A cooling and lubricating system for a nested drive shaft of a turboshaft engine

Abstract

This application discloses a cooling and lubrication system for a nested driveshaft of a turboshaft engine. The driveshaft includes a drive spindle, with a drive sleeve shaft fitted around it. A return oil channel is provided between the drive spindle and the drive sleeve shaft. A cooling and lubricating device is installed inside the burner. One end of the return oil channel is connected to the cooling and lubricating device, and the other end is connected to a reducer. A pump unit and an oil tank are fixedly installed on the reducer. The oil tank is connected to the reducer. The drive input end of the pump unit is connected to the driveshaft, the oil suction end of the pump unit is connected to the oil tank, and the oil outlet end of the pump unit is connected to the cooling and lubricating device. A negative pressure pipe is also provided between the reducer and the tailpipe. The advantages of this application are a compact structure, high-efficiency cooling and lubrication, good power coordination, and convenient maintenance of the nested driveshaft cooling and lubrication system.

Description

Technical Field

[0001] This application belongs to the field of turboshaft engine lubrication technology, and in particular relates to a cooling and lubrication system for a nested drive shaft of a turboshaft engine. Background Technology

[0002] As the core power unit of equipment such as helicopters and small unmanned aerial vehicles, the driveshaft system of turboshaft engines plays a crucial role in power transmission, directly affecting the engine's operational stability and service life. With the development of turboshaft engines towards higher power and higher speeds, the working environment of the driveshaft is becoming increasingly harsh. It not only needs to withstand large torque and speed loads but also faces high-temperature radiation from the combustor region, thus placing extremely high demands on the cooling and lubrication performance of the driveshaft.

[0003] To ensure reliable operation of the driveshaft, existing turboshaft engines typically employ a cooling and lubrication system, using circulating lubricating oil to cool and lubricate the driveshaft. Currently, most mainstream driveshaft cooling and lubrication systems adopt a single-shaft structure with an external cooling and lubrication circuit, meaning the cooling and lubrication components are separate from core components such as the burner and reducer. However, this design has several shortcomings in practical applications: First, the lubrication path of a single-shaft driveshaft is limited, making it difficult for lubricating oil to fully cover all working areas of the driveshaft, especially in high-temperature areas where insufficient cooling and lubrication can occur, leading to localized overheating of the driveshaft and accelerated component wear. Second, the external cooling and lubrication circuit has a complex piping layout and a long lubricating oil delivery path, increasing the overall size and weight of the system and causing lubricating oil pressure loss and temperature rise, reducing cooling and lubrication efficiency. Third, existing systems often use independent motor-driven pumps, requiring additional power, and the motor and driveshaft are interconnected. The system has poor coordination and it is difficult to adjust the lubricating oil supply in real time according to the operating conditions of the drive shaft, resulting in energy waste or insufficient supply. Fourth, the lubricating oil is prone to mixing with impurities and air bubbles during circulation. The existing filtration and defoaming structure design is not perfect. Impurities will aggravate the wear of the drive shaft and bearings, while air bubbles will affect the cooling and lubrication effect of the lubricating oil and even cause cavitation damage. Fifth, for some turboshaft engines that use nested drive shafts, the existing cooling and lubrication system does not have a dedicated return channel designed for its nested structure. The lubricating oil is prone to accumulate between the core shaft and the sleeve shaft, resulting in poor return flow and further deteriorating the cooling and lubrication effect.

[0004] Furthermore, the layout and maintenance design of the oil tank in existing cooling and lubrication systems are not rational enough. They often fail to fully utilize gravity for natural oil collection, increasing the difficulty of oil suction for the pump unit. Simultaneously, the lack of convenient level monitoring and impurity filtration structures makes it difficult for operators to monitor the oil status in real time. Impurities in the oil can easily enter precision components such as the pump unit and injectors, causing component failures. Additionally, the design of the drive shaft and support bearings is imperfect, easily leading to coaxiality deviations under high-speed operation, resulting in increased vibration and further affecting the uniform distribution of the cooling and lubricating medium, creating a vicious cycle.

[0005] In summary, the existing turboshaft engine driveshaft cooling and lubrication systems have significant shortcomings in terms of structural layout, cooling and lubrication efficiency, power coordination, and ease of maintenance. They are difficult to adapt to the stringent operating requirements of the nested driveshafts of high-power turboshaft engines, thus hindering the improvement of the overall performance of turboshaft engines.

[0006] Therefore, we need to design a cooling and lubrication system for the nested drive shaft of a turboshaft engine to solve these problems. Application content

[0007] This application provides a nested drive shaft cooling and lubrication system that is compact in structure, highly efficient in cooling and lubrication, has good power coordination, and is easy to maintain.

[0008] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0009] A cooling and lubrication system for a nested drive shaft of a turboshaft engine is disclosed. The turboshaft engine includes a reducer, a compressor, a burner, and a tail nozzle. The reducer and the burner are both fixedly connected to the compressor, and the input end of the burner is connected to the output end of the compressor. The tail nozzle is fixed to the output end of the burner. The reducer, compressor, and burner are linked together via a drive shaft. The drive shaft includes a drive spindle, and a drive sleeve is fitted around the drive spindle. A return oil channel is provided between the drive spindle and the drive sleeve. A cooling and lubricating device is installed inside the burner. One end of the return oil channel is connected to the cooling and lubricating device, and the other end is connected to the reducer. A pump unit and an oil tank are fixedly installed on the reducer. The oil tank is connected to the reducer. The drive input end of the pump unit is connected to the drive shaft. The oil suction end of the pump unit is connected to the oil tank. The oil outlet end of the pump unit is connected to the cooling and lubricating device. A negative pressure pipe is also provided between the reducer and the tail nozzle.

[0010] Preferably, a drive gear is fixedly mounted on the transmission sleeve shaft located inside the reducer, and a driven gear is rotatably mounted on the inner wall of the reducer on one side of the drive gear. The driven gear meshes with the drive gear, and a transmission gear is fixedly mounted on the driven gear. An oil pump gear is rotatably mounted on the inner wall of the reducer on one side of the transmission gear. The oil pump gear meshes with the transmission gear, and the drive input end of the pump unit is connected to the transmission shaft through the oil pump gear.

[0011] This configuration, through a multi-stage gear meshing transmission structure within the reducer—comprising drive gears, driven gears, transmission gears, and oil pump gears—achieves indirect linkage between the pump unit's drive input and the transmission shaft. This multi-stage gear transmission design not only converts the high-speed rotation of the transmission shaft into a speed suitable for the pump unit's operation, but also precisely matches the pump unit's flow output requirements by adjusting the transmission ratio of each gear, ensuring that the supply of cooling and lubricating medium is compatible with the engine's workload. Furthermore, the gear meshing transmission structure features high transmission efficiency and stable, reliable operation, adapting to the complex spatial layout within the reducer. It eliminates the need for an additional drive motor, simplifying the system structure and reducing overall weight and energy consumption.

[0012] Preferably, a filter screen and several oil injectors are provided inside the cooling lubricator. The several oil injectors are evenly distributed around the circumference of the cooling lubricator. The oil outlet end of the pump unit is provided with a lubricating oil supply pipe. The free end of the lubricating oil supply pipe is connected to several lubricating oil input pipes. The free ends of the several lubricating oil input pipes are connected to the several oil injectors one by one.

[0013] This design allows the internal filter of the coolant / lubricant to effectively filter the cooling / lubricating medium delivered by the pump, removing impurities and preventing them from entering the clearance between the drive shaft and the support structure. This reduces component wear and extends the service life of both the drive shaft and the coolant / lubricant. The design of several injectors evenly distributed around the circumference of the coolant / lubricant allows the cooling / lubricating medium to be sprayed evenly onto the outer surface of the drive shaft in a multi-beam flow pattern, achieving comprehensive, all-around cooling and lubrication, significantly improving the coverage and effectiveness of cooling and lubrication. Simultaneously, the lubricating oil supply pipe at the pump's outlet is connected to each injector via multiple lubricating oil input pipes, ensuring the stability of the medium supply pressure and flow rate for each injector and preventing localized insufficient cooling and lubrication.

[0014] Preferably, the lubricating oil tank is located at the bottom of the reducer, and a filling port, an observation window and a filter are provided on the lubricating oil tank. The filling port and the observation window are both located on the side wall of the lubricating oil tank, the filter is located at the bottom of the lubricating oil tank, and the input end of the filter is connected to the lubricating oil tank, and the output end is connected to the oil suction end of the pump unit through an oil suction pipe.

[0015] This design, placing the oil tank at the bottom of the reducer, allows the cooling and lubricating medium to naturally collect within the tank due to gravity. This facilitates the pump unit's suction of the medium through the suction pipe, improving the pump unit's oil suction efficiency. A filling port on the side wall of the oil tank allows for easy replenishment and replacement of the cooling and lubricating medium by operators, while an observation window enables real-time visual monitoring of the medium level within the tank, facilitating timely detection of leaks or losses. A filter at the bottom of the oil tank provides secondary filtration of the medium returning to the tank, further purifying it and preventing impurities generated during circulation from re-entering the system. This effectively ensures the normal operation of precision components such as the pump unit and injectors, improving the reliability and service life of the entire cooling and lubrication system.

[0016] Preferably, an antifoamer is also provided between the oil outlet of the pump unit and the lubricating oil supply pipe.

[0017] This configuration, with a defoamer installed between the pump unit's oil outlet and the lubricating oil supply pipe, effectively removes bubbles generated during high-pressure transport of the cooling and lubricating medium. A large number of bubbles in the medium can lead to unstable flow patterns in the injector, reducing cooling and lubrication efficiency. Furthermore, the bursting of bubbles under high pressure can cause cavitation damage to pipelines and components. The defoamer ensures that the medium entering the lubricating oil supply pipe is a pure, bubble-free flow, guaranteeing the injector's spray effect and the safe operation of the pipeline system, further enhancing the stability and reliability of the cooling and lubrication system.

[0018] Preferably, an inner support bearing and an outer support bearing are provided inside both the reducer and the coolant / lubricator. The transmission spindle is rotatably connected to the reducer and the coolant / lubricator through the inner support bearing, and the transmission sleeve shaft is rotatably connected to the reducer and the coolant / lubricator through the outer support bearing.

[0019] This configuration, with inner and outer support bearings respectively installed inside the reducer and cooling lubricator, provides rotational support for the drive spindle via the inner support bearing and the drive sleeve shaft via the outer support bearing. This dual-bearing support structure achieves layered independent support for the nested drive shaft. The inner and outer support bearings not only ensure the coaxiality of the drive spindle and drive sleeve shaft during high-speed rotation, reducing vibration and uneven wear, but also provide additional lubrication for the drive shaft's rotation through the bearing's lubrication structure. Furthermore, the layered support design makes the stress on the drive shaft more even, effectively reducing the load on individual bearings, extending bearing life, and ensuring stable and reliable operation of the nested drive shaft under complex working conditions.

[0020] Preferably, the compressor includes a housing and a compressor impeller, the compressor impeller being located inside the housing and fixedly connected to the drive shaft passing through the housing.

[0021] This configuration places the compressor impeller inside the compressor housing and fixes it to the drive shaft passing through the housing, achieving direct linkage between the drive shaft and the compressor. This structural design allows the compressor impeller's rotational power to come directly from the drive shaft, eliminating the need for an additional transmission mechanism, simplifying the connection between the compressor and the drive shaft, and improving power transmission efficiency. Simultaneously, the housing effectively protects the compressor impeller, preventing external impurities from entering the compressor and affecting its rotation. Furthermore, the housing's flow channel design guides airflow along a predetermined path, improving compressor compression efficiency and ensuring optimal engine intake performance.

[0022] Preferably, the burner includes a combustion chamber, the cooling lubricator is located in the combustion chamber, and a gas impeller is also provided in the combustion chamber on one side of the cooling lubricator. The gas impeller is fixedly connected to the transmission sleeve shaft passing through the combustion chamber.

[0023] This configuration places both the cooling lubricator and the gas impeller inside the burner's combustion chamber, with the gas impeller fixedly connected to the drive shaft passing through the combustion chamber, achieving an integrated layout of key components within the combustion chamber. The gas impeller is directly driven by the drive shaft, enabling rapid response to changes in shaft speed and ensuring efficient conversion and utilization of the gas expansion energy within the combustion chamber. Simultaneously, the cooling lubricator, positioned adjacent to the gas impeller, cools and lubricates the drive shaft while simultaneously reducing localized temperatures within the combustion chamber through the heat absorption of the lubricating medium, preventing thermal damage to the drive shaft and the cooling lubricator from high-temperature gas. This integrated structural design not only reduces the overall size of the burner but also shortens the transmission path of the cooling lubricating medium, improving the response speed and efficiency of cooling and lubrication.

[0024] This invention achieves highly efficient cooling and lubrication of nested drive shafts through innovative design of the drive shaft structure, cooling and lubrication circuit, and key components. This significantly improves the system's operational stability and reliability, extends the service life of core components, simplifies the system structure, and reduces energy consumption. Specific beneficial effects are as follows:

[0025] 1. This invention designs the drive shaft as a nested structure of a drive spindle and a drive sleeve shaft, with a pre-reserved oil return channel between them. Combined with a cooling lubricator integrated into the burner, this creates a closed-loop lubrication circuit. This design allows the cooling and lubricating medium to directly act on the drive shaft section operating in high-temperature environments, achieving precise cooling and lubrication. Simultaneously, the dedicated oil return channel effectively avoids mixing and interference between the lubricating medium and other working media in the engine, ensuring the purity and effectiveness of the medium. Furthermore, the negative pressure pipe between the reducer and the exhaust nozzle utilizes the exhaust negative pressure from the exhaust nozzle to assist in reducing the internal pressure of the reducer, significantly improving the medium return flow efficiency within the oil return channel and ensuring stable and efficient operation of the circulation circuit under high-speed engine operation.

[0026] 2. This invention achieves indirect linkage between the pump unit and the drive shaft by incorporating a multi-stage meshing transmission structure within the reducer, consisting of a drive gear, a driven gear, a transmission gear, and an oil pump gear. This structure not only converts the high-speed rotation of the drive shaft into a speed suitable for the pump unit's operation but also precisely matches the pump unit's flow output requirements by adjusting the gear transmission ratio, ensuring real-time adaptation of the cooling and lubrication medium supply to the engine's workload. Furthermore, the gear meshing transmission offers advantages such as high transmission efficiency and stable operation, eliminating the need for an additional drive motor, effectively simplifying the system structure, reducing overall weight and energy consumption, and adapting to the complex internal spatial layout of the reducer.

[0027] 3. This invention effectively filters the delivered cooling and lubricating medium through an integrated filter screen inside the coolant / lubricator, removing impurities and particles to prevent wear on the fit between the drive shaft and the support structure, thus extending the service life of core components. Several circumferentially distributed injectors are connected one-to-one with the lubricating oil supply pipe via the lubricating oil inlet pipe, ensuring stable medium supply pressure and flow rate for each injector. This allows the cooling and lubricating medium to be evenly sprayed onto the outer surface of the drive shaft in a multi-beam flow pattern, achieving all-around, dead-angle-free cooling and lubrication, significantly improving the coverage and effectiveness of cooling and lubrication. Furthermore, an anti-foamer added between the pump outlet and the lubricating oil supply pipe effectively removes air bubbles generated during high-pressure transport, preventing unstable jet flow caused by bubbles and preventing cavitation damage to pipelines and components from bubble rupture, thus ensuring both cooling and lubrication effectiveness and pipeline system safety.

[0028] 4. This invention places the lubricating oil tank at the bottom of the reducer, utilizing gravity to allow the cooling and lubricating medium to collect naturally, significantly improving the pump's oil suction efficiency. The filling port on the side wall of the lubricating oil tank facilitates operators to replenish and replace the medium, and the observation window enables real-time visual monitoring of the liquid level, facilitating timely detection of medium leakage or loss. The filter at the bottom can perform secondary filtration of the return medium, further purifying the medium and preventing impurities generated during circulation from re-entering the system, effectively ensuring the normal operation of precision components such as the pump and injectors, and improving the system's operational reliability.

[0029] 5. This invention incorporates inner and outer support bearings within the reducer and cooling / lubricating unit, respectively. The inner support bearing provides rotational support for the transmission spindle, while the outer support bearing provides rotational support for the transmission sleeve shaft, achieving layered independent support for the nested transmission shaft. This structure ensures the coaxiality of the transmission spindle and transmission sleeve shaft during high-speed rotation, reducing vibration and uneven wear. Simultaneously, the bearings' own lubrication structure provides additional protection for the transmission shaft's rotation. Layered support ensures more even force distribution on the transmission shaft, reducing the load on individual bearings, extending bearing life, and ensuring stable and reliable operation of the nested transmission shaft under complex working conditions.

[0030] 6. This invention achieves direct power transmission through a compressor impeller located inside the casing and directly fixed to the transmission shaft, eliminating the need for an additional transmission mechanism, simplifying the connection structure, and improving power transmission efficiency. Simultaneously, the casing protects the compressor impeller from external impurities and guides airflow through the flow channel design to enhance compression efficiency. The combustion chamber integrates a cooling lubricator and a gas impeller, with the gas impeller directly fixed to the transmission shaft. This allows for rapid response to changes in the transmission shaft speed and efficient conversion and utilization of gas expansion energy. Furthermore, the cooling lubricator, positioned adjacent to the gas impeller, helps reduce localized combustion chamber temperatures through heat absorption, preventing thermal damage to core components from high-temperature gas. This integrated layout not only reduces the overall size of the burner and compressor but also shortens the cooling lubrication medium transmission path, improving cooling lubrication response speed and efficiency. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application 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 only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the main view direction of the present invention;

[0033] Figure 2 This is a cross-sectional schematic diagram of the engagement state of the transmission sleeve shaft and the transmission mandrel of the present invention;

[0034] Figure 3 This is a schematic diagram of the internal structure of the speed reducer of the present invention;

[0035] Figure 4 This is a schematic diagram of the connection structure between the oil pump gear and the transmission shaft of the present invention.

[0036] The annotations in the attached figures are explained as follows:

[0037] 1. Compressor; 101. Casing; 102. Compressor impeller; 2. Burner; 201. Combustion chamber; 202. Cooling lubricator; 203. Gas impeller; 204. Filter screen; 205. External support bearing; 206. Lubricating oil inlet pipe; 207. Injector; 208. Internal support bearing; 3. Tail nozzle; 4. Reducer; 5. Transmission sleeve shaft; 6. Transmission spindle; 7. Oil return channel; 8. Defoamer; 9. Lubricating oil supply pipe; 10. Lubricating oil tank; 11. Filling port; 12. Observation window; 13. Negative pressure pipe; 14. Drive gear; 15. Driven gear; 16. Transmission gear; 17. Oil pump gear; 18. Pump assembly; 19. Filter; 20. Suction pipe. Detailed Implementation

[0038] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0039] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0040] The following description, in conjunction with the accompanying drawings, further illustrates this application:

[0041] Example 1: As Figures 1-4As shown, a cooling and lubrication system for a nested drive shaft of a turboshaft engine is disclosed. The turboshaft engine includes a reducer 4, a compressor 1, a burner 2, and a tail nozzle 3. The reducer 4 and the burner 2 are fixedly connected to both ends of the compressor 1, forming a series arrangement along the engine axis. The input end of the burner 2 is sealed and connected to the output end of the compressor 1 to ensure that the airflow compressed by the compressor 1 can stably enter the burner 2 to participate in combustion. The tail nozzle 3 is fixed to the output end of the burner 2 to guide the exhaust gas after combustion and generate thrust. The reducer 4, compressor 1, and burner 2 are linked by a drive shaft. The drive shaft adopts a nested structure design, specifically including a drive spindle 6, with a drive sleeve shaft 5 fitted around it. An annular oil return channel 7 is reserved between the drive spindle 6 and the drive sleeve shaft 5, providing a dedicated path for the return of the cooling and lubricating medium. To achieve precise cooling and lubrication of the drive shaft in the high-temperature area, a cooling lubricator 202 is installed inside the burner 2. One end of the oil return channel 7 is connected to the oil outlet of the cooling lubricator 202, and the other end extends into the reducer 4 and communicates with the inner cavity of the reducer 4, allowing the cooling and lubricating medium to flow from the cooling lubricator 202 through the oil return channel 7 into the reducer 4. A pump set 18 and a lubricating oil tank 10 are fixedly installed on the reducer 4. The 0 is connected to the inner cavity of the reducer 4 to ensure that the cooling and lubricating medium flowing through the reducer 4 can be stored in the lubricating oil tank 10; the drive input end of the pump set 18 is connected to the transmission shaft, and the rotation of the transmission shaft provides driving force for the pump set 18; the oil suction end of the pump set 18 is connected to the lubricating oil tank 10 through the pipeline to draw the cooling and lubricating medium in the lubricating oil tank 10; the oil outlet end of the pump set 18 is connected to the oil inlet of the cooler lubricator 202 through the pipeline to form a supply circuit for the cooling and lubricating medium; at the same time, a negative pressure pipe 13 is also provided between the reducer 4 and the tail nozzle 3. One end of the negative pressure pipe 13 is connected to the inner cavity of the reducer 4, and the other end is connected to the negative pressure area of ​​the tail nozzle 3. The negative pressure generated by the exhaust of the tail nozzle 3 forms a negative pressure environment in the inner cavity of the reducer 4 to assist the return of the cooling and lubricating medium.

[0042] To achieve power transmission between the pump unit 18 and the drive shaft, a drive gear 14 is fixedly mounted on the transmission sleeve shaft 5 inside the reducer 4, and the drive gear 14 rotates synchronously with the transmission sleeve shaft 5. A driven gear 15 is rotatably mounted on the inner wall of the reducer 4 on one side of the drive gear 14 via a bearing. The driven gear 15 meshes with the drive gear 14, and the rotation of the drive gear 14 drives the driven gear 15 to rotate synchronously. A transmission gear 16 is coaxially fixedly mounted on the driven gear 15, and the transmission gear 16 rotates with the driven gear. 15. The gears rotate synchronously. On the inner wall of the reducer 4 on one side of the transmission gear 16, the oil pump gear 17 is rotatably mounted via bearings. The oil pump gear 17 meshes with the transmission gear 16. When the transmission gear 16 rotates, it can drive the oil pump gear 17 to rotate. The drive input end of the pump group 18 is fixedly connected to the oil pump gear 17. Through the step-by-step meshing transmission of the drive gear 14, driven gear 15, transmission gear 16 and oil pump gear 17, the power of the transmission shaft is transmitted to the pump group 18, thereby driving the pump group 18 to run.

[0043] To improve the purity of the cooling and lubricating medium and achieve precise injection, a filter screen 204 and several injectors 207 are installed inside the cooling and lubricating unit 202. The filter screen 204 is located at the oil inlet end of the cooling and lubricating unit 202 to filter the cooling and lubricating medium entering the cooling and lubricating unit 202. The several injectors 207 are evenly distributed around the circumference of the cooling and lubricating unit 202, and the spray nozzles face the outer surface of the drive shaft. The oil outlet end of the pump unit 18 is fixedly provided with a lubricating oil supply pipe 9. The free end of the lubricating oil supply pipe 9 is branched and connected to several lubricating oil input pipes 206. The free ends of the several lubricating oil input pipes 206 are sealed and connected to the several injectors 207 one by one, so that the cooling and lubricating medium output by the pump unit 18 can be accurately delivered to each injector 207 through the lubricating oil supply pipe 9 and the lubricating oil input pipes 206, and then sprayed onto the surface of the drive shaft by the injectors 207 to achieve cooling and lubrication.

[0044] To facilitate the collection and maintenance of the cooling and lubricating medium, the lubricating oil tank 10 is fixedly installed at the bottom of the reducer 4. The cooling and lubricating medium flowing through the reducer 4 naturally flows into the lubricating oil tank 10 by gravity. The lubricating oil tank 10 is equipped with a filling port 11, an observation window 12, and a filter 19. The filling port 11 and the observation window 12 are both located on the side wall of the lubricating oil tank 10. The filling port 11 is used to replenish the cooling and lubricating medium into the lubricating oil tank 10, and the observation window 12 is used to visually observe the medium level in the lubricating oil tank 10. The filter 19 is located at the bottom of the lubricating oil tank 10, and the input end of the filter 19 is connected to the inner cavity of the lubricating oil tank 10. It is used to perform secondary filtration of the cooling and lubricating medium in the lubricating oil tank 10. The output end of the filter 19 is sealed to the suction end of the pump set 18 through the suction pipe 20, so that the filtered pure medium can be drawn and transported by the pump set 18.

[0045] To eliminate air bubbles generated during the transportation of the cooling and lubricating medium, an anti-foamer 8 is installed between the oil outlet of the pump set 18 and the lubricating oil supply pipe 9. The input end of the anti-foamer 8 is connected to the oil outlet of the pump set 18, and the output end is connected to the lubricating oil supply pipe 9. The cooling and lubricating medium output by the pump set 18 first flows through the anti-foamer 8 to remove air bubbles, and then enters the lubricating oil supply pipe 9 to be transported to the injector 207, ensuring that the medium sprayed by the injector 207 has a stable flow state.

[0046] To ensure stable rotation of the nested drive shaft, inner support bearings 208 and outer support bearings 205 are symmetrically arranged inside both the reducer 4 and the coolant / lubricator 202. The drive spindle 6 is rotatably connected to both the reducer 4 and the coolant / lubricator 202 via the inner support bearings 208, which provide radial support for the drive spindle 6. The drive sleeve shaft 5 is rotatably connected to both the reducer 4 and the coolant / lubricator 202 via the outer support bearings 205, which provide radial support for the drive sleeve shaft 5. Through the cooperation of the inner and outer support bearings 205, the independent and stable rotation of the drive spindle 6 and the drive sleeve shaft 5 is achieved, avoiding interference between them during rotation.

[0047] The compressor 1 includes a housing 101 and a compressor impeller 102. The housing 101 forms a closed working chamber for the compressor 1. The compressor impeller 102 is located inside the housing 101, and the hub of the compressor impeller 102 is fixedly connected to the drive shaft 5 passing through the housing 101. When the drive shaft 5 rotates, it can directly drive the compressor impeller 102 to rotate synchronously, so that the compressor 1 can draw in and compress outside air. The compressed air is sent to the burner 2 through the output end of the compressor 1.

[0048] The burner 2 includes a combustion chamber 201, and a cooling lubricator 202 is fixedly installed inside the combustion chamber 201. The inner hole of the cooling lubricator 202 is coaxially arranged with the drive shaft to provide precise cooling and lubrication for the drive shaft. A gas impeller 203 is also provided in the combustion chamber 201 on one side of the cooling lubricator 202. The gas impeller 203 is located in the gas expansion area of ​​the combustion chamber 201, and the hub of the gas impeller 203 is fixedly connected to the drive sleeve shaft 5 passing through the combustion chamber 201. The thrust generated by the combustion and expansion of the gas in the combustion chamber 201 drives the gas impeller 203 to rotate, which in turn drives the drive sleeve shaft 5 to rotate, realizing the conversion of gas energy into drive shaft power.

[0049] The working process of this embodiment is as follows: When the turboshaft engine starts, the thrust generated by the combustion and expansion of the gas in the combustion chamber 201 drives the gas impeller 203 to rotate. The gas impeller 203 drives the transmission sleeve shaft 5 to rotate synchronously through the fixed connection between the hub and the transmission sleeve shaft 5, thereby starting the entire nested transmission shaft to rotate. At this time, the transmission sleeve shaft 5 located in the reducer 4 drives the drive gear 14 fixed on it to rotate synchronously. The drive gear 14 drives the driven gear 15 to rotate through meshing with the driven gear 15. The transmission gear 16, which is coaxially fixed with the driven gear 15, rotates together. The transmission gear 16 then meshes with the oil pump gear 17, transmitting power step by step to the oil pump gear 17. Finally, the oil pump gear 17 drives the pump group 18 to start operation.

[0050] After the pump unit 18 starts, it draws the cooling and lubricating medium from the lubricating oil tank 10 through the suction pipe 20. The medium first undergoes secondary filtration through the filter 19 at the bottom of the lubricating oil tank 10 to remove impurities before entering the pump unit 18. The cooling and lubricating medium, pressurized by the pump unit 18, is output from the oil outlet and first flows through the defoamer 8 to remove air bubbles generated during high-pressure delivery, ensuring stable medium flow. Subsequently, the medium is distributed through the lubricating oil supply pipe 9 to each lubricating oil input pipe 206, and is precisely delivered by the lubricating oil input pipe 206 to the corresponding injector 207 in the cooling and lubricating unit 202.

[0051] The cooling and lubricating medium entering the injector 207 is evenly sprayed around the drive shaft and onto the outer surface of the nested drive shaft, achieving all-round cooling and lubrication of the drive shaft section in the high-temperature environment of the burner 2. At the same time, the filter screen 204 at the oil inlet of the cooling and lubricating device 202 performs initial filtration of the incoming medium, further ensuring the purity of the medium and preventing impurities from damaging the fit clearance between the drive shaft and the support structure.

[0052] After completing the cooling and lubrication process, the medium collects at the oil outlet of the cooler / lubricator 202 and then enters the return oil channel 7 reserved between the transmission spindle 6 and the transmission sleeve shaft 5. Under the action of the negative pressure pipe 13 between the reducer 4 and the tail nozzle 3, the negative pressure generated by the exhaust of the tail nozzle 3 creates a negative pressure environment inside the reducer 4. This negative pressure provides the return flow force for the medium in the return oil channel 7, pushing the medium to continuously flow into the inner cavity of the reducer 4 along the return oil channel 7. Under the action of gravity, the medium entering the inner cavity of the reducer 4 naturally flows into the lubricating oil tank 10 fixed at the bottom of the reducer 4, completing one cooling and lubrication cycle.

[0053] Throughout engine operation, the cooling and lubricating medium circulates continuously along the aforementioned closed-loop path, providing continuous cooling and lubrication for the nested drive shaft. Operators can monitor the medium level in real time through the observation window 12 on the side wall of the oil tank 10. When the level is insufficient, cooling and lubricating medium is added to the oil tank 10 through the filling port 11. Simultaneously, the inner support bearing 208 and the outer support bearing 205 provide radial support for the drive spindle 6 and drive sleeve shaft 5, respectively, ensuring independent and stable rotation of both and avoiding interference. This, combined with the cooling and lubrication system, ensures efficient and reliable operation of the drive shaft. Furthermore, while driving the overall rotation of the drive shaft, the drive sleeve shaft 5, through its fixed connection to the hub of the compressor impeller 102 of the compressor 1, drives the compressor impeller 102 to rotate synchronously. This allows the compressor 1 to draw in outside air, compress it, and send it to the burner 2, providing intake air for continuous engine operation.

[0054] The foregoing has provided a detailed description of one embodiment of this application, but the description is merely a preferred embodiment and should not be construed as limiting the scope of this application. All equivalent variations and improvements made within the scope of this application should still fall within the patent coverage of this application.

Claims

1. A cooling and lubrication system for a nested drive shaft of a turboshaft engine, the turboshaft engine comprising a reducer (4), a compressor (1), a burner (2), and a tailpipe (3), wherein the reducer (4) and the burner (2) are both fixedly connected to the compressor (1), and the input end of the burner (2) is connected to the output end of the compressor (1), the tailpipe (3) is fixed to the output end of the burner (2), and the reducer (4), the compressor (1), and the burner (2) are linked by a drive shaft, characterized in that: The drive shaft includes a drive spindle (6), and a drive sleeve shaft (5) is fitted around the drive spindle (6). A return oil channel (7) is reserved between the drive spindle (6) and the drive sleeve shaft (5). A cooling lubricator (202) is provided in the burner (2). One end of the return oil channel (7) is connected to the cooling lubricator (202), and the other end is connected to the reducer (4). A pump set (18) and a lubricating oil tank (10) are fixedly installed on the reducer (4). The lubricating oil tank (10) is connected to the reducer (4). The drive input end of the pump set (18) is connected to the drive shaft. The oil suction end of the pump set (18) is connected to the lubricating oil tank (10). The oil outlet end of the pump set (18) is connected to the cooling lubricator (202). A negative pressure pipe (13) is also provided between the reducer (4) and the tail nozzle (3).

2. The cooling and lubrication system for a nested drive shaft of a turboshaft engine according to claim 1, characterized in that: A drive gear (14) is fixedly mounted on the transmission sleeve shaft (5) located inside the reducer (4). A driven gear (15) is rotatably mounted on the inner wall of the reducer (4) on one side of the drive gear (14). The driven gear (15) meshes with the drive gear (14). A transmission gear (16) is fixedly mounted on the driven gear (15). An oil pump gear (17) is rotatably mounted on the inner wall of the reducer (4) on one side of the transmission gear (16). The oil pump gear (17) meshes with the transmission gear (16). The drive input end of the pump set (18) is connected to the transmission shaft through the oil pump gear (17).

3. The cooling and lubrication system for a nested drive shaft of a turboshaft engine according to claim 1, characterized in that: Inside the cooling lubricator (202), there is a filter screen (204) and several oil injectors (207). The several oil injectors (207) are evenly distributed around the circumference of the cooling lubricator (202). The oil outlet end of the pump set (18) is provided with a lubricating oil supply pipe (9). The free end of the lubricating oil supply pipe (9) is connected to several lubricating oil input pipes (206). The free ends of the several lubricating oil input pipes (206) are connected to the several oil injectors (207) one by one.

4. The cooling and lubrication system for a nested drive shaft of a turboshaft engine according to claim 1, characterized in that: The lubricating oil tank (10) is located at the bottom of the reducer (4). A filling port (11), an observation window (12), and a filter (19) are provided on the lubricating oil tank (10). The filling port (11) and the observation window (12) are both located on the side wall of the lubricating oil tank (10). The filter (19) is located at the bottom of the lubricating oil tank (10), and the input end of the filter (19) is connected to the lubricating oil tank (10), and the output end is connected to the oil suction end of the pump set (18) through the oil suction pipe (20).

5. The cooling and lubrication system for a nested drive shaft of a turboshaft engine according to claim 3, characterized in that: An antifoamer (8) is also provided between the oil outlet of the pump unit (18) and the lubricating oil supply pipe (9).

6. The cooling and lubrication system for a nested drive shaft of a turboshaft engine according to claim 1, characterized in that: An inner support bearing (208) and an outer support bearing (205) are provided inside the reducer (4) and the cooler / lubricator (202). The transmission spindle (6) is rotatably connected to the reducer (4) and the cooler / lubricator (202) through the inner support bearing (208). The transmission sleeve shaft (5) is rotatably connected to the reducer (4) and the cooler / lubricator (202) through the outer support bearing (205).

7. The cooling and lubrication system for a nested drive shaft of a turboshaft engine according to claim 1, characterized in that: The compressor (1) includes a housing (101) and a compressor impeller (102). The compressor impeller (102) is located inside the housing (101) and is fixedly connected to the transmission sleeve shaft (5) that passes through the housing (101).

8. The cooling and lubrication system for a nested drive shaft of a turboshaft engine according to claim 1, characterized in that: The burner (2) includes a combustion chamber (201), the cooling lubricator (202) is located in the combustion chamber (201), and a gas impeller (203) is also provided in the combustion chamber (201) on one side of the cooling lubricator (202). The gas impeller (203) is fixedly connected to the transmission sleeve shaft (5) passing through the combustion chamber (201).

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