Rotary electric machine, rotor for rotary electric machine, magnet protection ring for rotary electric machine

Abstract

The magnet protection ring includes: a cylindrical magnet protection portion; an inner peripheral flange part which is arranged on the radial inner side at one axial end of the magnet protection part and abuts against the disc part of the rotor; an outer peripheral flange section that is disposed on the outside in the radial direction at the other end of the protection section in the axial direction and that faces the end surface of the permanent magnet in the axial direction; and a displacement absorbing part which is located between the outer peripheral flange part and the magnet protecting part and absorbs position displacement in the radial direction of the outer peripheral flange part and the magnet protecting part. The outer diameter of the magnet protection part in a free state is larger than the inner diameter of the permanent magnet arrangement position of the rotor by a specified amount. The outer periphery of the magnet protection part abuts against the inner periphery of the permanent magnet in a state of being assembled on the rotor. Therefore, the displacement in the radial direction between the free state of the magnet protection part and the state of being assembled on the rotor is absorbed by the displacement absorption part.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority based on patent application No. 2023-35653 filed in Japan on March 8, 2023, and the entire contents of the priority base application are incorporated into this specification by reference. Technical Field

[0003] This specification relates to a rotating electric machine, a rotating electric machine rotor, a magnet protection ring for the rotating electric machine rotor, and a method for manufacturing the rotating electric machine rotor. The rotating electric machine is useful, for example, as a generator or starter for a two-wheeled vehicle. Background Art

[0004] Patent Document 1 discloses a device for assembling a magnet protection ring to a rotor.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2007 / 123171 Summary of the Invention

[0008] Means of solving problems

[0009] In the assembly device of Patent Document 1, after placing a magnet protection ring on the inner periphery of the permanent magnet, the ring is plastically deformed outward to secure the permanent magnet. Consequently, due to the reaction of radially outward extrusion of the metal plate, the ring may deform radially inward. In this case, the permanent magnet may not be adequately retained. Furthermore, this radially inward deformation may interfere with the stator.

[0010] An object of the present disclosure is to reliably hold the permanent magnets on the cylindrical portion side of the rotor using a magnet protection ring.

[0011] A first aspect of the present disclosure provides a rotating electric machine, comprising: a stator having an annular base portion and a plurality of coils extending radially outward from the base portion; and a rotor having a disc portion, a cylindrical portion, a plurality of permanent magnets and a magnet protection ring, wherein the disc portion rotates together with the shaft and extends from the axial radial outside, the cylindrical portion is formed on the radial outer portion of the disc portion, the plurality of permanent magnets are arranged radially inside the cylindrical portion and radially outside the coils, and the magnet protection ring is arranged radially inside the plurality of permanent magnets and protects the permanent magnets.

[0012] In the rotating electric machine of the first aspect of the present disclosure, the magnet protection ring has: a cylindrical magnet protection portion; an inner peripheral flange portion, which is arranged radially inward at one axial end of the magnet protection portion and abuts against the disc portion of the rotor; an outer peripheral flange portion, which is arranged radially outward at the other axial end of the magnet protection portion and is opposite to the axial end face of the permanent magnet; and an offset absorbing portion, which is located between the outer peripheral flange portion and the magnet protection portion to absorb radial position offset of the outer peripheral flange portion and the magnet protection portion.

[0013] In the rotating electrical machine according to the first aspect of the present disclosure, the outer diameter of the magnet protector, in its free state, is larger by a predetermined amount than the inner diameter of the rotor at the location where the permanent magnets are located. Furthermore, when assembled to the rotor, the outer periphery of the magnet protector abuts the inner periphery of the permanent magnets. Consequently, radial displacement of the magnet protector between its free state and its rotor-assembled state is absorbed by the displacement absorbing portion.

[0014] In the rotating electric machine of the first aspect of the present disclosure, the reduced diameter of the magnet protection portion is absorbed by the offset absorption portion. In other words, the magnet protection portion can be reduced in diameter so as to abut against the inner circumference of the permanent magnet. Therefore, the generation of a gap between the magnet protection portion and the permanent magnet can be avoided as much as possible. It should be noted that in the present disclosure, the axial direction refers to the direction along the central axis of the disc portion and the cylindrical portion of the rotor, and is also the axial direction of the shaft. In addition, the radial direction refers to the direction orthogonal to the central axis, and is also the direction in which the disc portion extends from the central axis. The radial inner side is the side close to the central axis, and the radial outer side is the side away from the central axis.

[0015] A second aspect of the present disclosure provides a rotor for a rotating electric machine, comprising: a disc portion that rotates together with a shaft and extends from the axially radially outer side; a cylindrical portion that is formed on the radially outer side of the disc portion; a plurality of permanent magnets that are circumferentially arranged on the radially inner side of the cylindrical portion; and a magnet protection ring that is arranged on the radially inner side of the plurality of permanent magnets and protects the permanent magnets.

[0016] The second aspect of the present disclosure discloses a magnet protection ring for a rotating electrical machine rotor comprising: a cylindrical magnet protection portion; an inner circumferential flange portion, located radially inward at one axial end of the magnet protection portion and abutting against the rotor's disc portion; an outer circumferential flange portion, located radially outward at the other axial end of the magnet protection portion and facing the axial end surface of the permanent magnet; and a displacement absorbing portion, located between the outer circumferential flange portion and the magnet protection portion, to absorb radial positional displacement between the outer circumferential flange portion and the magnet protection portion. Furthermore, the outer diameter of the magnet protection portion, in a free state, is larger by a predetermined amount than the inner diameter of the rotor at the location where the permanent magnets are disposed. Furthermore, the outer circumference of the magnet protection portion abuts against the inner circumference of the permanent magnet when assembled to the rotor. In other words, radial displacement of the magnet protection portion between its free state and its rotor-assembled state is absorbed by the displacement absorbing portion.

[0017] In the second aspect of the present invention, the rotor for a rotating electrical machine absorbs any reduction in diameter of the magnet protection portion by the offset absorption portion. This allows the magnet protection portion to reduce in diameter and abut against the inner circumference of the permanent magnet. This minimizes the formation of gaps between the magnet protection portion and the permanent magnet.

[0018] A third aspect of the present disclosure provides a magnet protection ring for a rotor of a rotating electric machine, the magnet protection ring comprising: a disc portion that rotates together with the shaft and extends from the axial radial outside; a cylindrical portion that is formed on the radial outer side of the disc portion; and a plurality of permanent magnets that are circumferentially arranged on the radial inner side of the cylindrical portion.

[0019] The third aspect of the present disclosure is a magnet protection ring for a rotor of a rotating electric machine, which is arranged radially inward of a plurality of permanent magnets and protects the permanent magnets. Furthermore, the third aspect of the present disclosure is a magnet protection ring for a rotor of a rotating electric machine, comprising: a cylindrical magnet protection portion; an inner peripheral flange portion, which is arranged radially inward at one axial end of the magnet protection portion and abuts against the disc portion of the rotor; an outer peripheral flange portion, which is arranged radially outward at the other axial end of the magnet protection portion and faces the axial end faces of the permanent magnets; and an offset absorbing portion, which is located between the outer peripheral flange portion and the magnet protection portion and absorbs radial positional offsets between the outer peripheral flange portion and the magnet protection portion.

[0020] Furthermore, in the magnet protection ring for a rotating electrical machine rotor according to the third aspect of the present disclosure, the outer diameter of the magnet protection portion, in its free state, is larger by a specified amount than the inner diameter of the rotor at the location where the permanent magnets are located. Furthermore, when assembled to the rotor, the outer periphery of the magnet protection portion abuts the inner periphery of the permanent magnets. Consequently, radial displacement of the magnet protection portion between its free state and its rotor-assembled state is absorbed by the displacement absorption portion.

[0021] In the third aspect of the present disclosure, a magnet protection ring for a rotating electrical machine rotor absorbs the reduced diameter of the magnet protection portion by the offset absorption portion. This allows the magnet protection portion to reduce in diameter and abut against the inner circumference of the permanent magnets. This minimizes the formation of gaps between the magnet protection portion and the permanent magnets.

[0022] In the fourth aspect of the present disclosure, the cross section of the displacement absorbing portion is in a semicircular arc shape. Due to the semicircular arc shape, the portion can smoothly deform inward in the radial direction.

[0023] In a fifth aspect of the present disclosure, a tapered shape is formed on the inner periphery of the permanent magnet, on the side opposite the outer peripheral flange. Furthermore, in a sixth aspect of the present disclosure, the tapered shape is configured to have an inclination angle of 20 to 30 degrees. This tapered shape allows the magnet guard to be smoothly reduced in diameter when it is positioned on the inner surface of the permanent magnet.

[0024] In a seventh aspect of the present disclosure, the peripheral flange portion has a plurality of notches at the peripheral end. However, in the peripheral flange portion, there are no notches at the locations between adjacent permanent magnets. First, since a plurality of notches are formed at the peripheral end of the peripheral flange portion, the peripheral flange portion will not excessively hinder the deformation of the magnet protection portion when the diameter is reduced. In addition, by not providing notches at the locations between adjacent permanent magnets, it is possible to prevent the magnet protection portion from excessively deforming at the locations between adjacent permanent magnets. The reason for this is that since the locations between adjacent permanent magnets become spaces, the magnet protection portion is easily deformed toward these spaces when the diameter is reduced. If notches are further provided at the locations that are easily deformed, deformation will be further promoted. In contrast, by providing notches at locations where permanent magnets are present, rather than at locations between adjacent permanent magnets, a balance in the ease of deformation can be achieved.

[0025] In the eighth aspect of the present disclosure, in the outer peripheral flange portion, the surface opposite to the axial end face of the permanent magnet does not contact the axial end face of the permanent magnet. The inner peripheral flange portion abuts against the disc portion of the rotor, which is important for keeping the magnet protection ring on the rotor. However, if the outer peripheral flange portion contacts the end face of the permanent magnet, the inner peripheral flange portion may not be able to abut against the disc portion of the rotor. In contrast, in the eighth aspect of the present disclosure, since the outer peripheral flange portion does not contact the permanent magnet, it does not hinder the inner peripheral flange portion from abutting against the disc portion of the rotor.

[0026] The ninth aspect of the present disclosure provides a method for manufacturing a rotor for a rotating electrical machine. In the manufacturing method of the ninth aspect of the present disclosure, the following steps are performed in chronological order: a configuration step in which the inner peripheral flange portion of the magnet protection tube is configured on the end face of one axial side of the permanent magnet; a pressing step in which the magnet protection tube is pressed in along the axial direction of the permanent magnet; and a contact step in which the inner peripheral flange portion of the magnet protection ring is contacted with the disc portion of the rotor. Furthermore, during the pressing step, the offset absorbing portion is deformed in the radial direction. Since the offset absorbing portion can absorb the deformation of the magnet protection portion when the diameter is reduced, the magnet protection portion can be pressed in smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a cross-sectional view of the rotating electrical machine in a state where it is assembled with the crankshaft and the cylinder block.

[0028] Figure 2 It is a perspective view showing a rotor, a coil, and a sensor case of a rotating electrical machine.

[0029] Figure 3 It is a perspective view showing a coil of a rotating electrical machine and a sensor case.

[0030] Figure 4 This is a front view showing steel plates constituting the stator.

[0031] Figure 5 This is a front view of a state where a coil is wound around a stator core.

[0032] Figure 6 This is a cross-sectional view of the rotor during manufacturing.

[0033] Figure 7 This is a cross-sectional view of the rotor during manufacturing.

[0034] Figure 8 1 is a cross-section showing a rotor of a rotating electrical machine.

[0035] Figure 9 This is a cross-sectional view showing a state where permanent magnets and a magnet protection ring are mounted on a rotor.

[0036] Figure 10 This is an explanatory diagram of the device for assembling the magnet protection ring.

[0037] Figure 11 It is a circumferential cross-sectional view showing a state where permanent magnets and a magnet protection ring are mounted on a rotor.

[0038] Figure 12 It is an axial cross-sectional view showing a state where permanent magnets and a magnet protection ring are mounted on a rotor.

[0039] Figure 13It is an axial cross-sectional view showing a state where permanent magnets and a magnet protection ring of a comparative example are mounted on a rotor.

[0040] Figure 14 It is a three-dimensional diagram of the magnet protection ring.

[0041] Figure 15 It is a circumferential cross-sectional view showing a state where permanent magnets and a magnet protection ring of a comparative example are mounted on a rotor. DETAILED DESCRIPTION

[0042] An example of the present disclosure will be described below with reference to the accompanying drawings. First, an example of a rotating electrical machine to which the present disclosure pertains will be described. Figure 1 This is a cross-sectional view showing the rotating electrical machine 1 assembled on a crankshaft 100. Reference numeral 101 denotes a cylinder block. Within cylinder block 101, a piston (not shown) reciprocates within a cylinder (not shown). The movement of the piston rotates crankshaft 100 via a connecting rod (not shown). Crankshaft 100 is made of iron with a diameter of approximately 20 mm and is rotatably supported by cylinder block 101 via bearings 102.

[0043] The rotor 300 of the rotating electrical machine 1 is fixed to the crankshaft 100 via a base 301. Therefore, the rotor 300 rotates integrally with the crankshaft 100. The rotor 300 is made of an iron material and includes a disc portion 302 extending radially outward from the base portion 301 engaged with the crankshaft 100, and a cylindrical portion 303 formed radially outward of the disc portion 302. Figure 2 As shown, twelve permanent magnets 304 are arranged circumferentially inside cylindrical portion 303. Permanent magnets 304 have a thickness of approximately 4 to 5 mm. It should be noted that the number of permanent magnets 304 is not limited to 12 and can be set to 10 or 24, for example, to provide the desired pole number or magnetic flux.

[0044] A spacer 370 is disposed between the permanent magnet 304 and the disk portion 302 to hold the permanent magnet 304 in a predetermined position. The spacer 370 is made of a resin material such as polyamide. Furthermore, a magnet protection ring 360 is disposed within the inner periphery of the permanent magnet 304. The magnet protection ring 360 is used to hold the permanent magnet 304 and is made of a non-magnetic thin plate material such as austenitic stainless steel.

[0045] like Figure 1 and Figure 2 As shown, the stator 400 is arranged inside the rotor 300 . Figure 2 This is a perspective view of the stator 400 as viewed from the cylinder 101 side. Figure 5The plurality of magnetic steel plates 430 shown are stacked. Furthermore, the stator 400 is integrally formed with a base plate portion 401 mounted on the cylinder block 101 and a plurality of teeth 402 extending radially outward from the base plate portion 401. The outer diameter of the stator 400 is approximately 110 to 130 mm, so the inner diameter of the rotor 300 is sized to form a small gap of approximately 1 mm between the outer diameter of the stator 400 and the permanent magnet 304. Specifically, the cumulative tolerances of the various components are determined so that this small gap is formed between the inner circumferential surface of the magnet protection ring 360 and the outer circumferential surface of the teeth 402 of the stator 400. By providing a small gap, deformation associated with the assembly of the rotor 300 and vibration associated with the operation of the internal combustion engine can be absorbed.

[0046] Three stator bolt through holes 403 are formed in the base portion 401 for fixing the stator 400 to the cylinder 101. In addition, two sensor housing bolt through holes (not shown) are formed in the base portion 401 for fixing the sensor housing 500 to the stator 400.

[0047] The teeth 402 are electrically insulated by a bobbin 410 made of an insulating resin such as polyamide, and a coil 404 made of a copper wire or an aluminum wire is wound around the bobbin 410 . Figure 3 It is shown from Figure 2 A perspective view of the stator 400 and the sensor housing 500 with the rotor 300 removed.

[0048] like Figure 3 As shown, gaps 405 are formed between adjacent coils 404, and these gaps 405 widen radially outward. Furthermore, a sensor housing 500 is disposed within this gap 405. Like the bobbin 410 described above, the sensor housing 500 is molded from a resin such as polyamide. Furthermore, a first magnetic detection sensor 541, a second magnetic detection sensor 542, a third magnetic detection sensor 543, and a fourth magnetic detection sensor 544 are disposed within the sensor housing 500.

[0049] The rotating electrical machine 1 is composed of the above elements. When the rotating electrical machine 1 is used as a generator, the rotor 300 rotates synchronously with the rotation of the crankshaft 100 of the internal combustion engine. As the rotor 300 rotates, it receives the magnetic flux of the permanent magnets 304, generating an electromotive force in the coils 404 of the stator 400. This electromotive force is converted into three-phase AC, which is rectified into DC to charge a battery (not shown). Conversely, when the rotating electrical machine 1 is used as a starter motor for the internal combustion engine, the voltage from the battery (DC power supply) (not shown) is converted into three-phase AC, causing the coils 404 to generate magnetic force. The magnetic force generated in the coils 404 and the magnetic force of the permanent magnets 304 attract and repel each other, causing the rotor 300 to rotate. The rotation of the rotor 300 also rotates the crankshaft 100, starting the internal combustion engine. Furthermore, the second to fourth magnetic detection sensors 542, 543, and 544 are used to control rotation during power generation and startup. It should be noted that the first magnetic detection sensor 541 is used to detect the reference position of the internal combustion engine.

[0050] Next, the assembly process of the stator 400 will be described. First, the stator 400 is formed by punching. Figure 4 The magnetic steel plate 430 shown has a base portion 401 and a tooth portion 402. Figure 4 The stator core 450 is manufactured by stacking a plurality of tooth magnetic steel plates corresponding to the teeth 402. Next, a bobbin 410 is assembled onto the stator core 450 to ensure insulation of the teeth 402. A copper conductor 421 coated with an insulating film such as enamel is then prepared and wound around the bobbin 410 around the teeth 402 to form the coil 404. However, as mentioned above, the conductor 421 is not limited to copper. Aluminum with an insulating coating can also be used.

[0051] Next, the manufacturing method of rotor 300 will be described. First, a flat plate punching process is performed. This flat plate punching process uses press forming to punch out a circular flat plate consisting of a disk portion 302 and a cylindrical portion 303 from a flat iron plate approximately 3 mm thick. The circular flat plate punched out by press forming has a central circular hole 320 concentric with the circular outer periphery.

[0052] Then, if Figure 6As shown, a cylindrical portion bending process is performed to bend the outer peripheral portion of the circular flat plate in the axial direction. The cylindrical portion bending process is also called a rolling process. Furthermore, through the cylindrical portion bending process, a disc-shaped bottom (disc portion 302) centered on the central axis of the central circular hole 320 and a cylindrical portion 303 arranged on the radial outer periphery of the disc portion 302 are formed. It should be noted that in the cylindrical portion bending process, the central axis of the disc portion 302 is made consistent with the central axis of the cylindrical portion 303. Furthermore, in the cylindrical portion bending process, the central circular hole 320 is also stamped and formed in a manner that increases in diameter, and is formed into a size for assembly of the boss portion 340 described later. However, the diameter expansion of the central circular hole 320 is not necessary in the cylindrical portion bending process, and the central circular hole 320 of a specified diameter can also be formed in the flat plate blanking process.

[0053] Then, if Figure 7 As shown, a punching process is performed to form fixing holes 323 for fixing the boss portion 340 to the disk portion 302. The plurality of fixing holes 323 have the same diameter and are arranged concentrically around the central axis.

[0054] Then, a caulking pin forming step is performed to forge the caulking pin 325. The caulking pin 325 is used in the fixing step of the permanent magnet 304 described later. Figure 7 Starting from the right side of the disc portion 302, the rivet pin 325 is die-forged using a punch. Then, an inward die-forging process is sometimes performed to die-forge the cylindrical portion 303 from the outer circumference to the inner circumference. When the inward die-forging process is performed, a magnet retaining portion 327 is formed on the inner circumference of the cylindrical portion 303. The magnet retaining portion 327 is formed in a portion of the cylindrical portion 303 close to the disc portion 302. This magnet retaining portion 327 is also used in the permanent magnet fixing process.

[0055] In the permanent magnet fixing process, such as Figure 8 As shown, the permanent magnet 304 is fixed to the inner circumference of the cylindrical portion 303. However, the permanent magnet 304 is magnetized after all the assembly is completed, so in this permanent magnet fixing process, the metal before magnetization is referred to as the permanent magnet 304. First, the spacer 370 is arranged at the boundary portion between the disk portion 302 and the cylindrical portion 303 of the rotor 300. Next, the permanent magnet 304 before magnetization is arranged on the inner circumference of the cylindrical portion 303, and then the magnet protection ring 360 is arranged on the inner circumference of the permanent magnet 304. The magnet retaining portion 327 obtained by the above-mentioned inward forging process is formed without using the spacer 370. Therefore, when the spacer 370 is used, the magnet retaining portion 327 is not formed.

[0056] The magnet protection ring 360 is a thin plate with a thickness of about 0.2 mm. Figure 9As shown, the magnet protection ring 360 has a cylindrical magnet protection portion 361 located on the inner circumference of the permanent magnet 304. Furthermore, the magnet protection ring 360 has an inner flange portion 362 integrally formed at one axial end of the magnet protection portion 361, extending radially inward. The width of the inner flange portion 362 is approximately 7 mm. Because the magnet protection portion 361 and the inner flange portion 362 are continuously and integrally formed, the continuous portion 365 forms a curved surface. After assembly, the inner flange portion 362 abuts the disc portion 302 of the rotor 300. The magnet protection ring 360 also has an outer flange portion 363 integrally formed at the other axial end of the magnet protection portion 361, extending radially outward. The width of the outer flange portion 363 is approximately 3 to 4 mm. Furthermore, after assembly, the outer flange portion 363 faces the end face 3040 on one axial side of the permanent magnet 304. It should be noted that the axial direction refers to the direction along the central axis of the disc portion 302 and cylindrical portion 303 of the rotor 300, which also coincides with the axial direction of the crankshaft 100. Furthermore, the radial direction refers to the direction perpendicular to the axial direction and is the direction in which the disc portion 302 extends. The radial inward direction is the direction toward the central axis, and the radial outward direction is the direction away from the central axis.

[0057] The magnet protection ring 360 further integrally forms an offset absorbing portion 364 between the outer peripheral flange portion 363 and the magnet protection portion 361. Figure 9 As shown, the cross section of the offset absorbing portion 364 is semicircular and easily deformed. Figure 9 and Figure 1 、 Figures 6 to 8 The same is a sectional view taken along a plane including the central axis. Therefore, the semicircular arc shape of the offset absorbing portion 364 is formed continuously in the circumferential direction. The outer diameter of the magnet protection portion 361 of the magnet protection ring 360 is larger by a specified amount than the inner diameter of the configuration position of the permanent magnet 304 of the rotor 300 in the free state. The specified amount is, for example, slightly less than 1 mm. In addition, the outer periphery of the magnet protection portion 361 abuts against the inner periphery 3042 of the permanent magnet 304 in the state after being assembled to the rotor 300. Therefore, during assembly, the magnet protection portion 361 is reduced in outer diameter. The offset absorbing portion 364 has the function of absorbing the radial positional offset of the outer peripheral flange portion 363 and the magnet protection portion 361 during this reduction in diameter. This positional offset absorption function will be described in detail later.

[0058] Next, the process of placing the magnet protection ring 360 on the inner periphery of the permanent magnet 304 will be described. Figure 10 The pressing device 600 of the magnet protection ring 360 is shown. The pressing device 600 has a base 610 and a punch 620. The punch 620 is located relative to the base 610. Figure 10The punch 620 moves forward and backward in the vertical direction. In other words, the punch 620 reciprocates along the axial direction of the rotor 300. The base 610 holds the disc portion 302 of the rotor 300 and has a retaining protrusion 611 corresponding to the central circular hole 320. The base 610 also has an annular portion 612 that secures the boundary between the disc portion 302 and the cylindrical portion 303 of the rotor 300. The inner diameter of the annular portion 612 matches the outer diameter of the cylindrical portion 303. The ring portion 612 and the retaining protrusion 611 securely hold the rotor 300.

[0059] The punch 620 is formed with a mounting portion 621 at the front end for mounting the magnet protection ring 360. That is, the mounting portion 621 includes a connecting portion 6210 and a front end portion 6211. The connecting portion 6210 and the magnet protection portion 361 of the magnet protection ring 360 extend radially inward, and the shape of the front end portion 6211 is the same as that of the inner peripheral flange portion 362. In addition, the punch 620 also has a cylindrical portion 622 opposite to the outer peripheral flange portion 363. Moreover, the connecting portion 6210 and the front end portion 6211 of the mounting portion 621 can be displaced radially inward by the reducing mechanism 625. It should be noted that the punch 620 and the base 610 are arranged in a manner such that their central axes are aligned. Therefore, the magnet protection ring 360 mounted on the punch 620 is also coaxially arranged with the rotor 300 retained on the base 610.

[0060] The diameter reduction mechanism 625 is composed of a connecting pin 623 and an engaging groove 624. A coil spring 626 is arranged in the engaging groove 624 and is compressed in the engaging groove 624 via a steel ball 627. The mounting portion 621 is arranged in a manner that is divided into multiple parts in the circumferential direction. The movement of the punch 620 is transmitted to the connecting portion 6210 and the front end portion 6211 of the mounting portion 621 via the connecting pin 623. The diameter reduction accompanying the movement can be achieved by rotating the mounting portion 621 around the connecting pin 623. The engaging groove 624 is a groove for allowing rotation at this time. Specifically, the coil spring 626 is further compressed in the engaging groove 624, allowing the connecting portion 6210 to move radially inward.

[0061] Next, the pressing process of pressing the magnet protection ring 360 into the inner circumference of the permanent magnet 304 will be described. Figure 9 As shown, a tapered portion 3041 is formed on the inner circumference of one end surface 3040 of the permanent magnet 304. The diameter of the tapered portion 3041 gradually increases in the axial direction. The inclination angle of the tapered portion 3041 is approximately 20 to 30 degrees. Furthermore, the axial length of the permanent magnet 304 is approximately 18 to 32 millimeters, and the thickness of the permanent magnet 304 is approximately 5 millimeters. The tapered portion 3041 increases the inner diameter of the axial end surface 3040 of the permanent magnet 304 by approximately 1 millimeter.

[0062] It should be noted that in Figure 9In the example, a tapered portion 3041 is formed on the inner circumference of the end surface 3040 on one side of the permanent magnet 304 to serve as a guide for pressing the magnet protection ring 360. However, the tapered portion can also be formed on the other end surface of the permanent magnet 304. In particular, when the axial length of the permanent magnet 304 is long, the radial deformation of the magnet protection ring 360 also increases. Therefore, when the axial length of the permanent magnet 304 is long, forming a tapered portion on the other end surface can suppress deformation of the magnet protection ring 360.

[0063] Therefore, when the punch 620 of the press-fitting device 600 advances toward the base 610, the curved surface of the continuous portion 365, formed by the continuous inner flange portion 362 and the magnet protection portion 361, first abuts against the tapered portion 3041 of the permanent magnet 304. As the punch 620 advances, the outer diameter of the mounting portion 621 is reduced by the diameter-reducing mechanism 625, in accordance with the curved surface of the continuous portion 365 and the tapered shape of the tapered portion 3041. As described above, the connecting portion 6210 and the front end portion 6211 of the mounting portion 621 are reduced in diameter. Meanwhile, the cylindrical portion 622 remains unchanged in diameter and faces the outer flange portion 363 of the magnet protection ring 360.

[0064] The punch 620 of the press-fitting device 600 continues to advance until the inner circumferential flange portion 362, mounted on the front end portion 6211 of the mounting portion 621, abuts the disc portion 302. In other words, the press-fitting process continues until the inner circumferential flange portion 362 abuts the disc portion, and the end of the press-fitting process becomes the abutment process. During the abutment process, the cylindrical portion 622 is configured so that the outer circumferential flange portion 363 does not abut the end face 3040 of the permanent magnet 304. Furthermore, even during the press-fitting process, the cylindrical portion 622 does not contact the outer circumferential flange portion 363.

[0065] Here, it is assumed that the cylindrical portion 622 is a mechanism that pushes the outer peripheral flange portion 363. Furthermore, it is assumed that the outer peripheral flange portion 363 contacts the end face 3040 of the permanent magnet 304 before the inner peripheral flange portion 362 contacts the disk portion 302. In this case, a gap is generated between the inner peripheral flange portion 362 and the disk portion 302. Conversely, it is assumed that the inner peripheral flange portion 362 contacts the disk portion 302 before the outer peripheral flange portion 363 contacts the end face 3040 of the permanent magnet 304. In this case, the cylindrical portion 622 advances further, and the outer peripheral flange portion 363 is flattened by the pressing load of the cylindrical portion 622.

[0066] In this example, during the press-fitting process achieved by the forward movement of the punch 620, it is the mounting portion 621 that applies the pressing load to the magnet protection ring 360. This ensures that during the abutment process, the inner circumferential flange portion 362 reliably abuts the disc portion 302. This abutment enables the magnet protection ring 360 to be properly secured, as described later. Therefore, in this example, when the inner circumferential flange portion 362 abuts the disc portion 302, a gap exists between the outer circumferential flange portion 363 and the end face 3040 of the permanent magnet 304.

[0067] Thus, in this example, the pushing load of the punch 620 is transmitted to the magnet protection ring 360 via the mounting portion 621. Furthermore, the mounting portion 621 is subjected to the pushing force of the punch 620 via the diameter-reducing mechanism 625 that reduces in diameter as the punch 620 advances. Therefore, the inner peripheral flange portion 362 and the magnet protection portion 361 of the magnet protection ring 360 pressed in by the press-in device 600 are reduced in diameter. On the other hand, the outer peripheral flange portion 363 of the magnet protection ring 360 does not bear the pushing force and is not actively reduced in diameter. Therefore, the magnet protection ring 360 will produce a radial positional offset between the magnet protection portion 361 and the outer peripheral flange portion 363. That is, the positional offset is the radial dimensional difference caused by the change in the diameter of the magnet protection portion 361 while the diameter of the outer peripheral flange portion 363 does not change much.

[0068] In this example, the offset absorbing portion 364 absorbs the radial offset. Specifically, the offset absorbing portion 364 protrudes in a semicircular shape in the axial direction and toward the side opposite to the end face 3040. In addition, as described above, the semicircular offset absorbing portion 364 is formed throughout the entire circumference. The magnet protection portion 361 is arranged radially inward of the semicircular offset absorbing portion 364, and the outer peripheral flange portion 363 is arranged radially outward. The semicircular shape of the offset absorbing portion 364 is formed by performing multiple bending processes within a narrow radial range and is affected by work hardening compared to other parts of the magnet protection ring 360. Therefore, when the magnet protection portion 361 is reduced in diameter, almost all of the force pulling the outer peripheral flange portion 363 radially inward will be borne by the semicircular offset absorbing portion 364. In other words, stress is concentrated at the boundary between the semicircular offset absorbing portion 364 and the magnet protection portion 361, causing deformation. Here, the outer flange portion 363 itself is annular with a width extending throughout the entire circumference, and is therefore less susceptible to radial deformation. Therefore, by providing the offset absorbing portion 364 between the outer flange portion 363 and the magnet protection portion 361, radial changes (positional offset) of the outer flange portion 363 can be suppressed.

[0069] In this way, the displacement absorbing portion 364 disposed between the magnet protection portion 361 and the outer peripheral flange portion 363 is deformed radially inward, thereby suppressing the outer peripheral flange portion 363 from deforming radially inward. Figure 11As shown in FIG. 3 , the magnet protection portion 361 abuts the inner periphery of the permanent magnet 304 over the entire periphery. Figure 12 As shown, the magnet protection portion 361 also abuts along the entire length of the axial direction of the permanent magnet 304. By reliably abutting in the circumferential direction and the axial direction, the magnet protection ring 360 can properly retain the permanent magnet 304.

[0070] Figure 13 A comparative example of a magnet protection ring 360 without an offset absorbing portion 364 is shown. In this comparative example, as the inner flange portion 362 and the magnet protection portion 361 of the magnet protection ring 360 shrink in diameter, the outer flange portion 363 is pulled radially inward and deformed. This deformation of the outer flange portion 363 causes rebound after the magnet protection ring 360 is removed from the press-fit device 600, resulting in a gap X between the magnet protection portion 361 and the permanent magnet 304. Figure 13 The gap X is caused by deformation of the outer peripheral flange portion 363 and is thus generated on the outer peripheral flange portion 363 side of the magnet protection portion 361. In this example, the provision of the misalignment absorbing portion 364 suppresses this gap X. Therefore, the misalignment absorbing portion 364 itself deforms in the radial direction. Furthermore, the misalignment absorbing portion 364 also acts as a variation suppressing portion that suppresses radial variations of the outer peripheral flange portion 363.

[0071] It should be noted that if Figure 14 As shown, a plurality of notch portions 366 are formed at equal intervals along the circumferential direction at the outer peripheral end of the outer flange portion 363. This means that in the magnet protection ring 360, the outer flange portion 363 does not shrink in diameter relative to the magnet protection portion 361 and the inner flange portion 362. Therefore, if the strength of the outer flange portion 363 is too high, the outer flange portion 363 may hinder the shrinkage of the magnet protection portion 361 and the inner flange portion 362. In this example, in order to alleviate this obstruction factor, notch portions 366 are formed on the outer flange portion 363 so that the outer flange portion 363 is easily deformed. The notch portion 366 is formed in the circumferential central portion of the permanent magnet 304. Therefore, the number of notch portions 366 corresponds to the number of permanent magnets 304. Figure 14 In the example of FIG, since the number of permanent magnets 304 is 12, the notches 366 are also formed at 12 locations.

[0072] However, if Figure 11As shown, a predetermined interval A is provided between adjacent permanent magnets 304. The interval A is approximately 1 to 2 mm. When the magnet protection ring 360 is pressed into place by the pressing device 600, the portion of the magnet protection portion 361 corresponding to the interval A is not supported by the permanent magnet 304. Therefore, the magnet protection portion 361 is easily deformed at the position corresponding to the interval A, and the magnet protection portion 361 undulates circumferentially at the portion corresponding to the interval A. More specifically, the circumferential deformation (flow of excess material) caused by the diameter reduction of the magnet protection portion 361 is directed toward the interval A, and the magnet protection portion 361 extends radially outwards further than the inner diameter of the permanent magnet 304 at the portion of the interval A.

[0073] Here, because the spacing A between adjacent permanent magnets 304 coincides with the location of the notch 366, corrugation deformation of the magnet protection portion 361 is promoted. This is because, as described above, the outer flange portion 363 is easily deformed around the notch 366, which further increases the spacing A and makes it easier for the magnet protection portion 361 to extend radially outward. To suppress this corrugation deformation, in this example, the notch 366 of the outer flange portion 363 is always formed in the area where the permanent magnet 304 is located. In the above example, the notch 366 is formed in the circumferential center of the permanent magnet 304. Figure 15 A comparative example is shown in which the notch portion 366 corresponds to the gap A. In this comparative example, the magnet protection portion 361 undulates at the position of the gap A. This corrugated deformation eventually causes a gap X to be generated at the portion facing the permanent magnet 304. Figure 15 The gap X is caused by the corrugation deformation caused by the gap A, and thus is generated at a location away from the gap A, that is, at the circumferential center of the permanent magnet 304 .

[0074] exist Figure 14 In the example, a notch 366 is formed at the outer peripheral end of the outer peripheral flange 363. However, this is not a necessary condition. Even in the example without notch 366, the radial and circumferential changes in the outer peripheral flange 363 cannot be eliminated. Regardless of the presence or absence of notch 366, corrugated deformation will occur in the interval A portion of the magnet protection portion 361 as the diameter is reduced. Figure 15 The example is an example in which the notch portion 366 is formed and the position of the notch portion 366 is not an ideal position.

[0075] In the above process, the magnet protection ring 360 is arranged on the inner periphery of the permanent magnet 304. Next, the magnet protection ring 360 is riveted and fixed to the disk portion 302 using the rivet pin 325. Specifically, the rivet pin 325 is inserted into the rivet fixing hole 367 (such as the inner periphery flange portion 362) formed on the magnet protection ring 360. Figure 14In this state, the head of the rivet pin 325 is flattened and riveted.

[0076] The above steps complete the fixation of the permanent magnets 304. It should be noted that, as described above, without using the spacers 370, the permanent magnets 304 are positioned axially by the magnet retaining portion 327. In this case, the magnet protection ring 360 is mechanically fixed to the rotor 300 by punching the aforementioned rivet pins 325.

[0077] Next, a boss fixing step is performed to fix boss 340 to disk 302 of rotor 300. In this step, boss 340 is first inserted into center circular hole 320. After insertion, boss 340 is fixed to disk 302 of rotor 300 using rivets 341 through fixing holes 323.

[0078] It should be noted that the above is an ideal example of the present disclosure, but the present disclosure can be modified in various ways. Figure 1 As shown, the base 301 and the rotor 300 may also be formed integrally. Figure 1 The base 301 corresponds to Figure 8 340. In addition, Figure 7 and Figure 8 In the example, the magnet holding portion 327 is formed, but as Figure 1 and Figure 9 As shown, spacers 370 may also be used. Both magnet holder 327 and spacer 370 have the function of axially positioning the permanent magnets 304 when inserted into cylindrical portion 303 of rotor 300. It should be noted that magnet holder 327 is used when the number of permanent magnets 304 is small (e.g., four or less), while spacer 370 is used when the number of permanent magnets 304 is large.

[0079] In the above example, a plurality of notches 366 are formed at the outer peripheral end of the outer peripheral flange 363, but the number of notches 366 can be appropriately set according to the required strength of the outer peripheral flange 363. The notches 366 can also be omitted as needed.

[0080] Furthermore, in the above example, the outer flange portion 363 is separated from the end face 3040 of the permanent magnet 304. However, it is sufficient to set a tolerance in the direction of separation. In other words, as long as the cumulative tolerance of the components related to the distance between the outer flange portion 363 and the end face 3040 is zero at its maximum, it is acceptable even if the outer flange portion 363 contacts the end face 3040. Furthermore, in the above example, a tapered portion 3041 is formed on one end face 3040 of the permanent magnet 304. This is an ideal shape because it guides the magnet protection ring 360 during press-fitting by the press-fit device 600. However, if the inner flange portion 362 of the magnet protection ring 360 and the continuous portion 365 of the magnet protection portion 361 are formed as curved surfaces, the tapered portion 3041 is not required. Alternatively, the inner periphery of the end face 3040 of the permanent magnet 304 can be formed as a curved surface. On the contrary, when the inner periphery of the end surface 3040 of the permanent magnet 304 is formed with the tapered portion 3041 or a curved surface, the continuous portion 365 of the magnet protection ring 360 does not necessarily need to be formed with a curved surface.

[0081] In addition, in the above example, the cross-sectional shape of the offset absorbing portion 364 is set to a semicircular arc shape. This is an ideal shape in terms of absorbing the radial offset of the magnet protection portion 361 and the outer peripheral flange portion 363 through the offset absorbing portion 364. However, the shape is not limited to a semicircular arc shape. It can also be set to other shapes such as a wave shape or a V shape. Figure 13 In the comparative example shown, the magnet protection portion 361 is continuous with the outer peripheral flange portion 363. The misalignment absorbing portion 364 only needs to avoid this continuity. Therefore, the misalignment absorbing portion 364 is located at the boundary between the magnet protection portion 361 and the outer peripheral flange portion 363 and can have any shape that can absorb radial misalignment.

[0082] As mentioned above, with Figure 13 and Figure 15 Compared with the comparative example shown, Figure 11 and Figure 12 The example shown can significantly reduce the gap X. However, the present disclosure aims to suppress the occurrence of gap X, not necessarily to completely eliminate it. Therefore, in the present disclosure, the outer periphery of the magnet protection portion 361, when assembled with the rotor 300, is not required to be in 100% close contact with the inner periphery 3042 of the permanent magnet 304. Generally speaking, as long as the outer periphery of the magnet protection portion 361 is in contact with the inner periphery 3042 of the permanent magnet 304, the magnet protection ring 360 can reliably protect the permanent magnet 304.

[0083] Furthermore, for example, setting the number of coils 404 to 18 is an example, and the number of coils 404 can be changed to other values. In addition, the sizes described in the above examples are also examples, and the material and size can be appropriately set according to the performance required of the rotating electrical machine 1.

[0084] Other implementations

[0085] The disclosure in this specification and the drawings, etc. is not limited to the illustrated embodiments. The present disclosure includes the illustrated embodiments and variations made by those skilled in the art based on these embodiments. For example, the present disclosure is not limited to the combination of parts and / or elements shown in the embodiments. The present disclosure can be implemented in various combinations. The present disclosure may have additional parts that can be added to the embodiments. The present disclosure includes technical solutions after omitting parts and / or elements in the embodiments. The present disclosure includes replacing or combining parts and / or elements between one embodiment and other embodiments. The disclosed technical scope is not limited to the description of the embodiments. Some of the disclosed technical scopes are shown by the description of the claims, and should also be understood to include all changes within the meaning and scope equivalent to the description of the claims.

[0086] (Disclosure of technical ideas)

[0087] This specification discloses multiple technical concepts described in the following multiple items. Some items are described by selectively referencing a previous item in a subsequent item in a multiple-dependent form. Further, some items are described by referring to another multiple-dependent form in a multiple-dependent form. Items described in these multiple-dependent forms define multiple technical concepts.

[0088] (Technical Concept 1) A rotating electrical machine comprising:

[0089] a stator having an annular base portion and a plurality of coils extending radially outward from the base portion; and

[0090] A rotor having a disc portion, a cylindrical portion, a plurality of permanent magnets, and a magnet protection ring, wherein the disc portion rotates together with the shaft and extends radially outward from the axial direction, the cylindrical portion is formed on the radially outer side of the disc portion, the plurality of permanent magnets are arranged radially inward of the cylindrical portion and radially outward of the coil, and the magnet protection ring is arranged radially inward of the plurality of permanent magnets and protects the permanent magnets.

[0091] The magnet protection ring comprises: a cylindrical magnet protection portion; an inner peripheral flange portion, wherein the inner peripheral flange portion is arranged on the radially inner side at one axial end of the magnet protection portion and abuts against the disc portion of the rotor; an outer peripheral flange portion, wherein the outer peripheral flange portion is arranged on the radially outer side at the other axial end of the magnet protection portion and faces the end face of one axial side of the permanent magnet; and an offset absorbing portion, wherein the offset absorbing portion is located between the outer peripheral flange portion and the magnet protection portion and absorbs the radial position offset of the outer peripheral flange portion and the magnet protection portion.

[0092] The outer diameter of the magnet protection portion is larger by a predetermined amount than the inner diameter of the rotor at the position where the permanent magnet is arranged in the free state.

[0093] The outer periphery of the magnet protection portion abuts against the inner periphery of the permanent magnet when assembled to the rotor.

[0094] The displacement absorbing portion absorbs radial displacement between the free state and the state in which the magnet protection portion is assembled to the rotor.

[0095] (Technical Concept 2) A rotor for a rotating electrical machine, wherein the rotor for a rotating electrical machine comprises:

[0096] a disc portion that rotates together with the shaft and extends from the radially outer side of the axial direction; a cylindrical portion that is formed on the radially outer side of the disc portion; a plurality of permanent magnets that are circumferentially arranged on the radially inner side of the cylindrical portion; and a magnet protection ring that is arranged on the radially inner side of the plurality of permanent magnets and protects the permanent magnets.

[0097] The magnet protection ring comprises: a cylindrical magnet protection portion; an inner peripheral flange portion, wherein the inner peripheral flange portion is arranged on the radially inner side at one axial end of the magnet protection portion and abuts against the disc portion of the rotor; an outer peripheral flange portion, wherein the outer peripheral flange portion is arranged on the radially outer side at the other axial end of the magnet protection portion and faces the end face of one axial side of the permanent magnet; and an offset absorbing portion, wherein the offset absorbing portion is located between the outer peripheral flange portion and the magnet protection portion and absorbs the radial position offset of the outer peripheral flange portion and the magnet protection portion.

[0098] The outer diameter of the magnet protection portion is larger by a predetermined amount than the inner diameter of the rotor at the position where the permanent magnet is arranged in the free state.

[0099] The outer periphery of the magnet protection portion abuts against the inner periphery of the permanent magnet when assembled to the rotor.

[0100] The displacement absorbing portion absorbs radial displacement between the free state and the state in which the magnet protection portion is assembled to the rotor.

[0101] (Technical Concept 3) A magnet protection ring for a rotor of a rotating electrical machine, wherein the magnet protection ring comprises:

[0102] a disc portion that rotates together with the shaft and extends from the radially outer side of the axial direction; a cylindrical portion that is formed on the radially outer side of the disc portion; and a plurality of permanent magnets that are arranged circumferentially on the radially inner side of the cylindrical portion.

[0103] The magnet protection ring is arranged on the radial inner side of the plurality of permanent magnets to protect the permanent magnets, and

[0104] The magnet protection ring comprises: a cylindrical magnet protection portion; an inner peripheral flange portion, wherein the inner peripheral flange portion is arranged on the radially inner side at one axial end of the magnet protection portion and abuts against the disc portion of the rotor; an outer peripheral flange portion, wherein the outer peripheral flange portion is arranged on the radially outer side at the other axial end of the magnet protection portion and faces the end face of one axial side of the permanent magnet; and an offset absorbing portion, wherein the offset absorbing portion is located between the outer peripheral flange portion and the magnet protection portion and absorbs the radial position offset of the outer peripheral flange portion and the magnet protection portion.

[0105] The outer diameter of the magnet protection portion is larger by a predetermined amount than the inner diameter of the rotor at the position where the permanent magnet is arranged in the free state.

[0106] The outer periphery of the magnet protection portion abuts against the inner periphery of the permanent magnet when assembled to the rotor.

[0107] The displacement absorbing portion absorbs radial displacement between the free state and the state in which the magnet protection portion is assembled to the rotor.

[0108] (Technical Concept 4) The rotating electrical machine according to Technical Concept 1, the rotating electrical machine rotor according to Technical Concept 2, or the magnet protection ring for the rotating electrical machine rotor according to Technical Concept 3, wherein:

[0109] The cross section of the displacement absorbing portion is in a semicircular arc shape.

[0110] (Technical Concept 5) The rotating electrical machine according to Technical Concept 1 or the rotating electrical machine rotor according to Technical Concept 2, wherein:

[0111] The inner periphery of the permanent magnet has a tapered shape on a side facing the outer peripheral flange portion.

[0112] (Technical Concept 6) The rotating electrical machine or the rotor for a rotating electrical machine according to Technical Concept 5, wherein:

[0113] The tapered shape has an inclination angle of 20 to 30 degrees.

[0114] (Technical Concept 7) A rotating electrical machine according to Technical Concept 1 or any one of Technical Concepts 4 to 6 subordinate to Technical Concept 1, a rotating electrical machine rotor according to Technical Concept 2 or any one of Technical Concepts 4 to 6 subordinate to Technical Concept 2, or a magnet protection ring for a rotating electrical machine rotor according to Technical Concept 3 or Technical Concept 4 subordinate to Technical Concept 3, wherein:

[0115] The outer peripheral flange portion has a plurality of notches at an outer peripheral end, and the notches are not present at locations between the adjacent permanent magnets in the outer peripheral flange portion.

[0116] (Technical Concept 8) A rotating electrical machine according to Technical Concept 1 or any one of Technical Concepts 4 to 7 subordinate to Technical Concept 1, a rotating electrical machine rotor according to Technical Concept 2 or any one of Technical Concepts 4 to 7 subordinate to Technical Concept 2, or a magnet protection ring for a rotating electrical machine rotor according to Technical Concept 3 or Technical Concept 4 or Technical Concept 7 subordinate to Technical Concept 3, wherein:

[0117] In the outer peripheral flange portion, a surface facing the axial end surface of the permanent magnet does not contact the axial end surface of the permanent magnet.

[0118] (Technical Concept 9) A method for manufacturing a rotor for a rotating electrical machine according to Technical Concept 2, wherein the following steps are performed in chronological order:

[0119] a placement step of placing the inner peripheral flange portion of the magnet protection ring on the end surface on the one side in the axial direction of the permanent magnet;

[0120] a pressing step of pressing the magnet protection ring into the permanent magnet along the axial direction; and

[0121] The abutting step brings the inner peripheral flange portion of the magnet protection ring into contact with the disc portion of the rotor, and during the press-fitting step, deforms the displacement absorbing portion in the radial direction.

Claims

1. A rotating electrical machine, wherein: The rotating electrical machine comprises: a stator having an annular base portion and a plurality of coils extending radially outward from the base portion; and A rotor having a disc portion, a cylindrical portion, a plurality of permanent magnets, and a magnet protection ring, wherein the disc portion rotates together with the shaft and extends radially outward from the axial direction, the cylindrical portion is formed on the radially outer side of the disc portion, the plurality of permanent magnets are arranged radially inward of the cylindrical portion and radially outward of the coil, and the magnet protection ring is arranged radially inward of the plurality of permanent magnets and protects the permanent magnets. The magnet protection ring comprises: a cylindrical magnet protection portion; an inner peripheral flange portion, wherein the inner peripheral flange portion is arranged on the radially inner side at one axial end of the magnet protection portion and abuts against the disc portion of the rotor; an outer peripheral flange portion, wherein the outer peripheral flange portion is arranged on the radially outer side at the other axial end of the magnet protection portion and faces the end face of one axial side of the permanent magnet; and an offset absorbing portion, wherein the offset absorbing portion is located between the outer peripheral flange portion and the magnet protection portion and absorbs the radial position offset of the outer peripheral flange portion and the magnet protection portion. The outer diameter of the magnet protection portion is larger by a predetermined amount than the inner diameter of the rotor at the position where the permanent magnet is arranged in the free state. The outer periphery of the magnet protection portion abuts against the inner periphery of the permanent magnet when assembled to the rotor. The displacement absorbing portion absorbs radial displacement between the free state and the state in which the magnet protection portion is assembled to the rotor.

2. A rotor for a rotating electrical machine, wherein: The rotor for a rotating electrical machine comprises: a disc portion that rotates together with the shaft and extends from the radially outer side of the axial direction; a cylindrical portion that is formed on the radially outer side of the disc portion; a plurality of permanent magnets that are circumferentially arranged on the radially inner side of the cylindrical portion; and a magnet protection ring that is arranged on the radially inner side of the plurality of permanent magnets and protects the permanent magnets. The magnet protection ring comprises: a cylindrical magnet protection portion; an inner peripheral flange portion, wherein the inner peripheral flange portion is arranged on the radially inner side at one axial end of the magnet protection portion and abuts against the disc portion of the rotor; an outer peripheral flange portion, wherein the outer peripheral flange portion is arranged on the radially outer side at the other axial end of the magnet protection portion and faces the end face of one axial side of the permanent magnet; and an offset absorbing portion, wherein the offset absorbing portion is located between the outer peripheral flange portion and the magnet protection portion and absorbs the radial position offset of the outer peripheral flange portion and the magnet protection portion. The outer diameter of the magnet protection portion is larger by a predetermined amount than the inner diameter of the rotor at the position where the permanent magnet is arranged in the free state. The outer periphery of the magnet protection portion abuts against the inner periphery of the permanent magnet when assembled to the rotor. The displacement absorbing portion absorbs radial displacement between the free state and the state in which the magnet protection portion is assembled to the rotor.

3. A magnet protection ring for a rotor of a rotating electrical machine, wherein: The magnet protection ring has: a disc portion that rotates together with the shaft and extends from the radially outer side of the axial direction; a cylindrical portion that is formed on the radially outer side of the disc portion; and a plurality of permanent magnets that are arranged circumferentially on the radially inner side of the cylindrical portion. The magnet protection ring is arranged on the radial inner side of the plurality of permanent magnets to protect the permanent magnets, and The magnet protection ring comprises: a cylindrical magnet protection portion; an inner peripheral flange portion, wherein the inner peripheral flange portion is arranged on the radially inner side at one axial end of the magnet protection portion and abuts against the disc portion of the rotor; an outer peripheral flange portion, wherein the outer peripheral flange portion is arranged on the radially outer side at the other axial end of the magnet protection portion and faces the end face of one axial side of the permanent magnet; and an offset absorbing portion, wherein the offset absorbing portion is located between the outer peripheral flange portion and the magnet protection portion and absorbs the radial position offset of the outer peripheral flange portion and the magnet protection portion. The outer diameter of the magnet protection portion is larger by a predetermined amount than the inner diameter of the rotor at the position where the permanent magnet is arranged in the free state. The outer periphery of the magnet protection portion abuts against the inner periphery of the permanent magnet when assembled to the rotor. The displacement absorbing portion absorbs radial displacement between the free state and the state in which the magnet protection portion is assembled to the rotor.

4. The rotating electrical machine according to claim 1, wherein The cross section of the displacement absorbing portion is in a semicircular arc shape.

5. The rotating electrical machine according to claim 1, wherein The rotating electrical machine has a tapered shape on the inner periphery of the permanent magnet on a side facing the outer peripheral flange portion.

6. The rotating electrical machine according to claim 5, wherein The tapered shape has an inclination angle of 20 to 30 degrees.

7. The rotating electric machine according to claim 1, wherein The outer peripheral flange portion has a plurality of notches at an outer peripheral end, and the notches are not present at locations between the adjacent permanent magnets in the outer peripheral flange portion.

8. The rotating electrical machine according to claim 1, wherein In the outer peripheral flange portion, a surface facing the axial end surface of the permanent magnet does not contact the axial end surface of the permanent magnet.

9. A method for manufacturing a rotor for a rotating electrical machine according to claim 2, wherein: In chronological order: a placement step of placing the inner peripheral flange portion of the magnet protection ring on the end surface on the one side in the axial direction of the permanent magnet; A pressing step of pressing the magnet protection ring into the permanent magnet along the axial direction; as well as a contacting step of causing the inner peripheral flange portion of the magnet protection ring to contact the disc portion of the rotor; During the press-fitting step, the displacement absorbing portion is deformed in the radial direction.

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