The new unit uses the pitman reserse mechanism instead of the crosshead slide reverse rack,adopts weight balancing instead of air balancing,and is provided with an improved guiding system.
英
美
- 这种抽油机以连杆式换向机构取代原有的十字滑块式换向架,以重块平衡代替气平衡,并改进了导向系统。