一、引言工作压力的大小是液压设备经济性的重要因素。所需空间、重量,各构件的效率、费用以及热量分布等之间的协调通常是其选择的方案。在标准液压系统中,按费用及重量的最有效的解决办法就是把系统压力提高到300～350个压力。对这些液压伺服试验机,这种说法几乎适于设备的各个部分,如泵、管道系统、 I. Introduction The size of the working pressure is an important factor in the economy of hydraulic equipment. The coordination between the required space, weight, efficiency of each component, cost and heat distribution is often the solution of choice. In the standard hydraulic system, the most effective solution to the cost and weight is to increase the system pressure to 300 ~ 350 pressure. For these hydraulic servo test machines, this argument is almost suitable for all parts of the equipment, such as pumps, piping systems,