Generator and gas turbine engine provided with same

Abstract

This generator is used in a gas turbine engine. The generator comprises: a stator including a stator core and an electric wire wound around the stator core; a rotor disposed inside the stator; and a case accommodating the stator and the rotor. The electric wire has a star-connected neutral point. The neutral point is disposed outside the case.

Description

Generator and gas turbine engine equipped with same

[0001] The present disclosure relates to a generator and a gas turbine engine including the same.

[0002] As disclosed in Patent Document 1, for example, a generator is disposed in the internal space of a casing of a gas turbine engine to generate electric power to be supplied to electric accessories provided in the engine.

[0003] Patent No. 7174169

[0004] A gas turbine engine includes a number of components, such as a compressor, a combustor, and a turbine, and the space available for arranging a generator is limited.

[0005] Therefore, one aspect of the present disclosure aims to increase the degree of freedom in the placement of a generator in a gas turbine engine equipped with a generator.

[0006] One aspect of the present disclosure is a generator for use in a gas turbine engine, comprising a stator including a stator core and an electric wire wound around the stator core, a rotor arranged inside the stator, and a case that houses the stator and the rotor, wherein the electric wire has a star-connected neutral point, and the neutral point is arranged outside the case.

[0007] According to one aspect of the present disclosure, in a gas turbine engine equipped with a generator, the degree of freedom in the arrangement of the generator can be increased.

[0008] Fig. 1 is a schematic diagram of a gas turbine engine according to an embodiment. Fig. 2 is a diagram showing the configuration of the generator of Fig. 1 and its surroundings. Fig. 3 is a diagram showing the configuration of a generator according to a first modified example and its surroundings. Fig. 4 is a schematic diagram of a gas turbine engine according to a second modified example.

[0009] Hereinafter, embodiments will be described with reference to the drawings. In this disclosure, unless otherwise specified, the following terms have the following meanings: "Axial direction" means the axial direction of the rotating shaft of the gas turbine engine; "Forward" means the upstream side in the flow direction of air inside the gas turbine engine; and "Aft" means the downstream side in the flow direction. In other words, "Forward" means the side of the axial direction where the fan is located; and "Aft" means the side of the axial direction opposite to the side where the fan is located. "Radial direction" means the direction perpendicular to the axial direction; and "Circumferential direction" means the direction around the rotation axis of the rotating shaft.

[0010] FIG. 1 is a schematic diagram of a gas turbine engine 1 (hereinafter also simply referred to as "engine 1") according to an embodiment. The engine 1 is, as an example, a gas turbine engine for an aircraft. However, the engine 1 is not limited to aircraft applications. As shown in FIG. 1, the engine 1 includes a generator 2.

[0011] Gas turbine engines have limited space inside them, making it difficult to locate a generator in a desired location inside the engine, and the space inside smaller gas turbine engines is even more limited.

[0012] On the other hand, in the engine 1, the electric wires 29 of the generator 2 have a star-connected neutral point 29d, and the neutral point 29d is disposed outside the case 27 of the generator 2. Therefore, the engine 1 can increase the degree of freedom in arranging the generator 2 even when the space for arranging the generator 2 is limited.

[0013] The engine 1 is a two-shaft gas turbine engine, but is not limited to this. The engine 1 includes a fan 3, a compressor 4, a combustor 5, a turbine 6, a rotating shaft 7 that mechanically connects the compressor 4 to the turbine 6, a casing 8 that houses the compressor 4, the combustor 5, and the turbine 6, and at least one electric accessory 9. The compressor 4 compresses air supplied from the outside of the engine 1 to the inside by the fan 3. The combustor 5 burns fuel to generate combustion gas. The turbine 6 is supplied with the combustion gas generated by the combustor 5. The rotating shaft 7 extends in the front-to-rear direction of the engine 1 and rotates around a predetermined rotation axis X (see FIG. 2 ). The rotating shaft 7 is rotatably supported by multiple bearings BR1 and BR2. The fan 3 is mechanically connected to the rotating shaft 7 and rotates together with the rotating shaft 7. The fan 3, the compressor 4, the combustor 5, and the turbine 6 are arranged in this order from front to rear.

[0014] The compressor 4 includes a low-pressure compressor 13 and a high-pressure compressor 14 arranged behind the low-pressure compressor 13. The low-pressure compressor 13 is an axial compressor. The high-pressure compressor 14 is a centrifugal compressor. The types of the low-pressure compressor 13 and the high-pressure compressor 14 are not limited thereto. The turbine 6 includes a low-pressure turbine 15 and a high-pressure turbine 16 arranged ahead of the low-pressure turbine 15. The rotating shaft 7 includes a low-pressure shaft 11 connecting the low-pressure compressor 13 to the low-pressure turbine 15, and a high-pressure shaft 12 connecting the high-pressure compressor 14 to the high-pressure turbine 16. The high-pressure shaft 12 is a hollow cylinder extending in the front-rear direction. The low-pressure shaft 11 is inserted inside the high-pressure shaft 12. The low-pressure turbine 15 is connected to the fan 3 via the low-pressure shaft 11.

[0015] The casing 8 is a cylindrical body extending in the axial direction of the rotation axis X. The casing 8 houses the fan 3, the compressor 4, the combustor 5, the turbine 6, and the rotating shaft 7. The casing 8 has an inner shell 80, an outer shell 81, and struts 82 and 83. The inner shell 80 houses the compressor 4, the combustor 5, and the turbine 6. The outer shell 81 is arranged concentrically with the inner shell 80 and spaced radially outward from the inner shell 80. A cylindrical bypass passage BP is formed between the inner shell 80 and the outer shell 81. A portion of the air drawn into the engine 1 by the fan 3 flows through the bypass passage BP and is discharged rearward. The electric accessory 9 is attached to the outer peripheral surface of the casing 8. The electric accessory 9 may be attached inside the casing 8. The electric accessory 9 is, for example, a power consuming device such as a fuel pump or a lubricating oil pump, but is not limited to these.

[0016] The struts 82 extend radially and connect the inner shell 80 and the outer shell 81. The struts 82 are disposed rearward of the low-pressure compressor 13. Note that the struts 82 may also be disposed between the low-pressure compressor 13 and the high-pressure compressor 14 in the axial direction.

[0017] The engine 1 further includes a cylindrical body 20 inside the inner shell 80, connecting the low-pressure compressor 13 and the high-pressure compressor 14 in the axial direction. The outer diameter and inner diameter of the cylindrical body 20 decrease from the front to the rear. The cylindrical body 20 defines a part of the compressed air flow path R from the low-pressure compressor 13 to the high-pressure compressor 14. The outer peripheral surface of the cylindrical body 20 faces the compressed air flow path R. The struts 83 extend radially and connect the cylindrical body 20 and the inner shell 80. The struts 83 are arranged rearward of the low-pressure compressor 13. Note that the struts 83 may be arranged between the low-pressure compressor 13 and the high-pressure compressor 14 in the axial direction.

[0018] The generator 2 is driven by the rotational driving force of the rotating shaft 7 to generate electricity. The electric power generated by the generator 2 is supplied to the electric accessory 9 to drive the electric accessory 9. The generator 2 may have a starter function that rotates the rotating shaft 7 when the engine 1 is started. In this case, the generator 2 is a motor generator. The generator 2 is disposed inside the casing 8. The generator 2 is disposed inside the cylindrical body 20 and in front of the high-pressure compressor 14.

[0019] FIG. 2 is a diagram showing the generator 2 of FIG. 1 and its surrounding configuration. FIG. 2 illustrates the interior of the generator 2 and a neutral point 29d of an electric wire 29. The generator 2 includes a rotating shaft 24, a rotor 25, a stator 26, a case 27, and a connector 31. The rotating shaft 24 and the rotor 25 are disposed inside the stator 26. The rotating shaft 24 extends in the axial direction and is supported so as to rotate around the rotation axis X. The rotor 25 is a cylindrical body having an internal space extending in the axial direction of the rotation axis X. The rotating shaft 24 is inserted into the internal space of the rotor 25. The rotor 25 is coupled to the rotating shaft 24 and rotates together with the rotating shaft 24 around the rotation axis X. The rotor 25 is surrounded by the stator 26 in the circumferential direction of the rotation axis X. The rotor 25 includes a permanent magnet 30. That is, the generator 2 is a permanent magnet type. The generator 2 is a three-phase AC generator that generates three-phase AC power including a U-phase, a V-phase, and a W-phase.

[0020] The stator 26 includes at least one stator core 28 arranged around the rotation axis X and electric wires 29 wound around the stator core 28. The stator 26 includes a plurality of stator cores 28. The case 27 houses the stator 26 and the rotor 25. For example, the case 27 covers the stator 26 and the rotor 25 from the radially outer side and from both sides in the axial direction.

[0021] The electric wire 29 is a three-phase winding. The electric wire 29 has a plurality of winding portions 29a wound around the stator core 28. The plurality of winding portions 29a are coil portions including a U-phase winding portion, a V-phase winding portion, and a W-phase winding portion. The plurality of winding portions 29a are wound around the stator core 28. The electric wire 29 is wound around the stator core 28 via a sheet-like insulating member. This insulates the electric wire 29 and the stator core 28 from each other.

[0022] The electric wire 29 has first lead-out portions 29b extending from one end of each of the plurality of winding portions 29a and second lead-out portions 29c extending from the other end of each of the plurality of winding portions 29a. The plurality of first lead-out portions 29b are star-connected, in other words, Y-connected. This allows the electric wire 29 to have a neutral point 29d, which is an electrical neutral point. The plurality of second lead-out portions 29c are electrically connected to wiring 40, which will be described later, outside the case 27. A connector 31 is attached to the electric wire 29. The connector 31 is attached to the plurality of second lead-out portions 29c.

[0023] In the generator 2, the Y-connection state through the neutral point 29d is maintained at least when the engine 1 is running. In the generator 2, the neutral point 29d is disposed outside the case 27. In the generator 2, the first lead-out portion 29b and the second lead-out portion 29c are disposed outside the case 27 together with the neutral point 29d.

[0024] The neutral point 29d may be disposed outside the case 27 in a direction perpendicular to the rotation axis X of the rotor 25. The neutral point 29d may be disposed outside the case 27 in the axial direction in which the rotation axis X of the rotor 25 extends.

[0025] The neutral point 29d may be disposed away from the case 27. As an example, the neutral point 29d is disposed away from both ends of the winding portion 29a and the case 27 in the axial direction.

[0026] The neutral point 29d may be located forward of the combustor 5. The neutral point 29d may also be located in a region that is lower in temperature than the region where the case 27 of the engine 1 reaches its maximum temperature when the engine 1 is running. As an example, the neutral point 29d is located in a region that is lower in temperature by 100° C. or more than the region where the case 27 of the engine 1 reaches its maximum temperature when the engine 1 is running.

[0027] The engine 1 includes a wiring 40 that transmits electric power generated by the generator 2 to the electric accessory 9 through the second lead-out portion 29c, and a connector 41 attached to the wiring 40. The connector 41 is connected to the connector 31. This electrically connects the wiring 40 to the second lead-out portion 29c to which the connector 31 is attached. The connector 31 includes, for example, a heat-resistant resin member.

[0028] The neutral point 29d is attached to the connector 31. The connector 31 has, for example, an internal space. The neutral point 29d is accommodated in this internal space. The neutral point 29d is attached to the connector 31 in a state insulated from the second lead-out wire portion 29c. Note that the neutral point 29d does not have to be grounded.

[0029] The generator 2 includes, for example, a voltage sensor 32 that detects the phase voltage of one of the three-phase AC power phases output from the electric wire 29, which is a three-phase winding. The voltage sensor 32 detects the voltage between one of the first lead wire portions 29b of the electric wire 29 and the neutral point 29d as the phase voltage. The voltage sensor 32 is connected to a processing circuit 33 included in the engine 1. The processing circuit 33 is configured to receive a detection signal from the voltage sensor 32. For example, the processing circuit 33 calculates the rotation speed of the generator 2 based on the detection signal from the voltage sensor 32. In this way, the configuration that detects the phase voltage allows the rotation speed of the generator 2 to be measured at a lower voltage than a configuration that detects line voltage. This makes it possible to suppress dielectric breakdown when the voltage is detected by the voltage sensor 32.

[0030] The processing circuit 33 is, for example, a controller 333 including a processor 330, a system memory 331, and a storage memory 332. The controller 333 receives a detection signal from the voltage sensor 32. A control program to be executed by the processor 330 is stored in the storage memory 332. The processor 330 executes the control program read from the storage memory 332 to the system memory 331, and calculates the rotation speed.

[0031] As described above, by arranging the neutral point 29d of the electric wire 29 of the generator 2 outside the case 27, the neutral point 29d can be arranged in any space inside the engine 1. Furthermore, a space for accommodating the neutral point 29d in the case 27 is not required. This allows the case 27 to be made smaller. This increases the degree of freedom in arranging the generator 2 in the engine 1.

[0032] Furthermore, by arranging the first lead wire portion 29b and the second lead wire portion 29c outside the case 27, the case 27 can be further reduced in size.

[0033] If the neutral point 29d is located in a region that is lower in temperature than the region where the case 27 of the engine 1 reaches its highest temperature when the engine 1 is running, the options for usable insulating materials increase, i.e., insulating materials with a low heat resistance temperature can be used.

[0034] (Modifications) The following describes modifications of the present disclosure, focusing on the differences from the embodiment. Fig. 3 is a diagram showing a generator 102 according to a first modification and its surrounding configuration. As shown in Fig. 3, the neutral point 29d of the first modification is not attached to the connector 31 and is disposed apart from the case 27. That is, the neutral point 29d is disposed apart from both the connector 31 and the case 27. The neutral point 29d is disposed outside the case 27 in a direction perpendicular to the rotation axis X.

[0035] The neutral point 29d may be disposed outside the case 27 in the axial direction in which the rotation axis X extends. Alternatively, the neutral point 29d may be attached to the case 27. Alternatively, the neutral point 29d may be attached to the case 27 via a support member.

[0036] Fig. 4 is a schematic diagram of a gas turbine engine 101 according to a second modified example. As shown in Fig. 4, the connector 31 of the second modified example is attached to the cylindrical body 20. The neutral point 29d is attached to the inner circumferential surface of the cylindrical body 20 while being attached to the connector 31. The neutral point 29d may be attached to the cylindrical body 20 via a support member while being attached to the connector 31. Alternatively, the neutral point 29d may be attached to the cylindrical body 20 separately from the connector 31.

[0037] Although the rotation axis X in the above embodiment coincides with the rotation axis of the rotating shaft 7, it does not have to coincide with the rotation axis. The case 27 may be composed of either a single member or multiple members. The "low-temperature region" of the engine 1 may be, for example, a region forward of the case 27, but is not limited to this. For example, by knowing in advance the temperature changes in the case 27 and its surroundings while the engine 1 is running, it is possible to determine which region of the engine 1 can be selected as the "low-temperature region" of the engine 1. The voltage sensor 32 may be used for purposes other than calculating the rotation speed of the generator 2. The neutral point 29d may be attached to, for example, the outer surface of the connector 31. If the neutral point 29d is not housed in the connector 31, the connector 31 can be made smaller.

[0038] Furthermore, the case 27 may cover at least a portion of each of the stator 26 and the rotor 25 from both or one of the axial sides in the axial direction of the rotation axis X. Furthermore, the case 27 may be open on both sides in the axial direction of the rotation axis X. In this case, the internal space of the case 27 refers to the space defined by the case 27 from one end to the other end of the case 27 in the axial direction of the rotation axis X.

[0039] (Disclosure Items) Each of the following items discloses a preferred embodiment. [Item 1] A generator for use in a gas turbine engine, comprising: a stator including a stator core and an electric wire wound around the stator core, a rotor disposed inside the stator, and a case that houses the stator and the rotor, wherein the electric wire has a star-connected neutral point, and the neutral point is disposed outside the case.

[0040] According to the above configuration, by locating the neutral point outside the case, the case and the neutral point can be located in separate spaces. This increases the degree of freedom in locating the generator in the gas turbine engine. As a result, even when the space for locating the generator in the gas turbine engine is limited, it becomes easier to locate the generator.

[0041] [Item 2] The generator according to item 1, wherein the neutral point is disposed outside the case in a direction perpendicular to the rotation axis of the rotor.

[0042] According to the above configuration, even when the space for arranging the generator is insufficient in the axial direction of the rotor, it is possible to easily arrange the generator in the gas turbine engine. Furthermore, the neutral point can be separated from the rotor axis in the orthogonal direction. This makes it possible to suppress the transmission of rotor vibration and heat to the neutral point when the gas turbine engine is running.

[0043] [Item 3] The generator according to item 1 or 2, wherein the neutral point is disposed outside the case in an axial direction in which a rotation axis of the rotor extends.

[0044] According to the above configuration, it is possible to easily install a generator in a gas turbine engine even when there is insufficient space for installing the generator in a direction perpendicular to the rotational axis of the rotor. Furthermore, when the generator is installed around the rotational axis of the gas turbine engine, by locating the neutral point in front of the case, it is possible to prevent vibrations and heat from the rotor from reaching the neutral point when the gas turbine engine is running.

[0045] [Item 4] The generator according to any one of items 1 to 3, wherein the neutral point is disposed away from the case.

[0046] According to the above configuration, it is possible to prevent vibrations and heat from the case from reaching the neutral point when the gas turbine engine is running, and it is also possible to improve the degree of freedom in the layout of the generator in the gas turbine engine.

[0047] [Item 5] The generator according to any one of items 1 to 4, further comprising a connector attached to the electric wire, wherein the neutral point is attached to the connector.

[0048] According to the above configuration, by attaching the neutral point to the connector attached to the electric wire, the neutral point can be easily positioned relative to the case. Furthermore, for example, if the neutral point is housed in the internal space of the connector, the neutral point can be protected from the outside. Furthermore, for example, if the connector is fixed to a gas turbine engine, the neutral point can be easily positioned relative to the gas turbine engine.

[0049] [Item 6] The generator according to any one of items 1 to 5, wherein the rotor includes a permanent magnet.

[0050] According to the above configuration, the generator can be configured as a permanent magnet generator, which allows the generator to be made smaller than an induction generator or the like.

[0051] [Item 7] The generator according to any one of Items 1 to 6, wherein the electric wire is a three-phase winding, and further comprising a voltage sensor that detects a phase voltage of AC power of any phase of the three-phase AC power output from the three-phase winding.

[0052] According to the above configuration, the occurrence of dielectric breakdown when detecting voltage with a voltage sensor can be suppressed compared to when detecting line voltage with a voltage sensor. Therefore, for example, the voltage sensor can be used to measure the rotation speed of a generator at a low voltage.

[0053] [Item 8] A gas turbine engine comprising: a compressor; a combustor that generates combustion gas; a turbine to which the combustion gas is supplied from the combustor; a rotating shaft that mechanically connects the compressor to the turbine; a casing that houses at least the compressor and the combustor; and the generator according to any one of Items 1 to 7, the generator being disposed in an internal space between the compressor and the rotating shaft and mechanically connected to the rotating shaft.

[0054] According to the above configuration, even when the space for arranging the generator is restricted by the multiple components of the gas turbine engine, the generator can be easily arranged.

[0055] [Item 9] The gas turbine engine according to item 8, wherein the neutral point is disposed forward of the combustor.

[0056] According to the above configuration, when the gas turbine engine is running, the heat of the combustor can be prevented from reaching the neutral point.

[0057] [Item 10] The gas turbine engine according to item 8 or 9, wherein the neutral point is disposed in front of the case.

[0058] According to the above configuration, even when the space for arranging the generator in the radial direction of the rotating shaft is insufficient in the gas turbine engine, it is possible to easily arrange the generator. Furthermore, by arranging the neutral point in front of the case, it is possible to prevent vibrations and heat from the case from reaching the neutral point when the gas turbine engine is running.

[0059] [Item 11] The gas turbine engine according to any one of Items 8 to 10, wherein the neutral point is disposed away from the case in the radial direction of the rotary shaft.

[0060] According to the above configuration, even when the space for arranging the generator in the axial direction of the rotating shaft is insufficient in the gas turbine engine, the generator can be easily arranged. Furthermore, by separating the neutral point from the case in the radial direction of the rotating shaft, it is possible to suppress the transmission of heat and vibration from the case or the rotating shaft to the neutral point when the gas turbine engine is running.

[0061] [Item 12] The gas turbine engine according to any one of Items 8 to 11, wherein the neutral point is disposed in a region that is lower in temperature than a region where the case has the highest temperature.

[0062] According to the above configuration, by locating the neutral point in a region that is lower in temperature than the region where the engine case reaches its highest temperature, it is possible to prevent the influence of heat from the gas turbine engine during operation on the neutral point. Furthermore, because the influence of heat on the neutral point is reduced, for example, materials other than those with high heat resistance can be used as the covering material for covering the electric wire. This allows for greater freedom in selecting and designing the covering material.

[0063] X: Rotation axis 1, 101: Gas turbine engine 2, 102: Generator 3: Fan 4: Compressor 5: Combustor 6: Turbine 7: Rotation shaft 8: Casing 25: Rotor 26: Stator 27: Case 29: Electric wire 29d: Neutral point 30: Permanent magnet 31: Connector

Claims

1. A generator for use in a gas turbine engine, comprising: a stator including a stator core and an electric wire wound around the stator core; a rotor arranged inside the stator; and a case that houses the stator and the rotor, wherein the electric wire has a star-connected neutral point, and the neutral point is arranged outside the case.

2. The generator according to claim 1, wherein the neutral point is disposed outside the case in a direction perpendicular to the rotation axis of the rotor.

3. A generator as claimed in claim 1 or 2, wherein the neutral point is disposed outside the case in the axial direction in which the rotation axis of the rotor extends.

4. A generator as claimed in any one of claims 1 to 3, wherein the neutral point is located away from the case.

5. A generator as claimed in any one of claims 1 to 4, further comprising a connector attached to the electric wire, and the neutral point is attached to the connector.

6. A generator as claimed in any one of claims 1 to 5, wherein the rotor includes a permanent magnet.

7. The generator according to any one of claims 1 to 6, wherein the electric wire is a three-phase winding, and further comprising a voltage sensor for detecting a phase voltage of any one of the three-phase AC power phases output from the three-phase winding.

8. A gas turbine engine comprising: a compressor; a combustor that generates combustion gas; a turbine to which the combustion gas is supplied from the combustor; a rotating shaft that mechanically connects the compressor to the turbine; a casing that houses at least the compressor and the combustor; and a generator according to any one of claims 1 to 7, disposed in an internal space between the compressor and the rotating shaft and mechanically connected to the rotating shaft.

9. A gas turbine engine according to claim 8, wherein said neutral point is located forward of said combustor.

10. A gas turbine engine according to claim 8 or 9, wherein the neutral point is disposed forward of the case.

11. A gas turbine engine according to any one of claims 8 to 10, wherein the neutral point is disposed away from the case in the radial direction of the rotating shaft.

12. A gas turbine engine according to any one of claims 8 to 11, wherein the neutral point is located in an area that is lower in temperature than an area where the case has the highest temperature.

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