gas turbine

Abstract

The objective is to provide a gas turbine that ensures sufficient lubrication supply to bearings with a simple structure. [Solution] The gas turbine comprises a rotating shaft extending in the axial direction and to which rotating blades are connected; a bearing supporting the rotating shaft from the radially outward direction of the axis; a housing supporting the bearing from the radially outward direction and extending in the circumferential direction of the axis; an outer member located radially outward from the housing and connected to the housing; a lubricant space defined by the housing and the outer member at the portion where the housing and the outer member are connected; a lubricant supply passage through which lubricant supplied to the lubricant space flows; and a lubricant hole extending from the lubricant space through at least one of the housing and the outer member and opening toward the bearing.

Description

Technical Field

[0001] The present disclosure relates to a gas turbine.

Background Art

[0002] Patent Document 1 discloses a bearing mechanism that lubricates a bearing of a rotor of a compressor in an engine of an unmanned aircraft by oil mist lubrication using compressed air from the compressor. An inlet housing including an outer wall and an inner wall having a rotating body shape and struts connecting the outer wall and the inner wall supports the bearing. The inner wall and a rotating shaft support mechanism of the inner wall define a chamber into which an oil mist supplied to the bearing is introduced. A supply passage for the oil mist is provided in the strut.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, the chamber is directly connected to two bearings. An oil mist is supplied to the entire chamber, and a part of the supplied oil mist is supplied to the bearings. Therefore, the supply amount of the oil mist to the bearings may be insufficient.

[0005] One aspect of the present disclosure aims to provide a gas turbine that realizes sufficient supply of a lubricant to a bearing with a simple structure.

Means for Solving the Problems

[0006] A gas turbine according to one aspect of the present disclosure includes: a rotating shaft extending in the axial direction and to which rotor blades are connected; a bearing supporting the rotating shaft from the radially outward direction of the axis; a housing supporting the bearing from the radially outward direction and extending in the circumferential direction of the axis; an outer member located radially outward from the housing and connected to the housing; a lubricant space defined by the housing and the outer member at the portion where the housing and the outer member are connected; a lubricant supply passage through which lubricant supplied to the lubricant space flows; and a lubricant hole extending from the lubricant space through at least one of the housing and the outer member and opening toward the bearing. [Effects of the Invention]

[0007] According to one aspect of this disclosure, sufficient supply of lubricant to the bearing can be achieved with a simple structure. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a cross-sectional view showing an example of the configuration of a gas turbine according to an embodiment. [Figure 2] Figure 2 is a cross-sectional view showing an enlarged view of the structure from the compressor to the turbine in Figure 1. [Figure 3] Figure 3 is a cross-sectional view showing an enlarged view of the lubricant supply structure in Figure 2. [Modes for carrying out the invention]

[0009] Illustrative embodiments of the present disclosure are described below with reference to the drawings. The embodiments described below are all comprehensive or specific examples. Components in the following embodiments that are not described in the independent claim representing the highest-level concept are described as optional components. The figures in the accompanying drawings are schematic and not necessarily strictly illustrative. In each figure, substantially identical components are denoted by the same reference numerals, and redundant descriptions may be omitted or simplified.

[0010] In the following explanation, axial direction X refers to the direction in which the axis L of the rotation shaft 2 of the gas turbine 1 extends. Furthermore, "front" refers to the side of the gas turbine 1 from which air is introduced from the outside in axial direction X, and "rear" refers to the side of the gas turbine 1 from which exhaust gas is discharged in axial direction X. Axial direction X is the front-to-back direction of the gas turbine 1.

[0011] Figure 1 is a cross-sectional view showing an example of the configuration of a gas turbine 1 according to an embodiment. As shown in Figure 1, in this embodiment, the gas turbine 1 is a twin-shaft gas turbine. The gas turbine 1 is used as an engine for aircraft such as unmanned aerial vehicles, but the application of the gas turbine 1 is not limited to aircraft. The gas turbine 1 can be used as a turbofan engine.

[0012] The gas turbine 1 comprises a rotating shaft 2, a fan 3, a compressor 4, a combustor 5, a turbine 6, a generator 7, and a casing 8. The fan 3 is connected to the front of the rotating shaft 2 and rotates together with the rotating shaft 2. The compressor 4, combustor 5, and turbine 6 are arranged in this order from front to rear along the rotating shaft 2. The casing 8 houses all or part of the rotating shaft 2, fan 3, compressor 4, combustor 5, turbine 6, and generator 7.

[0013] In this embodiment, the rotating shaft 2 includes a low-pressure shaft 2A and a high-pressure shaft 2B extending in the axial direction X. The high-pressure shaft 2B is arranged on the same axis as the low-pressure shaft 2A and is rotatable relative to the low-pressure shaft 2A. The high-pressure shaft 2B is a tubular hollow shaft. The low-pressure shaft 2A is inserted into the hollow space of the high-pressure shaft 2B and penetrates the hollow space. The low-pressure shaft 2A is longer in the front-rear direction than the high-pressure shaft 2B, and the front end 2Aa and rear end 2Ab of the low-pressure shaft 2A are exposed to the outside from the front end 2Ba and rear end 2Bb of the high-pressure shaft 2B, respectively. The front end 2Aa of the low-pressure shaft 2A is connected to the fan 3.

[0014] The compressor 4 includes a low-pressure side compressor 4A and a high-pressure side compressor 4B located behind the low-pressure side compressor 4A. The low-pressure side compressor 4A is an axial flow compressor and includes rotor blades connected to rotate integrally with the low-pressure shaft 2A. In this embodiment, the low-pressure side compressor 4A includes two rotor blades aligned in the axial direction X. The connection between the two rotor blades of the low-pressure side compressor 4A and the low-pressure shaft 2A is located between the front end 2Aa of the low-pressure shaft 2A and the front end 2Ba of the high-pressure shaft 2B. In this embodiment, the two rotor blades of the low-pressure side compressor 4A are connected to the front end 2Aa of the low-pressure shaft 2A together with the fan 3, although they may be connected to the low-pressure shaft 2A at a different position from the fan 3, further rearward from the front end 2Aa.

[0015] The high-pressure side compressor 4B is a centrifugal compressor and includes a rotor connected to the high-pressure shaft 2B so as to rotate integrally with it. In this embodiment, the high-pressure side compressor 4B includes one rotor. The connection between the rotor of the high-pressure side compressor 4B and the high-pressure shaft 2B is located in front of the combustor 5. The types of low-pressure side compressor 4A and high-pressure side compressor 4B are not limited to axial flow compressors and centrifugal compressors. A diffuser 12 is arranged on the outer circumference of the high-pressure side compressor 4B to send the air flowing out of the high-pressure side compressor 4B to the rear. Behind the diffuser 12 is the combustor 5. The combustor 5 is a back-flow type combustor.

[0016] The turbine 6 includes a high-pressure side turbine 6B and a low-pressure side turbine 6A located behind the high-pressure side turbine 6B. The low-pressure shaft 2A mechanically connects the low-pressure side compressor 4A to the low-pressure side turbine 6A. The high-pressure shaft 2B mechanically connects the high-pressure side compressor 4B to the high-pressure side turbine 6B. The low-pressure side turbine 6A includes rotor blades connected to the low-pressure shaft 2A to rotate integrally with it. In this embodiment, the low-pressure side turbine 6A includes two rotor blades aligned in the axial direction X. The connection between the two rotor blades of the low-pressure side turbine 6A and the low-pressure shaft 2A is located between the rear end 2Bb of the high-pressure shaft 2B and the rear end 2Ab of the low-pressure shaft 2A. The low-pressure side turbine 6A can rotate the low-pressure side compressor 4A and the fan 3 via the low-pressure shaft 2A.

[0017] The high-pressure turbine 6B includes a rotor blade connected to rotate integrally with the high-pressure shaft 2B. In this embodiment, the high-pressure turbine 6B includes one rotor blade. The connection portion between the rotor blade of the high-pressure turbine 6B and the high-pressure shaft 2B is located between the high-pressure compressor 4B and the rear end portion 2Bb of the high-pressure shaft 2B. The high-pressure turbine 6B can rotate the high-pressure compressor 4B via the high-pressure shaft 2B.

[0018] The casing 8 includes a cylindrical outer shell 8A and an inner shell 8B arranged concentrically with each other. The inner shell 8B houses the compressor 4, the combustor 5, the turbine 6, and the generator 7. A cylindrical bypass flow path B is formed between the inner shell 8B and the outer shell 8A.

[0019] The gas turbine 1 includes a first cylindrical body 9 extending in the axial direction X from the fan 3 to the high-pressure compressor 4B inside the inner shell 8B. The outer diameter and the inner diameter of the first cylindrical body 9 are reduced from the front to the rear. The first cylindrical body 9 defines a part of a compressed air flow path R from the low-pressure compressor 4A toward the high-pressure compressor 4B between the first cylindrical body 9 and the inner shell 8B. The outer peripheral surface of the first cylindrical body 9 faces the compressed air flow path R. The generator 7 is arranged inside the first cylindrical body 9. The first cylindrical body 9 is connected to the inner shell 8B by a plurality of struts 9A and supported by the inner shell 8B. The rotor blades of the low-pressure compressor 4A and the rotor blades of the high-pressure compressor 4B are located in the compressed air flow path R.

[0020] The gas turbine 1 includes a second cylindrical body 10 extending in the axial direction X from the high-pressure turbine 6B to the low-pressure turbine 6A inside the inner shell 8B. The second cylindrical body 10 defines at least a part of a gas flow path G extending rearward from the combustor 5 between the second cylindrical body 10 and the inner shell 8B inside the inner shell 8B. The outer peripheral surface of the second cylindrical body 10 faces the gas flow path G. The second cylindrical body 10 is connected to the inner shell 8B via a plurality of struts 10A etc. and supported by the inner shell 8B. The gas flow path G merges with the bypass flow path B behind the low-pressure turbine 6A. The rotor blades of the low-pressure turbine 6A and the rotor blades of the high-pressure turbine 6B are located in the gas flow path G.

[0021] The gas turbine 1 includes a strut housing 11. Part or all of the strut housing 11 is housed in an outer shell 8A. The strut housing 11 is located in front of the high-pressure side compressor 4B. In this embodiment, the strut housing 11 is located between the generator 7 and the high-pressure side compressor 4B in the axial direction X. The strut housing 11 extends from the first cylinder 9 across the outer shell 8A in the axial radial direction, which is the radial direction of the axis L. The strut housing 11 is connected to the outer shell 8A, the inner shell 8B and the first cylinder 9, and connects the outer shell 8A, the inner shell 8B and the first cylinder 9 to each other.

[0022] The strut housing 11 includes an outer shell portion 11a, an inner shell portion 11b, a cylindrical body portion 11c, and a plurality of struts 11d. The outer shell portion 11a is connected to the outer shell 8A and forms part of the outer shell 8A. The outer shell portion 11a has a cylindrical shape extending in the circumferential direction around the axis L, similar to the outer shell 8A. The inner shell portion 11b is connected to the inner shell 8B and forms part of the inner shell 8B. The inner shell portion 11b has a cylindrical shape extending in the circumferential direction, similar to the inner shell 8B. The cylindrical body portion 11c is connected to the first cylindrical body 9 and forms part of the first cylindrical body 9. The cylindrical body portion 11c has a cylindrical shape extending in the circumferential direction, similar to the first cylindrical body 9. The plurality of struts 11d extend radially in the axial direction from the cylindrical body portion 11c through the inner shell portion 11b to the outer shell portion 11a. Each of the multiple struts 11d connects an outer shell portion 11a, an inner shell portion 11b, and a cylindrical portion 11c to one another. The entire or a part of the strut housing 11 is an example of an outer member.

[0023] Part of the air sucked in by the fan 3 flows through the bypass flow path B and is discharged rearward. The remaining air sucked in by the fan 3 flows through the compressed air flow path R and flows into the low-pressure compressor 4A. The air sequentially passes through the low-pressure compressor 4A and the high-pressure compressor 4B in the compressed air flow path R, and flows into the combustor 5 through the diffuser 12. The combustion gas flowing out from the outlet of the combustor 5 passes through the nozzle unit 13 and flows into the gas flow path G. The combustion gas sequentially passes through the high-pressure turbine 6B and the low-pressure turbine 6A in the gas flow path G and is discharged rearward. The combustion gas discharged from the gas flow path G merges with the air discharged from the bypass flow path B, is accelerated by the air, and is discharged to the outside of the casing 8.

[0024] The high-pressure turbine 6B rotates by receiving the flow of the high-temperature and high-pressure combustion gas immediately after flowing out from the combustor 5. The low-pressure turbine 6A rotates by receiving the flow of the combustion gas whose temperature and pressure have been decreased in the process of passing through the high-pressure turbine 6B. Therefore, the high-pressure turbine 6B rotates at a higher rotational speed than the low-pressure turbine 6A. Further, the high-pressure compressor 4B rotated by the high-pressure turbine 6B rotates at a higher rotational speed than the low-pressure compressor 4A rotated by the low-pressure turbine 6A. The rotational speed means the number of rotations per unit time. The air flowing in the compressed air flow path R is pressurized by the low-pressure compressor 4A, and then is further pressurized to a higher pressure by the high-pressure compressor 4B and flows into the combustor 5. Since the high-pressure compressor 4B is affected by the heat generated by the combustor 5, it is exposed to an environment with a higher temperature and pressure than the low-pressure compressor 4A.

[0025] Figure 2 is an enlarged cross-sectional view showing the structure from the compressor 4 to the turbine 6 in Figure 1. As shown in Figure 2, the generator 7 generates electricity when the generator shaft 7A of the generator 7 is driven by the rotational driving force of the rotating shaft 2. In this embodiment, the generator shaft 7A is located coaxially with the low-pressure shaft 2A and the high-pressure shaft 2B. The generator 7 may also have a starter function that rotates the rotating shaft 2 when the gas turbine 1 is started. In this case, the generator 7 is a motor generator. The generator 7 is located inside the first cylinder 9 and in front of the high-pressure side compressor 4B. In this embodiment, the generator 7 is located between the low-pressure side compressor 4A and the high-pressure side compressor 4B.

[0026] The generator 7 includes a generator shaft 7A, a rotor 7B that rotates integrally with the generator shaft 7A, a stator 7C located around the rotor 7B, and a generator housing 7D. The generator shaft 7A and rotor 7B are located inside the stator 7C. The generator shaft 7A is a tubular hollow shaft extending in the axial direction X. The low-pressure shaft 2A is inserted into and penetrates the hollow space of the generator shaft 7A. The front end 2Ba of the high-pressure shaft 2B is inserted into the hollow space of the generator shaft 7A. The rear end 7Ab of the generator shaft 7A is connected to the front end 2Ba of the high-pressure shaft 2B to transmit rotational forces around axis L. The generator shaft 7A rotates together with the high-pressure shaft 2B around axis L.

[0027] In this embodiment, the rear end portion 7Ab of the generator shaft 7A and the front end portion 2Ba of the high-voltage shaft 2B are spline-connected. The inner circumferential surface of the rear end portion 7Ab of the generator shaft 7A includes a plurality of grooves spaced apart in the circumferential direction and extending in the axial direction X, which function as an internal spline. The outer circumferential surface of the front end portion 2Ba of the high-voltage shaft 2B includes a plurality of band-shaped projections spaced apart in the circumferential direction and extending in the axial direction X, which function as an external spline.

[0028] The rotor 7B is a cylindrical body having an internal space extending in the axial direction X. The generator shaft 7A is inserted into and passes through the internal space of the rotor 7B. The rotor 7B is coupled to the generator shaft 7A and rotates together with the generator shaft 7A around the axis L. The rotor 7B contains permanent magnets, and the stator 7C contains windings. The rotor 7B is surrounded by the stator 7C. Therefore, the generator 7 is of the permanent magnet type.

[0029] The generator housing 7D houses the rotor 7B and the stator 7C. The generator housing 7D covers the rotor 7B and the stator 7C from at least the outside in the radial direction. The generator housing 7D may also cover the rotor 7B and the stator 7C from both sides in the axial direction X.

[0030] The gas turbine 1 comprises a plurality of bearings 20 and a bearing housing 30 that supports the bearings 20. The bearings 20 include a low-pressure bearing 20A, a high-pressure bearing 20B, and a generator bearing 20C. The low-pressure bearing 20A rotatably supports the low-pressure shaft 2A, the high-pressure bearing 20B rotatably supports the high-pressure shaft 2B, and the generator bearing 20C rotatably supports the generator shaft 7A. In this embodiment, the low-pressure bearing 20A, the high-pressure bearing 20B, and the generator bearing 20C are radial bearings, for example, radial ball bearings or radial roller bearings.

[0031] The low-pressure bearing 20A includes a first low-pressure bearing 20Aa and a second low-pressure bearing 20Ab located at the front of the low-pressure shaft 2A, and a third low-pressure bearing 20Ac located at the rear of the low-pressure shaft 2A. In this embodiment, the first low-pressure bearing 20Aa and the second low-pressure bearing 20Ab are located between the front end 2Aa of the low-pressure shaft 2A and the front end 7Aa of the generator shaft 7A. The second low-pressure bearing 20Ab is located behind the first low-pressure bearing 20Aa. The third low-pressure bearing 20Ac is located between the low-pressure shaft 2A, the connection portion of the low-pressure side turbine 6A and the rear end 2Bb of the high-pressure shaft 2B. The first low-pressure bearing 20Aa and the second low-pressure bearing 20Ab are examples of a fourth bearing.

[0032] The high-pressure bearing 20B includes a first high-pressure bearing 20Ba located at the front of the high-pressure shaft 2B and a second high-pressure bearing 20Bb located at the rear of the high-pressure shaft 2B. In this embodiment, the first high-pressure bearing 20Ba is located between the rear end 7Ab of the generator shaft 7A and the connection portion between the high-pressure side compressor 4B and the high-pressure shaft 2B. The second high-pressure bearing 20Bb is located between the connection portion between the high-pressure side turbine 6B and the high-pressure shaft 2B and the rear end 2Bb of the high-pressure shaft 2B. The first high-pressure bearing 20Ba is an example of a first or third bearing.

[0033] The generator bearing 20C includes a first generator bearing 20Ca located at the front of the generator shaft 7A and a second generator bearing 20Cb located at the rear of the generator shaft 7A. The first generator bearing 20Ca is located in front of the rotor 7B, and the second generator bearing 20Cb is located behind the rotor 7B. In this embodiment, the first generator bearing 20Ca is located between the second low-pressure bearing 20Ab and the rotor 7B, and the second generator bearing 20Cb is located between the rotor 7B and the first high-pressure bearing 20Ba. The generator bearings 20Ca and 20Cb are fixed to the inner surface of the generator housing 7D and supported by the generator housing 7D from the radially outer side. The second generator bearing 20Cb is an example of a second or third bearing.

[0034] The bearing housing 30 includes a first bearing housing 30A and a second bearing housing 30B located rearward in the axial direction X from the first bearing housing 30A. The first bearing housing 30A extends in the axial direction X from the first low-pressure bearing 20Aa to the first high-pressure bearing 20Ba. The first bearing housing 30A extends in the circumferential direction and surrounds the first low-pressure bearing 20Aa, the second low-pressure bearing 20Ab, the first high-pressure bearing 20Ba and the generator 7 from the radially outer side.

[0035] The first low-pressure bearing 20Aa, the second low-pressure bearing 20Ab, and the first high-pressure bearing 20Ba are fixed to the inner surface of the first bearing housing 30A and supported by the first bearing housing 30A from the radially outer side. The generator housing 7D is fixed to the first bearing housing 30A and supported by the first bearing housing 30A in the axial X direction and the radial direction. Thus, the generator bearings 20Ca and 20Cb are supported by the first bearing housing 30A via the generator housing 7D. The first bearing housing 30A is connected to the first cylindrical body 9 by a plurality of struts 30Aa and is supported by the first cylindrical body 9. The rear part of the first bearing housing 30A is connected to the cylindrical portion 11c of the strut housing 11.

[0036] The second bearing housing 30B extends in the axial direction X from the second high-pressure bearing 20Bb to the third low-pressure bearing 20Ac. The second bearing housing 30B extends in the circumferential direction and surrounds the second high-pressure bearing 20Bb and the third low-pressure bearing 20Ac from the radially outer side. The second high-pressure bearing 20Bb and the third low-pressure bearing 20Ac are fixed to the inner surface of the second bearing housing 30B and supported by the second bearing housing 30B from the radially outer side. The second bearing housing 30B is connected to the second cylindrical body 10 by a plurality of struts 30Ba and is supported by the second cylindrical body 10.

[0037] The gas turbine 1 includes a lubricant supply structure 100 that supplies lubricant to a plurality of bearings 20. In this embodiment, the lubricant is a liquid, specifically a mist-like liquid. For example, the lubricant supply structure 100 is a structure that supplies oil mist to a plurality of bearings 20. The lubricant supply structure 100 described in this embodiment is a structure that supplies oil mist to bearings 20 located in front of the high-pressure side compressor 4B.

[0038] Figure 3 is a cross-sectional view showing an enlarged view of the lubricant supply structure 100 of Figure 2. As shown in Figure 3, the lubricant supply structure 100 includes a pump 101, a first lubricant supply passage 102, a second lubricant supply passage 103, a first lubricant space 104, a second lubricant space 105, and a plurality of lubricant holes 110.

[0039] The first lubrication space 104 is defined by the strut housing 11 and the first bearing housing 30A. The cylindrical portion 11c of the strut housing 11 is located radially outward relative to the first bearing housing 30A. The cylindrical portion 11c is connected to the first bearing housing 30A at its front and rear portions. The cylindrical portion 11c is connected to the radially outward portions of the second generator bearing 20Cb and the first high-pressure bearing 20Ba in the first bearing housing 30A.

[0040] The space enclosed by the inner surface 11ca of the cylindrical portion 11c in the axial radial direction and the outer surface 30Ab of the first bearing housing 30A in the axial radial direction is the first lubricant space 104. The first lubricant space 104 is a ring-shaped space extending in the circumferential direction. The first lubricant space 104 surrounds either or both of the second generator bearing 20Cb and the first high-pressure bearing 20Ba from the outside in the axial radial direction. In this embodiment, the first lubricant space 104 also extends in the axial direction X and surrounds both the second generator bearing 20Cb and the first high-pressure bearing 20Ba. The first lubricant space 104 is adjacent to the second generator bearing 20Cb and the first high-pressure bearing 20Ba on the outside in the axial radial direction.

[0041] The second lubricant space 105 extends axially in the X direction within the wall of the first bearing housing 30A. The second lubricant space 105 is a tubular space extending axially in the X direction. The rear end of the second lubricant space 105 is located at the connection portion C between the first bearing housing 30A and the cylindrical portion 11c, and opens rearward from the first bearing housing 30A. The connection portion C is the forward connection portion of the connection between the first bearing housing 30A and the cylindrical portion 11c. The second lubricant space 105 passes outward in the axial direction relative to the low-pressure bearings 20Aa and 20Ab and the first generator bearing 20Ca. The second lubricant space 105 is adjacent to the low-pressure bearings 20Aa and 20Ab and the first generator bearing 20Ca outward in the axial direction. The second lubricant space 105 is located forward of the first lubricant space 104.

[0042] The cross-sectional area of ​​the first lubricant space 104 in the axial direction is larger than the cross-sectional area of ​​the second lubricant space 105 in the axial direction. The cross-sectional area of ​​the first lubricant space 104 in the axial direction X is also larger than the cross-sectional area of ​​the second lubricant space 105 in the axial direction. The volume of the first lubricant space 104 is larger than the volume of the second lubricant space 105.

[0043] The first lubricant supply passage 102 and the second lubricant supply passage 103 pass through the interior of the strut housing 11. The first lubricant supply passage 102 extends radially through the interior of the strut 11d from the outer shell portion 11a to the cylindrical portion 11c. The first lubricant supply passage 102 opens at the radially outer surface of the outer shell portion 11a and the inner surface 11ca of the cylindrical portion 11c. The first lubricant supply passage 102 penetrates the outer shell portion 11a, the inner shell portion 11b, the cylindrical portion 11c and one strut 11d in the radial direction. The first lubricant supply passage 102 communicates with the first lubricant space 104.

[0044] The second lubricant supply passage 103 extends radially through the inside of the strut 11d from the outer shell portion 11a to the cylindrical portion 11c. The second lubricant supply passage 103 opens on the radially outer surface of the outer shell portion 11a and opens forward from the cylindrical portion 11c at the connection portion C between the first bearing housing 30A and the cylindrical portion 11c. The second lubricant supply passage 103 penetrates the outer shell portion 11a, the inner shell portion 11b, the cylindrical portion 11c, and one strut 11d. The second lubricant supply passage 103 communicates with the second lubricant space 105. The second lubricant supply passage 103 is located further forward than the first lubricant supply passage 102 and is less affected by heat from the high-pressure side compressor 4B and combustor 5 than the first lubricant supply passage 102.

[0045] The pump 101 is located outside the outer shell 8A. In this embodiment, the pump 101 is located in the outer shell portion 11a of the strut housing 11. The pump 101 communicates with both lubricant supply passages 102 and 103 and pumps mist-like lubricant into the lubricant supply passages 102 and 103, respectively. The lubricant from the first lubricant supply passage 102 is sent to the first lubricant space 104. The lubricant from the second lubricant supply passage 103 is sent to the second lubricant space 105.

[0046] In this embodiment, the discharge rate of lubricant from the pump 101 to the first lubricant supply passage 102 is greater than the discharge rate of lubricant from the pump 101 to the second lubricant supply passage 103. Therefore, the amount of lubricant sent to the first lubricant space 104 is greater than the amount of lubricant sent to the second lubricant space 105. The discharge rate and the amount of lubricant are amounts per unit time. Note that the discharge rates of the pump 101 to the lubricant supply passages 102 and 103 may be the same.

[0047] Of the multiple lubricant holes 110, lubricant holes 111 and 112 communicate with the first lubricant space 104, and lubricant holes 113, 114 and 115 communicate with the second lubricant space 105.

[0048] The first lubricant hole 111 extends from the first lubricant space 104 and opens toward the first high-pressure bearing 20Ba. The first lubricant hole 111 discharges the lubricant pumped into the first lubricant space 104 toward the first high-pressure bearing 20Ba. In this embodiment, the first lubricant hole 111 extends through the wall of the first bearing housing 30A from the outside to the inside in the axial direction. The first lubricant hole 111 may also extend through the wall of the first bearing housing 30A and the wall of the cylindrical portion 11c. In this embodiment, the first lubricant hole 111 is located behind the first high-pressure bearing 20Ba and opens forward toward the first high-pressure bearing 20Ba. This prevents the lubricant discharged from the first lubricant hole 111 from flowing into the high-pressure side compressor 4B, which is located behind the first lubricant hole 111.

[0049] The second lubricant hole 112 extends from the first lubricant space 104 and opens toward the second generator bearing 20Cb. The second lubricant hole 112 is located in front of the first lubricant hole 111. The second lubricant hole 112 discharges the lubricant pumped into the first lubricant space 104 toward the second generator bearing 20Cb. In this embodiment, the second lubricant hole 112 extends through the wall of the first bearing housing 30A from the outside to the inside in the axial direction. The second lubricant hole 112 may also extend through the wall of the first bearing housing 30A and the wall of the cylindrical portion 11c. In this embodiment, the second lubricant hole 112 is located behind the second generator bearing 20Cb and opens forward toward the second generator bearing 20Cb. This prevents the lubricant discharged from the second lubricant hole 112 from flowing into the high-pressure side compressor 4B, which is located behind the second generator bearing 20Cb.

[0050] The third lubricant hole 113 extends from the second lubricant space 105 and opens toward the first generator bearing 20Ca. The third lubricant hole 113 discharges the lubricant that has been pressurized into the second lubricant space 105 toward the first generator bearing 20Ca. In this embodiment, the third lubricant hole 113 extends radially inward through the wall of the first bearing housing 30A. Furthermore, the third lubricant hole 113 is located in front of the first generator bearing 20Ca and opens toward the rear and toward the first generator bearing 20Ca. As a result, the lubricant discharged from the third lubricant hole 113 flows through the first generator bearing 20Ca into the generator housing 7D, lubricating and cooling the components of the generator 7.

[0051] The fourth lubricant hole 114 extends from the second lubricant space 105 and opens toward the second low-pressure bearing 20Ab. The fourth lubricant hole 114 is located forward of the third lubricant hole 113. The fourth lubricant hole 114 discharges the lubricant that has been pressurized into the second lubricant space 105 toward the second low-pressure bearing 20Ab. In this embodiment, the fourth lubricant hole 114 extends radially inward through the wall of the first bearing housing 30A. Furthermore, the fourth lubricant hole 114 is located forward of the second low-pressure bearing 20Ab and opens toward the rear and toward the second low-pressure bearing 20Ab. As a result, the lubricant discharged from the fourth lubricant hole 114 flows through the second low-pressure bearing 20Ab into the interior of the generator housing 7D, lubricating and cooling the components of the generator 7. Furthermore, the lubricant released from the fourth lubricant hole 114 is prevented from flowing into the low-pressure side compressor 4A, which is located in front of the fourth lubricant hole 114.

[0052] The fifth lubricant hole 115 extends from the second lubricant space 105 and opens toward the first low-pressure bearing 20Aa. The fifth lubricant hole 115 is located forward of the fourth lubricant hole 114. The fifth lubricant hole 115 discharges the lubricant that has been pumped into the second lubricant space 105 toward the first low-pressure bearing 20Aa. In this embodiment, the fifth lubricant hole 115 extends inward in the radial direction within the wall of the first bearing housing 30A. Furthermore, the fifth lubricant hole 115 is located forward of the first low-pressure bearing 20Aa and opens toward the rear and toward the first low-pressure bearing 20Aa. As a result, the lubricant discharged from the fifth lubricant hole 115 flows toward the rear through the first low-pressure bearing 20Aa. Therefore, it is prevented that the lubricant discharged from the fifth lubricant hole 115 flows into the low-pressure side compressor 4A and fan 3.

[0053] The lubricant supply structure 100 can supply lubricant to the first high-pressure bearing 20Ba and the second generator bearing 20Cb via the first lubricant space 104, and can supply lubricant to the first generator bearing 20Ca, the second low-pressure bearing 20Ab, and the first low-pressure bearing 20Aa via the second lubricant space 105.

[0054] The first high-pressure bearing 20Ba and the second generator bearing 20Cb are located on the opposite side of the generator 7 in the axial direction X from the first generator bearing 20Ca, the second low-pressure bearing 20Ab, and the first low-pressure bearing 20Aa. Because the first high-pressure bearing 20Ba and the second generator bearing 20Cb are close to the high-pressure side compressor 4B and the combustor 5, they are exposed to a high-temperature environment due to the heat generated from the high-pressure side compressor 4B and the combustor 5.

[0055] The volume, flow path cross-sectional area, and lubricant supply amount of the first lubricant space 104 are larger than those of the second lubricant space 105. The flow path cross-sectional area may be the cross-sectional area in the axial radial direction. On the other hand, the number of lubricant holes 110 extending from the first lubricant space 104 is smaller than that of the second lubricant space 105. Therefore, the first high-pressure bearing 20Ba and the second generator bearing 20Cb can be effectively lubricated and cooled by receiving a higher flow rate of lubricant than the first generator bearing 20Ca, the second low-pressure bearing 20Ab, and the first low-pressure bearing 20Aa. The lubricant supply structure 100 can supply lubricant to the bearing 20 in an amount corresponding to the thermal environment of the bearing 20.

[0056] Furthermore, in the manufacturing process of the gas turbine 1 according to this embodiment, the low-pressure shaft 2A and the high-pressure shaft 2B are assembled, and then the generator 7 assembly is assembled by connecting the generator shaft 7A and the high-pressure shaft 2B. Next, the bearing 20 and the bearing housing 30 are assembled, and the strut housing 11 is assembled to the bearing housing 30. In parallel with or before or after the assembly of the strut housing 11, the first cylindrical body 9, the inner shell 8B, and the outer shell 8A are assembled. Next, the pump 101 is set in the outer shell 8A. The lubricant supply structure 100 is installed inside the gas turbine 1 by assembling the first bearing housing 30A and the strut housing 11, except for the setting of the pump 101. Since the installation of components other than the first bearing housing 30A and the strut housing 11, such as piping, is not required for the installation of the lubricant supply structure 100, the assembly of the gas turbine 1 is simplified.

[0057] While exemplary embodiments of the present disclosure have been described above, the disclosure is not limited to these embodiments. That is, various modifications and improvements are possible within the scope of the disclosure. For example, embodiments that have been modified in various ways, and forms constructed by combining components from different embodiments, are also included within the scope of the disclosure.

[0058] For example, in the gas turbine 1 according to this embodiment, the cylindrical portion 11c of the lubricant supply structure 100 is included in the strut housing 11, but it may be separate from the strut housing 11. For example, the cylindrical portion 11c may be configured to be connected to the strut housing 11. For example, the cylindrical portion 11c may be included in the first cylindrical body 9 or the inner shell 8B.

[0059] The gas turbine 1 according to this embodiment includes a strut housing 11 located between the generator 7 and the high-pressure side compressor 4B, but the structure of the strut housing is not limited thereto. For example, the gas turbine 1 may include, instead of or in addition to the strut housing 11, a strut housing between the low-pressure side compressor 4A and the generator 7, and include a lubricant supply structure 100 formed by the strut housing and the first bearing housing 30A. For example, the gas turbine 1 may include, instead of or in addition to the strut housing 11, a strut housing at the location of the second bearing housing 30B, or in front of or behind the second bearing housing 30B, and include a lubricant supply structure 100 formed by the strut housing and the second bearing housing 30B.

[0060] In the gas turbine 1 according to this embodiment, the strut housing 11 is a single component, but it may be divisible into multiple components. The components constituting the strut housing 11 may include one or more of the outer shell portion 11a, inner shell portion 11b, cylindrical portion 11c, and strut 11d.

[0061] In the gas turbine 1 according to this embodiment, the lubricant supply structure 100 is configured such that a pump 101 supplies lubricant to both lubricant supply passages 102 and 103, but the configuration of the lubricant supply structure 100 is not limited to this. For example, the lubricant supply structure 100 may include two pumps 101 that supply lubricant to each of the lubricant supply passages 102 and 103. In this case, the amount of lubricant supplied between the lubricant supply passages 102 and 103 is different, but the discharge capacities of the two pumps 101 may be different or the same.

[0062] In the lubricant supply structure 100 of the gas turbine 1 according to this embodiment, the plurality of lubricant holes 110 release lubricant through their openings, but one or more lubricant holes 110 may include a nozzle that limits the opening area, the release area, or both. This allows the lubricant to be efficiently released from the lubricant holes 110 toward the bearing 20.

[0063] In the gas turbine 1 according to this embodiment, the generator 7 has an inner rotor type structure in which the rotor 7B is located inside the stator 7C, but it may also have an outer rotor type structure in which the rotor surrounds the stator. Even with such a structure, the rotor can be connected to rotate integrally with the hollow generator shaft 7A.

[0064] The gas turbine 1 according to this embodiment is a twin-shaft gas turbine in which the rotating shaft 2 includes two shafts, a low-pressure shaft 2A and a high-pressure shaft 2B. However, it may also be a single-shaft gas turbine in which the rotating shaft 2 includes only one shaft. In this case, the single-shaft gas turbine may have a structure in which a part or all of the inner circumferential surface of the generator shaft 7A engages with a part of the outer circumferential surface of the rotating shaft 2, or a structure in which a part or all of the outer circumferential surface of the generator shaft 7A engages with a part of the inner circumferential surface of the rotating shaft 2. Alternatively, the generator shaft 7A and the rotating shaft 2 may be a single continuous shaft.

[0065] The structure of the gas turbine 1 according to this embodiment is such that the front end 2Ba of the high-pressure shaft 2B is inserted into the internal space of the rear end 7Ab of the generator shaft 7A, but is not limited thereto. For example, the gas turbine 1 may have a structure in which the rear end 7Ab of the generator shaft 7A is inserted into the internal space of the front end 2Ba of the high-pressure shaft 2B. For example, the high-pressure shaft 2B and the generator shaft 7A may be a single continuous shaft. The components of the generator 7 may then be assembled to this shaft.

[0066] Examples of each aspect of the technology of the present disclosure are as follows: A gas turbine according to a first aspect of the present disclosure comprises: a rotating shaft extending in the axial direction and to which rotor blades are connected; a bearing supporting the rotating shaft from the radially outward direction of the axis; a housing supporting the bearing from the radially outward direction and extending in the circumferential direction of the axis; an outer member located radially outward from the housing and connected to the housing; a lubricant space defined by the housing and the outer member at the portion where the housing and the outer member are connected; a lubricant supply passage through which lubricant supplied to the lubricant space flows; and a lubricant hole extending from the lubricant space through at least one of the housing and the outer member and opening toward the bearing.

[0067] According to the first embodiment, the housing and outer members form a lubricant space and lubricant holes. Therefore, there is no need to provide a separate structure for forming the lubricant space and lubricant holes. Furthermore, after the lubricant is supplied to the lubricant space, it is discharged toward the bearing, subject to restrictions on the flow path cross-sectional area and discharge direction by the lubricant holes. As a result, the lubricant is efficiently supplied to the bearing in a sufficient amount. Thus, sufficient supply of lubricant to the bearing is achieved with a simple structure.

[0068] In a second aspect of the present disclosure, the gas turbine may be configured such that, in the first aspect, the bearing includes a first bearing and a second bearing spaced apart in the axial direction, and the lubricant hole includes a first lubricant hole opening toward the first bearing and a second lubricant hole opening toward the second bearing.

[0069] According to the second embodiment, lubricant can be supplied to the first bearing and the second bearing using a single lubricant space.

[0070] A gas turbine according to a third aspect of this disclosure may be configured such that, in the first or second aspect, the outer member extends in the circumferential direction, and the lubricant space is a space that extends in the circumferential direction.

[0071] According to the third embodiment, the volume of the lubricant space can be increased while suppressing the radial dimension of the lubricant space. Therefore, lubricant can be supplied to the bearing in a sufficient and stable amount.

[0072] A gas turbine according to a fourth aspect of the present disclosure may, in a third aspect, include an outer shell housing the rotating shaft, the bearing, the housing and the outer member, an inner shell located radially outward from the housing inside the outer shell, and a strut connecting the outer shell and the inner shell and extending radially, wherein the outer member includes a portion of the inner shell located radially inward from the axis with respect to the strut.

[0073] According to the fourth embodiment, the outer member is a member that includes the portion of the inner shell on which the strut is located. The lubricant space is formed by connecting the outer member, which constitutes a part of the inner shell, with the housing. Therefore, there is no need to provide a separate structure for forming the lubricant space.

[0074] A gas turbine according to a fifth aspect of the present disclosure may be configured in any one of the first to fourth aspects to include: a third bearing as a bearing; a first lubricant space as a lubricant space; a third lubricant hole as a lubricant hole; a fourth bearing located axially away from the third bearing and supporting the rotating shaft from the radially outward direction; a housing supporting the third bearing and the fourth bearing from the radially outward direction; a second lubricant space located axially away from the first lubricant space and included in the wall of the housing, the second lubricant space extending axially; a fourth lubricant hole extending from the second lubricant space through the housing and opening toward the fourth bearing; and a lubricant supply passage through which lubricant supplied to the first lubricant space and the second lubricant space flows.

[0075] According to the fifth embodiment, the first lubricant space can supply lubricant to the third bearing, and the second lubricant space can supply lubricant to the fourth bearing, which is located axially away from the third bearing. This makes it possible to supply lubricant to lubricant spaces at different locations. Since the second lubricant space is included in the housing wall, it is formed at the target location by assembling the housing to the gas turbine. Therefore, there is no need to provide a separate structure for forming the second lubricant space.

[0076] A gas turbine according to a sixth aspect of the present disclosure may, in any one of the third to fifth aspects, include an outer shell housing the rotating shaft, the bearing, the housing and the outer member, an inner shell located radially outward from the housing inside the outer shell, and a strut connecting the outer shell and the inner shell and extending in the radial direction, wherein the lubricant supply passage extends radially through the strut and communicates with the lubricant space.

[0077] According to the sixth embodiment, since the lubricant supply passage is formed within the strut, there is no need to provide a separate structure for forming the lubricant supply passage.

[0078] A gas turbine according to a seventh aspect of this disclosure, in the fifth or sixth aspect, comprises a combustor for burning a mixture of air and fuel; a generator located forward of the combustor in the gas turbine and connected to the rotating shaft; an outer shell housing the rotating shaft, the third bearing, the fourth bearing, the housing, the outer member, the generator and the combustor; an inner shell located radially outward of the housing within the outer shell; and a strut connecting the outer shell and the inner shell and extending radially between the generator and the combustor, wherein the third bearing burns a mixture of air and fuel. The fourth bearing is located in the rearward direction of the turbine and in the forward direction of the combustor, and the outer member includes the portion of the inner shell located radially inward of the axis relative to the strut and extends in the circumferential direction, the first lubricant space is a space extending in the circumferential direction, and the lubricant supply passage may be configured to include a first lubricant supply passage that extends through the strut and communicates with the first lubricant space, and a second lubricant supply passage that extends through the strut at a position forward of the first lubricant supply passage and communicates with the second lubricant space.

[0079] According to the seventh embodiment, lubricant can be supplied to a third bearing located behind the generator and to a fourth bearing located in front of the generator. Since the third bearing is located closer to the combustor than the fourth bearing, it may be exposed to a higher temperature environment than the fourth bearing. Similarly, the first lubricant space may be exposed to a higher temperature environment than the second lubricant space. Since the first lubricant space has a shape that extends in the circumferential direction of the axis, it can ensure a sufficient supply of lubricant to lubricate and cool the third bearing. Since the thermal environment of the fourth bearing and the second lubricant space is not severe, the second lubricant space can ensure a sufficient supply of lubricant to lubricate and cool the fourth bearing with a small flow path cross-sectional area. Therefore, the gas turbine can be equipped with a first lubricant space and a second lubricant space having configurations corresponding to the thermal environments of the third bearing and the fourth bearing, respectively. Furthermore, since the first lubricant space, the second lubricant space, the first lubricant supply passage and the second lubricant supply passage are formed by the housing, an outer member constituting part of the inner shell, and a strut, they can be realized with a simple structure.

[0080] All ordinal numbers, quantities, and other figures used herein are illustrative to illustrate the technology of this disclosure, and this disclosure is not limited to such illustrative figures. The connections between components are illustrative to illustrate the technology of this disclosure, and the connections that realize the functions of this disclosure are not limited to these.

[0081] This disclosure can be implemented in various ways without departing from the scope of its essential features, and the scope of this disclosure is defined more by the appended claims than by the description in the specification; therefore, exemplary embodiments and modifications are illustrative and not limiting. All modifications within the claims and their scope, or equivalents within the claims and their scope, are intended to be encompassed by the claims. [Explanation of symbols]

[0082] 1 Gas turbine, 2 Rotating shaft, 4 Compressor, 5 Combustor, 6 Turbine, 7 Generator, 8A Outer shell, 8B Inner shell, 11 Strut housing, 11d Strut, 20Aa, 20Ab Low-pressure bearing (4th bearing), 20Ba 1st high-pressure bearing (1st bearing, 3rd bearing), 20Ca 1st generator bearing (4th bearing), 20Cb 2nd generator bearing (2nd bearing), 30A 1st bearing housing, 102 1st lubricant supply passage, 103 2nd lubricant supply passage, 104 1st lubricant space, 105 2nd lubricant space, 111 1st lubricant hole (1st lubricant hole, 3rd lubricant hole), 112 2nd lubricant hole, 113-115 3rd-5th lubricant holes (4th lubricant hole).

Claims

1. A gas turbine, A combustor that burns a mixture of air and fuel, A rotating shaft that extends in the axial direction and to which rotor blades are connected, A generator located in the forward direction of the gas turbine from the combustor and connected to the rotating shaft, A first bearing supports the rotating shaft from the radially outward direction of the axis, A second bearing is located away from the first bearing in the axial direction and supports the rotating shaft from the radially outward direction, A housing that supports the first and second bearings from the radially outward direction and extends in the circumferential direction of the axis, An outer member located radially outward from the housing and connected to the housing, In the portion where the housing and the outer member are connected, a first lubricant space is defined by the housing and the outer member, A second lubricant space located axially away from the first lubricant space and included in the wall of the housing, comprising: A lubricant supply passage through which the lubricant supplied to the first lubricant space and the second lubricant space flows, A first lubricant hole extends from the first lubricant space through at least one of the housing and the outer member and opens toward the first bearing, A second lubricant hole extends from the second lubricant space through the housing and opens toward the second bearing, The rotating shaft, the first bearing, the second bearing, the housing, the outer member, the generator, and the combustor are housed in an outer shell, Within the outer shell, there is an inner shell located radially outward relative to the housing, The system includes a strut that connects the outer shell and the inner shell and extends radially at a position between the generator and the combustor, The first bearing is located in the rearward direction of the gas turbine relative to the generator and in the forward direction of the combustor, The second bearing is located in the forward direction relative to the generator. The outer member includes the portion of the inner shell located radially inward from the axis with respect to the strut, and extends in the circumferential direction. The first lubricant space is a space that extends in the circumferential direction, The lubricant supply passage includes a first lubricant supply passage that extends through the strut and communicates with the first lubricant space, and a second lubricant supply passage that extends through the strut at a position further forward than the first lubricant supply passage and communicates with the second lubricant space. Gas turbine.

2. The first lubricant supply passage extends radially through the strut and communicates with the first lubricant space. The gas turbine according to claim 1.

Images