Rotor, motor, and manufacturing method of rotor

Abstract

The rotor includes: a cylindrical magnet structure including a magnet and configured to cover an outer peripheral surface of a shaft; and a cylindrical protection tube including a fiber body wound so as to cover the outer peripheral surface of the magnet structure and engaged with the outer peripheral surface of the magnet structure. The protection tube includes a one end portion in an axial direction of the shaft and another end portion on an opposite side to the one end portion in the axial direction. A tapered surface tapering in the axial direction further from the other end portion is formed on an engagement surface of the outer peripheral surface of the magnet structure engaged with the one end portion. A tapered surface tapering in the axial direction further from the one end portion is formed on an engagement surface of the outer peripheral surface of the magnet structure engaged with the other end portion.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a rotor, a motor, and a manufacturing method of a rotor. BACKGROUND

[0002] In the past, a rotor provided with a magnet structure arranged around a shaft and a protective tube arranged around the magnet structure is known (for example, Patent Document 1). As a method of forming such a protective tube, a so-called wire winding method can be used. In the case of using this method, for example, a fiber body (filament) constituting the protective tube is directly wound around an outer peripheral surface of the magnet structure, and then the fiber body wound around the outer peripheral surface is subjected to a heat treatment, whereby the protective tube is formed which is joined to the outer peripheral surface.

[0003] Patent Document 1: Japanese Patent Application Publication No. H7-046780

[0004] In the case of forming the protective tube using the method of directly winding the filament around the outer peripheral surface of the magnet structure, compared to the case of using the method of forming the protective tube in advance by a production jig and then mounting the protective tube to the magnet structure, there is an advantage in manufacturing that a production jig or the like for forming the protective tube is not needed. However, in the case of using the method of directly winding the filament around the outer peripheral surface of the magnet structure, there is a problem that the start end portion where the winding of the filament starts and the end portion where the winding of the filament ends are easily peeled off from the outer peripheral surface of the magnet structure due to centrifugal force or the like when the rotor is rotating. If such peeling occurs, the rotational balance of the rotor is broken, and an adverse condition such as a large vibration of the rotor can occur. SUMMARY

[0005] The rotor of one embodiment of the present disclosure includes a cylindrical magnet structure including a magnet and arranged to cover an outer peripheral surface of a shaft, and a protective tube including a fiber body wound around the outer peripheral surface of the magnet structure and joined to the outer peripheral surface of the magnet structure. The protective tube includes a first end portion in an axial direction of the shaft in which the protective tube extends, and a second end portion on the opposite side to the first end portion in the axial direction. A first tapered surface is formed on a joining surface of the outer peripheral surface of the magnet structure which joins the first end portion, and the first tapered surface is tapered in the axial direction to be smaller in diameter farther from the second end portion. A second tapered surface is formed on a joining surface of the outer peripheral surface of the magnet structure which joins the second end portion, and the second tapered surface is tapered in the axial direction to be smaller in diameter farther from the first end portion.

[0006] The present disclosure describes a rotor, a motor, and a manufacturing method of a rotor which can suppress peeling of a protective tube when rotating. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a cross-sectional view of a motor including a rotor of one embodiment.

[0008] Figure 2 is an enlarged view of one end side in the axial direction of the rotor of Figure 1

[0009] Figure 3 is an enlarged view of the other end side in the axial direction of the rotor of Figure 1

[0010] Figure 4 is a side view of the rotor of Figure 1

[0011] Figure 5 (a) of FIG. 10 is a side view of an example of a manufacturing process of the rotor of Figure 1 Figure 5 (b) of FIG. 10 is a side view of a subsequent process of (a) of FIG. 10. Figure 5

[0012] Figure 6 (a) of FIG. 11 is a side view of a subsequent process of (b) of FIG. 10. Figure 5 Figure 6 (b) of FIG. 11 is a side view of a subsequent process of (a) of FIG. 11. Figure 6

[0013] Figure 7 (a) of FIG. 12 is an enlarged view of a portion of the rotor of Figure 2 Figure 7 (b) of FIG. 12 is an enlarged view of a portion of the rotor of Figure 3

[0014] Figure 8 is a cross-sectional view of a rotor of a modification example.

[0015] Figure 9 (a) of FIG. 14 is a cross-sectional view of a rotor of a comparative example. Figure 9 Figure 9 (b) of FIG. 14 is an enlarged view of a portion of the rotor of (a) of FIG. 14. DETAILED DESCRIPTION

[0016] A rotor of one embodiment of the present disclosure includes a cylindrical magnet structure including a magnet and covering an outer peripheral surface of a shaft, and a protection tube including a fiber body wound so as to cover the outer peripheral surface of the magnet structure and engaged with the outer peripheral surface of the magnet structure. The protection tube includes a first end portion in the axial direction of the shaft in which the protection tube extends, and a second end portion on the side opposite to the first end portion in the axial direction. A first tapered surface is formed in an engaging surface of the outer peripheral surface of the magnet structure engaged with the first end portion, and the first tapered surface is tapered in the axial direction to be smaller in diameter farther from the second end portion. A second tapered surface is formed in an engaging surface of the outer peripheral surface of the magnet structure engaged with the second end portion, and the second tapered surface is tapered in the axial direction to be smaller in diameter farther from the first end portion. ​​​​​​​​​​

[0017] In the rotor, the first end portion and the second end portion of the protection tube are engaged with the first tapered surface and the second tapered surface formed on the outer circumferential surface of the magnet structure, respectively. The first tapered surface engaging the first end portion of the protection tube is tapered in the axial direction further away from the second end portion of the protection tube. In this case, with respect to a normal direction component of the centrifugal force acting on the first end portion in the rotation of the rotor, the engaging force of the first end portion in the normal direction of the first tapered surface acts as a resistance. Further, with respect to an in-plane direction component of the centrifugal force in the first tapered surface, the force in the shearing direction of the first end portion in the in-plane direction of the first tapered surface acts as a resistance. On the other hand, the second tapered surface engaging the second end portion of the protection tube is tapered in the axial direction further away from the first end portion of the protection tube. In this case, with respect to a normal direction component of the centrifugal force acting on the second end portion, the engaging force of the second end portion in the normal direction of the second tapered surface acts as a resistance. Further, with respect to an in-plane direction component of the centrifugal force in the second tapered surface, the force in the shearing direction of the second end portion in the in-plane direction of the second tapered surface acts as a resistance. In this way, in the first tapered surface and the second tapered surface, in addition to the engaging force of the first end portion and the second end portion, the force in the shearing direction of the first end portion and the second end portion also acts as a resistance to the centrifugal force in the rotation of the rotor, and thus the first end portion and the second end portion can be made difficult to peel off from the first tapered surface and the second tapered surface in the rotation of the rotor. Therefore, according to the above-described rotor, it is possible to suppress the peeling of the protection tube in the rotation of the rotor.

[0018] In some modes, the magnet structure can also have an inner sleeve sandwiched between the shaft and the magnet in the radial direction of the shaft. One end portion of the inner sleeve in the axial direction can also extend to a position outside the magnet in the axial direction. The first tapered surface can also be formed on the one end portion of the inner sleeve. In this case, compared with the case where the first tapered surface is formed on the magnet, the engaging force of the first end portion of the protection tube with respect to the first tapered surface can be more reliably ensured. Thus, the first end portion of the protection tube can be made further difficult to peel off from the first tapered surface in the rotation of the rotor.

[0019] In some modes, a flange portion protruding to the outside in the radial direction can also be provided on the one end portion of the inner sleeve. The flange portion can also be located at a position more radially inward than the magnet. The first tapered surface can also be formed on the flange portion. In this case, compared with the case where the first tapered surface is formed on the magnet, the radial distance (rotational radius) from the axis of the rotation center to the first tapered surface is smaller. Thus, the centrifugal force acting on the first end portion of the protection tube engaged with the first tapered surface can be suppressed to be smaller. As a result, the first end portion of the protection tube can be made even further difficult to peel off from the first tapered surface in the rotation of the rotor.

[0020] In some aspects, the other end portion of the inner sleeve in the axial direction can extend to a position outside the other side of the magnet in the axial direction, or can be located at a position radially inside the magnet. A second tapered surface can also be formed on the other end portion of the inner sleeve. In this case, compared to a case where the second tapered surface is formed on the magnet, the radial distance from the axis of the rotation center to the second tapered surface (i.e., the radius of rotation) is smaller. Thus, the centrifugal force acting on the second end portion of the protective tube engaged with the second tapered surface can be suppressed to be small. As a result, the second end portion of the protective tube can be further prevented from peeling off from the second tapered surface when the rotor is rotating.

[0021] In some aspects, the magnet structure can also have a first end ring and a second end ring disposed on both sides of the magnet in the axial direction. The second end ring can also be located on the other end portion side of the inner sleeve with respect to the magnet in the axial direction. A second tapered surface can also be formed on the second end ring. In a case where the boundary surface between the second end ring and the other end portion of the inner sleeve in the axial direction is a surface perpendicular with respect to the axial direction, winding of the fiber body using the wire-winding method is difficult with respect to the boundary surface. Therefore, if the structure in which the second tapered surface is formed on the second end ring, when winding the fiber body on the outer peripheral surface of the magnet structure, the fiber body can be prevented from being wound from the second end ring to the other end portion of the inner sleeve, and thus the protective tube can be formed without a gap from the first end portion to the second end portion. That is, the protective tube covering the outer peripheral surface of the magnet structure can be appropriately formed.

[0022] In some aspects, the magnet structure can also have a first end ring and a second end ring disposed on both sides of the magnet in the axial direction. The first tapered surface can also be formed on the first end ring. The second tapered surface can also be formed on the second end ring. In this case, when winding the fiber body on the outer peripheral surface of the magnet structure, the protective tube can be formed without a gap from the first end portion to the second end portion as described above. That is, the protective tube covering the outer peripheral surface of the magnet structure can be appropriately formed.

[0023] A motor of one embodiment of the present disclosure includes any of the above-described rotors and a stator disposed around the rotor.

[0024] Since the motor includes any of the above-described rotors, in the motor, peeling of the protective tube when the rotor is rotating can be suppressed as described above.

[0025] A manufacturing method of a rotor of one embodiment of the present disclosure is a manufacturing method of any of the above-described rotors. The manufacturing method of the rotor includes a winding step of forming a tubular fiber bundle covering an outer peripheral surface of a magnet structure by winding a fiber body on the outer peripheral surface of the magnet structure, and a heat treatment step of forming a protective tube by performing heat treatment on the tubular fiber bundle covering the outer peripheral surface of the magnet structure.

[0026] In the manufacturing method of the rotor, the protective tube that is joined to the outer peripheral surface of the magnet structure body can be formed by winding the fiber body after the outer peripheral surface of the magnet structure body and then performing heat treatment on the tubular fiber bundle arranged on the outer peripheral surface. In the case where the rotor is manufactured using this method, since the first end portion and the second end portion of the protective tube are joined to the first tapered surface and the second tapered surface, the first end portion and the second end portion can be made difficult to peel off from the first tapered surface and the second tapered surface when the rotor rotates, as described above. Therefore, according to the above-described manufacturing method of the rotor, the above-described effect of suppressing peeling of the protective tube when the rotor rotates can be suitably obtained.

[0027] In some modes, in the winding process, the fiber body can also be wound from the outer peripheral surface of the magnet structure body arranged at one end in the axial direction to the outer peripheral surface of the magnet structure body arranged at the other end in the axial direction in a state where a plurality of magnet structure bodies are arranged in the axial direction, thereby forming a tubular fiber bundle that collectively covers the outer peripheral surfaces of the plurality of magnet structure bodies. In the heat treatment process, the tubular fiber bundle that collectively covers the outer peripheral surfaces of the plurality of magnet structure bodies can be subjected to heat treatment, and then the tubular fiber bundle can be cut at the boundaries in the axial direction of the respective magnet structure bodies, thereby forming respective protective tubes corresponding to the respective magnet structure bodies. In this way, in the case where the method of collectively winding a plurality of magnet structure bodies with a fiber body is employed, the manufacturing time of each rotor can be shortened compared to the case where the method of independently winding the magnet structure bodies with a fiber body is employed. In addition, an increase in the amount of fiber body required to be wound around each magnet structure body can be suppressed. Therefore, according to the above-described method, an improvement in the manufacturing efficiency of the rotor can be achieved.

[0028] Hereinafter, one embodiment will be described with reference to the drawings. In the description of the drawings, cases where the same elements are denoted by the same reference numerals and repeated description is omitted will exist.

[0029] <MOTOR>

[0030] Referring to Figure 1 A motor 1 provided with the rotor 10 of the present embodiment will be described. Figure 1 The motor 1 illustrated is suitable for use in the aerospace field, for example. In the present embodiment, the motor 1 is a rotary aircraft motor that functions as a power source for a fuel pump. The motor 1 can also be used for other purposes. Figure 1 A cross-sectional surface of the motor 1 when the motor 1 is cut by a plane passing through the rotational axis L of the shaft 2 to be described later.

[0031] As Figure 1As shown, the motor 1 has a rotor 10 as a rotating member and a stator 20 as a fixed member. The rotor 10 is fixed to a shaft 2 to which an impeller of a fuel pump is coupled. The shaft 2 is in a cylindrical shape with the rotational axis L as a central axis. The shaft 2 is configured to be rotatable about the rotational axis L. The rotor 10 is rotatable about the rotational axis L together with the shaft 2.

[0032] The stator 20 includes a cylindrical core 20a arranged around the rotor 10 and a coil 20b formed by winding a wire around the core 20a. If an alternating current flows through the wire to the coil 20b, the stator 20 generates a magnetic field around the shaft 2 to rotate the rotor 10. In the following description, an axial direction D1 indicates a direction extending along the rotational axis L. A radial direction D2 indicates a direction orthogonal to the rotational axis L. The radial direction D2 is a radial direction of the shaft 2 and is orthogonal to the axial direction D1.

[0033] <ROTOR>

[0034] The rotor 10 has a magnet structure 30 and a protection tube 40. The magnet structure 30 is arranged around the shaft 2. The magnet structure 30 is in a cylindrical shape with the rotational axis L as a central axis. The magnet structure 30 includes a magnet 31, a pair of end rings 33 and 34, and an inner sleeve 36. The magnet 31 of the present embodiment is a permanent magnet in a cylindrical shape with the rotational axis L as a central axis. As a material of the magnet 31, for example, a neodymium magnet (Nd-Fe-B) and a samarium-cobalt magnet, or the like can be used. The magnet 31 is arranged so as to cover an outer peripheral surface 2a of the shaft 2. The inner sleeve 36 is inserted through the inside of the magnet 31 together with the shaft 2. The magnet 31 includes one end surface 31a toward one side in the axial direction D1 and another end surface 31b toward the opposite side to the one end surface 31a. The one end surface 31a and the other end surface 31b can be, for example, planes orthogonal to the rotational axis L, respectively. The manner of the magnet 31 can be appropriately changed within the scope of the purpose of the present disclosure. For example, the magnet 31 can also be configured by a plurality of magnet pieces divided in the circumferential direction of the shaft 2. Alternatively, the magnet 31 can also be configured by a plurality of magnet pieces divided in the radial direction D2 as well as in the circumferential direction. In this case, by assembling the plurality of magnet pieces in the circumferential direction and the radial direction D2, the cylindrical magnet 31 can be configured. A plurality of grooves can also be formed in an outer peripheral surface 36a of the inner sleeve 36, and the plurality of magnet pieces configuring the magnet 31 can be fitted into these grooves. Alternatively, a plurality of protrusions (wall surfaces) can also be formed which protrude radially outward from the outer peripheral surface 36a of the inner sleeve 36. Each of the plurality of magnet pieces configuring the magnet 31 can be fitted between each of the protrusions. That is, each of the plurality of magnet pieces configuring the magnet 31 can be arranged in the circumferential direction in such a manner as to be adjacent to each of the protrusions in the circumferential direction.

[0035] The end ring 33 (first end ring) and the end ring 34 (second end ring) are each a circular ring-shaped (annular) member with the rotation axis L as a central axis. As the material of each of the end rings 33 and 34, for example, a non-magnetic metal such as titanium (e.g., Ti-6Al-4V), a thermosetting resin, a thermoplastic resin, or the like can be used. The end rings 33 and 34 are disposed on the outer side of the magnet 31 in the axial direction D1. That is, the end rings 33 and 34 are disposed on both sides of the magnet 31 in the axial direction D1 with the magnet 31 interposed therebetween. The end rings 33 and 34 are disposed so as to cover one end surface 31a and the other end surface 31b of the magnet 31 in the axial direction D1, respectively. The end ring 33 is disposed at a position opposite the one end surface 31a in the axial direction D1. The end ring 34 is disposed at a position opposite the other end surface 31b in the axial direction D1.

[0036] Inside the end rings 33 and 34, the inner sleeve 36 is inserted through together with the shaft 2. Each of the end rings 33 and 34 is shrink-fitted to the inner sleeve 36. The inner circumferential surface of each of the end rings 33 and 34 is in close contact with the outer circumferential surface 36a of the inner sleeve 36. The outer diameter of each of the outer circumferential surfaces 33a and 34a of each of the end rings 33 and 34 can be the same as the outer diameter of the outer circumferential surface 31c of the magnet 31, for example. That is, in the radial direction D2, each of the outer circumferential surfaces 33a and 34a can be located at the same position as the outer circumferential surface 31c of the magnet 31.

[0037] The end rings 33 and 34 have a function of transmitting the rotational force (torque) of the magnet 31 to the shaft 2. The rotational force of the magnet 31 is transmitted to the inner sleeve 36 via the protective tube 40 and the end rings 33 and 34, and is transmitted from the inner sleeve 36 to the shaft 2. In addition, the end rings 33 and 34 also have a function of preventing the magnet 31 from moving in the axial direction D1.

[0038] The inner sleeve 36 is a cylindrical member with the rotation axis L as a central axis. As the material of the inner sleeve 36, for example, a steel material such as stainless steel (SUS) can be used. As described above, the inner sleeve 36 is inserted through inside the end ring 33, inside the magnet 31, and inside the end ring 34. Therefore, the inner sleeve 36 is interposed between the shaft 2 and the magnet 31 and between the shaft 2 and the end rings 33 and 34 in the radial direction D2. The inner circumferential surface of the inner sleeve 36 is fixed to the outer circumferential surface 2a of the shaft 2.

[0039] The inner sleeve 36 includes one end surface 36b facing one side in the axial direction D1, and the other end surface 36c facing the opposite side to the one end surface 36b. The one end surface 36b and the other end surface 36c can each be a plane perpendicular to the rotation axis L, for example. The one end surface 36b constitutes one end surface of the magnet structure 30 in the axial direction D1. The other end surface 36c constitutes the other end surface of the magnet structure 30 in the axial direction D1. The length of the inner sleeve 36 in the axial direction D1 is longer than the length of the total axial direction D1 including the magnet 31 and the end rings 33 and 34. As a result, the inner sleeve 36 extends to a position on the outer side of the magnet 31 in the axial direction D1 with respect to the end rings 33 and 34.

[0040] One end portion 36d of the inner sleeve 36 in the axial direction D1 (i.e., an end portion of the inner sleeve 36 including the one end face 36b) protrudes to the outside of the magnet 31 side in the axial direction D1 with respect to the end ring 33. In other words, the one end portion 36d protrudes to the side opposite to the magnet 31 with respect to the end ring 33. The other end portion 36e of the inner sleeve 36 in the axial direction D1 (i.e., an end portion of the inner sleeve 36 including the other end face 36c) protrudes to the outside of the magnet 31 side in the axial direction D1 with respect to the end ring 34. In other words, the other end portion 36e protrudes to the side opposite to the magnet 31 with respect to the end ring 34.

[0041] The inner sleeve 36 includes a cylindrical body portion 37 extending from the one end face 36b to the other end face 36c in the axial direction D1 and a flange portion 38 protruding from the outer peripheral surface 37a of the cylindrical body portion 37 to the outside in the radial direction D2. The cylindrical body portion 37 is in a cylindrical shape with the rotation axis L as the central axis. The flange portion 38 is provided to the one end portion 36d of the inner sleeve 36. The flange portion 38 protrudes from the outer peripheral surface 37a of the cylindrical body portion 37 to the outside in the radial direction D2 to a position opposite to the magnet 31 with the end ring 33 interposed in the axial direction D1. The maximum outer diameter of the flange portion 38 (specifically, the outer diameter of the circumferential surface S1 described later) is smaller than the outer diameter of the outer peripheral surface 31c of the magnet 31, the outer diameter of the outer peripheral surface 33a of the end ring 33, and the outer diameter of the outer peripheral surface 34a of the end ring 34. As a result, the flange portion 38 is located radially inward of the magnet 31, the end ring 33, and the end ring 34.

[0042] Figure 2 Enlarged view Figure 1 of the one end portion 36d of the rotor 10. As shown in Figure 2 , the flange portion 38 provided to the one end portion 36d includes an end face 38b connecting the outer peripheral surface 38a of the flange portion 38 and the outer peripheral surface 37a of the cylindrical body portion 37 in the radial direction D2. The end face 38b faces the side opposite to the one end face 36b in the axial direction D1. The end face 38b opposes the end ring 33 (specifically, the vertical surface S3 of the one end face 33b described later) in the axial direction D1. The end face 38b can be, for example, a plane perpendicular to the rotation axis L.

[0043] A conical surface S2 (first conical surface) is formed on the outer peripheral surface 38a of the flange portion 38. The conical surface S2 is formed on the portion of the outer peripheral surface 38a other than the circular surface S1. The circular surface S1 is the surface of the outer peripheral surface of a cylinder with the rotation axis L as its central axis. The normal direction of the circular surface S1 is along the radial direction D2. The circular surface S1 is located on the end face 38b side of the outer peripheral surface 38a in the axial direction D1. The conical surface S2 connects the circular surface S1 and an end face 36b. The conical surface S2 is inclined relative to the circular surface S1 and the end face 36b. Specifically, the conical surface S2 becomes more constricted in the axial direction D1 the further away from the end face 38b (i.e., the further away from the other end P2 of the protective tube 40, which will be described later). In other words, the conical surface S2 is located more on the inner side of the radial direction D2 the further away from the end face 38b side in the axial direction D1 the end face 36b side.

[0044] As a result, the conical surface S2 becomes an inclined surface relative to the axial direction D1, and the normal direction of the conical surface S2 is inclined relative to the radial direction D2. The angle of the normal direction of the conical surface S2 relative to the radial direction D2 is in the range greater than 0° and less than 90°. For example, the angle of the normal direction of the conical surface S2 relative to the radial direction D2 can be in the range greater than 0° and less than 45°, or it can be in the range greater than 45° and less than 90°.

[0045] As described above, the flange 38 provided at one end 36d is located radially inner than the magnet 31, end ring 33, and end ring 34 by a distance of D2. Therefore, the conical surface S2 formed on the flange 38 is also located radially inner than the magnet 31, end ring 33, and end ring 34 by a distance of D2. In other words, the conical surface S2 is located radially inner than the outer peripheral surface 31c of the magnet 31, the outer peripheral surface 33a of the end ring 33, and the outer peripheral surface 34a of the end ring 34.

[0046] like Figure 2 As shown, the end ring 33 includes an end face 33b that faces the end face 38b of the flange portion 38 in the axial direction D1, and another end face 33c that faces the end face 31a of the magnet 31 in the axial direction D1. The end face 33b and the other end face 33c connect to the outer peripheral surface 33a of the end ring 33. The other end face 33c may be, for example, a plane perpendicular to the rotation axis L. An inclined surface S4 is formed on the end face 31a, which is inclined from the vertical plane S3 perpendicular to the rotation axis L. The vertical plane S3 is located in the axial direction D1 opposite to the end face 38b of the flange portion 38. The inclined surface S4 is located radially outward from the circumferential surface S1 of the flange portion 38. The inclined surface S4 connects the vertical plane S3 and the outer peripheral surface 33a. The inclined surface S4 is inclined such that the further outward it is radially D2, the closer it is to the other end face 33c in the axial direction D1.

[0047] Figure 3 Magnification Figure 1 Near the other end 36e of the rotor 10 shown. (As shown)Figure 3 As shown, a tapered surface S6 (second tapered surface) is formed on the outer peripheral surface 37a of the cylindrical body portion 37 at the other end portion 36e. The tapered surface S6 is located between the circumferential surface S5 and the other end surface 36c of the outer peripheral surface 37a. The circumferential surface S5 is a surface along the outer peripheral surface of a cylinder having the rotational axis L as a central axis. The normal direction of the circumferential surface S5 is along the radial direction D2. The outer diameter of the other end portion 36e is defined by the outer diameter of the circumferential surface S5. The outer diameter of the circumferential surface S5 is smaller than the outer diameter of the outer peripheral surface 31c of the magnet 31, the outer diameter of the outer peripheral surface 33a of the end ring 33, and the outer diameter of the outer peripheral surface 34a of the end ring 34. As a result, the other end portion 36e is located at a position that is radially D2 inward of the magnet 31, the end ring 33, and the end ring 34.

[0048] The tapered surface S6 connects the circumferential surface S5 and the other end surface 36c. The tapered surface S6 is inclined with respect to the circumferential surface S5 and the other end surface 36c. Specifically, the tapered surface S6 is tapered in the axial direction D1 as it approaches the other end surface 36c (i.e., as it moves away from the one end portion P1 of the protection tube 40 described later). In other words, the tapered surface S6 is located at a position that is radially D2 inward as it approaches the end surface 38b side in the axial direction D1.

[0049] As a result, the tapered surface S6 becomes a surface that is inclined with respect to the axial direction D1, and the normal direction of the tapered surface S6 is inclined with respect to the radial direction D2. The angle of the normal direction of the tapered surface S6 with respect to the radial direction D2 is in a range that is larger than 0° and smaller than 90°. The angle of the normal direction of the tapered surface S6 with respect to the radial direction D2 can also be the same as the angle of the normal direction of the tapered surface S2 (see FIG. 2) with respect to the radial direction D2. Alternatively, the angle of the normal direction of the tapered surface S6 with respect to the radial direction D2 can be larger than the angle of the normal direction of the tapered surface S2 with respect to the radial direction D2, or it can be smaller. Figure 2

[0050] As described above, the other end portion 36e is located at a position that is radially D2 inward of the magnet 31, the end ring 33, and the end ring 34. Therefore, the tapered surface S6 formed on the other end portion 36e is also located at a position that is radially D2 inward of the magnet 31, the end ring 33, and the end ring 34. In other words, the tapered surface S2 is located at a position that is radially D2 inward of the outer peripheral surface 31c of the magnet 31, the outer peripheral surface 33a of the end ring 33, and the outer peripheral surface 34a of the end ring 34.

[0051] As described above, the other end portion 36e is located at a position that is radially D2 inward of the magnet 31, the end ring 33, and the end ring 34. Therefore, the tapered surface S6 formed on the other end portion 36e is also located at a position that is radially D2 inward of the magnet 31, the end ring 33, and the end ring 34. In other words, the tapered surface S2 is located at a position that is radially D2 inward of the outer peripheral surface 31c of the magnet 31, the outer peripheral surface 33a of the end ring 33, and the outer peripheral surface 34a of the end ring 34. Figure 3 ​As shown, the end ring 34 includes an end surface 34b facing the other end surface of the magnet 31 in the axial direction D1, and another end surface 34c facing the opposite side of the end surface 34b in the axial direction D1. The end surface 34b and the other end surface 34c connect the outer peripheral surface 34a of the end ring 34. The end surface 34b can be, for example, a plane perpendicular to the rotation axis L. The other end surface 34c is formed with an inclined surface S7 inclined from a plane perpendicular to the rotation axis L. The inclined surface S7 is formed on the entire other end surface 34c. The inclined surface S7 is inclined so as to approach the end surface 34b in the axial direction D1 more as it approaches the outer side in the radial direction D2. As a result, the inclined surface S7 is inclined with respect to the plane perpendicular to the rotation axis L.

[0052] Referring again to Figure 1 The protection tube 40 is a cylindrical member having the rotation axis L as a center axis. The protection tube 40 includes an end surface 40a facing one side in the axial direction D1, and another end surface 40b facing the opposite side of the end surface 40a in the axial direction D1. The magnet structure 30 is disposed inside the protection tube 40. The length of the axial direction D1 of the protection tube 40 is, for example, the same as the length of the axial direction D1 of the magnet structure 30. The end surface 40a of the protection tube 40 is located at the same position as the end surface 36b of the magnet structure 30 in the axial direction D1. The other end surface 40b of the protection tube 40 is located at the same position as the other end surface 36c of the magnet structure 30 in the axial direction D1. Therefore, the end surface 40a of the protection tube 40 and the end surface 36b of the magnet structure 30 become the same surface. The other end surface 40b of the protection tube 40 and the other end surface 36c of the magnet structure 30 become the same surface.

[0053] The protection tube 40 completely covers the outer peripheral surface 30a of the magnet structure 30. The inner peripheral surface of the protection tube 40 is engaged (bonded) with the outer peripheral surface 30a of the magnet structure 30. Specifically, the inner peripheral surface of the protection tube 40 is engaged with the outer peripheral surface 31c of the magnet 31, the outer peripheral surface 33a of the end ring 33, the outer peripheral surface 34a of the end ring 34, the outer peripheral surface 38a of the flange portion 38 of the inner sleeve 36, and the outer peripheral surface 37a of the other end portion 36e of the inner sleeve 36.

[0054] The protection tube 40 has a function of preventing the fragments of the magnet 31 from flying in the radial direction D2 in the case where the magnet 31 is broken. In order to suppress the deformation of the magnet 31 to reduce the possibility of the magnet 31 being broken, the protection tube 40 is required to have a certain degree of rigidity. The protection tube 40 is composed of, for example, a fiber body 40F such as carbon fiber reinforced plastic (CFRP). The material of the fiber body 40F is not limited to CFRP, and can be another material such as glass fiber reinforced plastic (GFRP).

[0055] Figure 4 represents a side surface of the rotor 10 as viewed from a direction perpendicular to the rotation axis L. As shown in Figure 4 The protective tube 40 has a structure in which a plurality of turns of the fiber body 40F (filament) are wound around the outer peripheral surface 30a of the magnet structure body 30, as shown in

[0056] If the fiber body 40F is wound around the outer peripheral surface 30a of the magnet structure body 30 using the filament winding method, the start end portion (or the end end portion) that becomes the start of winding of the fiber body 40F is located at one end portion P1 (first end portion) in the axial direction D1 of the protective tube 40. Also, the end end portion (or the start end portion) that becomes the end of winding of the fiber body 40F is located at the other end portion P2 (second end portion) in the axial direction D1 of the protective tube 40. The one end portion P1 of the protective tube 40 can be defined as a portion including at least a portion of the start end portion (or the end end portion) of the fiber body 40F in a portion on the side of the one end surface 40a of the protective tube 40. The other end portion P2 of the protective tube 40 can be defined as a portion including at least a portion of the end end portion (or the start end portion) of the fiber body 40F in a portion on the side of the other end surface 40b of the protective tube 40.

[0057] As shown in Figure 2 The one end portion P1 of the protective tube 40 is located on and joined to the tapered surface S2 of the flange portion 38. Thus, the tapered surface S2 becomes a joining surface with the one end portion P1 in the outer peripheral surface 30a of the magnet structure body 30. The one end portion P1 can be joined not only to the tapered surface S2 but also to other structures such as the circumferential surface S1. Figure 3 As shown in The other end portion P2 of the protective tube 40 is located on and joined to the tapered surface S6 of the cylindrical body portion 37. Thus, the tapered surface S6 becomes a joining surface with the other end portion P2 in the outer peripheral surface 30a of the magnet structure body 30. The other end portion P2 can be joined not only to the tapered surface S6 but also to other structures such as the circumferential surface S5.

[0058]

[0059] Next, the manufacturing method of the rotor will be described with reference to Figure 5 (a) of FIG. 1, Figure 5 (b) of FIG. 2, Figure 6 (a) of FIG. 3, and Figure 6(b) describes a manufacturing method of the rotor 10. In the present embodiment, the wire-winding method is collectively applied to the plurality of magnet assemblies 30 when the protective tube 40 is formed. That is, the protective tube 40 is formed by collectively winding the fiber body 40F around the plurality of magnet assemblies 30 arranged in series in the axial direction Dl.

[0060] First, the magnet assembly 30 formed with the tapered surfaces S2 and S6 is prepared. The magnet assembly 30 is obtained by inserting the inner sleeve 36 formed with the tapered surfaces S2 and S6 into the interiors of the magnet 31, the end ring 33, and the end ring 34. Also, as shown in (a) of FIG. 6, the plurality of magnet assemblies 30 are arranged in the axial direction Dl (arrangement step SIl). At this time, the cylindrical jig 80 is inserted into the interior of each of the plurality of magnet assemblies 30, and the plurality of magnet assemblies 30 are fastened in the axial direction Dl by a pair of fastening members 81 such as screws. Thus, the plurality of magnet assemblies 30 are held in a state of being arranged in series in the axial direction Dl. Figure 5

[0061] Each of the magnet assemblies 30 is arranged so that the flange portion 38 of each of the magnet assemblies 30 faces one side in the axial direction Dl. Here, the magnet assembly 30 located at one end in the axial direction Dl among the plurality of magnet assemblies 30 is referred to as "magnet assembly 30A". The magnet assembly 30 located at the other end in the axial direction Dl is referred to as "magnet assembly 30C". The magnet assemblies 30 interposed between the magnet assemblies 30A and 30C are referred to as "magnet assemblies 30B". In the case where the magnet assemblies 30A, 30B, and 30C are not particularly distinguished, the magnet assemblies 30A, 30B, and 30C are collectively referred to as "magnet assemblies 30". The one end surface 36b of the magnet assembly 30A abuts against one of the fastening members 81 in the axial direction Dl. The other end surface 36c of the magnet assembly 30A abuts against the one end surface 36b of the magnet assembly 30B. The other end surface 36c of the magnet assembly 30B abuts against the one end surface 36b of the magnet assembly 30C. The other end surface 36c of the magnet assembly 30C abuts against the other of the fastening members 81.

[0062] Next, as shown in (b) of FIG. 6, the plurality of magnet assemblies 30 are collectively wound with the fiber body 40F (winding step S12). At this time, the plurality of magnet assemblies 30 are held in a state of being arranged in series in the axial direction Dl by the fastening members 81. Thus, the plurality of magnet assemblies 30 are collectively wound with the fiber body 40F. Figure 5 ​As shown in (b), the magnetic structures 30A, 30B, and 30C are wound together using the fiber body 40F constituting the protective tube 40 (winding process S12). That is, the fiber body 40F is wound from the outer peripheral surface 30a of the magnetic structure 30A to the outer peripheral surface 30a of the magnetic structure 30C. Specifically, the starting end of the fiber body 40F is arranged on the conical surface S2 of the flange portion 38 of the magnetic structure 30A. Moreover, the fiber body 40F is wound around the outer peripheral surface 30a of each magnetic structure 30A, 30B, and 30C from the magnetic structure 30A side toward the magnetic structure 30C side in the axial direction D1. At this time, the fiber body 40F is wound by rotating the clamp 80 about the rotation axis L while applying tension f in the extending direction of the fiber body 40F.

[0063] After the fiber body 40F is wound to the magnet structure 30C, the fiber body 40F is wound from the magnet structure 30C side toward the magnet structure 30A side. Thus, within the interval R from one end face 36b of the magnet structure 30A to the other end face 36c of the magnet structure 30C, the fiber body 40F is repeatedly wound relative to the outer peripheral surface 30a of each magnet structure 30A, 30B, and 30C. Furthermore, the winding of the fiber body 40F ends at the conical surface S6 of the magnet structure 30C. At this time, the end portion of the fiber body 40F is positioned at the conical surface S6 of the magnet structure 30C. The tubular fiber bundle formed by winding the fiber body 40F around the magnet structures 30A, 30B, and 30C is called a "tubular fiber bundle 41F" (see reference). Figure 6 (a)). The tubular fiber bundle 41F centrally covers the outer peripheral surfaces 30a of the magnet structures 30A, 30B, and 30C. In this embodiment, the tubular fiber bundle 41F is formed by winding the fiber body 40F in a manner that repeatedly moves from one end face 36b of the magnet structure 30A to the other end face 36c of the magnet structure 30C. However, the winding of the fiber body 40F may not be performed in this reciprocating manner. For example, the fiber body 40F may be wound in multiple layers radially D2 in the interval from one end face 36b of the magnet structure 30A to the other end face 36c of the magnet structure 30C. In this case, the tubular fiber bundle 41F may be formed without the reciprocating motion during the winding of the fiber body 40F.

[0064] Next, by heat-treating the tubular fiber bundle 41F covering the outer peripheral surface 30a of the magnet structures 30A, 30B, and 30C, protective tubes 40A, 40B, and 40C corresponding to each magnet structure 30A, 30B, and 30C are formed (heat treatment step S13). Specifically, as... Figure 6As shown in (a), the magnet structures 30A, 30B, and 30C, covered by the tubular fiber bundle 41F, are arranged together with the fixture 80 inside the furnace 90. Then, inside the furnace 90, the resin impregnated with the tubular fiber bundle 41F is thermo-cured, so that the inner circumferential surface of the tubular fiber bundle 41F is joined to the outer circumferential surface 30a of each magnet structure 30A, 30B, and 30C. At this time, the portion of the tubular fiber bundle 41F corresponding to one end P1 and the other end P2 of the protective tube 40 is joined to the conical surfaces S2 and S6 of each magnet structure 30A, 30B, and 30C.

[0065] Next, as Figure 6 As shown in (b), after the magnet structures 30A, 30B, and 30C, to which the tubular fiber bundles 41F are joined, are removed from the furnace 90, the tubular fiber bundles 41F of each magnet structure 30A, 30B, and 30C are cut (cutting step S14). Specifically, the tubular fiber bundles 41F are cut at cutting surfaces C1 and C2. Cutting surface C1 is the boundary surface between adjacent magnet structures 30A and 30B in the axial direction D1, that is, the abutting surface between the other end face 36c of magnet structure 30A and one end face 36b of magnet structure 30B. Cutting surface C2 is the boundary surface between adjacent magnet structures 30B and 30C in the axial direction D1, that is, the abutting surface between the other end face 36c of magnet structure 30B and one end face 36b of magnet structure 30C.

[0066] By cutting the tubular fiber bundle 41F in cutting surfaces C1 and C2, protective tubes 40A, 40B, and 40C corresponding to each of the magnet structures 30A, 30B, and 30C are formed. Specifically, the protective tube 40A, which engages with the outer peripheral surface 30a of the magnet structure 30A, the protective tube 40B, which engages with the outer peripheral surface 30a of the magnet structure 30B, and the protective tube 40C, which engages with the outer peripheral surface 30a of the magnet structure 30C, are formed from the tubular fiber bundle 41F. The cutting of the tubular fiber bundle 41F in cutting surfaces C1 and C2 can also be performed using a cutting tool such as a cutter.

[0067] The protective tube 40A obtained by cutting at the cutting surface C1 becomes a fiber body 40F, which is wound around the outer peripheral surface 30a from one end face 36b to the other end face 36c of the magnet structure 30A. The end portion of the fiber body 40F can be considered as being located in the other end face 36c, which is the cutting surface C1. Similarly, the beginning and end portions of the fiber body 40F can be considered as being located in one end face 36b and the other end face 36c of the protective tube 40B. Similarly, the beginning portion of the fiber body 40F can be considered as being located in one end face 36b of the protective tube 40C. Therefore, the beginning and end portions of the fiber body 40F are respectively located at one end P1 and the other end P2 of each of the protective tubes 40A, 40B, and 40C.

[0068] By the above procedure, the protection tube 40 joined to the magnet structure 30 can be obtained. Then, by inserting the shaft 2 inside the magnet structure 30, the rotor 10 shown in Fig. 1 can be obtained. Figure 1 In the above procedure, the case where three magnet structures 30A, 30B and 30C are arranged in series in the axial direction Dl is exemplified. However, the number of magnet structures 30 arranged in the axial direction Dl is not limited to three, and can be two or more than four.

[0069] In the above procedure, the winding method is applied to the plurality of magnet structures 30A, 30B and 30C collectively. However, the winding method can be applied to each of the magnet structures 30A, 30B and 30C. That is, the protection tube 40 can be formed by winding the fiber body 40F around one magnet structure 30. In this case, in the range from one end surface 36b to the other end surface 36c of the magnet structure 30, the fiber body 40F is wound around the outer peripheral surface 30a of the magnet structure 30. Then, the magnet structure 30 covered with the cylindrical fiber bundle 41F is disposed inside the furnace 90, and the resin impregnated in the cylindrical fiber bundle 41F is cured by heating. Thus, the protection tube 40 joined to the outer peripheral surface 30a of the magnet structure 30 is formed. In the case where this method is used, the leading end portion of the fiber body 40F is located at one end portion P1 of the protection tube 40, and the trailing end portion of the fiber body 40F is located at the other end portion P2 of the protection tube 40.

[0070] <Effects>

[0071] Next, the effects achieved by the rotor 10, the motor 1 and the manufacturing method of the rotor 10 of the present embodiment will be described together with the problems of the comparative example. Figure 9 (a) of Fig. 1 shows the rotor 100 of the comparative example. Figure 9 (b) of Fig. 1 shows an enlarged view of Figure 9 (a) of Fig. 1. In the rotor 100 of the comparative example, unlike the rotor 10 of the present embodiment, the tapered surface is not formed at the other end portion 36e of the inner sleeve 136. Therefore, as shown in Figure 9 (a) of Fig. 1, at the other end portion 36e, the peripheral surface S5 of the cylindrical body portion 137 is directly connected to the other end surface 36c, and the other end portion P2 of the protection tube 40 is joined to the peripheral surface S5.

[0072] In the rotor 100 of the comparative example, as shown in Figure 9As shown in (b), during the rotation of the rotor 100, the protective tube 40 is subjected to an external force radially outward due to centrifugal force F and wind pressure. The centrifugal force F acting on the other end P2 of the protective tube 40 acts in the direction radially outward. As a resistance to this centrifugal force F, the engagement force F100 acting only in the normal direction of the circumferential surface S5 (i.e., the inner side of radial D2) of the other end P2 acts. In this case, if the centrifugal force F is greater than the engagement force F100, the other end P2 will peel off from the circumferential surface S5.

[0073] When forming the protective tube 40, whether the wire winding method is applied to each magnet structure 130 or the wire winding method is applied to multiple magnet structures 130 together, as described above, the beginning and end ends of the fiber body 40F are located at one end P1 and the other end P2 of the protective tube 40. Therefore, in either case, when the rotor 100 rotates, it is easy for the protective tube 40 to peel off from the outer peripheral surface 30a of the magnet structure 130, starting from one end P1 and the other end P2.

[0074] In contrast, in the rotor 10 of this embodiment, as... Figure 7 As shown in (a) and (b), the interface between the outer peripheral surface 30a of the magnet structure 130 and one end P1 is a conical surface S2, and the interface between the outer peripheral surface 30a of the magnet structure 130 and the other end P2 is a conical surface S6. Figure 7 (a) magnified representation Figure 2 Near one end P1. Figure 7 (b) magnified representation Figure 3 Near the other end P2.

[0075] like Figure 7 As shown in (a), during the rotation of the rotor 10, for the normal component Fa of the centrifugal force F acting on one end P1, the engaging force F1 acting on the normal component of the conical surface S2 at one end P1 acts as a resistance. Furthermore, for the in-plane component Fb of the centrifugal force F acting on the conical surface S2, the shear force F2 acting on the in-plane component of the conical surface S2 at one end P1 acts as a resistance. Similarly, as... Figure 7As shown in (b), with respect to a normal line direction component Fa of the centrifugal force F acting on the tapered surface S6, an engagement force Fl of the other end portion P2 acting in the normal line direction of the tapered surface S6 acts as a resistance. Also, with respect to an in-plane direction component Fb of the centrifugal force F, a force F2 of the other end portion P2 acting in the shearing direction of the in-plane direction of the tapered surface S6 acts as a resistance. The engagement force Fl of the one end portion Pl is an engagement force (adhesion force) of the one end portion Pl with respect to the tapered surface S2. The engagement force Fl of the other end portion P2 is an engagement force (adhesion force) of the other end portion P2 with respect to the tapered surface S6.

[0076] Thus, in the tapered surfaces S2 and S6, in addition to the engagement force Fl of the one end portion Pl and the other end portion P2, the force F2 of the one end portion Pl and the other end portion P2 in the shearing direction also acts as a resistance to the centrifugal force F. Thereby, it is possible to make it difficult for the one end portion Pl and the other end portion P2 to peel off from the tapered surfaces S2 and S6 at the time of rotation of the rotor 10. That is, it is possible to suppress peeling of the protective tube 40 at the time of rotation of the rotor 10. As a result, it is possible to suppress a situation in which the rotational balance of the rotor 10 is broken, and it is possible to suppress a situation in which an undesirable condition such as a large vibration of the rotor 10 occurs.

[0077] Also, in the present embodiment, the protective tube 40 is formed using a method in which the fiber body 40F is directly wound around the outer peripheral surface 30a of the magnet structure body 30. In a case where this method is used, compared to a case where a method in which the protective tube 40 is joined to the outer peripheral surface 30a of the magnet structure body 30 after the protective tube 40 is formed using a production jig is employed, a production jig for forming the protective tube 40 is not required, and a release agent for pulling out the protective tube 40 from the production jig is not required. As a result, since it is possible to suppress manufacturing costs and manufacturing time for forming the protective tube 40, it is possible to achieve an improvement in manufacturing efficiency of the rotor 10.

[0078] In the present embodiment, the tapered surface S2 is formed at the one end portion 36d of the inner sleeve 36, and the tapered surface S6 is formed at the other end portion 36e of the inner sleeve 36. Thus, in a case where the tapered surfaces S2 and S6 are formed in a structure other than the magnet 31 in the magnet structure body 30, compared to a case where the tapered surfaces S2 and S6 are formed in the magnet 31, it is possible to more reliably ensure the engagement force of the one end portion Pl and the other end portion P2 with respect to the tapered surfaces S2 and S6. Thereby, it is possible to further make it difficult for the one end portion Pl and the other end portion P2 to peel off from the tapered surfaces S2 and S6 at the time of rotation of the rotor 10.

[0079] In the present embodiment, the tapered surface S2 is formed in the flange portion 38. In this structure, the distance (rotational radius) of the radial direction D2 from the axis 2 of the center of rotation to the tapered surface S2 becomes smaller than in the case where the tapered surface S2 is formed in the magnet 31 or the end ring 33. Thus, the centrifugal force F acting on the one end portion P1 engaged with the tapered surface S2 can be suppressed to be smaller. As a result, the one end portion P1 can be further more difficult to peel off from the tapered surface S2 at the time of rotation of the rotor 10.

[0080] In the present embodiment, the tapered surface S6 is formed in the other end portion 36e of the inner sleeve 36. In this structure, the distance (i.e., rotational radius) of the radial direction D2 from the axis 2 of the center of rotation to the tapered surface S6 becomes smaller than in the case where the tapered surface S6 is formed in the magnet 31 or the end ring 34. Thus, the centrifugal force F acting on the other end portion P2 engaged with the tapered surface S6 can be suppressed to be smaller. As a result, the other end portion P2 can be further more difficult to peel off from the tapered surface S6 at the time of rotation of the rotor 10.

[0081] In the present embodiment, the inclined surface S4 is formed in the one end surface 33b of the end ring 33, and the inclined surface S7 is formed in the other end surface 34c of the end ring 34. When the fiber body 40F of the protection tube 40 is directly wound around the outer peripheral surface 30a of the magnet structure body 30, it is difficult to perform the winding of the fiber body 40F with respect to a plane perpendicular to the rotational axis L in the magnet structure body 30. In contrast to this, by forming the inclined surface S4 in the one end surface 33b of the end ring 33, the fiber body 40F can be wound without a gap from the end ring 33 to the flange portion 38 of the inner sleeve 36. Similarly, by forming the inclined surface S7 in the other end surface 34c of the end ring 34, the fiber body 40F can be wound without a gap from the end ring 34 to the other end portion 36e of the inner sleeve 36.

[0082] In the manufacturing method of the rotor 10 of the present embodiment, when the protection tube 40 is formed, the magnet structure bodies 30A, 30B, and 30C arranged in series in the axial direction D1 are collectively wound with the fiber body 40F. In this way, in the case where the method of collectively winding the magnet structure bodies 30A, 30B, and 30C with the fiber body 40F is employed, compared to the case where the method of independently winding the magnet structure bodies 30A, 30B, and 30C with the fiber body 40F is employed, the manufacturing time of each rotor 10 can be shortened. Also, the increase in the amount of use of the fiber body 40F required for winding each magnet structure body 30 can be suppressed. Thus, in this method, the improvement of the manufacturing efficiency of the rotor 10 can be achieved.

[0083]

[0084] The present disclosure is not limited to the above-described embodiments, and various modifications can be made.

[0085] Figure 8 ​This is a cross-sectional view of the rotor 10A, showing a modified example. In the above embodiment, an example is shown where a tapered surface S6 is formed on the outer peripheral surface 37a of the other end 36e of the inner sleeve 36. Figure 8 In the rotor 10A shown, an example is given where a tapered surface S8 is formed on the outer circumferential surface 34a of the end ring 34A, but not on the outer circumferential surface 37a of the inner sleeve 36A. For example... Figure 8 As shown, the outer peripheral surface 37a of the other end 36e of the cylindrical main body 37 is entirely a circular surface S5. Furthermore, a conical surface S8 is formed entirely on the outer peripheral surface 34a of the end ring 34A. Figure 8 In the example shown, the other end 36e of the inner sleeve 36 does not protrude beyond the outer side of the end ring 34A in the axial direction D1 (i.e., the side opposite to the magnet 31 relative to the end ring 34A), but is housed inside the end ring 34A. In one example, the other end face 34c of the end ring 34A is located in the same position in the axial direction D1 as the other end face 36c of the inner sleeve 36. That is, the other end face 34c of the end ring 34A and the other end face 36c of the inner sleeve 36 are the same surface.

[0086] The conical surface S8 becomes increasingly constricted along the axial direction D1 as it approaches the other end face 34c (i.e., the end P1 furthest from the protective tube 40D along the axial direction D1). In other words, the conical surface S8 is located more inwardly in the radial direction D2 as it approaches the other end face 34c along the axial direction D1. As a result, the conical surface S8 becomes an inclined surface relative to the axial direction D1, and the normal direction of the conical surface S8 is inclined relative to the radial direction D2. The angle between the normal direction of the conical surface S8 and the radial direction D2 can be the same as that of the conical surface S2 (refer to...). Figure 2 The angle of the normal direction of the cone surface S2 relative to the radial direction D2 is the same, or it can be different from the angle of the normal direction of the cone surface S2 relative to the radial direction D2.

[0087] The other end P2 of the protective tube 40D is located on the conical surface S8 of the end ring 34A and engages with the conical surface S8. In one example, the other end face 40b of the protective tube 40D is located at the same position as the other end face 34c of the end ring 34A in the axial direction D1. In this case, the other end face 40b of the protective tube 40D and the other end face 34c of the end ring 34A are the same surface. Similar to the above embodiment, one end P1 of the protective tube 40D engages with the conical surface S2 of the flange portion 38 of the inner sleeve 36A.

[0088] In the rotor 10A, the outer diameter of the circumferential surface S1 of the flange portion 38 is the same as the outer diameter of the outer peripheral surface 33a of the end ring 33A. That is, in the radial direction D2, the circumferential surface S1 of the flange portion 38 is located at the same position as the outer peripheral surface 33a of the end ring 33A. Therefore, no step difference is generated between the circumferential surface S1 and the outer peripheral surface 33a, and the circumferential surface S1 and the outer peripheral surface 33a are continuously connected to each other. In this case, since no vertical surface is formed between the circumferential surface S1 and the outer peripheral surface 33a, when the protective tube 40D is formed using the filament winding method, the fiber body 40F can be continuously wound without a gap from the circumferential surface S1 to the outer peripheral surface 33a. Therefore, in the rotor 10A, unlike the above-described embodiment, it is not necessary to form the inclined surface for continuously winding the fiber body 40F on the one end surface 33b of the end ring 33A.

[0089] In the case where the protective tube 40D is formed using the method of independently winding the magnet structure body 30D with the fiber body 40F, by winding the fiber body 40F on the outer peripheral surface 30a of the magnet structure body 30D in the range from the one end surface 36b of the inner sleeve 36A to the other end surface 34c of the end ring 34A, it is possible to form the protective tube 40D as shown in FIG. 6. Figure 8 In the case where the protective tube 40D is formed using the method of collectively winding the plurality of magnet structure bodies 30D arranged in series with the fiber body 40F, as in the above-described embodiment, it is also possible to form the protective tube 40D as shown in FIG. 6 by continuously winding the fiber body 40F on the outer peripheral surface 30a of each of the magnet structure bodies 30D in the range from the one end surface 36b of the inner sleeve 36A of the magnet structure body 30D located at one end in the axial direction D1 to the other end surface 34c of the end ring 34A of the magnet structure body 30D located at the other end in the axial direction D1. Figure 8 In the case where the protective tube 40D is formed using the method of collectively winding the plurality of magnet structure bodies 30D arranged in series with the fiber body 40F, as in the above-described embodiment, it is also possible to form the protective tube 40D as shown in FIG. 6 by continuously winding the fiber body 40F on the outer peripheral surface 30a of each of the magnet structure bodies 30D in the range from the one end surface 36b of the inner sleeve 36A of the magnet structure body 30D located at one end in the axial direction D1 to the other end surface 34c of the end ring 34A of the magnet structure body 30D located at the other end in the axial direction D1.

[0090] In the rotor 10A, since the one end portion P1 and the other end portion P2 of the protection tube 40D are engaged with the tapered surfaces S2 and S8, respectively, the same effects as those of the above-described embodiment can be obtained. Also, in the rotor 10A, since the other end portion P2 of the protection tube 40D is located on the tapered surface S8 of the end ring 34A, when the fiber body 40F is wound around the outer peripheral surface 30a of the magnet structure 30D, the fiber body 40F can be prevented from being wound from the end ring 34A to the other end portion 36e of the inner sleeve 36A. Assuming that the fiber body 40F is wound from the end ring 34A to the other end portion 36e of the inner sleeve 36A, since the other end surface 34c of the end ring 34A becomes a surface perpendicular to the axial direction D1, the winding of the fiber body 40F to the other end surface 34c becomes difficult. In contrast, in the rotor 10A, the range in which the fiber body 40F is wound becomes a range from the one end surface 36b of the inner sleeve 36A to the other end surface 34c of the end ring 34A. Since the fiber body 40F is not wound on a surface perpendicular to the axial direction D1 in this range, the fiber body 40F can be continuously wound around the outer peripheral surface 30a of the magnet structure 30D without a gap in this range. As a result, the protection tube 40D that covers the outer peripheral surface 30a of the magnet structure 30D can be appropriately formed.

[0091] In the above-described embodiment, a case in which the tapered surfaces S2 and S6 that engage the one end portion P1 and the other end portion P2 of the protection tube 40, respectively, are formed in the structure other than the magnet 31 in the magnet structure 30 is exemplified. However, at least one of the above-described tapered surfaces S2 and S6 can be formed in the magnet 31. For example, the tapered surfaces S2 and S6 can be formed at both ends of the outer peripheral surface 31c of the magnet 31 in the axial direction D1, respectively, or the tapered surface S2 or S6 can be formed at one end or the other end of the outer peripheral surface 31c of the magnet 31.

[0092] In the above-described embodiment, a case in which the tapered surface S2 that engages the one end portion P1 of the protection tube 40 is formed in the outer peripheral surface 38a of the flange portion 38 of the inner sleeve 36 is exemplified. However, the tapered surface S2 that engages the one end portion P1 of the protection tube 40 is not limited to being formed in the inner sleeve 36, and can be formed in the outer peripheral surface 33a of the end ring 33. The magnet structure 30 can not have the inner sleeve 36, and the magnet 31 can be directly attached to the shaft 2. In this case, the end rings 33 and 34 can be integrated with the shaft 2. The tapered surface S2 can be formed in the outer peripheral surface 33a of the end ring 33. The tapered surface S6 can be formed in the outer peripheral surface 34a of the end ring 34.

[0093] BRIEF DESCRIPTION OF THE DRAWINGS

[0094] 1…motor; 2…shaft; 2a, 30a…outer peripheral surface; 10, 10A…rotor; 20…stator; 30, 30A, 30B, 30C, 30D…magnet structure; 31…magnet; 33, 33A…end ring (first end ring); 34, 34A…end ring (second end ring); 36, 36A…inner sleeve; 36d…one end portion; 36e…other end portion; 38…flange portion; 40, 40A, 40B, 40C, 40C…protective tube; 40F…fibrous body; 41F…cylindrical fiber bundle; D1…axial direction; D2…radial direction; P1…one end portion (first end portion); P2…other end portion (second end portion); S2…tapered surface (first tapered surface); S6, S8…tapered surface (second tapered surface).

Claims

1. A rotor characterized by, Possessing: a cylindrical magnet structure configured to include a magnet and arranged to cover an outer peripheral surface of a shaft; and a protection tube configured to include a fiber body wound in a manner to cover the outer peripheral surface of the magnet structure and engaged with the outer peripheral surface of the magnet structure, the protection tube includes a first end portion in an axial direction of the shaft in which the protection tube extends, and a second end portion on an opposite side to the first end portion in the axial direction, a first taper surface is formed on an engagement surface of the outer peripheral surface of the magnet structure engaged with the first end portion, the first taper surface being tapered in the axial direction further away from the second end portion, a second taper surface is formed on an engagement surface of the outer peripheral surface of the magnet structure engaged with the second end portion, the second taper surface being tapered in the axial direction further away from the first end portion, a start end portion of the fiber body that is a start of winding is located at the first end portion of the protection tube and arranged on an outer peripheral surface of the first taper surface and exposed to the outside in a manner not covered by other components, a terminal end portion of the fiber body that is an end of winding is located at the second end portion of the protection tube and arranged on an outer peripheral surface of the second taper surface and exposed to the outside in a manner not covered by other components.

2. The rotor according to claim 1, wherein the magnet structure has an inner sleeve sandwiched between the shaft and the magnet in a radial direction of the shaft, one end portion of the inner sleeve in the axial direction extends to a position outside the magnet in the axial direction, the first taper surface is formed on the one end portion of the inner sleeve.

3. The rotor according to claim 2, wherein a flange portion that protrudes outward in the radial direction is provided on the one end portion of the inner sleeve, the flange portion is located inward of the magnet in the radial direction, the first taper surface is formed on the flange portion.

4. The rotor according to claim 2 or 3, wherein the other end portion of the inner sleeve in the axial direction extends to a position outside the magnet in the axial direction and is located inward of the magnet in the radial direction, the second taper surface is formed on the other end portion of the inner sleeve.

5. The rotor according to claim 2 or 3, wherein the magnet structure further has a first end ring and a second end ring arranged on both sides in the axial direction across the magnet, the second end ring is located on the other end portion side of the inner sleeve with respect to the magnet in the axial direction, the second taper surface is formed on the second end ring.

6. The rotor according to claim 1, wherein the magnet structure has a first end ring and a second end ring arranged on both sides in the axial direction across the magnet, the first taper surface is formed on the first end ring, the second taper surface is formed on the second end ring.

7. A motor characterized by Possessing: the rotor according to any one of claims 1 to 6; and a stator arranged around the rotor.

8. A method of manufacturing a rotor according to any one of claims 1 to 6, characterized by, Possessing: a winding process of forming a cylindrical fiber bundle that covers the outer peripheral surface of the magnet structure by winding the fiber body on the outer peripheral surface of the magnet structure; and a The heating treatment step forms the protective tube by performing a heating treatment on the tubular fiber bundle that covers the outer circumferential surfaces of the magnet structures.

9. The method of manufacturing a rotor according to claim 8, characterized in that, In the winding step, the fiber body is wound from the outer circumferential surface of the magnet structure disposed at one end in the axial direction to the outer circumferential surface of the magnet structure disposed at the other end in the axial direction in a state in which a plurality of the magnet structures are arranged in the axial direction, thereby forming the tubular fiber bundle that collectively covers the outer circumferential surfaces of the plurality of magnet structures, In the heating treatment step, the tubular fiber bundle that collectively covers the outer circumferential surfaces of the plurality of magnet structures is subjected to a heating treatment, and then the tubular fiber bundle is cut at boundaries in the axial direction of the respective magnet structures, thereby forming the respective protective tubes corresponding to the respective magnet structures.

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