Anti-overturning device for lateral vibration of super-large and super-heavy vibration system based on linear bearing

Abstract

The application provides a large and super-heavy vibration system lateral vibration anti-overturning device based on a linear bearing, which is installed at a position of a vibration tool and a butt joint surface of a product to be tested, and comprises a bearing connecting device, a bearing and an auxiliary supporting device; the bearing connecting device comprises a bearing connecting plate and a bearing support which are connected with a bearing guide light pole; the bearing connecting plate is connected with the vibration tool and the bearing guide light pole, and transmits an overturning torque to the bearing guide light pole; the bearing support positions the bearing and transmits a load force to the ground through the auxiliary supporting device. The application can effectively enhance the lateral anti-overturning capacity of the vibration test system, and ensure the loading and test safety of high-level tests.

Description

Technical Field

[0001] This invention belongs to the field of reusable rocket development, testing and verification under low-frequency vibration environment. Specifically, it relates to a transverse vibration anti-overturning device for ultra-large and ultra-heavy vibration systems based on linear bearings, which can meet the anti-overturning requirements of ultra-large and ultra-heavy components such as single-section and combined-section of medium and heavy launch vehicles during transverse vibration. Background Technology

[0002] Vibration testing refers to simulating the various vibration environments a product encounters during transportation, installation, and use in a laboratory to determine its ability to withstand various environmental vibrations. For launch vehicles, flight involves complex and diverse vibration environments, including steady-state vibration of the rocket engine, boundary layer pulsating pressure, POGO vibration, tank liquid sloshing, and interstage separation. These significantly impact the safety and normal operation of astronauts, instruments, equipment, launch vehicles, and upper stages; especially for reusable launch vehicles, the vibration loads experienced during recovery are even more severe than during takeoff. Therefore, ground-based mechanical environment testing is necessary. Based on the launch vehicle flight profile load environment analysis, the first and second stages of the lower stage launch vehicle primarily bear the low-frequency vibration loads and high-frequency aerodynamic loads from the rocket engine. Therefore, the ground-based mechanical environment testing method involves using a low-frequency sinusoidal sweep test to assess the low-frequency vibration environment adaptability of the stages and using a reverberation noise test to assess the high-frequency aerodynamic load environment adaptability of the stages.

[0003] Low-frequency vibration tests of launch vehicle modules employ either high-thrust electromagnetic vibration tables or multiple tables operating in parallel to apply loads. Considering the current development progress of high-thrust vibration tables in China (single electromagnetic vibration tables of 70 tons and 100 tons have already been delivered and put into use), the difficulty of multi-table parallel excitation tests, and the extremely long test cycles, low-frequency vibration tests of medium, large, and heavy launch vehicle modules mostly use a single high-thrust electromagnetic vibration table.

[0004] The test requires vibration assessment of the module in three directions: X-axis (axial direction), Y-axis (quadrants I and III), and Z-axis (quadrants II and IV). During the X-axis test, the module's center of mass is essentially aligned with its geometric center, resulting in a relatively small overturning moment. For the Y and Z-axis tests, a lateral sliding platform system is required. This system consists primarily of a hydrostatic oil film sliding support platform. Under the combined action of the high-pressure oil film and sliding bearings, the support platform possesses high load-bearing capacity and axial free sliding capability, while also providing a certain anti-overturning moment. Due to the characteristics of the medium-to-heavy-lift launch vehicle—excessive mass, extremely high center of mass, and large test magnitude—the overturning moment generated during lateral vibration is exceptionally large, reaching a maximum of 2.5 x 10⁻⁶ at resonance. 7Exceeding the overturning resistance limit of the test system (N*m) can lead to serious consequences such as product overturning, damage to test equipment and modules, and test abort. Currently, this problem is often mitigated by reducing the scale of the test; however, with the development of launch vehicles and the demand for reusable launch vehicles, reducing the scale of the test cannot effectively evaluate the modules, posing a risk of undertesting and seriously affecting the development process of new launch vehicles. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes a transverse vibration anti-overturning device for ultra-large and ultra-heavy vibration systems based on linear bearings. By introducing linear bearings into the vibration testing system and designing auxiliary support devices to enhance the transverse anti-overturning capability of the vibration testing system, the testing capability is effectively improved. This allows for effective mechanical environment assessment of medium-to-large and heavy rocket sections, ensuring the loading and safety of high-volume tests.

[0006] A transverse vibration anti-overturning device for an ultra-large and ultra-heavy vibration system based on linear bearings is installed on the mating surface between the vibration fixture and the test specimen. It includes a bearing connection device, a bearing, and an auxiliary support device. The bearing connection device includes a bearing connecting plate and a bearing support connected to a bearing guide rod. The bearing connecting plate connects the vibration fixture and the bearing guide rod, and transmits the overturning moment to the bearing guide rod. The bearing support positions the bearing and transmits the load force to the ground through the auxiliary support device.

[0007] The auxiliary support device includes a support platform, an upright column, a base, and diagonal supports. The support platform is used to install bearing supports, the upright column is used to support the height and, as the main load-bearing component, transmits the load force to the ground through the base. The base is fixed to the ground, providing sufficient rigidity and strength to the anti-overturning device system, and the diagonal supports are used to enhance the rigidity in the vibration direction.

[0008] The specific selection of the bearing is as follows: Based on the predicted overturning moment results and the overturning moment parameters of the test system, the required overturning moment difference is obtained; the load borne by a single bearing is determined based on the number of bearings and the bearing lever arm length; and the bearing model is determined based on the load.

[0009] The preferred method for connecting the bearing guide rod and the bearing connecting plate is welding, followed by screwing, and finally, tightening bushing connection.

[0010] The deformation of the bearing guide rod is less than the oil film gap of the hydrostatic oil film sliding support platform.

[0011] The surface of the bearing guide rod is reinforced by chrome plating.

[0012] The beneficial effects of this invention are as follows: (1) It can improve the level of lateral vibration test of medium and heavy launch vehicle sections.

[0013] Its beneficial effects are as follows: Compared with the traditional method of reducing the test scale for lateral vibration tests of medium and heavy rocket sections, the anti-overturning device proposed in this invention can improve the anti-overturning capability of the lateral vibration test system, thereby enabling high-scale lateral vibration assessment tests and ensuring the high-scale test assessment requirements of medium and heavy launch vehicle sections.

[0014] (2) The lateral overturning resistance of the high-thrust electromagnetic vibration table can be expanded and improved according to the test requirements.

[0015] Its beneficial effects are as follows: The overturning resistance parameters of the lateral vibration test system of a single high-thrust electromagnetic vibration table are fixed at the factory. Improving the overturning resistance by modifying the hydraulic oil film support platform is often costly, and the number of hydraulic bearings that can be added is limited by size, the improvement is certain, and the modification cycle is long. This invention can quickly improve the overturning resistance of the lateral vibration test system according to the test requirements by changing the lever arm length, bearings and other components, which has the advantages of low cost and short cycle.

[0016] (3) It can be extended to other small and medium-sized transverse vibration test systems.

[0017] Its beneficial effects are as follows: Except for the high-thrust electromagnetic vibration table, whose lateral overturning resistance parameters are fixed, the lateral overturning resistance parameters of other small and medium-sized electromagnetic vibration systems and hydraulic vibration systems are also fixed, making it impossible to conduct high-level tests on high-center-of-gravity, slender products; this invention can improve the lateral overturning resistance of small and medium-sized lateral vibration test systems by reducing the size of the device.

[0018] (4) It can be applied to multiple parallel-excited transverse vibration systems.

[0019] Its beneficial effects are as follows: For the lateral vibration test of ultra-large and ultra-heavy components such as single-section and combined-section modules of medium and heavy launch vehicles, the test and evaluation can also be carried out by parallel excitation of multiple vibration tables. One of the key technologies is the lateral vibration system, which is an ultra-large hydraulic oil film support platform with an extremely large added mass, which seriously consumes the thrust of the test system. This invention can provide sufficient anti-overturning moment by increasing the lever arm and selecting large-load bearings, effectively reducing the added mass of the test system. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the design of a transverse vibration anti-overturning device for an ultra-large and ultra-heavy vibration system based on linear bearings. Figure 2 This is a schematic diagram of a transverse vibration anti-overturning device for an ultra-large and ultra-heavy vibration system based on linear bearings. Figure 3This is a schematic diagram of the bearing connection design; Figure 4 This is a schematic diagram of the geometric dimensions of the bearing connecting plate; Figure 5 This is a schematic diagram of the geometric dimensions of the bearing support; Figure 6 This is a schematic diagram of the auxiliary support structure. Detailed Implementation

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection claimed by the present invention.

[0022] Figure 1 This paper presents a design scheme for an anti-overturning device for a transverse vibration system based on linear bearings in an ultra-large and ultra-heavy vibration system. The vibration fixture is a load transfer component connecting the electromagnetic vibration table and the test specimen. At the same time, the overturning moment during resonance is also transmitted in reverse to the electromagnetic vibration table through the vibration fixture. Therefore, installing the anti-overturning device on the mating surface between the vibration fixture and the test specimen can effectively share the overturning moment and ensure the safety of the test equipment.

[0023] The design of the anti-overturning device for the lateral vibration of the ultra-large and ultra-heavy vibration system mainly includes bearing selection, bearing connection device design, and auxiliary support device design.

[0024] Bearing selection. Based on the predicted overturning moment results and the overturning moment parameters of the test system, the required overturning moment difference can be determined. The load that a single bearing can withstand is determined by comprehensively considering the number of installable bearings and the bearing lever arm length. The bearing model is then determined based on the applied load.

[0025] Bearing connection design. The bearing connection includes the bearing guide rod, bearing support, and bearing connecting plate. The diameter and length of the bearing guide rod are determined based on the bearing model and the experimental lateral vibration displacement. The dimensions of the bearing support are determined based on the bearing model and installation height. The dimensions of the bearing connecting plate are determined based on the dimensions of the bearing guide rod and the tooling connection mechanical interface. Finally, strength simulation methods are used for strength verification to ensure that the stress and deformation of the bearing guide rod, bearing support, and bearing connecting plate meet the service requirements.

[0026] Auxiliary support design. The auxiliary support design mainly refers to the installation platform design. It can be constructed using modular components such as cast blocks to build a bearing installation platform, which is used to install the bearing and transfer the load to the ground.

[0027] 1. Bearing selection The overturning moment required for the test can be estimated using simulation methods or engineering experience methods.

[0028] The simulation method is as follows: ① Establish the finite element model of the test object and the finite element model of the tooling, and assign corresponding material properties; ② Assemble the finite element models, establish connection relationships, pre-evaluate the mass of the anti-overturning device, and apply it to the tooling in the form of mass points to establish boundary constraints; ③ Apply loads according to the test conditions, give the damping coefficient, and perform harmonic response analysis; ④ Extract the overturning moment at the docking surface based on the simulation results.

[0029] Engineering experience methods are as follows: In the formula, For the quality of the test sample, The center of mass of the sample to be tested. For the quality of the vibration fixture, The center of mass of the vibrating fixture, For the estimated mass of the anti-overturning device, For the estimated center of gravity of the anti-overturning device, s is the magnification factor.

[0030] The load borne by a single bearing is determined based on the overturning moment difference, lever arm, and number of bearings: After determining the load capacity of a single bearing, the bearing model must be determined according to the principle of a safety margin of not less than 1.2 times.

[0031] 2. Bearing connection design The bearing connection design includes the bearing guide rod, bearing connecting plate, and bearing support, such as... Figure 3 As shown.

[0032] 1) Bearing guide rod The bearing guide rod is a key component, connecting both the bearing and the bearing connecting plate, and undertaking the functions of motion decoupling and load-bearing. The main parameters of the bearing guide rod include material properties, diameter, length, and the transition method with the bearing connecting plate. ① The diameter and length of the bearing guide rod are determined based on the selected bearing and the tested lateral vibration displacement. ② Material properties are determined based on strength criteria, requiring that the deformation of the bearing guide rod should be less than the oil film clearance of the hydrostatic oil film sliding support platform. ③ To ensure good sliding characteristics with the bearing, the surface roughness of the bearing guide rod should be as small as possible, while its hardness should be sufficiently high. Surface enhancement processes, such as chrome plating, are recommended. ④ The preferred transition method between the bearing guide rod and the bearing connecting plate is welding, followed by screwing, and lastly, a tightened bushing connection.

[0033] 2) Bearing connecting plate The bearing connecting plate connects the vibration fixture and the bearing guide rod, transmitting the overturning moment to the bearing guide rod. Key parameters include the connection method with the bearing guide rod, the connection method with the vibration fixture, geometric dimensions, and strength. ① The connection method with the bearing guide rod must be consistent with that of the bearing guide rod itself; welding is preferred, followed by screw connection, and finally, a shrink-fit bushing connection. ② For the connection with the vibration fixture, screw connection is recommended for ease of installation and state transition; the shear strength of the screws must be checked during the design phase. ③ The geometric dimensions of the bearing connecting plate include length L1, width L2, and thickness T. The length is determined based on the lever arm parameters during bearing selection, and the width and thickness of the connecting plate are determined based on strength principles. ④ The bearing connecting plate must be checked based on strength principles, requiring that the deformation of the bearing connecting plate be less than the oil film clearance of the hydrostatic oil film sliding support platform. Figure 4 As shown.

[0034] 3) Bearing support A bearing support is a component that secures the bearing, positions it, and transfers the load to the ground via auxiliary support. Key parameters include length (a), width (b), height (c), bearing slot, and the auxiliary support connection method. Figure 5 As shown. ① The bearing shape needs to be designed according to the test space and checked based on the strength criterion, requiring that the deformation be less than the oil film gap of the hydrostatic oil film sliding support platform. ② The bearing slot is used to limit the lateral displacement of the bearing, and its dimensional parameters must be consistent with the selected bearing. ③ The auxiliary support adapter is used to connect with the auxiliary support and transfer the load force to the ground through the auxiliary support.

[0035] 3. Auxiliary support design Auxiliary support design primarily involves the design of the installation platform. This platform can be constructed using modular components such as cast blocks to install bearings and transfer loads to the ground. Auxiliary support designs can be divided into two categories. The first category is based on the vibration table body, mainly used for installing inner bearings. Depending on actual needs, the height of the bearing support can be increased to directly connect it to the vibration table body. The second category is based on modular components, such as standard cast blocks and steel beams, to build the installation platform. ① The support platform uses bearing supports and must ensure sufficient flatness and parallelism. ② The upright column supports the height and, as the main load-bearing component, transfers the load to the ground through the base. ③ The base is used to fix the system to the ground, providing sufficient rigidity and strength to the anti-overturning device system. ④ Diagonal supports enhance the rigidity in the vibration direction, improving the dynamic characteristics of the anti-overturning device system. Figure 6 As shown.

[0036] 4. Verification The assembly system needs to be verified, mainly including dynamic characteristic verification and strength verification. It is recommended to use digital simulation methods for response prediction. ① The auxiliary support should have sufficient stiffness characteristics, with a first-order frequency higher than 100Hz. ② It should have sufficient strength characteristics; the system strength level should be less than 1 / 5 of the material's ultimate strength to ensure test safety.

[0037] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transverse vibration anti-overturning device for ultra-large and ultra-heavy vibration systems based on linear bearings, characterized in that, Installed on the mating surface between the vibration fixture and the test specimen, it includes a bearing connection device, a bearing, and an auxiliary support device; the bearing connection device includes a bearing connecting plate and a bearing support connected to a bearing guide rod, the bearing connecting plate connects the vibration fixture and the bearing guide rod, and transmits the overturning moment to the bearing guide rod, and the bearing support positions the bearing and transmits the load force to the ground through the auxiliary support device.

2. The lateral vibration anti-overturning device according to claim 1, characterized in that, The auxiliary support device includes a support platform, an upright column, a base, and diagonal supports. The support platform is used to install bearing supports, the upright column is used to support the height and, as the main load-bearing component, transmits the load force to the ground through the base. The base is fixed to the ground, providing sufficient rigidity and strength to the anti-overturning device system, and the diagonal supports are used to enhance the rigidity in the vibration direction.

3. The lateral vibration anti-overturning device according to claim 1, characterized in that, The specific selection of the bearing is as follows: Based on the predicted overturning moment results and the overturning moment parameters of the test system, the required overturning moment difference is obtained; the load borne by a single bearing is determined based on the number of bearings and the bearing lever arm length; and the bearing model is determined based on the load.

4. The lateral vibration anti-overturning device according to claim 1, characterized in that, The preferred method for connecting the bearing guide rod and the bearing connecting plate is welding, followed by screwing, and finally, tightening bushing connection.

5. The lateral vibration anti-overturning device according to claim 1, characterized in that, The deformation of the bearing guide rod is less than the oil film gap of the hydrostatic oil film sliding support platform.

6. The lateral vibration anti-overturning device according to claim 1, characterized in that, The surface of the bearing guide rod is reinforced by chrome plating.

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