Rotor magnet recovery method and magnet recovery device, separation auxiliary device, and magnet separation device

Abstract

To efficiently recover magnets from a rotor without undergoing rapid cooling using water. [Solution] A method for recovering magnets from a rotor having multiple stacked steel plates and magnets fixed in holes in the steel plates, comprising a heating step in which the rotor is heated to demagnetize the magnets and embrittle the resin used to fix the magnets, a cooling step in which the rotor is slowly cooled after the heating step, a pressing step in which the cooled rotor is pressed to elastically deform the steel plates, and a separation step in which the magnets are separated from the rotor after the pressing step.

Description

[Technical Field]

[0001] The present invention relates to a magnet recovery method and a magnet recovery device for recovering magnets from rotors of used automobile motors and the like.

[0002] In recent years, the number of xEVs (electric vehicles), including electric vehicles (EVs) and hybrid electric vehicles (HEVs), has been increasing. xEVs are equipped with large drive motors, the rotors of which contain many rare earth magnets, which pose a high procurement risk, and reliable recycling is required. As xEVs become more powerful and powerful, their drive motors have also become larger and more robust, making dismantling and magnet recovery a heavy and inefficient task.

[0003] Until now, the common method has been to heat the rotor to a high temperature to demagnetize the magnets and embrittle the resin that holds the magnets in place, then cool the rotor to a temperature where it can be worked on, and then vibrate or impact the rotor and magnets to separate and recover the magnets from the steel plate.

[0004] For example, in Patent Document 1, after heating and rapidly cooling a rotor, a magnet recovery device is used to vibrate the rotor to recover the magnets. The magnet recovery device is disclosed to include a horizontally arranged shaft and a vibrator that vibrates the shaft in the vertical direction, the shaft is passed through a through-hole in the rotor core, the rotor core is supported below the shaft with a sufficient gap between the outer circumferential surface of the shaft and the inner circumferential surface of the rotor core, and the shaft is vibrated in the vertical direction by the vibrator, thereby applying vertical vibrations to the rotor core and causing the outer circumferential surface of the shaft to continuously collide with the inner circumferential surface of the rotor core.

[0005] Furthermore, the applicant has previously proposed in Patent Document 2 a method comprising a heating step in which the rotor is heated to demagnetize the magnets and embrittle the resin used to secure the magnets, a rapid cooling step in which the rotor is rapidly cooled after the heating step, and a vibration conveying step in which the rapidly cooled rotor is conveyed while being vibrated and impacted, in which the vibration conveying step applies forces to the steel plate and magnets in vertical directions and along the conveying surface.

[0006] Furthermore, Patent Document 3 describes a method of crushing and recovering magnets by deforming adjacent laminated steel plates by shifting their relative positions in a direction perpendicular to the lamination direction of the laminated steel plates. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-166966 [Patent Document 2] Patent No. 7626291 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-166967 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in recent motors (rotors), the resin that secures the magnets is often not sufficiently embrittled by heating alone, and the magnets cannot be separated by subsequent impact alone. In such cases, it is necessary to peel off the laminated steel plates one by one to recover only the magnets, which is extremely inefficient and requires a heavy workload.

[0009] Furthermore, the methods disclosed in Patent Documents 1 and 2 require rapid cooling with water as a pretreatment, and because this method utilizes deformation due to temperature differences, the steel plates are significantly deformed, causing the magnet insertion holes formed by multiple laminated steel plates to lose their straightness, resulting in the problem that the long magnets inserted into these magnet insertion holes cannot be removed. Furthermore, pretreatment using water cooling poses several problems, such as the generation of wastewater and wet residue from adhesive resin in the water tank used for rapid cooling, and the risk of water evaporating suddenly and scattering when the rotor is immersed in water at a high temperature. The method disclosed in Patent Document 3 is also expected to cause the rotor to be deformed by applying a strong pressure, resulting in the slots losing their linearity and the magnets being firmly fixed.

[0010] The present invention has been made in view of the above circumstances, and has as its object to efficiently recover magnets from a rotor without undergoing rapid cooling using water. [Means for solving the problem]

[0011] The method for recovering magnets from a rotor of the present invention is a method for recovering the magnets from a rotor having a plurality of stacked steel plates and magnets fixed in holes in the steel plates, the method comprising the steps of: The method includes a heating step in which the rotor is heated to demagnetize the magnets and embrittle the resin used to fix the magnets; a pressing step in which the heated rotor is pressed to elastically deform the steel plate; and a separation step in which the magnets are separated from the rotor after the pressing step.

[0012] This magnet recovery method involves a heating process to demagnetize the magnets and embrittle the resin, and then pressing the steel plates after heating to elastically deform them, thereby releasing the fixed state between the stacked steel plates and between the steel plates and the magnets, making it easier to separate the magnets in the subsequent separation process. In this case, rapid cooling using water as in the prior art is not required, and therefore, equipment such as a water tank is not required, plastic deformation of the steel plate due to rapid cooling is suppressed, corrosion such as rust caused by the use of water does not occur, and wastewater and residue treatment, etc. are also not required.

[0013] Furthermore, by elastically deforming the steel plates during the pressing process, it is possible to effectively destroy the crimped joints between the steel plates and the resin fixing parts to the magnets, and since the steel plates are not plastically deformed, it is possible to easily separate the magnets afterwards.

[0014] In the rotor magnet recovery method of the present invention, the pressing step may press the rotor in a direction perpendicular to the stacking direction of the steel plates. By pressing in a direction perpendicular to the stacking direction of the steel plate, in other words, in the plane direction of the steel plate, it is possible to appropriately cause elastic deformation in the steel plate, making it easier to peel the steel plate and separate the magnet from the steel plate.

[0015] In the rotor magnet recovery method of the present invention, the separating step may include applying vibration or impact to the rotor. Since the steel plates are released from their respective attachments and from the magnets during the pressing process, the steel plates can be easily peeled off and the magnets separated from the steel plates by applying vibration or impact.

[0016] In the rotor magnet recovery method of the present invention, it is preferable to have a cooling step of cooling the heated rotor between the heating step and the pressing step. Since the rotor is pressed after cooling, there is no need to handle the rotor in a hot state, making the work easier. The cooling method is a slow cooling method, and the rotor can be simply left as it is. By temporarily storing the rotor for slow cooling as a cooling process after the heating process and then performing the pressing process, the temporary storage time can be used as a buffer time, improving work efficiency.

[0017] The rotor magnet recovery device of the present invention is a device for recovering magnets from a rotor having a plurality of stacked steel plates and magnets fixed in holes in the steel plates, The device comprises a heating means for heating the rotor to the higher of the Curie temperature or the embrittlement temperature of the resin for fixing the magnets, a pressing means for pressing the rotor heated by the heating means to elastically deform the steel plate, and a separation means for separating the magnets from the rotor after pressing.

[0018] In the rotor magnet recovery device of the present invention, the pressing means may press the rotor in a direction perpendicular to the lamination direction of the steel plates.

[0019] In the rotor magnet recovery device of the present invention, the separating means may be a vibrating means for applying vibration or impact to the rotor.

[0020] The rotor magnet recovery device of the present invention may further include a cooling means for cooling the rotor heated by the heating means.

[0021] The separation auxiliary device of the present invention is used to separate magnets from a rotor having a plurality of stacked steel plates and magnets fixed in holes in the steel plates, and The rotor has a support base that supports a portion of the outer peripheral surface of the rotor, a pressing tool that is arranged opposite the support base and can abut against the outer peripheral surface of the rotor on the side opposite the support base, and a press mechanism that brings the pressing tool and the support base closer together to press the rotor in a direction perpendicular to the stacking direction of the steel plates, thereby elastically deforming the steel plates.

[0022] The support base and pressing tool press the rotor in a direction perpendicular to the stacking direction of the steel plates, in other words, in the direction of the steel plate's surface, causing the steel plates to elastically deform, making it easier to separate the magnets.The support base and pressing tool are brought close together by a press mechanism, and the device configuration is simple.

[0023] The rotor magnet separating device of the present invention includes the separation auxiliary device and a separating means for separating the magnets from the rotor after elastically deforming the steel plate. [Effects of the Invention]

[0024] According to the present invention, the rotor has been heated to demagnetize the magnets and embrittle the resin, and then cooled. This is then pressed to elastically deform the steel plates, thereby releasing the fixed state between the stacked steel plates and between the steel plates and the magnets, making it easy to separate the magnets. In this process, slow cooling after heating suppresses plastic deformation of the steel plates, making it easier to separate the magnets, and also prevents corrosion and eliminates the need for wastewater treatment, thereby reducing the workload and enabling the magnets to be recovered efficiently. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a plan view showing an example of a rotor handled by a magnet recovery device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a longitudinal cross-sectional view of the rotor of FIG. 1 taken along line AA. [Figure 3] FIG. 1 is a configuration diagram of a magnet recovery device according to an embodiment. [Figure 4] FIG. 2 is a perspective view showing an example of a cooling means in the magnet recovery device of the embodiment. [Figure 5] FIG. 2 is a perspective view showing an example of a pressing means in the magnet recovery device of the embodiment. [Figure 6] 6 is a top view of a mounting block in the pressing means of FIG. 5. FIG. [Figure 7] FIG. 2 is a perspective view showing an example of a vibration conveying means in the magnet recovery device of the embodiment. [Figure 8] 10 is a flowchart illustrating magnet retrieval according to an embodiment. [Figure 9] FIG. 10 is a perspective view showing a modified example of the separating means. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, regarding the rotor, as shown in Figures 1 and 2, rotor 1 is formed into an overall cylindrical shape by joining multiple annular steel plates 2 made of magnetic material in a stacked state by crimping or the like. A central hole 3 is formed in the center to which a shaft (not shown) is fixed. Each steel plate 2 also has multiple holes 4 formed at intervals in the circumferential direction, and the steel plates 2 are stacked in a state where the holes 4 are connected in the axial direction. In other words, the holes 4 that are connected in the axial direction are formed to the same size in each steel plate 2, and the stacked steel plates 2 form one long, straight magnet insertion hole 4. Magnets 5 are fixed in this connected magnet insertion hole 4 with magnet fixing resin 6.

[0027] The steel plate 2 is preferably a silicon steel plate having a thickness of, for example, 0.35 mm, the magnet 5 is preferably a rare earth magnet such as neodymium, and the magnet fixing resin 6 is preferably an epoxy resin. The dimensions of the rotor 1 are not particularly limited, but for example, the diameter is 130 mm to 250 mm, and the length (height of the stack of steel plates 2) is about 50 mm to 150 mm.

[0028] <One embodiment> A magnet recovery device and a magnet recovery method according to one embodiment of the present invention will be described. As shown in Figure 3, this magnet recovery device 10 has a heating means 11 that heats the rotor 1, a cooling means 12 that slowly cools the rotor 1 heated by the heating means 11, a pressing means 13 that presses the rotor 1 after cooling to elastically deform the steel plate, and a separation means 14 that separates the magnets from the rotor after pressing.

[0029] A heating furnace (not shown) is used as the heating means 11, and by heating the rotor to the higher of the Curie temperature or the embrittlement temperature of the magnet fixing resin or higher, the magnets 5 in the rotor 1 are demagnetized and the magnet fixing resin 6 is embrittled.

[0030] The cooling means 12 uses a slow cooling method, and for example, as shown in Fig. 4, a mounting table 22 is provided on which the heated rotor 1 is placed on a pallet 21 and left. The mounting table 22 is formed into a table shape using, for example, a frame, and multiple pallets 21 can be placed on it. It is preferable to provide multiple sets of these mounting tables 22 and pallets 21 so that many rotors 1 can be handled. In this case, it is even better to create a structure in which the surface of the rotor 1 is as easily exposed to air as possible by leaving as much space between the rotors 1 as possible or by leaving gaps like a bamboo sieve on the surface of the pallet 21.

[0031] As a method of slow cooling, a plurality of heated rotors 1 may be placed on a pallet 21 and the pallet 21 may be left to cool while placed on a mounting table 22. However, other methods may also be used in combination, such as blowing air onto the rotor with a fan or spraying the rotor with a sprayer and utilizing the heat of vaporization. If the cooling method is rapid cooling, the steel plate 2 may be plastically deformed, impairing the straightness of the magnet insertion holes 4 and making it difficult to remove the magnets 5 from the deformed magnet insertion holes 4. For this reason, in this embodiment, slow cooling is used to prevent plastic deformation of the steel plate 2, and cooling may be accelerated by spraying or the like as long as it is to an extent that does not cause plastic deformation of the steel plate 2 (to an extent that does not cause rapid cooling).

[0032] The pressing means 13 is a press device or the like, and as shown in Figure 5, is provided with a support base 25 that holds the rotor 1 in a placed state, a pressing tool 26 that abuts the rotor 1 placed on the support base 25 from the opposite side of the support base 25, and a pressing mechanism 27 that propels the pressing tool 26 to press the rotor 1.

[0033] The support base 25 is formed in a block shape, and has a groove 28 formed on its upper surface that is V-shaped in cross section, thereby forming two support surfaces 29 for receiving the rotor 1, with the outer circumferential surface of the rotor 1 being supported and placed on the support surfaces 29. In addition, a recess 30 is formed in the middle of the length of each support surface 29 (the length direction of the grooves 28) in a direction that crosses the support surfaces 29, as shown in Fig. 6. The formation of this recess 30 divides the support surface 29, and the rotor 1 placed in the groove 28 of the support base 25 has a portion that abuts against the support surfaces 29 and a portion that is not supported by the support base 25 due to the recess 30.

[0034] In the example shown in FIG. 5, the pressing tool 26 is formed in a flat plate shape and is held by a press mechanism 27 . The press mechanism 27 holds the pressing tool 26 by a cylinder or the like so that it can move up and down, and is configured to press the rotor 1 placed on the support base 25 downward from above using the pressing tool 26. The lower surface of this pressing tool 26 is formed as a flat surface. Therefore, the rotor 1 is positioned with its central axis horizontal, the lower surface of the outer circumferential surface is supported by two support surfaces 29 of the V-shaped grooves 28 of the support base 25, and the upper surface is pressed by the lower surface of the pressing tool 26. In this case, the pressing is performed so as to impart deformation within the range of elastic deformation so as not to cause plastic deformation in the steel plate 2 of the rotor 1.

[0035] In this embodiment, the separation auxiliary device of the present invention is composed of a support base 25 , a pressing tool 26 , and a pressing mechanism 27 .

[0036] The separating means 14 is a vibrating means for applying vibration or impact to the rotor 1 after pressing, and in this embodiment, a vibrating conveying means is used for conveying while applying vibration. As shown in Figure 7, the vibration conveying means 14 includes a conveying path 33 formed by a screen 31 of a predetermined length on which the rotor 1 is placed and conveyed, and side walls 32 erected on both sides of the screen 31, and a vibration imparting means 34 that vibrates the conveying path 33. The screen 31 is made of a perforated plate such as punched metal with many through holes 35 formed therein. The through holes 35 are formed to a size that does not allow the steel plates 2 of the rotor 1 to pass through, but allows the magnets 5 and magnet fixing resin 6 separated from the rotor 1 to pass through. Side walls 32 are erected on both sides of the screen 31, and the screen 31 and the side walls 32 together form a trough structure or a gutter-shaped transport path 33 having a bottom and side surfaces.

[0037] In this embodiment, the vibration imparting means 14 imparts vibration and impact to the trough-structured conveying path 33 while supporting it on a horizontal base 41, and a vibration motor 43 with its rotation axis 42 facing diagonally is attached to the outer surface of the side wall 32 of the conveying path 33, and the rotation of this vibration motor 43 imparts vibration and impact diagonally to the conveying path 33, in other words, the screen 31. In order to prevent the vibration of the screen 31 from being transmitted to the base 41, an elastic member 44 such as a spring is interposed between the base 41 and the transport path 33 along the vertical direction.

[0038] The vibration motor 43 has a weight eccentrically mounted on the rotating shaft 42, and the rotation of this eccentric weight can apply vibration and impact in a direction perpendicular to the rotating shaft 42. Furthermore, since the vibration motor 43 is mounted on the outer surface of the side wall 32 with the rotating shaft 42 facing diagonally, vibration and impact can be applied to the side wall 32 in an oblique direction. As a result of this vibration, the conveying path 33 vibrates diagonally, and vibrations and impacts are applied to the rotor 1 on the screen 31 by a component of force mainly along the thickness direction (vertical direction) of the screen 31, and the rotor 1 on the screen 31 is conveyed by a component of force along the surface direction (horizontal direction) of the screen 31.

[0039] A plurality of baffle plates 45 are provided to protrude from the inside of the side wall 32. These baffle plates 45 protrude in an inclined state toward the center in the width direction of the screen 31 and toward the downstream in the conveying direction, and are provided at predetermined intervals in the conveying direction. 7, reference numeral 46 denotes a steel plate discharge port at the downstream end of the conveying path 33, and reference numeral 48 denotes a box that receives the steel plates 2 that fall from the conveying path 33. Also, an exhaust device may be provided below the screen 31 to prevent the magnet fixing resin 6 that has separated from the steel plates 2 from scattering.

[0040] In this embodiment, the magnetic separating device of the present invention is composed of the above-described separation auxiliary device (support base 25, pressing tool 26, press mechanism 27) and separating means 14.

[0041] A method for recovering magnets 5 from rotor 1 using magnet recovery device 10 configured as above will be described. As shown in Figure 8, this magnet recovery method includes a heating step in which the rotor 1 is heated by a heating means 11 to demagnetize the magnets 5 and embrittle the magnet fixing resin 6, a cooling step in which the rotor 1 is cooled by a cooling means 12 after the heating step, a pressing step in which the cooled rotor 1 is pressed by a pressing means to elastically deform the steel plate 2, and a separation step in which the magnets 5 are separated while applying vibration and impact to the rotor 1 after the pressing step. The steps will be explained below in order.

[0042] (Heating process) As mentioned above, in the heating process, rotor 1 is heated to the higher of its Curie temperature or the embrittlement temperature of the magnet fixing resin. In the case of a neodymium magnet, it will be demagnetized by holding it at a temperature of 380°C or higher relative to its Curie temperature (330°C to 380°C) for about 15 minutes. Embrittlement of the magnet fixing resin will depend on the type of resin, but typically heating to a temperature higher than the Curie temperature of the magnet will cause decomposition and embrittlement, so it is sufficient to set the temperature to promote demagnetization of magnet 5 and embrittlement of magnet fixing resin 6.

[0043] (cooling process) In the cooling step, the rotors 1 that have reached a high temperature in the heating step are arranged on a pallet 21, and the pallet 21 is placed on a mounting table 22 and left in the air to slowly cool the rotors 1. For example, after the heating step is completed, the rotors 1 may be left on the mounting table 22 for storage for, for example, one day. When a rapid cooling process is used as in the past, it is necessary to carry out the rapid cooling process immediately after the heating process, and since the rotor 1 is immersed in a water tank shortly after the heating process, it is necessary to secure a lead wire from the heating furnace to the water tank, which makes the work complicated.However, in the case of this embodiment, the rotor can be cooled simply by being left alone, making the work easy.

[0044] When carrying out the recovery work for multiple rotors 1, the rotors 1 are heated sequentially in the heating process, arranged on a pallet 21, and the pallet 21 is then placed on the mounting table 22, and this process is repeated.The heating process and the cooling process are carried out sequentially, separate from the next pressing process. Furthermore, since the next pressing step can be performed on the rotor 1 that has been left standing, the time that the rotor 1 is left standing for slow cooling after the heating step can be used as a buffer time period, thereby improving work efficiency.

[0045] As long as the cooling is not rapid, a fan may be used to blow air onto the rotor 1 on the mounting table 22. Alternatively, a sprayer may be used to spray water onto the rotor 1 in the form of a fine mist.

[0046] (Pressing process) The pressing step is carried out sequentially on the plurality of rotors 1 that have been left on the mounting table 22 after the cooling step. For example, the pressing step can be carried out on the day following the cooling step. In this pressing step, the cooled rotor 1 is pressed by pressing means 13 to cause elastic deformation in the steel plates 2. The rotor 1 is placed in a groove 28 of a support base 25 with its axial direction facing horizontally, and the lower part of its outer circumferential surface is supported by a support surface 29 of the support base 25. Then, a pressing tool 26 is brought into contact with the upper part of the outer circumferential surface of the rotor 1 from the side opposite the support base 25, and the rotor 1 is pressed vertically by a press mechanism 27. This pressing presses the rotor 1 in a direction perpendicular to the stacking direction of the steel plates 2 (in the plane direction of the steel plates 2), causing elastic deformation in the steel plates 2.

[0047] For this reason, for example, the amount of depression of the pressing tool 26 by the press mechanism 27 is set to a predetermined amount within the range in which the steel plate 2 of the rotor 1 is elastically deformed, and the steel plate 2 is pressed down by that predetermined amount to deform. Alternatively, the pressing force generated by the pressing tool 26 may be set to a predetermined amount within the range in which the steel plate 2 is elastically deformed, and the steel plate 2 may be pressed down by that pressing force to deform it. In this case, a recess 30 is formed in the support surface 29 of the support base 25, and the rotor 1 loses support from the support base 25 at this recess 30, making it possible to shift the steel plate 2 in the surface direction as well, allowing for more efficient separation. This pressing step causes elastic deformation of the steel plates 2, which releases the crimping between the steel plates 2 and creates gaps between the steel plates 2, while also crushing the magnet fixing resin 6 in the magnet insertion holes 4.

[0048] In this pressing step, the rotor 1 may be pressed multiple times. For example, the rotor 1 may be rotated on the support base 25 by a predetermined angle (for example, 120°) and pressed multiple times while shifting the pressing points in the circumferential direction. In this case, each pressing is performed within the elastic deformation range of the steel plate 2.

[0049] (separation process) In the separation process, in this embodiment, the rotor 1 is vibrated by placing the rotor 1 on the screen 31 of the conveying path 33 while vibration and impact are applied to the screen 31 of the vibration conveying means 14 by the vibration applying means 34. Since the screen 31 is vibrated obliquely, the rotor 1 vibrates on the screen 31 while moving in the surface direction of the screen 31. At this time, the frequency of the vibrations imparted by the vibration imparting means 34 is set to be relatively high and the amplitude to be large so that an impact can be imparted to the rotor 1 along with the vibration.

[0050] The vibrations and impacts applied to the rotor 1 by the screen 31 promote the separation of the steel plates 2, causing the magnet fixing resin 6, which had been embrittled in the previous process, to collapse and the magnets 5 to separate from the steel plates 2. Multiple steel plates 2 are stacked on top of each other, and magnets 5 were fixed in holes 4 in each of the multiple steel plates 2. However, the steel plates 2 that have separated due to the diagonal vibrations and impacts begin to shift in the planar direction, and the magnets 5 that were fixed inside also fall out of the holes 4 as the steel plates 2 shift.

[0051] Then, the magnets 5 and magnet fixing resin 6 that have separated and fallen off the steel plate 2 pass through the through holes 35 formed in the screen 31 and fall below the screen 31 while being transported on the screen 31. On the other hand, since the steel plate 2 is larger than the through holes 35, it is transported on the screen 31 and sent downstream, drops from the steel plate discharge port 46, and only the steel plate 2 can be collected in the box 48.

[0052] In this way, the magnets 5 in the rotor 1 can be separated and recovered from the steel plates 2. In this case, after the magnets 5 are demagnetized and the fixing resin 6 is embrittled by heating, the steel plates 2 are cooled and then pressed to elastically deform, facilitating the peeling of the steel plates 2 and the separation of the magnets 5. Thereafter, the rotor 1 is transported using a method that involves vibration and impact, which allows the magnets 5 to be separated while shifting the peeled steel plates 2 in the planar direction. The magnets 5 are then dropped through the through-holes 35 in the screen 31 and recovered, and the steel plates 2 can be recovered separately from the magnets 5 at the end of the transport path 33.

[0053] In this case, slow cooling is used instead of rapid cooling using water as in the prior art, which eliminates the need for equipment such as a water tank, and also suppresses plastic deformation of the steel sheet 2 due to rapid cooling, and also prevents corrosion such as rust caused by the use of water, and eliminates the need for drainage and residue disposal. Furthermore, since the slow cooling method simply requires leaving the steel sheet to stand, the work is easy, and by temporarily storing the steel sheet for slow cooling after the heating process and then performing the pressing process, the temporary storage time can be used as a buffer period, which improves work efficiency and thereby reduces work time.

[0054] <Modification of Separation Means> In the embodiment, the separation means is a vibration conveying means 14, but since the rotor 1 is formed in a circular ring shape and has a central hole 3 in the center through which an axis is inserted and fixed, as shown in Figure 9, a shaft 51 having an outer diameter smaller than the inner diameter of this central hole 3 can be inserted into this central hole 3, and vibration or impact can be applied to this shaft 51 by a vibration motor or the like not shown, thereby applying vibration or impact to the rotor 1 from inside the central hole 3 (excitation).

[0055] In this separation means, a vibration means is configured by a vibration motor or the like and a shaft 51, and when the shaft 51 is inserted into the central hole 3 of the rotor 1 after the pressing process to apply vibration or impact, the steel plates 2 are separated and the magnets 5 in the magnet insertion holes 4 fall out. The magnets 5 fall downward, but the steel plates 2 are held in place with the shaft 51 still inserted.

[0056] Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention.

[0057] For example, in the cooling process, immersing the rotor in water will result in rapid cooling, but this does not exclude the possibility of immersing the rotor in a bath filled with a coolant such as oil instead of water to the extent that rapid cooling is not achieved. However, this requires the disposal of oil, etc. Furthermore, after the heating step, the pressing step may be carried out while the rotor is still in a high temperature state, without carrying out the cooling step. Because the rotor is in a high temperature state, great care must be taken in handling it, but because the magnets are demagnetized and the resin used to fix the magnets is embrittled in the heating step, it is possible to release the fixed state of the steel plates and magnets by carrying out the pressing step without going through the cooling step.

[0058] The shapes of the support base and pressing tool of the pressing means are not limited to those in the embodiments, and the support surface of the support base does not have to be V-shaped, but may be a concave surface or a flat surface with a smaller curvature than the outer circumferential surface of the rotor. The support base may not have a recess. Alternatively, the support surface may be a continuously uneven surface. The recesses provided on the support surface of the support base of the pressing means are not limited to those in the embodiment, and the support base may be provided with steps or unevenness.

[0059] Furthermore, although the pressing means supports the rotor from below and presses it from above, it may be configured to press the rotor radially inward from multiple points (e.g., three points) around the circumference using, for example, multiple cylinders. In this case, the steel plate of the rotor may be pressed in a position where it is arranged horizontally. [Explanation of symbols]

[0060] 1 rotor 2 steel plate 3 central hole 4 holes (magnet insertion holes) 5. Magnets 6 Magnet fixing resin 10 Magnet recovery device 11 Heating means 12 Cooling means 13 Pressing means 14 Separation means (excitation means) 21 Palettes 22 Mounting table 25 Support stand 26 Pressing tool 27 Press mechanism 28 Groove 29 Support surface 30 recess 31 screens 32 Side wall 33 Transport path 34 Vibration applying means 35 through holes 41 Base 42 Rotation axis 43 Vibration motor 44 Elastic member 45 Baffle board 46 Steel plate outlet 48 boxes 51 Shaft

Claims

1. A method for recovering magnets from a rotor having a plurality of stacked steel plates and magnets fixed in holes in the steel plates, comprising: A method for recovering magnets from a rotor, comprising: a heating step of heating the rotor to demagnetize the magnets and embrittle the resin used to fix the magnets; a pressing step of supporting a portion of the outer surface of the rotor after heating and pressing the outer surface of the rotor opposite the supported portion in a direction perpendicular to the stacking direction of the steel plates to elastically deform the steel plates; and a separation step of separating the magnets from the rotor after the pressing step.

2. 2. The method for recovering magnets from a rotor according to claim 1, wherein the separating step applies vibration or impact to the rotor.

3. 2. The method for recovering magnets from a rotor according to claim 1, further comprising a cooling step of cooling the heated rotor without using water between the heating step and the pressing step.

4. 1. An apparatus for recovering magnets from a rotor having a plurality of stacked steel plates and magnets fixed in holes in the steel plates, comprising: A rotor magnet recovery device characterized by comprising: a heating means for heating the rotor to a temperature equal to or higher than the Curie temperature or the embrittlement temperature of the magnet fixing resin, whichever is higher; a pressing means for supporting a portion of the outer surface of the rotor after heating by the heating means and pressing the outer surface of the rotor opposite the supporting portion in a direction perpendicular to the stacking direction of the steel plate to elastically deform the steel plate; and a separation means for separating the magnet from the rotor after pressing.

5. 5. The rotor magnet recovery device according to claim 4, wherein the separating means is a vibrating means for applying vibration or impact to the rotor.

6. 5. The magnet recovery device for a rotor according to claim 4, further comprising a cooling means for cooling the rotor heated by the heating means without using water.

7. A separation assisting device used to separate magnets from a rotor having a plurality of stacked steel plates and magnets fixed in holes in the steel plates, a support base for supporting a portion of the outer peripheral surface of the rotor; a pressing tool disposed opposite the support base and capable of contacting the outer peripheral surface of the rotor on the side opposite the support base; and a press mechanism for pressing the rotor in a direction perpendicular to the stacking direction of the steel plates by bringing the pressing tool and the support base closer together, thereby elastically deforming the steel plates.

8. A rotor magnet separating device comprising: the separation auxiliary device according to claim 7; and separating means for separating the magnets from the rotor after elastically deforming the steel plate.

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