Helicopter propeller hub test fixing device and method

Abstract

The invention provides a helicopter propeller hub test fixing device and method. The device comprises a propeller hub rotor shaft; the propeller hub rotor wing shaft can be sleeved with the propeller hub center piece; one end of the transition shaft is connected with the propeller hub rotor wing shaft; a settlement type foundation pit; the steel frame concrete platform is arranged in the settlement type foundation pit; wherein the other end of the transition shaft is connected with the steel frame concrete platform; by adopting the design of the settlement type foundation, the height of the whole test device can be reduced, and the loading stability and rigidity of the test device are improved.

Description

Technical Field

[0001] This application belongs to the technical field of helicopter hub large-load fixed platform test technology, and specifically relates to a helicopter hub test fixing device and method. Background Art

[0002] As one of the core components of the helicopter rotor system, the helicopter hub is mainly used to provide lift and main control force for the helicopter, and is a key stressed component on the helicopter. The helicopter hub bears the centrifugal force, lift force, flapping force, lag force, and damping force transmitted from the rotor blades, and its stress situation is very complex.

[0003] Therefore, the fatigue life of the central part and the rotor shaft in the hub directly affects the life determination of the entire helicopter, and its performance directly affects the strength and flight safety of the helicopter.

[0004] The existing ordinary welded steel frame fixing device is non-detachable and non-replaceable, and the fatigue strength at the welded joints is weak, and it can no longer meet the loading and fixing requirements of large-tonnage helicopter hubs in terms of load-bearing, maintainability, and replaceability. Summary of the Invention

[0005] Object of the Invention: Aiming at the helicopter hub large-load loading test technology, a detachable and replaceable fixed test device for a hundred-ton large load is provided.

[0006] In a first aspect, this application provides a helicopter hub test fixing device, which includes:

[0007] Hub rotor shaft;

[0008] Hub central part, which can be sleeved on the hub rotor shaft;

[0009] Transition shaft, one end of which is connected to the hub rotor shaft;

[0010] Settling foundation pit;

[0011] Steel frame concrete platform, arranged in the settling foundation pit; wherein, the other end of the transition shaft is connected to the steel frame concrete platform.

[0012] Preferably, the device further includes:

[0013] Spindle nut, used to lock the hub central part on the hub rotor shaft.

[0014] Lifting ring, used for hoisting the hub assembly; wherein, the hub assembly includes a hub rotor shaft, a hub central part, a transition shaft, and a spindle nut.

[0015] Preferably, the hub central member has an internal spline and upper and lower end faces provided at both ends of the internal spline.

[0016] Preferably, the hub rotor shaft includes:

[0017] A body;

[0018] An external spline provided on the body;

[0019] A stop end face provided on the body, the stop end face being located below the external spline;

[0020] An external thread provided on the body, the external thread being located above the external spline;

[0021] A threaded lifting hole provided at the upper end of the body, the threaded lifting hole being used for installing a sling;

[0022] A first positioning surface provided at the lower end of the body.

[0023] Preferably, the hub rotor shaft further includes:

[0024] A first boss connected to the first positioning surface.

[0025] Preferably, the transition shaft includes:

[0026] A cylinder;

[0027] An upper positioning surface provided at the upper end of the cylinder;

[0028] A lower positioning surface provided at the lower end of the cylinder;

[0029] A groove provided on the upper positioning surface;

[0030] A second boss provided on the lower positioning surface.

[0031] Preferably, the surface of the foundation pit of the sunken foundation pit is set at a certain depth H from the horizontal plane.

[0032] Preferably, the steel frame concrete platform includes:

[0033] A platform groove for installing the second boss;

[0034] An inspection passage extending deep into the sunken foundation pit.

[0035] In a second aspect, the present application also provides a method for fixing a helicopter hub test, the method including:

[0036] Step 1, first, the hub central member is sleeved onto the external spline of the hub rotor shaft through the internal spline, and in the axial direction, it is matched with the stop end face through the lower end face.

[0037] Step 2: Design an external thread on the hub rotor shaft, screw the internal thread of the main shaft nut into the external thread in 2 - 5, and lock it on the upper end face of the central part.

[0038] Step 3: Through the cooperation of the spline shaft and the relative constraint of the end face, the movement of the central part in the three - dimensional directions on the rotor shaft is constrained. The connection between the central part and the hub rotor shaft is uniformly stressed. The total contact area of the spline connection is large and the centering property is good.

[0039] Step 4: The hub rotor shaft and the transition shaft are connected through bolt holes. The two bolt holes have the same aperture and radius. Use standard bolts to fasten the two shafts together. The positioning surface is used to determine the 0 - degree starting position of the hub rotor shaft and the transition shaft.

[0040] Step 5: Design a boss at the bottom of the hub rotor shaft and a groove at the top of the transition shaft. The boss and the groove are assembled together. The test load of hundreds of tons can be transmitted not only through the bolt holes of the rotor shaft and the transition shaft, but also through the cylindrical surfaces of the boss and the groove, and the test load is transmitted downward, ensuring the uniformity of multi - path force transmission of the load, reducing the local load stress, and reducing the deformation of the root of the rotor shaft.

[0041] Step 6: Design a special threaded lifting hole at the middle position of the top of the hub rotor shaft, and cooperate with the lifting ring to carry out lifting work such as disassembly, replacement, and maintenance of the fixing device.

[0042] Step 7: The hub central part, the hub rotor shaft, the transition shaft, the main shaft nut, the lifting ring, and the connecting bolts can be disassembled and replaced as needed during the test installation process, and the fatigue tests of each component are fully verified.

[0043] Step 8: Design a circular sunken foundation pit on the horizontal ground. The surface of the foundation pit is set at a certain depth H from the horizontal plane. The purpose of the sunken type is to lower the installation plane of the hub assembly and improve the convenience, safety, and effectiveness of test installation and replacement.

[0044] Step 9: Maintenance channels are opened on both the left and right sides of the sunken foundation pit and the steel - frame concrete platform. Through the maintenance channels, it is possible to reach deep into the foundation pit to install and disassemble various components and connecting bolts of the platform, improving the convenience of installation and replacement.

[0045] Step 10: Install a steel - frame concrete platform in the sunken foundation pit.

[0046] Step 11: The hub assembly is hoisted onto the steel-frame concrete platform by a lifting ring. The boss of the transition shaft is fitted with the groove of the steel-frame concrete platform, and the bolt holes are connected to the bolt holes of the steel-frame concrete platform. Through the support of the cylindrical surface and the connection of the bolt holes, the uniformity of multi-path force transmission of the load is ensured, the local load stress is reduced, and the deformation at the root of the transition shaft is minimized.

[0047] The present application has the following technical effects:

[0048] A helicopter hub fixing test device designed by the present invention adopts a sunken foundation design, which can reduce the height of the entire test device and improve the stability and rigidity of the test device during loading. By designing a steel-frame concrete platform in the sunken foundation pit, the structure in which the platform is connected to the foundation pit by bolts achieves the purpose of being detachable. This sunken detachable fixing test device can meet the test requirements of general-purpose and large-load helicopter hubs, and truly and accurately simulate the boundary conditions and load transfer characteristics of helicopter hubs. Using this fixing test device for helicopter hub fatigue tests, the test platform is stable and reliable, and it can adapt to the fatigue test requirements of various types of large-load hubs by disassembling and replacing different components. Description of the Drawings

[0049] Figure 1 It is a diagram of the hub central part provided by an embodiment of the present application;

[0050] Figure 2 It is an axonometric view of the hub rotor of the present application embodiment;

[0051] Figure 3 It is a front view of the hub rotor of the present application embodiment;

[0052] Figure 4 It is an axonometric view of the transition shaft provided by an embodiment of the present application;

[0053] Figure 5 It is a front view of the transition shaft provided by an embodiment of the present application;

[0054] Figure 6 It is a schematic structural diagram of the main shaft nut provided by an embodiment of the present application;

[0055] Figure 7 It is a diagram of the lifting ring provided by an embodiment of the present application;

[0056] Figure 8 It is a schematic structural diagram of the hub assembly provided by an embodiment of the present application;

[0057] Figure 9 It is a schematic structural diagram of the sunken foundation pit provided by an embodiment of the present application;

[0058] Figure 10It is a schematic structural diagram of a settling and detachable helicopter hub test fixing device provided by an embodiment of the present application;

[0059] Among them: 1. Hub central part; 1-1. Internal spline; 1-2. Lower end face; 1-3. Upper end face; 2. Hub rotor shaft; 2-1. External spline; 2-2. Stopping end face; 2-3. First bolt hole; 2-4. First positioning surface; 2-5. First external thread; 2-6. Thread lifting hole; 2-7. First boss; 3. Transition shaft; 3-1. Upper bolt hole; 3-2. Upper positioning surface; 3-3. Lower bolt hole; 3-4. Lower positioning surface; 3-5. Groove; 3-6. Second boss; 4. Main shaft nut; 4-1. Internal thread; 5. Hoisting ring; 5-1. Second external thread; A. Hub assembly; 6. Settling foundation pit; 7. Steel frame concrete platform; 7-1. Platform groove; 7-2. Second bolt hole; 7-3. Maintenance passage. Specific implementation manners

[0060] The present invention relates to a helicopter hub fatigue test loading and fixing device for withstanding greater test loads. In order to meet the load-bearing requirements of the hub components of large-tonnage helicopters, a settling and detachable test fixing device for helicopter hubs is formed by combining steel frames and concrete. This fixing device improves the connection strength, enhances the overall rigidity, and improves the maintainability and replaceability of each component to meet the strength, stiffness, and maintainability requirements of helicopter hub fatigue tests.

[0061] Regarding the helicopter hub large-load loading test technology, a fixed test device with a load of up to one hundred tons that is detachable and replaceable is provided. This device simulates the load-bearing boundary conditions of the helicopter hub. Through this fixed test platform, the central part, rotor shaft, transition shaft, large base plate, and steel frame concrete platform on the helicopter hub can form a set of fixed test devices.

[0062] Through this fixing device, the test load can be transmitted from the central part to the rotor shaft, from the rotor shaft to the transition shaft, from the transition shaft to the large base plate, and from the large base plate to the steel frame concrete platform, simulating the load transmission route in the actual installation environment and forming a helicopter hub fixed test platform that can withstand large loads of up to one hundred tons. This fixed test platform has a simple structure, good economy, good maintainability and replaceability, and stable and reliable load-bearing performance. It can withstand large loads of up to one hundred tons and can well meet the requirements of test loading and fixing.

[0063] Please refer to Figures 1 - 10 , the technical solution of the present invention: This fixed test platform is composed of a hub central part 1, a hub rotor shaft 2, a transition shaft 3, a main shaft nut 4, a hoisting ring 5, a settling foundation pit 6, and a steel frame concrete platform 7.

[0064] Tests have shown that this fixed test device can withstand the coordinated loading of a hundred-ton large load in the fatigue test of the helicopter central component.

[0065] The fixed device for helicopter hub tests has undergone multiple iterations. It has evolved from a discrete fixed device to an integrated welded fixed frame, and its load-bearing capacity has gradually increased from small loads to large loads. Since this type of device is formed into a whole by welding, it cannot be partially disassembled and modified. According to current technical requirements, this type of device not only needs to meet the replacement of the hub rotor shaft, but also needs to adapt to the tests of hub central components of other configurations, meeting the requirements of a general-purpose and large-load design.

[0066] A fixed test device for helicopter hubs designed in the present invention adopts a settlement-type foundation design, which can reduce the height of the entire test device and improve the stability and rigidity of the test device during loading. By designing a steel frame concrete platform in the settlement-type foundation pit, the platform is connected to the foundation pit through bolts to achieve the purpose of being detachable. This settlement-type detachable fixed test device can meet the requirements of general-purpose and large-load helicopter hub tests, and truly and accurately simulate the boundary conditions and load transfer characteristics of helicopter hubs. Using this fixed test device for helicopter hub fatigue tests, the test platform is stable and reliable, and different components can be disassembled and replaced to meet the requirements of various types of large-load hub fatigue tests.

[0067] The steps of the method provided in this application are as follows:

[0068] Step 1: Please refer to Figure 1 , first, the hub central component 1 is sleeved onto the external spline 2-1 of the hub rotor shaft 2 through the internal spline 1-1, and the lower end face 1-2 is matched with the stop end face 2-2 in the axial direction.

[0069] Step 2: Design an external thread 2-5 on the hub rotor shaft 2, and screw the internal thread 4-1 of the main shaft nut 4 (see Figure 6 ) into the external thread 2-5 and lock it on the upper end face 1-3 of the central component.

[0070] Step 3: Through the cooperation of the spline shaft and the relative constraint of the end faces, the movement of the central component in the three-dimensional directions on the rotor shaft is constrained, the connection force between the central component and the hub rotor shaft is uniform, the total contact area of the spline connection is large, and the centering is good.

[0071] Step 4: The hub rotor shaft and the transition shaft are connected through the bolt holes 2-3 and 3-1. The two bolt holes have the same aperture and radius, and the two shafts are fastened together with standard bolts. The positioning surfaces of 2-4 and 3-2, 3-4 are used to determine the 0-degree starting position of the hub rotor shaft and the transition shaft.

[0072] Step 5: Design a boss 2-7 at the bottom of the hub rotor shaft and a groove 3-5 at the top of the transition shaft. The boss 2-7 and the groove 3-5 are assembled together, enabling the transfer of the test load of hundreds of tons not only through the bolt holes 2-3 and 3-1 of the rotor shaft and the transition shaft but also through the cylindrical surfaces of the boss 2-7 and the groove 3-5, transmitting the test load downward, ensuring the uniformity of multi-path force transmission of the load, reducing the local load stress, and minimizing the deformation at the root of the rotor shaft.

[0073] Step 6: Design a special threaded lifting hole 2-6 at the middle position of the top of the hub rotor shaft 2 to cooperate with the lifting ring 5 (see Figure 7 ) for the lifting work such as disassembling, replacing, and repairing the fixing device.

[0074] Step 7: Please refer to Figure 8 , the hub central member 1, the hub rotor shaft 2, the transition shaft 3, the main shaft nut 4, the lifting ring 5, and the connecting bolt 6 form the hub assembly A. During the test installation process of the hub assembly A, each component such as the central member and the hub rotor shaft can be disassembled and replaced as needed, and the fatigue tests of each component can be fully verified.

[0075] Step 8: Please refer to Figure 9 , design a circular sunken foundation pit 6 on the horizontal ground. The surface of the foundation pit is set at a certain depth H from the horizontal plane. The purpose of the sunken design is to lower the installation plane of the hub assembly and improve the convenience, safety, and effectiveness of test installation and replacement.

[0076] Step 9: Maintenance channels 7-3 are opened on both the left and right sides of the sunken foundation pit 6 and the steel frame concrete platform 7. Through the maintenance channels 7-3, it is possible to reach the interior of the foundation pit to install and disassemble various components and connecting bolts of the platform, improving the convenience of installation and replacement.

[0077] Step 10: Install a steel frame concrete platform 7 in the sunken foundation pit 6.

[0078] Step 11: Please refer to Figure 10 , the hub assembly is hoisted onto the steel frame concrete platform 7 through the lifting ring 5. The boss 3-6 of the transition shaft 3 cooperates with the groove 7-1 of the steel frame concrete platform, and the bolt hole 3-3 is connected to the bolt hole 7-2 of the steel frame concrete platform. Through the support of the cylindrical surface and the connection of the bolt holes, the uniformity of multi-path force transmission of the load is also ensured, the local load stress is reduced, and the deformation at the root of the transition shaft is minimized.

[0079] In summary, the settlement-type detachable helicopter hub test fixture can accurately simulate the boundary conditions and load transfer characteristics of the helicopter hub, meet the fatigue test requirements of the central component and the hub rotor shaft, and achieve a multi-channel load transfer loading path for large loads in the hundreds of tons. This fixture makes full use of the combined strength effect of the steel frame and concrete, with an ingenious settlement design, resulting in good economy, convenient installation, replaceability, maintainability, and ease of installation, disassembly, and replacement. The entire settlement-type detachable helicopter hub test fixture is fixed in the foundation pit and can provide high-strength support for the helicopter hub test bench for large loads in the hundreds of tons.

Claims

1. A helicopter hub test fixture, characterized in that The device includes: A hub rotor shaft; A hub central member that can be sleeved onto the hub rotor shaft; A transition shaft, one end of which is connected to the hub rotor shaft; A sunken foundation pit; A steel-frame concrete platform disposed within the sunken foundation pit; wherein, the other end of the transition shaft is connected to the steel-frame concrete platform.

2. The device according to claim 1, wherein The device further includes: A main shaft nut for locking the hub central member to the hub rotor shaft. A lifting ring for hoisting the hub assembly; wherein, the hub assembly includes a hub rotor shaft, a hub central member, a transition shaft, and a main shaft nut.

3. The device according to claim 1, characterized in that, The hub central member has an internal spline and upper and lower end faces provided at both ends of the internal spline.

4. The device according to claim 2, characterized in that, The hub rotor shaft includes: A body; An external spline provided on the body; A stop end face provided on the body, the stop end face being located below the external spline; External threads provided on the body, the external threads being located above the external spline; A threaded lifting hole provided at the upper end of the body, the threaded lifting hole being used for installing the lifting ring; A first positioning surface provided at the lower end of the body.

5. The device according to claim 4, characterized in that, The hub rotor shaft further includes: A first boss connected to the first positioning surface.

6. The device according to claim 5, wherein, The transition shaft includes: A cylinder; An upper positioning surface provided at the upper end of the cylinder; A lower positioning surface provided at the lower end of the cylinder; A groove provided on the upper positioning surface; A second boss provided on the lower positioning surface.

7. The device according to claim 6, characterized in that, The surface of the foundation pit of the sunken foundation pit is set at a certain depth H from the horizontal plane.

8. The device according to claim 6, characterized in that, The steel-frame concrete platform includes: A platform groove for installing the second boss; An inspection passage extending into the interior of the sunken foundation pit.

9. A fixed method for helicopter hub test, characterized in that, The method includes: Step 1: First, sleeved the hub central member onto the external spline of the hub rotor shaft through the internal spline, and cooperate with the lower end face and the stop end face in the axial direction. Step 2: Design external threads on the hub rotor shaft, screw the internal threads of the main shaft nut into the external threads 2-5, and lock it on the upper end face of the central member. Step 3: Through the cooperation of the spline shaft and the relative constraint of the end faces, the movement of the central member in the three-dimensional directions on the rotor shaft is constrained, the connection force between the central member and the hub rotor shaft is uniform, the total contact area of the spline connection is large, and the centering is good; Step 4: Connect the hub rotor shaft and the transition shaft through bolt holes. The two bolt holes have the same aperture and radius. Use standard bolts to fasten the two shafts together. The positioning surface is used to determine the 0-degree starting position of the hub rotor shaft and the transition shaft; Step 5: Design a boss at the bottom of the hub rotor shaft and a groove at the top of the transition shaft. The boss and the groove are assembled together, which can not only transfer the test load of hundreds of tons through the bolt holes of the rotor shaft and the transition shaft, but also transfer the test load through the cylindrical surfaces of the boss and the groove, transfer the test load downward, ensure the uniformity of the multi-way force transmission of the load, reduce the local load stress, and reduce the deformation of the root of the rotor shaft; Step 6: Design a special threaded lifting hole at the middle position of the top of the hub rotor shaft, and cooperate with the lifting ring to perform lifting work such as disassembly, replacement, and maintenance of the fixing device; Step 7: The hub central member, hub rotor shaft, transition shaft, spindle nut, lifting ring, and connecting bolts can be disassembled and replaced as needed during the test installation process to fully verify the fatigue tests of each component; Step 8: Design a circular sunken foundation pit on the horizontal ground. The surface of the foundation pit is set at a certain depth H from the horizontal plane. The purpose of the sunken design is to lower the installation plane of the hub assembly and improve the convenience, safety, and effectiveness of test installation and replacement; Step 9: Maintenance channels are provided on both the left and right sides of the sunken foundation pit and the steel frame concrete platform. Through the maintenance channels, it is possible to reach the interior of the foundation pit to install and disassemble various components and connecting bolts of the platform, improving the convenience of installation and replacement; Step 10: Install a steel frame concrete platform in the sunken foundation pit; Step 11: The hub assembly is hoisted onto the steel frame concrete platform by means of a lifting ring. The boss of the transition shaft is fitted with the groove of the steel frame concrete platform, and the bolt holes are connected to the bolt holes of the steel frame concrete platform. Through the support of the cylindrical surface and the connection of the bolt holes, the uniformity of multi-path force transmission of the load is ensured, the local load stress is reduced, and the deformation at the root of the transition shaft is minimized.

Images