Drilling pump is the heart of drilling rig, its core structure is crank-linkage mechanism. However, the drilling pump is criticized for its short stroke and high stroke frequency. Aiming at these defects, a long stroke reciprocating (LSR) pump combined the crank-linkage with a rack-pinion mechanism is proposed, and its dynamic and flow characteristics are researched. The results reveal that the stroke of the LSR pump is extended twice when the crank radius stays the same. The stroke frequency and flow pulsation rate are lowered under the same rated power. A new multi-fulcrum crankshaft is designed to extend its fatigue life, and the reaction forces of each fulcrum are solved by simulation. The influence of the fulcrums position on the crankshaft modal frequency is further investigated. The flexible characteristics of the multi-fulcrum crankshaft are studied by rigid-flexible coupled analysis. The results show that more fulcrums can effectively reduce the stress of crankshaft, and the maximum stress of the multi-fulcrum crankshaft is only 178.6 MPa. The modal frequency of the multi-fulcrum crankshaft is increased due to more fulcrums, which proved its stiffness and stability are improved. The fatigue life of the multi-fulcrum crankshaft is predicted to reach 30,000 h by finite element analysis. This study would provide a theoretical basis for further development of the LSR pump.

This research is based on a new drilling fluids circulation treatment device, which belongs to solid control system, namely pulsating negative pressure shale shaker. The purpose of this article is to better understand the operating principle and provide basis for setting working parameters and optimizing design. The above content depends on the dynamic analysis of the throwing motion of particles. To be specific, the motion equation of particle is established from the viewpoint of force state, and the influence of various parameters on particle conveyance velocity is discussed. Factors influencing the throwing index are also analyzed. Higher solid conveyance speed means higher handling capacity, but it also reduces the efficiency of particle dehydration; therefore, a trade-off should be considered among high removal efficiency, low energy consumption, and high handling capacity. The results show that negative pressure in pulsating form can effectively improve the disadvantage of low conveyance velocity of particles in constant negative pressure shale shaker.