JP6311274B2 - Manufacturing method of rotor for rotating electrical machine - Google Patents

Description

The present invention relates to a manufacturing method of a rotating electric machine for low-data to be used as an electric motor and a generator. The permanent magnet can be securely fixed in the magnet insertion hole of the rotor core.

  Conventionally, some rotary electric machines have a so-called embedded magnet type rotor in which a permanent magnet is embedded and fixed in a rotor core. This rotor is arranged, for example, so that a rectangular parallelepiped permanent magnet is inserted into a magnet insertion hole extending in the axial direction formed in a rotor core formed by laminating electromagnetic steel plates of ferromagnetic plates and perpendicular to the radial direction. Is known. In a rotating electrical machine (referred to as an IPM motor) having such an embedded magnet type rotor, not only magnet torque by a permanent magnet but also reluctance torque is generated. Therefore, a so-called surface magnet type in which a permanent magnet is fixed to the surface of a rotor core. Higher torque can be obtained compared to a rotating electrical machine (SPM motor) having a rotor.

  In this IPM motor, the permanent magnet is fixed to the inside of the magnet insertion hole with an adhesive having a large adhesive force so that the permanent magnet can be securely fixed inside the magnet insertion hole (see, for example, Patent Document 1). An electrical steel sheet in which the magnet insertion hole is not formed at both ends in the longitudinal direction of the magnet insertion hole after devising the adhesion structure so as to increase the adhesive force, or after inserting the permanent magnet into the magnet insertion hole The structure which covers and closes from both sides in the axial direction is proposed (for example, refer to Patent Document 2).

JP 2007-68318 A JP 2009-38906 A

  However, in the conventional IPM motor, since it takes time to harden the adhesive after first inserting the permanent magnet into the magnet insertion hole, the productivity is poor, and the coating amount of the adhesive is made constant. Therefore, the fixed position of the permanent magnet varies in each magnet insertion hole. Furthermore, the adhesive may be displaced or peeled off due to the centrifugal force due to the high-speed rotation of the rotor and the difference in thermal expansion during heat generation between the rotor core and the permanent magnet. As a result, the permanent magnet may rattle in the magnet insertion hole and an abnormal noise may be generated.

  In addition, when a lid (pressing plate) of an electromagnetic steel plate is provided on the end face in the axial direction of the rotor core to prevent the movement of the permanent magnet, the magnetic flux of the permanent magnet flows directly to the lid so-called between the permanent magnet and this lid. Since the magnetic flux is short-circuited and the magnetic flux flowing through the stator coil is reduced, the torque generated by the IPM motor is reduced. Furthermore, when the magnetic flux changes inside the lid of the electromagnetic steel sheet, an eddy current may be generated to reduce the generated torque of the IPM motor. By fixing the permanent magnet in the magnet insertion hole by the method as described above, it takes a lot of labor and work time and increases the manufacturing cost.

The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a rotating electrical machine wire that can securely fix a permanent magnet to a magnet insertion hole by using a magnetostrictive material and can simplify a manufacturing process. It is to provide a method for manufacturing a capacitor.

In order to solve the above-mentioned problems, the invention described in claim 1 is a method of manufacturing a rotor for a rotating electrical machine, wherein the rotor is formed by a plurality of laminated ferromagnetic plates, and a plurality of magnet insertion holes are formed in the axial direction. At least two of the permanent magnets, the permanent magnets disposed in the circumferential direction of the rotor core and extending linearly with a uniform thickness in the axial direction, and accommodated in the magnet insertion holes, A plate-like magnetostrictive material covering the surface or more, and after the permanent magnet and the magnetostrictive material are simultaneously inserted and arranged in the magnet insertion hole, the permanent magnet is magnetized, and the magnetostrictive material is by deformed outwardly extending largely by the magnetic, the permanent magnet is fixed to the inside of the magnet insertion holes, and summarized in that said permanent magnets to said rotor core and said magnetostrictive material is disposed That.

  According to the above configuration, in the rotor used in the rotating electric machine, the magnetostrictive material is in close contact with at least two surfaces of the permanent magnet and is fitted into the magnet insertion hole formed in the rotor core. A change (expansion) of the outer dimension accompanying the elastic deformation of the magnetostrictive material caused by the magnetic field can be generated, and the permanent magnet can be securely fixed inside the magnet insertion hole. As a result, the permanent magnet can be easily fixed with an extremely simple structure, the manufacturing cost can be reduced, and abnormal noise of the rotating electrical machine can be generated due to the permanent magnet moving in the magnet insertion hole when the rotor rotates. It becomes possible to prevent.

Furthermore , since the permanent magnet and the magnetostrictive material can be simultaneously inserted and fitted in the magnet insertion hole formed in the rotor core, the manufacturing process of the rotor is simplified. Thereby, the manufacturing time of a rotor can be shortened and manufacturing cost can be reduced.

According to the present invention, using a magnetostrictive material, a permanent magnet can be securely fixed to the magnet insertion holes, and the manufacturing process can be provided a method of manufacturing a rotary electric machine for low-data can be simplified.

A sectional view showing a schematic structure of a rotary electric machine concerning one embodiment of the present invention. The fragmentary sectional view of the rotor for rotary electric machines which shows the state which inserted the permanent magnet and the magnetostriction material in the rotor core. The fragmentary sectional view of the rotor for rotary electric machines which shows the state after the rotor shaping | molding which fixed the permanent magnet to the rotor core. The fragmentary sectional view of the rotor for rotary electric machines which shows the state after rotor shaping | molding in other embodiment.

  Hereinafter, a rotating electrical machine in which a rotor according to an embodiment of the present invention is used will be described with reference to the drawings. In the following description, the radial direction and the axial direction refer to the radial direction and the axial direction of the rotor (rotor core).

  FIG. 1 is a cross-sectional view showing a schematic configuration of a rotating electrical machine 10 according to an embodiment of the present invention. The rotating electrical machine 10 is mounted on a vehicle and used as an electric motor for a drive source such as an electric power steering device that assists steering operation and an electric oil pump device that generates hydraulic pressure. In this embodiment, a three-phase brushless motor is used as the rotating electrical machine 10, and an IPM motor (embedded magnet motor) including the rotor 1 in which the permanent magnet 3 is embedded and fixed to the rotor core 2 is used. .

  As shown in FIG. 1, the rotating electrical machine 10 includes a stator 13 housed in a cylindrical case 11 and a rotor 1 that is rotatably supported on the radially inner side of the stator 13. The stator 13 includes a stator core 14 fixed to the inner periphery of the case 11, and a plurality of (12 in this embodiment) slots 12 are formed at equal intervals in the circumferential direction on the inner peripheral surface side. The stator core 14 includes a cylindrical portion (yoke) 15 between adjacent slots 12 and a plurality of (in this embodiment, 12) teeth 16 extending radially inward from the yoke 15. . A plurality of (in this embodiment, 12) stator coils 17 wound around the slots 12 are wound around the teeth 16.

  The rotor 1 includes a rotating shaft 8, a cylindrical rotor core 2 fixed so as to be rotatable integrally with the rotating shaft 8, and a permanent magnet 3. A plurality of (four in this embodiment) permanent magnets 3 are embedded in the rotor core 2 and fixed to the rotor core 2. That is, the rotor 1 of the present embodiment is configured as a so-called embedded magnet type rotor.

  The rotating electrical machine 10 configured as described above is configured such that the rotor is driven by a magnetic attractive force and a repulsive force generated between the magnetic field formed by supplying driving power to each stator coil 17 and the magnetic flux of the permanent magnet 3. 1 is configured to rotate.

  The rotor core 2 is made of a soft magnetic material such as iron or an electromagnetic steel plate, and is formed in a substantially cylindrical shape having a rotation shaft insertion hole 9 into which the rotation shaft 8 of the rotating electrical machine 10 is inserted. The rotor core 2 is formed with a plurality of magnet insertion holes 5 in which substantially rectangular plate-like permanent magnets 3 are arranged. In addition, the magnet insertion hole 5 of this embodiment is formed in the hole (cavity) shape which has substantially the same cross-sectional shape as the cross-sectional shape of the permanent magnet 3, respectively.

  The permanent magnets 3 are respectively housed in four magnet insertion holes 5 that are formed in the vicinity of the outer peripheral edge of the rotor core 2 at intervals of 90 degrees in the axial direction, and are fixedly held on the rotor core 2. For the permanent magnet 3 of the present embodiment, a sintered magnet (for example, neodymium) is used, and a surface treatment material such as plating is applied. Further, the permanent magnet 3 is fixed in the magnet insertion hole 5 in a state where the three surfaces on the radially outer side and the both sides in the longitudinal direction are covered with a magnetostrictive material 4 in a U-shape.

  The permanent magnet 3 is magnetized (magnetized) so that the permanent magnet 3 of one polarity (for example, N pole) is adjacent to the permanent magnet 3 of the other polarity (for example, S pole) in the circumferential direction. The permanent magnet 3 is magnetized in a direction substantially along each plate thickness direction, and the rotor core 2 is a magnetic path of the magnetic flux of the permanent magnet 3 that passes through the outer peripheral edge of the rotor core 2. The permanent magnet 3 may be magnetized after being disposed in the magnet insertion hole 5, or the permanent magnet 3 may be disposed and fixed in the magnet insertion hole 5.

  Next, FIG. 2 is a partial sectional view of the rotor 1 showing a state in which the permanent magnet 3 and the magnetostrictive material 4 are fitted in the magnet insertion hole 5 of the rotor core 2, and FIG. 3 shows the permanent magnet 3 fixed to the rotor core 2. It is a fragmentary sectional view of the rotor 1 which shows the state after rotor shaping | molding.

  As shown in FIG. 2, the permanent magnet 3 is covered with the magnetostrictive material 4 so as to cover the three sides of the radially outer side and the circumferential (rotating direction) side surfaces of the permanent magnet 3 in a U shape with respect to the radially outer side. 3 is inserted into the inner wall surface of the magnet insertion hole 5 with a gap (before deformation of the magnetostrictive material 4).

  The magnetostrictive material 4 changes its shape (outer dimensions) when applied with magnetism (magnetic field), and specifically, a magnetostrictive element or a giant magnetostrictive element having a large change amount is used. The giant magnetostrictive element is made of, for example, terbium, dysprosium, and iron, and can obtain a large elastic deformation and a large mechanical force exceeding 1,000 ppm (when a 120 kA / m magnetic field is applied) in a magnetic field. Moreover, since this giant magnetostrictive element has heat resistance, there is little change in thermal expansion. Thus, the permanent magnet 3 and the magnetostrictive material 4 can be simultaneously inserted and fitted into the magnet insertion hole 5 without using an adhesive or the like. The giant magnetostrictive element has a practically appropriate magnetic permeability (easiness of magnetism), and the magnetic permeability changes when the outer shape is changed. Utilizing this effect, the rotor 1 can reduce the magnetic flux of the magnetic path by applying pressure to the giant magnetostrictive element in a high rotation range, for example. In addition, since unnecessary leakage magnetic flux can be prevented when the rotor 1 rotates at low speed, cogging torque and torque ripple of the rotating electrical machine 10 can be reduced.

  The four magnet insertion holes 5 are configured by a rectangular opening 6 having a substantially rectangular cross section and a trapezoidal opening 7 extending from both ends of the rectangular opening 6 toward the outer peripheral edge of the rotor core 2. . The two trapezoidal openings 7 are formed as air gaps for magnetism. Here, for example, when the permanent magnet 3 is magnetized in the direction of the arrow shown in FIG. 2, an N pole is formed on the radially outer side in the longitudinal direction and an S pole is formed on the radially inner side.

  Next, as shown in FIG. 3, the magnetostrictive material 4 is deformed by extending the outer dimensions on both the radially outer side and the circumferential (rotational direction) side surfaces so as to close the rectangular opening 6 by the magnetic field of the permanent magnet 3. Then, it closely contacts the inner wall surface of the magnet insertion hole 5 (after deformation of the magnetostrictive material 4). Thereby, the permanent magnet 3 can be fixed in the magnet insertion hole 5 in the radial direction and the circumferential direction.

  Next, a method for manufacturing the rotor 1 will be described. Here, the permanent magnet 3 has a substantially rectangular cross-sectional shape in the radial direction and is linearly formed in the axial direction of the rotor core 2. The rotor core 2 is made of a soft magnetic material. For example, a rotor (not shown) made of a plurality of thin laminated steel plates formed into a predetermined shape by punching out an electromagnetic steel plate such as a silicon steel plate whose surface is insulated. The plate is a laminated body in which the plates are laminated and fixed in the axial direction of the rotor 1.

  Specifically, each rotor plate in which an insertion hole is formed in advance to form the rotor core 2 is rolled up, that is, the direction of the rotor plate is rotated and stacked in the axial direction, and a plurality of (in this embodiment, four) ) Magnet insertion hole 5 is formed (lamination step). A U-shaped magnetostrictive material 4 covering the permanent magnet 3 and the three surfaces on both the radial outer side and the circumferential side surface of the permanent magnet 3 is simultaneously inserted into the magnet insertion hole 5 (insertion step).

  Subsequently, the permanent magnet 3 is magnetized in the circumferential direction, for example, in the direction along the plate thickness direction so that the N-pole permanent magnet 3 is adjacent to the S-pole permanent magnet 3 (magnetization step). Thereafter, the magnetostrictive material 4 is greatly extended and deformed by the magnetism (magnetic field) of the applied permanent magnet 3, whereby each permanent magnet 3 is fixed inside the magnet insertion hole 5 (fixing step), and the rotor core. 2, the permanent magnet 3 and the magnetostrictive material 4 are arranged. Then, the rotor core 2 in which the permanent magnet 3 is embedded in the fixed rotating shaft 8 is fitted by press fitting, and the rotor 1 is assembled.

  Next, operations and effects of the rotor 1 for a rotating electrical machine and the manufacturing method thereof according to the embodiment of the present invention configured as described above will be described.

  According to the above embodiment, in the rotor 1 used in the rotating electrical machine (for example, IPM motor) 10, at least two or more surfaces of the permanent magnet 3 (in this embodiment, three surfaces on both the radially outer side and the circumferential side surface). Since the permanent magnet 3 and the magnetostrictive material 4 are simultaneously inserted and fitted into the magnet insertion hole 5 formed in the rotor core 2 while the magnetostrictive material 4 is in close contact with the magnetostrictive material 4, magnetostriction caused by the magnetic field of the permanent magnet 3 is obtained. A change (expansion) of the outer dimension accompanying the elastic deformation of the material 4 is caused, and the permanent magnet 3 can be reliably fixed in the magnet insertion hole 5. As a result, the permanent magnet 3 can be easily fixed with an extremely simple structure without using a strong adhesive or a fixing part on the magnet insertion hole 5 side, and the manufacturing cost can be reduced. It is possible to prevent abnormal noise of the rotating electrical machine 10 due to the movement of the magnet 3.

  In addition, a giant magnetostrictive element (or a magnetostrictive element) can be used as the magnetostrictive material 4. The giant magnetostrictive element has a large elastic deformation due to the application of a magnetic field and has heat resistance, so that it hardly changes due to thermal expansion. For this reason, the permanent magnet 3 can be stably and reliably fixed in the magnet insertion hole 5 of the rotor core 2. Furthermore, since the magnetostrictive material 4 is disposed radially outside the permanent magnet 3 on the inner peripheral wall surface of the magnet insertion hole 5, adverse effects on the permanent magnet 3 and the rotating electrical machine 10 (for example, motor characteristics, etc.) due to rotational centrifugal force. Can be suppressed.

  Moreover, according to the manufacturing method in the rotor 1 of the above embodiment, the permanent magnet 3 and the magnetostrictive material 4 can be simultaneously inserted and fitted into the magnet insertion hole 5 formed in the rotor core 2 in a state where the permanent magnet 3 and the magnetostrictive material 4 are in close contact with each other. The manufacturing process is simplified. Thereby, the manufacturing time of the rotor 1 can be shortened and manufacturing cost can be reduced. Further, when the permanent magnet 3 is inserted into the magnet insertion hole 5, the outer surface of the permanent magnet 3 is prevented from being rubbed, so that the surface treatment material (for example, plating) is not peeled off.

As described above, according to the embodiment of the present invention, using a magnetostrictive material, a permanent magnet can be securely fixed to the magnet insertion holes, and the manufacturing process to provide a method of manufacturing a low motor for rotating electric machine can be simplified be able to.

  As mentioned above, although embodiment which concerns on this invention was described, this invention can also be implemented with another form.

  In the above-described embodiment, the case where the permanent magnet 3 is covered with the magnetostrictive material 4 on the radially outer side and the circumferential side surfaces on both sides is fixed in the magnet insertion hole 5 has been described. Instead, the magnetostrictive material 4 may be formed in, for example, a rectangular cylinder. Further, the magnetostrictive material 4 may cover either one of the two surfaces on the circumferential side surface including the radially outer side of the permanent magnet 3.

  Here, FIG. 4A is a partial cross-sectional view of the rotor 1 showing a state after the rotor molding in the embodiment of the rectangular cylindrical magnetostrictive material 4. As shown in FIG. 4A, the permanent magnet 3 is covered with four surfaces extending in the axial direction by a magnetostrictive material 4 whose cross section is formed in a rectangular cylinder shape. The outer shape is greatly deformed outward by the magnetic field, and the permanent magnet 3 can be fixed in the magnet insertion hole 5.

  In the above embodiment, the permanent magnet 3 is formed of a flat plate having a uniform plate thickness, and the radial cross-sectional shape is a substantially rectangular plate shape, but is not limited to this, and the cross section of the permanent magnet 3 is not limited thereto. The shape may be, for example, a substantially reverse arc shape, an inverted U-shape or V-shape, a flat trapezoidal shape, or a permanent magnet having a flat shape extending radially outward from the center of the rotating shaft 8.

Here, FIG.4 (b) is a fragmentary sectional view of the rotor 1 which shows the state after rotor shaping | molding in embodiment of the permanent magnet 3 which forms V shape. FIG 4 (b) as shown in, the cross-sectional shape are two permanent magnets 3 of substantially rectangular are arranged in a V-shape, a magnetostrictive material 4 and the permanent magnet 3 which is molded into a U-shape with respect to the radial direction outside Are inserted into the magnet insertion hole 5 in close contact with each other, and the permanent magnet 3 is fixed by deformation of the magnetostrictive material 4.

  In the above embodiment, a neodymium sintered magnet is used for the permanent magnet 3, but the present invention is not limited to this, and for example, a bond magnet (for example, a plastic magnet, a rubber magnet, a rare earth magnet, etc.) may be used.

  In the above embodiment, the present invention is embodied in an electric motor used for a drive source such as an electric power steering device or an electric oil pump device. However, the present invention is not limited to this and is used as a drive source for other devices. It may also be used as a generator.

1: rotor, 2: rotor core, 3: permanent magnet, 4: magnetostrictive material (giant magnetostrictive element),
5: magnet insertion hole, 6: rectangular opening, 7: trapezoidal opening, 8: rotating shaft,
9: Rotating shaft insertion hole, 10: Rotating electric machine (IPM motor), 11: Case, 12: Slot, 13: Stator, 14: Stator core, 15: Yoke, 16: Teeth,
17: Stator coil

Claims (1)

A rotor core formed by a plurality of laminated ferromagnetic plates and having a plurality of magnet insertion holes in the axial direction;
A permanent magnet disposed in the circumferential direction of the rotor core and extending linearly with a uniform thickness in the axial direction and accommodated in the magnet insertion hole,
A plate-like magnetostrictive material covering at least two surfaces of the permanent magnet,
After the permanent magnet and the magnetostrictive material are simultaneously inserted and arranged in the magnet insertion hole, the permanent magnet is magnetized, and the magnetostrictive material is extended and deformed by the magnetism of the permanent magnet so that the permanent magnet is deformed. magnet is fixed to the inside of the magnet insertion holes, a manufacturing method of a rotating electric machine rotor, characterized in that said permanent magnets to said rotor core and said magnetostrictive material is disposed.

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