曲轴摆缸式阀配流水液压马达工作特性研究

Working Characteristics of Crankshaft Swing Cylinder Water Hydraulic Motor with Flow Distribution Valve

为解决盘配流和轴配流低速大扭矩水液压马达配流副存在的磨损和泄漏问题,提出一种新型阀配流结构的低速大扭矩水液压马达,柱塞配流通过配流凸轮控制配流阀的通断实现。研究柱塞运动学规律和马达输出扭矩形成,揭示配流阀推杆位移、阀芯通断、柱塞进回液间的对应关系,分析马达角排量波动随转角、结构设计参数K的变化规律,当结构设计参数K为0.13时,马达输出扭矩波动率为6.59%。在AMESim中建立了配流阀及单柱塞配流过程的仿真模型,分析配流阀的工作特性及单柱塞动态配流性能,工作中配流阀产生最大压降为0.08 MPa,进/回液配流阀无高低压串液。为验证阀配流结构在水液压马达中的工作性能,建立阀配流单柱塞试验台,并研究不同工况下的配流工作特性。试验结果表明,配流阀在马达转速0~60 r/min、压力0~21 MPa的工况下稳定配流,进液阀口压力在柱塞腔进回液转换时存在瞬间小幅压力波动,但对配流过程基本无影响,阀配流结构能够满足曲轴摆缸式马达柱塞的配流需求,为低速大扭矩水液压马达的配流提供了思路。

Low speed and high torque water hydraulic motor is widely used in environmental protection and explosion-proof working conditions, such as coal mine, underwater action, military explosion-proof construction, etc. However, the low viscosity of water leads to serious wear and leakage of flow port pair in traditional motor with plate and shaft flow distribution. A type of water hydraulic motor with valve flow distribution structure was proposed and the piston flow distribution was realized by controlling on-off of valve through distribution cam. The kinematics of piston and motor output torque were theoretically calculated, and the corresponding relationship among push rod of flow distribution valve, valve core on-off and piston flow distribution states was revealed. The variation law of motor angular displacement fluctuation with angle and structure parameter K was analyzed. When structure design parameter K was 0.13, the fluctuation rate of motor torque was 6.59%. The simulation model of single piston with valve flow distribution was established in AMESim. Simulation results indicated that the maximum pressure drop of valve in flow distribution process was 0.08 MPa. In single piston flow distribution, the valve port pressure responded quickly without high-pressure and low-pressure liquid connection. To verify the working performance of valve flow distribution in water hydraulic motor, a single piston with valve flow distribution test bench was established, and the working characteristics of valve under different working conditions were studied. The experimental results showed that the valve was stable under the working conditions of motor speed of 0~60 r/min and pressure of 0~21 MPa. The pump outlet pressure fluctuated slightly when flow distribution state of piston chamber was switched, which had little effect on flow distribution process. The valve flow distribution structure can meet the flow distribution demand of crankshaft piston motor with swing cylinder. The relative sliding of the traditional motor flow port pair under water lubrication was converted into the valve on-off, which provided an idea for flow distribution of the water hydraulic motor with low speed and high torque.