高水基液压马达配流机构的研究

Study of Distribution Structure for High Water-Based Hydraulic Motor

高水基液压马达由于其介质友好性可用于煤矿、食品、水下作业等领域,但目前水马达仍沿用油马达结构,仅将介质更换为高水基乳化液。马达的传统轴、盘配流机构在低速、高压、高水基工况下会产生严重泄漏、锈蚀现象,且阀配流机构存在的问题是一个柱塞需要配备两个单向配流阀,导致马达体积较大,同时配流阀间需准确配合,否则会出现窜、困液现象。针对以上问题提出了一种阀配流机构来控制马达配流,其由梭阀和凸轮组成,其中凸轮驱动顶杆实现柱塞的进排液过程。文中首先对配流阀进行结构设计和理论分析,揭示其配流原理;其次在AMESim中分析其参数的动态响应特性,选择正弦加速度函数曲线控制的凸轮来驱动阀芯,并选取压力和流量波动小的直径0.6 mm的阀芯通流孔,优化了配流结构。对马达整机性能进行仿真,整机扭矩波动为7.39%,验证了该机构良好的配流性能。运用Fluent仿真优化阀内流场,选用压降小、速度分布均匀的豁槽结构,并在此基础上进行样机制备和实验分析。在16 MPa工况下,柱塞腔可建压迅速,配流阀入口的压力波动率为12.5%,且泄漏量仅为2滴/min。可知此配流梭阀应用于高水基液压马达后,可以实现稳定配流。

High water-based hydraulic motors can be used in fields such as coal mining,food,and underwater operation due to their medium-friendly nature.However,currently high water-based motors still use hydraulic oil motor structure,only replacing the medium with high-water-based emulsion.Traditional shaft and disk flow structures will suffer severe leakage and rusting phenomena under low-speed,high-pressure,and high water-based conditions.Additionally,the current valve flow structure problem is that one plunger needs to be equipped with two check valves,which causes the motor to have a larger volume,and the flow valves must be accurately matched.Otherwise,there will be channeling and fluid entrapment phenomena.In view of the above problems,a shuttle valve flow struc⁃ture was proposed to control the motor flow distribution,which consists of a shuttle valve and a cam.The cam drives the plunger’s liquid intaking and discharging process.Firstly,the flow valve was structurally designed and theoreti⁃cally analyzed,revealing its flow distribution principle.Secondly,the dynamic response characteristics of its parameters were analyzed in AMESim.The cam driven by the sine acceleration function curve was selected to control the valve core,and the flow-through hole with a diameter of 0.6 mm,with small pressure and flow fluctuations,was used.Additionally,the motor’s torque fluctuation was 7.39%,verifying the shuttle valve’s good flow distribution performance.Fluent simulation was used to optimize the valve’s internal flow field and select the notch structure with small pressure drop and uniform velocity distribution.Based on this,prototype preparation and experimental analysis were carried out.Under 16 MPa working condition,the plunger chamber can quickly build pressure,the pressure fluctuation at the inlet of the flow valve is 12.5%,and the leakage is 2 drops/min.It can be seen that after the shuttle valve is applied to the high water-based hydraulic motor,stable flow distribution can be achieved.