Rotor, rotating electric machine, and rotor manufacturing method

Abstract

In order to provide a rotor capable of suppressing the scattering of an outer-diameter-side iron core, a rotor (20) according to the present disclosure comprises: inner-diameter-side iron cores (30) having an axisymmetric shape about the rotation axis; a plurality of magnets (40) arranged in the circumferential direction on the radial outer side of the inner-diameter-side iron cores; a plurality of outer-diameter-side iron cores (50) arranged in the circumferential direction on the radial outer side of the magnets; and a low-permeability portion (60) disposed in contact with the outer-diameter-side iron cores and having a lower permeability than those of the inner-diameter-side iron cores and the outer-diameter-side iron cores. The outer-diameter-side iron cores are each formed with a recessed portion (52) at an interface with the low-permeability portion.

Description

Rotor, Rotating Electric Machine, and Method for Manufacturing Rotor

[0001] The present disclosure relates to a rotor, a rotating electric machine, and a method for manufacturing a rotor.

[0002] An IPM (Interior Permanent Magnet) structure rotating electric machine composed of a stator consisting of an armature wound around an annular core and a rotor in which a plurality of magnets are embedded in the core is known. The IPM structure rotating electric machine is excellent in that a rare earth magnet with a high residual magnetic flux density and coercive force can be used with good yield. However, in order to fix the magnet to the core, it is necessary to provide a bridge, which is a part of the core, between adjacent magnets in the circumferential direction. Since a part of the magnetic flux of the magnet leaks to adjacent magnets via this bridge, there has been a problem that the magnetic flux cannot be effectively utilized.

[0003] In order to avoid such a problem, in the rotor included in the IPM structure rotating electric machine, it is necessary to devise a structure for fixing the magnet to the core. For example, in Patent Document 1, the core is separated inside and outside in the radial direction of the magnet, and resin is filled between adjacent magnets arranged side by side in the circumferential direction to fix the magnet and the core, thereby eliminating the bridge and reducing magnetic flux leakage. A rotor is disclosed.

[0004] International Publication No. 2019 - 189217

[0005] Since the above rotor has a core separated inside and outside in the radial direction of the magnet, there has been a problem that the outer diameter side core is separated due to forces generated during rotation, such as the magnetic force or centrifugal force that attracts the stator and the rotor.

[0006] The present disclosure has been made to solve the above problems, and provides a rotor capable of suppressing separation of the outer diameter side core.

[0007] The rotor according to the present disclosure includes an inner diameter side core having an axially symmetric shape about a rotation axis, a plurality of magnets arranged in the circumferential direction outside the inner diameter side core in the radial direction, a plurality of outer diameter side cores arranged in the circumferential direction outside the magnets in the radial direction, and a low magnetic permeability portion arranged in contact with the outer diameter side core and having a lower magnetic permeability than the inner diameter side core and the outer diameter side core. A concave portion is formed at the interface between the outer diameter side core and the low magnetic permeability portion.

[0008] The rotor according to this disclosure has a recess formed at the interface between the outer diameter side core and the low permeability portion, and the low permeability portion injected into this recess can receive the force generated when the rotor rotates, thereby suppressing the dispersion of the outer diameter side core.

[0009] This is a plan view of a rotating electric machine according to Embodiment 1. This is a side view of a rotor according to Embodiment 1. This is a cross-sectional view taken along line A-A in Figure 2. This is a cross-sectional view taken along line B-B in Figure 2. This is a diagram showing the state of the recess formed in the inner diameter side core of the rotor according to Embodiment 1. This is a diagram showing the state of the recess formed in the inner diameter side core of the rotor according to Embodiment 1. This is a diagram showing the state of the recess formed in the inner diameter side core of the rotor according to Embodiment 1. This is a flowchart showing the manufacturing method of a rotor according to Embodiment 1. This is a plan view showing the state of the rotor components before molding placed in the first mold according to Embodiment 1. This is a cross-sectional view taken along line C-C in Figure 9. This is a diagram showing the force generated by the flow of resin in the manufacturing method of a rotor according to Embodiment 1. This is a diagram showing the state of the recess formed in the outer diameter side core of the rotor according to Embodiment 2. This is a diagram showing the state of the recess formed in the inner diameter side core of the rotor according to Embodiment 2. This is a diagram showing the state of the recess formed in the inner diameter side core of the rotor according to Embodiment 2. This is a diagram showing the state of the recess formed in the inner diameter side core of the rotor according to Embodiment 2. This is a diagram showing the configuration of the inner diameter side core of the rotor according to Embodiment 2. This is a diagram showing the configuration of a rotor according to Embodiment 3. This is a diagram showing the configuration of the rotor according to Embodiment 3. This is a diagram showing the state of the recess formed in the inner diameter side core piece in the rotor according to Embodiment 3. This is a diagram showing the state of the gap between the inner diameter side core pieces in the rotor according to Embodiment 3. This is a diagram showing the configuration of the inner diameter side core piece and the pin in the rotor according to Embodiment 3. This is a diagram showing the configuration of the inner diameter side core in the rotor according to Embodiment 3. This is a diagram showing an example of the configuration of the rotor according to Embodiment 4. This is a flowchart showing the manufacturing method of the rotor according to Embodiment 4. This is a diagram showing the force generated by the flow of resin containing a magnetic material in the manufacturing method of the rotor according to Embodiment 4. This is a diagram showing the state after resin has been injected in the manufacturing method of the rotor according to Embodiment 4. This is a diagram showing an example of the configuration of the rotating stage of the molding machine according to Embodiment 4. This is a diagram showing an example of the configuration of the rotor according to Embodiment 4.

[0010] The embodiments will be described in detail below with reference to the drawings. Note that the embodiments described below are illustrative examples. Furthermore, each embodiment can be combined as appropriate.

[0011] In this application, when the terms axis (direction), diameter (direction), inner diameter (side, direction), outer diameter (side, direction), and circumference (direction) are used, unless otherwise specified, they refer to the axis of rotation (direction), radius (direction), relative to the radial center (side, direction), relative to the radially outward (side, direction), and circumference (direction) of the axis of rotation in a cylindrical coordinate system centered on the rotation axis of the rotor.

[0012] Embodiment 1. The rotor, rotating electric machine, and method for manufacturing the rotor according to Embodiment 1 will be described with reference to Figures 1 to 11.

[0013] A rotating electric machine 1 according to Embodiment 1 will be described with reference to Figure 1. Figure 1 is a plan view of the rotating electric machine 1 according to Embodiment 1 as seen from the axial end face. As shown in Figure 1, the rotating electric machine 1 comprises a stator 4 having teeth 2 that protrude radially by the number of slots from a yoke that is connected in a single circle at its outermost diameter, and a stator winding 3 made of copper wire wound around the teeth 2 with an insulating layer (not shown) in between, and a rotor 20 in which magnets are embedded in an iron core integrated with the main shaft 10. The stator 4 is provided on the outer diameter side of the rotor 20, and the stator 4 and rotor 20 exchange magnetic flux through an air gap 5, and the rotating magnetic field of the stator winding 3 generates torque and operates as a rotating electric machine 1.

[0014] Next, the rotor 20 according to Embodiment 1 will be described using Figures 2 to 4. Figure 2 is a side view of the rotor 20, Figure 3 is a cross-sectional view taken along line A-A in Figure 2, and Figure 4 is a cross-sectional view taken along line B-B in Figure 2.

[0015] The rotor 20 comprises an inner diameter core 30, a plurality of magnets 40, a plurality of outer diameter cores 50, and a low permeability section 60, with a main shaft 10, which coincides with the rotation axis of the rotating electric machine 1, passing through the center of the rotor 20. On the outer diameter side of the inner diameter core 30, a plurality of structures in which the outer diameter cores 50 are arranged on the outer diameter side of the magnets 40 are arranged at regular intervals in the circumferential direction.

[0016] The inner diameter core 30 has a shape that is axially symmetric with respect to the axis of rotation and has multiple poles. In Figure 3, an octagonal prism is used as an example of the shape of the inner diameter core 30 that is axially symmetric with respect to the axis of rotation, and the positions where the magnets 40 and the outer diameter core 50 are arranged at regular intervals in the circumferential direction correspond to the poles of the inner diameter core 30. On the outer diameter side of the inner diameter core 30, the magnets 40 are arranged with a low permeability portion 60 in contact with the magnet-side outer diameter end face 31, and the inner diameter core 30 is responsible for the magnetic path between adjacent magnets 40 in the circumferential direction. Here, the magnets 40 are arranged on the outer diameter side of the inner diameter core 30 such that opposite polarities (N, S) appear alternately in the circumferential direction. For example, in Figure 3, the pole shown at the top is designated as the first pole. Counting clockwise from this first pole, the magnets 40 are positioned such that the outer diameter side of the magnet 40 is the north pole at the 1st, 3rd, 5th, and 7th poles, and the outer diameter side of the magnet 40 is the south pole at the 2nd, 4th, 6th, and 8th poles. Furthermore, to determine the relative circumferential position of the magnet 40 with respect to the inner diameter core 30, projections or the like with contact surfaces that come into contact with the circumferential side surface of the magnet 40 may be provided on the inner diameter core 30.

[0017] The main shaft 10 passes through the center of the inner diameter core 30, and the main shaft 10 and the inner diameter core 30 are connected. The main shaft 10 and the inner diameter core 30 are connected, for example, by welding. In addition, as will be explained later, the rotor 20 is integrally molded from resin or the like, but at the same time as integrally molding the rotor 20 from resin or the like, the main shaft 10 and the inner diameter core 30 may also be connected from resin or the like. In this case, the inner diameter dimension of the inner diameter core 30 is increased to create a gap between the main shaft 10 and the inner diameter core 30, and this gap is filled with resin or the like to connect the main shaft 10 and the inner diameter core 30. Here, when the inner diameter dimension of the inner diameter core 30 is increased, the radial thickness of the inner diameter core 30, which is the length indicated by arrow X in Figure 3, becomes smaller, but this radial thickness of the inner diameter core 30 is assumed to be longer than the length that can secure a magnetic path that does not saturate with respect to the magnetic flux formed by the magnet 40. In this way, when integrally molding the rotor 20 with resin or the like, the main shaft 10 and the inner diameter side iron core 30 are also joined using resin or the like, thereby eliminating the need to join the main shaft 10 and the inner diameter side iron core 30 by welding or the like.

[0018] The outer diameter side core 50 is in contact with the magnet 40 at the inner diameter end face 51 on the magnet side, and forms the magnetic path between the stator 4 and the magnet 40, with a small air gap 5 in the outer diameter direction in between.

[0019] The low-permeability section 60 is filled between the inner diameter core 30 and the magnet 40, and between the magnet 40 and the outer diameter core 50 at adjacent poles, and is made of a material with lower permeability than the inner diameter core 30 and the outer diameter core 50 (low-permeability material). Examples of materials with lower permeability than the inner diameter core 30 and the outer diameter core 50 include thermoplastic resin, cement, or glassy material. Because the low-permeability section 60 is made of such a material, magnetic flux does not easily pass through it.

[0020] The low-permeability section 60 fills the inner core 30, fixing the magnet 40 and the outer core 50 in the circumferential and radial directions. By filling the space between adjacent magnets 40 and outer cores 50 with the low-permeability section 60, which prevents magnetic flux from passing through easily, leakage of magnetic flux to adjacent magnets 40 can be prevented. Therefore, by providing the low-permeability section 60, the leakage of magnetic flux in the circumferential direction can be reduced while fixing the magnets 40 and outer cores 50.

[0021] Furthermore, the low-permeability portion 60 may be filled between the outer diameter core 50 and the magnet 40. In addition, as will be explained later in Embodiment 4 using Figure 28, in the rotor 20b, when the magnet 40 and the outer diameter core 50 are provided only at odd-numbered poles rather than adjacent poles, the low-permeability portion 60 may be filled in the gaps between the outer diameter core 50 and the magnet 40 that are aligned in the circumferential direction. That is, the low-permeability portion 60 is filled in at least one of the gaps between the outer diameter core 50 and the magnet 40 and the gap between the inner diameter core 30 and the magnet 40, and between the magnet 40 and the outer diameter core 50 that are aligned in the circumferential direction.

[0022] Furthermore, as shown in Figure 11, a recess 52 may be formed at the interface between the outer diameter core 50 and the low permeability portion 60. Figure 11 shows an example in which a recess 52 is formed on the circumferential side surface of the outer diameter core 50. When a recess 52 is formed in the outer diameter core 50, the low permeability portion 60 is filled in to match the shape of the recess 52 of the outer diameter core 50, and the low permeability portion 60 takes on a shape that fits into the recess 52. If there is no recess 52, if the adhesion at the interface between the outer diameter core 50 and the low permeability portion 60 peels off, the outer diameter core 50 will disintegrate due to centrifugal force. However, if there is a recess 52, as long as the low permeability portion 60 filled to match the shape of the recess 52 and the recess 52 are not destroyed by bending, it is possible to prevent the outer diameter core 50 from disintegrating due to the centrifugal force generated when the rotor 20 rotates. Although Figure 11 shows an example in which two recesses 52 are formed, it is sufficient for at least one recess 52 to be formed at the interface with the low-permeability portion 60.

[0023] Furthermore, as shown in Figures 5, 6, and 7, the inner diameter side core 30 according to Embodiment 1 may have recesses 33a, 33b, and 33c on its radial outer surface that are recessed radially inward, facing the magnet 40. The recesses 33 of the inner diameter side core 30 are filled with a low permeability portion 60. There should be at least one recess 33 in the inner diameter side core 30, and in Figure 5, a recess 33a is provided in the inner diameter side core 30 near the center of the magnet 40, but as shown in Figure 6, recesses 33b may be provided near both ends of the magnet.

[0024] Furthermore, as shown in Figure 7, by making the edges of the recesses 33 provided at both ends of the magnet smooth, the space between the low-permeability portion 60 filling the circumferential direction of the magnet 40 and the outer diameter side core 50 and the space between the low-permeability portion 60 filling the recesses 33 can be actively connected. Compared to Figure 6, Figure 7 allows the low-permeability portion 60 to be filled into a wider space, so the pressure of the low-permeability portion 60 flowing into the recesses 33 increases, and the magnet 40 and the outer diameter side core 50 can be pressed more firmly toward the outer diameter side.

[0025] Furthermore, as shown in Figure 4, end plate portions 62 and 63 may be provided. The end plate portions 62 and 63 are provided at both axial ends of the rotor 20, and are in contact with both axial end faces of the inner diameter core 30, magnet 40, and outer diameter core 50, and are connected to the low permeability portion 60. By providing the end plate portions 62 and 63, it is possible to prevent the inner diameter core 30, magnet 40, outer diameter core 50, and low permeability portion 60 from moving outward in the axial and radial directions. Note that the low permeability portion 60 and the end plate portions 62 and 63 may be integrally molded using the same material.

[0026] Next, the method for manufacturing the rotor according to Embodiment 1 will be described using Figures 8 to 11. Here, resin will be used as an example material for molding the low-permeability portion 60 of the rotor 20, but the material is not limited to resin as long as its permeability is lower than that of the inner diameter core 30 and the outer diameter core 50. Furthermore, the low-permeability portion 60 and the end plate portions 62 and 63 will be integrally molded using resin.

[0027] Figure 8 is a flowchart showing a method for manufacturing a rotor according to Embodiment 1. First, a first positioning step (step S01) is performed in which the inner diameter side core 30 is positioned in the lower mold 110 of the cylindrical first mold 100 so that the rotation axis and the central axis of the first mold 100 are coaxial. Second, a second positioning step (step S02) is performed in which a plurality of magnets 40 are positioned at the poles of the inner diameter side core 30 in the lower mold 110 of the first mold 100 so that opposite polarities alternate in the circumferential direction on the outer diameter side of the inner diameter side core 30, and a plurality of outer diameter side cores 50 are positioned on the outer diameter side of the magnets 40 in the lower mold 110 of the first mold 100.

[0028] Figure 9 is a plan view showing the rotor 20 components, namely the main shaft 10, inner diameter core 30, magnet 40, and outer diameter core 50, arranged inside the first mold 100 before molding. Figure 10 is a cross-sectional view taken along the line C-C shown in Figure 9. In Figure 10, gravity is assumed to be acting in the direction of the bottom surface.

[0029] The first mold 100 is a mold for integrally molding the rotor 20 and comprises a lower mold 110 and an upper mold 120. The lower mold 110 is cylindrical in shape and has an inner diameter that is, for example, a predetermined outer diameter for the rotor 20. The upper mold 120 is for closing the first mold 100 and molding the end plate portion 62.

[0030] As shown in Figure 9, the bottom surface 115 of the lower mold 110 is provided with a first positioning pin 112, a second positioning pin 113, and a third positioning pin 114 for positioning the main shaft 10, the inner diameter core 30, the magnet 40, and the outer diameter core 50, which are components of the rotor 20 before molding. In the first positioning step, the first positioning pin 112, which is positioned on the outer diameter side of the inner diameter core 30 so as not to interfere with the magnet 40, is used as a reference to position the inner diameter core 30 in the radial and circumferential directions. In the second positioning step, the second positioning pin 113, which is positioned on the circumferential side of the magnet 40, is used as a reference to position the magnet 40 in the circumferential direction, and the third positioning pin 114, which is positioned on the circumferential side of the outer diameter core 50, is used as a reference to position the outer diameter core 50 in the circumferential direction.

[0031] Furthermore, if a gap is provided between the main shaft 10 and the inner diameter side core 30 in order to integrally mold the rotor 20 with resin using the first mold 100 and simultaneously join the main shaft 10 and the inner diameter side core 30 with resin, positioning pins for positioning the inner diameter side core 30 in the radial and circumferential directions may be placed on the inner diameter side of the inner diameter side core 30.

[0032] Furthermore, the shapes of the first positioning pin 112, the second positioning pin 113, and the third positioning pin 114 can be any shape as long as they can position the inner diameter iron core 30, the magnet 40, and the outer diameter iron core 50. Examples include cylindrical shapes, tapered shapes, polygonal prism shapes, and shapes that conform to the inner diameter iron core 30, the magnet 40, or the outer diameter iron core 50.

[0033] Furthermore, the number and arrangement of the first positioning pin 112, second positioning pin 113, and third positioning pin 114 are not limited to the example shown in Figure 9, and it is sufficient if they can position the inner diameter core 30, magnet 40, and outer diameter core 50. Also, the axial height of the first positioning pin 112, second positioning pin 113, and third positioning pin 114 can be freely set within the range that contacts the inner diameter core 30, magnet 40, and outer diameter core 50. In addition, the first positioning pin 112, second positioning pin 113, and third positioning pin 114 may be integrated or independent. Furthermore, with respect to the third positioning pin 114, if it can position the outer diameter core 50, a projection or the like for fixing the outer diameter core 50 to the inner diameter end face 111 of the lower mold 110 may be used instead of a pin shape.

[0034] As shown in Figure 10, a spacer 116 is provided on the bottom surface 115 of the lower mold 110, and the inner diameter core 30, magnet 40, and outer diameter core 50 are placed on the spacer 116. If the spacer 116 is not provided, there is no gap between the bottom surface 115 of the lower mold 110 and the inner diameter core 30, magnet 40, and outer diameter core 50 to form the end plate portion 63, and the end plate portion 63 cannot be molded. Therefore, by providing the spacer 116 and raising the inner diameter core 30, magnet 40, and outer diameter core 50 from the bottom surface 115 by the axial thickness of the end plate portion 63, resin flows into the gap between the inner diameter core 30, magnet 40, and outer diameter core 50 placed inside the lower mold 110 and the bottom surface 115, and the end plate portion 63 is molded.

[0035] The shape of the spacer 116 can be any shape as long as it does not separate the low-permeability section 60 and the end plate section 63, for example, it can be a polygonal prism or a pin shape. Also, the spacer 116 that determines the axial direction of the inner diameter iron core 30, the magnet 40 and the outer diameter iron core 50 may be a single unit or each may be independent. Furthermore, the spacer 116 may be made of the same material as the material used to form the end plate section 63, so that after the rotor 20 is formed, the spacer 116 becomes part of the end plate section 63.

[0036] Furthermore, the axial height of the lower mold 110 is designed such that a gap equal to the axial thickness of the end plate portion 62 is formed between the upper surfaces of the inner diameter iron core 30, magnet 40, and outer diameter iron core 50, which are arranged inside the lower mold 110, and the lower surface of the upper mold 120. As a result, resin flows into the gap between the inner diameter iron core 30, magnet 40, and outer diameter iron core 50, which are arranged inside the lower mold 110, and the upper mold 120, thereby forming the end plate portion 62.

[0037] Next, a step (step S03 in Figure 8) is performed in which a material with a lower magnetic permeability than the outer diameter core 50 and the inner diameter core 30 is injected between the inner diameter core 30 and the magnet 40 in the first mold 100. The low-permeability portion 60 and the end plate portions 62 and 63 are integrally molded by the resin injected as a material with a lower magnetic permeability than the outer diameter core 50 and the inner diameter core 30. Here, the resin injection gate provided in the upper mold 120 of the first mold 100 is positioned so that resin can be injected between the inner diameter core 30 and the magnet 40. Figure 11 shows the force generated by the flow of resin in the step of injecting a low-permeability material. The white arrows shown in Figure 11 indicate the force acting on the magnet 40 due to the flow of resin.

[0038] In the first and second positioning steps, when the inner diameter core 30, magnet 40, and outer diameter core 50 are positioned within the lower mold 110 of the first mold 100, a minute gap exists between the outer diameter core 50 and the magnet 40, and between the inner diameter core 30 and the magnet 40, due to the dimensional accuracy of the inner diameter core 30, magnet 40, and outer diameter core 50. There is a concern that this minute gap will worsen the dimensions of the air gap 5, but by injecting resin between the inner diameter core 30 and the magnet 40, as shown in Figure 11, the resin flows between the inner diameter side surface of the magnet 40 and the outer diameter side surface of the inner diameter core 30, applying a force that pushes the magnet 40 toward the outer diameter. As a result, a force is applied to the outer diameter side core 50 positioned on the outer diameter side of the magnet 40, and resin can be filled while pressing the outer diameter side core 50 against the lower inner diameter end face 111 of the lower mold 110 of the first mold 100. This improves the roundness of the outer diameter of the rotor 20 and stabilizes the dimensions of the air gap 5.

[0039] Furthermore, in the process of injecting a material with low magnetic permeability, the injection site of the resin only needs to be a position where the flow of the injected resin generates a force that pushes the outer diameter core 50 toward the outer diameter, for example, between the outer diameter core 50 and the magnet 40. Similarly, the position of the resin injection gate provided in the upper mold 120 of the first mold 100 also only needs to be a position where the flow of resin injected from the gate generates a force that pushes the outer diameter core 50 toward the outer diameter. For example, when injecting resin between the outer diameter core 50 and the magnet 40, the gate is provided at a position where resin can be injected between the outer diameter core 50 and the magnet 40.

[0040] Furthermore, when molding the rotor 20 using the first mold 100 and simultaneously joining the main shaft 10 and the inner diameter iron core 30 with resin, as shown in Figure 10, the main shaft 10 is inserted into the fitting portion 117 provided in the center of the bottom surface 115 of the lower mold 110, and the resin injected into the first mold 100 flows into the gap between the main shaft 10 and the inner diameter iron core 30, thereby enabling the main shaft 10 and the rotor 20 to be integrally molded within the first mold 100 while ensuring coaxiality.

[0041] In the description of the rotor 20 and the manufacturing method of the rotor 20 according to Embodiment 1, an 8-pole cylindrical rotor 20 was given as an example, but as long as the configuration of Embodiment 1 is followed, a rotor with a different number of poles, or a so-called petal-shaped rotor in which the outer diameter curvature of the outer diameter side core is greater than the curvature of the outermost diameter of the rotor 20 may also be used.

[0042] Furthermore, in the description of the rotor 20 and the manufacturing method of the rotor 20 according to Embodiment 1, an example was given in which the inner diameter side core 30 is a single unit. However, the inner diameter side core 30 may also be formed by arranging inner diameter side core pieces 35 (see Figures 17 and 18), which are divided around the axis of rotation, in the circumferential direction.

[0043] Furthermore, the rotating electric machine 1 according to Embodiment 1 is equipped with a stator 4 provided on the radially outer side of the rotor 20 described above. By using the rotor 20, the magnetic flux of the magnet 40 can be effectively utilized, and the driving torque generated by the exchange of magnetic flux between the stator 4 and the rotor 20 can be improved.

[0044] As described above, the rotor 20 according to the first embodiment includes an inner diameter side iron core 30 having a plurality of poles with an axially symmetric shape about the rotation axis, a plurality of magnets 40 arranged at the poles so that opposite polarities appear alternately in the circumferential direction on the outer side in the radial direction of the inner diameter side iron core 30, a plurality of outer diameter side iron cores 50 arranged on the outer side in the radial direction of the magnets 40, and a low magnetic permeability portion 60 filled between the magnets and the outer diameter side iron cores arranged in the circumferential direction and having a lower magnetic permeability than the outer diameter side iron core 50 and the inner diameter side iron core 30. According to such a configuration, since the low magnetic permeability portion 60 is filled between the magnets 40 and the outer diameter side iron cores 50 arranged in the circumferential direction, leakage of magnetic flux to adjacent magnets 40 can be prevented, and circumferential leakage magnetic flux can be reduced.

[0045] Furthermore, in the first embodiment, the outer diameter side iron core 50 of the rotor 20 has a concave portion 52 formed at the interface with the low magnetic permeability portion 60 on the circumferential side surface. According to such a configuration, the low magnetic permeability portion 60 is filled in accordance with the shape of the concave portion 52 of the outer diameter side iron core 50, and the low magnetic permeability portion 60 has a shape that enters the concave portion 52, so that it is possible to prevent the outer diameter side iron core 50 from being separated due to the centrifugal force generated when the rotor 20 rotates.

[0046] Furthermore, in the first embodiment, the inner diameter side iron core 30 of the rotor 20 has concave portions 33a, 33b, and 33c recessed inward in the radial direction. Since the rotor 20 can be molded while pressing the outer diameter side iron core 50 against the inner diameter end surface 111 of the lower mold of the first mold 100 by the flow of the low magnetic permeability portion 60 injected into the concave portions 33a, 33b, and 33c of the inner diameter side iron core 30, the roundness of the rotor 20 becomes good. As a result, it is possible to stabilize the dimensions of the air gap 5, which is the gap between the rotor 20 and the stator 4 included in the rotating electrical machine 1.

[0047] Furthermore, in the first embodiment, the rotor 20 includes end plate portions 62 and 63 that are in contact with both axial end faces of the inner diameter side core 30, the magnet 40, and the outer diameter side core 50, and are connected to the low magnetic permeability portion 60. According to such a configuration, since the end plate portions 62 and 63 are in contact with both axial end faces of the inner diameter side core 30, the magnet 40, and the outer diameter side core 50, it is possible to prevent the inner diameter side core 30, the magnet 40, the outer diameter side core 50, and the low magnetic permeability portion 60 from moving axially outward. Furthermore, since the end plate portions 62 and 63 are connected to the low magnetic permeability portion 60, it is possible to prevent the inner diameter side core 30, the magnet 40, the outer diameter side core 50, and the low magnetic permeability portion 60 from moving radially outward.

[0048] Furthermore, the manufacturing method of the rotor 20 according to the first embodiment is a manufacturing method of the rotor 20 including an inner diameter side core 30 having a plurality of poles in an axially symmetric shape centered on the rotation axis, and includes a first positioning step of positioning the inner diameter side core 30 in a cylindrical first mold 100 so that the rotation axis and the central axis of the first mold 100 are coaxial, and a second positioning step of positioning a plurality of magnets 40 at the poles so that opposite polarities appear alternately in the circumferential direction on the outer side in the radial direction of the inner diameter side core 30, and positioning a plurality of outer diameter side cores 50 on the outer side in the radial direction of the magnets 40, and a step of injecting a material having a lower magnetic permeability than the outer diameter side core 50 and the inner diameter side core 30 into at least one of the space between the outer diameter side core 50 and the magnet 40 and the space between the inner diameter side core 30 and the magnet 40 in the first mold 100. According to such a configuration, by injecting the material into at least one of the space between the outer diameter side core 50 and the magnet 40 and the space between the inner diameter side core 30 and the magnet 40 positioned in the first mold 100, the rotor 20 can be molded while pressing the outer diameter side core 50 against the inner diameter end face 111 of the lower mold of the first mold 100 by the flow of the injected material, so that the roundness of the rotor 20 becomes good. As a result, it is possible to stabilize the dimensions of the air gap 5, which is the gap between the rotor 20 and the stator 4 included in the rotating electrical machine 1. In addition, when concave portions 33a, 33b, and 33c that are recessed radially inward are formed in the inner diameter side core 30, a greater effect is obtained.

[0049] Furthermore, the method for manufacturing the rotor 20 according to Embodiment 1 is characterized in that the first positioning step is performed using a first positioning pin 112, which is positioned radially outside the inner diameter core 30, as a reference. With this configuration, the inner diameter core 30 is positioned within the first mold 100 using the first positioning pin 112 as a guide, so the positioning of the inner diameter core 30 can be performed accurately and easily.

[0050] Furthermore, the manufacturing method of the rotor 20 according to Embodiment 1 is characterized in that the second positioning step is performed using a second positioning pin 113, which is positioned on the circumferential outside of the magnet 40, and a third positioning pin 114, which is positioned on the circumferential outside of the outer diameter side core 50, as references. With this configuration, the magnet 40 and the outer diameter side core 50 are positioned within the first mold 100 using the second positioning pin 113 and the third positioning pin 114 as guides, so that the positioning of the magnet 40 and the outer diameter side core 50 can be performed accurately and easily.

[0051] Although the diagram shows the low-permeability portion 60 completely filled between the inner diameter core 30 and the magnet 40, it is sufficient for it to be filled in the recess 33, and the above effect can be obtained even if the low-permeability portion 60 is not partially filled in the gaps between the inner diameter core 30 and the magnet 40 other than the recess 33.

[0052] Embodiment 2. The rotor 20, the rotating electric machine 1, and the method for manufacturing the rotor 20 according to Embodiment 2 will be described with reference to Figure 12. In Embodiment 2, the same reference numerals are used for the same components as in Embodiment 1, and the differences from the other embodiments will be mainly described.

[0053] As shown in Figure 12, a recess 52a is formed on the radially outer side of the outer diameter core 50 according to Embodiment 2. By forming a recess 52a in the outer diameter core 50, the low permeability portion 60 is filled in accordance with the shape of the recess 52a of the outer diameter core 50, and the low permeability portion 60 takes on a shape that fits into the recess 52a. If there is no recess 52a, if the adhesion at the interface between the outer diameter core 50 and the low permeability portion 60 peels off, the outer diameter core 50 will disintegrate due to centrifugal force, etc. However, if there is a recess 52a, the anchor effect of the low permeability portion 60 filled in accordance with the shape of the recess 52a restrains the outer diameter core 50 by becoming one with the low permeability portion 60 outside the outer diameter core 50, thereby preventing the outer diameter core 50 from disintegrating due to the centrifugal force generated when the rotor 20 rotates.

[0054] Furthermore, since the recess 52a is located radially outward of the outer diameter side core 50, it is possible to visually confirm whether the recess 52a is filled with the low permeability portion 60. Although Figure 12 shows an example in which two recesses 52a are formed, it is sufficient for at least one recess 52a to be formed at the interface with the low permeability portion 60. In addition, it is possible to have both the recess 52 formed on the circumferential side surface of the outer diameter side core 50 in Embodiment 1 and the recess 52a formed on the radially outward side of the outer diameter side core in Embodiment 3.

[0055] Furthermore, as shown in Figures 13, 14, and 15, the inner diameter side core 30 according to Embodiment 2 may have a recess 33 on the radially outward side, similar to the inner diameter side core 30 according to Embodiment 1. The recess 33 of the inner diameter side core 30 is filled with a low permeability portion 60. The method for manufacturing the rotor according to Embodiment 2 is the same as that of Embodiment 1, but in the step of injecting a low permeability material (step S03), the same low permeability material will naturally be injected into each of the above-mentioned recesses (recess 52a and recess 33).

[0056] In the description of the rotor 20 and the manufacturing method of the rotor 20 according to Embodiment 2, an example was given in which the inner diameter side core 30 is a single unit. However, the inner diameter side core 30 may be formed by arranging inner diameter side core pieces 35 (see Figures 17 and 18), which are divided around the axis of rotation, in the circumferential direction.

[0057] Furthermore, although an octagonal prism was shown as an example of the shape of the inner diameter core 30 as shown in Figure 3, the shape of the inner diameter core 30 is not limited to this as long as it is axially symmetric with respect to the axis of rotation. For example, as shown in Figure 16, the inner diameter core 30a may have a protrusion 32.

[0058] As described above, the rotor 20, rotating electric machine 1, and method for manufacturing the rotor 20 according to Embodiment 2 have the same effects as the method for manufacturing the rotor 20, rotating electric machine 1, and rotor 20 according to Embodiment 1. Furthermore, in the rotor 20 according to Embodiment 2, a recess 52a is formed on the radially outer side of the outer diameter side core 50. With this configuration, the low permeability portion 60 is filled in to match the shape of the recess 52a of the outer diameter side core 50, and the low permeability portion 60 is shaped to fit into the recess 52a, so that the outer diameter side core 50 does not disperse due to centrifugal force etc. generated when the rotor 20 rotates.

[0059] Embodiment 3. The rotor 20, the rotating electric machine 1, and the method for manufacturing the rotor 20 according to Embodiment 3 will be described with reference to Figures 17 to 22. In Embodiment 3, the same reference numerals are used for components that are the same as those in Embodiments 1 or 2, and the differences from the other embodiments will be mainly described.

[0060] Figure 17 shows an example of the configuration of the rotor 20 according to Embodiment 3. The inner diameter side core piece 35 is formed by dividing the inner diameter side core 30 with a plane passing through the center of the magnet 40 centered on the rotation axis. Compared with a single-piece inner diameter side core 30, the inner diameter side core 30 formed by arranging the inner diameter side core pieces 35 in the circumferential direction can improve material yield.

[0061] In other embodiments, the inner diameter core 30 may be formed by circumferentially arranging inner diameter core pieces 35, and the arrangement relationship between adjacent inner diameter core pieces 35 and the recesses 33 of the inner diameter core 30 was arbitrary (for example, the arrangement relationship shown in Figure 18). Embodiment 3 focuses on the effective relationship between adjacent inner diameter core pieces 35 and the recesses 33 of the inner diameter core 30.

[0062] As shown in Figure 19, a recess 52a is formed on the radially outer side of the outer diameter core 50, similar to Embodiment 2. Alternatively, instead of the recess 52a, a recess 52 may be formed on the circumferential side surface of the outer diameter core 50, similar to Embodiment 1, or both the recess 52 and the recess 52a may be formed. As shown in Figure 19, the inner diameter core 30 is formed by arranging a plurality of inner diameter core pieces 35 in the circumferential direction. There is a gap between the ends 36 of adjacent inner diameter core pieces 35, and the low permeability portion 60 is filled into this gap. In Figure 19, the inner diameter sides of the ends 36 of adjacent inner diameter core pieces 35 are abutted together, forming a recess 33 that widens on the outer diameter side.

[0063] As shown in Figure 20, adjacent inner diameter core pieces 35 have a gap between them, and the ends 36 do not need to abut against each other. In the case of Figure 20, for example, the radial gap between the inner diameter core piece 35 and the main shaft 10 may be filled with a low-permeability portion 60, and this low-permeability portion 60 filled between the inner diameter core piece 35 and the main shaft 10 may form the bottom surface of the recess 33 of the inner diameter core 30. Note that the gap between the ends 36 does not have to be a perfectly flat plane as shown in Figure 20.

[0064] A modified example of Figure 20 is shown in Figure 21. The pin 150 is a modified example of the first positioning pin 112 described in Embodiment 1 and is fixed to the lower mold 110. The inner diameter side core piece 35 forms a fitting portion with the pin 150 on the inner diameter side of its circumferential side surface. The fitting of the pin 150 and the inner diameter side core piece 35 determines the circumferential and radial positions of the inner diameter side core piece 35. A recess 33 is formed by adjacent inner diameter side core pieces 35 and the pin 150.

[0065] The recess 33 of the inner diameter iron core 30 is filled with a low-permeability portion 60, and the magnet 40 and the outer diameter iron core 50 are pressed against the lower die inner diameter end face 111 of the lower die 110. This improves the roundness of the outer diameter of the rotor 20 and stabilizes the dimensions of the air gap 5. The manufacturing method of the rotor 20 according to Embodiment 3 is the same as that of Embodiment 1.

[0066] Furthermore, although an octagonal prism was shown as an example of the shape of the inner diameter core 30 as shown in Figure 17, the shape of the inner diameter core 30 is not limited to this as long as it is axially symmetric with respect to the axis of rotation. For example, as shown in Figure 22, the inner diameter core 30b may have a protrusion 32.

[0067] As described above, the rotor 20, rotating electric machine 1, and rotor manufacturing method according to Embodiment 3 have the same effects as those of Embodiment 1. Furthermore, the gap between adjacent inner diameter iron core pieces 35 can be effectively utilized to improve the roundness of the rotor 20.

[0068] Embodiment 4. The rotor, rotating electric machine, and method for manufacturing the rotor according to Embodiment 4 will be described with reference to Figures 23 to 28. In Embodiment 4, the same reference numerals are used for components that are the same as those in Embodiments 1 to 3, and the description will mainly focus on configurations that differ from Embodiments 1 to 3.

[0069] Figure 23 shows an example of the configuration of the rotor 20a according to Embodiment 4. In Embodiment 4, the rotor 20a includes a magnetic body portion 64.

[0070] The magnetic material portion 64 is filled between the inner diameter iron core 30 and the magnet 40 and is made of a material containing magnetic material (magnetic material). Examples of materials containing magnetic material include thermoplastic resin, cement, or glassy material mixed with magnetic material such as iron powder. In the rotor 20 according to Embodiment 1, a low permeability portion 60 was filled in the minute gap between the inner diameter iron core 30 and the magnet 40. However, since the low permeability portion 60 is made of a material through which magnetic flux does not easily pass, there is a risk that the magnetic flux will decrease due to the low permeability portion 60 filled between the inner diameter iron core 30 and the magnet 40. Therefore, in the rotor 20a according to Embodiment 4, a magnetic material portion 64 containing a magnetic material that allows magnetic flux to easily pass is filled between the inner diameter iron core 30 and the magnet 40, thereby preventing a decrease in magnetic flux and allowing effective utilization of the magnetic flux of the magnet.

[0071] The magnetic material portion 64 may also be provided between the outer diameter iron core 50 and the magnet 40. That is, the magnetic material portion 64 is provided at least one of the following: between the outer diameter iron core 50 and the magnet 40, and between the inner diameter iron core 30 and the magnet 40.

[0072] Furthermore, the low-permeability section 60a is filled between the magnets 40 and the outer diameter core 50 provided at adjacent poles, and is made of a material with lower permeability than the inner diameter core 30 and the outer diameter core 50. In this way, by filling the space between the magnets 40 and the outer diameter core 50 provided at adjacent poles with a low-permeability section 60a that prevents magnetic flux from passing through easily, the circumferential leakage flux can be reduced, and the magnets 40 and the outer diameter core 50 can be fixed in place.

[0073] As shown in Figures 25 and 26, the inner diameter core 30 according to Embodiment 4 has a recess 33 formed at the interface with the magnetic material 64. The inner diameter core 30 only needs to have at least one recess 33. The outer diameter core 50 according to Embodiment 4 also has a recess 52 at the interface with the magnetic material 64. The outer diameter core 50 only needs to have at least one recess 52.

[0074] Next, the manufacturing method of the rotor 20a according to Embodiment 4 will be described with reference to Figures 24 to 28. The manufacturing method of the rotor 20a according to Embodiment 4 includes the steps of injecting a material containing a magnetic material, removing the second mold 130, and injecting a material with low magnetic permeability. Here, a resin containing a magnetic material will be used as an example of the material used to mold the magnetic material portion 64 of the rotor 20a, but it is not limited to a resin containing a magnetic material as long as it is a material containing a magnetic material. Also, a resin will be used as an example of the material used to mold the low magnetic permeability portion 60a of the rotor 20a, but it is not limited to a resin as long as it is a material with lower magnetic permeability than the inner diameter iron core 30 and the outer diameter iron core 50. Furthermore, the low magnetic permeability portion 60a and the end plate portions 62 and 63 will be integrally molded using resin.

[0075] Figure 24 is a flowchart showing a method for manufacturing a rotor according to Embodiment 4. First, a first positioning step (step S01) is performed, similar to the method for manufacturing the rotor 20 according to Embodiment 1. Next, in a second positioning step (step S12), the multiple magnets 40 and the multiple outer diameter iron cores 50 are positioned, and a second mold 130 is placed inside the first mold 100 to partition the space between the magnets 40 and outer diameter iron cores 50 provided at adjacent poles. By placing the second mold 130 inside the first mold 100, the portion filled with the magnetic material 64 and the portion filled with the low permeability portion 60a can be separated.

[0076] The second mold 130 can have any shape as long as it can partition the space between the magnets 40 and the outer diameter iron core 50 provided at adjacent poles. For example, the second mold 130 is connected to the upper mold 120 and is provided so as to be in contact with the circumferential end faces of the magnets 40 and the outer diameter iron core 50, as shown in Figure 25. Another example of the second mold 130 is a core block that fills the portion of the first mold 100 where the low permeability section 60a is provided. When a core block is used as the second mold 130, in the second positioning step, the core block is placed inside the lower mold 110 of the first mold 100 while sliding the outer circumferential surface of the core block against the lower inner diameter end face 111 of the lower mold 110. Furthermore, in cases where the magnets 40 and outer diameter core 50 are provided only on odd-numbered poles, rather than on adjacent poles, as shown in the rotor 20b which will be explained later using Figure 28, the second mold 130 only needs to be able to partition the space between the magnets 40 and outer diameter core 50 provided on adjacent poles and the protrusion 32.

[0077] Next, a step (step S13) is performed in which a material containing magnetic material is injected between the inner diameter side core 30 and the magnet 40 in the first mold 100. The magnetic material part 64 is formed by the resin containing magnetic material injected into the first mold 100 as the material containing magnetic material. Here, the gate for injecting the resin containing magnetic material, which is provided in the upper mold 120 of the first mold 100, is provided at a position that allows the resin to be injected between the inner diameter side core 30 and the magnet 40. Figure 25 is a diagram showing the force generated by the flow of the resin containing magnetic material in the process of injecting the material containing magnetic material. The white arrows shown in Figure 25 indicate the force acting on the magnet 40 due to the flow of the resin containing magnetic material. By injecting the resin containing magnetic material between the inner diameter side core 30 and the magnet 40, the resin containing magnetic material flows between the inner diameter side surface of the magnet 40 and the outer diameter side surface of the inner diameter side core 30, applying a force that pushes the magnet 40 outwards. As a result, a force is applied to the outer diameter side core 50 positioned on the outer diameter side of the magnet 40, and the resin containing the magnetic material is filled while the outer diameter side core 50 is pressed against the lower inner diameter end face 111 of the lower mold 110 of the first mold 100 to form the magnetic material portion 64, thereby improving the roundness of the outer diameter of the rotor 20a.

[0078] Furthermore, the first mold 100 may be provided with a pin or the like to move the outer diameter side core 50 toward the lower mold inner diameter end face 111 side. For example, a pin may be provided between the inner diameter side core 30 and the magnet 40. By providing such a pin, the minute gaps that exist between the inner diameter side core 30 and the magnet 40, and between the outer diameter side core 50 and the magnet 40, are moved toward the inner diameter side core 30 and the magnet 40. The smaller the gap into which the resin containing the magnetic material flows, the more difficult it is for the resin containing the magnetic material to flow into this gap. In order to allow the resin containing the magnetic material to flow into this gap, it is necessary to increase the pressure at which the resin containing the magnetic material is injected. Therefore, by moving the gaps that occur between the inner diameter side core 30, the magnet 40, and the outer diameter side core 50 toward the inner diameter side core 30 and the magnet 40, the resin can flow more easily between the inner diameter side core 30 and the magnet 40 during the process of injecting the material containing the magnetic material, and the flow of the resin containing the magnetic material can be stabilized.

[0079] Furthermore, in the process of injecting a material containing a magnetic material, the location where the resin containing the magnetic material is injected should be such that the flow of the injected resin generates a force that pushes the outer diameter core 50 toward the outer diameter, for example, between the outer diameter core 50 and the magnet 40. Similarly, the location of the gate for injecting the resin containing the magnetic material, which is provided in the upper mold 120 of the first mold 100, should be such that the flow of the resin containing the magnetic material injected from the gate generates a force that pushes the outer diameter core 50 toward the outer diameter. For example, when injecting resin containing a magnetic material between the outer diameter core 50 and the magnet 40, the gate is provided at a location where the resin containing the magnetic material can be injected between the outer diameter core 50 and the magnet 40.

[0080] Furthermore, although step S13 involves injecting a material containing a magnetic material, injecting a material with low magnetic permeability (such as a low-permeability part 60 made of resin) can also generate a force that pushes the outer diameter side core 50 toward the outer diameter. Therefore, although the reduction in magnetic flux cannot be suppressed, an improvement in roundness can be obtained. Depending on the required specifications, it may be possible to simplify the manufacturing process by omitting steps S01, S12, S13, and S14 and manufacturing the product using only the step of injecting a material with low magnetic permeability.

[0081] Next, the process of removing the second mold 130 from the first mold 100 (step S14) is performed. Here, if the second mold 130 is connected to the upper mold, the second mold 130 can be removed from the first mold 100 by replacing the upper mold to which the second mold 130 is connected with the upper mold 120 to which the second mold 130 is not connected. Also, when a core block is used as the second mold 130, the upper mold 120 is removed, and the outer circumferential surface of the core block is slid against the lower inner diameter end face 111 of the lower mold 110 to remove it, and then the first mold 100 is closed using the same upper mold 120. In this way, when a core block is used as the second mold 130, there is no need to replace the upper mold 120 with another one in the process of removing the second mold 130, so the number of molds required to mold the rotor 20a can be reduced.

[0082] Next, a step (step S15) is performed in which a material with a lower magnetic permeability than the outer diameter core 50 and the inner diameter core 30 is injected into the space left by the removal of the second mold 130 within the first mold 100. The resin injected as a material with a lower magnetic permeability than the outer diameter core 50 and the inner diameter core 30 forms the low magnetic permeability section 60a and the end plate sections 62 and 63. Figure 26 shows the state after the resin has been injected in the step of injecting the low magnetic permeability material. The resin is injected into the space left by the removal of the second mold 130, and the resin fills the gaps between the inner diameter core 30, the magnet 40, the outer diameter core 50, and the magnetic material section 64 within the first mold 100, thereby forming the low magnetic permeability section 60a and the end plate sections 62 and 63.

[0083] Thus, in the process of injecting a material containing magnetic material, the flow of the injected resin containing magnetic material presses the outer diameter side core 50 against the lower inner diameter end face 111 of the first mold 100, thereby improving the roundness of the outer diameter of the rotor 20a. Furthermore, by performing the steps of removing the second mold 130 and injecting a material with low magnetic permeability, a material with low magnetic permeability is injected between the magnets 40 and the outer diameter side core 50 provided at adjacent poles, separate from the resin containing magnetic material. As a result, the low-permeability portion 60a formed by the low-permeability material prevents magnetic flux from leaking in the circumferential direction of the magnet 40, and the magnetic material portion 64 formed by the resin containing magnetic material prevents a reduction in the magnetic flux of the magnet 40, thus allowing for effective utilization of the magnetic flux of the magnet 40.

[0084] When manufacturing the rotor 20a using the manufacturing method described above, the rotor 20a may also be manufactured using a molding machine having a rotating stage 140. Figure 27 shows an example of the configuration of the rotating stage 140 of the molding machine. Three or more stages are provided on the rotating stage 140 of the molding machine, and an example of a case with three stages will be described.

[0085] A first stage 141, a second stage 142, and a third stage 143 are provided on the rotating stage 140. In the first stage 141, a first positioning step and a second positioning step are performed. The second stage 142 is provided with an injection mechanism for injecting a material containing a magnetic material and a mechanism for clamping the lower mold 110 and upper mold 120 of the first mold 100, and in the second stage 142, a step of injecting a material containing a magnetic material is performed. The third stage 143 is provided with an injection mechanism for injecting a material with low magnetic permeability and a mechanism for clamping the lower mold 110 and upper mold 120 of the first mold 100, and in the step of removing the second mold 130 and a step of injecting a material with low magnetic permeability are performed. In this way, by manufacturing the rotor 20a with a molding machine having a rotating stage 140, it becomes easier to mass-produce the rotor 20a.

[0086] In the description of the rotor 20a and the manufacturing method of the rotor 20a according to Embodiment 4, an 8-pole cylindrical rotor 20a was given as an example, but as long as the configuration of Embodiment 4 is followed, a rotor with a different number of poles, or a so-called petal-shaped rotor in which the outer diameter curvature of the outer diameter side core is greater than the curvature of the outermost diameter of the rotor 20a may also be used.

[0087] Furthermore, in the description of the rotor 20 and the manufacturing method of the rotor 20 according to Embodiment 4, an example was given in which the inner diameter side core 30 is a single unit. However, as shown in Figure 17 or Figure 18, the inner diameter side core 30 may be formed by arranging inner diameter side core pieces 35, which are divided around the axis of rotation, in the circumferential direction.

[0088] Furthermore, the rotating electric machine according to Embodiment 4 is equipped with a stator 4 located radially outside the rotor 20a described above. By using the rotor 20a, the magnetic flux of the magnet 40 can be effectively utilized, and the driving torque generated by the exchange of magnetic flux between the stator 4 and the rotor 20a can be improved.

[0089] Furthermore, although an octagonal prism was shown as an example of the shape of the inner diameter core 30 as shown in Figure 23, the shape of the inner diameter core 30 is not limited to this as long as it is axially symmetric with respect to the axis of rotation. For example, the inner diameter core 30c may have a protrusion 32.

[0090] An example of the configuration of a rotor 20b when the inner diameter core 30c has a protrusion 32 will be explained using Figure 28. Here, the poles of the inner diameter core 30c are numbered sequentially clockwise from the pole shown at the top of Figure 28, which is the first pole. The magnets 40, the outer diameter core 50, and the magnetic material 64 are provided only on the odd-numbered poles. Here, in order for opposite polarities to appear alternately in the circumferential direction on the outer diameter side of the inner diameter core 30, the magnets 40 are arranged so that they have the same polarity on the radially outward side. The inner diameter core 30c has a protrusion 32 formed only on the even-numbered pole adjacent to the odd-numbered pole. The shape of the radially outward end face of the protrusion 32 is the same as the shape of the radially outward end face of the outer diameter core 50, and is an arc shape of the same radius. A low-permeability portion 60a is filled between the magnets 40 and outer diameter iron core 50 and the protruding portion 32, which are located at adjacent poles.

[0091] In this way, the protrusions 32, magnets 40, outer diameter core 50, and magnetic material 64 are arranged alternately, and the magnets 40 are arranged so that they have the same polarity on their outer diameter side, so that the protrusions 32 have the opposite polarity to the magnets 40. For example, if the outer diameter side of the magnets 40 is arranged to be the north pole at odd-numbered poles, then the outer diameter side of the protrusions 32 formed at even-numbered poles will be the south pole. Therefore, similar to the rotor 20a shown in Figure 23, the rotor 20b shown in Figure 28 acts as a rotating electric machine by exchanging magnetic flux with the stator 4 to generate torque, and the magnetic flux of the magnets 40 can be effectively utilized by preventing leakage of circumferential magnetic flux with the low permeability section 60a and preventing a decrease in magnetic flux with the magnetic material 64. Compared to the rotor 20a shown in Figure 23, the rotor 20b uses half the number of magnets 40 and outer diameter iron core 50, and the portion filled with magnetic material 64 is also halved. As a result, the number of parts can be reduced by nearly half, thus reducing processing costs.

[0092] As described above, the rotor 20a according to Embodiment 4 comprises an inner diameter core 30 having multiple poles in an axially symmetric shape around the axis of rotation, multiple magnets 40 arranged on the radially outer side of the inner diameter core 30 such that opposite polarities alternate in the circumferential direction, multiple outer diameter cores 50 arranged radially outside the magnets 40, and a magnetic material portion 64 filled in at least one of the gaps between the outer diameter core 50 and the magnets 40 and between the inner diameter core 30 and the magnets 40, and formed of a material containing a magnetic material. With this configuration, the magnetic material portion 64, which contains a magnetic material through which magnetic flux can easily pass, is filled in at least one of the gaps between the outer diameter core 50 and the magnets 40 and the gap between the inner diameter core 30 and the magnets 40, which are caused by variations in the dimensions of the inner diameter core 30, the outer diameter core 50, and the magnets 40. As a result, the gaps on the side filled with the magnetic material 64 can be reduced, thereby preventing a decrease in magnetic flux due to these gaps and improving the driving torque of the rotating electric machine.

[0093] Furthermore, in Embodiment 4, the method for manufacturing the rotor 20a includes, in addition to the magnets 40 and the outer diameter side core 50, a second mold 130 which partitions the space between the magnets 40 and the outer diameter side core 50 provided at adjacent poles within the first mold 100, and after the second positioning step, a step of injecting a material containing a magnetic material into at least one of the spaces between the outer diameter side core 50 and the magnets 40 and between the inner diameter side core 30 and the magnets 40 within the first mold 100, a step of removing the second mold 130 from within the first mold 100, and a step of injecting a material with a lower magnetic permeability than the outer diameter side core 50 and the inner diameter side core 30 into the space where the second mold 130 was removed within the first mold 100. With this configuration, by injecting a material containing a magnetic material into at least one of the spaces between the outer diameter core 50 and the magnet 40 positioned within the first mold 100, and between the inner diameter core 30 and the magnet 40, the rotor 20a can be formed while the flow of the injected magnetic material presses the outer diameter core 50 against the lower inner diameter end face 111 of the first mold 100, resulting in good roundness of the rotor 20a. Furthermore, by partitioning the space between the magnets 40 and the outer diameter core 50 located at adjacent poles within the first mold 100 using the second mold 130, injecting a material containing a magnetic material, and then removing the second mold 130 and injecting a material with low magnetic permeability, the rotor 20a can be formed using two different materials. As a result, the magnetic portion 64 is formed by a material containing a magnetic material, and the low-permeability portion 60a is formed by a material with low magnetic permeability. Therefore, the magnetic portion 64 prevents a decrease in magnetic flux, and the low-permeability portion 60a prevents magnetic flux from leaking to adjacent magnets 40, making it possible to manufacture a rotor 20a that can effectively utilize the magnetic flux of the magnets 40.

[0094] Furthermore, in Embodiment 4, the rotor 20b has magnets 40, outer diameter core 50, and magnetic material 64 provided only on odd-numbered poles, and the inner diameter core 30c has protrusions 32 formed only on even-numbered poles, the protrusions 32 having the same shape as the radially outer end face of the outer diameter core 50. With this configuration, the magnets 40, outer diameter core 50, and magnetic material 64 are provided only on odd-numbered poles, and the protrusions 32 are provided only on even-numbered poles, so that the protrusions 32 have the opposite polarity to the magnets 40, outer diameter core 50, and magnetic material 64 on the radially outward side. As a result, the magnetic flux of the magnets 40 can be effectively utilized while reducing the number of parts in the rotor 20b and suppressing processing costs.

[0095] While this disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but are applicable individually or in various combinations to the embodiments. Accordingly, countless variations not illustrated are envisioned within the scope of the art disclosed in this specification. For example, these include modifying, adding or omitting at least one component, or extracting at least one component and combining it with a component from another embodiment.

[0096] 1 Rotating electric machine, 2 Teeth, 3 Stator winding, 4 Stator, 5 Air gap, 10 Main shaft, 20, 20a, 20b Rotor, 30, 30a, 30b, 30c Inner diameter side iron core, 31 Magnet side outer diameter end face, 32 Protrusion, 33a, 33b, 33c Recess, 35 Inner diameter side iron core piece, 36 End, 40 Magnet, 50 Outer diameter side iron core, 51 Magnet side inner diameter end face, 52 Recess, 60, 60a Low permeability part, 62, 63 End plate part, 64 Magnetic material part, 100 First mold, 110 Lower mold, 111 Lower mold inner diameter end face, 112 First positioning pin, 113 Second positioning pin, 114 Third positioning pin, 115 Bottom surface, 116 Spacer, 117 Fitting section, 120 Upper mold, 130 Second mold, 140 Rotating stage, 141 First stage, 142 Second stage, 143 Third stage, 150 Pin

Claims

1. A rotor comprising: an inner diameter core having an axisymmetric shape with respect to the axis of rotation; a plurality of magnets arranged circumferentially on the radially outer side of the inner diameter core; a plurality of outer diameter cores arranged circumferentially on the radially outer side of the magnets; and a low permeability portion arranged in contact with the outer diameter core and having a lower permeability than the inner diameter core and the outer diameter core, wherein the outer diameter core has a recess formed at its interface with the low permeability portion.

2. The rotor according to claim 1, wherein the outer diameter side core has the recess formed on the circumferential side surface of the outer diameter side core, and the low permeability portion is filled between a plurality of the outer diameter side cores.

3. The rotor according to claim 1 or 2, wherein the outer diameter side core has the recess formed on the radially outer side surface of the outer diameter side core, and the low permeability portion is filled into the recess.

4. The rotor according to any one of claims 1 to 3, comprising an end plate portion that contacts both axial end faces of the inner diameter side core, the magnet, and the outer diameter side core, and is connected to the low permeability portion.

5. The rotor according to any one of claims 1 to 4, wherein the inner diameter side core has a plurality of poles formed in the circumferential direction, the plurality of magnets are arranged such that opposite polarities alternate in the circumferential direction, the magnets and the outer diameter side core are provided only at the odd-numbered poles, and the inner diameter side core has a projection formed only at the even-numbered poles, the outer end face in the radial direction having the same shape as the outer end face in the radial direction of the outer diameter side core.

6. The rotor according to any one of claims 1 to 5, further comprising a magnetic material portion filled in at least one of the spaces between the outer diameter iron core and the magnet and between the inner diameter iron core and the magnet, and formed of a material containing a magnetic material.

7. The rotor according to any one of claims 1 to 6, wherein the low permeability portion is filled between the outer diameter side core and the magnet and between the inner diameter side core and the magnet.

8. The rotor according to any one of claims 1 to 7, wherein the inner diameter side core has a recess formed on its radially outer side surface facing the magnet, and the low permeability portion is filled into the recess formed in the inner diameter side core.

9. The rotor according to any one of claims 1 to 8, wherein the inner diameter core is formed by a plurality of inner diameter core pieces arranged in the circumferential direction, the gap between adjacent inner diameter core pieces in the circumferential direction is wider towards the radially outer side, and the low permeability portion is filled in the gap.

10. A rotating electric machine comprising a rotor according to any one of claims 1 to 9, and a stator provided on the radially outer side of the rotor.

11. A method for manufacturing a rotor comprising an inner diameter core having an axis of rotation symmetric shape, a plurality of magnets, and a plurality of outer diameter cores having recesses formed therein, comprising: a first positioning step of positioning the inner diameter core in a cylindrical first mold such that the axis of rotation and the central axis of the first mold are coaxial; a second positioning step of positioning the plurality of magnets radially outside the inner diameter core and positioning the plurality of outer diameter cores radially outside the magnets; a step of injecting a low-permeability material with a lower magnetic permeability than the outer diameter core and the inner diameter core into the recesses; and a step of injecting the low-permeability material into at least one of the space between the outer diameter core and the magnets and the space between the inner diameter core and the magnets in the first mold.

12. The method for manufacturing a rotor according to claim 11, comprising: a second positioning step, wherein in addition to the magnet and the outer diameter side core, a second mold is placed in the first mold to partition the space between the magnet and the outer diameter side core; after the second positioning step, a magnetic material containing a magnetic body is injected into at least one of the spaces between the outer diameter side core and the magnet and between the inner diameter side core and the magnet in the first mold; a second mold is removed from the first mold; and a low permeability material is injected into the space in the first mold where the second mold was removed.

13. The method for manufacturing a rotor according to claim 11 or 12, characterized in that the first positioning step is performed with reference to a first positioning pin located on the radially outer side of the inner diameter side core.

14. The method for manufacturing a rotor according to any one of claims 11 to 13, characterized in that the second positioning step is performed with reference to a second positioning pin arranged on the circumferential outside of the magnet and a third positioning pin arranged on the circumferential outside of the outer diameter side core.

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