Collaborative design method and device of gear transmission system facing marine environment

Abstract

The invention discloses a collaborative design method and device for a gear transmission system facing a marine environment, and relates to the field of mechanical design, and the method comprises the steps: obtaining the working depth of the gear transmission system in the marine environment, and calculating the environmental parameters of the ocean based on the depth and a first relation; state parameters of lubricating oil used in the gear transmission system are calculated according to the environment parameters and the second relation; selecting an initial gear material from a material performance parameter database according to the state parameters of the lubricating oil and the environmental parameters of the ocean; selecting an initial configuration in the configuration database according to the design requirement of the gear transmission system; and taking the initial gear material and the initial configuration as initial conditions, inputting the gear material and the configuration into a coupling performance prediction model to predict and obtain a performance index, and carrying out iterative solution on an objective function by adopting a multi-objective optimization algorithm under constraint conditions to obtain the optimal gear material and configuration. The method overcomes the limitation of a traditional separated design, and can capture a complex coupling relationship.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mechanical design, in particular to a collaborative design method and device for a gear transmission system in marine environment. BACKGROUND

[0002] With the deepening of marine resource development, the performance requirements of the core components of underwater vehicles, deep-sea robots, and seabed operation platforms and other marine equipment are increasingly stringent. As the key component for power transmission in these equipment, the gear transmission system has been working in extreme marine environments such as high hydrostatic pressure, low temperature, and high salt mist corrosion for a long time. These environments pose a serious challenge to the reliability, life, and transmission efficiency of the system.

[0003] High hydrostatic pressure and low temperature can significantly change the mechanical properties of materials and the physical properties of lubricants. Low temperature can easily induce low-temperature brittleness of traditional steel, reducing its toughness; while high pressure puts higher requirements on the strength and fatigue resistance of materials. At the same time, the viscosity of lubricants is extremely sensitive to pressure and temperature: the increase of pressure will cause the viscosity to increase exponentially, and the decrease of temperature will also cause the viscosity to rise sharply. Such a dramatic change in viscosity directly interferes with the formation of elastohydrodynamic lubrication oil film in the gear meshing area. High viscosity not only increases the oil stirring loss and friction loss, reducing the transmission efficiency; more seriously, the oil film failure will exacerbate the tooth surface wear, and even cause galling failure, seriously affecting the contact stress distribution.

[0004] Currently, the design method of marine gear transmission system is usually a fragmented and experience-driven process. The designers often independently select materials, design geometric configurations, and determine lubrication schemes, lacking a unified collaborative framework to comprehensively evaluate the complex interactions between the three and the marine environment. Therefore, it is urgent to develop a collaborative design method that integrates the effects of marine environment, material performance, gear configuration, and lubrication characteristics. This method should systematically explore the optimal balance point between materials, configurations, and performance through multi-objective optimization means in a unified framework, and ultimately achieve performance breakthroughs in marine environment gear transmission systems. SUMMARY

[0005] The present application aims to solve the technical problems in the existing design method of marine gear transmission system, such as the disconnection between material selection, geometric configuration design, and lubrication analysis, the inability to effectively consider the comprehensive impact of high pressure and low temperature environment on the coupled performance of the system, and the resulting low reliability, low efficiency, and low optimization level of the design scheme. A collaborative design method and device for a gear transmission system in marine environment are proposed.

[0006] In a first aspect, the present application provides a collaborative design method for a gear transmission system in marine environment, comprising the following steps:

[0007] The material performance parameter database of the gear transmission system and the configuration database are constructed, the material performance parameter database includes gear materials and corresponding performance parameters, and the configuration database includes planetary gear transmission configurations and series and corresponding configuration parameters;

[0008] A first relationship between the depth of the ocean and environmental parameters and a second relationship between state parameters of lubricating oil and environmental parameters are constructed, a coupling performance prediction model of the gear transmission system is constructed, a target function including configuration parameters of the gear is constructed, and a constraint condition is set;

[0009] The depth at which the gear transmission system works in the ocean environment is obtained, the environmental parameters of the ocean are calculated based on the depth and the first relationship, the state parameters of the lubricating oil used in the gear transmission system are calculated according to the environmental parameters and the second relationship, the initial gear material is selected in the material performance parameter database according to the state parameters of the lubricating oil and the environmental parameters of the ocean, and the initial configuration is selected in the configuration database according to the design requirements of the gear transmission system.

[0010] The initial gear material and the initial configuration are taken as initial conditions, the gear material and the configuration are input into the coupling performance prediction model to obtain performance indexes, and the target function is iteratively solved under the constraint condition by using a multi-objective optimization algorithm to obtain the best gear material and configuration, so that the corresponding performance indexes meet or are better than the target performance indexes.

[0011] Preferably, the environmental parameters include the pressure and temperature of seawater, the first relationship includes a temperature function changing with the depth and a pressure function changing with the depth, the state parameters of the lubricating oil include viscosity, density, specific heat capacity and thermal conductivity, the second relationship includes a viscosity function changing with the environmental parameters, a density function changing with the environmental parameters, a specific heat capacity function changing with the environmental parameters and a thermal conductivity function changing with the environmental parameters, the viscosity function adopts a Roelands equation of viscosity-temperature-pressure, and the density function adopts a Dowson-Higginson equation of density-temperature-pressure.

[0012] Preferably, the gear material includes high-strength low-alloy steel, chromium-nickel-molybdenum alloy steel and austenitic stainless steel, the material parameters include elastic modulus, Poisson's ratio, yield strength, allowable contact stress, allowable bending stress, density and seawater corrosion resistance grade, the planetary gear transmission configuration includes an NGW type planetary gear transmission mechanism, an NWN type planetary gear transmission mechanism and an NN type planetary gear transmission mechanism, the configuration parameters include macro-geometric configuration parameters and micro-geometric configuration parameters, the macro-geometric configuration parameters include modulus, tooth number, pressure angle and spiral angle, the micro-geometric configuration parameters include tooth profile modification and tooth orientation modification, and the design requirements include transmission power, transmission ratio, transmission efficiency and service life.

[0013] As preferred, the coupling performance prediction model comprises a contact stress module, a bending stress module, a transmission efficiency module and a fatigue life module, the contact stress module and the bending stress module are respectively used for calculating the minimum oil film thickness and the film thickness ratio based on the elastohydrodynamic lubrication theory through the viscosity of lubricating oil, obtaining the dynamic load coefficient according to the film thickness ratio, combining the dynamic load coefficient with the configuration parameters and the load of the gear to calculate the contact stress of the tooth surface according to the ISO 6336 standard, and combining the dynamic load coefficient with the configuration parameters of the gear to calculate the bending stress; the transmission efficiency module is used for calculating the total loss power of the gear transmission system according to the ISO / RT 14179 standard, and calculating the transmission efficiency according to the total loss power; the fatigue life module is used for adopting the nominal stress method and combining the Miner linear cumulative damage theory to evaluate the fatigue life of the gear transmission system according to the ISO 6336 series standard.

[0014] As preferred, the objective function is:

[0015] ;

[0016] Wherein, represents the input vector of the objective function, is the modulus, and represent the number of teeth of a pair of gears, represents the helix angle, and b represents the tooth width, and represent the modification coefficient of a pair of gears; , , and respectively represent the first optimization function, the second optimization function, the third optimization function and the fourth optimization function, and min represents taking the minimum value, represents the contact stress, represents the transmission error, represents the system volume, represents the transmission efficiency;

[0017] The constraint conditions include strength constraints, geometric constraints and transmission performance constraints; the strength constraints include the tooth surface contact strength constraint, the pinion root tooth root bending strength constraint and the gear tooth root bending strength constraint;

[0018] The tooth surface contact strength constraint is:

[0019] ;

[0020] The pinion root tooth root bending strength constraint is:

[0021] ;

[0022] The bending strength constraint of the big gear tooth root is:

[0023] ;

[0024] wherein, , and respectively represent the tooth surface contact strength constraint function, the pinion root tooth bending strength constraint function and the big gear tooth root bending strength constraint function, , and represent the minimum contact stress of the material, the minimum root bending stress of the pinion and the minimum root bending stress of the big gear, , and represent the allowable contact stress of the material, the root allowable bending stress of the pinion and the root allowable bending stress of the big gear;

[0025] The geometric constraints include the addendum thickness constraint and the center distance matching constraint, the addendum thickness constraint is:

[0026] ;

[0027] The center distance matching constraint is:

[0028] ;

[0029] wherein, and respectively represent the addendum thickness constraint function and the center distance matching constraint function, represents the allowable addendum thickness, represents the minimum addendum thickness, represents the minimum center distance, represents the allowable center distance, represents the allowable tolerance;

[0030] The performance constraints include the transmission efficiency constraint and the transmission smoothness constraint, the transmission efficiency constraint is: ;

[0031] The transmission smoothness constraint is: ;

[0032] wherein, and respectively represent the transmission efficiency constraint function and the transmission smoothness constraint function, represents the minimum transmission efficiency, represents the maximum transmission error.

[0033] Preferably, the multi-objective optimization algorithm adopts the NSGA-II algorithm, a population size and an iteration number are set, a simulated binary crossover operator is used for non-dominated sorting and crowded distance calculation, and a stable Pareto optimal solution set is finally converged through multi-generation iteration, and the best gear material and configuration are selected from the Pareto optimal solution set.

[0034] In a second aspect, the application provides a collaborative design device for a gear transmission system in a marine environment, comprising:

[0035] A database construction module is configured to construct a material performance parameter database and a configuration database of the gear transmission system, the material performance parameter database including gear materials and corresponding performance parameters, and the configuration database including planetary gear transmission configurations and corresponding configuration parameters;

[0036] A relationship construction module is configured to construct a first relationship between the depth of the ocean and environmental parameters and a second relationship between state parameters of lubricating oil and environmental parameters, construct a coupling performance prediction model of the gear transmission system, and construct a target function containing configuration parameters of the gear and set a constraint condition;

[0037] A calculation module is configured to obtain the depth at which the gear transmission system works in the marine environment, calculate the environmental parameters of the ocean based on the depth and the first relationship, calculate the state parameters of the lubricating oil used in the gear transmission system according to the environmental parameters and the second relationship, select an initial gear material in the material performance parameter database according to the state parameters of the lubricating oil and the environmental parameters of the ocean, and select an initial configuration in the configuration database according to the design requirements of the gear transmission system.

[0038] An optimization module is configured to take the initial gear material and the initial configuration as initial conditions, input the gear material and the configuration into the coupling performance prediction model to predict performance indicators, and iteratively solve the target function under the constraint condition by using a multi-objective optimization algorithm to obtain the best gear material and configuration, so that the corresponding performance indicators meet or are better than the target performance indicators.

[0039] In a third aspect, the application provides an electronic device, comprising one or more processors; a storage device configured to store one or more programs, when the one or more programs are executed by the one or more processors, the one or more processors implement the method described in any of the implementation manners of the first aspect.

[0040] In a fourth aspect, the application provides a computer-readable storage medium having a computer program stored thereon, when the computer program is executed by a processor, the method described in any of the implementation manners of the first aspect is implemented.

[0041] In a fifth aspect, the present application provides a computer program product comprising a computer program which, when executed by a processor, implements the method as described in any implementation form of the first aspect.

[0042] Compared with the prior art, the present application has the following beneficial effects:

[0043] (1) The collaborative design method for the gear transmission system facing the marine environment proposed in the present application can more accurately predict the mechanical performance and energy efficiency of the gear transmission system under the real marine working condition by establishing the dynamic bending stress model and the transmission efficiency model associated with the lubrication state, thereby improving the reliability of the design.

[0044] (2) The collaborative design method for the gear transmission system facing the marine environment proposed in the present application converts the complex design problem into a standardized and repeatable calculation process, greatly shortens the design cycle, reduces the dependence on the physical prototype and expensive experiments, and provides a quantitative and scientific basis for the design decision, thereby significantly improving the design quality of the core transmission components of the marine equipment.

[0045] (3) The collaborative design method for the gear transmission system facing the marine environment proposed in the present application provides a systematic design method integrating the marine environment, materials, geometric configuration, lubrication and performance prediction, which overcomes the limitations of the traditional separate design and can fully capture the complex coupling relationship between various factors. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0047] Figure 1 The flowchart of the collaborative design method for the gear transmission system facing the marine environment of the embodiments of the present application;

[0048] Figure 2 The fitting surface graph of the VG320 lubricating oil kinematic viscosity of the collaborative design method for the gear transmission system facing the marine environment of the embodiments of the present application;

[0049] Figure 3 The structural diagram of the gear transmission system of the collaborative design method for the gear transmission system facing the marine environment of the embodiments of the present application;

[0050] Figure 4 The transmission efficiency calculation flowchart of the collaborative design method for the gear transmission system facing the marine environment of the embodiments of the present application;

[0051] Figure 5 The main framework diagram of the marine environment gear transmission system design analysis software of the collaborative design method of the marine environment gear transmission system of the embodiments of the present application is shown in the figure;

[0052] Figure 6 The parameterized modeling interface diagram of the marine environment gear transmission system design analysis software of the collaborative design method of the marine environment gear transmission system of the embodiments of the present application is shown in the figure;

[0053] Figure 7 The schematic diagram of the collaborative design device of the marine environment gear transmission system of the embodiments of the present application is shown in the figure;

[0054] Figure 8 The hardware structure schematic diagram of the electronic device provided by the embodiments of the present application is shown in the figure. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be described in further detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0056] Figure 1 A collaborative design method of a marine environment gear transmission system provided by the embodiments of the present application is shown in the figure, which includes the following steps:

[0057] S1, a material performance parameter database and a configuration database of the gear transmission system are constructed, the material performance parameter database includes gear materials and corresponding performance parameters, and the configuration database includes planetary gear transmission configurations and series and corresponding configuration parameters.

[0058] In specific embodiments, the gear materials include high-strength low-alloy steel, chromium-nickel-molybdenum alloy steel and austenitic stainless steel, the material parameters include elastic modulus, Poisson's ratio, yield strength, allowable contact stress, allowable bending stress, density and seawater corrosion resistance level, the planetary gear transmission configurations include NGW type planetary gear transmission mechanism, NWN type planetary gear transmission mechanism and NN type planetary gear transmission mechanism, the configuration parameters include macro-geometric configuration parameters and micro-geometric configuration parameters, the macro-geometric configuration parameters include modulus, tooth number, pressure angle and spiral angle, the micro-geometric configuration parameters include tooth profile modification and tooth orientation modification, and the design requirements include transmission power, transmission ratio, transmission efficiency and service life.

[0059] Specifically, the core of the embodiments of the present application is to construct a digital model system that closely couples environmental parameters, materials, configurations, lubrication, and system performance (contact stress, bending stress, transmission efficiency), and to perform global optimization with the help of multi-objective optimization algorithms. Therefore, a performance parameter database of gear transmission system materials and a configuration database are first established. The performance parameter database includes high-strength low-alloy steel, chromium-nickel-molybdenum alloy steel, and austenitic stainless steel, etc. with excellent seawater corrosion resistance and high strength to weight ratio. The material performance parameter database can be used to select gear materials suitable for high pressure, low temperature and seawater corrosion resistance based on the working conditions of the gear transmission system in the marine environment, and store them in the material performance parameter database for subsequent design and selection. Example materials include commonly used high-strength, corrosion-resistant gear materials such as 42CrMoA, 18CrNiMo7-6, and aluminum bronze. The performance parameters in the material database include elastic modulus, Poisson's ratio, yield strength, allowable contact stress, allowable bending stress, density, seawater corrosion resistance level, and other material parameters.

[0060] The types of planetary gears in the configuration database include at least NGW type planetary gear transmission mechanism, NWN type planetary gear transmission mechanism, and NN type planetary gear transmission mechanism. Macroscopic geometric configuration parameters include module, tooth number, pressure angle, and spiral angle. Microscopic geometric configuration parameters include tooth profile modification and tooth orientation modification.

[0061] S2, a first relationship between the depth of the ocean and the environmental parameters and a second relationship between the state parameters of the lubricating oil and the environmental parameters are constructed, a coupling performance prediction model of the gear transmission system is constructed, a target function including the configuration parameters of the gear is constructed, and constraint conditions are set.

[0062] In specific embodiments, the environmental parameters include the pressure and temperature of seawater, the first relationship includes a temperature function that changes with depth and a pressure function that changes with depth; the state parameters of the lubricating oil include viscosity, density, specific heat capacity, and thermal conductivity; the second relationship includes a viscosity function that changes with environmental parameters, a density function that changes with environmental parameters, a specific heat capacity function that changes with environmental parameters, and a thermal conductivity function that changes with environmental parameters. The viscosity function uses the Roelands viscosity-temperature-pressure equation, and the density function uses the Dowson-Higginson density-temperature-pressure equation.

[0063] Specifically, the environmental parameters of the target ocean are obtained, including the hydrostatic pressure corresponding to the depth of seawater and the temperature of seawater, and a temperature function and a pressure function that change with depth are constructed. The environmental parameters of the target ocean are determined by the working conditions of the gear transmission system at different depths in the ocean. Based on the environmental parameters of the ocean, a viscosity function, a density function, a specific heat capacity function, and a thermal conductivity function of the lubricating oil that change with the environmental parameters of the ocean are established, which can be used to calculate the values of the state parameters of the lubricating oil under different pressure and temperature conditions in the subsequent design.

[0064] The temperature function and pressure function with depth in marine environment are constructed, and the corresponding environmental parameters can be calculated according to the different depths of the gear transmission system, such as the pressure function of tropical seawater as shown in the following formula:

[0065] ;

[0066] Wherein, represents the pressure of seawater, is the atmospheric pressure, is the density of seawater, taking 1.025×10 3 kg / m 3 , g is the acceleration of gravity, taking 9.8m / s 2 , h represents the depth of seawater, is the flow velocity of seawater, is the movement speed of marine equipment relative to seawater.

[0067] The formula of the temperature function is:

[0068] ;

[0069] Wherein, represents the temperature of seawater at the depth of h.

[0070] Taking VG320 lubricating oil as an example, the viscosity function, density function, specific heat capacity function and thermal conductivity function of the lubricating oil are measured by experiment. The viscosity function of the lubricating oil adopts the viscosity-temperature-pressure Roelands equation, as shown in the following formula:

[0071] ;

[0072] Wherein, represents the viscosity of the lubricating oil, T is the temperature of the lubricating oil, is the environmental temperature, is the environmental viscosity, and are the Roelands viscosity-pressure coefficient and viscosity-temperature coefficient respectively, by measuring the viscosity of the lubricating oil at different temperatures and pressures, and then fitting by the Roelands equation, the specific lubricant viscosity-pressure-temperature characteristics can be obtained, and finally the environmental temperature, the environmental viscosity, the Roelands viscosity-pressure coefficient and the viscosity-temperature coefficient are determined, such as Figure 2 is the experimental result and curve fitting result of VG320 lubricating oil.

[0073] The pressure equalizer in the gear transmission system in the embodiment of the application can ensure that the pressure in the gear box is the same as the pressure of the external environment, the density function is fitted to the VG320 lubricating oil by using the Dowson-Higginson density-temperature-pressure equation, and the fitted equation is:

[0074] ;

[0075] wherein, represents the density of the lubricating oil, is the density of the lubricating oil at the ambient temperature .

[0076] The specific heat capacity and the thermal conductivity can be measured by experiments, wherein the specific heat capacity is measured by a differential scanning calorimeter DSC 214 Polyma, and the thermal conductivity is measured by a TC3000E thermal conductivity instrument.

[0077] S3, obtaining the depth at which the gear transmission system works in the marine environment, calculating the environmental parameters of the sea based on the depth and the first relationship, calculating the state parameters of the lubricating oil used in the gear transmission system according to the environmental parameters and the second relationship, selecting the initial gear material in the material performance parameter database according to the state parameters of the lubricating oil and the environmental parameters of the sea, and selecting the initial configuration in the configuration database according to the design requirements of the gear transmission system.

[0078] Specifically, in the design process, the corresponding temperature and pressure of the seawater are calculated according to the depth at which the gear transmission system works in the marine environment and the temperature function and the pressure function. The viscosity, density, specific heat capacity and thermal conductivity of the lubricating oil are further calculated according to the temperature and pressure of the seawater and the viscosity function, density function, specific heat capacity function and thermal conductivity function of the lubricating oil.

[0079] Based on the lubrication state and the marine environmental parameters, a gear material suitable for high-pressure and low-temperature environment is selected, considering the toughness retention rate of the material at low temperature, the anti-deformation ability of the material at high pressure, and the comprehensive performance under the coupling action of corrosion and wear. According to the design requirements of the gear transmission system, such as transmission power, transmission ratio, transmission efficiency and service life, a suitable planetary gear transmission type or multi-stage planetary gear transmission configuration is selected. Taking the transmission ratio of 35.4 and the transmission efficiency of more than 80% as an example, a two-stage NGW type planetary gear can be selected, and a structural diagram thereof is shown in Figure 3 . The structure has space efficiency and adaptability to extreme working conditions in deep-sea equipment, and provides stable power support for complex underwater operations. Then, appropriate modulus, tooth number, pressure angle and helix angle are selected, and tooth profile and tooth direction modification are performed to adapt to deep-sea environment transmission.

[0080] According to the above requirements, an initial material and an initial configuration are selected to form an initial design scheme, a coupling performance prediction model of the gear transmission system related to the marine environment is established, the thermal-fluid-solid coupling effect and the corrosion and wear interaction effect are comprehensively considered, the comparison results are obtained, and performance evaluation is performed.

[0081] S4, taking the initial gear material and the initial configuration as initial conditions, inputting the gear material and the configuration into the coupling performance prediction model to obtain performance indexes, and iteratively solving the target function under constraint conditions by using a multi-objective optimization algorithm to obtain the optimal gear material and configuration, so that the corresponding performance indexes meet or are better than the target performance indexes.

[0082] In specific embodiments, the coupling performance prediction model includes a contact stress module, a bending stress module, a transmission efficiency module, and a fatigue life module. The contact stress module and the bending stress module are respectively used to calculate the minimum oil film thickness and the film thickness ratio based on the elastic fluid dynamic lubrication theory through the viscosity of the lubricating oil, to obtain the dynamic load coefficient according to the film thickness ratio, to calculate the contact stress of the tooth surface by combining the dynamic load coefficient with the configuration parameters and the load of the gear according to the ISO 6336 standard, and to calculate the bending stress by combining the dynamic load coefficient with the configuration parameters of the gear. The transmission efficiency module is used to calculate the total loss power of the gear transmission system by using the ISO / RT14179 standard, and to calculate the transmission efficiency according to the total loss power. The fatigue life module is used to perform fatigue life evaluation on the gear transmission system according to the ISO 6336 series standard by using the nominal stress method and combining the Miner linear cumulative damage theory.

[0083] In specific embodiments, the target function is:

[0084] ;

[0085] wherein, represents an input vector of the target function, is a module, and represents the number of teeth of a pair of gears, represents a helix angle, and b represents a tooth width, and represents a pair of gears, , , and respectively represent a first optimization function, a second optimization function, a third optimization function, and a fourth optimization function, and min represents taking the minimum value, represents a contact stress, represents a transmission error, represents a system volume, represents a transmission efficiency;

[0086] The constraint conditions include strength constraints, geometric constraints and transmission performance constraints; the strength constraints include a tooth surface contact strength constraint, a pinion root tooth root bending strength constraint and a gear wheel tooth root bending strength constraint;

[0087] The tooth surface contact strength constraint is:

[0088] ;

[0089] The pinion root tooth root bending strength constraint is:

[0090] ;

[0091] The gear wheel tooth root bending strength constraint is:

[0092] ;

[0093] wherein, , and respectively represent a tooth surface contact strength constraint function, a pinion root tooth root bending strength constraint function and a gear wheel tooth root bending strength constraint function, , and represent a minimum contact stress of a material, a minimum tooth root bending stress of a pinion and a minimum tooth root bending stress of a gear wheel, , and represent an allowable contact stress of a material, an allowable tooth root bending stress of a pinion and an allowable tooth root bending stress of a gear wheel;

[0094] The geometric constraints include a tooth thickness constraint and a center distance matching constraint, the tooth thickness constraint is:

[0095] ;

[0096] The center distance matching constraint is:

[0097] ;

[0098] wherein, and respectively represent a tooth thickness constraint function and a center distance matching constraint function, represents an allowable tooth thickness, represents a minimum tooth thickness, represents a minimum center distance, represents an allowable center distance, represents an allowable tolerance;

[0099] The performance constraints include a transmission efficiency constraint and a transmission smoothness constraint, the transmission efficiency constraint is: ;

[0100] The transmission smoothness constraint is: ;

[0101] wherein, and respectively represent a transmission efficiency constraint function and a transmission smoothness constraint function, represents a minimum transmission efficiency, represents a maximum transmission error.

[0102] In specific embodiments, the multi-objective optimization algorithm adopts the NSGA-II algorithm, sets the population size and the number of iterations, adopts the simulated binary crossover operator for non-dominated sorting and crowded distance calculation, and finally converges to a stable Pareto optimal solution set through multiple generations of iterations, and the best gear material and configuration are selected from the Pareto optimal solution set.

[0103] Specifically, the gear transmission system coupling performance prediction model includes a contact stress module, a bending stress module, a transmission efficiency module and a fatigue life module. Among them, the contact stress module is based on the elastic fluid dynamics lubrication theory, taking the viscosity of the working lubricating liquid as the input, combining the configuration parameters and the load of the gear, and calculating the contact stress of the tooth surface. The bending stress module is based on the ISO 6336 standard, and the function relationship between the dynamic coefficient and the viscosity of the working lubricating liquid is established, the influence of the lubrication state on the dynamic behavior of the system is introduced into the bending stress calculation, so as to realize the coupling analysis of lubrication and bending stress. The meshing friction loss of the transmission efficiency module is calculated based on the friction coefficient, and the friction coefficient is determined by comprehensively considering the viscosity of the working lubricating liquid, the entrainment speed, the slide-roll ratio and the oil film thickness calculated by the elastic fluid dynamics lubrication theory. The classical calculation formula (Dowson-higginson formula) of the minimum oil film thickness is the function of the viscosity , the entrainment speed , the curvature radius R and the load W, as shown in the following formula:

[0104] ;

[0105] wherein, is the viscosity-pressure coefficient of the lubricating oil, is the comprehensive elastic modulus.

[0106] The contact stress module and the bending stress module both adopt the basic formula of the ISO 6336 standard, and the expression of the contact stress module is:

[0107] ;

[0108] wherein, is the node area coefficient, is the coefficient of elasticity, is the coefficient of coincidence, is the coefficient of helix angle, is the nominal tangential force on the inside division circle of the end face, is the pinion division circle diameter, b is the working tooth face width, and u is the gear ratio, is the coefficient of use, is the coefficient of dynamic load, is the coefficient of load distribution between teeth, is the coefficient of load distribution in the direction of teeth.

[0109] The expression of the bending stress module is:

[0110] ;

[0111] wherein, is the normal modulus, is the tooth profile coefficient, is the stress correction coefficient, is the helix angle coefficient, is the load distribution coefficient between teeth for bending strength calculation, is the load distribution coefficient in the direction of teeth for bending strength calculation. According to the influence of marine environment on material performance, the influence of gear geometric size and the influence of multi-field coupling, correction is made to ensure the accuracy of the calculation.

[0112] The modeling of the dynamic load coefficient establishes an empirical or semi-empirical model to associate with the minimum film thickness ratio, as shown in the following formula:

[0113] ;

[0114] wherein, is the comprehensive surface roughness. When (boundary lubrication), the probability of direct metal contact increases, the impact and vibration intensify, the value is higher; when (full film lubrication), the lubricating film completely separates the tooth surface, the meshing is smooth, the value is lower. Through the chain of ← ← ← indirect coupling between the viscosity of the lubricant.

[0115] The transmission efficiency adopts the ISO / RT 14179 standard to calculate the power loss of the gear transmission system, such as Figure 4The force and speed of each component of the gear transmission system are calculated according to the input power and some response parameters, and the influences of the lubricating oil viscosity, material properties and geometric parameters under the marine environment are considered to calculate the gear meshing loss power , the oil stirring wind resistance loss power , the bearing loss power and the oil seal loss power , and the sum of the powers is taken as the total loss power of the gear transmission system , so that the transmission efficiency of the gear transmission system can be calculated as shown in the following formula: ;

[0116] wherein, is the input power.

[0117] The total thermal resistance of the gear box in the marine environment is calculated , and the heat dissipation is equal to the total loss power to estimate the oil pool temperature of the gear box , and the oil pool temperature change further affects the performance of the lubricating oil, and the oil pool temperature of the gear box is taken as the temperature of the lubricating oil, and the state parameters of the lubricating oil are repeatedly calculated, and the transmission efficiency of the gear transmission system is calculated through multiple iterations.

[0118] In one example, the gear meshing loss power includes the external meshing loss power and the internal meshing loss power ; the formula of the meshing loss power of the planetary gear is: wherein, is the number of planetary gears.

[0119] The oil stirring wind resistance loss power of the planetary gear is: ; wherein, is the oil stirring wind resistance loss power, is the sun gear oil stirring loss, is the planetary gear oil stirring loss, is the planet carrier oil stirring loss.

[0120] The bearing loss power includes the no-load friction torque (the wind resistance and oil stirring loss of the bearing), the radial load friction torque and the axial load friction torque , and the calculation formula is:

[0121] ;

[0122] wherein, Bearing rotational speed.

[0123] Oil seal loss power is: ; wherein, is the friction torque of the oil seal, and n is the rotational speed of the shaft.

[0124] The fatigue life module of the embodiments of the present application adopts the nominal stress method and combines the Miner linear cumulative damage theory to evaluate the fatigue life of the gear transmission system according to the ISO 6336 series standards. Under the action of the full life cycle load spectrum, the cumulative damage degree of the gear transmission system is calculated according to the following formula:

[0125] ;

[0126] wherein, U represents the total cumulative damage degree, is the damage degree under the i-th level load; is the actual cycle number under the i-th level load; is the corresponding failure cycle number of the i-th level load on the S-N curve. When the cumulative damage degree U = 1.0, it is determined that the gear transmission system has fatigue failure; when U < 1.0, the corresponding fatigue life is the expected life of the system that can be safely worked under the condition of the load spectrum.

[0127] The performance index obtained by the coupling performance prediction model is compared with the set target performance index, the target performance index including a target value of transmission efficiency, a target value of contact stress, a target value of bending stress and a target value of fatigue life, if the target performance index is not reached, the material, the configuration or the combination thereof is reselected or adjusted, and the multi-objective optimization algorithm is used for iterative calculation and evaluation until the result meets or is better than the target performance index.

[0128] In the multi-objective collaborative optimization process, first, the objective function containing the macro-geometric configuration parameters of the gear (such as modulus , number of teeth , , helix angle , tooth width b and coefficient , ) is constructed, and the conflicting engineering indexes are optimized at the same time, including minimizing the contact stress , transmission error and system volume , and maximizing the transmission efficiency ((maximization by taking negative value), while setting constraints to meet material strength requirements (tooth surface contact stress and tooth root bending stress not exceeding allowable value), geometric requirements (such as addendum thickness, center distance matching) and transmission performance (such as efficiency threshold and smoothness), then input the objective function into the optimization platform based on NSGA-II algorithm (such as MATLAB global optimization toolbox), by setting population size, iteration number, using simulated binary crossover operator for non-dominated sorting and crowded distance calculation, and finally converging to stable Pareto optimal solution set through multiple generations of iteration. The final scheme can be selected from the Pareto optimal solution set according to actual needs, and the objective function and the constraint condition can be dynamically adjusted according to the specific scene.

[0129] The embodiment of the application also designs a marine environment gear transmission system design and analysis software. The software is a collaborative design platform constructed based on high-level architecture (HLA), adopts a hierarchical multi-module design idea, contains a user interaction layer, a core function layer and a data management layer, realizes the association and cooperation between layers through the data management layer, and uses Python language as a core development language, combines self-developed algorithms and third-party technology stacks to construct a collaborative simulation platform, as shown in Figure 5 The user interaction layer integrates software operation interface, parameterized modeling visualization and graphical result display functions, constructs a graphical user interface through a Qt framework, and accesses an OpenGL three-dimensional model generation tool to realize design parameter input and result dynamic visualization, as shown in Figure 6 The core function layer contains a contact stress module, a bending stress module, a transmission efficiency module and a fatigue life module. The data management layer serves as a cooperation hub, stores parameterized modeling data, imported graphics and calculation results through a SQLite database engine, and constructs a local model library (such as a configuration database and a material performance parameter database) to support rapid design iteration. This layer realizes real-time data transmission and reception with the user interaction layer and the core function layer through API, for example, feeding back the optimization results to the visualization interface.

[0130] Further referring to Figure 7 , as an implementation of the method shown in the above figures, the application provides an embodiment of a collaborative design device for a marine environment gear transmission system. The device embodiment corresponds to the method embodiment shown in Figure 1 , and the device can be applied to various electronic devices.

[0131] The embodiment of the application provides a collaborative design device for a marine environment gear transmission system, which comprises:

[0132] The database construction module 1 is configured to construct a material performance parameter database of the gear transmission system and a configuration database, the material performance parameter database including gear materials and corresponding performance parameters, and the configuration database including planetary gear transmission configurations and corresponding configuration parameters;

[0133] The relationship construction module 2 is configured to construct a first relationship between the depth of the ocean and environmental parameters and a second relationship between state parameters of lubricating oil and environmental parameters, construct a coupling performance prediction model of the gear transmission system, and construct a target function containing configuration parameters of the gear and set a constraint condition;

[0134] The calculation module 3 is configured to obtain the depth at which the gear transmission system works in the ocean environment, calculate the environmental parameters of the ocean based on the depth and the first relationship, calculate the state parameters of the lubricating oil used in the gear transmission system according to the environmental parameters and the second relationship, select an initial gear material in the material performance parameter database according to the state parameters of the lubricating oil and the environmental parameters of the ocean, and select an initial configuration in the configuration database according to the design requirements of the gear transmission system.

[0135] The optimization module 4 is configured to take the initial gear material and the initial configuration as initial conditions, input the gear material and the configuration into the coupling performance prediction model to obtain performance indicators, and iteratively solve the target function under the constraint condition by using a multi-objective optimization algorithm to obtain the best gear material and configuration, so that the corresponding performance indicators meet or are better than target performance indicators.

[0136] Figure 8 A hardware structure schematic diagram of an electronic device provided by the embodiment of the present application is shown in FIG. 1. Figure 8 As shown in FIG. 1, the electronic device of the embodiment includes a processor 801 and a memory 802; the memory 802 is configured to store computer execution instructions; and the processor 801 is configured to execute the computer execution instructions stored in the memory to implement each step performed by the electronic device in the above-mentioned embodiment. For details, refer to the related description in the foregoing method embodiment.

[0137] Optionally, the memory 802 can be independent or integrated with the processor 801.

[0138] When the memory 802 is independently arranged, the electronic device further includes a bus 803 for connecting the memory 802 and the processor 801.

[0139] The embodiment of the present application further provides a computer storage medium, and the computer storage medium stores computer execution instructions; when the processor 801 executes the computer execution instructions, the method described above is implemented.

[0140] The embodiment of the present application further provides a computer program product comprising a computer program, which, when executed by the processor 801, implements the method as above.

[0141] In the embodiments of the present application, it should be understood that the disclosed device and method can be implemented in other manners. For example, the described device embodiment is merely schematic. For example, the division of the modules is merely a logical function division. There can be another division manner for the actual implementation. For example, a plurality of modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections can be indirect couplings or communication connections through some interfaces, devices or modules, and can be electrical, mechanical or in other forms.

[0142] The modules illustrated as separated components can or can not be physical separated, and the components illustrated as modules can or can not be physical units. That is, they can be located in one position or distributed on a plurality of network units. Part or all of the modules can be selected according to the actual needs to implement the embodiments of the present application.

[0143] In addition, each function module in each embodiment of the present application can be integrated in a processing unit, or each module can be a physical unit, or two or more modules can be integrated in one unit. The units formed by the above modules can be realized in the form of hardware, or in the form of hardware and software function units.

[0144] The integrated modules realized in the form of software function modules can be stored in a computer readable storage medium. The above software function modules stored in a storage medium include a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or the processor 801 to perform some steps of the methods of the embodiments of the present application.

[0145] It should be understood that the processor 801 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), or the like. The general-purpose processor can be a microprocessor, or the processor 801 can also be any conventional processor, etc. The steps of the methods disclosed in the present application can be directly embodied as the processor 801 executing hardware, or a combination of hardware and software modules in the processor 801 executing.

[0146] The memory 802 can include a high-speed RAM memory and can also include a non-volatile storage NVM, for example at least one disk memory, and can also be a U disk, a mobile hard disk, a read-only memory, a magnetic or optical disk, etc.

[0147] The bus 803 can be an Industry Standard Architecture (ISA), a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus 803 can be divided into an address bus, a data bus, a control bus, etc. For the sake of representation, the bus 803 in the drawings of the present application does not limit to only one bus 803 or one type of bus 803.

[0148] The storage medium described above can be realized by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0149] An exemplary storage medium is coupled to the processor 801, so that the processor 801 can read information from the storage medium and can write information to the storage medium. Of course, the storage medium can also be an integral part of the processor 801. The processor 801 and the storage medium can be located in an Application Specific Integrated Circuit (ASIC). Of course, the processor 801 and the storage medium can also exist as discrete components in an electronic device or a host device.

[0150] Those of ordinary skill in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction-related hardware. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the foregoing storage medium includes various storage media that can store program codes, such as ROM, RAM, magnetic disk or optical disk.

[0151] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A collaborative design method for gear transmission systems in marine environments, characterized in that, Includes the following steps: Construct a material performance parameter database and a configuration database for a gear transmission system. The material performance parameter database includes gear materials and their corresponding performance parameters, and the configuration database includes planetary gear transmission configurations and stages and their corresponding configuration parameters. Construct the first relationship between ocean depth and environmental parameters, and the second relationship between lubricating oil state parameters and environmental parameters. Construct a coupled performance prediction model for the gear transmission system, construct an objective function that includes gear configuration parameters, and set constraints. The depth at which the gear transmission system operates in the marine environment is obtained, and marine environmental parameters are calculated based on the depth and a first relationship; the state parameters of the lubricating oil used in the gear transmission system are calculated based on the environmental parameters and a second relationship; and an initial gear material is selected from the material performance parameter database based on the lubricating oil state parameters and the marine environmental parameters. According to the design requirements of the gear transmission system, an initial configuration is selected from the configuration database; Using the initial gear material and initial configuration as initial conditions, the gear material and configuration are input into the coupled performance prediction model to predict the performance index. Under the constraints, a multi-objective optimization algorithm is used to iteratively solve the objective function to obtain the optimal gear material and configuration, so that the corresponding performance index meets or exceeds the target performance index.

2. The collaborative design method for gear transmission systems oriented towards marine environments according to claim 1, characterized in that, The environmental parameters include seawater pressure and temperature. The first relationship includes a temperature function and a pressure function that vary with depth. The lubricating oil's state parameters include viscosity, density, specific heat capacity, and thermal conductivity. The second relationship includes a viscosity function, a density function, a specific heat capacity function, and a thermal conductivity function that vary with environmental parameters. The viscosity function uses the viscosity-temperature-pressure Roelands equation, and the density function uses the Dowson-Higginson density-temperature-pressure equation.

3. The collaborative design method for gear transmission systems oriented towards marine environments according to claim 1, characterized in that, The gear materials include high-strength low-alloy steel, chromium-nickel-molybdenum alloy steel, and austenitic stainless steel. The material parameters include elastic modulus, Poisson's ratio, yield strength, allowable contact stress, allowable bending stress, density, and seawater corrosion resistance. The planetary gear transmission configurations include NGW type planetary gear transmission mechanisms, NWN type planetary gear transmission mechanisms, and NN type planetary gear transmission mechanisms. The configuration parameters include macroscopic geometric configuration parameters and microscopic geometric configuration parameters. The macroscopic geometric configuration parameters include module, number of teeth, pressure angle, and helix angle. The microscopic geometric configuration parameters include tooth profile modification and tooth direction modification. The design requirements include transmission power, transmission ratio, transmission efficiency, and service life.

4. The collaborative design method for gear transmission systems oriented towards marine environments according to claim 1, characterized in that, The coupled performance prediction model includes a contact stress module, a bending stress module, a transmission efficiency module, and a fatigue life module. The contact stress module and the bending stress module are used to calculate the minimum oil film thickness and the film thickness ratio based on the viscosity of the lubricating oil using elastohydrodynamic lubrication theory. Based on the film thickness ratio, the dynamic load coefficient is obtained. Using the ISO 6336 standard, the dynamic load coefficient is combined with the gear configuration parameters and load to calculate the contact stress on the tooth surface. The bending stress is also calculated by combining the dynamic load coefficient with the gear configuration parameters. The transmission efficiency module is used to calculate the total power loss of the gear transmission system using the ISO / RT 14179 standard, and the transmission efficiency is calculated based on the total power loss. The fatigue life module is used to evaluate the fatigue life of the gear transmission system using the nominal stress method combined with Miner's linear cumulative damage theory, according to the ISO 6336 series of standards.

5. The collaborative design method for gear transmission systems oriented towards marine environments according to claim 1, characterized in that, The objective function is: ； in, The input vector represents the objective function. For modulus, and Indicates the number of teeth in a pair of gears. b represents the helix angle, and b represents the tooth width. and This represents the coefficient of change for a pair of gears; , , and Let these represent the first, second, third, and fourth optimization functions, respectively, with min indicating the minimum value. Indicates contact stress, Indicates transmission error. Indicates the system volume. Indicates transmission efficiency; The constraints include strength constraints, geometric constraints, and transmission performance constraints; the strength constraints include tooth surface contact strength constraints, pinion root tooth root bending strength constraints, and gear tooth root bending strength constraints. The tooth surface contact strength constraint is: ； The bending strength constraint of the pinion root is: ； The bending strength constraint at the root of the large gear is: ； in, , and Let represent the tooth surface contact strength constraint function, the pinion root bending strength constraint function, and the gear root bending strength constraint function, respectively. , and This represents the minimum contact stress of the material, the minimum tooth root bending stress of the pinion, and the minimum tooth root bending stress of the gear. , and This indicates the allowable contact stress of the material, the allowable bending stress at the root of the pinion tooth, and the allowable bending stress at the root of the gear tooth. The geometric constraints include tooth tip thickness constraints and center distance matching constraints. The tooth tip thickness constraint is as follows: ； The center distance matching constraint is: ； in, and Let these represent the tooth tip thickness constraint function and the center distance matching constraint function, respectively. Indicates the allowable tooth tip thickness. This indicates minimizing the tooth tip thickness. This represents minimizing the center distance. Indicates the allowable center distance. This indicates that tolerances are allowed; The performance constraints include transmission efficiency constraints and transmission smoothness constraints. The transmission efficiency constraints are as follows: ; The transmission smoothness constraint is: ; in, and Let these represent the transmission efficiency constraint function and the transmission smoothness constraint function, respectively. This represents the minimum transmission efficiency. This indicates the maximum transmission error.

6. The collaborative design method for gear transmission systems oriented towards marine environments according to claim 1, characterized in that, The multi-objective optimization algorithm adopts the NSGA-II algorithm. By setting the population size and number of iterations, it uses a simulated binary crossover operator to perform non-dominated sorting and crowding distance calculation. After multiple generations of iteration, it finally converges to a stable Pareto optimal solution set. The best gear material and configuration are selected from the Pareto optimal solution set.

7. A collaborative design device for gear transmission systems in marine environments, characterized in that, include: The database construction module is configured to construct a material performance parameter database and a configuration database for a gear transmission system. The material performance parameter database includes gear materials and their corresponding performance parameters, and the configuration database includes planetary gear transmission configurations and stages and their corresponding configuration parameters. The relationship building module is configured to build a first relationship between ocean depth and environmental parameters and a second relationship between lubricating oil state parameters and environmental parameters, build a coupling performance prediction model for the gear transmission system, build an objective function containing gear configuration parameters and set constraints. The calculation module is configured to obtain the operating depth of the gear transmission system in a marine environment, calculate marine environmental parameters based on the depth and a first relationship, calculate the state parameters of the lubricating oil used in the gear transmission system according to the environmental parameters and a second relationship, and select an initial gear material from the material performance parameter database according to the lubricating oil state parameters and the marine environmental parameters. According to the design requirements of the gear transmission system, an initial configuration is selected from the configuration database; The optimization module is configured to take the initial gear material and initial configuration as initial conditions, input the gear material and configuration into the coupled performance prediction model to predict the performance index, and use a multi-objective optimization algorithm to iteratively solve the objective function under the constraints to obtain the optimal gear material and configuration, so that the corresponding performance index meets or exceeds the target performance index.

8. An electronic device, comprising: One or more processors; Storage device for storing one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1-6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-6.

Images