JP5971648B2 - Rare earth magnet recovery method and rare earth magnet recovery apparatus - Google Patents

Description

  The present invention relates to a rare earth magnet recovery method and a rare earth magnet recovery device.

  Motors using rare earth magnets, which are permanent magnets using rare earth metals, are used as drive sources for rotational drive in various devices such as air conditioners, electric appliances such as washing machines, and automobiles.

  Recently, as part of environmental conservation, the rare earth magnets are recovered from the motor. For example, a method has been proposed in which the shaft of the rotor is cut or the shaft is removed from the rotor, the rare earth magnet is demagnetized, and the electromagnetic steel sheet is further removed to extract the rare earth magnet. In addition, a method has been proposed in which the rotor core is extracted from the rotor, the rotor core is heated to melt or thermally degrade the resin in the rotor core, and then the rare earth magnet is extruded (see, for example, Patent Document 1). The reason for cutting the rotor shaft or pulling the rotor shaft is to reduce the overall capacity by separating the rotor and the bracket, and to facilitate handling during storage and carrying.

However, these proposed technologies require a process of cutting the shaft, a process of removing the shaft from the rotor, a process of removing the electromagnetic steel sheet, a process of removing the rotor core from the rotor, etc. There's a problem.
Also, when removing the shaft from the rotor, the laminated magnetic steel sheet moves or deforms and comes into contact with the rare earth magnet due to the removal of the shaft that has fixed the central axis, making it difficult to remove the rare earth magnet. There is.

  Accordingly, the present situation is that there is a demand for a method and apparatus for collecting a rare earth magnet that is simple and requires less man-hours, and that can easily extract a rare earth magnet from a rotor.

JP 2010-110167 A

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide a method and an apparatus for recovering a rare earth magnet that is simple and requires less man-hours, and that can easily extract a rare earth magnet from a rotor.

Means for solving the problems are as follows. That is,
<1> A shaft attached to a rotating shaft, a laminate formed of a plurality of electromagnetic steel plates laminated in the axial direction of the shaft around the shaft, and passing through the laminate in the axial direction of the shaft. The rare earth magnet is recovered from a motor having at least a rare earth magnet housed in a magnet housing hole formed in the laminate and a rotor having a protective portion that closes the magnet housing hole of the laminate. A method,
A removal step of removing the protection part from the rotor;
A method of collecting a rare earth magnet, comprising: removing the shaft from the rotor and removing the rare earth magnet from the magnet housing hole without cutting the shaft.
<2> The motor further includes a bracket for holding the rotor,
The removal step is the method for recovering a rare earth magnet according to <1>, wherein the removing step is performed with the bracket being fixed in a state where the rotor is held by the bracket.
<3> The method for recovering a rare earth magnet according to any one of <1> to <2>, including a demagnetization step of demagnetizing the rare earth magnet before the magnet removal step.
<4> A shaft attached to a rotating shaft, a laminate formed of a plurality of electromagnetic steel plates laminated in the axial direction of the shaft around the shaft, and penetrating the laminate in the axial direction of the shaft. The rare earth magnet is recovered from a motor having at least a rare earth magnet housed in a magnet housing hole formed in the laminate and a rotor having a protective portion that closes the magnet housing hole of the laminate. A device,
Removing means for removing the protection part from the rotor;
A rare earth magnet recovery device comprising: a magnet take-out means for taking out the rare earth magnet from the magnet housing hole without removing the shaft from the rotor and cutting the shaft.
<5> The motor further includes a bracket for holding the rotor,
The removal device according to <4>, wherein the removing means includes a fixing member that fixes the bracket in a state where the rotor is held by the bracket.
<6> The rare earth magnet recovery device according to any one of <4> to <5>, further including a demagnetizing unit that demagnetizes the rare earth magnet.

  According to the present invention, it is possible to solve the conventional problems, and to provide a method and an apparatus for recovering a rare earth magnet that is simple and requires less man-hours, and that allows the rare earth magnet to be easily extracted from the rotor.

FIG. 1 is an exploded perspective view showing an example of a motor. FIG. 2A is a schematic side view of the motor used in Example 1. FIG. 2B is a schematic cross-sectional view of the motor shown in FIG. 2A. FIG. 3 is a schematic side view of the motor shown in FIG. 2A in which a part of the stator container is cut. FIG. 4 is a schematic side view of the motor shown in FIG. 3 with the stator removed. FIG. 5A is a schematic side view in which the motor shown in FIG. 4 is fixed to a fixing member. FIG. 5B is a schematic top view of the motor shown in FIG. 4 fixed to a fixing member. FIG. 6 is a schematic top view of the motor shown in FIG. 4 with the protective part removed. FIG. 7A is a schematic side view showing a state in which the outer periphery of the multilayer body is surrounded by a heater in the demagnetization step. FIG. 7B is a schematic top view showing a state in which the outer periphery of the multilayer body is surrounded by a heater in the demagnetization step. FIG. 8 is a schematic view showing a state in which the rare earth magnet is taken out with the surface from which the protective portion is removed being directed downward. FIG. 9 is a schematic top view of the motor after removing the rare earth magnet. FIG. 10 is a schematic cross-sectional view of the rotor without the shaft being pulled out. FIG. 11 is a schematic cross-sectional view of the rotor with the shaft removed.

(Rare earth magnet recovery method and rare earth magnet recovery device)
The rare earth magnet recovery method of the present invention includes at least a removal step and a magnet removal step, preferably includes a demagnetization step, and further includes other steps as necessary.
The method for collecting rare earth magnets is a method for collecting rare earth magnets from a motor having at least a rotor.
The rare earth magnet recovery apparatus of the present invention has at least a removing means and a magnet taking out means, preferably a demagnetizing means, and further has other means as required.
The rare earth magnet collecting device is a device for collecting rare earth magnets from a motor having at least a rotor.
The rare earth magnet recovery method can be preferably performed by the rare earth magnet recovery device, the removal step can be preferably performed by the removal means, and the magnet removal step can be preferably performed by the magnet removal means, The demagnetizing step can be suitably performed by the demagnetizing means, and the other steps can be suitably performed by the other means.

<Motor>
The motor includes at least a rotor (rotor), preferably a bracket, and further includes other members such as a stator (stator) as necessary.

-Rotor-
The rotor includes at least a shaft, a laminated body, a rare earth magnet, and a protective part, and further includes other parts as necessary.

--- Shaft-
The shaft is attached to a rotating shaft of the rotor.
For example, in an air conditioner such as a home room air conditioner, a fan such as a cross flow fan or a propeller fan is attached to the shaft. The fan rotates as the shaft rotates.
There is no restriction | limiting in particular as a material of the said shaft, a shape, a magnitude | size, and a structure, According to the objective, it can select suitably.

--Laminated body--
The laminate is formed from a plurality of electromagnetic steel plates laminated in the axial direction of the shaft around the shaft.
There is no restriction | limiting in particular as a shape and a magnitude | size of the said electromagnetic steel plate, According to the objective, it can select suitably, For example, the plate shape etc. whose average thickness is 0.05 mm-0.5 mm are mentioned.
There is no restriction | limiting in particular as a material of the said electromagnetic steel plate, According to the objective, it can select suitably, For example, ferromagnetic materials, such as a silicon steel plate, etc. are mentioned.

  The plurality of electromagnetic steel sheets may or may not be in contact with the shaft.

  The plurality of electromagnetic steel sheets may be bonded to each other or may not be bonded. The bonding method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of bonding with a resin.

When the plurality of electromagnetic steel sheets are not bonded to each other and are in contact with the shaft, when the shaft is removed from the rotor or the shaft is cut, the electromagnetic steel sheet moves, The magnet housing holes formed in the laminate are narrowed irregularly. Therefore, it becomes difficult to take out the rare earth magnet from the magnet accommodation hole.
On the other hand, in the present invention, when the rare earth magnet is taken out from the magnet housing hole, the shaft is not detached from the rotor and the shaft is not cut. Therefore, even when the plurality of electromagnetic steel sheets are not bonded to each other and are in contact with the shaft, the magnet accommodation hole is not irregularly narrowed and the rare earth magnet is easily produced.

  There is no restriction | limiting in particular as a shape of the said laminated body, According to the objective, it can select suitably, For example, cylindrical shape etc. are mentioned.

--- Rare earth magnet--
The rare earth magnet is accommodated in a magnet accommodation hole formed in the laminate so as to penetrate the laminate in the axial direction of the shaft.
There is no restriction | limiting in particular as a material of the said rare earth magnet, According to the objective, it can select suitably, For example, a samarium cobalt magnet, a neodymium magnet, a praseodymium magnet, a samarium iron nitrogen magnet etc. are mentioned.
There is no restriction | limiting in particular as a shape of the said rare earth magnet, Although it can select suitably according to the objective, A rectangular solid is preferable at the point which is easy to take out from the said magnet accommodation hole.
There is no restriction | limiting in particular as a magnitude | size of the said rare earth magnet, According to the objective, it can select suitably.

--Protection part--
The protective part is not particularly limited as long as it is a part that closes the magnet accommodation hole of the laminate, and can be appropriately selected according to the purpose.
The protection part may cover the entire at least one surface of the laminate in the axial direction of the shaft.
The said protection part is installed in order to prevent the said rare earth magnet from coming out of the said magnet accommodation hole, for example.
There is no restriction | limiting in particular as a material of the said protection part, According to the objective, it can select suitably, For example, stainless steel, brass, etc. are mentioned.
There is no restriction | limiting in particular as a shape, a magnitude | size, and a structure of the said protection part, According to the objective, it can select suitably.
The protection part is fixed to the laminate, for example. There is no restriction | limiting in particular as a method to fix the said protection part to the said laminated body, According to the objective, it can select suitably, For example, the method etc. which fix with a rivet are mentioned.

-Bracket-
The bracket is a member that holds the rotor.
The bracket includes, for example, a bearing that supports the shaft in one axial direction of the shaft.
When recovering the rare earth magnet from the motor, it is preferable that the rotor of the motor is held by the bracket. By doing so, since the rotor can stand with its axial direction substantially parallel to the direction of gravity without falling down, handling becomes easy.
The bracket may include a stator container that covers a side surface of the stator.

-Stator-
The stator is a member that surrounds the outer periphery of the rotor and generates a rotational moment by interacting with the rotor.
A gap is provided between the stator and the rotor.
The stator includes, for example, a cylindrical stator core provided with a plurality of slots, and windings inserted into the slots.
There is no restriction | limiting in particular as a material of the said coil | winding, According to the objective, it can select suitably, For example, copper etc. are mentioned.

<Removal process and removal means>
The removal step is not particularly limited as long as it is a step of removing the protection part from the rotor, and can be appropriately selected according to the purpose. For example, the removal step can be performed by the removal means.
The removing means is not particularly limited as long as it is a means for removing the protective part from the rotor, and can be appropriately selected according to the purpose. Examples thereof include a drill.
When the protection part is fixed to the electromagnetic steel plate by a rivet, the protection part can be removed from the rotor by removing the rivet.
There is no restriction | limiting in particular as a method of removing the said rivet, According to the objective, it can select suitably, For example, the method etc. which break the said rivet with a drill are mentioned.

It is preferable that the removing step is performed by fixing the bracket in a state where the motor further includes the bracket for holding the rotor, and the rotor is held by the bracket. By doing so, the protection part can be easily removed.
The fixing can be performed by, for example, the following fixing member.

In the rare earth magnet recovery device, the motor further includes a bracket for holding the rotor, and the take-out means further fixes the bracket in a state where the rotor is held by the bracket. It is preferable to have a fixing member. By doing so, it becomes easy to remove the protection part. The fixing member is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include a vise. Examples of the vise include a horizontal vise, a machine vise, and a super vice.

<Magnet removal process and magnet removal means>
The magnet removal step is not particularly limited as long as it is a step of removing the shaft from the rotor and removing the shaft from the magnet housing hole without cutting the shaft. For example, a step of taking out the dead weight of the rare earth magnet can be used.
The magnet ejecting means is not particularly limited as long as it is a means for ejecting the rare earth magnet from the magnet accommodation hole without removing the shaft from the rotor and cutting the shaft. For example, means for taking out the dead weight of the rare earth magnet can be used.

  Specifically, for example, the step of removing the magnet includes removing the protective portion from the rotor and exposing the surface of the magnet housing hole so that the surface of the rare earth magnet faces in a substantially gravitational direction (downward). Examples include a step of taking out the rare earth magnet from the inside of the magnet accommodation hole by gravity drop due to its own weight. In that case, the rare earth magnet is more likely to come out of the magnet accommodation hole by giving an impact to the rotor. The impact on the rotor can be applied by, for example, an impact applying member. When applying an impact, the direction of the rotor is not particularly limited. Examples of the impact imparting member include a hammer.

It is preferable that the magnet taking-out step is performed by fixing the bracket in a state where the motor further includes the bracket for holding the rotor, and the rotor is held by the bracket. By doing so, the impact by the said impact provision member can be more reliably given to the said rotor.
The fixing can be performed by the fixing member, for example.

  In the rare earth magnet recovery apparatus, the motor further includes a bracket for holding the rotor, and the magnet take-out means further fixes the bracket in a state where the rotor is held by the bracket. It is preferable to have the fixing member. By doing so, the impact by the said impact provision member can be more reliably given to the said rotor.

<Demagnetizing step and demagnetizing means>
The demagnetization step is not particularly limited as long as it is a step of demagnetizing the rare earth magnet before the magnet removal step, and can be appropriately selected according to the purpose. It can be carried out.
The demagnetizing means is not particularly limited as long as it is a means for demagnetizing the rare earth magnet, and can be appropriately selected according to the purpose. Examples thereof include a heater.
The shape of the heater is not particularly limited and may be appropriately selected according to the purpose. However, the shape of the heater surrounds the laminate and efficiently heats the rare earth magnet, so that it is efficient. It is preferable in that the rare earth magnet can be demagnetized.

More preferably, the demagnetizing step is performed by surrounding the laminated body with a cylindrical heater in the motor from which the stator is removed. By doing so, the rare earth magnet can be efficiently heated, and the rare earth magnet can be efficiently demagnetized.
Since the winding of the stator is usually recovered and reused, the process of removing the stator is not a useless process.

Preferably, the demagnetizing step is performed by fixing the bracket in a state where the motor further includes the bracket for holding the rotor, and the rotor is held by the bracket. If the motor is not fixed, the motor moves and interferes with the shaft, and during the demagnetizing step (for example, during heating), the heater hits the shaft and the shaft is heated. However, even if the rotor has the shaft, the shaft does not get in the way and the operation of the demagnetizing process is safe and safe. It becomes easy.
The fixing can be performed by the fixing member, for example.

  In the rare earth magnet recovery device, the motor further includes a bracket for holding the rotor, and the demagnetizing means further fixes the bracket in a state where the rotor is held by the bracket. It is preferable to have the fixing member. By doing so, demagnetization can be performed safely and easily.

There is no restriction | limiting in particular as a demagnetizing time in the said demagnetizing process, Although it can select suitably according to the objective, In order to shorten working time, 1 minute-10 minutes are preferable.
The demagnetization temperature in the demagnetization step is not particularly limited and may be appropriately selected according to the purpose. However, in terms of reliable demagnetization, a temperature equal to or higher than the Curie temperature of the rare earth magnet is preferable, and the Curie temperature More preferably, the temperature is within 200 ° C. plus the Curie temperature.
The demagnetization temperature is the temperature of the rare earth magnet itself to be heated.

  Here, an example of the motor used in the rare earth magnet recovery method and the rare earth magnet recovery device will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing an example of the motor. The motor of FIG. 1 includes a rotor 1, a stator 11 that surrounds the outer periphery of the rotor 1 and interacts with the rotor 1 to generate a rotational moment, and a bracket 21 that holds the rotor 1 and the stator 11. The rotor 1 includes a shaft 2 attached to a rotating shaft, a laminated body 3 formed of a plurality of electromagnetic steel plates, a protection unit 4 that closes a magnet accommodation hole of the laminated body 3, and a bearing 5. A magnet housing hole is formed in the laminate 3 and a rare earth magnet is housed therein. The stator 11 has a cylindrical stator core 12 provided with a plurality of slots, and windings 13 inserted into the slots. The bracket 21 supports the shaft 2 with a bearing 23 at the lower part and covers the side surface of the stator 11 with a stator container 22. The stator 11 is provided with lead wires 31 for connection to a power source or a drive circuit.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
The rare earth magnet was recovered from the motor for the air conditioner by using the rare earth magnet recovery method and the rare earth magnet recovery apparatus of the present invention. Hereinafter, it demonstrates in detail using figures.

As the motor, a motor (DDN-X8 type compressor, manufactured by Sanyo Electric Co., Ltd.) as shown in FIGS. 2A and 2B was used. This motor has a rotor, a stator, and a bracket. FIG. 2A is a schematic side view of the motor. FIG. 2B is a schematic cross-sectional view of the motor.
The rotor includes a shaft 2 attached to a rotating shaft, a laminated body 3 formed of a plurality of electromagnetic steel plates laminated in the axial direction of the shaft 2 around the shaft 2, and the laminated body 3 penetrates in the axial direction of the shaft 2. Thus, the eight rare earth magnets 6 housed in the magnet housing holes formed in the laminated body 3 and the protective portion 4 that closes the magnet housing holes of the laminated body 3 are provided.
The stator has a cylindrical stator core 12. The stator core 12 surrounds the outer periphery of the rotor.
The bracket has a stator container 22 and a bearing 23. The stator container 22 covers the side surface of the stator. The bearing 23 supports the shaft 2.
Each of the plurality of electromagnetic steel sheets is not bonded with a resin or the like.
The shaft 2 is in contact with a plurality of electromagnetic steel plates.

First, about 1/3 from the lower part of the stator container 22 was cut so that the stator core 12 was exposed (see FIG. 3).
Subsequently, the stator was removed from the motor (see FIG. 4). At this time, the rotor is still held by the bracket.

<Removal process>
Subsequently, the motor with the stator removed is placed on the fixing base 52, and a vise 51 as a fixing member is applied to the side surface of the stator container 22, so that the motor does not move (see FIGS. 5A and 5B). ).
With the motor fixed, the rivet attached to the protective part 4 was removed using a drill. When the rotor from which the protection part 4 is removed is viewed from above, the rare earth magnet 6 accommodated in the magnet accommodation hole 7 formed in the laminate 3 can be confirmed (see FIG. 6).

<Demagnetization process>
Subsequently, in a state where the motor was fixed by the vise 51 and the fixing base 52, the laminated body 3 was surrounded by the cylindrical heater 61 and heated to demagnetize the rare earth magnet. Demagnetization was performed for 1 minute at a temperature (300 ° C.) near the Curie temperature of a rare earth magnet (neodymium magnet) (see FIGS. 7A and 7B).

<Magnet removal process>
Then, after making the surface which removed the protection part faced the gravitational direction (downward), the laminated body 3 was lightly hit with the hammer, and the laminated body 3 was shocked. By doing so, the rare earth magnet 6 came out of the magnet accommodation hole 7 by its own weight (refer FIG.8 and FIG.9).

  In the rotor of Example 1 in which the shaft 2 is not pulled out, as shown in the schematic cross-sectional view shown in FIG. 10, since the shaft 2 is in contact with the electromagnetic steel plate, the electromagnetic steel plate does not move and the shape of the magnet housing hole is maintained. A certain gap was maintained between the laminate 3 and the rare earth magnet 6, and the rare earth magnet 6 could move within the magnet accommodation hole. Therefore, in the magnet removal process, the rare earth magnet could be easily removed from the magnet accommodation hole as described above.

(Comparative Example 1)
In Example 1, the removal process, the demagnetization process, and the magnet removal process were performed in the same manner as in Example 1 except that the shaft was removed after the removal process and before the demagnetization process.
As shown in the cross-sectional view of FIG. 11, since the rotor does not have a shaft, the electromagnetic steel sheet moves irregularly, the shape of the magnet accommodation hole changes, and the rare earth magnet 6 moves in the magnet accommodation hole. Thus, as in Example 1, the rare earth magnet 6 could not be taken out from the magnet housing hole only by its own weight.

  The rare earth magnet recovery method and rare earth magnet recovery apparatus of the present invention are simple and have few man-hours, and the rare earth magnet can be easily extracted from the rotor. Can do.

DESCRIPTION OF SYMBOLS 1 Rotor 2 Shaft 3 Laminated body 4 Protection part 5 Bearing 6 Rare earth magnet 7 Magnet accommodation hole 11 Stator 12 Stator core 13 Winding 21 Bracket 22 Stator container 23 Bearing 31 Lead wire 510,000 vise 52 Fixing base

Claims (6)

A shaft attached to a rotating shaft, a laminate formed of a plurality of electromagnetic steel plates laminated in the axial direction of the shaft around the shaft, and the laminate so as to penetrate the laminated body in the axial direction of the shaft A rare earth magnet recovery method for recovering the rare earth magnet from a motor including at least a rare earth magnet housed in a magnet housing hole formed in a body and a rotor having a protective portion that closes the magnet housing hole of the laminate. And
A removal step of removing the protection part from the rotor;
A demagnetization step of demagnetizing the rare earth magnet by heating the rare earth magnet before the magnet removal step;
A step of removing the shaft from the rotor, and a step of removing the magnet from the magnet accommodation hole by gravity drop due to the weight of the rare-earth magnet without removing the shaft from the rotor. Recovery method for rare earth magnets. The motor further comprises a bracket for holding the rotor;
The method for recovering a rare earth magnet according to claim 1, wherein the removing step is performed by fixing the bracket in a state where the rotor is held by the bracket. The method for recovering a rare earth magnet according to claim 1, further comprising a step of applying an impact to the rotor when the rare earth magnet is taken out. A shaft attached to a rotating shaft, a laminate formed of a plurality of electromagnetic steel plates laminated in the axial direction of the shaft around the shaft, and the laminate so as to penetrate the laminated body in the axial direction of the shaft A rare earth magnet recovery device that recovers the rare earth magnet from a motor having at least a rare earth magnet housed in a magnet housing hole formed in the body and a rotor having a protective portion that closes the magnet housing hole of the laminate. And
Removing means for removing the protection part from the rotor;
Demagnetizing means for demagnetizing the rare earth magnet by heating the rare earth magnet;
Magnet removing means for extracting the rare earth magnet from the inside of the magnet housing hole by gravity drop due to the weight of the rare earth magnet without removing the shaft from the rotor and cutting the shaft. Rare earth magnet recovery device. The motor further comprises a bracket for holding the rotor;
The rare earth magnet recovery apparatus according to claim 4, wherein the removing means includes a fixing member that fixes the bracket in a state where the rotor is held by the bracket. 6. The rare earth magnet recovery device according to claim 4, further comprising an impact applying member that applies an impact to the rotor when the rare earth magnet is taken out.