Civil turboshaft engine simulation windmill test tooling

Abstract

The application discloses a civil turboshaft engine simulation windmill test tool which is used for simulating windmill test of a gas generator and comprises a positioning mechanism, a driving mechanism, an oil supply mechanism and simulation blades; the positioning mechanism comprises a bearing seat for mounting a support bearing; the driving mechanism comprises a transmission shaft, a power input flange and a power output flange, the first end of the transmission shaft is used for being connected with a driving motor, the second end of the transmission shaft is connected with the power input flange, the power output flange is used for being connected with a rotor, and the power input flange and the power output flange are fixed through bolt connection; the oil supply mechanism is used for supplying lubricating oil for the support bearing; the simulation blades are used for being mounted on a gas turbine disc to replace real blades, the inertia parameters of the simulation blades are the same as those of the real blades, and the simulation blades adopt a solid straight strip structure. The civil turboshaft engine simulation windmill test tool can reduce the cost of windmill test, shorten the cycle and reduce the test risk.

Description

Technical Field

[0001] This invention relates to the field of windmill testing technology for aero-engines, and in particular, to a testing fixture for simulating a windmill on a civil turboshaft engine. Background Technology

[0002] When an aircraft engine shuts down during operation, it enters a stopped state, and the bearings are cut off from oil. However, as the aircraft taxis, the airflow in front of it continuously enters the fan and compressor, driving the engine rotor to continue rotating. The rotor speed at this time is the windmill speed. This state of the aircraft engine where the airflow drives the engine rotor to continue rotating while the bearings are cut off from oil is called the windmill state of the aircraft engine.

[0003] Currently, aero engines are required to possess safe windmilling capability, necessitating windmilling tests. Compared to military turboshaft engines, the windmilling test requirements for civilian turboshaft engines are more stringent, primarily manifested in longer test durations and greater uncertainties and risks. Civil aviation engine airworthiness regulations stipulate that a civilian turboshaft engine's rotor must possess sustained windmilling capability throughout its longest flight cycle. This means that the engine must be able to continuously rotate within its entire operating envelope without damaging the engine, causing excessive oil consumption, or affecting its in-flight restart and normal operation capabilities.

[0004] Traditional windmill testing methods for aero-engines involve directly mounting the entire aero-engine on a high-altitude test stand. This allows the gas generator rotor and power turbine rotor to continue rotating via airflow even when the engine is shut down, with the bearings operating under lubrication-free conditions. However, this method is extremely expensive, requiring the installation of the entire aero-engine and significant investment in manpower, resources, and equipment. Furthermore, the testing cycle is lengthy, involving the assembly of the entire engine and the high-altitude test stand. Issues such as parts rework during assembly further extend the testing period. Moreover, the complexity of the high-altitude test stand system increases the likelihood of non-engine-related malfunctions, leading to numerous uncertainties and significant testing risks. Summary of the Invention

[0005] This invention provides a civil turboshaft engine simulated windmill test fixture to solve the technical problems of high cost, long cycle and safety hazards in existing aero-engine windmill test methods.

[0006] A civil turboshaft engine simulated windmill test fixture is used to conduct simulated windmill tests on the gas generator of a civil turboshaft engine. The gas generator includes a rotor and a plurality of support bearings spaced apart on the rotor along the axial direction of the rotor, and a gas turbine disk mounted on the rotor. The civil turboshaft engine simulated windmill test fixture includes a positioning mechanism, a drive mechanism, an oil supply mechanism, and simulated blades.

[0007] The positioning mechanism includes multiple bearing seats that correspond one-to-one with multiple support bearings on the gas generator, and the bearing seats are used to install the support bearings.

[0008] The drive mechanism includes a drive shaft, a power input flange, and a power output flange. The first end of the drive shaft is used to connect to the drive motor, the second end of the drive shaft is connected to the power input flange, and the power output flange is used to connect to the rotor. The power input flange and the power output flange are fixed together by bolts.

[0009] The oil supply mechanism is connected to the bearing housing and is used to provide lubricating oil to the support bearing;

[0010] The simulated blades are used to be installed on the gas turbine disk to replace the real blades. The inertia parameters of the simulated blades are the same as those of the real blades. The simulated blades adopt a solid straight strip structure.

[0011] Preferably, both the first and second ends of the drive shaft are provided with external splines, and the key teeth of the external splines have a parabolic structure with a high middle and low ends along the axial direction of the drive shaft. The power input flange is provided with a first internal spline that meshes with the external spline on the second end of the drive shaft.

[0012] Preferably, the drive shaft includes a shaft body and two protruding rings integrally formed with the shaft body and disposed at both ends of the shaft body. The outer diameter of the protruding rings is larger than the outer diameter of the shaft body. The external spline is disposed on the side of the protruding rings closer to the shaft body. The side of the protruding rings away from the shaft body is used to adjust the dynamic balance of the drive shaft by removing part of the material.

[0013] Preferably, the power input flange further includes an axial limiting plate, and the end face of the convex ring abuts against the axial limiting plate to axially limit the drive shaft through the cooperation of the convex ring and the axial limiting plate.

[0014] More preferably, the power input flange further includes a tool relief groove formed between the first internal spline and the axial limiting plate, wherein the groove wall and the groove bottom are provided with rounded corners.

[0015] Preferably, the power input flange includes a first connecting plate and a limiting ring surrounding the first connecting plate, the limiting ring and the first connecting plate together forming a limiting groove, and the power output flange includes a second connecting plate embedded in the limiting groove, and connecting holes for bolts are opened at corresponding positions on the first connecting plate and the second connecting plate.

[0016] Preferably, the power output flange includes a first collar and a second collar arranged sequentially along the axial direction. The inner diameter of the first collar is larger than the inner diameter of the second collar to form a receiving cavity between the first collar and the rotor. The inner wall of the second collar is provided with a second internal spline for engaging with a pre-set spline on the rotor. The rotor is pre-set with an external thread at a position corresponding to the first collar. The drive mechanism also includes a fastening nut placed in the receiving cavity and used for threaded connection with the rotor.

[0017] Furthermore, the positioning mechanism also includes a support base and a limiting seat connected to the top of the support base. Both the support base and the limiting seat are provided with semi-circular grooves. The semi-circular grooves on the support base and the limiting seat together form a limiting hole. The limiting hole is adapted to the bearing seat and is used to fix the bearing seat.

[0018] Furthermore, the positioning mechanism also includes a lug disposed on the support base and a positioning component connected to the support base and used to fix the support base.

[0019] Furthermore, the civilian turboshaft engine simulated windmill test fixture also includes a test chamber, in which the positioning mechanism and the drive mechanism are both located.

[0020] The present invention has the following beneficial effects:

[0021] The civil turboshaft engine windmill simulation test fixture provided by this invention first installs and fixes the gas generator through a positioning mechanism, then drives the rotor of the gas generator to rotate at a preset speed through a drive mechanism, and provides or stops lubrication to the support bearing of the gas generator through an oil supply mechanism. This allows for precise simulation of the speed and oil cut-off conditions of an aero-engine under windmill conditions on the ground, testing the wear of the support bearing under windmill conditions, and detecting whether the support bearing is damaged due to windmill testing under oil cut-off conditions. This effectively reduces the cost of windmill testing for aero-engines, shortens the test cycle, and avoids the testing risks present on high-altitude test platforms. Secondly, because the speed of the power turbine rotor in the windmill condition with bearing oil cut-off is much lower than that of the gas generator rotor, the failure risk of the gas generator is much greater than that of the power turbine under windmill conditions. This civil turboshaft engine windmill simulation test fixture only performs simulated windmill testing on the gas generator to determine whether the entire turboshaft engine meets the windmill performance requirements. Compared with windmill testing of the entire turboshaft engine, this effectively reduces assembly steps, further reduces test costs, and shortens the test cycle. Third, the power input flange and power output flange of the drive mechanism are fixed together by bolts, and the original bevel gear on the rotor of the gas generator is replaced with a flange structure, which makes assembly more convenient and faster, and can better transmit power, reduce the overall vibration during the simulated windmill test, ensure stable and accurate power transmission, and improve the accuracy and reliability of the test structure. Fourth, simulated blades are configured on the gas turbine disk of the gas generator to replace the real blades. Under the premise of consistent inertia parameters, the simulated blades adopt a solid straight strip structure, replacing the hollow structure of the real blades with a solid structure, and the curved surface structure of the real blades with a straight strip structure. At the same time, it is possible to use lower-cost materials for processing and manufacturing, which greatly saves the cost of test pieces, facilitates flexible replacement of different specifications of simulated blades to meet different test requirements, and avoids damage to the real blades during the test.

[0022] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0023] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 A reference diagram showing the usage status of the civilian turboshaft engine simulated windmill test fixture provided in an embodiment of the present invention;

[0025] Figure 2 for Figure 1A schematic cross-sectional view of the drive mechanism shown.

[0026] Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure of the drive shaft in the drive mechanism shown.

[0027] Figure 4 for Figure 3 A magnified view of region A of the drive shaft shown;

[0028] Figure 5 for Figure 2 The diagram shows the assembly structure of the power input flange and the power output flange in the drive mechanism.

[0029] Figure 6 for Figure 2 The diagram shows the assembly structure of the power output flange and rotor in the drive mechanism.

[0030] Figure 7 for Figure 1 The diagram shows the structure of the positioning mechanism.

[0031] Figure 8 To adopt Figure 1 The diagram shows the temperature change curve of the support bearing after the simulated windmill test of the civilian turboshaft engine windmill test fixture. The temperature of the support bearing before the simulated windmill test was about 50°C.

[0032] Figure 9 To adopt Figure 1 The graph shown is a curve of the temperature change of the support bearing after the simulated windmill test of the civilian turboshaft engine windmill test fixture. The temperature of the support bearing before the simulated windmill test is room temperature.

[0033] Legend:

[0034] 100. Civilian turboshaft engine simulated windmill test fixture; 1. Positioning mechanism; 11. Bearing seat; 12. Support seat; 13. Limiting seat; 14. Lifting lug; 15. Positioning assembly; 2. Drive mechanism; 21. Transmission shaft; 210. External spline; 211. Shaft body; 212. Convex ring; 22. Power input flange; 221. First internal spline; 222. Axial limiting plate; 223. Relief groove; 224. First connecting plate; 225. Limiting ring; 23. Power output flange; 231. Second connecting plate; 232. First collar; 2321. Receiving cavity; 233. Second collar; 2331. Second internal spline; 234. Positioning wall; 24. Fastening nut; 25. Nut locking piece; 3. Simulated blade; 4. Test chamber; 200. Gas generator; 201. Rotor; 202. Support bearing; 203. Gas turbine disk. Detailed Implementation

[0035] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0036] Figures 1 to 9 The invention provides a civil turboshaft engine simulated windmill test fixture, which is used to conduct simulated windmill tests on the gas generator of a civil turboshaft engine. By simulating the rotational speed and fuel cut-off conditions of a civil turboshaft engine under windmill conditions, the fixture tests the wear of the support bearings under windmill conditions and detects whether the support bearings are damaged due to windmill tests under fuel cut-off conditions. This effectively reduces the cost of windmill tests for aero engines, shortens the test cycle, and avoids the test risks present on high-altitude test platforms.

[0037] Please combine Figure 1 and Figure 2 The gas generator 200 includes a rotor 201 and a plurality of support bearings 202 spaced apart along the axial direction of the rotor 201, as well as a gas turbine disk 203 mounted on the rotor 201. The civil turboshaft engine simulated windmill test fixture 100 includes a positioning mechanism 1, a drive mechanism 2, and an oil supply mechanism (not shown in the figure, the same below). The positioning mechanism 1 includes a plurality of bearing seats 11, which are arranged one-to-one with the plurality of support bearings 202 on the gas generator 200. The bearing seats 11 are used to install the support bearings 202 to position and fix the support bearings 202 and allow the support bearings 202 to rotate within the bearing seats 11.

[0038] Preferably, the drive mechanism 2 includes a drive shaft 21, a power input flange 22, and a power output flange 23. The first end of the drive shaft 21 is connected to a drive motor to drive the drive shaft 21 to rotate. The second end of the drive shaft 21 is connected to the power input flange 22 and drives the power input flange 22 to rotate synchronously. The power output flange 23 is connected to the rotor 201 and drives the rotor 201 to rotate synchronously. The power input flange 22 and the power output flange 23 are fixed together by bolts. The oil supply mechanism is connected to the bearing housing 11 and provides lubricating oil to the support bearing 202. The oil supply mechanism is also used to stop oil supply during simulated windmill tests.

[0039] The civil turboshaft engine windmill test fixture 100 first installs and fixes the gas generator 200 through the positioning mechanism 1, and then drives the rotor 201 of the gas generator 200 to rotate at a preset speed through the drive mechanism 2. The oil supply mechanism provides lubricating oil to the support bearing 202 of the gas generator 200 or stops the oil supply. It can accurately simulate the speed and oil cut-off conditions of the aircraft engine in windmill state on the ground, test the wear of the support bearing 202 in windmill state, and detect whether the support bearing 202 is damaged due to windmill test under oil cut-off conditions. It effectively reduces the windmill test cost of aircraft engines, shortens the test cycle, and avoids the test risks that exist on high-altitude test platforms. Secondly, because the rotational speed of the power turbine rotor in a windmill state with the bearings cut off is much lower than that of the gas generator rotor in a civilian turboshaft engine, the failure risk of the gas generator 200 is much greater than that of the power turbine in windmill state. The civilian turboshaft engine simulated windmill test fixture 100 only performs simulated windmill tests on the gas generator 200 to determine whether the entire turboshaft engine meets the windmill performance requirements. Compared with the method of conducting windmill tests on the entire turboshaft engine, it effectively reduces assembly steps, further reduces test costs, and shortens the test cycle. Thirdly, the power input flange 22 and the power output flange 23 of the drive mechanism 2 are fixed by bolts, and the original bevel gear on the rotor 201 of the gas generator 200 is replaced with a flange structure, which makes assembly more convenient and faster, and can better transmit power, reduce overall vibration during the simulated windmill test, ensure stable and accurate power transmission, and improve the accuracy and reliability of the test structure.

[0040] Preferably, the civilian turboshaft engine simulated windmill test fixture 100 further includes simulated blades 3, which are mounted on the gas turbine disk 203 to replace the real blades. The inertia parameters of the simulated blades 3 are the same as those of the real blades, and the simulated blades 3 adopt a solid straight strip structure. First, it is ensured that the mass and moment of inertia of the simulated blades 3 are consistent with those of the real blades to accurately simulate them. Based on the premise of consistent inertia parameters, the simulated blades 3 adopt a solid straight strip structure, replacing the hollow structure of the real blades with a solid structure and the curved surface structure of the real blades with a straight strip structure. Simultaneously, the simulated blades 3 can be manufactured using lower-cost materials, greatly saving the cost of test pieces, facilitating flexible replacement of simulated blades 3 of different specifications to meet different test requirements, and avoiding damage to the real blades during the test.

[0041] Preferably, the civilian turboshaft engine simulated windmill test fixture 100 further includes a detection mechanism (not shown in the figure, the same below). The detection mechanism includes an axial vibration detection component, a vertical vibration detection component, and a lateral vibration detection component, each connected to the bearing housing 11. The detection direction of the axial vibration detection component is set along the axial direction of the rotor 201, the detection direction of the vertical vibration detection component is set along the vertical direction, and the detection direction of the lateral vibration detection component is set along the horizontal direction and perpendicular to the rotor 201. During the windmill test, the detection mechanism detects the axial vibration, vertical vibration, and lateral vibration data of the support bearing 202, respectively. The vibration of the support bearing 202 is detected along the three axes of the spatial rectangular coordinate system, and the wear condition of the support bearing 202 during the test is comprehensively judged. This allows for the determination of the performance parameters and service life of the support bearing 202, providing effective data support for the simulated windmill test.

[0042] Furthermore, the testing mechanism also includes a lubricating oil testing component connected to the bearing housing 11. The lubricating oil testing component is used to detect the amount, pressure and / or temperature of the lubricating oil in the bearing housing 11, thereby realizing the regulation and monitoring of the amount, temperature and pressure of the lubricating oil in the support bearing 202, and indirectly detecting the temperature of the support bearing 202 during the simulated windmill test, providing more test data, and comprehensively evaluating the parameter performance of the support bearing 202.

[0043] Please combine Figure 3 and Figure 4 The first and second ends of the drive shaft 21 are both provided with external splines 210. The key teeth of the external splines 210 have a parabolic structure with a high center and low ends along the axial direction of the drive shaft 21. The power input flange 22 is provided with a first internal spline 221 (in... Figure 5 As shown in the figure, the first internal spline 221 is adapted to the external spline 210 and engages with the external spline 210 on the second end of the transmission shaft 21. In addition, the external spline 210 on the first end of the transmission shaft 21 is used to engage with the output structure of the drive motor.

[0044] The external spline 210, by grinding its outer surface into a parabolic structure with a high center and low ends, can effectively optimize the working load distribution on the spline surface, enabling a tighter meshing with the power input flange 22 and the output structure of the drive motor. This makes the contact stress of the internal and external splines more uniform in the working state, resulting in less stress on the spline tooth surface compared to conventional splines, improving fatigue resistance, reducing wear on the spline meshing structure, and thus extending service life.

[0045] Furthermore, the external spline 210 is configured as an involute spline to have a strong load-bearing capacity, be able to automatically center, have high installation accuracy, and have a large minor diameter for the same external dimensions, which is beneficial to increasing the rigidity of the drive shaft 21.

[0046] Preferably, the drive shaft 21 includes a shaft body 211 and two protruding rings 212 disposed at both ends of the shaft body 211. The protruding rings 212 are coaxially arranged relative to the shaft body 211 and integrally formed with the shaft body 211. The outer diameter of the protruding rings 212 is larger than the outer diameter of the shaft body 211. The external spline 210 is disposed on the side of the protruding rings 212 close to the shaft body 211. The side of the protruding rings 212 away from the shaft body 211 is used to adjust the dynamic balance of the drive shaft 21 by removing part of the material.

[0047] First, because the outer diameter of the convex ring 212 is larger and its strength is higher, machining the external spline 210 on the convex ring 212 can ensure the strength and rigidity of the external spline 210, improve the transmission accuracy and stability of the external spline 210, and avoid the external spline 210 affecting the structural strength of the transmission shaft 21. Second, placing the external spline 210 on the side of the convex ring 212 closer to the shaft body 211, compared to placing the external spline 210 at the end of the transmission shaft 21, can further improve the stability of the external spline 210, prevent the external spline 210 from shaking in its position, prevent the key teeth of the external spline 210 from breaking during transmission, and effectively improve the service life of the external spline 210. More importantly, this structure also allows the side of the convex ring 212 away from the shaft 211 to form a boss structure. This boss structure not only serves as an axial limiting mechanism when connected to the object, but also allows for adjustment of the dynamic balance of the drive shaft 21 by removing some material along the outer periphery of the boss structure. Since the convex ring 212 is a structure that protrudes radially outward from the drive shaft 21, adjusting the thickness of the convex ring 212 will not affect the strength of the drive shaft 21 itself, nor will it affect the axial limiting effect of the convex ring 212. Therefore, by removing some material from the convex ring 212, the overall dynamic balance of the drive shaft 21 can be adjusted, facilitating dynamic balance correction of the drive shaft 21 and improving its stability.

[0048] Preferably, a rounded corner is provided between the shaft body 211 and the convex ring 212 to optimize the stress situation at the corner position between the shaft body 211 and the convex ring 212, avoid the transmission shaft 21 from breaking along the position between the shaft body 211 and the convex ring 212, and further improve the structural strength of the transmission shaft 21.

[0049] like Figure 5As shown, the power input flange 22 also includes an axial limiting plate 222. The end face of the convex ring 212 abuts against the axial limiting plate 222, so as to axially limit the transmission shaft 21 through the cooperation of the convex ring 212 and the axial limiting plate 222. The limiting structure is simple and efficient.

[0050] Preferably, the power input flange 22 further includes a relief groove 223 formed between the first internal spline 221 and the axial limiting plate 222, wherein the groove wall and the bottom of the relief groove 223 are rounded. The relief groove 223 separates the first internal spline 221 and the axial limiting plate 222, allowing for smooth tool retraction during machining of the first internal spline 221, avoiding damage to other parts of the power input flange 22, and preventing localized stress concentration. The relief groove 223 and its rounded corner structure effectively release the stress experienced by the first internal spline 221 during transmission, thereby extending the service life of the first internal spline 221.

[0051] Preferably, the power input flange 22 further includes a first connecting plate 224 and a limiting ring 225 surrounding the first connecting plate 224. The limiting ring 225 is located on the side of the first connecting plate 224 near the axis and together with the first connecting plate 224 forms a limiting groove. The power output flange 23 includes a second connecting plate 231 embedded in the limiting groove. The first connecting plate 224 and the second connecting plate 231 are provided with connecting holes for bolts at corresponding positions. A plurality of connecting holes are evenly distributed along the circumference of the first connecting plate 224 or the second connecting plate 231. During assembly, the power input flange 22 and the power output flange 23 can be pre-positioned axially and radially by the limiting groove and the second connecting plate 231. Then, bolts are sequentially inserted into the connecting holes of the first connecting plate 224 and the second connecting plate 231 to connect the first connecting plate 224 and the second connecting plate 231 into a whole, thereby fixing the power input flange 22 and the power output flange 23 in the circumferential direction. The assembly and positioning are convenient and quick, and the positioning accuracy is high, which can ensure accurate power transmission and stable operation during the test.

[0052] Please combine Figure 5 and Figure 6The power output flange 23 includes a first collar 232 and a second collar 233 coaxially arranged along the direction close to the rotor 201. The inner diameter of the first collar 232 is larger than the inner diameter of the second collar 233, forming a receiving cavity 2321 between the first collar 232 and the rotor 201. The inner wall of the second collar 233 is provided with a second internal spline 2331 for engaging with a pre-set spline on the rotor 201. The rotor 201 has a pre-set external thread corresponding to the position of the first collar 232. The drive mechanism 2 also includes a fastening nut 24 placed in the receiving cavity 2321 and used for threaded connection with the rotor 201. The fastening nut 24 connects and fixes the power output flange 23 and the rotor 201 into a whole, and can play a good axial limiting role. The fastening structure is simple and efficient.

[0053] Furthermore, the drive mechanism 2 also includes a nut locking piece 25, which abuts against the fastening nut 24 and is used to lock and fix the fastening nut 24, thus playing a role in preventing the nut from loosening during the test.

[0054] Furthermore, since the inner diameters of the first collar 232 and the second collar 233 are different, a positioning wall 234 is provided at the radial drop position between the first collar 232 and the second collar 233. The positioning wall 234 connects the first collar 232 and the second collar 233 into a whole. The positioning wall 234 can also be used for the fastening nut 24 and the nut locking piece 25 to abut and be positioned, which facilitates the positioning and locking of the fastening nut 24 and improves the assembly positioning accuracy between the power output flange 23 and the rotor 201.

[0055] like Figure 7 As shown, the positioning mechanism 1 further includes a support base 12 and a limiting seat 13 connected to the top of the support base 12. Both the support base 12 and the limiting seat 13 have semi-circular grooves. The semi-circular grooves on the support base 12 and the limiting seat 13 together form a limiting hole. The limiting hole is adapted to the bearing seat 11 and used to fix the bearing seat 11. The limiting hole is split into upper and lower parts. After removing the limiting seat 13, the semi-circular groove of the support base 12 can be directly exposed. Therefore, a crane can be used to hoist the bearing seat 11 along with the gas generator 200 into the semi-circular groove of the support base 12 for pre-fixation. Then, the limiting seat 13 is installed in place to form the limiting hole, and the bearing seat 11 is locked and fixed through the limiting hole, thus achieving the positioning and fixing of the gas generator 200. Assembly is convenient and quick.

[0056] Furthermore, the positioning mechanism 1 also includes a lifting lug 14 disposed on the support base 12 and a positioning component 15 connected to the support base 12 and used to fix the support base 12. A crane can be used to lift the support base 12 through the lifting lug 14, flexibly adjusting the installation position of the support base 12. After the support base 12 is moved into place, the positioning component 15 is used to position and fix the support base 12, so that the support base 12 can be adapted to different specifications of gas generators 200, meeting diverse testing needs and demonstrating strong applicability.

[0057] Furthermore, the positioning component 15 includes a positioning strip extending along the axial direction of the gas generator 200, and the support base 12 is provided with a positioning groove adapted to the positioning strip. The support base 12 can move along the axial direction of the gas generator 200 through the sliding fit between the positioning groove and the positioning strip to adapt to the support bearings 202 supporting different axial positions on the gas generator 200.

[0058] like Figure 1 As shown, the civil turboshaft engine simulated windmill test fixture 100 also includes a test chamber 4. The positioning mechanism 1 and the driving mechanism 2 are both located in the test chamber 4. The test chamber 4 creates a closed test environment to avoid the test process being affected by external environmental factors, ensure the accuracy of the test results, and seal and protect the gas generator 200 to prevent damage to the gas generator 200.

[0059] Furthermore, the positioning component 15 also includes a positioning bolt connected to the support base 12. The positioning bolt is used to tighten and fix the support base 12 relative to the preset positioning hole on the test chamber 4, thereby locking and fixing the support base 12 in the test chamber 4, and realizing the installation and fixation of the support base 12.

[0060] Please combine Figure 8 and Figure 9 The present invention also provides a method for conducting a simulated windmill test using the civil turboshaft engine simulated windmill test fixture 100, and provides data on the temperature change of the support bearing after conducting a simulated windmill test on the gas generator 200, to verify the feasibility of the civil turboshaft engine simulated windmill test fixture 100.

[0061] First, the gas generator 200 is positioned and fixed by the positioning mechanism 1. Then, the drive mechanism 2 is connected to the rotor 201 of the gas generator 200, and the simulated blade 3 is installed on the gas turbine disk 203 of the gas generator 200 to complete the test assembly of the gas generator 200.

[0062] The simulated windmill test steps include: (1) first driving the rotor 201 of the gas generator 200 to rotate at the normal operating speed, and supplying oil to the support bearing 202 normally through the oil supply mechanism; (2) simulating the rotor running state of a civil turboshaft engine before the high-altitude typhoon test, driving the rotor 201 to the slow speed of the civil turboshaft engine, staying at this speed for 3 minutes, measuring the temperature of the support bearing 202 of the gas generator 200, and then stopping quickly. During this stage, the support bearing 202 is supplied with oil normally; (3) for the support bearing 202 to rotate at the normal operating speed. (3) Stop supplying oil to bearing 202, keep other test conditions unchanged, drive rotor 201 to windmill speed, run at windmill speed for 2 hours and then stop; (4) After the gas generator 200 cools to room temperature, drive rotor 201 to windmill speed again under the condition of oil cut-off of support bearing 202, run at windmill speed for 2 hours and then stop; (5) Disassemble gas generator 200, perform physical and chemical analysis on support bearing 202 of gas generator 200, and check whether support bearing 202 is damaged due to windmill test under oil cut-off conditions.

[0063] In this embodiment, the gas generator 200 includes two support bearings 202, wherein the support bearing 202 axially closer to the drive mechanism 2 is designated as bearing number 3, and the support bearing 202 axially farther from the drive mechanism 2 is designated as bearing number 4. Figure 8 The figure shows the temperature-time curves of the two support bearings 202 after operating at windmill speed for 2 hours. The temperature of the support bearings 202 before the simulated windmill test was approximately 50°C. Figure 9 The figure shows the temperature-time curves of the two support bearings 202 after operating at windmill speed for 2 hours. The temperature of the support bearings 202 before the simulated windmill test was room temperature. The curves show that during the windmill speed test, bearings 3 and 4 of the gas generator 200 only experienced a small temperature rise during the acceleration phase, gradually reaching thermal equilibrium and stabilizing during the windmill test pauses. The gas generator 200 operated smoothly throughout the entire test, indicating that the two support bearings 202 have the ability to operate stably at windmill speed for extended periods even with oil cut-off.

[0064] Secondly, after the gas generator 200 underwent a windmill speed test, the gas generator 200 was disassembled and inspected, with particular attention paid to the rotational flexibility of bearings 3 and 4, and observation for any jamming. Subsequent inspection revealed no issues such as overheating, discoloration, or burning of the support bearing 202 due to oil cut-off, indicating that the windmill speed test did not cause any substantial damage to bearings 3 and 4, and that the support bearing 202 still has the ability to continue to operate normally.

[0065] Therefore, the civilian turboshaft engine simulated windmill test fixture 100 provided in this embodiment of the invention not only reduces test costs and shortens the test cycle, but also avoids the test risks present on high-altitude test benches. Furthermore, after testing, it has been verified that it can accurately simulate the rotational speed and bearing oil cut-off test conditions of a civilian turboshaft engine under windmill conditions. A windmill speed test was conducted on the gas generator 200 using this test fixture. Based on the results of this experimental research, the civilian turboshaft engine has successfully completed a 3-hour windmill test on a high-altitude test bench, demonstrating the feasibility of the present invention and providing technical reference for other models.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A civil turboshaft engine simulated windmill test fixture, used for conducting simulated windmill tests on the gas generator (200) of a civil turboshaft engine, the gas generator (200) comprising a rotor (201) and a plurality of support bearings (202) spaced axially along the rotor (201), and a gas turbine disk (203) mounted on the rotor (201), characterized in that, The civilian turboshaft engine simulated windmill test fixture includes a positioning mechanism (1), a drive mechanism (2), an oil supply mechanism, and simulated blades (3). The positioning mechanism (1) includes a plurality of bearing seats (11) that correspond one-to-one with a plurality of support bearings (202) on the gas generator (200), and the bearing seats (11) are used to install the support bearings (202). The drive mechanism (2) includes a drive shaft (21), a power input flange (22), and a power output flange (23). The first end of the drive shaft (21) is used to connect to the drive motor, the second end of the drive shaft (21) is connected to the power input flange (22), and the power output flange (23) is used to connect to the rotor (201). The power input flange (22) and the power output flange (23) are fixed together by bolts. The oil supply mechanism is connected to the bearing housing (11) and is used to provide lubricating oil to the support bearing (202); The simulated blade (3) is used to be installed on the gas turbine disk (203) to replace the real blade. The inertia parameter of the simulated blade (3) is the same as that of the real blade. The simulated blade (3) adopts a solid straight strip structure. The first and second ends of the drive shaft (21) are provided with external splines (210). The key teeth of the external splines (210) are in a parabolic structure with a high middle and low ends along the axial direction of the drive shaft (21). The power input flange (22) is provided with a first internal spline (221) that meshes with the external spline (210) on the second end of the drive shaft (21). The drive shaft (21) includes a shaft body (211) and two protruding rings (212) integrally formed with the shaft body (211) and disposed at both ends of the shaft body (211). The outer diameter of the protruding rings (212) is larger than the outer diameter of the shaft body (211). The external spline (210) is disposed on the side of the protruding rings (212) close to the shaft body (211). The side of the protruding rings (212) away from the shaft body (211) is used to adjust the dynamic balance of the drive shaft (21) by removing part of the material. The power input flange (22) also includes an axial limiting plate (222), and the end face of the convex ring (212) abuts against the axial limiting plate (222) to axially limit the transmission shaft (21) through the cooperation of the convex ring (212) and the axial limiting plate (222).

2. The civilian turboshaft engine simulated windmill test fixture according to claim 1, characterized in that, The power input flange (22) also includes a tool relief groove (223) formed between the first internal spline (221) and the axial limiting plate (222), and the tool relief groove (223) has rounded corners between the groove wall and the groove bottom.

3. The civilian turboshaft engine simulated windmill test fixture according to claim 1, characterized in that, The power input flange (22) includes a first connecting plate (224) and a limiting ring (225) surrounding the first connecting plate (224). The limiting ring (225) and the first connecting plate (224) together form a limiting groove. The power output flange (23) includes a second connecting plate (231) embedded in the limiting groove. The first connecting plate (224) and the second connecting plate (231) are provided with connecting holes for bolts at corresponding positions.

4. The civilian turboshaft engine simulated windmill test fixture according to claim 1, characterized in that, The power output flange (23) includes a first collar (232) and a second collar (233) arranged sequentially along the axial direction. The inner diameter of the first collar (232) is larger than the inner diameter of the second collar (233) to form a receiving cavity (2321) between the first collar (232) and the rotor (201). The inner wall of the second collar (233) is provided with a second internal spline (2331) for engaging with a pre-set spline on the rotor (201). The rotor (201) has a pre-set external thread corresponding to the position of the first collar (232). The drive mechanism (2) also includes a fastening nut (24) placed in the receiving cavity (2321) and used for threaded connection with the rotor (201).

5. The civilian turboshaft engine simulated windmill test fixture according to claim 1, characterized in that, The positioning mechanism (1) further includes a support base (12) and a limiting seat (13) connected to the top of the support base (12). Both the support base (12) and the limiting seat (13) are provided with semi-circular grooves. The semi-circular grooves on the support base (12) and the limiting seat (13) together form a limiting hole. The limiting hole is adapted to the bearing seat (11) and is used to fix the bearing seat (11).

6. The civilian turboshaft engine simulated windmill test fixture according to claim 5, characterized in that, The positioning mechanism (1) further includes a lug (14) provided on the support base (12) and a positioning component (15) connected to the support base (12) and used to fix the support base (12).

7. The civilian turboshaft engine simulated windmill test fixture according to claim 1, characterized in that, The civil turboshaft engine simulated windmill test fixture also includes a test chamber (4), and the positioning mechanism (1) and the driving mechanism (2) are both located in the test chamber (4).

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