一种新型电液驱动水液压泵的设计与特性研究

Study on characteristics of a novel water-hydraulic pump with electro-hydrostatic actuator

  • 摘要: 为了解决传统斜盘式轴向柱塞泵在水介质环境下易磨损、寿命低及噪声大的问题,同时满足煤矿井下等特殊工况对液压泵可靠性的要求,开发了一种新型的集成了电静液作动器的水液压泵。该泵采用2个平行缸,由创新的二维活塞泵电静液作动器驱动,从而使整个系统具有较高的功重比。首先介绍了电静液作动器驱动的水液压泵的结构和工作原理,建立了电静液作动器系统的数学模型,并进行了仿真分析。随后搭建了样机实验台,对样机进行了运行实验、空载特性评估和加载性能评估。实验结果有助于全面分析这种新型泵设计的基本特性。最后,利用这些实验结果来推断泵在不同额定功率电机驱动下的输出性能参数。实验结果表明,样机液压泵的输出流量脉动较小,噪声小,容积效率超过84%。容积效率随电机转速的升高而增大,随加载压力的升高而减小,压力脉动随转速的增加而降低,压力脉动率随加载压力的增加而增加,而压力波动的强度保持相对稳定,而与加载压力变化无关。不同加载压力下水液压泵腔内压力脉动大约为0.5 MPa。驱动泵输出是有脉动的,但是水柱塞截面积大,引起的速度波动小,水柱塞做匀速运动,所以水液压泵输出流量和压力脉动就比较小,从而提高了系统的整体性能和可靠性。此外,水柱塞的受力方向与运动方向一致,避免传统泵因倾覆力矩导致的附加摩擦,水柱塞和缸体之间的磨损很小,因此在整个寿命周期内都能维持较高的容积效率。

     

    Abstract: In order to resolve the issues of wear, limited lifespan, and excessive noise commonly associated with traditional swashplate axial piston pumps in aqueous environments,while meeting the reliability requirements for hydraulic pumps in demanding conditions such as underground coal mines,a novel water hydraulic pump has been developed that integrates an electro-hydrostatic actuator. This pump features two parallel cylinders driven by an innovative two-dimensional piston pump electro- hydrostatic actuator, resulting in a high power-to-weight ratio for the entire system. The structure and operational principles of the hydraulic pump driven by the electro-hydrostatic actuator are first presented. Following this, a mathematical model for the electro- hydrostatic actuator system is established and subjected to simulation analysis. Subsequently, a prototype testing platform is constructed to perform operational tests, no-load characteristics assessments, and load performance evaluations on the prototype. The experimental results facilitate a comprehensive analysis of the fundamental characteristics of this novel pump design. Finally, the findings from these experiments are utilized to infer the output performance parameters of the pump when powered by motors of various power ratings. Experimental results indicate that the prototype hydraulic pump exhibits minimal output flow pulsation, low noise levels, and a volumetric efficiency exceeding 84%. Moreover, the volumetric efficiency increases with rising motor speeds and decreases with elevated load pressures. The rate of pressure pulsation within the pump chamber diminishes as both speed and load pressure increase, while the intensity of pressure fluctuations remains relatively stable irrespective of load pressure variations. Under varying loading pressures, the pressure pulsation within the water hydraulic pump chamber is approximately 0.5 MPa. While the pump output exhibits pulsation, the large cross-sectional area of the water piston minimizes velocity fluctuations. The water piston operates at a constant speed, resulting in reduced flow and pressure pulsations in the water hydraulic pump output. This enhances the overall system performance and reliability. Furthermore, the force acting on the water piston aligns with its direction of motion, eliminating additional friction caused by overturning moments in conventional pumps. Minimal wear occurs between the water piston and cylinder body, enabling sustained high volumetric efficiency throughout the entire service life.

     

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