ABSTRACT Hydraulic cylinder hydraulic system is the implementation of the most important components, its structure is simple, flexible configuration, design, manufacture relatively easy operation, easy maintenance, Suo Yi Deng Bi hydraulic motor actuator applications more extensively. Meanwhile, the demand for hydraulic cylinders greatly increased. Long, thread-oriented hydraulic cylinder sleeve has been installed by manual operation, often require several people "millstone" set screw can be driven on the labor intensity greatly, efficient production is very low, so in order to reduce the labor intensity improve efficiency-oriented, designed a machine on the cap. The machine should be able to adapt to a variety of bore, stroke and various forms of column-oriented set of fixed; to meet the requirements of the basis of simple structure, easy operation; structure, durable, easy to maintain, and reserved a room for the secondary development. In this paper, the design on the cap machine, introduced the machine hydraulic cylinder on the cap structure, features, functions, advantages and disadvantages, and operational procedures. Articles include hydraulic cylinder seals, hydraulic cylinder on the cap of the preparatory work on the cap machine bed design, motor selection, design, etc. reducer. Keyword: the cap machine ；reducer ；worm gear ；worm
