Motor

Abstract

A motor according to one embodiment of the present disclosure comprises a rotor and a stator. The rotor rotates around a center axis. The stator is opposite the rotor in the axial direction. This rotor comprises a rotor frame, a rotor cover, and a plurality of magnets. The rotor cover is opposite the rotor frame in the axial direction. The plurality of magnets are arranged along the circumferential direction between the rotor frame and the rotor cover.

Description

Motor

[0001] This disclosure relates to a motor. This application claims priority based on Japanese Patent Application No. 2025-015556 filed in Japan on January 31, 2025, the content of which is incorporated herein by reference.

[0002] Conventionally, an axial flux motor including a rotor in which a plurality of magnets are arranged along the circumferential direction and a stator facing the rotor in the axial direction is known. Conventionally, a technique for fixing a magnet by inserting a connector such as a pin or a blade from a direction orthogonal to the axial direction into a groove provided in the side edge of the magnet or the side edge of the fan ring has been disclosed (see, for example, Patent Document 1).

[0003] Japanese Patent Publication No. 2024-507005

[0004] In the above-described conventional technology, since assembly is required not only in the axial direction of the motor but also from a direction orthogonal to the axial direction, there is room for improvement in the ease of assembling the rotor.

[0005] This disclosure provides a technique capable of improving the ease of assembling a rotor.

[0006] The motor according to one aspect of this disclosure includes a rotor and a stator. The rotor rotates about a central axis. The stator faces the rotor in the axial direction. The rotor includes a rotor frame, a rotor cover, and a plurality of magnets. The rotor cover faces the rotor frame in the axial direction. The plurality of magnets are arranged along the circumferential direction and are disposed between the rotor frame and the rotor cover.

[0007] According to this disclosure, the ease of assembling the rotor can be improved.

[0008] Figure 1 is a perspective view showing an example of a motor according to an exemplary embodiment. Figure 2 is a perspective view showing an example of a rotor according to an exemplary embodiment. Figure 3 is an exploded perspective view showing an example of a rotor according to an exemplary embodiment. Figure 4 is a cross-sectional perspective view taken along the line IV-IV shown in Figure 2. Figure 5 is an enlarged view of region V in Figure 2. Figure 6 is an enlarged view of region VI in Figure 2. Figure 7 is a schematic cross-sectional perspective view showing the configuration of a rotor according to another exemplary embodiment (part 1). Figure 8 is a schematic cross-sectional perspective view showing the configuration of a rotor according to another exemplary embodiment (part 2). Figure 9 is a schematic cross-sectional perspective view showing the configuration of a rotor according to another exemplary embodiment (part 3). Figure 10 is a schematic cross-sectional perspective view showing the configuration of a rotor according to another exemplary embodiment (part 4). Figure 11 is a schematic perspective view showing the configuration of a rotor according to another exemplary embodiment (part 5). Figure 12 is a schematic exploded perspective view showing the configuration of a rotor according to another exemplary embodiment (part 5).

[0009] The embodiments for implementing the motor according to this disclosure (hereinafter referred to as "Embodiments") will be described in detail below with reference to the drawings. However, this disclosure is not limited by these embodiments. Furthermore, each embodiment can be combined as appropriate, provided that the processing content is not inconsistent. Also, the same parts are denoted by the same reference numerals in each of the following embodiments, and redundant descriptions are omitted.

[0010] (Exemplary Embodiments) In the embodiments described below, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not require that the objects be strictly "constant," "orthogonal," "perpendicular," or "parallel." That is, each of the above expressions allows for deviations such as manufacturing accuracy or installation accuracy.

[0011] Figure 1 is a perspective view showing an example of a motor 2 according to an exemplary embodiment. The motor 2 shown in Figure 1 is a DSSR (Double Stator Single Rotor) type axial flux motor comprising one rotor 3 centered on a central axis A and two annular stators 4 and 5. The two stators 4 and 5 are arranged opposite each other in the axial direction of the central axis A. The rotor 3 is positioned between the two stators 4 and 5 and rotates around the central axis A. Note that the motor 2 does not necessarily have to be of the DSSR type. For example, the motor 2 may be of the SSDR (Single Stator Double Rotor) type.

[0012] Next, the configuration of the rotor 3 according to an exemplary embodiment will be described with reference to Figures 2 to 6. Figure 2 is a perspective view showing an example of the rotor 3 according to an exemplary embodiment. Figure 3 is an exploded perspective view showing an example of the rotor 3 according to an exemplary embodiment. Figure 4 is a cross-sectional perspective view taken along the line IV-IV shown in Figure 2. Figure 5 is an enlarged view of region V in Figure 2. Figure 6 is an enlarged view of region VI in Figure 2. Note that the shaft 8 is not shown in Figure 3.

[0013] In this application, "one axial direction" refers to the stator 5 side in the axial direction, and "the other axial direction" refers to the stator 4 side in the axial direction. In other words, "one axial direction" refers to the rotor cover 40 side, which will be described later, and "the other axial direction" refers to the rotor frame 20 side, which will be described later. Also, when simply referred to as "radially inward," it refers to the radially inward side of the rotor 3. When simply referred to as "radially outward," it refers to the radially outward side of the rotor 3. When simply referred to as "circumferential direction," it refers to the circumferential direction of the rotor 3.

[0014] As shown in Figures 2 and 3, the rotor 3 comprises a rotor frame 20 and a rotor cover 40. The rotor cover 40 faces the rotor frame 20 in the axial direction.

[0015] The rotor frame 20 has a plurality of first wall portions 21. The plurality of first wall portions 21 extend along the radial direction of the rotor frame 20 and are located between two adjacent magnets 10 on the rotor frame 20 side. The plurality of first wall portions 21 extend radially from a first base end portion 35 located radially inward of the rotor frame 20.

[0016] The rotor cover 40 has a plurality of second wall portions 41. The plurality of second wall portions 41 extend along the radial direction of the rotor cover 40 and are located between two adjacent magnets 10 on the rotor cover 40 side. The plurality of second wall portions 41 extend radially from a second base end portion 55 located radially inward of the rotor cover 40.

[0017] The rotor frame 20 has a projection 36 that protrudes in one axial direction from the first base end 35 in the center when viewed from above. The rotor cover 40 has a hollow portion 56 that penetrates axially in the center when viewed from above. The rotor 3 is assembled by placing the magnet 10 between the rotor frame 20 and the rotor cover 40 and inserting the projection 36 into the hollow portion 56.

[0018] The shaft 8 is fixed to the rotor cover 40 by a plurality of fastening members 9. The magnet 10 may have a foam sheet attached to its side. The magnet 10 may be fixed to the rotor frame 20 and rotor cover 40 by heating, which causes the foam sheet to expand.

[0019] With the rotor 3 configured in this way, the rotor frame 20, magnet 10, and rotor cover 40 are mounted in that order from the axial direction. This makes the assembly of the rotor 3 easier. More specifically, it is not necessary to invert the rotor 3 upside down during assembly. Therefore, the increase in work time can be suppressed.

[0020] As shown in Figure 2, the rotor 3 has joints 6 and 7. The joints 6 and 7 are laser-bonded to the rotor frame 20 and the rotor cover 40. Joint 6 is located radially inward from the multiple magnets 10. Joint 7 is located radially outward from the multiple magnets 10.

[0021] With the rotor 3 configured in this way, the rotor frame 20 and the rotor cover 40 are joined by laser bonding. This allows the two holding members that hold the multiple magnets 10 to be stably maintained in a fixed state.

[0022] As shown in Figure 4, the rotor frame 20 comprises a first end face 22, a second end face 23, and a first circumferential surface 24. The first end face 22 is an annular surface facing in the axial direction. The first end face 22 is located on one axial side of the first base end 35. The second end face 23 is an annular surface located radially inward from the first end face 22 and protruding axially from the first end face 22. The second end face 23 is located radially outward on one axial side of the protruding portion 36. The first circumferential surface 24 connects the first end face 22 and the second end face 23.

[0023] The rotor cover 40 comprises a third end face 42 and a second circumferential surface 44. The third end face 42 is in contact with the first end face 22. The third end face 42 is the other axial surface of the second base end 55. The second circumferential surface 44 is in contact with the first circumferential surface 24. The second circumferential surface 44 is the radially outer surface of the projection 36. The joint 6 is located at the boundary between the first circumferential surface 24 and the second circumferential surface 44 in a plan view.

[0024] With the rotor 3 configured in this way, the rotor frame 20 and the rotor cover 40 are joined by laser bonding radially inward from the multiple magnets 10. This allows the two holding members that hold the multiple magnets 10 to be stably fixed radially inward from the multiple magnets 10.

[0025] Furthermore, by irradiating the rotor frame 20 with a laser in the axial direction, laser bonding can be performed along the boundary between the first circumferential surface 24 and the second circumferential surface 44, thus increasing the axial distance of the joint 6. This increases the bonding strength between the rotor frame 20 and the rotor cover 40.

[0026] The rotor frame 20 is provided with a first recess 26. The first recess 26 is located between the second end face 23 and the first circumferential surface 24, and is recessed in the other axial direction from the second end face 23 and radially inward from the first circumferential surface 24.

[0027] The rotor cover 40 includes a fourth end face 45 and a second recess 46. The fourth end face 45 is located axially opposite to the third end face 42. The fourth end face 45 is one axial surface of the second base end 55. The second recess 46 is located between the fourth end face 45 and the second circumferential surface 44, recessed axially from the fourth end face 45 in the other direction, and recessed radially outward from the second circumferential surface 44. The joint 6 is located in the annular groove 60 formed by the first recess 26 and the second recess 46. For example, the annular groove 60 is formed in a concave shape. The joint 6 is located in the radial center of the groove 60.

[0028] With the rotor 3 configured in this way, the joint portion 6 is located recessed in the other axial direction from the second end face 23 and the fourth end face 45. This prevents the joint portion 6 from bulging in one axial direction, allowing for high-precision adjustment of the clearance between the stators 4 and 5 and the rotor 3.

[0029] Furthermore, the rotor frame 20 and the rotor cover 40 can be joined around the entire circumference. This increases the strength of the joint between the rotor cover 40 and the rotor frame 20. In addition, laser joining can be performed by rotating the other part while the laser or rotor 3 is fixed. This increases the efficiency of the laser joining process.

[0030] As shown in Figures 5 and 6, the rotor frame 20 includes a plurality of first fixing portions 27. The plurality of first fixing portions 27 are located radially outward from the plurality of magnets 10. The plurality of first fixing portions 27 are formed to have a greater circumferential width than the first wall portion 21 (see Figure 3).

[0031] The rotor cover 40 includes a plurality of second fixing portions 47. The plurality of second fixing portions 47 are located radially outward from the plurality of magnets 10. The plurality of second fixing portions 47 are formed to have a greater circumferential width than the second wall portion 41.

[0032] The first fixing portion 27 has a first outer peripheral surface 28. The first outer peripheral surface 28 faces radially. The second fixing portion 47 has a second outer peripheral surface 48. The second outer peripheral surface 48 faces radially. The joint portion 7 is located at the boundary between the first outer peripheral surface 28 and the second outer peripheral surface 48. The joint portion 7 extends along the circumferential direction.

[0033] With the rotor 3 configured in this way, the rotor frame 20 and the rotor cover 40 are joined by laser bonding radially outward from the multiple magnets 10. This makes it possible to stably maintain a fixed state of the two holding members that hold the multiple magnets 10 radially outward from the multiple magnets 10.

[0034] Furthermore, the rotor frame 20 and the rotor cover 40 are joined by laser bonding at the boundary between the first outer surface 28 and the second outer surface 48. This allows the two holding members that hold the multiple magnets 10 to be stably fixed at the boundary between the first outer surface 28 and the second outer surface 48.

[0035] The first outer circumferential surface 28 includes a fourth recess 29. The fourth recess 29 is recessed radially inward relative to the first outer circumferential surface 28. The second outer circumferential surface 48 includes a fifth recess 49. The fifth recess 49 is recessed radially inward relative to the second outer circumferential surface 48. The joint portion 7 is located in the groove 70 formed by the fourth recess 29 and the fifth recess 49. For example, the groove 70 is formed in a concave shape. The joint portion 7 is located in the axial center of the groove 70.

[0036] With the rotor 3 configured in this way, the joint portion 7 is located in a recessed area radially inward from the first outer peripheral surface 28 and the second outer peripheral surface 48. This prevents the joint portion 7 from bulging radially outward.

[0037] The first fixing portion 27 includes a first side surface 30. The first side surface 30 extends radially inward from both circumferential ends of the first outer peripheral surface 28. The second fixing portion 47 includes a second side surface 50. The second side surface 50 extends radially inward from both circumferential ends of the second outer peripheral surface 48. The joint portion 7 is located only on the first outer peripheral surface 28 and the second outer peripheral surface 48, out of the first outer peripheral surface 28, the second outer peripheral surface 48, the first side surface 30, and the second side surface 50. In other words, the joint portion 7 is not formed on the first outer peripheral surface 28 and the second outer peripheral surface 48.

[0038] With the rotor 3 configured in this way, laser bonding can be performed by rotating the other while fixing either the laser or the rotor 3. This improves the efficiency of the laser bonding process. Furthermore, since the distance between the magnet 10 and the bonding portion 7 can be increased, the thermal influence on the magnet 10 can be reduced.

[0039] The first fixing portion 27 is provided with a first through hole 31. The first through hole 31 penetrates the first fixing portion 27 in the axial direction. The second fixing portion 47 is provided with a second through hole 51. The second through hole 51 penetrates the second fixing portion 47 in the axial direction. The rotor 3 is provided with a crimping member 80 that straddles the first through hole 31 and the second through hole 51 and is crimped and fixed. For example, a rivet may be used as the crimping member 80, which is deformed into a shape with a larger diameter at the end of a pin when pressure is applied to the end.

[0040] With the rotor 3 configured in this way, the joint strength against repeated vibrations and stresses is increased. This improves the reliability of the joint over time.

[0041] After the crimping members 80 are driven into the first through-hole 31 and the second through-hole 51 of the rotor 3, laser welding of the joint 7 is performed. In laser welding, the laser is irradiated radially inward to the joint 7. The joint 7 reaches the crimping members 80.

[0042] With the rotor 3 configured in this way, the radial distance of the joint 7 can be maximized. This increases the joint strength of the joint 7.

[0043] (Another exemplary embodiment (Part 1)) Next, a rotor 3 according to another exemplary embodiment (Part 1) will be described with reference to Figure 7. Figure 7 is a schematic cross-sectional perspective view showing the configuration of the rotor 3 according to another exemplary embodiment (Part 1).

[0044] As shown in Figure 7, the rotor 3 may have a plurality of joints 6 that are circumferentially located along the boundary in a plan view and spaced apart from each other. That is, the plurality of joints 6 may be formed in a dot shape in a plan view.

[0045] According to the rotor 3 configured as described above, by rotating the rotor 3 in the axial direction in accordance with the irradiation and stop of the laser, the rotor frame 20 and the rotor cover 40 can be joined. Thereby, the joining of the rotor frame 20 and the rotor cover 40 can be easily performed.

[0046] (Another exemplary embodiment (Part 2)) Next, the rotor 3 according to another exemplary embodiment (Part 2) will be described with reference to FIG. 8. FIG. 8 is a schematic cross-sectional perspective view showing the configuration of the rotor 3 according to another exemplary embodiment (Part 2).

[0047] The rotor cover 40 includes a third recess 52. The third recess 52 is located between the second circumferential surface 44 and the magnet 10 and is recessed in the other axial direction from the fourth end surface 45. The joint portion 6 is located in a circumferential groove portion 61 formed by the third recess 52. The axial length of the groove portion 61 can be adjusted to a predetermined length.

[0048] According to the rotor 3 configured as described above, it becomes easier to adjust the depth of the joint portion 6. Thereby, a joint with high strength and less distortion can be performed.

[0049] (Another exemplary embodiment (Part 3)) Next, the rotor 3 according to another exemplary embodiment (Part 3) will be described with reference to FIG. 9. FIG. 9 is a schematic cross-sectional perspective view showing the configuration of the rotor 3 according to another exemplary embodiment (Part 3).

[0050] The second end surface 23 protrudes in one axial direction from the fourth end surface 45. The joint portion 6 is located at a corner portion C formed by the first circumferential surface 24 and the fourth end surface 45. The laser L is irradiated obliquely with respect to the axial direction.

[0051] According to the rotor 3 configured as described above, the joint portion 6 is located at the end of the fourth end surface 45. Thereby, since the swelling of the joint portion 6 at the position facing the stator 5 can be prevented, the clearance between the stator 5 and the rotor 3 can be adjusted with high precision.

[0052] (Another exemplary embodiment (4)) Next, a rotor 3 according to another exemplary embodiment (4) will be described with reference to Figure 10. Figure 10 is a schematic cross-sectional perspective view showing the configuration of the rotor 3 according to another exemplary embodiment (4).

[0053] As shown in Figure 10, the rotor frame 20 is provided with a sixth recess 53. The sixth recess 53 is located in the second fixed portion 47 and is recessed in the other axial direction from the fourth end face 45. The joint portion 7 is located in the circumferential groove 71 formed by the sixth recess 53. The axial length of the groove 71 is adjustable to a predetermined length.

[0054] With the rotor 3 configured in this way, it becomes easier to adjust the depth of the joint 7. This makes it possible to perform a joint with high joint strength and low distortion.

[0055] (Another exemplary embodiment (5)) Next, a rotor 3 according to another exemplary embodiment (5) will be described with reference to Figures 11 and 12. Figure 11 is a schematic perspective view showing the configuration of the rotor 3 according to another exemplary embodiment (5). Figure 12 is a schematic exploded perspective view showing the configuration of the rotor 3 according to another exemplary embodiment (5). Note that the shaft 8 is not shown in Figure 12.

[0056] As shown in Figures 11 and 12, the rotor 3 includes a plurality of fastening members 91, 92 that fasten the rotor frame 20 and the rotor cover 40 together. For example, the plurality of fastening members 91, 92 may be male screws.

[0057] With the rotor 3 configured in this way, the rotor frame 20 and the rotor cover 40 are joined by fastening members 91 and 92 such as screws. This allows the two holding members that hold the multiple magnets 10 to be stably maintained in a fixed state.

[0058] The rotor frame 20 includes a plurality of third through holes 93 and a plurality of fourth through holes 94. The plurality of third through holes 93 are located radially inward from the plurality of magnets 10. The plurality of fourth through holes 94 are located radially outward from the plurality of magnets 10.

[0059] Multiple third through holes 93 are arranged circumferentially, radially inward from the magnet 10. Multiple third through holes 93 penetrate the rotor frame 20 in the axial direction. Multiple fourth through holes 94 are each located in the first fixing portion 27. Multiple fourth through holes 94 penetrate the rotor frame 20 in the axial direction.

[0060] The rotor cover 40 includes a plurality of fifth through holes 95 and a plurality of sixth through holes 96. The plurality of fifth through holes 95 are located radially inward from the plurality of magnets 10. The plurality of sixth through holes 96 are located radially outward from the plurality of magnets 10.

[0061] Multiple fifth through holes 95 are arranged circumferentially, radially inward from the magnet 10. Multiple fifth through holes 95 penetrate the rotor cover 40 in the axial direction. Multiple sixth through holes 96 are each located in the second fixing portion 47. Multiple sixth through holes 96 penetrate the rotor cover 40 in the axial direction.

[0062] The multiple fastening members 91 and 92 comprise a plurality of first fastening members 91 and a plurality of second fastening members 92. The plurality of first fastening members 91 are arranged in the third through hole 93 and the fifth through hole 95. The plurality of second fastening members 92 are arranged in the fourth through hole 94 and the sixth through hole 96.

[0063] With the rotor 3 configured in this way, the rotor frame 20 and the rotor cover 40 are joined by fastening members 91 and 92 such as screws at the radially inward and radially outward sides of the multiple magnets 10, respectively. This makes it possible to stably maintain a fixed state of the two holding members that hold the multiple magnets 10 at the radially inward and radially outward sides of the multiple magnets 10, respectively.

[0064] The diameter of the second fastening member 92 is smaller than the diameter of the first fastening member 91.

[0065] With the rotor 3 configured in this way, the distance between adjacent second fastening members 92 becomes larger. This improves the magnetic properties of the magnet 10.

[0066] The number of second fastening members 92 is greater than the number of first fastening members 91.

[0067] With the rotor 3 configured in this way, even if the second fastening member 92 has a small diameter, the strength of fastening the rotor frame 20 and the rotor cover 40 can be improved radially outward from the multiple magnets 10. As a result, the two holding members that hold the multiple magnets 10 can be stably maintained in a fixed state radially outward from the multiple magnets 10.

[0068] The head of the fastening member 9 is located on the rotor cover 40 side. If the fastening member 9 is a male screw, the head of the fastening member 9 refers to the head of the male screw, that is, the part with a larger diameter than the threaded portion in which the screw groove is formed.

[0069] With the rotor 3 configured in this way, the rotor frame 20, magnet 10, rotor cover 40, and fastening members 91 and 92 are attached in the order from the axial direction. This improves the ease of assembly of the rotor 3.

[0070] The above describes configurations in which the radially outer and radially inner surfaces of the magnet 10 are fixed by laser bonding, and configurations in which the radially outer and radially inner surfaces of the magnet 10 are fixed by fastening members 91 and 92. However, the rotor 3 is not limited to these configurations. For example, the rotor 3 may be configured in which the radially inner surface of the magnet 10 is fixed by fastening member 91, and the radially outer surface is fixed by laser bonding.

[0071] Furthermore, this technology can also be configured as follows: <Note> (1) A motor comprising a rotor that rotates about a central axis, and a stator facing the rotor in the axial direction, wherein the rotor comprises a rotor frame, a rotor cover facing the rotor frame in the axial direction, and a plurality of magnets arranged along the circumferential direction and positioned between the rotor frame and the rotor cover. (2) The motor according to (1), wherein the rotor has a joint, and the joint is laser-bonded to the rotor frame and the rotor cover. (3) The motor according to (2), wherein the joint is located radially inward from the plurality of magnets. (4) The motor according to (3), wherein the rotor frame comprises an annular first end face facing in the axial direction, an annular second end face located radially inward from the first end face and projecting in one axial direction from the first end face, and a first circumferential surface connecting the first end face and the second end face, and the rotor cover comprises a third end face in contact with the first end face and a second circumferential surface in contact with the first circumferential surface, and the joint portion is located at the boundary between the first circumferential surface and the second circumferential surface in a plan view. (5) The motor according to (4), wherein the rotor frame has a first recess located between the second end face and the first circumferential surface, recessed in the other axial direction from the second end face and recessed radially inward from the first circumferential surface, the rotor cover has a fourth end face located opposite the third end face in the axial direction, and a second recess located between the fourth end face and the second circumferential surface, recessed in the other axial direction from the fourth end face and recessed radially outward from the second circumferential surface, and the joint is located in an annular groove formed by the first recess and the second recess. (6) The motor according to (4) or (5), wherein the rotor has a plurality of joints located circumferentially along the boundary in a plan view and spaced apart from each other.(7) The motor according to (3), wherein the rotor frame comprises an annular first end face facing in the axial direction, an annular second end face located radially inward from the first end face and projecting in one axial direction from the first end face, and a first circumferential surface located between the first end face and the second end face, and the rotor cover comprises a third end face in contact with the first end face, a second circumferential surface in contact with the first circumferential surface, a fourth end face located opposite the third end face, and a third recess located between the second circumferential surface and the magnet and recessing in the other axial direction from the fourth end face, and the joint portion is located in a circumferential groove formed by the third recess. (8) The motor according to (4), wherein the rotor cover comprises a fourth end face located opposite the third end face, the second end face projecting in one axial direction from the fourth end face, and the joint portion is located in a corner formed by the first circumferential surface and the fourth end face. (9) The motor according to (3), wherein the joint is located radially outward from the plurality of magnets. (10) The motor according to (9), wherein the rotor frame comprises a plurality of first fixing portions located radially outward from the plurality of magnets, the rotor cover comprises a plurality of second fixing portions located radially outward from the plurality of magnets, the first fixing portion comprises a first outer peripheral surface facing radially, the second fixing portion comprises a second outer peripheral surface facing radially, and the joint is located at the boundary between the first outer peripheral surface and the second outer peripheral surface. (11) The motor according to (10), wherein the first outer peripheral surface comprises a fourth recess recessed radially inward from the first outer peripheral surface, the second outer peripheral surface comprises a fifth recess recessed radially inward from the second outer peripheral surface, and the joint is located at the groove formed by the fourth recess and the fifth recess. (12) The motor according to (10) or (11), wherein the first fixing portion has first side surfaces extending radially inward from both circumferential ends of the first outer surface, the second fixing portion has second side surfaces extending radially inward from both circumferential ends of the second outer surface, and the joint portion is located only on the first outer surface and the second outer surface among the first outer surface, the second outer surface, the first side surface and the second side surface.(13) The motor according to any one of (10) to (12), wherein the first fixing portion has a first through hole that penetrates the first fixing portion in the axial direction, the second fixing portion has a second through hole that penetrates the second fixing portion in the axial direction, and the rotor has a crimping member that is positioned across the first through hole and the second through hole and is crimped to fix it. (14) The motor according to (13), wherein the joint portion reaches the crimping member. (15) The motor according to any one of (10) to (12), wherein the rotor frame comprises an annular first end face facing in the axial direction, an annular second end face located radially inward from the first end face and projecting in one axial direction from the first end face, and a first circumferential surface located between the first end face and the second end face, and the rotor cover comprises a third end face in contact with the first end face, a second circumferential surface in contact with the first circumferential surface, a fourth end face located opposite the third end face, and a sixth recess located in the second fixing portion and recessed in the other axial direction from the fourth end face, and the joint portion is located in a circumferential groove formed by the sixth recess. (16) The motor according to (1), wherein the rotor comprises a plurality of fastening members for fastening the rotor frame and the rotor cover. (17) The motor according to (16), wherein the rotor frame comprises a plurality of third through holes located radially inward from the plurality of magnets and a plurality of fourth through holes located radially outward from the plurality of magnets, the rotor cover comprises a plurality of fifth through holes located radially inward from the plurality of magnets and a plurality of sixth through holes located radially outward from the plurality of magnets, and the plurality of fastening members comprises a plurality of first fastening members disposed in the third through holes and the fifth through holes and a plurality of second fastening members disposed in the fourth through holes and the sixth through holes. (18) The motor according to (17), wherein the diameter of the second fastening member is smaller than the diameter of the first fastening member. (19) The motor according to (18), wherein the number of second fastening members is greater than the number of first fastening members. (20) The motor according to any one of (16) to (19), wherein the heads of the fastening members are located on the rotor cover side.

[0072] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. Indeed, the above embodiments can be embodied in a variety of forms. Furthermore, the above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0073] 2 Motor 3 Rotor 4 Stator 5 Stator 6 Joint 7 Joint 10 Magnet 20 Rotor frame 22 First end face 23 Second end face 24 First circumferential surface 26 First recess 27 First fixing part 28 First outer surface 29 Fourth recess 30 First side surface 31 First through hole 40 Rotor cover 42 Third end face 44 Second circumferential surface 45 Fourth end face 46 Second recess 47 Second fixing part 48 Second outer surface 49 Fifth recess 50 Second side surface 51 Second through hole 52 Third recess 53 Sixth recess 60 Groove 61 Groove 70 Groove 71 Groove 80 Crimping member 91 First fastening member (fastening member) 92 Second fastening member (fastening member) 93 Third through hole 94 Fourth through hole 95 Fifth through hole 96 Sixth through hole A Central axis C Corner

Claims

1. A motor comprising a rotor that rotates about a central axis, and a stator facing the rotor in the axial direction, wherein the rotor comprises a rotor frame, a rotor cover facing the rotor frame in the axial direction, and a plurality of magnets arranged along the circumferential direction and positioned between the rotor frame and the rotor cover.

2. The motor according to claim 1, wherein the rotor has a joint, and the joint is formed by laser bonding the rotor frame and the rotor cover.

3. The motor according to claim 2, wherein the joint is located radially inward from the plurality of magnets.

4. The motor according to claim 3, wherein the rotor frame comprises an annular first end face facing in the axial direction, an annular second end face located radially inward from the first end face and projecting in one axial direction from the first end face, and a first circumferential surface connecting the first end face and the second end face, and the rotor cover comprises a third end face in contact with the first end face and a second circumferential surface in contact with the first circumferential surface, and the joint portion is located at the boundary between the first circumferential surface and the second circumferential surface in a plan view.

5. The motor according to claim 4, wherein the rotor frame has a first recess located between the second end face and the first circumferential surface, recessed in the other axial direction from the second end face and recessed radially inward from the first circumferential surface, the rotor cover has a fourth end face located opposite the third end face in the axial direction, and a second recess located between the fourth end face and the second circumferential surface, recessed in the other axial direction from the fourth end face and recessed radially outward from the second circumferential surface, and the joint is located in an annular groove formed by the first recess and the second recess.

6. The motor according to claim 4, wherein the rotor comprises a plurality of joints positioned circumferentially along the boundary in a plan view and spaced apart from each other.

7. The motor according to claim 3, wherein the rotor frame comprises an annular first end face facing in the axial direction, an annular second end face located radially inward from the first end face and projecting in one axial direction from the first end face, and a first circumferential surface located between the first end face and the second end face, and the rotor cover comprises a third end face in contact with the first end face, a second circumferential surface in contact with the first circumferential surface, a fourth end face located opposite the third end face, and a third recess located between the second circumferential surface and the magnet and recessing in the other axial direction from the fourth end face, and the joint portion is located in a circumferential groove formed by the third recess.

8. The motor according to claim 4, wherein the rotor cover has a fourth end face located opposite the third end face, the second end face protrudes more in one axial direction than the fourth end face, and the joint is located at the corner formed by the first circumferential surface and the fourth end face.

9. The motor according to claim 3, wherein the joint is located radially outward from the plurality of magnets.

10. The motor according to claim 9, wherein the rotor frame comprises a plurality of first fixing portions located radially outward from the plurality of magnets, the rotor cover comprises a plurality of second fixing portions located radially outward from the plurality of magnets, the first fixing portion comprises a first outer peripheral surface facing radially, the second fixing portion comprises a second outer peripheral surface facing radially, and the joint portion is located at the boundary between the first outer peripheral surface and the second outer peripheral surface.

11. The motor according to claim 10, wherein the first outer peripheral surface has a fourth recess recessed radially inward relative to the first outer peripheral surface, the second outer peripheral surface has a fifth recess recessed radially inward relative to the second outer peripheral surface, and the joint is located in the groove formed by the fourth recess and the fifth recess.

12. The motor according to claim 11, wherein the first fixing portion has first side surfaces extending radially inward from both circumferential ends of the first outer surface, the second fixing portion has second side surfaces extending radially inward from both circumferential ends of the second outer surface, and the joint portion is located only on the first outer surface and the second outer surface among the first outer surface, the second outer surface, the first side surface and the second side surface.

13. The motor according to claim 10, wherein the first fixing portion has a first through hole that penetrates the first fixing portion in the axial direction, the second fixing portion has a second through hole that penetrates the second fixing portion in the axial direction, and the rotor has a crimping member that is positioned across the first through hole and the second through hole and is fixed by crimping.

14. The motor according to claim 13, wherein the joint reaches the crimping member.

15. The motor according to claim 10, wherein the rotor frame comprises an annular first end face facing in the axial direction, an annular second end face located radially inward from the first end face and projecting axially from the first end face, and a first circumferential surface located between the first end face and the second end face; the rotor cover comprises a third end face in contact with the first end face, a second circumferential surface in contact with the first circumferential surface, a fourth end face located opposite the third end face, and a sixth recess located in the second fixing portion and recessed axially from the fourth end face; and the joint portion is located in a circumferential groove formed by the sixth recess.

16. The motor according to claim 1, wherein the rotor comprises a plurality of fastening members for fastening the rotor frame and the rotor cover.

17. The motor according to claim 16, wherein the rotor frame comprises a plurality of third through holes located radially inward from the plurality of magnets and a plurality of fourth through holes located radially outward from the plurality of magnets, the rotor cover comprises a plurality of fifth through holes located radially inward from the plurality of magnets and a plurality of sixth through holes located radially outward from the plurality of magnets, and the plurality of fastening members comprises a plurality of first fastening members disposed in the third through hole and the fifth through hole and a plurality of second fastening members disposed in the fourth through hole and the sixth through hole.

18. The motor according to claim 17, wherein the diameter of the second fastening member is smaller than the diameter of the first fastening member.

19. The motor according to claim 18, wherein the number of the second fastening members is greater than the number of the first fastening members.

20. The motor according to claim 16, wherein the head of the fastening member is located on the rotor cover side.

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