Propulsion shafting longitudinal vibration isolation device and design method thereof

Abstract

The invention relates to a propulsion shafting longitudinal vibration isolation device and a design method thereof. The device comprises a raceway, a rolling bearing, a friction convex column, a force transducer and a supporting mechanism, the raceway is fixedly connected with the outer ring of the rolling bearing; the inner ring of the rolling bearing is rigidly fixed with the propulsion shafting so as to synchronously rotate along with the propulsion shafting; the friction convex column is mounted on the supporting mechanism and is in close contact with the roller path; the supporting mechanism is installed on a base of the ship body. The force measuring sensor is located below the friction protruding column and used for monitoring the numerical value of the contact force in real time. Under the condition that the propulsion shafting vibrates longitudinally, the vibration is transmitted to the raceway through the rolling bearing and drives the raceway to generate longitudinal displacement, so that longitudinal relative sliding is formed between the raceway and the friction convex column. Therefore, the longitudinal inherent frequency of the propulsion shafting can be effectively reduced, it is ensured that the propulsion shafting avoids the resonance frequency band within the working rotating speed range, the preset vibration isolation performance index is met, and efficient suppression of longitudinal vibration of the propulsion shafting is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ship propulsion, in particular to a longitudinal vibration isolation device for a propulsion shafting and a design method thereof. BACKGROUND

[0002] Under low-speed operating conditions, the noise of the propulsion system becomes one of the main noise sources affecting the acoustic environment of the ship. From the characteristics of the excitation source, the excitation force generated by the operation of the propeller is transmitted to the ship body through the shafting, inducing the vibration of the ship body structure and radiating noise. Among them, compared with the revolving vibration excitation force, the propeller longitudinal excitation force dominates in all directions and has a more significant effect on the initiation of the ship body vibration noise.

[0003] In the traditional technology, the control of the longitudinal vibration of the ship propulsion shafting is mainly divided into two categories: active control method and passive control method. For the active control method, the publication number CN113153962B discloses a shafting longitudinal vibration active control method based on an electromagnetic actuator, which realizes the suppression of the shafting longitudinal vibration by monitoring the vibration signal in real time and applying a reverse control force. For the passive control method, it can be further divided into two technical approaches: dynamic vibration absorption and vibration isolation. In the dynamic vibration absorber technology, additional substructures can be introduced to absorb and dissipate vibration energy; in the vibration isolation technology, the main focus is on the optimization design of the vibration isolation structure of the thrust bearing.

[0004] However, in the active control technology, although it has dynamic adjustment capability, the method has strict requirements for the stability and reliability of the control system, and the environmental adaptability is weak. In complex working conditions, the propulsion shafting longitudinal vibration may even be intensified due to the mismatch of control parameters, which limits the engineering application range. In the passive control scheme of the dynamic vibration absorber, whether it is directly arranged on the shafting body or the thrust bearing base, in order to achieve the ideal vibration absorption effect, the dynamic vibration absorber often needs to have a large additional mass; this design requirement is in sharp conflict with the development trend of lightweight and compactness of ship equipment, and it is difficult to meet the strict requirements of overall arrangement of modern ships for weight control. In the vibration isolation technology path, the existing scheme mostly adopts the design idea of integrating vibration isolation elements inside the thrust bearing; this mode significantly increases the structural complexity and overall size of the thrust bearing, which is contrary to the demand of space intensive utilization of the ship; on the other hand, the introduction of vibration isolation elements may change the stress distribution and dynamic characteristics of the thrust bearing, which has a potential impact on its operation reliability, restricting the engineering landing of the technology. SUMMARY

[0005] Therefore, it is necessary to provide a propulsion shaft longitudinal vibration isolation device and a design method thereof, which can avoid interference with the original structure and performance of the thrust bearing, simplify the overall structure, avoid the addition of extra mass on the shafting, avoid the adverse effects on the dynamic characteristics of the shafting, and meet the lightweight design requirements.

[0006] In a first aspect, the application provides a propulsion shaft longitudinal vibration isolation device, which comprises a raceway, a rolling bearing, a frictional convex column, a force sensor, and a support mechanism; the raceway is fixedly connected with the outer ring of the rolling bearing; the inner ring of the rolling bearing is rigidly fixed with the propulsion shaft to rotate synchronously with the propulsion shaft; the frictional convex column is installed on the support mechanism and is in close contact with the raceway under the action of the support mechanism; the support mechanism is installed on the base of the ship body; the force sensor is located below the frictional convex column and is used to monitor the value of the contact force in real time. In the case where the propulsion shaft generates longitudinal vibration, the vibration is transmitted to the raceway through the rolling bearing and drives the raceway to generate longitudinal displacement, so that the raceway and the frictional convex column form relative sliding in the longitudinal direction.

[0007] In one of the embodiments, the profile curve of the raceway is used to control the contact force of the frictional convex column acting on the raceway, so that the component of the contact force acting on the raceway in the longitudinal direction forms a mechanical coupling relationship with the axial force transmitted by the thrust bearing.

[0008] In one of the embodiments, the rolling bearing is used to bear the axial force transmitted by the shafting, and the rolling bearing adopts an angular contact ball bearing or a tapered roller bearing.

[0009] In one of the embodiments, the support mechanism comprises a jack or a hydraulic oil cylinder.

[0010] In one of the embodiments, the profile curve of the raceway is related to at least one of the following: the installation position of the propulsion shaft longitudinal vibration isolation device on the shafting, the vibration isolation starting frequency of the propulsion shaft, the first-order longitudinal vibration modal mass of the propulsion shaft, the first-order longitudinal vibration modal stiffness of the propulsion shaft, the first-order modal shape value of the propulsion shaft longitudinal vibration isolation device at the installation position on the shafting, the support stiffness of the support mechanism, the output force of the support mechanism, the radius of the frictional convex column, and the longitudinal vibration displacement of the propulsion shaft at the installation position of the propulsion shaft longitudinal vibration isolation device.

[0011] In a second aspect, the application further provides a design method of a propulsion shaft longitudinal vibration isolation device, which comprises the following steps: determining the installation position of the propulsion shaft longitudinal vibration isolation device on the shafting; A finite element model of the longitudinal vibration of the propulsion shaft system is constructed, and the first-order longitudinal vibration modal mass, first-order longitudinal vibration modal stiffness, and first-order mode shape value at the installation position of the vibration isolation device are determined through simulation of the finite element model of the longitudinal vibration of the propulsion shaft system. Determine the starting frequency for vibration isolation of the propulsion shaft system; Based on the initial vibration isolation frequency of the propulsion shaft system, determine the modal stiffness of the propulsion shaft system after installing the longitudinal vibration isolation device; The support stiffness and output force of the support mechanism were determined through experimental testing. Determine the radius of the friction protrusion; Based on the profile curve of the raceway and the installation position of the longitudinal vibration isolation device of the propulsion shaft system on the shaft system, the vibration isolation starting frequency of the propulsion shaft system, the mass of the first longitudinal vibration mode of the propulsion shaft system, the stiffness of the first longitudinal vibration mode of the propulsion shaft system, the mode shape value of the first mode of the longitudinal vibration isolation device of the propulsion shaft system at the installation position on the shaft system, the support stiffness of the support mechanism, the output force of the support mechanism, the radius of the friction protrusion, and the longitudinal vibration displacement of the propulsion shaft system at the installation position of the longitudinal vibration isolation device of the propulsion shaft system, the profile curve equation of the raceway is constructed, and the profile curve of the raceway is determined.

[0012] In one embodiment, after determining the profile curve of the raceway, the method further includes: The machining difficulty of the raceway contour curve is checked; If the machining difficulty does not meet the requirements, at least one of the following should be readjusted: the support stiffness of the support mechanism, the output force of the support mechanism, and the radius of the friction protrusion. The profile curve of the raceway should be redefined until the machining difficulty of the profile curve of the raceway meets the requirements.

[0013] In one embodiment, if the processing difficulty meets the requirements, the method further includes: Construct the longitudinal vibration differential equation of the propulsion shaft system-vibration isolator coupling, and describe the dynamic behavior of the shaft system and the longitudinal vibration isolation device of the propulsion shaft system working together; Based on the dynamic behavior of the longitudinal vibration isolation device of the shaft system and the propulsion shaft system working together, the vibration response of the propulsion shaft system-isolation device coupling system under different excitation frequencies is simulated, and the performance indicators of the longitudinal vibration isolation device of the propulsion shaft system in a wide frequency range are obtained by simulation. The performance indicators include: vibration isolation efficiency and / or resonant frequency shift. The performance indicators obtained from the simulation are compared with the preset indicators to obtain the comparison results; If the comparison results meet the requirements, then the processing and installation of the longitudinal vibration isolation device for the propulsion shaft system will be carried out. If the comparison results do not meet the requirements, the modal stiffness of the propulsion shaft system after installing the longitudinal vibration isolation device is determined again based on the initial vibration isolation frequency of the propulsion shaft system, until the performance indicators obtained by simulation meet the requirements of the comparison results with the preset indicators.

[0014] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method steps described in any one of the second aspects.

[0015] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method steps described in any one of the second aspects.

[0016] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the method steps described in any one of the second aspects.

[0017] The aforementioned longitudinal vibration isolation device and its design method for the propulsion shaft system comprises a raceway, rolling bearings, friction cams, a force sensor, and a support mechanism. The raceway is fixedly connected to the outer ring of the rolling bearing; the inner ring of the rolling bearing is rigidly fixed to the propulsion shaft system to rotate synchronously with it; the friction cams are mounted on the support mechanism and, under its action, maintain close contact with the raceway; the support mechanism is mounted on the hull base; and the force sensor is located below the friction cams to monitor the contact force in real time. When longitudinal vibration occurs in the propulsion shaft system, the vibration is transmitted to the raceway through the rolling bearings, causing longitudinal displacement of the raceway and resulting in longitudinal relative sliding between the raceway and the friction cams. This effectively reduces the longitudinal natural frequency of the propulsion shaft system, ensuring it avoids the resonant frequency band within its operating speed range, meeting preset vibration isolation performance indicators, and achieving highly efficient suppression of longitudinal vibration in the propulsion shaft system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A shaft view of a longitudinal vibration isolation device for a propulsion shaft system provided in an embodiment of this application; Figure 2This is a front view of a longitudinal vibration isolation device for a propulsion shaft provided in an embodiment of this application; Figure 3 This is a side view of a longitudinal vibration isolation device for a propulsion shaft provided in an embodiment of this application; Figure 4 This is a schematic diagram of the installation of a longitudinal vibration isolation device for a propulsion shaft provided in an embodiment of this application; Figure 5 A flowchart illustrating the design method of a longitudinal vibration isolation device for a propulsion shaft provided in an embodiment of this application; Figure 6 This is a dimensional schematic diagram of a propulsion shaft system provided in one embodiment of this application; Figure 7 This is a schematic diagram of the raceway profile curve to be processed in one embodiment of this application; Figure 8 This is a schematic diagram illustrating the vibration isolation efficiency of an embodiment of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0021] For example, Figure 1 This is an axial view of a longitudinal vibration isolation device for a propulsion shaft system provided in an embodiment of this application. Figure 2 This is a front view of a longitudinal vibration isolation device for a propulsion shaft provided in an embodiment of this application. Figure 3 This is a side view of a longitudinal vibration isolation device for a propulsion shaft system provided in an embodiment of this application. Figures 1-3 As shown, the longitudinal vibration isolation device for the propulsion shaft system includes: a raceway 1, a rolling bearing 2, a friction cam 3, a force sensor 4, and a support mechanism 5; the raceway 1 is fixedly connected to the outer ring of the rolling bearing 2; the inner ring of the rolling bearing 2 is rigidly fixed to the propulsion shaft system to rotate synchronously with the propulsion shaft system; the friction cam 3 is mounted on the support mechanism 5 and is in close contact with the raceway 1 under the action of the support mechanism 5; the support mechanism 5 is mounted on the base of the hull; the force sensor 4 is located below the friction cam 3 and is used to monitor the value of the contact force in real time; when the propulsion shaft system experiences longitudinal vibration, the vibration is transmitted to the raceway 1 through the rolling bearing 2 and causes the raceway 1 to generate longitudinal displacement, so that a longitudinal relative sliding is formed between the raceway 1 and the friction cam 3.

[0022] In this embodiment, the surface profile curve of raceway 1 needs to be determined through precise dynamic modeling and parameter optimization, and it is a key structure for achieving vibration isolation. The rolling bearing 2, capable of bearing thrust, can be an angular contact ball bearing or a tapered roller bearing, bearing the axial force transmitted by the shaft system. The friction protrusion 3, as the core element for force transmission and interaction, is an arc surface with a radius to be designed. The force sensor 4 is used to monitor contact force parameters in real time. The support mechanism 5 provides a controllable preload driving force. Raceway 1 is fixedly connected to the outer ring of the rolling bearing 2, and the friction protrusion 3 forms a tight contact with raceway 1 under the driving force of the support mechanism 5. The entire device is installed on the ship's base using jacks to ensure structural stability.

[0023] For example, the profile curve of the raceway is used to control the contact force exerted by the friction protrusion on the raceway, so that a mechanical coupling relationship is formed between the longitudinal component of the contact force acting on the raceway and the axial force transmitted by the thrust bearing. This coupling effect can effectively reduce the longitudinal natural frequency of the propulsion shaft system, ensuring that it avoids the resonant frequency band within the operating speed range, meeting the preset vibration isolation performance indicators, and ultimately achieving efficient suppression of longitudinal vibration of the propulsion shaft system.

[0024] For example, rolling bearings are used to bear the axial force transmitted by the shaft system. Rolling bearings are either angular contact ball bearings or tapered roller bearings.

[0025] For example, the support mechanism includes: a jack or a hydraulic cylinder.

[0026] For example, the profile curve of the raceway is related to at least one of the following: the installation position of the longitudinal vibration isolation device of the propulsion shaft system on the shaft system; the vibration isolation initiation frequency of the propulsion shaft system; the mass of the first longitudinal vibration mode of the propulsion shaft system; the stiffness of the first longitudinal vibration mode of the propulsion shaft system; the mode shape value of the first mode of the longitudinal vibration isolation device of the propulsion shaft system at the installation position on the shaft system; the support stiffness of the support mechanism; the output force of the support mechanism; the radius of the friction protrusion; and the longitudinal vibration displacement of the propulsion shaft system at the installation position of the longitudinal vibration isolation device of the propulsion shaft system.

[0027] For example, Figure 4 This is an installation diagram of a longitudinal vibration isolation device for a propulsion shaft system provided in an embodiment of this application. When the propulsion shaft system experiences longitudinal vibration, the vibration is transmitted to the raceway 1 through the rolling bearing 2, causing the raceway 1 to generate longitudinal displacement, thereby causing longitudinal relative sliding between the raceway 1 and the friction protrusion 3.

[0028] The implementation principle of this embodiment is to break through the structural dependence of traditional devices on shaft systems or thrust bearings by synergistically optimizing structural parameters and mechanical properties, thus providing a new technical paradigm for longitudinal vibration control of propulsion shaft systems.

[0029] This application also provides a design method for a longitudinal vibration isolation device for a propulsion shaft system. The method includes: determining the installation position of the longitudinal vibration isolation device on the propulsion shaft system; constructing a finite element model of the longitudinal vibration of the propulsion shaft system, and determining the first-order longitudinal vibration modal mass, first-order longitudinal vibration modal stiffness, and first-order mode shape value at the installation position of the isolation device through simulation of the finite element model; determining the initial frequency of the propulsion shaft system isolation; determining the modal stiffness of the propulsion shaft system after installing the longitudinal vibration isolation device based on the initial isolation frequency; and determining the modal stiffness of the propulsion shaft system through experimental testing. The supporting stiffness and output force of the supporting mechanism are determined; the radius of the friction protrusion is determined; based on the profile curve of the raceway and the installation position of the longitudinal vibration isolation device of the propulsion shaft system on the shaft system, the vibration isolation initiation frequency of the propulsion shaft system, the mass of the first longitudinal vibration mode of the propulsion shaft system, the stiffness of the first longitudinal vibration mode of the propulsion shaft system, the mode shape value of the first mode of the longitudinal vibration isolation device of the propulsion shaft system at the installation position on the shaft system, the supporting stiffness of the supporting mechanism, the output force of the supporting mechanism, the radius of the friction protrusion, and the longitudinal vibration displacement of the propulsion shaft system at the installation position of the longitudinal vibration isolation device of the propulsion shaft system, the profile curve equation of the raceway is constructed and the profile curve of the raceway is determined.

[0030] Optionally, after determining the profile curve of the raceway, the machining difficulty of the profile curve of the raceway can be checked; if the machining difficulty does not meet the requirements, at least one of the following can be readjusted: the support stiffness of the support mechanism, the output force of the support mechanism, and the radius of the friction protrusion, and the profile curve of the raceway can be re-determined until the machining difficulty of the profile curve of the raceway meets the requirements.

[0031] Optionally, provided the processing difficulty meets the requirements, a longitudinal vibration differential equation for the propulsion shaft system-isolation device coupling can be constructed to describe the dynamic behavior of the shaft system and the propulsion shaft system longitudinal vibration isolation device working together. Based on the dynamic behavior of the shaft system and the propulsion shaft system longitudinal vibration isolation device working together, the vibration response of the propulsion shaft system-isolation device coupling system under different excitation frequencies is simulated to obtain the performance indicators of the propulsion shaft system longitudinal vibration isolation device in a wide frequency range. The performance indicators include: isolation efficiency and / or resonance frequency shift. The simulated performance indicators are compared with preset indicators to obtain the comparison results. If the comparison results meet the requirements, the processing and installation of the propulsion shaft system longitudinal vibration isolation device are carried out. If the comparison results do not meet the requirements, the modal stiffness of the propulsion shaft system after installing the propulsion shaft system longitudinal vibration isolation device is re-determined based on the initial isolation frequency of the propulsion shaft system until the comparison results of the simulated performance indicators and the preset indicators meet the requirements.

[0032] For example, Figure 5 A flowchart illustrating the design method of a longitudinal vibration isolation device for a propulsion shaft system according to an embodiment of this application is shown below. Figure 5As shown, it may include the following steps: Step 1: Determine the installation position of the vibration isolation device on the propulsion shaft system, and set the distance between the vibration isolation device and the propeller as follows: Vibration isolation devices are typically installed next to the thrust bearing housing, near one end of the propeller.

[0033] Step 2: Construct a finite element model of the longitudinal vibration of the propulsion shaft system using the finite element analysis method. Obtain the mass of the first-order longitudinal vibration mode of the propulsion shaft system through simulation calculations. First-order longitudinal vibration mode stiffness And the first-order mode shape value at the installation location of the vibration isolation device. These modal parameters are the core basis for the subsequent stiffness matching and vibration control design of vibration isolation devices, reflecting the inherent vibration characteristics of the shaft system itself.

[0034] Step 3: Determine the starting frequency for vibration isolation of the propulsion shaft system. For underwater noise, vibration isolation typically starts at a frequency of 10Hz.

[0035] Step 4: Based on the initial vibration isolation frequency of the propulsion shaft system, the modal stiffness of the system after installing the vibration isolation device can be determined. The values ​​are taken as follows: in, The value is a coefficient, ranging from 0.1 to 1, which can be flexibly adjusted according to the vibration isolation requirements of the shafting (such as vibration isolation efficiency, stiffness adaptability, etc.) to adapt to the personalized vibration isolation design of different ship propulsion shafting systems.

[0036] Step 5: Select a suitable jack and determine its supporting stiffness through experimental testing. At the same time, select the output force of the jack. As the power support component of the vibration isolation device, the stiffness and output force parameters of the jack directly affect the device's ability to actively control shaft vibration. It needs to be precisely matched with the requirements of shaft load, vibration amplitude, etc.

[0037] Step Six: Determine the radius of the friction protrusion Friction protrusions are key structural components in vibration isolation devices for dissipating vibration energy and controlling force transmission. Their radius affects the contact mechanical characteristics with the raceway, thus impacting the vibration isolation effect. Therefore, it is necessary to comprehensively consider factors such as contact stress and friction energy consumption to optimize their selection.

[0038] Step 7: Derive the equation for the raceway profile curve as follows. : In the formula, x is the longitudinal vibration displacement of the propulsion shaft system at the installation position of the vibration isolator; Here is the profile function expression for raceway ①. These are coordinate values; Let be the radius of the friction protrusion; For a specific function, for The derivative; It can be represented as: In the formula, This refers to the longitudinal vibration displacement of the vibration isolation device at its shaft mounting location. This is a coefficient, with a value ranging from 0.1 to 1; To advance the starting frequency of shaft system vibration isolation; To improve the first-order longitudinal vibration mode mass of the shaft system; To improve the first-order longitudinal vibration mode stiffness of the shaft system; This represents the first-order mode shape value of the vibration isolation device at its shaft installation location; The supporting stiffness of the jack; This is the output force of the jack.

[0039] Step 8: Verify the machining difficulty of the raceway profile curve. If the machining difficulty is within a reasonable and achievable range, proceed to the next step; if the machining difficulty is high, the support stiffness of the jacks needs to be readjusted. Output force and the radius of the friction protrusion Starting from step five, the design is iterated again to ensure that the vibration isolation device meets both the vibration isolation performance requirements and is manufacturable.

[0040] Step Nine: Construct the longitudinal vibration differential equations of the propulsion shaft system-vibration isolator coupling to accurately describe the dynamic behavior of the shaft system and vibration isolation device working together: In the formula, To increase the total mass of the shafting system; To promote shaft damping; This is the total longitudinal stiffness of the propulsion shaft system after the vibration isolator is installed; For environmental incentives; To excite the circular frequency; For time; It is the imaginary unit.

[0041] Step 10: Conduct simulation studies on the dynamic behavior formulas from Step 9, simulating different excitation frequencies (covering the vibration frequency range corresponding to the shaft's operating speed) to improve the vibration response of the shaft-isolation coupling system. Through simulation, key performance indicators such as isolation efficiency and resonant frequency shift of the isolation device in a wide frequency range can be obtained. Step 11: Compare the vibration isolation performance obtained from the simulation with the preset isolation targets (such as isolation efficiency threshold, resonant frequency avoidance requirements, etc.): If the requirements are met, the preliminary design of the isolation device is completed; if not, it is necessary to go back to Step 4 and readjust the overall stiffness. The process is repeated after adjusting the design parameters until the performance meets the standards. This iterative mechanism ensures that the design fully adapts to the shaft isolation requirements and improves the reliability of the solution.

[0042] Step 12: Machining core components such as rolling bearings and raceways according to design parameters, and sequentially completing the shaft system integration and installation, and jack placement. By adjusting the jack spacing and coordinating real-time monitoring with force sensors, the contact force between the friction protrusions and the raceways is precisely controlled. To ensure that the physical characteristics of the device are consistent with the design model, after assembly, conduct field tests on the vibration isolation performance to verify the effect of the vibration isolation device on suppressing longitudinal vibration and evaluate the engineering practicality of the design.

[0043] For example, a simulation example is taken from the propulsion shafting system of an actual ship in engineering, as shown in Figure 6. The total length of the shafting system is 20m, the outer radius of the shaft is 250mm, and the inner radius is 120mm. Table 1 gives its main material parameters.

[0044] Table 1 For example, in the design, the jack load is selected as 10t and the jack stiffness is 10. 7 N / m, the vibration isolator is installed next to the thrust bearing, and the total stiffness of the vibration isolator is 10. 7 N / m. The designed raceway profile curve is shown in Figure 7. The vibration isolation effect is shown in Figure 8. It can be seen that, within the frequency range of 20Hz to 200Hz, after installing this vibration isolator, the load amplitude transmitted from the propulsion shaft to the base is significantly lower than that without the vibration isolator. This result fully verifies that the designed vibration isolator has good vibration isolation performance in this frequency band, indicating that it can effectively block the energy transfer of longitudinal vibration of the propulsion shaft to the base.

[0045] This application describes a longitudinal vibration isolation device for a propulsion shaft system, designed and installed outside the thrust bearing. Its core principle is to achieve vibration isolation by precisely constructing a contour curve on the raceway, coordinating the functions of the rolling bearing and the jack. This contour curve is not designed in isolation but is determined through theoretical modeling and iterative optimization based on multiple parameters, including the mass, stiffness, natural frequency, vibration isolation initiation frequency of the propulsion shaft system, and the supporting stiffness and output force of the jack. This ensures the device's efficient suppression of longitudinal vibration of the shaft system, overcoming the limitations of traditional vibration isolation schemes in thrust bearing integration and shaft system dynamic adaptability.

[0046] In an exemplary embodiment, a computer device, which may be a server, is provided. The computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is connected to the system bus via the I / O interfaces. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network connection. When the computer program is executed by the processor, it implements a design method for a longitudinal vibration isolation device for a propulsion shaft.

[0047] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0048] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0049] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0050] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0051] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0052] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0053] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A longitudinal vibration isolation device for a propulsion shaft system, characterized in that, The device includes: a raceway, a rolling bearing, a friction protrusion, a force sensor, and a support mechanism; the raceway is fixedly connected to the outer ring of the rolling bearing; the inner ring of the rolling bearing is rigidly fixed to the propulsion shaft system to rotate synchronously with the propulsion shaft system; the friction protrusion is mounted on the support mechanism and, under the action of the support mechanism, is in close contact with the raceway; the support mechanism is mounted on the base of the hull; the force sensor is located below the friction protrusion and is used to monitor the value of the contact force in real time. When the propulsion shaft system experiences longitudinal vibration, the vibration is transmitted to the raceway through the rolling bearing and causes the raceway to undergo longitudinal displacement, thereby creating a longitudinal relative sliding between the raceway and the friction protrusion.

2. The apparatus according to claim 1, characterized in that, The profile curve of the raceway is used to control the contact force of the friction protrusion on the raceway, so that a mechanical coupling relationship is formed between the longitudinal component of the contact force on the raceway and the axial force transmitted by the thrust bearing.

3. The apparatus according to claim 1, characterized in that, The rolling bearing is used to bear the axial force transmitted by the shaft system. The rolling bearing is an angular contact ball bearing or a tapered roller bearing.

4. The apparatus according to claim 1, characterized in that, The support mechanism includes: a jack or a hydraulic cylinder.

5. The apparatus according to claim 2, characterized in that, The profile curve of the raceway is related to the installation position of the longitudinal vibration isolation device of the propulsion shaft system on the shaft system, the vibration isolation initiation frequency of the propulsion shaft system, the mass of the first longitudinal vibration mode of the propulsion shaft system, the stiffness of the first longitudinal vibration mode of the propulsion shaft system, the mode shape value of the first mode of the longitudinal vibration isolation device of the propulsion shaft system at the installation position on the shaft system, the support stiffness of the support mechanism, the output force of the support mechanism, the radius of the friction protrusion, and the longitudinal vibration displacement of the propulsion shaft system at the installation position of the longitudinal vibration isolation device of the propulsion shaft system.

6. A design method for a longitudinal vibration isolation device for a propulsion shaft system, characterized in that, The method includes: Determine the installation location of the longitudinal vibration isolation device for the propulsion shaft system on the shaft system; A finite element model of the longitudinal vibration of the propulsion shaft system is constructed, and the first-order longitudinal vibration modal mass, first-order longitudinal vibration modal stiffness, and first-order mode shape value at the installation position of the vibration isolation device are determined through simulation of the finite element model of the longitudinal vibration of the propulsion shaft system. Determine the starting frequency for vibration isolation of the propulsion shaft system; Based on the initial vibration isolation frequency of the propulsion shaft system, determine the modal stiffness of the propulsion shaft system after installing the longitudinal vibration isolation device; The support stiffness and output force of the support mechanism were determined through experimental testing. Determine the radius of the friction protrusion; Based on the profile curve of the raceway and the installation position of the longitudinal vibration isolation device of the propulsion shaft system on the shaft system, the vibration isolation starting frequency of the propulsion shaft system, the mass of the first longitudinal vibration mode of the propulsion shaft system, the stiffness of the first longitudinal vibration mode of the propulsion shaft system, the mode shape value of the first mode of the longitudinal vibration isolation device of the propulsion shaft system at the installation position on the shaft system, the support stiffness of the support mechanism, the output force of the support mechanism, the radius of the friction protrusion, and the longitudinal vibration displacement of the propulsion shaft system at the installation position of the longitudinal vibration isolation device of the propulsion shaft system, the profile curve equation of the raceway is constructed, and the profile curve of the raceway is determined.

7. The method according to claim 6, characterized in that, After determining the profile curve of the raceway, the method further includes: The machining difficulty of the raceway contour curve is checked; If the machining difficulty does not meet the requirements, at least one of the following should be readjusted: the support stiffness of the support mechanism, the output force of the support mechanism, and the radius of the friction protrusion. The profile curve of the raceway should be redefined until the machining difficulty of the profile curve of the raceway meets the requirements.

8. The method according to claim 7, characterized in that, When the processing difficulty meets the requirements, the method further includes: Construct the longitudinal vibration differential equation of the propulsion shaft system-vibration isolator coupling, and describe the dynamic behavior of the shaft system and the longitudinal vibration isolation device of the propulsion shaft system working together; Based on the dynamic behavior of the longitudinal vibration isolation device of the shaft system and the propulsion shaft system working together, the vibration response of the propulsion shaft system-isolation device coupling system under different excitation frequencies is simulated, and the performance indicators of the longitudinal vibration isolation device of the propulsion shaft system in a wide frequency range are obtained by simulation. The performance indicators include: vibration isolation efficiency and / or resonant frequency shift. The performance indicators obtained from the simulation are compared with the preset indicators to obtain the comparison results; If the comparison results meet the requirements, then the processing and installation of the longitudinal vibration isolation device for the propulsion shaft system will be carried out. If the comparison results do not meet the requirements, the modal stiffness of the propulsion shaft system after installing the longitudinal vibration isolation device is determined again based on the initial vibration isolation frequency of the propulsion shaft system, until the performance indicators obtained by simulation meet the requirements of the comparison results with the preset indicators.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 6 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 6 to 8.

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