then the next steps S5 and S6 are performed.

[0059] In step S5, adhesive is applied to the recovered permanent magnet and attached to the iron core of the new rotor. In step S6, the permanent magnet is remagnetized. If the recovered permanent magnet has sufficient magnetic force, step S6 may be omitted. Also, the order of steps S5 and S6 may be reversed depending on the manufacturing process.

[0060] As described above, this embodiment provides a method for separating magnets that can easily recover the permanent magnets of an SPM motor. It also provides a method for reusing the recovered magnets.

[0061] Each of the embodiments described above can be used individually or in combination.

[0062] Furthermore, insofar as the above-described technical concept is applied, variations and equivalents are also included within the scope of the description in this specification.

[0063] Furthermore, an example of the present invention described using the above embodiments can also be expressed as follows.

[0064] <Part 1> An SPM motor having a stator, a rotor having an iron core disposed inside the stator, and a shaft disposed at the center of the rotor, with permanent magnets disposed on the surface of the iron core, The iron core is an SPM motor having permanent magnet opposing holes that face the permanent magnets. <Part 2> The SPM motor described in <Part 1>, wherein the hole opposite the permanent magnet has a shape in which the hole becomes smaller as it approaches the permanent magnet. <Part 3> The SPM motor described in <Part 2>, wherein the permanent magnet opposing hole is positioned corresponding to the central part of the permanent magnet. <Part 4> The SPM motor described in <Part 3>, wherein the hole facing the permanent magnet has a triangular shape, and one of its vertices is positioned opposite the permanent magnet. <Part 5> The SPM motor as described in <Part 4>, wherein the distance from the end of the permanent magnet-facing hole to the permanent magnet is 1 / 4 or less of the distance from the center of the iron core to the permanent magnet. <Part 6> The SPM motor as described in <Part 5>, wherein the distance from the end of the permanent magnet-facing hole to the permanent magnet is 1 / 50 or more of the distance from the center of the iron core to the permanent magnet. <Part 7> The SPM motor according to <Part 2>, wherein the iron core has a notch or a micro-hole in the region between the permanent magnet opposing hole and the permanent magnet. <Part 8> The SPM motor according to <7>, wherein the notched portion or the minute hole portion has a plurality of notches or holes. <Part 9> The SPM motor according to <8>, wherein the notched portion or the minute hole portion is configured in which plate material having notches is stacked in the direction of extension of the shaft. <Part 10> The SPM motor according to <8>, wherein the notched portion or the minute hole portion is configured in which plate material having holes is stacked in the direction of extension of the shaft. <Part 11> A method for separating the magnets of a motor having an iron core and permanent magnets attached to the surface of the iron core, wherein the iron core has permanent magnet opposing holes that face the permanent magnets, and a jig is inserted and pressed into the permanent magnet opposing holes to deform the iron core and separate the permanent magnets from the iron core. <Part 12> The method for separating the magnets of a motor as described in <No. 11>, wherein the jig has a shape similar to the permanent magnet opposing hole and is larger from the bottom surface to the top surface. <Part 13> A method for reusing motor magnets, comprising separating the permanent magnets using the method for separating motor magnets described in <No. 12>, cleaning and removing the adhesive from the permanent magnets, and then attaching the permanent magnets to a new iron core with adhesive. <Part 14> A method for reusing the magnets of a motor as described in <Part 13>, wherein the permanent magnets are remagnetized in a step before or after attaching the permanent magnets to an iron core with an adhesive. [Explanation of Symbols]

[0065] 1: Stator 2: Rotor 5: Shaft 10: Rotor core 20A: Permanent magnet with one polarity 20B: Permanent magnet of the other polarity 30: Permanent magnet opposing holes 50: Magnetic field lines 70: Wedge jig 70A: Wedge jig bottom surface 70B: Wedge jig top surface 71: Hibi 72: Deformed part 90: Cutting section 91: Micro hole part 100: Iron core plate 101: Micro hole

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