【作者】 张志彬；

【导师】 刘银水；

【作者基本信息】 华中科技大学 ， 机械工程， 2020， 硕士

【摘要】 深海探测离不开深海液压装备的支持,结构紧凑效率高的水压柱塞泵是深海液压装备系统的重要组成部件。泵的性能直接影响着液压装备作业可靠性。而在全水润滑柱塞泵中,柱塞副既要保证密封性又要减小运动卡滞与磨损,这就保证精密的柱塞副密封间隙。然而,在高等静压环境下,海深渗透压力使得柱塞套径向变形严重。在复杂交变载荷的作用下,精密密封间隙发生形变失调,致使间隙变小甚至消失,造成柱塞副的卡滞、加剧磨损,甚至导致柱塞泵卡死失效。同时在高等静压环境下,柱塞副组件O型密封圈工作过程中受到连续的挤压咬合作用,频繁导致密封失效。因此对高等静压环境下全水润滑轴向柱塞泵柱塞副的海深压力渗透特性、卡滞特性以及柱塞副组件O型圈密封失效特性的研究显得尤为重要。本文主要针对柱塞副及其组件的三个特性开展研究。首先,对柱塞套/缸体海深压力渗透特性进行分析,得到柱塞套海深压力渗透特性,为柱塞副卡滞特性研究提供依据。其次,对高等静压条件下柱塞副卡滞特性进行研究:针对不同海深、不同注排水工况,通过流固耦合仿真计算模型,计算得到不同工况下柱塞套与柱塞的接触应力、等效应力以及pv值的动态曲线,为柱塞副卡滞、磨损现象提供理论依据。最后,针对柱塞副组件O型密封圈进行动态挤压咬合失效特性研究,确定了O型圈挤压咬合失效的主要原因。通过本文研究发现,当柱塞套与缸体孔的单边过盈量为0.01mm,在海深超过300m时,柱塞套/缸体过盈配合面发生海深压力渗透,改变了柱塞套外表面受载状态。若要保证柱塞泵工作海深为1500m时,过盈配合面不发生海深压力渗透,需要满足单边过盈量不小于0.05mm。同时,发现单边过盈量为0.01mm时,海深超过600m时,柱塞泵进行注水作业且柱塞位于压水区时,柱塞副pv值已经超出许用值。此外,对柱塞副组件O型圈挤压咬合失效现象进行分析,发现等效应力随着摆动间隙的变大而变大,证明摆动间隙过大是O型圈发生挤压咬合失效的主要原因。更多还原

【Abstract】 Deep sea exploration can not be separated from the support of deep sea hydraulic equipment.The hydraulic plunger pump with compact structure and high efficiency is an important component of the deep sea hydraulic equipment system.The performance of pump directly affects the reliability of hydraulic equipment.In the water lubricated plunger pump,the plunger pair should not only ensure the tightness,but also reduce the movement stagnation and wear,which ensures the precise sealing clearance of the plunger pair.However,in the high static pressure environment,the radial deformation of the plunger sleeve is serious because of the deep sea seepage pressure.Under the action of complex alternating load,the precision seal clearance is deformed and misaligned,which makes the clearance smaller or even disappear,causes the plunger pair to be stuck,aggravates the wear,and even causes the plunger pump to be stuck.At the same time,in the high static pressure environment,the O-ring of the plunger assembly is continuously squeezed and occluded during the working process,which frequently leads to the seal failure.Therefore,it is very important to study the deep sea pressure permeability characteristics,the sticking characteristics and the failure characteristics of O-ring seal of the plunger pair of the all water lubricated axial piston pump under the high static pressure environment.In this paper,three characteristics of plunger pair and its components are studied.First of all,the penetration characteristics of the deep sea pressure of the plunger sleeve / cylinder are analyzed,and the penetration characteristics of the deep sea pressure of the plunger sleeve are obtained,which provides the basis for the research of the piston pair’s stuck characteristics.Secondly,the characteristics of piston pair’s stagnation under high static pressure are studied: according to different sea depth and different water injection and drainage conditions,the dynamic curves of contact stress,equivalent stress and PV value of plunger sleeve and plunger under different conditions are calculated by fluid structure coupling simulation model,which provides theoretical basis for the phenomenon of piston pair’s stagnation and wear.At last,the main reason of the failure of O-ring is determined according to the research of the dynamic extrusion and engagement failure characteristics of the O-ring.Through this study,it is found that when the single side interference between the plunger sleeve and the cylinder block hole is 0.01 mm,and the sea depth is more than 300 m,the sea depth pressure penetration occurs on the plunger sleeve / cylinder block interference fitting surface,which changes the load state on the outer surface of the plunger sleeve.To ensure that when the working sea depth of the plunger pump is 1500 m,the interference fitting surface will not have sea depth pressure penetration,and the single side interference should not be less than 0.05 mm.At the same time,when the single side interference is 0.01 mm and the sea depth is more than 600 m,when the plunger pump carries out water injection and the plunger is located in the water pressure area,the PV value of the plunger pair has exceeded the allowable value.In addition,through the analysis of the failure of Oring of the plunger assembly,it is found that the equivalent stress increases with the increase of the swing clearance,which proves that the excessive swing clearance is the main reason for the failure of O-ring.更多还原