Rotor, motor, and method for manufacturing the rotor

Abstract

The present invention provides a rotor, an electric motor, and a method for manufacturing the rotor. In a rotor (10) of an electric motor or the like, in order to suppress the scattering of a part of a magnet (21) disposed around a rotating shaft (20), the rotor (10) has a cylindrical magnet (21) through which the rotating shaft (20) passes, a first cage (131) covering the magnet (21) from one side (L1) in the axial direction of the rotating shaft (20), and a second cage (136) covering the magnet (21) from the other side (L2) in the axial direction. The magnet (21) is press-fitted into the inside of a first main body portion (134) of the first cage (131) and the inside of a second main body portion (139) of the second cage (136), and a first end portion (132) of the first main body portion (134) and a second end portion (137) of the second main body portion (139) are joined by welding or the like. The inner diameter of the first end portion (132) and the inner diameter of the second end portion (137) are larger than the outer diameter of the magnet (21).

Description

Technical Field

[0001] The present invention relates to a rotor, an electric motor, and a method for manufacturing a rotor. Background Art

[0002] An inner-rotor type electric motor includes: a rotor, and a stator disposed on the outer peripheral side of the rotor; the rotor includes: a magnet held on the outer peripheral surface of a rotating shaft (see Patent Document 1). Here, when the rotor rotates, the exfoliated powder of the magnet may scatter. Thus, a structure in which a non-magnetic pipe is fitted on the outside of the magnet has been proposed.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 5-146102 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] However, there is a problem that it is not easy to fit a pipe around a permanent magnet extending in the axial direction.

[0008] In view of the above problems, an object of the present invention is to provide a rotor, an electric motor, and a method for manufacturing a rotor, which have a structure suitable for suppressing the scattering of a part of a magnet provided around a rotating shaft.

[0009] Technical Solution for Solving the Technical Problem

[0010] To solve the above technical problem, an embodiment of the rotor of the present invention includes: a rotating shaft; a cylindrical magnet provided with a through-hole through which the rotating shaft passes; a first cage including: a circular first bottom plate portion covering the magnet from one side in the axial direction of the rotating shaft, and a cylindrical first main body portion protruding from the first bottom plate portion to the other side in the axial direction and covering a first part of the outer peripheral surface of the magnet; and a second cage including: a circular second bottom plate portion covering the magnet from the other side, and a cylindrical second main body portion protruding from the second bottom plate portion to the one side and covering a second part of the outer peripheral surface of the magnet, wherein the magnet is press-fitted into the inside of the first main body portion and the inside of the second main body portion, an end portion on the other side of the first main body portion, i.e., a first end portion, and an end portion on the one side of the second main body portion, i.e., a second end portion, are joined, and the inner diameter of the first end portion and the inner diameter of the second end portion are larger than the outer diameter of the magnet.

[0011] In the rotor of the present invention, there are provided: a first cage that covers a first part on one side in the axial direction of the outer peripheral surface of the magnet, and a second cage that covers a second part on the other side in the axial direction of the outer peripheral surface of the magnet. Therefore, when the rotor rotates at a high speed, even if the magnet is damaged, it is possible to suppress the scattering of debris (a part of the magnet) by the first cage and the second cage. In addition, since the magnet is covered by the first cage and the second cage, it is easier to cover the magnet compared to the case where the magnet is covered by a single pipe. Further, although the magnet is press-fitted into the first main body portion of the first cage and the second main body portion of the second cage, since the inner diameter of the first end portion of the first main body portion and the inner diameter of the second end portion of the second main body portion are larger than the outer diameter of the magnet, the press-fitting is easy, and the joining of the first end portion and the second end portion is easy.

[0012] In the rotor of the present invention, the following embodiment can be adopted. The first end portion includes: a first flange portion that bends radially outward from the first main body portion; the second end portion includes: a second flange portion that bends radially outward from the second main body portion, and the first flange portion and the second flange portion are joined. According to the embodiment, the first cage and the second cage can be manufactured by stamping, and the joining of the first end portion and the second end portion is easy.

[0013] In the rotor of the present invention, the following embodiment can be adopted. The first flange portion and the second flange portion are joined by welding over the entire circumference. According to the embodiment, it is not easy to generate a gap between the first flange portion and the second flange portion, and therefore, it is possible to suppress the scattering of the exfoliated powder (a part of the magnet) generated when the magnet is press-fitted into the first cage and the second cage.

[0014] In the rotor of the present invention, the following embodiment can be adopted. The first main body portion and the second main body portion bend radially inward in the middle portion in the axial direction. When a structure is set in which a load in a direction in which the first main body portion and the second main body portion approach each other in the axial direction is applied to reduce the gap between the first flange portion and the second flange portion, thereby facilitating the welding of the first flange portion and the second flange portion, the first main body portion and the second main body portion sometimes bend radially inward in the middle portion in the axial direction. According to the embodiment, the first cage and the second cage can hold the magnet more reliably.

[0015] In the rotor of the present invention, the following embodiment can be adopted. The gap between the first flange portion and the second flange portion is filled with a molten portion during welding. According to the embodiment, it is not easy to generate a gap between the first flange portion and the second flange portion, and therefore, it is possible to suppress the scattering of the powder exfoliated from the magnet.

[0016] In the rotor of the present invention, the following embodiments can be adopted. A circular first support plate that overlaps with the first cage from one side and a circular second support plate that overlaps with the second cage from the other side are fixed to the rotating shaft. According to this embodiment, the first cage and the second cage can be fixed to the rotating shaft through the first support plate and the second support plate. Therefore, the thicknesses of the first bottom plate portion of the first cage and the second bottom plate portion of the second cage can be thin. In addition, the rotational balance of the rotor can be adjusted by processing the first support plate and the second support plate, etc.

[0017] In the rotor of the present invention, the following embodiments can be adopted. The first bottom plate portion is joined to the first support plate, and the second bottom plate portion is joined to the second support plate.

[0018] Another embodiment of the rotor of the present invention can be as follows. It includes: a rotating shaft; a cylindrical magnet provided with a through hole through which the rotating shaft passes; a first cage having a circular first bottom plate portion that covers the magnet from one side in the axial direction of the rotating shaft and a cylindrical first main body portion that protrudes from the first bottom plate portion to the other side in the axial direction and covers the outer peripheral surface of the magnet; and a circular second cage that covers the magnet from the other side. Among them, the magnet is press-fitted into the inside of the first main body portion, and the first end portion, which is the end portion on the other side of the first main body portion, is joined to the second cage, and the inner diameter of the first end portion is larger than the outer diameter of the magnet.

[0019] In the rotor of the present invention, the following embodiments can be adopted. The first end portion has a first flange portion that bends radially outward from the first main body portion, and the first flange portion is joined to the second cage.

[0020] In the rotor of the present invention, the following embodiments can be adopted. The first flange portion elastically deforms toward the one side by abutting against the second cage.

[0021] In the rotor of the present invention, the following embodiments can be adopted. The first flange portion abuts against the second cage in the middle part in the radial direction; the portion of the first flange portion that is radially outside the middle part warps toward the one side.

[0022] In the rotor of the present invention, the following embodiments can be adopted. The first bottom plate portion has a circular region located on the center side in the radial direction and an annular region that connects the circular region and the first main body portion. The circular region is located on the side opposite to the second cage with respect to the annular region.

[0023] In the rotor of the present invention, the following implementation manner can be adopted, and a stepped portion is provided between the circular region and the annular region.

[0024] In the rotor of the present invention, the following implementation manner can be adopted, and the first annular region is an inclined surface inclined with respect to the first circular region.

[0025] In the rotor of the present invention, the following implementation manner can be adopted, and the magnet is a sintered magnet. In the present invention, the exfoliated powder of the magnet is not likely to scatter, and thus high reliability can be obtained even when a sintered magnet is used.

[0026] The rotor of the present invention and the stator opposed to the rotor are used together for an electric motor.

[0027] The present invention provides a method for manufacturing a rotor, the rotor including: a rotating shaft; a cylindrical magnet provided with a through hole through which the rotating shaft passes; a first cage including: an annular first bottom plate portion covering the magnet from one side in the axial direction of the rotating shaft, and a cylindrical first main body portion protruding from the first bottom plate portion to the other side in the axial direction and covering a first part of the outer peripheral surface of the magnet; and a second cage including: an annular second bottom plate portion covering the magnet from the other side, and a cylindrical second main body portion protruding from the second bottom plate portion to the one side and covering a second part of the outer peripheral surface of the magnet. In the method for manufacturing the rotor, the inner diameters of the first main body portion and the second main body portion are smaller than the outer diameter of the magnet in at least a part in the axial direction, and the inner diameters of the first end portion, which is the end portion on the other side of the first main body portion, and the second end portion, which is the end portion on the one side of the second main body portion, are larger than the outer diameter of the magnet. The method for manufacturing the rotor includes: a first step of fixing the first cage to the rotating shaft; a second step of pressing the first part of the magnet into the inside of the first main body portion; a third step of fixing the second cage to the rotating shaft in such a manner that the second part of the magnet is pressed into the inside of the second main body portion; and a fourth step of joining the first end portion and the second end portion.

[0028] In the method for manufacturing a rotor of the present invention, there are provided: a first cage that covers a first part on one side in the axial direction of the outer peripheral surface of the magnet, and a second cage that covers a second part on the other side in the axial direction of the outer peripheral surface of the magnet. Therefore, when the rotor rotates at high speed, it is possible to suppress the scattering of a part of the magnet, such as fragments or exfoliated powder of the magnet, by the first cage and the second cage. In addition, since the magnet is covered by the first cage and the second cage, it is easier to cover the magnet than in the case where the magnet is covered by a single pipe. Further, although the magnet is press-fitted into the first main body portion of the first cage and the second main body portion of the second cage, since the inner diameter of the first end portion of the first main body portion and the inner diameter of the second end portion of the second main body portion are larger than the outer diameter of the magnet, the press-fitting is easy and the joining of the first end portion and the second end portion is easy.

[0029] In the method for manufacturing a rotor of the present invention, the following embodiment can be adopted. The first end portion includes: a first flange portion that bends radially outward from the first main body portion. The second end portion includes: a second flange portion that bends radially outward from the second main body portion. In the fourth step, the first flange portion and the second flange portion are joined. According to the embodiment, the first cage and the second cage can be manufactured by stamping, and the joining of the first end portion and the second end portion is easy.

[0030] In the method for manufacturing a rotor of the present invention, the following embodiment can be adopted. In the fourth step, the first flange portion and the second flange portion are joined by welding over the entire circumference. According to the embodiment, it is difficult to generate a gap between the first flange portion and the second flange portion, and therefore, it is possible to suppress the scattering of exfoliated powder (a part of the magnet) generated when the magnet is press-fitted into the first cage and the second cage.

[0031] In the method for manufacturing a rotor of the present invention, the following embodiment can be adopted. In the fourth step, a laser beam is irradiated from a direction inclined with respect to the axial direction, and the first flange portion and the second flange portion are joined by laser welding. According to the embodiment, it is difficult for the laser beam to enter the inside between the first flange portion and the second flange portion, and therefore, it is possible to suppress the deterioration of the magnet.

[0032] In the method for manufacturing a rotor of the present invention, the following embodiment can be adopted. After the third step and before the fourth step, a load in a direction in which the first main body portion and the second main body portion approach each other in the axial direction is applied to reduce the gap between the first flange portion and the second flange portion. According to the embodiment, the joining of the first flange portion and the second flange portion is easy.

[0033] In the method for manufacturing the rotor of the present invention, the following embodiment can be adopted. In the fourth process, the first flange portion and the second flange portion are melted to fill the gap between the first flange portion and the second flange portion. According to this embodiment, when the fourth process is performed, even if there is a gap between the first flange portion and the second flange portion, the gap can be filled by welding.

[0034] In the method for manufacturing the rotor of the present invention, the following embodiment can be adopted. When the fourth process is performed, the gap between the first flange portion and the second flange portion is narrower than the protruding dimension of the first flange portion radially outward from the first main body portion and the protruding dimension of the second flange portion radially outward from the second main body portion. According to this embodiment, it is easy to melt the first flange portion and the second flange portion to fill the gap between the first flange portion and the second flange portion.

[0035] In the method for manufacturing the rotor of the present invention, the following embodiment can be adopted. When the fourth process is performed, the gap between the first flange portion and the second flange portion is narrower than the thickness of the first flange portion and the thickness of the second flange portion. According to this embodiment, it is easy to melt the first flange portion and the second flange portion to fill the gap between the first flange portion and the second flange portion.

[0036] In the method for manufacturing the rotor of the present invention, the following embodiment can be adopted. In the first process, the first cage is fixed to the rotating shaft by fixing a circular first support plate that overlaps the first cage from one side to the rotating shaft. In the third process, the second cage is fixed to the rotating shaft by fixing a circular second support plate that overlaps the second cage from the other side to the rotating shaft. According to this embodiment, the first cage and the second cage can be fixed to the rotating shaft by the first support plate and the second support plate. Therefore, the thicknesses of the first bottom plate portion of the first cage and the second bottom plate portion of the second cage can be thinner. In addition, the rotational balance of the rotor can be adjusted by processing the first support plate and the second support plate, etc.

[0037] In the method for manufacturing the rotor of the present invention, the following embodiment can be adopted. The first process is performed in a state where the first support plate is joined to the first bottom plate portion, and the third process is performed in a state where the second support plate is joined to the second bottom plate portion.

[0038] In the method for manufacturing the rotor of the present invention, the following embodiment can be adopted. By applying a load in the direction in which the first main body portion and the second main body portion approach each other in the axial direction, the first flange portion and the second flange portion are elastically deformed, and the first flange portion and the second flange portion are brought into contact with each other over the entire circumference.

[0039] In the method for manufacturing the rotor of the present invention, the following embodiment can be adopted. When a load is applied in the direction in which the first main body portion and the second main body portion approach each other in the axial direction, the distance between the first bottom plate portion and the second bottom plate portion is reduced to a target value. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 FIG. is a perspective view of a main part of a motor according to an embodiment of the present invention as viewed from the output side.

[0041] Figure 2 is Figure 1 a cross-sectional view of the main part of the motor shown.

[0042] Figure 3 is a view from the output side looking at Figure 2 a perspective view of the rotor shown.

[0043] Figure 4 is a cross-sectional view taken along the axis when cutting Figure 3 the rotor shown.

[0044] Figure 5 is a view from Figure 3 a state diagram showing the state where the first support plate, the second support plate, and the second cage are removed from the state shown.

[0045] Figure 6 is a cross-sectional view taken along a direction orthogonal to the axis when cutting through the rotor at the position of the magnet shown in Figure 3 FIG.

[0046] Figure 7 is a schematic view showing Figure 5 the shape and the like of the through-hole of the magnet in the rotor shown in FIG.

[0047] Figure 8 is a schematic view showing Figure 5 the position and the like of the through-hole of the magnet in the rotor shown in FIG.

[0048] Figure 9 is an explanatory view of the rotor of Modification Example 1 of the embodiment of the present invention.

[0049] Figure 10 is an explanatory view of the rotor of Modification Example 2 of the embodiment of the present invention.

[0050] Figure 11 It is an explanatory view of the rotor of Modified Example 3 of the embodiment of the present invention.

[0051] Figure 12 It is an explanatory view of the rotor of Modified Example 4 of the embodiment of the present invention.

[0052] Figure 13 It is an explanatory view of the rotor of another embodiment of the present invention. Detailed Embodiment

[0053] The motor 2 of the embodiment of the present invention will be described with reference to the accompanying drawings. In this specification, the symbol L represents the axial direction of the motor 2 (the axial direction of the rotating shaft 20). In the embodiments described below, one side L1 in the direction in which the axis L extends (axis L direction) is the output side where the rotating shaft 20 protrudes from the stator 5, and the other side L2 is the output opposite side opposite to the side where the rotating shaft 20 protrudes from the stator 5. In addition, the direction orthogonal to the axis L is defined as the radial direction, and the periphery of the axis L is defined as the circumferential direction.

[0054] (Overall Structure of Motor 2)

[0055] Figure 1 It is a perspective view of the main part of the motor 2 of the embodiment of the present invention as viewed from the output side. Figure 2 It is Figure 1 A cross-sectional view of the main part of the motor 2 shown. Figure 1 And Figure 2 The motor 2 shown is a three-phase DC brushless motor, which has a rotor 10 and a stator 5 disposed on the outer peripheral side of the rotor 10. The motor 2 is used for a pump or the like in a state where the stator 5 is covered with a housing (not shown).

[0056] A first bearing member 15 is held on the housing. The first bearing member 15 supports the vicinity of the end of the rotating shaft 20 of the rotor 10 on the output opposite side (the other side L2 in the axis L direction) so as to be rotatable. In addition, a second bearing member 16 is held on the housing. The second bearing member 16 supports the middle part of the rotating shaft 20 in the axis L direction so as to be rotatable. The first bearing member 15 is annular and abuts against the stepped portion 201 of the rotating shaft 20 from the output side (one side L1 in the axis L direction). Therefore, the movement of the rotating shaft 20 toward the output side is restricted by the first housing via the bearing member 15. The end of the output side of the rotating shaft 20 protrudes from the housing.

[0057] The first bearing member 15 is a cylindrical ball bearing. The outer ring of the first bearing member 15 is supported by the housing via a cylindrical cage 19. The space between the cage 19 and the housing is sealed by an annular sealing member 14. On the output opposite side with respect to the first bearing member 15, a cup-shaped cage 18 is held by the housing, and a cage 17 is disposed inside the cage 18. Inside the cage 17, a compression coil spring 181 is disposed between the inner ring of the first bearing member 15 and the bottom of the cage 18. The inner ring of the first bearing member 15 is supported from the output opposite side by the compression coil spring 181. A spacer 182 is disposed between the inner ring of the first bearing member 15 and the compression coil spring 181.

[0058] The stator 5 has a stator core 50 made of a magnetic material, an insulator 6 made of an insulating resin or the like covering the stator core 50, and a wire 4 for forming a coil. The stator core 50 is a laminated core formed by laminating thin magnetic plates. Omitting detailed description, the stator core 50 includes a cylindrical core main body 51 and a plurality of salient poles 52 protruding radially inward from the core main body 51. The plurality of salient poles 52 are arranged at equal angular intervals around the axis L. The stator core 50 is covered by the insulator 6 by insert molding. However, the end faces on the radially inner side of the salient poles 52 are exposed from the insulator 6. The insulator 6 has a winding portion 65 covering the periphery of the salient poles 52, and the wire 4 is wound around the periphery of the salient poles 52 via the winding portion 65 to form coils 40 for each phase (U phase, V phase, and W phase).

[0059] (Rotor 10)

[0060] Figure 3 is a perspective view of the rotor 10 as viewed from one side L1 in the direction of the axis L Figure 2 as shown. Figure 4 is a cross-sectional view of the rotor 10 when cut along the axis L Figure 3 as shown. Figure 5 is Figure 3 a disassembled perspective view of the rotor 10 as shown.

[0061] As Figure 3 , Figure 4 and Figure 5 shown, the rotor 10 includes a rotating shaft 20, a magnet 21 disposed on the outer peripheral surface of the rotating shaft 20, and a magnet holder 13 fixed to the rotating shaft 20 so as to cover the outer peripheral surface of the magnet 21. The magnet 21 is cylindrical with a through hole 210 formed therein through which the rotating shaft 20 passes, and is coaxially disposed with the rotating shaft 20. The magnet holder 13 fixes the magnet 21 to the rotating shaft 20 and prevents the magnet 21 from being damaged and flying off when the rotor 10 rotates.

[0062] On the outer peripheral surface 215 of the magnet 21, N poles and S poles are alternately magnetized in the circumferential direction. In this embodiment, the magnet 21 is an anisotropic magnet, which is a sintered magnet obtained by molding ferromagnetic powder, alnico powder, or rare earth-based magnetic powder into a cylindrical shape under a magnetic field. A chamfered portion formed by an inclined surface 218 is provided between the outer peripheral surface 215 of the magnet 21 and the first end surface 213 on one side L1, and a chamfered portion formed by an inclined surface 219 is provided between the outer peripheral surface 215 of the magnet 21 and the second end surface 214 on the other side L2. The outer peripheral surface 205 of the rotating shaft 20 is a rod-shaped member with a perfect circular cross-section, and is made of, for example, stainless steel. The magnet holder 13 is made of a metal member such as stainless steel.

[0063] The magnet holder 13 is composed of a cup-shaped first holder 131 that covers the magnet 21 from one side L1 (output side) in the axial direction L of the rotating shaft 20 and a cup-shaped second holder 136 that covers the magnet 21 from the other side L2 (anti-output side) in the axial direction L. The first holder 131 covers the first portion 216 on one side L1 of the outer peripheral surface 215 of the magnet 21, and the second holder 136 covers the second portion 217 on the other side L2 of the outer peripheral surface 215 of the magnet 21.

[0064] The magnet holder 13 has a structure in which parts of the same shape are arranged in opposite directions in the axial direction L to form the first holder 131 and the second holder 136. More specifically, the first holder 131 has an annular first bottom plate portion 133 formed with a shaft hole 133a into which the rotating shaft 20 is press-fitted, and a cylindrical first main body portion 134 extending from the outer edge of the first bottom plate portion 133 to the other side L2. The first bottom plate portion 133 covers the magnet 21 from one side L1, and the first main body portion 134 covers the first portion 216 from the radially outer side. The second holder 136 has an annular second bottom plate portion 138 formed with a shaft hole 138a into which the rotating shaft 20 is press-fitted, and a cylindrical second main body portion 139 extending from the outer edge of the second bottom plate portion 138 to one side L1. The second bottom plate portion 138 covers the magnet 21 from the other side L2, and the second main body portion 139 covers the second portion 217 from the radially outer side.

[0065] The end portion on the other side L2 of the first main body portion 134 of the first holder 131, i.e., the first end portion 132, and the end portion on one side L1 of the second main body portion 139 of the second holder 136, i.e., the second end portion 137, are joined. In this embodiment, the first end portion 132 and the second end portion 137 are joined by welding over the entire circumference.

[0066] On the rotating shaft 20, a first support plate 11 is fixed to one side L1 with respect to the first cage 131, and a second support plate 12 is fixed to the other side L2 with respect to the second cage 136. Shaft holes 111 and 121 for fitting the rotating shaft 20 by press-fitting are formed in the first support plate 11 and the second support plate 12. The first support plate 11 and the second support plate 12 are made of metal components such as stainless steel. The first support plate 11 supports the first cage 131 from one side L1 in the direction of the axis L, and the second support plate 12 supports the second cage 136 from the other side L2 in the direction of the axis L. Therefore, the thicknesses of the first bottom plate portion 133 of the first cage 131 and the second bottom plate portion 138 of the second cage 136 can be made thinner. In addition, the rotational balance of the rotor 10 can be adjusted by processing the first support plate 11 and the second support plate 12, etc.

[0067] In this embodiment, the first bottom plate portion 133 of the first cage 131 and the first support plate 11 are joined by welding at a plurality of portions 133c as shown in Figure 5 The second bottom plate portion 138 of the second cage 136 and the second support plate 12 are joined by welding at a plurality of portions in the same manner as the joining of the first bottom plate portion 133 of the first cage 131 and the first support plate 11.

[0068] In the motor 2 configured in this way, the inner diameter of the magnet 21 is larger than the outer diameter of the rotating shaft 20 Therefore, a gap G1 is provided between the inner peripheral surface 211 of the magnet 21 and the outer peripheral surface of the rotating shaft 20. In addition, a gap G5 is provided between the first end surface 213 of the magnet 21 and the first bottom plate portion 133, and a gap G7 is provided between the second end surface 214 of the magnet 21 and the second bottom plate portion 138. Therefore, the load applied to the magnet 21 from the rotating shaft 20 can be reduced. Therefore, deformation and damage of the magnet 21 can be suppressed.

[0069] (Detailed structure of the magnet cage 13, etc.)

[0070] In the rotor 10, in a state before the magnet 21 is disposed inside, the outer diameter of the magnet 21 is larger than the inner diameter of the first main body portion 134 and the inner diameter of the second main body portion 139 Therefore, the magnet 21 is fixed inside the first main body portion 134 and inside the second main body portion 139 by press-fitting. On the contrary, the inner diameter of the first end portion 132 and the inner diameter of the second end portion are larger than the outer diameter of the magnet 21 Therefore, gaps are formed between the first end portion 132 and the magnet 21 and between the second end portion 137 and the magnet 21.

[0071] In this method, the first end portion 132 has a first flange portion 132a that bends radially outward from the first main body portion 134, and the second end portion 137 has a second flange portion 137a that bends radially outward from the second main body portion 139. The first flange portion 132a and the second flange portion 137a are joined. The first cage 131 and the second cage 136 are each manufactured by stamping. Therefore, the first flange portion 132a is the portion that bends radially outward from the first main body portion 134, and the second flange portion 137a is the portion that bends radially outward from the second main body portion 139.

[0072] The first bending portion 133b between the first bottom plate portion 133 and the first main body portion 134 and the second bending portion 138b between the second bottom plate portion 138 and the second main body portion 139 are bent. In contrast, a chamfered portion formed by an inclined surface 218 is provided between the outer peripheral surface 215 of the magnet 21 and the first end surface 213 on one side L1, and a chamfered portion formed by an inclined surface 219 is provided between the outer peripheral surface 215 and the second end surface 214 on the other side L2. Therefore, a gap exists between the first bending portion 133b of the first cage 131 and the inclined surface 218 of the magnet 21, and a gap exists between the second bending portion 138b of the second cage 136 and the inclined surface 219 of the magnet 21.

[0073] (Manufacturing method of the rotor 10)

[0074] Figure 6 is an explanatory diagram showing Figure 3 the manufacturing method of the rotor 10 shown. In addition, Figure 6 shows a situation where the first cage 131 is arranged on the lower side, contrary to Figure 4 etc. When manufacturing the rotor 10, the inner diameter of the first main body portion 134 of the first cage 131 and the inner diameter of the second main body portion 139 of the second cage 136 are made smaller than the outer diameter of the magnet 21 in at least a part in the axial direction of the axis L The inner diameter of the first end portion 132 of the first cage 131 and the inner diameter of the second end portion 137 of the second cage 136 are made larger than the outer diameter of the magnet 21

[0075] In this method, first, in the Figure 6 shown previous process ST0, the first bottom plate portion 133 of the first cage 131 is joined to the first support plate 11 by welding at multiple locations, and the second bottom plate portion 138 of the second cage 136 is joined to the second support plate 12 by welding at multiple locations.

[0076] Next, in the first process ST1, the first cage 131 is fixed to the rotating shaft 20. More specifically, in the first process ST1, the annular first support plate 11 that overlaps the first cage 131 from one side L1 is fixed to the rotating shaft 20 by press-fitting, whereby the first cage 131 is fixed to the rotating shaft 20. In this mode, the first process ST1 is performed in a state where the first support plate 11 is joined to the first bottom plate portion 133.

[0077] Next, in the second process ST2, the first part of the magnet 21 is press-fitted into the inside of the first main body portion 134 of the first cage 131.

[0078] Next, in the third process ST3, the second cage 136 is fixed to the rotating shaft 20 in such a manner that the second part 217 of the magnet 21 is press-fitted into the inside of the second main body portion 139 of the second cage 136. More specifically, in the third process ST3, the second cage 136 is fixed to the rotating shaft 20 by fixing the annular second support plate 12 that overlaps the second cage 136 from the other side L2 to the rotating shaft 20. In this mode, the third process ST3 is performed in a state where the second support plate 12 is joined to the second bottom plate portion 138.

[0079] Next, in the fourth process ST4, the first flange portion 132a (first end portion 132) of the first cage 131 and the second flange portion 137a (second end portion 137) of the second cage 136 are joined by welding. In this mode, a laser beam La is irradiated from a direction inclined with respect to the axis L direction, and the first flange portion 132a and the second flange portion 137a are joined by laser welding.

[0080] (First example of control of the gap G3)

[0081] Figure 7 It is an explanatory diagram showing the state of the first flange portion 132a and the second flange portion 137a when performing the Figure 6 shown fourth process ST4. In the fourth process ST4 shown in Figure 6 , when welding the first flange portion 132a and the second flange portion 137a, if there is a large gap G3 between the first flange portion 132a and the second flange portion 137a, the gap cannot be filled by welding. Therefore, before the fourth process ST4 after the third process ST3, a load is applied in a direction in which the first main body portion 134 and the second main body portion 139 approach each other. More specifically, a load is applied in a direction in which the first main body portion 134 and the second main body portion 139 approach each other via the first support plate 11 and the second support plate 12, and the gap G3 between the first flange portion 132a and the second flange portion 137a is reduced. In this case, as Figure 7As schematically shown by the single-dot dash lines L134 and L139, the first main body portion 134 and the second main body portion 139 are bent toward the radially inner side in the middle portion in the direction of the axis L.

[0082] (Second Example of Control of Clearance G3)

[0083] Figure 8 It represents the progress of Figure 6 An explanatory diagram showing the state of the first flange portion 132a and the second flange portion 137a during the fourth process ST4 shown. In Figure 6 In the fourth process ST4 shown, when welding the first flange portion 132a and the second flange portion 137a, if there is a large clearance G3 between the first flange portion 132a and the second flange portion 137a, the clearance cannot be filled by welding. On the other hand, even if a load in the direction in which the first main body portion 134 and the second main body portion 139 approach each other is applied via the first support plate 11 and the second support plate 12, due to the frictional force between the first support plate 11 and the rotating shaft 20 and the frictional force between the second support plate 12 and the rotating shaft 20, the first cage 131 and the second cage 136 do not move, and the clearance G3 cannot be reduced.

[0084] Therefore, manage the tolerances of each part, etc., and in each process described with reference to Figure 6 Manage the position when pressing in each component, and reduce the clearance G3 between the first flange portion 132a and the second flange portion 137a during the fourth process ST4. For example, make the clearance G3 narrower than the protruding dimension d132 of the first flange portion 132a from the first main body portion 134 of the first cage 131 toward the radially outer side and the protruding dimension d137 of the second flange portion 137a from the second main body portion 139 of the second cage 136 toward the radially outer side. In addition, the clearance G3 is narrower than the thickness t132 of the first flange portion 132a and the thickness t137 of the second flange portion 137a. For example, since the protruding dimensions d132 and d137 are 0.5 mm, the clearance G3 is set to 0.05 mm or less.

[0085] Then, in the fourth process ST4, when laser welding the first flange portion 132a and the second flange portion 137a, the first flange portion 132a and the second flange portion 137a are melted, and the clearance G3 is filled by the melted portion. Therefore, the first flange portion 132a and the second flange portion 137a are melted more than the amount required for joining. However, the remaining portion that overflows from the clearance G3 in the melted portion flows into the clearance between the first flange portion 132a and the magnet 21 and the clearance between the second flange portion 137a, so it does not flow out to the outside.

[0086] (Main Effects of This Method)

[0087] As described above, the motor 2 and the rotor 10 of the present embodiment are provided with a first cage 131 that covers the first portion 216 on one side L1 in the axial direction L of the outer peripheral surface 215 of the magnet 21 and a second cage 136 that covers the second portion 217 on the other side L2 in the axial direction L of the outer peripheral surface 215 of the magnet 21. Therefore, when the rotor 10 rotates at high speed, even if the magnet 21 is damaged, it is possible to suppress the scattering of debris (a part of the magnet 21) by the first cage 131 and the second cage 136. In addition, since the magnet 21 is covered by the first cage 131 and the second cage 136, it is easier to cover the magnet 21 than in the case of covering the magnet with a single pipe. In addition, although the magnet 21 is press-fitted into the first main body portion 134 of the first cage 131 and the second main body portion 139 of the second cage 136, since the inner diameter of the first end portion 132 of the first main body portion 134 and the inner diameter of the second end portion 137 of the second main body portion 139 are larger than the outer diameter of the magnet 21, the press-fitting is easy, and the joining of the first end portion 132 and the second end portion 137 is easy.

[0088] In addition, the first end portion 132 is provided with a first flange portion 132a that bends radially outward from the first main body portion 134, and the second end portion 137 is provided with a second flange portion 137a that bends radially outward from the second main body portion 139, and the first flange portion 132a and the second flange portion 137a are joined. Therefore, the first cage 131 and the second cage 136 can be manufactured by stamping, and the joining of the first end portion 132 and the second end portion 137 is easy.

[0089] In addition, since the first flange portion 132a and the second flange portion 137a are joined by welding over the entire circumference, it is difficult to generate a gap between the first flange portion 132a and the second flange portion 137a. Therefore, it is possible to suppress the scattering of the exfoliated powder (a part of the magnet 21) generated when the magnet 21 is press-fitted into the first cage 131 and the second cage 136. Therefore, it is possible to suppress the exfoliated powder from entering the bearings of the motor, etc.

[0090] [Modified Example 1 of the Embodiment of the Present Invention]

[0091] Figure 9 is an explanatory view of the rotor of Modified Example 1 of the embodiment of the present invention. In Figure 9 , the state (a) before the first cage 131 and the second cage 136 are abutted and the state (b) after the first cage 131 and the second cage 136 are firmly abutted are shown enlarged. In addition, since the basic structure of this example is the same as the embodiment described with reference to Figures 1 to 8 , the same reference numerals are given to the common parts and the description thereof is omitted.

[0092] As Figure 9 shown, in the state (a) before the first cage 131 and the second cage 136 are brought into contact with each other, the first flange portion 132a of the first cage 131 and the second flange portion 137a of the second cage 136 are respectively bent from the first main body portion 134 and the second main body portion 139 with a large radius of curvature. For example, when the radius of curvature of the first flange portion 132a and the second flange portion 137a is set to 0.5 mm, the elasticity of the first flange portion 132a and the second flange portion 137a is insufficient. Therefore, in this embodiment, the radius of curvature of the first flange portion 132a and the second flange portion 137a is increased to 0.75 mm.

[0093] Therefore, the first flange portion 132a and the second flange portion 137a respectively have an elasticity capable of elastically deforming in a direction of separating from each other. Therefore, even when there are deviations in the shape accuracy etc. of the first flange portion 132a and the second flange portion 137a in the circumferential direction, as Figure 6 shown, in the state (b) where after the first flange portion 132a and the second flange portion 137a are brought into contact with each other by applying a load for the first main body portion 134 and the second main body portion 139 to approach in the axial direction L and then further pressed in by 0.2 mm, the first flange portion 132a and the second flange portion 137a elastically deform, and on the entire circumference, the first flange portion 132a and the second flange portion 137a are in contact with each other.

[0094] For example, the middle portion 132b in the radial direction of the first flange portion 132a comes into contact with the second flange portion 137a of the second cage 136, and the front end portion 132c of the first flange portion 132a on the radially outer side of the middle portion 132b is in a warped state toward the side L1 in the axial direction L. In addition, the middle portion 137b in the radial direction of the second flange portion 137a comes into contact with the first flange portion 132a of the first cage 131, and the front end portion 137c of the second flange portion 137a on the radially outer side of the middle portion 137b is in a warped state toward the other side L2 in the axial direction L. Therefore, regardless of whether the middle portion in the axial direction L of the first main body portion 134 and the second main body portion 139 bends toward the radially inner side due to the load in the axial direction L (refer to Figure 7 ), on the entire circumference, the first flange portion 132a and the second flange portion 137a are in a state of being in contact with each other, so joining by welding etc. is easy.

[0095] In addition, when applying a load in the direction of the first main body portion 134 and the second main body portion 139 approaching in the axial direction L, Figure 4The distance between the first bottom plate portion 133 and the second bottom plate portion 138 shown is reduced to a target value, so that the first flange portion 132a and the second flange portion 137a can be brought into contact with each other over the entire circumference. In this mode, as described with reference to Figure 6 The first bottom plate portion 133 of the first cage 131 is fixed to the first support plate 11 and the second bottom plate portion 138 of the second cage 136 is fixed to the second support plate 12. Therefore, when a load is applied in the direction in which the first main body portion 134 and the second main body portion 139 approach each other in the axial direction of the axis L, by reducing the distance between the first support plate 11 and the second support plate 12 to the target value, the first flange portion 132a and the second flange portion 137a can be brought into contact with each other over the entire circumference.

[0096] [Modification Example 2 of the Embodiment of the Present Invention]

[0097] Figure 10 is an explanatory view of the rotor of Modification Example 1 of the embodiment of the present invention. In Figure 10 , the state (a) before the first cage 131 and the second cage 136 are brought into contact with each other and the state (b) after the first cage 131 and the second cage 136 are firmly brought into contact with each other are shown in an enlarged manner. In addition, since the basic structure of this example is the same as the mode described with reference to Figures 1 to 8 , the same reference numerals are given to the common parts and the description thereof is omitted.

[0098] As Figure 10 shown, in the state (a) before the first cage 131 and the second cage 136 are brought into contact with each other, the first flange portion 132a of the first cage 131 and the second flange portion 137a of the second cage 136 are respectively bent to form a large angle with respect to the first main body portion 134 and the second main body portion 139. For example, the first flange portion 132a and the second flange portion 137a are bent to form an angle of 45° or more and less than 90° with respect to the first main body portion 134 and the second main body portion 139.

[0099] Therefore, the first flange portion 132a and the second flange portion 137a respectively have elasticity that can be elastically deformed in the direction of separating from each other. Therefore, even when there are deviations in the shape accuracy and the like of the first flange portion 132a and the second flange portion 137a in the circumferential direction, as Figure 6 shown, in the state (b) where a load is applied in the direction in which the first main body portion 134 and the second main body portion 139 approach each other in the axial direction of the axis L to bring the first flange portion 132a and the second flange portion 137a into contact with each other and then further press-fitted by 0.2 mm, the first flange portion 132a and the second flange portion 137a are elastically deformed, and the first flange portion 132a and the second flange portion 137a are brought into contact with each other over the entire circumference.

[0100] For example, the first flange portion 132a abuts against the second flange portion 137a of the second cage 136 at the intermediate portion 132b in the radial direction, and the front end portion 132c of the first flange portion 132a, which is radially outside the intermediate portion 132b, is warped toward the side L1 in the direction of the axis L. Further, the second flange portion 137a abuts against the first flange portion 132a of the first cage 131 at the intermediate portion 137b in the radial direction, and the front end portion 137c of the second flange portion 137a, which is radially outside the intermediate portion 137b, is warped toward the other side L2 in the direction of the axis L. Therefore, in the same manner as shown in Figure 9 a state where the first flange portion 132a and the second flange portion 137a are in contact with each other over the entire circumference is achieved, and thus joining by welding or the like is facilitated.

[0101] [Modified Example 3 of the Embodiment of the Present Invention]

[0102] Figure 11 is an explanatory view of the rotor of Modified Example 3 of the embodiment of the present invention. Figure 11 shows a state where the first cage 131 and the second cage 136 are in contact with each other. In addition, since the basic structure of this example is the same as the manner described with reference to Figures 1 to 8 the same reference numerals are given to the common parts and the description thereof is omitted.

[0103] As Figure 11 shown, when the first cage 131 and the second cage 136 are brought into contact with each other, in this manner, by reducing the distance between the first bottom plate portion 133 and the second bottom plate portion 138 to a target value, the first flange portion 132a and the second flange portion 137a are brought into contact with each other over the entire circumference. In this manner, the first bottom plate portion 133 of the first cage 131 is fixed to the first support plate 11 and the second bottom plate portion 138 of the second cage 136 is fixed to the second support plate 12. Therefore, when a load in the direction in which the first main body portion 134 and the second main body portion 139 approach each other in the direction of the axis L is applied, the distance between the first support plate 11 and the second support plate 12 is reduced to the target value.

[0104] In this manner, as described below, after the first flange portion 132a and the second flange portion 137a are in contact with each other, the deformation of the first bottom plate portion 133 and the second bottom plate portion 138 is used to absorb the externally applied load until the distance between the first bottom plate portion 133 and the second bottom plate portion 138 (the distance between the first support plate 11 and the second support plate 12) reaches the target value.

[0105] More specifically, the first bottom plate portion 133 includes a circular region 133e located on the center side in the radial direction and an annular region 133f connecting the circular region 133e and the first main body portion 134. The circular region 133e is located on the side opposite to the second cage 136 with respect to the annular region 133f. Therefore, the first support plate 11 is joined to the circular region 133e. In this embodiment, a stepped portion 133g is provided between the circular region 133e and the annular region 133f. Thus, after the first flange portion 132a and the second flange portion 137a come into contact with each other, the load applied until the distance between the first bottom plate portion 133 and the second bottom plate portion 138 (the distance between the first support plate 11 and the second support plate 12) reaches the target value can be absorbed by the deformation of the stepped portion 133g.

[0106] In addition, the second bottom plate portion 138 includes a circular region 138e located on the center side in the radial direction and an annular region 138f connecting the circular region 138e and the second main body portion 139. The circular region 138e is located on the side opposite to the first cage 131 with respect to the annular region 138f. Therefore, the second support plate 12 is joined to the circular region 138e. In this embodiment, a stepped portion 138g is provided between the circular region 138e and the annular region 138f. Thus, after the first flange portion 132a and the second flange portion 137a come into contact with each other, the load applied until the distance between the first bottom plate portion 133 and the second bottom plate portion 138 (the distance between the first support plate 11 and the second support plate 12) reaches the target value can be absorbed by the deformation of the stepped portion 138g.

[0107] [Modified Example 4 of the Embodiment of the Present Invention]

[0108] Figure 12 It is an explanatory diagram of the rotor of Modified Example 4 of the embodiment of the present invention. Figure 12 shows a state in which the first cage 131 and the second cage 136 are in contact with each other. In addition, the basic structure of this example is the same as the embodiment described with reference to Figures 1 to 8 Therefore, the same reference numerals are given to the common parts and their description is omitted.

[0109] As Figure 12As shown, when the first cage 131 and the second cage 136 are brought into contact with each other, in this embodiment, as in the third modified example, by reducing the distance between the first bottom plate portion 133 and the second bottom plate portion 138 to the target value, the first flange portion 132a and the second flange portion 137a are brought into contact with each other over the entire circumference. In this embodiment, the first bottom plate portion 133 of the first cage 131 is fixed to the first support plate 11 and the second bottom plate portion 138 of the second cage 136 is fixed to the second support plate 12. Therefore, when a load in the direction in which the first main body portion 134 and the second main body portion 139 approach each other in the axial direction of the axis L is applied, the distance between the first support plate 11 and the second support plate 12 is reduced to the target value.

[0110] In this embodiment, as shown below, after the first flange portion 132a and the second flange portion 137a are brought into contact with each other, the load applied until the distance between the first bottom plate portion 133 and the second bottom plate portion 138 (the distance between the first support plate 11 and the second support plate 12) reaches the target value is absorbed by the deformation of the first bottom plate portion 133 and the second bottom plate portion 138.

[0111] More specifically, the first bottom plate portion 133 includes a circular region 133e located on the center side in the radial direction and an annular region 133f connecting the circular region 133e to the first main body portion 134. The circular region 133e is located on the side opposite to the second cage 136 with respect to the annular region 133f. Therefore, the first support plate 11 is joined to the circular region 133e. In this embodiment, the annular region 133f is an inclined surface. Therefore, after the first flange portion 132a and the second flange portion 137a are brought into contact with each other, the load applied until the distance between the first bottom plate portion 133 and the second bottom plate portion 138 (the distance between the first support plate 11 and the second support plate 12) reaches the target value can be absorbed by the deformation of the annular region 133f.

[0112] In addition, the second bottom plate portion 138 includes a circular region 138e located on the center side in the radial direction and an annular region 138f connecting the circular region 138e to the second main body portion 139. The circular region 138e is located on the side opposite to the first cage 131 with respect to the annular region 138f. Therefore, the second support plate 12 is joined to the circular region 138e. In this embodiment, the annular region 138f is an inclined surface. Therefore, after the first flange portion 132a and the second flange portion 137a are brought into contact with each other, the load applied until the distance between the first bottom plate portion 133 and the second bottom plate portion 138 (the distance between the first support plate 11 and the second support plate 12) reaches the target value can be absorbed by the deformation of the annular region 138f.

[0113] [Another Embodiment]

[0114] Figure 13Explanatory drawing of the rotor 10 according to another embodiment of the present invention. In Figure 13 shows a cross-section when the rotor 10 is cut along the axis L. In the above-described embodiment, both the first cage 131 and the second cage 136 for the magnet cage 13 are cup-shaped, but as Figure 13 shown, in this embodiment, only one cage is cup-shaped and the other cage is flat. More specifically, in the magnet cage 13, the first cage 131 includes an annular first bottom plate portion 133 that covers the magnet 21 from one side L1 and a cylindrical first main body portion 134 that projects from the first bottom plate portion 133 toward the other side L2 and covers the outer peripheral surface of the magnet 21, and the magnet 21 is press-fitted into the inside of the first main body portion 134. The second cage 136x is flat and is joined to the end portion on the other side L2 of the first main body portion 134, that is, the first end portion 132, by welding or the like. Here, the inner diameter of the first end portion 132 is larger than the outer diameter of the magnet 21 In addition, in this embodiment, compared with the embodiment shown in Figure 4 etc., the dimension in the axis L direction of the magnet 21 is shorter. For example, the dimension in the axis L direction of the magnet 21 is smaller than the outer diameter dimension (diameter) of the magnet 21. Therefore, it is easy to press-fit the magnet 21 into the inside of the first main body portion 134.

[0115] In this embodiment, the first end portion 132 includes a first flange portion 132a that bends radially outward from the first main body portion 134, and the first flange portion 132a and the second cage 136x are joined by welding.

[0116] Regarding the rotor 10 having the above-described structure, if Improvement Examples 1 and 2 are applied to the first flange portion 132a of the first cage 131, the first flange portion 132a and the second cage 136x come into contact with each other over the entire circumference, so joining by welding or the like is easy. In addition, if Improvement Examples 3 and 4 are applied to the first flange portion 132a of the first cage 131, the load can be absorbed by the deformation of the first bottom plate portion 133.

[0117] [Other Embodiments]

[0118] In the above-described embodiment, one side L1 in the axis L direction is the output side and the other side L2 in the axis L direction is the opposite side of the output, but the present invention can also be applied when one side in the axis L direction is the opposite side of the output and the other side in the axis L direction is the output side.

[0119] In the above-described embodiment, the magnet cage 13 has a structure in which parts having the same shape are arranged in opposite directions in the axis L direction as the first cage 131 and the second cage 136. However, the lengths (heights) of the first cage 131 and the second cage 136 may also be different.

[0120] Industrial Applicability

[0121] In the present invention, a first cage covering a first portion on one side in the axial direction of the outer peripheral surface of the magnet and a second cage covering a second portion on the other side in the axial direction of the outer peripheral surface of the magnet are provided. Therefore, when the rotor rotates at a high speed, even if the magnet is damaged, it is possible to suppress the scattering of debris (a part of the magnet) by the first cage and the second cage. In addition, since the magnet is covered by the first cage and the second cage, it is easier to cover the magnet than in the case of covering the magnet with a single pipe. Further, the magnet is press-fitted into the first main body portion of the first cage and the second main body portion of the second cage. However, the inner diameter of the first end portion of the first main body portion and the inner diameter of the second end portion of the second main body portion are larger than the outer diameter of the magnet, so that the press-fitting is easy and the joining of the first end portion and the second end portion is easy.

[0122] In the present invention, a first cage covering the magnet from one side in the axial direction and an annular second cage covering the magnet from the other side in the axial direction are provided. Therefore, when the rotor rotates at a high speed, even if the magnet is damaged, it is possible to suppress the scattering of debris (a part of the magnet) by the first cage and the second cage. In addition, the magnet is press-fitted into the first main body portion of the first cage. However, the inner diameter of the first end portion of the first main body portion is larger than the outer diameter of the magnet, so that the press-fitting is easy and the joining of the first end portion and the second cage is easy.

Claims

1. A rotor of an inner rotor motor, characterized in that, Comprising: A rotating shaft; A cylindrical magnet provided with a through-hole for the rotating shaft to pass through; A first cage having: a circular first bottom plate portion covering the magnet from one side in the axial direction of the rotating shaft, and a cylindrical first main body portion protruding from the first bottom plate portion to the other side in the axial direction and covering a first portion of the outer peripheral surface of the magnet; And A second cage having: a circular second bottom plate portion covering the magnet from the other side, and a cylindrical second main body portion protruding from the second bottom plate portion to the one side and covering a second portion of the outer peripheral surface of the magnet, wherein the magnet is press-fitted into the interior of the first main body portion and the interior of the second main body portion, the first end, which is the end of the first main body portion on the other side, and the second end, which is the end of the second main body portion on the one side, are joined together, the inner diameter of the first end and the inner diameter of the second end are greater than the outer diameter of the magnet; wherein, the first end has: a first flange portion bent radially outward from the first main body portion, the second end has: a second flange portion bent radially outward from the second main body portion, and the first flange portion and the second flange portion are joined together.

2. The rotor of an inner rotor motor according to claim 1, wherein the first flange portion and the second flange portion are joined together by welding over the entire circumference.

3. The rotor of an inner rotor motor according to claim 2, wherein the first main body portion and the second main body portion are bent radially inward in the middle portion in the axial direction.

4. The rotor of an inner rotor motor according to claim 2, wherein the space between the first flange portion and the second flange portion is filled with a molten portion during welding.

5. The rotor of an inner rotor motor according to any one of claims 1 to 4, wherein fixed to the rotating shaft are: a circular first support plate overlapping with the first cage from the one side, and a circular second support plate overlapping with the second cage from the other side.

6. The rotor of an inner rotor motor according to claim 5, wherein the first bottom plate portion and the first support plate are joined together, and the second bottom plate portion and the second support plate are joined together.

7. The rotor of an inner rotor motor according to claim 1, wherein the first flange portion is elastically deformed toward the one side by abutting against the second cage.

8. The rotor of an inner rotor motor according to claim 1, wherein the magnet is a sintered magnet.

9. A rotor of an inner rotor motor, characterized in that, Comprising: A rotating shaft; A cylindrical magnet provided with a through-hole for the rotating shaft to pass through; A first cage having: a circular first bottom plate portion covering the magnet from one side in the axial direction of the rotating shaft, and a cylindrical first main body portion protruding from the first bottom plate portion and covering the outer peripheral surface of the magnet; And A circular second cage that covers the magnet from the other side, wherein the magnet is press-fitted into the interior of the first main body portion, the first end portion, which is the end portion on the other side of the first main body portion, engages with the second cage, the inner diameter of the first end portion is larger than the outer diameter of the magnet; wherein, the first end portion includes: a first flange portion that bends radially outward from the first main body portion, the first flange portion engages with the second cage.

10. The rotor of an inner rotor motor according to claim 9, characterized in that, the first flange portion elastically deforms toward the one side by abutting against the second cage.

11. The rotor of an inner rotor motor according to claim 10, characterized in that, the first flange portion abuts against the second cage at a midway portion in the radial direction, the front end portion of the first flange portion that is radially outside the midway portion warps toward the one side.

12. The rotor of an inner rotor motor according to claim 10, characterized in that, the first bottom plate portion includes: a circular region located on the center side in the radial direction, and an annular region connecting the circular region and the first main body portion, the circular region is located on the side opposite to the second cage with respect to the annular region.

13. The rotor of an inner rotor motor according to claim 12, characterized in that, a stepped portion is provided between the circular region and the annular region.

14. The rotor of an inner rotor motor according to claim 12, characterized in that, the annular region is an inclined surface inclined with respect to the circular region.

15. The rotor of an inner rotor motor according to claim 9, characterized in that, the magnet is a sintered magnet.

16. An inner rotor motor, characterized in that, Comprising: the rotor of the inner rotor motor according to claim 1 or 9; and a stator opposed to the rotor of the inner rotor motor.

17. A method for manufacturing a rotor of an inner rotor motor, the rotor of the inner rotor motor including: a rotating shaft; a cylindrical magnet provided with a through hole through which the rotating shaft passes; a first cage including: a circular first bottom plate portion that covers the magnet from one side in the axial direction of the rotating shaft, and a cylindrical first main body portion that projects from the first bottom plate portion to the other side in the axial direction and covers the first part of the outer peripheral surface of the magnet; and a second cage including: a circular second bottom plate portion that covers the magnet from the other side, and a cylindrical second main body portion that projects from the second bottom plate portion to the one side and covers the second part of the outer peripheral surface of the magnet, the method for manufacturing the rotor of the inner rotor motor is characterized in that, The inner diameters of the first main body portion and the second main body portion are made smaller than the outer diameter of the magnet in at least a part of the axial direction, and the inner diameters of the first end portion, which is the end portion on the other side of the first main body portion, and the second end portion, which is the end portion on one side of the second main body portion, are made larger than the outer diameter of the magnet. The method for manufacturing a rotor of the inner rotor motor includes: a first step of fixing the first cage to the rotating shaft; a second step of press-fitting the first portion of the magnet into the inside of the first main body portion; a third step of fixing the second cage to the rotating shaft in such a manner that the second portion of the magnet is press-fitted into the inside of the second main body portion; and a fourth step of joining the first end portion and the second end portion; wherein the first end portion includes a first flange portion that bends radially outward from the first main body portion, the second end portion includes a second flange portion that bends radially outward from the second main body portion, and in the fourth step, the first flange portion and the second flange portion are joined.

18. The method for manufacturing a rotor of the inner rotor motor according to claim 17, wherein in the fourth step, the first flange portion and the second flange portion are joined by welding over the entire circumference.

19. The method for manufacturing a rotor of the inner rotor motor according to claim 18, wherein in the fourth step, a laser beam is irradiated from a direction inclined with respect to the axial direction, and the first flange portion and the second flange portion are joined by laser welding.

20. The method for manufacturing a rotor of the inner rotor motor according to claim 18, wherein after the third step and before the fourth step, a load in a direction in which the first main body portion and the second main body portion approach each other in the axial direction is applied to reduce the gap between the first flange portion and the second flange portion.

21. The method for manufacturing a rotor of the inner rotor motor according to claim 18, wherein in the fourth step, the first flange portion and the second flange portion are melted to fill the gap between the first flange portion and the second flange portion.

22. The method for manufacturing a rotor of the inner rotor motor according to claim 20 or 21, wherein when the fourth step is performed, the gap between the first flange portion and the second flange portion is narrower than the protruding dimension of the first flange portion radially outward from the first main body portion and the protruding dimension of the second flange portion radially outward from the second main body portion.

23. The method for manufacturing a rotor of the inner rotor motor according to claim 20 or 21, wherein when the fourth step is performed, the gap between the first flange portion and the second flange portion is narrower than the thickness of the first flange portion and the thickness of the second flange portion.

24. The method for manufacturing a rotor of the inner rotor motor according to any one of claims 17 to 19, wherein In the first process, the first cage is fixed to the rotating shaft by fixing an annular first support plate that overlaps the first cage from the one side to the rotating shaft. In the third process, the second cage is fixed to the rotating shaft by fixing an annular second support plate that overlaps the second cage from the other side to the rotating shaft.

25. The method for manufacturing a rotor of an inner rotor motor according to claim 24, wherein: The first process is performed in a state where the first support plate is joined to the first bottom plate portion. The third process is performed in a state where the second support plate is joined to the second bottom plate portion.

26. The method for manufacturing a rotor of an inner rotor motor according to claim 20, wherein: By applying a load in a direction in which the first main body portion and the second main body portion approach each other in the axial direction, the first flange portion and the second flange portion are elastically deformed, and the first flange portion and the second flange portion are brought into contact with each other over the entire circumference.

27. The method for manufacturing a rotor of an inner rotor motor according to claim 26, wherein: When applying a load in a direction in which the first main body portion and the second main body portion approach each other in the axial direction, the distance between the first bottom plate portion and the second bottom plate portion is reduced to a target value.

Images