Rotating body, rotor, and motor

Abstract

In the present invention, a cylindrical rotor core is fitted to the outer peripheral surface of a rotating body, and the rotating body rotates integrally with the rotor core. The rotating body comprises a cylindrical hub onto which the rotor core is fitted on the outer peripheral surface, a boss positioned inside the hub, and a connecting wall that connects the hub and the boss. The connecting wall includes a hub-side connection part connected to the hub, and a boss-side connection part connected to the boss. In the axial direction along the central axis of the hub, the hub-side connection part and the boss-side connection part are offset from each other. This rotor comprises the rotating body and the cylindrical rotor core fitted onto the outer peripheral surface of the hub of the rotating body. This motor comprises the rotor and a stator disposed to face the outer peripheral surface of the rotor.

Description

Rotating body, rotor, and motor

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

[0002] Patent Document 1 describes a rotor for a rotating electric machine for a vehicle, which includes a cylindrical hub and a cylindrical rotor core fitted onto the outside of the hub.

[0003] In this rotor, the outer diameter of the outer peripheral surface of the hub where the wall protrudes from the inner peripheral surface is reduced, which makes the reaction force input to the rotor core when the rotor core is fitted onto the hub more uniform, thereby preventing a weakening of the fastening force of the rotor core to the hub.

[0004] However, in the rotor described in Patent Document 1, the outer diameter of a portion of the outer peripheral surface of the hub is reduced, which shortens the interference fit length between the rotor core and the hub. Therefore, in the portion where the outer diameter is not reduced, it is necessary to increase the interference between the rotor core and the hub to maintain the fastening force.

[0005] In this case, the reaction force acting on the rotor core and hub increases, which may reduce the strength of the rotor core and hub. Also, the hub needs to be machined to have a step, which may increase the manufacturing cost of the hub.

[0006] Japanese Patent Application Laid-Open No. 2021-27732

[0007] In view of the above circumstances, the present disclosure aims to provide a rotating body, a rotor, and a motor that can easily equalize the reaction force input to the rotor core when the rotor core is externally fitted onto the hub, and that can suppress a decrease in the strength of the rotor core and the hub.

[0008] A rotating body according to one aspect of the present disclosure is a rotating body having a cylindrical rotor core fitted onto its outer peripheral surface and rotating integrally with the rotor core. The rotating body includes a cylindrical hub into which the rotor core is fitted onto its outer peripheral surface, a boss located inside the hub, and a connecting wall connecting the hub and the boss. The connecting wall includes a hub-side connecting portion connected to the hub and a boss-side connecting portion connected to the boss. The hub-side connecting portion and the boss-side connecting portion are positioned offset from each other in the axial direction along the central axis of the hub.

[0009] A rotor according to one aspect of the present disclosure includes the rotating body and a cylindrical rotor core fitted to the outer peripheral surface of the hub of the rotating body.

[0010] A motor according to one aspect of the present disclosure includes the rotor and a stator disposed opposite an outer peripheral surface of the rotor.

[0011] In the rotating body, rotor, and motor of the above aspects of the present disclosure, it is easy to equalize the reaction force input to the rotor core when the rotor core is externally fitted onto the hub, and it is possible to suppress a decrease in the strength of the rotor core and hub.

[0012] Fig. 1 is a cross-sectional view showing a rotor including a rotating body according to an embodiment of the present disclosure. Fig. 2 is a perspective view showing the rotor. Fig. 3 is a perspective view showing the rotating body. Fig. 4 is another perspective view showing the rotating body. Fig. 5 is a cross-sectional view showing the rotating body. Fig. 6 is a perspective view showing a motor including the rotor. Fig. 7 is a perspective view showing the motor with a cover removed. Fig. 8 is a cross-sectional view showing the motor. Fig. 9 is a cross-sectional view showing a modified example of the rotor.

[0013] (One Embodiment) 1. Overview FIG. 1 is a cross-sectional view showing a rotor 4 including a rotating body 1 according to one embodiment of the present disclosure. FIG. 2 is a perspective view showing the rotor 4. The rotating body 1 of one embodiment shown in FIGS. 1 and 2 is a rotating body having a cylindrical rotor core 2 fitted onto its outer peripheral surface and rotating integrally with the rotor core 2. The rotating body 1 includes a cylindrical hub 10 having an outer peripheral surface 100 onto which the rotor core 2 is fitted, a boss 11 located inside the hub 10, and a connecting wall 12 connecting the hub 10 and the boss 11. The connecting wall 12 includes a hub-side connecting portion 120 connected to the hub 10 and a boss-side connecting portion 121 connected to the boss 11. In an axial direction D1 along a central axis L1 of the hub 10, the hub-side connecting portion 120 and the boss-side connecting portion 121 are positioned offset from each other.

[0014] The rotor 4 of one embodiment includes a rotating body 1 and a cylindrical rotor core 2 fitted onto an outer peripheral surface 100 of a hub 10 of the rotating body 1 .

[0015] Fig. 6 is a perspective view showing a motor 5 including a rotor 4. Fig. 7 is a perspective view showing a state in which a cover 9 is removed from the motor 5. Fig. 8 is a cross-sectional view showing the motor 5. The motor 5 of one embodiment shown in Figs. 6 to 8 includes a rotor 4 and a stator 7 arranged to face the outer peripheral surface of the rotor 4.

[0016] In the rotating body 1, rotor 4, and motor 5 of one embodiment having the above configuration, the hub-side connecting portion 120 and the boss-side connecting portion 121 of the connecting wall 12 connecting the hub 10 and the boss 11 are positioned offset from each other in the axial direction D1 of the hub 10. Therefore, in the rotating body 1, rotor 4, and motor 5 of one embodiment, when the rotor core 2 is externally fitted onto the hub 10, the reaction force at the portion of the hub 10 where the connecting wall 12 protrudes from the inner circumferential surface 102 is less likely to be large. As a result, in the rotating body 1, rotor 4, and motor 5 of one embodiment, the reaction force input from the hub 10 to the rotor core 2 can be made nearly uniform. Furthermore, in the rotating body 1, rotor 4, and motor 5 of one embodiment, the outer diameter of the outer circumferential surface 100 of the hub 10 can be made constant, eliminating the need to partially increase the interference between the rotor core 2 and the hub 10 and suppressing a decrease in the strength of the rotor core 2 and the hub 10 due to an increase in reaction force. Therefore, in one embodiment of the rotating body 1, rotor 4, and motor 5, it is easy to equalize the reaction force input to the rotor core 2 when the rotor core 2 is externally fitted onto the hub 10, and it is possible to suppress a decrease in the strength of the rotor core 2 and the hub 10.

[0017] 2. Details Next, the rotating body 1, rotor 4, and motor 5 of one embodiment shown in FIGS. 1 to 8 will be described in more detail with reference to the drawings. As described above, FIG. 1 is a cross-sectional view showing the rotor 4 including the rotating body 1 of one embodiment according to the present disclosure. FIG. 2 is a perspective view showing the rotor 4. FIG. 3 is a perspective view showing the rotating body 1 of the same. FIG. 4 is another perspective view showing the rotating body 1 of the same. FIG. 5 is a cross-sectional view showing the rotating body 1 of the same. FIG. 6 is a perspective view showing the motor 5 including the rotor 4 of the same. FIG. 7 is a perspective view showing the motor 5 with the cover 9 removed. FIG. 8 is a cross-sectional view showing the motor 5 of the same. The motor 5 is used in a driving vehicle equipped with an engine as a driving power source for traveling, a hybrid vehicle equipped with an engine and a driving motor, an electric vehicle, or the like. The motor 5 is connected to the engine crankshaft, for example. The motor 5 is used as a generator or for starting the engine.

[0018] The rotating body 1 includes a cylindrical hub 10. Each component will be described below with reference to an axial direction D1 along (more specifically, parallel to) a central axis L1 of the hub 10.

[0019] 2-1. Rotating Body As shown in Figures 1 to 5, the rotating body 1 includes a cylindrical hub 10 having an outer peripheral surface 100 onto which the rotor core 2 is fitted, a boss 11 located inside the hub 10, and a connecting wall 12 connecting the hub 10 and the boss 11. As shown in Figure 1, the rotating body 1 further includes a rotor core receiving portion 13 that protrudes from the outer peripheral surface 100 of the hub 10 and receives one end of the rotor core 2 in the axial direction D1. The rotating body 1 is made of metal and is formed, for example, by forging.

[0020] As shown in Figures 3 to 5, the rotor core receiving portion 13 protrudes radially outward from a portion of the outer peripheral surface 100 in the axial direction D1. The rotor core receiving portion 13 is provided in an annular shape when viewed in the axial direction D1. A portion of the outer peripheral surface 100 of the hub 10 on one side in the axial direction D1 from the rotor core receiving portion 13 forms a fitting surface 101 into which the rotor core 2 is fitted. The fitting surface 101 has a constant outer diameter over the entire length in the axial direction D1. The inner peripheral surface 102 of the hub 10 has a constant inner diameter over the entire length in the axial direction D1.

[0021] The connecting wall 12 includes a hub-side connecting portion 120 connected to the hub 10 and a boss-side connecting portion 121 connected to the boss 11. In the axial direction D1 along the central axis L1 of the hub 10, the hub-side connecting portion 120 and the boss-side connecting portion 121 are positioned offset from each other.

[0022] The hub-side connection portion 120 is connected to a portion of the inner circumferential surface 102 of the hub 10 that is behind the fitting surface 101 (i.e., that portion is located at the same position in the axial direction D1 as the fitting surface 101). In this embodiment, as shown in FIG. 1 , the hub-side connection portion 120 is connected to a portion of the inner circumferential surface 102 that is behind a point slightly farther from the rotor core receiving portion 13 than the midpoint of the fitting surface 101 in the axial direction D1. As a result, the rotor core receiving portion 13 and the hub-side connection portion 120 are located apart in the axial direction D1. The connection position of the hub-side connection portion 120 is set to an appropriate position that makes it easy to equalize the reaction force generated between the fitting surface 101 and the rotor core 2.

[0023] 5, the cross-sectional shape of the connecting wall 12 on an imaginary plane including the central axis L1 is a curved line. The cross-sectional shape of the connecting wall 12 is a line curved in an S-shape.

[0024] 3 to 5 , the boss 11 includes a disk-shaped main body portion 110 concentric with the hub 10. The boss 11 further includes a shaft portion 111 that protrudes from the center of the main body portion 110 to one side in the axial direction D1 and is concentric with the main body portion 110. The main body portion 110 is located in the center of the hub 10 in the axial direction D1. The space inside the hub 10 is divided into two in the axial direction D1 by the main body portion 110 and the connecting wall 12.

[0025] A plurality of insertion holes 112, through which fasteners 6 (see FIGS. 1 and 2) for fixing the shaft 3 are inserted, are provided on the outer periphery of the main body 110 so as to penetrate the main body 110 in the axial direction D1. Six insertion holes 112 are provided in the main body 110. The six insertion holes 112 are positioned at equal intervals in the circumferential direction of the main body 110. When viewed in the axial direction D1, the six insertion holes 112 are positioned so as to surround the shaft portion 111.

[0026] The shaft 3 shown in Fig. 1 is an output shaft that connects the motor 5 to a load other than the motor 5 (an engine in this embodiment). The shaft 3 has a cylindrical shaft body 30 and a flange portion 31 that protrudes radially outward from one end of the shaft body 30 in the axial direction D1. The flange portion 31 is provided with a plurality of (six in this embodiment) fixing holes 310 to which fixing devices 6 are fixed, and the fixing holes 310 penetrate the flange portion 31 in the axial direction D1. The arrangement of the six fixing holes 310 is the same as the arrangement of the six insertion holes 112.

[0027] The shaft 3 is fixed to the boss 11 by fastening the plurality of fasteners 6 inserted into the plurality of insertion holes 112 in the main body 110 of the boss 11 to the plurality of fastening holes 310 in the flange portion 31 of the shaft 3, respectively. The shaft 3 is arranged concentrically with the axial portion 111 of the boss 11.

[0028] A boss-side connecting portion 121 of the connecting wall 12 is connected to an outer peripheral surface 113 of the main body 110. More specifically, the boss-side connecting portion 121 is connected to one half of the outer peripheral surface 113 on one side in the axial direction D1 (the lower side in FIG. 1 ).

[0029] The connecting wall 12 connects the outer peripheral surface 113 of the main body 110 and the inner peripheral surface 102 of the hub 10 over the entire circumferential direction. Therefore, the cross-sectional shape of the connecting wall 12 in an imaginary plane including the central axis L1 is constant over the entire circumferential direction of the hub 10.

[0030] In this embodiment, the connecting wall 12 is composed of a linear first portion 122 , an arc-shaped second portion 123 , an arc-shaped third portion 124 , and a linear fourth portion 125 .

[0031] The first portion 122 extends linearly radially outward from the outer peripheral surface 113. The second portion 123 extends in an arc shape from one end of the first portion 122 (the end opposite the outer peripheral surface 113) toward one side in the axial direction D1. The third portion 124 extends in an arc shape convex toward the opposite side from the second portion 123 from one end of the second portion 123 (the end opposite the first portion 122). The fourth portion 125 extends linearly radially outward from one end of the third portion 124 (the end opposite the second portion 123).

[0032] One end of the first part 122 (the end opposite the second part 123) constitutes the boss side connection part 121, and one end of the fourth part 125 (the end opposite the third part 124) constitutes the hub side connection part 120.

[0033] 2-2 Rotor As shown in Figures 1 and 2, the rotor 4 includes the above-described rotating body 1 and a cylindrical rotor core 2 fitted onto the outer peripheral surface 100 of the hub 10 of the rotating body 1.

[0034] The rotor core 2 has a cylindrical main body 21 provided with a plurality of accommodating holes 210 in which permanent magnets 20 are arranged, and a pair of annular plates 22, 23 that sandwich the main body 21 in the axial direction D1. The plurality of accommodating holes 210 are provided at intervals in the circumferential direction so as to extend over the entire circumferential circumference of the main body 21. A plurality of block-shaped permanent magnets 20 are arranged in each of the plurality of accommodating holes 210 so as to be aligned in the axial direction D1. Both ends of each of the plurality of accommodating holes 210 in the main body 21 in the axial direction D1 are closed by the pair of plates 22, 23.

[0035] The rotor core 2 is fitted onto the hub 10 so that the plate 23 on one side in the axial direction D1 abuts the rotor core receiving portion 13. The rotor core 2 is fitted onto the hub 10 by shrink fitting. The rotor core 2 may also be fitted onto the hub 10 by force fitting. The inner circumferential surfaces of the main body 21 and the pair of plates 22, 23 are fitted onto the fitting surface 101 of the hub 10. This allows the rotor core 2 to rotate integrally with the rotating body 1.

[0036] 6 to 8, the motor 5 includes the rotor 4 described above and a stator 7 disposed opposite the outer peripheral surface of the rotor 4.

[0037] The motor 5 further includes a cylindrical motor housing 8 that covers the rotor 4 and the stator 7 from the outer periphery, and a cover 9 that is attached to the motor housing 8 so as to cover an opening on one side of the motor housing 8 in the axial direction D1.

[0038] The stator 7 has an iron core 70, a frame-shaped insulator 71 that houses the iron core 70, a coil 72 wound around the insulator 71, and an outer frame 73 that holds the iron core 70. The stator 7 has multiple sets of the iron core 70, the insulator 71, and the coil 72, and the multiple sets are arranged at intervals in the circumferential direction. In this embodiment, the coil 72 is a coil formed by winding a rectangular conductor wire having a square cross section by edgewise bending.

[0039] As shown in Figure 8, the cover 9 has a retaining portion 90 that protrudes inside the hub 10. A bearing 91 is held in the retaining portion 90. The retaining portion 90 is cylindrical. The bearing 91 is an annular ball bearing. The bearing 91 is attached to the inner peripheral surface of the retaining portion 90. The shaft portion 111 of the rotating body 1 is rotatably supported by the bearing 91. The tip end of the shaft portion 111 in the axial direction D1 is contained within the retaining portion 90 and does not penetrate the cover 9.

[0040] The cover 9 is attached to the motor housing 8 with fasteners 14 such as screws. When the cover 9 is attached to the motor housing 8, the retaining portion 90 and a part of the bearing 91 are disposed in the space inside the hub 10.

[0041] The motor housing 8 is attached to a bracket 15. The shaft 3 is rotatably supported by the bracket 15 and protrudes from the bracket 15 toward the motor 5. The shaft 3 is an output shaft that connects the motor 5 to a load other than the motor 5.

[0042] The bracket 15 has a cylindrical holding portion 150 that protrudes to one side in the axial direction D1. A bearing 151 made of an annular ball bearing is attached to the inner peripheral surface of the holding portion 150. The bearing 151 rotatably supports the shaft 3. The bracket 15 has an insertion hole 152 through which the shaft 3 passes in the axial direction D1. The insertion hole 152 is located inside the holding portion 150.

[0043] The bracket 15 is provided with a plurality of bolts 16 that protrude toward one side in the axial direction D1 (toward the motor 5). The motor housing 8 is provided with a plurality of insertion holes 80 into which the plurality of bolts 16 are inserted.

[0044] The motor 5 is attached to the bracket 15 by inserting the multiple bolts 16 protruding from the bracket 15 into the multiple insertion holes 80 in the motor housing 8. With the cover 9 removed, fasteners 6 are inserted into the multiple insertion holes 112 in the boss 11 and fastened to the multiple fixing holes 310 in the flange portion 31 of the shaft 3, thereby fixing the shaft 3 to the boss 11. In this way, the motor 5 is attached to the bracket 15 and the shaft 3. After the shaft 3 is fixed to the boss 11, the cover 9 is fixed to the motor housing 8 with the multiple fixing devices 14.

[0045] With the motor 5 attached to the bracket 15 and the shaft 3, a portion of the holding portion 150 of the bracket 15 and the bearing 151 in the axial direction D1 are housed inside the hub 10. This allows the motor 5 to be attached to the bracket 15 with its thickness in the axial direction D1 kept small.

[0046] The motor 5 functions as a generator that generates electricity by, for example, rotating the rotor 4 due to rotation of the shaft 3. Alternatively, the motor 5 rotates the shaft 3 by passing current through the stator 7 to rotate the rotor 4, thereby functioning as a motor for starting the engine.

[0047] 3. Effects In the rotating body 1 of this embodiment described above, the hub-side connecting portion 120 and the boss-side connecting portion 121 of the connecting wall 12 are positioned offset from each other in the axial direction D1, as shown in Figure 1. Therefore, in the rotating body 1 of this embodiment, when the rotor core 2 is fitted onto the hub 10, the reaction force at the portion of the hub 10 where the connecting wall 12 protrudes from the inner circumferential surface 102 is less likely to become large, and the reaction force input from the hub 10 to the rotor core 2 can be made more uniform.

[0048] Furthermore, in the rotating body 1 of this embodiment, the outer diameter of the fitting surface 101 of the hub 10 is constant along the axial direction D1, so it is possible to increase the interference fit length (i.e., the length of the fitted portions in the axial direction D1) between the hub 10 and the rotor core 2. Therefore, in the rotating body 1 of this embodiment, it is not necessary to partially increase the interference (i.e., the length of the fitted portions in the radial direction) between the rotor core 2 and the hub 10, and it is possible to suppress a decrease in the strength of the rotor core 2 and the hub 10 due to an increase in reaction force.

[0049] Therefore, in the rotating body 1 of this embodiment, when the rotor core 2 is externally fitted onto the hub 10, it is easy to equalize the reaction force input to the rotor core 2, and it is possible to suppress a decrease in the strength of the rotor core 2 and the hub 10.

[0050] Furthermore, in the rotating body 1 of this embodiment, the cross-sectional shape of the connecting wall 12 in the imaginary plane including the central axis L1 is a curved line, which makes the connecting wall 12 prone to deflection. Therefore, in this respect as well, the rotating body 1 of this embodiment makes it easy to suppress the reaction force acting on the rotor core 2 at the portion of the hub 10 where the connecting wall 12 protrudes from the inner circumferential surface 102.

[0051] Furthermore, in the rotating body 1 of this embodiment, the hub side connection portion 120 is located away from the rotor core receiving portion 13, so the portion of the hub 10 where the connecting wall 12 protrudes is less affected by the increased strength provided by the rotor core receiving portion 13, making it easier to achieve uniform reaction force during external fitting.

[0052] Furthermore, since the rotor 4 and motor 5 of this embodiment are equipped with the above-mentioned rotating body 1, it is easy to equalize the reaction force input to the rotor core 2 when the rotor core 2 is externally fitted onto the hub 10, and it is possible to suppress a decrease in the strength of the rotor core 2 and the hub 10.

[0053] 8, the motor 5 of this embodiment is assembled with the bracket 15 so that a retaining portion 150 and a portion of the bearing 151 provided on the bracket 15 are positioned inside the hub 10. Therefore, the motor 5 of this embodiment can be easily assembled with the bracket 15 while minimizing the amount of protrusion from the bracket 15.

[0054] In addition, in the motor 5 of this embodiment, the cover 9 is attached to the motor housing 8 so that the retaining portion 90 of the cover 9 and a portion of the bearing 91 are located inside the hub 10, making it easy to reduce the axial length D1 of the motor 5.

[0055] (Modifications) Next, a description will be given of modifications of the rotating body 1, the rotor 4, and the motor 5 of the embodiment described above. The modifications shown below can be combined as appropriate.

[0056] The rotating body 1 does not need to include the rotor core receiving portion 13. When the rotor core 2 is force-fitted onto the outer peripheral surface 100 of the hub 10, the rotor core receiving portion 13 may be omitted.

[0057] The connecting wall 12 is not limited to the structure shown in FIG. 1 and the like, as long as the hub-side connecting portion 120 and the boss-side connecting portion 121 are positioned so as to be shifted from each other in the axial direction D1.

[0058] The cross-sectional shape of the connecting wall 12 in an imaginary plane including the central axis L1 may be any curved linear shape and is not limited to the S-shape shown in Fig. 1. This cross-sectional shape may be, for example, an inverted S-shape (i.e., the arcs of the second portion 123 and the third portion 124 are convex in opposite directions), or may be an arc shape that is convex on one side in the axial direction D1 or an arc shape that is convex on the other side in the axial direction D1.

[0059] 9 is a cross-sectional view illustrating a modified example of the rotor 4 according to an embodiment of the present disclosure. The cross-sectional shape of the connecting wall 12 in an imaginary plane including the central axis L1 may be a shape that is mainly composed of straight portions, as in the modified example illustrated in FIG. 9 . In this modified example, the connecting wall 12 further includes a straight intermediate portion 126 located between the arc-shaped second portion 123 and the arc-shaped third portion 124. The intermediate portion 126 extends in a direction intersecting with the axial direction D1. In this modified example, the arc-shaped second portion 123 and the arc-shaped third portion 124 are shorter than the second portion 123 and the third portion 124 of the embodiment.

[0060] The cross-sectional shape of the connecting wall 12 in an imaginary plane including the central axis L1 does not have to be constant around the entire circumferential direction of the hub 10. For example, the cross-sectional shape of the connecting wall 12 in one imaginary plane including the central axis L1 may be different from the cross-sectional shape of the connecting wall 12 in another imaginary plane including the central axis L1. The connecting wall 12 may be composed of multiple walls positioned at intervals in the circumferential direction of the hub 10. In this case, each of the multiple walls is configured so that the hub-side connecting portion 120 and the boss-side connecting portion 121 are positioned offset from each other in the axial direction D1.

[0061] The boss 11 does not have to have the disk-shaped main body portion 110 concentric with the hub 10, and the shape and arrangement of the main body portion 110 are not limited to the shape and arrangement shown in FIG.

[0062] The boss 11 is not limited to one to which the shaft 3 is fixed, but may be one in which the shaft portion 111 is provided so as to protrude from the main body portion 110 on both sides in the axial direction D1.

[0063] The boss 11 may not have the shaft portion 111, and the shaft 3 may be fixed to pass through the main body portion 110. The boss 11 may have the shafts 3 fixed to both sides of the main body portion 110 in the axial direction D1.

[0064] The shaft 3 may be a crankshaft of an engine or a clutch shaft of a clutch, in which case the bracket 15 is a housing of the engine or a housing of the clutch.

[0065] The rotor 4 and the motor 5 are not limited to the structures shown in Figures 1 and 8. For example, the shaft 3 and the bracket 15 do not have to be part of the engine or clutch configuration. The motor 5 may include the shaft 3 and the bracket 15.

[0066] (Summary) As in the embodiment and its modified example described above, the rotating body (1) of the first aspect has the following configuration.

[0067] That is, the rotating body (1) of the first embodiment is a rotating body (1) having a cylindrical rotor core (2) fitted onto its outer peripheral surface and rotating integrally with the rotor core (2). The rotating body (1) includes a cylindrical hub (10) having an outer peripheral surface (100) into which the rotor core (2) is fitted, a boss (11) located inside the hub (10), and a connecting wall (12) connecting the hub (10) and the boss (11). The connecting wall (12) includes a hub-side connecting portion (120) connected to the hub (10) and a boss-side connecting portion (121) connected to the boss (11). In the axial direction (D1) along the central axis (L1) of the hub (10), the hub-side connecting portion (120) and the boss-side connecting portion (121) are positioned offset from each other.

[0068] In the rotating body (1) of the first aspect having the above configuration, the hub-side connecting portion (120) and the boss-side connecting portion (121) of the connecting wall (12) connecting the hub (10) and the boss (11) are positioned offset from each other in the axial direction (D1) of the hub (10). Therefore, in the rotating body (1) of the first aspect, when the rotor core (2) is fitted onto the hub (10), the reaction force at the portion of the hub (10) where the connecting wall (12) protrudes from the inner peripheral surface (102) is unlikely to be large. As a result, in the rotating body (1) of the first aspect, the reaction force input from the hub (10) to the rotor core (2) can be made nearly uniform. Furthermore, in the rotating body (1) of the first aspect, the outer diameter of the outer peripheral surface (100) of the hub (10) can be made constant, eliminating the need to partially increase the interference between the rotor core (2) and the hub (10), and thus suppressing a decrease in the strength of the rotor core (2) and the hub (10) due to an increase in the reaction force. Therefore, in the first embodiment of the rotating body (1), when the rotor core (2) is externally fitted onto the hub (10), the reaction force input to the rotor core (2) is easily made uniform, and a decrease in the strength of the rotor core (2) and the hub (10) can be suppressed.

[0069] As in the above-described embodiment and its modified example, the rotating body (1) of the second aspect additionally includes the following configuration in addition to the configuration of the first aspect.

[0070] That is, in the rotating body (1) of the second embodiment, the cross-sectional shape of the connecting wall (12) in an imaginary plane including the central axis (L1) is a curved line.

[0071] In the second aspect of the rotating body (1) having the above configuration, the connecting wall (12) is easily deflected when the rotor core (2) is fitted onto the hub (10), making it easier to equalize the reaction force during fitting.

[0072] Furthermore, as in the above-described embodiment and its modified example, the rotating body (1) of the third aspect additionally includes the following configuration in addition to the configuration of the first or second aspect.

[0073] That is, the rotating body (1) of the third aspect further includes a rotor core receiving portion (13) that protrudes from the outer peripheral surface (100) of the hub (10) and receives one end of the rotor core (2) in the axial direction (D1). The rotor core receiving portion (13) and the hub-side connecting portion (120) are positioned apart from each other in the axial direction (D1).

[0074] In the third embodiment of the rotating body (1) having the above-described configuration, the portion of the hub (10) where the connecting wall (12) protrudes is less susceptible to the effect of the rotor core receiving portion (13) improving the strength of the hub (10), making it easier to achieve uniform reaction forces during external fitting.

[0075] Furthermore, as in the above-described embodiment and its modified example, the rotating body (1) of the fourth aspect additionally has the following configuration in addition to the configuration of any one of the first to third aspects.

[0076] That is, in the rotating body (1) of the fourth embodiment, the boss (11) includes a disk-shaped main body portion (110) concentric with the hub (10). The boss-side connecting portion (121) is connected to the outer peripheral surface (113) of the main body portion (110). The hub-side connecting portion (120) is connected to the inner peripheral surface (102) of the hub (10). The cross-sectional shape of the connecting wall (12) in an imaginary plane including the central axis (L1) is constant over the entire circumferential direction of the hub (10).

[0077] In the rotating body (1) of the fourth aspect having the above configuration, the cross-sectional shape of the connecting wall (12) is constant over the entire circumference in the circumferential direction, so that it is easy to make the reaction force during external fitting uniform over the circumferential direction.

[0078] Furthermore, as in the above-described embodiment and its variant, the rotor (4) of the fifth aspect comprises a rotating body (1) of any one of the first to fourth aspects and a cylindrical rotor core (2) fitted onto the outer peripheral surface (100) of the hub (10) of the rotating body (1).

[0079] The rotor (4) of the fifth aspect having the above-mentioned configuration is provided with the above-mentioned rotating body (1), which makes it easier to make the reaction force uniform during external fitting and also makes it possible to suppress a decrease in the strength of the rotor core (2) and the hub (10).

[0080] Furthermore, as in the above-described embodiment and its variant, the motor (5) of the sixth aspect includes the rotor (4) of the fifth aspect and a stator (7) arranged to face the outer peripheral surface of the rotor (4).

[0081] In the sixth aspect of the motor (5) having the above-mentioned configuration, since it is equipped with the above-mentioned rotating body (1), it is easy to make the reaction force uniform during external fitting and it is possible to suppress a decrease in the strength of the rotor core (2) and the hub (10).

[0082] The present disclosure has been described above based on the embodiments shown in the accompanying drawings. However, the present disclosure is not limited to the above-described embodiments and modifications, and appropriate design changes are possible within the intended scope of the present disclosure.

[0083] REFERENCE SIGNS LIST 1 Rotating body 10 Hub 100 Outer peripheral surface 102 Inner peripheral surface 11 Boss 110, 21 Main body 111 Shaft 112 Insertion hole 113 Outer peripheral surface 12 Connecting wall 120 Hub-side connection portion 121 Boss-side connection portion 122 First portion 123 Second portion 124 Third portion 125 Fourth portion 126 Intermediate portion 13 Rotor core receiving portion 14 Fixing device 15 Bracket 150 Holding portion 151 Bearing 152 Insertion hole 16 Bolt 2 Rotor core 210 Accommodating hole 22 Plate 23 Plate 3 Shaft 31 Flange portion 310 Fixing hole 4 Rotor 5 Motor 6 Fixing device 7 Stator 70 Iron core 71 Insulator 72 Coil 73 Outer frame 8 Motor housing 80 Insertion hole 9 Cover 90 Holding portion 91 Bearing D1 Axial direction L1 Central axis

Claims

A rotating body having a cylindrical rotor core fitted to its outer peripheral surface and rotating integrally with the rotor core, a cylindrical hub whose outer circumferential surface is fitted with the rotor core; a boss located inside the hub; a connecting wall connecting the hub and the boss; Preparation, The connecting wall is a hub-side connection portion connected to the hub; a boss-side connection portion connected to the boss, The hub-side connecting portion and the boss-side connecting portion are positioned offset from each other in the axial direction along the central axis of the hub. Rotating body. 　 The cross-sectional shape of the connecting wall in a virtual plane including the central axis is a curved line. The rotating body according to claim 1 . 　 a rotor core receiving portion that projects from the outer peripheral surface of the hub and receives one end of the rotor core in the axial direction, The rotor core receiving portion and the hub side connecting portion are positioned apart in the axial direction. The rotating body according to claim 1 or 2. 　 The boss is a disk-shaped body portion concentric with the hub; the boss-side connecting portion is connected to the outer peripheral surface of the main body portion, the hub-side connection portion is connected to the inner circumferential surface of the hub, a cross-sectional shape of the connecting wall in an imaginary plane including the central axis is constant over the entire circumferential direction of the hub; The rotating body according to claim 1 or 2. 　 A rotating body according to any one of claims 1 to 4; the rotor core having a cylindrical shape fitted to the outer peripheral surface of the hub of the rotating body; Equipped with Rotor. 　 The rotor according to claim 5; a stator disposed opposite to an outer peripheral surface of the rotor; Equipped with Motor.

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