基于相轨迹图的轴向柱塞泵振动特性研究

Vibration characteristics of axial piston pump based on phase trajectory diagram

考虑到柱塞泵壳体的振动既包含运动状态信息也包含能量状态信息,提出采用柱塞泵壳体振动相轨迹图示化方法揭示柱塞泵振动信号与运行状态间的关系。首先,在分析柱塞泵流体振动传递路径,阐明高压流体激励与泵壳体振动速度、位移及振动能量之间的关系。其次,依据振动频率溯源结果,采用多重同步压缩变换方法(Multi-synchrosqueezing Transform,MSST)对柱塞泵壳体振动加速度信号进行重构,经积分变换后可进一步得到振动速度和位移信息。最后,利用振动速度和位移信息构建壳体振动相轨迹图,并通过实验揭示了不同工况下壳体振动相轨迹图中蕴含的柱塞泵动能、势能变化规律。结果表明,结合振动溯源,MSST能够准确提取壳体振动加速度信号中液压激励引起的振动频率和相位信息。柱塞泵运行工况对柱塞泵壳体动能及势能有显著影响。随系统压力增大,相轨迹与垂直零位移轴的距离明显增大,壳体势能显著增加;随转速增加,相轨迹图的最大振动速度明显增大,壳体动能显著增加。轴向柱塞泵相轨迹图可以更直观地显示壳体动能及势能变化规律。本研究为液压泵、马达等关键元件的故障诊断和健康评估提供了理论依据和方法支持。

Considering that the vibration of the piston pump shell includes not only motion state information,but also energy state information,this study discloses the relationship between the piston pump vibration signal and the operating state by the piston pump shell vibration phase trajectory.Firstly,the high pressure fluid excitation and the vibration speed,displacement,and vibration energy of the pump shell are related.This relationship can be set forth by analysis of the piston pump fluid vibration transmission path.Secondly,according to the vibration frequency traceability,multi-synchrosqueezing transform(MSST)method is used to reconstruct signal.After the integral transformation of the reconstructed signal,the information of vibration speed and displacement can be obtained further.Finally,the trajectory diagram of the shell vibration is constructed based on the vibration speed and displacement.The experiment under different operating conditions are carried out to expound the variation rules of the kinetic energy and potential energy of the piston pump contained in the phase trajectory diagram of the shell vibration.The results show that combined with vibration frequency traceability,MSST can accurately extract the vibration frequency and phase information of shell vibration acceleration signal caused by hydraulic excitation.The operating condition of piston pump has significant influence on kinetic energy and potential energy of piston pump shell.With the increase of system pressure,the distance between the phase trajectory and the vertical zero-shift axis,and the potential energy of the shell increase significantly.With the increase of speed,the maximum vibration speed of phase trajectory diagram and the kinetic energy of shell increase significantly.The phase trajectory diagram of axial piston pump can reflect the kinetic energy and potential energy of the shell more intuitively.This study can provide a theoretical basis and method support for the fault diagnosis and health assessment of key components such as hydraulic pumps,motors.