WZ2A型液压挖掘装载机是在原WZ2型(又称DY4-55型,1969年投产,已累计生产近2000台)的基础上改进设计而成。1980年制出两台样机,1981年按部标准的规定,进行了性能测定,完成了1000小时的挖掘作业、1000小时装载作业、1500公里行驶试验和解体检查。全面考核的结果表明,新机性能良好,使用安全可靠,并于1981年10月通过了国家鉴定。 (?)Z2A仍采用铁牛-55拖拉机的动力、传动系及后桥,另配专用的前桥和转向系,前端装 The WZ2A hydraulic excavating loader is based on the original WZ2 type (also known as DY4-55 type, put into operation in 1969, has accumulated production of nearly 2000 units) based on improved design. In 1980, two prototypes were produced. In 1981, performance tests were performed according to the provisions of the Ministry of Standards, and 1,000 hours of excavation work, 1,000 hours of loading operations, 1,500 kilometers of driving tests and dismantling inspections were completed. The results of the comprehensive assessment show that the new machine has good performance and is safe and reliable to use. It passed the national appraisal in October 1981. (?) The Z2A still uses the power, transmission and rear axle of the Tie-55 tractor, and it is equipped with a dedicated front axle and steering system.