JP7635607B2 - Rotor and method for manufacturing the rotor - Google Patents

Description

The present invention relates to a rotor and a method for manufacturing a rotor.

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

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. In addition, a cylindrical portion of the flange-shaped member that faces the rotor core in the radial direction (hereinafter, the cylindrical portion) 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. In addition, in the cylindrical portion of the flange-shaped member, the portion where the key groove is provided so as to be recessed radially inward has a smaller radial thickness than the portion where the key groove is not provided.

JP 2005-102460 A

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 portion of the flange-shaped member (rotor core support member) may be fitted and fixed to the radial inside of the rotor core by a tight fit. In this case, an external force toward the radial inside from the rotor core is applied to the cylindrical portion, and stress is generated in the cylindrical portion. However, in the rotor described in the above Patent Document 1, 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 thickness than the portion without the key groove, and therefore has a smaller strength (allowable stress) than the portion without the key groove. For this reason, when the cylindrical portion of the flange-shaped member (rotor core support member) is fixed to the radial inside of the rotor core by a tight fit, a rotor and a manufacturing method for the rotor that can reduce the stress generated in the portion near the key groove (key groove portion) of the cylindrical portion are desired.

This invention was made to solve the above problems, and one object of the invention is to provide a rotor and a method for manufacturing the rotor that can reduce the stress that occurs in the portion of the cylindrical portion near the key groove when the cylindrical portion of the rotor core support member is fixed to the radial inside of the rotor core by an interference fit.

In order to achieve the above-mentioned 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 supporting the rotor core radially inward of the rotor core, the rotor core includes a key portion protruding radially inward, the cylindrical portion including a key groove portion recessed radially inward at a position opposite the key portion and engaging with the key portion, the rotor core includes a gap fit portion in which the cylindrical portion is gap-fitted near the key portion in the circumferential direction of the rotor core, a press fit portion in which the cylindrical portion is press-fitted other than near 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, and the gap fit portion is provided so as to extend circumferentially on the opposite side from the key portion relative 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.

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 the 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 the portion of the cylindrical portion near the key portion where the gap fitting portion is provided and the portion near the key groove portion facing the key portion. Also, in the rotor according to the first aspect, as described above, the rotor core includes a press-fit portion in which the cylindrical portion is press-fitted in the vicinity of the key portion in the circumferential direction. As a result, the press-fit portion can fix the cylindrical portion of the rotor core support member to the radially inner side of the rotor core by press-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 the stress that occurs in the portion of the cylindrical portion near the key groove. This effect of reducing stress has been confirmed by a simulation conducted by the inventor of the present application.

In addition, in order to achieve the above-mentioned object, a manufacturing method of a rotor in 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 supporting the rotor core radially inward of the rotor core, and includes a fitting step of fitting a cylindrical portion including a key groove portion that is recessed radially inward in a position opposite the key portions and engages with the key portions into a rotor core that includes a key portion protruding radially inward and a relief portion that is recessed radially outward in a position adjacent to the key portions in the circumferential direction of the rotor core, the fitting step being a step 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 circumferentially opposite the key portions relative to the relief portion , and performing a tight fit other than in the vicinity of the key portions in the circumferential direction.

In the manufacturing method of the rotor in the second aspect of the present invention, as described above, the fitting step is a step of fitting the rotor core in the vicinity of the key portion in the circumferential direction. As a result, in the fitting step, a radial gap is formed between the portion of the rotor core that is fitted in the gap and the portion of the cylindrical portion that faces the portion of the rotor core that is fitted in the gap in the circumferential direction near the key portion, so that an external force toward the radial inside from the rotor core is not applied to the portion of the cylindrical portion that faces the portion that is fitted in the gap. As a result, as with the rotor in the first aspect, when the cylindrical portion is fitted into the rotor core, the stress generated in the portion of the cylindrical portion near the key groove portion that faces the portion of the cylindrical portion that is fitted in the gap can be reduced. Also, in the manufacturing method of the rotor in the second aspect, as described above, the fitting step is a step of fitting the rotor core in the circumferential direction other than the vicinity of the key portion. As a result, in the fitting step, the cylindrical portion of the rotor core support member can be fixed to the radial inside of the rotor core by fitting in the portion other than the vicinity of the key portion. As a result, similar to the rotor in the first aspect above, when the cylindrical portion of the rotor core support member is fixed to the radial inside of the rotor core by a tight fit, it is possible to reduce stress that occurs in the portion of the cylindrical portion near the key groove portion.

According to the present invention, as described above, 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 provide a manufacturing method for a rotor and a rotor core that can reduce the stress generated in the portion of the cylindrical portion near the key groove portion.

1 is a cross-sectional view showing a portion of a vehicle drive device including a rotor according to an embodiment. 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. FIG. 3 is a partially enlarged cross-sectional view of FIG. 2 . 5A to 5C are diagrams illustrating a manufacturing flow of a rotor according to one embodiment.

The following describes an embodiment of the present invention with reference to the drawings.

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

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) and the other side (radially outer) in the R direction are referred to as the R1 side and the R2 side, respectively.

(Overall configuration of rotor)
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.

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 cutting off driving force. The clutch unit 104 is provided on the R1 side of the 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.

The rotor 100 comprises 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.

The rotor core 10 is formed with a rotor hub insertion hole 11 extending in the Z direction (axial direction). 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 described below, the rotor hub 30 is fixed to the rotor core 10.

As shown in FIG. 1, the rotor core 10 is made of multiple stacked electromagnetic steel sheets. The rotor core 10 is formed with magnet insertion holes 12 that extend in the stacking direction (Z direction) of the electromagnetic steel sheets. The magnet insertion holes 12 are arranged in the R2 side portion of the rotor core 10. As shown in FIG. 2, the 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.

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: Interior Permanent Magnet 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 (magnetization direction) is the short side direction.

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

The rotor core 10 includes a key portion 15 that protrudes from the inner peripheral surface of the rotor core 10 toward the R1 side (radially inward). When viewed in the Z direction, the key portion 15 has a rectangular shape. Two key portions 15 are provided in the rotor core 10. When viewed in the Z direction, the two key portions 15 are arranged at equal angular intervals (180 degrees) along the C direction. As shown in FIG. 3, 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). The key portions 15 are provided over the entire rotor core 10 in the Z direction.

As shown in FIG. 1, end plate 21 is provided on the Z1 side of rotor core 10 so as to abut end face 10a on the Z1 side of rotor core 10. End plate 22 is provided on the Z2 side of rotor core 10 so as to abut end face 10b on the Z2 side of rotor core 10. End plate 21 and end plate 22 are provided to prevent permanent magnet 13 from jumping out of magnet insertion hole 12.

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 so 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 the 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. The 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 the joint portion 51a joined to the end portion 41 on the Z1 side of the cylindrical portion 40.

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 arranged at equal angular intervals (180 degrees) along the C direction when 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.

The rotor core 10 includes relief portions 16 that are recessed toward the R2 side (radially outward) at positions adjacent to the key portions 15 in the C direction (circumferential direction). Specifically, the relief portions 16 are provided adjacent to the key portions 15 on both sides of the key portions 15 in the C direction. The relief portions 16 are provided to prevent the corners on the R2 side of the key groove portions 42 that engage with the key portions 15 from coming into contact with the bases of the key portions 15.

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 that face 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).

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. 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.

This makes it difficult for the key groove portion 42, which is recessed in the cylindrical portion 40 toward the R1 side (radially inward), and the multiple spline recesses 43, which are recessed in the cylindrical portion 40 toward the R2 side (radially outward), to overlap in the R direction (radial direction). 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.

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 that is continuous with the bottom surface portion 43a at both ends of the bottom surface portion 43a in the C direction. Specifically, in 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 in 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 that overlaps with the inclined side surface portion 43b in the R direction (radially) in the C direction. Specifically, the end 42a of the key groove portion 42 in the C direction overlaps with the center of the inclined side portion 43b in the R direction (radial direction) in the C direction.

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 gap is formed between the key groove portion 42 and the spline recess 43. As a result, it is possible to relatively increase the width of the spline recess 43 in the C direction while preventing the occurrence of a wide area 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). Furthermore, because the thickness of the spline recesses 43 in the C direction is relatively large, the clutch portion 104 (see FIG. 1) can be engaged with the multiple spline recesses 43 of the cylindrical portion 40 over a relatively wide range in the C direction, allowing torque to be transmitted efficiently between the cylindrical portion 40 (flange portion 50) and the clutch portion 104.

(Fixing structure between rotor core and cylindrical portion)
Here, rotor core 10 includes a gap fit portion 17 into which cylindrical portion 40 is gap-fitted near key portion 15 in direction C (circumferential direction) of rotor core 10. That is, near 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 that faces gap fit portion 17. The gap of the gap fit is, for example, several hundred μm to several mm .

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, the 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 can be reduced (Effect 1). Note that this effect of stress reduction has been confirmed by a simulation performed by the present inventor.

The rotor core 10 also includes a shrink fit portion 18 into which the cylindrical portion 40 is squeezed in a region other than the vicinity of the key portion 15 in the C direction (circumferential direction). That is, in the shrink fit portion provided in the region other than the vicinity of the key portion 15 in the C direction, the portion of the cylindrical portion 40 that faces the shrink fit portion 18 is squeezed in the R direction by the shrink fit portion 18 of the rotor core 10. This allows the cylindrical portion 40 of the rotor hub 30 to be fixed by a shrink fit to the R1 side (radially inward) of the rotor core 10 in a region other than the vicinity of the key portion 15 by the shrink fit portion 18 (effect 2).

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 a tight fit, the stress generated in the portion of the cylindrical portion 40 near the key groove portion 42 can be reduced.

The gap fitting portion 17 is provided adjacent to the relief portion 16 on the opposite side of 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 arranged in this order in the C direction. The relief portion 16 is provided over the entire rotor core 10 in the Z direction.

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 inward) 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 when the relief portion 16 is not provided at a position adjacent to the key portion 15 in the C direction.

The rotor core 10 also includes a refrigerant passage recess 19 that is adjacent to the clearance fitting portion 17 on the opposite side of the relief portion 16 in the C direction (circumferential direction) and recessed toward the R2 side (radially outward), through which a cooling refrigerant flows to cool the rotor core 10. Specifically, in the rotor core 10, the key portion 15, the relief portion 16, the clearance fitting portion 17, and the refrigerant passage recess 19 are arranged in this order in the C direction. The refrigerant passage recess 19 is provided over the entire rotor core 10 in the Z direction.

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 toward the R1 side (radial inward) is not applied from the rotor core 10 to the portion of the cylindrical portion 40 facing the gap fitting portion 17, the portion of the cylindrical portion 40 facing the relief portion 16, and the portion of the cylindrical portion 40 facing the refrigerant flow path recess 19. This makes it possible to further reduce stress in the area near the key groove 42 compared to when the refrigerant flow path recess 19 is not provided in a position adjacent to the gap fit portion 17 on the opposite side of the relief portion 16 in the C direction.

The gap fitting portion 17 is provided near both sides of the key portion 15 in the C direction (circumferential direction). Specifically, in the rotor core 10, the refrigerant passage recess 19, the gap fitting portion 17, the relief portion 16, the key portion 15, the relief portion 16, the gap fitting portion 17, and the refrigerant passage recess 19 are arranged in this order in the C direction. The gap fitting portion 17, the relief portion 16, and the refrigerant passage recess 19 provided on one side of the key portion 15 in the C direction, and the gap fitting portion 17, the relief portion 16, and the refrigerant passage recess 19 provided on the other side of the key portion 15 in the C direction are provided symmetrically with respect to the center position (d-axis) of the key portion 15 in the C direction.

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 near both sides of the key portion 15. This makes it possible to further reduce stress generated in the portion of the cylindrical portion 40 near the key groove portion 42, compared to when the gap fitting portion 17 is provided only near one side of the key portion 15 in the C direction (circumferential direction).

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 q-axis adjacent to each other in the C direction (circumferential direction), so that the gap fitting portion 17 can be easily arranged near the key portion 15 in the C direction.

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, which is 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 on the inclined side surface portion 43b side of the bottom surface portion 43a. 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), so that the gap fitting portion 17 can be easily positioned near the key portion 15 in the C direction.

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

First, in step S1, a preparation process is performed to prepare the rotor core 10 and the rotor hub 30. Specifically, in the preparation process (S1), the rotor core 10 is prepared, which includes the key portion 15 that protrudes toward the R1 side. In addition, the rotor hub 30 is prepared, which includes a cylindrical portion 40 that includes a key groove portion 42 that engages with the key portion 15 that is recessed toward the R1 side at a position opposite the key portion 15. The key portion 15 and the key groove portion 42 are formed in the rotor core 10 and the cylindrical portion 40, respectively, for example, by cutting.

Next, in step S2, a fitting process is performed in which the cylindrical portion 40 of the rotor hub 30 is fitted into the rotor core 10. Specifically, in the fitting process (S2), the cylindrical portion 40 of the rotor hub 30 is inserted (fitted) into the rotor hub insertion hole 11 that extends in the Z direction of the rotor core 10.

The fitting step (S2) is a step of performing a gap fit in the vicinity of the key portion 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 portion 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 portion 15 in the C direction and the portion of the cylindrical portion 40 that faces the gap fit portion.

As a result, in the fitting step (S2), a gap is formed in the R direction (radial direction) between the gap-fitted portion of the rotor core 10 (gap-fitting portion 17) and the portion of the cylindrical portion 40 facing the gap-fitted portion of the rotor core 10 near the key portion 15 in the C direction (circumferential direction), so that an external force 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-fitted portion. 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 groove portion 42 facing the portion of the cylindrical portion 40 near the gap-fitted key portion 15 (effect 1).

The fitting step (S2) is a step of fitting the rotor core 10 in the C direction (circumferential direction) except near the key portion 15. Specifically, in the preparation step (S1), the rotor core 10 and the rotor hub 30 are prepared in which the inner diameter of the part of the rotor core 10 to be fitted in the C direction other than near the key portion 15 (the fitting part 18) is smaller than the outer diameter of the part of the cylindrical portion 40 facing the fitting part. Then, in the fitting step (S2), the inner diameter of the rotor core 10 is temporarily increased by the 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, due to the cooling contraction of the rotor core 10, the part of the cylindrical portion 40 facing the fitting part (the fitting part 18) is tightened to the part of the rotor core 10 to be fitted in the C direction other than near the key portion 15.

As a result, in the fitting process (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 fitting in a portion other than the vicinity of the key portion 15 (effect 2).

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 a tight fit, the stress generated in the portion of the cylindrical portion 40 near the key groove portion 42 can be reduced.

[Modification]
It should be noted that the embodiments disclosed herein are 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.

For example, in the above embodiment, the gap 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 gap 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 in the radial direction.

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

In the above embodiment, the multiple spline recesses 43 each include an inclined side 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 multiple spline recesses may each be configured to include a side portion whose width in the circumferential direction does not increase toward the radially inward side.

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 of the d-axis from the q-axis of the rotor core adjacent to the d-axis on which the key portion is provided in the circumferential direction.

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.

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.

In the above embodiment, the gap fitting portion 17 is provided at a position where it overlaps in the R direction (radial direction) with the portion of the spline recess 43 that is adjacent to the key groove portion 42 in the C direction (circumferential direction) on the key groove portion 42 side, but the present invention is not limited to this. In the present invention, the gap fitting portion may be provided at a position where it does not overlap in the radial direction with the portion of the spline recess that is adjacent to the key groove portion in the circumferential direction on the key groove portion side.

In addition, in the above embodiment, an example was shown in which the key groove portion 42 is disposed between multiple 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 multiple adjacent spline recesses in the circumferential direction.

In the above embodiment, an example was shown in which the cylindrical portion 40 includes multiple 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 multiple spline recesses recessed toward the radially outward to engage with the clutch portion.

In the above embodiment, the rotor core 10 includes a refrigerant flow passage recess 19 that is adjacent to the gap fitting portion 17 on the opposite side of the relief portion 16 in the C direction (circumferential direction) and recessed toward the R2 side (radially outward) and through which the cooling refrigerant that cools the 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 passage recess through which the cooling refrigerant that cools the rotor core flows, which is adjacent to the gap fitting portion on the opposite side of the relief portion in the circumferential direction.

In addition, in the above embodiment, an example was shown in which 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 so as to be separated from the relief portion on the opposite side to the key portion in the circumferential direction.

In addition, in the above embodiment, an example was shown in which the rotor core 10 includes the relief portion 16 that is 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 that is recessed toward the radially outward at a position adjacent to the key portion in the circumferential direction.

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. In the present invention, the rotor core support member in the claims may also be used as a rotor shaft in which the clutch portion is not provided on the radially inward side.

In the above embodiment, an example was 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 each of the rotor core and the cylindrical portion.

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 only in a portion of the axial direction of the rotor core, and the key groove portion may be provided only in a portion of the axial direction of the cylindrical portion.

10...rotor core, 15...key portion, 16...relief portion, 17...gap fit portion, 18...tight fit portion, 19...refrigerant flow 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 (5)

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, a tight fit portion in which the cylindrical portion is tightly 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 a side opposite to the key portion with respect to the relief portion in the circumferential direction . The rotor according to claim 1 , wherein the clearance fitting portion is provided adjacent to the relief portion on a side opposite to the key portion in the circumferential direction. The rotor according to claim 2, further comprising a refrigerant passage recess that is adjacent to the clearance fitting portion on the opposite side of the relief portion in the circumferential direction and recessed radially outward, through which a cooling refrigerant for cooling the rotor core flows. 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. 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 with respect 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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