Rotating Electric Machine

Abstract

The cooling device includes a first cooling passage (82a) formed in an end plate (7a) that holds the rotor (4) in the axial direction of the rotating shaft (3), and a second cooling passage (81) that is connected to the first cooling passage (82a) and is formed so as to penetrate the rotating shaft (3) in the axial direction, and the refrigerant introduced into the second cooling passage (81) from one side of the rotating shaft (3) flows into the first cooling passage (82a) to cool the end plate (7a), and the refrigerant that has cooled the end plate (7a) flows out into the second cooling passage (81) and is discharged to the other side of the rotating shaft (3). With this configuration, the cooling liquid moves only inside the rotating shaft (3) and the end plate (7a), so that the cooling performance of the magnets (42) embedded in the rotor can be improved without leakage of the cooling liquid from the rotor (4).

Description

[Technical field]

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

[0002] Rotating electric machines, such as high-power motors for vehicles, have a rotor and a stator on the outer diameter side or axial side of the rotor, and the rotor magnet generates heat, causing the rotor magnet to reach a high temperature. When the rotor magnet becomes hot, it is demagnetized and causes problems, so it is necessary to reduce the rotor magnet temperature. For this reason, a structure is known that has a cooling flow path structure inside the rotor for cooling the rotor magnets, and improves the cooling performance of the rotor magnets by flowing a coolant through this cooling flow path (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-107336 A [Patent Document 2] International Publication No. 2010 / 123635 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, the coolant is discharged from the rotor in the centrifugal direction, and the coolant gets between the rotor and stator, which increases friction loss and reduces the efficiency of the rotating electric machine. In addition, in Patent Document 2, the coolant can be prevented from getting between the rotor and stator by making the rotor shaft into a double-tube structure and using it as a cooling flow path, but the cooling performance of the rotor magnet is low because the magnet is indirectly cooled by cooling the rotor shaft.

[0005] The present application has been made to solve the problems described above, and aims to provide a rotating electric machine that can improve the cooling performance of rotor magnets embedded in the rotor without causing coolant to leak from the rotor. [Means for solving the problem]

[0006] The rotating electric machine disclosed in the present application includes a housing, a rotating shaft penetrating the housing, a rotor fixed to the rotating shaft and provided on the outer periphery of the rotating shaft, a stator provided on the outer periphery of the rotor with a gap therebetween, and an end plate located at an end of the rotor and holding the rotor in the axial direction of the rotating shaft. Equipped with One end plate has a flow path that runs from the rotating shaft side to the radially outer periphery perpendicular to the axial direction, and a return flow path that runs from the radially outer periphery to the rotating shaft side, through which the coolant circulates. First Cooling Channel is formed, The rotating shaft is inside, Inside the rotating shaft Through Formed to pass through The refrigerant is introduced Second Cooling Channel an outlet for allowing the coolant to flow into the first cooling flow path, an inlet for returning the coolant from the first cooling flow path, and a partition plate or guide for directing the flow of the second cooling flow path to the first cooling flow path, The coolant introduced into the second cooling passage from one side of the rotating shaft is From the outlet First Cooling Channel Flow path The refrigerant flows into the end plate to cool it down, and the refrigerant that cooled the end plate is From the inlet via the return flow path The cooling fluid flows into a second cooling passage and is discharged to the other side of the rotating shaft. Effect of the Invention

[0007] According to the rotating electric machine disclosed in the present application, the refrigerant moves only within the rotating shaft and the end plates, thereby improving the cooling performance of the magnets embedded in the rotor without the coolant leaking from the rotor. [Brief description of the drawings]

[0008] [Figure 1] 2 is a cross-sectional view illustrating the flow of a cooling medium in the rotating electric machine according to the first embodiment. FIG. [Diagram 2] 2 is an enlarged cross-sectional view showing a portion of the rotor of the rotating electric machine according to the first embodiment. FIG. [Diagram 3] 5A to 5C are diagrams illustrating a partition plate disposed in a cooling flow path in an end plate according to the first embodiment. [Figure 4] 5 is a schematic diagram illustrating a cooling flow path in an end plate according to the first embodiment. FIG. [Diagram 5] FIG. 11 is a cross-sectional view of a rotating electric machine according to a second embodiment. [Figure 6] 10 is a diagram illustrating the flow of a cooling medium for a rotating electric machine according to the second embodiment. FIG. [Figure 7] 6 is a cross-sectional view illustrating the flow of a cooling medium in a rotating electric machine according to a second embodiment. FIG. [Figure 8] 6 is a cross-sectional view illustrating the flow of a cooling medium in a rotating electric machine according to a second embodiment. FIG. [Figure 9] 6 is a cross-sectional view illustrating the flow of a cooling medium in a rotating electric machine according to a second embodiment. FIG. [Figure 10] 13 is a diagram illustrating the flow of a cooling medium for a rotating electric machine according to Embodiment 3. FIG. [Figure 11] 11 is a cross-sectional view illustrating the flow of a cooling medium in a rotating electric machine according to embodiment 4. FIG. [Figure 12] 11 is a cross-sectional view illustrating the flow of a cooling medium in a rotating electric machine according to embodiment 4. FIG. [Figure 13] 11 is a cross-sectional view illustrating the flow of a cooling medium in a rotating electric machine according to embodiment 4. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, preferred embodiments of a rotating electric machine according to the present invention will be described with reference to the drawings. Note that the same reference numerals are used to designate the same contents and corresponding parts, and detailed descriptions thereof will be omitted. In the following embodiments, the same reference numerals are used to designate the same components, and redundant descriptions will be omitted.

[0010] Embodiment 1 1 is a cross-sectional view illustrating the flow of a cooling refrigerant in a rotating electric machine according to the first embodiment. The rotating electric machine 1 is mounted on an internal combustion engine such as a gasoline engine or a diesel engine, or a hybrid vehicle powered by a motor supplied with power from a rechargeable secondary battery. The rotating electric machine 1 has at least one of the following functions: a function as a motor that receives power and generates driving force, and a function as a generator.

[0011] The rotating electric machine 1 is composed of a housing 2, a rotating shaft 3 penetrating the housing 2, a rotor 4 fixed to the rotating shaft 3 and provided on the outer periphery of the rotating shaft 3, and a stator 5 provided on the outer periphery of the rotor 4. The rotating shaft 3 extends in the axial direction along the rotating axis X (see FIG. 2), is supported by bearings 11, and is provided rotatable about the rotating axis X. Hereinafter, when the axial direction, radial direction, and circumferential direction are mentioned in this specification, they refer to the axial direction, radial direction, and circumferential direction of the rotating shaft 3, respectively.

[0012] Rotor 4 has rotor core 41 shown in Fig. 2 and permanent magnets 42 embedded in rotor core 41. That is, rotating electric machine 1 of embodiment 1 is an interior permanent magnet motor (IPM motor), but may be an SPM motor (Surface Permanent Magnet Motor) in which a plurality of permanent magnets are attached to the outer periphery of rotor 4. Rotor core 41 has a cylindrical shape and is made of a plurality of electromagnetic steel plates laminated in the axial direction. Rotor core 41 is fitted to the outer periphery of rotating shaft 3 and is capable of rotating integrally with the rotating shaft.

[0013] The stator 5 is disposed on the outer periphery of the rotor 4, and has a stator core (not shown) and a coil 51 wound around the stator core. The stator core is made of a plurality of electromagnetic steel plates laminated in the axial direction. The stator core and the rotor core 41 are not limited to electromagnetic steel plates, and may be integrally molded using a powder magnetic core. The stator 5 is fitted with a plurality of coils 51 spaced apart in the circumferential direction. When each coil 51 is energized, a rotating magnetic field is generated around the stator 5, and the rotating shaft 3, the rotor 4, and the permanent magnet 42 rotate integrally with the housing 2 and the stator 5 due to the action of this rotating magnetic field.

[0014] End plates 7a, 7b are provided so as to face axial end faces located at both ends of rotor 4 in the axial direction. The end plates 7a, 7b axially sandwich the laminated structure of rotor core 41 made of electromagnetic steel sheets that constitutes rotor 4. When the end of rotor core 41 facing permanent magnet 42 is magnetized, a force acts on rotor core 41 that tries to separate due to the action of magnetic force, but separation is prevented by arranging end plates 7a, 7b to sandwich the laminated structure of rotor core 41. The end plates 7a, 7b are fixed integrally to rotating shaft 3 by a method such as screwing or crimping, and rotate as rotating shaft 3 rotates.

[0015] FIG. 2 is an enlarged cross-sectional view of a part of the rotor 4 shown in FIG. 1. As shown in FIG. 2, the end plate 7a includes a disk-shaped annular plate portion 71 and a tubular portion 72 protruding from the outer edge of the annular plate portion. A hole is formed in the center of the annular plate portion 71, and the rotating shaft 3 is inserted into the hole to fix the annular plate portion to the rotating shaft 3, thereby fixing the end plate 7a to the rotating shaft 3. The annular plate portion 71 is arranged axially separated from the axial end face of the rotor 4. The annular tip portion of the tubular portion 72 abuts against the rotor core at the axial end of the rotor 4, or contacts the rotor core via another part 73 as shown in FIG. 2, thereby holding the laminated structure of the rotor core 41 in the axial direction. With this structure, the end plates 7a and 7b have a hollow portion surrounded by the annular plate portion 71, the tubular portion 72, and the rotor core or other part 73, and a cooling flow path 82a is formed. In a structure in which the annular tip of the tubular portion 72 contacts the rotor core, it is necessary to provide a seal so that the cooling refrigerant does not come into direct contact with the rotor core. Also, in a structure in which the annular tip of the tubular portion 72 contacts the rotor core via another part 73, it is necessary to provide a seal between the annular tip and the other part 73. The cooling refrigerant may be air, water, oil, or a refrigerant, or may be a mixed fluid of these.

[0016] The housing 2 is cylindrical and has a bottom, and houses a rotor 4 and a stator 5 therein, and rotatably supports the rotating shaft 3 via a pair of bearings 11 .

[0017] 2, the rotating shaft 3 is formed to be hollow, and the cooling flow passage 81 is formed in the hollow portion. As described above, the cooling flow passages 82a, 82b are formed in the hollow portions of the end plates 7a, 7b. The cooling flow passage 81 extends in the axial direction of the rotating shaft 3, and the cooling flow passages 82a, 82b communicate with the cooling flow passage 81 and extend in the end plates 7a, 7b in a direction perpendicular to the axial direction (in the radial direction of the end plates 7a, 7b). It is necessary to form an inflow flow passage and an outflow flow passage in the hollow portion to guide the flow of the cooling refrigerant.

[0018] For example, as shown in FIG. 3(a), a partition plate 9 may be provided in the center or near the center of the cooling flow passages 82a and 82b, which is fixed to the rotating shaft 3 and extends in the radial direction of the end plates 7a and 7b. The partition plate 9 may have any shape that introduces the flow in the cooling flow passage 81 into the end plates 7a and 7b. For example, the partition plate 9 may have a substantially rotationally symmetric shape including a disk shape as shown in FIG. 3(a), a spiral shape as shown in FIG. 3(b), or a plate shape that is neither disk-shaped nor substantially rotationally symmetric. In addition, in FIG. 3(a), a gap P is formed between the partition plate 9 and the ends of the cooling flow passages 82a and 82b to allow the cooling refrigerant to pass through. However, as shown in FIG. 3(c), a flow passage may be formed by passing the cooling refrigerant through a hole Q formed in a part of the partition plate 10 that extends to the ends of the cooling flow passages 82a and 82b. At least one of the inflow and outflow sides of the hole Q formed in the partition plate 10 may have a minute arc shape at the corner to reduce pressure loss. Also, holes Q may be provided at the axial projection position of the permanent magnet 42 to enhance the cooling performance of the end of the permanent magnet. With this structure, the partition plate 10 is connected to the inner walls of the end plates 7a and 7b, increasing the strength of the partition plate. The number and position of the holes formed in the partition plate 10 may be provided at positions corresponding to the positions on the extension line of the end of the permanent magnet 42, but may be changed depending on the way the flow passage is formed. Also, a guide may be provided to guide the direction of the inflow and outflow when the cooling refrigerant flows from the cooling flow passage 81 to the cooling flow passages 82a and 82b without providing a partition plate or together with the partition plate. For example, as shown in FIG. 3(a), a structure may be used in which the walls of the upper inner surfaces of the end plates 7a and 7b are angled to guide the flow of the cooling refrigerant downward. Furthermore, although not shown in FIG. 3(a), an angled guide may be formed at the outlet from the cooling flow passage 81 to the cooling flow passages 82a and 82b so that the cooling refrigerant flows upward. When such partition plates 9, 10 are disposed to form the flow passages, the cooling medium flowing from cooling passage 81 into cooling passages 82a, 82b fills the insides of end plates 7a, 7b, thereby cooling the entire surfaces of end plates 7a, 7b.

[0019] 4(a) to 4(c) are schematic diagrams for explaining another example of forming an outlet flow passage and an inlet flow passage in the end plates 7a and 7b. The cooling refrigerant flowing out from the cooling flow passage 81 formed in the rotating shaft 3 to the cooling flow passages 82a and 82b flows through the flow passages indicated by arrows in FIG. 4(a) to FIG. 4(c), which are formed so as to circulate at positions corresponding to the extensions of the ends of the multiple permanent magnets 42 embedded in the rotor core 41 and in the vicinity thereof. Guides such as grooves are provided in the end plates 7a and 7b so as to form an annular flow passage through which the cooling refrigerant circulates. Furthermore, the rotation of the rotating shaft 3 may be utilized to form an annular flow passage. Since the outer periphery of the rotor 4 generates more heat than the inner periphery, only an annular flow passage for cooling the permanent magnets 42 and the rotor core 41 on the outer periphery of the permanent magnets 42 may be formed.

[0020] In FIG. 4(a), cooling flow passage outlets for flowing the cooling refrigerant from the cooling flow passage 81 to the cooling flow passages 82a and 82b, and inlets for returning the cooling refrigerant to the cooling flow passage 81 after circulating through the cooling flow passages 82a and 82b are arranged in parallel in the rotating shaft 3, and the cooling refrigerant flowing out from the outlets to the cooling flow passages 82a and 82b proceeds radially toward the outer periphery in the end plates 7a and 7b, and the cooling flow passages 82a and 82b are branched into a right-handed flow passage and a left-handed flow passage at a position corresponding to the position of the rotor in which the permanent magnets 42 are embedded, and the flow passages are joined on the opposite radial side and return to the inlet of the cooling flow passage 81. By branching the cooling flow passage in this way, it is possible to reduce flow passage pressure loss. Alternatively, a flow passage having a one-stroke shape may be formed as shown in FIG. 4(b) without branching the cooling flow passage. In this case, for example, the cooling refrigerant flows in the cooling flow passages 82a and 82b in the clockwise direction, which is the same as the rotation direction of the rotating shaft 3, and the cooling refrigerant returns to the inlet from the same side as the side from which it flowed out from the outlet. Fig. 4(c) shows an example of cooling passages 81a and 81b of a double-pipe structure in the second embodiment described later, in which the outlet and inlet of the cooling refrigerant are separated by the cooling passage 81a on the outer periphery side and the cooling passage 81b on the inner periphery side of the double-pipe structure. The other structures are the same as those in Fig. 4(a). Fig. 4 shows that one passage is formed in the circumferential direction from the rotating shaft 3 and proceeds to the radially outer periphery side, but multiple parallel passages may be formed in the circumferential direction, and similarly, multiple parallel passages may be formed in the circumferential direction for returning the cooling refrigerant from the radially outer periphery side to the rotating shaft 3.

[0021] The flow of the cooling refrigerant through the cooling flow passage thus formed will be described. The cooling refrigerant is transported by a pump (not shown) and introduced into the cooling flow passage 81 in the rotating shaft 3 from one end of the rotating shaft 3. The introduced cooling refrigerant flows radially outward due to the action of centrifugal force generated by the rotation of the rotor 4, and flows into the cooling flow passage 82a in the end plate 7a on one end side of the rotor 4. The cooling refrigerant that flows into the cooling flow passage 82a is branched, for example, as shown in FIG. 4(a), circulates in the end plate 7a, and then combines. In the course of circulation, it cools the ends of the permanent magnets 42 and the rotor core 41 that are in contact with the end plate 7a or arranged in a coolable vicinity. The cooling refrigerant that has circulated in the end plate 7a flows into the cooling flow passage 81. In addition, as shown in FIG. 3(a), the refrigerant flows and moves through the flow passage from left to right of the left and right end plates 7a separated by the partition plate 9, thereby cooling the entire inner surface of the end plate, thereby cooling the ends of the permanent magnets 42 and the rotor core 41. The cooling refrigerant that has flowed into the cooling passage 81 advances axially inside the rotating shaft 3 and flows into the cooling passage 82b in the end plate 7b on the other end side of the rotor 4. The cooling refrigerant that has flowed into the cooling passage 82b circulates or moves inside the end plate 7b, just like inside the end plate 7a. During the circulation or movement, it cools the permanent magnets 42 and rotor core 41 that are in contact with the end plate 7b or are disposed in close proximity so that they can be cooled. The cooling refrigerant that has circulated or moved inside the end plate 7b flows back into the cooling passage 81 and is discharged from the other end of the rotating shaft 3. The discharged cooling refrigerant may be collected in a cooling tank and used again for cooling.

[0022] By forming an annular cooling flow passage in this manner, the permanent magnets 42 and the rotor core 41 around them can be cooled, thereby reducing the amount of refrigerant required compared to the partition guide shown in Fig. 3, which cools the entire surface of the end plates. It goes without saying that a cooling flow passage for the inflow and outflow of the cooling refrigerant may be formed by combining both guides such as partitions 9 and 10 shown in Fig. 3 and the annular guide shown in Fig. 4.

[0023] As described above, in the first embodiment, the cooling refrigerant passes through the end plates 7a, 7b and the rotating shaft 3, thereby preventing the cooling refrigerant from leaking out of the rotor 4, thereby preventing the cooling refrigerant from entering between the rotor 4 and the stator 5 and suppressing an increase in friction loss. With this configuration, the magnet temperature of the permanent magnets 42 embedded in the rotor 4 can be reduced so as not to exceed the Curie point, thereby eliminating problems due to demagnetization.

[0024] Embodiment 2 FIG. 5 is a cross-sectional view of a rotating electric machine according to the second embodiment, and FIG. 6 is a diagram for explaining the flow of a cooling refrigerant. Only parts different from the first embodiment will be explained. In FIG. 5, a cooling passage 81 in the rotating shaft 3 has a double pipe structure, and a cooling passage 82a formed in the end plate 7a is connected to and communicates with a refrigerant outlet of a cooling passage 81a on the outer periphery side of the double pipe structure. Similarly, a cooling passage 82b formed in the end plate 7b is connected to and communicates with a refrigerant outlet of the cooling passage 81a. Furthermore, the cooling passage 82b is connected to and communicates with a refrigerant inlet of the cooling passage 81b on the inner periphery side of the double pipe structure. An example of a connection structure between the cooling passage 81a and the cooling passage 82a is shown in FIG. 6(a). Such a connection structure is called a serial passage.

[0025] The flow of the cooling refrigerant in the cooling flow passage formed in the serial flow passage will be described with reference to Figs. 5 and 6. The cooling refrigerant is transported by a pump (not shown) and introduced into the cooling flow passage 81a from one end of the rotating shaft 3. The introduced cooling refrigerant flows radially outward due to the action of centrifugal force generated by the rotation of the rotor 4, and flows into the cooling flow passage 82a in one end plate 7a. The cooling refrigerant that flows into the cooling flow passage 82a moves through the flow passage formed by the partition plates 9 and 10 as described in Fig. 3 in the first embodiment, and cools the entire inside of the end plate 7a. Alternatively, as described in Fig. 4, the cooling refrigerant is cooled by circulating inside the end plate 7a. In the cooling process, the end of the permanent magnet 42 that is in contact with the end plate 7a or arranged in a coolable vicinity thereof and the rotor core 41 are cooled. The cooling refrigerant that has cooled the inside of the end plate 7a flows into the cooling flow passage 81a in the rotating shaft 3. The cooling refrigerant that has flowed into the cooling passage 81a advances axially inside the rotating shaft 3 and flows into the cooling passage 82b inside the end plate 7b. The cooling refrigerant that has flowed into the cooling passage 82b cools the inside of the end plate 7b, as well as the inside of the end plate 7a, thereby cooling the ends of the permanent magnets 42 that are in contact with the end plate 7b or disposed in a coolable vicinity thereof, and the rotor core 41. The cooling refrigerant that has cooled the inside of the end plate 7b flows into the cooling passage 81b and is discharged from one end of the rotating shaft 3, which is the same as the cooling refrigerant inlet side. Such a flow of the cooling refrigerant is shown diagrammatically in FIG. 6(b).

[0026] By making the cooling flow passage 81 into a double pipe structure in this way, the cooling refrigerant is discharged to the anti-output side which is not the output side, rather than to the output side where the gear 12 is arranged as in the first embodiment, so that the introduction and discharge of the cooling refrigerant can be consolidated on the anti-output side, eliminating the need to provide space for the cooling refrigerant on the output side, and increasing the space margin when mounting the rotating electric machine 1 on a vehicle. Furthermore, it is necessary to provide a sealed location only in the bearing on the anti-output side, and the number of sealed locations can be reduced to one compared to the first embodiment.

[0027] 5, the cooling channels 81a, 81b are formed up to the end plates 7a, 7b on both sides, but as shown in Fig. 7, the cooling channels 81a, 81b may be extended into the rotating shaft 3 up to a position supported by the bearing 11 in order to cool the bearing 11. In this case, the cooling refrigerant that has moved or circulated inside the end plate 7b may flow again into the cooling channel 81a, and then flow into the cooling channel 81b at the position of the rotating shaft 3 supported by the bearing 11, and the cooling refrigerant may be returned to the cooling refrigerant inlet side.

[0028] Furthermore, as shown in FIG. 8, the gear 12 connected to the rotating shaft 3 may also be cooled. Specifically, the cooling passages 81a and 81b are extended to the outside of the rotating shaft 3 and formed within the gear 12. With this configuration, the cooling refrigerant that has cooled the bearing 11 flows back into the cooling passage 81a, cools the gear 12 by the cooling passage that extends into the gear 12, and then flows into the cooling passage 81b. Thereafter, the cooling refrigerant may be returned to the cooling refrigerant introduction side (opposite the output side). FIG. 6(c) shows a schematic diagram of such a flow of the cooling refrigerant.

[0029] Furthermore, in response to a temperature rise in the permanent magnets 42, if it is determined that cooling the end plate 7a on one end side is sufficient as shown in Fig. 9, cooling channels 81a and 81b may be formed only in the end plate 7a. In this case, the cooling refrigerant that flows from the cooling channel 81a into the cooling channel 82a cools the inside of the end plate 7a as described in Fig. 3 or 4, thereby cooling the ends of the permanent magnets 42 that are in contact with the end plate 7a or disposed in a coolable vicinity thereof and the rotor core 41. The cooling refrigerant that has cooled the inside of the end plate 7a may flow into the cooling channel 81b and be returned to the cooling refrigerant inlet side.

[0030] As described above, according to the second embodiment, as in the first embodiment, the cooling refrigerant passes through the end plates 7a and 7b and the rotating shaft 3, and thus the cooling refrigerant is prevented from leaking out of the rotor 4, preventing the cooling refrigerant from entering between the rotor 4 and the stator 5, and suppressing an increase in friction loss. Furthermore, the cooling refrigerant is introduced and discharged from the same end face of the rotating electric machine, which increases the space margin for mounting the rotating electric machine and improves the cooling performance of the rotor 4. In addition, by making the cooling flow path a double-pipe structure, when only the rotor 4 is cooled, the number of seals for preventing leakage of the cooling refrigerant from the rotating shaft 3 can be reduced to one, that is, the bearing 11 on the opposite output side, and a cooling structure for a rotating electric machine that is inexpensive and has a low risk of leakage can be formed.

[0031] Embodiment 3 In the second embodiment, the cooling flow passage of the double pipe structure is described as a serial flow passage as shown in FIG. 6. Alternatively, the cooling refrigerant may be passed through a parallel flow passage. That is, as shown in FIG. 10(a), the cooling refrigerant that flows out from the cooling flow passage 81a to the cooling flow passages 82a and 82b does not flow back into the cooling flow passage 81a after circulating or moving through the end plates 7a and 7b, but flows into the cooling flow passage 81b and is returned to the cooling refrigerant introduction side (opposite output side). That is, the outlets of the cooling flow passages 82a and 82b communicate with the cooling flow passage 81b. By passing the cooling refrigerant through the parallel flow passages in this way, for example, the cooling refrigerant that cools the inside of the end plate 7a and whose temperature has increased is discharged without continuing to cool the inside of the end plate 7b, so that the cooling performance of the cooling refrigerant that cools the inside of the end plate 7b is not reduced. 10(b), the cooling refrigerant that cools the bearing 11 directly cools the bearing 11 without cooling the inside of the end plates 7a, 7b, and the cooling refrigerant that cools the gear 12 directly cools the gear 12 without passing through the end plates 7a, 7b and the bearing 11. In this way, the introduced cooling refrigerant cools only the parts to be cooled.

[0032] As described above, according to the third embodiment, the cooling flow paths are arranged in parallel, so that each component can be cooled without reducing the cooling performance of the cooling refrigerant.

[0033] Embodiment 4 FIG. 11 is a cross-sectional view for explaining the cooling passage of a rotating electric machine according to the fourth embodiment. Only the parts different from the first embodiment will be explained. In FIG. 11, a part of the cooling passage 81 in the rotating shaft 3 has a double pipe structure, and the cooling passage 81a on the outer periphery of the double pipe communicates with the cooling passage 82a in the end plate 7a. As explained in the first and second embodiments, the cooling passage 82a extending in the end plate 7a cools the permanent magnet 42 embedded in the rotor core 41. Furthermore, in order to cool the axial side surface of the permanent magnet 42, for example, a cooling passage 83 is formed in the rotor 4 in contact with the axial side surface of the permanent magnet 42 or at a position where it can be cooled. One end side of the cooling passage 83 is connected and communicates with the cooling passage 82a in the end plate 7a. The cooling passage 83 extends in the axial direction, and the other end side of the cooling passage 83 is connected and communicates with the cooling passage 82b extending in the end plate 7b in the end plate 7b. Since a plurality of permanent magnets 42 are embedded, a plurality of cooling channels 83 may be formed corresponding to the respective permanent magnets 42 .

[0034] The flow of the cooling refrigerant in the cooling passage thus formed will be described. The cooling refrigerant is transported by a pump (not shown) and introduced into the cooling passage 81a formed on the outer periphery of the double pipe structure from one end of the rotating shaft 3. The introduced cooling refrigerant flows radially outward due to the action of centrifugal force generated by the rotation of the rotor 4, and flows into the cooling passage 82a in one end plate 7a. The cooling refrigerant that flows into the cooling passage 82a cools the inside of the end plate 7a as shown in FIG. 3 or FIG. 4, thereby cooling the end of the permanent magnet 42 arranged in contact with or in a coolable vicinity of the end plate 7a and the rotor core 41. Furthermore, the cooling refrigerant is introduced into the cooling passage 83 connected to the cooling passage 82a, so that the permanent magnet 42 arranged in contact with or in a coolable distance from the cooling passage 83 can be cooled in the axial direction.

[0035] The cooling refrigerant in the cooling passage 83 flows into a cooling passage 82b in the other end plate 7b. The cooling refrigerant that flows into the cooling passage 82b cools the inside of the end plate 7b, as well as the inside of the end plate 7a, thereby cooling the ends of the permanent magnets 42 that are in contact with the end plate 7b or disposed in close proximity so as to be coolable, and the rotor core 41. The cooling refrigerant that has cooled the end plate 7b flows into a cooling passage 81b formed in the rotating shaft 3, and is discharged from the same side as the one end side of the rotating shaft 3 where the cooling refrigerant was introduced. The discharged cooling refrigerant may be collected in a cooling tank and used again for cooling.

[0036] In the above-mentioned flow of the cooling refrigerant, the cooling refrigerant is introduced from one end of the rotating shaft 3 through the cooling flow passage 81a on the outer periphery side of the cooling flow passage having a double pipe structure, and after cooling each component, the cooling refrigerant is discharged to one end side of the rotating shaft 3 through the cooling flow passage 81b on the inner periphery side, but as shown in Fig. 12, the cooling refrigerant may be introduced from one end side of the rotating shaft 3 through the cooling flow passage 81b on the inner periphery side of the cooling flow passage having a double pipe structure, and after cooling each component, the cooling refrigerant may be discharged to one end side of the rotating shaft 3 through the cooling flow passage 81a on the outer periphery side. That is, the cooling refrigerant introduced into the cooling flow passage 81b from one side of the rotating shaft 3 flows into the cooling flow passage 82b to cool the end plate 7b, and also flows into the cooling flow passage 83 to cool the axial side surface of the permanent magnet 42, flows into the cooling flow passage 82a to cool the end plate 7a, flows out of the cooling flow passage 82a, and is discharged to one side of the rotating shaft into which the cooling refrigerant was introduced.

[0037] As described above, according to embodiment 4, in addition to the effects of embodiment 2, by forming a cooling flow passage 83 in contact with or in close proximity to the axially extending surface of permanent magnet 42 so as to be able to be cooled, it is possible to cool permanent magnet 42 embedded in rotor 4 from both the radial and axial directions of rotor 4.

[0038] In the above description, cooling passages 82a, 82b are formed in the end plates, but as shown in FIG. 13, cooling passage 84 that branches off cooling passage 81a to cooling passage 83 may be formed in rotor core 41.

[0039] Although the present application describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless modifications not exemplified are assumed within the scope of the technology disclosed in the present specification, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component and combining it with a component of another embodiment. [Explanation of symbols]

[0040] 1: rotating electric machine, 2: housing, 3: rotating shaft, 4: rotor, 5: stator, 7a, 7b: end plates, 9, 10: partition plates, 11: bearings, 12: gears, 41: rotor core, 42: permanent magnets, 81, 81a, 81b, 82a, 82b, 83, 84: cooling channels.

Claims

1. a housing, a rotating shaft penetrating the housing, a rotor fixed to the rotating shaft and provided on an outer periphery of the rotating shaft, a stator provided on the outer periphery of the rotor with a gap therebetween, and an end plate located at an end of the rotor and holding the rotor in an axial direction of the rotating shaft, a first cooling flow passage is formed inside the one end plate, the first cooling flow passage including a flow passage proceeding from the rotating shaft side to a radially outer periphery side perpendicular to the axial direction and a return flow passage flowing from the radially outer periphery side to the rotating shaft side, through which a coolant circulates; the rotating shaft includes a second cooling flow passage formed inside the rotating shaft so as to pass through the rotating shaft and into which the coolant is introduced, an outlet for causing the coolant to flow into the first cooling flow passage, an inlet for returning the coolant from the first cooling flow passage, and a partition plate or guide for guiding the flow of the second cooling flow passage to the first cooling flow passage, a first passageway through which the refrigerant flows and cools the end plate; and a second passageway through which the refrigerant flows and cools the end plate. The first passageway is a passageway through which the refrigerant flows and cools the end plate. The second passageway is a passageway through which the refrigerant flows and cools the end plate.

2. a housing, a rotating shaft penetrating the housing, a rotor fixed to the rotating shaft and provided on an outer periphery of the rotating shaft, a stator provided on the outer periphery of the rotor with a gap therebetween, and an end plate located at an end of the rotor and holding the rotor in an axial direction of the rotating shaft, a first cooling flow passage is formed inside the one end plate, the first cooling flow passage including a flow passage proceeding radially toward the outer periphery perpendicular to the axial direction and a return flow passage flowing from the radially outer periphery toward the rotating shaft, through which a coolant circulates; the rotating shaft includes within itself a second cooling flow passage formed in the axial direction within the rotating shaft and into which the refrigerant is introduced, an outlet for causing the refrigerant to flow into the first cooling flow passage, an inlet for returning the refrigerant from the first cooling flow passage, a partition plate or guide for directing the flow of the second cooling flow passage to the first cooling flow passage, and a third cooling flow passage within the second cooling flow passage, communicating with the second cooling flow passage and forming a double pipe structure with the second cooling flow passage; a cooling passage that is connected to the second cooling passage and that flows through the first cooling passage and returns to the first passage, thereby cooling the end plate; and a cooling passage that is connected to the second cooling passage and that flows through the second cooling passage and returns to the first passage, thereby cooling the end plate.

3. a housing, a rotating shaft penetrating the housing, a rotor fixed to the rotating shaft and provided on an outer periphery of the rotating shaft, a stator provided on the outer periphery of the rotor with a gap therebetween, and an end plate located at an end of the rotor and holding the rotor in an axial direction of the rotating shaft, a first cooling flow passage is formed inside the one end plate, the first cooling flow passage including a flow passage proceeding radially toward the outer periphery perpendicular to the axial direction and a return flow passage flowing from the radially outer periphery toward the rotating shaft, through which a coolant circulates; the rotating shaft includes a second cooling flow passage formed in the rotating shaft in the axial direction and serving as a side into which the coolant is introduced, an outlet for flowing the coolant into the first cooling flow passage, an inlet for returning the coolant from the first cooling flow passage, and a third cooling flow passage in the second cooling flow passage, communicating with the second cooling flow passage and forming a double pipe structure with the second cooling flow passage, serving as a side from which the coolant is discharged, a first cooling passage that is connected to the first cooling passage and that is connected to the second cooling passage, and ...

4. A rotor having a housing, a rotating shaft passing through the housing, a rotor fixed to the rotating shaft and provided on the outer periphery of the rotating shaft, a stator provided on the outer periphery of the rotor with a gap therebetween, and an end plate located at an end of the rotor and clamping the rotor in the axial direction of the rotating shaft, a first cooling flow passage is formed inside the one end plate, the first cooling flow passage including a flow passage proceeding radially toward the outer periphery perpendicular to the axial direction and a return flow passage flowing from the radially outer periphery toward the rotating shaft, through which a coolant circulates; the rotating shaft includes a second cooling flow passage formed inside the rotating shaft in the axial direction and into which the coolant is introduced, an outlet for causing the coolant to flow into the first cooling flow passage, an inlet for returning the coolant from the first cooling flow passage, and a partition plate or guide for guiding the flow of the second cooling flow passage at the outlet into the end plate, A rotating electric machine characterized in that the refrigerant is connected so as to flow in the order of the outlet, the forward flow path of the first cooling flow path, the return flow path of the first cooling flow path, the inlet, and the second cooling flow path.

5. A rotor having a housing, a rotating shaft passing through the housing, a rotor fixed to the rotating shaft and provided on the outer periphery of the rotating shaft, a stator provided on the outer periphery of the rotor with a gap therebetween, and an end plate located at an end of the rotor and clamping the rotor in the axial direction of the rotating shaft, a first cooling flow passage is formed inside the one end plate, the first cooling flow passage including a flow passage proceeding radially toward the outer periphery perpendicular to the axial direction and a return flow passage flowing from the radially outer periphery toward the rotating shaft, through which a coolant circulates; the rotating shaft includes a second cooling flow passage formed to extend in the axial direction and serving as a side through which the coolant is introduced, a third cooling flow passage formed to extend in the axial direction and serving as a side through which the coolant is discharged, an outlet for causing the coolant to flow into the first cooling flow passage, and an inlet for returning the coolant from the first cooling flow passage, A rotating electric machine characterized in that the refrigerant is connected so as to flow in the following order: the second cooling flow path, the outlet, the forward flow path of the first cooling flow path, the return flow path of the first cooling flow path, the inlet, and the third cooling flow path.

6. 6. The rotating electric machine according to claim 1, wherein the first cooling passage further cools a bearing that supports the rotating shaft.

7. 4. The rotating electric machine according to claim 2, wherein the first cooling passage further cools a drive section connected to the rotating shaft on the other side of the rotating shaft.

8. 3. The rotating electric machine according to claim 1, further comprising a guide member disposed within said end plate for guiding the inflow and outflow of said coolant.

9. 9. The rotating electric machine according to claim 8, wherein the guide member is a partition plate having one end fixed to the rotating shaft and extending radially within the end plate.

10. 9. The rotating electric machine according to claim 8, wherein the guide member is a groove provided on an inner surface of the end plate.

11. The rotating electric machine according to claim 9, characterized in that the partition plate has the other end fixed to an inner wall of an end plate, and a hole through which the refrigerant passes is formed on the surface of the partition plate on an extension line of the axial end of the magnet embedded in the rotor.

12. 11. The rotating electric machine according to claim 10, wherein the groove is provided annularly on the inner surface of the end plate on an extension line of an axial end of the magnet embedded in the rotor.

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