Rotor of rotary electric machine

Abstract

To provide a rotor of a rotary electric machine in which the rotary electric machine can be downsized and the cooling performance of the rotor can be increased.SOLUTION: A rotor 12 of a rotary electric machine includes a rotor body 15, a rotary shaft 16, and a permanent magnet 17 embedded in the rotor body 15. The rotor body 15 has a cylindrical core portion 18 that is coaxially supported by the rotary shaft 16, is formed by layering electromagnetic steal sheets, and has a cylindrical shape, and a closing portion that is connected to the cylindrical core portion 18 so as to close one opening of the cylindrical core portion 18. A cylindrical space 30 is formed by the cylindrical core portion 18 and the closing portion. The cylindrical core portion 18 has a magnet insertion hole 18 in which the permanent magnet 17 is inserted, and a ventilation path 31 formed in the axis direction along the permanent magnet 17. A connection path 32 formed in the closing portion side of the cylindrical core portion 18 and connecting the ventilation path 31 and the cylindrical space 30 is included. A fan that rotates integrally with the rotor body 15 is disposed in the cylindrical space 30.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a rotor for a rotating electrical machine. [Background technology]

[0002] As a conventional technique related to the rotor of a rotating electric machine, for example, the electric motor disclosed in Patent Document 1 is known. In the electric motor disclosed in Patent Document 1, a rotor core is disposed in a stator core facing the stator core, and a shaft is inserted into the rotor core. A main fan is attached to the shaft so as to face one axial end face of the rotor core, and an internal fan is provided between the inner surface of the rotor core and the outer surface of the shaft at the axial center of the rotor core. A rotor core support plate and a partition plate are attached near the axial end on the opposite side to the axial end of the shaft to which the main fan is attached. A plurality of grooves extending in the radial direction are formed in the rotor core and the stator core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Microfilm of Utility Model Application No. 58-183861 (Utility Model Application No. 60-93480) Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the electric motor disclosed in Patent Document 1, the main fan faces one end face of the rotor, so the airflow generated by the main fan has difficulty passing through grooves in the rotor near the main fan. Although an internal fan is provided, the rotor core does not have grooves through which air can pass along the axial direction. This causes variations in cooling of the rotor, and it is not possible to cool it sufficiently. In addition, since the main fan is provided facing one end face of the rotor, the length of the rotating shaft increases by the length of the main fan, making it impossible to avoid an increase in the size of the rotating electric machine.

[0005] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a rotor for a rotating electric machine which enables the rotating electric machine to be made smaller and the cooling of the rotor to be improved. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides a rotor for a rotating electric machine having a rotor body, a rotating shaft inserted through the center of the rotor body and integrated with the rotor body, and a permanent magnet embedded in the rotor body along the axial direction of the rotating shaft, the rotor body having a cylindrical core portion supported coaxially on the rotating shaft and formed by stacking electromagnetic steel sheets, and a blocking portion connected to the cylindrical core portion so as to block one opening of the cylindrical core portion, an intra-cylinder space is formed by the cylindrical core portion and the blocking portion, the cylindrical core portion has a magnet insertion hole through which the permanent magnet is inserted and a flow path formed in the axial direction along the permanent magnet, and a connecting passage formed on the blocking portion side of the cylindrical core portion and communicating the flow path with the intra-cylinder space, and a fan rotating integrally with the rotor body is arranged in the intra-cylinder space.

[0007] In the present invention, since the fan is disposed in the cylinder space, it is possible to prevent an increase in the length of the rotating shaft, which contributes to the miniaturization of the rotating electric machine. In addition, as the rotor rotates, the fluid flows in one direction through the cylinder space, the connecting passage, and the flow path. The fluid flows through the flow path formed along the axial direction, which improves the cooling of the permanent magnets.

[0008] In addition, in the rotor of the rotating electric machine, the flow passages are provided in a plurality of places, and a total flow passage cross-sectional area of ​​the plurality of flow passages is smaller than a flow passage cross-sectional area of ​​the cylinder space, The fan may be configured to generate a flow of fluid that flows from the cylinder space through the connecting passage to the flow passage by rotation of the rotor body. In this case, the rotor rotates, causing the fan to introduce fluid into the in-cylinder space. The fluid introduced into the in-cylinder space flows through the multiple flow paths via the connecting passage. The flow direction of the fluid in the multiple flow paths is opposite to the flow direction of the fluid in the in-cylinder space. Since the combined flow path cross-sectional area of ​​the multiple flow paths is smaller than the passage cross-sectional area of ​​the in-cylinder space, when the fluid introduced into the in-cylinder space flows through the multiple flow paths via the connecting passage, the flow velocity of the fluid in the multiple flow paths increases more than the flow velocity of the fluid in the in-cylinder space. As the flow velocity in the multiple flow paths increases, the cooling of the permanent magnet can be further promoted.

[0009] In the rotor for the rotating electric machine described above, a cross-sectional area of ​​the connecting passage may be reduced from the in-cylinder space toward the flow passage. In this case, the cross-sectional area of ​​the connecting passage connecting the in-cylinder space and the flow passage is reduced from the in-cylinder space toward the flow passage, making it easier to introduce the fluid from the in-cylinder space to the flow passage.

[0010] In the rotor of the rotating electric machine described above, a portion of the permanent magnet may be exposed to the flow passage. In this case, a portion of the permanent magnet is exposed to the flow path, and thus cooling of the permanent magnet can be promoted by direct heat exchange between the permanent magnet and the fluid, compared to a case in which a portion of the permanent magnet is not exposed to the flow path.

[0011] In the rotor for the rotating electric machine described above, the fan may be an axial flow fan that generates an axial flow in the cylinder space. In this case, since the fan is an axial flow fan, an axial flow can be generated in the space inside the cylinder, and cooling of the permanent magnets can be further promoted. Effect of the Invention

[0012] According to the present invention, it is possible to provide a rotor for a rotating electric machine that enables miniaturization of the rotating electric machine and improvement of cooling of the rotor. [Brief description of the drawings]

[0013] [Figure 1] 1 is a vertical sectional view that illustrates a rotating electric machine according to a first embodiment. [Diagram 2] 1 is a front view of a rotor of a rotating electric machine according to a first embodiment. [Diagram 3] 1 is a vertical sectional view that illustrates a rotor of a rotating electric machine according to a first embodiment. [Figure 4] 4(a) is a view taken along line AA in FIG. 3, and (b) is a view taken along line BB in FIG. [Diagram 5] FIG. 4 is an explanatory diagram illustrating an air flow in the rotor. [Figure 6] FIG. 11 is a vertical cross-sectional view that illustrates a rotor of a rotating electric machine according to a second embodiment. [Figure 7] FIG. 11 is a vertical sectional view that illustrates a rotor of a rotating electric machine according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] (First embodiment) Hereinafter, a rotor of a rotating electric machine according to a first embodiment will be described with reference to the drawings. The rotating electric machine of this embodiment is a permanent magnet embedded synchronous motor. As shown in FIG. 1, a permanent magnet type rotating electric machine (hereinafter simply referred to as a "rotating electric machine") 10 includes a stator 11 and a rotor 12.

[0015] The stator 11 has a cylindrical stator core 13. A plurality of slots (not shown) are formed on the inner circumferential side of the stator core 13. Each slot opens to the inner circumferential surface of the stator core 13. Teeth (not shown) are formed between each slot. Coils 14 are wound around the teeth. Note that FIG. 1 shows only the coil ends of the coils 14. The rotor 12 is disposed inside the stator 11 such that a gap is formed between the rotor 12 and the inner circumferential surface of the stator core 13.

[0016] The rotor 12 has a cylindrical rotor body 15 with a bottom, a rotating shaft 16 integrated with the rotor body 15, and a permanent magnet 17 embedded in the rotor body 15 along the axial direction of the rotating shaft 16. The rotor body 15 and the rotating shaft 16 rotate integrally. The rotor body 15 has a cylindrical core portion 18 formed by laminating a plurality of sheets (e.g., several tens of sheets) of annular electromagnetic steel sheets (not shown), and a closed core portion 19 connected to the cylindrical core portion 18 so as to close one opening of the cylindrical core portion 18.

[0017] The closed core portion 19 corresponds to a closed portion. In this embodiment, the closed core portion 19 is formed by stacking a plurality of disk-shaped electromagnetic steel plates (not shown). The rotating shaft 16 is inserted through the center of the closed core portion 19, which is the center of the rotor body 15, and is fixed to the closed core portion 19. The rotating shaft 16 is rotatably supported by a motor housing 20 via bearings 21 and 22.

[0018] The motor housing 20 has a main body 23 that holds the stator core 13, and end plate portions 24, 25 that are connected to end faces of the main body 23. A through hole 26 in which the bearing 21 is attached is formed in the end plate portion 24, and a through hole 27 in which the bearing 22 is attached is formed in the end plate portion 25. An opening 29 that can take in air as a fluid is formed in the end plate portion 25 on the opposite side to the closed core portion 19 in the axial direction of the rotating shaft 16.

[0019] Incidentally, the cylindrical core portion 18 of this embodiment is located coaxially with the axis P of the rotating shaft 16, as shown in FIG. 2. A plurality of magnet insertion holes 28 are formed in the cylindrical core portion 18. The magnet insertion holes 28 are formed for each magnetic pole of the rotor body 15. The magnet insertion holes 28 penetrate the cylindrical core portion 18 from one end face 18A to the other end face 18B along the axis P direction of the rotating shaft 16, and a part of the magnet insertion holes 28 is formed up to the closed core portion 19. A permanent magnet 17 is inserted into each of the magnet insertion holes 28. The permanent magnets 17 are plate-shaped and embedded in the cylindrical core portion 18 so that the magnetic poles are alternately different in the circumferential direction of the rotor body 15.

[0020] An in-cylinder space 30 is defined by the cylindrical core portion 18 and the closed core portion 19. The other opening of the cylindrical core portion 18 is open. As shown in FIG. 1, an outer surface 19A of the closed core portion 19 faces the end plate portion 24, and an inner surface 19B of the closed core portion 19 faces the in-cylinder space 30.

[0021] The rotor 12 of this embodiment has a configuration for cooling the permanent magnets 17 with air. In the cylindrical core portion 18, an air passage 31 is formed as a flow path in the axial direction along the permanent magnets 17. The air passage 31 is a passage for passing air, and is formed by a through hole penetrating from one end face 18A to the other end face 18B of the cylindrical core portion 18. One opening of the air passage 31 is closed by the closed core portion 19.

[0022] In this embodiment, the cross section of the air passage 31 has a rectangular shape. In the air passage 31, a part of the permanent magnet 17 is exposed to the air passage 31 in the axial direction so that the permanent magnet 17 can be easily cooled. Specifically, a part of the inner surface of the permanent magnet 17 is exposed in the axial direction. The air passage 31 is defined by the rotor body 15, the permanent magnet 17, and the closed core portion 19. The permanent magnet 17 is located radially outward of the air passage 31. Therefore, even if the permanent magnet 17 is subjected to centrifugal force when the rotor 12 rotates, the permanent magnet 17 is unlikely to come out of the magnet insertion hole 28.

[0023] A connection passage 32 that communicates between the air passage 31 and the in-cylinder space 30 is formed in the cylindrical core portion 18. The connection passage 32 is a through hole that penetrates from the inner peripheral surface of the cylindrical core portion 18 to the air passage 31. In this embodiment, the connection passage 32 is defined by the cylindrical core portion 18 and the closed core portion 19. As shown in FIG. 3, the wall surfaces that form the connection passage 32 are a pair of wall surfaces 33 that are formed in the cylindrical core portion 18 and face each other, a wall surface 34 that faces the inner surface 19B of the closed core portion 19, and the inner surface 19B that faces the wall surface 34.

[0024] As shown in Fig. 4(a), a pair of wall surfaces 33 extend so as to approach each other as they go from the inner space 30 of the cylinder toward the ventilation passage 31. The wall surface 34 is a surface substantially parallel to the inner surface 19B. The connection passage 32 formed by the wall surfaces 33, 34 and the inner surface is formed such that the passage cross-sectional area decreases as it goes from the inner space 30 of the cylinder toward the ventilation passage 31. By reducing the passage cross-sectional area as it goes from the inner space 30 of the cylinder toward the ventilation passage 31, when air goes from the inner space 30 of the cylinder toward the ventilation passage 31, it becomes easier for the air to pass through to the ventilation passage 31, and in addition, the flow velocity of the ventilation passage 31 increases smoothly.

[0025] Since the inner space 30 of the cylinder and the ventilation passage 31 communicate with each other via the connection passage 32, it becomes possible to pass air from the inner space 30 of the cylinder through the connection passage 32 to the ventilation passage 31. Also, it becomes possible to pass air from the ventilation passage 31 through the connection passage 32 to the inner space 30 of the cylinder. As shown in Fig. 4(b), the flow passage cross-sectional area S2 of the ventilation passage 31 is smaller than the flow passage cross-sectional area S1 when an axial air flow occurs in one direction in the inner space 30 of the cylinder (S1 > S2). The flow passage cross-sectional area S2 is the sum of the flow passage cross-sectional areas Sa of all the ventilation passages 31 (S2 = Sa × 4). The passage cross-sectional areas of the inner space 30 of the cylinder and the ventilation passage 31 are constant in the axial direction. Also, the flow passage cross-sectional area of the connection passage 32 is smaller than the flow passage cross-sectional area of the inner space 30 of the cylinder.

[0026] The reason for making the flow passage cross-sectional area S2 of the ventilation passage 31 smaller than the flow passage cross-sectional area of the inner space 30 of the cylinder is to increase the flow velocity in the ventilation passage 31 when air flows through the ventilation passage 31 from the inner space 30 of the cylinder through the connection passage 32. If the amount of air passing through the flow passage cross-sectional area S1 and the flow passage cross-sectional area S2 is the same, the air flow velocity V2 in the ventilation passage 31 is greater than the air flow velocity V1 in the inner space 30 of the cylinder (V1 < V2). In addition, in this embodiment, the case where there are a plurality of ventilation passages 31 has been described, but when there is a single ventilation passage 31, the flow passage cross-sectional area Sa of the ventilation passage 31 corresponds to S2 (Sa = S2).

[0027] In this embodiment, an axial flow fan 35 is accommodated in the in-cylinder space 30 as a fan. The axial flow fan 35 has a function of introducing air into the in-cylinder space 30 by rotating integrally with the rotor 12, and in particular generates an axial flow in the in-cylinder space 30. The axial flow fan 35 has a boss portion 36 fixed to the rotating shaft 16, and a plurality of blades 37 provided on the boss portion 36. The plurality of blades 37 are disposed in the circumferential direction on the boss portion 36, and extend radially outward in the radial direction. The outer peripheral side tips of the blades 37 are fixed to the cylindrical core portion 18. The axial flow fan 35 may be attached only to the rotating shaft 16.

[0028] When the rotor 12 rotates forward, the axial flow fan 35 introduces air from the outside into the in-cylinder space 30 and generates an axial flow of the air toward the closed core portion 19. When the rotor 12 rotates reversely, the axial flow fan 35 sends air from the in-cylinder space 30 to the outside. Note that, although the axial flow fan 35 is preferably housed in the in-cylinder space 30, a portion of the axial flow fan 35 may protrude from the in-cylinder space 30.

[0029] Next, cooling of the permanent magnets 17 by the rotation of the rotor 12 according to this embodiment will be described. The rotor 12 is rotated by energizing the coil 14, and the rotating electric machine 10 is driven. When the rotor 12 rotates forward, the axial flow fan 35 rotating integrally with the rotor 12 introduces air into the in-cylinder space 30. As shown in FIG. 5, in the in-cylinder space 30, an axial flow toward the closed core portion 19 is generated by the axial flow fan 35. The air in the in-cylinder space 30 becomes a radial flow near the closed core portion 19, passes through the connecting passage 32, and is introduced into the ventilation passage 31. In FIG. 5, the air flow is typically indicated by an outlined arrow.

[0030] In the connecting passage 32, the air flow velocity increases. This is because the flow path cross-sectional area of ​​the connecting passage 32 is smaller than that of the in-cylinder space 30 and decreases from the in-cylinder space 30 to the air passage 31. Since the flow path cross-sectional areas of the connecting passage 32 and the air passage 31 are smaller than that of the in-cylinder space 30, the air in the in-cylinder space 30 is compressed. The air guided to the air passage 31 via the connecting passage 32 flows in the axial direction and exchanges heat with the permanent magnets 17 and the rotor body 15. The permanent magnets 17 and the rotor body 15 are cooled by the heat exchange.

[0031] In this embodiment, since a portion of the permanent magnet 17 is exposed in the air passage 31, the heat of the permanent magnet 17 can be efficiently transferred to the air. Since the cross-sectional area of ​​the air passage 31 is constant in the axial direction, the flow rate of air passing through the air passage 31 is constant, and heat exchange between the permanent magnet 17 and the rotor body 15 and the air is stable. In addition, since the flow speed of the air in the air passage 31 is greater than the flow speed in the in-cylinder space 30, heat dissipation from the permanent magnet 17 and the rotor body 15 is further promoted. The air in the air passage 31 is discharged to the outside from an opening on the end face 18B side.

[0032] Thus, in this embodiment, a unidirectional airflow is generated in the in-cylinder space 30 by the axial flow fan 35, from the opening of the in-cylinder space 30 toward the closed core portion 19. The air in the in-cylinder space 30 passes through the connecting passage 32, where the air flow speed is increased, and an airflow is generated in the ventilation passage 31 in a turning-back manner in the opposite direction to the airflow in the in-cylinder space 30. The air passing through the ventilation passage 31 cools the permanent magnets 17 and the rotor body 15.

[0033] Next, a case where the rotor 12 rotates in the reverse direction will be described. When the rotor 12 rotates in the reverse direction, the axial flow fan 35 exhausts the air in the in-cylinder space 30 to the outside. This reduces the pressure in the in-cylinder space 30, and air is introduced from the outside into the air passage 31. The air introduced into the air passage 31 is introduced into the in-cylinder space 30 via the connecting passage 32. The air flowing through the connecting passage 32 cools the permanent magnets 17 and the rotor body 15.

[0034] The rotor 12 according to this embodiment provides the following advantages. (1) Since the axial flow fan 35 is disposed in the in-cylinder space 30, an increase in the length of the rotating shaft 16 can be prevented, which contributes to a reduction in the size of the rotating electric machine 10. In addition, as the rotor 12 rotates, air flows in one direction through the in-cylinder space 30, the connecting passage 32, and the ventilation passage 31 serving as a flow path. Air flows through the ventilation passage 31 formed along the axial direction, which improves the cooling of the permanent magnets 17.

[0035] (2) The axial flow fan 35 generates an air flow that flows from the in-cylinder space 30 to the air passage 31 through the connecting passage 32 by the rotation of the rotor body 15. Therefore, the axial flow fan 35 introduces air into the in-cylinder space 30 by the rotation of the rotor 12. The air introduced into the in-cylinder space 30 flows through the air passage 31 through the connecting passage 32. The direction of the air flow in the air passage 31 is opposite to the direction of the air flow in the in-cylinder space 30. Therefore, since the passage cross-sectional area of ​​the air passage 31 is smaller than the passage cross-sectional area of ​​the in-cylinder space 30, when the air introduced into the in-cylinder space 30 flows through the air passage 31 through the connecting passage 32, the flow velocity of the air in the air passage 31 is higher than the flow velocity of the air in the in-cylinder space 30. As the flow velocity in the air passage 31 increases, the cooling of the permanent magnets 17 can be further promoted.

[0036] (3) The cross-sectional area of ​​the connecting passage 32 connecting the in-cylinder space 30 and the ventilation passage 31 decreases from the in-cylinder space 30 toward the ventilation passage 31. This makes it easier to introduce air from the in-cylinder space 30 to the ventilation passage 31. In addition, since the cross-sectional area of ​​the ventilation passage 31 is constant, the amount of air flowing through the ventilation passage 31 is constant, and there is almost no variation in the cooling of the permanent magnets 17.

[0037] (4) A portion of the permanent magnet 17 is exposed to the air passage 31. Therefore, compared to a case in which a portion of the permanent magnet 17 is not exposed to the air passage 31, cooling of the permanent magnet 17 is promoted by direct heat exchange between the permanent magnet 17 and the air.

[0038] (5) The fan is the axial flow fan 35 that generates an axial flow in the in-cylinder space 30, so that an axial flow can be generated in the in-cylinder space 30, and the cooling of the permanent magnets 17 can be further promoted.

[0039] (6) The inner surface 19B of the closed core portion 19 forms the connecting passage 32 together with the wall surfaces 33, 34, and forms a part of the air passage 31. Therefore, air introduced from the outside into the in-cylinder space 30 by the axial flow fan 35 easily flows along the inner surface 19B to the connecting passage 32 and the air passage 31. As a result, when air passes from the in-cylinder space 30 through the connecting passage 32 to the air passage 31, an increase in the flow rate is not easily hindered.

[0040] (7) Because the rotor body 15 is cylindrical with a bottom, air for cooling the permanent magnets 17 can be taken in from the end face 18A side of the cylindrical core portion 18, the air flow can be turned back at the rotor body 15, and the air can be discharged to the outside from the end face 18A side of the cylindrical core portion 18. Therefore, an axial flow fan 35 can be accommodated in the in-cylinder space 30.

[0041] Second Embodiment Next, a rotor of a rotating electric machine according to a second embodiment will be described. This embodiment differs from the first embodiment in that a cross-flow fan is used instead of an axial flow fan. In this embodiment, the same configuration as in the first embodiment will be referred to and the same reference numerals will be used.

[0042] As shown in FIG. 6, the rotor 41 of the rotating electric machine of this embodiment includes a rotor body 15, a rotating shaft 16, and a permanent magnet 17. The rotating shaft 16 includes a diagonal flow fan 42. The diagonal flow fan 42 has a function of forming an air flow inclined with respect to the axial direction in the in-cylinder space 30. The position of the diagonal flow fan 42 with respect to the rotating shaft 16 is the same as the position of the axial flow fan 35 in the first embodiment. By rotating the rotor 41, the diagonal flow fan 42 introduces air from the outside into the in-cylinder space 30, and forms an air flow inclined with respect to the axial direction in the in-cylinder space 30. More specifically, the air flow formed by the diagonal flow fan 42 becomes an inclined flow from near the center of the in-cylinder space 30 toward the outer periphery of the closed core portion 19.

[0043] According to the present embodiment, the same effects as those of the first embodiment are achieved. In addition, the airflow formed by the mixed flow fan 42 is an inclined flow flow from near the center of the in-cylinder space 30 toward the outer periphery of the closed core portion 19, so that the air is more easily introduced into the connecting passage 32.

[0044] (Third embodiment) Next, a rotor of a rotating electric machine according to a third embodiment will be described. This embodiment differs from the first embodiment in that a centrifugal fan is used instead of an axial fan. In this embodiment, the same configuration as in the first embodiment will be referred to and the same reference numerals will be used.

[0045] As shown in FIG. 7, the rotor 51 of the rotating electric machine of this embodiment includes a rotor body 15, a rotating shaft 16, and a permanent magnet 17. The rotating shaft 16 includes a centrifugal fan 52. The rotor 51 includes a rotor body 15, a rotating shaft 16, and a permanent magnet 17. The centrifugal fan 52 is an impeller and has a function of taking in air from the axial direction in the in-cylinder space 30 and forming an air flow toward the outside in the radial direction. Therefore, the centrifugal fan 52 is fixed to the rotating shaft 16 so as to be adjacent to the closed core portion 19. The centrifugal fan 52 introduces air from the outside into the in-cylinder space 30 by the rotation of the rotor 51, and the air introduced into the centrifugal fan 52 from the axial direction in the in-cylinder space 30 flows toward the outside in the radial direction. The shape of the cylindrical core portion 18 may be changed according to the flow of the centrifugal fan 52, or a member may be added to the cylindrical core portion 18.

[0046] According to the present embodiment, the same effects as those of the first embodiment are achieved. In addition, the airflow formed by the centrifugal fan 52 flows radially outward from the center of the in-cylinder space 30 toward the outer periphery of the closed core portion 19 in the vicinity of the closed core portion 19, making it easier for the air to be introduced into the connecting passage 32.

[0047] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the spirit of the invention. For example, the following modifications may be made.

[0048] In the above embodiment, the cross-sectional area of ​​the connecting passage is reduced from the in-cylinder space to the flow path, but is not limited to this. For example, the cross-sectional area of ​​the connecting passage may be constant from the in-cylinder space to the flow path. In the above embodiment, the blocking portion is a part of the rotor core, but this is not limited thereto. The blocking portion may be, for example, a plate member that does not function as a core. In this case, the rotor core may be made up of only a cylindrical core portion, and a plate member serving as the blocking portion may be connected to the cylindrical core portion so as to block one opening of the cylindrical core portion. In the above embodiment, the permanent magnets are partially exposed in the flow passages. However, this is not limited to the above. For example, the flow passages may be such that the permanent magnets are not exposed. In this case, the permanent magnets can be cooled via the rotor body. In the above embodiment, the permanent magnets are cooled using air as a fluid, but the present invention is not limited to this. A fluid other than air may be used as a refrigerant to cool the permanent magnets. [Explanation of symbols]

[0049] 10 Permanent magnet type rotating electric machine 11 Stator 12, 41, 51 Rotor 15 Rotor body 16 Rotation Axis 17 Permanent Magnets 18 Cylindrical core 18A end face 18B End face 19 Blocking core section 19A Outer surface 19B Inner surface 28 Magnet insertion hole 30 Cylinder space 31 Air passage (flow path) 32 Connecting Passage 33 Wall 34 Wall 35 Axial fan (fan) 42 Diagonal flow fan (fan) 52 Centrifugal fan (fan) P axis center

Claims

1. A rotor body; a rotating shaft that is inserted through the center of the rotor body and integrated with the rotor body; a permanent magnet embedded in the rotor body along the axial direction of the rotating shaft, The rotor body includes: A cylindrical core portion that is coaxially supported on the rotating shaft and is formed by laminating electromagnetic steel sheets; a closing portion connected to the cylindrical core portion so as to close one of the openings of the cylindrical core portion, a cylindrical core portion and a closing portion form an internal space of the cylinder; The cylindrical core portion is a magnet insertion hole through which the permanent magnet is inserted; a flow path formed in an axial direction along the permanent magnet, a connecting passage formed on the closed portion side of the cylindrical core portion and communicating the flow path with the cylinder internal space, A rotor for a rotating electric machine, comprising: a fan that rotates integrally with said rotor body and is disposed in said cylindrical space.

2. The flow passage includes a plurality of flow passages, and a total flow passage cross-sectional area of ​​the plurality of flow passages is smaller than a flow passage cross-sectional area of ​​the cylinder space, 2. The rotor for a rotating electric machine according to claim 1, wherein the fan generates a flow of fluid that flows from the space inside the cylinder through the connecting passage to the flow passage by rotation of the rotor body.

3. 3. The rotor for a rotating electric machine according to claim 2, wherein a cross-sectional area of ​​the connecting passage is gradually reduced from the cylinder space toward the flow passage.

4. 4. The rotor for a rotating electric machine according to claim 1, wherein a portion of the permanent magnet is exposed to the flow passage.

5. 4. The rotor for a rotating electric machine according to claim 1, wherein the fan is an axial flow fan that generates an axial flow in the space inside the cylinder.

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