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, and which also allows size reduction of a feed pump.SOLUTION: A rotary electric machine system 10 comprises: a rotary electric machine 12 having a rotary electric machine body 18 and a bearing part 20; a feed pump 30 for feeding liquid oil; an oil passage 32; and a heat exchanger 34. The rotary electric machine has: a rotor cooling passage 38 which circulates the oil through the rotor 24; a stator cooling passage 40 which circulates the oil through the stator 26; and a lubricating passage 42. The oil cooled by the heat exchanger flows after branching into the rotor cooling passage and the stator cooling passage. The oil that has circulated through the stator cooling passage is blown from the lubricating passage against the bearing part by the pressure from the feed pump.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 having a rotating electric machine main body having a rotor and a stator, and a bearing portion that rotatably supports the rotor; a supply pump for supplying liquid oil; an oil flow path that guides the oil sent from the supply pump to the rotating electric machine; and a heat exchanger provided in the oil flow path that cools the oil, wherein the rotating electric machine is provided with a rotor cooling flow path that circulates the oil to the rotor, a stator cooling flow path that circulates the oil to the stator, and a lubrication flow path that supplies the oil to the bearing portion, and the oil cooled by the heat exchanger is divided and flows into the rotor cooling flow path and the stator cooling flow path, and the oil that has circulated through the stator cooling flow path is sprayed from the lubrication flow path onto the bearing portion by the pressure of the supply pump. [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, the viscosity of the oil is relatively high, which may increase the frictional resistance of the bearing.On the other hand, when oil at a temperature suitable for lubricating the bearing is supplied to the rotating electrical machine body, the rotating electrical machine body may not be cooled efficiently.

[0012] The rotating electric machine is provided with a rotor cooling passage that circulates oil to the rotor, a stator cooling passage that circulates oil to the stator, and a lubrication passage that supplies oil to the bearing. The rotating electric machine system also includes a supply pump for supplying oil to the rotating electric machine. In such a rotating electric machine system, if the rotor cooling passage, the stator cooling passage, and the lubrication passage are arranged in parallel, the oil flow rate required for the rotating electric machine becomes relatively large, making it difficult to miniaturize the supply pump. The present disclosure has been made in consideration of these issues and provides a rotating electric machine system that can efficiently cool the rotating electric machine body while suppressing an increase in frictional resistance of the bearing, and that can further miniaturize the supply pump.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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 a 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. The casing 22 houses the rotating electric machine main body 18 and the bearing unit 20.

[0018] The oil supply device 14 supplies liquid oil to the rotating electrical machine 12. An example of the oil is gas turbine oil. The oil supply device 14 includes a supply pump 30, an oil flow path 32, and a heat exchanger 34.

[0019] An oil flow path 32 is connected to the supply pump 30. Oil supplied (discharged) from the supply pump 30 flows through the oil flow path 32. A heat exchanger 34 is provided in the oil flow path 32. The heat exchanger 34 cools the oil flowing through the oil flow path 32. A cooling medium for cooling the oil flows through the heat exchanger 34. Liquid water is used as the cooling medium, for example, 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 the cooling air. The oil cooled by the heat exchanger 34 is guided to the rotating electrical machine body 18.

[0020] The rotating electric machine 12 is provided with a rotor cooling passage 38, a stator cooling passage 40, a lubrication passage 42, a storage section 46, a first discharge passage 48, a second discharge passage 50, and a third discharge passage 52.

[0021] The oil guided from oil passage 32 is relatively low temperature oil that has been cooled by heat exchanger 34. Specifically, the oil guided from oil passage 32 flows separately into rotor cooling passage 38 and stator cooling passage 40. In other words, rotor cooling passage 38 and stator cooling passage 40 are arranged in parallel. Rotor cooling passage 38 and stator cooling passage 40 are isolated by partition member 21. Therefore, the oil flowing through rotor cooling passage 38 and the oil flowing through stator cooling passage 40 do not mix along the way.

[0022] 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.

[0023] The oil that flows through the stator cooling passage 40 is warmed by the heat of the stator 26. Therefore, the oil that flows through the stator cooling passage 40 becomes relatively hot oil. The relatively hot oil that flows through the stator cooling passage 40 is used to lubricate the bearing portion 20. Specifically, the oil that flows through the stator cooling passage 40 is led to the lubrication passage 42.

[0024] The lubrication passage 42 includes a first lubrication passage 42a and a second lubrication passage 42b. The stator cooling passage 40 and the lubrication passage 42 are connected in series. The oil that flows through the stator cooling passage 40 is divided into the first lubrication passage 42a and the second lubrication passage 42b. The first lubrication passage 42a supplies relatively high-temperature oil to the first bearing 20a. The oil that flows through the first lubrication passage 42a 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 passage 42a onto the first bearing 20a. The second lubrication passage 42b supplies relatively high-temperature oil to the second bearing 20b. The oil that flows through the second lubrication passage 42b 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 passage 42b 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, and a tank 70. 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. The tank 70 is provided in the circulation flow path 68. Liquid oil is stored in the tank 70.

[0028] Next, we will explain the flow of oil in the rotating electrical machine system 10. When the supply pump 30 is driven, the liquid oil stored in the tank 70 is sent to the oil flow path 32 via the supply pump 30. The oil flowing through the oil flow path 32 is cooled by the heat exchanger 34, and therefore becomes relatively low-temperature oil.

[0029] The relatively low-temperature oil that has circulated through the heat exchanger 34 is divided into a rotor cooling passage 38 and a stator cooling passage 40. 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 gravity and centrifugal force generated by the rotation of the rotor 24. The oil flowing through the third discharge passage 52 is mixed with gas (air). In other words, the oil flowing through the third discharge passage 52 is a gas-liquid mixed fluid.

[0030] The rotor cooling passage 38 is open to the atmosphere. Therefore, the pressure of the oil that flows through the rotor cooling passage 38 is lower than the pressure of the supply pump 30. That is, the pressure of the oil that flows through the rotor cooling passage 38 is relatively low. Therefore, in this embodiment, the oil that flows through the rotor cooling passage 38 is not used to lubricate the bearing portion 20.

[0031] After cooling the stator 26, the oil flowing through the stator cooling passage 40 is divided into the first lubrication passage 42a and the second lubrication passage 42b. The oil flowing through the stator cooling passage 40 is heated by the heat of the stator 26 and becomes relatively hot. In other words, the oil flowing through the stator cooling passage 40 has a temperature suitable for lubricating the bearing 20. The stator cooling passage 40 is not open to the atmosphere. In other words, the oil flowing through the stator cooling passage 40 is not mixed with gas (air). In other words, the pressure of the oil flowing through the stator cooling passage 40 is equal to the pressure of the supply pump 30. Because the oil flowing through the stator cooling passage 40 maintains a high pressure, it is used to lubricate the bearing 20.

[0032] The oil flowing through the first lubrication flow path 42a is sprayed onto the first bearing 20a by the pressure of the supply pump 30. This causes the first bearing 20a to be lubricated by the oil. The oil that has flowed through the first bearing 20a flows down into the first reservoir 46a via the first discharge flow path 48 by 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 42b is sprayed onto the second bearing 20b by the pressure of the supply pump 30. This causes the second bearing 20b to be lubricated by the oil. 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.

[0035] According to this embodiment, the relatively low-temperature oil cooled by the heat exchanger 34 flows separately through the rotor cooling passage 38 and the stator cooling passage 40, thereby efficiently cooling the rotor 24 and the stator 26. The oil that flows through the stator cooling passage 40 becomes relatively high-temperature oil that has been warmed by the heat of the stator 26. The relatively high-temperature oil that has flowed through the stator cooling passage 40 is sprayed onto the bearing 20 by the pressure of the supply pump 30, thereby suppressing an increase in frictional resistance of the bearing 20. This makes it possible to efficiently cool the rotating electrical machine main body 18 while suppressing an increase in frictional resistance of the bearing 20.

[0036] In addition, since the oil flowing through the stator cooling passage 40 is used to lubricate the bearing portion 20, the required flow rate of oil for the rotating electric machine 12 can be reduced compared to when the rotor cooling passage 38, the stator cooling passage 40, and the lubrication passage 42 are arranged in parallel.

[0037] Specifically, for example, the oil flow rate required to cool the rotor 24 is defined as a first flow rate L1, the oil flow rate required to cool the stator 26 is defined as a second flow rate L2, and the oil flow rate required to lubricate the bearing 20 is defined as a third flow rate L3. It is assumed that the first flow rate L1 is greater than the third flow rate L3. When the rotor cooling passage 38, the stator cooling passage 40, and the lubrication passage 42 are arranged in parallel, the supply pump 30 needs to supply oil to the rotating electrical machine 12 at a flow rate that is the sum of the first flow rate L1, the second flow rate L2, and the third flow rate L3. In this embodiment, the oil that has flowed through the stator cooling passage 40 is sprayed onto the bearing 20 from the lubrication passage 42, so the supply pump 30 only needs to supply oil to the rotating electrical machine 12 at a flow rate that is the sum of the first flow rate L1 and the second flow rate L2. In other words, in this example, the oil flow rate that the supply pump 30 needs to supply to the rotating electrical machine 12 can be reduced by the third flow rate L3. This allows the supply pump 30 to be made smaller, thereby providing a better rotating electrical machine system 10.

[0038] The following additional notes are further disclosed regarding the above embodiment.

[0039] (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 supply pump (30) for supplying liquid oil, an oil flow path (32) that guides the oil sent from the supply pump to the rotating electric machine, and a heat exchanger (34) provided in the oil flow path that cools the oil, wherein the rotating electric machine is provided with a rotor cooling flow path (38) that circulates the oil to the rotor, a stator cooling flow path (40) that circulates the oil to the stator, and a lubrication flow path (42) that supplies the oil to the bearing portion, and the oil cooled by the heat exchanger is divided and flows into the rotor cooling flow path and the stator cooling flow path, and the oil that has circulated through the stator cooling flow path is sprayed from the lubrication flow path onto the bearing portion by the pressure of the supply pump.

[0040] With this configuration, the relatively low-temperature oil cooled by the heat exchanger flows separately through the rotor cooling channel and the stator cooling channel, thereby efficiently cooling the rotor and stator. The oil flowing through the stator cooling channel becomes relatively high-temperature oil warmed by the heat of the stator. The relatively high-temperature oil flowing through the stator cooling channel is sprayed onto the bearing section by the pressure of the supply pump, thereby suppressing an increase in frictional resistance of the bearing section. This allows the rotating electrical machine main body to be efficiently cooled while suppressing an increase in frictional resistance of the bearing section. Furthermore, because the oil flowing through the stator cooling channel is used to lubricate the bearing section, the required oil flow rate for the rotating electrical machine can be reduced compared to when the rotor cooling channel, stator cooling channel, and lubrication channel are arranged in parallel. This allows the supply pump to be made smaller. Therefore, a better rotating electrical machine system can be obtained.

[0041] (Appendix 2) In the rotating electrical machine system according to Supplementary Note 1, the rotor cooling passage may be a passage that is open to the atmosphere.

[0042] With this configuration, the rotor cooling passage can be easily provided in the main body of the rotating electrical machine.

[0043] (Appendix 3) In the rotating electrical machine system according to Supplementary Note 1, the stator cooling passage may be a passage that is not open to the atmosphere.

[0044] With this configuration, it is possible to suppress a decrease in oil pressure when the oil flows through the stator cooling passage.

[0045] (Appendix 4) The rotating electric machine system described in Appendix 2 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.

[0046] With this configuration, the oil used to cool the rotating electrical machine body and lubricate the bearings 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 lubrication efficiency due to gas being mixed into the oil.

[0047] (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.

[0048] With this configuration, the oil stored in the reservoir can be reliably sent to the gas-liquid separator by the recovery pump.

[0049] 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]

[0050] 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...Oil flow path 34...Heat exchanger 38...Rotor cooling channel 40... Stator cooling passage 42... Lubrication passage 46...storage section 60...recovery flow path 62...Recovery pump 66...Gas-liquid separator 68...Circulation 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 supply pump for delivering liquid oil; an oil flow path that guides the oil sent from the supply pump to the rotating electric machine; a heat exchanger provided in the oil flow path to cool the oil; Equipped with 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; a lubrication flow path for supplying the oil to the bearing portion; is established, The oil cooled by the heat exchanger is divided and flows into the rotor cooling passage and the stator cooling passage, The oil that has flowed through the stator cooling passage is sprayed onto the bearing portion from the lubrication passage by the pressure of the supply pump.

2. 2. The rotating electrical machine system according to claim 1, The rotor cooling passage is a passage that is open to the atmosphere.

3. 2. The rotating electrical machine system according to claim 1, A rotating electric machine system, wherein the stator cooling flow path is a flow path that is not open to the atmosphere.

4. 3. The rotating electrical machine system according to claim 2, 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.

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