牵引工况下大功率液力变矩器总成热特性研究  

Thermal characteristics of assembly of high power torque converter in traction condition

作　　者：张泽宇[1] 卜正锋 惠记庄[1] 张富强[1] 谷立臣[1,3] ZHANG Ze-yu;BU Zheng-feng;HUI Ji-zhuang;ZHANG Fu-qiang;GU Li-chen(National Engineering Laboratory for Highway Maintenance Equipment, Chang＇an University, Xi＇an 710064, Shaanxi, China;Shaanxi Aerospace Power CO. , LTD, Xi＇an 710077, Shaanxi, China;School of Mechanical Electronic Engineering, Xi＇an University of Architecture and Technology, Xi＇an 710055, Shaanxi, China)

机构地区：[1]长安大学公路养护装备国家工程实验室,陕西西安710064 [2]陕西航天动力高科技股份有限公司,陕西西安710077 [3]西安建筑科技大学机电工程学院,陕西西安710055

出　　处：《长安大学学报（自然科学版）》2018年第3期116-126,共11页Journal of Chang’an University(Natural Science Edition)

基　　金："十二五"国家科技支撑计划项目(2015BAF07B02);国家自然科学基金项目(51605041);中央高校基本科研业务费专项资金项目(310825175010)

摘　　要：针对推土机在往返工况下液力变矩器油温经常超工作范围问题,分析其液力变矩器内部油温与车辆工况的变化规律,并对液力变矩器液压供油系统进行温度调节与保护,开展牵引工况下大功率液力变矩器总成的热特性研究。以热平衡理论为基础,分析推导液力变矩器的能量损失、传递效率、热量的产生和散失与油温之间关系。利用液力变矩器总成的台架试验,测试了YJ380型大功率液力变矩器在牵引工况下的扭矩、转速、流量、油温等基本特性参数。以试验数据为基础,建立了140kW柴油发动机与该大功率液力变矩器的数学模型,并对其共同工作的数学模型进行了分析;在发动机与液力变矩器功率匹配的基础上,通过计算液力变矩器的能量损失以及散热器的散热效率,得出液力变矩器在不同工况下的内部油温。针对液压系统由于泵排量不足导致的油温过高现象,搭建供油系统模型,通过对液压系统的流量调节优化了液力变矩器总成的热平衡特性,通过控制液力变矩器的闭锁离合器对系统进行了温度保护。最后,将试验结果与数值模拟结果进行了对比验证。研究结果表明:利用发动机与液力变矩器共同工作数学模型计算的油温与实测出口、入口油温均值的相对误差约为2%,验证了该数学模型的正确性;在液力变矩器供油系统基础上,建立了恒温控制及温度的自动保护方案,当油温为60℃~80℃,或100℃~120℃时,通过调节系统流量能保持温度恒定,当油温小于60℃或大于120℃时,通过闭解锁控制可以保证液力变矩器动力总成的可靠性。In the round-trip conditions, the oil temperature of the torque converter often exceeds the bulldozers working range, in order to study the variation principle of the oil temperature inside hydraulic torque converters, adjust and protect its hydraulic system, the study on thermal characteristics of the assembly of high power torque converter in traction condition was proposed. Based on the theory of thermal equilibrium, the relationship among energy loss, transmission efficiency, generation and dissipation of heat, and oil temperature was analyzed and deduced. The bench was used to test the characteristic parameters of torque, speed, flow rate and oil temperature of YJ380 high-power torque converter for bulldozers under traction condition. According to the experimental data, the mathematical models of 140 kW diesel engine and the torque converter were established, and the cooperating model was analyzed. Based on the power matching between the engine and the torque converter, the oil temperature at the different speed ratio was obtained by calculating the energy loss of the torque converter and the dissipation efficiency of the radiator. Aiming at the phenomenon that the excess oil temperature in the hydraulic, due to the insufficient displacement of the hydraulic system, an oil supply system model was set up. The thermal balance characteristic of the torque converter assembly was optimized by adjusting the flow rate of the hydraulic system, and the temperature of the system was protected by controlling the lock-up clutch. Based on the comparison of the experimental data and the calculated results, the deviation was about 2%, which verified the correctness of the mathematical model. Based on the oil supply system of the torqueconverter, a thermostatic control and temperature automatic protection scheme was established. When the oil temperature was in the range of 60 ℃ -80 ℃, or 100 ℃ -120 ℃, the flow rate could be kept constant by adjusting the flow of the system. When the oil temperature was less than 120

关 键 词：机械工程 热特性 热平衡理论 大功率液力变矩器 推土机 

分 类 号：U415.512[交通运输工程—道路与铁道工程]