Motor rotor, motor and supercharger

Abstract

This motor rotor includes: a magnet including a magnet circumferential surface, a first magnet end surface, and a second magnet end surface; a C shaft including a C shaft end surface abutting against the first magnet end surface; and an armoring covering the magnet circumferential surface and a portion of the first magnet end surface that contacts the C shaft end surface. The C shaft includes: a C shaft insertion portion covered by the armoring; a C shaft protruding portion not covered by the armoring; and a C shaft coupling portion positioned between the C shaft insertion portion and the C shaft protruding portion and contacting an end of the armoring. The end of the armoring includes a ring-shaped fastening portion bent in such a manner as to approach a rotation axis of the C shaft.

Description

Technical Field

[0001] The present disclosure relates to a motor rotor, a motor, and a supercharger.

Background Art

[0002] Patent Document 1 discloses a technique related to a rotor used in a brushless motor. The rotor of Patent Document 1 fixes a permanent magnet to a rotating shaft using a cover. The structure disclosed in Patent Document 1 can fix the permanent magnet to the rotating shaft by a uniform fixing load. The structure disclosed in Patent Document 1 can prevent damage to the permanent magnet even when used in an environment where the temperature fluctuates.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Like the rotor of Patent Document 1, the rotor is composed of several parts including a shaft and a magnet. The materials of the plurality of parts constituting the rotor are different from each other. The difference in materials results in a difference in the coefficient of thermal expansion. The degree of thermal deformation that occurs when the rotor receives heat is different for each part. In the environment where the rotor is used, the temperature changes over a wide range. When the rotor is exposed to a temperature cycle in which it alternates between a high-temperature environment and a low-temperature environment, the expansion and contraction of the parts are repeated with different degrees for each part. As a result, the positional relationship between the parts may shift. The rotor exposed to the temperature cycle gradually approaches a state where it cannot exhibit the desired performance.

[0005] The present disclosure describes a motor rotor capable of continuously maintaining the desired performance, a motor including the motor rotor, and a supercharger including the motor. [Means for solving the problem]

[0006] A motor rotor in one embodiment of the present disclosure comprises a magnet including a magnet circumferential surface and a pair of magnet end faces, a shaft unit including a shaft end face that abuts the magnet end faces, and an armor ring covering the portion where the magnet end faces are in contact with the shaft end faces and the magnet circumferential surface. The shaft unit includes an insertion portion covered by the armor ring, a projection portion not covered by the armor ring, and a connecting portion located between the insertion portion and the projection portion and in contact with the end of the armor ring. The end of the armor ring includes a crimped portion bent to approach the axis of the shaft unit.

[0007] The motor rotor has a crimped portion at the end of the armor ring. The crimped portion is bent so as to approach the axis of the shaft unit. Therefore, it can exert a force that presses the shaft unit toward the magnet. As a result, the direction of movement of the shaft unit during thermal expansion and contraction can be determined to move toward the magnet. With this configuration, the relative positional relationship between the shaft unit and the magnet can be maintained even when thermal expansion and contraction are repeated. Therefore, the motor rotor can continue to maintain the desired performance. [Effects of the Invention]

[0008] This disclosure describes a motor rotor capable of maintaining desired performance, a motor equipped with the motor rotor, and a supercharger equipped with the motor. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a cross-sectional view of a supercharger equipped with a motor including a motor rotor according to a first embodiment. [Figure 2] Figure 2(a) is a cross-sectional view of the motor rotor shown in Figure 1. Figure 2(b) is a cross-sectional view showing an enlarged view of the main part of Figure 2(a). [Figure 3]Figure 3(a) is a cross-sectional view of a motor rotor which is a modified example 1 of the first embodiment. Figure 3(b) is a cross-sectional view of a motor rotor which is a modified example 2 of the first embodiment. [Figure 4] Figure 4(a) is a cross-sectional view of the motor rotor of the second embodiment. Figure 4(b) is a cross-sectional view of the motor rotor along the line IV-IV in Figure 4(a). [Figure 5] Figure 5(a) is a cross-sectional view of a motor rotor, which is a modified example of the second embodiment. Figure 5(b) is a cross-sectional view of the motor rotor along the VV line in Figure 5(a). [Figure 6] Figure 6 is an enlarged cross-sectional view showing the main part of the motor rotor of the third embodiment. [Figure 7] Figure 7(a) is a cross-sectional view of the main part in the process of forming a double crimp structure. Figure 7(b) is a cross-sectional view of the main part in the process of forming a double crimp structure following Figure 7(a). Figure 7(c) is a cross-sectional view of the main part in the process of forming a double crimp structure following Figure 7(b). Figure 7(d) is a cross-sectional view of the main part in the process of forming a double crimp structure following Figure 7(c). [Modes for carrying out the invention]

[0010] This disclosure includes the following components:

[0011] A motor rotor in one embodiment of the present disclosure comprises a magnet including a magnet circumferential surface and a pair of magnet end faces, a shaft unit including a shaft end face that abuts the magnet end faces, and an armor ring covering the portion where the magnet end faces are in contact with the shaft end faces and the magnet circumferential surface. The shaft unit includes an insertion portion covered by the armor ring, a projection portion not covered by the armor ring, and a connecting portion located between the insertion portion and the projection portion and in contact with the end of the armor ring. The end of the armor ring includes a crimped portion bent to approach the axis of the shaft unit.

[0012] The motor rotor has a crimped portion at the end of the armor ring. The crimped portion is bent so as to approach the axis of the shaft unit. Therefore, it can exert a force that presses the shaft unit toward the magnet. As a result, the direction of movement of the shaft unit during thermal expansion and contraction can be determined to move toward the magnet. With this configuration, the relative positional relationship between the shaft unit and the magnet can be maintained even when thermal expansion and contraction are repeated. Therefore, the motor rotor can continue to maintain the desired performance.

[0013] The connecting portion of the motor rotor may include a tapered surface that contacts the crimped portion. This configuration makes it possible to both allow thermal expansion of the shaft unit and determine the direction of movement when the shaft unit thermally contracts.

[0014] The motor rotor armor ring may include a first housing portion in which a magnet is housed, a second housing portion in which an insertion portion is located, and a third housing portion in which a connecting portion is located and which includes a ring contact surface. The connecting portion may include a shaft contact surface that contacts the ring contact surface along the axial direction of the shaft unit. This configuration allows for determining the insertion depth of the shaft unit into the armor ring.

[0015] The motor rotor's connecting portion may be sandwiched between the crimped portion and the ring contact surface. This configuration makes it possible to determine both the insertion depth of the shaft unit into the armor ring and the direction of movement when the shaft unit undergoes thermal contraction.

[0016] The outer diameter of the shaft contact surface of the motor rotor may be larger than the outer diameter of the insertion portion. This configuration ensures that the shaft unit can be reliably brought into contact with the armor ring.

[0017] The shaft end face of the motor rotor may be the end face of the insertion part. The first magnet end face may face the first shaft end face of the first shaft unit. The second magnet end face on the side opposite to the first magnet end face may face the second shaft end face of the second shaft unit. According to this configuration, a solid-type magnet can be adopted.

[0018] The magnet of the motor rotor may include a magnet through-hole that penetrates from the first magnet end face to the second magnet end face on the side opposite to the first magnet end face. The shaft unit may include a shaft member including a protruding portion and a portion inserted into the magnet through-hole, and a sleeve member including a connecting portion. According to this configuration, a hollow-type magnet can be adopted.

[0019] The connecting portion of the motor rotor may include a shaft groove. The caulking portion may include a neck portion including a portion contacting the connecting portion, and a head portion that is bent with respect to the neck portion and is disposed in the shaft groove. The head portion may include a surface that contacts the surface constituting the shaft groove. According to this configuration, the caulking portion of the armoring can be reliably hooked on the shaft unit.

[0020] Another form of the motor according to the present disclosure includes a motor rotor and a motor stator including a coil disposed around the motor rotor. The motor rotor includes a magnet including a magnet circumferential surface and a pair of magnet end faces, a shaft unit including a shaft end face that contacts the magnet end face, a portion where the magnet end face contacts the shaft end face, and a magnet circumferential surface, and an armoring that covers them. The shaft unit includes an insertion portion covered by the armoring, a protruding portion not covered by the armoring, and a connecting portion located between the insertion portion and the protruding portion and contacting the end of the armoring. The end of the armoring includes a caulking portion bent so as to approach the axis of the shaft unit. This motor includes the above-described motor rotor. Therefore, this motor can also continue to maintain desired performance.

[0021] A supercharger in yet another form of the present disclosure comprises a motor and an impeller rotated by the motor. The motor includes a motor rotor and a motor stator including coils arranged around the motor rotor. The motor rotor includes a magnet including a magnet circumferential surface and a pair of magnet end faces, a shaft unit including a shaft end face abutting the magnet end faces, and an armor ring covering the portion where the magnet end faces are in contact with the shaft end faces and the magnet circumferential surface. The shaft unit includes an insertion portion covered by the armor ring, a projection portion not covered by the armor ring, and a coupling portion located between the insertion portion and the projection portion and in contact with the end of the armor ring. The end of the armor ring includes a crimped portion bent to approach the axis of the shaft unit. This supercharger comprises the motor rotor described above. Thus, this supercharger can also maintain the desired performance.

[0022] Hereinafter, with reference to the drawings, embodiments of a motor rotor, motor, and supercharger relating to one aspect of this disclosure will be described in detail. In each figure, the same parts are denoted by the same reference numerals, and redundant explanations are omitted.

[0023] <First Embodiment> Figure 1 is a cross-sectional view of a supercharger 9 including a motor rotor 1 according to the first embodiment of this disclosure. The supercharger 9 is a vehicle supercharger equipped with a motor rotor 1. In the following description, when "axial direction," "radial direction," and "circumferential direction" are used, they refer to the axial direction, radial direction, and circumferential direction of the T-shaft 4, which will be described later.

[0024] As shown in Figure 1, the supercharger 9 is an electric supercharger. The supercharger 9 is applied, for example, to an internal combustion engine in a ship or vehicle. The supercharger 9 has a turbine 91, a compressor 92, and a motor 8. The supercharger 9 is required to generate compressed air in a predetermined state. To generate compressed air, the rotating body 8R needs to have a predetermined torque. This torque is generated by the exhaust gas of the internal combustion engine. However, the torque generated by the exhaust gas of the internal combustion engine may not be sufficient to generate compressed air in a predetermined state. Therefore, the motor 8 generates auxiliary torque to compensate for the insufficient torque.

[0025] The turbine 91 comprises a turbine housing 911 and a turbine impeller 912. The turbine housing 911 houses the turbine impeller 912. The turbine housing 911 has a scroll flow path 914. The scroll flow path 914 extends circumferentially around the turbine impeller 912.

[0026] The turbine housing 911 has an inlet 913 and an outlet 915. Exhaust gas discharged from the internal combustion engine flows into the turbine housing 911 through the inlet 913. The exhaust gas flows into the turbine impeller 912 through the scroll passage 914. The exhaust gas rotates the turbine impeller 912. The exhaust gas then flows out of the turbine housing 911 through the outlet 915.

[0027] The compressor 92 comprises a compressor housing 921 and a compressor impeller 922. The compressor housing 921 houses the compressor impeller 922. The compressor housing 921 has a scroll channel 924. The scroll channel 924 extends circumferentially around the compressor impeller 922.

[0028] The compressor housing 921 has an intake port 923 and a discharge port 925. When the turbine impeller 912 rotates, the compressor impeller 922 rotates via a rotating body 8R, which will be described later. The rotating compressor impeller 922 draws in outside air through the intake port 923. The drawn-in air is compressed as it passes through the compressor impeller 922 and the scroll passage 924. The air is discharged as compressed air from the discharge port 925. The compressed air is supplied to the internal combustion engine.

[0029] Motor 8 is, for example, a brushless DC motor. Motor 8 includes a motor rotor 1, a motor stator 7, and a motor housing 94.

[0030] The motor rotor 1 is housed in the motor housing 94. In the axial direction, the motor rotor 1 is positioned between bearings 951 and 952. The motor stator 7 is also housed in the motor housing 94. In the axial direction, the motor stator 7 is positioned approximately at the same location as the motor rotor 1. The motor stator 7 surrounds the motor rotor 1. The inner circumferential surface of the motor stator 7 is spaced apart from the outer circumferential surface of the motor rotor 1.

[0031] The motor rotor 1, T-shaft 4, and C-shaft 3 constitute a rotating body 8R. The rotating body 8R is rotatably supported with respect to the turbine housing 911 and the compressor housing 921. A turbine impeller 912 is provided at one end of the T-shaft 4. A compressor impeller 922 is provided at one end of the C-shaft 3.

[0032] The C shaft 3 has a thrust collar 931. The thrust collar 931 protrudes radially from the C shaft 3. The shape of the thrust collar 931 is, for example, disc-shaped. A pair of air bearings 961 and 962 are provided on both sides of the thrust collar 931. A spacer 97 is provided between the pair of air bearings 961 and 962, surrounding the thrust collar 931.

[0033] A pair of air bearings 961, 962 and a spacer 97 are joined together by a number of fastening bolts. The air bearings 961, 962 and the spacer 97 support the C shaft 3 in the thrust direction. The thrust collar 931 is rotatable without contacting the air bearings 961, 962 and the spacer 97.

[0034] <Motor Rotor> Figure 2(a) is a cross-sectional view of the motor rotor 1. Figure 2(b) is an enlarged view of the main part D shown in Figure 2(a). The motor rotor 1 includes a magnet 2, a C shaft 3 (shaft unit), a T shaft 4 (shaft unit), and an armor ring 5. The C shaft 3 and T shaft 4 are components of the T shaft 4 described above.

[0035] <Magnet> The shape of magnet 2 is cylindrical. Magnet 2 is solid. Magnet 2 does not have a through hole. Magnet 2 has a magnet circumferential surface 21, a first magnet end face 22, and a second magnet end face 23. The material of magnet 2 may be, for example, neodymium (Nd-Fe-B) or samarium cobalt.

[0036] <Cシャフト> The C shaft 3 is connected to the compressor impeller 922. The C shaft 3 has a C shaft insertion portion 31, a C shaft projection portion 32, and a C shaft connecting portion 33. These parts are integrated.

[0037] The shape of the C-shaft insertion portion 31 is cylindrical. The C-shaft insertion portion 31 has a C-shaft end face 311 and a C-shaft friction surface 312. The C-shaft insertion portion 31 is covered by the armor ring 5. More specifically, the C-shaft insertion portion 31 is positioned in an interference fit with respect to the armor ring 5. The outer diameter of the C-shaft insertion portion 31 is the same as the outer diameter of the magnet 2. In other words, the outer diameter of the C-shaft insertion portion 31 is the same as the inner diameter of the armor ring 5.

[0038] The C-shaft end face 311 is in contact with the first magnet end face 22. The C-shaft end face 311 only needs to be in contact with the first magnet end face 22 and does not need to be fixed with adhesive or anything like that.

[0039] The shape of the C-shaft projection 32 is cylindrical. The C-shaft projection 32 is not covered by the armor ring 5. A compressor impeller 922 is connected to the tip of the C-shaft projection 32 (see Figure 1). In the example shown in Figure 2(a), the outer diameter of the C-shaft projection 32 is smaller than the outer diameter of the C-shaft insertion portion 31. The relationship between the outer diameter of the C-shaft projection 32 and the outer diameter of the C-shaft insertion portion 31 is not limited to the size relationship shown in Figure 2(a). For example, the outer diameter of the C-shaft projection 32 may be the same as the outer diameter of the C-shaft insertion portion 31.

[0040] The C-shaft connecting portion 33 is provided between the C-shaft insertion portion 31 and the C-shaft protruding portion 32. Part of the C-shaft connecting portion 33 is covered by the armor ring 5. Another part of the C-shaft connecting portion 33 protrudes from the armor ring 5. The length of the C-shaft insertion portion 31 along the direction of the rotation axis H is longer than the length of the C-shaft connecting portion 33 along the direction of the rotation axis H.

[0041] The C-shaft connecting portion 33 has an inward contact surface 331 of the C-shaft, an outer circumferential surface 332 of the C-shaft, a tapered surface 333 of the C-shaft, and a connecting surface 334 of the C-shaft. The inward contact surface 331 of the C-shaft, the outer circumferential surface 332 of the C-shaft, and the tapered surface 333 of the C-shaft constitute the C-shaft flange portion 33S.

[0042] The inward contact surface 331 of the C shaft faces the same direction as the end face 311 of the C shaft. The shape of the inward contact surface 331 of the C shaft is annular when viewed from the direction of the rotation axis H. The inner diameter of the inward contact surface 331 of the C shaft is the same as the outer diameter of the C shaft insertion portion 31. The outer diameter of the inward contact surface 331 of the C shaft is larger than the outer diameter of the C shaft insertion portion 31. The C shaft connecting portion 33 includes a portion that is thicker than the C shaft insertion portion 31.

[0043] The inward contact surface 331 of the C shaft contacts the ring contact surface 522, which will be described later. The inward contact surface 331 of the C shaft is housed in the armor ring 5. Specifically, the inward contact surface 331 of the C shaft is pressed against the ring contact surface 522. As a result, the insertion depth of the C shaft 3 into the armor ring 5 is determined. The outer circumferential surface 332 of the C shaft is a cylindrical surface. The first edge of the outer circumferential surface 332 of the C shaft is the outer circumferential edge of the inward contact surface 331 of the C shaft. The second edge of the outer circumferential surface 332 of the C shaft is the first edge of the tapered surface 333 of the C shaft.

[0044] The outer circumferential surface 332 of the C shaft faces the inner circumferential surface 523d ​​of the crimp, which will be described later. The outer circumferential surface 332 of the C shaft is housed in the armor ring 5. In the example shown in Figure 2(b), the outer circumferential surface 332 of the C shaft is not in contact with the inner circumferential surface 523d ​​of the crimp. A gap exists between the outer circumferential surface 332 of the C shaft and the inner circumferential surface 523d ​​of the crimp. Therefore, the outer diameter of the outer circumferential surface 332 of the C shaft is slightly smaller than the inner diameter of the inner circumferential surface 523d ​​of the crimp. The length of the outer circumferential surface 332 of the C shaft along the direction of the rotation axis H is approximately the same as the length of the inner circumferential surface 523d ​​along the direction of the rotation axis H.

[0045] The tapered surface 333 of the C shaft connects the outer circumferential surface 332 of the C shaft to the C shaft connection surface 334. The outer diameter of the tapered surface 333 decreases along the direction from the C shaft insertion portion 31 toward the C shaft connection surface 334. For example, with respect to the axis of rotation H, the angle K from the axis of rotation H to the tapered surface 333 of the C shaft is between 20 degrees and 90 degrees. In the example shown in Figure 2(b), the angle K from the axis of rotation H to the tapered surface 333 of the C shaft is 45 degrees.

[0046] A portion of the C-shaft tapered surface 333 is covered by the armor ring 5. The C-shaft insertion portion 31 side of the C-shaft tapered surface 333 is covered by the ring crimping portion 523 of the armor ring 5. More specifically, the ring crimping portion 523 is in contact with the C-shaft tapered surface 333. In this contact, the entire surface of the ring crimping portion 523 may be in contact with the C-shaft tapered surface 333, or a portion of the ring crimping portion 523 may be in contact with the C-shaft tapered surface 333. For example, the tip of the ring crimping portion 523 may be in contact with the C-shaft tapered surface 333.

[0047] Another portion of the C-shaft tapered surface 333 protrudes from the armor ring 5. The length of the C-shaft tapered surface 333 along the direction of the rotation axis H is longer than the length of the ring crimping portion 523 along the direction of the rotation axis H.

[0048] The C-shaft connection surface 334 connects the C-shaft flange portion 33S to the C-shaft projection portion 32. The C-shaft connection surface 334 is a circumferential surface. The outer diameter of the C-shaft connection surface 334 is constant.

[0049] The functional relationship between the C shaft 3 and the armor ring 5 can be described as follows:

[0050] Firstly, the C shaft 3 is fixed to the armor ring 5. More specifically, the outer surface of the C shaft, the friction surface 312, is in contact with the ring friction surface 521. The C shaft friction surface 312 is subjected to a pressing force from the ring friction surface 521. This pressing force generates a frictional force between the C shaft friction surface 312 and the ring friction surface 521. This frictional force fixes the C shaft 3 to the armor ring 5.

[0051] Secondly, the position of the C-shaft 3 relative to the armor ring 5 is maintained by the armor ring 5. More specifically, the C-shaft flange 33S of the C-shaft connector 33 is sandwiched between the ends of the armor ring 5. As a result, the position of the C-shaft connector 33 along the axis of rotation H is maintained. This maintenance includes suppressing movement of the C-shaft connector 33 along the axis of rotation H. This maintenance also includes restoring the position of the C-shaft connector 33 that has moved along the axis of rotation H to its original position.

[0052] <Tシャフト> The T-shaft 4 is connected to the turbine impeller 912. The T-shaft 4 has approximately the same configuration as the C-shaft 3. The T-shaft 4 has a T-shaft insertion portion 41, a T-shaft projection portion 42, and a T-shaft connecting portion 43. The difference between the T-shaft 4 and the C-shaft 3 is that the T-shaft connecting portion 43 does not include the portion corresponding to the C-shaft connection surface 334. The length of the T-shaft tapered surface 432 along the direction of the rotation axis H is the same as the length of the ring crimping portion 533 along the direction of the rotation axis H. Despite these differences, the T-shaft 4 can perform the same function as the C-shaft 3. The T-shaft 4 is fixed to the armor ring 5. The position of the T-shaft 4 relative to the armor ring 5 is maintained by the armor ring 5.

[0053] <Armoring> The armor ring 5 prevents damage to the magnet 2 caused by centrifugal force. The shape of the armor ring 5 is cylindrical. The armor ring 5 houses the magnet 2. The armor ring 5 covers a portion of the C shaft 3 and a portion of the T shaft 4.

[0054] The armor ring 5 has a first ring housing section 51, a second ring housing section 52, and a third ring housing section 53. The first ring housing section 51 houses the magnet 2. The second ring housing section 52 houses the C shaft 3. The third ring housing section 53 houses the T shaft 4. The first ring housing section 51 is sandwiched between the second ring housing section 52 and the third ring housing section 53. Because the T shaft 4 has a configuration that is roughly the same as the C shaft 3, the third ring housing section 53 that houses the T shaft 4 also has a configuration that is roughly the same as the second ring housing section 52 that houses the C shaft 3. Therefore, a detailed explanation of the third ring housing section 53 will be omitted, and the second ring housing section 52 will be explained in detail.

[0055] The second ring housing portion 52 has a ring friction surface 521, a ring contact surface 522, and a ring crimping portion 523. The ring friction surface 521 is in contact with the C shaft friction surface 312 of the C shaft insertion portion 31. The inner diameter of the ring friction surface 521 is the same as the inner diameter of the first ring housing portion 51. There is no explicit boundary between the inner circumferential surface 511 of the first ring housing portion 51 and the ring friction surface 521.

[0056] The ring contact surface 522 is pressed against the C shaft inward contact surface 331. The shape of the ring contact surface 522 is annular when viewed from the direction of the rotation axis H. The inner diameter of the ring contact surface 522 is the same as the inner diameter of the ring friction surface 521. The outer diameter of the ring contact surface 522 may be slightly smaller than the inner diameter of the ring crimping portion 523.

[0057] The ring crimping portion 523 is thinner than the first ring housing portion 51. Referring to the cross-sectional shape shown in Figure 2(b), the cross-sectional shape of the ring crimping portion 523 can be described as a cantilever beam. When a force perpendicular to the axis of rotation H is applied to the tip of the ring crimping portion 523, the ring crimping portion 523 deforms in the direction of the force. For example, the ring crimping portion 523 deforms by bending in the direction of the force. The plastically deformed portion of the ring crimping portion 523 is referred to as the crimped deformed portion 523a. The crimped deformed portion 523a includes a crimped contact portion 523b that contacts the C shaft tapered surface 333. The portion of the ring crimping portion 523 that does not deform is referred to as the crimped non-deformed portion 523c. The crimped non-deformed portion 523c has a crimped inner circumferential surface 523d.

[0058] Due to this deformation, the C shaft flange portion 33S is sandwiched between the crimped deformation portion 523a and the ring contact surface 522. The ring crimping portion 523 exerts a force that presses the C shaft 3 toward the magnet 2 along the rotation axis H.

[0059] The crimped deformation portion 523a can elastically deform in accordance with the deformation of the C shaft 3. For example, suppose the C shaft 3 is stretched in the direction of the rotation axis H as a result of being exposed to a high-temperature environment. In this case, the tapered surface 333 of the C shaft moves to the right side of the plane of the paper in Figure 2(b). Along with this movement, the crimped deformation portion 523a can also bend. Since this deformation is slight, the deformation of the crimped deformation portion 523a does not reach the plastic deformation region. The deformation of the crimped deformation portion 523a remains in the elastic deformation region.

[0060] Next, we assume that when the C shaft 3 is returned from a high-temperature environment to a room-temperature environment, the elongation in the direction of the rotation axis H is eliminated and it returns to its original length. Movement of the C shaft 3 occurs due to the contraction of the C shaft 3. The C shaft 3 is subjected to a force from the crimped deformation portion 523a that presses the inward contact surface 331 of the C shaft against the ring contact surface 522. As a result, the direction of movement of the C shaft 3 due to the contraction of the C shaft 3 is uniquely determined by the force originating from the crimped deformation portion 523a. The direction of movement of the C shaft 3 due to the contraction of the C shaft 3 is always in the direction that presses the inward contact surface 331 of the C shaft against the ring contact surface 522.

[0061] Therefore, even if the C-shaft 3 expands and contracts repeatedly, when the C-shaft 3 contracts, it can return to its original position. Consequently, even if the C-shaft 3 expands and contracts repeatedly, there will be no misalignment in the positional relationship between the C-shaft 3 and the armor ring 5. Similarly, there will be no misalignment in the positional relationship between the C-shaft 3 and the magnet 2.

[0062] If the direction of movement of the C shaft 3 is not uniquely determined, the changes caused by the expansion and contraction of the C shaft 3 are irreversible. As a result, each time the C shaft 3 expands and contracts, the deviation from its original state accumulates. If the accumulation of deviations becomes large, the motor rotor 1 will have difficulty performing as desired. Therefore, in the motor rotor 1 of this disclosure, the direction of movement of the C shaft 3 caused by the contraction of the C shaft 3 is uniquely determined by the force generated by the crimped deformation portion 523a. As a result, the changes caused by the expansion and contraction of the C shaft 3 become reversible. Even if the C shaft 3 expands and contracts repeatedly, it can return to its original state. As a result, deviations do not accumulate. Therefore, the motor rotor 1 can maintain a state in which it can perform as desired.

[0063] The motor rotor 1 described above includes a magnet 2 including a magnet circumferential surface 21, a first magnet end face 22, and a second magnet end face 23; a C shaft 3 including a C shaft end face 311 that abuts against the first magnet end face 22; and an armor ring 5 covering the portion where the first magnet end face 22 contacts the C shaft end face 311 and the magnet circumferential surface 21. The C shaft 3 includes a C shaft insertion portion 31 covered by the armor ring 5, a C shaft projection portion 32 not covered by the armor ring 5, and a C shaft connecting portion 33 located between the C shaft insertion portion 31 and the C shaft projection portion 32 and in contact with the end of the armor ring 5. The end of the armor ring 5 includes a ring crimping portion 523 that is bent to approach the rotation axis H of the C shaft 3.

[0064] The motor rotor 1 has a ring crimping portion 523 provided at the end of the armor ring 5. The ring crimping portion 523 is bent so as to approach the rotation axis H of the C shaft 3, and can exert a force that presses the C shaft 3 toward the magnet 2. As a result, the direction of movement of the C shaft 3 that occurs during thermal expansion and contraction can be determined to be toward the magnet 2. With this configuration, the relative positional relationship between the C shaft 3 and the magnet 2 can be maintained even when thermal expansion and contraction are repeated. Therefore, the motor rotor 1 can continue to maintain the desired performance.

[0065] The C-shaft connecting portion 33 includes a C-shaft tapered surface 333 that contacts the ring crimping portion 523. This configuration makes it possible to both accommodate the thermal expansion of the C-shaft 3 and determine the direction of movement when the C-shaft 3 thermally contracts.

[0066] The armor ring 5 includes a first ring housing portion 51 that houses the magnet 2, a second ring housing portion 52 where the C shaft insertion portion 31 is located, and a third ring housing portion 53 where the C shaft connecting portion 33 is located and which includes a ring contact surface 522. The C shaft connecting portion 33 includes a C shaft inward contact surface 331 that contacts the ring contact surface 522 along the rotation axis H of the C shaft 3. This configuration allows for determining the insertion depth of the C shaft 3 into the armor ring 5.

[0067] The C-shaft connecting portion 33 is sandwiched between the ring crimping portion 523 and the ring contact surface 522. This configuration makes it possible to determine both the insertion depth of the C-shaft 3 into the armor ring 5 and the direction of movement when the C-shaft 3 undergoes thermal contraction.

[0068] The outer diameter of the inward contact surface 331 of the C shaft is larger than the outer diameter of the C shaft insertion portion 31. This configuration ensures that the C shaft 3 can be reliably brought into contact with the armor ring 5.

[0069] The C-shaft end face 311 is in contact with the first magnet end face 22. The T-shaft end face 411 faces the second magnet end face 23, which is on the opposite side of the first magnet end face 22. With this configuration, a solid magnet 2 can be used.

[0070] The motor 8 comprises a motor rotor 1 and a motor stator 7 including coils arranged around the motor rotor 1. This motor 8 has the motor rotor 1 described above. Therefore, this motor 8 can also maintain the desired performance.

[0071] The supercharger 9 comprises a motor 8 and a compressor impeller 922 rotated by the motor 8. The motor 8 includes a motor rotor 1 and a motor stator 7 including coils arranged around the motor rotor 1. The supercharger 9 is equipped with the motor rotor 1 described above. Therefore, this supercharger 9 can also maintain the desired performance.

[0072] Below, two modified examples of the motor rotor 1 of the first embodiment will be described.

[0073] <Modification 1 of the first embodiment> Figure 3(a) shows a motor rotor 1A, which is a modification 1 of the first embodiment. The motor rotor 1A of modification 1 differs from the motor rotor 1 of the first embodiment in that the angle of the ring crimping portion 523A with respect to the rotation axis H is approximately 90°. Below, the structure of the motor rotor 1A of modification 1 that differs from the motor rotor 1 of the first embodiment will be described in detail. Regarding the structure of the motor rotor 1A of modification 1, parts that are common with the structure of the motor rotor 1 of the first embodiment will be omitted from the explanation as appropriate.

[0074] The C-shaft connecting portion 33A of the C-shaft 3A has an inward contact surface 331 of the C-shaft, an outer peripheral surface 332 of the C-shaft, a C-shaft connecting surface 334, and an outward contact surface 335 of the C-shaft.

[0075] The C-shaft outward contact surface 335 corresponds to the C-shaft tapered surface 333 of the first embodiment. The ring crimping portion 523A contacts the C-shaft outward contact surface 335. The ring crimping portion 523A may apply a pressing force to the C-shaft outward contact surface 335. The ring crimping portion 523A may simply be in contact with the C-shaft outward contact surface 335.

[0076] The outward contact surface 335 of the C shaft is at an angle of 90° with respect to the axis of rotation H. The orientation of the outward contact surface 335 of the C shaft is opposite to that of the inward contact surface 331 of the C shaft. The shape of the outward contact surface 335 of the C shaft is annular when viewed from the direction of the axis of rotation H.

[0077] The outer diameter of the C-shaft outward contact surface 335 is the same as the outer diameter of the C-shaft outer circumferential surface 332. The inner diameter of the C-shaft outward contact surface 335 is smaller than the outer diameter of the C-shaft inward contact surface 331. The inner diameter of the C-shaft outward contact surface 335 is the same as the outer diameter of the C-shaft connection surface 334.

[0078] The armor ring 5A has a ring crimping portion 523A. In the armor ring 5A of the modified example 1, the shape before the formation of the ring crimping portion 523A is the same as that of the armor ring 5 of the first embodiment. In the modified example 1, the structure of the C shaft connecting portion 33A is different from the structure of the C shaft connecting portion 33 of the first embodiment. In the modified example 1, the shape of the armor ring 5A after the formation of the ring crimping portion 523A is different from that of the armor ring 5 of the first embodiment.

[0079] The ring crimping portion 523A is bent from the portion including the crimping inner circumferential surface 523d. Even with this structure, the C shaft flange portion 33S is sandwiched between the ring crimping portion 523A and the ring contact surface 522. In the case of Modification 1, the bending angle of the ring crimping portion 523A is approximately 90°. Therefore, the ring crimping portion 523A can generate a strong counterforce with respect to the direction of movement of the C shaft 3 (from left to right in Figure 3(a)). As a result, the ring crimping portion 523A of Modification 1 can more strongly suppress the movement of the C shaft connecting portion 33A along the rotation axis H.

[0080] <Modification 2 of the first embodiment> Figure 3(b) shows a motor rotor 1B, which is a modification 2 of the first embodiment. The motor rotor 1B of modification 2 differs from the motor rotor 1 of the first embodiment in that it does not have an inward contact surface 331 on the C shaft. The motor rotor 1B of modification 2 also differs from the motor rotor 1 of the first embodiment in that the armor ring 5B does not have a ring contact surface 522. Below, the structure of the motor rotor 1B of modification 2 that differs from the motor rotor 1 of the first embodiment will be described in detail. Regarding the structure of the motor rotor 1B of modification 2, parts that are common with the structure of the motor rotor 1 of the first embodiment will be omitted from the explanation as appropriate.

[0081] The C-shaft connecting portion 33B of the C-shaft 3B has a C-shaft tapered surface 333 and a C-shaft connecting surface 334. One edge of the C-shaft tapered surface 333 coincides with the edge of the C-shaft insertion portion 31. In the modified example 2, the maximum outer diameter of the C-shaft tapered surface 333 is the same as the outer diameter of the C-shaft insertion portion 31.

[0082] In the modified example 2, the motor rotor 1B does not have an inward contact surface 331 for the C shaft, so it is not possible to determine the insertion depth of the C shaft 3. In the first embodiment, which has an inward contact surface 331 for the C shaft, the C shaft 3 could be inserted into the armor ring 5 until the inward contact surface 331 for the C shaft contact surface 522 contacted the ring contact surface 522. When the inward contact surface 331 for the C shaft contact surface 522 contacts the ring contact surface 522, the end face 311 of the C shaft is in contact with the first magnet end face 22, or a very small gap is formed between the end face 311 of the C shaft and the first magnet end face 22. In the modified example 2, the C shaft 3B can be inserted into the armor ring 5 until it contacts the magnet 2. As a result, in the modified example 2, the end face 311 of the C shaft 3 contacts the first magnet end face 22.

[0083] The motor rotor 1B of the modified example 2 also includes a C-shaft tapered surface 333 and a ring crimping portion 523. Therefore, the function of maintaining the position of the C-shaft 3B relative to the armor ring 5B can be achieved in the same way.

[0084] <Second Embodiment> The motor rotor 1C of the second embodiment will be described with reference to Figures 4(a) and 4(b). Figure 4(b) is a cross-sectional view along the line IV-IV in Figure 4(a). The motor rotor 1 of the first embodiment used a solid magnet 2. The motor rotor 1C of the second embodiment uses a hollow magnet 2C.

[0085] The motor rotor 1C has two magnets 2C, one shaft 61, and two sleeves 62. The magnets 2C are of the so-called hollow type. The magnets 2C have a magnet through hole 21C, a first magnet end face 22C, and a second magnet end face 23C. The shape of the magnets 2C is cylindrical. The shaft 61 is inserted through the magnet through hole 21C.

[0086] The shaft unit 6C of the motor rotor 1C in the second embodiment is composed of one shaft 61 and two sleeves 62.

[0087] The sleeve 62 corresponds to the C shaft connecting portion 33 of the first embodiment. The sleeve 62 has a sleeve through hole 62h. The shaft 61 is inserted through this sleeve through hole 62h. For example, the sleeve 62 is attached to the shaft 61 by shrink fitting or the like.

[0088] Two magnets 2C are positioned between the first sleeve 62 and the second sleeve 62. The sleeves 62 are fixed to the shaft 61. This fixing maintains the position of the magnets 2C.

[0089] The sleeve 62 includes a sleeve contact surface 621, a sleeve outer circumferential surface 622, a sleeve tapered surface 623, a sleeve friction surface 624, a sleeve end surface 625, and a sleeve front surface 626. The sleeve contact surface 621 corresponds to the inward contact surface 331 of the C shaft. The sleeve outer circumferential surface 622 corresponds to the outer circumferential surface 332 of the C shaft. The sleeve tapered surface 623 corresponds to the tapered surface 333 of the C shaft. The sleeve friction surface 624 corresponds to the friction surface 312 of the C shaft of the magnet 2. The sleeve end surface 625 contacts the magnet end surface 22 or magnet end surface 23 of the magnet 2.

[0090] With this structure, when the shaft 61, which has expanded due to exposure to high temperatures, contracts, the direction of contraction can be determined to be from the sleeve 62 toward the magnet 2C. As a result, even if a gap is created between the ring contact surface 522 and the sleeve contact surface 621 when the shaft 61 has expanded due to exposure to high temperatures, when it returns to room temperature and the shaft 61 has contracted, the sleeve contact surface 621 can return to contact the ring contact surface 522.

[0091] The magnet 2C of the motor rotor 1C includes a magnet through-hole 21C that penetrates from the first magnet end face 22C to the second magnet end face 23C on the opposite side of the first magnet end face 22C. The shaft unit 6C includes a shaft 61 and a sleeve 62. With this configuration, a hollow type magnet 2C can be used.

[0092] <Modified form of the second embodiment> The magnet 2C of the second embodiment was a single, cylindrical component even when it was in the state of being a separate part. Figure 5(a) is a cross-sectional view of a modified motor rotor 1D of the second embodiment. Figure 5(b) is a cross-sectional view of the motor rotor 1D along the VV line in Figure 5(a). As shown in Figures 5(a) and 5(b), the magnet 2D may be composed of a plurality of magnet pieces 2D1, 2D2, 2D3, and 2D4, respectively. The plurality of magnet pieces 2D1, 2D2, 2D3, and 2D4 each have a fan-shaped cross-section (see Figure 5(b)). The magnet 2D includes a first magnet end face 22D and a second magnet end face 23D. The magnet 2D also has a sleeve 62, which is the same as the sleeve 62 of the magnet 2C of the second embodiment.

[0093] <Third Embodiment> A motor rotor 1E of the third embodiment will now be described. As shown in Figure 2(b), in the first embodiment, the crimping contact portion 523b of the ring crimping portion 523 was in contact with the C shaft tapered surface 333. As shown in Figure 6, in the motor rotor 1E of the third embodiment, the crimping head 56 of the ring crimping portion 523E is fitted into the C shaft groove 35 provided in the C shaft tapered surface 333E. In the following description, the structure in which the crimping head 56 is fitted into the C shaft groove 35 will be referred to as the "double crimping structure". As an example of the third embodiment, the case in which the double crimping structure is applied to the C shaft 3 of the motor rotor 1 of the first embodiment will be described. The double crimping structure can also be applied to the T shaft 4 of the motor rotor 1 of the first embodiment.

[0094] Similarly, the double crimping structure can also be applied to the motor rotor 1A of Modification 1 of the First Embodiment (see Figure 3(a)) and the motor rotor 1B of Modification 2 of the First Embodiment (see Figure 3(b)). The double crimping structure can also be applied to the motor rotor 1C of the Second Embodiment (see Figure 4(a)). The double crimping structure can also be applied to the motor rotor 1D of Modification 2 of the Second Embodiment (see Figure 4(b)).

[0095] The C shaft 3E has a C shaft connecting portion 33E. The C shaft connecting portion 33E has an inward contact surface 331 of the C shaft, an outer circumferential surface 354 of the C shaft, and a tapered surface 333E of the C shaft.

[0096] A C-shaft groove 35 is provided on the C-shaft tapered surface 333E. The C-shaft groove 35 is a recessed portion extending from the C-shaft tapered surface 333E along the direction normal to the C-shaft tapered surface 333E. The C-shaft groove 35 may extend in an arc shape around the axis of rotation H on the conical C-shaft tapered surface 333E. The C-shaft groove 35 may be a continuous recess. The C-shaft groove 35 may be provided at predetermined arrangement angles with respect to the axis of rotation H. For example, the C-shaft groove 35 may be configured as four grooves provided at 90-degree intervals with respect to the axis of rotation H.

[0097] The C-shaft groove 35 is the region enclosed by the rear surface 351 of the C-shaft groove, the front surface 352 of the C-shaft groove, and the bottom surface 353 of the C-shaft groove. The tip (crimping head 56) of the ring crimping portion 523 is fitted into the C-shaft groove 35. The armor ring 5E has the ring crimping portion 523E.

[0098] The ring crimping portion 523E has a crimping neck portion 55 and a crimping head portion 56. The crimping neck portion 55 extends from the outer circumference of the ring contact surface 522 in the direction of the rotation axis H. The thickness of the crimping neck portion 55 becomes thinner towards the tip (see Figure 7(a)). The inner surface of the crimping neck portion 55 is referred to as the inner circumferential surface 551 of the crimping neck.

[0099] The crimping head 56 is provided at the tip of the crimping neck 55. The crimping head 56 has a crimping head rear surface 561, a crimping head front surface 562, and a crimping head bottom surface 563. The crimping head rear surface 561 connects to the inner circumferential surface 551 of the crimping neck. When the crimping head 56 is fitted into the C shaft groove 35, the crimping head rear surface 561 is in contact with the C shaft groove rear surface 351. The crimping head front surface 562 faces the C shaft groove front surface 352. There is a small gap between the crimping head front surface 562 and the C shaft groove front surface 352. The crimping head bottom surface 563 faces the C shaft groove bottom surface 353. There is also a small gap between the crimping head bottom surface 563 and the C shaft groove bottom surface 353.

[0100] The function of the ring crimping portion 523E will be explained in detail. The ring crimping portion 523E prevents the crimping head 56 from coming off the C shaft groove 35 by having the crimping head 56 catch on the C shaft groove 35.

[0101] The Armor Ring 5E is made of a heat-resistant and high-strength material such as Inconel. For example, Inconel, a high-strength material, has higher strength than steel materials such as mild steel. During the crimping process, when force is applied to the tip of the ring crimping portion 523E, even if the tip of the ring crimping portion 523E is in contact with the C-shaft tapered surface 333E, when the force applied to the tip of the ring crimping portion 523E is released, the tip of the ring crimping portion 523E will try to return slightly to its original state. This phenomenon is called springback. For example, when springback occurs, a small gap may be created between the tip of the ring crimping portion 523E and the C-shaft tapered surface 333E.

[0102] The double crimping structure exerts a force that counteracts the force FS that causes this springback. As a result, the state in which the crimping head 56 is caught in the C shaft groove 35 is maintained. As shown in Figure 6, the rear surface 561 of the crimping head is in contact with the rear surface 351 of the C shaft groove. The force FS that causes springback has a component that presses the rear surface 561 of the crimping head against the rear surface 351 of the C shaft groove. The rear surface 561 of the crimping head is pressed against the rear surface 351 of the C shaft groove. As a result, a frictional force FR is generated between the rear surface 561 of the crimping head and the rear surface 351 of the C shaft groove. The frictional force FR can counteract the force FS that causes springback.

[0103] The process of forming the double crimp structure will be explained with reference to Figures 7(a) to 7(d).

[0104] Figure 7(a) shows the state immediately before the crimping operation begins. Before the crimping operation begins, the crimp neck portion 55 is not bent. In this configuration, a force FP is applied to the crimp head 56.

[0105] Figure 7(b) shows a state in which the crimp neck 55 is slightly bent from the state shown in Figure 7(a). In this state, the crimp neck 55 bends in the direction of force FP, starting from the corner 57 between the inner circumferential surface 551 of the crimp neck and the ring contact surface 522. In this state, the crimp neck 55 and the crimp head 56 bend together as a single unit. Therefore, the relative positional relationship between the crimp neck 55 and the crimp head 56 does not change.

[0106] Figure 7(c) shows the result of applying a further force FP to the crimp head 56 from the state shown in Figure 7(b). In this state, the inner circumferential surface 551 of the crimp neck is in contact with the outer circumferential surface 354 of the C shaft (see point 58). In this state, the crimp head 56 is fitted into the C shaft groove 35. The rear surface 561 of the crimp head is not in contact with the rear surface 351 of the C shaft groove. The crimp head 56 is not caught in the C shaft groove 35.

[0107] Figure 7(d) shows the result of applying a further force FP to the crimp head 56 from the state shown in Figure 7(c). In the state of Figure 7(c), the inner circumferential surface 551 of the crimp neck is in contact with the outer circumferential surface 332 of the C shaft (point 58). Therefore, when a further force FP is applied from the state of Figure 7(c), the part bends from point 58 towards the tip. The crimp neck portion 55 does not bend. The crimp head 56 bends relative to the crimp neck portion 55. Due to this bending, the rear surface 561 of the crimp head gradually approaches the rear surface 351 of the C shaft groove. Finally, the rear surface 561 of the crimp head comes into contact with the rear surface 351 of the C shaft groove.

[0108] The double crimping structure is formed by two bends: the crimping neck 55 is bent relative to the ring body 5S, which includes the ring friction surface 521, and the crimping head 56 is bent relative to the crimping neck 55. Because it is formed by these two bends, it is called a "double crimping structure".

[0109] When the force FP is released, springback occurs as described above. This springback causes the rear surface 561 of the crimp head to press against the rear surface 351 of the C shaft groove, so the crimp head 56 does not come out of the C shaft groove 35.

[0110] The C-shaft connecting portion 33E of the motor rotor 1E includes a C-shaft groove 35. The ring crimping portion 523E includes a crimping neck portion 55 that includes a portion (point 58) that contacts the C-shaft connecting portion 33E, and a crimping head portion 56 that includes a portion that is positioned in the C-shaft groove 35. The crimping head portion 56 includes a crimping head rear surface 561 that contacts the rear surface 351 of the C-shaft groove. With this configuration, the ring crimping portion 523E of the armor ring 5E can be securely hooked onto the C-shaft 3E.

[0111] The motor rotor, motor, and supercharger of this disclosure are not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the present invention.

[0112] The motor rotor of the present disclosure is a motor rotor comprising: [1] a magnet including a magnet circumferential surface and a pair of magnet end faces; a shaft unit including a shaft end face that abuts the magnet end faces; an armor ring covering the portion of the magnet end faces that contacts the shaft end faces and the magnet circumferential surface, wherein the shaft unit includes an insertion portion covered by the armor ring, a protruding portion not covered by the armor ring, and a connecting portion located between the insertion portion and the protruding portion and in contact with the end of the armor ring, and the end of the armor ring includes a crimped portion bent to approach the axis of the shaft unit.

[0113] The motor rotor of the present disclosure is [2] "the motor rotor according to [1] above, wherein the connecting portion includes a tapered surface in contact with the crimped portion."

[0114] The motor rotor of the present disclosure is [3] "the motor rotor according to [1] or [2] above, wherein the armor ring includes a first housing portion in which the magnet is housed, a second housing portion in which the insertion portion is arranged, and a third housing portion in which the connecting portion is arranged and which includes a ring contact surface, the connecting portion including a shaft contact surface that contacts the ring contact surface along the axial direction of the shaft unit."

[0115] The motor rotor of the present disclosure is [4] "the motor rotor according to [3] above, wherein the connecting portion is sandwiched between the crimping portion and the ring contact surface."

[0116] The motor rotor of the present disclosure is [5] "the motor rotor according to [3] or [4] above, wherein the outer diameter of the shaft contact surface is larger than the outer diameter of the insertion portion."

[0117] The motor rotor of the present disclosure is [6] "the motor rotor according to any one of [1] to [5] above, wherein the shaft end face is the end face of the insertion portion, the first shaft end face of the first shaft unit is in contact with the first magnet end face, and the second shaft end face of the second shaft unit is in contact with the second magnet end face on the side opposite to the first magnet end face."

[0118] The motor rotor of the present disclosure is [7] "the motor rotor according to any one of [1] to [5] above, wherein the magnet includes a magnet through-hole that penetrates from a first magnet end face to a second magnet end face opposite to the first magnet end face, and the shaft unit includes a shaft member including the protruding portion and the portion inserted into the magnet through-hole, and a sleeve member including the connecting portion."

[0119] The motor rotor of the present disclosure is [8] "the motor rotor according to [1] above, wherein the connecting portion includes a shaft groove, and the crimping portion includes a neck portion including a portion in contact with the connecting portion, and a head portion including a portion that is bent relative to the neck portion and positioned in the shaft groove, and the head portion includes a surface that abuts against the surface constituting the shaft groove." [Explanation of Symbols]

[0120] 1, 1A, 1B, 1C, 1D, 1E Motor Rotor 2.2C Magnet 21 Magnet Circumferential Surface 21C Magnetic through-hole 22 First magnet end face 23 Second magnet end face 3.3A C shaft (shaft unit) 31 C Shaft insertion section 311 C shaft end face 312 C shaft friction surface 32 C shaft protrusion 33,33A C Shaft Connection Section 33S C Shaft Flange 331 C shaft inward contact surface 332 C Shaft Outer Surface 333 C shaft tapered surface 334 C shaft connection surface 335 C shaft outward contact surface 35 C shaft groove 351 C shaft groove rear surface 352 C Shaft Groove Front 353 C Shaft groove bottom surface 4 T-shaft (shaft unit) 41 T-shaft insertion section 411 T-shaft end face 42 T-shaft protrusion 43 T-shaft connecting section 432 T-shaft tapered surface 5 Armoring 51 First Ring Storage Section 511 Inner surface 52 Second Ring Storage Section 521 Ring friction surface 522 Ring contact surface 523 Ring crimping section 523a Crimped deformation part 523A Ring crimping section 523b Crimping contact part 523c Crimped non-deformable part 523d Crimp inner surface 523E Ring crimping section 53 Third Ring Storage Section 55 Crimp neck 551 Crimp neck inner surface 56 Crimp head 561 Rear view of the crimp head 562 Crimp head front 563 Crimp head base 6C Shaft Unit 61 Shaft (Shaft component) 62 sleeves 621 Sleeve contact surface 622 Sleeve outer surface 623 Sleeve Tapered Face 624 Sleeve friction surface 625 Sleeve end face 62h sleeve through hole 7 Motor Stator 8 motors 9. Supercharger 91 Turbine 911 Turbine Housing 912 Turbine Blade Car 913 Inlet 914 Scroll channel 92 Compressor 921 Compressor Housing 922 Compressor impeller 923 Inlet 924 Scroll channel 931 Thrust Color 94 Motor Housing 951,952 bearings 961,962 Air bearings 97 Spacer H rotation axis

Claims

1. A magnet including a circumferential surface and a pair of end faces, A shaft unit including a shaft end face that contacts the magnet end face, The system comprises an armor ring covering the portion of the magnet end face that is in contact with the shaft end face, and the circumferential surface of the magnet, The shaft unit includes an insertion portion covered by the armor ring, a protruding portion not covered by the armor ring, and a connecting portion located between the insertion portion and the protruding portion and in contact with the end of the armor ring. The end of the armor ring includes a crimped portion that is bent to approach the axis of the shaft unit, The armor ring includes a first housing portion in which the magnet is housed, a second housing portion in which the insertion portion is located, and a third housing portion in which the connecting portion is located and which includes a ring contact surface. The connecting portion includes a shaft contact surface that contacts the ring contact surface along the axial direction of the shaft unit, A motor rotor in which the outer diameter of the shaft contact surface is larger than the outer diameter of the insertion portion.

2. The motor rotor according to claim 1, wherein the connecting portion includes a tapered surface in contact with the crimped portion.

3. The motor rotor according to claim 1, wherein the connecting portion is sandwiched between the crimping portion and the ring contact surface.

4. The shaft end face is the end face of the insertion portion, The first magnet end face faces the first shaft end face of the first shaft unit, The motor rotor according to claim 1, wherein the second magnet end face opposite to the first magnet end face faces the second shaft end face of the second shaft unit.

5. The magnet includes a magnet through-hole that penetrates from the first magnet end face to the second magnet end face on the opposite side of the first magnet end face. The motor rotor according to claim 1, wherein the shaft unit includes a shaft member including the protruding portion and the portion inserted into the magnet through hole, and a sleeve member including the connecting portion.

6. The aforementioned connecting portion includes a shaft groove, The crimping portion includes a neck portion that contacts the connecting portion, and a head portion that is bent relative to the neck portion and is positioned in the shaft groove, The motor rotor according to claim 1, wherein the head portion includes a surface that contacts the surface constituting the shaft groove.

7. Motor rotor and, The motor stator includes a coil arranged around the motor rotor, The motor rotor is A magnet including a circumferential surface and a pair of end faces, A shaft unit including a shaft end face that contacts the magnet end face, The armor ring includes the portion of the magnet end face that is in contact with the shaft end face, and the circumferential surface of the magnet, The shaft unit includes an insertion portion covered by the armor ring, a protruding portion not covered by the armor ring, and a connecting portion located between the insertion portion and the protruding portion and in contact with the end of the armor ring. The end of the armor ring includes a crimped portion that is bent to approach the axis of the shaft unit, The armor ring includes a first housing portion in which the magnet is housed, a second housing portion in which the insertion portion is located, and a third housing portion in which the connecting portion is located and which includes a ring contact surface. The connecting portion includes a shaft contact surface that contacts the ring contact surface along the axial direction of the shaft unit, A motor in which the outer diameter of the shaft contact surface is larger than the outer diameter of the insertion portion.

8. Motor and, The system comprises an impeller that is rotated by the motor, The aforementioned motor is Motor rotor and, A motor stator including coils arranged around the motor rotor, The motor rotor is A magnet including a circumferential surface and a pair of end faces, A shaft unit including a shaft end face that contacts the magnet end face, The armor ring includes the portion of the magnet end face that is in contact with the shaft end face, and the circumferential surface of the magnet, The shaft unit includes an insertion portion covered by the armor ring, a protruding portion not covered by the armor ring, and a connecting portion located between the insertion portion and the protruding portion and in contact with the end of the armor ring. The end of the armor ring includes a crimped portion that is bent to approach the axis of the shaft unit, The armor ring includes a first housing portion in which the magnet is housed, a second housing portion in which the insertion portion is located, and a third housing portion in which the connecting portion is located and which includes a ring contact surface. The connecting portion includes a shaft contact surface that contacts the ring contact surface along the axial direction of the shaft unit, A supercharger in which the outer diameter of the shaft contact surface is larger than the outer diameter of the insertion portion.

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