Rotating electric machine

Abstract

The present application provides a rotary electric machine in which stress concentration on a thin-walled portion of a rotor core can be reduced.　A rotary electric machine (100) comprises a stator (200) and a rotor (300) configured of a rotor core (311), which is arranged through a magnetic gap with the stator (200) and in which electromagnetic steel sheets are laminated, and a plurality of permanent magnets (321) arranged at equal intervals in the circumferential direction in the rotor core (311). The rotary electric machine is provided with axial holders (331) arranged for half the number of magnetic poles of the rotor (300) on the radially inner side of the permanent magnets (321), a rotary holder (400) configured in a cylindrical shape with a rotor core (311) being arranged as an outer tubular part, and a suppressing structure (351) that suppresses the bending moments about the axial holders (331) as fulcrums.

Description

Technical Field

[0001] This application relates to a rotating electrical machine.

Background Art

[0002] In a conventional rotating electrical machine, for example, in a rotor structure in which a rotor core widely used in a rotating electrical machine for an electric vehicle is held by a cylindrical rotating holder connected to a shaft, the ratio of the diameter of the rotating holder to the outer diameter of the rotor core is high. As a result, a structure may be adopted in which the radial thickness of the rotor core is small. (See, for example, Patent Document 1)

[0003] Also, in order to ensure the centrifugal strength in the structure of the rotor, a structure is shown in which the lamination of the rotor core is fixed in a shape with the inner diameter part welded and stress relief holes are provided to suppress thermal strain deformation during welding. (See, for example, Patent Document 2)

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above-described conventional rotating electrical machine, in the structure of Patent Document 1, since a rotor structure with a small radial thickness of the rotor core is adopted as described above, when the rotor core is press-fitted into the rotating holder, a caulking becomes a fulcrum and a bending moment is applied, resulting in stress concentration in the thin-walled part of the core outer diameter of the rotor core and a problem of strength reduction of the rotor core.

[0006] Furthermore, while Patent Document 2 describes a method for lamination fixing by welding that provides sufficient margin in the radial thickness and includes stress relaxation holes to suppress thermal distortion deformation during welding, there was a problem in that the effect of stress reduction becomes small when the radial thickness is small, requiring the stress relaxation holes to be made larger.

[0007] This invention was made to solve the above-mentioned problems, and its purpose is to obtain a rotating electric machine that can reduce stress concentration in the thin-walled portion of the rotor core. [Means for solving the problem]

[0008] The rotating electric machine disclosed herein comprises a stator and a rotor disposed from the stator via a magnetic gap and comprising a rotor core made of laminated electromagnetic steel sheets and a plurality of permanent magnets arranged at equal intervals in the circumferential direction on the rotor core, wherein half the number of magnetic poles of the rotor are located radially inward of the permanent magnets. The rotor core The system includes an axially positioned support body, a rotating support body with a cylindrical shape and the rotor core positioned in the outer cylinder, and a suppression structure that suppresses the bending moment with the axial support body as the pivot point. The suppression structure consists of a recess formed on the inner circumference of the rotor core at the position of the axial holder, or the suppression structure consists of a recess formed on the outer cylinder of the rotating holder. It is. [Effects of the Invention]

[0009] According to the rotating electric machine disclosed in this application, axial holders equal to half the number of magnetic poles of the rotor are arranged radially inside the permanent magnet, the rotor core is placed on the outer cylinder portion of the cylindrical rotating holder, and the bending moment with the axial holder as a fulcrum is suppressed by a suppression structure, thereby making it possible to obtain a rotating electric machine that can reduce stress concentration on the thin-walled portion of the rotor core. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view showing a rotating electric machine according to Embodiment 1. [Figure 2] It is a perspective view showing a rotor core in a rotating electric machine according to Embodiment 1. [Figure 3] It is a perspective view showing a rotation holder in a rotating electric machine according to Embodiment 1. [Figure 4] It is a cross-sectional view showing the circumferential direction of the rotation axis of a rotor in a rotating electric machine according to Embodiment 1. [Figure 5] It is an enlarged cross-sectional view of the main part of FIG. 4 in a rotating electric machine according to Embodiment 1. [Figure 6] It is a cross-sectional view showing the circumferential direction of the rotation axis of a rotor in a rotating electric machine according to Embodiment 2. [Figure 7] It is a cross-sectional view showing the circumferential direction of the rotation axis of a rotor in a rotating electric machine according to Embodiment 2. [Figure 8] [[ID=第十九]]It is a cross-sectional view showing a modified example of a rotation holder in a rotating electric machine according to Embodiment 3. [Figure 9] It is a cross-sectional view showing a modified example of a rotation holder in a rotating electric machine according to Embodiment 3. [Figure 10] It is a main part cross-sectional view showing a modified example of the circumferential direction of the rotation axis of a rotor in a rotating electric machine according to Embodiment 4. [Figure 11] It is a cross-sectional view showing the circumferential direction of the rotation axis of a rotor in a rotating electric machine according to Embodiment 5. [Figure 12] It is an enlarged cross-sectional view of the main part of FIG. 11 in a rotating electric machine according to Embodiment 5. [Figure 13] It is a cross-sectional view showing the circumferential direction of the rotation axis of a rotor in a rotating electric machine according to Embodiment 6. [Figure 14] It is an enlarged cross-sectional view of the main part of FIG. 13 in a rotating electric machine according to Embodiment 6.

MODE FOR CARRYING OUT THE INVENTION

[0011] Embodiment 1. Hereinafter, Embodiment 1 of the present application will be described based on FIGS. 1 to 5. In each figure, the same or corresponding members and parts will be denoted by the same reference numerals and described. FIG. 1 is a cross-sectional view showing a rotating electrical machine according to Embodiment 1. FIG. 2 is a perspective view showing a rotor core in the rotating electrical machine according to Embodiment 1. FIG. 3 is a perspective view showing a rotation retaining body in the rotating electrical machine according to Embodiment 1. FIG. 4 is a cross-sectional view showing the circumferential direction of the rotation axis of the rotor in the rotating electrical machine according to Embodiment 1. FIG. 5 is an enlarged cross-sectional view of the main part of FIG. 4 in the rotating electrical machine according to Embodiment 1.

[0012] As shown in FIG. 1, the rotating electrical machine 100 includes a housing 210 composed of a bottomed cylindrical frame 211 and an end plate 212 closing the opening of the frame 211, and a stator 220 which is a stator fixed in a fitting state to the cylindrical portion of the frame 211.

[0013] The stator 220 is composed of a plurality of coils 221 that generate magnetic flux, a connection board 222 that distributes current to the plurality of coils 221, and a stator core 223 through which magnetic flux flows. The coil 221, the connection board 222, and the stator core 223 are each fixed to a bobbin 224 and electrically insulated.

[0014] Also, three connection boards 222 are provided for three phases, and each is connected to coils 221 of different phases.

[0015] The rotor 300 is disposed via a magnetic gap portion from the stator 220, and is composed of a rotor core 311 in which electromagnetic steel sheets are laminated, and a plurality of permanent magnets 321 disposed at equal intervals in the circumferential direction on the rotor core 311.

[0016] The rotor core 311 is disposed on the outer cylinder portion of a rotation retaining body 400 having a cylindrical shape, and is structurally connected to the rotor 300 and extends in the rotation axis direction. The rotation retaining body 400 is rotatably supported by a bearing 500 provided on the housing 210.

[0017] With the above configuration, the diameter of the rotating holder 400 accounts for a high proportion of the outer diameter of the rotor core 311, and a structure is adopted in which the thickness of the rotor core 311 in the radial direction of the rotation axis is relatively thin. This structure is advantageous for cost reduction by reducing the amount of electrical steel sheet used to make up the rotor core 311, or for weight reduction of the rotating shaft member by providing a space between the rotating shaft and the cylindrical rotating holder 400 that holds the rotor core 311.

[0018] In the example configuration shown in Figure 1, the rotating holder 400 that holds the rotor core 311 is directly supported by bearings 500 so as to be rotatable. However, it is not limited to this configuration. For example, a shaft (not shown) with a smaller diameter than the rotating holder 400 is provided separately at the position of the rotation axis via a cavity in the inner diameter of the rotating holder 400, and this shaft is rotatably supported by bearings 500. Furthermore, the rotating holder 400 and the shaft are integrally connected via a radially extending connecting member (not shown) to form a rotating holder member that holds the rotor core 311.

[0019] Thus, even when a shaft is provided in the inner diameter portion of the rotating holder 400 via a cavity, the presence of a space between the rotating shaft and the rotating holder allows for a structure that is advantageous for weight reduction, similar to the configuration shown in Figure 1.

[0020] Furthermore, the permanent magnets 321 are embedded on the outer circumferential surface of the rotor core 311 and arranged at equal intervals with a predetermined pitch in the circumferential direction to form magnetic poles. The permanent magnets 321 and the rotor core 311 are structurally fixed by using a silicone resin-based adhesive and heat curing it.

[0021] As shown in Figure 2, the rotor core 311 has multiple permanent magnets 321 arranged at equal intervals in the circumferential direction of the rotation axis, with alternating polarities. Axial holders 331 are arranged radially inside the permanent magnets 321 at equal intervals, with half the number of magnetic poles of the rotor 300. A core fitting portion 340 for circumferential positioning of the rotor core 311 is provided on the inner circumference of the rotor core 311.

[0022] A recess, for example, is provided as a suppression structure on the inner circumference of the rotor core 311, radially inside the axial holder 331. The recess 351 is arranged in a number equal to half the number of magnetic poles of the axial holder 331, and suppresses the bending moment with the axial holder 331 as the pivot point. A characteristic feature is that the circumferential width of the recess 351, which is a suppression structure, is greater than or equal to the angle of the number of poles of the permanent magnet 321.

[0023] The axial holder 331 is equipped with a V-crimping structure that holds the electrical steel sheet in the direction of the rotation axis during punching, so that the cross-sectional shape in the circumferential direction of the rotation axis becomes V-shaped when the sheet is press-formed. Furthermore, because eddy current losses are likely to occur due to residual stress and a decrease in interlayer insulation during punching, the axial holder 331 is positioned inside the permanent magnet 321 in the radial direction of the rotation axis in order to minimize the influence of magnetic properties.

[0024] Furthermore, as shown in Figure 3, the rotating holder 400 is the rotating holder 400 into which the rotor core 311 is press-fitted. Rotation hold The device is characterized by having an outer cylinder portion 410 and a rotating holding inner cylinder portion 420 for providing a cavity in the inner diameter of the rotating holder 400, and by having a structure that allows a shaft or vibration suppression component for axial force transmission to be assembled to the rotating holding inner cylinder portion 420.

[0025] Furthermore, the rotating holder 400 is equipped with a rotating holding fitting portion 440 for positioning the core fitting portion 340 of the rotor core 311, and the structure is characterized by a small gap between the core fitting portion 340 of the rotor core 311 and the rotating holding fitting portion 440 to facilitate assembly. If positioning accuracy is required, the core fitting portion 340 of the rotor core 311 and the rotating holding fitting portion 440 may be provided in multiple locations rather than one to adjust the positioning.

[0026] Figures 4 and 5 show a rotor structure 600 in which a rotor 300 is positioned on a rotating holder 400. The rotor core 311 and the rotating holder 400 are positioned in the circumferential direction of the rotation axis by the core fitting portion 340 and the rotating holder fitting portion 440, and the rotor 300 is press-fitted into the rotating holder 400. Shrink fitting or cold fitting may be used for fitting.

[0027] When the angle 601 between the core fitting portion 340 of the rotor core 311 and the axial holder 331 in the rotational axis circumferential position is defined as θ1, and the width angle 611 of the recess 351, which is a suppression component, in the rotational axis circumferential direction is defined as θ2,

number

[0028] Furthermore, if the outermost diameter portion 602 of the rotor core 311 is φa and the innermost diameter portion 603 of the rotor core 311 is φb,

number

[0029] Furthermore, if the diameter 604 of the inner cylindrical part 420 of the rotating holder 400 is defined as φc,

number

[0030] As in the basic configuration of this embodiment 1, the rotor 300 is configured such that the rotor core 311, which is fixed to the outer cylinder portion of the cylindrical rotating holder 400 connected to the rotating shaft, is equipped with axial holders 331 arranged at equal intervals on the radially inner side of the permanent magnets 321 at half the number of magnetic poles of the rotor 300, and recesses 351 which are suppression components arranged on the radially inner side of the axial holders 331 in the direction of rotational shaft. This configuration provides recesses 351 which are suppression components that suppress the bending moment that occurs when the rotor core 311 is pressed into the rotating holder 400, which occurs when the rotor core 311 is pressed in, due to the rotor structure having a small radial thickness of the rotor core 311, with the axial holders 331 acting as the pivot point.

[0031] As a result, it is possible to suppress the generation of local stress in the area where the outermost diameter portion 602 of the rotor core 311 and the permanent magnet 321 have small thickness in the direction of rotation axis. However, when the ratio of the thickness of the outermost diameter portion 602 of the rotor core 311 or the rotating holder 400 to the outer diameter is 10% or less as described above, the effect of the present invention becomes even more pronounced, as explained below.

[0032] When the rotor core 311 and the rotating holder 400 are fitted together, if there is a large axial misalignment, the innermost diameter portion 603 of the rotor core 311 is corrected in the direction of the rotation axis by the rotating holder 400. At this time, a bending moment with the axial holder 331 as the pivot point is transmitted to the next layer of the rotor core 311 in the direction of the rotation axis via the axial holder 331. In this case, if the radial thickness of the rotor core 311 in the direction of the rotation axis is small, less than 10% of the outermost diameter portion 602, local stress is generated at the point where the radial thickness of the outermost diameter portion 602 and the permanent magnet 321 is small, which is a factor that leads to fatigue failure at high rotation speeds.

[0033] In this embodiment 1, by providing a recess 351, which is a restraining component, located on the inner side of the rotor core 311 in the radial direction of the rotation axis of the axial holder 331, the bending moment when the innermost diameter portion 603 of the rotor core 311 is straightened in the direction of the rotation axis is restrained by the axial holder 331 It is characterized by a structure that does not transmit stress to the outermost diameter portion 602 and the permanent magnet 321, and is less likely to generate local stress in the area where the thickness in the radial direction of the rotation axis is small.

[0034] Embodiment 2. Embodiment 2 of the present application will be described with reference to Figures 6 and 7, in which the same or equivalent members and parts will be denoted by the same reference numerals in each figure. Figure 6 is a cross-sectional view showing the circumferential direction of the rotation axis of the rotor in a rotating electric machine according to Embodiment 2. Figure 7 is a cross-sectional view showing the circumferential direction of the rotation axis of the rotor in a rotating electric machine according to Embodiment 2.

[0035] Figures 6 and 7 show a rotor structure 700 in which a rotor 300 is arranged on a rotating holder 400. In this embodiment 2, as shown in the cross-section along line AA in Figure 6 and line BB in Figure 7, the permanent magnet 321 has a structure in which it is divided into two parts in the direction of the rotation axis.

[0036] The permanent magnet 321 may be a single, undivided shape, or instead of a sintered magnet, it may be a bonded magnet directly injection-molded onto the rotor core 311, or a field winding with an armature winding inserted into the core. In this embodiment 2, by dividing the permanent magnet 321 in the direction of the rotation axis, the optimal number of divisions can be set from the shape before cutting, which determines the aspect ratio of the radial surface area. This improves machinability and reduces processing costs, and also makes it easier to adjust the magnetic domain orientation within the permanent magnet 321, thereby stabilizing its magnetic properties.

[0037] Furthermore, the recess 351, which is located on the inside of the axial holder 331 in the radial direction of the rotation axis, is positioned in the rotation axis direction, and is characterized by having a structure in which the thickness of the recess 351 in the radial direction of the rotation axis is greater than the interference fit when the rotor core 311 and the rotating holder 400 are press-fitted.

[0038] Embodiment 3. Embodiment 3 of the present application will be described with reference to Figures 8 and 9, in which the same or equivalent members and parts will be denoted by the same reference numerals in each figure. Figure 8 is a cross-sectional view showing a modified example of the rotating holder in a rotating electric machine according to Embodiment 3. Figure 9 is a cross-sectional view showing a modified example of the rotating holder in a rotating electric machine according to Embodiment 3.

[0039] Figures 8 and 9 show a modified structure of the rotary holder 400 in the embodiment 1 described above. In the rotary holder 400 of embodiment 1, as shown in Figure 1, the rotor core 311 and the rotary holder 400 are fitted together by press-fitting, with an overlap for press-fitting.

[0040] Figures 8 and 9 show a modified configuration of the rotary holder 400 in Embodiment 1. For example, when the rotor core 311 does not have a recess 351 on the inside in the radial direction of the rotation axis, or when the contact state of each component during press-fitting is unstable due to the accuracy of the inner diameter of the rotor core 311 and the outer diameter of the rotary holder 400, the rotary holder 400 is provided with a structure in which recesses or uneven parts such as knurling 401 or staking 402, which are suppression components, are provided on the outer cylinder portion of the rotary holder 400 to increase the fastening force structurally.

[0041] Furthermore, the recesses or uneven surfaces, such as the knurling 401 or staking 402, which are suppression structures provided on the outer cylinder portion of these rotating holders 400, function as a substitute for the suppression structure for the bending moment generated with the axial holder 331 as a fulcrum, which is achieved by providing a recess 351 on the inner side of the rotor core 311 in the direction of the rotation axis in the configuration of Embodiment 1. In other words, the recess 351 provided on the inner diameter of the rotor core 311 that functions as the bending moment suppression structure in Embodiment 1 may also be provided on the rotating holder 400 side.

[0042] When recesses are provided on the rotating holder side, particularly in the outer cylinder portion of the rotating holder, it is preferable to provide them at positions where the axial holder and circumferential position overlap, similar to the recesses 351 provided in the inner diameter of the rotor core 311, and this can effectively function as a means of suppressing the bending moment.

[0043] Embodiment 4. Embodiment 4 of the present application will be described with reference to Figure 10. Figure 10 is a cross-sectional view of a key part showing a modified example of the rotor in the circumferential direction of the rotation axis in a rotating electric machine according to Embodiment 4.

[0044] In the embodiments described above, examples of axial holders 331 were explained using a V-crimp structure having a longitudinal direction parallel to the circumferential direction of the rotation axis. However, in this embodiment 3, as shown in Figure 10, a round crimp core 370 using round crimps 371 may be used for the axial holder 331. Although not shown, methods of axial holding such as pin crimping, screw fastening, welding, and bonding may also be used. Furthermore, the axial holders 331 do not have to be equally spaced in the circumferential direction for half the number of magnetic poles, and can be arranged in multiple locations for structural strength and magnetic circuit configuration.

[0045] Embodiment 5. Embodiment 5 of the present application will be described with reference to Figures 11 and 12, in which the same or equivalent members and parts are denoted by the same reference numerals in the figures. Figure 11 is a cross-sectional view showing the circumferential direction of the rotation axis of the rotor in the rotating electric machine according to Embodiment 5. Figure 12 is an enlarged cross-sectional view of the main part of Figure 11 in the rotating electric machine according to Embodiment 5.

[0046] Figures 11 and 12 show a rotor structure 800 in which a rotor 300 is arranged on a rotating holder 400. The rotor structure according to this embodiment 5 consists of a rotation axis radial V-crimp core 811, a rotation axis radial V-crimp 361 as an axial holder, a permanent magnet 321, and a rotation-holding outer cylinder portion 410 and a rotation-holding inner cylinder portion 420 of the rotation holder 400. As a result, a structure with a relatively thin thickness in the rotation axis radial direction is adopted, similar to the rotor of embodiment 1 described above.

[0047] Furthermore, in this embodiment 5, as an alternative to the configuration in embodiment 1 described above, which includes an axial holder 331 and a recess 351 arranged on the inside in the radial direction of its rotation axis, a configuration is adopted in which rotation axis radial V-crimps 361, which serve as axial holders, are arranged at equal intervals in the circumferential direction at half the number of magnetic poles on the radial inside of the permanent magnet 321, thereby creating a structure in which local stress is less likely to occur in areas with a small thickness in the radial direction of the rotation axis.

[0048] More specifically, as shown in Figures 11 and 12, the rotational axis radial V-crimp core 811 and permanent magnets 321 are arranged at equal intervals in the circumferential direction of the rotational axis, with the polarities of the permanent magnets 321 alternating. The rotational axis radial V-crimps 361 are arranged at equal intervals in the circumferential direction at half the number of magnetic poles, radially inside the permanent magnets 321, and the rotational axis radial V-crimp core 811 is provided with a core fitting portion 340 for circumferential positioning. The rotational axis radial V-crimp 361 has a V-crimp structure that holds the electromagnetic steel sheet in the direction of the rotational axis during punching so that the cross-sectional shape in the circumferential direction of the rotational axis becomes V-shaped when the electromagnetic steel sheet is press-formed.

[0049] Furthermore, the V-shaped crimping 361 in the radial direction of the rotation axis is prone to eddy current loss due to residual stress during punching and a decrease in interlayer insulation. Therefore, to minimize the influence of magnetic properties, it is characterized by being positioned inside the permanent magnet 321 in the radial direction of the rotation axis.

[0050] Furthermore, if the outermost diameter portion 802 of the rotational axis radial V crimping core 811 is φa and the innermost diameter portion 803 of the rotational axis radial V crimping core 811 is φb,

number

[0051] Furthermore, if the diameter 804 of the inner cylindrical part 420 of the rotating holder 400 is defined as φc,

number

[0052] When the rotational axis radial V-crimp core 811 is fitted into the rotating holder 400, if there is a large axial misalignment, a bending moment with the rotational axis radial V-crimp 361 as the pivot point is not generated when the innermost diameter portion 803 of the rotational axis radial V-crimp core 811 is straightened in the direction of the rotation axis within the rotating holder 400.

[0053] The V-shaped crimping 361 in the radial direction of the rotation axis is offset in the radial direction of the rotation axis, which is a feature of this structure in that local stress is less likely to occur in the outermost diameter portion 802 of the V-shaped crimping core 811 and in the area where the thickness in the radial direction of the rotation axis of the permanent magnet 321 is small.

[0054] As shown in the basic configuration of this embodiment 5, the rotor 300 is configured such that the rotation axis radial V crimping 361 is arranged circumferentially at half the number of magnetic poles on the radially inner side of the permanent magnet 321 as an axial holder and suppression structure. This configuration provides a suppression structure that suppresses the bending moment that occurs when the rotation axis radial V crimping core 811 is press-fitted into the rotation holder 400, which is due to the rotor structure having a small radial thickness of the rotor core, with the rotation axis radial V crimping 361 acting as a fulcrum.

[0055] As a result, it becomes possible to suppress the generation of local stress in the area where the outermost diameter portion 802 of the rotational axis radial V-crimp core 811 and the permanent magnet 321 have small thickness in the rotational axis radial direction. Furthermore, when the ratio of the rotational axis radial thickness of the rotational axis radial V-crimp core 811 or the rotational holder 400 to the outer diameter of the outermost diameter portion 802 is 10% or less as described above, the effects of the present invention become even more pronounced as explained above.

[0056] Embodiment 6. Embodiment 6 of the present application will be described with reference to Figures 13 and 14, in which the same or equivalent members and parts are denoted by the same reference numerals in the figures. Figure 13 is a cross-sectional view showing the circumferential direction of the rotation axis of the rotor in the rotating electric machine according to Embodiment 6. Figure 14 is an enlarged cross-sectional view of the main part of Figure 13 in the rotating electric machine according to Embodiment 6.

[0057] Figures 13 and 14 show a rotor structure 900 in which the rotor 300 is arranged on the rotating holder 400. This embodiment 6 is a modification of embodiment 5 described above, and as shown in Figures 13 and 14, it is partially modified from the structure shown in Figures 4 and 5 of embodiment 1 described above, and a rotation axis radial direction V crimping core 811 This is a V-crimp structure 361 with a rotational axis radial direction V-crimp 361 that serves as an axial holder, which is arranged with the direction of the long side rotated 90 degrees in the direction of the rotational axis radial direction.

[0058] Furthermore, the V-shaped crimping 361 in the radial direction of the rotation axis is prone to eddy current loss due to residual stress during punching and a decrease in interlayer insulation. Therefore, to minimize the influence of magnetic properties, it is characterized by being positioned inside the permanent magnet 321 in the radial direction of the rotation axis.

[0059] The core fitting portion 340 of the rotor core 311 and Rotation axis radial direction V crimping 361 The structure is characterized by the relationship θ1≦θ2 when the angle 901 of the rotation axis circumferential position of the component is defined as θ1, and the width angle 911 of the recess 351, which is a suppression component, in the rotation axis circumferential direction is defined as θ2.

[0060] Furthermore, the outermost diameter portion 902 of the rotor core 311 is φa, and the rotor core If the innermost diameter portion 903 of 311 is defined as φb,

number

[0061] Furthermore, if the diameter 904 of the inner cylindrical part 420 of the rotating holder 400 is defined as φc,

number

[0062] When the rotor core 311 and the rotating holder 400 are fitted together, if there is a large misalignment of the shaft, the innermost diameter part of the rotor core 311 will be attached to the rotating holder 400. 903 When straightened in the direction of the rotation axis, no bending moment is generated with the rotation axis radial V-crimp 361 as the pivot point.

[0063] As the rotation axis radial V-crimp 361 shifts in the rotation axis radial direction, the outermost diameter of the rotor core 311 902 Furthermore, it is characterized by a structure that makes it less likely for local stress to occur in areas where the thickness in the radial direction of the rotation axis of the permanent magnet 321 is small.

[0064] By using the rotational axis radial V crimp 361, when the rotor core 311 and the rotating holder 400 are fitted together and there is a large axial misalignment, the innermost diameter portion 903 of the rotor core 311 is straightened in the direction of the rotation axis by the rotating holder 400, and no bending moment is generated with the rotational axis radial V crimp 361 as the pivot point. As the rotational axis radial V crimp 361 shifts in the direction of the rotation axis, the rotor core 311 This design is characterized by its structure, which makes it less likely for localized stress to occur in areas where the thickness in the radial direction of the rotation axis of the outermost diameter 902 and the permanent magnet 321 is small.

[0065] It should be noted that the configurations are not limited to those of the embodiments described above. Similar effects can be obtained by adopting a configuration that has a function to suppress the generation of a bending moment with the axial holder as a fulcrum when the rotor core is press-fitted into the core near the axial holder. For example, it is effective to provide an opening in the core near the axial holder or near the inner diameter of the core and place the opening at an appropriate position that can suppress the bending moment. In particular, it is good to place the opening in the core near the inner diameter of the core at each position that overlaps with the circumferential direction of the axial holder.

[0066] Furthermore, in each embodiment, the permanent magnets 321 constituting the magnetic poles of the rotor were shown as an example of a configuration in which a single flat magnet is arranged in cross-section. However, when applied to a structure in which the thickness of the rotor core in the radial direction is reduced, a pair of flat magnets may be arranged in a straight line parallel to the circumferential direction to constitute each magnetic pole, or a pair of flat magnets may be arranged in a V-shape inclined with respect to the circumferential direction. In either case, the basic effects of the present invention described in each embodiment can be obtained in the same manner.

[0067] Although this application 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 can be applied individually or in various combinations to the embodiments. Accordingly, countless variations not illustrated are conceivable within the scope of the technology disclosed herein. These include, for example, modifications, additions, or omissions of at least one component, as well as the extraction of at least one component and its combination with components of other embodiments. [Industrial applicability]

[0068] This invention is suitable for realizing a rotating electric machine that can reduce stress concentration in the thin-walled portion of the rotor core. [Explanation of Symbols]

[0069] 100 Rotating electric machine, 210 Housing, 211 Frame, 212 End plate, 220 Armature, 221 Coil, 222 Connection plate, 223 Armature core, 224 Bobbin, 300 Rotor, 311 Rotor core, 321 Permanent magnet, 331 Axial retainer, 340 Core fitting section, 351 Recess, 361 Rotating axis radial V-crimp, 370 Round crimp core, 371 Round crimp, 400 Rotating retainer, 401 Knurling, 402 Staking, 410 Rotating retainer outer cylinder, 420 Rotating retainer inner cylinder, 440 Rotating retainer fitting section, 500 Bearing

Claims

1. A rotating electric machine comprising a stator and a rotor disposed from the stator via a magnetic gap, the rotor being composed of a rotor core made of laminated electromagnetic steel sheets and a plurality of permanent magnets arranged at equal intervals in the circumferential direction on the rotor core, The facility includes an axial holder positioned radially inside the permanent magnet and on the rotor core at half the number of magnetic poles of the rotor, a rotational holder configured in a cylindrical shape with the rotor core positioned on the outer cylinder, and a suppression structure that suppresses the bending moment with the axial holder acting as a fulcrum. The rotating electric machine is characterized in that the suppression structure consists of a recess formed on the inner circumference of the rotor core at the position of the axial holder, or the suppression structure consists of a recess formed on the outer cylinder of the rotating holder.

2. The rotating electric machine according to claim 1, characterized in that the axial holders are arranged at equal intervals with half the number of magnetic poles of the rotor.

3. The rotating electric machine according to claim 1, characterized in that the axial holder has a rounded crimp shape.

4. The rotating electric machine according to any one of claims 1 to 3, characterized in that the radial thickness of the rotor core is 10% or less of the outermost diameter of the rotor core.

5. The rotating electric machine according to any one of claims 1 to 3, characterized in that the radial thickness from the outer cylinder portion of the rotating holder to the rotor core is 10% or less of the outermost diameter of the rotor core.

6. The rotating electric machine according to claim 1, characterized in that the circumferential angle of the recess is 360° / number of poles or more.

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