中文摘要：

针对一种液压机械无级变速器建立换挡仿真模型。以输出轴的速度降幅度、动载荷系数、最大冲击度和换挡时间作为换挡品质评价指标,以发动机转速、负载转矩、主油路压力和调速阀流量作为影响因素。建立L9（34）正交表,采用极差法确定影响因素各水平的主次和优劣,并预测最佳方案。使用统计学方法分析试验数据,验证仿真结果的正确性。结果表明：采用较低的发动机转速,较小的负载转矩,较小的主油路压力,以及较大的调速阀流量可有效提升变速器器换挡品质。

英文摘要：

We build the shifting simulation model of a hydro-mechanical continuously variable transmission （HMCVT）. The speed drop amplitude, dynamic load coefficient, maximum degree of shock of output shaft and shifting time are regarded as the shifting quality evaluation indices to establish the engine speed, load torque, pressure of main circuit and flow of speed control valves as factors of influence. An L9（ 34） orthogonal table is used to determine the primary-secondary and optimal-worst levels of influence factors and to predict the optimum scheme. The simulation datas are calculated by using a statistical method in order to verify the reliability of the simulation results, which show that the shifting quality is improved by the lower engine speed, smaller load torque, lower pressure of main circuit, and the larger flow of speed control valves.