JP2020114091A - Rotor and motor - Google Patents

Abstract

To provide a rotor and a motor capable of suppressing the occurrence of cracks in a magnet part and capable of securing a desired magnetic path.SOLUTION: A rotor 4 is provided with: a rotating shaft part 40; a magnet part 41 having polar anisotropic orientation and being a molded solidification article of magnetic powder and resin; and a resin formation part 42 integrally connecting between the rotating shaft part 40 and the magnet part 41. The resin formation part 42 is a resin molded article not containing magnetic powder. The resin formation part 42 is provided with: an inner circumferential edge part 420 connected to the rotating shaft part 40; an outer circumferential edge part 421 connected to the inner circumference part of the magnet part 41; and a plurality of bridging parts 423 partially connecting between the inner circumferential edge part 420 and the outer circumferential edge part 421. A joining part 424 between the bridging part 423 and the outer circumferential edge part 421 locates on a link line connecting between a magnetic pole part 410 of the magnet part 41 and the rotating shaft part 40.SELECTED DRAWING: Figure 2

Description

The disclosure in this specification relates to rotors and electric motors.

Patent Document 1 discloses a plastic magnet rotor including a magnetic pole portion, an inner cylinder, a shaft portion, and a rib. The plastic magnet rotor can be manufactured by injection molding a material in which magnetic powder is mixed with plastic. The portion of the rib on the magnetic pole portion side is formed to have a wall thickness as large as possible. According to this structure, the magnetic flux density in the rib can be increased.

Japanese Patent No. 3664871

In the plastic magnet rotor molded in this way, cracks may occur due to expansion and contraction in the molding process. The crack may occur in the magnetic pole portion or the rib, for example. When a crack occurs, a magnetic path may not be formed at a desired place.

The object disclosed in this specification is to provide a rotor and an electric motor that can suppress the occurrence of cracks in the magnet portion and can secure a desired magnetic path.

The aspects disclosed in this specification employ different technical means to achieve their respective purposes. Further, the claims and the reference numerals in parentheses in this section are examples showing the correspondence with specific means described in the embodiments described later as one aspect, and limit the technical scope. is not.

One of the disclosed rotors does not include a rotating shaft portion (40), a magnet portion (41) having a polar anisotropic orientation, which is a solidification product of magnetic substance powder and resin, and magnetic substance powder. And a resin forming part (42; 142; 242; 342) which is a resin molded product and integrally connects the rotating shaft part and the magnet part,
The resin forming portion partially connects the outer peripheral edge portion (421) coupled to the inner peripheral portion of the magnet portion, and a portion of the rotary shaft portion located radially inside the outer peripheral edge portion and the outer peripheral edge portion. And a plurality of bridge portions (423; 1423; 2423; 3423) for connecting the bridge portion and the outer peripheral edge portion, the coupling portion (424) includes a magnetic pole portion (410) provided in the magnet portion and a rotating shaft portion. It is located on the connecting line that connects the shortest distance.

According to this rotor, the magnet portion is a polar anisotropic magnet, and the connecting portion between the magnet portion and the rotating shaft portion is a resin molded product that does not contribute to the magnetic path. Even if a crack is generated in the connecting portion, it does not affect the desired magnetic path. Furthermore, a connecting portion between the bridging portion and the outer peripheral edge portion of the resin molded product is present on the connecting line connecting the magnetic pole portion of the magnet portion and the rotating shaft portion, and the bridging portion supports the inner peripheral portion of the magnet portion. There is. Radial contraction or expansion in the magnet portion is relatively likely to occur when the magnetic pole portion is extended. With this configuration, the bridge portion formed of the resin can support the contracted portion when the magnet portion contracts and flex when the magnet portion expands, in response to stress during manufacturing or temperature change. Therefore, the bridging portion exerts a function of following and deforming according to the deformation state of the magnet portion, and contributes to suppressing the occurrence of cracks in the magnet portion. According to this disclosure, it is possible to provide a rotor capable of suppressing the occurrence of cracks in the magnet portion and ensuring a desired magnetic path.

One of the disclosed electric motors includes the above-described rotor (4; 104; 204; 304) and a stator (6) including a plurality of coils annularly arranged on the outer peripheral side of the rotor.

According to this electric motor, as described above, the rotor having the bridging portion that exerts the function of following and deforming according to the deformed state of the magnet portion and that contributes to the suppression of crack generation in the magnet portion is provided. By including this rotor, it is possible to provide an electric motor that can suppress the occurrence of cracks in the magnet portion and can secure a desired magnetic path.

It is sectional drawing which showed the electric motor of 1st Embodiment. It is the top view which looked at the rotor of a 1st embodiment in the direction of an axis of rotation. It is the top view which looked at the rotor of a 2nd embodiment in the axis of rotation. It is the top view which looked at the rotor of a 3rd embodiment to the axis of rotation. It is the top view which looked at the rotor of a 4th embodiment in the axis of rotation.

Hereinafter, a plurality of modes for carrying out the present disclosure will be described with reference to the drawings. In each form, parts corresponding to the items described in the preceding form may be designated by the same reference numerals, and redundant description may be omitted. In the case where only a part of the configuration is described in each mode, the other mode described above can be applied to the other part of the configuration. Not only the combination of the parts clearly showing that the respective embodiments can be specifically combined, but also the combination of the embodiments is partially combined even if the combination is not particularly specified, unless there is a problem in the combination. It is also possible.

(First embodiment)
A first embodiment, which is an example of a rotor 4 and an electric motor capable of achieving the object disclosed in the specification, will be described with reference to FIGS. 1 and 2. The rotor 4 and the electric motor can be applied to a brushless motor used for vehicle equipment, home electric appliances and the like.

As shown in FIG. 1, the electric motor includes a motor assembly 1. The motor assembly 1 includes a housing 10, a frame 20, a motor cover 30 and the like. The motor assembly 1 includes a rotation chamber 2 that accommodates the rotor 4, and a control chamber 3 that accommodates the circuit board 50.

The housing 10 has a bottomed cylindrical shape having an opening on one end side. A stator 6 and a rotor 4 are provided inside the housing 10. A frame 20 that closes the opening is provided at the opening of the housing 10. The rotation chamber 2 corresponds to a region of the motor assembly 1 surrounded by the housing 10 and the frame 20. The frame 20 is made of, for example, a non-magnetic material such as aluminum and a material that is a conductive material.

The stator 6 is also called a stator thanked in an electric motor. The stator 6 has a cylindrical shape having a hollow portion. The stator 6 includes a stator core 61 having a plurality of teeth formed in the circumferential direction around the rotor 4, and a stator coil 63 wound around each tooth via an insulator 62. The stator 6 is housed inside the large-diameter portion 10a so as to come into contact with the stepped portion between the large-diameter portion and the small-diameter portion of the housing 10. The stator 6 is sandwiched and fixed by the step portion and the frame 20.

The rotor 4 is also called a rotor that rotates in the electric motor. The rotor 4 is rotatably housed inside the inner peripheral portion of the stator 6. The rotor 4 includes a rotating shaft portion 40, a resin forming portion 42 integrally provided on the rotating shaft portion 40 forming a central axis, and a magnet portion 41 integrally provided with an outer peripheral edge portion 421 of the resin forming portion 42. Equipped with. Since the rotor 4 has a configuration in which the rotating shaft portion 40 and the magnet portion 41 are connected by the resin forming portion 42 formed of a resin material, the rotor 4 has an effect of reducing the moment of inertia of the rotor 4. The rotor 4 may have a sensor magnet. The rotating shaft portion 40 is rotatably supported by bearings 11 and 12 provided on the housing 10 and the frame 20. The rotating shaft portion 40 includes the center of rotation of the magnet portion 41 and the resin forming portion 42. The rotary shaft portion 40 is a shaft and is made of metal.

The magnet part 41 is formed of a permanent magnet. As shown in FIG. 2, the magnet part 41 has a cylindrical shape as a whole. The magnet portion 41 is provided with a plurality of magnetic pole portions 410 arranged in the circumferential direction at predetermined intervals in the circumferential direction. The plurality of magnetic pole portions 410 are arranged so that N poles and S poles are alternately arranged. That is, the magnetic pole portion 410 corresponds to the pole center of the N pole or the S pole. In the magnet portion 41, magnetic force lines are formed from each N pole toward the adjacent S pole. This magnetic line of force extends in the radial direction from the N pole along the connecting line to approach the inner peripheral portion of the magnet portion 41, and is curved in the vicinity of the inner peripheral portion while reversing in the radial outer direction toward the S pole. Make up. The connecting line is an imaginary connecting line that connects the magnetic pole portion 410 and the rotating shaft portion 40 with the shortest distance, and is shown by a chain double-dashed line in FIG. The magnetic path in the rotor 4 is arranged in the magnet portion 41 so as not to extend to the resin forming portion 42 made of a resin material.

The magnet part 41 can be manufactured by molding a resin material containing magnetic powder in a mold. The magnet portion 41 is also called a bond magnet. The magnetic pole portion 410 is magnetized when the magnet portion 41 is molded in the mold, so that the magnetic pole portion 410 is installed at a predetermined position on the outer peripheral surface of the magnet portion 41. The magnet portion 41 constitutes a polar anisotropic magnet.

The resin forming portion 42 includes an inner peripheral edge portion 420, an outer peripheral edge portion 421, and a plurality of bridging portions 423, and these portions are integrally formed of a resin material. Unlike the magnet portion 41, the resin forming portion 42 does not include a magnetic substance inside or on the surface thereof, and thus has a structure that is hard to be magnetized. The resin forming part 42 can be integrally molded with the magnet part 41 by solidifying the resin material melted in a predetermined cavity in the mold. The inner peripheral edge portion 420 may be formed integrally with the rotary shaft portion 40 inserted into the mold, or may be integrally formed by press-fitting the rotary shaft portion 40 into the molded product of the resin forming portion 42. But it's okay.

As shown in FIG. 2, the plurality of bridging portions 423 are arranged in the resin forming portion 42 at equal intervals in the circumferential direction over the entire circumference and are radially provided to connect the inner peripheral edge portion 420 and the outer peripheral edge portion 421. doing. A space is provided between the adjacent bridge portions 423 and 423. The bridge portion 423 has the same axial length as the magnet portion 41. The bridge portion 423 is a plate-shaped portion that extends in the axial direction over the entire axial length of the magnet portion 41. Each of the bridge portions 423 is provided at a position including an imaginary connecting line connecting the magnetic pole portion 410 and the rotating shaft portion 40. The bridge portion 423 is joined to the outer peripheral edge portion 421 at the joint portion 424. The connecting portion 424 is provided at a position including a virtual connecting line.

The rotor 4 can be manufactured by integrally molding the magnet part 41 and the resin forming part 42 in a mold. The manufacturing method of the rotor 4 includes a molding step of the resin forming part 42, a molding step of the magnet part 41, a fixing step of the rotating shaft part 40, and the like. In the molding step of the resin forming portion 42, the rotating shaft portion 40 is made by injecting and solidifying the resin into the cavity for molding the resin forming portion 42 in a state where the rotating shaft portion 40 made of metal is inserted into the mold. The inner peripheral edge portion 420 and the rotary shaft portion 40 are integrally connected. Alternatively, the rotation shaft portion 40 may be press-fitted into the resin forming portion 42 integrally formed with the magnet portion 41 to fix the rotation shaft portion 40 to the resin forming portion 42.

In the molding process of the magnet part 41, a resin in a molten state containing magnetic substance powder is injected into a cavity for the magnet part 41 in a state where the molded and solidified resin forming part 42 is housed in a mold, A magnetic field orientation process for performing magnetic field orientation is performed. Then, the magnet part 41 having the predetermined magnetic field orientation completed is solidified, and the inner peripheral part of the magnet part 41 and the outer peripheral part 421 of the resin forming part 42 are integrally coupled. The rotor 4 is taken out after opening the mold.

In the magnetic field orientation step, magnetic field orientation is formed such that the magnetic force waveform formed by the magnetic force lines generated inside the magnet portion 41 approximates a sine waveform. When the permanent magnets are embedded in the mold so that the N poles and the S poles are alternately arranged at equal intervals in the circumferential direction, the magnetic lines of force generated from the N pole permanent magnets pass through the cavity and are adjacent to the S pole permanent magnets. A magnetic circuit leading to is formed. The N pole and the S pole are arranged so as to be located on an imaginary connecting line that connects the coupling portion 424 and the rotating shaft portion 40 in the resin forming portion 42. With this arrangement, the magnetic powder contained in the magnet material is oriented along the magnetic circuit in the cavity, and magnetic field orientation for forming the magnetic lines of force in the magnet portion 41 as described above can be performed.

The outer ring of the bearing 11 is fixed to the inner peripheral surface of the central portion of the housing 10. The inner ring of the bearing 11 is fixed to the rotary shaft portion 40. The central portion of the rotary shaft portion 40 is rotatably supported by the bearing 11. An oil seal 13 is provided on the bottom side of the bearing 10 in the center of the housing 10. The oil seal 13 seals the gap between the housing 10 and the rotary shaft 40.

The outer ring of the bearing 12 is fixed to the center of the surface of the frame 20 on the side of the rotation chamber 2 via an elastic member. The inner ring of the bearing 12 is fixed to the rotary shaft portion 40. Since the elastic member is arranged between the outer ring of the bearing 12 and the frame 20, the rotor vibration transmitted to the frame 20 can be suppressed.

The sensor magnet rotates integrally with the rotation of the rotor 4. The sensor magnet has a ring shape in which N poles and S poles are alternately provided at predetermined angles. An EDU (Electric Driver Unit) 52 including a circuit board 50, a connector housing 51, and the like is provided on the surface of the frame 20 on the control room 3 side. The circuit board 50 is an EDU board made of a ceramic board.

A connector housing 51 is provided on the surface of the frame 20 on the control chamber 3 side. A circuit board 50 is provided in a region surrounded by the connector housing 51 on the surface of the control chamber 3 side in FIG. The control chamber 3 is formed in a region of the motor assembly 1 surrounded by the frame 20 and the connector housing 51. A frame 20 is installed between the rotation chamber 2 and the control chamber 3. Further, the rotary chamber 2 and the control chamber 3 are partitioned by a frame 20 in a state where airtightness is maintained. The control chamber 3 is hermetically sealed by the connector housing 51 so that the circuit board 50 and the like in the control chamber 3 are not exposed to the outside air.

The circuit board 50 includes a control circuit 53 that controls the rotation of the rotor 4. The circuit board 50 is provided with a magnetic sensor such as a Hall IC or a magnetoresistive element at a position facing the sensor magnet with the frame 20 interposed therebetween. The magnetic sensor is installed in the control room 3. A part of the frame 20 is located between the magnetic sensor and the sensor magnet.

A plurality of connection terminals 54 are integrally provided on the connector housing 51. Each connection terminal 54 is a power supply terminal for supplying a three-phase drive current, a signal terminal for inputting/outputting a control signal to/from an ECU for engine control, and the like. The lead terminal 55 extending from the connection terminal 54 is led out from the connector housing 51. The lead terminal 55 is connected to the power supply terminal 64 of the stator 6 by resistance welding. One end of the power supply terminal 64 is led out to the connector housing 51 side through a through hole formed in the frame 20. The other end of the power supply terminal 64 is connected to the terminal of the stator coil 63 in the rotating chamber 2 by fusing.

A power supply plate 56 is installed on the surface of the connector housing 51 opposite to the control chamber 3 side. The power supply plate 56 is provided with a noise filter 58 including a smoothing capacitor 57a and a choke coil 57b in addition to the power supply wiring. The noise filter 58 removes noise of the three-phase drive current supplied to the electric motor.

The motor cover 30 is provided integrally with the housing 10 via the frame 20 and the connector housing 51. With this configuration, the motor assembly 1 includes the housing 10, the frame 20, the motor cover 30, and the like. A drain hole is formed in a portion of the frame 20 that constitutes the outer wall of the motor assembly 1. The rotation chamber 2 and the outside are in communication with each other through this drainage hole. The rotation chamber 2 communicates with the outside through a through hole and a drain hole through which the power supply terminal 64 of the frame 20 penetrates.

In the electric motor, the magnetic field strength of the sensor magnet acting on the magnetic sensor changes according to the rotational position of the rotor 4. The magnetic sensor outputs an electric signal according to the magnetic field strength of the sensor magnet to the control circuit 53, so that the control circuit 53 detects the rotation state of the rotor 4 based on the electric signal. The control circuit 53 generates a drive signal based on a control signal such as a rotation direction and a speed command from the ECU and a rotation state of the rotor 4, and outputs the drive signal from the connection terminal 54 of the connector housing 51 to the ECU. The ECU receives the drive signal and supplies a drive current to the connection terminal 54 so that the excitation timing of the stator coil 63 becomes appropriate. The driving current is supplied to the stator coil 63 through the power feeding plate 56 and the like, so that a rotating magnetic field is generated in the stator 6, and the rotating magnetic field causes the rotor 4 to rotate.

The function and effect of the rotor 4 of the first embodiment will be described. The rotor 4 includes a rotating shaft portion 40, a magnet portion 41 which is a molded and solidified product of magnetic powder and resin having a polar anisotropic orientation, and a resin molded product containing no magnetic powder, and the rotating shaft portion. The resin forming portion 42 integrally connecting the magnet 40 and the magnet portion 41 is provided. The resin forming portion 42 includes an outer peripheral edge portion 421 coupled to the inner peripheral portion of the magnet portion 41, a portion on the rotary shaft portion 40 side located radially inside the outer peripheral edge portion 421, and the outer peripheral edge portion 421. And a plurality of bridge portions 423 that are connected to each other. The connecting portion 424 of the bridging portion 423 and the outer peripheral edge portion 421 is located on the connecting line connecting the magnetic pole portion 410 of the magnet portion 41 and the rotating shaft portion 40.

According to the rotor 4, the magnet portion 41 is a polar anisotropic magnet, and the connecting portion between the magnet portion 41 and the rotating shaft portion 40 is a resin molded product that does not contribute to the magnetic path. Therefore, even if a crack is generated in the connecting portion between the magnet portion 41 and the rotating shaft portion 40, it does not affect the desired magnetic path. Further, a connecting portion between the bridging portion 423 and the outer peripheral edge portion 421 in the resin molded product is present on the connecting line connecting the magnetic pole portion 410 and the rotating shaft portion 40, and the bridging portion 423 extends from the inner peripheral portion of the magnet portion 41. I support you.

Radial contraction or expansion of the magnet portion 41 is relatively likely to occur on extension of the magnetic pole portion 410, and it is necessary to take measures against this phenomenon. Therefore, according to the configuration of the rotor 4, the bridge portion 423 formed of resin supports the contracted portion when the magnet portion 41 contracts in accordance with the stress during manufacturing or temperature change, and the magnet portion 41 is The volume expansion of the magnet part 41 can be absorbed by bending when expanded. In this way, the bridging portion 423 contributes to suppressing the occurrence of cracks in the magnet portion 41 by exerting the function of following and deforming according to the deformed state of the magnet portion 41. According to the rotor 4, it is possible to suppress the generation of cracks in the magnet portion 41, which contributes to preventing the preset magnetic path from being impaired, as compared with the above-described conventional technique.

The electric motor disclosed in this specification includes a rotor according to each of the first to fourth embodiments, and a stator 6 including a plurality of coils annularly arranged on the outer peripheral side of the rotor. According to this electric motor, as described above, the rotor having the bridging portion that exhibits the function of following and deforming according to the deformed state of the magnet portion 41 and contributes to the suppression of crack generation in the magnet portion 41 is provided. Therefore, this electric motor can suppress the generation of cracks in the magnet portion 41 and can secure a desired magnetic path.

(Second embodiment)
The second embodiment will be described with reference to FIG. The second embodiment differs from the first embodiment in the configuration of the resin forming portion 142 in the rotor 104. The configurations, operations, and effects not particularly described in the second embodiment are the same as those in the first embodiment, and only different points will be described below.

As shown in FIG. 3, the resin forming portion 142 includes a plurality of bridging portions 1423 arranged circumferentially at intervals over the entire circumference. Each of the plurality of bridging portions 1423 has a shape inclined with respect to the connecting line, and is an inclined piece that connects the inner peripheral edge portion 420 and the outer peripheral edge portion 421. The bridge portion 1423 is joined to the outer peripheral edge portion 421 at the joint portion 424. The plurality of bridge portions 1423 are provided at equal intervals in the circumferential direction over the entire circumference of the resin forming portion 142. A space is provided between the adjacent bridge portions 1423 and 1423.

The manufacturing method of the rotor 104 is the same as the process described in the first embodiment. Since the structure of the resin forming part 142 molded together with the inserted magnet part 41 in the mold is different, the cavity of the mold used to mold the resin forming part 142 in the manufacturing method of the first embodiment. The configuration is different.

According to the second embodiment, the plurality of bridging portions 1423 are provided so as to be inclined with respect to the connecting line so that the portion on the rotating shaft 40 side is displaced in the circumferential direction with respect to the coupling portion 424. With this configuration, it is possible to provide the bridging portion 1423 that is easily bent so as to contract in the radial direction with respect to thermal stress or the like in which the magnet section 41 expands in the radial direction. Due to the function of the bridge portion 1423 that absorbs the expansion of the magnet portion 41, the generation of cracks in the magnet portion 41 can be suppressed.

The plurality of bridge portions 1423 included in the resin forming portion 142 are provided so as to be inclined in the same direction with respect to the connecting line. According to this configuration, the effect of absorbing the expansion of the magnet part 41 evenly over the entire circumference is obtained, and when the expansion of the magnet part 41 converges, the bent bridge part 1423 rises and the magnet part 41 is evenly distributed over the entire circumference. It is possible to provide the resin forming portion 142 that can obtain the effect of following the change in the shape.

(Third Embodiment)
The third embodiment will be described with reference to FIG. The third embodiment is different from the first embodiment in the configuration of the resin forming portion 242 in the rotor 204. The configurations, operations, and effects that are not particularly described in the third embodiment are the same as those in the first embodiment, and only different points will be described below.

As shown in FIG. 4, the resin forming portion 242 includes an intermediate peripheral edge portion 425 between the inner peripheral edge portion 420 and the outer peripheral edge portion 421. The intermediate peripheral edge portion 425 is a cylindrical portion or an annular portion provided radially outside the inner peripheral edge portion 420 and radially inward of the outer peripheral edge portion 421, and has an inner peripheral edge portion 420 and an outer peripheral edge portion 421 via a bridge portion. Is connected to.

The resin forming portion 242 includes a plurality of outer bridging portions 2423 that partially connect the outer peripheral edge portion 421 and the intermediate peripheral edge portion 425. The plurality of outer cross-linking portions 2423 are radially arranged in the resin forming portion 242 at equal intervals in the circumferential direction over the entire circumference. A space is provided between the adjacent outer bridge portions 2423 and the outer bridge portions 2423. The outer bridge portion 2423 has the same axial length as the magnet portion 41. The outer bridge portion 2423 is a plate-shaped portion that extends in the axial direction over the entire axial length of the magnet portion 41. The outer bridge portion 2423 is provided at a position including an imaginary connecting line connecting the magnetic pole portion 410 and the rotating shaft portion 40. The outer bridge portion 2423 is joined to the outer peripheral edge portion 421 at the joint portion 424.

The resin forming portion 242 includes a plurality of inner bridging portions 426 that partially connect the intermediate peripheral edge portion 425 and the inner peripheral edge portion 420. The plurality of inner cross-linking portions 426 are radially arranged in the resin forming portion 242 at equal intervals in the circumferential direction over the entire circumference. A space is provided between the adjacent inner bridge portions 426 and the inner bridge portions 426. The inner bridge portion 426 has the same axial length as the magnet portion 41. The inner bridge portion 426 is a plate-shaped portion that extends in the axial direction over the entire axial length of the magnet portion 41.

The inner bridge portion 426 is located between the outer bridge portion 2423 and the outer bridge portion 2423 that are adjacent to each other in the circumferential direction. The outer bridge portion 2423 and the inner bridge portion 426 are provided at positions displaced in the circumferential direction.

The manufacturing method of the rotor 204 is the same as the process described in the first embodiment. Since the structure of the resin forming part 242 molded together with the inserted magnet part 41 in the mold is different, the cavity of the mold used to mold the resin forming part 242 with respect to the manufacturing method of the first embodiment. The configuration is different.

According to the third embodiment, the resin forming part 242 includes an outer peripheral edge part 421, an inner peripheral edge part 420, an intermediate peripheral edge part 425, a plurality of outer bridging parts 2423, and a plurality of inner bridging parts 426. The connecting portion 424 between the outer bridge portion 2423 and the outer peripheral edge portion 421 is provided on the connecting line between the magnetic pole portion 410 and the rotating shaft portion 40.

According to this configuration, the outer bridging portion 2423 supports the contracted portion when the magnet portion 41 contracts and flexes when the magnet portion 41 expands in response to stress during manufacturing or temperature change. It is possible to absorb the volume expansion of. Further, according to this configuration, the resin forming portion capable of providing a difference in deformation rate due to bending between the magnet portion 41 side and the rotating shaft portion 40 side by the plurality of outer bridging portions 2423 and the plurality of inner bridging portions 426. 242 can be provided.

Further, in the resin forming portion 242, the plurality of outer bridging portions 2423 and the plurality of inner bridging portions 426 are provided at positions displaced in the circumferential direction. According to this configuration, since the circumferential position of the outer bridging portion 2423 and the circumferential position of the inner bridging portion 426 do not match, the joint portion of the outer bridging portion 2423 with the intermediate peripheral edge portion 425 is located on the rotating shaft portion 40 side. It is possible to provide the resin forming portion 242 that is easily displaced. Thus, the outer bridging portion 2423 that absorbs the expansion of the magnet portion 41 can suppress the occurrence of cracks in the magnet portion 41.

(Fourth Embodiment)
A fourth embodiment will be described with reference to FIG. The fourth embodiment is different from the first embodiment in the configuration of the resin forming portion 342 in the rotor 304. The configurations, operations, and effects that are not particularly described in the fourth embodiment are similar to those in the first embodiment, and only different points will be described below.

As shown in FIG. 5, the resin forming part 342 includes an outer peripheral edge part 421, an inner peripheral edge part 420, an intermediate peripheral edge part 425, a plurality of outer bridging parts 3423, and a plurality of inner bridging parts 1426. The connecting portion 424 of the outer bridging portion 3423 and the outer peripheral edge portion 421 is provided at a position including a virtual connecting line between the magnetic pole portion 410 and the rotating shaft portion 40.

The resin forming portion 342 includes a plurality of outer bridging portions 3423 that partially connect the outer peripheral edge portion 421 and the intermediate peripheral edge portion 425. The plurality of outer bridge portions 3423 are provided in the resin forming portion 342 so as to be arranged at equal intervals in the circumferential direction over the entire circumference. A space is provided between the adjacent outer bridge portions 3423 and the outer bridge portions 3423. The outer bridge portion 3423 has an axial length equivalent to that of the magnet portion 41. The outer bridge portion 3423 is a plate-shaped portion that extends in the axial direction over the entire axial length of the magnet portion 41. The outer bridging portion 3423 is provided so that the coupling portion 424 with the outer peripheral edge portion 421 includes a virtual connecting line connecting the magnetic pole portion 410 and the rotating shaft portion 40. The outer bridging portion 3423 is provided so as to be inclined with respect to the connecting line so that the portion on the rotating shaft 40 side is displaced in the circumferential direction with respect to the coupling portion 424.

The resin forming portion 342 includes a plurality of inner bridge portions 1426 that partially connect the intermediate peripheral edge portion 425 and the inner peripheral edge portion 420. The plurality of inner bridge portions 1426 are provided in the resin forming portion 342 so as to be arranged at equal intervals in the circumferential direction over the entire circumference. A space is provided between the adjacent inner bridge portions 1426 and the inner bridge portions 1426. The inner bridge portion 1426 has the same axial length as the magnet portion 41. The inner bridge portion 1426 is a plate-shaped portion that extends in the axial direction over the entire axial length of the magnet portion 41. The inner bridge portion 426 is provided so as to be inclined with respect to the connecting line so that the portion on the rotating shaft portion 40 side is displaced in the circumferential direction with respect to the joint portion with the intermediate peripheral edge portion 425.

In the resin forming portion 342, the inclination of the inner bridge portion 426 is set to be opposite to the inclination of the outer bridge portion 3423. The inner bridge portion 1426 is located between the outer bridge portion 3423 and the outer bridge portion 3423 that are adjacent to each other in the circumferential direction. The outer bridge portion 3423 and the inner bridge portion 1426 are provided at positions displaced in the circumferential direction.

The manufacturing method of the rotor 304 is the same as the process described in the first embodiment. Since the structure of the resin forming part 342 molded together with the inserted magnet part 41 in the mold is different, the cavity of the mold used to mold the resin forming part 342 with respect to the manufacturing method of the first embodiment. The configuration is different.

According to the fourth embodiment, the outer bridge portion 3423 is provided so as to be inclined with respect to the connecting line so that the portion on the rotating shaft 40 side is displaced in the circumferential direction with respect to the coupling portion 424. According to this configuration, it is possible to provide the outer bridging portion 3423 that easily bends so as to contract in the radial direction with respect to the thermal stress or the like in which the magnet section 41 expands in the radial direction. The outer bridging portion 3423 that absorbs the expansion of the magnet portion 41 can suppress the occurrence of cracks in the magnet portion 41.

According to the fourth embodiment, the resin forming part 342 includes an outer peripheral edge part 421, an inner peripheral edge part 420, an intermediate peripheral edge part 425, a plurality of outer bridging parts 3423, and a plurality of inner bridging parts 1426. The connecting portion 424 of the outer bridging portion 3423 and the outer peripheral edge portion 421 is provided on the connecting line between the magnetic pole portion 410 and the rotating shaft portion 40.

According to this configuration, the outer bridging portion 3423 supports the contracted portion when the magnet portion 41 contracts and flexes when the magnet portion 41 expands in response to stress during manufacturing or temperature change. It is possible to absorb the volume expansion of. Further, according to this configuration, the resin forming portion capable of providing a difference in deformation rate due to bending between the magnet portion 41 side and the rotating shaft portion 40 side by the plurality of outer bridge portions 3423 and the plurality of inner bridge portions 426. 342 can be provided.

According to the fourth embodiment, the plurality of outer bridge portions 3423 and the plurality of inner bridge portions 1426 are provided at positions displaced in the circumferential direction. According to this configuration, since the circumferential position of the outer bridging portion 3423 and the circumferential position of the inner bridging portion 1426 do not match, the coupling portion of the outer bridging portion 3423 with the intermediate peripheral edge portion 425 is located on the rotating shaft portion 40 side. It is possible to provide the resin forming portion 342 that is easily displaced. Thus, the outer bridging portion 3423 that absorbs the expansion of the magnet portion 41 can suppress the occurrence of cracks in the magnet portion 41.

According to the fourth embodiment, the outer bridging portion 3423 is provided so as to be inclined with respect to the connecting line so that the portion on the intermediate peripheral edge portion 425 side is displaced in the circumferential direction with respect to the coupling portion 424. The inner bridge portion 1426 is provided so as to be inclined with respect to the connecting line so that the portion on the side of the intermediate peripheral edge 425 is displaced in the circumferential direction from the portion on the side of the inner peripheral edge 420.

According to this configuration, it is possible to provide the outer bridging portion 3423 that easily bends so as to contract in the radial direction with respect to the thermal stress or the like in which the magnet section 41 expands in the radial direction. The outer bridging portion 3423 that absorbs the expansion of the magnet portion 41 can suppress the occurrence of cracks in the magnet portion 41. Further, according to this configuration, the resin formation capable of providing a difference in the deformation rate due to bending between the magnet portion 41 side and the rotating shaft portion 40 side by the plurality of outer bridge portions 3423 and the plurality of inner bridge portions 1426. A section 342 can be provided.

According to the fourth embodiment, the outer bridge portion 3423 and the inner bridge portion 1426 are provided so as to be inclined in opposite directions with respect to the connecting line. According to this structure, the resin forming portion 342 in which the bridging portion bends toward the rotating shaft portion 40 and rises toward the magnet portion 41 has opposite deforming operation directions on the magnet portion 41 side and the rotating shaft portion 40 side. Can be provided.

(Other embodiments)
The disclosure of this specification is not limited to the illustrated embodiments. The disclosure encompasses the illustrated embodiments and variations on them based on them. For example, the disclosure is not limited to the combination of parts and elements shown in the embodiments, and various modifications can be implemented. The disclosure can be implemented in various combinations. The disclosure may have additional parts that may be added to the embodiments. The disclosure includes parts and elements of the embodiments omitted. The disclosure includes replacements or combinations of parts, elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is shown by the description of the claims, and should be understood to include meanings equivalent to the description of the claims and all modifications within the scope.

In the rotor 104 of the above-described second embodiment, the resin forming portion 142 may be configured to include the intermediate peripheral edge portion 425 as in the third and fourth embodiments. According to this configuration, the inner bridge portion located radially inside the intermediate peripheral edge portion 425 is provided at a position displaced in the circumferential direction with respect to the outer bridge portion radially outside the intermediate peripheral edge portion 425. It will be.

4, 104, 204, 304... Rotor, 40... Rotating shaft portion 41... Magnet portion, 42, 142, 242, 342... Resin forming portion 410... Magnetic pole portion, 420... Inner peripheral edge portion, 421... Outer peripheral edge portion 423 1423... bridge part, 424... joint part, 425... middle peripheral edge part 426, 1426... inner bridge part, 2423, 3423... outer bridge part (bridge part)

Claims (7)

A rotating shaft portion (40),
A magnet part (41) which is a molded and solidified product of magnetic powder and resin having a polar anisotropic orientation;
A resin molded part containing no magnetic powder, the resin forming part (42; 142; 242; 342) integrally connecting the rotating shaft part and the magnet part;
Equipped with
The resin forming portion includes an outer peripheral edge portion (421) coupled to the inner peripheral portion of the magnet portion, a portion on the rotary shaft portion side located radially inside the outer peripheral edge portion, and the outer peripheral edge portion. A plurality of cross-linking portions (423; 1423; 2423; 3423) that partially connect
The coupling part (424) of the bridging part and the outer peripheral part is located on a connecting line connecting the magnetic pole part (410) provided on the magnet part and the rotary shaft part at the shortest distance. The rotor according to claim 1, wherein the bridging portion is provided so as to be inclined with respect to the connecting line so that a portion of the bridging portion on the rotary shaft side is displaced in the circumferential direction with respect to the coupling portion. The resin forming portion,
An inner peripheral edge portion (420) integrally connected to the rotating shaft portion,
An intermediate peripheral edge portion (425) provided radially outside of the inner peripheral edge portion and radially inward of the outer peripheral edge portion,
A plurality of outer bridge portions (2423; 3423) that partially connect the outer peripheral edge portion and the intermediate peripheral edge portion,
A plurality of inner bridge portions (426; 1426) that partially connect the intermediate peripheral portion and the inner peripheral portion,
Including
The rotor according to claim 1 or 2, wherein the connecting portion (424) of the outer bridging portion and the outer peripheral edge portion is located on a connecting line that connects the magnetic pole portion and the rotating shaft portion at the shortest distance. The rotor according to claim 3, wherein the plurality of outer bridging portions and the plurality of inner bridging portions are provided at positions displaced in the circumferential direction. The outer bridging portion is provided so as to be inclined with respect to the connecting line so that the portion on the intermediate peripheral edge side is displaced in the circumferential direction with respect to the coupling portion,
The rotation according to claim 4, wherein the inner bridging portion is provided so as to be inclined with respect to the connecting line such that a portion on the intermediate peripheral edge side is displaced in the circumferential direction with respect to a portion on the inner peripheral edge side. Child. The rotor according to claim 5, wherein the outer bridging portion and the inner bridging portion are provided so as to be inclined in directions opposite to each other with respect to the connection line. A rotor (4; 104; 204; 304) according to any one of claims 1 to 6,
A stator (6) including a plurality of coils arranged in an annular shape on the outer peripheral side of the rotor;
An electric motor equipped with.

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