rotating electrical machines

Abstract

A rotating electrical machine in which a cooling oil path is formed by easy assembly is provided. [Solution] The device comprises a shaft (1) having a first internal shaft conduit (11) with an opening at one end and a second internal shaft conduit (12) that is connected to the first internal shaft conduit and has an opening on its side; end plates (2, 5) having a first groove (21) that overlaps the entire intersection of a plane perpendicular to the rotation axis and the side of the shaft and is connected to the second internal shaft conduit, and a second groove (22) that is connected to the first groove and extends to the end in a direction perpendicular to the rotation axis; a first magnet cover (3) having a first guide groove (31) that is connected to the second groove at the end of the end plate in a direction perpendicular to the rotation axis; a rotor core (4) having a rotor core internal conduit (43) that is connected to the first guide groove; and a second magnet cover (6) having a second guide groove (62) that is connected to the rotor core internal conduit and an oil discharge path (63) that is connected to the second guide groove and to the outside of the rotor.

Description

[Technical Field]

[0001] The present invention relates to a rotating electric machine. [Background technology]

[0002] Rotating electric machines such as motors and generators sometimes have difficulty operating efficiently due to heat generated by coils during operation. For this reason, technologies for cooling the coils mounted on rotating electric machines have been developed. Examples of such technologies include the rotating electric machine disclosed in Patent Document 1 and the motor disclosed in Patent Document 2. The rotating electric machine disclosed in Patent Document 1 is provided with a flow path for supplying a liquid refrigerant. The motor disclosed in Patent Document 2 is provided with an oil path for circulating cooling oil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6279059 [Patent Document 2] Japanese Patent Publication No. 2020-14355 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the rotating electric machine disclosed in Patent Document 1, in order to form flow passage outlets for the flow passages provided in the rotor core, holes must be formed in the end plates, and the rotor core and the end plates must be assembled in a state where the angle around the axis of the rotor core and the angle around the axis of the end plates are aligned. Here, the end plates are disk-shaped members that sandwich the rotor core from both sides in the axial direction. Furthermore, in order to achieve this assembly, the rotating electric machine disclosed in Patent Document 1 must be provided with keyways or the like in the rotor core and the end plates.

[0005] Similarly, in the motor of Patent Document 2, in order to form the supply flow paths provided in the shaft and rotor core, the shaft and rotor core must be assembled while the angle around the axis of the shaft and the angle around the axis of the rotor core are aligned.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a rotating electrical machine that allows a cooling oil path to be configured through easy assembly. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the rotating electric machine of the present invention comprises a shaft in which a first internal shaft conduit having an opening at one end in the direction of the rotation axis of the rotor is formed, and a second internal shaft conduit communicating with the first internal shaft conduit and having an opening on a side surface thereof; an end plate in which a first groove overlaps with the entire intersection line between a plane perpendicular to the rotation axis and the side surface of the shaft and overlaps with the opening of the second internal shaft conduit, and a second groove communicating with the first groove and extending to an end portion in the direction perpendicular to the rotation axis is formed; a first magnet cover in which a first guide groove communicating with the second groove is formed at an end portion of the end plate in the direction perpendicular to the rotation axis; a rotor core in which a rotor core internal conduit overlapping with the first guide groove in the direction of the rotation axis is formed; and a second magnet cover in which a second guide groove overlapping with the rotor core internal conduit in the direction of the rotation axis and an oil discharge path communicating with the second guide groove and to the outside of the rotor are formed.

[0008] The oil discharge path is an oil discharge conduit that is connected to the second guide groove, is formed along the direction of the rotation axis, and leads to the outside of the rotor on an end face of the second magnet cover that is perpendicular to the rotation axis.

[0009] The oil discharge path is an oil discharge groove formed on the surface of the second magnet cover that contacts the rotor core, connected to the second guide groove, and extending to the end in a direction perpendicular to the rotation axis.

[0010] The end plate further has a third groove formed around the entire periphery of the end in a direction perpendicular to the rotation axis, and in this case, the first guide groove communicates with the second groove via the third groove.

[0011] The third groove has a circular inner end in a direction perpendicular to the rotation axis.

[0012] The first groove has a circular outer end in a direction perpendicular to the rotation axis.

[0013] The first guide groove is a curved groove that smoothly connects the second groove and the rotor core internal conduit.

[0014] The second guide groove is a curved groove that is smoothly connected to the rotor core internal conduit.

[0015] On a circumference passing through the entire end of the end plate in a direction perpendicular to the rotation axis, the arc length of the first guide groove is equal to or greater than the arc length of the second groove. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a rotating electrical machine that allows a cooling oil path to be configured through easy assembly. [Brief explanation of the drawings]

[0017] [Figure 1] 4 is a cross-sectional view of a plane passing through the rotation axis of the shaft, first end plate, first magnet cover, rotor core, second end plate, and second magnet cover according to the first embodiment. FIG. [Figure 2] FIG. 4 is a view of the first end plate according to the first embodiment as seen from the −X direction side. [Figure 3] FIG. 4 is a view of the first magnet cover according to the first embodiment as seen from the −X direction side. [Figure 4] 4 is a cross-sectional view showing the BB cross section of the first magnet cover according to the first embodiment. FIG. [Figure 5] 2 is a cross-sectional view taken along a plane perpendicular to the rotation axis of the rotor core according to the first embodiment. FIG. [Figure 6] FIG. 2 is a diagram showing details of a conduit in a rotor core according to the first embodiment. [Figure 7] FIG. 4 is a view of the second magnet cover according to the first embodiment as seen from the +X direction side. [Figure 8] 4 is a cross-sectional view showing the CC cross section of the second magnet cover according to the first embodiment. FIG. [Figure 9] FIG. 10 is a view of a first end plate according to a second embodiment as viewed from the −X direction side. [Figure 10] FIG. 10 is a view of the second magnet cover according to the second embodiment as seen from the +X direction side. [Figure 11] FIG. 10 is a cross-sectional view showing a CC cross section of a second magnet cover according to a second embodiment. [Figure 12] FIG. 11 is a view of the second magnet cover according to the second embodiment as seen from the −X direction side. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0019] (First embodiment) Fig. 1 is a cross-sectional view of a plane passing through the rotation axis of a shaft, first end plate, first magnet cover, rotor core, second end plate, and second magnet cover according to the first embodiment. The motor according to the first embodiment includes the shaft 1, first end plate 2, first magnet cover 3, rotor core 4, second end plate 5, and second magnet cover 6 shown in Fig. 1. The first end plate 2, first magnet cover 3, rotor core 4, second end plate 5, and second magnet cover 6 form the rotor of the motor according to the first embodiment.

[0020] In the following description, an X-axis parallel to the rotor rotation axis A, a Y-axis perpendicular to the X-axis, and a Z-axis perpendicular to the X-axis and Y-axis are used. The X-axis, Y-axis, and Z-axis form a right-handed system.

[0021] The shaft 1 is a cylindrical member that is fitted into the rotor and supports the rotor so that the rotor can rotate about the rotation axis A. The shaft 1 is supported at its +X-direction end and its -X-direction end by, for example, bearings fitted into the housing of the motor. As shown in FIG. 1 , the shaft 1 is formed with a first shaft internal conduit 11. The first shaft internal conduit 11 has an opening at one end in the direction of the rotation axis A of the rotor. Specifically, the first shaft internal conduit 11 has an opening at its end on the +X-direction side. As shown in FIG. 1 , the shaft 1 is formed with a second shaft internal conduit 12. The second shaft internal conduit 12 is connected to the first shaft internal conduit 11 and has an opening on a side surface of the shaft 1.

[0022] The first end plate 2 is a disk-shaped member that contacts the end face of the rotor core 4 on the +X direction side and, together with the second end plate 5, sandwiches and fixes the rotor core 4 from both sides in the direction of the rotation axis A.

[0023] Fig. 2 is a view of the first end plate according to the first embodiment as seen from the -X direction side. As shown in Fig. 2, the first end plate 2 has a first groove 21 recessed toward the +X direction side and a second groove 22 recessed toward the +X direction side formed therein.

[0024] The first groove 21 overlaps the entire intersection line between a plane perpendicular to the rotation axis A and the side surface of the shaft 1, and also overlaps with the opening of the second internal-shaft conduit 12. The first groove 21 contacts the side surface of the shaft 1 over the entire circumference around the rotation axis A. Therefore, the first groove 21 communicates with the opening of the internal-shaft conduit 12 regardless of the angle of the first end plate 2 around the rotation axis A relative to the shaft 1. Furthermore, the first groove 21 increases the overall volume of the cooling oil conduit, which will be described later, thereby increasing the amount of cooling oil flowing through the cooling oil conduit. The outer end of the first groove 21 in the direction perpendicular to the rotation axis A is circular.

[0025] The second grooves 22 communicate with the first grooves 21 and extend to the end of the first end plate 2 in a direction perpendicular to the rotation axis A. Furthermore, a total of eight second grooves 22 extend radially within a plane perpendicular to the rotation axis A, with a point on the rotation axis as the center.

[0026] The first magnet cover 3 is a disk-shaped member that covers a portion of the surface on the +X direction side of the first end plate 2. The first magnet cover 3 also covers a portion of the end face on the +X direction side of the rotor core 4. This prevents the magnets from falling out of the holes 41 and 42 formed in the rotor core 4.

[0027] FIG. 3 is a view of the first magnet cover according to the first embodiment as seen from the −X direction. FIG. 4 is a cross-sectional view showing the BB cross section of the first magnet cover according to the first embodiment. The first magnet cover 3 has a first guide groove 31 that communicates with the second groove 22 at an end of the first end plate 2 in a direction perpendicular to the rotation axis A. The first guide groove 31 is formed on the −X direction surface of the first magnet cover 3 and is a curved groove that smoothly connects the second groove 22 with a rotor core internal conduit 43, which will be described later. On a circumference that passes through the entire end of the first end plate 2 in a direction perpendicular to the rotation axis A, the arc length of the first guide groove 31 is equal to the arc length of the second groove 62. Note that, on this circumference, the arc length of the first guide groove 31 is preferably equal to or greater than the arc length of the second groove 62.

[0028] The rotor core 4 is a cylindrical member formed by stacking plate-shaped members in the direction of the rotation axis A. The plate-shaped members are circular and made of electromagnetic steel. As shown in FIG. 1, the rotor core 4 is in contact with the first magnet cover 3 and the first end plate 2 at a boundary surface B1 that passes through the boundary between the first magnet cover 3 and the rotor core 4. As shown in FIG. 1, the rotor core 4 is in contact with the second magnet cover 6 and the second end plate 5 at a boundary surface B2 that passes through the boundary between the second magnet cover 6 and the rotor core 4.

[0029] 5 is a cross-sectional view of the rotor core according to the first embodiment taken along a plane perpendicular to the rotation axis of the rotor core 4. As shown in FIG. 5, the rotor core 4 has a hole 41, a hole 42, and an internal conduit 43 formed therein.

[0030] The holes 41 are rectangular parallelepiped holes into which magnets M41 for forming the magnetic poles of the rotor core 4 are inserted, and may be integrated with the flux barrier. The cross section of the hole 41 taken along a plane perpendicular to the rotation axis A has substantially the same dimensions as the hole 41, and a plurality of magnets M41 whose dimensions in the direction of the rotation axis A are smaller than those of the rotor core 4 are inserted in a row in the direction of the rotation axis A. Each magnet M41 is formed into a rectangular parallelepiped and fixed to adjacent magnets M41 in the direction of the rotation axis A and to the inner wall of the hole 41 with an adhesive. Note that instead of a row of magnets M41, the hole 41 may have substantially the same dimensions as the hole 41 in a cross section taken along a plane perpendicular to the rotation axis A, and a single magnet whose dimensions in the direction of the rotation axis A are substantially the same as those of the hole 41 may be inserted.

[0031] Hole 42 is a rectangular parallelepiped hole into which magnets M421 and M422 are inserted to form the magnetic poles of rotor core 4, and may be integrated with the flux barrier. Magnets M421, each having the same dimensions as magnet M41, are inserted in hole 42 in a row toward rotation axis A and closer to rotation axis A. Magnets M422, each having the same dimensions as magnet M41, are inserted in hole 42 in a row toward rotation axis A and closer to rotation axis A.

[0032] Note that a magnet other than the row of magnets M421 may be inserted into hole 42. For example, hole 42 may have one magnet inserted therein, the dimensions of each part of a cross section taken along a plane perpendicular to rotation axis A being equal to those of magnet M421, and the dimensions in the direction of rotation axis A being approximately the same as those of hole 42. Similarly, hole 42 may have one magnet other than the row of magnets M422 inserted therein. For example, hole 42 may have one magnet inserted therein, the dimensions of each part of a cross section taken along a plane perpendicular to rotation axis A being equal to those of magnet M422, and the dimensions in the direction of rotation axis A being approximately the same as those of hole 42.

[0033] Furthermore, a magnet other than the row of magnets M421 and the row of magnets M422 may be inserted into hole 42. For example, one magnet may be inserted into hole 42. The dimension of the long side of this magnet in a cross section taken along a plane perpendicular to rotation axis A is equal to twice that of magnets M421 and M422. The dimension of the short side of this magnet in the cross section is equal to that of magnets M421 and M422. The dimension of this magnet in the direction of rotation axis A is approximately the same as that of hole 42.

[0034] The magnet M421 is formed into a rectangular parallelepiped and is fixed with an adhesive to the magnet 422, the magnet M421 adjacent to it in the direction of the rotation axis A, and the inner wall of the hole 42. Similarly, the magnet M422 is formed into a rectangular parallelepiped and is fixed with an adhesive to the magnet 421, the magnet M422 adjacent to it in the direction of the rotation axis A, and the inner wall of the hole 42. Note that the magnets need not be inserted in the same order as the row of magnets M421 and the row of magnets M422, but may be inserted in a manner that follows the inner wall of the hole 42 as closely as possible.

[0035] The rotor-core internal conduit 43 overlaps with the first guide groove 31 in the direction of the rotation axis A. The rotor-core internal conduit 43 is a pipe that extends in the direction of the rotation axis A and has a teardrop-shaped cross section taken along a plane perpendicular to the rotation axis A. FIG. 6 is a diagram showing details of the rotor-core internal conduit according to the first embodiment. The rotor-core internal conduit 43 is plane-symmetric with respect to a plane S passing through the rotation axis A. Furthermore, within a predetermined distance from the rotation axis A, the rotor-core internal conduit 43 has a cross-sectional area defined by a cylinder C whose central axis is the rotation axis A and whose radius is variable, which increases with increasing distance from the rotation axis A. Furthermore, within the predetermined distance from the rotation axis A, the rotor-core internal conduit 43 has a cross-sectional area defined by a cylinder C whose central axis is the rotation axis A and whose radius is variable, which decreases with increasing distance from the rotation axis A.

[0036] At least a portion of the rotor core internal conduit 43 overlaps with the region sandwiched between the first imaginary cylinder C1 and the second imaginary cylinder C2 shown in Fig. 5. The first imaginary cylinder C1 is a cylinder whose central axis is the rotation axis A and passes through a surface P421 facing the rotation axis A of the magnet M421 inserted into the hole 42 formed in the rotor core 4. The second imaginary cylinder C2 is a cylinder whose central axis is the rotation axis A and is parallel to the surface P421 and passes through a surface P422 that bisects the entire magnet inserted into the hole 42. The surface P422 forms a boundary between a row of the plurality of magnets M421 and a row of the plurality of magnets M422, which will be described later.

[0037] As shown in Fig. 6, the rotor core internal conduit 43 has a rectangle R circumscribing the rectangle R on a plane perpendicular to the rotation axis A. The rectangle R has a long side length La and a short side length Lb. Therefore, the aspect ratio La / Lb of the rectangle R is greater than 1. Furthermore, the long side of the rectangle R is parallel to the plane of symmetry S.

[0038] The rotor core internal conduit 43 includes an outer portion, which is a region outside a third imaginary cylinder C3 that passes through a line segment L connecting the midpoints of the long sides of the rectangle R and has the rotation axis A as its center axis, and an inner portion, which is a region inside the third imaginary cylinder C3. The outer portion mainly relieves stress caused by centrifugal force generated by rotation of the rotor. It is preferable that at least a portion of the outer portion overlaps with the region sandwiched between the first imaginary cylinder C1 and the second imaginary cylinder C2. The inner diameter portion mainly relieves stress generated by shrink-fitting the rotor core 4 and the shaft 1. It is also preferable that at least a portion of the inner diameter portion overlaps with the region inside the first imaginary cylinder C1. The third imaginary cylinder C3 shown in FIG. 5 coincides with the first imaginary cylinder C1. However, the third imaginary cylinder C3 does not have to coincide with the first imaginary cylinder C1.

[0039] As shown in FIG. 6 , the rotor-core internal conduit 43 has intersection lines N and F with the plane S, which is a plane of symmetry. The intersection line N is the intersection line between the rotor-core internal conduit 43 and the plane S that is closer to the rotation axis. The intersection line F is the intersection line between the rotor-core internal conduit 43 and the plane S that is farther from the rotation axis. The end of the intersection line F on the +X direction side is perpendicular to the rotation axis A and coincides with the point of the first guide groove 31 that is farthest from the rotation axis A on the boundary plane B1 that passes through the boundary between the first magnet cover 3 and the rotor core 4. The end of the intersection line F on the −X direction side is perpendicular to the rotation axis A and coincides with the point of the second guide groove 62 (described later) that is farthest from the rotation axis A on the boundary plane B2 that passes through the boundary between the second magnet cover 6 and the rotor core 4.

[0040] The rotor core internal conduit 43 is perpendicular to the rotation axis A, passes through boundary surface B1 that passes through the boundary between the first magnet cover 3 and the rotor core 4, and entirely overlaps with the first guide groove 31 on a straight line that passes through the first guide groove 31. The rotor core internal conduit 43 is perpendicular to the rotation axis A, passes through boundary surface B2 that passes through the boundary between the second magnet cover 6 and the rotor core 4, and entirely overlaps with the second guide groove 62 on a straight line that passes through the second guide groove 62.

[0041] The second end plate 5 is a disk-shaped member that contacts the end face of the rotor core 4 on the −X direction side and, together with the first end plate 2, sandwiches and fixes the rotor core 4 from both sides in the direction of the rotation axis A.

[0042] The second magnet cover 6 is a disk-shaped member that covers a portion of the surface on the +X direction side of the second end plate 5. The second magnet cover 6 also covers a portion of the end face on the -X direction side of the rotor core 4. In this way, the second magnet cover 6 prevents the magnets from falling out of the holes 41 and 42 formed in the rotor core 4.

[0043] FIG. 7 is a view of the second magnet cover according to the first embodiment as seen from the +X direction side. FIG. 8 is a cross-sectional view showing the CC cross section of the second magnet cover according to the first embodiment. The second magnet cover 6 is formed with a second guide groove 62 and an oil discharge path. The second guide groove 62 is formed on the surface of the second magnet cover 6 on the +X direction side and is a curved groove that is smoothly connected to the rotor core internal conduit 43. The second guide groove 62 also overlaps with the rotor core internal conduit 43 in the direction of the rotation axis A. The oil discharge path is connected to the second guide groove 62 and the outside of the rotor. Specifically, the oil discharge path is an oil discharge groove 63 that is formed on the surface of the second magnet cover 6 that contacts the rotor core 4, is connected to the second guide groove 62, and extends to the end in a direction perpendicular to the rotation axis A.

[0044] The motor according to the first embodiment includes a cooling oil conduit formed by the first shaft internal conduit 11, the second shaft internal conduit 12, the first groove 21, the second groove 22, the first guide groove 31, the rotor core internal conduit 43, the second guide groove 62, and the oil discharge path 63. The motor according to the first embodiment cools the rotor, stator, etc. by the cooling oil flowing through the cooling oil conduit.

[0045] The above describes the motor according to the first embodiment. The motor according to the first embodiment includes the shaft 1, the first end plate 2, the first magnet cover 3, the rotor core 4, the second end plate 5, and the second magnet cover 6.

[0046] The shaft 1 is formed with a first internal-shaft conduit 11 having an opening at one end in the direction of the rotor's rotation axis, and a second internal-shaft conduit 12 that communicates with the first internal-shaft conduit 11 and has an opening on a side surface of the shaft 1. The first end plate 2 is formed with a first groove 21 and a second groove 22. The first groove 21 overlaps the entire intersection line between a plane perpendicular to the rotation axis A and the side surface of the shaft 1, and therefore overlaps with the opening of the second internal-shaft conduit 12 regardless of the angle of the first end plate 2 around the rotation axis A relative to the shaft 1. The second groove 22 communicates with the first groove 21 and extends to its end in the direction perpendicular to the rotation axis A.

[0047] The first magnet cover 3 is formed with a first guide groove 31 that communicates with the second groove 22 at an end of the first end plate 2 in a direction perpendicular to the rotation axis A. The rotor core 4 is formed with an internal rotor core conduit 43 that overlaps with the first guide groove 31 in the direction of the rotation axis A. The second end plate 5, together with the first end plate 2, sandwiches and fixes the rotor core 4 from both sides in the direction of the rotation axis A. The second magnet cover 6 is formed with a second guide groove 62 and an oil discharge groove 63. The second guide groove 62 overlaps with the internal rotor core conduit 43 in the direction of the rotation axis A. The oil discharge groove 63 communicates with the second guide groove 62 and the outside of the rotor.

[0048] The motor according to the first embodiment includes the first groove 21 described above, which makes it possible to assemble the shaft 1 and the first end plate 2 without considering the angle of the first end plate 2 relative to the shaft 1 around the rotation axis A. Therefore, the motor according to the first embodiment makes it possible to configure the cooling oil conduit described above through easy assembly.

[0049] On a circumference passing through the entire end of the first end plate 2 in a direction perpendicular to the rotation axis A, the arc length of the first guide groove 31 is equal to or greater than the arc length of the second groove 22. As a result, in the motor according to the first embodiment, the cooling oil conduit does not narrow from the second groove 22 to the first guide groove 31, and therefore pressure loss of the cooling oil flowing from the second groove 22 into the first guide groove 31 can be reduced.

[0050] The rotor core internal conduit 43 has a cross-sectional shape taken along a plane perpendicular to the rotation axis A that is plane-symmetrical with respect to a plane S that passes through the rotation axis A. Within a predetermined distance from the rotation axis A, the cross-sectional area of ​​a cylinder C with the rotation axis A as its central axis increases, forming a teardrop shape. Therefore, in the cross-section taken along a plane perpendicular to the rotation axis A, the rotor core internal conduit 43 has a cross-sectional area of ​​an outer diameter portion that is larger than the cross-sectional area of ​​an inner diameter portion. Therefore, the motor according to the first embodiment can efficiently flow cooling oil even if the cooling oil is biased toward the outer diameter portion due to centrifugal force generated by rotation around the rotation axis A.

[0051] At least a portion of the rotor core internal conduit 43 overlaps with the region sandwiched between the first imaginary cylinder C1 and the second imaginary cylinder C2. The first imaginary cylinder C1 is a cylinder whose central axis is the rotation axis A and passes through a surface P421 facing the rotation axis A of the magnet M421 inserted into a hole formed in the rotor core 4. The second imaginary cylinder C2 is a cylinder whose central axis is the rotation axis A and is parallel to the surface P421 and passes through a plane P422 that bisects the entire magnet inserted into the hole 42.

[0052] As a result, the motor according to the first embodiment can efficiently cool the magnets M421 and M422, which are located in positions where their magnetic force is likely to decrease due to heat. Therefore, the motor according to the first embodiment can employ, as the magnets M421 and M422, magnets that are inexpensive but whose magnetic force decreases relatively greatly due to heat.

[0053] The rotor-core internal conduit 43 circumscribes the rotor-core internal conduit 43 on a plane perpendicular to the rotation axis A, has a long side parallel to the plane S serving as a symmetry plane, and has a rectangle R with an aspect ratio La / Lb greater than 1. As a result, in the motor according to the first embodiment, the outer shape of the rotor-core internal conduit 43 can relieve stress due to centrifugal force generated by rotation about the rotation axis A. Also, as a result, in the motor according to the first embodiment, the inner shape of the rotor-core internal conduit 43 can relieve stress generated by shrink-fitting the rotor core 4 and the shaft 1. In this way, the motor according to the first embodiment has the effect of relieving two types of stress in the rotor-core internal conduit 43, so there is no need to provide separate stress relief holes for relieving these stresses. Therefore, the rotor according to the first embodiment has higher strength than a rotor having separate stress relief holes and is less likely to break even when rotated at high speeds.

[0054] The rotor core internal conduit 43 has an outer portion that at least partially overlaps with the region sandwiched between the first imaginary cylinder C1 and the second imaginary cylinder C2. As a result, in the motor according to the first embodiment, the outer portion, which receives a larger flow rate of cooling oil than the inner diameter portion due to centrifugal force generated by rotor rotation, is disposed in the region where heat is particularly likely to build up, thereby enabling efficient cooling of the magnets M422 and M421.

[0055] The rotor core internal conduit 43 has an inner diameter portion that at least partially overlaps with an area inside the first imaginary cylinder C1, thereby enabling the motor according to the first embodiment to particularly effectively relieve stress that occurs when the rotor core 4 and the shaft 1 are shrink-fitted together.

[0056] The rotor core internal conduit 43 has an intersection line F with plane S that is farther from the rotation axis than the other intersection lines, which is perpendicular to the rotation axis A and coincides with the point of the first guide groove 31 that is farthest from the rotation axis A on the plane that passes through the boundary between the first magnet cover 3 and the rotor core 4. This allows the motor according to the first embodiment to smoothly connect the first guide groove 31 and the rotor core internal conduit 43, allowing cooling oil to smoothly flow from the first guide groove 31 into the rotor core internal conduit 43.

[0057] The rotor core internal conduit 43 has an intersection line F with plane S that is farther from the rotation axis than the other intersection lines, which is perpendicular to the rotation axis A and coincides with the point on the second guide groove 62 that is farthest from the rotation axis A on the plane that passes through the boundary between the second magnet cover 6 and the rotor core 4. This allows the motor according to the first embodiment to smoothly connect the rotor core internal conduit 43 and the second guide groove 62, allowing the cooling oil to smoothly flow from the rotor core internal conduit 43 into the second guide groove 62.

[0058] The rotor core internal conduit 43 is perpendicular to the rotation axis A, passes through boundary surface B1 that passes through the boundary between the first magnet cover 3 and the rotor core 4, and entirely overlaps with the first guide groove 31 on a straight line that passes through the first guide groove 31. This allows the motor according to the first embodiment to maximize the overlapping area between the first guide groove 31 and the rotor core internal conduit 43, allowing cooling oil to smoothly flow from the first guide groove 31 into the rotor core internal conduit 43.

[0059] The rotor core internal conduit 43 is perpendicular to the rotation axis A, passes through boundary surface B2 which is the boundary between the second magnet cover 6 and the rotor core 4, and entirely overlaps with the second guide groove 62 on a straight line which passes through the second guide groove 62. This maximizes the overlapping area between the rotor core internal conduit 43 and the second guide groove 62 in the motor according to the first embodiment, allowing the cooling oil to flow smoothly from the rotor core internal conduit 43 into the second guide groove 62.

[0060] The oil discharge groove 63 is formed on the surface of the second magnet cover 6 that comes into contact with the rotor core 4, communicates with the second guide groove 62, and extends to the end in a direction perpendicular to the rotation axis A. As a result, in the motor according to the first embodiment, centrifugal force generated by rotation around the rotation axis A acts on the cooling oil that has flowed into the second guide groove 62, and the cooling oil is discharged in a direction perpendicular to the rotation axis A by the oil discharge groove 63, thereby directly cooling the stator core, coils, etc.

[0061] The first groove 21 has a circular outer end in a direction perpendicular to the rotation axis A. This allows the first end plate 2 to be formed using a milling machine or the like. Therefore, the motor according to the first embodiment makes it possible to reduce the labor, time, cost, etc. required to manufacture the rotor.

[0062] The first guide groove 31 is formed on the surface of the first magnet cover 3 on the -X direction side, and is a curved groove that smoothly connects the second groove 22 to a rotor core internal conduit 43, which will be described later. This allows the motor according to the first embodiment to smoothly flow the cooling oil from the second shaft internal conduit 12 to the rotor core internal conduit 43, reducing pressure loss of the cooling oil. In other words, the motor according to the first embodiment can reduce pressure loss that occurs when the cooling oil flow direction changes from a direction perpendicular to the rotation axis A to the direction of the rotation axis A.

[0063] The second guide groove 62 is formed on the surface of the second magnet cover 6 on the +X direction side, and is a curved groove that is smoothly connected to the rotor core internal conduit 43. As a result, the motor according to the first embodiment allows the cooling oil to flow smoothly from the rotor core internal conduit 43 to the second guide groove 62, and the cooling oil that has flowed into the second guide groove 62 to flow smoothly into the oil discharge groove 63, thereby reducing pressure loss of the cooling oil. In other words, the motor according to the first embodiment can reduce pressure loss that occurs when the flow direction of the cooling oil changes from the direction of the rotation axis A to a direction perpendicular to the rotation axis A.

[0064] In the first embodiment, the rotor core internal conduit 43 is described as entirely overlapping with the first guide groove 31 on a straight line that is perpendicular to the rotation axis A, passes through the boundary surface B1, and passes through the first guide groove 31. However, this is not limited to this. The rotor core internal conduit 43 may have an outer portion that is perpendicular to the rotation axis A, passes through the boundary surface B1 that passes through the boundary between the first magnet cover 3 and the rotor core 4, and entirely overlaps with the first guide groove 31 on a straight line that is perpendicular to the rotation axis A, passes through the boundary surface B1 that passes through the boundary between the first magnet cover 3 and the rotor core 4, and passes through the first guide groove 31. This allows the motor according to the first embodiment to direct the cooling oil that has flowed into the first guide groove 31 into the outer portion, which can flow a larger amount of cooling oil than the inner diameter portion, thereby allowing the cooling oil to flow smoothly within the cooling oil conduit.

[0065] In the first embodiment, the rotor core internal conduit 43 is described as entirely overlapping with the second guide groove 62 on a straight line that is perpendicular to the rotation axis A, passes through the boundary surface B2, and passes through the second guide groove 62. However, this is not limiting. The rotor core internal conduit 43 may have an outer portion that is entirely overlapping with the second guide groove 62 on a straight line that is perpendicular to the rotation axis A, passes through the boundary surface B2 that passes through the boundary between the second magnet cover 6 and the rotor core 4, and passes through the second guide groove 62. This allows the motor according to the first embodiment to allow cooling oil to flow into the second guide groove 62 from the outer portion, which can flow a larger amount of cooling oil than the inner diameter portion, and allows the cooling oil to flow smoothly within the cooling oil conduit.

[0066] In the first embodiment, the case where the outer end of the first groove 21 in the direction perpendicular to the rotation axis A is circular has been described as an example, but the present invention is not limited to this. The outer end of the first groove according to the first embodiment in the direction perpendicular to the rotation axis A may have a shape other than circular.

[0067] Second Embodiment Next, a first end plate and a second magnet cover according to a second embodiment will be described with reference to Figures 9 to 12. In the second embodiment, differences from the first embodiment will be mainly described, and descriptions of the same aspects as in the first embodiment will be omitted.

[0068] FIG. 9 is a view of a first end plate according to the second embodiment as viewed from the −X direction. As shown in FIG. 9, in addition to the first groove 21 and second groove 22 described above, the first end plate 2a is formed with a third groove 23a formed around the entire periphery of the end portion in a direction perpendicular to the rotation axis A. The third groove 23a contacts the inner peripheral edge of the first magnet cover 3 around the entire periphery of the end portion of the first end plate 2a in a direction perpendicular to the rotation axis A. Therefore, the third groove 23a communicates with the first guide groove 31 regardless of the angle of the first end plate 2a relative to the first magnet cover 3 around the rotation axis A. Therefore, the first guide groove 31 communicates with the second groove via the third groove 23a. Furthermore, the inner end portion of the third groove 23a in a direction perpendicular to the rotation axis A is circular.

[0069] FIG. 10 is a view of the second magnet cover according to the second embodiment as seen from the +X direction. FIG. 11 is a cross-sectional view showing the CC section of the second magnet cover according to the second embodiment. FIG. 12 is a view of the second magnet cover according to the second embodiment as seen from the -X direction. The second magnet cover 6a has a second guide groove 62 and an oil discharge path formed therein. The second guide groove 62 overlaps with the rotor core internal conduit 43 in the direction of the rotation axis A. The oil discharge path leads to the second guide groove 62 and the outside of the rotor. Specifically, the oil discharge path is an oil discharge conduit 63a that leads to the second guide groove 62, is formed along the direction of the rotation axis A, and leads to the outside of the rotor on the end face of the second magnet cover 6a perpendicular to the rotation axis A.

[0070] The motor according to the second embodiment includes a cooling oil conduit formed by the first shaft internal conduit 11, the second shaft internal conduit 12, the first groove 21, the second groove 22, the third groove 23a, the first guide groove 31, the rotor core internal conduit 43, the second guide groove 62, and the oil discharge conduit 63a. The motor according to the second embodiment cools the rotor, stator, etc. by the cooling oil flowing through the cooling oil conduit.

[0071] The motor according to the second embodiment has been described above. The first end plate 2a has the third groove 23a formed therein. The third groove 23a is formed around the entire circumference of the end portion in a direction perpendicular to the rotation axis A, and therefore communicates with the first guide groove 31 regardless of the angle of the first end plate 2a relative to the first magnet cover 3 about the rotation axis A. This makes it possible to assemble the first magnet cover 3 and the first end plate 2a in the motor according to the second embodiment without considering the angle of the first end plate 2a relative to the first magnet cover 3 about the rotation axis A. Therefore, the motor according to the second embodiment makes it possible to configure the cooling oil conduit described above through easy assembly.

[0072] The second magnet cover 6a is connected to the second guide groove 62, is formed along the direction of the rotation axis A, and has an oil discharge conduit 63a that leads to the outside of the rotor on an end face of the second magnet cover 6a that is perpendicular to the rotation axis A. As a result, the motor according to the second embodiment can discharge cooling oil in the direction of the rotation axis A through the oil discharge conduit 63a, and directly cool components located on the -X direction side of the second magnet cover 6a.

[0073] The third groove 23a has a circular inner end in a direction perpendicular to the rotation axis A. This allows the first end plate 2a to be formed using a milling machine or the like. Therefore, the motor according to the second embodiment makes it possible to reduce the labor, time, cost, etc. required to manufacture the rotor.

[0074] In the second embodiment, the second magnet cover 6a is provided with an oil discharge conduit 63a extending along the direction of the rotation axis A, but the present invention is not limited to this. The second magnet cover 6a may also be provided with an oil discharge conduit formed in a direction that intersects the rotation axis A without being perpendicular thereto. This oil discharge conduit leads to the outside of the rotor at an end face perpendicular to the rotation axis A or at an end in a direction perpendicular to the rotation axis A, depending on the angle relative to the rotation axis A. As a result, the motor according to the second embodiment can discharge cooling oil in a desired direction through this oil discharge conduit to directly cool components located around the second magnet cover 6a.

[0075] In the second embodiment, the case where the inner end of the third groove 23a in the direction perpendicular to the rotation axis A is circular has been described as an example, but the present invention is not limited to this. The inner end of the third groove according to the second embodiment in the direction perpendicular to the rotation axis A may have a shape other than circular.

[0076] In the first and second embodiments, the rotating electric machine according to the embodiment is a motor, but the present invention is not limited to this. The rotating electric machine according to the embodiment may be, for example, a generator.

[0077] In the first and second embodiments, the second grooves 22 extend radially from a point on the rotation axis A in a plane perpendicular to the rotation axis A, but this is not limiting. The position and shape of the second grooves according to the first embodiment are not particularly limited as long as they can connect the first groove 21 and the first guide groove 31. The position and shape of the second grooves according to the second embodiment are not particularly limited as long as they can connect the first groove 21 and the first guide groove 31. Alternatively, the position and shape of the second grooves according to the second embodiment are not particularly limited as long as they can connect the first groove 21 and the third groove 23a.

[0078] The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the first and second embodiments. In other words, the present invention includes embodiments in which various modifications, substitutions, design changes, etc. have been made based on the spirit of the present invention, and does not exclude these embodiments. [Explanation of symbols]

[0079] 1...shaft, 2...first end plate, 3...first magnet cover, 4...rotor core, 5...second end plate, 6...second magnet cover

Claims

1. a shaft having a first internal shaft conduit having an opening at one end in the direction of the rotation axis of the rotor, and a second internal shaft conduit communicating with the first internal shaft conduit and having an opening on a side surface; an end plate having a first groove formed therein, the first groove overlapping the entire intersection of a plane perpendicular to the rotation axis and a side surface of the shaft and overlapping an opening of the second shaft internal conduit, and a second groove communicating with the first groove and extending to an end in a direction perpendicular to the rotation axis; a first magnet cover having a first guide groove formed at an end of the end plate in a direction perpendicular to the rotation axis, the first guide groove communicating with the second groove; a rotor core having an internal conduit formed therein that overlaps with the first guide groove in the direction of the rotation axis; a second guide groove overlapping the rotor core internal conduit in the direction of the rotation axis, and a second magnet cover having an oil discharge path communicating with the second guide groove and the outside of the rotor; A rotating electric machine comprising:

2. The oil discharge path is an oil discharge conduit that communicates with the second guide groove, is formed in a direction that intersects the rotation axis without being perpendicular to it, or is formed along the direction of the rotation axis, and communicates with the outside of the rotor. The rotating electric machine according to claim 1 .

3. The oil discharge path is an oil discharge groove formed on a surface of the second magnet cover that contacts the rotor core, communicates with the second guide groove, and extends to an end in a direction perpendicular to the rotation axis. The rotating electric machine according to claim 1 .

4. the end plate further has a third groove formed around the entire periphery of the end in a direction perpendicular to the rotation axis, The first guide groove communicates with the second groove via the third groove. The rotating electric machine according to claim 1 .

5. an inner end of the third groove in a direction perpendicular to the rotation axis is circular; The rotating electric machine according to claim 4.

6. The first groove has an outer end portion that is circular in a direction perpendicular to the rotation axis. The rotating electric machine according to claim 1 .

7. the first guide groove is a curved groove that smoothly connects the second groove and the rotor core internal conduit; The rotating electric machine according to claim 1 .

8. The second guide groove is a curved groove that is smoothly connected to the rotor core internal conduit. The rotating electric machine according to claim 1 .

9. an arc length of the first guide groove is equal to or greater than an arc length of the second groove on a circumference passing through the entire end of the end plate in a direction perpendicular to the rotation axis; The rotating electric machine according to claim 1 .

Images