Paddle-shaft-shell coupling system high-precision vibration simulation experiment device

Abstract

The invention discloses a high-precision vibration simulation experiment device for a paddle-shaft-shell coupling system, and belongs to the technical field of ocean engineering vibration simulation. Comprising a test structure module, a quick disassembly tool module, a signal input module and a signal acquisition and processing module, the test structure module comprises a shell, and a motor, a balancing weight, a propulsion shafting and an eccentric block which are coaxially mounted in the shell; a propeller is mounted at the output end of the propulsion shafting; the quick disassembly tool module suspends and lifts the test structure module in a flexible connection mode, and is used for simulating the boundary-free constraint of the underwater vehicle under the actual working condition; the signal input module is used for sending an instruction to a driving part of the test structure module; the signal acquisition and processing module comprises a sensor and an upper computer. The problems that in the prior art, constraint conditions and excitation in fluid are difficult to accurately simulate, and a fixed constraint method is high in error are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of marine engineering vibration simulation, and in particular relates to a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system. Background Art

[0002] Underwater vehicles play an indispensable role in national defense with their strong concealment and sudden attack capabilities. Good concealment not only ensures the ability of underwater vehicles to launch sudden attacks, but is also the key to maintaining their survival. Studies have shown that for every 5 decibel increase in the radiation noise of such systems, the enemy's alarm distance will increase by 50% and the effective hit rate will decrease by 25%. Underwater vehicles are essentially an internal high-speed rotating power system. According to the source and transmission path of its vibration noise, it can be simplified into a propeller-shaft-shell coupling structure. The vibration radiation noise mainly comes from the internal engine. The engine outputs torque during operation, which drives the spiral to rotate at high speed through the propulsion shaft system, resulting in a sudden change in the external surrounding flow field to generate flow noise; the other part mainly comes from the vibration of the propeller and the engine, which is transmitted to the shell through the connection structure, thereby driving the fluid medium around the outer surface to cause radiation noise.

[0003] Conducting vibration analysis experiments on propeller-shaft-shell coupling models is an important means to optimize structural parameters, evaluate device performance, and reduce vibration and noise. Deepwater experiments can truly simulate the actual working conditions and operating environment of the system. However, the deepwater basin environment is special and has many uncertain factors, which poses huge risks. Each acquisition of sensor data requires a lot of manpower and high costs. At present, the vibration and noise analysis research of such systems is concentrated in the theoretical numerical simulation stage.

[0004] Building a simulation experiment device on land instead of water experiments provides a new solution. However, it is difficult to accurately simulate the constraints and excitations in the fluid. The fixed constraint method has a high error. Using the theoretical model numerical solution feedback guidance has become an urgent need for the design of an onshore vibration simulation test bench for the propeller-shaft-shell coupling system. To this end, starting from theoretical layout, three-dimensional design and other aspects, a high-precision vibration simulation test system and method for the propeller-shaft-shell coupling system is provided to solve the above problems and realize accurate vibration simulation of underwater vehicles on land. Summary of the invention

[0005] Technical issues to be solved:

[0006] In order to avoid the shortcomings of the prior art, the present invention provides a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, which connects the propeller-shaft-shell as an integral unit and adopts a hoisting form for positioning to simulate the actual working condition of an underwater vehicle, and optimizes the counterweight block and the eccentric block to solve the problems that the prior art is difficult to accurately simulate the constraints and excitations in the fluid, and the fixed constraint method has high errors.

[0007] The technical solution of the present invention is: a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, comprising a test structure module, a quick disassembly tooling module, a signal input module, and a signal acquisition and processing module;

[0008] The test structure module includes a housing and a motor, a counterweight, a propulsion shaft system and an eccentric block coaxially installed therein. A propeller is coaxially installed at the output end of the propulsion shaft system to simulate a physical underwater vehicle. The propeller is placed in a water tank to simulate the underwater working state of the propeller.

[0009] The quick-detachable tooling module suspends and hoists the test structure module in a flexible connection manner to simulate the unbounded constraints of the underwater vehicle under actual working conditions;

[0010] The signal input module is used to send instructions to the driving components of the test structure module to adjust the different speeds of the propeller and the water level in the water tank to simulate external excitations under different working conditions;

[0011] The signal acquisition and processing module includes a sensor and a host computer. The sensor sends test data to the host computer through a data acquisition device, and the host computer analyzes and processes the received data to obtain experimental results.

[0012] A further technical solution of the present invention is: a counterweight block is arranged on the periphery of the motor, eccentric blocks are installed at both ends of its rotating shaft, the output end of the rotating shaft is coaxially connected with the input end of the propulsion shaft system, and the deviation amount is controlled by adjusting the overlapping angle of the eccentric blocks at both ends.

[0013] A further technical solution of the present invention is: the method for selecting the counterweight block is:

[0014] Preliminary calculation: According to the experimental requirements, calculate the total counterweight required for the experimental device to ensure that the system can maintain balance under static and dynamic conditions;

[0015] Select the number of ballast blocks: According to the calculated total ballast weight, select the appropriate number of standard ballast blocks to ensure that the final total weight meets the calculation requirements;

[0016] Counterweight installation: Install the selected counterweight to the housing and motor to ensure that the weight is evenly distributed to maintain the balance of the test structure module.

[0017] A further technical solution of the present invention is: a method for selecting the overlap angle of the eccentric block is to construct a dynamic model of the actual underwater vehicle physical model, and obtain a predicted value of the shell vibration acceleration through simulation; then the true value of the shell vibration acceleration is measured through experiments; the predicted value of the shell vibration acceleration is compared with the experimental value, and when the two basically coincide, the corresponding eccentric angle is judged to be a certain deflection angle; the eccentric block is a cylindrical structure with a cross-section that is approximately semicircular.

[0018] A further technical solution of the present invention is: the method for constructing a dynamic model of an actual underwater vehicle physical model is:

[0019] The physical model of the underwater vehicle is simplified to a propeller-shaft-shell double-beam model, where the shell is a hollow beam and the propulsion shaft system is a solid beam. The finite element method is used to derive the dynamic differential equation as follows:

[0020]

[0021] Where M, K, C, G represent the total mass matrix, stiffness matrix, damping matrix, and gyroscopic matrix of the double beam system respectively; Ω is the rotational angular velocity of the propulsion shaft system; F g is the gravity acting on the system; F b The Hertzian contact force between the propulsion shaft system and the housing bearing, i.e., the nonlinear restoring force, is expressed as

[0022]

[0023] Among them, C b represents the Hertz contact stiffness coefficient; H(δ j )=ycosβ j +zsinβ j -G0 is the Heaviside function of the bearing, G0 is the radial clearance of the bearing, y,z represent the displacement of the center of the inner ring of the bearing in the radial horizontal and vertical directions; F e is the rotational eccentric force, expressed as

[0024]

[0025] Among them, F ex ,F ey To be applied in the radial horizontal and radial vertical directions of the propulsion shaft system respectively;

[0026] The eccentric mass and eccentricity of the propeller-shaft-shell double beam model are based on the actual model of the underwater vehicle rotating body mass M m Assembly deviation e m Equivalent replacement;

[0027] The system dynamic response is calculated according to formula (1), and the overlap angle of the eccentric block is found by comparing it with the experimentally measured response signal.

[0028] A further technical solution of the present invention is that two ends of the housing of the motor are coaxially installed in the housing through flanges.

[0029] A further technical solution of the present invention is: the water tank is provided with a water inlet, a water outlet and a propeller shaft mounting hole, the water inlet and the water outlet are both provided with valves for controlling on and off and adjusting the flow, the propeller shaft mounting hole is dynamically sealed and connected to the propeller shaft, which can ensure sealing while selecting the right rotation.

[0030] A further technical solution of the present invention is: the quick-disassembly tooling module includes an electric cylinder, a flexible rope, a hook and a gantry bracket, and the gantry bracket is installed on the basic platform as a suspension support; two electric cylinders are symmetrically installed on the top crossbeam of the gantry bracket, and their output ends are respectively fixedly connected to the roots of the flexible ropes; the free end of the head of the flexible rope passes through the guide hole on the gantry bracket and is connected to the hook; the hook is installed in cooperation with the lifting ring on the test structure module housing, and the vertical height position of the test structure module can be adjusted by driving the electric cylinder.

[0031] A further technical solution of the present invention is: a method for regulating the external excitation received by the propeller is to adjust the water level in the water tank by adjusting the water inlet and outlet valves of the water tank. The higher the water level, the more propeller blades are immersed in the water, and the greater the external excitation received during the rotation process; the lower the water level, the fewer propeller blades are immersed in the water, and the smaller the external excitation received during the rotation process.

[0032] A testing method for a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, characterized by the following specific steps:

[0033] Step 1: Layout of experimental device structure; According to the actual vibration test requirements, build a high-precision vibration simulation test system for the propeller-shaft-shell coupling system;

[0034] Step 2: Parameter design and preparation; determine the number of counterweights to be installed according to the model of the underwater vehicle to be simulated; determine the overlap angle of the eccentric blocks according to the eccentricity of the motors of different models; determine the water volume of the water tank according to the external excitations received by the propeller at different speeds;

[0035] Step 3: Quickly disassemble the tooling; relying on the quick disassembly tooling module, install the corresponding counterweight blocks on the motor and the inside of the shell, install the flange to connect the propulsion shaft system and the shell, connect the shells and the shells, and adjust the height of the test structure module;

[0036] Step 4: Verify the feasibility of the coupling system and test method. Based on the test results, compare the test target values ​​and evaluate the performance and reliability of the propeller-shaft-shell coupling system in the vibration test system and method.

[0037] Beneficial Effects

[0038] The beneficial effect of the present invention is that the high-precision vibration simulation experimental device for the propeller-shaft-shell coupling system proposed by the present invention is designed in modules, and each module is independent of each other, which is convenient for installation and maintenance. The test structure module in the experimental device can simulate the real working conditions of the underwater vehicle, and through the selection of the counterweight block and the eccentric block, the experiment is stable and accurate test values ​​can be obtained.

[0039] The invention makes equipment installation and parts adjustment more convenient by quickly disassembling the tooling module, greatly improving the test efficiency. Secondly, through the design of the water tank, various underwater excitation requirements can be met by adjusting different water volumes, and various working conditions can be flexibly simulated.

[0040] The fixing method of the present invention optimizes the simulation of boundary constraints, and the hoisting constraints truly reproduce the boundary state of the vehicle under water. The design of the water tank and the hoisting improves the accuracy of the vibration simulation of the underwater vehicle and realizes the high-precision simulation of the vibration of the complex propeller-shaft-shell coupling system.

[0041] The cooperation of various modules jointly improves the overall performance and test accuracy of the system, ensuring the reliability and validity of the test results. Therefore, the present invention has the advantages of accurate verification results, good stability, simple operation, and easy promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The layout of the high-precision vibration simulation test system of the propeller-shaft-shell coupling system of the present invention;

[0043] Figure 2 It is a cross-sectional schematic diagram of the experimental device of the present invention;

[0044] Figure 3 It is a schematic diagram of the structure of the power device of the present invention;

[0045] Figure 4 It is a schematic diagram of the motor structure of the present invention;

[0046] Figure 5 The system testing method steps of the present invention;

[0047] Figure 6 The eccentric blocks of the invention overlap at an angle of 15° every time;

[0048] Figure 7 The shell time domain / frequency domain signal of the present invention;

[0049] Explanation of the reference numerals: 11-housing, 12-flange, 13-motor, 14-counterweight, 15-sealing ring, 16-propeller, 17-propulsion shaft system, 18-eccentric block, 19-water tank; 21-electric cylinder, 22-wire rope, 23-lifting ring, 24-gantry bracket, 25-pulley bracket, 26-horizontal guide rail, 27-basic platform; 31-control cabinet, 32-transmission line; 41-acceleration, 42-transmission line, 43-data collector, 44-lower computer. DETAILED DESCRIPTION

[0050] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0051] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0052] Based on the problems that it is difficult to accurately simulate the constraint conditions and excitations in the fluid in the prior art, and the high error of the fixed constraint method, the present invention provides a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, including a test structure module, a quick-disassembly tooling module, a signal input module, and a signal acquisition and processing module; the test structure module includes a shell and a motor, a counterweight, a propulsion shaft system and an eccentric block coaxially installed therein, and a propeller is coaxially installed at the output end of the propulsion shaft system to simulate a physical underwater vehicle; the propeller is placed in a water tank to simulate the underwater working state of the propeller; the quick-disassembly tooling module suspends and hoists the test structure module in a flexible connection manner to simulate the boundless constraint of the underwater vehicle under actual working conditions; the signal input module is used to send instructions to the driving components of the test structure module to adjust different speeds of the propeller and the water level in the water tank to simulate the external excitations under different working conditions; the signal acquisition and processing module includes a sensor and a host computer, the sensor sends the test data to the host computer through a data collector, and the host computer analyzes and processes the received data to obtain experimental results.

[0053] The present invention adjusts the water level of the water tank to meet the external excitation of the propeller of the underwater vehicle under different actual working conditions. The test structure module is constrained by flexible rope hoisting, which reduces the degree of freedom in three directions and is closer to the boundaryless constraint mode of the underwater vehicle under actual working conditions.

[0054] The above technical solution is further described below in conjunction with the accompanying drawings:

[0055] Reference Figure 1-Figure 4 As shown, the present invention provides a high-precision underwater vehicle vibration simulation test bench, that is, a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, including 1 test structure module, 2 position adjustment module, 3 signal input module, and 4 signal acquisition and processing module. 1 Test structure module includes 11 shell and its internal 13 motor, 14 counterweight block, 16 propeller, 17 propulsion shaft system and 18 eccentric block are connected through 12 flange plate; 2 Position adjustment module includes: 21 electric cylinder connected to 22 wire rope and 23 lifting ring and both are installed on 24 gantry bracket, 24 gantry bracket is connected to 27 basic platform, 27 basic platform is installed with 25 pulley bracket and 26 horizontal guide rail; 3 Signal input module includes: 31 control cabinet input signal and adjust 13 motor speed through 32 transmission line; 4 Signal acquisition and processing module includes: 41 acceleration sensor is fixed to the surface of 11 shell, signal is transmitted to 43 data collector through 42 transmission line, and connected to 44 lower computer for data analysis and processing.

[0056] Further, the shell 11 is divided into seven sections according to the connection conditions. Wherein, the end of the shell 11 is connected to the water tank 19 through a sealing ring 15 to prevent fluid leakage.

[0057] Preferably, the eccentric force of the propulsion shaft system 16 during the rotation process is changed by adjusting the overlap angle of the eccentric block 17. The water tank 19 can simulate the working condition of the propeller 16 in the real watershed.

[0058] It is worth noting that the 21 electric cylinder adjusts the length of the extended steel wire rope 22, thereby freely adjusting the upper and lower heights of the 1 test structure module to facilitate installation and disassembly.

[0059] The working principle and use process of the present invention refer to Figure 5 :

[0060] Step 1: Test system structure layout. According to the actual vibration test requirements, build a high-precision vibration simulation test system for the propeller-shaft-shell coupling system, including: 1 test structure module, 2 quick disassembly tooling module, 3 signal input module, 4 signal acquisition and processing module. Demand analysis and system planning: 1) Clarify test requirements: According to the requirements of the actual vibration test, determine the working conditions, accuracy requirements and test range that the test system needs to simulate; 2) System planning: Determine the four main modules of the system and their interconnections.

[0061] Step 2: Parameter design and preparation.

[0062] 1) Selection of 14 counterweights: In order to ensure the balance and stability of the 1 test structure module, it is necessary to select an appropriate number of 14 counterweights according to specific test requirements. The steps for selecting 14 counterweights are as follows: Preliminary calculation: According to the experimental requirements, calculate the total counterweight weight required by the system. Taking into account the structure of the system and the experimental environment, this total weight should ensure that the system can maintain balance under static and dynamic conditions; Select the number of 14 counterweights: According to the calculated total counterweight weight, select an appropriate number from the standard counterweights to ensure that the final total weight meets the calculation requirements; 14 counterweight installation: Install the selected 14 counterweights on the 11 housing and the 13 motor to ensure that the weight is evenly distributed to maintain the balance of the 1 test structure module.

[0063] 2) Selection of the overlap angle of 18 eccentric blocks: The overlap angle of 18 eccentric blocks directly affects the vibration characteristics of the test structure module. Different vibration conditions can be simulated by adjusting the overlap angle. The steps for selecting the overlap angle of 18 eccentric blocks are as follows: Construct a dynamic model of the actual underwater vehicle physical model, simulate the shell vibration acceleration, and calculate the overlap angle of the eccentric blocks of the test device based on the acceleration and mass. The underwater vehicle is simplified into a propeller-shaft-shell double beam (Timushenko beam) model, the shell is a hollow beam, and the propulsion shaft system is a solid beam. The finite element method is used to derive the dynamic differential equation as follows:

[0064]

[0065] Where M, K, C, and G represent the total mass matrix, stiffness matrix, damping matrix, and gyroscopic matrix of the double-beam system, respectively, and Ω is the rotational angular velocity of the propulsion shaft system. g is the gravity acting on the system. b The Hertzian contact force between the propulsion shaft system and the housing bearing, i.e. the nonlinear restoring force, can be expressed as

[0066]

[0067] Among them, C b Represents the Hertz contact stiffness coefficient, which is related to the material and shape of the bearing; H(δ j )=ycosβ j +zsinβ j -G0 is the Heaviside function of the bearing, G0 is the radial clearance of the bearing, and y,z represent the displacement of the center of the inner ring of the bearing in the radial horizontal and vertical directions. e The rotational eccentric force can be written as

[0068]

[0069] Among them, F ex ,F ey The eccentric mass and eccentricity of the simulation model can be calculated using the actual model of the underwater vehicle rotating body mass M. m Assembly deviation e m Equivalent replacement. According to formula (1), the system dynamic response can be calculated, and the overlap angle of the eccentric block can be found by comparing it with the experimentally measured response signal. The overlap angles of the two sets of approximate semicircular eccentric blocks provided by the present invention are 15° apart. Figure 6 , refer to Table 1 for the corresponding moments of inertia and eccentricity. When the overlap angles and are straight angles, their moments of inertia are the same. Since the x direction is the axial direction, the overlap angle of the eccentric block does not affect the moment of inertia and eccentricity in this direction. Adjust the overlap angle of the two 18 eccentric blocks at both ends of the 13 motor as required, and install and fix them to ensure that the eccentric blocks are firmly fixed after adjustment to prevent displacement or loosening during vibration.

[0070] 3) Selection of the water level line of the 19 water tank: The higher the water level, the more blades of the 16 propeller are immersed in the water, and the greater the external excitation during the rotation process. The water level can be adjusted to the corresponding height by adjusting the water inlet and outlet valves of the water tank.

[0071] Step 3: Quickly disassemble the tooling. Relying on the quick disassembly tooling module, install the corresponding counterweights on the motor and the inside of the shell, install the flange to connect the propulsion shaft system and the shell, connect the shells and the shells, and adjust the height of the test structure module. When conducting a vibration test, the use of an electric cylinder can precisely adjust the height of the shell in the vertical direction to meet the height position requirements of different test conditions. A bracket structure with a pulley is provided at the lower end. The pulley bracket allows the shell to rotate freely in the axial direction, which facilitates the removal of the bolts between the shell sections. At the same time, a horizontal guide rail is attached under the pulley bracket to allow the shell to move freely in the axial direction, reducing the workload of manual handling. During the experiment, the height of the 1 test structure module is increased by reducing the extended length of the 21 electric cylinder and shortening the length of the 22 wire rope.

[0072] When the experiment is over, the position of the 25 pulley bracket needs to be reasonably adjusted to ensure that it is evenly distributed under the 11 housing, and then the length of the 21 electric cylinder is increased, the length of the 22 wire rope is lengthened, and the 1 test structure module is lowered to land safely on the 25 pulley bracket. The position adjustment of the 1 test structure module in the three degrees of freedom of vertical, axial and axial rotation is realized to meet the requirements of different test conditions.

[0073] Table 1 Attributes of eccentric blocks at different overlap angles

[0074]

[0075]

[0076] Step 4: Signal input and acquisition. Verify the feasibility of the coupling system and test method. According to the test results, compare the test target values, and evaluate the performance and reliability of the propeller-shaft-shell coupling system in the vibration test system and method; Signal input: 31 The control cabinet inputs the 13 motor speed signal, which is transmitted to the 13 motor through the 32 transmission line, thereby adjusting its actual speed; Signal acquisition: 41 The acceleration sensor is pasted to the surface of the shell 11, and the 42 transmission line transmits the measured acceleration electrical signal to the 43 data collector, and the data is analyzed and processed by the 44 lower computer. When the motor speed is 600, 900, and 1200r / min respectively, the shell dynamic response refers to Figure 7 .

[0077] Table 2 Test results

[0078]

[0079] The corresponding main frequencies in Table 2 are 9.8, 14.8, and 19.8 Hz, respectively, which indicates that the coupling system is sufficiently stable, the simulation accuracy is sufficiently high, and the error is small (in line with the speed of 60 r / min, corresponding to 1 Hz, and the error of 0.2 Hz is due to the sampling frequency).

[0080] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A high-precision vibration simulation experimental device for propeller-shaft-shell coupling system, Features: It includes test structure module, quick disassembly tooling module, signal input module, signal acquisition and processing module; The test structure module includes a housing and a motor, a counterweight, a propulsion shaft system and an eccentric block coaxially installed therein. A propeller is coaxially installed at the output end of the propulsion shaft system to simulate a physical underwater vehicle. The propeller is placed in a water tank to simulate the underwater working state of the propeller. The quick-detachable tooling module suspends and hoists the test structure module in a flexible connection manner to simulate the unbounded constraints of the underwater vehicle under actual working conditions; The signal input module is used to send instructions to the driving components of the test structure module to adjust the different speeds of the propeller and the water level in the water tank to simulate external excitations under different working conditions; The signal acquisition and processing module includes a sensor and a host computer. The sensor sends test data to the host computer through a data acquisition device, and the host computer analyzes and processes the received data to obtain experimental results.

2. According to claim 1, a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, Features: The motor is provided with a counterweight block on the periphery, and eccentric blocks are respectively installed at both ends of its rotating shaft. The output end of the rotating shaft is coaxially connected with the input end of the propulsion shaft system, and the deflection amount is regulated by adjusting the overlap angle of the eccentric blocks at both ends.

3. According to the high-precision vibration simulation experimental device of the propeller-shaft-shell coupling system described in claim 1, Features: The method for selecting the counterweight block is: Preliminary calculation: According to the experimental requirements, calculate the total weight of the experimental device to ensure that the system can maintain balance under static and dynamic conditions; Select the number of ballast blocks: According to the calculated total ballast weight, select the appropriate number of standard ballast blocks to ensure that the final total weight meets the calculation requirements; Counterweight installation: Install the selected counterweight to the housing and motor to ensure that the weight is evenly distributed to maintain the balance of the test structure module.

4. According to claim 1, a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, Features: The method for selecting the overlap angle of the eccentric block is to construct a dynamic model of the actual underwater vehicle physical model, obtain the predicted value of the shell vibration acceleration through simulation; then measure the real value of the shell vibration acceleration through experiments; compare the predicted value of the shell vibration acceleration with the experimental value, and when the two basically coincide, judge that the corresponding eccentric angle is a certain deflection angle; the eccentric block is a columnar structure with a cross-section approximately semicircular.

5. According to claim 1, a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, Features: The dynamic model method for constructing the actual underwater vehicle physical model is: The physical model of the underwater vehicle is simplified to a propeller-shaft-shell double-beam model, where the shell is a hollow beam and the propulsion shaft system is a solid beam. The finite element method is used to derive the dynamic differential equation as follows: Where M, K, C, G represent the total mass matrix, stiffness matrix, damping matrix, and gyroscopic matrix of the double beam system respectively; Ω is the rotational angular velocity of the propulsion shaft system; F g is the gravity acting on the system; F b The Hertzian contact force between the propulsion shaft system and the housing bearing, i.e., the nonlinear restoring force, is expressed as Among them, C b represents the Hertz contact stiffness coefficient; H(δ j )=ycosβ j +zsinβ j -G 0 is the Heaviside function of the bearing, G 0 is the radial clearance of the bearing, y and z represent the displacement of the center of the inner ring of the bearing in the radial horizontal and vertical directions; F e is the rotational eccentric force, expressed as Among them, F ex ,F ey To be applied in the radial horizontal and radial vertical directions of the propulsion shaft system respectively; The eccentric mass and eccentricity of the propeller-shaft-shell double beam model are based on the actual model of the underwater vehicle rotating body mass M m Assembly deviation e m Equivalent replacement; The system dynamic response is calculated according to formula (1), and the overlap angle of the eccentric block is found by comparing it with the experimentally measured response signal.

6. According to claim 1, a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, Features: The two ends of the housing of the motor are coaxially installed in the housing through flanges.

7. According to claim 1, a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, Features: The water tank is provided with a water inlet, a water outlet and a propeller shaft mounting hole. The water inlet and the water outlet are both provided with valves for controlling on and off and adjusting the flow rate. The propeller shaft mounting hole is dynamically sealed to the propeller shaft, which can ensure sealing while selecting the right rotation.

8. According to claim 1, a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, Features: The quick-disassembly tooling module includes an electric cylinder, a flexible rope, a hook and a gantry bracket, wherein the gantry bracket is installed on a basic platform as a suspension support; two electric cylinders are symmetrically installed on the top crossbeam of the gantry bracket, and their output ends are respectively fixedly connected to the roots of the flexible ropes; the free end of the head of the flexible rope passes through the guide hole on the gantry bracket and is connected to the hook; the hook is installed in cooperation with the lifting ring on the test structure module housing, and the vertical height position of the test structure module can be adjusted by driving the electric cylinder.

9. According to claim 1, a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system, Features: The method for controlling the external excitation received by the propeller is to adjust the water level in the water tank by adjusting the water inlet and outlet valves of the water tank. The higher the water level, the more propeller blades are immersed in the water, and the greater the external excitation received during the rotation process; the lower the water level, the fewer propeller blades are immersed in the water, and the smaller the external excitation received during the rotation process.

10. A test method for a high-precision vibration simulation experimental device for a propeller-shaft-shell coupling system. Features The specific steps are as follows: Step 1: Layout of experimental device structure; According to the actual vibration test requirements, build a high-precision vibration simulation test system for the propeller-shaft-shell coupling system; Step 2: Parameter design and preparation; determine the number of counterweights to be installed according to the model of the underwater vehicle to be simulated; determine the overlap angle of the eccentric blocks according to the eccentricity of the motors of different models; determine the water volume of the water tank according to the external excitations received by the propeller at different speeds; Step 3: Quickly disassemble the tooling; relying on the quick disassembly tooling module, install the corresponding counterweight blocks on the motor and the inside of the shell, install the flange to connect the propulsion shaft system and the shell, connect the shells and the shells, and adjust the height of the test structure module; Step 4: Verify the feasibility of the coupling system and test method. Based on the test results, compare the test target values ​​and evaluate the performance and reliability of the propeller-shaft-shell coupling system in the vibration test system and method.

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