浮动式配流盘柱塞泵马达系统动力学建模及特性研究

Dynamic Modeling and Characteristic Study of the Floating Valve Plate Piston Pump-Motor System

浮动式配流盘设计从根本上解决了轴向柱塞泵/马达高转速下缸体倾覆的难题,契合了其高速化的发展趋势,在近年来得到重视。然而,针对浮动式配流盘柱塞泵马达系统所特有的结构,仍然缺乏系统级的动力学建模及动态特性研究,限制了浮动式配流盘柱塞泵马达产品的设计。本文针对浮动式配流盘柱塞泵马达系统,建立了考虑其详细结构特征的完全参数化描述的系统动力学模型,着重研究了其高压油路以及辅助液压腔油液压力的动态变化规律,并通过台架试验验证了模型的正确性。研究结果表明,高压油路表现出“瞬降缓升”的“锯齿形”压力脉动特征,且脉动剧烈。在泵转速1 000 r/min,高压油路平均压力20、40 MPa两个压力等级下,脉动幅值分别高达±1.5和±3 MPa。辅助液压腔油液压力呈现“快速跟随、缓慢下降”的动态变化规律,即辅助液压腔一旦与高速旋转的柱塞腔接通,其油液压力几乎立即无衰减、无滞后地跟随柱塞腔压力变化。而当与柱塞腔脱离之后,其还能很好地维持住腔内压力。

The design of the floating valve plate effectively addresses the problem of cylinder block tilting at high speed in axial piston pumps/motors,aligning with the trend towards high-speed development of axial piston pumps/motors and gaining attention in recent years.However,there is still a lack of systematic dynamic modeling and dynamic characteristic research for the piston pump/motor system designed with floating valve plate,which lim-its the design of floating valve plate piston pump/motor products.A comprehensive parameterized dynamic model of the system that considers its detailed structural features is established for the piston pump motor system designed with floating valve plate.The study focuses on the laws of dynamic changes of the pressure in the high-pressure oil circuit and the auxiliary hydraulic chambers,and the model's correctness is verified through bench tests.The re-sults show that the high-pressure oil circuit exhibits a"sharp drop and slow rise"characteristic of"sawtooth"pres-sure pulsations,which are intense.At a pump speed of 1000 revolutions per minute(r/min),the average pressure in the high-pressure oil circuit at 20 and 40 MPa pressure levels results in pulsation amplitudes as high as±1.5 and±3 MPa,respectively.The fluid pressure in the auxiliary hydraulic chamber exhibits a dynamic change pattern of"rapid follow-up and slow decline,"meaning that once the auxiliary hydraulic chamber is connected with the high-speed rotating piston chamber,its fluid pressure almost immediately follows the piston chamber pressure changes without attenuation or lag.After disconnection from the piston chamber,it can still maintain the chamber pressure effectively.