Rotary electric machine system

Abstract

To provide a rotary electric machine system which can efficiently cool a rotary electric machine body while suppressing an increase in frictional resistance of a bearing part.SOLUTION: A rotary electric machine system 10 comprises: a rotary electric machine 12 which has a rotary electric machine body 18 having a rotor 24 and a stator 26, and a bearing part 20 rotatably supporting the rotor; a first oil passage 32 through which liquid oil flows; a heat exchanger 34 which is provided in the first oil passage so as to cool the oil; and a second oil passage 36 which branches from a portion, of the first oil passage, upstream the heat exchanger. The oil cooled by the heat exchanger is guided to a rotary electric machine body, and the oil that circulates through the second oil passage is guided to the bearing part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In recent years, technological developments have been made in rotating electrical machine systems that contribute to energy efficiency in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy.

[0003] Patent Document 1 discloses a rotating electrical machine system including a rotating electrical machine main body having a rotor and a stator, and a bearing that rotatably supports the rotor. In this rotating electrical machine system, the rotor and the stator are cooled by circulating liquid oil through each of them. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-137790 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a need for better rotating electrical machine systems.

[0006] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0007] An aspect of the present disclosure is a rotating electric machine system comprising: a rotating electric machine main body having a rotor and a stator; and a bearing portion that rotatably supports the rotor; a first oil flow path through which liquid oil flows; a heat exchanger provided in the first oil flow path that cools the oil; and a second oil flow path that branches off from a portion of the first oil flow path upstream of the heat exchanger, wherein the oil cooled by the heat exchanger is guided to the rotating electric machine main body, and the oil circulating through the second oil flow path is guided to the bearing portion. [Effects of the Invention]

[0008] According to the present invention, a better rotating electrical machine system can be obtained. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a rotating electrical machine system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] In a rotating electrical machine system, it is necessary to supply liquid oil to the bearings for lubrication purposes, but the temperature of the oil suitable for lubricating the bearings is higher than the temperature of the oil suitable for cooling the rotating electrical machine body.

[0011] Therefore, when oil at a temperature suitable for cooling the rotating electrical machine body is supplied to the bearing portion, the viscosity of the oil is relatively high, which may increase frictional resistance of the bearing portion. On the other hand, when oil at a temperature suitable for lubricating the bearing portion is supplied to the rotating electrical machine body, the rotating electrical machine body may not be cooled efficiently. The present disclosure has been made in view of these problems and can provide a rotating electrical machine system that can efficiently cool the rotating electrical machine body while suppressing an increase in frictional resistance of the bearing portion.

[0012] FIG. 1 is a schematic diagram of a rotating electric machine system 10 according to an embodiment of the present invention. The rotating electric machine system 10 is mounted on, for example, an aircraft. The aircraft is, for example, an electric vertical take-off and landing aircraft (eVTOL). Note that the aircraft is not limited to an electric vertical take-off and landing aircraft. Furthermore, the rotating electric machine system 10 is not limited to being mounted on an aircraft, and may be mounted on a ship, a vehicle, or the like. The rotating electric machine system 10 may also be provided in a stationary power generation device.

[0013] As shown in FIG. 1 , the rotating electric machine system 10 includes a rotating electric machine 12, an oil supply device 14, and an oil recovery device 16. The rotating electric machine 12 includes a rotating electric machine main body 18, a bearing unit 20, a partition member 21, and a casing 22. The rotating electric machine main body 18 includes a rotor 24 and a stator 26. The rotor 24 includes a rotating shaft 24a and a magnet unit 24b provided on the outer periphery of the rotating shaft 24a. The rotating shaft 24a is connected to, for example, a shaft of a gas turbine engine (not shown). The magnet unit 24b is, for example, a permanent magnet. The stator 26 is formed in an annular shape. The rotor 24 is inserted into a hole in the interior of the stator 26. The stator 26 includes a stator core 26a and an electromagnetic coil 26b. The rotor 24 and the stator 26 are not limited to the configurations described above.

[0014] For example, when starting to drive a gas turbine engine, the rotating electric machine 12 functions as a motor that rotates the shaft of the gas turbine engine by supplying an AC current to the electromagnetic coil 26b of the stator core 26a to rotate the rotor 24. The rotating electric machine 12 also functions as a generator that generates electricity when the rotor 24 is rotated by the driving force of the gas turbine engine. In the rotating electric machine 12, the rotor 24 and the stator 26 generate heat. Specifically, in the rotating electric machine 12, the magnet portion 24b of the rotor 24 and the electromagnetic coil 26b of the stator 26 are particularly likely to become hot.

[0015] The bearing unit 20 has a first bearing 20a and a second bearing 20b. The first bearing 20a rotatably supports one end of the rotating shaft 24a. The second bearing 20b rotatably supports the other end of the rotating shaft 24a. Each of the first bearing 20a and the second bearing 20b is, for example, a rolling bearing. Each of the first bearing 20a and the second bearing 20b may also be a sliding bearing. The casing 22 houses the rotating electric machine main body 18 and the bearing unit 20.

[0016] The partition member 21 is formed in a cylindrical shape. The rotor 24 is disposed inside the partition member 21, and the stator 26 is disposed outside the partition member 21. The partition member 21 is made of, for example, a ceramic material. The partition member 21 can be fixed to the casing 22. The partition member 21 separates the space in which the rotor 24 is disposed from the space in which the stator 26 is disposed in a liquid-tight and airtight manner.

[0017] The oil supply device 14 supplies liquid oil to the rotating electrical machine 12. Examples of the oil include gas turbine oil. The oil supply device 14 includes a supply pump 30, a first oil flow path 32, a heat exchanger 34, and a second oil flow path 36.

[0018] A first oil flow path 32 is connected to the supply pump 30. Oil supplied (discharged) from the supply pump 30 flows through the first oil flow path 32. A heat exchanger 34 is provided in the first oil flow path 32. The heat exchanger 34 cools the oil flowing through the first oil flow path 32. A cooling medium for cooling the oil flows through the heat exchanger 34. The cooling medium may be, for example, liquid water, but is not limited to this. The cooling medium that has cooled the oil in the heat exchanger 34 returns to the heat exchanger 34, for example, via a cooling jacket and a radiator (not shown) formed on the casing 22. The cooling medium can cool the stator 26 by flowing through the cooling jacket. The radiator exchanges heat between the cooling medium and external air (cooling air). That is, the radiator cools the cooling medium using cooling air.

[0019] The first oil flow path 32 includes a supply flow path 32a and an introduction flow path 32b. The supply flow path 32a connects the supply pump 30 and the heat exchanger 34. In other words, the supply flow path 32a forms a portion of the first oil flow path 32 that is upstream of the heat exchanger 34. The introduction flow path 32b connects the heat exchanger 34 and the rotating electrical machine 12. The oil cooled by the heat exchanger 34 is guided to the rotating electrical machine main body 18.

[0020] The second oil flow path 36 branches off from the supply flow path 32a. The second oil flow path 36 guides the oil flowing through the supply flow path 32a to the rotating electric machine 12. In other words, the second oil flow path 36 guides the oil before it is cooled by the heat exchanger 34 to the rotating electric machine 12. The second oil flow path 36 connects the supply flow path 32a and the rotating electric machine 12.

[0021] The rotating electric machine 12 is provided with a rotor cooling passage 38, a stator cooling passage 40, a first lubrication passage 42, a second lubrication passage 44, a storage section 46, a first discharge passage 48, a second discharge passage 50, and a third discharge passage 52.

[0022] The oil introduced from the inlet flow path 32b of the first oil flow path 32 is a relatively low-temperature oil cooled by the heat exchanger 34, and is therefore used to cool the rotating electrical machine main body 18. Specifically, the oil introduced from the inlet flow path 32b flows separately into the rotor cooling flow path 38 and the stator cooling flow path 40. In other words, the rotor cooling flow path 38 and the stator cooling flow path 40 are arranged in parallel. The rotor cooling flow path 38 and the stator cooling flow path 40 are isolated by the partition member 21. Therefore, the oil flowing through the rotor cooling flow path 38 and the oil flowing through the stator cooling flow path 40 do not mix along the way.

[0023] The rotor cooling passage 38 circulates relatively low-temperature oil through the rotor 24. The rotor cooling passage 38 includes a passage formed inside the rotor 24. In this case, the rotor 24 can be efficiently cooled by the oil flowing inside the rotor 24. The rotor cooling passage 38 is a passage open to the atmosphere. Therefore, gas (air) is mixed with the oil flowing through the rotor cooling passage 38. The stator cooling passage 40 circulates relatively low-temperature oil through the stator 26. The stator cooling passage 40 is formed to surround the stator 26. In this case, the oil can come into contact with the electromagnetic coil 26b of the stator 26, so the stator 26 can be efficiently cooled. The stator cooling passage 40 is a passage not open to the atmosphere. Therefore, gas (air) is not mixed with the oil flowing through the stator cooling passage 40.

[0024] The oil guided from the second oil flow path 36 is relatively high-temperature oil that has not flowed through the heat exchanger 34, and is therefore used to lubricate the bearing portion 20. Specifically, the oil guided from the second oil flow path 36 is divided into a first lubrication flow path 42 and a second lubrication flow path 44. The first lubrication flow path 42 supplies relatively high-temperature oil to the first bearing 20a. The oil that has flowed through the first lubrication flow path 42 is sprayed onto the first bearing 20a by the pressure of the supply pump 30. Gas (air) is mixed with the oil sprayed from the first lubrication flow path 42 onto the first bearing 20a. The second lubrication flow path 44 supplies relatively high-temperature oil to the second bearing 20b. The oil that has flowed through the second lubrication flow path 44 is sprayed onto the second bearing 20b by the pressure of the supply pump 30. Gas (air) is mixed with the oil sprayed from the second lubrication flow path 44 onto the second bearing 20b.

[0025] The storage section 46 is formed, for example, in the bottom of the casing 22. The storage section 46 includes a first storage section 46a and a second storage section 46b. The first storage section 46a is located, for example, below the first bearing 20a (in the direction of gravity). The second storage section 46b is located, for example, below the second bearing 20b (in the direction of gravity). The size, shape, position, etc. of the storage section 46 can be set as appropriate.

[0026] The first discharge flow path 48 guides the oil that has flowed through the first bearing 20a to the first reservoir 46a. The second discharge flow path 50 guides the oil that has flowed through the second bearing 20b to the second reservoir 46b. The third discharge flow path 52 guides the oil that has flowed through the rotor cooling flow path 38 to the second reservoir 46b. The oil flowing through the first discharge flow path 48, the second discharge flow path 50, and the third discharge flow path 52 is mixed with gas (air). In other words, the reservoir 46 stores a gas-liquid mixed fluid that is a mixture of liquid oil and gaseous air.

[0027] The oil recovery device 16 has a recovery flow path 60, a recovery pump 62, an outlet flow path 64, a gas-liquid separator 66, a circulation flow path 68, a tank 70, and a bypass flow path 72. The recovery flow path 60 is connected to the first storage section 46a, the second storage section 46b, and the recovery pump 62. The outlet flow path 64 connects the recovery pump 62 and the gas-liquid separator 66. The recovery pump 62 sends the gas-liquid mixed fluid stored in the first storage section 46a and the second storage section 46b to the gas-liquid separator 66. The gas-liquid separator 66 separates gas from the gas-liquid mixed fluid guided from the storage section 46. The circulation flow path 68 is a flow path for returning the oil from which gas has been removed by the gas-liquid separator 66 to the supply pump 30.

[0028] The tank 70 is provided in the circulation flow path 68. The circulation flow path 68 includes a first flow path section 68a that connects the gas-liquid separator 66 and the tank 70, and a second flow path section 68b that connects the tank 70 and the supply pump 30. Liquid oil is stored in the tank 70. The bypass flow path 72 connects the stator cooling flow path 40 and the first flow path section 68a to each other. The bypass flow path 72 returns the oil that has circulated through the stator cooling flow path 40 to the circulation flow path 68 without passing through the recovery pump 62 and the gas-liquid separator 66.

[0029] Next, the flow of oil in the rotating electrical machine system 10 will be described. When the supply pump 30 is driven, liquid oil stored in the tank 70 is sent to the supply flow path 32a of the first oil flow path 32 via the supply pump 30. The oil flowing through the supply flow path 32a is divided into the heat exchanger 34 and the second oil flow path 36. The oil flowing through the heat exchanger 34 is cooled by the heat exchanger 34 and therefore becomes relatively low-temperature oil. The oil flowing through the second oil flow path 36 does not pass through the heat exchanger 34 and therefore becomes relatively high-temperature oil.

[0030] The relatively low-temperature oil that has circulated through the heat exchanger 34 is divided into the rotor cooling passage 38 and the stator cooling passage 40 via the inlet passage 32b. After cooling the rotor 24, the oil flowing through the rotor cooling passage 38 is guided to the second reservoir 46b via the third discharge passage 52 by the centrifugal force and gravity generated by the rotation of the rotor 24. Gas (air) is mixed into the oil flowing through the third discharge passage 52. In other words, the oil flowing through the third discharge passage 52 is a gas-liquid mixed fluid.

[0031] The oil flowing through the stator cooling passage 40 cools the stator 26, and then is guided to the tank 70 via the bypass passage 72 and the first passage portion 68a. No gas is mixed with the oil flowing through the stator cooling passage 40. Therefore, the pressure of the supply pump 30 allows the oil to circulate through the supply passage 32a, the heat exchanger 34, the introduction passage 32b, the stator cooling passage 40, the bypass passage 72, the first passage portion 68a, the tank 70, and the second passage portion 68b.

[0032] The relatively high-temperature oil flowing through the second oil flow path 36 is divided into the first lubrication flow path 42 and the second lubrication flow path 44. The oil flowing through the first lubrication flow path 42 is sprayed onto the first bearing 20a. This causes the first bearing 20a to be lubricated by the oil. The oil that has circulated through the first bearing 20a flows down into the first reservoir 46a via the first discharge flow path 48 due to gravity. Gas (air) is mixed into the oil flowing through the first discharge flow path 48. In other words, the oil flowing through the first discharge flow path 48 is a gas-liquid mixed fluid.

[0033] The oil flowing through the second lubrication flow path 44 is sprayed onto the second bearing 20b. This lubricates the second bearing 20b. The oil that has flowed through the second bearing 20b flows down into the second reservoir 46b via the second discharge flow path 50 due to gravity. Gas (air) is mixed into the oil flowing through the second discharge flow path 50. In other words, the oil flowing through the second discharge flow path 50 is a gas-liquid mixed fluid.

[0034] The gas-liquid mixture fluid stored in the first storage section 46a and the second storage section 46b is sent to the gas-liquid separator 66 by the recovery pump 62 via the recovery flow path 60 and the outlet flow path 64. The gas-liquid mixture fluid sent to the gas-liquid separator 66 is separated into oil and gas (air) by the gas-liquid separator 66. The oil from which the gas has been separated by the gas-liquid separator 66 is led to the tank 70 via the first flow path section 68a.

[0035] According to this embodiment, the relatively low-temperature oil cooled by the heat exchanger 34 is guided to the rotating electrical machine body 18, thereby enabling efficient cooling of the rotating electrical machine body 18. Furthermore, the oil flowing through the second oil flow path 36 is relatively high temperature oil because it does not pass through the heat exchanger 34. Since the relatively high-temperature oil flowing through the second oil flow path 36 is guided to the bearing portion 20, an increase in frictional resistance of the bearing portion 20 can be suppressed. This allows efficient cooling of the rotating electrical machine body 18 while suppressing an increase in frictional resistance of the bearing portion 20. Therefore, a better rotating electrical machine system 10 can be obtained.

[0036] This embodiment is not limited to the above-described configuration. The rotating electrical machine system 10 may cool only one of the rotor 24 and the stator 26. The rotating electrical machine system 10 may be configured not to include the bypass flow path 72, but to guide the oil that has flowed through the stator cooling flow path 40 to the reservoir 46.

[0037] The following additional notes are further disclosed regarding the above embodiment.

[0038] (Appendix 1) The rotating electric machine system (10) of the present disclosure comprises a rotating electric machine (12) having a rotating electric machine main body (18) having a rotor (24) and a stator (26) and a bearing portion (20) that rotatably supports the rotor, a first oil flow path (32) through which liquid oil flows, a heat exchanger (34) provided in the first oil flow path that cools the oil, and a second oil flow path (36) that branches off from a portion of the first oil flow path upstream of the heat exchanger, and the oil cooled by the heat exchanger is guided to the rotating electric machine main body, and the oil flowing through the second oil flow path is guided to the bearing portion.

[0039] With this configuration, the relatively low-temperature oil cooled by the heat exchanger is guided to the rotating electrical machine body, allowing the rotating electrical machine body to be cooled efficiently. Furthermore, the oil flowing through the second oil flow path is relatively high temperature oil because it does not pass through the heat exchanger. Because the relatively high-temperature oil flowing through the second oil flow path is guided to the bearing, an increase in frictional resistance in the bearing can be suppressed. This allows the rotating electrical machine body to be cooled efficiently while suppressing an increase in frictional resistance in the bearing. Therefore, a better rotating electrical machine system can be obtained.

[0040] (Appendix 2) In the rotating electric machine system described in Appendix 1, the rotating electric machine is provided with a rotor cooling passage (38) that circulates the oil to the rotor and a stator cooling passage (40) that circulates the oil to the stator, and the oil cooled by the heat exchanger may flow separately through the rotor cooling passage and the stator cooling passage.

[0041] With this configuration, the rotor and the stator can be efficiently cooled by the oil.

[0042] (Appendix 3) The rotating electric machine system described in Appendix 2 may include a supply pump (30) that supplies the oil to the first oil flow path, the first oil flow path including a supply flow path (32a) that connects the supply pump and the heat exchanger, and the second oil flow path may be connected to the supply flow path.

[0043] With this configuration, the oil can be divided and sent to the heat exchanger and the second oil flow path by the supply pump.

[0044] (Appendix 4) The rotating electric machine system described in Appendix 3 may include a storage section (46) for storing the oil mixed with gas after flowing through the rotor cooling flow path and the oil mixed with gas after flowing through the bearing section, a recovery flow path (60) for recovering the oil stored in the storage section, a gas-liquid separator (66) for separating the gas from the oil introduced through the recovery flow path, and a circulation flow path (68) for introducing the oil from which the gas has been separated by the gas-liquid separator to the supply pump.

[0045] With this configuration, the oil that has flowed through the rotor cooling passage and the oil that has flowed through the bearing can be returned to the supply pump for reuse. In addition, because the gas is separated by the gas-liquid separator, it is possible to prevent a decrease in cooling efficiency and a decrease in lubrication efficiency due to gas being mixed with the oil.

[0046] (Appendix 5) The rotating electrical machine system according to Supplementary Note 4 may further include a recovery pump (62) for guiding the oil stored in the storage portion to the gas-liquid separator.

[0047] With this configuration, the oil stored in the reservoir can be reliably sent to the gas-liquid separator by the recovery pump.

[0048] (Appendix 6) The rotating electric machine system described in Appendix 5 may further include a bypass flow path (72) that returns the oil that has circulated through the stator cooling flow path to the circulation flow path without passing through the recovery pump and the gas-liquid separator.

[0049] With this configuration, the oil that does not contain gas flowing through the stator cooling flow path can be returned to the supply pump and reused. Furthermore, the oil that flows through the stator cooling flow path does not pass through the recovery pump or the gas-liquid separator. Therefore, compared to a configuration in which the oil that flows through the stator cooling flow path passes through the recovery pump and the gas-liquid separator, the amount of oil that flows through the recovery pump and the gas-liquid separator when a predetermined amount of oil is circulated once can be reduced. This reduces the load on the recovery pump and the gas-liquid separator, allowing the recovery pump and the gas-liquid separator to be made smaller.

[0050] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values or mathematical expressions are used in the description of the above-described embodiments. [Explanation of symbols]

[0051] 10... Rotating electric machine system 12... Rotating electric machine 18... Rotating electric machine body 20... Bearing portion 24...Rotor 26...Stator 30...supply pump 32...first oil flow path 32a...supply flow path 34...heat exchanger 36... Second oil passage 38... Rotor cooling passage 40... Stator cooling channel 46... Reservoir 60... Recovery flow path 62... Recovery pump 66...gas-liquid separator 68...circulation flow path 72...Detour flow path

Claims

1. a rotating electric machine having a rotating electric machine body having a rotor and a stator, and a bearing portion that rotatably supports the rotor; a first oil flow path through which liquid oil flows; a heat exchanger provided in the first oil flow path to cool the oil; a second oil flow path branching from a portion of the first oil flow path upstream of the heat exchanger; Equipped with The oil cooled by the heat exchanger is guided to the rotating electrical machine body, The oil flowing through the second oil flow path is guided to the bearing portion.

2. 2. The rotating electrical machine system according to claim 1, The rotating electric machine includes: a rotor cooling passage for circulating the oil through the rotor; a stator cooling passage for circulating the oil through the stator; is established, The oil cooled by the heat exchanger is divided and flows through the rotor cooling passage and the stator cooling passage.

3. 3. The rotating electrical machine system according to claim 2, a supply pump for supplying the oil to the first oil flow path; the first oil flow path includes a supply flow path connecting the supply pump and the heat exchanger, The second oil flow path is connected to the supply flow path.

4. 4. The rotating electrical machine system according to claim 3, a reservoir for storing the oil mixed with gas after flowing through the rotor cooling flow path and the oil mixed with gas after flowing through the bearing; a recovery flow path for recovering the oil stored in the storage section; a gas-liquid separator that separates the gas from the oil guided through the recovery passage; a circulation flow path that guides the oil from which the gas has been separated by the gas-liquid separator to the supply pump; A rotating electric machine system comprising:

5. 5. The rotating electrical machine system according to claim 4, a recovery pump for guiding the oil stored in the storage portion to the gas-liquid separator.

6. 6. The rotating electrical machine system according to claim 5, a bypass flow path that returns the oil that has flowed through the stator cooling flow path to the circulation flow path without passing through the recovery pump and the gas-liquid separator;

Images