Rotor and method for manufacturing the rotor

Abstract

To provide a rotor and a manufacturing method thereof that can reduce the stress on a cylindrical portion of a rotor core support member near a keyway when the cylindrical portion is fixed radially inwardly of the rotor core by interference fit.SOLUTION: A rotor 100 includes a rotor core 10 and a rotor hub 30 (rotor core support member). The rotor hub 30 includes a cylindrical portion 40 that supports rotor core 10 on the R1 side (radially inward) of the rotor core 10. The rotor core 10 includes a clearance fit portion 17 in which the cylindrical portion 40 is loosely fitted in the vicinity of a key portion 15 in the C direction (circumferential direction), and an interference fit portion 18 in which the cylindrical portion 40 is tightly fitted except in the vicinity of the key portion 15 in the C direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a rotor and a method for manufacturing a rotor. [Background technology]

[0002] 2. Description of the Related Art Conventionally, rotors have been known that include a rotor support member that includes a cylindrical portion that supports a rotor core on the radially inner side of the rotor core (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a rotor in which a flange-shaped member (rotor core support member) is fitted into a rotor core. In the rotor described in the above-mentioned Patent Document 1, the rotor core is provided with a key that protrudes radially inward. A cylindrical portion (hereinafter, cylindrical portion) of the flange-shaped member that faces the rotor core in the radial direction is provided with a key groove that is recessed radially inward at a position facing the key. The key of the rotor core and the key groove of the flange-shaped member are engaged. Note that the portion of the cylindrical portion of the flange-shaped member in which the key groove is provided so as to be recessed radially inward has a smaller radial thickness than a portion where the key groove is not provided. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-102460 A Summary of the Invention [Problem to be solved by the invention]

[0005] Here, although it is not specified in the above Patent Document 1, in the conventional rotor as described in the above Patent Document 1, the cylindrical part of the flange-shaped member (rotor core support member) may be fitted and fixed to the radially inner side of the rotor core by interference fit. In this case, an external force toward the radially inner side from the rotor core is applied to the cylindrical part, and stress is generated in the cylindrical part. However, in the rotor described in the above Patent Document 1, the part of the cylindrical part of the flange-shaped member in which the key groove is provided so as to be recessed radially inward has a smaller thickness than the part not provided with the key groove, and therefore has a smaller strength (allowable stress) than the part not provided with the key groove. For this reason, a rotor and a manufacturing method of the rotor are desired that can reduce the stress generated in the part near the key groove (key groove part) of the cylindrical part when the cylindrical part of the flange-shaped member (rotor core support member) is fixed to the radially inner side of the rotor core by interference fit.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a rotor and a manufacturing method for a rotor that can reduce stress generated in the portion of the cylindrical portion near the key groove portion when the cylindrical portion of the rotor core support member is fixed to the radially inner side of the rotor core by an interference fit. [Means for solving the problem]

[0007] In order to achieve the above object, a rotor in a first aspect of the present invention comprises a rotor core, and a rotor core support member including a cylindrical portion that supports the rotor core radially inward of the rotor core, the rotor core including a key portion that protrudes radially inward, the cylindrical portion including a key groove portion that is recessed radially inward at a position opposite to the key portion and engages with the key portion, the rotor core including a clearance fit portion in the vicinity of the key portion in the circumferential direction of the rotor core, and an interference fit portion in which the cylindrical portion is interference fit in the circumferential direction other than in the vicinity of the key portion, a relief portion provided at a position adjacent to the key portion in the circumferential direction so as to be recessed radially outward; Including The clearance fitting portion is provided so as to extend in the circumferential direction on the opposite side to the key portion with respect to the relief portion.In this specification, the term "a portion near the key portion (key groove portion) of the cylindrical portion" refers to both the portion where the key portion (key groove portion) of the cylindrical portion is provided and the portion near the portion where the key portion (key groove portion) of the cylindrical portion is provided in the circumferential direction. In addition, in this specification, the term "interference fit" refers to both an interference fit and an intermediate fit that is an intermediate state between an interference fit and a clearance fit.

[0008] In the rotor according to the first aspect of the present invention, as described above, the rotor core includes a gap fitting portion in which the cylindrical portion is gap-fitted in the vicinity of the key portion in the circumferential direction. As a result, when the cylindrical portion is fitted into the rotor core, a radial gap is formed between the gap fitting portion of the rotor core and a portion of the cylindrical portion facing the gap fitting portion in the vicinity of the key portion in the circumferential direction, so that an external force directed radially inward from the rotor core is not applied to the portion of the cylindrical portion facing the gap fitting portion. As a result, when the cylindrical portion is fitted into the rotor core, it is possible to reduce stress generated in a portion of the cylindrical portion near the key portion where the gap fitting portion is provided and a portion near the key groove portion facing the portion of the cylindrical portion. Also, in the rotor according to the first aspect, as described above, the rotor core includes an interference fitting portion in which the cylindrical portion is interference-fitted in the vicinity of the key portion in the circumferential direction. As a result, the interference fitting portion can fix the cylindrical portion of the rotor core support member to the radially inner side of the rotor core by interference fitting in the portion other than the vicinity of the key portion. As a result, when the cylindrical portion of the rotor core support member is fixed to the radial inside of the rotor core by an interference fit, it is possible to reduce stress generated in the portion of the cylindrical portion near the key groove. This effect of stress reduction has been confirmed by simulations performed by the present inventors.

[0009] In order to achieve the above object, a manufacturing method of a rotor according to a second aspect of the present invention is a manufacturing method of a rotor including a rotor core and a rotor core support member including a cylindrical portion that supports the rotor core on a radially inner side of the rotor core, the manufacturing method including the manufacturing method of a rotor including a key portion that protrudes radially inward. a relief portion provided at a position adjacent to the key portion in the circumferential direction of the rotor core so as to be recessed radially outward;a fitting step of fitting a cylindrical portion including a key groove portion that is recessed radially inward at a position facing the key portion into a rotor core including the key portion, the key groove portion being engaged with the key portion, the fitting step being performed by fitting a cylindrical portion including a key groove portion that is recessed radially inward at a position facing the key portion into the rotor core including the key portion in a circumferential direction of the rotor core. and a portion extending in the circumferential direction on the opposite side of the key portion with respect to the relief portion. This is a process of providing a clearance fit at the key portions and a tight fit in the circumferential direction other than near the key portions.

[0010] In the manufacturing method of the rotor according to the second aspect of the present invention, as described above, the fitting step is a step of performing a clearance fit in the vicinity of the key portion in the circumferential direction of the rotor core. As a result, in the fitting step, a radial gap is formed between the portion of the rotor core that is clearance fit and the portion of the cylindrical portion that faces the portion of the rotor core that is clearance fit in the vicinity of the key portion in the circumferential direction, so that an external force directed radially inward from the rotor core is not applied to the portion of the cylindrical portion that faces the portion that is clearance fit. As a result, similar to the rotor according to the first aspect, when the cylindrical portion is fitted into the rotor core, stress generated in the portion of the cylindrical portion that faces the portion of the key groove that is clearance fit can be reduced. Also, in the manufacturing method of the rotor according to the second aspect, as described above, the fitting step is a step of performing an interference fit in the vicinity of the key portion in the circumferential direction. As a result, in the fitting step, the cylindrical portion of the rotor core support member can be fixed to the radially inner side of the rotor core by interference fit in the portion other than the vicinity of the key portion. As a result, as with the rotor in the first aspect described above, when the cylindrical portion of the rotor core support member is fixed to the radially inner side of the rotor core by an interference fit, the stress generated in the portion of the cylindrical portion near the key groove portion can be reduced. Effect of the Invention

[0011] According to the present invention, as described above, it is possible to provide a manufacturing method for a rotor and a rotor core that can reduce stress generated in the portion of the cylindrical portion near the key groove portion when the cylindrical portion of the rotor core support member is fixed to the radially inner side of the rotor core by an interference fit. [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view showing a portion of a vehicle drive device including a rotor according to an embodiment. [Diagram 2] 1 is a cross-sectional view of a rotor core and a cylindrical portion of a rotor according to an embodiment, viewed in the axial direction. [Diagram 3] FIG. 3 is a partially enlarged cross-sectional view of FIG. 2. [Figure 4] 5A to 5C are diagrams illustrating a manufacturing flow of a rotor according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] [Rotor configuration] The configuration of a rotor 100 according to one embodiment will be described with reference to FIGS.

[0015] In the following description, the axial, radial, and circumferential directions of the rotor 100 (rotor core 10 (see FIG. 1)) are referred to as the Z direction, R direction, and C direction, respectively. One side and the other side in the Z direction are referred to as the Z1 side and the Z2 side, respectively. One side (radially inner side) and the other side (radially outer side) in the R direction are referred to as the R1 side and the R2 side, respectively.

[0016] (Overall rotor configuration) As shown in FIG. 1, the rotor 100 and the stator 101 constitute a part of a rotating electric machine 102. The rotating electric machine 102 is, for example, a motor, a generator, or a motor / generator. The rotor 100 and the stator 101 are each formed in an annular shape. The rotor 100 is configured to rotate around a rotation axis 90. The rotor 100 is disposed on the R1 side of the stator 101 such that the outer peripheral surface of the rotor 100 and the inner peripheral surface of the stator 101 face each other in the R direction. That is, the rotor 100 is configured as a part of an inner rotor type rotating electric machine 102.

[0017] The rotating electric machine 102, together with an engine (not shown), is provided in a vehicle drive device 103 as a drive source for driving a vehicle. The vehicle drive device 103 is provided with a clutch unit 104 for transmitting and interrupting driving force. The clutch unit 104 is provided on the R1 side of a cylindrical portion 40 (described later) of the rotor 100. The clutch unit 104 includes a first clutch unit 104a provided on the Z2 side and a second clutch unit 104b provided on the Z1 side on the R1 side of the cylindrical portion 40 of the rotor 100.

[0018] The rotor 100 includes a rotor core 10, an end plate 21, an end plate 22, and a rotor hub 30. The rotor hub 30 is an example of a "rotor core support member" in the claims.

[0019] A rotor hub insertion hole 11 extending in the Z direction (axial direction) is formed in the rotor core 10. As shown in FIG. 2, the rotor hub insertion hole 11 is provided in the center of the rotor core 10 when viewed in the Z direction. The rotor hub 30 is inserted into the rotor hub insertion hole 11. In other words, the rotor hub 30 is provided on the R1 side of the rotor core 10. As will be described later, the rotor hub 30 is fixed to the rotor core 10.

[0020] As shown in Fig. 1, rotor core 10 is formed by stacking multiple electromagnetic steel sheets. Magnet insertion holes 12 extending in the stacking direction (Z direction) of the electromagnetic steel sheets are formed in rotor core 10. Magnet insertion holes 12 are arranged in the R2 side portion of rotor core 10. As shown in Fig. 2, rotor core 10 is provided with multiple magnet insertion holes 12 (32 in this embodiment). The multiple magnet insertion holes 12 are arranged at equal angular intervals along the C direction when viewed in the Z direction.

[0021] A permanent magnet 13 is housed (placed) in each of the multiple magnet insertion holes 12. That is, the rotating electric machine 102 is configured as an interior permanent magnet motor (IPM motor). The permanent magnet 13 has a rectangular cross section perpendicular to the Z direction. The permanent magnet 13 is configured, for example, so that the magnetization direction is in the short direction.

[0022] In rotor core 10, magnetic poles 14 are formed by a pair of permanent magnets 13 adjacent to each other in the C direction. That is, a plurality of magnetic poles 14 (16 in this embodiment) are formed on rotor core 10. The pair of permanent magnets 13 forming magnetic poles 14 are arranged in a V-shape that protrudes toward the R1 side. Note that the shape of the pair of permanent magnets 13 forming magnetic poles 14 is not limited to this.

[0023] Rotor core 10 includes key portions 15 that protrude from the inner circumferential surface of rotor core 10 toward the R1 side (radially inward). Key portions 15 have a rectangular shape when viewed in the Z direction. Two key portions 15 are provided in rotor core 10. When viewed in the Z direction, the two key portions 15 are disposed at equal angular intervals (180 degrees) along the C direction. As shown in FIG. 3, key portions 15 are provided at positions corresponding to the d-axis of rotor core 10 in the C direction (circumferential direction). Key portions 15 are provided over the entire rotor core 10 in the Z direction.

[0024] 1, end plate 21 is provided on the Z1 side of rotor core 10 so as to abut against Z1 side end face 10a of rotor core 10. End plate 22 is provided on the Z2 side of rotor core 10 so as to abut against Z2 side end face 10b of rotor core 10. End plate 21 and end plate 22 are provided to prevent permanent magnets 13 from jumping out of magnet insertion holes 12.

[0025] The rotor hub 30 includes a cylindrical portion 40 and a flange portion 50. As shown in FIG. 2, the cylindrical portion 40 has a cylindrical shape. The cylindrical portion 40 is provided on the R1 side of the rotor core 10 such that the inner peripheral surface of the rotor core 10 and the outer peripheral surface of the cylindrical portion 40 face each other. The cylindrical portion 40 supports the rotor core 10 on the R1 side (radially inner side) of the rotor core 10. As shown in FIG. 1, the flange portion 50 is joined to an end portion 41 on the Z1 side of the cylindrical portion 40. The flange portion 50 is provided on the R1 side of the cylindrical portion 40. A cylindrical portion side portion 51 provided on the cylindrical portion 40 side (R2 side) of the flange portion 50 extends toward the R1 side from a joint portion 51a joined to the end portion 41 on the Z1 side of the cylindrical portion 40.

[0026] The cylindrical portion 40 includes a key groove portion 42 that engages with the key portion 15. The key groove portion 42 is provided on the outer circumferential surface of the cylindrical portion 40 at a position facing the key portion 15 so as to be recessed toward the R1 side (diametrically inward). The key groove portion 42 is recessed in a rectangular shape on the R1 side so as to engage with the rectangular key portion 15 protruding toward the R1 side. Two key groove portions 42 are provided on the cylindrical portion 40. The two key groove portions 42 are disposed at equal angular intervals (180 degrees) along the C direction as viewed in the Z direction. As shown in FIG. 3, the key groove portion 42 is provided at a position corresponding to the d-axis of the rotor core 10 in the C direction. The key groove portion 42 is provided over the entire cylindrical portion 40 in the Z direction.

[0027] Rotor core 10 includes relief portions 16 recessed toward the R2 side (radially outward) at positions adjacent to key portion 15 in the C direction (circumferential direction). Specifically, relief portions 16 are provided adjacent to key portion 15 on both sides of key portion 15 in the C direction. Note that relief portions 16 are provided to prevent a corner portion on the R2 side of key groove portion 42 that engages with key portion 15 from contacting the base of key portion 15.

[0028] 2, the cylindrical portion 40 includes a plurality of spline recesses 43 recessed toward the R2 side (radially outward) to engage with the clutch portion 104 (see FIG. 1). Specifically, the clutch portion 104 includes a plurality of spline protrusions (not shown) protruding toward the R2 side at positions on the outer circumferential surface of the clutch portion 104 facing the plurality of spline recesses 43 of the cylindrical portion 40. Each of the plurality of spline recesses 43 of the cylindrical portion 40 engages with the plurality of spline protrusions of the clutch portion 104. The plurality of spline recesses 43 are provided over the entire cylindrical portion 40 in the Z direction (axial direction).

[0029] Moreover, the key groove portion 42 is disposed between adjacent spline recesses 43 in the C direction (circumferential direction). Specifically, as shown in Fig. 3, each of the spline recesses 43 is provided at a position corresponding to the q axis of the rotor core 10 in the C direction. Moreover, as described above, the key groove portion 42 is provided at a position corresponding to the d axis of the rotor core 10 in the C direction.

[0030] This makes it difficult for the key groove portion 42 provided in the cylindrical portion 40 to be recessed toward the R1 side (radially inward) and the multiple spline recesses 43 provided in the cylindrical portion 40 to be recessed toward the R2 side (radially outward) to overlap in the R direction (radially). This makes it possible to prevent the occurrence of a wide area in the C direction where the thickness of the cylindrical portion 40 in the R direction becomes excessively small (the strength is reduced) due to the key groove portion 42 and the multiple spline recesses 43 overlapping in the R direction.

[0031] Each of the spline recesses 43 includes a bottom surface portion 43a extending along the C direction (circumferential direction) and an inclined side surface portion 43b continuous with the bottom surface portion 43a at both ends of the bottom surface portion 43a in the C direction. Specifically, in each of the spline recesses 43, the inclined side surface portion 43b, the bottom surface portion 43a, and the inclined side surface portion 43b are arranged in this order in the C direction. The inclined side surface portion 43b is inclined so that its width in the C direction (circumferential direction) increases toward the R1 side (radially inward). That is, each of the spline protrusions of the clutch portion 104 that engage with each of the spline recesses 43 increases its width in the C direction toward the R1 side. The end portion 42a in the C direction (circumferential direction) of the key groove portion 42 is provided at a position overlapping the inclined side surface portion 43b in the R direction (radially) in the C direction. Specifically, an end 42a of the key groove portion 42 in the C direction overlaps with a center portion of the inclined side surface portion 43b in the R direction (radial direction) in the C direction.

[0032] As a result, the inclined side surface portion 43b, which is the end portion of the spline recess 43 on the key groove portion 42 side in the C direction (circumferential direction), overlaps with the key groove portion 42 in the R direction (radial direction). That is, the key groove portion 42 and the spline recess 43 slightly overlap in the R direction. In addition, since the bottom surface portion 43a is inclined so that the width in the C direction increases toward the R1 side (radially inward), even if the key groove portion 42 and the spline recess 43 slightly overlap in the R direction, a certain interval is formed between the key groove portion 42 and the spline recess 43. As a result, it is possible to prevent a portion in the C direction in which the thickness of the cylindrical portion 40 in the R direction (radial direction) becomes excessively small (the strength is reduced) due to the key groove portion 42 and the multiple spline recesses 43 overlapping in the R direction (radial direction) from occurring over a wide area in the C direction, while making it possible to make the width of the spline recess 43 in the C direction relatively large. Furthermore, since the thickness of the spline recesses 43 in the direction C is relatively large, by engaging the clutch portion 104 (see Figure 1) with the multiple spline recesses 43 of the cylindrical portion 40 over a relatively wide range in the direction C, torque can be efficiently transmitted between the cylindrical portion 40 (flange portion 50) and the clutch portion 104.

[0033] (Fixing structure between rotor core and cylindrical part) Here, rotor core 10 includes a gap fit portion 17 into which cylindrical portion 40 is loosely fitted in the vicinity of key portion 15 in direction C (circumferential direction) of rotor core 10. That is, in the vicinity of key portion 15 in direction C (circumferential direction), a gap in direction R is always formed between gap fit portion 17 of rotor core 10 and a portion of cylindrical portion 40 facing gap fit portion 17. The gap of the gap fit is, for example, several hundred μm to several mm It is.

[0034] As a result, when the cylindrical portion 40 is fitted into the rotor core 10, a gap is formed in the R direction (radial direction) between the gap fitting portion 17 of the rotor core 10 and the portion of the cylindrical portion 40 facing the gap fitting portion 17 in the vicinity of the key portion 15 in the C direction (circumferential direction), so that an external force from the rotor core 10 toward the R1 side (radial inward) is not applied to the portion of the cylindrical portion 40 facing the gap fitting portion 17. As a result, when the cylindrical portion 40 is fitted into the rotor core 10, it is possible to reduce stress generated in the portion of the cylindrical portion 40 near the key portion 15 where the gap fitting portion 17 is provided and the portion near the key groove portion 42 facing the portion of the cylindrical portion 40 near the key portion 15 where the gap fitting portion 17 is provided (Effect 1). Note that this effect of stress reduction has been confirmed by a simulation performed by the present inventor.

[0035] Furthermore, rotor core 10 includes interference-fitted portions 18 into which cylindrical portion 40 is interference-fitted in a portion other than the vicinity of key portions 15 in the C direction (circumferential direction). That is, in the interference-fitted portions provided in the portion other than the vicinity of key portions 15 in the C direction, a portion of cylindrical portion 40 facing interference-fitted portion 18 is fastened in the R direction by interference-fitted portion 18 of rotor core 10. This allows cylindrical portion 40 of rotor hub 30 to be fixed by interference fit to the R1 side (radially inner side) of rotor core 10 in a portion other than the vicinity of key portions 15 by interference-fitting with interference-fitted portion 18 (effect 2).

[0036] As a result of the above effects 1 and 2, when the cylindrical portion 40 of the rotor hub 30 is fixed to the R1 side of the rotor core 10 by an interference fit, the stress generated in the portion of the cylindrical portion 40 near the key groove portion 42 can be reduced.

[0037] Furthermore, the gap fitting portion 17 is provided adjacent to the relief portion 16 on the opposite side to the key portion 15 in the C direction (circumferential direction). Specifically, in the rotor core 10, the key portion 15, the relief portion 16, and the gap fitting portion 17 are aligned in this order in the C direction. The relief portion 16 is provided over the entire rotor core 10 in the Z direction.

[0038] As a result, when the cylindrical portion 40 is fitted into the rotor core 10, a gap is formed in the R direction (radial direction) between the clearance fitting portion 17 of the rotor core 10 and the portion of the cylindrical portion 40 facing the clearance fitting portion 17, as well as between the relief portion 16 of the rotor core 10 and the portion of the cylindrical portion 40 facing the relief portion 16. As a result, when the cylindrical portion 40 is fitted into the rotor core 10, an external force toward the R1 side (radial inner side) is not applied from the rotor core 10 to the portion of the cylindrical portion 40 facing the clearance fitting portion 17, as well as to the portion of the cylindrical portion 40 facing the relief portion 16. As a result, the stress generated in the portion near the key groove portion 42 can be further reduced compared to a case where the relief portion 16 is not provided at a position adjacent to the key portion 15 in the C direction.

[0039] Furthermore, rotor core 10 includes a refrigerant flow passage recess 19 adjacent to gap fitting portion 17 on the opposite side to relief portion 16 in the C direction (circumferential direction) and recessed toward R2 side (radially outward), through which a cooling refrigerant for cooling rotor core 10 flows. Specifically, in rotor core 10, key portion 15, relief portion 16, gap fitting portion 17, and refrigerant flow passage recess 19 are aligned in this order in the C direction. Note that refrigerant flow passage recess 19 is provided over the entire rotor core 10 in the Z direction.

[0040] As a result, when the cylindrical portion 40 is fitted into the rotor core 10, a gap is formed in the R direction (radial direction) between the gap fitting portion 17 of the rotor core 10 and the portion of the cylindrical portion 40 facing the gap fitting portion 17, and between the relief portion 16 of the rotor core 10 and the portion of the cylindrical portion 40 facing the relief portion 16, as well as between the refrigerant flow path recess 19 of the rotor core 10 and the portion of the cylindrical portion 40 facing the refrigerant flow path recess 19. As a result, when the cylindrical portion 40 is fitted into the rotor core 10, an external force directed toward the R1 side (radial inward) from the rotor core 10 is not applied to the portion of the cylindrical portion 40 facing the gap fitting portion 17 and the portion of the cylindrical portion 40 facing the relief portion 16, as well as to the portion of the cylindrical portion 40 facing the refrigerant flow path recess 19. This makes it possible to further reduce the stress generated in the area near the key groove portion 42 compared to a case where the refrigerant flow path recess 19 is not provided at a position adjacent to the gap fit portion 17 on the opposite side of the escape portion 16 in the C direction.

[0041] Moreover, the gap fitting portions 17 are provided near both sides of the key portions 15 in the C direction (circumferential direction). Specifically, in the rotor core 10, the refrigerant flow path recesses 19, the gap fitting portions 17, the relief portions 16, the key portions 15, the relief portions 16, the gap fitting portions 17, and the refrigerant flow path recesses 19 are arranged in this order in the C direction. The gap fitting portions 17, the relief portions 16, and the refrigerant flow path recesses 19 provided on one side of the key portions 15 in the C direction, and the gap fitting portions 17, the relief portions 16, and the refrigerant flow path recesses 19 provided on the other side of the key portions 15 in the C direction are provided symmetrically with respect to the center position (d-axis) of the key portions 15 in the C direction.

[0042] As a result, when the cylindrical portion 40 is fitted into the rotor core 10, a gap is formed in the R direction (radial direction) between the gap fit portion 17 of the rotor core 10 and a portion of the cylindrical portion 40 facing the gap fit portion 17, near both sides of the key portion 15. As a result, stress generated in the portion of the cylindrical portion 40 near the key groove portion 42 can be further reduced, compared to a case in which the gap fit portion 17 is provided only near one side of the key portion 15 in the C direction (circumferential direction).

[0043] Furthermore, the gap fitting portion 17 is provided in the C direction (circumferential direction) closer to the d-axis than the q-axis of the rotor core 10 adjacent to the d-axis on which the key portion 15 is provided. Specifically, the refrigerant flow path recess 19 is provided at a position corresponding to the q-axis of the rotor core 10 in the C direction. The gap fitting portion 17 is provided on the key portion 15 side provided at a position corresponding to the d-axis than the refrigerant flow path recess 19 provided at a position corresponding to the q-axis in the C direction. This allows the distance between the gap fitting portion 17 and the key portion 15 in the C direction (circumferential direction) to be smaller than the distance between the d-axis and the q-axis adjacent to each other in the C direction (circumferential direction), so that the gap fitting portion 17 can be easily disposed in the vicinity of the key portion 15 in the C direction.

[0044] Furthermore, the gap fitting portion 17 is provided at a position overlapping in the R direction (radial direction) with a portion of the spline recess 43 on the key groove portion 42 side, the portion being provided so as to be adjacent to the key groove portion 42 in the C direction (circumferential direction). Specifically, the gap fitting portion 17 is provided at a position overlapping in the R direction (radial direction) with a portion of the bottom surface portion 43a on the inclined side surface portion 43b side. This allows the gap fitting portion 17 to be provided at a position overlapping in the R direction (radial direction) with a portion relatively close to the key groove portion 42 in the C direction (circumferential direction), and therefore the gap fitting portion 17 can be easily disposed in the vicinity of the key portion 15 in the C direction.

[0045] [Rotor manufacturing method] A method for manufacturing the rotor 100 according to one embodiment will now be described with reference to FIG.

[0046] First, in step S1, a preparation step is performed to prepare rotor core 10 and rotor hub 30. Specifically, in the preparation step (S1), rotor core 10 is prepared, which includes key portions 15 protruding on the R1 side. In addition, rotor hub 30 is prepared, which includes cylindrical portion 40 including key groove portions 42 that engage with key portions 15 provided in a position opposite key portions 15 so as to be recessed on the R1 side. Note that key portions 15 and key groove portions 42 are formed in rotor core 10 and cylindrical portion 40, respectively, by, for example, cutting.

[0047] Next, in step S2, a fitting step is performed to fit the cylindrical portion 40 of the rotor hub 30 into the rotor core 10. Specifically, in the fitting step (S2), the cylindrical portion 40 of the rotor hub 30 is inserted (fitted) into the rotor hub insertion hole 11 of the rotor core 10 extending in the Z direction.

[0048] Here, the fitting step (S2) is a step of performing a gap fit in the vicinity of the key portions 15 in the C direction (circumferential direction) of the rotor core 10. Specifically, in the preparation step (S1), the rotor core 10 and the rotor hub 30 are prepared in which the inner diameter of the gap fit portion (gap fit portion 17) in the vicinity of the key portions 15 in the C direction of the rotor core 10 is larger than the outer diameter of the portion of the cylindrical portion 40 that faces the gap fit portion. Then, in the fitting step (S2), a gap in the R direction is always formed between the gap fit portion (gap fit portion 17) of the rotor core 10 in the vicinity of the key portions 15 in the C direction and the portion of the cylindrical portion 40 that faces the gap fit portion.

[0049] As a result, in the fitting step (S2), a gap is formed in the R direction (radial direction) between the gap-fitted portion of rotor core 10 (gap fit portion 17) and the portion of cylindrical portion 40 facing the gap-fitted portion of rotor core 10 in the vicinity of key portion 15 in the C direction (circumferential direction), so that an external force toward the R1 side (radial inward) from rotor core 10 is not applied to the portion of cylindrical portion 40 facing the gap-fitted portion. As a result, when cylindrical portion 40 is fitted into rotor core 10, it is possible to reduce stress generated in the portion of cylindrical portion 40 near key groove portion 42 facing the portion near key portion 15 that is gap-fitted (effect 1).

[0050] The fitting step (S2) is a step of performing interference fitting in a portion of the rotor core 10 other than the vicinity of the key portion 15 in the C direction (circumferential direction). Specifically, in the preparation step (S1), the rotor core 10 and the rotor hub 30 are prepared in which the inner diameter of the portion of the rotor core 10 to be interference fitted (interference fitted portion 18) other than the vicinity of the key portion 15 in the C direction is smaller than the outer diameter of the portion of the cylindrical portion 40 facing the interference fitted portion. Then, in the fitting step (S2), the inner diameter of the rotor core 10 is temporarily increased by thermal expansion of the rotor core 10 due to shrink fitting, for example, so that the cylindrical portion 40 of the rotor hub 30 is inserted into the rotor hub insertion hole 11 extending in the Z direction of the rotor core 10. Then, by cooling and contracting the rotor core 10, the portion of the cylindrical portion 40 facing the interference fitted portion (interference fitted portion 18) is fastened to the portion of the rotor core 10 to be interference fitted other than the vicinity of the key portion 15 in the C direction.

[0051] As a result, in the fitting step (S2), the cylindrical portion 40 of the rotor hub 30 can be fixed to the R1 side (radially inner side) of the rotor core 10 by tight fit at a portion other than the vicinity of the key portions 15 (effect 2).

[0052] As a result of the above effects 1 and 2, when the cylindrical portion 40 of the rotor hub 30 is fixed to the R1 side of the rotor core 10 by an interference fit, the stress generated in the portion of the cylindrical portion 40 near the key groove portion 42 can be reduced.

[0053] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the embodiments above, and further includes all modifications (variations) within the meaning and scope of the claims.

[0054] For example, in the above embodiment, the clearance fitting portion 17 is provided at a position where it overlaps with the portion of the bottom surface portion 43a on the inclined side surface portion 43b side in the R direction (radial direction), but the present invention is not limited to this. In the present invention, the clearance fitting portion may be provided at a position where it does not overlap with the portion of the bottom surface portion on the inclined side surface portion side in the radial direction.

[0055] In the above embodiment, an example has been shown in which the end 42a of the key groove portion 42 in the C direction (circumferential direction) is provided at a position that overlaps the inclined side surface portion 43b in the R direction (radial direction) in the C direction (circumferential direction), but the present invention is not limited to this. In the present invention, the end of the key groove portion in the circumferential direction may be provided at a position that does not overlap the inclined side surface portion in the radial direction in the circumferential direction.

[0056] In the above embodiment, the spline recesses 43 each include an inclined side surface portion 43b that is inclined so that the width in the C direction (circumferential direction) increases toward the R1 side (radially inward), but the present invention is not limited to this. In the present invention, the spline recesses may each include a side surface portion whose width in the circumferential direction does not increase toward the radially inward.

[0057] In the above embodiment, the gap fitting portion 17 is provided on the d-axis side of the q-axis of the rotor core 10 adjacent to the d-axis on which the key portion 15 is provided in the C direction (circumferential direction), but the present invention is not limited to this. In the present invention, the gap fitting portion may be provided on the opposite side to the d-axis of the q-axis of the rotor core adjacent to the d-axis on which the key portion is provided in the circumferential direction.

[0058] In the above embodiment, the key portion 15 is provided at a position corresponding to the d-axis of the rotor core 10 in the C direction (circumferential direction), but the present invention is not limited to this. In the present invention, the key portion may be provided at a position that does not correspond to the d-axis of the rotor core in the circumferential direction.

[0059] In the above embodiment, the gap fitting portion 17 is provided near both sides of the key portion 15 in the C direction (circumferential direction), but the present invention is not limited to this. In the present invention, the gap fitting portion may be provided only near one side of the key portion in the circumferential direction.

[0060] In the above embodiment, the clearance fit portion 17 is provided at a position overlapping in the R direction (radial direction) with a portion of the spline recess 43 adjacent to the key groove portion 42 in the C direction (circumferential direction), but the present invention is not limited to this. In the present invention, the clearance fit portion may be provided at a position not overlapping in the radial direction with a portion of the spline recess 43 adjacent to the key groove portion in the circumferential direction.

[0061] In the above embodiment, the key groove portion 42 is disposed between the adjacent spline recesses 43 in the C direction (circumferential direction), but the present invention is not limited to this. In the present invention, the key groove portion may be disposed at a position other than between the adjacent spline recesses in the circumferential direction.

[0062] In the above embodiment, the cylindrical portion 40 includes a plurality of spline recesses 43 recessed toward the R2 side (radially outward) to engage with the clutch portion 104, but the present invention is not limited to this. In the present invention, the cylindrical portion may be configured not to include a plurality of spline recesses recessed toward the radially outward to engage with the clutch portion.

[0063] In the above embodiment, an example has been shown in which rotor core 10 includes refrigerant flow path recess 19 that is adjacent to gap fit portion 17 on the side opposite escape portion 16 in direction C (circumferential direction) and recessed toward R2 (radially outward) and through which a cooling refrigerant for cooling rotor core 10 flows, but the present invention is not limited to this. In the present invention, the rotor core may be configured not to include a refrigerant flow path recess through which a cooling refrigerant for cooling rotor core flows, that is adjacent to the gap fit portion on the side opposite escape portion in the circumferential direction.

[0064] In the above embodiment, the gap fitting portion 17 is provided adjacent to the relief portion 16 on the opposite side to the key portion 15 in the C direction (circumferential direction), but the present invention is not limited to this. In the present invention, the gap fitting portion may be provided away from the relief portion on the opposite side to the key portion in the circumferential direction.

[0065] In the above embodiment, the rotor core 10 includes the relief portion 16 provided so as to be recessed toward the R2 side (radially outward) at a position adjacent to the key portion 15 in the C direction (circumferential direction), but the present invention is not limited to this. In the present invention, the rotor core may be configured not to include a relief portion provided so as to be recessed toward the radially outward at a position adjacent to the key portion in the circumferential direction.

[0066] In the above embodiment, the rotor hub 30 in which the clutch portion 104 is provided on the R1 side (radially inward) of the cylindrical portion is used as the "rotor core support member" in the claims, but the present invention is not limited to this. The rotor shaft in which the clutch portion is not provided on the radially inward side may be used as the "rotor core support member" in the claims.

[0067] In the above embodiment, an example has been shown in which two key portions 15 and two key groove portions 42 are provided in the rotor core 10 and the cylindrical portion 40, respectively, but the present invention is not limited to this. In the present invention, only one key portion and one key groove portion may be provided in the rotor core and the cylindrical portion, respectively, or three or more key portions and one key groove portion may be provided in the rotor core and the cylindrical portion, respectively.

[0068] In the above embodiment, the key portion 15 and the key groove portion 42 are provided over the entire Z direction (axial direction) of the rotor core 10 and the cylindrical portion 40, respectively, but the present invention is not limited to this. In the present invention, the key portion may be provided on only a portion of the axial direction of the rotor core, and the key groove portion may be provided on only a portion of the axial direction of the cylindrical portion. [Explanation of symbols]

[0069] 10... rotor core, 15... key portion, 16... relief portion, 17... clearance fit portion, 18... interference fit portion, 19... refrigerant passage recess, 30... rotor hub (rotor core support member), 40... cylindrical portion, 41... key groove portion, 42... spline recess, 100... rotor, 104... clutch portion

Claims

1. A rotor core; a rotor core support member including a cylindrical portion supporting the rotor core on a radially inner side of the rotor core, The rotor core includes a key portion protruding radially inward, the cylindrical portion includes a key groove portion that is recessed radially inward at a position facing the key portion and engages with the key portion, the rotor core includes: a clearance fit portion in which the cylindrical portion is clearance-fitted in a vicinity of the key portion in a circumferential direction of the rotor core; an interference fit portion in which the cylindrical portion is interference-fitted in a portion other than the vicinity of the key portion in the circumferential direction; and a relief portion provided at a position adjacent to the key portion in the circumferential direction so as to be recessed radially outward; The clearance fitting portion is provided so as to extend on an opposite side to the key portion with respect to the relief portion in the circumferential direction.

2. A rotor as described in claim 1, wherein the gap fitting portion is arranged adjacent to the escape portion on the opposite side to the key portion in the circumferential direction.

3. 3. The rotor according to claim 2, wherein the rotor core further includes a refrigerant flow passage recess adjacent to the clearance fitting portion on the opposite side to the escape portion in the circumferential direction and recessed radially outward, through which a cooling refrigerant for cooling the rotor core flows.

4. The cylindrical portion further includes a plurality of spline recesses recessed radially outward to engage with a clutch portion provided on the radially inner side of the cylindrical portion, The key groove portion is disposed between the plurality of spline recessed portions adjacent to each other in the circumferential direction, The rotor according to any one of claims 1 to 3, wherein the clearance fit portion is provided at a position overlapping in the radial direction with a portion of the spline recess on the key groove portion side, the portion being adjacent to the key groove portion in the circumferential direction.

5. A manufacturing method of a rotor including a rotor core and a rotor core support member including a cylindrical portion supporting the rotor core on a radially inner side of the rotor core, a fitting step of fitting the cylindrical portion into the rotor core including a key portion protruding radially inward and a relief portion provided adjacent to the key portion in the circumferential direction of the rotor core and recessed radially outward, the key portion including a key groove portion provided opposite the key portion and recessed radially inward to engage with the key portion, a rotor manufacturing method, wherein the fitting process is a process of performing a clearance fit in the vicinity of the key portions in the circumferential direction of the rotor core and in a portion extending on the opposite side of the key portions in the circumferential direction relative to the relief portions, and performing a tight fit other than in the vicinity of the key portions in the circumferential direction.

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