A turboshaft engine

Abstract

The application provides a turboshaft engine and belongs to the technical field of engines.The turboshaft engine comprises a gas turbine, a power turbine, a transmission device, a second speed reducer, a main transmission shaft and a transmission sleeve.The transmission device comprises an accessory gear train and a first speed reducer.The first speed reducer, the power turbine and the second speed reducer are sequentially connected in transmission through the main transmission shaft.The transmission sleeve is rotatably installed on the outside of the main transmission shaft, and the main transmission shaft is coaxial with the transmission sleeve.The accessory gear train and the gas turbine are fixedly installed on the transmission sleeve, and the accessory gear train is located on the side of the gas turbine close to the first speed reducer.The main transmission shaft and the transmission sleeve of the application adopt concentric output, which reduces the aircraft profile size, reduces the windward area and is beneficial to the aerodynamic shape design of the aircraft.The main transmission shaft and the transmission sleeve make the structure layout of the turboshaft engine compact compared with the same power level turboshaft engine with the existing configuration, which is beneficial to reducing the weight of the engine.

Description

Technical Field

[0001] This invention belongs to the field of engine technology, and specifically relates to a turboshaft engine. Background Technology

[0002] Turboshaft engines, also known as gas turbine shaft engines, are primarily used in helicopters, but can also be used in tanks, ships, and ground-based power stations. Structurally, a turboshaft engine includes a compressor, combustion chamber, gas turbine, power turbine, and accessory drive system. At the same power level, excessively large engine dimensions and frontal area increase aerodynamic design complexity and drag, while excessive weight increases overall aircraft tonnage or reduces payload. Therefore, reducing engine size and weight is particularly important in the design of small to medium power turboshaft engines.

[0003] Meanwhile, traditional turboshaft engines use front-output or rear-output turbine shafts, which can only directly drive one load. With the increasing number of electronic devices on modern aircraft and the growing demand for electricity, traditional turboshaft engines use accessory drives to rotate small AC generators, which have limited power output. If a turbine shaft were used to drive the generator, the engine would become a gas turbine, and the turbine would not directly drive the helicopter's gearbox and rotor, leading to a decrease in the overall system efficiency of the helicopter.

[0004] In summary, existing turboshaft engines have the following drawbacks:

[0005] 1. Large overall dimensions and large frontal area are not conducive to aircraft aerodynamic design;

[0006] 2. The structural layout is not very compact, which is not conducive to reducing the overall weight of the engine;

[0007] 3. Engine power output, whether front-end or rear-end, can only directly drive one load. The power turbine cannot simultaneously drive the transmission system and generator, which is not conducive to improvement, modification, or serialization.

[0008] Therefore, a small, compact turboshaft engine capable of driving multiple loads is needed. Summary of the Invention

[0009] To address the aforementioned problems, this invention proposes a turboshaft engine, comprising a gas turbine, a power turbine, a transmission device, a second reducer, a main drive shaft, and a transmission sleeve.

[0010] The transmission device includes an accessory gear train and a first reducer, wherein the first reducer, the power turbine, and the second reducer are sequentially connected via a main drive shaft.

[0011] The transmission sleeve is rotatably mounted on the outside of the main drive shaft, and the main drive shaft and the transmission sleeve are coaxial; the transmission sleeve is located between the first reducer and the power turbine, and an accessory gear system and a gas turbine are fixedly mounted on the transmission sleeve, with the accessory gear system located on the side of the gas turbine closer to the first reducer.

[0012] Furthermore, the gas turbine includes a gas generator rotor, which includes a compressor rotor and a gas turbine rotor fixedly mounted on the outer surface of the transmission sleeve, with the compressor rotor located at the end of the gas turbine rotor closer to the transmission device.

[0013] Furthermore, the power turbine includes a power turbine rotor, which is fixedly mounted on the main drive shaft and is located on the side of the gas turbine rotor away from the compressor rotor.

[0014] Furthermore, the first reducer includes a first compensation shaft that is driven to the main drive shaft and a first output gear disposed on the outer surface of the first compensation shaft.

[0015] Furthermore, the first compensation shaft and the main drive shaft are connected by a floating shaft transmission. A limit ring is provided in the groove on the outer wall of the first compensation shaft, and the limit ring is engaged in the groove on the inner wall of the floating shaft.

[0016] Furthermore, a spline is provided on the outer wall of the first compensation shaft near the end of the floating shaft, and a keyway that mates with the spline is provided on the inner wall of the floating shaft, with the spline installed in the keyway.

[0017] Furthermore, the accessory gear system includes an accessory gear disposed on the transmission sleeve, the accessory gear being located between the first reducer and the gas turbine.

[0018] Furthermore, the second reducer includes a second reducer rotor, the second reducer rotor includes a second compensation shaft, the second compensation shaft is connected to the end of the main drive shaft away from the transmission device via a floating shaft, and a second output gear is provided on the second compensation shaft.

[0019] Furthermore, the turboshaft engine also includes an intake casing, an outer casing, and a stator structure connected in sequence. The end of the intake casing away from the outer casing is connected to a transmission device. A combustion chamber and a compressor are disposed inside the outer casing, with the compressor's inlet communicating with the intake casing, and the compressor located between the intake casing and the combustion chamber. An exhaust device communicating with the combustion chamber's exhaust port is disposed on the outer surface of the outer casing, with the exhaust outlet of the exhaust device located on the side of the combustion chamber away from the compressor. The outer casing is located outside the gas turbine and the power turbine, and the stator structure is located outside the second reduction gear. Furthermore, several through holes are provided on the outer surface of the intake casing.

[0020] Beneficial effects:

[0021] 1. The main drive shaft and drive sleeve of the present invention adopt concentric output, which reduces the aircraft's external dimensions and frontal area, and is beneficial to the aircraft's aerodynamic shape design; the use of the main drive shaft and drive sleeve makes the turboshaft engine of the present invention have a compact structural layout compared with existing turboshaft engines of the same power level, which is beneficial to reducing the overall weight of the engine.

[0022] 2. The power turbine of the present invention is connected to the first reducer and the second reducer through a transmission sleeve. Therefore, the power generated by the power turbine can be transmitted to the load simultaneously through the power output shafts on the first reducer and the second reducer, so that one engine can drive two loads at the same time. At the same time, both the first reducer and the second reducer adopt a unit structure design. After removing one of the reducers, the engine becomes a front-output (or rear-output) turboshaft engine.

[0023] 3. This invention adopts a modular structure design. Without changing the compressor, combustion chamber, and turbines (gas turbine and power turbine), it can be modified into a turboprop engine or hybrid system as needed, facilitating serialization and development. The interfaces between the components of this invention are clear, which helps to rationally divide the unit and improve engine maintainability.

[0024] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of the turboshaft engine in an embodiment of the present invention is shown.

[0027] Figure 2 A partial structural schematic diagram of a turboshaft engine in an embodiment of the present invention is shown.

[0028] Figure 3 A schematic diagram of the intake casing of a turboshaft engine in an embodiment of the present invention is shown.

[0029] Figure 4 A schematic diagram of the structure of the floating shaft connecting the first compensation shaft and the main drive shaft of the turboshaft engine in an embodiment of the present invention is shown.

[0030] In the diagram, 1. Intake casing; 101. Through hole; 2. Compressor; 3. Combustion chamber; 4. Gas turbine; 40. Gas generator rotor; 41. Compressor rotor; 42. Gas turbine rotor; 5. Power turbine; 50. Power turbine rotor; 6. Exhaust device; 61. Exhaust outlet; 7. Transmission device; 70. Accessory gear train; 71. Accessory gear; 30. First reducer; 31. First compensating shaft; 32. First output gear; 8. Second reducer; 80. Second reducer rotor; 81. Second compensating shaft; 82. Second output gear; 9. Bearing system; 91. First bearing; 92. Second bearing; 93. Third bearing; 94. Fourth bearing; 95. Fifth bearing; 96. Sixth bearing; 10. Stator structure; 11. Floating shaft; 12. Limiting retaining ring; 13. Housing; 141. Main drive shaft; 142. Transmission sleeve; 15. Spline. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] refer to Figure 1 A turboshaft engine includes a gas turbine 4, a power turbine 5, a transmission device 7, a second reducer 8, a main drive shaft 141, and a transmission sleeve 142. The transmission device 7 includes an accessory gear system 70 and a first reducer 30. The first reducer 30, the power turbine 5, and the second reducer 8 are connected by transmission through the main drive shaft 141. The accessory gear system 70 and the gas turbine 4 are connected by transmission through the transmission sleeve 142, and the accessory gear system 70 and the gas turbine 4 are located between the first reducer 30 and the power turbine 5. The transmission sleeve 142 is rotatably mounted on the outside of the main drive shaft 141, and the main drive shaft 141 and the transmission sleeve 142 are coaxial.

[0033] In the above embodiments, another optional implementation is that the transmission sleeve 142 is rotatably mounted on the outside of the main drive shaft 141, and the main drive shaft 141 and the transmission sleeve 142 are coaxial; the transmission sleeve 142 is located between the first reducer 30 and the power turbine 5, and an accessory gear system 70 and a gas turbine 4 are fixedly mounted on the transmission sleeve 142, and the accessory gear system 70 is located on the side of the gas turbine 4 closer to the first reducer 30.

[0034] Specifically, the present invention provides a compact turboshaft engine having a gas turbine 4 and a power turbine 5. The power generated by the power turbine 5 can be simultaneously transmitted to a load through the power output shafts on the first reducer 30 and the second reducer 8, enabling one engine to drive two loads simultaneously. Both the first reducer 30 and the second reducer 8 adopt a modular design. By eliminating one of the reducers, the engine becomes a front-output (or rear-output) turboshaft engine.

[0035] In this invention, the power generated by the power turbine 5 is output through the output shafts of the first reducer 30 and the second reducer 8. This overall layout and the structural integration between components can effectively improve the compactness of the engine structure, reduce the overall external dimensions and frontal area of ​​the engine, and have excellent scalability.

[0036] In the above embodiment, another optional implementation is that the gas turbine 4 includes a gas generator rotor 40, the gas generator rotor 40 includes a compressor rotor 41 and a gas turbine rotor 42 disposed on the transmission sleeve 142, and the compressor rotor 41 is located at the end of the gas turbine rotor 42 near the transmission device 7.

[0037] Specifically, the accessory gear train 70 and the first reducer 30 are arranged at the front end of the intake casing 1. The gas generator rotor 40 includes a compressor rotor 41 and a gas turbine rotor 42. The gas generator rotor 40 is connected to the accessory gear train 70 via a transmission sleeve 142 and an accessory gear 71 to transmit engine power to the accessory gear train 70, which needs to extract power from the engine.

[0038] In a specific embodiment, the power turbine 5 includes a power turbine rotor 50, which is fixedly mounted on the main drive shaft 141 and is located on the side of the gas turbine rotor 42 away from the compressor rotor 41. Specifically, the power turbine rotor 50 is driven to rotate by gas combustion, which in turn drives the first reducer 30 and the second reducer 8 to rotate, thereby providing power.

[0039] Furthermore, the first reducer 30 includes a first compensation shaft 31 that is driven by the main drive shaft 141 and a first output gear 32 disposed on the first compensation shaft 31. Specifically, the first reducer 30 outputs power through the output shaft. The first compensation shaft 31 and the main drive shaft 141 are driven by a floating shaft 11. A limiting ring 12 is disposed in a groove on the outer wall of the first compensation shaft 31, and the limiting ring 12 is engaged in a groove on the inner wall of the floating shaft 11. The limiting ring 12 is used to limit the first compensation shaft 31, thereby preventing the first compensation shaft 31 from disengaging from the floating shaft 11.

[0040] Furthermore, a spline 15 is provided on the outer wall of the first compensation shaft 31 near the floating shaft 11, and a keyway that mates with the spline 15 is provided on the inner wall of the floating shaft 11, with the spline 15 installed in the keyway.

[0041] Specifically, the connection between the main drive shaft 141 and the first compensation shaft 31, the connection between the main drive shaft 141 and the second compensation shaft 81, the connection between the output shaft of the first reducer 30 and the front load, and the connection between the output shaft of the second reducer 8 and the rear load are all connected by floating shafts 11.

[0042] Taking the main drive shaft 141 and the first compensation shaft 31 as an example, such as Figure 4 As shown, torque is transmitted between the main drive shaft 141 and the floating shaft 11 via a spline 15, and torque is also transmitted between the floating shaft 11 and the first compensation shaft 31 via a spline 15. The retaining ring 12 serves as an axial retainer. This achieves dynamic decoupling between the rotors, reducing rotor vibration response, and is adaptable to various types of loads (including but not limited to load compressor 2, load generator, helicopter transmission system, etc.). The cost of the floating shaft 11 is significantly lower than that of traditional couplings.

[0043] refer to Figure 2 The accessory gear system 70 includes an accessory gear 71 mounted on the transmission sleeve 142, located between the first reducer 30 and the gas turbine 4. The accessory gear 71 transmits power to the accessory gear system 70, which in turn outputs power to the accessory mechanism.

[0044] refer to Figure 2 The second reducer 8 includes a second reducer rotor 80, which includes a second compensating shaft 81. The second compensating shaft 81 is connected to the end of the main drive shaft 141 away from the transmission device 7 via a floating shaft 11. A second output gear 82 is provided on the second compensating shaft 81. The second reducer 8 is located at the rear end of the power turbine 5.

[0045] Specifically, both the first reducer 30 and the second reducer 8 adopt a unit structure. The engine's output speed can be customized according to user needs, and the power output position can be changed (power can be output to the front, power to the rear, or power can be output to both front and rear simultaneously).

[0046] refer to Figure 1The turboshaft engine also includes an intake casing 1, an outer casing 13, and a stator structure 10 connected in sequence. The end of the intake casing 1 away from the outer casing 13 is connected to a transmission device 7. The combustion chamber 3 and a compressor 2 are disposed inside the outer casing 13. The air inlet of the compressor 2 is connected to the intake casing 1, and the compressor 2 is located between the intake casing 1 and the combustion chamber 3. An exhaust device 6 is disposed on the outer surface of the outer casing 13, which is connected to the exhaust port of the combustion chamber 3. The exhaust outlet 61 of the exhaust device 6 is located on the side of the combustion chamber 3 away from the compressor 2. The outer casing 13 is located outside the gas turbine 4 and the power turbine 5, and the stator structure 10 is disposed outside the second reducer 8. Further, the exhaust device 6 adopts a configuration without support plates and with exhaust on both sides. The exhaust device 6 is provided with an exhaust outlet 61, which is cyclically symmetrical with respect to the engine axis. The compressor 2 adopts a single-stage centrifugal structure to reduce the number of parts. At the same time, taking advantage of the high surge margin of the centrifugal compressor 2, the engine anti-surge bleed-out related structure is eliminated.

[0047] Specifically, the turboshaft engine, in the order of airflow, comprises a compressor 2, a combustion chamber 3, a gas turbine 4, a power turbine 5, and an exhaust system 6. The engine's structural features are described in [reference needed]. Figure 1 Among other systems or features, alternative engines may also include, for example, eccentric compensation shafts, inter-component adapters, or components in different configurations.

[0048] refer to Figure 3 The air intake casing 1 has multiple through holes 101 on its outer surface. The air intake casing 1 uses a radial air intake design (air intake through the through holes 101). The airflow first enters the flow channel of the air intake casing 1 through an inlet at a large angle to the engine axis, and then deflects approximately 90° before entering the compressor 2. The air intake casing 1 has through holes 101 for air intake, and the compressor 2 has no internal support plates. This design simplifies the structure, reduces size and weight, and lowers assembly difficulty. The shape of the air intake casing 1 can be adjusted according to the aircraft's air intake design to meet the needs of different aircraft.

[0049] Further, refer to Figure 2 The turboshaft engine also includes a bearing system 9, which comprises a first bearing 91, a second bearing 92, a third bearing 93, a fourth bearing 94, a fifth bearing 95, and a sixth bearing 96. The outer rings of the first bearing 91, second bearing 92, third bearing 93, fourth bearing 94, fifth bearing 95, and sixth bearing 96 are all installed inside the housing 13, the stator structure 10, and the transmission device 7. The inner rings of the first bearing 91, second bearing 92, third bearing 93, fourth bearing 94, fifth bearing 95, and sixth bearing 96 are all installed on the outer surface of the main drive shaft 141. The first bearing 91, second bearing 92, and third bearing 93 are located in the same oil chamber. This shared-cavity design for the bearings and gears requiring lubrication reduces the number of oil chambers, simplifies the structure, and lowers costs. Figure 2 The first bearing 91, the first output gear 32, the second bearing 92, the accessory gear 71, and the third bearing 93 share a common cavity; the fourth bearing 94 and the fifth bearing 95 share a common cavity; and the sixth bearing 96 and the second output gear 82 share a common cavity. Specifically, the first compensating shaft 31, the intake casing 1, the gas turbine 4, and the second compensating shaft 81 are mounted on the housing 13 and the stator structure 10 via several bearing systems 9 and rotate relative to the engine axis A. It should be understood that the various bearing systems 9 located at different positions can be provided alternatively or additionally.

[0050] Working principle:

[0051] Air is rectified through the through-hole 101 of the intake casing 1 and enters the compressor 2. The compressor 2 drives the air along the flow channel to compress it and connect it to the combustion chamber 3. The air mixes and burns with fuel in the combustion chamber 3 to form high-temperature and high-pressure gas. The gas turbine 4 extracts energy from the gas and drives the rotor of the gas turbine 4 and the compressor 2 to rotate continuously, thereby driving the accessory gear system 70 and driving related accessories (including but not limited to the lubricating oil pump and fuel pump). The power turbine 5 extracts energy from the gas and drives the power turbine rotor 50, the first reducer 30 and the second reducer 8 to rotate. The exhaust device 6 rectifies the gas after the power turbine 5 and discharges it at a certain angle to the engine axis.

[0052] The structural form of this invention can be extended from the field of turboshaft engines to other aero engines, ground gas turbines, shipboard turbine engines, and hybrid systems. The interfaces between the components of this invention are clear, facilitating the rational division of unit modules and improving engine maintainability. The engine adopts a unit-module structure design; with the compressor 2, combustion chamber 3, and turbines (gas turbine 4 and power turbine 5) remaining unchanged, it can be modified into a turboprop engine or hybrid system as needed, facilitating serialization and development.

[0053] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A turboshaft engine, characterized in that, It includes a gas turbine (4), a power turbine (5), a transmission device (7), a second reducer (8), a main drive shaft (141), and a transmission sleeve (142). The transmission device (7) includes an accessory gear train (70) and a first reducer (30). The first reducer (30), the power turbine (5), and the second reducer (8) are sequentially connected by a main drive shaft (141). The transmission sleeve (142) is rotatably mounted on the outside of the main drive shaft (141), and the main drive shaft (141) and the transmission sleeve (142) are coaxial; the transmission sleeve (142) is located between the first reducer (30) and the power turbine (5), and an accessory gear system (70) and a gas turbine (4) are fixedly mounted on the transmission sleeve (142), and the accessory gear system (70) is located on the side of the gas turbine (4) closer to the first reducer (30); The first reducer (30) includes a first compensation shaft (31) that is connected to the main drive shaft (141) and a first output gear (32) disposed on the outer surface of the first compensation shaft (31). The first compensation shaft (31) and the main drive shaft (141) are connected by a floating shaft (11). A limit ring (12) is provided in the groove of the outer wall of the first compensation shaft (31), and the limit ring (12) is engaged in the groove of the inner wall of the floating shaft (11). The second reducer (8) includes a second reducer rotor (80), the second reducer rotor (80) includes a second compensation shaft (81), the second compensation shaft (81) is connected to the end of the main drive shaft (141) away from the transmission device (7) through a floating shaft (11), and a second output gear (82) is provided on the second compensation shaft (81).

2. A turboshaft engine according to claim 1, characterized in that, The gas turbine (4) includes a gas generator rotor (40), which includes a compressor rotor (41) and a gas turbine rotor (42) fixedly mounted on the outer surface of the transmission sleeve (142). The compressor rotor (41) is located at one end of the gas turbine rotor (42) near the transmission device (7).

3. A turboshaft engine according to claim 2, characterized in that, The power turbine (5) includes a power turbine rotor (50), which is fixedly mounted on the main drive shaft (141) and is located on the side of the gas turbine rotor (42) away from the compressor rotor (41).

4. A turboshaft engine according to claim 1, characterized in that, A spline (15) is provided on the outer wall of the first compensation shaft (31) near the floating shaft (11), and a keyway that mates with the spline (15) is provided on the inner wall of the floating shaft (11), and the spline (15) is installed in the keyway.

5. A turboshaft engine according to claim 1, characterized in that, The accessory gear system (70) includes an accessory gear (71) disposed on the transmission sleeve (142), the accessory gear (71) being located between the first reducer (30) and the gas turbine (4).

6. A turboshaft engine according to claim 1, characterized in that, The turboshaft engine also includes an intake casing (1), an outer casing (13), and a stator structure (10) connected in sequence. The end of the intake casing (1) away from the outer casing (13) is connected to the transmission device (7). The outer casing (13) is provided with a combustion chamber (3) and a compressor (2) that are connected in the middle. The air inlet of the compressor (2) is connected to the intake casing (1), and the compressor (2) is located between the intake casing (1) and the combustion chamber (3). An exhaust device (6) connected to the exhaust port of the combustion chamber (3) is provided on the outer surface of the outer casing (13). The exhaust outlet (61) of the exhaust device (6) is located on the side of the combustion chamber (3) away from the compressor (2). The outer casing (13) is located outside the gas turbine (4) and the power turbine (5), and the stator structure (10) is located outside the second reducer (8).

7. A turboshaft engine according to claim 6, characterized in that, The outer surface of the air intake casing (1) is provided with several through holes (101).

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