Rotor component which is fixed to a rotatable shaft of an electric rotary machine, rotor, rotatable electric machine and method for disassembling a rotor

Abstract

A rotor component (210) is fixed to a rotatable shaft (282) of a rotatable electric machine (270). The rotor component (210) comprises: a plurality of magnet mounting component segments (216) arranged in the circumferential direction of the rotatable shaft (282), each magnet mounting component segment (216) comprising: an inner circumference (226) and an outer circumference (228), each of which are flat surfaces; and a projection (230) which extends radially outwards from the outer circumference (228); several magnets (214) arranged on the outer circumferences (228) of the respective magnet attachment component segments (216); and a tubular retaining component (16) which is arranged radially outside the multiple magnets (214) in such a way that it surrounds the multiple magnets (214).

Description

FIELD OF THE INVENTION 1. Technical field

[0001] The present invention relates to a rotor component fixed to a rotatable shaft of a rotating electrical machine, a rotor, and a rotating electrical machine. The invention also relates to a method for disassembling a rotor. 2. Description of the state of the art

[0002] A synchronous motor comprises a rotor, a rotatable shaft housed within the rotor, and magnets arranged radially outwardly of the rotatable shaft. The magnets must be firmly fixed to the rotatable shaft by a reinforcing structure so that they can withstand the centrifugal force exerted on the magnets during rotation of the synchronous motor. Generally, a reinforcing structure, such as a tubular support member made of, for example, carbon fiber or titanium, is provided for covering the magnets. For example, JP H11-89142 A discloses a synchronous motor subject to high-speed rotations, wherein magnets each having a ring-like shape are used, and the magnets are reinforced on their outer periphery with carbon fiber reinforced plastic (CFRP).

[0003] The synchronous motor disclosed in JP H11-89142 A, which is concerned with high-speed rotations, uses a tubular sleeve provided with a sufficiently large interference or mounting clearance, which is shrunk or press-fitted over a rotating shaft so that the sleeve will not become loose relative to the rotating shaft during high-speed operation. Magnets are arranged on an outer periphery of the sleeve, and a holding member is shrunk or press-fitted over the magnets so that the magnets and the sleeve are pushed against the rotating shaft, thereby pressing the magnets and the sleeve into place. The motor disclosed in JP H11-89142 A, which is provided with the above-described structure, can achieve high-speed operation.

[0004] The rotor disclosed in JP H11-89142 A is designed to perform the primary function of operating at a high rotational speed, which is why the rotor requires a tight shrink-fit or press-fit by means of a large fastening clearance or interference. Therefore, disassembly of the rotor disclosed in the document after it has been assembled is not contemplated. Accordingly, the rotor disclosed in the document is not easy to disassemble, and the magnets and the rotor sleeve may be damaged during disassembly with excessive force applied to the tightly shrunk-fit or press-fitted rotor.

[0005] Some electric motors are primarily used to provide high torque, rather than providing improved high rotational speed, where high rotational speed operation is unnecessary. One highly effective means of improving the torque of an electric motor is to increase a dimension of the electric motor, such as increasing its diameter and / or increasing its overall length. The rotor disclosed in JP H11-89142 A requires greater force for radially outward expansion of the sleeve when the rotor is assembled because the rotor is provided with a larger diameter and overall length.

[0006] A rotor with a diameter larger than a predetermined length requires extremely large forces during assembly, which may lead to unsuccessful assembly of the rotor. In other words, a rotor with the structure disclosed in JP H11-89142 A and a diameter larger than a predetermined length may not be successfully manufactured in some cases.

[0007] There is a growing demand for reusing rotor components such as magnets. Besides the fact that a rotor does not necessarily require a high rotational speed, the cost of materials for magnets used in a rotor is increasing. In particular, the cost of a rare earth magnet such as a neodymium magnet has increased, and raw materials for rare earth magnets are difficult to obtain. Therefore, reusing such a magnet is highly desirable. Unfortunately, it is difficult to disassemble a rotor having a structure disclosed in JP H11-89142 A, and therefore, the collection and reuse of components of such a rotor cannot be performed.

[0008] DE 10 2012 011 913 A1 discloses an electric motor in which a shaft has an outer circumferential surface with a decreasing diameter and in which a sleeve with a likewise decreasing diameter is fastened to the outer surface of the shaft by means of a press fit. SUMMARY OF THE INVENTION

[0009] It is therefore an object of the present invention to provide an improved rotor that allows for easy disassembly and reuse of the components. This object is achieved by a rotor component according to claim 1.

[0010] According to one aspect of the invention, a rotor member fixed to a rotatable shaft of a rotary electric machine comprises a magnet attachment member having a first end on a first side in the axial direction and a second end on a second side in the axial direction; a plurality of magnets arranged radially outwardly on the magnet attachment member; and a tubular support member arranged radially outwardly on the plurality of magnets so as to surround the plurality of magnets. The magnet attachment member includes a slot extending in the radial direction through the magnet attachment member. The slot extends over a predetermined axially directed portion. The axially directed portion includes at least one of the first end and the second end. The magnet attachment member may be made of a magnetic material.

[0011] The slot may be arranged at a position between the magnets that are adjacent to each other in the circumferential direction. The plurality of magnets may be arranged within the axially directed portion. The magnet attachment member may include a tapered inner periphery that continuously widens radially outward as it extends from the first side in the axial direction to the second side in the axial direction.

[0012] The rotor component may further be provided with a wedge component arranged radially inside the magnet holding component. The magnet holding component may include a cylindrical inner circumference having an inner diameter that is constant in the axial direction. The wedge component may have a tapered inner circumference that continuously widens radially outward as it extends from the first side in the axial direction to the second side in the axial direction.

[0013] A plurality of slots may be arranged in the circumferential direction. The slot may extend across the axially directed portion including the second end and excluding the first end. The magnet mounting member may include a first slot extending across the axially directed portion including the second end and excluding the first end; and a second slot provided circumferentially adjacent to the first slot and extending across the axially directed portion including the first end and excluding the second end. The slot may extend across the entire axially directed portion extending from the first end to the second end. The inner periphery of the magnet mounting member may include a flat surface.

[0014] The support member may comprise fibers selected from a group consisting of carbon fibers, glass fibers, aramid fibers, silicon carbide fibers, boron fibers, titanium alloy fibers, ultra-high molecular weight polyethylene, polybutylene terephthalate fibers, and a combination of two or more of these fibers. The support member may comprise a fiber-reinforced resin with fibers selected from a group consisting of carbon fibers, glass fibers, aramid fibers, silicon carbide fibers, boron fibers, titanium alloy fibers, ultra-high molecular weight polyethylene, polybutylene terephthalate fibers, and a combination of two or more of these fibers.

[0015] According to another aspect of the invention, a rotor comprises a rotatable shaft and the rotor member described above. The rotatable shaft includes a tapered outer peripheral surface that continuously widens radially outward in an axially directed portion in which the rotor member is fixed, extending from the first side in the axial direction to the second side in the axial direction. The magnet attachment member is arranged on the outer periphery of the rotatable shaft. The magnet attachment member and the plurality of magnets are pressed radially outward by the rotatable shaft and held between the rotatable shaft and the holding member by the action of a radially inward elastic restoring force generated at the holding member.

[0016] The slots may comprise a gap with a predetermined width in the circumferential direction. The rotatable shaft may comprise a projection that protrudes radially outward from the outer periphery of the rotatable shaft and extends in the axial direction. The projection may be received in the gap such that it engages with the gap in such a way that movement of the magnet mounting member in the circumferential direction relative to the outer periphery of the rotatable shaft is prevented.

[0017] According to yet another aspect of the invention, a rotary electric machine includes the rotor described above. According to yet another aspect of the invention, a method for disassembling a rotor includes the steps of cutting the holding member at a position between the magnets adjacent to each other in the circumferential direction in the axial direction; and pushing a second end of the magnet attachment member toward the first side in the axial direction of the rotatable shaft and detaching the magnet attachment member from the rotatable shaft. The step of cutting the holding member may include a step of cutting a part of the holding member along the axial direction and developing the cut on the holding member by the action of a tensile strength generated in the holding member over the entire axially directed portion of the holding member. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The objects, features and advantageous effects of the invention will be clearly understood from the description of the preferred embodiments described below with reference to the accompanying drawings, in which Fig. 1 is an appearance view of a rotor component according to an embodiment of the invention, as seen from the front side in the axial direction; Fig. 2 a sectional view of the Fig. 1 shown rotor component along the line II-II in Fig. 1 is; Fig. 3 a view of the appearance of the device shown in Fig. 1 shown magnet attachment component; Fig. 4 a sectional view of the Fig. 3 shown magnet attachment component along the line IV-IV in Fig. 3 is; Fig. 5 a perspective view of one of the Fig. 1 shown magnets; Fig. 6 a perspective view of the Fig. 1 shown holding component; Fig. 7 is an appearance view of a magnet mounting member according to another embodiment of the invention; Fig. 8 a sectional view of the Fig. 7 shown magnet attachment component along the line VIII-VIII in Fig. 7 is; Fig. 9 is an appearance view of a rotor component according to another embodiment of the invention, as seen from the front side in the axial direction; Fig. 10 a sectional view of the Fig. 9 shown rotor component along the line XX in Fig. 9 is; Fig. 11 is an appearance view, as seen from the front side in the axial direction, of a magnet attachment member according to still another embodiment of the invention; Fig. 12 a sectional view of the Fig. 11 shown magnet attachment component along the line XII-XII in Fig. 11 is; Fig. 13 a perspective view of a segment of the Fig. 11 shown magnet attachment component; Fig. 14 is an appearance view of a rotor component according to still another embodiment of the invention, as seen from the front side in the axial direction; Fig. 15 is a view of the appearance of the device shown in Fig. 14 shown rotor component; Fig. 16 a sectional view of the Fig. 14 shown rotor component along the line XVI-XVI in Fig. 14 ( Fig. 15) is; Fig. 17 a perspective view of a segment of the Fig. 14 shown rotor component; Fig. 18 a perspective view of one of the Fig. 14 shown magnets; Fig. 19 is a perspective view of an assembly of the segment and the magnet; Fig. 20 is an appearance view of a rotor component according to still another embodiment of the invention, as seen from the front side in the axial direction; Fig. 21 a sectional view of the Fig. 20 shown rotor component along the line XXI-XXI in Fig. 20 is; Fig. 22 a sectional view of the Fig. 21 shown wedge component; Fig. 23 a sectional view of the Fig. 21 shown magnet attachment component; Fig. 24 is a sectional view of an electric motor according to an embodiment of the invention; Fig. 25 a sectional view of the Fig. 24 shown rotatable shaft; Fig. 26 is a sectional view of an electric motor according to another embodiment of the invention; Fig. 27 a sectional view of the Fig. 26 shown rotor; Fig. 28 one from the axially front side (ie, in the direction indicated by the arrow XXVIII in Fig. 27) of the appearance of the Fig. 27 shown rotor; Fig. 29 one from the rear side in the axial direction (ie, in the direction indicated by the arrow XXIX in Fig. 27) of the appearance of the Fig. 27 shown rotor; Fig. 30 a sectional view of the Fig. 27 shown rotatable shaft; Fig. 31 one from the rear side in the axial direction (ie, in the direction indicated by the arrow XXXI in Fig. 30 direction) of the appearance of the Fig. 30 shown rotatable shaft; Fig. 32 is a flowchart of a method of manufacturing a rotor according to an embodiment of the invention; Fig. 33 is a view for explaining a process of press-fitting the rotor member to the rotor with the front end of the magnet mounting member in contact with the outer periphery of the rotary shaft; Fig. 34 shows that the rotor component is press-fitted to the rotor at a predetermined fixed position; Fig. 35 is a view for explaining the deformation of the magnet mounting member in the radial direction; Fig. 36 is a flow diagram of a method for disassembling a rotor according to an embodiment of the invention; and Fig. 37 is a perspective view of a portion of a rotatable shaft according to another embodiment of the invention. DESCRIPTION OF EMBODIMENTS

[0019] Embodiments of the invention will be described in detail with reference to the drawings. First, with reference to Fig. 1 to 6, a rotor component 10 according to an embodiment of the invention will be described. It should be noted that in the following description, the axial direction indicates the direction along the axis O in the figures. In addition, for the clarity of the description, the front side in the axial direction (front in the axial direction) corresponds to the left in Fig. 2, while on the right in Fig. 2 corresponds to the rear side in the axial direction (rear in the axial direction).

[0020] However, it should be noted that the axially forward side and the axially rearward side are indicated in the following description for convenience and ease of understanding, and do not specifically limit directions of a rotor component and an electric motor, such as their forward and reverse directions. Furthermore, the radial direction in the following description indicates the direction of the radius of a circle with the O axis as the center, while the circumferential direction in the following description indicates the circumferential direction of the circle with the O axis as the center.

[0021] As in Fig. 1 and Fig. As shown in Figure 2, a rotor component 10 includes a magnet mounting member 12; a plurality of magnets 14 arranged radially outwardly in the circumferential direction on the magnet mounting member 12; and a tubular support member 16 arranged radially outwardly on the magnets 14. The magnets 14 may be separated in the axial direction depending on the economics of manufacturing or forming the magnet 14. As shown in Fig. 2, in the present embodiment, two of the magnets 14 which are separated from each other are arranged so as to be aligned in the axial direction.

[0022] As in Fig. 3 and Fig. 4, the magnet attachment member 12 is a tubular member having an axis O. The magnet attachment member 12 has a first end 18 at the axially rear side (the first side in the axial direction); a second end 20 at the axially front side (the second side in the axial direction); and a cylindrical outer periphery 22 extending along the axial direction. The magnet attachment member 12 is provided with a protrusion 24 disposed at the axially rear end of the member 12 so as to protrude radially outward from the outer periphery 22 of the member 12. The protrusion 24 is an example of a member used to coordinate the positions of the magnets in the axial direction 14 with each other during a manufacturing process.

[0023] The magnet mounting member 12 is made of a magnetic metal material, such as SS400 and S45C. The magnet mounting member 12 includes a tapered inner periphery 26 that continuously widens radially outward as it extends from the first end 18 to the second end 20. In the present embodiment, the inner periphery 26 has an inner diameter that increases as it approaches the axially forward side over the entire axially directed portion from the first end 18 to the second end 20.

[0024] The inner circumference 26 may be a linearly tapered surface. In this case, a radius of the inner circumference 26 increases linearly from a radius R1 at the first end 18 to a radius R2 at the second end 20. The taper ratio of the inner circumference 26 in this case may range, for example, from 1 / 200 to 1 / 30.

[0025] On the other hand, the outer circumference 22 of the magnet mounting member 12 is a cylindrical surface with an outer diameter that is constant in the axial direction. Accordingly, the magnet mounting member 12 has a thickness in the radial direction that gradually decreases from the first end 18 to the second end 20.

[0026] The magnet attachment member 12 is designed with a total of four slots 28, 30, 32, and 34. Each of the slots 28, 30, 32, and 34 is formed to extend from the inner circumference 26 to the outer circumference 22 of the magnet attachment member 12 through the magnet attachment member 12. As a result, the magnet attachment member 12 is divided in the circumferential direction at the slots 28, 30, 32, and 34. Each of the slots 28, 30, 32, and 34 is defined by two wall surfaces that are in contact with each other in the circumferential direction and extends over the Fig. 4. It should be noted that the slots 28, 30, 32 and 34 may be defined to have a predetermined width in the circumferential direction.

[0027] The axially directed portion 36 is a portion along the axial direction that includes the second end 20 and excludes the first end 18. In other words, the slots 28, 30, 32, and 34 extend rearwardly in the axial direction from the second end 20 and terminate at a position separated by a predetermined distance forwardly in the axial direction from the first end 18.

[0028] In the present embodiment, the slots 28, 30, 32, and 34 are arranged at regular intervals (ie, approximately 90°) in the circumferential direction. The magnet mounting member 12 is divided at the slots 28, 30, 32, and 34 in the circumferential direction. The function of the slots 28, 30, 32, and 34 will be described later.

[0029] As in Fig. As shown in Figure 5, each of the magnets 14 is a circular arc-shaped member including an axially leading end surface 38; an axially trailing end surface 40; first and second circumferential end surfaces 42 and 44; an inner periphery 46; and an outer periphery 48. The inner periphery 46 of the magnet 14 is a circular arc-shaped surface having an inner diameter with a predetermined radius of curvature. On the other hand, the outer periphery 48 of the magnet 14 may be any of a curved surface or a combination of curved surfaces with different radii of curvature.

[0030] It should be noted that the end faces 42, 44, 46 and 48 in Fig. 5 are clearly shown; however, each of them may be a curved surface or a very small surface depending on a magnetic circuit design or an electric motor specification. Therefore, it should be noted that in some actual cases, they may not be clearly defined. It should also be noted that edges defining each surface are actually beveled or gently curved and therefore may not be clearly defined.

[0031] As in Fig. 6, the holding member 16 is a tubular member having an axis O. In particular, the holding member 16 includes a front end surface 50 in the axial direction; a rear end surface 52 in the axial direction; an inner circumference 54 and an outer circumference 56. It should be noted that the end surfaces 50, 52 in Fig. 6 are clearly illustrated for easy understanding; however, they may not be clearly defined depending on the material or structure of the holding member 16 or the method of manufacturing the holding member 16.

[0032] The holding member 16 has high resistance to deformation for radial outward expansion. In other words, the holding member 16 has a radius that does not change easily. The holding member 16 is preferably made of a non-magnetic material to prevent heat generation from the magnetic flux and performance degradation caused by magnetic flux leakage. Furthermore, the holding member 16 preferably has a low density to reduce the centrifugal force generated by the rotation of the holding member 16.

[0033] Fibers selected from a group consisting of carbon fibers, glass fibers, aramid fibers, silicon carbide fibers, boron fibers, titanium alloy fibers, ultra-high molecular weight polyethylene, polybutylene terephthalate fibers, and a combination of two or more of these fibers can be used as the material for the holding member 16. Alternatively, a fiber-reinforced resin selected from a group consisting of carbon fibers, glass fibers, aramid fibers, silicon carbide fibers, boron fibers, titanium alloy fibers, ultra-high molecular weight polyethylene, polybutylene terephthalate fibers, and a combination of two or more of these fibers can be used as the material for the holding member 16.

[0034] With further reference to Fig. 1 and Fig. 2, a total of eight magnets 14 are arranged in the rotor component 10 according to the present embodiment. In particular, a pair of two magnets 14 arranged as in Fig. 2 are arranged so that they are adjacent to each other in the axial direction, at the circumferential position A in Fig. 1. Likewise, pairs of two magnets 14 arranged so as to be adjacent to each other in the axial direction are arranged at the circumferential positions B, C and D in Fig. 4 arranged.

[0035] Thus, four pairs of magnets 14 are arranged at regular intervals in the circumferential direction on the outer periphery 22 of the magnet attachment member 12. The magnets 14 arranged on the rear side in the axial direction are positioned so that their positions in the axial direction are coordinated with each other, for example, by providing a structure such as the protrusion 24 on the magnet attachment member 12. The holding member 16 is arranged radially outwardly of the magnets 14 so as to surround all the magnets 14 from the radial outside.

[0036] The magnet 14 can be fixed to the outer periphery 22 of the magnet mounting member 12 by an adhesive. In this case, the magnet 14 is preferably bonded in such a way that it can be removed from the outer periphery 22 of the magnet mounting member 12 with relatively little force for easy disassembly of the rotor member 10. The operation of disassembling the rotor member 10 will be described later.

[0037] It is possible to prevent the relative movement of the magnet 14 and the magnet attachment member 12 during operation of the rotor component 10 by fixing the magnet 14 and the magnet attachment member 12 to each other. On the other hand, if the magnet 14 is arranged on the outer periphery 22 of the magnet attachment member 12 without adhesive, a movement-restricting member may be provided therebetween to restrict the relative movement between the magnet 14 and the magnet attachment member 12.

[0038] As the above movement-restricting member, a protrusion or a recess may be provided on at least one of the outer periphery 22 of the magnet mounting member 12 and the inner periphery 46 of the magnet 14. Alternatively, a structure for increasing a friction coefficient, such as a high-friction resin coating, an adhesive resin coating layer, a sandblasted surface, a coating layer containing a material with a high friction coefficient, and a chemically processed surface with a high friction coefficient, may be formed on at least one of the outer periphery 22 of the magnet mounting member 12 and the inner periphery 46 of the magnet 14.Alternatively, a friction-increasing sheet having a surface on which a process for increasing a friction coefficient has been performed, an adhesive sheet having a surface on which an adhesive is applied, or a sticky sheet such as an NBR or a silicone rubber sheet may be inserted between the magnet attachment member 12 and the magnet 14.

[0039] Each of the slots 28, 30, 32, and 34 is arranged at a position between the magnets 14 that are adjacent to each other in the circumferential direction. Specifically, the slot 28 is arranged at a position between the pair of magnets 14 arranged at the circumferential position A and the pair of magnets 14 arranged at the circumferential position D.

[0040] Likewise, the slot 30 is arranged at a position between the pair of magnets 14 arranged at the circumferential position D and the pair of magnets 14 arranged at the circumferential position C. The slot 32 is arranged at a position between the pair of magnets 14 arranged at the circumferential position C and the pair of magnets 14 arranged at the circumferential position B. The slot 34 is arranged at a position between the pair of magnets 14 arranged at the circumferential position A and the pair of magnets 14 arranged at the circumferential position B.

[0041] As in Fig. 2, all of the magnets 14 are arranged within the axially directed portion 36. More specifically, the axially forward end faces 38 of the magnets 14, located on the axially forward side, are positioned to be separated rearward in the axial direction from the second end 20, while the axially rear end faces 40 of the magnets 14, located on the axially rear side, are positioned to be separated frontward in the axial direction from the rear ends of the slots 28, 30, 32, and 34.

[0042] Next, with reference to Fig. 7 and Fig. 8a, a magnet attachment component 62 according to another embodiment of the invention will be described. The magnet attachment component 62 can be applied to the magnet attachment component shown in Fig. 1 and Fig. 2. The magnet attachment member 62 is a tubular member having an axis O. The member 62 includes a first end 63 at a rear side in the axial direction; a second end 64 at a front side in the axial direction; a cylindrical outer periphery 66 extending in the axial direction; and a tapered inner periphery 68 continuously widening radially outward as it extends from the first end 63 to the second end 64. A protrusion 70 projecting radially outward from the outer periphery 66 of the member 62 is formed at the end in the axial direction of the outer periphery 66. Like the protrusion 24 mentioned above, the protrusion 70 is an example of a member for facilitating the alignment of the positions in the axial direction of the magnets 14 with each other during a manufacturing process.

[0043] The magnet attachment member 62 is provided with a total of four slots 72, 74, 76, and 78. Each of the slots 72, 74, 76, and 78 is formed to extend through the magnet attachment member 62 in the radial direction from the inner periphery 68 to the outer periphery 66 of the magnet attachment member 62. The slots 72, 74, 76, and 78 extend over an axially directed portion 80 of the magnet attachment member 62. The axially directed portion 80 is a portion along the axial direction that includes the second end 64 and excludes the first end 63.

[0044] Specifically, the slot 72 includes a gap 72a extending rearward in the axial direction from the second end 64, and a substantially circular hole 72b formed at the rearward end of the gap 72a in the axial direction. The gap 72a has a predetermined width in the circumferential direction. The gap 72a is defined by two walls facing each other in the circumferential direction so as to be separated by a predetermined distance therebetween. The hole 72b is formed to have a diameter larger than the circumferential width of the gap 72a.

[0045] Likewise, the slots 74, 76, and 78 each include gaps 74a, 76a, and 78a extending rearward in the axial direction from the second end 64, and holes 74b, 76b, and 78b formed at the axially rear ends of the gaps 74a, 76a, and 78a. The axially directed portion 80 in the present embodiment extends from the second end 64 to the axially rear ends of the holes 72b, 74b, 76b, and 78b.

[0046] When the magnet attachment member 62 is Fig. 1, the magnets 14 are arranged on the outer periphery 66 of the magnet mounting member 62 so that they are located within the axially directed portion 80. Furthermore, each of the slots 72, 74, 76, and 78 is positioned between two magnets 14 that are adjacent to each other in the circumferential direction.

[0047] Next, with reference to Fig. 9 and Fig. 10A, a rotor component 300 according to another embodiment of the invention will be described. Note that elements similar to those in the above-mentioned embodiments are assigned the same reference numerals, and their detailed description will be omitted. The rotor component 300 includes a magnet attachment member 302; a plurality of magnets 304 arranged radially outwardly on the magnet attachment member 302 so as to be lined up in the circumferential direction; and a tubular support member 16 arranged radially outwardly on the magnets 304.

[0048] The magnet mounting member 302 is a tubular member having an axis O. The magnet mounting member 302 includes a first end 306 at a rear side in the axial direction; a second end 308 at a front side in the axial direction; a cylindrical outer periphery 310 extending in the axial direction; and a tapered inner periphery 312 continuously widening radially outward as it extends from the first end 306 to the second end 308.

[0049] The magnet attachment component 302 is configured with a total of eight slots 314, 316, 318, 320, 322, 324, 326, and 328. The slots 314, 316, 318, 320, 322, 324, 326, and 328 extend from the inner periphery 312 to the outer periphery 310 of the magnet attachment component 302 through the magnet attachment component 302.

[0050] The slots 314, 316, 318, 320, 322, 324, 326, and 328 are arranged so that they are lined up at regular intervals (i.e., approximately 45°) in the circumferential direction. The magnet mounting member 302 is divided at the slots 314, 316, 318, 320, 322, 324, 326, and 328 in the circumferential direction.

[0051] As in Fig. As shown in Figure 10, the slots 314 and 318 extend across an axially directed portion 330. The axially directed portion 330 is a portion along the axial direction that includes the second end 308 while excluding the first end 306. In other words, the slots 314 and 318 extend rearwardly in the axial direction from the second end 308 and terminate at a position separated forwardly from the first end 306 by a predetermined distance in the axial direction.

[0052] Like slots 314 and 318, slots 322 and 326 extend beyond axially directed portion 330. Thus, slots 314, 318, 322 and 326 form a first slot extending beyond axially directed portion 330.

[0053] On the other hand, they extend the slots 316 and 320, which are respectively adjacent in the circumferential direction to the slots 314 and 318, as in Fig. 10 via an axially directed portion 332. The axially directed portion 332 is a portion along the axial direction that includes the first end 306 and excludes the second end 308. In other words, the slots 316 and 320 extend forward in the axial direction from the first end 306 and terminate at a position separated rearward from the second end 308 by a predetermined distance in the axial direction.

[0054] Like slots 316 and 320, slots 324 and 328, which are adjacent to slots 322 and 326, respectively, extend beyond axially directed portion 332. Thus, slots 316, 320, 324 and 328 form a second slot adjacent to the first slot and extending beyond axially directed portion 332.

[0055] In the present embodiment, a total of sixteen magnets 304 are arranged. In particular, at each of the circumferential positions O, P, Q, R, S, T, U, and V shown in Fig. 9, a pair of two magnets 304 are arranged so that they are arranged as in Fig. 10 are adjacent to each other in the axial direction. Each of the slots 314, 316, 318, 320, 322, 324, 326, and 328 formed on the magnet mounting member 302 is arranged at a position between the magnets 304 that are adjacent to each other in the circumferential direction.

[0056] Next, with reference to Fig. 11 and Fig. 12A, a magnet attachment member 82 according to yet another embodiment of the invention will be described. The magnet attachment member 82 may be used instead of the above magnet attachment member 12 on the Fig. 1 and Fig. 2. The magnet mounting member 82 includes a first end 84 at a rear side in the axial direction; a second end 86 at a front side in the axial direction; a cylindrical outer periphery 85 extending in the axial direction; and a tapered inner periphery 87 continuously widening radially outward as it extends from the first end 84 to the second end 86.

[0057] The magnet mounting member 82 according to the present embodiment includes slots 88, 90, 92, and 94 formed at four positions. In the present embodiment, the slots 88, 90, 92, and 94 extend over the entire axially directed portion of the magnet mounting member 82, ranging from the first end 84 to the second end 86. In other words, the magnet mounting member 82 is divided into four pieces at the slots 88, 90, 92, and 94, whereby the magnet mounting member 82 is formed by a total of four segments 96 arranged in the circumferential direction.

[0058] With reference to Fig. 13, one of the segments 96 constituting the magnet mounting member 82 will be described. The segment 96 includes an axially forward end 98; an axially rearward end 100; circumferential end surfaces 102 and 104; an inner periphery 106; and an outer periphery 108.

[0059] The inner circumference 106 of the segment 96 is a tapered surface which continuously widens radially outwardly as it extends from the end 100 to the end 98 in the axial direction (see Fig. 12). On the other hand, the outer circumference 108 of the segment 96 is a circular arc surface with an outer diameter that is constant in the axial direction. Accordingly, the thickness in the radial direction of the segment 96 gradually decreases as it extends from the end 98 to the end 100 forward in the axial direction. Furthermore, the end 100 of the segment 96 is provided with a projection 110 that projects radially outward from the outer circumference 108 of the segment 96.

[0060] A tubular magnet mounting member 82 is formed by attaching the segments 96 at the circumferential positions A to D shown in Fig. 11. Here, the end face 104 of the segment 96 located at the circumferential position A and the end face 102 of the segment 96 located at the circumferential position B face each other, thereby defining a slot 88 between these end faces 104 and 102.

[0061] Likewise, a slot 90 is defined between the end surface 104 of the segment 96 located at the circumferential position B and the end surface 102 of the segment 96 located at the circumferential position C. Furthermore, a slot 92 is defined between the end surface 104 of the segment 96 located at the circumferential position C and the end surface 102 of the segment 96 located at the circumferential position D. Furthermore, a slot 94 is defined between the end surface 104 of the segment 96 located at the circumferential position D and the end surface 102 of the segment 96 located at the circumferential position A.

[0062] When four segments 96 are arranged as indicated above, their axially rear end surfaces 100 are oriented in the circumferential direction, forming the annular first end 84 of the magnet attachment member 82. Likewise, their axially front end surfaces 100 are oriented in the circumferential direction, forming the annular second end 86 of the magnet attachment member 82. Furthermore, the inner surfaces 106 of the segments 96 are oriented in the circumferential direction, forming a tubular tapered inner surface 87 of the magnet attachment member 82. Furthermore, the outer surfaces 108 of the segments 96 are oriented in the circumferential direction, forming the cylindrical outer periphery 85 of the magnet attachment member 82.

[0063] When the magnet attachment member 82 is Fig. 1, the pair of magnets 14 adjacent to each other in the axial direction are arranged on the outer periphery 108 of each segment 96. Therefore, each of the slots 88, 90, 92, and 78 is inevitably arranged at a position between the magnets 14 adjacent to each other in the circumferential direction.

[0064] Next, with reference to Fig. 14 to 16, a rotor component 210 according to yet another embodiment of the invention will be described. Note that elements similar to those in the above-mentioned embodiment are denoted by the same reference numerals, and their detailed description will be omitted. The rotor component 210 includes a magnet attachment component 212; a plurality of magnets 214 arranged radially outward in the circumferential direction on the magnet attachment component 212; and a tubular support component 16 arranged radially outward on the magnets 214. The magnet attachment component 212 consists of a total of eight segments 216 arranged in the circumferential direction. The magnet 214 is arranged between each segment 216 and the support component 16.

[0065] Next, with reference to Fig. 17, one of the segments 216 forming the magnet mounting member 212 will be described. The segment 216 includes an axially forward end 218; an axially rearward end 220; circumferential end surfaces 222 and 224; an inner periphery 226; and an outer periphery 228.

[0066] The inner circumference 226 of the segment 216 is a tapered flat surface that is chamfered with respect to the axis O so as to continuously widen radially outward as it extends from the axially rearward end 220 to the axially forward end 218. On the other hand, the outer circumference 228 of the segment 216 is a flat surface that runs parallel to the axis O (i.e., the distance from the axis O is constant in the axial direction). The axially rearward end 220 of the segment 216 is provided with a projection 230 that projects radially outward from the outer circumference 228.

[0067] Next, with reference to Fig. 18, the magnet 214 according to the present embodiment will be described. Each magnet 214 includes an axially leading end surface 232; an axially trailing end surface 234; circumferential end surfaces 236 and 238; an inner surface 240; and an outer periphery 242. The inner periphery 240 of the magnet 214 is a flat surface parallel to the axis O (i.e., the distance from the axis O is constant in the axial direction). On the other hand, the outer periphery 242 is a curved surface with a predetermined radius of curvature. The outer periphery 242 may be formed by any curved surface or a combination of curved surfaces with different radii of curvature.

[0068] As in Fig. 19, a pair of magnets 214 arranged in the axial direction is arranged on the outer circumference 228 of the segment 216. The structures, each of which is as shown in Fig. 19 is constructed from the segment 216 and the magnets 214, are arranged at regular intervals at the points shown in Fig. 14 and Fig. 15. As in the above embodiments, the magnets 214 are arranged in the circumferential direction such that the magnetic poles of the magnets 214 change in the circumferential direction in an alternating manner. The holding member 16 is arranged such that it surrounds the outer circumferences 242 of all the magnets 214 from the radial outside. In this way, the Fig. 14 and Fig. 15 shown rotor component 210 is constructed.

[0069] If, as in Fig. 14 and Fig. 15, a total of eight segments 216 are arranged in the circumferential direction, the rear ends 220 of the segments 216 in the axial direction are aligned in the circumferential direction, whereby a first end 260 ( Fig. 16) is defined on the axially rear side of the magnet mounting member 212. Likewise, the axially front ends 218 of the segments 216 are aligned in the circumferential direction, thereby forming a second end 262 ( Fig. 16) is defined on the front side of the magnet mounting member 212 in the axial direction.

[0070] Furthermore, each of the segments 216 is formed from gaps 244, 246, 248, 250, 252, 254, 256, and 258, which are adjacent to each other in the circumferential direction. The gaps 244, 246, 248, 250, 252, 254, 256, and 258 act as slots that extend across the entire axially directed portion of the magnet mounting member 212, ranging from the first end 260 to the second end 262, and divide the magnet mounting member 212 in the circumferential direction.

[0071] Next, with reference to Fig. 20 to 23, a rotor component 120 according to yet another embodiment of the invention will be described. Note that elements similar to those in the above-mentioned embodiments are denoted by the same reference numerals, and their detailed description will be omitted. The rotor component 120 includes a wedge component 124; a magnet attachment component 122 disposed radially outwardly of the wedge component 124; a plurality of magnets 14 disposed radially outwardly of the magnet attachment component 122; and a holding component 16 disposed radially outwardly of the magnets 14.

[0072] As in Fig. As shown in FIG. 22, the wedge member 124 is a tubular member having an axis O, and includes an axially rearward end surface 126; an axially forward end surface 128; an inner periphery 130; and an outer periphery 132. The inner periphery 130 is a tapered surface that progressively widens radially outward as it extends from the end surface 126 to the end surface 128. The outer periphery 132, on the other hand, is a cylindrical surface with an outer diameter that is constant in the axial direction. Accordingly, the thickness in the radial direction of the wedge member 124 gradually decreases as it extends forward in the axial direction. Like the magnet attachment member described above, the wedge member 124 may be provided with a plurality of slits.

[0073] As in Fig. As shown in Fig. 23, the magnet attachment member 122 is a cylindrical member having an axis O, and includes a first end 134 at an axially rear side; a second end 136 at an axially front side; an inner periphery 138; and an outer periphery 140. A protrusion 142 is formed on the axially rear end portion of the outer periphery 140 of the magnet attachment member 122 so as to protrude radially outward from the outer periphery 140. Like the above protrusion 24, the protrusion 142 is an example of a member for facilitating the alignment of the axial directions of the magnets 14 during the manufacturing process.

[0074] The magnet mounting member 122 includes slots 144, 146, 148, and 150 formed at four locations. Each of the slots 144, 146, 148, and 150 is formed to extend radially through the magnet mounting member 122 from the inner periphery 138 to the outer periphery 140, and extends beyond the axially directed portion 152 of the magnet mounting member 122. The axially directed portion 152 includes the second end 136 and excludes the first end 134. The inner periphery 138 and the outer periphery 140 of the magnet mounting member 122 are tubular surfaces having radii that are constant in the axial direction.

[0075] Next, with reference to Fig. 24, an electric motor 160 according to an embodiment of the invention will be described. It should be noted that on the left in Fig. 24 corresponds to the front side in the axial direction, and right in Fig. 24 corresponds to the rear side in the axial direction. The electric motor 160 is an example of a rotary electric machine. The electric motor 160 includes a housing 164 defining an interior space 162; a stator 166 stationarily disposed within the interior space 162; and a rotor 180 rotatably disposed radially within the stator 166. The stator 166 includes a stator core 168 and a coil 170 wound around the stator core 168. The stator core 168 may, for example, be made of thin electromagnetic plates stacked one upon another.

[0076] A power line (not shown), electrically connected to the coil 170, is led out of the stator 166 and connected to a power source (not shown) installed outside the electric motor 160 via a through hole formed in the housing 164. The rotor 180 rotates about the axis O. The rotor 180 includes a rotatable shaft 182 extending in the axial direction within the interior space 162; and the above-mentioned rotor component 10 fixed radially outwardly to the rotatable shaft 182.

[0077] Next, with reference to Fig. 25, the rotatable shaft 182 will be described. The rotatable shaft 182 is a tubular member having an axis O and includes a central opening 184 formed to be concentric with the axis O. In the present embodiment, the rotatable shaft 182 is designed with the central opening 184 for application to a built-in motor used in a main shaft of a machine tool. However, the rotatable shaft may be formed of a solid member without the central opening.

[0078] The axially front portion of the rotatable shaft 182 is rotatably supported by the housing 164 via a bearing (not shown) mounted on an axially front wall of the housing 164. Similarly, the axially rear portion of the rotatable shaft 182 is rotatably supported by the housing 164 via a bearing (not shown) mounted on an axially rear wall of the housing 164.

[0079] The rotatable shaft 182 includes a tapered outer circumference 186 that continuously widens radially outward as it extends from the rear side in the axial direction to the front side in the axial direction. The outer circumference 186 may preferably be a linearly tapered surface (ie, a conical surface). In this case, the outer diameter of the outer circumference 186 increases linearly as it extends forward in the axial direction. A taper ratio of the outer circumference 186 in this case ranges, for example, from 1 / 200 to 1 / 30.

[0080] The rotor component 10 is fixed to the outer circumference 186 of the rotatable shaft 182 such that the inner circumference 26 of the magnet attachment component 12 is in surface contact with the outer circumference 186 of the rotatable shaft 182. The degree (or ratio) of the taper of the inner circumference 26 of the magnet attachment component 12 is set to correspond to that of the outer circumference 186 of the rotatable shaft 182. For example, if both the outer circumference 186 of the rotatable shaft 182 and the inner circumference 26 of the magnet attachment component 12 are linearly tapered surfaces, the outer circumference 186 and the inner circumference 26 have the same taper ratio (e.g., 1 / 100).

[0081] When the rotor component 10 is press-fitted over the rotatable shaft 182 to Fig. To assemble the rotor 180 shown in Figure 24, the magnet attachment member 12 and the magnets 14 are pressed and displaced radially outward by the rotatable shaft 182, thereby imparting tensile strength to the holding member 16. Due to the tensile strength imparted to the holding member 16, an elastic pressing force is generated in the holding member 16, whereby the magnets 14 and the magnet attachment member 12 are firmly held between the holding member 16 and the rotatable shaft 182 by the action of the elastic pressing force.

[0082] Next, with reference to Fig. 26 to 29, an electric motor 270 according to another embodiment of the invention will be described. It should be noted that elements similar to those of the above-described embodiments are designated by the same reference numerals, and their detailed description will be omitted. Furthermore, the left side of Fig. 26 of the front side in the axial direction, while on the right in Fig. 26 corresponds to the rear side in the axial direction. The electric motor 270 includes a housing 164; a stator 166 disposed in the interior space 162 of the housing 164; and a rotor 280 rotatably disposed radially within the stator 166.

[0083] The rotor 280 rotates about an axis O. The rotor 280 includes a rotatable shaft 282 extending in the axial direction within the interior space 162, and the above-mentioned rotor component 210 fixed radially outwardly to the rotatable shaft 282.

[0084] Next, with reference to Fig. 30 and Fig. 31, the rotatable shaft 282 according to the present embodiment will be described. The rotatable shaft 282 is a tubular member having an axis O and includes a central opening 284 formed to be concentric with the axis O. It should be noted that the rotatable shaft 282 may be formed of a solid member without the central opening.

[0085] The rotatable shaft 282 includes a total of eight outer surfaces 286a, 286b, 286c, 286d, 286e, 286f, 286g, and 286h. Each of the outer surfaces 286a to 286h is a tapered flat surface inclined with respect to the axis O so as to continuously widen radially outward from the axially rearward side to the axially frontward side.

[0086] A projection 288a is formed between the outer surfaces 286a and 286b. The projection 288a projects radially outward from the outer surfaces 286a and 286b and extends in the axial direction. Likewise, a projection 288b, 288c, 288d, 288e, 288f, 288g, and 288h is formed between the outer surfaces 286b and 286c, between the outer surfaces 286c and 286d, between the outer surfaces 286d and 286e, between the outer surfaces 286e and 286f, between the outer surfaces 286f and 286g, between the outer surfaces 286g and 286h, and between the outer surfaces 286h and 286a, respectively.

[0087] With further reference to Fig. 27 to 29, when assembling the rotor 280, a Fig. 19, consisting of the segment 216 and the magnet 214, is arranged. Furthermore, the projections 288a, 288b, 288c, 288d, 288e, 288f, 288g, and 288h are inserted into the gaps 244, 246, 248, 250, 252, 254, 256, and 258, respectively. The projections 288a to 288h restrict the movement of the segments 216 in the circumferential direction so that the segments 216 are positioned at predetermined circumferential positions at regular intervals.

[0088] Next, with reference to Fig. 32 to 35, an example of a method for manufacturing the rotor 180 will be described. In step S1, the user arranges a total of eight magnets 14 on the outer circumference 22 of the magnet attachment member 12. Specifically, the user aligns two magnets 14 in the circumferential direction to form a pair of magnets 14, and arranges them at the position shown in Fig. 1 shown circumferential position A on the outer circumference 22 of the magnet attachment component 12.

[0089] Likewise, the user aligns two magnets 14 in the axial direction to form a pair of magnets 14 and arranges them at each of the circumferential positions B, C, and D on the outer periphery 22 of the magnet attachment member 12. At this time, each of the slots 28, 30, 32, and 34 is located at a position between the magnets 14 that are adjacent to each other in the circumferential direction. By arranging the magnets 14 at the predetermined circumferential positions in this manner, the user can use a template to arrange the magnets 14 at regular intervals. Thanks to such a template, it is possible to facilitate the manufacturing process.

[0090] The direction of the magnetic field of the magnets 14 arranged at the circumferential position A is set so that the S pole is directed to the inner circumference 46 side of the magnets 14, while the N pole is directed to the outer circumference 48 side. On the other hand, the direction of the magnetic field of the magnets 14 arranged at the circumferential position B is set so that the N pole is directed to the inner circumference 46 side of the magnets 14, while the S pole is directed to the outer circumference 48 side.

[0091] In addition, the direction of the magnetic field of the magnets 14 arranged at the circumferential position C is set so that the S pole is directed to the inner circumference 46 side of the magnets 14, while the N pole is directed to the outer circumference 48 side. Furthermore, the direction of the magnetic field of the magnets 14 arranged at the circumferential position D is set so that the N pole is directed to the inner circumference 46 side of the magnets 14, while the S pole is directed to the outer circumference 48 side. Thus, the magnets 14 are arranged in the circumferential direction such that their S and N poles alternate in the circumferential direction.

[0092] Preferably, the magnets 14 are magnetized before step S1. In this case, due to their magnetic attraction forces, it is possible to facilitate the work of attaching the magnets 14 to the predetermined positions on the outer periphery 22 of the magnet attachment member 12 made of a magnetic material.

[0093] On the other hand, in the case of the Fig. 11 and Fig. 12, in this step, the user aligns two magnets 14 in the axial direction so as to form a pair of magnets 14 and arranges them on the outer circumference 108 of each of the segments 96. Furthermore, when manufacturing the magnet attachment member 82 shown in Fig. 26, in this step S1, two magnets 214 are arranged in the axial direction so that a pair of magnets 14 is formed, and arranges this on the outer circumference 228 of each of the segments 216, whereby the Fig. 19 is made from the segment 216 and the magnets 214.

[0094] In step S2, the user attaches the holding member 16 radially outward to the magnets 14 such that the magnets 14 are surrounded from the radial outside. Specifically, the user places the holding member 16 radially outward over the magnets 14 such that the inner periphery 54 of the holding member 16 faces the outer periphery 48 of each magnet 14.

[0095] At this time, the holding member 16 can be loosely fitted to the outer peripheries of the magnets 14 or press-fitted with an appropriate interference to the outer peripheries of the magnets 14. When the holding member 16 is press-fitted, the holding member 16 can be given such an appropriate interference that the holding member 16 does not fall off the magnet 14.

[0096] Alternatively, in this step S2, the user may attach the holding member 16 to the outer peripheries of the magnets 14 by directly wrapping the material of the holding member 16 around the outer peripheries of the magnets 14. For example, the user may wrap a thread-like, a ribbon-like, or a sheet-like material several times around the outer peripheries of the magnets 14 until it has a predetermined radial thickness to form the holding member 16 with a predetermined radial thickness.

[0097] On the other hand, in the case of the Fig. 11 and Fig. 12, the user attaches the holding member 16 to the outer peripheries of the magnets 14 in the state in which the segments 96 are arranged appropriately in the circumferential direction, e.g. by using a suitable template. Furthermore, in the case of the magnet attachment member 82 shown in Fig. 26 shown rotor 280, the holding member 16 in the state in which the in Fig. 19 shown structures of the segment 216 and the magnet 214 are arranged in the circumferential direction, e.g. by using a template, on the outer circumferences of the magnets 214.

[0098] As a result of step S2, the Fig. 1 is manufactured. In step S3, the user press-fits the rotor component 10 to the rotatable shaft 182. This step S3 will be described in detail below. First, the user places the rotor component 10 manufactured in step S2 from the rear side of the shaft 182 in the axial direction onto the rotatable shaft 182. As a result, the front end of the inner circumference 26 of the magnet attachment member 12 in the axial direction is as shown in Fig. 33 at a contact point P with the outer circumference 186 of the rotatable shaft 182.

[0099] Then, the user pushes the first end 18 of the magnet attachment member 12 forward in the axial direction to press-fit the rotor member 10 further forward in the axial direction to the rotatable shaft 182 until a Fig. 34 is reached. During the press fit of the rotor component 10, the magnet mounting component 12 receives a radially outward force from the rotatable shaft 182.

[0100] As mentioned above, the magnet mounting member 12 according to the embodiment is designed with slots 28, 30, 32, and 34 extending across the axially directed portion 36. Thanks to these slots 28, 30, 32, and 34, the magnet mounting member 12 can easily deform radially outward when receiving the force from the rotatable shaft 182.

[0101] This deformation of the magnet attachment component 12 is in Fig. 35 shown schematically. It should be noted that in Fig. 35 particularly illustrates the deformation of the magnet attachment component 12 at the position of the slot 34. As in Fig. As shown in Figure 35, the magnet attachment member 12 can be divided in the circumferential direction at the position of the slot 34. Therefore, the magnet attachment member 12 can be moved by a relatively small force from the position shown in Fig. 35 is indicated by the dashed line E, in the direction shown in Fig. 35 indicated by the arrow G, into the position shown in Fig. 35 by the solid line F, when it receives the radially outward force from the rotatable shaft 182. On the other hand, when the magnet mounting member 12 is deformed radially outward, the elastic restoring force exerted by the magnet mounting member 12 on the rotatable shaft 182 becomes much smaller compared to the case where the magnet mounting member 12 does not include the slit.

[0102] During the press-fitting of the rotor component 10 to the rotatable shaft 182, the magnet attachment component 12 is pushed radially outward by the rotatable shaft 182 to deform it, and along with this process, the magnets 14 are also pushed radially outward. As a result, the holding component 16 receives a force from the magnets 14 and expands slightly outward. In response to this force, the holding component 16 generates a radially inward elastic restoring force to push the magnets 14 back radially inward. This firmly holds the magnets 14 and the magnet attachment component 12 between the rotatable shaft 182 and the holding component 16.

[0103] As described above, the elastic restoring force exerted by the magnet mounting member 12 on the rotatable shaft 182 is reduced by the slots 28, 30, 32, and 34 formed on the magnet mounting member 12. Therefore, most of the force exerted by the rotor member 10 on the rotatable shaft 182 comes from the elastic restoring force generated by the retaining member 16. In other words, it is assumed that the rotor member 10 of the rotor 180 in this embodiment is press-fitted to the rotatable shaft 182 only by the interference imparted to the retaining member 16.

[0104] Thus, since the magnet mounting member 12 according to the present embodiment is prone to deforming slightly in the radial direction thanks to the slots 28, 30, 32, and 34, it is possible to significantly reduce the force required to deform the magnet mounting member 12 when the rotor member 10 is press-fitted to the rotating shaft 182. Accordingly, it is possible to fix the rotor member 10 to the rotating shaft 182 with a lower pressing force. As a result, it is possible to facilitate the work of assembling the rotor 180 and also reduce the number of assembly processes.

[0105] Furthermore, it is possible to mount a rotor with a larger diameter or a larger overall length, which was not possible in the prior art, and therefore a synchronous electric motor capable of generating a larger torque can be easily mounted.

[0106] Furthermore, in the present embodiment, the magnet mounting member 12 has the slots 28, 30, 32, and 34 extending across the axially directed portion 36, and the magnet mounting member 12 therefore has a monolithic structure. This allows the user to handle the rotor component 10 as a single component, thereby facilitating the operation of transporting the rotor component 10 and fixing it to the rotatable shaft 182.

[0107] The advantageous effect resulting from the feature that the magnet attachment member can be easily deformed is also obtained in the case where the magnet attachment members 62, 82 shown in Fig. 7 and Fig. 11 are applied to the rotor component 10, and in which the rotor components 300, 210 and 120 shown in Fig. 9, Fig. 14 and Fig. 20 may be applied. For example, in the case of applying the magnet attachment member 62 to the rotor member 10, the member 62 may be slightly deformed thanks to the slots 72, 74, 76, and 78 when the magnet attachment member 62 receives a radially outward force from the rotatable shaft 182 during press-fitting of the rotor member 10.

[0108] Furthermore, the slots 72, 74, 76, and 78 are provided with gaps 72a, 74a, 76a, and 78a having widths in the circumferential direction that can prevent friction from being generated at these slots 72, 74, 76, and 78 when the magnet attachment member 62 deforms. This allows the magnet attachment member 62 to deform radially outward more easily. Furthermore, the elastic recovery force exerted by the magnet attachment member 62 on the rotatable shaft 182 when the magnet attachment member 62 deforms radially outward becomes even smaller than that of the magnet attachment member 12.

[0109] Furthermore, thanks to the holes 72b, 74b, 76b, and 78b formed at the rear ends of the gaps 72a, 74a, 76a, and 78a, respectively, it is possible to prevent the generation of stress concentration at the rear ends of the slots 72, 74, 76, and 78 when the magnet mounting member 62 is deformed. This makes it possible to prevent the generation of cracks at the rear ends of the slots 72, 74, 76, and 78 of the magnet mounting member 62 during the operation of press-fitting the rotor member 10 to the rotatable shaft 182.

[0110] On the other hand, with respect to the magnet mounting member 82, since this magnet mounting member 82 is circumferentially divided at the slots 88, 90, 92, and 94, the magnet mounting member 82 can move radially outward without generating any reaction force when receiving the radially outward force from the rotatable shaft 182. Furthermore, the magnet mounting member 82 does not generate any elastic restoring force applied to the rotatable shaft 182 when moving radially outward.

[0111] As a result, when the magnet attachment components 62, 82 are applied to the rotor component 10, it is possible to significantly reduce the force required to deform the magnet attachment components 62, 82 when the rotor component 10 is press-fitted to the rotatable shaft 182. Accordingly, it is possible to fix the rotor component 10 to the rotatable shaft 182 with a lower pressing force.

[0112] Furthermore, in the case of manufacturing the rotor 280, the magnet attachment member 212 of the rotor 280 is divided at the gaps 244, 246, 248, 250, 254, 256, and 258 in the circumferential direction, similar to the above magnet attachment member 82. Therefore, it is possible to significantly reduce the force required to deform the magnet attachment member 212 when the rotor member 210 is press-fitted to the rotatable shaft 282. Accordingly, it is possible to fix the rotor member 210 to the rotatable shaft 282 with a lower pressing force.

[0113] Furthermore, in the case of manufacturing the rotor 280, since the segments 216 of the magnet mounting member 212 and the magnets 214 include the flat outer peripheries 228 and the flat inner peripheries 240, respectively, it is possible to facilitate the machining operation for forming the segments 216 and the magnets 214, thereby reducing the manufacturing cost.

[0114] Next, with reference to Fig. 36, an example of a method for disassembling the rotor 180 will be described. In step S11, the user cuts the holding member 16 at a position between the magnets 14 that are adjacent to each other in the circumferential direction, along the axial direction. For example, when the holding member 16 is made of a fiber, the user cuts a part of the holding member 16 along the axial direction, whereby the holding member 16 can be broken from the initial separation point progressively over its entire length in the axial direction by the action of a tensile strength generated on the holding member 16. In this way, the user can easily remove the holding member 16 from the outer periphery of the magnets 14.

[0115] In step S12, the user pushes the second end 20 of the magnet attachment member 12 backward in the axial direction to detach the magnet attachment member 12 from the rotating shaft 182. As described above, in the rotor 180, the elastic restoring force exerted by the magnet attachment member 12 on the rotating shaft 182 is reduced thanks to the slots 28, 30, 32, and 34. Therefore, the user can easily detach the magnet attachment member 12 from the rotating shaft 182 with a relatively small force.

[0116] Then, the user can disassemble the rotor 180 by removing the magnets 14 from the magnet attachment member 12. Thus, according to the present embodiment, the user can remove the magnets 14 and the magnet attachment member 12 from the rotor 180 simply by cutting the holding member 16, and can reuse them. As a result, it is possible to effectively utilize raw materials used in these components. This is particularly advantageous in the case where a rare earth element such as neodymium, whose production is limited to a certain extent, is used as the material for the magnet.

[0117] If the magnets 14 and the magnet attachment member 12 are fixed to each other by an adhesive, the user can assemble the magnets 14 and the magnet attachment member 12 as a single unit in step S12. In this case, this step S12 may include a step of separating the magnets 14 and the magnet attachment member 12 by removing the adhesive, for example, using a solvent. On the other hand, if the magnets 14 and the magnet attachment member 12 are not fixed to each other by an adhesive, the user can assemble the magnets 14 and the magnet attachment member 12 separately in step S12.

[0118] The rotor may further be provided with a means for preventing movement of the magnet mounting member relative to the rotatable shaft in the circumferential direction. Next, with reference to Fig. 37 a rotatable shaft 190 provided with such a means will be described. It should be noted that in Fig. 37, for ease of understanding, only a part of the rotatable shaft 190 extending in the axial direction is shown. In addition, the left side of Fig. 37 in the front axial direction.

[0119] The rotatable shaft 190 according to the embodiment differs from the above rotatable shaft 182 in the following structure. The rotatable shaft 190 includes protrusions 194, 196, 198, and 200 that project radially outward from the outer surface 192 of the rotatable shaft 190. Each of the protrusions 194, 196, 198, and 200 extends straight in the axial direction on the outer periphery 192 of the rotatable shaft 190. The protrusions 194, 196, 198, and 200 are provided at positions that correspond to slots of a magnet attachment member that would be fixed radially outward to the rotatable shaft 190. In the present embodiment, a total of four protrusions 194, 196, 198, and 200 are arranged at regular intervals (i.e., at 90° intervals) in the circumferential direction.

[0120] The projections 194, 196, 198, and 200 function as a member for guiding a magnet attachment member when the magnet attachment member is press-fitted to the rotatable shaft 190. In addition, the projections 194, 196, 198, and 200 also function as a member for preventing movement of the magnet attachment member with respect to the rotatable shaft 190 after the magnet attachment member has been fixed to the rotatable shaft 190. This function will be explained below by an example in which the Fig. 7 and Fig. 8 is fixed to the rotatable shaft 190 will be described.

[0121] When the magnet attachment member 62 is press-fitted to the rotary shaft 190 from the rear side in the axial direction, the magnet attachment member 62 is positioned with respect to the rotary shaft 190 such that the positions of the axially front openings of the gaps 72a, 74a, 76a, and 78a of the member 62 respectively coincide with the positions of the projections 194, 196, 198, and 200 of the rotary shaft 190. Here, the circumferential widths of the gaps 72a, 74a, 76a, and 78a are set to be equal to or slightly larger than the circumferential widths of the projections 194, 196, 198, and 200.

[0122] Then, the user press-fits the magnet attachment member 62 to the rotatable shaft 190 by pushing the magnet attachment member 62 forward in the axial direction, with the projections 194, 196, 198, and 200 received in the gaps 72a, 74a, 76a, and 78a and engaging with the walls defining the gaps 72a, 74a, 76a, and 78a.

[0123] During press-fitting of the magnet attachment member 62 to the rotary shaft 190, the projections 194, 196, 198, and 200 guide the magnet attachment member 62 to move straight forward in the axial direction by engaging with the gaps 72a, 74a, 76a, and 78a. This allows the magnet attachment member 62 to be smoothly press-fitted to the rotary shaft 190.

[0124] After fixing the magnet mounting member 62 at a predetermined position, the projections 194, 196, 198 and 200 can prevent movement of the magnet mounting member 62 with respect to the rotatable shaft 190 in the circumferential direction during operation of the rotor by engaging the gaps 72a, 74a, 76a and 78a.

[0125] In this way, the projections 194, 196, 198 and 200 act as a guide member for the magnet mounting member when it is press-fitted to the rotatable shaft 190, and also as a relative movement restricting member to prevent relative movement of the magnet mounting member with respect to the rotatable shaft 190.

[0126] The magnet attachment member described in the above embodiment is provided with four slots; however, the number of slots is not limited, and one slot or any number of slots may be provided on the magnet attachment member. Furthermore, in the embodiment, the slots are provided at regular intervals (specifically, at 90° intervals) in the circumferential direction. However, the slots may be provided at any intervals in the circumferential direction on the magnet attachment member.

[0127] According to the invention described above, the magnet attachment member is provided with the slits for releasing engagement of the magnet attachment member. Therefore, press-fitting tonnage used for engagement is eliminated, thereby reducing press-fitting tonnage used for assembly and thereby allowing the rotor to be manufactured in a larger size. Furthermore, a rotor can be disassembled simply by removing a holding member, making it possible to easily reuse magnets, a magnet attachment member, and a rotary shaft. Furthermore, a magnet attachment member provided with a tapered inner surface does not require a means for temporarily enlarging the inner circumference of the magnet attachment member by oil pressure when a rotor member is press-fitted to a rotary shaft. This can simplify the assembly work.

[0128] The above-described embodiments should not be construed as limiting the scope of the invention described in the claims. Any embodiments combined with particular features described in the embodiments of the invention may be included within the technical scope of the invention, although not all combinations of features are essential to solving the problem of the invention. Furthermore, it would be apparent to a person skilled in the art that various modifications or improvements may also be applied to the above-described embodiments.

[0129] Furthermore, a sequence of motions, processes, steps, acts, and operations in an apparatus, system, program, and method described in the claims, description, and drawings should be performed in any order, unless otherwise indicated by the phrase "before" or "before," etc., and unless it is specified that the output of a previous processing will be used in a subsequent processing. The phrases "first" and "next," etc., used in the claims, description, and drawings for convenience in explaining a sequence of operations do not necessarily imply a limitation of a sequence of operations to that order.

Claims

[1] A rotor component (210) fixed to a rotatable shaft (282) of a rotatable electrical machine (270), comprising: a plurality of magnet attachment member segments (216) arranged in the circumferential direction of the rotatable shaft (282), each magnet attachment member segment (216) comprising: an inner circumference (226) and an outer circumference (228), each of which is a flat surface; and a projection (230) projecting radially outward from the outer periphery (228); a plurality of magnets (214) arranged on the outer peripheries (228) of the respective magnet attachment component segments (216); and a tubular holding member (16) arranged radially outwardly of the plurality of magnets (214) such that it surrounds the plurality of magnets (214), wherein the inner periphery (226) of each magnet attachment member segment (216) is a tapered flat surface that is tapered with respect to an axis (O) of the rotatable shaft (282) such that it continuously widens radially outwardly as it extends from a first end (220) of the magnet attachment member segment (216) in the direction of the axis (O) to a second end (218) opposite the first end (218). [2] The rotor component (210) of claim 1, wherein the outer periphery (228) of each magnet mounting component segment (216) extends parallel to the axis (O). [3] Rotor (280), comprising: a rotatable shaft (282); and a rotor component (210) according to one of claims 1 or 2, which is attached to an outer circumference of the rotatable shaft (282), wherein the outer circumference of the rotatable shaft (282) comprises a plurality of flat surface portions (286a, 286b, 286c, 286d, 286e, 286f, 286g, 286h) which are in contact with the inner circumferences (226) of the respective magnet attachment component segments (216), wherein the plurality of magnet attachment member segments (216) and the plurality of magnets (214) are pressed radially outward by the rotatable shaft (282), and are held between the rotatable shaft (282) and the magnet attachment member segments (216) by the action of a radially inward elastic restoring force generated at the magnet attachment member segments (216). [4] Rotor (280) according to claim 3, wherein a projection (288a, 288b, 288c, 288d, 288e, 288f, 288g, 288h) is formed between two circumferentially adjacent flat surface portions (286a, 286b, 286c, 286d, 286e, 296f, 286g, 286h) such that it protrudes radially outward from the two of the flat surface portions (286a, 286b, 286c, 286d, 286e, 296f, 286g, 286h) and extends in the direction of the axis (O), wherein the projection (288a, 288b, 288c, 288d, 288e, 288f, 288g, 288h) is fitted into a gap formed between two circumferentially adjacent ones of the magnet attachment member segments (216) to limit movement of the magnet attachment member segments (216) in the circumferential direction.

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