下冲程 meaning in English

down stroke

The new unit has following technical features : ( 1 ) the unit ' s load is balanced by means of the accumulator and hydraulic cylinder with special structure ; ( 2 ) the installed power of the unit can be reduced greatly by adopting the accumulator ; ( 3 ) variable frequency speed regulation ensures good energy saving effect , and the closed oil circuit requires less hydraulic oil ; ( 4 ) a bi - directional hydraulic lock in the oil circuit ensures the stability and safety of the operation of the pumping unit
新型机具有4个技术特点： ( 1 )由于活塞柱塞式液压缸的特殊结构和液压蓄能器的配合使用，在平衡抽油机大部分载荷时，不需另外增加配重，可减小抽油机体积、质量和占地面积； ( 2 )抽油机下冲程时，与活塞柱塞式液压缸相连接的蓄能器吸收能量，上冲程时储存在蓄能器中的能量补充载荷上行所需的能量，大幅度降低抽油机装机功率； ( 3 )利用变频容积调速节能效率高，闭式油路节省液压油，同时大大减小液压泵站的体积； ( 4 )在闭式油路中采用双向液压锁可使抽油机的启停更加平稳、迅速，其工作的稳定性和安全性更好。