A lot of new drilling technologies were developed in the world in order to meet demands of oil exploration ad development,increase drilling efficiency,decrease drilling cost,and thus improve the overall benefits of oil exploration and development,including rotary steerable drilling,vertical drilling,casing drilling,solid expandable tubular,managed pressure drilling,and logging while drilling,etc.

Starting with the basic control principles of the two main pressures for gearshift in AT—— pressure at throttle valves and speed control pressure, this paper expatiates on the controlling and regulating process of the output characteristics and discusses the influential factors in the regulating process.

Study of new hydraulic power system for CNC punch press;

Design and Experimental Research on Fast Hydraulic Driving System for CNC Punch Press;