基于MPS方法液力变矩器低温启动搅油力矩研究  

Research on the Churning Torque of Torque Converter during Low Temperature Start-up Based on MPS Method

作　　者：韦春辉 吴维[1] 桂鹏[3] 邹天刚[3] 苑士华[1] WEI Chunhui;WU Wei;GUI Peng;ZOU Tiangang;YUAN Shihua(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081;Yangtze Delta Region Academy of Beijing Institute of Technology,Jiaxing 314019;China North Vehicle Research Institute,Beijing 100072)

机构地区：[1]北京理工大学机械与车辆学院,北京100081 [2]北京理工大学长三角研究院,嘉兴314019 [3]中国北方车辆研究所,北京100072

出　　处：《机械工程学报》2025年第2期257-267,共11页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(51975045)。

摘　　要：车辆传动润滑油在低温环境下黏度增大,流动性变差,使得传动系统启动力矩增大。液力变矩器为车辆传动系统的重要部件,低温下液力变矩器启动过程搅油力矩尚不清楚。采用基于无网格粒子(Moving particle semi-implicit,MPS)方法研究润滑油在不同工作温度及不同液面高度液力变矩器搅油力矩随转速的变化规律,并通过所搭建的搅油力矩测试试验台验证数值计算的可行性。通过流变仪测试了5W-40润滑油在低温下流变特性,分析液力变矩器在低温工况下不同启动方式瞬态搅油力矩的变化规律以及润滑油分布和流场特性,并提出了降低低温启动搅油力矩装置。研究结果表明,5W-40润滑油在低温下为非牛顿流体,液力变矩器转速为284 r/min时,-43℃时搅油力矩是-20℃的2.5倍。相比线性启动,采用分段启动能量损失小。提出的此装置可有效降低液力变矩器低温启动搅油力矩,且转速越高,效果越明显。为液力变矩器搅油力矩计算提供了一种数值计算方法,同时为降低车辆传动系统液力变矩器低温启动搅油力矩设计提供理论支撑。The viscosity of vehicle transmission lubricating oil increases in low temperature environment,and its fluidity becomes poor,which increases the starting torque of transmission system.The torque converter is an important part of the vehicle transmission system.The churning torque during the starting process of the torque converter at low temperature is still unclear.The method based on moving particle semi-implicit(MPS)is used to study the variation of churning torque of torque converter with rotational speed at different operating temperature and different oil level.The feasibility of the numerical calculations is validated by the churning torque test bench built.The rheological properties of 5W-40 oil at low temperatures are tested using a rheometer.The transient variation of the churning torque in the torque converter under different starting modes at low temperature,as well as the distribution of lubricating oil and flow field characteristics,are analyzed.A device for reducing the churning torque during low temperature start-up is proposed.The research results indicate that the 5W-40 oil is a non-Newtonian fluid at low temperature.When the speed of the torque converter is 284 r/min,the churning torque at-43℃is 2.5 times that at-20℃.Compared with linear start-up,segmented start-up has less energy loss.The proposed device can effectively reduce the churning torque during low temperature start-up of the torque converter,and the higher the speed,the more significant the effect.A numerical calculation method is provided for the calculation of the churning torque in the torque converter,along with theoretical support for designing a reduction in the churning torque during low temperature start-up in vehicle transmission systems.

关 键 词：液力变矩器 无网格粒子法 低温启动 搅油力矩 非牛顿流体 

分 类 号：TH132[机械工程—机械制造及自动化]