Rotor and rotor manufacturing method

Abstract

This rotor (10) is provided with: an annular magnet part (22) in which a plurality of permanent magnets (31) are annularly disposed along the circumferential direction; a scattering prevention member (23) that is formed from a fiber-reinforced resin material obtained by solidifying a fiber bundle (52) with a resin base material (53), and that covers an outer peripheral surface (22a) of the annular magnet part over the entire circumference; and a magnet holding part (24) that has a pair of flange parts (26, 27) that extend outward in the radial direction and hold both sides in the axial direction of the annular magnet part. Each of the pair of flange parts has a flange outer peripheral surface (26a, 27a) having a circular shape when viewed from the axial direction. The outer peripheral surface of the annular magnet part has a circular shape when viewed from the axial direction. The scattering prevention member has: a magnet covering part (40) that covers the outer peripheral surface of the annular magnet part; and a pair of flange covering parts (41, 42) that respectively cover the flange outer peripheral surfaces of the pair of flange parts. At least one of the pair of flange parts is the small-diameter flange part (26, 27) in which radial dimensions (D1, D2) of the flange outer peripheral surface are set to be smaller than a diameter dimension (D3) of the outer peripheral surface of the annular magnet part.

Description

Rotor and method of manufacturing the rotor CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2023-207899, filed on December 8, 2023, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a rotor in a motor and a method for manufacturing the rotor.

[0003] For example, the rotor described in Patent Document 1 includes an annular magnet portion formed by circumferentially arranging multiple permanent magnets in a circular pattern, and a shatterproof member covering the entire outer periphery of the annular magnet portion. The rotor also has a pair of flanges that hold both axial ends of the annular magnet portion. The shatterproof member is formed from a fiber-reinforced resin material formed by solidifying fiber bundles with a resin base material. To form the shatterproof member, first, a sheet material in which the fiber bundles are impregnated with the resin base material is spirally wound around the outer periphery of the annular magnet portion. The sheet material is then heated to melt and harden it. This forms a cylindrical shatterproof member around the outer periphery of the annular magnet portion.

[0004] In the rotor described above, a large holding force of the shatterproof member is required to prevent each permanent magnet forming the annular magnet portion from falling off in the centrifugal direction. Therefore, when winding the sheet material forming the shatterproof member, the sheet material is wound while applying a large tension in the longitudinal direction. At this time, the sheet material begins to be wound around the outer circumferential surface of the flange portion one or more times along a plane perpendicular to the rotor axis. Then, once the desired tension can be applied to the sheet material, it is wound spirally around the outer circumferential surface of the annular magnet portion. This allows the shatterproof member to exert a large holding force throughout the entire axial direction of the annular magnet portion.

[0005] Patent No. 7064850

[0006] The shatterproof member formed as described above has a problem in that the axial end of the shatterproof member, which corresponds to the start of winding the sheet material, protrudes radially outward beyond the other parts of the shatterproof member. This requires a large gap between the shatterproof member and the stator to prevent interference between the protruding part of the axial end of the shatterproof member and the stator, which can result in a decrease in motor performance.

[0007] In a first aspect of the present disclosure, the rotor includes an annular magnet portion including a plurality of permanent magnets arranged in a circumferential direction, an anti-scattering member formed of a fiber-reinforced resin material formed by solidifying fiber bundles with a resin matrix and covering the entire outer periphery of the annular magnet portion, and a magnet holder having a pair of flanges extending radially outward and holding both axial sides of the annular magnet portion, wherein each of the pair of flanges has a flange outer periphery that is circular when viewed axially, the anti-scattering member has a magnet covering portion covering the outer periphery of the annular magnet portion, and a pair of flange covering portions covering the flange outer periphery of the pair of flanges, at least one of the pair of flanges being a small-diameter flange portion whose diameter is smaller than the diameter of the outer periphery of the annular magnet portion.

[0008] According to this configuration, the sheet material forming the shatterproof member starts to be wound from the small-diameter flange, which has an outer diameter smaller than that of the annular magnet. This allows the sheet material to be wound with the desired tension while suppressing radial outward protrusion of the winding start portion. Therefore, it is possible to suppress radial outward protrusion of the portion of the shatterproof member corresponding to the winding start of the sheet material. This allows the gap between the shatterproof member and the stator to be reduced, resulting in improved motor performance.

[0009] In a second aspect of the present disclosure, a method for manufacturing a rotor includes: an annular magnet portion formed by arranging a plurality of permanent magnets in a ring shape along the circumferential direction; a shatterproof member formed of a fiber-reinforced resin material formed by solidifying fiber bundles with a resin base material and covering the entire outer periphery of the annular magnet portion; and a magnet holding portion having a pair of flange portions extending radially outward and holding both axial sides of the annular magnet portion, each of the pair of flange portions having a flange outer periphery that is circular when viewed axially, the outer periphery of the annular magnet portion also being circular when viewed axially, and at least one of the pair of flange portions being a small-diameter flange portion whose diameter is set smaller than the diameter of the outer periphery of the annular magnet portion, and the manufacturing method includes, when starting to wind a sheet material that forms the shatterproof member, winding the sheet material around the outer periphery of the small-diameter flange portion along a plane perpendicular to the axis of the rotor to form a temporary winding portion, and then winding the sheet material spirally around the outer periphery of the annular magnet portion to form a main winding portion.

[0010] According to this manufacturing method, the sheet material forming the shatterproof member begins to be wound from the small-diameter flange, which has an outer diameter smaller than that of the annular magnet. This allows the sheet material to be wound with the desired tension while suppressing radial outward protrusion of the winding start portion. Therefore, it is possible to suppress radial outward protrusion of the portion of the shatterproof member corresponding to the winding start of the sheet material. This allows the gap between the shatterproof member and the stator to be reduced, resulting in improved motor performance.

[0011] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a perspective view of a rotor according to one embodiment, Fig. 2 is a perspective view showing a manufacturing process of the rotor according to the same embodiment, Fig. 3 is a cross-sectional view of the rotor according to the same embodiment, and Fig. 4 is a cross-sectional view showing a manufacturing process of the rotor according to the same embodiment.

[0012] An embodiment of a rotor and a method for manufacturing the rotor will now be described. A rotor 10 according to this embodiment, shown in FIG. 1, is one of the components constituting a motor. The rotor 10 is rotatably disposed on the inner periphery of a stator (not shown) that is configured in a substantially annular shape. The stator generates a rotating magnetic field for driving the rotor 10 to rotate when current is applied to its coil magnetic poles. The rotor 10 according to this embodiment is intended for use in a high-speed motor with a maximum operating speed of 12,000 rpm or more, for example.

[0013] (Configuration of Rotor 10) As shown in FIGS. 1 and 2, the rotor 10 of this embodiment includes a rotor base 21, an annular magnet portion 22, and a scattering prevention member 23.

[0014] The rotor base 21 is generally cylindrical and has a hollow structure for weight reduction, etc. One axial end of the rotor base 21 is integrally formed as an output shaft 21x.

[0015] 1 and 3, the rotor base 21 has a magnet holding portion 24 on the outer peripheral surface of the rotor base 21. The magnet holding portion 24 is formed around the entire circumferential circumference of the outer peripheral surface of the rotor base 21.

[0016] The magnet holding portion 24 includes a base portion 25, a first flange portion 26, and a second flange portion 27. The base portion 25 is, for example, cylindrical and centered on the axis L1 of the rotor 10. The first flange portion 26 and the second flange portion 27 each extend radially outward from the outer peripheral surface of the base portion 25. The first flange portion 26 and the second flange portion 27 each are provided around the entire circumference of the base portion 25. The magnet holding portion 24 has a magnet accommodating groove 28 formed by the outer peripheral surface of the base portion 25, the first flange portion 26, and the second flange portion 27. The magnet accommodating groove 28 is formed around the entire circumferential circumference of the magnet holding portion 24.

[0017] The first flange portion 26 has a first outer peripheral surface 26a that is circular and centered on the axis L1 when viewed in the axial direction. The outer diameter of the first flange portion 26, i.e., the diameter dimension D1 of the first outer peripheral surface 26a, is uniform throughout the entire first flange portion 26 in the axial direction.

[0018] The second flange portion 27 has a second outer peripheral surface 27a that is circular and centered on the axis L1 when viewed in the axial direction. The outer diameter of the second flange portion 27, i.e., the diameter dimension D2 of the second outer peripheral surface 27a, is uniform throughout the entire axial direction of the second flange portion 27. In the rotor 10 of this embodiment, the diameter dimension D1 of the first outer peripheral surface 26a and the diameter dimension D2 of the second outer peripheral surface 27a are set to be the same. Furthermore, for example, the axial lengths of the first outer peripheral surface 26a and the second outer peripheral surface 27a are set to be equal to each other.

[0019] (Configuration of the annular magnet portion 22) The annular magnet portion 22 is a permanent magnet group consisting of multiple permanent magnets 31 arranged in a ring shape along the circumferential direction. Each permanent magnet 31 forming the annular magnet portion 22 has, for example, a substantially rectangular shape. The annular magnet portion 22 has a cylindrical shape centered on the axis L1. The outer peripheral surface 22a of the annular magnet portion 22 is formed by the radially outer surfaces 31a of each permanent magnet 31. The outer peripheral surface 22a of the annular magnet portion 22 has a circular shape centered on the axis L1 when viewed from the axial direction. The outer diameter of the annular magnet portion 22, i.e., the diameter dimension D3 of the outer peripheral surface 22a, is uniform throughout the entire axial direction of the annular magnet portion 22. The outer peripheral surface 22a of the annular magnet portion 22 is covered by a shatterproof member 23 along the entire circumference.

[0020] The annular magnet portion 22 is disposed in the magnet accommodating groove 28 of the magnet holder 24. That is, the annular magnet portion 22 is disposed between the first flange portion 26 and the second flange portion 27 of the magnet holder 24. The first flange portion 26 of the magnet holder 24 abuts against one axial end of each permanent magnet 31 in the axial direction. The second flange portion 27 of the magnet holder 24 abuts against the other axial end of each permanent magnet 31 in the axial direction. Therefore, the first flange portion 26 and the second flange portion 27 respectively hold both axial ends of the annular magnet portion 22. The diameter D1 of the first outer peripheral surface 26a of the first flange portion 26 and the diameter D2 of the second outer peripheral surface 27a of the second flange portion 27 are each set smaller than the diameter D3 of the outer peripheral surface 22a of the annular magnet portion 22. The inner surface of each permanent magnet 31 abuts against the outer peripheral surface of the base 25 of the magnet holder 24. Furthermore, the side end faces 31b on both sides of each permanent magnet 31 in the circumferential direction of the rotor 10 abut against the side end faces 31b of adjacent permanent magnets 31 (see FIG. 1).

[0021] (Configuration of the Anti-Scattering Member 23) The anti-scattering member 23 constituting the rotor 10 has a generally cylindrical shape centered on the axis L1. The anti-scattering member 23 includes a magnet covering portion 40 covering the outer peripheral surface 22a of the annular magnet portion 22, a first flange covering portion 41 covering the first outer peripheral surface 26a of the first flange portion 26, and a second flange covering portion 42 covering the second outer peripheral surface 27a of the second flange portion 27. The magnet covering portion 40 covers the outer peripheral surface 22a of the annular magnet portion 22 over the entire circumferential direction. The first flange covering portion 41 covers the first outer peripheral surface 26a of the first flange portion 26 over the entire circumferential direction. The second flange covering portion 42 covers the second outer peripheral surface 27a of the second flange portion 27 over the entire circumferential direction. The first flange covering portion 41 and the second flange covering portion 42 are formed at both axial ends of the anti-scattering member 23, respectively.

[0022] The first flange cover portion 41 has a first abutment portion 43 that abuts against the outer peripheral edge of the axial end 22b of the annular magnet portion 22 in the axial direction. The first abutment portion 43 abuts against the axial end 22b of the annular magnet portion 22 at a step formed by the difference in outer diameter between the annular magnet portion 22 and the first flange portion 26. The second flange cover portion 42 has a second abutment portion 44 that abuts against the outer peripheral edge of the other axial end 22c of the annular magnet portion 22 in the axial direction. The second abutment portion 44 abuts against the other axial end 22c of the annular magnet portion 22 at a step formed by the difference in outer diameter between the annular magnet portion 22 and the second flange portion 27. The first abutment portion 43 and the second abutment portion 44 prevent the anti-scattering member 23 from shifting in the axial direction relative to the annular magnet portion 22.

[0023] (Regarding the Forming of the Shatterproof Member 23) As shown in FIG. 2 , the shatterproof member 23 is formed by winding a sheet material 51 multiple times around a portion of the rotor 10, including the outer circumferential surface 22 a of the annular magnet portion 22. The sheet material 51 is a sheet-like material in which fiber bundles 52 are impregnated with a resin substrate 53. For example, a carbon fiber reinforced plastic (CFRP) material is used for the sheet material 51. When a carbon fiber reinforced plastic material is used for the sheet material 51, the fiber bundles 52 are made of carbon fiber. The resin substrate 53 is made of a thermosetting resin, for example. In this embodiment, the sheet material 51 has a volume content of the fiber bundles 52 of, for example, 60 to 70%. After being wound multiple times around the outer circumferential surface 22 a of the annular magnet portion 22, the sheet material 51 is heated to melt and harden. This forms the shatterproof member 23.

[0024] (Method for Manufacturing the Rotor 10) Next, a method for manufacturing the rotor 10 will be described along with the operation of this embodiment. First, a plurality of permanent magnets 31 are arranged in the circumferential direction in the magnet accommodating grooves 28 of the magnet holding portion 24 in the rotor base 21. This forms the annular magnet portion 22 made up of the plurality of permanent magnets 31.

[0025] Next, the sheet material 51 is wound around the first outer peripheral surface 26a of the first flange portion 26, the outer peripheral surface 22a of the annular magnet portion 22, and the second outer peripheral surface 27a of the second flange portion 27. At this time, the winding of the sheet material 51 is started from either the first outer peripheral surface 26a of the first flange portion 26 or the second outer peripheral surface 27a of the second flange portion 27. Figures 2 and 4 show an example in which the winding of the sheet material 51 is started from the first outer peripheral surface 26a of the first flange portion 26. Furthermore, when winding the sheet material 51, tension is applied to the sheet material 51 in the longitudinal direction.

[0026] When starting to wind the sheet material 51, first, the provisionally wound portion 61 is wound, for example, one turn, around the first outer peripheral surface 26a of the first flange portion 26. The provisionally wound portion 61 is wound along a plane perpendicular to the axis L1 of the rotor 10. In other words, the provisionally wound portion 61 is wound without being displaced in the axial direction.

[0027] The temporary winding portion 61 is wound around one axial end 22b of the annular magnet portion 22. As shown in Figure 4, one axial end 61a of the temporary winding portion 61 abuts against one axial end 22b of the annular magnet portion 22. The width of the sheet material 51 is set smaller than the axial length of the first outer peripheral surface 26a of the first flange portion 26. This prevents the temporary winding portion 61 from protruding from the first flange portion 26 in the axial direction.

[0028] In a configuration in which the temporary winding portion 61 is wound only once, it is preferable to set the difference Da between the diameter D1 of the first outer peripheral surface 26a of the first flange portion 26 and the diameter D3 of the outer peripheral surface 22a of the annular magnet portion 22 to be equal to the thickness T of the sheet material 51. This makes the outer peripheral surface 61b of the temporary winding portion 61 and the outer peripheral surface 22a of the annular magnet portion 22 flush with each other, preventing any step from occurring between these outer peripheral surfaces 61b and 22a.

[0029] After the temporary winding portion 61 has been wound one turn, the sheet material 51 is wound spirally while being displaced in the axial direction to form the final winding portion 62. The final winding portion 62 starts to be wound on the outer peripheral surface of the winding start end 61c (see FIG. 2) of the temporary winding portion 61. As a result, the winding start end 61c of the temporary winding portion 61 is sandwiched and fixed between the first outer peripheral surface 26a of the first flange portion 26 and the final winding portion 62. This makes it possible to wind the final winding portion 62 while applying a desired tension to the sheet material 51.

[0030] The main winding portion 62 is wound from the outer peripheral surface 61b of the temporary winding portion 61 onto the outer peripheral surface 61b of the annular magnet portion 22. As described above, the outer peripheral surface 61b of the temporary winding portion 61 and the outer peripheral surface 22a of the annular magnet portion 22 are flush with each other, so the main winding portion 62 can be wound without bending at the boundary between the temporary winding portion 61 and the annular magnet portion 22. In addition, the main winding portion 62 is wound, for example, up to the second outer peripheral surface 27a of the second flange portion 27.

[0031] In the spirally wound main winding portion 62, the axial end faces of axially adjacent sheet material 51 may be in contact with each other, or a gap may be provided between the axial end faces, as shown in Fig. 4. The main winding portion 62 may be configured with only one layer, or may be configured with multiple layers as shown by the two-dot chain line in Fig. 4. In the case where the main winding portion 62 is configured with multiple layers, the sheet material 51 may be cut for each layer, or all layers may be continuously wound with a single sheet material 51.

[0032] After the sheet material 51 is wound as described above, a heating step is carried out in which the sheet material 51 is heated to melt and harden the resin base material 53. As a result, the resin base material 53 is fused and hardened integrally to form a cylindrical shatter prevention member 23 on the outer periphery of the annular magnet portion 22. Note that in this heating step, it is preferable to heat the sheet material 51 while maintaining a state in which tension is applied to the sheet material 51 using a jig (not shown) or the like.

[0033] (Advantages of the Present Embodiment) The advantages of the present embodiment are described below. (1) The first flange portion 26 of the rotor 10 is configured as a small-diameter flange portion in which the diameter D1 of the first outer peripheral surface 26a is set smaller than the diameter D3 of the outer peripheral surface 22a of the annular magnet portion 22. With this configuration, by starting to wind the sheet material 51 forming the shatterproof member 23 from the first outer peripheral surface 26a of the first flange portion 26 serving as the small-diameter flange portion, it is possible to wind the sheet material 51 with a desired tension while suppressing radial outward protrusion of the first flange covering portion 41 corresponding to the winding start portion. This makes it possible to reduce the gap between the shatterproof member 23 and the stator, thereby improving motor performance.

[0034] In the rotor 10 of this embodiment, the second flange portion 27 is also configured as a small-diameter flange portion in which the diameter D2 of the second outer peripheral surface 27a is set smaller than the diameter D3 of the outer peripheral surface 22a of the annular magnet portion 22. Therefore, even if the sheet material 51 is wound multiple times at the end of the winding at a position corresponding to the second flange portion 27, it is possible to prevent the second flange covering portion 42 of the shatter prevention member 23 from protruding radially outward.

[0035] (2) The first flange covering portion 41 of the shatter prevention member 23 has a first contact portion 43 that axially contacts the one axial end 22b of the annular magnet portion 22. The second flange covering portion 42 of the shatter prevention member 23 has a second contact portion 44 that axially contacts the other axial end 22c of the annular magnet portion 22. Therefore, the first contact portion 43 and the second contact portion 44 axially contact both axial ends 22b, 22c of the annular magnet portion 22, respectively, thereby preventing the shatter prevention member 23 from shifting axially relative to the annular magnet portion 22.

[0036] (3) When starting to wind the sheet material 51 that forms the shatterproof member 23, the sheet material 51 is wound around the first outer peripheral surface 26a of the first flange portion 26 along a plane perpendicular to the axis L1 of the rotor 10, forming a provisionally wound portion 61. The sheet material 51 is then spirally wound around the outer peripheral surface 22a of the annular magnet portion 22, forming a final wound portion 62. According to this aspect, the provisionally wound portion 61 is sandwiched and fixed between the first flange portion 26 and the final wound portion 62, thereby applying a desired tension to the sheet material 51, and then the sheet material 51 is spirally wound around the outer peripheral surface 22a of the annular magnet portion 22. Therefore, a large holding force for the shatterproof member 23 can be exerted throughout the entire axial direction of the annular magnet portion 22.

[0037] (4) When winding the sheet material 51, the temporary winding portion 61 is wound so as to be in axial contact with the axial end 22b of the annular magnet portion 22. According to this embodiment, the temporary winding portion 61 can be wound so as not to create a gap between the temporary winding portion 61 and the axial end 22b of the annular magnet portion 22. Therefore, the shatter prevention member 23 can be suitably formed.

[0038] (5) The temporary winding portion 61 is wound N times around the first outer peripheral surface 26a of the first flange portion 26. When the thickness of the sheet material 51 is T, the dimensional difference Da between the diameter D3 of the outer peripheral surface 22a of the annular magnet portion 22 and the diameter D1 of the first outer peripheral surface 26a of the first flange portion 26 is set to be Da = T × N. That is, in this embodiment, since the temporary winding portion 61 is wound one time around the first outer peripheral surface 26a of the first flange portion 26, the dimensional difference Da between the diameter D3 of the outer peripheral surface 22a of the annular magnet portion 22 and the first outer peripheral surface 22a of the annular magnet portion 22 is set to be equal to the thickness T of the sheet material 51. According to this aspect, the outer peripheral surface 61b of the temporary winding portion 61 and the outer peripheral surface 22a of the annular magnet portion 22 can be made flush with each other. Furthermore, by making the outer surface 61b of the temporary winding portion 61 flush with the outer surface 22a of the annular magnet portion 22, it is possible to wind the main winding portion 62 without bending it at the boundary between the temporary winding portion 61 and the annular magnet portion 22.

[0039] (6) The width of the sheet material 51 is set to be smaller than the axial length of the first outer peripheral surface 26 a of the first flange portion 26. This prevents the temporary winding portion 61 from protruding from the first flange portion 26 in the axial direction.

[0040] (Other Embodiments) The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0041] The number of turns of the temporary winding portion 61 is not limited to one, but may be two or more. It is desirable that the diameter D1 of the first outer peripheral surface 26 a of the first flange portion 26 and the diameter D2 of the second outer peripheral surface 27 a of the second flange portion 27 be changed as appropriate depending on the number of turns of the temporary winding portion 61.

[0042] In the above embodiment, both the first flange portion 26 and the second flange portion 27 are configured as small-diameter flange portions having an outer diameter smaller than that of the annular magnet portion 22, but this is not limited to this, and for example, only the first flange portion 26 may be configured as a small-diameter flange portion.

[0043] In the rotor 10 of the above embodiment, the fiber bundles 52 included in the sheet material 51 may be changed to fibers other than carbon fiber. Additionally, the configuration of the rotor 10 may be changed as appropriate. Furthermore, the shape of the rotor base 21 may be changed as appropriate.

[0044] In the above embodiment, the rotor 10 and the stator are radially opposed to each other, but the present invention may be applied to an axial type in which the rotor and the stator are axially opposed to each other.

[0045] While the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0046] (Note) The features of the present disclosure are as follows: [1] A rotor (10) including an annular magnet portion (22) in which a plurality of permanent magnets (31) are arranged in an annular shape along the circumferential direction, a scattering prevention member (23) formed of a fiber-reinforced resin material in which fiber bundles (52) are solidified with a resin base material (53) and covering the entire outer periphery (22a) of the annular magnet portion, and a magnet holding portion (24) having a pair of flange portions (26, 27) extending radially outward and holding both axial sides of the annular magnet portion, each of the pair of flange portions being a flange outer periphery that forms a circle when viewed in the axial direction. a rotor having a surface (26a, 27a) of the annular magnet portion, the outer peripheral surface of which is circular when viewed in the axial direction, the anti-scattering member having a magnet covering portion (40) that covers the outer peripheral surface of the annular magnet portion, and a pair of flange covering portions (41, 42) that cover the flange outer peripheral surfaces of the pair of flange portions, at least one of the pair of flange portions being a small-diameter flange portion (26, 27) having a diameter dimension (D1, D2) of the flange outer peripheral surface that is set smaller than a diameter dimension (D3) of the outer peripheral surface of the annular magnet portion.

[0047] [2] The rotor described in [1] above, wherein at least one of the pair of flange covering portions has an abutment portion (43, 44) that abuts axially against the axial end portion (22b, 22c) of the annular magnet portion.

[0048] [3] A method for manufacturing a rotor (10) comprising: an annular magnet portion (22) in which a plurality of permanent magnets (31) are arranged in a ring shape along the circumferential direction; a scattering prevention member (23) formed of a fiber-reinforced resin material in which fiber bundles (52) are solidified with a resin base material (53) and covering the entire outer periphery of the outer periphery of the annular magnet portion; and a magnet holding portion (24) having a pair of flange portions (26, 27) extending radially outward and holding both axial sides of the annular magnet portion, respectively, wherein each of the pair of flange portions has a flange outer periphery surface (26a, 27a) that is circular when viewed from the axial direction, and the outer periphery surface of the annular magnet portion is also circular when viewed from the axial direction, At least one of the pair of flange portions is a small-diameter flange portion (26, 27) having a diameter dimension (D1, D2) of the flange outer peripheral surface set smaller than a diameter dimension (D3) of the outer peripheral surface of the annular magnet portion, and the manufacturing method includes, when starting to wind a sheet material (51) that forms the anti-scattering member, forming a temporary winding portion (61) by winding the sheet material along a plane perpendicular to the axis (L1) of the rotor on the outer peripheral surface of the small-diameter flange portion, and then winding the sheet material spirally around the outer peripheral surface of the annular magnet portion to form a main winding portion (62).

[0049] [4] The manufacturing method of the rotor according to the above [3], wherein the temporary wound portion is wound so as to be in axial contact with the axial ends (22 b, 22 c) of the annular magnet portion. [5] The manufacturing method of the rotor according to the above [3] or [4], wherein the temporary wound portion is wound N times around the outer circumferential surface of the small diameter flange portion, and the dimensional difference Da between the diameter of the outer circumferential surface of the annular magnet portion and the diameter of the outer circumferential surface of the small diameter flange portion is set so as to satisfy Da = T × N, where T is the thickness of the sheet material.

Claims

1. An annular magnet section (22) in which multiple permanent magnets (31) are arranged in a ring along the circumferential direction, A scattering prevention member (23) is formed from a fiber-reinforced resin material, which is made by solidifying a fiber bundle (52) with a resin base material (53), and covers the entire outer surface (22a) of the annular magnet portion. A rotor (10) comprising a magnet holder (24) having a pair of flange portions (26, 27) that extend radially outward and hold the axial sides of the annular magnet portion, Each of the pair of flange portions has a circular flange outer surface (26a, 27a) when viewed from the axial direction. The outer surface of the annular magnet portion is circular when viewed from the axial direction. The scattering prevention member has a magnet covering portion (40) that covers the outer peripheral surface of the annular magnet portion, and a pair of flange covering portions (41, 42) that cover the outer peripheral surfaces of the flanges of the pair of flange portions, At least one of the pair of flange portions is a small-diameter flange portion (26, 27) in which the diameter dimensions (D1, D2) of the outer surface of the flange are set to be smaller than the diameter dimension (D3) of the outer surface of the annular magnet portion. The aforementioned scattering prevention member is formed by winding a sheet material (51) around the portion of the rotor including the outer circumferential surface of the annular magnet portion. The width of the sheet material is set to be smaller than the axial length of the outer surface of the small diameter flange portion. Rotor.

2. At least one of the pair of flange covering portions has contact portions (43, 44) that abut in the axial direction against the axial ends (22b, 22c) of the annular magnet portion. The rotor according to claim 1.

3. The difference in dimensions (Da) between the outer diameter (D1) of the small diameter flange portion and the outer diameter (D3) of the annular magnet portion is set to be equal to the thickness (T) of the sheet material. The rotor according to claim 1.

4. An annular magnet section (22) in which multiple permanent magnets (31) are arranged in a ring along the circumferential direction, A scattering prevention member (23) is formed from a fiber-reinforced resin material, which is made by solidifying a fiber bundle (52) with a resin base material (53), and covers the entire outer surface (22a) of the annular magnet portion. A method for manufacturing a rotor (10) comprising a magnet holder (24) having a pair of flange portions (26, 27) that extend radially outward and hold the axial sides of the annular magnet portion, respectively, Each of the pair of flange portions has a circular flange outer surface (26a, 27a) when viewed from the axial direction. The outer surface of the annular magnet portion is circular when viewed from the axial direction. At least one of the pair of flange portions is a small-diameter flange portion (26, 27) in which the diameter dimensions (D1, D2) of the outer surface of the flange are set to be smaller than the diameter dimension (D3) of the outer surface of the annular magnet portion. The aforementioned manufacturing method is At the start of winding the sheet material (51) that forms the scattering prevention member, a temporary winding portion (61) is formed by winding the sheet material along a plane perpendicular to the axis (L1) of the rotor on the outer circumferential surface of the small diameter flange portion, The method then involves winding the sheet material spirally around the outer surface of the annular magnet portion to form the main winding portion (62), The width of the sheet material is set to be smaller than the axial length of the outer surface of the small diameter flange portion. A method for manufacturing a rotor.

5. The temporary winding portion is wound so as to be in axial contact with the axial ends (22b, 22c) of the annular magnet portion. The method for manufacturing a rotor according to claim 4.

6. The temporary winding portion is wound N times around the outer circumferential surface of the small diameter flange portion. When the thickness of the sheet material is T, the dimensional difference Da between the diameter of the outer surface of the annular magnet portion and the diameter of the outer surface of the small-diameter flange portion is Da = T × N It is set to be so The method for manufacturing a rotor according to claim 4.