通过理论分析建立了液力变矩器的分段线性化扭振计算模型 ,并对其进行了简化 .采用实验参数辨识的方法 ,借助Matlab/Ident工具箱 ,得到了系统的频率特性 ,通过逐段线性化方法 ,确定了系统的参数模型 ,从而确定了模型中的阻尼参数 .通过曲线拟合得到了阻尼随转速比的变化曲线 .为了验证辨识精度 ,取转矩为输入量 ,转速为输出量 ,利用Matlab/Ident工具箱比较了辨识和试验的输出结果 ,表明所建立的模型是准确的 。

The three dimensional temperature field of the gap between piston and cylinder was obtained by numerically solving energy equation. The boundary condition of the equation was given in the form of heat transfer coefficient, instead of solving the temperature field of solid parts. The temperature field was calculated both under high speed high pressure condition and low speed low pressure condition. The numerical result was compared to experimental result under low speed low pressure condition and showed good agreement. It was shown that the influence of heat transfer coefficient on film temperature was significant. The adiabatic condition was reasonable under low speed low pressure condition, but invalid under high speed high pressure condition. It was a good way to describe the influence of solid parts on temperature using heat transfer coefficient but avoiding solving the temperature field of solids parts.

研究PWM高速开关阀的频率响应特性与其开关特性间的关系,提出了一种方法,据此可以计算在输入正弦信号的周期与载波同期之比为一整数点上PWM高速开关阀的频率响应特性,通过仿真研究得出了该环节的描述函数。