Multi-objective Optimization Of Sliding Bearing Based On Kriging Surrogate Model

The sliding bearing system is one of the core components of a rotating machine and plays a vital role in the mechanical transmission process.With the continuous development of modern industry,the industry has put forward higher and higher requirements for the performance of bearing systems.The temperature of the oil film of the sliding bearing is obviously increased at high speed,and the oil film thickness,pressure and flow rate at different points are different,which tends to form a temperature field with uneven distribution.The viscosity of the lubricating oil is greatly affected by temperature,which affects the static,dynamic characteristics and Stability of the bearing;Therefore,considering the characteristics of the bearing oil film,the effects of cavitation and thermal effects are more in line with the actual working conditions of the bearing.In the design process of the sliding bearing,the conventional design method can generally obtain a feasible design,but it cannot guarantee that the bearing can achieve better performance while meeting the design requirements.In order to improve the performance of the bearing,it is necessary to select the appropriate optimization method to optimize the design of the dynamic and static bearing,and seek the best design to improve the design quality.In this paper,the experimental study on the influence of gas content on the viscosity of lubricating oil is carried out by using the No.32 turbine oil commonly used in sliding bearings.The mathematical model of the relationship between two-phase flow density and viscosity as a function of gas content is established.For the dynamic and hydrostatic bearings with deep and shallow cavities,the Reynolds equation for controlling the pressure distribution,the energy equation for controlling the temperature distribution and the temperature-viscosity relationship are established respectively,and appropriate boundary conditions are established.The oil film is meshed,and the finite element method is used to solve the Reynolds equation and the finite difference method to solve the energy equation.On this basis,the static and dynamic characteristics of the oil film under different working conditions arecalculated.Parameter.In this paper,the optimal design mathematical model is established with the minimum friction power consumption per unit bearing capacity and the minimum average temperature rise as the objective function.The structural parameters such as shallow cavity angle and shallow cavity depth are used as design variables to adopt Kriging surrogate model for different gas content.The dynamic and static bearing of the rate is modeled and analyzed.The multi-objective genetic algorithm is used to find the Pareto optimal solution set of the Kriging model.The range of the optimal design variables of the optimized bearing is obtained,and the TOPSIS method is used to obtain the optimal according to the design requirements.Non-inferior solution.The optimization results show that the optimized sliding bearing meets the design requirements of bearing capacity,and the bearing friction power consumption and temperature rise are reduced.The Kriging proxy model method has high application value in the optimization design of sliding bearing.