近年来,为了节约能源、降低成本,在液压元件的高效率、长寿命、小型化等方面,国内外的液压工作者做了大量工作。液压系统已从过去使用定量泵和阀组合的阀控制系统转向广泛采用变量泵组成系统。变量泵能根据系统需要调整输出流量,这样不仅节省功率,而且能减小油箱容量,降低噪声 In recent years, in order to save energy and reduce costs, a great deal of work has been done by hydraulic workers at home and abroad in terms of high efficiency, long life and miniaturization of hydraulic components. Hydraulic systems have evolved from valve control systems that used to use a combination of fixed displacement pumps and valves to a system that uses variable displacement pumps for a wide range of applications. The variable pump can adjust the output flow according to the need of the system, thus not only can save the power, but also can reduce the fuel tank capacity, reduce the noise