中小型轮式挖掘机的液压工作装置主要由铲斗、斗杆、动臂及回转机构等组成，大部分液压操纵方式为手动式，因此液压系统相对比较简单、可靠。但对某些维修人员来说，由于缺乏基础的专业知识，加之经验不足，对故障的排除往往感到困难，修理时盲目性较大，一遇故障就大拆大卸。 The hydraulic working device of small and medium-sized wheel excavators is mainly composed of a bucket, an arm, a boom, and a turning mechanism. Most of the hydraulic control methods are manual, and therefore the hydraulic system is relatively simple and reliable. However, for some maintenance personnel, due to the lack of basic professional knowledge and lack of experience, it is often difficult to troubleshoot failures, and blindness is greater when repairs are made.