Rotating electric machines

Abstract

The rotating electric machine comprises: a rotor; a shaft that passes through the rotor along the rotating shaft and is supported by a bearing; a stator that accommodates the rotor inside; a rotor cover that is mounted on the axial end surface of the rotor; and a housing that has a flow path for supplying oil to the bearing. The rotor cover has: an oil receiving portion that forms a concentric gap with the shaft and receives oil from the bearing through the gap; and an oil distribution path that communicates from the oil receiving portion to the axial end surface of the rotor. The rotating electric machine cools the rotor by supplying the oil introduced into the gap to the oil distribution path through centrifugal force.

Description

Technical Field

[0001] The present invention relates to rotating electrical machines. Background Art

[0002] The magnets housed in the rotor of a rotating electrical machine experience a reduction in magnetic flux at high temperatures (high-temperature demagnetization). While this high-temperature demagnetization can be suppressed, for example, by using magnets containing a high percentage of heavy rare earth elements, it increases the manufacturing cost of the rotating electrical machine. Generally, the rotor is air-cooled by dissipating heat to the air. However, to improve the performance of the rotating electrical machine, more efficient rotor cooling is desired.

[0003] For example, cooling structures are also known in which a refrigerant such as oil is flowed into the rotor of a rotating electrical machine to cool the rotor. As an example of such a cooling structure, Patent Document 1 proposes a configuration in which an oil supply passage is formed axially within the rotor shaft, and cooling oil is supplied radially outward from the rotor shaft by centrifugal force.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-220340 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, in a cooling structure like that disclosed in Patent Document 1, which supplies oil to the rotor from within the rotor shaft, a pump is required to sufficiently increase the pressure of the cooling oil in order to deliver the oil into the shaft. Furthermore, an oil seal is required at the portion where the oil is delivered relative to the rotating shaft. This increases the cost of the cooling structure. Furthermore, in the configuration disclosed in Patent Document 1, the rotor shaft is hollow, which reduces its rigidity.

[0009] The present invention has been made in view of the above-mentioned circumstances, and provides a rotating electrical machine in which a rotor can be cooled by oil without forming an oil flow path in the rotor shaft.

[0010] Solutions to Problems

[0011] A rotating electrical machine according to one embodiment of the present invention includes: a rotor; a shaft extending through the rotor along a rotating axis and supported by bearings; a stator housing the rotor; a rotor cover mounted on an axial end surface of the rotor; and a housing having a flow path for supplying oil to the bearings. The rotor cover includes an oil receiving portion, which forms a concentric gap with the shaft and receives oil from the bearings through the gap; and an oil distribution passage, which communicates from the oil receiving portion to the axial end surface of the rotor. The rotating electrical machine cools the rotor by supplying oil introduced into the gap to the oil distribution passage using centrifugal force.

[0012] In the rotating electrical machine of the above embodiment, the rotor may have a gap portion extending through the rotor in the axial direction, and the oil distribution passage may be connected to the gap portion. Furthermore, the rotor may be cooled by allowing oil to flow from the oil distribution passage to the gap portion.

[0013] Alternatively, the gap portion may face the magnets disposed on the rotor, or the oil flowing through the gap portion may come into contact with the magnets.

[0014] In the rotating electrical machine of the above-described aspect, the shaft may include a delivery portion that projects radially inside the gap and delivers the oil to the oil receiving portion.

[0015] In the rotating electrical machine of the above embodiment, the housing may further include an oil spreading portion for spreading oil from above the coil and an oil supply passage for supplying oil to the oil spreading portion.

[0016] Effects of the Invention

[0017] According to one aspect of the present invention, the rotor can be cooled by oil without forming an oil flow path in the rotor shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a perspective view showing an example of the rotating electrical machine according to the present embodiment.

[0019] Figure 2 yes Figure 1 A-A line cross-sectional view.

[0020] Figure 3 It is a front view showing the axial end surface of the rotor.

[0021] Figure 4 This is a front view of the rotating electrical machine with the load-side housing cover removed.

[0022] Figure 5 This is a diagram showing the inner surface of the housing cover on the load side.

[0023] Figure 6 This is a cutaway perspective view of the rotor cover on the load side.

[0024] Figure 7 This is a perspective view of the rotor as viewed from the load side.

[0025] Figure 8 yes Figure 2 An enlarged view of the area around the bearing on the load side. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0027] In the embodiments, for ease of understanding, the structures and elements of the present invention other than the essential parts are simplified or omitted for description. In the accompanying drawings, identical elements are denoted by the same reference numerals. Furthermore, the shapes and sizes of the elements shown in the accompanying drawings are for illustrative purposes only and do not represent actual shapes, sizes, etc.

[0028] In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional rectangular coordinate system. In the XYZ coordinate system, the Z direction is a direction parallel to the rotation axis. The X direction is a direction orthogonal to the Z direction and is perpendicular to the X direction. Figure 2 The Y direction is perpendicular to both the X direction and the Z direction. Figure 2 The vertical direction corresponds to the vertical direction. In the drawings, the rotating shaft of the rotating electrical machine is represented by the reference symbol AX as needed. In the following description, the circumferential direction centered on the rotating shaft AX is simply referred to as the circumferential direction, and the radial direction centered on the rotating shaft AX is simply referred to as the radial direction.

[0029] Figure 1 It is a perspective view showing an example of the rotating electrical machine 1 according to the present embodiment. Figure 2 yes Figure 1 A-A line cross-sectional view. Figure 3 It is a front view showing the axial end surface of the rotor. Figure 4 It is a front view of the rotating electrical machine 1 in a state where the housing cover 6 on the load side is removed. Figure 5 1 is a diagram showing the inner surface of the housing cover 6 on the load side. Figure 3 In FIG. 1 , the arrangement of the oil distribution passage 24 described later is shown by a dotted line.

[0030] The rotating electrical machine 1 of this embodiment is an inner rotor type motor and includes a rotor 2, a shaft 3, and a stator 4. The rotor 2, shaft 3, and stator 4 are housed in a housing having a housing body 5 and a housing cover 6. The housing body 5 and the housing cover 6 are both manufactured by casting.

[0031] The rotor 2 is, for example, a magnet embedded type or surface magnet type rotor. The core of the rotor 2 is formed by laminating a plurality of electromagnetic steel sheets in the axial direction. A shaft 3 is embedded in the center of the rotor 2 so as to pass through the core along the rotation axis AX. Figure 2 As shown, end plates 11 a and 11 b and rotor covers 12 a and 12 b are mounted on both axial ends of the rotor 2 , respectively.

[0032] like Figure 3 As shown, a plurality of permanent magnets 9 are arranged at equal intervals along the circumferential direction to form main magnetic poles in the core of the rotor 2. The permanent magnets 9 are arranged so that the main magnetic poles adjacent to each other in the circumferential direction of the rotor 2 have opposite polarities.

[0033] The permanent magnets 9 are formed into rectangular blocks with an axial dimension approximately equal to that of the core, and are embedded in magnet holes 10 in the core. Furthermore, gaps 10a, which function as flux barriers, are formed at the circumferential ends of the permanent magnets 9 in the core of the rotor 2. These gaps 10a face the permanent magnets 9. Furthermore, the magnet holes 10 and gaps 10a extend axially through the core.

[0034] Axis 3 Figure 2 As shown in FIG, from the core of the rotor 2 toward the opposite side of the load ( Figure 2 The exposed portion of the shaft 3 has a flange portion 3b. In addition, the shaft 3 extends from the core of the rotor 2 to the load side ( Figure 2 The exposed portion (on the left side) has a tapered area 3a.

[0035] The flange portion 3b of the shaft 3 protrudes annularly in the radial direction of the shaft 3 and contacts the end plate 11b on the opposite side of the load. Furthermore, the tapered region 3a of the shaft 3 has a tapered shape that decreases in diameter as it moves away from the rotor 2 and tapers toward the load side. The tapered region 3a is an example of a delivery portion.

[0036] The end plates 11a and 11b have holes in their centers for the shaft 3 to pass through, and are annular members with a smaller diameter than the rotor 2. Figure 2 End plate 11a (located on the left side of the shaft) is in close contact with the load-side axial end surface (first end surface) of rotor 2. Furthermore, end plate 11b, located on the opposite side of the load, is interposed between flange portion 3b of shaft 3 and rotor 2 and is in close contact with the opposite side of the load (second end surface) of rotor 2. End plates 11a and 11b press rotor 2 from both axial sides, thus holding the core of rotor 2, which is composed of laminated steel plates.

[0037] The rotor cover 12a, disposed on the load side, covers the end plate 11a and the first end surface of the rotor 2 from the outside, and is in close contact with the first end surface and fixed to the rotor 2. Furthermore, the rotor cover 12b, disposed on the opposite load side, covers the end plate 11b and the second end surface of the rotor 2 from the outside, and is in close contact with the second end surface and fixed to the rotor 2. The structures of the rotor covers 12a and 12b will be described later.

[0038] The stator 4 comprises a cylindrical stator core, housing the rotor 2 with a small air gap therebetween. Multiple slots (not shown) are formed axially along the inner circumference of the stator 4, and coils are wound in these slots. Coil ends 7 extend from the stator 4 at either axial end, forming a circumferential annular shape.

[0039] In rotating electrical machine 1, the magnetic field of stator 4 is sequentially switched by controlling the current flowing through the coils, generating an attractive or repulsive force with the magnetic field of rotor 2. This causes rotor 2 and shaft 3 to rotate, driving rotating electrical machine 1. During this process, the coils heat up due to the current flowing through them. Furthermore, electromagnetic induction also heats the permanent magnets 9 housed in rotor 2.

[0040] The housing body 5 of the rotating electrical machine 1 is a shell having a cylindrical space open on both sides in the axial direction. Within the cylindrical space of the housing body 5, the stator 4 and the rotor 2, into which the shaft 3 is embedded, are concentrically arranged. The stator 4 is fitted into the inner circumference of the housing body 5, which is attached to cover the outer circumference of the stator 4.

[0041] Housing covers 6 are attached to both axial sides of the housing body 5. Thus, the openings on both sides of the housing body 5 are sealed by the housing covers 6. Furthermore, bearings 8 are provided in each housing cover 6, and the shaft 3 is rotatably supported by the bearings 8 of the housing covers 6. Furthermore, the load-side end of the shaft 3 passes through the housing covers 6 and protrudes outward.

[0042] In addition, the housing body 5 has an oil supply passage 13 for oil cooling the coil end 7. The oil supply passage 13 is an oil passage for cooling oil flowing through an oil cooler and an oil pump (neither of which are shown in the figure), and is connected to an oil inlet 14 for receiving cooling oil. The oil supply passage 13 is arranged at a position closer to the stator 4 than the stator 4. Figure 2 The oil supply passage 13 extends axially within the housing body 5 and is sealed on both sides by the housing cover 6. The ends of the oil supply passage 13 are connected to a first flow passage 15 and a second flow passage 16. The first flow passage 15 and the second flow passage 16 are formed on the load side and the opposite load side of the rotating electrical machine 1, respectively, and have substantially the same structure.

[0043] First flow path 15 branches from oil supply path 13 and extends circumferentially. Multiple holes are formed downwardly in the flow path. Each hole in first flow path 15 communicates with the interior space of housing body 5 at a position facing the outer circumference of coil end 7. First flow path 15 is an example of an oil dispersing portion, distributing cooling oil from oil supply path 13 from above toward the coil end.

[0044] The second flow path 16 is a flow path for supplying oil to the bearing 8 via the housing cover 6. The second flow path 16 includes a groove 17 formed in the housing cover 6 and a communication hole 18 connecting the oil supply path 13 and the groove 17.

[0045] The groove portion 17 of the second flow path 16 is formed on the inner surface side of the housing cover 6. Figure 2 、 Figure 4 As shown in FIG. 1 , the oil supply passage 13 extends up and down along the radial direction of the rotating electrical machine 1 to the bearing 8. Figure 4 , the groove portion 17 of the case cover 6 on the load side is shown, but the groove portion 17 of the case cover 6 on the opposite side of the load side is also configured in the same manner as that on the load side.

[0046] A connecting hole 18 of the second flow passage 16 is formed in the housing cover 6 at an angle downward in the axial direction from the end of the oil supply passage 13, and is connected to the upper end of the groove portion 17. Thus, a portion of the cooling oil from the oil supply passage 13 is supplied to the bearing 8 through the connecting hole 18 of the second flow passage 16 and the groove portion 17.

[0047] The bottom of the housing body 5 also functions as an oil pan for storing oil after heat exchange with the coil end 7. The housing body 5 is provided with an oil outlet 19 for sucking out the oil stored in the oil pan. The oil outlet 19 of the housing body 5 is connected to an oil pump.

[0048] The rotating electrical machine 1 of this embodiment has a function of guiding the oil supplied to the bearing 8 from the rotor cover 12a to the axial end surface of the rotor 2 to cool the rotor 2 and the permanent magnets 9. The cooling of the rotor 2 in this embodiment will be described below.

[0049] Figure 6 It is a cutaway perspective view of the rotor cover 12 a on the load side. Figure 7 This is a perspective view of the rotor 2 as viewed from the load side. Figure 8 yes Figure 2 An enlarged view of the bearing near the load side. Figure 7 In FIG. 1 , the rotor cover 12 a is shown by a dotted line in order to illustrate the arrangement of an oil distribution passage 24 to be described later.

[0050] The rotor cover 12a is a metal, disc-shaped member comprising a cover body 21, an oil receiving portion 22, and an oil distribution passage 24. The cover body 21 of the rotor cover 12 has an opening in its center for insertion of the shaft 3 and is disc-shaped with dimensions corresponding to the outer diameter of the rotor 2. The front surface of the cover body 21 faces the inner surface of the housing cover 6, while the back surface of the cover body 21 faces the end plate 11a and the axial end surface of the rotor 2. By covering the axial end surface of the rotor 2, the cover body 21 prevents the permanent magnets 9 from falling out of the rotor 2.

[0051] The oil receiving portion 22 is formed in an annular shape on the outer edge of the inner circumference of the cover body 21 and serves to receive oil from the bearing 8 through a gap formed between the cover body 21 and the outer circumference of the shaft 3. The oil receiving portion 22 protrudes from the front surface of the cover body 21 in the axial direction of the rotating electric machine 1 and has a tapered shape in which the inner circumference increases in diameter from the front side to the back side of the rotor cover 12a.

[0052] like Figure 2 、 Figure 8 As shown, the oil receiving portion 22 of the rotor cover 12a is arranged at a position corresponding to the tapered region 3a of the shaft 3. The oil receiving portion 22 is arranged concentrically with respect to the tapered region 3a of the shaft 3 and covers the tapered region 3a from the outside.

[0053] The inner diameter of the oil receiving portion 22 is set larger than the outer diameter of the shaft 3, forming a concentric gap around the shaft 3 and between the oil receiving portion 22. The rotor cover 12a is attached to the rotor 2 so that the distal end of the oil receiving portion 22 faces the bearing 8 in the axial direction.

[0054] The oil distribution passage 24 is formed on the back side of the rotor cover 12a and plays the role of guiding the oil from the bearing 8 received by the oil receiving portion 22 to the radial outer peripheral side of the rotor 2. The oil distribution passage 24 extends from the oil receiving portion 22 in the radial direction of the rotor cover 12a, and a plurality of oil distribution passages 24 are formed in the rotor cover 12a in a radial pattern with the oil receiving portion 22 as the center. For example, Figure 3 、 Figure 7 As shown in FIG, eight oil distribution passages 24 are formed at intervals of 45 degrees in the circumferential direction. Figure 7 As shown, grooves may be formed on the surface of the end plate 11 a so as to correspond to the positions of the oil distribution passages 24 .

[0055] Each oil distribution passage 24 has a cross section along the axial direction ( Figure 2 、 Figure 8 ) presents a step difference shape that connects to the axial end face of the rotor 2 after passing through the surface and peripheral surface of the end plate 11a. Figure 3 As indicated by the dashed lines, each oil distribution passage 24 is positioned between the magnetic poles of the rotor 2 (on the q-axis of the d-q coordinate system). The width of each oil distribution passage 24 is sized to overlap the positions of two circumferentially opposing gaps 10a. Therefore, the oil distribution passage 24 is connected to the gaps 10a, and the oil flowing through the oil distribution passage 24 is directed from the oil distribution passage 24 to the gaps 10a.

[0056] Here, the rotor cover 12b on the opposite side of the load is a metal disc-shaped member similar to the rotor cover 12a on the load side, but is different from the rotor cover 12a in that it does not have the oil receiving portion 22. Figure 2 As shown, a discharge port 25 is provided for discharging the oil guided to the gap 10a from the rotor 2. The discharge port 25 is arranged between the magnetic poles of the rotor 2 at a position corresponding to the gap 10a and is formed to penetrate the rotor cover 12b.

[0057] Hereinafter, the flow of oil in the rotating electrical machine 1 according to the present embodiment will be described.

[0058] In the rotating electrical machine 1, the oil stored in the oil pan of the housing body 5 is drawn out from the oil outlet 19 by the oil pump and cooled by the oil cooler. The oil cooled by the oil cooler is then delivered from the oil inlet 14 to the oil supply passage 13 located on the upper side of the housing body 5. In the oil supply passage 13, oil flows axially to one side (the counter-load side) and the other side (the load side). The following description focuses on the oil flowing to the load side of the oil supply passage 13, and redundant description of the oil flowing to the counter-load side will be omitted.

[0059] Oil flowing toward the load side of oil supply passage 13 branches off at the ends of oil supply passage 13 into first passage 15 and second passage 16. The oil flowing into first passage 15 is distributed from above over coil end 7, flowing counterclockwise and clockwise around the periphery of coil end 7 toward the bottom. The oil in contact with coil end 7 absorbs heat, cooling coil end 7.

[0060] On the other hand, the oil flowing into the second flow path 16 is as follows Figure 8 As shown by the middle arrow, the oil passes through the communication hole 18 and the groove 17 and is guided to the bearing 8. Furthermore, oil is supplied from between the housing cover 6 and the bearing 8 through the second flow path 16 to ensure lubrication of the bearing 8.

[0061] In addition, on the load side of the rotating electrical machine 1, as shown in FIG. Figure 8 As indicated by the middle arrow, oil supplied from between the housing cover 6 and the bearing 8 passes through the bearing 8 and reaches the rotor 2. The oil then flows along the shaft 3 into the gap formed between the shaft 3 and the oil receptacle 22 of the rotor cover 12a. When the rotating electric machine 1 is driven, the rotor 2 and shaft 3 rotate, causing centrifugal force to act on the oil flowing into the gap between the shaft 3 and the oil receptacle 22. Furthermore, the oil flowing into the gap between the shaft 3 and the oil receptacle 22 is scraped and delivered radially outward by the radially protruding tapered region 3a of the shaft 3.

[0062] So, if Figure 8 As indicated by the middle arrow, oil flows from the oil receiving portion 22 into the oil distribution passage 24, where it is directed radially outward by centrifugal force. The oil then flows from the oil distribution passage 24 into the gap 10a, passing through the gap 10a, which axially penetrates the rotor 2, from the load side of the rotor 2 to the opposite load side. The oil is then discharged from the rotor 2 through the discharge port 25 of the rotor cover 12b.

[0063] As described above, by flowing oil through the oil distribution passages 24 of the rotor cover 12b and the gap 10a of the rotor 2, the oil contacts the permanent magnets 9 embedded in the magnet holes 10 and the iron core of the rotor 2, exchanging heat and cooling the rotor 2. While the permanent magnets 9 and the rotor 2 are particularly susceptible to thermal stagnation in the axially central portion, which can lead to high temperatures, this embodiment minimizes temperature variations in the axial direction of the permanent magnets 9 and the rotor 2 by flowing the oil in the axial direction of the rotor.

[0064] In this embodiment, the oil is delivered to each oil distribution passage 24 by the centrifugal force generated by the rotation of the rotor 2 and the shaft 3, so the oil is distributed substantially evenly to each oil distribution passage 24. Therefore, temperature unevenness among the oil distribution passages 24 in the circumferential direction is less likely to occur.

[0065] The oil distributed from the upper side toward the coil end 7 and the oil discharged from the discharge port 25 of the rotor cover 12b are both returned to the oil pan and stored. The oil in the oil pan is then sent out again toward the oil cooler by the driving of the oil pump.

[0066] As described above, in the rotating electric machine 1 of this embodiment, the rotor cover 12a, which includes the oil receiving portion 22 and the oil distribution passage 24, is attached to the rotor 2. The oil receiving portion 22 forms a concentric gap with the shaft 3, and receives oil from the bearing 8 through the gap. The oil guided into the gap is supplied to the oil distribution passage 24 and the gap 10a by centrifugal force, thereby cooling the rotor 2. Cooling the rotor 2 with oil can suppress performance degradation due to demagnetization at high temperatures, even when magnets with a low heavy rare earth content are used in the rotor, for example, and can contribute to reducing the manufacturing cost of the rotating electric machine 1.

[0067] Furthermore, in the configuration of this embodiment, since an oil flow path is not provided in the shaft, the cost of the cooling structure can be suppressed, and the rigidity of the shaft is not reduced.

[0068] The present invention is not limited to the above-described embodiment, and various improvements and design changes are possible without departing from the scope of the present invention.

[0069] In the above embodiment, a configuration example of a motor is described as an example of the rotating electrical machine 1 , but the rotating electrical machine of the present invention can also be applied to an oil-cooled generator.

[0070] Furthermore, in the above embodiment, a configuration example is described in which a tapered region 3a is formed on the shaft 3 as a delivery portion, and is directed toward the oil receiving portion 22 of the rotor cover 12a. However, the configuration of the delivery portion is not limited to this configuration. For example, a configuration in which one or more protrusions are formed circumferentially on the shaft 3, and the protrusions scrape the oil from the bearing 8 and deliver it to the oil receiving portion 22, may also be employed. Alternatively, a configuration in which the oil from the bearing 8 is moved to the oil receiving portion 22 by centrifugal force, rather than forming a tapered region or protrusions on the shaft 3 side, may be employed.

[0071] The arrangement and shape of the permanent magnets 9 and the gaps 10a in the rotor 2 of the above embodiment are merely examples and may be modified as appropriate. Furthermore, the gaps in the rotor 2 connected to the oil distribution passages 24 of the rotor cover 12a do not necessarily need to be in contact with the permanent magnets 9.

[0072] Furthermore, the shape of the oil distribution passage 24 in the rotor cover 12 a in the above-described embodiment is merely an example, and other configurations such as a spiral shape may be employed.

[0073] Furthermore, in the above embodiment, the oil distribution passage 24 is formed in the rotor cover 12a, and oil is discharged from the discharge port 25 of the rotor cover 12b. However, for example, the rotor cover having the oil receiving portion 22, the oil distribution passage 24, and the discharge port 25 may be disposed on the load side and the anti-load side of the rotor 2, respectively. In this case, the oil distribution passage 24 and the discharge port 25 of the rotor cover can be arranged with the phases thereof shifted on the load side and the anti-load side of the rotor 2, thereby alternating the direction of oil flow.

[0074] Furthermore, in the above embodiment, a cooling structure may be provided that sprays oil onto the inner circumference of the coil end 7 to cool the coils of the stator 4. For example, radial holes may be formed in the oil receiving portion 22 of the rotor cover 12a to spray oil onto the coil end 7 using centrifugal force. Alternatively, the direction of the discharge port 25 of the rotor cover 12b may be adjusted to spray oil onto the coil end 7.

[0075] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to encompass all modifications within the meaning and scope of the claims, which are equivalent thereto.

[0076] Description of Reference Numerals

[0077] 1…rotating electric machine, 2…rotor, 3…shaft, 3a…tapered region, 4…stator, 5…housing body, 6…housing cover, 7…coil end, 8…bearing, 9…permanent magnet, 10…magnet hole, 10a…gap, 12a, 12b…rotor cover, 13…oil supply path, 15…first flow path, 16…second flow path, 17…groove, 18…connecting hole, 21…housing body, 22…oil receiving portion, 24…oil distribution path, 25…discharge port.

Claims

1. A rotating electrical machine, characterized in that: The rotating electrical machine comprises: a rotor; a shaft that passes through the rotor along a rotating axis and is axially supported by a bearing; a stator that accommodates the rotor inside; a rotor cover that is mounted on an axial end surface of the rotor; and a housing that has a flow path for supplying oil to the bearing. The rotor has a gap portion penetrating the rotor in the axial direction. The rotor cover has: an oil receiving portion, the oil receiving portion forming a concentric gap with the shaft and receiving the oil from the bearing through the gap; and an oil distribution passage, the oil distribution passage being in communication with the axial end surface of the rotor from the oil receiving portion and being connected to the gap portion, The rotating electrical machine supplies the oil introduced into the gap to the oil distribution passage by centrifugal force, so that the oil flows from the oil distribution passage to the gap portion to cool the rotor. The rotor cover is mounted on one side and the other side of the axial direction of the rotor, respectively. The rotor cover on one side allows the oil to flow from one side to the other side in the gap portion of the rotor. The rotor cover on the other side allows the oil to flow from the other side to one side in the gap portion of the rotor. The oil distribution passage of the rotor cover on one side and the oil distribution passage of the rotor cover on the other side are arranged with their phases shifted in the circumferential direction of the rotor.

2. The rotating electrical machine according to claim 1, characterized in that The gap portion faces the magnet disposed on the rotor. The oil flowing in the gap portion comes into contact with the magnet.

3. The rotating electrical machine according to claim 1, characterized in that The shaft includes a delivery portion that protrudes in a radial direction inside the gap and delivers the oil to the oil receiving portion.

4. The rotating electrical machine according to any one of claims 1 to 3, characterized in that: The housing further includes an oil spreading portion that spreads the oil from the upper side of the coil provided on the stator, and an oil supply passage that supplies the oil to the oil spreading portion. The flow passage supplies the oil branched from the oil supply passage.

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