JP2022123775A - Manufacturing method of rotor for rotary electric machine - Google Patents

Abstract

To quickly fix a magnet to a magnet mounting hole by heating a composite material arranged between the magnet mounting hole and the magnet in a short time.SOLUTION: A rotor core 22 in which a composite material 44 is arranged between a flux barrier (magnet mounting hole) 36 and a magnet 24 is mounted on a magnet mounting jig 62, and a closed space 64 is formed so as to include the flux barrier 36. When gas pressure in the closed space 64 is increased by the compressor 104, the temperature of the gas in the closed space 64 rises due to adiabatic compression, and the composite material 44 is heated, the magnet 24 is fixed to the flux barrier 36 by the expansion pressure of the porous molding material as a porous material of the composite material 44 expands and changes into a porous molding material. When the gas in the closed space 64 is in contact with the surface of the composite material 44, and the porous material begins to expand and a gap becomes larger, the gas also penetrates into the gap, and therefore, the composite material 44 is efficiently heated by the high-temperature gas, and the time and energy are reduced.SELECTED DRAWING: Figure 10

Description

The present invention relates to a method of manufacturing a rotor for a rotating electrical machine, and more particularly to a technique for fixing magnets to a rotor core.

(a) A rotor core, magnets inserted into magnet mounting holes axially penetrating through the rotor core, and a plurality of gaps communicating with the outside between the magnet mounting holes and the magnets. (b) the porous mold material is a mixture of a porous material and a binder and pressurized. The composite material integrated by is interposed in the annular space between the magnet mounting hole and the magnet, and the composite material is heated to soften the binding material, thereby expanding the porous material. Rotors for rotary electric machines are known. A rotor for a rotary electric machine described in Patent Literature 1 is an example of such a rotor, and a magnet can be effectively cooled by allowing a cooling fluid to flow through the gaps in the porous molding material.

JP 2019-9866 A

By the way, as a method of heating the composite material arranged between the magnet mounting hole and the magnet, for example, the atmosphere including the rotor core having a large heat capacity may be heated from the outside using a heating furnace. A lot of time and energy are required, and the magnetic properties of the magnets and rotor core may deteriorate due to long-term heating.

The present invention has been made against the background of the above circumstances, and its object is to heat the composite material disposed between the magnet mounting hole and the magnet in a relatively short period of time to quickly remove the magnet. To enable fixing to a magnet mounting hole.

In order to achieve this object, the first invention provides (a) a rotor core, magnets inserted in magnet mounting holes axially penetrating the rotor core, and a large number of gaps communicating with the outside. a porous molding material disposed between the magnet mounting hole and the magnet, and fixing the magnet to the magnet mounting hole; (b) the porous molding material having The composite material is interposed in the annular space between the magnet mounting hole and the magnet, and the composite material is heated to form the bond. In a method for manufacturing a rotor for a rotary electric machine, wherein the porous material is expanded by softening the material, (c) the magnet mounting holes are hermetically sealed while the composite material is interposed in the annular space. (d) a temperature control device provided in an air passage communicating with the sealed space to increase the temperature of the gas in the sealed space, thereby increasing the temperature of the gas in the sealed space; and a heating step of heating the composite material to expand the porous material and change it into the porous molding material.
The gas in the sealed space may be air, nitrogen gas, argon gas, or the like, and is not limited to a specific type.

In a second aspect of the invention, in the method of manufacturing a rotor for a rotary electric machine according to the first aspect, the composite material is heated in the heating step, and after the porous material expands and changes into the porous molding material, the temperature is adjusted. The method is characterized by comprising a cooling step of cooling the porous molding material by lowering the gas temperature using a device.

A third invention is the method for manufacturing a rotor for a rotary electric machine according to the first invention or the second invention, wherein in the sealing step, the inner wall surface of the magnet mounting hole is sealed with a heat insulating sealing material, A coupler provided in an airtight manner on at least one of the pair of heat insulating members to form the sealed space by covering the openings on both axial end faces of the heat insulating member with a pair of heat insulating members and sealing with an O-ring. The airtight space is connected to the air passage through.

In such a method for manufacturing a rotor for a rotary electric machine, a sealed space including the magnet mounting holes is formed in a state in which the composite material is arranged in the annular space between the magnet mounting holes and the magnets, and a As the gas temperature is raised by the temperature control device, the composite material in the magnet mounting hole is heated, the porous material expands and changes into a porous mold material, and the expansion pressure of the porous mold material causes the magnet to expand. is fixed to the magnet mounting hole. In that case, the gas in the sealed space including the magnet mounting holes is in contact with the surface of the composite material, and when the porous material begins to expand due to heating and the gaps become larger, the gas also penetrates into the gaps, resulting in a high temperature. The gas efficiently heats the composite. This reduces the time and energy required for heating and suppresses the deterioration of the magnetic properties of the magnets and the rotor core, compared to the case where the rotor core and the rotor core are heated from the outside using a heating furnace or the like.

Here, it is conceivable to heat the composite material by using liquid such as lubricating oil instead of gas, for example, by circulating a high-temperature liquid including a closed space. However, since composite materials have poor liquid permeability and the pressure loss of liquids is large, it takes time to heat the inside of the composite material and expand the porous material. can't

In the second invention, after the porous material expands in the heating process and is changed into the porous molding material, the gas temperature is lowered to cool the porous molding material. In addition to further shortening, the magnets and rotor core are quickly cooled, further suppressing the deterioration of the magnetic properties. Since the porous mold material has voids communicating with the outside, the gas enters or flows through the voids, so that the porous mold material is efficiently cooled as the gas temperature decreases. .

In the third invention, the inner wall surface of the magnet mounting hole is sealed with a heat insulating sealing material, and the opening of the magnet mounting hole is covered with a pair of heat insulating members and sealed with an O-ring to form a sealed space. In the case where the closed space is connected to the air passage through a connector provided airtightly on at least one of the heat insulating members, the closed space has high airtightness and heat insulation, and the internal volume is minimized, and the composite material can be efficiently heated.

FIG. 3 is a schematic diagram for explaining a rotary electric machine provided with a rotary electric machine rotor manufactured according to the method of the present invention, and is a cross-sectional view taken along the line II of FIG. 2. FIG. FIG. 2 is a cross-sectional view perpendicular to the rotation center line O of the rotor of FIG. 1 and enlarged compared to FIG. 1; It is a figure explaining the attachment structure of the magnet in the rotor of FIG. 2, and is sectional drawing which expanded the vicinity part of one magnet further from FIG. FIG. 3 is a perspective view illustrating magnets used in the rotor of FIG. 2; FIG. 4 is a cross-sectional view illustrating a composite in its original state of porous molding material that secures magnets to a rotor core; 4 is a flowchart for explaining a manufacturing process for fixing magnets to a rotor core; FIG. 7 is a flow chart for more specifically explaining the heating step of step S3 and the cooling step of step S4 of FIG. 6. FIG. FIG. 7 is a diagram illustrating an example of a magnet placement process in which magnets and composite materials are inserted into flux barriers (magnet mounting holes) of the rotor core in step S1 of FIG. 6 ; FIG. 7 is a diagram illustrating another example of the magnet placement process in step S1 of FIG. 6; FIG. 8 is a view for explaining the rotor manufacturing apparatus used when performing the heating process and the cooling process according to the flowchart of FIG. 7, and shows a state in which the rotor core is attached to the magnet mounting jig. FIG. 11 is a view showing a fixed magnet state in which the composite material in FIG. 10 is heated so that the porous material expands and changes into a porous molding material. FIG. 8 is a diagram explaining another example of the heating process of step S3 and the cooling process of step S4 of FIG. 6, and is a flow chart executed instead of FIG. 7; FIG. 13 is a view for explaining the rotor manufacturing apparatus used when performing the heating process and the cooling process according to the flowchart of FIG. 12, and shows a state in which the rotor core is attached to the magnet mounting jig. FIG. 14 is a view showing a fixed magnet state in which the composite material in FIG. 13 is heated and the porous material expands and changes into a porous mold material.

A rotating electrical machine is a rotating electrical machine, and is sometimes called a rotating machine, and is a motor generator used as an electric motor, a generator, or both, such as a permanent magnet type synchronous motor. The rotor may be an inner rotor type arranged on the inner peripheral side, or an outer rotor type arranged on the outer peripheral side. A rare earth magnet is preferably used as the magnet, but other permanent magnets may be used. The magnet is provided with an insulating film such as a synthetic resin or an oxide film, if necessary. Moreover, a plurality of types of magnets having different polarities, magnetic fluxes, coercive forces, cross-sectional shapes, etc. may be used.

In the porous molding material that fixes the magnets to the rotor core, the porous material and the binder are mixed and the composite material is heated to soften the binder and expand the porous material. It is. That is, when a composite material, which is formed into a thin plate or the like from a porous material by the action of a binding material by pressure molding, is placed in the magnet mounting hole together with a magnet, and the binding material is softened by heating, the porous material is affected by residual stress, etc. The magnets are fixed to the rotor core by the pressing force caused by the expansion. Examples of the porous material include porous glass, porous ceramic, and porous metal. Glass fiber is preferably used as the porous glass, and metal fiber is preferably used as the porous metal. The binder functions as an adhesive and is softened by heating, and thermoplastic synthetic resins such as polyethylene, polypropylene, polyvinyl chloride and polyamide are preferably used. This binding material may be melted and removed by heating, but may remain in the porous mold material in which the porous material has expanded. Since the porous molding material has a large number of voids communicating with the outside, it is possible to effectively cool the magnets by circulating cooling fluid such as lubricating oil when the rotating electrical machine is in use.

When a plurality of magnet mounting holes are provided around the rotational center line of the rotor core and magnets are mounted in each of the plurality of magnet mounting holes, for example, O-rings or the like are attached to both the inner and outer peripheral sides of all the magnet mounting holes. to form a sealed space including all the magnet mounting holes by sealing with, and by adjusting the gas temperature inside the sealed space, fixing the magnets to all the magnet mounting holes at the same time. can be done. Also, by sealing the openings of one or more magnet mounting holes, which are part of the many magnet mounting holes, with an O-ring or the like, and adjusting the gas temperature, the magnet can be attached to each of the one or more magnet mounting holes. You can fix it. By housing the entire rotor core in a predetermined hermetic container and adjusting the gas temperature in the hermetic container, it is also possible to fix the magnets to all the magnet mounting holes at the same time. is in contact with the surface of the composite material, the effect of the present invention can be obtained.

The temperature control device is configured, for example, to raise the gas pressure in the air passage and the sealed space by a compressor to raise the gas temperature in the sealed space. In addition, (a) the ventilation path is provided so as to form, for example, a circulation circuit through which gas flows, including the closed space, and (b) the temperature control device is provided, for example, with the gas flowing through the circulation circuit. is heated by a heating device to raise the gas temperature in the closed space.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following examples, the drawings are appropriately simplified or modified for explanation, and the dimensional ratios, shapes, angles, etc. of each part are not necessarily drawn accurately.

FIG. 1 is a schematic diagram for explaining a rotating electrical machine 10 having a rotating electrical machine rotor 12 (hereinafter simply referred to as rotor 12) manufactured according to the method of the present invention, and is a cross-sectional view taken along the line II in FIG. 2 is a cross-sectional view perpendicular to the rotation center line O of the rotor 12, and is an enlarged view as compared with FIG. The rotary electric machine 10 is a permanent magnet embedded synchronous motor, a motor generator that can be used alternatively as an electric motor or a generator, and is suitably used as a driving force source for electric vehicles including hybrid vehicles, for example. The rotary electric machine 10 includes a rotor 12 and a stator 14 that are provided concentrically with the rotation centerline O. As shown in FIG. In the description of this embodiment, the rotation centerline O of the rotary electric machine 10 is also used as the rotation centerline of the rotor 12 . The stator 14 includes a cylindrical stator core 16 arranged on the outer peripheral side of the rotor 12 and a plurality of stator coils 18 wound around the stator core 16 . The stator core 16 is made by laminating a large number of annular steel plates 17 in a posture perpendicular to the rotation center line O in the axial direction, that is, in a direction parallel to the rotation center line O. It is fixed to a case (not shown).

The rotor 12 has a cylindrical rotor core 22 attached to the outer peripheral surface of the rotor shaft 20 and a large number of magnets 24 embedded in the rotor core 22 . The rotor core 22 is made by laminating a large number of annular steel plates 23 in a posture perpendicular to the rotation center line O in the axial direction, that is, in a direction parallel to the rotation center line O. 28 , 30 are provided and fixed to the rotor shaft 20 . A rotor shaft 20 is provided with a collar portion 32 and a nut 34 is screwed thereon. and fixed to the rotor shaft 20 .

A large number of flux barriers 36 are provided through the outer periphery of the rotor core 22 in the axial direction, and the magnets 24 are inserted and fixed to the flux barriers 36 respectively. The flux barrier 36 is a through hole that restricts passage of magnetic flux, and a part of it is used as a magnet mounting hole. A large number of flux barriers 36 are arranged at equal angular intervals around the rotation center line O, with a pair of flux barriers 36 provided close to each other so as to form a shallow V shape toward the outer peripheral side in FIG. A plurality of sets (eight sets in the embodiment) are provided. The magnets 24 are inserted and fixed in the pair of V-shaped flux barriers 36 in such a manner that the polarities of the N and S poles are opposite to each other. The number, shape, arrangement pattern, etc. of the magnets 24 and the flux barriers 36 can be changed as appropriate, and the magnetization of the magnets 24 can also be performed after the magnets 24 are fixed to the rotor core 22 . The flux barriers 36 correspond to magnet mounting holes, but are larger than the magnets 24 and leave predetermined cavities at both ends of the magnets 24 , which can be used as passages for cooling fluid for cooling the magnets 24 . A plurality of hollow portions 46 are provided in the inner peripheral portion of the rotor core 22 so as to penetrate in the axial direction, and function, for example, as magnetic flux detour holes for regulating the flow of magnetic flux.

FIG. 3 is a diagram for explaining the mounting structure of the magnets 24, and is a cross-sectional view showing the vicinity of one magnet 24 provided at the upper end of FIG. The magnet 24 has a length dimension substantially equal to the axial length of the rotor core 22, and has a rectangular cross-sectional shape perpendicular to the axial direction, which is the longitudinal direction, that is, a cross-sectional shape perpendicular to the rotation center line O. It has a quadrangular prism shape. FIG. 4 is a perspective view of the magnet 24, which has the shape of a rectangular flat plate elongated in the axial direction. The magnets 24 are rare earth magnets, optionally coated with an insulating coating. A gap is provided between the magnet 24 and the flux barrier 36 , and the gap is filled with a porous molding material 38 to fix the magnet 24 inside the flux barrier 36 . The porous molding material 38 has a large number of voids communicating with the outside, and when the rotary electric machine 10 is in use, cooling fluid such as lubricating oil is allowed to flow through the voids, thereby effectively cooling the magnets 24 . can be done.

Porous molding material 38 is included in composite material 44 by heating composite material 44 shown in FIG. The porous material 40 is expansion-molded. The porous material 40 is, for example, a entangled porous member such as a non-woven fabric such as glass fiber or metal fiber. It is a thin plate-like member integrated with a bonding material 42 in a state in which the voids of the porous material 40 are crushed. As the binding material 42 functioning as an adhesive, a thermoplastic synthetic resin having a lower melting point than the porous material 40, such as polyethylene, polypropylene, or polyvinyl chloride, is used. Therefore, when the composite material 44 arranged in the annular space between the flux barrier 36 and the magnet 24 is heated, the binding material 42 softens and the porous material 40 expands due to its own residual stress or the like, increasing the gap. The magnet 24 is fixed to the flux barrier 36 of the rotor core 22 by the pressing force caused by the expansion of the porous mold material 38 . The binding material 42 may be melted and removed by heating, but may remain in the porous molding material 38 and be cooled and hardened to serve as an adhesive to fix the magnets 24 .

FIG. 6 is a flow chart for explaining the manufacturing process for fixing the magnet 24 to the flux barrier 36 of the rotor core 22 by means of the porous molding material 38. Steps S1 to S5 (hereinafter simply referred to as S1 to S5 are omitted). The same applies to other flow charts.). FIG. 7 is a flowchart for more specifically explaining the heating step S3 and the cooling step S4 in FIG. 6. Q1 to Q4 are the heating step S3, and Q5 to Q7 are the cooling step S4. Each step may be performed manually by an operator, or may be performed automatically using a robot or the like.

S 1 in FIG. 6 is a magnet placement step, in which the magnets 24 and the composite material 44 are inserted into the flux barrier 36 of the rotor core 22 . Specifically, for example, as shown in FIG. 8(a), a thin plate-like composite material 44 is wrapped around the magnet 24, or the magnet 24 is fitted inside the thin-plate cylindrical composite material 44. Then, the composite material 44 is attached to the outer peripheral surface of the magnet 24 to cover the entire outer peripheral surface of the magnet 24 with the composite material 44 . As a method for pasting the composite material 44, for example, an adhesive is suitable, but various modes such as press bonding and hydraulic transfer are possible. The composite material 44 in a molten or plastic state may be pressure-molded around the magnet 24 by injection molding, press molding, or the like, and fixed at the same time. Then, the magnet 24 coated with the composite material 44 is inserted into the flux barrier 36 of the rotor core 22, as shown in FIG. 8(b). In this embodiment, the magnets 24 coated with the composite material 44 are inserted into all the flux barriers 36 provided on the rotor core 22 . In order to form a sealed space 64 (see FIG. 10) on the inner wall surface of the flux barrier 36, a heat-resistant heat-insulating sealing material 48 is adhered in advance by coating or the like. As the heat insulating sealing material 48, for example, polyethylene or the like is used. A heat insulating sheet may be used as the heat insulating sealing material 48 and attached to the inner wall surface of the flux barrier 36 with an adhesive or the like.

Alternatively, as shown in FIG. 9, a cylindrical composite material 44 may be inserted into the flux barrier 36 in advance, and the magnet 24 may be inserted inside the composite material 44 . That is, since the composite material 44 can be interposed in the annular space between the flux barrier 36 and the magnet 24, the side surface of the magnet 24 facing the inner wall surface of the flux barrier 36, that is, the longitudinal direction of the magnet 24 is shown in FIG. Only the side surfaces parallel to the direction (vertical direction in FIG. 8) may be covered with the composite material 44 .

S2 in FIG. 6 is a sealing step, in which the rotor core 22 is attached to the magnet mounting jig 62 of the rotor manufacturing apparatus 60 shown in FIG. to form The magnet mounting jig 62 includes a pair of flat plate-shaped clamping plates 70 and 72 parallel to each other, and heat insulating plates 74 and 76 fixed to the inner surfaces of the clamping plates 70 and 72 facing each other. The rotor core 22 is held between the heat insulating plates 74 and 76 while being sandwiched from both sides in the axial direction. The heat insulating plates 74 and 76 correspond to heat insulating members, and polyethylene or the like is used, for example. A plurality of tightening bolts 78 are provided on the outer peripheral side of the pair of clamping plates 70 and 72 relative to the rotor core 22, and the rotor core 22 is secured between the heat insulating plates 74 and 76 by screwing nuts 80 together. pinched. A fluid pressure cylinder such as a hydraulic cylinder, or a pressing device such as an electric motor and a feed screw mechanism may be used to press the rotor core 22 between the pair of pressing plates 70 and 72 with a constant pressing force. .

Three O-rings 82, 84, 86 are arranged concentrically with the rotation center line O of the rotor core 22 on the upper surface of the lower heat insulating plate 74, and are airtightly attached to the lower end surface of the rotor core 22. , three O-rings 88, 90, 92 are arranged concentrically with the rotation center line O of the rotor core 22 on the lower surface of the upper heat insulating plate 76 so as to be in airtight contact with the upper end surface of the rotor core 22. It has become. The O-rings 82, 88 are brought into close contact with the outer peripheral side of the flux barrier 36, and the O-rings 84, 86, 90, 92 are brought into close contact with the inner peripheral side of the flux barrier 36. An airtight closed space 64 is formed that includes all the flux barriers 36 provided in the rotor core 22 . These O-rings 82, 84, 86, 88, 90, and 92 have heat resistance, and fluorinated rubber, for example, is preferably used. The innermost O-rings 86 and 92 are provided to improve airtightness on the inner peripheral side, but may be omitted. The magnet mounting jig 62 is of a vertical type, and the rotor core 22 is held in a posture in which the rotation center line O is substantially vertical. can also

A connector 100 such as a coupler is airtightly fixed to the clamping plate 72 and the heat insulating plate 76 on the upper side of the magnet mounting jig 62 so as to pass through them. A pipe 102 is connected as an air passage to the connecting end portion of the connecting tool 100 protruding from the clamping plate 72 , and a compressor 104 and a pressure gauge 106 are connected to the pipe 102 . The rotor manufacturing apparatus 60 includes a magnet mounting jig 62, a connector 100, a pipe 102, a compressor 104, and a pressure gauge 106. In the sealing process of S2, the rotor core 22 is attached to the magnet mounting jig 62. When installed, the compressor 104 is operated to increase the gas pressure in the sealed space 64. By detecting the gas pressure at that time with the pressure gauge 106, whether or not the sealed space is sealed can be determined from the rate of increase in the gas pressure. can be confirmed. The gas in the closed space 64 may be the atmosphere (air), but the compressor 104 may be operated in reverse to exhaust the atmosphere in the closed space 64 and replace it with a predetermined gas such as argon gas.

In the heating step S3 in FIG. 6, the composite material 44 in the closed space 64 is heated according to Q1 to Q4 in FIG. At Q1, the compressor 104 is started (ON) and the gas is sent into the sealed space 64 through the pipe 102, thereby increasing the gas pressure in the sealed space 64. As a result, the gas temperature rises due to the adiabatic compression of the gas in the closed space 64, and the composite material 44 in contact with the gas is heated (Q2). That is, by using the work energy applied from the outside to increase the gas pressure as a heat source, the internal energy increases according to the first law of thermodynamics, and the gas temperature rises. In Q3, the operation of the compressor 104 is controlled by feedback control or the like so that the gas pressure or gas temperature in the closed space 64 is maintained at a predetermined target value for a predetermined period of time. When the binding material 42 softens due to the heating of the composite material 44 during this period, the porous material 40 expands due to its own residual stress or the like and changes into the porous molding material 38 , and the expansion pressure of the porous molding material 38 causes the magnet 24 to move. is fixed to the flux barrier 36 (Q4). The gas in the sealed space 64 including the flux barrier 36 is in contact with the surface of the composite material 44, and when the porous material 40 begins to expand due to heating and the gaps become larger, the gas also penetrates into the gaps. The composite material 44 is efficiently heated by . As a result, the heating step of S3 in FIG. 6 is completed. FIG. 11 shows a state in which the porous material 40 expands to become the porous molding material 38 , and the magnet 24 is fixed to the flux barrier 36 by the pressing force of the porous molding material 38 . In this embodiment, the compressor 104 functions as a temperature control device.

In the cooling step of S4 in FIG. 6, the closed space 64 is cooled according to Q5 to Q7 in FIG. At Q5, the gas in the enclosed space 64 is exhausted by operating the compressor 104 in reverse. As a result, the pressure of the gas in the closed space 64 is lowered, the temperature of the gas is lowered by the adiabatic expansion of the closed space 64, and the porous molding material 38 in contact with the gas is cooled (Q6). Since the gas also penetrates into the voids of the porous molding material 38, the porous molding material 38 is efficiently cooled as the temperature of the gas decreases due to adiabatic expansion. The binding material 42 contained in the composite material 44 may be melted and removed by heating, but a part may remain in the porous mold material 38, and the binding material 42 cools and hardens to form a magnet. 24 are more firmly fixed to the flux barrier 36 . After that, the compressor 104 is stopped (turned off) in Q7, and the cooling process of S4 in FIG. 6 ends.

S5 in FIG. 6 is a removal step, in which the rotor core 22 having the magnets 24 fixed to the plurality of flux barriers 36 is removed from the magnet mounting jig 62 of the rotor manufacturing apparatus 60. FIG. That is, by loosening the nuts 80 of the plurality of tightening bolts 78 to separate the pair of clamping plates 70 and 72 from each other, the rotor core 22 can be taken out from between them. As a result, a series of magnet mounting operations for fixing the magnets 24 to the plurality of flux barriers 36 of the rotor core 22 is completed.

As described above, in the method of manufacturing the rotor 12 of the rotary electric machine 10 of this embodiment, the composite material 44 is arranged in the annular space between the flux barrier 36 of the rotor core 22 and the magnets 24 as shown in FIG. In this state, the rotor core 22 is attached to a magnet mounting jig 62 shown in FIG. 10, thereby forming a closed space 64 including the flux barrier 36 which is a magnet mounting hole. When the gas pressure in the sealed space 64 is increased by the compressor 104, the temperature of the gas in the sealed space 64 rises due to adiabatic compression, the composite material 44 in the flux barrier 36 is heated, and the porous material 40 expands. The magnet 24 is fixed to the flux barrier 36 by the expansion pressure of the porous mold material 38 . In that case, the gas in the sealed space 64 is in contact with the surface of the composite material 44, and when the porous material 40 begins to expand due to heating and the gaps become larger, the gas also enters the gaps. Composite material 44 is efficiently heated. This reduces the time and energy required for heating, and suppresses the deterioration of the magnetic properties of the magnets 24 and the rotor core 22, as compared with the case where the rotor core 22 and the rotor core 22 are heated from the outside using a heating furnace or the like. .

After the porous material 40 expands and changes into the porous mold material 38, the gas in the sealed space 64 is exhausted by the reverse operation of the compressor 104, the gas pressure is lowered, and the gas temperature is lowered by the adiabatic expansion. Since the porous molding material 38 is cooled down, the time required for fixing the magnets 24 is further shortened, and the magnets 24 and the rotor core 22 are quickly cooled, further suppressing the deterioration of the magnetic properties. Since the porous mold material 38 has gaps that communicate with the outside, the gas in the closed space 64 enters the gaps, and the porous mold material 38 is efficiently cooled as the gas temperature decreases. Cooled.

A heat-insulating sealing material 48 is provided on the inner wall surface of the flux barrier 36, which is the magnet mounting hole, for airtight sealing. By hermetically or hermetically sealing at 82 , 84 , 86 , 88 , 90 , 92 an enclosed space 64 is formed. Since the piping 102 connected to the compressor 104 and the like is connected via the connecting tool 100 airtightly fixed to the upper clamping plate 72 and the heat insulating plate 76, the sealed space 64 is highly airtight and heat insulating. In addition, the internal volume is minimized, so that the composite material 44 can be efficiently heated, and the porous molding material 38 whose composite material 44 has changed can be efficiently cooled.

In the heating step of S3, the compressor 104 increases the gas pressure in the pipe 102 and the sealed space 64, and according to the first law of thermodynamics, the gas temperature in the sealed space 64 increases due to adiabatic compression, and the flux barrier 36 The composite material 44 inside is heated. That is, since the composite material 44 can be heated simply by operating the compressor 104 to increase the gas pressure in the sealed space 64, the heating process can be easily performed.

Another embodiment of the present invention will now be described. In the following embodiments, the same reference numerals are given to the parts that are substantially the same as those in the previous embodiment, and detailed description thereof will be omitted.

FIG. 12 is a diagram for explaining another example of the heating process of S3 and the cooling process of S4 in FIG. 6, and is a flowchart executed instead of FIG. A manufacturing device 120 is used. QQ1 to QQ5 in FIG. 12 are the heating process of S3, and QQ6 to QQ8 are the cooling process of S4. Each step may be performed manually by an operator, or may be performed automatically using a robot or the like. 13 is a diagram corresponding to FIG. 10 and shows a rotor core in which the magnets 24 and the composite material 44 are pre-arranged in the flux barrier 36. 22 is a diagram showing a state in which the magnet mounting jig 122 is mounted. FIG. 14 is a view corresponding to FIG. 11, and shows the fixed state of the magnets in which the porous material 40 expands by heating the composite material 44 and changes into the porous mold material 38. As shown in FIG.

The magnet mounting jig 122 is basically the same as the magnet mounting jig 62, but the lower clamping plate 70 and the heat insulating plate 74 are also provided with couplings 124 such as couplers so as to pass through them. The difference is that they are airtightly fixed. A pipe 128 is connected as an air passage to the connection end portion of the connector 124 protruding outward from the clamping plate 70 so as to be connected to the upper connector 100 to form a circulation circuit 126 . A heating device 130 for heating the gas in the pipe 128, a flow meter 132 for detecting the flow rate of the gas flowing through the pipe 128, and an electric pump 134 are connected to the pipe 128. The gas in the circulation circuit 126 including the closed space 64 is circulated, for example, as indicated by arrow A while being temperature-controlled by the heating device 130 . The heating device 130 is, for example, a heat exchanger having a heating wire heater, a boiler, or the like as a heat source. In such a magnet mounting jig 122, after the rotor core 22 is attached to the magnet mounting jig 122 in the sealing process of S2, the pump 134 is operated to circulate the gas in the circulation circuit 126 including the sealed space 64, By detecting the flow rate of the gas at that time with the flow meter 132, it is possible to confirm whether or not it is in a sealed state.

In QQ1 of FIG. 12, the heating device 130 is started (ON) to heat the gas in the pipe 128 to raise the gas temperature. In QQ2, the pump 134 is started (ON) to circulate the gas in the circulation circuit 126 including the closed space 64 . As a result, the high-temperature gas temperature-controlled by the heating device 130 is allowed to flow through the closed space 64, and the composite material 44 in contact with the gas is heated (QQ3). In QQ4, the heating temperature by the heating device 130 and the circulation flow rate by the pump 134 are controlled by feedback control or the like so that the gas temperature in the closed space 64 is maintained at a predetermined target value for a predetermined period of time. When the binding material 42 softens due to the heating of the composite material 44 during this period, the porous material 40 expands due to its own residual stress or the like and changes into the porous molding material 38 , and the expansion pressure of the porous molding material 38 causes the magnet 24 to move. is fixed to the flux barrier 36 (QQ5). The gas in the sealed space 64 including the flux barrier 36 is in contact with the surface of the composite material 44, and when the porous material 40 begins to expand due to heating and the gaps become larger, the gas also flows through the gaps. The composite material 44 is efficiently heated by . As a result, the heating step of S3 in FIG. 6 is completed. FIG. 14 shows a state in which the porous material 40 expands to become the porous molding material 38 , and the magnet 24 is fixed to the flux barrier 36 by the pressing force of the porous molding material 38 . In this embodiment, the heating device 130 and the pump 134 function as a temperature control device that regulates the gas temperature within the enclosed space 64 .

In the next QQ6, the heating by the heating device 130 is stopped (OFF), and the temperature of the gas circulating in the circulation circuit 126 including the closed space 64 is lowered. This cools the porous molding material 38 in contact with the gas (QQ7). Since the gas also flows through the voids of the porous molding material 38, the porous molding material 38 is efficiently cooled as the gas temperature decreases. After that, the cooling process of S4 in FIG. 6 ends by stopping (OFF) the pump 134 in QQ8.

Also in this embodiment, by raising the gas temperature in the closed space 64 and heating the composite material 44 in the flux barrier 36, the porous material 40 expands and changes into the porous mold material 38, The expansion pressure of the porous molding material 38 fixes the magnet 24 to the flux barrier 36, and the same effects as in the above-described embodiment can be obtained. Further, a pipe 128 is provided so as to form a circulation circuit 126 through which gas flows, including the closed space 64 , and the gas flowing through the circulation circuit 126 is heated by a heating device 130 to increase the gas temperature in the closed space 64 . In order to raise the , it is only necessary to heat the gas with the heating device 130 and circulate the heated gas with the pump 134, and the heating process can be carried out easily.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, these are only one embodiment, and the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art. be able to.

10: Rotating electric machine 12: Rotor for rotating electric machine 22: Rotor core 24: Magnet 36: Flux barrier (magnet mounting hole) 38: Porous molding material 40: Porous material 42: Binder 44: Composite material 48: Thermal insulation sealing material 64 : Sealed space 74, 76: Insulation plate (insulation member) 82, 84, 86, 88, 90, 92: O-ring 100, 124: Connector 102, 128: Piping (ventilation path) 104: Compressor (temperature control device) 130: Heating device (temperature control device) 134: Pump (temperature control device) S2: Sealing process S3, Q1 to Q4, QQ1 to QQ5: Heating process S4, Q5 to Q7, QQ6 to QQ8: Cooling process

Claims (3)

A rotor core, magnets inserted in magnet mounting holes axially penetrating through the rotor core, and a large number of gaps communicating with the outside are arranged between the magnet mounting holes and the magnets. a porous molding material provided therein and securing the magnet to the magnet mounting hole;
The porous molding material is formed by interposing a composite material, which is a mixture of a porous material and a binding material and integrated by pressure, in an annular space between the magnet mounting hole and the magnet. is heated to soften the binding material, thereby expanding the porous material,
a sealing step of airtightly closing the magnet mounting hole with the composite material interposed in the annular space to form a sealed space including the magnet mounting hole;
A temperature control device provided in an air passage communicating with the sealed space increases the temperature of the gas in the sealed space to heat the composite material, thereby expanding the porous material and changing it into the porous molding material. a heating step to cause
A method for manufacturing a rotor for a rotary electric machine, comprising: After the composite material is heated in the heating step and the porous material expands and changes into the porous mold material, the temperature control device lowers the gas temperature to cool the porous mold material. The method for manufacturing a rotor for a rotary electric machine according to claim 1, comprising the steps of: In the sealing step, an inner wall surface of the magnet mounting hole is sealed with a heat insulating sealing material, and an opening of the magnet mounting hole that opens to both axial end surfaces of the rotor core is covered with a pair of heat insulating members and an O-ring is provided. The sealed space is formed by sealing with, and the sealed space is connected to the air passage via a connector airtightly provided to at least one of the pair of heat insulating members. 3. The method for manufacturing a rotor for a rotary electric machine according to 2.

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