Thermal Load Characteristic Analysis And Life Prediction Of Wet Clutch Friction Pair

With the implementation of the maritime power and the One Belt One Road strategy,my country’s shipbuilding industry has developed rapidly.The wet friction clutch is an important part of the marine transmission system,and its reliability will directly determine whether the transmission system can work normally.The main torsion transmission parts of the wet clutch are the friction plate and the mating plate.During the working process,the two sliding and rubbing against each other generate a lot of heat,causing the friction element to crack,wear severely,and even fall off the friction material.The thermal stability of the friction element is opposite to the transmission.Torsion performance and service life play a decisive role.Therefore,it is necessary to carry out a thermo-mechanical coupling study on friction elements to analyze the thermal load characteristics and service life of the friction element.The main research contents of this paper are as follows:(1)According to the basic structure and working process of the wet multi-plate friction clutch,the heat generation model of the friction plate pair joining process is established,and the heat flux distribution during the joining process is calculated.Based on the theory of heat transfer,a theoretical model of heat transfer within the fins and convective heat transfer between the friction fins and the oil is established,and the convective heat transfer coefficient of the lubricating oil in the clutch is calculated.(2)Clarify the load and boundary conditions in the clutch engagement process.Based on the thermal-mechanical coupling analysis of the friction plate pair,the temperature field and thermal stress field of the friction plate and the mating plate change with space and time.Analyze the influence of the structure of the oil sump and the structure parameters of the oil sump on the thermal load characteristics of the wet clutch friction pair.(3)Optimize the structural parameters of the oil groove of the friction lining to reduce the maximum temperature and the maximum thermal stress of the friction lining as the optimization goal to improve the thermal performance of the friction lining pair.Carry out the thermal load characteristics analysis of the entire set of friction plate pairs,and optimize the clutch quality and thermal performance according to the analysis results.(4)Carry out the failure life prediction for the two main failure modes of the friction plate,establish the life prediction model of the friction plate crack initiation based on the low cycle thermal fatigue theory,calculate the service life of the friction plate crack initiation,and use FEMFAT to verify the life prediction reliability.Based on the Archard wear model,the wear amount of the friction lining during a single engagement process is calculated,and the service life of the friction lining when wear failure occurs is calculated according to the wear threshold.This paper analyzes the thermal load characteristics of the wet clutch friction pair,optimizes the oil groove structure,and predicts fatigue failure and wear failure life.It has certain reference value and guiding significance for the research and development of wet clutches.