Model DQ70BS top drive drilling system (TDDS)is developed based on Model DQ60D and Model DQ60P DC TDDS and Model DQ20Y hydraulic TDDS.

• 摘要在DQ60D、DQ60P直流电顶驱和DQ20Y液压顶驱的基础上，研制了DQ70BS交流变频顶部驱动钻井装置。