Rotating electric machine

Abstract

The present invention is a rotating electric machine wherein a stator and a rotor are accommodated in a housing, and the rotor is supported by the housing via a bearing and is cooled and lubricated by using a refrigerant. The refrigerant is composed of a mixed refrigerant obtained by mixing a first refrigerant and a second refrigerant having a lower boiling point than the first refrigerant. The present invention comprises a refrigerant separation unit that separates, into a first mixed refrigerant and a second mixed refrigerant having a larger volume ratio of the second refrigerant than the first mixed refrigerant, the mixed refrigerant that has passed through the interior of the rotating electric machine, and that discharges the first and second mixed refrigerants. The discharged first mixed refrigerant is supplied to the bearing, and the discharged second mixed refrigerant is supplied to the stator.

Description

Rotating electric machines

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

[0002] To increase the power output and speed of rotating electrical machines, it is necessary to promote cooling of the rotating electrical machines. JPH10-336968A discloses a configuration in which a gas-liquid two-phase refrigerant is circulated within the machine compartment of the rotating electrical machine, and the refrigerant is turned into a gas phase to cool the rotating electrical machine.

[0003] In the configuration described in JPH10-336968A, the refrigerant that has become a gas inside the rotating electrical machine is converted to a liquid phase in an external radiator. In this configuration, the refrigerant does not function as a refrigerant until it becomes a liquid phase in the radiator. Therefore, in order to efficiently cool the rotating electrical machine, it is necessary to constantly circulate a refrigerant sufficient to fill the interior of the machine, which increases the required amount of refrigerant and therefore raises the problem of rising costs.

[0004] The present invention has been made in view of the above problems, and has an object to provide a rotating electric machine that can be cooled more efficiently.

[0005] One embodiment of the present invention is applied to a rotating electric machine in which a stator and a rotor are accommodated in a housing, the rotor is supported by the housing via bearings, and the rotating electric machine is cooled and lubricated by a refrigerant. The refrigerant is a mixed refrigerant containing a first refrigerant and a second refrigerant having a lower boiling point than the first refrigerant. A refrigerant separation unit is provided to separate the mixed refrigerant flowing into the housing into the first mixed refrigerant and the second mixed refrigerant, in which the volume ratio of the second refrigerant is higher than that of the first mixed refrigerant, and discharge the separated mixed refrigerants. The discharged first mixed refrigerant is supplied to the bearings, and the discharged second mixed refrigerant is supplied to the stator.

[0006] Fig. 1 is a cross-sectional view of a rotating electric machine according to an embodiment of the present invention. Fig. 2 is a cross-sectional view of the rotating electric machine. Fig. 3 is a perspective view of the rotating electric machine. Fig. 4 is a top view of a separator. Fig. 5 is a perspective view of a separator. Fig. 6 is an explanatory diagram of a modified example of the separator.

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0008] 1, 2, and 3 are explanatory diagrams of a motor 10 as a rotating electric machine according to an embodiment of the present invention. Fig. 1 is a vertical cross-sectional view of the motor 10. Fig. 2 is a horizontal cross-sectional view of the motor 10. Fig. 3 is a perspective view of the motor 10.

[0009] The motor 10 of this embodiment is mounted on a vehicle and functions as a driving power source for the vehicle. The motor 10 may also be used as a driving device for devices other than vehicles, such as various electrical appliances and industrial machines.

[0010] As shown in FIG. 1 , the motor 10 includes a housing 11 , a stator 20 , and a rotor 30 .

[0011] The housing 11 is composed of a cylindrical portion 12 and a disk-shaped front cover 13 and a disk-shaped rear cover 14 fixed to both axial ends of the cylindrical portion 12 so as to close the opening of the cylindrical portion 12 .

[0012] The stator 20 has a cylindrical shape, and coils are wound in slots (not shown). Coil ends 22 are formed at both axial ends of the stator 20. The stator 20 is accommodated in a cylindrical housing 11 so as to be inscribed therein. A rotor 30 is provided inside the stator 20.

[0013] The rotor 30 has a permanent magnet (not shown) and is driven to rotate by the action of the magnetic field of the stator 20. The rotor 30 has a rotation shaft 32 at its rotation center. The rotation shaft 32 is rotatably supported by a pair of bearings 15, 16 provided on the front cover 13 and the rear cover 14, respectively.

[0014] The bearings 15 and 16 are disposed in bearing chambers 13a and 14a provided in the front cover 13 and the rear cover 14, respectively.

[0015] A coil cover 40 is provided between the stator 20 and the rotor 30, circumferentially covering the inner periphery of the stator 20. The coil cover 40 is a cylindrical member open at both ends, and extends axially from the front cover 13 to the rear cover 14. The coil cover 40 divides the interior of the housing 11 into a stator chamber 11a and a rotor chamber 11b. The stator chamber 11a is an annular space surrounded by the inside of the cylindrical portion 12, the front cover 13, the rear cover 14, and the outside of the coil cover 40. The rotor chamber 11b is a cylindrical space surrounded by the inside of the front cover 13, the rear cover 14, and the coil cover 40.

[0016] A refrigerant flows into the housing 11 to cool and lubricate the motor 10. The motor 10 of this embodiment uses a mixed refrigerant that is a mixture of two types of refrigerants (a first refrigerant and a second refrigerant) that have different boiling points and densities.

[0017] The first refrigerant is a medium whose boiling point is higher than the temperature (e.g., the maximum temperature) that a high-temperature portion (e.g., the coil end 22) in the housing 11 reaches when the motor 10 is running, and which remains in a liquid phase within the housing 11. The first refrigerant is a lubricating oil that is generally used to cool and lubricate components in a motor or the like.

[0018] The second refrigerant has a boiling point lower than the temperature (e.g., the maximum temperature) that the high-temperature portion of the housing reaches when the motor 10 is running. The second refrigerant evaporates upon contact with the high-temperature portion, and is a medium (gas-liquid two-phase refrigerant) capable of cooling the high-temperature portion by the latent heat of vaporization. The second refrigerant is, for example, a fluorine-based inert liquid. The second refrigerant has a lower boiling point than the first refrigerant and a higher density (specific gravity) than the first refrigerant.

[0019] As described below, the mixed refrigerant of the first refrigerant and the second refrigerant is separated into a first mixed refrigerant and a second mixed refrigerant by a refrigerant separation unit 18 disposed at the bottom (lower part) of the motor 10. The first mixed refrigerant has a smaller mixing ratio (e.g., volume ratio) of the second refrigerant to the first refrigerant than the second mixed refrigerant. The second mixed refrigerant has a larger mixing ratio of the second refrigerant to the first refrigerant than the first mixed refrigerant.

[0020] The first mixed refrigerant and the second mixed refrigerant pass through circulation paths (first circulation path 61 and second circulation path 62) outside the motor 10 and flow into the interior of the motor 10 from inlets (first inlet 141 and second inlet 142) at the top of the housing 11.

[0021] The first mixed refrigerant and second mixed refrigerant that have flowed into the motor 10 cool and lubricate the interior of the motor 10, and then flow down to the bottom of the housing 11. The first mixed refrigerant and second mixed refrigerant that have flowed down to the bottom of the housing 11 mix together to form a mixed refrigerant in which the first and second mixed refrigerants are indistinguishable from each other.

[0022] A refrigerant separation unit 18 is provided at the bottom of the housing 11, which separates the mixed refrigerant into a first mixed refrigerant and a second mixed refrigerant and discharges them outside the housing 11. The refrigerant separation unit 18 is composed of a refrigerant storage chamber 19, which is a space formed at the bottom of the housing 11, and a separator 50. The separator 50 separates the mixed refrigerant that has flowed down into the refrigerant storage chamber 19 into the first mixed refrigerant and the second mixed refrigerant by utilizing the difference in density (difference in specific gravity) between the first refrigerant and the second refrigerant. The detailed configuration of the separator 50 will be described later.

[0023] 2, the bottom of the housing 11 is provided with a first outlet 121 for discharging the first mixed refrigerant separated by the separator 50, and a second outlet 122 for discharging the second mixed refrigerant. The first outlet 121 is located above the second outlet 122. At least one of the first outlet 121 and the second outlet 122 may be provided with a strainer for removing contaminants, etc.

[0024] One end of a first circulation path 61 that circulates the first mixed refrigerant is connected to the first outlet 121. The other end of the first circulation path 61 is connected to a first inlet 141 provided at the top of the housing 11. A first pump 71 that circulates the first mixed refrigerant in the first circulation path 61 is provided midway along the first circulation path 61.

[0025] Similarly, one end of a second circulation path 62, which circulates the second mixed refrigerant, is connected to the second outlet 122. The other end of the second circulation path 62 is connected to a second inlet 142 provided at the top of the housing 11. A second pump 72 is provided midway through the second circulation path 62, which circulates the second mixed refrigerant through the second circulation path 62. Furthermore, a cooler 82 is provided midway through the second circulation path 62, which lowers the temperature of the second mixed refrigerant flowing through the second circulation path 62. The cooler 82 lowers the temperature of the second mixed refrigerant, for example, by exchanging heat between cooling water and the second mixed refrigerant. It is sufficient that the cooler 82 is provided in at least one of the first circulation path 61 and the second circulation path 62.

[0026] Next, the flow of the refrigerant in the motor 10 configured as above will be described.

[0027] The first mixed refrigerant flows into the first inlet 141 of the housing 11 by the first pump 71 of the first circulation path 61. The second mixed refrigerant flows into the second inlet 142 of the housing 11 by the second pump 72 of the second circulation path 62. The first pump 71 and the second pump 72 are, for example, electric pumps.

[0028] 3, the first inlet 141 is connected to a bearing-side flow passage 17a formed inside the housing 11, the front cover 13, or the rear cover 14. The first mixed refrigerant is supplied to the bearing chambers 13a and 14a via the bearing-side flow passage 17a.

[0029] When the first mixed refrigerant flows into the bearing chambers 13a and 14a, the first refrigerant contained in the first mixed refrigerant in large amounts lubricates the bearings 15 and 16 disposed in the bearing chambers 13a and 14a. At this time, the bearings 15 and 16 are also cooled by the first and second refrigerants.

[0030] 3, the second inlet 142 is connected to a stator-side flow passage 17b formed in the housing 11. The second mixed refrigerant flows into the stator chamber 11a via the stator-side flow passage 17b and fills the stator chamber 11a.

[0031] When the second mixed refrigerant flows into the stator chamber 11a, the second refrigerant, which is contained in large amounts in the second mixed refrigerant, evaporates from liquid to gas on the surfaces of the coil ends 22, which are high-temperature areas, thereby using the latent heat of vaporization to cool the coil ends 22. At this time, areas within the stator chamber 11a other than the surfaces of the coil ends 22 are not hot, and furthermore, due to the presence of the inflowing second mixed refrigerant, which is at a relatively low temperature, and particularly the first refrigerant, which is in a liquid phase, the second refrigerant, which has changed from a gas phase, immediately changes to a liquid phase.

[0032] The first mixed refrigerant that flows into the bearing chambers 13a, 14a flows downward to the bottom of the housing 11 via flow paths 17c (see FIG. 3) formed in the front cover 13 and the rear cover 14. Meanwhile, the second mixed refrigerant that flows into the stator chamber 11a flows downward to the bottom of the housing 11 via flow path 17d (see FIG. 2) provided in the lower part of the stator chamber 11a. At this time, the first mixed refrigerant and the second mixed refrigerant mix together to form a mixed refrigerant in which no distinction is made between them, and then flows into the refrigerant separation unit 18 arranged at the bottom of the housing 11.

[0033] In refrigerant separation section 18, the mixed refrigerant that has flowed down to refrigerant storage chamber 19 is separated into a first mixed refrigerant and a second mixed refrigerant by separator 50. The separated first mixed refrigerant flows from first discharge port 121 to first circulation path 61, and the separated second mixed refrigerant flows from second discharge port 122 to second circulation path 62.

[0034] In this manner, cooling and lubrication of the motor 10 are achieved. In particular, in the stator chamber 11a, the coil ends 22, which become particularly hot due to the latent heat of vaporization of the second refrigerant in the second mixed refrigerant, can be efficiently cooled. At this time, the vaporized second refrigerant is cooled by the surrounding first refrigerant and becomes liquid, so the volume of the second refrigerant can be minimized compared to when the stator chamber 11a is filled with only the second refrigerant.

[0035] For example, it is preferable that the volume ratio of the first refrigerant to the second refrigerant in the mixed refrigerant circulating throughout the motor 10 is 4:1. In such a case, the motor 10 can be appropriately cooled by setting the volume ratio of the first refrigerant to the second refrigerant in the first mixed refrigerant to 6:1 and the volume ratio of the first refrigerant to the second refrigerant in the second mixed refrigerant to 2:1.

[0036] Next, the configuration of the separator 50 will be described.

[0037] FIG. 4 is a top view of the separator 50, and FIG. 5 is a perspective view of the separator 50. As shown in FIG.

[0038] The separator 50 is configured to include a cylindrical conical portion 51, a pair of inlet passages 52a and 52b, a first discharge portion 53, and a second discharge portion .

[0039] The cylindrical cone portion 51 has a cylindrical portion 51a having a cylindrical shape and a cone portion 51b having a conical shape whose diameter decreases downward from the cylindrical portion 51a in a mortar-like shape.

[0040] The inlet channels 52a and 52b are passages that allow the mixed refrigerant that has flowed down into the refrigerant separation section 18 to flow into the cylindrical-conical section 51 of the separator 50. The inlet channels 52a and 52b each open to a side surface of the cylindrical section 51a of the cylindrical-conical section 51, and are arranged at positions that are point-symmetrical with each other about the center of the cylindrical-conical section 51. The inlet channels 52a and 52b form passages that connect to the cylindrical-conical section 51 in the tangential direction of the cylindrical-conical section 51.

[0041] The first discharge portion 53 is a passage for discharging the first mixed refrigerant from the cylindrical-conical portion 51. The first discharge portion 53 opens at a position on the side surface of the cylindrical portion 51 a of the cylindrical-conical portion 51, different from the inlet channels 52 a and 52 b, bends at a position spaced apart from the cylindrical-conical portion 51, and connects to the first discharge port 121.

[0042] The second discharge section 54 is a passage for discharging the second mixed refrigerant from the cylindrical-conical section 51. As shown in Fig. 2 , the second discharge section 54 communicates with a circular opening at the bottom of the conical section 51 b of the cylindrical-conical section 51, and as shown in Fig. 4 , bends at a position spaced apart from the cylindrical-conical section 51 to connect to the second discharge port 122.

[0043] In separator 50 configured as described above, the mixed refrigerant that has flowed down into refrigerant separation section 18 in housing 11 flows tangentially from inflow passages 52a and 52b into cylindrical section 51a of cylindrical-conical section 51. As a result, the mixed refrigerant flows down in cylindrical-conical section 51 while rotating counterclockwise, as shown in FIG.

[0044] At this time, due to the difference in density (difference in specific gravity) between the first refrigerant and the second refrigerant in the mixed refrigerant, the first refrigerant, which has a low density (i.e., a low specific gravity), tends to accumulate in the upper part of the cylindrical-conical portion 51, and the second refrigerant, which has a high density (i.e., a high specific gravity), tends to accumulate in the lower part. As a result, in the separator 50, the first mixed refrigerant, which has a relatively low volume ratio (mixing ratio) of the second refrigerant, tends to accumulate in the upper part of the cylindrical-conical portion 51, and the second mixed refrigerant, which has a relatively high volume ratio (mixing ratio) of the second refrigerant, tends to accumulate in the lower part. As a result, the first mixed refrigerant and the second mixed refrigerant are separated.

[0045] The first discharge portion 53 opens at the top of the cylindrical conical portion 51 , and the first mixed refrigerant is discharged from the first discharge portion 53 to the first discharge port 121 .

[0046] The second discharge portion 54 opens at the bottom of the cylindrical conical portion 51 , and the second mixed refrigerant is discharged from the second discharge portion 54 to the second discharge port 122 .

[0047] The first mixed refrigerant and the second mixed refrigerant are introduced back into the housing 11 by the first pump 71 of the first circulation path 61 and the second pump 72 of the second circulation path 62, respectively.

[0048] In this way, the mixed refrigerant flowing down inside the housing 11 rotates and accumulates in the cylindrical-conical portion 51 of the separator 50, thereby roughly separating the first mixed refrigerant from the second mixed refrigerant by utilizing the density difference between the first refrigerant and the second refrigerant.

[0049] Next, a modified example of the motor 10 of this embodiment will be described. Fig. 6 is an explanatory diagram of the motor 10 of this modified example of the embodiment.

[0050] The modified example shown in Figure 6 differs from the above-described configuration in that the refrigerant separation unit 18, which has the function of separating the first refrigerant and the second refrigerant, is composed of a refrigerant storage chamber 19 at the bottom of the housing 11 and a refrigerant tank 150 provided outside the motor 10.

[0051] In motor 10, refrigerant separation unit 18 at the bottom of housing 11 does not include separator 50, but instead includes outlet 221 that discharges the mixed refrigerant that has flowed down into refrigerant reservoir chamber 19 at the bottom of housing 11 into refrigerant tank 150 provided outside motor 10. One end of third mixed refrigerant circulation path 163 is connected to outlet 221. Third mixed refrigerant circulation path 163 includes third pump 173 that circulates the refrigerant.

[0052] The other end of the third mixed refrigerant circulation path 163 is connected to the mixed refrigerant inlet 153 of the refrigerant tank 150. Similar to the separator 50 described above, the refrigerant tank 150 separates the first mixed refrigerant from the second mixed refrigerant.

[0053] Refrigerant tank 150 has an upright cylindrical portion 150a that is hollow. A mixed refrigerant inlet 153 is formed on the top surface of cylindrical portion 150a. A first mixed refrigerant discharge port 151 is provided on the upper side of cylindrical portion 150a, and a second mixed refrigerant discharge port 152 is provided on the lower side of cylindrical portion 150a. A first mixed refrigerant circulation path 161 is connected to first mixed refrigerant discharge port 151, and a second mixed refrigerant circulation path 162 is connected to second mixed refrigerant discharge port 152. A fourth pump 172 is provided in second mixed refrigerant circulation path 162, which raises the mixed refrigerant to mixed refrigerant inlet 153 at the top of refrigerant tank 150 and circulates it.

[0054] The mixed refrigerant that flows in from the top of refrigerant tank 150 accumulates in cylindrical portion 150a. Due to the density difference (difference in specific gravity) between the first refrigerant and the second refrigerant, the mixed refrigerant that accumulates inside cylindrical portion 150a gradually accumulates more of the first refrigerant, which has a lower density, in the top of refrigerant tank 150, and more of the second refrigerant, which has a higher density, in the bottom.

[0055] A first mixed refrigerant discharge port 151 opens at the top of the refrigerant tank 150, and the refrigerant with a large volume ratio of the first refrigerant, i.e., the first mixed refrigerant, flows from the first mixed refrigerant discharge port 151 through the first mixed refrigerant circulation path 161 into the first inlet 141 of the motor 10.

[0056] A second mixed refrigerant discharge port 152 opens at the bottom of the refrigerant tank 150, and the refrigerant with a large volume ratio of the second refrigerant, i.e., the second mixed refrigerant, flows from the second mixed refrigerant discharge port 152 through a second mixed refrigerant circulation path 162 into the second inlet 142 of the motor 10. Since the second mixed refrigerant discharge port 152 is located at the bottom of the refrigerant tank 150, a fourth pump 172 is provided to promote the circulation of the second mixed refrigerant.

[0057] In this way, by providing the refrigerant tank 150 as shown in FIG. 6 outside the motor 10, the first mixed refrigerant and the second mixed refrigerant can be separated due to the density difference between the first refrigerant and the second refrigerant.

[0058] In the embodiment described above, the motor 10 includes the stator 20 and the rotor 30 housed in the housing 11, the rotor 30 supported by the housing 11 via bearings 15 and 16, and is cooled and lubricated by a refrigerant. The refrigerant is a mixed refrigerant that is a mixture of a first refrigerant and a second refrigerant that has a lower boiling point than the first refrigerant. The motor 10 includes a refrigerant separation unit 18 that separates the mixed refrigerant that has passed through the motor 10 into the first mixed refrigerant and the second mixed refrigerant, in which the volume ratio of the second refrigerant is greater than that of the first mixed refrigerant, and discharges the separated refrigerants. The discharged first mixed refrigerant flows into the bearings 15 and 16, and the discharged second mixed refrigerant flows into the stator 20.

[0059] In this configuration, by flowing a second mixed refrigerant having a large volume ratio of the second refrigerant with a low boiling point into the stator 20, the stator 20 (including the coil end 22) can be cooled by the second refrigerant which is easily vaporized, thereby efficiently cooling the motor 10 and also lubricating the bearings 15 and 16.

[0060] In addition, in this embodiment, the second refrigerant is a refrigerant that cools the high-temperature portion (coil end 22) of the stator 20 by contacting the high-temperature portion within the housing 11 and using the latent heat of vaporization, and the first refrigerant is a lubricating oil that maintains its liquid phase within the housing 11.

[0061] In this configuration, the coil ends 22 of the stator 20 can be cooled by the latent heat of vaporization of the second refrigerant, so that the motor 10 can be cooled more efficiently.

[0062] In addition, in this embodiment, the boiling point of the first refrigerant is higher than the temperature of the high-temperature portion, and the boiling point of the second refrigerant is lower than the temperature of the high-temperature portion and higher than the temperature of the second mixed refrigerant supplied into the housing.

[0063] In this configuration, the second refrigerant vaporized by cooling the coil end 22, which is a high-temperature portion, is converted into a liquid phase by the second mixed refrigerant supplied into the housing 11, so that the area around the coil end 22 can always be filled with the second refrigerant in liquid phase, thereby more efficiently cooling the motor 10.

[0064] In addition, in this embodiment, the first mixed refrigerant and the second mixed refrigerant flow into the housing 11 via refrigerant circulation paths (first circulation path 61 and second circulation path 62), and the first circulation path 61 and the second circulation path 62 are provided with coolers 82 that cool at least one of the first mixed refrigerant and the second mixed refrigerant.

[0065] In this configuration, by cooling at least one of the first mixed refrigerant and the second mixed refrigerant outside the housing 11 of the motor 10, the temperatures of the first mixed refrigerant and the second mixed refrigerant flowing into the motor 10 can be lowered, and the motor 10 can be cooled more efficiently.

[0066] In addition, in this embodiment, the refrigerant separation unit 18 has a refrigerant storage chamber 19 formed at the bottom of the housing 11, and the refrigerant storage chamber 19 is provided with a separator 50 that separates the mixed refrigerant that flows down into a first mixed refrigerant and a second mixed refrigerant based on the difference in density.

[0067] In this configuration, the refrigerant storage chamber 19 at the bottom of the housing 11 is provided with a separator 50 that separates the refrigerant into a first mixed refrigerant and a second mixed refrigerant based on density difference, so that the refrigerant can be separated into the first mixed refrigerant and the second mixed refrigerant inside the motor 10.

[0068] In this embodiment, separator 50 includes inlet channels 52a, 52b for receiving the mixed refrigerant that has flowed down, a cylindrical-conical portion 51 for separating the mixed refrigerant sent from inlet channels 52a, 52b, a first discharge section 53 for discharging the first mixed refrigerant from cylindrical-conical portion 51, and a second discharge section 54 for discharging the second mixed refrigerant from cylindrical-conical portion 51. First discharge section 53 is connected to first circulation channel 61, and second discharge section 54 is connected to second circulation channel 62. First circulation channel 61 has a first pump 71 and is connected to first inlet 141 through which the first mixed refrigerant flows into bearings 15, 16. Second circulation channel 62 has a second pump 72 and is connected to second inlet 142 through which the second mixed refrigerant flows into stator 20.

[0069] In this configuration, the mixed refrigerant that flows into the cylindrical-conical portion 51 from the inflow passages 52 a, 52 b accumulates in the separator 50, and the first mixed refrigerant and the second mixed refrigerant are separated due to the difference in density (mass difference) between the first and second refrigerants of the mixed refrigerant. The separated first and second mixed refrigerants are circulated to the bearings 15, 16 and the stator 20 via the first circulation passage 61 and the second circulation passage 62.

[0070] In this embodiment, the cylindrical-conical portion 51 has a cylindrical portion 51a having a cylindrical periphery and a conical portion 51b recessed downward from the cylindrical portion 51a. A pair of inflow channels 52a, 52b are connected to the cylindrical portion 51a along a tangential direction of the cylindrical portion 51a. These inflow channels 52a, 52b are arranged to face each other (for example, arranged point-symmetrically with respect to the center of the cylindrical portion 51a). The cylindrical portion 51a is connected to the first discharge portion 53, and the bottom surface of the conical portion 51b is connected to the second discharge portion 54.

[0071] In this configuration, the mixed refrigerant flows from inlet passages 52a and 52b into cylindrical portion 51a in mutually tangential directions, allowing the mixed refrigerant to be retained while rotating. Therefore, due to the density difference between the first refrigerant and the second refrigerant, it becomes easier to separate the first mixed refrigerant into upper cylindrical portion 51a and the second mixed refrigerant into lower conical portion 51b.

[0072] In this embodiment, the housing 11 is made up of a cylindrical portion 12, a front cover 13, and a rear cover 14. The stator 20 is disposed in a stator chamber 11a, which is a closed space formed by the front cover 13, the rear cover 14, and the cylindrical portion 12, and the coil cover 40 disposed on the inner periphery of the stator 20. A stator-side flow path 17b is provided for allowing the second mixed refrigerant to flow into the stator chamber 11a. Bearings 15, 16 are disposed in the front cover 13 and the rear cover 14, respectively, and bearing-side flow paths 17a are provided for allowing the first mixed refrigerant to flow into bearing chambers 13a, 14a around the bearings 15, 16.

[0073] In this configuration, the second mixed refrigerant can be flowed into the stator chamber 11a, and the first mixed refrigerant can be flowed into the bearing chambers 13a and 14a, respectively. This makes it possible to simultaneously cool the stator 20 with the second mixed refrigerant and lubricate the bearings 15 and 16 with the first mixed refrigerant, and also minimize the amounts of the second mixed refrigerant flowing into the stator chamber 11a and the first mixed refrigerant flowing into the bearing chambers 13a and 14a.

[0074] In addition, in this embodiment, the stator side flow path 17b is connected to the second inlet 142 to which the second circulation path 62 through which the second mixed refrigerant circulates is connected, so that the second mixed refrigerant can be reliably sucked into the stator 20 and the coil end 22.

[0075] In this embodiment, refrigerant separation unit 18 includes refrigerant tank 150 and has an upright cylindrical portion 150a that is different from housing 11. A mixed refrigerant inlet 153 is provided at the top of cylindrical portion 150a, through which the mixed refrigerant in housing 11 flows in via third mixed refrigerant circulation path 163 having third pump 173. On the sides of cylindrical portion 150a, a first mixed refrigerant discharge port 151 is provided at the top, and a second mixed refrigerant discharge port 152 is provided at the bottom. Inside cylindrical portion 150a, the mixed refrigerant is separated vertically into the first mixed refrigerant and the second mixed refrigerant due to the difference in density.

[0076] In this configuration, even by providing refrigerant tank 150 external to motor 10, the mixed refrigerant discharged from motor 10 remains in refrigerant tank 150, and the first mixed refrigerant and the second mixed refrigerant can be separated due to the density difference between the first refrigerant and the second refrigerant. By providing the separation function externally, motor 10 itself can be made smaller, thereby increasing the flexibility in layout of motor 10.

[0077] The above describes embodiments of the present invention and their modifications. However, the above embodiments and modifications merely illustrate some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Claims

1. A rotating electric machine in which a stator and a rotor are contained in a housing, the rotor is supported on the housing via bearings, and is cooled and lubricated by a refrigerant, the refrigerant being a mixed refrigerant obtained by mixing a first refrigerant and a second refrigerant having a lower boiling point than the first refrigerant, the rotating electric machine having a refrigerant separation section which separates and discharges the mixed refrigerant that has passed through the rotating electric machine into the first mixed refrigerant and a second mixed refrigerant having a larger volumetric ratio of the second refrigerant than the first mixed refrigerant, the discharged first mixed refrigerant being supplied to the bearings, and the discharged second mixed refrigerant being supplied to the stator.

2. A rotating electric machine as claimed in claim 1, wherein the second refrigerant is a refrigerant that comes into contact with a high-temperature portion of the stator within the housing and cools the high-temperature portion by latent heat of vaporization, and the first refrigerant is a lubricating oil that is maintained in a liquid phase within the housing.

3. A rotating electric machine as claimed in claim 2, wherein the first refrigerant has a boiling point higher than the temperature of the high temperature portion, and the second refrigerant has a boiling point lower than the temperature of the high temperature portion and higher than the temperature of the second mixed refrigerant supplied into the housing.

4. A rotating electric machine as described in claim 1, wherein the first mixed refrigerant and the second mixed refrigerant flow into the housing via a refrigerant circulation path, and the refrigerant circulation path is provided with a cooler that cools at least one of the first mixed refrigerant and the second mixed refrigerant.

5. A rotating electric machine as described in claim 1, wherein the refrigerant separation section has a refrigerant storage chamber formed in the bottom of the housing, and the refrigerant storage chamber is provided with a separator that separates the mixed refrigerant that flows down into the first mixed refrigerant and the second mixed refrigerant.

6. A rotating electric machine as described in claim 5, wherein the separator comprises an inlet passage for receiving the flowing mixed refrigerant, a cylindrical-conical portion for separating the mixed refrigerant sent from the inlet passage, a first discharge portion for discharging the first mixed refrigerant from the cylindrical-conical portion, and a second discharge portion for discharging the second mixed refrigerant from the cylindrical-conical portion, a first circulation passage is connected to the first discharge portion, and a second circulation passage is connected to the second discharge portion, the first circulation passage has a first pump and communicates with a first inlet for receiving the first mixed refrigerant into the bearing, and the second circulation passage has a second pump and communicates with a second inlet for receiving the second mixed refrigerant into the stator.

7. A rotating electric machine as claimed in claim 6, wherein the cylindrical-conical portion has a cylindrical portion having a cylindrical periphery and a conical portion recessed downward from the cylindrical portion, a set of the inlet passages are connected to the cylindrical portion in the tangential direction, the cylindrical portion communicates with the first discharge portion, and the bottom surface of the conical portion communicates with the second discharge portion.

8. A rotating electric machine as claimed in claim 1, wherein the housing is composed of a tubular portion, a front cover and a rear cover, a closed space is formed by a cylindrical coil cover arranged on the inner periphery of the stator, the front cover, the rear cover and the tubular portion, and a stator side flow passage is provided for flowing the second mixed refrigerant into the closed space, the front cover and the rear cover each have a bearing arranged therein and are provided with a bearing side flow passage for flowing the first mixed refrigerant around the bearing.

9. A rotating electric machine according to claim 8, wherein the stator side flow passage communicates with an inlet connected to a second circulation passage through which the second mixed refrigerant circulates.

10. A rotating electric machine as described in claim 1, wherein the refrigerant separation section comprises a refrigerant tank having an upright cylindrical section distinct from the housing, the refrigerant tank having a refrigerant inlet at the top of the cylindrical section through which the mixed refrigerant in the housing flows in via a third mixed refrigerant circulation path having a third pump, and the sides of the cylindrical section have a first mixed refrigerant discharge section at the top and a second mixed refrigerant discharge section at the bottom, and within the cylindrical section, the mixed refrigerant is separated in the vertical direction into the first mixed refrigerant and the second mixed refrigerant due to density difference.

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