装载机整车行走变排量液压系统功率特征仿真及实验研究

Simulation and Experimental Study on Power Characteristics of Loader Vehicle Walking Variable Displacement Hydraulic System

为使装载机发动机和外负载形成良好匹配状态,设计一种行走变排量液压系统。在分析行走系统动力学特性的基础上,开展仿真分析及实验。结果表明:从总体上看,仿真结果能够较好地反映直线行驶的运行工况,仿真和实验结果一致性良好;对装载机进行单边转向测试时,内侧车轮马达存在泄漏现象;之后进入滚动阶段,内侧车轮变量泵受到马达带动,形成高压油液以及部分流量,柱塞泵进入泵-马达运行工况,并产生一定程度的寄生功率;进入匀速双边转向阶段时,内、外侧车轮受到的阻力存在差异,需要进行适当调节,从而满足各类工况都达到良好行驶状态的功能;进入单边转向过程时,内侧车轮开始受到制动作用,在内侧车轮变量泵内的油液出现高压状态并形成部分流量。

In order to make the loader engine and the external load form a good matching state,a kind of walking hydraulic system with variable displacement was designed.On the basis of analyzing the dynamic characteristics of the walking system,the simulation analysis and experimental were carried out.The results show that on the whole,the simulation results can well reflect the operating conditions of straight line driving,and the simulation results and experimental results are in good agreement;during the unilateral turnning test on the loader,there is leakage in the inner wheel motor;after entering the rolling stage,the inner wheel variable pump is driven by the motor,forming a high pressure oil and part of the flow,the plunger pump enters into the pump-motor operation condition,and a certain degree of parasitic power is produced;when entering the uniform bilateral steering stage,the inner and outer wheels resistances are different,which needs to be properly adjusted,so the function of various working conditions can be met to achieve a good running state;when entering the unilateral steering stage,the inner wheels begins to be braking,and the oil in the inner wheel variable pump appears high pressure and forms partial flow.