液力变矩器泵轮离合器及其在装载机上的应用研究

发布时间：2017-12-27 23:15

本文关键词：液力变矩器泵轮离合器及其在装载机上的应用研究　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：轮式装载机是一种广泛应用于现代化工程建设的多功能铲土运输机械。发动机作为轮式装载机的动力来源,其产生的功率除了少部分用于驱动散热风扇等附件外,其余大部分功率主要有两个流向,一部分功率用于驱动工作装置液压系统工作,另一部分功率流经液力机械传动系统传递到车轮以驱动装载机行走。液力变矩器与发动机之间的匹配是否合理,直接关系着轮式装载机的动力性、经济性和作业效率。但是目前轮式装载机上使用的液力变矩器性能单一,不能同时满足行驶和铲装两种典型工作状态下的理想匹配性能要求。为了解决发动机输出功率在液力机械传动系统和工作装置液压系统之间动态合理分配的问题,以某7吨轮式装载机为应用对象,设计了带有泵轮离合器的液力变矩器,并研究其特性对轮式装载机性能的影响。主要研究内容如下。(1)设计了带有泵轮离合器的液力变矩器,用以解决发动机输出功率的动态合理分配问题。采用相似设计方法设计了有效直径为370mm的液力变矩器循环圆,应用等倾角射影法分别设计了液力变矩器的泵轮叶片、涡轮叶片和导轮叶片。基于液力变矩器结构,设计了泵轮离合器及其他辅助零部件,最终得到液力变矩器加装泵轮离合器的整体结构。采用CFD数值计算方法分析了液力变矩器的原始特性和侧腔压力分布情况。通过建立泵轮离合器的受力平衡方程,分析了泵轮离合器不同控制压力下的转矩特性,建立了控制压力与转速比、滑差率的关系,求解了液力变矩器与泵轮离合器的共同工作特性。(2)基于某7吨轮式装载机动力传动系统组成和整机参数,详细分析了轮式装载机V型铲装作业循环各阶段的工作状态。根据发动机与带有泵轮离合器的液力变矩器的特性,构建了数学模型并进行了静态变功率匹配计算,得到了行驶工作状态和铲装工作状态下的共同工作输入特性、输出特性。根据共同工作匹配特性分析了装载机的动力性、经济性以及铲装作业效率。分析表明,泵轮离合器具有调节液力机械传动系统与工作装置液压系统之间功率分配的作用,有助于提高发动机的功率利用率;泵轮离合器有助于加快工作装置的动作响应速度,提高铲装作业效率;装载机工作在附着系数较小的路面时,泵轮离合器可减少轮胎打滑情况。(3)为了使泵轮离合器的滑差率无级可调,设计了变功率控制系统并提出了变功率控制方法。运用MATLAB/Simulink构建了基于变功率控制系统的动态匹配仿真模型,为了获得动态匹配仿真模型的输入信号及相关数据,对某7吨轮式装载机V型铲装作业循环进行了试验测试。运用构建的仿真模型,对液力变矩器加装泵轮离合器后与发动机的匹配性能进行了一个V型铲装作业循环下的仿真分析,将仿真得到的发动机功率、泵轮输入功率、涡轮输出功率、工作装置液压系统消耗功率和整机燃油消耗量等性能参数与原机进行了对比分析。研究表明,设计的带有泵轮离合器的液力变矩器及其变功率控制系统,有效解决了发动机输出功率的合理分配问题,使轮式装载机铲装工作状态下的性能显著提高。
[Abstract]:Wheel loader is a kind of multi-function shovelling machine which is widely used in modern engineering construction. The power source of the engine as the wheel loader, the power generated in addition to a small part for driving cooling fan and other accessories, most of the remaining power has two main flow driven hydraulic system working for a part of power, the other part of the power flow through the hydraulic mechanical transmission system is transmitted to the wheels to drive loader walking. Whether the matching between the torque converter and the engine is reasonable is directly related to the power, economy and operation efficiency of the wheel loader. But at present, the torque converter used on wheel loaders is single, which can not satisfy the ideal matching performance requirements of two typical working conditions of driving and shovel. In order to solve the engine output power between the hydraulic mechanical transmission system and working device system dynamic allocation problem, a 7 ton loader as the application object, designed with the pump wheel clutch torque converter, and study its influence on the performance characteristics of wheel loader. The main research contents are as follows. (1) a hydraulic torque converter with a pump wheel clutch is designed to solve the problem of dynamic and rational distribution of engine output power. A circular ring of hydrodynamic torque converter with an effective diameter of 370mm is designed by using the similar design method. The pump impeller blades, turbine blades and guide vanes of the torque converter are designed by using the equal inclination projection method. Based on the structure of hydraulic torque converter, the pump wheel clutch and other auxiliary parts are designed, and the overall structure of the clutch of the pump wheel is obtained by the hydraulic torque converter. The CFD numerical method is used to analyze the original characteristics of the torque converter and the pressure distribution in the side cavity. By establishing the force balance equation of the pump wheel clutch, the torque characteristics of the pump wheel clutch under different control pressures are analyzed, and the relationship between the control pressure and speed ratio and slip ratio is established, and the working characteristics of the torque converter and the pump wheel clutch are solved. (2) based on the composition and parameters of a 7 ton wheeled loader's power transmission system, the working condition of wheel loader V operation cycle is analyzed in detail. According to the characteristics of the torque converter of the engine and the pump wheel clutch, a mathematical model is built, and the static variable power matching calculation is carried out. The common working input characteristics and output characteristics of the driving working state and the working condition of the shovel are obtained. According to the characteristics of the common work matching, the power, economy and the efficiency of the loader are analyzed. Analysis shows that the pump wheel clutch has the power distribution between the regulation of hydraulic system of hydraulic mechanical transmission system and device, helps to improve the utilization rate of the power of the engine; the pump wheel clutch speed help to speed up the work device action response, increase loading efficiency; loader working in smaller road adhesion coefficient the pump wheel, the clutch can reduce tire slipping. (3) in order to make the slip difference of the clutch of the pump wheel stepless, the variable power control system is designed and the variable power control method is put forward. A dynamic matching simulation model based on variable power control system is built by using MATLAB/Simulink. In order to get input signal and related data of dynamic matching simulation model, V type shovel operation cycle of a 7 ton wheel loader is tested. By using the simulation model, the torque converter pump wheel installed after the clutch and the matching performance of engine is analyzed under cyclic loading simulation operation of a V type shovel, engine power, pump wheel input power performance simulation of hydraulic system, the output power of the turbine, the working device of the power consumption and the fuel consumption the parameters were compared with the original machine. The research shows that the design of torque converter and variable power control system with pump wheel clutch effectively solve the problem of reasonable distribution of engine output power, and improve the performance of wheel loader under shovel loading.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH137.332;TH243

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