The Pumping unit has a double-chain synchronous driving and reversemechanism, and can realize flexible reverse with stroke increment;
抽油机具有双链条同步驱动换向机构，可实现增距式柔性换向；
2
The drum type pumping unit with the new reversemechanism has the advantages of impact structure, light weight and extended gear reducer life.
采用这种机构设计出的滚筒机具有结构紧凑、重量轻及减速器寿命长等优点。
3
The chain link is the reversemechanism, functions as sliding bearing and makes the cycle chain and main drive chain parallel to change the circulation into reciprocation.