An equivalent loading device for realizing the interference of the locating collar of the rotor flange-bolt connection structure

Abstract

The present invention discloses an equivalent loading device for realizing the interference of the mating surface of a rotor flange-bolt connection structure. This device can achieve the equivalent interference of the mating surface during the assembly of the rotor flange-bolt connection structure, and includes a square support with a boss, a C-shaped beam simulating the flange edge, an upper and lower split-type stiffness adjuster simulating the radial stiffness of the real rotor cylindrical shell, and a bench fixedly connected to a universal tensile testing machine. The present invention has the advantages of convenient installation and disassembly, easy implementation, high universality, etc., and can be used for the mechanical properties and other in-depth studies of the rotor connection structure of an aeroengine under the condition of interference fitting of the mating surface.

Description

Technical Field

[0001] The invention belongs to the technical field of aeroengines, and particularly relates to an equivalent loading device for realizing interference fit of a rotor flange-bolt connection structure stop. Background Technique

[0002] The interference fit connection of the stop has the advantages of simple structure, good centering property, strong bearing capacity, etc., but has high requirements for assembly technology and fitting accuracy. The flange-bolt stop connection part in the rotor structure of an aeroengine is a typical interference fit connection, whose function is to center and bear a certain torque. The research on the interference assembly loading technology for the stop part is the key part to improve the rotor assembly loading quality.

[0003] In practical engineering applications, the interference stop of the rotor usually adopts the hot-fitting method to make the containing part and the contained part generate a fitting clearance or reduce the interference amount. After the mating parts are in contact, the parts are pressed tightly to avoid the generation of gaps due to cooling shrinkage or improper assembly at the interference stop end face, which affects the concentricity and balance quality of the rotor. Relevant domestic and foreign enterprises have developed large rotor press-fitting workbenches and used hydraulic devices to assemble the stop connection structure. However, the above-mentioned assembly loading method has too high requirements for the working site, equipment and assembly technology, and often only a few types of engine assemblies are adapted to one workbench, which brings great obstacles to the daily research on the mechanical characteristics of aeroengine rotors by scholars. Moreover, it is unrealistic to use the original-size complete rotor system during the daily test process. Therefore, it is necessary to design a local equivalent loading device that can simulate the structural characteristics, mechanical characteristics and load environment of the real flange-bolt connection structure of an aeroengine rotor. Summary of the Invention

[0004] To solve the above technical problems, the invention provides an equivalent loading device for realizing interference fit of a rotor flange-bolt connection structure stop, which can simulate the structural characteristics, mechanical characteristics and load environment of the real flange-bolt connection structure of an aeroengine rotor and realize the equivalent loading of the interference fit of the flange-bolt connection structure stop. The invention realizes the equivalent loading of the interference fit of the flange-bolt connection structure of the aeroengine rotor through the above equivalent loading device. After the interference fit assembly loading is completed, relevant problems such as the mechanical process of the rotor connection structure and the mechanical process of interface damage evolution under different loads can be further explored.

[0005] To achieve the above object, the technical solution adopted by the invention is:

[0006] An equivalent loading device for realizing interference fit of a rotor flange-bolt connection structure stop includes a square support with a boss for simulating the stop, a C-shaped beam for simulating the flange edge of the turbine disk, an upper and lower split stiffness adjuster, and a bench connected to the tabletop of a universal tensile machine;

[0007] The square support simulates a single bolt sector of the sealing grate tooth plate, and its geometric dimensions are consistent with the actual connection structure. The boss on the square support simulates the constraint effect of the centering cylindrical surface in the real connection structure; the square support is fixed to the stand by two first bolts, and the stand is connected to the table of a commonly used universal stretching machine;

[0008] The C-beam is provided with an upper through hole and a lower through hole, so as to facilitate the application of an eccentric axial tension to the rotor end face by a stretching device, and to simulate the axial tension that the rotor connection structure end face may be subjected to under actual working conditions;

[0009] The C-shaped beam is provided with thick columns on both sides of the first C-shaped beam and thick columns on both sides of the second C-shaped beam on the left and right sides, so that the stopper is still in a plane state under radial load and the overall radial rigidity is strong;

[0010] The C-beam through hole protruding part is provided with a large chamfer, which reduces stress concentration and avoids deformation of the stopper;

[0011] The upper and lower petal stiffness adjuster comprises an upper petal of the stiffness adjuster and a lower petal of the stiffness adjuster, adopts an upper and lower petal structure, and is assembled and connected by 8 third bolts; during the test, the radial loading displacement boundary condition of the tensile machine is used to simulate the relative slip trend of the connection interface caused by the uncoordinated displacement of the components on both sides under the real load environment; in order to simulate the radial stiffness of the column shell of the real rotor, the wall thickness and cone angle of the upper and lower petal stiffness adjuster are set so that its actual stiffness is one order of magnitude lower than the radial stiffness of the C-beam.

[0012] Furthermore, the C-beam is connected to the square support through a second aviation material bolt, and the preload force is controlled to be 1 / 3 of the standard value.

[0013] Furthermore, when the stopper is subjected to interference loading, the C-beam is pre-stretched by changing the displacement boundary conditions of the universal stretching machine; the radial contact force under the interference state is calculated by the finite element simulation analysis software, and then the pre-stretching amount of the universal stretching machine is calculated. ; Stretching machine As the starting position, the test load is applied.

[0014] Furthermore, the end face contact between the square support and the C-beam is used to simulate the end face contact in the real connection structure, and the connection between the lower surface of the boss on the square support and the upper surface of the C-beam is used to simulate the constraint effect of the centering cylindrical surface in the real connection structure. The two are tightened by applying the normal initial preload force through the actual size of the aviation bolt. The tightening force can be converted from the tightening torque.

[0015] Further, the upper lobe of the stiffness adjuster is connected to the universal tensile machine through a pin, and the lower lobe of the stiffness adjuster is connected to the C-beam through two screws. The C-beam is pre-tensioned by the tensile machine to generate a predetermined pre-tightening force with the spigot. The pre-tension amount of the C-beam pre-tensioned by the tensile machine can be obtained by corresponding formula conversion based on the radial contact force in the interference state calculated by a commercially available finite element simulation analysis software. Thus, the interference fit state between the simulated spigot centering cylindrical surfaces is achieved.

[0016] The beneficial effects of the present invention are as follows: It can achieve equivalent loading of the spigot interference of the aero-engine rotor flange-bolt connection structure at low cost, and is convenient for installation and disassembly. After the spigot interference assembly loading is completed, relevant issues such as the mechanical process of the rotor connection structure and the mechanical process of interface damage evolution under different loadings can be further explored. Description of the Drawings

[0017] Figure 1 is a schematic diagram of the spigot assembly of the aero-engine flange-bolt connection structure.

[0018] Figure 2 is a schematic diagram of the assembly of the present invention.

[0019] Figure 3 is Figure 2 a schematic diagram of the square base structure in

[0020] Figure 4 is Figure 2 a schematic diagram of the C-beam structure in

[0021] Figure 5 is Figure 2 a schematic diagram of the upper and lower split-type stiffness adjuster structure in

[0022] In the figure, A. The sealing labyrinth disc of the aero-engine; B. The high-pressure turbine disc of the aero-engine; C. The cylindrical centering surface of the front flange of the turbine disc; D. The end face contact surface between the turbine disc and the labyrinth disc.

[0023] 1. Square support, 2. C-beam, 3. Upper lobe of the stiffness adjuster, 4. Lower lobe of the stiffness adjuster, 5. Bench, 6. First bolt, 7. Second aviation material bolt, 8. Third bolt, 9. Fourth screw, 10. Boss, 11. Upper through hole of the C-beam, 12. Lower through hole of the C-beam, 13. Large chamfer at the through hole extension, 14. Thick columns on both sides of the first C-beam, 15. Thick columns on both sides of the second C-beam. Detailed Embodiment

[0024] The present invention will be further described below with reference to the drawings and embodiments.

[0025] As shown in Figure 1As shown in the figure, it is a typical connecting structure of the rotor column shell and disk in an aero-engine, including the sealing labyrinth disk A of the aero-engine, the high-pressure turbine disk B of the aero-engine, the cylindrical centering surface C of the front flange of the turbine disk, and the end face contact surface D between the turbine disk and the labyrinth disk. Based on this structure, the present invention designs an equivalent loading device for realizing the interference of the rotor flange-bolt connection structure.

[0026] As Figures 2-5 shown, an equivalent loading device for realizing the interference of the rotor flange-bolt connection structure of the present invention includes a square support 1 with a boss 10 simulating the stop of the cylindrical centering surface C of the front flange of the turbine disk, a C-shaped beam 2 simulating the flange edge of the turbine disk, an upper and lower split stiffness adjuster, a bench 5 connected to the tabletop of a universal tensile testing machine. The square support 1 is connected to the bench 5 through a first bolt 6, the square support 1 is connected to the C-shaped beam 2 through a second aviation material bolt 7, the upper and lower split stiffness adjusters are connected through eight third bolts 8, and the lower flap of the stiffness adjuster is fixed to the C-shaped beam 2 through a fourth screw 9. The C-shaped beam 2 is provided with an upper through hole 11 and a lower through hole 12 in the C-shaped beam, which is convenient for applying eccentric axial forces received by the rotor end face in different stop flanging directions through a stretching device. The C-shaped beam 2 is also provided with thick columns 14 on both sides of the first C-shaped beam and thick columns 15 on both sides of the second C-shaped beam, so that the boss 10 simulating the stop is still in a planar state under radial loads, and the overall radial stiffness of the C-shaped beam 2 is relatively strong. The C-shaped beam 2 is also provided with a large chamfer 13 at the extension of the through hole, which is used to reduce stress concentration and avoid deformation of the boss 10 simulating the stop. The upper and lower split stiffness adjusters include an upper flap 3 of the stiffness adjuster and a lower flap 4 of the stiffness adjuster.

[0027] The specific assembly scheme and loading method of the present invention are as follows:

[0028] 1) Connect the bench 5 to the tabletop of the universal tensile testing machine, and by adjusting the position, make the square support 1 directly below the force arm of the tensile testing machine.

[0029] 2) Connect the C-shaped beam 2 to the square support 1 through the second aviation material bolt 7 (at this time, control the pre-tightening force to be 1 / 3 of the standard value).

[0030] 3) Fix the C-shaped beam 2 to the lower flap 4 of the stiffness adjuster through two fourth screws 9.

[0031] 4) Connect the assembled structure to the bench 5 through two first bolts 6.

[0032] 5) The upper flap 3 and the lower flap 4 of the stiffness adjuster are closed. By adjusting the height of the force arm of the stretching machine, the upper flap 3 of the stiffness adjuster is gradually brought closer to the lower flap 4 of the stiffness adjuster. After they are close, the upper flap 3 and the lower flap 4 of the stiffness adjuster are tightened with 8 third bolts 8. During this process, it is necessary to observe the stress state of the force arm of the stretching machine to ensure that after the upper flap 3 and the lower flap 4 of the stiffness adjuster are finally closed, the force arm is neither under tension nor under pressure.

[0033] 6) The C-beam 2 is pre-stretched by a universal stretching machine to generate a predetermined pre-tightening force on the boss 10 simulating the mating surface, thereby simulating the interference fit state between the centering cylindrical surfaces of the mating surface.

[0034] 7) After the interference of the mating surface is completed, the required bolt pre-tightening force for the test is applied to the second aviation material bolt 7 by the torque control method.

[0035] When performing the interference loading of the mating surface, it is achieved by pre-stretching the C-beam 2 by changing the displacement boundary conditions of the universal stretching machine, and the pre-stretching amount is:

[0036] (1)

[0037] In the formula, is the radial interaction force generated between the cylindrical surfaces in the interference state, and the radial contact stress in the interference state can be obtained through finite element simulation calculation. After that, the specific magnitude of is obtained by integrating the contact stress. Subsequently, the stretching machine starts from and performs the formal test load loading. Therefore, the displacement boundary condition of the test piece is actually .

[0038] The torque control method mentioned above includes that there is a conversion relationship between the tightening torque and the jacking force of the second aviation material bolt 7:

[0039] (2)

[0040] In the formula, is the tightening torque, is the tightening force coefficient (related to the surface state and hardness of the material), is the jacking force of the bolt acting on the contact interface, is the nominal diameter of the bolt.

[0041] The up-and-down split type stiffness adjuster is mainly used to connect the tensile machine and the C-shaped beam 2. During the test, the radial loading displacement boundary condition is applied through the tensile machine to simulate the relative slip trend generated at the connection interface due to the displacement incoordination of the components on both sides under the real load environment. In order to simulate the radial stiffness of the cylindrical shell of the real rotor, after simulation calculation, the stiffness adjuster is designed with an appropriate wall thickness and taper angle so that its actual stiffness is one order of magnitude lower than the radial stiffness of the C-shaped beam.

[0042] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. An equivalent loading device for realizing the interference of the locating ring of the rotor flange-bolt connection structure, characterized in that: It includes a square support (1) with a boss-simulated stop, a C-shaped beam (2) simulating the flange edge of a turbine disk, an upper and lower split-type stiffness adjuster, and a bench (5) connected to the tabletop of a universal tensile testing machine; The square support (1) simulates a single bolt sector of a seal labyrinth disk, and its geometric dimensions are consistent with the actual connection structure. The boss (10) on the square support simulates the constraint effect generated by the centering cylindrical surface in the real connection structure. The square support (1) is fixedly connected to the bench (5) through two first bolts (6). The C-shaped beam (2) is provided with an upper through-hole (11) and a lower through-hole (12) of the C-shaped beam, which is convenient for applying the eccentric axial tension received by the rotor end face through a stretching device, and is used to simulate the axial tension effect that the rotor connection structure end face may receive under the actual working conditions; The C-shaped beam (2) is provided with first thick columns (14) on both sides and second thick columns (15) on both sides of the C-shaped beam, so that the stop is still in a flat state under the radial load; A large chamfer (13) is provided at the extension of the through-hole of the C-shaped beam (2), which reduces stress concentration and avoids stop deformation at the same time; The upper and lower split-type stiffness adjuster includes an upper stiffness adjuster flap (3) and a lower stiffness adjuster flap (4), and adopts an upper and lower split-type structure, which is assembled and connected through eight third bolts (8). During the test, the displacement boundary conditions are radially loaded by a tensile testing machine to simulate the relative slip trend generated by the displacement incoordination of the two-side components at the connection interface under the real load environment. To simulate the radial stiffness of the cylindrical shell of a real rotor, the wall thickness and taper angle of the upper and lower split-type stiffness adjuster are set so that its actual stiffness is one order of magnitude lower than the radial stiffness of the C-shaped beam.

2. An equivalent loading device for achieving interference of the rabbet of the rotor flange-bolt connection structure according to claim 1, characterized in that: The C-shaped beam (2) is connected to the square support (1) through second aviation material bolts (7), and at this time, the pre-tightening force is controlled to be 1 / 3 of the standard value.

3. An equivalent loading device for achieving interference of the rabbet of the rotor flange-bolt connection structure according to claim 2, characterized in that: When performing rabbet interference loading, it is achieved by pre-tensioning the C-beam by changing the displacement boundary conditions of the universal tensile testing machine; the radial contact force in the interference state is calculated by a finite element simulation analysis software, and then the pre-tensioning amount of the universal tensile testing machine is calculated. ; The tensile testing machine starts from and conducts test load loading.

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