JP2021027602A - Rotor for rotary electric machine, rotary electric machine, and manufacturing method of rotor for rotary electric machine - Google Patents

Abstract

To effectively cool a rotor core and the like using an oil hole on a rotor shaft while improving the transmission performance of rotational torque between the rotor core and the rotor shaft.SOLUTION: A rotor (30) for a rotary electric machine includes a rotor core (32, 232) having a shaft hole, and an oil passage (802) in a core which opens into the shaft hole, and a tubular rotor shaft (34, 34', 234) having an outer peripheral surface facing the shaft hole and an inner peripheral surface forming an axial core oil passage, and having an oil hole (343) communicating the outer peripheral surface and the inner peripheral surface, and the outer peripheral surface of the rotor shaft includes a plurality of shaft small diameter portions (3462), a plurality of shaft large diameter portion (3461) having an outer diameter larger than that of the shaft small diameter portion, and a shaft tooth surface portion (3463), and in the oil hole, an outer peripheral surface side opening (3431) is formed in the shaft small diameter portion or the shaft large diameter portion, and the shaft small diameter portion or the shaft large diameter portion in which the outer peripheral surface side opening is formed, and a shaft hole in which the shaft hole side opening (8021A) of the oil passage in the core is formed are in contact with each other in the radial direction without a gap, and the oil passage in the core and the oil hole communicate with each other.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a rotor for a rotary electric machine, a rotary electric machine, and a method for manufacturing a rotor for a rotary electric machine.

Rotor shafts for rotary electric machines that spline-couple with a rotor core on the outer side in the radial direction are known.

Japanese Unexamined Patent Publication No. 2009-130977

However, in the above-mentioned conventional technique, it is difficult to effectively cool the rotor core or the like by utilizing the oil holes of the rotor shaft while improving the transmission performance of the rotational torque between the rotor core and the rotor shaft.

Therefore, on one aspect, it is an object of the present invention to effectively cool the rotor core and the like by utilizing the oil holes of the rotor shaft while improving the transmission performance of the rotational torque between the rotor core and the rotor shaft. ..

On one side, a rotor core having a shaft hole in the center and an oil passage in the core that opens into the shaft hole,
A rotor shaft that fits into the shaft hole and has a tubular shape that includes an outer peripheral surface facing the shaft hole and an inner peripheral surface that forms an axial oil passage, and has the outer peripheral surface and the inner peripheral surface. Equipped with a rotor shaft with oil holes to communicate with
The outer peripheral surface of the rotor shaft includes a shaft small diameter portion having a predetermined outer diameter, a shaft large diameter portion having an outer diameter larger than the shaft small diameter portion, and a circumferential distance between the shaft small diameter portion and the shaft large diameter portion. Including multiple shaft tooth surfaces provided in
The oil hole has an opening on the outer peripheral surface side formed in at least one of the shaft small diameter portion and the shaft large diameter portion.
The small diameter portion of the shaft or the large diameter portion of the shaft on which the outer peripheral surface side opening is formed and the shaft hole on which the shaft hole side opening of the oil passage in the core is formed are in contact with each other without a gap in the radial direction. , A rotor for a rotary electric machine is provided, in which the oil passage in the core and the oil hole communicate with each other.

On one side, according to the present invention, it is possible to effectively cool the rotor core and the like by utilizing the oil holes of the rotor shaft while improving the transmission performance of the rotational torque between the rotor core and the rotor shaft. ..

It is sectional drawing which shows schematic the sectional structure of the motor by one Example. It is sectional drawing of a rotor. It is an enlarged view of the Q1 part of FIG. It is an enlarged view which shows the Q1 part by 1st comparative example. It is an enlarged view which shows the Q1 part by the 2nd comparative example. It is a schematic diagram corresponding to the enlarged view of the P1 part of FIG. 1 by this Example. It is a schematic diagram corresponding to the enlarged view of the P1 part by the 2nd comparative example. It is a schematic flowchart which shows the manufacturing method of the rotor core of the motor by this Example. It is explanatory drawing of the inconvenience which occurs at the time of press-fitting. It is an enlarged view which shows a part of the spline joint part between a rotor core and a rotor shaft by one modification.

Hereinafter, each embodiment will be described in detail with reference to the accompanying drawings. In addition, in FIG. 1 and the like, for the sake of easy viewing, there are cases where a reference reference numeral is only partially attached to a plurality of parts having the same attribute.

FIG. 1 is a cross-sectional view schematically showing a cross-sectional structure of a motor 1 (an example of a rotary electric machine) according to an embodiment. FIG. 2 is a cross-sectional view of the rotor 30 (cross-sectional view taken along a plane perpendicular to the axial direction). FIG. 1 corresponds to a cross section along the line AA shown in FIG.

FIG. 1 shows the rotating shaft 12 of the motor 1. In the following description, the axial direction refers to the direction in which the rotation shaft (rotation center) 12 of the motor 1 extends, and the radial direction refers to the radial direction centered on the rotation shaft 12. Therefore, the radial outer side refers to the side away from the rotating shaft 12, and the radial inner side refers to the side toward the rotating shaft 12. Further, the circumferential direction corresponds to the rotation direction around the rotation shaft 12.

The motor 1 may be a vehicle driving motor used in, for example, a hybrid vehicle or an electric vehicle. However, the motor 1 may be used for any other purpose.

The motor 1 is an inner rotor type, and the stator 21 is provided so as to surround the radial outer side of the rotor 30. The outer side of the stator 21 in the radial direction is fixed to the motor housing 10. The stator 21 is made of, for example, an annular soft magnetic laminated steel plate, and a plurality of slots (not shown) around which the coil 22 is wound are formed in the inner peripheral portion of the stator 21.

The rotor 30 is arranged inside the stator 21 in the radial direction. The rotor 30 includes a rotor core 32 and a rotor shaft 34. The rotor core 32 is fixed to the outside in the radial direction of the rotor shaft 34, and rotates integrally with the rotor shaft 34. In this embodiment, the rotor core 32 has a shaft hole and fits the rotor shaft 34 into the shaft hole. At this time, the rotor core 32 is spline-coupled to the rotor shaft 34. In this embodiment, the spline coupling portion extends over the entire section SC1 in which the rotor core 32 and the rotor shaft 34 overlap in the axial direction. Further, in this embodiment, the spline joint portion extends over the entire circumference in the circumferential direction. However, in the modified example, the spline coupling portion may extend in the axial direction over a part of the section SC1. The rotor shaft 34 is rotatably supported by the motor housing 10 via bearings 14a and 14b. The rotor shaft 34 defines the rotating shaft 12 of the motor 1.

The rotor core 32 is formed of, for example, an annular soft magnetic laminated steel plate. A permanent magnet 321 (see FIG. 2) is inserted inside the rotor core 32. That is, the rotor core 32 has a magnet hole 324 penetrating in the axial direction, and the permanent magnet 321 is inserted and fixed in the magnet hole 324. The number and arrangement of the permanent magnets 321 are arbitrary. In the modified example, the rotor core 32 may be formed of a green compact obtained by compressing and solidifying the magnetic powder.

As shown in FIG. 1, the rotor core 32 has a gap 322 penetrating in the axial direction. The void 322 extends parallel to the axial direction. The gap 322 is formed radially inward with respect to the radial outer surface of the rotor core 32. That is, the gap 322 is formed inside the rotor core 32 so that the radial outer side of the rotor core 32 does not open. The number of voids 322 and the cross-sectional shape (opening shape in the axial direction) are arbitrary.

As shown in FIG. 2, the rotor core 32 has a rotationally symmetric form centered on the rotating shaft 12 when viewed in the axial direction. In the example shown in FIG. 2, the rotor core 32 has a form in which each set of permanent magnets 321 and voids 322 (oil passage 802) overlap each time the rotor core 32 rotates about 45 degrees around the rotation shaft 12. Further, in the example shown in FIG. 2, the rotor core 32 has a form in which the configurations related to the ridges 326 overlap each time the rotor core 32 rotates 90 degrees around the rotation shaft 12.

In this embodiment, the void 322 functions as an axial oil passage 803 (an example of an axial oil passage). The oil passing through the oil passage 803 can cool the permanent magnet 321 by removing heat from the permanent magnet 321. In order to enhance such cooling function, the void 322 is preferably provided in the vicinity of the plurality of permanent magnets 321 (that is, in a manner adjacent to the magnet holes 324). In the example shown in FIG. 2, the gap 322 is provided in each set of two permanent magnets 321 radially inside the set of permanent magnets 321.

Further, as shown in FIG. 1, the rotor core 32 has an oil passage 802 in the radial direction (an example of an oil passage in the core). The radially inner end of the oil passage 802 communicates with the oil hole 343 (described later) of the rotor shaft 34, and the radially outer end communicates with the oil passage 803.

As shown in FIG. 2, one oil passage 802 may be provided for one void 322 corresponding to each of the plurality of voids 322. That is, one oil passage 802 is provided for each set of two permanent magnets 321 for each set of permanent magnets 321. However, in the modified example, one oil passage 802 may be provided for every two or three or more voids 322.

Each of the oil passages 802 extends radially, as shown in FIG. Each of the oil passages 802 may have a linear shape, but in this embodiment, as shown in FIG. 1, it has a shape of branching in the axial direction. Specifically, each of the oil passages 802 is radially extending from both ends of the oil passage portion 8021 extending in the radial direction, the oil passage portion 8022 extending in the axial direction, and both ends in the axial direction of the oil passage portion 8022. Includes the extending oil passage 8023. In this case, the radially inner end of the oil passage 8021 communicates with the oil hole 343 (described later) of the rotor shaft 34, and the radially outer end of each oil passage 8023 communicates with the oil passage 803.

End plates 35A and 35B are attached to both sides of the rotor core 32 in the axial direction. The end plates 35A and 35B may have a support function for supporting the rotor core 32 and a function for adjusting the imbalance of the rotor 30 (a function for eliminating the imbalance by cutting or the like).

The rotor shaft 34 has a hollow shape (cylindrical shape) and has a hollow portion 34A as shown in FIG. The hollow portion 34A extends over the entire length of the rotor shaft 34 in the axial direction. In this embodiment, the hollow portion 34A functions as an oil passage 801 (an example of an axial core oil passage).

The rotor shaft 34 has an oil hole 343 as shown in FIG. The oil hole 343 is a through-type oil hole formed in the radial direction. That is, the oil hole 343 has an opening 3431 (an example of an opening on the outer peripheral surface side) on the radial outer surface of the rotor shaft 34 (see also FIG. 3 below), and the radial inner surface of the rotor shaft 34. Has an opening in. The oil hole 343 does not need to be formed linearly as long as it is formed in the radial direction. Further, the oil hole 343 may be formed in the radial direction in such a manner that the oil hole 343 is slightly inclined with respect to the radial direction.

The oil hole 343 extends radially, as shown in FIGS. 1 and 2. As shown in FIG. 2, one oil hole 343 may be provided for one void 322 corresponding to each of the plurality of voids 322, similarly to the oil passage 802 of the rotor core 32. That is, one oil hole 343 is provided for each set of two permanent magnets 321 for each set of permanent magnets 321. However, in the modified example, one oil hole 343 may be provided for every two or three or more voids 322.

The oil hole 343 is preferably formed at a substantially central position in the axial direction in the section SC1 in which the rotor core 32 and the rotor shaft 34 overlap in the axial direction, as shown in FIG. In this case, when the rotor core 32 is cooled by the oil (described later) passing through the oil hole 343, one side portion and the other side portion with respect to the oil hole 343 can be cooled substantially evenly in the axial direction of the rotor core 32. However, in the modified example, the oil hole 343 may be formed at a position significantly offset in the axial direction with respect to the central position in the axial direction in the section SC1.

Like the rotor core 32, the rotor shaft 34 has a rotationally symmetric form centered on the rotating shaft 12 when viewed in the axial direction, as shown in FIG. In the example shown in FIG. 2, the rotor shaft 34 has a form in which oil holes 343 and the like overlap each time it is rotated 45 degrees around the rotation shaft 12.

Here, the oil cooling method for the motor 1 shown in FIG. 1 will be outlined.

As shown by an arrow R1 in FIG. 1, oil is supplied to the hollow portion 34A of the rotor shaft 34 from one end side in the axial direction, and the oil flows along the inner peripheral surface of the rotor shaft 34 to flow the rotor core 32. Can be cooled from the inner circumference side. The oil flowing along the inner peripheral surface of the rotor shaft 34 is ejected radially outward through the oil hole 343 of the rotor shaft 34 due to the centrifugal force of the rotating shaft of the rotor 30 (arrow R2). The oil ejected from the oil hole 343 of the rotor shaft 34 to the outside in the radial direction flows outward in the radial direction through the oil passage 802 (arrow R3) and reaches the oil passage 803. The oil reaching the oil passage 803 flows in the axial direction (arrow R4), and the rotor core 32 can be cooled internally. At this time, the oil flowing in the oil passage 803 in the axial direction can cool the permanent magnet 321 assembled to the rotor core 32 from the inside in the radial direction. Since the oil passage 803 is formed in the vicinity of the permanent magnet 321, the permanent magnet 321 can be effectively cooled. The oil flowing in the oil passage 803 in the axial direction flows outward in the radial direction from both ends in the axial direction of the oil passage 803 due to the centrifugal force of the rotating shaft of the rotor 30, and is used for cooling the coil ends 22A and 22B. (Arrow R5). The oil flowing along the inner peripheral surface of the rotor shaft 34 is further ejected radially outward through the oil holes 341 and 342 formed at both ends of the rotor shaft 34 (arrows R6 and R7). It may be used for cooling the coil ends 22A and 22B.

Although the motor 1 having a specific structure is shown in FIG. 1, the structure of the motor 1 is arbitrary as long as the rotor shaft 34 in a hollow form is spline-coupled to the rotor core 32 and has an oil hole 343. Therefore, for example, the rotor shaft 34 does not expand in diameter in the axial range in which it is splined with the rotor core 32, and in a region where a hollow portion (for example, bearings 14a and 14b) having a significantly smaller inner diameter than the hollow portion 34A is provided. It may have a hollow portion having the same inner diameter as the hollow portion). Further, although a specific cooling method is disclosed in FIG. 1, the cooling method of the motor 1 is arbitrary. Therefore, for example, an oil introduction pipe to be inserted into the hollow portion 34A may be provided, or even if oil is dropped from the outside in the radial direction toward the coil ends 22A and 22B through the oil passage in the motor housing 10. Good. Further, cooling using the oil holes 341 and 342 may be omitted.

Next, with reference to FIGS. 3 and later, the configuration mainly related to the oil passage 802 of the rotor core 32 and the oil hole 343 of the rotor shaft 34 will be further described.

FIG. 3 is an enlarged view of the Q1 portion of FIG. 2, which is an enlarged view showing a part (a part in the circumferential direction) of the spline coupling portion between the rotor core 32 and the rotor shaft 34. FIG. 4 is a diagram showing the same portion according to the first comparative example.

The rotor core 32 and the rotor shaft 34 may have the cross-sectional shape shown in FIG. 3 over the entire length in the axial direction of the rotor core 32. That is, the shape of the spline joint portion may be an equicross-sectional shape along the axial direction. However, in the modified example, the rotor core 32 and / or the rotor shaft 34 may have a cross-sectional shape different from the cross-sectional shape shown in FIG. 3 in a part of the section of the rotor core 32 in the axial direction.

The rotor core 32 has a ridge portion 326 (an example of a second ridge portion). The ridge portion 326 extends along the axial direction. Further, a plurality of ridge portions 326 are formed. The plurality of ridges 326 may be formed at a constant pitch along the circumferential direction, but in this embodiment, they are formed at a plurality of different pitches. The plurality of ridge portions 326 may be formed by, for example, rolling, or may be formed by another processing method (for example, cutting processing or press processing of each steel plate related to a laminated steel plate). In the following, the concave portion (an example of the second concave portion) formed between the adjacent convex portions 326 in the circumferential direction by forming a plurality of convex portions 326 in the circumferential direction is referred to as "concave portion". Also referred to as "327". When N convex portions 326 are provided in the entire circumferential direction, N concave portions 327 are formed in the entire circumferential direction.

The rotor core 32 has a plurality of convex portions 326 (and concave portions 327 accordingly) on the inner side in the radial direction, so that the surface on the inner side in the radial direction has a relatively large inner diameter 3261 (hereinafter, "large inner diameter portion"). (Also referred to as "surface 3261") (an example of a core large diameter portion) and a surface 3262 having a relatively small inner diameter (hereinafter, also referred to as "small inner diameter portion surface 3262") (an example of a core small diameter portion) are included. That is, the large inner diameter portion surface 3261 is the surface of the bottom portion of the concave portion 327, and the small inner diameter portion surface 3262 is the surface of the top portion of the convex groove portion 326. A tooth surface portion (an example of a core tooth surface portion) is formed between the surface of the large inner diameter portion 3261 and the surface of the small inner diameter portion 3262 in the circumferential direction.

In this embodiment, as an example, when the inner diameter of the large inner diameter portion surface 3261 is r3 and the inner diameter of the small inner diameter portion surface 3262 is r4, the inner diameter r4 is the surface of the small inner diameter portion related to each of the plurality of convex portions 326. It shall be the same in 3262. However, in the modified example, the inner diameter r4 may be different from the other ridges 326 in a part of the plurality of ridges 326. On the other hand, the inner diameter r3 may be constant, or as shown in FIG. 3, may change within a range significantly larger than the inner diameter r4, even within one recessed portion 327.

In this embodiment, the radial inner opening 8021A (an example of the shaft hole side opening) of the oil passage 802 is formed on the large inner diameter portion surface 3261 as shown in FIG. At this time, the opening 8021A is preferably formed in a region where the inner diameter of the large inner diameter portion surface 3261 is substantially constant. Here, "substantially constant" is a concept that allows minute differences due to manufacturing errors, etc., and processing to flatten the surface of the large inner diameter portion 3261, which is substantially flat but strictly curved. is there. As described above, assuming that the inner diameter of the large inner diameter portion surface 3261 is r3, the opening 8021A is preferably formed in a region where the inner diameter r3 is kept substantially constant.

The oil passage portion 8021 of the oil passage 802 may be formed by punching (pressing) the corresponding steel plate in the laminated steel plate. In this case, the number of steel plates having a punched shape corresponding to the oil passage portion 8021 may be adapted so that the entire thickness of the number of steel plates corresponds to the outer diameter φr of the oil hole 343.

The rotor shaft 34 has a ridge portion 346 (an example of a first ridge portion). The ridge portion 346 extends along the axial direction. Further, a plurality of ridge portions 346 are formed. The plurality of convex portions 346 are formed so as not to face the plurality of convex portions 326 of the rotor core 32 in the radial direction.

The plurality of ridges 346 may be formed by, for example, rolling, or may be formed by another processing method (for example, cutting). In the following, the concave portion (an example of the first concave portion) formed between the adjacent convex portions 346 in the circumferential direction by forming a plurality of convex portions 346 in the circumferential direction is referred to as "concave portion". Also referred to as "347". When M ridges 346 are provided in the entire circumferential direction, M ridges 327 are formed in the entire circumferential direction. The number M of the ridges 346 on the rotor shaft 34 may be the same as or different from the number N of the ridges 326 on the rotor core 32. In this embodiment, as an example, as can be seen from FIG. 3, the number M of the ridges 346 in the rotor shaft 34 is significantly larger than the number N of the ridges 326 in the rotor core 32.

The rotor shaft 34 has a plurality of convex portions 346 (and correspondingly concave portions 347) on the outer side in the radial direction, so that the surface on the inner side in the radial direction has a relatively large outer diameter 3461 (hereinafter, "large"). (Also referred to as "outer diameter portion surface 3461") (an example of a shaft large diameter portion) and a relatively small outer diameter surface 3462 (hereinafter, also referred to as "small outer diameter portion surface 3462") (an example of a shaft small diameter portion). Will be included. That is, the large outer diameter portion surface 3461 is the surface of the top portion of the convex portion 346, and the small outer diameter portion surface 3462 is the surface of the bottom portion of the concave portion 347. A surface 3436 (an example of a shaft tooth surface portion) is formed between the surface of the large outer diameter portion 3461 and the surface of the small outer diameter portion 3462 in the circumferential direction. The surface 3436 may be inclined with respect to the radial direction when viewed in the axial direction. That is, the surfaces 3436 on both sides in the circumferential direction of one convex portion 346 incline toward each other as they go outward in the radial direction. Hereinafter, the surface 3463 is also referred to as an "inclined surface 3464".

In this embodiment, the plurality of ridges 346 of the rotor shaft 34 has a ridge 346 having a larger outer diameter surface 3461 than the other ridges 346 in the circumferential direction (hereinafter, when distinguished). Includes "convex portion 346A"). The ridge portion 346A comes into contact with the rotor core 32 in the radial direction without a gap. The ridge portion 346A will be described later.

Further, at least one of the plurality of ridges 346 of the rotor shaft 34 has the ridge 346 facing the radial direction of the plurality of ridges 327 of the rotor core 32 in the circumferential direction. By fitting without a gap, meshing related to spline coupling is realized. In this embodiment, as an example, as shown in FIG. 3, a specific convex portion 346 adjacent to the convex portion 346A via one convex portion 346 (in FIG. 3, when distinguishing, "convex". The "strip portion 346B") fits into the concave portion 327 (in FIG. 3, when distinguished, it is described as "recessed portion 327B") without a gap in the circumferential direction. In this case, the convex portion 346B and the concave portion 327B cooperate to realize the meshing related to the spline coupling. Such meshing related to spline coupling can be realized by press-fitting or tightening (for example, shrink fitting) when integrating the rotor core 32 and the rotor shaft 34.

Of the plurality of ridges 346 of the rotor shaft 34, the number of ridges 346B that fit into the ridges 327B of the rotor core 32 without gaps in the circumferential direction (that is, the ridges that realize meshing related to spline coupling). The number of portions 346B), the arrangement, and the like may be determined according to the transmission performance of the rotational torque to be secured between the rotor shaft 34 and the rotor core 32.

As is clear from the above, in the present specification, the term "spline coupling portion" refers to the entire portion where the spline coupling is realized between the rotor shaft 34 and the rotor core 32, and the meshing related to the spline coupling is realized. It does not mean only the part related to the specific convex part. That is, the spline coupling portion between the rotor shaft 34 and the rotor core 32 always includes a ridge portion that contributes to the transmission of rotational torque between the two, but does not contribute to the transmission of rotational torque between the two. It may also include a part. Therefore, in the present specification, the term "spline coupling portion" is the entire range in which the meshing related to the spline coupling is realized in the axial direction in each of the rotor shaft 34 and the rotor core 32, and the entire circumference in the circumferential direction. Is.

Further, at least one of the plurality of convex portions 346 of the rotor shaft 34 may come into contact with the concave portion 327 of the rotor core 32 in the radial direction. This makes it easy to align the axes of the rotor shaft 34 and the rotor core 32. In the example shown in FIG. 3, of the plurality of ridges 346, the ridges 346 on both sides of the ridge 346A in the circumferential direction come into contact with the ridges 327 of the rotor core 32 in the radial direction. Such radial contact can be realized by press-fitting or tightening (for example, shrink fitting) when integrating the rotor core 32 and the rotor shaft 34. In the example shown in FIG. 3, the surface of the large inner diameter portion 3261 of the concave portion 327 is set so that the inner diameter r3 is slightly smaller than that of the other regions in the region where the radial contact is realized. In the modified example, instead of or in addition to the ridge portion 346, at least one of the plurality of ridge portions 326 of the rotor core 32 may abut in the concave portion 347 of the rotor shaft 34 in the radial direction. ..

In this embodiment, as an example, when the outer diameter of the large outer diameter portion surface 3461 is r1 and the outer diameter of the small outer diameter portion surface 3462 is r2, the outer diameter r1 is formed on each of the plurality of convex portions 346. It is assumed that the same applies to the surface of the large outer diameter portion 3461. However, in the modified example, the outer diameter r1 may be different from the other ridges 346 in a part of the plurality of ridges 346. Similarly, the outer diameter r2 may be constant among the plurality of recesses 347.

The plurality of ridges 346 may be formed at a constant pitch along the circumferential direction, but in this embodiment, they are formed at a plurality of different pitches. Specifically, the plurality of pitches include the first pitch p1 and the second pitch p2, and the second pitch p2 is significantly larger than the first pitch p1. The first pitch p1 is a basic pitch, and may be set from the viewpoint of enhancing the transmission performance of rotational torque by spline coupling, for example.

Here, as a method of realizing the second pitch p2 which is significantly larger than the first pitch p1, among a plurality of large outer diameter portion surfaces 3461 while keeping the length of the small outer diameter portion surface 3462 in the circumferential direction constant. A method of making the circumferential length of some large outer diameter surface 3461 longer than the circumferential length of another large outer diameter surface 3461 (hereinafter, also referred to as "first method") and the large outer diameter. While keeping the circumferential length of the radial surface 3461 constant, the circumferential length of some of the small outer diameter surfaces 3462 of the plurality of small outer diameter surfaces 3462 can be set to the other small outer diameter surfaces. There are a method of making the length of 3462 longer than the circumferential length (hereinafter, also referred to as "second method") and a method of combining these (hereinafter, also referred to as "third method"). In this embodiment, as an example, the first method is used, but the second method and the third method described above may be used.

Specifically, in the present embodiment, as described above, the plurality of ridges 346 have a longer circumferential length (circumferential width) of the large outer diameter portion surface 3461 than the other ridges 346. Includes ridge 346A. In this case, the ridge portion 346A has a second pitch p2 with respect to other ridge portions 346 adjacent in the circumferential direction. One ridge portion 346A is a plurality of ridge portions 346 formed at the first pitch p1 of two or more ridge portions 346 that are continuous in the circumferential direction (in the example shown in FIG. 3, two ridges). It may be a form formed by joining (merging) the strips 346) in the circumferential direction (that is, eliminating the recesses 347 between them). In other words, the plurality of ridges 346 may be in the form of gears formed on the radial outer surface of the rotor shaft 34, and the ridges 346A may be in the form of gear coupling teeth.

The ridge portion 346A is formed corresponding to the portion where the oil hole 343 is formed. Therefore, one ridge portion 346A is provided for one oil hole 343 corresponding to each of the plurality of oil holes 343.

The radial outer opening 3431 (see FIG. 3) in the oil hole 343 is formed on the large outer diameter portion surface 3461 of the ridge portion 346A. At this time, the opening 3431 is preferably formed in a region where the outer diameter of the large outer diameter portion surface 3461 is substantially constant. Here, too, "substantially constant" is a concept that allows minute differences due to manufacturing errors, etc., and processing to flatten the surface of the large outer diameter portion 3461, which is substantially flat but strictly curved. Is. As described above, assuming that the outer diameter of the large outer diameter portion surface 3461 is r1, the opening 3431 is preferably formed in a region where the outer diameter r1 is kept substantially constant.

Here, the oil hole 343 can be formed by, for example, cutting (drilling). In general, it is easier to drill a hole with higher accuracy when it is performed on a flat region than when it is performed on a region having irregularities or the like.

In this regard, in the first comparative example shown in FIG. 4, the plurality of ridges 346 of the rotor shaft 34'are formed at a constant first pitch p1, and the oil holes 343' are such a plurality of ridges. Of the 346, it is formed between two specific ridges 346 (concave 347) that are adjacent to each other in the circumferential direction. In this case, the opening 3431' extends not only to the small outer diameter surface 3462 but also to the inclined surface 3464 due to the relatively short circumferential length of the small outer diameter surface 3462. That is, in this case, it is necessary to perform the hole drilling related to the oil hole 343'on the region including the inclined surface 3436. In such a case, the hole drilling itself related to the oil hole 343'cannot be performed, or even if the hole drilling related to the oil hole 343'is possible, it is difficult to form a highly accurate oil hole 343'. .. In FIG. 4, the oil hole 343'is formed so that the center of the hole diameter coincides with the center of the concave portion 347 in the circumferential direction, but the hole diameter is formed at the center of the convex portion 346 in the circumferential direction. Similarly, when the centers are formed so as to coincide with each other, the opening 3431'of the oil hole 343' extends to the inclined surface 3436. Therefore, also in this case, the hole drilling itself related to the oil hole 343'cannot be performed, or even if the hole drilling related to the oil hole 343'is possible, the oil hole 343'with high accuracy is formed. Is difficult.

On the other hand, according to the present embodiment, the oil hole 343 has an opening 3431 in a region (planar region) in which the outer diameter r1 is kept substantially constant, so that the oil hole 343 is accurately machined (formed). )it can.

Specifically, in the present embodiment, as described above, the ridge portion 346A has a larger outer diameter portion surface 3461 in the circumferential direction than the other ridge portions 346. Therefore, according to the present embodiment, by forming the oil hole 343 in the specific convex portion 346A among the plurality of convex portions 346, it becomes easy to form the oil hole 343 with high accuracy. For example, in this embodiment, assuming that the hole diameter (outer diameter) of the oil hole 343 is φr, the length of the large outer diameter portion surface 3461 of the ridge portion 346A in the circumferential direction is significantly larger than the outer diameter φr. For the convex portion 346 other than the convex portion 346A, the length of the large outer diameter portion surface 3461 in the circumferential direction may be smaller than the outer diameter φr.

In this embodiment, the center of the oil hole 343 (center related to the outer diameter φr) coincides with the center in the circumferential direction of the large outer diameter portion surface 3461 (reference position related to the second pitch p2). It is formed. In this case, the entire opening 3431 is located within the large outer diameter surface 3461 of the ridge 346A without excessively lengthening the circumferential length of the large outer diameter surface 3461 of the ridge 346A. An oil hole 343 can be formed. However, in the modified example, the center of the oil hole 343 (center related to the outer diameter φr) is slightly circumferential with respect to the circumferential center of the large outer diameter portion surface 3461 (reference position related to the second pitch p2). It may be formed in a manner offset by.

In this embodiment, as shown in FIG. 3, the oil passage portion 8021 of the oil passage 802 has an opening dimension d1 (circumferential direction) which is the same as the hole diameter (outer diameter φr) of the oil hole 343, and The center (center of the hole shape) coincides with the center of the oil hole 343, but is not limited to this. For example, the oil passage portion 8021 of the oil passage 802 may have an opening dimension d1 slightly smaller or slightly larger than the oil hole 343. This also applies to the axial opening size (not shown) of the oil passage portion 8021 of the oil passage 802. Further, the center of the oil passage portion 8021 of the oil passage 802 may be slightly offset in the circumferential direction and / or the axial direction with respect to the center of the oil hole 343 as long as it communicates with the oil hole 343.

According to the present embodiment described above, the following excellent effects are particularly exhibited.

According to this embodiment, since the rotor core 32 and the rotor shaft 34 are spline-coupled as described above, the rotor core 32 and the rotor shaft 34 are spline-coupled as compared with other coupling methods (for example, mere tightening or key coupling). It is possible to improve the transmission performance of the rotational torque between the two.

Further, according to this embodiment, although the rotor core 32 and the rotor shaft 34 are spline-coupled, the oil hole 343 on the rotor shaft 34 side can be established at the spline coupling portion. That is, in general, it is difficult to form an oil hole such as an oil hole 343 in a spline joint portion where a gear is formed from the viewpoint of workability, but in this embodiment, in the spline joint portion, The oil hole 343 can be established. As a result, it is possible to effectively cool the rotor core 32 by utilizing the oil holes 343 of the rotor shaft 34 while improving the transmission performance of the rotational torque between the rotor core 32 and the rotor shaft 34.

Further, according to the present embodiment, the oil hole 343 is a region in which the outer diameter r1 at the spline joint portion is kept substantially constant (a large outer diameter portion whose circumferential length is longer than the outer diameter φr of the oil hole 343). The opening 3431 is formed so as to be located in the surface 3461). As a result, the workability is improved, and it is possible to form the oil hole 343 with high accuracy even at the spline joint portion.

Further, according to the present embodiment, since the plurality of convex portions 346 are formed by two or more different pitches (first pitch p1 and second pitch p2), the transmission performance of rotational torque by spline coupling is enhanced. The second pitch is such that the circumferential length of the large outer diameter portion surface 3461 of the convex portion 346A is significantly longer than the hole diameter of the oil hole 343 while setting the optimum first pitch p1 from the viewpoint and the like. p2 can be set. As a result, the oil hole 343 can be machined (formed) with high accuracy while efficiently improving the transmission performance of the rotational torque by spline coupling. In other words, the transmission performance of the rotational torque due to the spline coupling can be efficiently improved as compared with the configuration in which all are the second pitch p2 instead of the first pitch p1. However, in the modified example, the plurality of convex portions 346 may be formed at a constant pitch. In this case, the constant pitch may be adapted so that the hole related to the oil hole 343 can be machined while ensuring the transmission performance of the required rotational torque by the spline coupling.

Further, according to this embodiment, although the rotor core 32 and the rotor shaft 34 are spline-coupled, the oil passage 802 on the rotor core 32 side can be established at the spline coupling portion. That is, in general, it is difficult to form an oil passage such as an oil passage 802 in a spline joint portion where a gear is formed from the viewpoint of workability, but in this embodiment, in the spline joint portion, The oil passage 802 can be established. As a result, while improving the transmission performance of the rotational torque between the rotor core 32 and the rotor shaft 34, the radial outer portion of the rotor core 32 and the permanent portion by utilizing the oil hole 343 of the rotor shaft 34 and the oil passage 802 of the rotor core 32 are permanently used. It is possible to effectively cool the magnet 321.

Further, according to the present embodiment, the oil passage 802 is a region in which the inner diameter r3 at the spline joint portion is kept substantially constant (the surface of the large inner diameter portion 3261 whose circumferential length is longer than the outer diameter φr of the oil passage 802). ), The opening 8021A is formed so as to be located. As a result, the continuity (continuity in the radial direction) between the oil hole 343 and the oil passage 802 becomes good, and the oil from the oil hole 343 can be efficiently introduced into the oil passage 802. That is, the amount of oil leaking in the axial direction from the opening 3431 of the oil hole 343 can be effectively reduced.

Further, according to the present embodiment, as shown in FIG. 3, the ridge portion 346A of the rotor shaft 34 (the ridge portion 346 in which the opening 3431 of the oil hole 343 is formed) is in the radial direction with respect to the rotor core 32. Contact. That is, the ridge portion 346A abuts on the rotor core 32 in the radial direction facing each other (here, the concave portion 327) without a gap in the radial direction. According to such a configuration, inconvenience (described later) that occurs when the convex portion 346A is separated from the rotor core 32 in the radial direction can be reduced.

Here, regarding the effect of reducing the inconvenience that occurs when the ridge portion 346A is separated from the rotor core 32 in the radial direction, a specific comparative example (hereinafter, "second comparative example") is referred to with reference to FIGS. 5 to 6B. ”), And will be explained in detail.

FIG. 5 is an enlarged view of the Q1 portion of FIG. 2 according to the second comparative example, and is an enlarged view showing a part (a part in the circumferential direction) of the spline coupling portion between the rotor core 32A and the rotor shaft 34.

The second comparative example is different from the present embodiment in that the rotor core 32 is replaced with the rotor core 32A. The rotor core 32A according to the comparative example differs from the rotor core 32 according to the present embodiment in that the concave portion 327 facing the convex portion 346A in the radial direction is replaced with the concave portion 1327, and the concave portion 1327 is different. The difference is that the inner diameter r3 of the large inner diameter portion surface 3261A is slightly larger in the region facing the convex portion 346A in the radial direction with respect to the concave portion 327 according to the present embodiment. Specifically, the concave portion 1327 facing the convex portion 346A in the radial direction has an inner diameter r3 slightly larger than the outer diameter r1 of the large outer diameter portion surface 3461 of the convex portion 346A. Therefore, when the rotor shaft 34 is assembled to the rotor core 32A, the ridge portion 346A faces the portion of the rotor core 32A that faces in the radial direction (here, the concave portion 1327) in the radial direction via the gap Δ1. To do.

As described above, in the present embodiment, as described above, the convex portion 346A abuts on the rotor core 32A in the radial direction facing portion (here, the concave portion 1327) without a gap in the radial direction. In the second comparative example, the convex portion 346A faces (that is, does not abut) the portion of the rotor core 32 that faces in the radial direction (here, the concave portion 327) in the radial direction via the gap Δ1.

FIG. 6A is a schematic view corresponding to an enlarged view of the P1 portion of FIG. 1, and is an enlarged view schematically showing a part (a part in the axial direction) of the spline coupling portion between the rotor core 32 and the rotor shaft 34. is there. FIG. 6B is a diagram schematically showing the same portion according to the second comparative example.

In the second comparative example, as described above, the convex portion 346A faces the portion of the rotor core 32A that faces in the radial direction (here, the concave portion 1327) in the radial direction via the gap Δ1. Therefore, in the second comparative example, as schematically shown in FIG. 6B, a part of the oil (see arrow R2 in FIG. 1) ejected radially outward from the oil hole 343 is a ridge portion 346A. Due to the radial gap Δ1 between the rotor core 32A and the rotor core 32A, leakage occurs in the axial direction (see arrow R21). If such an axial leakage occurs, there is a possibility that the desired cooling performance (cooling performance by oil passing through the oil hole 343) may not be realized.

On the other hand, according to the present embodiment, as described above, the convex portion 346A abuts in the rotor core 32 in the radial direction facing the portion (here, the concave portion 327) without a gap in the radial direction. , The inconvenience that may occur in the second comparative example described above can be reduced. That is, according to the present embodiment, unlike the second comparative example described above, the oil ejected radially outward from the oil hole 343 (see arrow R2 in FIG. 1) substantially leaks in the axial direction. Instead, it is introduced into the oil passage 802 of the rotor core 32 (see FIG. 6A). As a result, the desired cooling performance (cooling performance by oil passing through the oil hole 343) can be realized.

In particular, in this embodiment, the opening 3431 of the oil hole 343 is formed in a region where the outer diameter r1 on the large outer diameter portion surface 3461 is substantially constant, and the opening 8021A of the oil passage 802 is the inner diameter r3 on the large inner diameter portion surface 3261. Is formed in a substantially constant region, and the diameters in the respective regions are substantially the same, so that a contact along the surface is realized between the large outer diameter portion surface 3461 and the large inner diameter portion surface 3261. As a result, among the oil ejected from the oil hole 343 to the outside in the radial direction, the oil that leaks in the axial direction can be substantially eliminated.

In this embodiment, as shown in FIG. 3, the radial contact between the ridge portion 346A of the rotor shaft 34 and the rotor core 32 is applied to the ridge portion 346A on the surface 3261 of the large inner diameter portion of the rotor core 32. It is realized by making the inner diameter r3 of the region facing in the radial direction slightly smaller locally (only in the range facing the convex portion 346A in the radial direction) as compared with other regions on the surface 3261 of the large inner diameter portion. ing. In this case, since the outer diameter r1 of the large outer diameter portion surface 3461 related to the convex portion 346 of the rotor shaft 34 can be made the same for all the convex portions 346, the manufacturability of the rotor shaft 34 is good. Further, since the rotor core 32 is formed of the laminated steel plate as described above, changing the inner diameter r3 of the surface 3261 of the large inner diameter portion of the rotor core 32 as described above does not cause any particular problem in manufacturing. .. However, in the modified example, the radial contact between the convex portion 346A of the rotor shaft 34 and the rotor core 32 replaces or in addition to changing the inner diameter r3 of the large inner diameter portion surface 3261 of the rotor core 32. It may be realized by making the outer diameter r1 of the large outer diameter portion surface 3461 related to the convex portion 346A of the rotor shaft 34 slightly larger than that of the large outer diameter portion surface 3461 related to the other convex portion 346. ..

Next, with reference to FIG. 7, a method of manufacturing the rotor core 32 of the motor 1 according to this embodiment will be outlined.

FIG. 7 is a schematic flowchart showing a method of manufacturing the rotor core 32 of the motor 1 according to the present embodiment. In addition, each of the following steps may be automatically realized by a machine such as a robot, or may be realized by a combination of a machine and a person (worker).

The method for manufacturing the rotor core 32 first includes a step of preparing the rotor core 32 (step S1). The rotor core 32 is formed of a laminated steel plate as described above. A permanent magnet 321 may be mounted on the rotor core 32.

Next, the method for manufacturing the rotor core 32 includes a step of preparing the rotor shaft 34 (step S2). The order of steps S1 and S2 may be reversed or may be simultaneous.

Next, in the method of manufacturing the rotor core 32, the rotor core 32 and the rotor shaft 34 are joined (integrated) by tightening (for example, shrink fitting) (step S3). At this time, as shown in FIG. 6A, the tightening fit forms a large outer diameter surface 3461 in which the opening 3431 of the oil hole 343 in the rotor shaft 34 is formed and an opening 8021A in the oil passage 802 in the rotor core 32. It is realized in such a manner that the surface of the large inner diameter portion 3261 abuts tightly in the radial direction as a result of the tightening.

By the way, as a method of integrating the rotor core 32 and the rotor shaft 34 in a manner in which the large outer diameter portion surface 3461 related to the convex portion 346A of the rotor shaft 34 and the large inner diameter portion surface 3261 of the rotor core 32 are in contact with each other in the radial direction. In addition to tightening, there is press fitting. Also in the case of press-fitting, for example, by making the inner diameter r3 of the large inner diameter portion surface 3261 of the rotor core 32 slightly smaller, the large outer diameter portion surface 3461 and the large inner diameter portion surface of the rotor core 32 related to the convex portion 346A of the rotor shaft 34 The rotor core 32 and the rotor shaft 34 can be integrated in such a manner that the 3261 abuts in the radial direction.

However, the motor 1 according to the present embodiment is preferably tightened and fitted as a method of integrating the rotor core 32 and the rotor shaft 34 (however, in the modified example, the motor 1 may be integrated by press fitting). This is because in the case of tightening, inconvenience (described later) caused by deformation of the rotor core 32 at the time of press fitting can be reduced.

Specifically, as shown in FIG. 8, when the rotor core 32 and the rotor shaft 34 are press-fitted together, the portion of the rotor core 32 facing the convex portion 346A is likely to be plastically deformed in the axial direction. That is, as schematically shown in FIG. 8, when press-fitting is realized in such a manner that the rotor shaft 34 moves relative to the rotor core 32 in the direction of arrow 500, it faces the convex portion 346A in the rotor core 32. The portion to be plastically deformed easily in a manner in which the inner end portion in the radial direction is tilted in the direction of the arrow 500. As a result, as shown in FIG. 8, the portion of the rotor core 32 facing the ridge portion 346A closes the opening 3431 of the oil hole 343 at least partially. If the opening 3431 is closed in this way, the desired cooling performance (cooling performance by oil passing through the oil hole 343) may not be realized.

In this respect, in the case of tightening, inconvenience caused by deformation of the rotor core 32 at the time of press fitting (blockage of the opening 3431 due to axial tilt of the rotor core 32 as shown in FIG. 8) can be reduced. That is, the rotor core 32 capable of achieving the desired cooling performance (cooling performance by oil passing through the oil hole 343) can be manufactured without the opening 3431 of the oil hole 343 being affected by the plastic deformation of the rotor core 32 that occurs during press fitting. ..

Next, with reference to FIG. 9, a modification to the above-described embodiment will be described. In the following description of FIG. 9, components substantially the same as those of the above-described embodiment may be designated by the same reference numerals in FIG. 9 and the description thereof may be omitted.

FIG. 9 is an enlarged view showing a part (a part in the circumferential direction) of the spline coupling portion between the rotor core 232 and the rotor shaft 234 according to one modification.

This modification is different from the above-described embodiment in that the rotor core 32 is replaced by the rotor core 232 and the rotor shaft 34 is replaced by the rotor shaft 234.

In the above-described embodiment, the opening 3431 (diameter outer opening) of the oil hole 343 is formed on the surface of the large outer diameter portion 3461 of the rotor shaft 34, whereas in this modification, as shown in FIG. In addition, the opening 3431 (diameter outer opening) of the oil hole 343 is formed on the surface 3462 of the small outer diameter portion of the rotor shaft 234.

Also in this case, the opening 3431 of the oil hole 343 is preferably formed in a region where the outer diameter of the small outer diameter portion surface 3462 is substantially constant. As a result, the oil hole 343 can be machined (formed) with high accuracy.

In the example shown in FIG. 9, the plurality of concave portions 347 have a smaller outer diameter portion surface 3462 that is longer in the circumferential direction than the other concave portions 347 (hereinafter, when distinguished, "concave". Includes "Article 347A"). In this case, the convex portions 346 on both sides in the circumferential direction with respect to the concave portion 347A have a second pitch p2 with respect to each other. That is, the ridges 346 on both sides in the circumferential direction with respect to the surface 3462 of the small outer diameter portion on which the opening 3431 is formed have a second pitch p2. The one concave portion 347A is one or more convex portion 346s that are continuous in the circumferential direction among the plurality of convex portions 346 formed at the first pitch p1 (in the example shown in FIG. 9, two convex portions 346). It may be a form formed by eliminating the strip 346). In other words, the plurality of convex portions 346 may be in the form of a gear formed on the radial outer surface of the rotor shaft 34, and the concave portion 347A may be in the form of a missing tooth of the gear.

Therefore, in the example shown in FIG. 9, the small outer diameter portion surface 3462 in which the opening 3431 is formed is longer in the circumferential direction than the other small outer diameter portion surface 3462 in which the opening 3431 is not formed. In this way, the second pitch p2 may be adjusted so that the length in the circumferential direction of the region having a substantially constant outer diameter is significantly larger than the outer diameter φr of the oil hole 343. In this way, while setting the optimum first pitch p1 from the viewpoint of enhancing the transmission performance of the rotational torque by spline coupling, the small outer diameter having a length in the circumferential direction significantly larger than the outer diameter φr of the oil hole 343. The diameter surface 3462 can be formed (that is, the recess 347A forming the small outer diameter surface 3462 can be formed). The optimum first pitch p1 from the viewpoint of enhancing the transmission performance of rotational torque by spline coupling is, for example, in the concave portion 347 other than the concave portion 347A, the surface of the small outer diameter portion 3462 is larger than the outer diameter φr of the oil hole 343. It may be a value that becomes smaller. In the example shown in FIG. 9, the second pitch p2, which is significantly larger than the first pitch p1, is realized by the above-mentioned second method.

In the example shown in FIG. 9, the center of the oil hole 343 (center related to the outer diameter φr) is the center in the circumferential direction of the small outer diameter portion surface 3462 (small outer diameter portion surface 3462 in which the opening 3431 is formed). Formed to match. In this case, the oil hole 343 is formed in such a manner that the entire opening 3431 is located within the small outer diameter surface 3462 without excessively increasing the circumferential length of the small outer diameter surface 3462 in which the opening 3431 is formed. Can be formed. However, in the modified example, the oil hole 343 may be formed so that its center (center related to the outer diameter φr) is slightly offset in the circumferential direction with respect to the circumferential center of the small outer diameter portion surface 3462. Good.

Further, in the above-described embodiment, the opening 8021A (diameter inner opening) of the oil passage 802 is formed on the surface of the large inner diameter portion 3261 of the rotor core 32, whereas in this modification, as shown in FIG. In addition, the opening 8021A (diameter inner opening) of the oil passage 802 is formed on the surface 3262 of the small inner diameter portion of the rotor core 232.

Also in this case, the opening 8021A of the oil passage 802 is preferably formed in a region where the outer diameter of the small inner diameter portion surface 3262 is substantially constant. As a result, the oil passage 802 can be processed (formed) with high accuracy.

In the example shown in FIG. 9, the small inner diameter portion surface 3262 on which the opening 8021A is formed is compared with the small inner diameter portion surface 3262 formed by the convex portion 326 that meshes with the concave portion 347 of the rotor shaft 234. And the length in the circumferential direction is long. As described above, the surface of the small inner diameter portion 3262 is so that the length in the circumferential direction of the region having a substantially constant outer diameter is significantly larger than the opening dimension d1 (dimension in the circumferential direction) of the opening 8021A of the oil passage 802. The length in the circumferential direction may be set.

Further, in this modification, the convex portion 326 facing the concave portion 347A in the rotor core 232, that is, the convex portion 326 in which the opening 8021A is formed, is formed with respect to the rotor shaft 234 as shown in FIG. Abut without gaps in the radial direction. That is, the ridge portion 326 in which the opening 8021A is formed abuts on the rotor shaft 234 in the radial direction facing the portion (here, the concave portion 347A) without a gap in the radial direction. As a result, even when the rotor core 232 and the rotor shaft 234 are press-fitted together, the inconvenience that occurs when the ridge portion 326 is radially separated from the rotor shaft 234 (that is, as described above with reference to FIG. 6B). In addition, the inconvenience of oil leakage in the axial direction due to the gap Δ1) can be reduced.

In this way, the same effect as that of the above-described embodiment can be obtained by this modification. In this modification as well, the rotor core 232 may be integrated with the rotor shaft 234 by press fitting, but is preferably integrated by tightening. In this case, the inconvenience caused by the deformation of the rotor core 32 at the time of press-fitting (that is, the inconvenience that the opening 3431 is closed due to the axial tilt of the rotor core 32 at the time of press-fitting as described above with reference to FIG. 8). Can be reduced.

Although each embodiment has been described in detail above, the present invention is not limited to a specific embodiment, and various modifications and changes can be made within the scope of the claims. It is also possible to combine all or a plurality of the components of the above-described embodiment.

For example, in the above-described embodiment (the same applies to the first modification and the like), the oil hole 343 is formed so that the opening 3431 does not cover the inclined surface 3436 in consideration of the workability of hole processing. Not limited. That is, the oil hole 343 may be formed in such a manner that the opening 3431 covers the inclined surface 3436 (see FIG. 4). In this case, all of the ridges 346 may be formed with the same first pitch p1.

Further, in the above-described embodiment (the same applies to the first modification and the like), the meshing related to the spline coupling is such that there is no gap in the circumferential direction between the specific convex portion 346B and the specific concave portion 327B. It is realized through contact, but it is not limited to this. For example, in place of or in addition to a circumferentially tight abutment between a particular ridge 346B and a particular ridge 327B, with a particular ridge 347 and a particular ridge 326. It may be realized through an abutting with no gap in the circumferential direction between the two. Further, the meshing related to the spline coupling may be realized through a slight gap in the circumferential direction. Further, between the specific ridge portion 346B that realizes the meshing related to the spline coupling and the specific concave portion 327B (the specific concave portion 347 that realizes the meshing related to the spline coupling and the specific ridge portion 326 The same applies to the space), and radial contact may be realized.

Further, in the above-described embodiment, the rotor core 32 has two convex portions 326 of the convex portions 326 that fit into the concave portion 347 of the rotor shaft 34 every 90 degrees around the rotation shaft 12. Each has, but is not limited to this. For example, the rotor core 32 may have four ridges 326 of the ridges 326 that fit into the ridges 347 of the rotor shaft 34 at 90 degrees around the rotation shaft 12. .. In this case, for example, in FIG. 3, two ridges 326 that fit into the ridges 347 of the rotor shaft 34 are provided on the left side of the ridges 346A of the rotor shaft 34 in a symmetrical manner to the right side. You may. In this case, the rotor core 32 has a form in which the configurations related to the ridges 326 overlap each time the rotor core 32 rotates 45 degrees around the rotation shaft 12.

<Additional notes>
The following will be further disclosed with respect to the above examples. Of the effects described below, the effect relating to each additional form with respect to one form is an additional effect resulting from each of the additional forms.

(1) One form includes a rotor core (32, 232) having a shaft hole at the center and an oil passage (802) in the core that opens into the shaft hole.
A rotor shaft that fits into the shaft hole and has a tubular shape that includes an outer peripheral surface facing the shaft hole and an inner peripheral surface that forms an axial core oil passage (801). It is provided with a rotor shaft (34, 234) having an oil hole (343) that communicates with the peripheral surface.
The outer peripheral surface of the rotor shaft includes a shaft small diameter portion (3462) having a predetermined outer diameter, a shaft large diameter portion (3461) having an outer diameter larger than the shaft small diameter portion, and the shaft small diameter portion and the shaft large diameter portion. Each includes a plurality of shaft tooth surface portions (3463) provided between the portions in the circumferential direction.
The oil hole has an outer peripheral surface side opening (3431) formed in at least one of the shaft small diameter portion and the shaft large diameter portion.
There is a radial gap between the small diameter portion of the shaft or the large diameter portion of the shaft on which the outer peripheral surface side opening is formed and the shaft hole on which the shaft hole side opening (8021A) of the oil passage in the core is formed. It is a rotor (30) for a rotary electric machine that comes into contact with each other without any contact and allows the oil passage in the core and the oil hole to communicate with each other.

According to this embodiment, an oil having an outer peripheral surface of a rotor shaft having a shaft large diameter portion, a shaft small diameter portion, and a shaft tooth surface portion and a shaft hole of the rotor core facing each other, and having an outer peripheral surface side opening in the rotor shaft. Since the holes are formed, it is possible to effectively cool the rotor core and the like by utilizing the oil holes of the rotor shaft while improving the transmission performance of the rotational torque between the rotor core and the rotor shaft. Further, since the opening on the outer peripheral surface side of the oil hole is formed in at least one of the shaft small diameter portion and the shaft large diameter portion, the processing accuracy of the oil hole can be improved. By improving the processing accuracy of the oil holes, the rotor core and the like can be cooled more effectively. Further, the small diameter portion of the shaft or the large diameter portion of the shaft on which the opening on the outer peripheral surface side of the oil hole in the rotor shaft is formed is in contact with the shaft hole of the rotor core in the radial direction without a gap, and the oil passage in the core and the oil hole. Since they communicate with each other, it is possible to reduce the inconvenience that may occur when they face each other through a gap. For example, in a configuration in which a shaft small diameter portion or a shaft large diameter portion in which an opening on the outer peripheral surface side of an oil hole is formed in a rotor shaft faces a shaft hole of a rotor core via a gap, the shaft is caused by the gap. The inconvenience that oil leaks in the direction (as a result, the amount of oil to be supplied from the outer peripheral surface side opening of the oil hole to the oil passage in the core through the shaft hole side opening is reduced) may occur. According to this embodiment, such inconvenience can be reduced.

(2) Further, in the present embodiment, preferably, the outer peripheral surface side opening is within a region having a substantially constant outer diameter in at least one large diameter portion of the shaft or at least one small diameter portion of the shaft. Is formed in.

In this case, since the opening on the outer peripheral surface side of the oil hole is formed in a region where the outer diameter of the spline joint portion is substantially constant, the machining accuracy of the oil hole can be improved. By improving the machining accuracy of the oil holes, it becomes possible to cool the rotor core and the like more effectively.

(3) Further, in the present embodiment, preferably, the inner peripheral surface of the rotor core has a core large diameter portion (3261) having a predetermined inner diameter and a core small diameter portion (3622) having an inner diameter smaller than the core large diameter portion. ), And a plurality of core tooth surface portions provided between the core small diameter portion and the core large diameter portion in the circumferential direction, respectively.
The shaft hole side opening is formed in at least one large diameter portion of the core or in at least one small diameter portion of the core.

In this case, at least one of the core large diameter portion and the core small diameter portion having different inner diameters can be used to form the shaft hole side opening of the oil passage in the core.

(4) Further, in the present embodiment, preferably, the shaft hole side opening is within a region having a substantially constant inner diameter in at least one large diameter portion of the core or at least one small diameter portion of the core. It is formed.

In this case, between the surface of the rotor core where the shaft hole side opening of the oil passage is formed (core large diameter portion or core small diameter portion) and the surface of the rotor shaft where the outer peripheral surface side opening is formed, along the surface. Contact is possible, and the continuity (radial continuity) between the outer peripheral surface side opening and the shaft hole side opening can be enhanced. As a result, oil leaking in the axial direction between the outer peripheral surface side opening and the shaft hole side opening (as a result, is supplied from the outer peripheral surface side opening of the oil hole to the oil passage through the shaft hole side opening). The possibility of insufficient amount of oil to be used) can be reduced.

(5) Further, in the present embodiment, preferably, at least one of the plurality of first convex portions (346) formed by the shaft large diameter portion and the shaft tooth surface portion of the rotor shaft is the rotor core. Fits into or at least one of a plurality of second recesses (327) formed by the core large diameter portion and the core tooth surface portion.
At least one of the plurality of second convex portions (326) formed by the core small diameter portion and the core tooth surface portion of the rotor core is formed by the shaft small diameter portion and the shaft tooth surface portion of the rotor shaft. It fits into at least one of a plurality of first recesses (347).

In this case, at least one of the plurality of first ridges or at least one of the plurality of second ridges is used to realize the transmission performance of the required rotational torque at the spline joint. it can.

(6) Further, in the present embodiment, preferably, each of the plurality of first convex portions has the same outer diameter (r1).

In this case, the workability of the plurality of first convex portions is improved. The outer diameter of the first convex portion corresponds to the outer diameter of the large diameter portion of the shaft forming the first convex portion.

(7) Further, in the present embodiment, preferably, the rotor core has a magnet hole (324) extending in the axial direction and an axial oil passage (803) extending in the axial direction adjacent to the magnet hole. And the oil passage (802) in the core.
The oil passage in the core communicates with the axial oil passage on the outer side in the radial direction.

In this case, it is possible to effectively cool the permanent magnets and the like in the rotor core and the magnet holes by utilizing the oil holes of the rotor shaft, the axial oil passages of the rotor core, and the oil passages in the core.

(8) Further, in the present embodiment, preferably, the rotor shaft and the rotor core are integrated by tightening.

In this case, the spline joint can be strengthened by tightening, and the transmission performance of the rotational torque at the spline joint can be effectively improved. Further, the small diameter portion of the shaft or the large diameter portion of the shaft on which the opening on the outer peripheral surface side of the oil hole in the rotor shaft is formed comes into contact with the shaft hole of the rotor core without a gap in the radial direction. Since the contact is realized, it is possible to reduce the inconvenience (the possibility that the opening on the outer peripheral surface side may be closed due to the axial tilt of the rotor core at the time of press fitting) when the contact is realized by press fitting.

(9) Further, another form is a rotary electric machine (1) including a rotor for a rotary electric machine according to each of the above-described forms.

According to this embodiment, it is possible to realize a rotary electric machine capable of effectively cooling the rotor core and the like by utilizing the oil holes of the rotor shaft while improving the transmission performance of the rotational torque between the rotor core and the rotor shaft.

(10) Further, another form is a rotor core having a shaft hole in the central portion and an oil passage (802) in the core that opens into the shaft hole, and the shaft hole has a predetermined inner diameter. The core large diameter portion (3261), the core small diameter portion (3622) having an inner diameter smaller than the core large diameter portion, and the core tooth surface portion provided between the core small diameter portion and the core large diameter portion in the circumferential direction. A rotor core (32, 232) is prepared, which includes a plurality of each and has a shaft hole side opening (8021A) of the oil passage in the core formed in at least one small diameter portion of the core or at least one large diameter portion of the core. ,
A cylindrical rotor shaft having an outer peripheral surface facing the shaft hole and an inner peripheral surface forming an axial center oil passage, and an oil hole (343) communicating the outer peripheral surface and the inner peripheral surface. The shaft small diameter portion (3462) having the outer peripheral surface having a predetermined outer diameter, the shaft large diameter portion (3461) having an outer diameter larger than the shaft small diameter portion, and the shaft small diameter portion and the shaft large portion. A plurality of shaft tooth surface portions (3463) provided between the diameter portion and the circumferential direction are included, and an outer peripheral surface side opening of the oil hole is formed in at least one of the shaft small diameter portions or at least one of the shaft large diameter portions. Prepare the rotor shaft (34, 234) to be
The rotor shaft and the rotor core are integrated by tightening in a manner in which the plurality of core small diameter portions do not face the plurality of shaft large diameter portions in the radial direction.
The small diameter portion of the shaft or the large diameter portion of the shaft on which the opening on the outer peripheral surface side is formed by the tightening fitting, and the small diameter portion of the core or the large diameter portion of the core on which the opening on the shaft hole side is formed. This is a method for manufacturing a rotor (30) for a rotary electric machine, in which the oil passage in the core and the oil hole are communicated with each other by abutting without a gap in the radial direction.

According to this embodiment, since the spline coupling portion between the rotor core and the rotor shaft can be realized by tightening, the transmission performance of the rotational torque at the spline coupling portion can be effectively enhanced. Further, by utilizing the tightening fit, the shaft small diameter portion or the shaft large diameter portion in which the outer peripheral surface side opening of the oil hole in the rotor shaft is formed, and the core in which the shaft hole side opening of the oil passage in the rotor core is formed. The oil passage in the core and the oil hole can be communicated with each other while the small diameter portion or the large diameter portion of the core are brought into contact with each other without a gap in the radial direction. As a result, the continuity (radial continuity) between the outer peripheral surface side opening and the shaft hole side opening is enhanced, and leakage occurs in the axial direction between the outer peripheral surface side opening and the shaft hole side opening. Oil (as a result, there is a possibility that the amount of oil to be supplied from the outer peripheral surface side opening of the oil hole to the oil passage through the shaft hole side opening may be insufficient) can be reduced.

1 Motor 10 Motor housing 12 Rotation axis (center of rotation)
14a Bearing 14b Bearing 21 Stator 22 Coil 22A Coil end 22B Coil end 30 Rotor 32, 232 Rotor core 34, 34'234 Rotor shaft 34A Hollow part 321 Permanent magnet 322 Void 326 Convex part 327, 327B Concave part 341 Oil hole 342 Oil hole 343 Oil hole 346, 346A, 346B Convex part 347 Concave part 801 Oil passage 802 Oil passage 803 Oil passage 3261 Large inner diameter part surface 3262 Small inner diameter part surface 3431 Opening 3461 Large outer diameter part surface 3462 Small outer diameter part surface 3436 Inclined surface 8021 Oil passage 8021A Opening 8022 Oil passage 8023 Oil passage

Claims (10)

A rotor core having a shaft hole in the center and an oil passage in the core that opens into the shaft hole,
A rotor shaft that fits into the shaft hole and has a tubular shape that includes an outer peripheral surface facing the shaft hole and an inner peripheral surface that forms an axial oil passage, and has the outer peripheral surface and the inner peripheral surface. Equipped with a rotor shaft with oil holes to communicate with
The outer peripheral surface of the rotor shaft includes a shaft small diameter portion having a predetermined outer diameter, a shaft large diameter portion having an outer diameter larger than the shaft small diameter portion, and a circumferential distance between the shaft small diameter portion and the shaft large diameter portion. Including multiple shaft tooth surfaces provided in
The oil hole has an opening on the outer peripheral surface side formed in at least one of the shaft small diameter portion and the shaft large diameter portion.
The small diameter portion of the shaft or the large diameter portion of the shaft on which the outer peripheral surface side opening is formed and the shaft hole on which the shaft hole side opening of the oil passage in the core is formed are in contact with each other without a gap in the radial direction. , A rotor for rotary electric machines, in which the oil passage in the core and the oil hole communicate with each other. The rotary electric machine according to claim 1, wherein the outer peripheral surface side opening is formed in a region having a substantially constant outer diameter in at least one large diameter portion of the shaft or in at least one small diameter portion of the shaft. For rotor. The inner peripheral surface of the rotor core includes a core large diameter portion having a predetermined inner diameter, a core small diameter portion having an inner diameter smaller than the core large diameter portion, and a circumferential distance between the core small diameter portion and the core large diameter portion. Including multiple core tooth surfaces provided in each
The rotor for a rotary electric machine according to claim 1 or 2, wherein the shaft hole side opening is formed in at least one large diameter portion of the core or in at least one small diameter portion of the core. The rotary electric machine according to claim 3, wherein the shaft hole side opening is formed in a region having a substantially constant inner diameter in at least one large diameter portion of the core or at least one small diameter portion of the core. Rotor. At least one of the plurality of first convex portions formed by the shaft large diameter portion and the shaft tooth surface portion of the rotor shaft is formed by the core large diameter portion and the core tooth surface portion of the rotor core. Fits in at least one of the second recesses of the
At least one of the plurality of second convex portions formed by the core small diameter portion and the core tooth surface portion of the rotor core is a plurality of second portions formed by the shaft small diameter portion and the shaft tooth surface portion of the rotor shaft. The rotor for a rotary electric machine according to claim 3 or 4, which fits in at least one of the concave portions. The rotor for a rotary electric machine according to claim 5, wherein each of the plurality of first convex portions has the same outer diameter. The rotor core includes a magnet hole extending in the axial direction, an axial oil passage extending in the axial direction adjacent to the magnet hole, and an oil passage in the core.
The rotor for a rotary electric machine according to any one of claims 1 to 6, wherein the oil passage in the core communicates with the axial oil passage on the outer side in the radial direction. The rotor for a rotary electric machine according to any one of claims 1 to 7, wherein the rotor shaft and the rotor core are integrated by tightening. A rotary electric machine including the rotary electric machine rotor according to any one of claims 1 to 8. A rotor core having a shaft hole in the center and an oil passage in the core that opens into the shaft hole, and the shaft hole has a core large diameter portion having a predetermined inner diameter and an inner diameter larger than the core large diameter portion. Each includes a plurality of small core small diameter portions and a plurality of core tooth surface portions provided between the core small diameter portion and the core large diameter portion in the circumferential direction, and the at least one core small diameter portion or at least one core large diameter portion includes. Prepare the rotor core to form the shaft hole side opening of the oil passage in the core.
A cylindrical rotor shaft having an outer peripheral surface facing the shaft hole and an inner peripheral surface forming an axial center oil passage, and having an oil hole communicating the outer peripheral surface and the inner peripheral surface. The outer peripheral surface is provided between a shaft small diameter portion having a predetermined outer diameter, a shaft large diameter portion having an outer diameter larger than the shaft small diameter portion, and a circumferential direction between the shaft small diameter portion and the shaft large diameter portion. A rotor shaft is prepared, which includes a plurality of tooth surfaces of the shaft to be formed, and an opening on the outer peripheral surface side of the oil hole is formed in at least one small diameter portion of the shaft or at least one large diameter portion of the shaft.
The rotor shaft and the rotor core are integrated by tightening in a manner in which the plurality of core small diameter portions do not face the plurality of shaft large diameter portions in the radial direction.
The small diameter portion of the shaft or the large diameter portion of the shaft on which the opening on the outer peripheral surface side is formed by the tightening fitting, and the small diameter portion of the core or the large diameter portion of the core on which the opening on the shaft hole side is formed. A method for manufacturing a rotor for a rotary electric machine, in which the oil passage in the core and the oil hole are communicated with each other by abutting without a gap in the radial direction.