Rotor, motor, and method of manufacturing rotor

Abstract

To suppress the performance degradation and enable the performance to be properly demonstrated.SOLUTION: A rotor according to the present disclosure includes a shaft rotatable around a rotation axis, a cylindrical bonded magnet covering the outer surface of the shaft, a cylindrical armature ring made of fiber reinforced resin and covering the outer surface of the bonded magnet, and an annular end ring covering the outer surface of the shaft and positioned facing the end face of the bonded magnet in the axial direction of the rotation axis. A groove extending in the axial direction is formed on one of the inner surface of the armature ring and the outer surface of the end ring, and the other of the inner surface of the armature ring and the outer surface of the end ring includes a protrusion that fits into the groove.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a rotor, a motor, and a method for manufacturing a rotor. [Background technology]

[0002] Patent Document 1 discloses a technology related to a rotor. This rotor is configured by forming multiple magnetic poles around a shaft member. The multiple magnetic poles are formed by injecting a molding material, which is a mixture of magnetic material powder and resin as a binder, into a mold around which multiple magnets are arranged. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-7998 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a rotor as described in Patent Document 1, an armor is disposed around the magnetic poles. Unlike an armor made of metal, an armor made of fiber-reinforced resin may not be suitable for shrink fitting to connect to an end ring, and may not be properly connected to the end ring. Due to this factor, when the rotor rotates at high speed, the members constituting the rotor may not be properly connected to each other, and the efficiency of torque transmission from the bonded magnet to the shaft may decrease. Such a decrease in torque transmission efficiency may lead to a decrease in the output efficiency of the rotor, which may cause a decrease in rotor performance.

[0005] The present disclosure describes a rotor, a motor, and a method for manufacturing a rotor that are capable of suppressing performance degradation and allowing performance to be appropriately exhibited. [Means for solving the problem]

[0006] A rotor according to one embodiment of the present disclosure comprises a shaft rotatable about a rotation axis, a cylindrical bonded magnet covering the outer peripheral surface of the shaft, a cylindrical armature made of fiber-reinforced resin and covering the outer peripheral surface of the bonded magnet, and annular end rings covering the outer peripheral surface of the shaft and positioned facing the end face of the bonded magnet in the axial direction of the rotation axis, wherein a groove extending in the axial direction is formed on one of the inner peripheral surface of the armature and the outer peripheral surface of the end ring, and the other of the inner peripheral surface of the armature and the outer peripheral surface of the end ring has a protrusion that fits into the groove.

[0007] In the rotor of the present disclosure, torque is transmitted from the bonded magnet to the shaft by utilizing the frictional force generated between the outer peripheral surface of the bonded magnet and the inner peripheral surface of the armor ring. This frictional force is proportional to the normal force acting on these surfaces. Here, the rotation of the bonded magnet causes a centrifugal force to act on the bonded magnet, which presses the armor ring outward in the radial direction of the rotation axis. This increases the normal force described above, so that the frictional force generated between the outer peripheral surface of the bonded magnet and the inner peripheral surface of the armor ring increases, making it difficult for slippage to occur between the outer peripheral surface of the bonded magnet and the inner peripheral surface of the armor ring. This frictional force is transmitted to the end ring connected to the armor ring. Here, the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring have grooves and protrusions that fit together. By fitting the protrusions into the grooves formed on the peripheral surface, the side surfaces of the protrusions face the side surfaces of the grooves in the circumferential direction, so that the relative movement of the grooves in the circumferential direction with respect to the protrusions is restricted. In other words, the grooves and protrusions function as a circumferential slip stopper (rotation stopper) of the armor ring relative to the end ring. This makes it possible to prevent slippage in the circumferential direction between the inner circumferential surface of the armor ring and the outer circumferential surface of the end ring, and to prevent a decrease in the efficiency of torque transmission from the armor ring to the end ring, thereby preventing a decrease in rotor performance and enabling the rotor to perform optimally.

[0008] In some embodiments, the armor ring may be provided between a first end ring and a second end ring that is different from the first end ring, and may be spaced apart from the first end ring along the axial direction. In this case, the armor ring, the first end ring, and the second end ring can adequately cover the space into which the material of the bonded magnet is injected. In addition, even if an axial force is applied to the armor ring by the thermally expanding bonded magnet, the armor ring can move or extend toward the first end ring while keeping the protrusions engaged with the grooves. Therefore, even if the bonded magnet thermally expands when the armor ring is provided between the first end ring and the second end ring, the connection between the armor ring and the end rings is maintained, and therefore a decrease in torque transmission efficiency can be suppressed.

[0009] In some embodiments, one of the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring may have a first groove that is a groove and a second groove that is different from the first groove, and the other of the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring may have a first protrusion that is a protrusion and a second protrusion that is different from the first protrusion. In this case, when the armor ring rotates in conjunction with the rotation of the bonded magnet, the rotational force is prevented from concentrating only on the first groove and the first protrusion, and the rotational force can be distributed to multiple grooves and multiple protrusions.

[0010] A motor according to one embodiment of the present disclosure includes any one of the rotors described above and a stator arranged to surround the rotor. Since this motor includes any one of the rotors described above, torque is transmitted from the bonded magnet to the shaft via the armature, as described above. In addition, by properly maintaining the connection between the armature and the end rings, it is possible to prevent the armature from slipping against the end rings in the circumferential direction. As a result, it is possible to prevent the performance of the rotor and the motor from deteriorating, and to allow the rotor and the motor to perform appropriately.

[0011] A manufacturing method of a rotor according to one embodiment of the present disclosure includes the steps of forming a groove extending in the axial direction of the rotation axis on one of the inner surface of an armour ring made of fiber reinforced resin and the outer surface of an annular end ring, forming a protrusion on the other of the inner surface of the armour ring and the outer surface of the end ring, positioning the armour ring so as to cover the outer surface of a shaft that can rotate around the rotation axis, positioning the end ring at the end of the armour ring in the axial direction so as to cover the outer surface of the shaft and fitting the protrusion into the groove, and injection molding a bonded magnet into a space surrounded by the armour ring and the end ring so as to cover the outer surface of the shaft.

[0012] In the rotor manufacturing method of the present disclosure, an armor ring and an end ring are respectively arranged on a shaft. A bonded magnet is injection molded in a space surrounded by the armor ring and the end ring so as to cover the outer circumferential surface of the shaft. The armor ring and the end ring, which are made of fiber-reinforced resin, are properly connected by grooves and protrusions extending in the axial direction, even if they are not shrink-fitted. As described above, in the rotor manufactured by the above process, torque is transmitted from the bonded magnet to the shaft via the armor ring. In addition, the connection between the armor ring and the end ring is properly maintained, and slippage of the inner peripheral surface of the armor ring against the outer peripheral surface of the bonded magnet in the circumferential direction can be suppressed. As a result, deterioration of the performance of the rotor can be suppressed, and the performance of the rotor can be properly exhibited. Effect of the Invention

[0013] According to some aspects of the present disclosure, a rotor, a motor, and a method for manufacturing a rotor are provided that are capable of suppressing performance degradation and allowing the performance to be appropriately exhibited. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing a motor including a rotor according to one embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing the rotor of FIG. [Diagram 3]FIG. 3 is a plan view showing the inner circumferential surface of the armouring in the rotor. [Figure 4] FIG. 4 is a flowchart showing a method for manufacturing a rotor. [Diagram 5] FIG. 5 is a cross-sectional view showing a rotor according to a first modified example. [Figure 6] FIG. 6 is a cross-sectional view showing a rotor according to a second modified example. [Figure 7] FIG. 7 is a cross-sectional view showing a rotor according to a third modified example. [Figure 8] FIG. 8 is a cross-sectional view showing a rotor according to a fourth modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment will be described with reference to the drawings. In the description of the drawings, the same elements or corresponding elements are denoted by the same reference numerals, and redundant description may be omitted.

[0016] <Motor> A motor 1 including a rotor 10 according to this embodiment will be described with reference to FIG. 1. The motor 1 shown in FIG. 1 is, for example, a high-speed rotating electric motor. The motor 1 shown in FIG. 1 is applied, for example, to the aerospace field. In this embodiment, the motor 1 is a rotary aircraft motor, and functions as a power source for a fuel pump (not shown). The motor 1 may also be used for other purposes. Note that FIG. 1 shows a cross section of the motor 1 taken along a plane passing through a rotation axis L of a shaft 11, which will be described later.

[0017] As shown in FIG. 1, the motor 1 includes a rotor 10, which is a rotor, and a stator 20, which is a stator. The stator 20 includes a cylindrical core 21 arranged around the rotor 10, and a coil 22 formed by winding a conductor around the core 21. When an alternating current is supplied to the coil 22 through the conductor, the stator 20 generates a rotating magnetic field around the rotor 10. This rotating magnetic field generates a torque F (see FIG. 2 described later) in the rotor 10. As a result, the rotor 10 rotates around the rotation axis L. In the following description, the axial direction D1 indicates a direction extending along the rotation axis L, and the circumferential direction D2 indicates a direction along a ring centered on the rotation axis L. The radial direction indicates a direction perpendicular to the rotation axis L.

[0018] <Rotor> The rotor 10 has, for example, a shaft 11 to which an impeller (not shown) of a fuel pump is connected, a bonded magnet 12 arranged to surround the shaft 11, an armor ring 50 arranged to surround the bonded magnet 12, and a first end ring 30 and a second end ring 40 that sandwich the bonded magnet 12 in the axial direction D1. The shaft 11 has a cylindrical shape with the rotation axis L as its central axis, and is arranged to be rotatable around the rotation axis L.

[0019] The bonded magnet 12 has a cylindrical shape with the rotation axis L as the central axis. The shaft 11 is inserted inside the bonded magnet 12, and the inner peripheral surface 12a of the bonded magnet 12 covers the outer peripheral surface 11a of the shaft 11. The bonded magnet 12 is a magnet formed by kneading fine magnets into resin, rubber, or the like. The bonded magnet 12 is also called a rubber magnet or a plastic magnet. The bonded magnet 12 is formed, for example, by injection molding between the shaft 11 and the armor ring 50. Specifically, a binder material is injected in a molten state between the outer peripheral surface 11a of the shaft 11 and the inner peripheral surface 50a of the armor ring 50, and the binder material is cooled and solidified to form the bonded magnet 12. As a result, the inner peripheral surface 12a of the bonded magnet 12 is directly bonded (adhered) to the outer peripheral surface 11a of the shaft 11. Similarly, the outer peripheral surface 12 b of the bonded magnet 12 is directly joined (adhered) to the inner peripheral surface 50 a of the armoring 50 .

[0020] Each of the first end ring 30 and the second end ring 40 is an annular member with the rotation axis L as the central axis. Each of the first end ring 30 and the second end ring 40 has, for example, a circular ring shape. The first end ring 30 and the second end ring 40 are arranged so as to cover both end faces of the bonded magnet 12 in the axial direction D1, respectively.

[0021] The shaft 11 is inserted through central holes (central holes 31a, 32a, 41a, 42a described below) of the first end ring 30 and the second end ring 40. Specifically, the first end ring 30 and the second end ring 40 are attached to the shaft 11 by fastening with screws or by press fitting, and the central holes of the first end ring 30 and the second end ring 40 are in close contact with the outer circumferential surface 11a of the shaft 11. The first end ring 30 and the second end ring 40 do not have to be press fitted into the shaft 11.

[0022] The first end ring 30 and the second end ring 40 may be made of a non-magnetic metal such as titanium (e.g., Ti-6Al-4V), a thermosetting resin, or a thermoplastic resin. The first end ring 30 and the second end ring 40 have a function of transmitting the torque F of the bonded magnet 12 to the shaft 11. The first end ring 30 and the second end ring 40 also have a function of restricting (preventing) the movement of the bonded magnet 12 in the axial direction D1 relative to the shaft 11.

[0023] The first end ring 30 has a vent hole (not shown), and the second end ring 40 has a molding hole (not shown). The vent hole is a hole that can discharge gas from the space surrounded by the armor ring 50, the first end ring 30, and the second end ring 40. The molding hole is a hole that can inject a molten binder material. In this embodiment, a bond magnet 12 is formed in the vent hole and the molding hole. Note that the present disclosure is not limited to the case where the bond magnet 12 is formed in the vent hole and the molding hole, and the bond magnet 12 may not be formed inside at least one of the vent hole and the molding hole.

[0024] The armor ring 50 has a cylindrical shape with the rotation axis L as the central axis. The armor ring 50 accommodates the bond magnet 12 and at least a part of each of the first end ring 30 and the second end ring 40. The inner peripheral surface 50a of the armor ring 50 covers the outer peripheral surface 12b of the bond magnet 12 and at least a part of the outer peripheral surfaces of the first end ring 30 and the second end ring 40 (outer peripheral surfaces 31b, 41b described below). In the example shown in FIG. 1, the armor ring 50 accommodates a part of the first end ring 30 and the second end ring 40 on the bond magnet 12 side (lid portions 31, 41 described below). The armor ring 50 and the first end ring 30 are connected by a groove 60 and a protrusion 70 described below. The armor ring 50 and the second end ring 40 may be bonded by an adhesive or may not be bonded.

[0025] A space 15 is formed on the radial outside of the outer circumferential surface 11a of the shaft 11, which is covered by the armor ring 50, the first end ring 30, and the second end ring 40. The space 15 is a cylindrical space. The bonded magnet 12 is disposed in the space 15. The armor ring 50 is made of, for example, fiber reinforced resin. The armor ring 50 may be made of, for example, carbon fiber reinforced plastic (CFRP). The shaft 11, the armor ring 50, the bonded magnet 12, the first end ring 30, and the second end ring 40 rotate together around the rotation axis L.

[0026] Next, the configuration of the rotor 10 will be described in more detail with further reference to Figures 1 and 2. Figure 2 shows a cross section of the rotor 10 in a direction perpendicular to the rotation axis L. As shown in Figures 1 and 2, the first end ring 30 has a cover portion 31 and a protruding portion 32. The second end ring 40 has a cover portion 41 and a protruding portion 42.

[0027] The lids 31, 41 cover both end faces of the bonded magnet 12 in the axial direction D1. The lids 31, 41 are disk-shaped. The lids 31, 41 have central holes 31a, 41a extending along the rotation axis L and through which the shaft 11 can be inserted. The outer peripheral surfaces 31b, 41b of the lids 31, 41 face the inner peripheral surface 50a of the armor ring 50. The outer peripheral surfaces 31b, 41b of the lids 31, 41 are in contact with, for example, the inner peripheral surface 50a of the armor ring 50. In the axial direction D1, at least a part of the lids 31, 41 is provided at a position covered by the armor ring 50. The lids 31, 41 have a function of restricting (preventing) the movement of the armor ring 50 in the rotational radial direction relative to the shaft 11.

[0028] The protrusions 32, 42 are provided on the opposite side of the lid portions 31, 41 from the bonded magnet 12 in the axial direction D1. The protrusions 32, 42 are each integrally formed with the lid portions 31, 41 in the axial direction D1. The protrusions 32, 42 protrude radially outward from the lid portions 31, 41, respectively. The outward direction refers to the direction moving away from the shaft 11 in the radial direction. The protrusions 32, 42 are disk-shaped portions. The protrusions 32, 42 are formed with central holes 32a, 42a that extend along the rotation axis L and through which the shaft 11 can be inserted.

[0029] The protrusion 32 has an end face 32b extending in the radial and circumferential directions. The end face 32b of the protrusion 32 faces one end face 50b of the armor ring 50 in the axial direction D1. The protrusion 42 has an end face 42b extending in the radial and circumferential directions. The end face 42b of the protrusion 42 faces the other end face 50c of the armor ring 50 in the axial direction D1. The armor ring 50 is provided at a position sandwiched between the end faces 32b, 42b of the protrusions 32, 42. The protrusions 32, 42 have the function of restricting (preventing) movement of the armor ring 50 in the axial direction D1 relative to the shaft 11.

[0030] The length from the end face 32b of the protrusion 32 to the end face 42b of the protrusion 42 in the axial direction D1 is longer than the length of the armor ring 50 in the axial direction D1. The armor ring 50 is spaced apart from the first end ring 30 along the axial direction D1. Specifically, when the armor ring 50 is not moved at least by the bond magnet 12, the end face 50b of the armor ring 50 is disposed at a position spaced apart from the end face 32b of the protrusion 32 in the axial direction D1. Even when the armor ring 50 is moved or extended by the bond magnet 12, the end face 50b of the armor ring 50 is spaced apart from the end face 32b of the protrusion 32 in the axial direction D1. When the armor ring 50 is moved or extended by the bond magnet 12, the end face 50c of the armor ring 50 may be in contact with the end face 42b of the protrusion 42 in the axial direction D1 or may be spaced apart.

[0031] A groove extending in the axial direction D1 is formed on one of the inner circumferential surface 50a of the armor ring 50 and the outer circumferential surface 31b of the cover portion 31 of the first end ring 30. In addition, the other of the inner circumferential surface 50a of the armor ring 50 and the outer circumferential surface 31b of the cover portion 31 of the first end ring 30 has a protrusion that fits into the groove 60. In this embodiment, the groove 60 extending in the axial direction D1 is formed on the inner circumferential surface 50a of the armor ring 50, and the outer circumferential surface 31b of the cover portion 31 of the first end ring 30 has a protrusion 70 that fits into the groove 60. In this embodiment, the first end ring 30 has one protrusion 70.

[0032] FIG. 3 shows a view of a part of the inner peripheral surface 50a of the armor ring 50 as seen from the inside. As shown in FIGS. 1 to 3, the groove 60 extends in the axial direction D1 from the end face 50b of the armor ring 50 toward the end face 50c. When the armor ring 50 is not moved by at least the bond magnet 12, the groove 60 may be connected to the space 15. The groove 60 opens toward the first end ring 30 side. That is, the groove 60 is formed in a part of the end face 50b. The end of the groove 60 on the end face 50c side in the axial direction D1 is arc-shaped when viewed from the radial direction. The depth of the groove 60 in the radial direction is, for example, smaller than the thickness of the armor ring 50. The cross-sectional shape of the groove 60 on a plane perpendicular to the extension direction of the groove 60 is, for example, rectangular. The cross-sectional shape of the groove 60 is not limited to a rectangular shape and may be another shape. The groove 60 is formed, for example, by groove-grooving the inner circumferential surface 50a of the armoring 50.

[0033] The protrusion 70 is disposed so as to correspond to the groove 60 in the overlapping region between the cover portion 31 of the first end ring 30 and the armor ring 50. That is, the protrusion 70 is disposed at a position overlapping the groove 60 in the axial direction D1 in the overlapping region, and is engaged with the groove 60. The protrusion 70 extends in the radial direction. The protrusion 70 is a portion protruding from the outer circumferential surface 31b of the cover portion 31 of the first end ring 30, which is formed by pressing the pin member 71 into the outer circumferential surface 31b of the cover portion 31 of the first end ring 30 along the radial direction. The protrusion 70, which is a part of the pin member 71, is longer than, for example, the portion pressed into the cover portion 31. In this case, even if the protrusion 70 hits the wall surface of the armor ring 50 forming the groove 60 in the axial direction D1 and the protrusion 70 is pressed by the movement or expansion / contraction of the armor ring 50, the curvature of the protrusion 70 can be suppressed. The pin member 71 is, for example, a cylindrical member. The pin member 71 is made of metal. Pin member 71 is made of a metal, such as stainless steel or titanium, that has a strength greater than that of bonded magnet 12. The material of pin member 71 is not limited to metal, and may be any material that will not break when rotor 10 rotates and can withstand the heat generated by bonded magnet 12.

[0034] The cross-sectional shape of the protrusion 70 on a plane perpendicular to the axial direction D1 is, for example, the same shape as the cross-sectional shape of the groove 60 (i.e., rectangular). The cross-sectional shape of the protrusion 70 is not limited to a rectangular shape, and may be another shape. The top surface of the protrusion 70 contacts, for example, the bottom surface of the groove 60. The peripheral surface of the protrusion 70 contacts both circumferential side surfaces of the armoring 50 that form the groove 60. Therefore, the width of the groove 60 (i.e., the distance between both circumferential side surfaces of the groove 60) is the same as the width of the protrusion 70 (i.e., the diameter of the protrusion 70). Note that a slight gap may be generated between the groove 60 and the protrusion 70 to an extent that the protrusion 70 can move relative to the groove 60. In addition, the groove 60 extends on both sides of the protrusion 70 in the direction in which the groove 60 extends in this embodiment. That is, when the binder material of the bonded magnet 12 is introduced into the space 15, or before the binder material cools and solidifies, the protrusion 70 engages with the groove 60 at a position between both ends of the groove 60 in the axial direction D1.

[0035] In this manner, the grooves 60 and the protrusions 70 formed in the cover portion 31 of the first end ring 30 and the armor ring 50 are fitted together, so that the peripheral surface of the protrusions 70 faces the wall surface of the armor ring 50 in the circumferential direction D2 that constitutes the groove 60. This restricts relative rotation of the armor ring 50 with respect to the first end ring 30. In other words, the grooves 60 and the protrusions 70 function to prevent the armor ring 50 from rotating with respect to the first end ring 30 (i.e., to prevent slipping in the circumferential direction D2).

[0036] Furthermore, the groove 60 extends in the axial direction D1. As a result, when the protrusion 70 moves relative to the groove 60 in the axial direction D1, the armor ring 50 moves relative to the first end ring 30 in the axial direction D1. In other words, the armor ring 50 is capable of moving relative to the first end ring 30 in the axial direction D1.

[0037] <Rotor manufacturing method> Next, a method for manufacturing the rotor 10 according to this embodiment will be described with reference to Fig. 4. The method for manufacturing the rotor 10 starts by preparing the shaft 11, the first end ring 30, the second end ring 40, the armor ring 50, and the pin member 71. The rotor 10 is manufactured by carrying out the following steps S1 to S5.

[0038] First, in step S1, a groove 60 extending in the axial direction D1 is formed on the inner circumferential surface 50a of the armor ring 50. The groove 60 is formed, for example, by groove-grooving the inner circumferential surface 50a of the armor ring 50. Note that the method of forming the groove 60 is not limited to groove-grooving. The method of forming the groove 60 may be, for example, milling. Furthermore, the groove 60 may be formed together with the armor ring 50 when the armor ring 50 is formed by sheet winding, filament winding, or the like. In this case, step S1 does not need to be performed.

[0039] Next, in step S2, a protrusion 70 is formed on the other side of the outer circumferential surface 31b of the lid portion 31 of the first end ring 30. A pin member 71 is press-fitted into the outer circumferential surface 31b of the lid portion 31 toward the inside in the radial direction (i.e., the side approaching the shaft 11). The pin member 71 is press-fitted such that the protrusion 70 protrudes from the outer circumferential surface 31b of the lid portion 31 by the depth of the groove 60.

[0040] Next, in step S3, the armor ring 50 is disposed so as to cover the outer circumferential surface 11a of the shaft 11 that is rotatable around the rotation axis L (circumferential direction D2).

[0041] Next, in step S4, the first end ring 30 and the second end ring 40 are arranged so as to cover the outer peripheral surface 11a of the shaft 11 at both ends of the armor ring 50 in the axial direction D1, and the protrusion 70 of the first end ring 30 is fitted into the groove 60 formed in the armor ring 50. The shaft 11 is inserted into the central hole 31a of the cover portion 31 and the central hole 32a of the protrusion portion 32 of the first end ring 30. As a result, the outer peripheral surface 31b of the cover portion 31 faces the inner peripheral surface 50a of the armor ring 50. In addition, the end face 32b of the protrusion portion 32 faces the end face 50b of the armor ring 50. Furthermore, the protrusion 70 enters the groove 60 that opens at the end face 50b of the armor ring 50, and fits into the groove 60. The shaft 11 is inserted into the central hole 41a of the cover portion 41 and the central hole 42a of the protrusion portion 42 of the second end ring 40. As a result, the outer peripheral surface 41b of the cover portion 41 faces the inner peripheral surface 50a of the armor ring 50. In addition, the end face 42b of the protrusion 42 faces the end face 50c of the armor ring 50. At this time, the first end ring 30 and the second end ring 40 face each other in the axial direction D1. As a result, a space 15 surrounded by the armor ring 50, the first end ring 30, and the second end ring 40 is formed so as to cover the outer peripheral surface 11a of the shaft 11.

[0042] Next, in step S5, the bond magnet 12 is injection molded in the space 15. The molten binder material is introduced into the space 15 at a predetermined pressure through a molding hole formed in the second end ring 40. Gas present in the space 15 is discharged to the outside of the space 15 through a gas vent hole formed in the first end ring 30. The binder material contacts the shaft 11, the armor ring 50, the first end ring 30, and the second end ring 40 in the space 15. The binder material may enter into the groove 60 communicating with the space 15. The binder material is cooled and solidified to form the bond magnet 12 that contacts the shaft 11, the armor ring 50, the first end ring 30, and the second end ring 40. In this embodiment, the binder material may enter the groove 60 during injection molding and be cooled to form the bond magnet 12 in the groove 60. The bond magnet 12 may not be formed in the groove 60.

[0043] <Action and effect> Next, the effects achieved by the rotor 10 and motor 1 according to this embodiment will be described together with the problems of the prior art. Below, as a reference example of a prior art rotor, a rotor in which the armoring and end rings are not provided with the grooves 60 and the protrusions 70 will be considered. In prior art rotors, the transmission of torque from the inner peripheral surface of the bonded magnet to the outer peripheral surface of the shaft may be performed by utilizing the frictional force generated between the inner peripheral surface of the bonded magnet and the outer peripheral surface of the shaft. The frictional force between the inner peripheral surface of the bonded magnet and the outer peripheral surface of the shaft is proportional to the normal force acting on these surfaces. Therefore, the smaller this normal force is, the smaller the frictional force between the inner peripheral surface of the bonded magnet and the outer peripheral surface of the shaft becomes, and the torque transmission efficiency decreases.

[0044] Here, for example, when a sintered magnet is used in the rotor, an armor ring made of metal is fixed to the sintered magnet and the end ring by shrink fitting. Specifically, the armor ring is heated to expand, and then the sintered magnet and the end ring are placed in the armor ring. The armor ring is cooled and contracts, so that the sintered magnet and the end ring are pressed toward the shaft. As a result, the sintered magnet is attached to the shaft, and the armor ring is attached to the end ring. In this case, a large normal force acts on the inner peripheral surface of the sintered magnet and the outer peripheral surface of the shaft. On the other hand, when a bonded magnet is used in the rotor, the bonded magnet is formed around the outer peripheral surface of the shaft by injection molding a binder material between the outer peripheral surface of the shaft and the inner peripheral surface of the armor ring. The magnitude of the normal force acting on the inner peripheral surface of the bonded magnet and the outer peripheral surface of the shaft is determined according to the pressure during this injection molding.

[0045] The normal force determined by the pressure during injection molding tends to be smaller than the normal force acting on the inner peripheral surface of the sintered magnet and the outer peripheral surface of the shaft. In addition, due to insufficient pressure during injection molding or shrinkage of the bonded magnet after injection molding, the bonded magnet may not adhere to at least one of the shaft and the armoring, and a gap may be formed between the bonded magnet and at least one of the shaft and the armoring. In this case, when the rotor rotates, the bonded magnet may float up from the shaft due to centrifugal force and move to the armoring side, and the bonded magnet may not come into proper contact with the shaft, resulting in a smaller normal force acting on the inner peripheral surface of the bonded magnet and the outer peripheral surface of the shaft.

[0046] Accordingly, the frictional force between the inner peripheral surface of the bonded magnet and the outer peripheral surface of the shaft is also reduced, making it easier for slippage to occur in the rotational direction between the inner peripheral surface of the bonded magnet and the outer peripheral surface of the shaft. Therefore, in rotors using bonded magnets, the efficiency of torque transmission from the inner peripheral surface of the bonded magnet to the outer peripheral surface of the shaft tends to be lower than in rotors using sintered magnets. Such a decrease in torque transmission efficiency can be a factor that hinders improvements in rotor performance.

[0047] Furthermore, as the rotor continues to rotate, the bonded magnet generates heat, and the thermal expansion may affect each component constituting the rotor. The heated bonded magnet may expand in the axial direction. In this case, the armature adjacent to the bonded magnet receives a force toward the end ring due to the thermal expansion of the bonded magnet. In conventional rotors, the armature may be fixed immovably relative to the end ring, and therefore the armature cannot move or expand or contract relative to the end ring. In other words, the armature cannot properly deflect the force received from the thermally expanding bonded magnet. As a result, the armature continues to be stressed, which may cause fatigue of the armature.

[0048] Furthermore, when the rotor is manufactured using an armor made of metal, the armor and the end ring are connected (fixed) by shrink fitting as described above. Unlike an armor made of metal, an armor made of fiber reinforced resin may not be suitable for shrink fitting to connect to an end ring. For example, this is because an armor made of fiber reinforced resin may melt due to shrink fitting. For this reason, it is difficult to insert a bond magnet and an end ring into the armor after the armor expands, and press the bond magnet and the end ring against the shaft side by contracting the armor. In addition, when a clearance fit is applied in which the armor is fitted between a pair of end rings, rattling may occur between the armor and the end ring when the rotor rotates. Therefore, the armor and the end ring made of fiber reinforced resin may not be properly connected.

[0049] When the rotor is rotated at a low speed and the grooves 60 and the protrusions 70 are not provided on the armoring and the end rings, the torque generated in the bonded magnet can be transmitted by the portions of the bonded magnet formed in the gas vent holes and the molding holes. When the rotor rotates at a high speed during normal operation, the portions of the bonded magnet formed in the gas vent holes and the molding holes may not be able to transmit the torque generated in the bonded magnet. Here, high speed rotation means that the force generated in the bonded magnet is greater than the shear strength of the bonded magnet formed in the gas vent holes or the molding holes. In addition, when the bonded magnet is not formed in the gas vent holes and the molding holes, or when the bonded magnet is not sufficiently filled in the gas vent holes and the molding holes, the torque generated in the bonded magnet may not be transmitted properly for the above-mentioned reasons.

[0050] Due to these factors, when the rotor of the reference example rotates at high speed, the members constituting the rotor may not be properly connected to each other, and the efficiency of torque transmission from the bonded magnet to the shaft may decrease. Such a decrease in torque transmission efficiency may lead to a decrease in the output efficiency of the rotor, which may cause the rotor performance to decrease and may be a factor in preventing the rotor from performing properly.

[0051] In contrast, in the rotor 10 according to this embodiment, the torque is transmitted from the bond magnet 12 to the shaft 11 by utilizing the frictional force generated between the outer peripheral surface 12b of the bond magnet 12 and the inner peripheral surface 50a of the armor ring 50. This frictional force is proportional to the normal force acting on these surfaces. Here, the rotation of the bond magnet 12 causes a centrifugal force to act on the bond magnet 12, which presses the armor ring 50 outward in the radial direction of the rotation axis L. As a result, the above-mentioned normal force becomes larger, so that the frictional force generated between the outer peripheral surface 12b of the bond magnet 12 and the inner peripheral surface 50a of the armor ring 50 becomes larger, and slippage between the outer peripheral surface 12b of the bond magnet 12 and the inner peripheral surface 50a of the armor ring 50 becomes less likely to occur. This frictional force is transmitted to the first end ring 30 and the second end ring 40 connected to the armor ring 50.

[0052] Here, the inner peripheral surface 50a of the armor ring 50 and the outer peripheral surface 31b of the cover portion 31 of the first end ring 30 have grooves 60 and protrusions 70 that fit together. By fitting the protrusions 70 into the grooves 60 formed on the peripheral surface, the side surfaces of the protrusions 70 face the side surfaces of the grooves 60 in the circumferential direction D2, so that the relative movement of the grooves 60 in the circumferential direction D2 with respect to the protrusions 70 is restricted. In other words, the grooves 60 and the protrusions 70 function as anti-slip (anti-rotation) devices for the armor ring 50 in the circumferential direction D2 with respect to the first end ring 30. In addition, the pin member 71 including the protrusions 70 is made of a metal having a higher shear strength than the bonded magnet 12, so that the possibility of breakage is reduced compared to the bonded magnet 12 that may be formed in the gas vent hole or the molding hole. This makes it possible to suppress slippage in the circumferential direction D2 between the inner circumferential surface 50a of the armoring 50 and the outer circumferential surface 31b of the cover portion 31 of the first end ring 30, and to suppress a decrease in the efficiency of torque transmission from the armoring 50 to the first end ring 30. As a result, it is possible to suppress a decrease in performance of the rotor 10 and to allow the rotor 10 to perform appropriately.

[0053] The groove 60 extends in the axial direction D1. As a result, the relative movement of the groove 60 with respect to the protrusion 70 in the axial direction D1 is not restricted, so the armor ring 50 can move or expand in the axial direction D1 relative to the first end ring 30 even when it is affected by thermal expansion from the bonded magnet 12. This allows the connection between the armor ring 50 and the first end ring 30 to be appropriately maintained.

[0054] In addition, the armor ring 50 containing fiber reinforced resin and the first end ring 30 are connected by the groove 60 and the protrusion 70 extending in the axial direction D1, even if they are not shrink-fitted. The armor ring 50 has a cylindrical shape, and its inner peripheral surface 50a faces the outer peripheral surface 31b of the first end ring 30, so that the radial relative movement of the armor ring 50 with respect to the first end ring 30 is restricted. In addition, the peripheral surface of the protrusion 70 faces the wall surface of the armor ring 50 that constitutes the groove 60 in the circumferential direction D2, so that the relative movement of the armor ring 50 with respect to the first end ring 30 in the circumferential direction D2 is restricted. As a result, the occurrence of rattling of the armor ring 50 with respect to the first end ring 30 is suppressed. Therefore, the torque is appropriately transmitted from the bond magnet 12 to the shaft 11 via the armor ring 50 and the first end ring 30. As a result, it is possible to suppress deterioration in the performance of the rotor 10 having the armoring 50 containing fiber reinforced resin, and to allow the rotor 10 to exhibit its proper performance.

[0055] In this embodiment, the armor ring 50 is provided between the first end ring 30, which is an end ring, and the second end ring 40, which is different from the first end ring 30, and is spaced apart from the first end ring 30 along the axial direction D1. In this case, the armor ring 50, the first end ring 30, and the second end ring 40 can adequately cover the space 15 into which the material of the bonded magnet 12 is injected. Furthermore, even if a force in the axial direction D1 is applied to the armor ring 50 by the thermally expanding bonded magnet 12, the armor ring 50 can move or extend toward the first end ring 30 while keeping the protrusions 70 engaged with the grooves 60, since the armor ring 50 is spaced apart from the first end ring 30 along the axial direction D1. Therefore, even if thermal expansion of the bonded magnet 12 occurs when the armour ring 50 is provided between the first end ring 30 and the second end ring 40, the load on the armour ring 50 and the first end ring 30 does not increase and the connection is maintained, so that a decrease in torque transmission efficiency can be suppressed. Furthermore, by providing the armour ring 50 between the first end ring 30 and the second end ring 40, the armour ring 50 can be appropriately positioned in the axial direction D1 and radial directions in step S4.

[0056] A motor 1 according to an embodiment of the present disclosure includes any one of the rotors 10 described above and a stator 20 arranged to surround the rotor 10. Since the motor 1 includes any one of the rotors 10 described above, torque is transmitted from the bond magnet 12 to the shaft 11 via the armature 50, as described above. In addition, by appropriately maintaining the connection between the armature 50 and the first end ring 30, it is possible to suppress the occurrence of slippage of the armature 50 relative to the first end ring 30 in the circumferential direction D2. As a result, it is possible to suppress the deterioration of the performance of the rotor 10 and the motor 1, and to allow the rotor 10 and the motor 1 to exhibit their performance appropriately.

[0057] The manufacturing method of the rotor according to the present embodiment includes the above-mentioned steps S1 to S5. In this manufacturing method, the armor ring 50, the first end ring 30, and the second end ring 40 are arranged on the shaft 11. The bonded magnet 12 is injection molded in the space 15 surrounded by the armor ring 50, the first end ring 30, and the second end ring 40 so as to cover the outer circumferential surface 11a of the shaft 11. The armor ring 50 and the first end ring 30 made of fiber reinforced resin are appropriately connected by the grooves 60 and the protrusions 70 extending in the axial direction D1 without shrink fitting. As described above, in the rotor 10 manufactured by the above-mentioned steps S1 to S5, torque is transmitted from the bonded magnet 12 to the shaft 11 via the armor ring 50, the connection between the armor ring 50 and the first end ring 30 is appropriately maintained, and the occurrence of slippage of the armor ring 50 relative to the first end ring 30 in the circumferential direction D2 can be suppressed. As a result, the deterioration of the performance of the rotor 10 can be suppressed, and the rotor 10 can exhibit its proper performance.

[0058] The rotor 10 and the motor 1 of the present disclosure are not limited to the above-described embodiment. The rotor 10 and the motor 1 of the present disclosure may be modified as appropriate within the scope of the spirit of the claims.

[0059] <First Modification> In the rotor 10A shown in FIG. 5, a groove 60A extending in the axial direction D1 is formed on the outer peripheral surface 31b of the lid portion 31 of the first end ring 30, and the inner peripheral surface 50a of the armoring 50 has a protrusion 70A that fits into the groove 60A. The groove 60A and the protrusion 70A in the rotor 10A are in a state where the formation positions of the groove 60 and the protrusion 70 in the rotor 10 of the above-described embodiment are interchanged. The pin member 71A is press-fitted into the armoring 50, and the protrusion 70A protrudes radially inward. Even in such a form, the same effects as those of the above-described embodiment are achieved. Note that a groove extending in the axial direction D1 is formed on one of the inner peripheral surface 50a of the armoring 50 on the second end ring 40 side and the outer peripheral surface 41b of the lid portion 41 of the second end ring 40, and the inner peripheral surface 50a of the armoring 50 on the second end ring 40 side and the outer peripheral surface 41b of the lid portion 41 of the second end ring 40 may have protrusions that fit into the groove.

[0060] <Second Modified Example> On one of the inner peripheral surface 50a of the armoring 50 and the outer peripheral surface 31b of the lid portion 31 of the first end ring 30, a first groove 60B corresponding to the groove 60 and a second groove 61B different from the first groove 60B are formed, and the other of the inner peripheral surface 50a of the armoring 50 and the outer peripheral surface 31b of the lid portion 31 of the first end ring 30 may have a first protrusion 70B corresponding to the protrusion 70 and a second protrusion 72B different from the first protrusion 70B. In the rotor 10B shown in FIG. 6, the first groove 60B and the second groove 61B are formed on the inner peripheral surface 50a of the armoring 50, and the outer peripheral surface 31b of the lid portion 31 of the first end ring 30 has the first protrusion 70B and the second protrusion 72B.

[0061] Although the second groove 61B is provided at a position different from the first groove 60B on the inner peripheral surface 50a of the armor ring 50, it extends in the axial direction D1 and has a similar configuration to the first groove 60B. The first groove 60B and the second groove 61B are formed, for example, at positions symmetrical with respect to the rotation axis L. Although the second protrusion 72B is provided at a position different from the first protrusion 70B on the outer peripheral surface 31b of the cover portion 31 of the first end ring 30, it protrudes radially outward and has a similar configuration to the first protrusion 70B. The first protrusion 70B and the second protrusion 72B are formed, for example, at positions symmetrical with respect to the rotation axis L. The first protrusion 70B and the second protrusion 72B are protruding portions of the pin members 71B and 73B press-fitted into the outer peripheral surface 31b of the cover portion 31, respectively. In this case, when the rotor 10B rotates, the rotational force is prevented from concentrating only on the first groove 60B and the first protrusion 70B, and the rotational force can be dispersed to a plurality of grooves (the first groove 60B and the second groove 61B) and a plurality of protrusions (the first protrusion 70B and the second protrusion 72B). In addition, since the first groove 60B and the second groove 61B are formed at positions symmetrical with respect to the rotation axis L, weight imbalance due to components of the rotor 10B around the rotation axis L is prevented, and smooth rotation is achieved.

[0062] In addition, a first groove and a second groove different from the first groove may be formed in the outer peripheral surface 31b of the cover portion 31 of the first end ring 30, and an inner peripheral surface 50a of the armor ring 50 may have a first protrusion and a second protrusion different from the first protrusion. A first groove corresponding to the groove 60 and a second groove different from the first groove may be formed in one of the inner peripheral surface 50a of the armor ring 50 and the outer peripheral surface 41b of the cover portion 41 of the second end ring 40, and the other of the inner peripheral surface 50a of the armor ring 50 and the outer peripheral surface 41b of the cover portion 41 of the second end ring 40 may have a first protrusion corresponding to the protrusion 70 and a second protrusion different from the first protrusion.

[0063] <Third Modification> In the rotor 10C shown in Figure 7, a first groove 60C equivalent to groove 60 is formed at one end in the axial direction D1 of the inner surface 50a of the armor ring 50, and a second groove 61C separate from the first groove 60C is formed at the other end in the axial direction D1 of the inner surface 50a of the armor ring 50, the outer peripheral surface 31b of the cover portion 31 of the first end ring 30 has a first protrusion 70C equivalent to the protrusion 70, and the outer peripheral surface 41b of the cover portion 41 of the second end ring 40 has a second protrusion 72C separate from the first protrusion 70C.

[0064] Although the second groove 61C is provided at a position different from the first groove 60C on the inner peripheral surface 50a of the armoring 50, it extends in the axial direction D1 and has a similar configuration to the first groove 60C. Although the second protrusion 72C is provided at a position different from the first protrusion 70C, it protrudes radially outward and has a similar configuration to the first protrusion 70C. The first protrusion 70C and the second protrusion 72C are protruding portions of the pin members 71C and 73C press-fitted into the outer peripheral surfaces 31b and 41b of the lid portions 31 and 41, respectively. In this case, when the rotor 10C rotates, the rotational force is prevented from concentrating only on the first groove 60C and the first protrusion 70C, and the rotational force can be distributed to a plurality of grooves (the first groove 60C and the second groove 61C) and a plurality of protrusions (the first protrusion 70C and the second protrusion 72C).

[0065] Also, the portions 12c, 12c of the bonded magnet 12 may be located inside the first groove 60C and the second groove 61C. When the bonded magnet 12 is formed in the space 15, it is injection molded inside at least one of the first groove 60C and the second groove 61C. The portions 12c, 12c of the bonded magnet 12, together with the first protrusion 70C and the second protrusion 72C, fit into the first groove 60C and the second groove 61C, respectively, and can function as a slip stopper (rotation stopper) in the circumferential direction D2 of the armor ring 50 relative to the first end ring 30 and the second end ring 40.

[0066] In addition, a first groove may be formed in the outer peripheral surface 31b of the cover portion 31 of the first end ring 30, and a second groove separate from the first groove may be formed in the outer peripheral surface 41b of the cover portion 41 of the second end ring 40, and one end in the axial direction D1 of the inner peripheral surface 50a of the armor ring 50 may have a first protrusion, and the other end in the axial direction D1 of the inner peripheral surface 50a of the armor ring 50 may have a second protrusion separate from the first protrusion.

[0067] <Fourth Modification> In the rotor 10D shown in FIG. 8, the outer peripheral surface 41b of the cover portion 41 of the second end ring 40 has a first protrusion 72D corresponding to the protrusion 70. A second groove 60D different from the first groove 61D described below is formed in the outer peripheral surface 31b of the cover portion 31 of the first end ring 30. One end portion in the axial direction D1 of the inner peripheral surface 50a of the armor ring 50 has a second protrusion 70D different from the first protrusion 72D. A first groove 61D corresponding to the groove 60 is formed in the other end portion in the axial direction D1 of the inner peripheral surface 50a of the armor ring 50.

[0068] The second groove 60D extends in the axial direction D1 on the outer circumferential surface 31b of the cover portion 31 of the first end ring 30, and has a configuration similar to that of the groove 60A. The second protrusion 70D protrudes radially inward on the inner circumferential surface 50a of the armor ring 50, and has a configuration similar to that of the protrusion 70A. The first protrusion 72D is a protruding portion of the pin member 73D press-fitted into the outer circumferential surface 41b of the cover portion 41. The second protrusion 70D is a protruding portion of the pin member 71D press-fitted into the inner circumferential surface 50a of the armor ring 50. In this case, when the rotor 10D rotates, the rotational force is prevented from concentrating only on the first groove 61D and the first protrusion 72D, and the rotational force can be distributed to a plurality of grooves (the first groove 61D and the second groove 60D) and a plurality of protrusions (the first protrusion 72D and the second protrusion 70D). Note that a portion of bonded magnet 12 may be located inside first groove 61D and second groove 60D.

[0069] The outer peripheral surface 31b of the cover portion 31 of the first end ring 30 may have a first protrusion corresponding to the protrusion 70. In this case, the outer peripheral surface 41b of the cover portion 41 of the second end ring 40 may have a second groove different from the first groove described below. A first groove corresponding to the groove 60 may be formed at one end of the inner peripheral surface 50a of the armor ring 50 in the axial direction D1. The other end of the inner peripheral surface 50a of the armor ring 50 in the axial direction D1 may have a second protrusion different from the first protrusion.

[0070] <Other Modifications> The rotor and motor according to the present disclosure are not limited to the above-described embodiment, and various other modifications are possible. For example, the above-described embodiment and each modification may be combined with each other according to the required purpose and effect. In the above-described embodiment and each modification, the groove 60 is described as opening toward the end of the axial direction D1. However, the groove 60 may be a hole (recess) that is not opening toward the end of the axial direction D1. Although the groove 60 is described as extending along the axial direction D1, the groove 60 may have a tapered shape along the axial direction D1. In the axial direction D1, the projection 70 fits into the groove 60, thereby suppressing the armor ring 50 from moving relative to the first end ring 30. The groove 60 may also penetrate the armor ring 50 in the radial direction (depth direction).

[0071] In addition, at least one of the outer peripheral surfaces 31b, 41b of the lid parts 31, 41 may not be in contact with the inner peripheral surface 50a of the armor ring 50, but may be spaced apart from it. That is, the inner diameter of the armor ring 50 may be larger than the diameter of at least one of the lid parts 31, 41. When the binder material, which is the molding material of the bonded magnet 12, is injected into the space 15 in step S5, some of the binder material may enter the gap between the outer peripheral surfaces 31b, 41b of the lid parts 31, 41 and the inner peripheral surface 50a of the armor ring 50. If the binder material shrinks after injection molding, the binder material that has entered the gap is drawn toward the space 15, so that the space 15 can be filled with a sufficient amount of bonded magnets 12 at a sufficient pressure.

[0072] Furthermore, the first end ring 30 may not have the protrusion 32. The second end ring 40 may not have the protrusion 42. That is, the armor ring 50 may not be provided between the first end ring 30 and the second end ring 40. In this case, the protrusion 70 abuts against the wall surface of the armor ring 50 that forms the groove 60 in the axial direction D1, thereby preventing the armor ring 50 from detaching from the first end ring 30.

[0073] An inner sleeve may be provided between the shaft 11 and the bonded magnet 12. At least one of the first end ring 30 and the second end ring 40 may be integrally formed with the shaft 11. In this case, the arrangement of at least one of the first end ring 30 and the second end ring 40 in step S4 does not need to be performed.

[0074] [Note] The rotor, the motor, and the method for manufacturing the rotor include the following configuration.

[0075] The present disclosure relates to a shaft rotatable about a rotation axis, A cylindrical bonded magnet covering an outer circumferential surface of the shaft; A cylindrical armoring made of fiber reinforced resin and covering the outer peripheral surface of the bonded magnet; an annular end ring covering an outer circumferential surface of the shaft and provided at a position facing an end face of the bonded magnet in the axial direction of the rotation axis; A groove extending in the axial direction is formed on one of the inner circumferential surface of the armor ring and the outer circumferential surface of the end ring, The other of the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring has a protrusion that fits into the groove. Rota."

[0076] The present disclosure is [2] "A rotor as described in [1] above, wherein the armature is provided between a first end ring which is the end ring and a second end ring which is different from the first end ring, and is spaced apart from the first end ring along the axial direction."

[0077] The present disclosure is [3] "A rotor as described in [1] or [2] above, wherein a portion of the bonded magnet is located inside the groove."

[0078] The present disclosure states, [4] "A first groove, which is the groove, and a second groove different from the first groove are formed on one of the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring, The rotor according to any one of the above [1] to [3], wherein the other of the inner circumferential surface of the armoring and the outer circumferential surface of the end ring has a first protrusion which is the protrusion, and a second protrusion which is different from the first protrusion."

[0079] The present disclosure is [5] "A rotor as described in the above [4], wherein the first groove and the second groove are formed in symmetrical positions with respect to the rotation axis."

[0080] The present disclosure is [6] "A rotor described in any one of the above [1] to [3], wherein a first groove, which is the groove, is formed in one of the inner circumferential surface of the armor ring and the outer circumferential surface of the end ring, and a second groove different from the first groove is formed in the other of the inner circumferential surface of the armor ring and the outer circumferential surface of the end ring, the other of the inner circumferential surface of the armor ring and the outer circumferential surface of the end ring has a first protrusion, which is the protrusion, and one of the inner circumferential surface of the armor ring and the outer circumferential surface of the end ring has a second protrusion different from the first protrusion."

[0081] The present disclosure relates to a rotor according to any one of the above items [1] to [6], and a stator disposed so as to surround the rotor.

[0082] The present disclosure further describes a method for manufacturing a rotary knives by forming a groove extending in the axial direction of a rotation axis on one of an inner peripheral surface of an armor ring made of fiber-reinforced resin and an outer peripheral surface of an annular end ring; forming a protrusion on the other of the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring; disposing the armor ring over an outer circumferential surface of a shaft rotatable about a rotation axis; A step of disposing the end ring at an end of the armor ring in the axial direction so as to cover an outer circumferential surface of the shaft and fitting the protrusion into the groove; A step of injection molding a bonded magnet into a space surrounded by the armor ring and the end ring so as to cover an outer circumferential surface of the shaft; "A method for manufacturing a rotor, comprising: [Explanation of symbols]

[0083] 1 Motor 10, 10A, 10B, 10C, 10D rotor 11 Shaft 11a Outer surface 12 Bonded magnets 12a Inner surface 12b Outer surface 15 Space 20 Stator 30 First End Ring 31b Outer surface 40 The Second End Ring 41b Outer surface 50 Armoring 50a Inner surface 60,60A Groove 60B, 60C, 61D First groove 61B, 61C, 60D Second groove 70,70A protrusion 70B, 70C, 72D First protrusion 72B, 72C, 70D Second protrusion D1 Axial direction D2 Circumferential direction F Torque L Rotation axis

Claims

1. A shaft rotatable about a rotation axis; A cylindrical bonded magnet covering an outer circumferential surface of the shaft; A cylindrical armoring made of fiber reinforced resin and covering the outer peripheral surface of the bonded magnet; an annular end ring covering an outer circumferential surface of the shaft and provided at a position facing an end face of the bonded magnet in the axial direction of the rotation axis; A groove extending in the axial direction is formed on one of the inner circumferential surface of the armor ring and the outer circumferential surface of the end ring, The other of the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring has a protrusion that fits into the groove. Rotor.

2. 2. The rotor according to claim 1, wherein the armor ring is provided between a first end ring that is the end ring and a second end ring that is different from the first end ring, and is spaced apart from the first end ring along the axial direction.

3. The rotor according to claim 1 or 2, wherein a portion of the bonded magnet is located inside the groove.

4. A first groove, which is the groove, and a second groove different from the first groove are formed on one of the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring, 3. The rotor according to claim 1, wherein the other of the inner peripheral surface of the armoring and the outer peripheral surface of the end ring has a first protrusion which is the protrusion, and a second protrusion which is different from the first protrusion.

5. The rotor according to claim 4 , wherein the first groove and the second groove are formed at positions symmetrical with respect to a rotation axis.

6. A first groove is formed in one of the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring, A second groove separate from the first groove is formed in the other of the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring, The other of the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring has a first projection which is the projection, The rotor according to claim 1 or 2, wherein one of the inner peripheral surface of the armoring and the outer peripheral surface of the end ring has a second projection different from the first projection.

7. A rotor according to claim 1 or 2; a stator disposed to surround the rotor.

8. A step of forming a groove extending in an axial direction of a rotation axis on one of an inner peripheral surface of an armor ring made of a fiber reinforced resin and an outer peripheral surface of an annular end ring; forming a protrusion on the other of the inner peripheral surface of the armor ring and the outer peripheral surface of the end ring; disposing the armor ring over an outer circumferential surface of a shaft rotatable about a rotation axis; A step of disposing the end ring at an end of the armor ring in the axial direction so as to cover an outer circumferential surface of the shaft and fitting the protrusion into the groove; A step of injection molding a bonded magnet into a space surrounded by the armor ring and the end ring so as to cover an outer circumferential surface of the shaft; A method for manufacturing a rotor comprising:

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