泵—马达液压传动系统中的压力拍振分析

Analysis of Pressure Beat Vibration of Pump-motor Hydraulic Transmission System

在泵—马达液压传动系统中,由于泵和马达的周期性吸油排油,不可避免地存在流量脉动,当泵和马达脉动的频率相接近时,系统会发生压力拍振现象。建立泵-马达传动系统的压力脉动数学模型,从理论上分析压力拍振的周期和幅值特点。采用集中参数法建立泵-马达传动系统的仿真模型,并通过仿真和试验分析系统压力拍振的规律,结果表明当泵和马达脉动频率比较接近时会发生压力拍振且拍振幅值随频率接近程度增加而增加。在压力拍振机理分析的基础上,提出合理选取传动比和柱塞数目可以有效抑制系统压力拍振。

In pump-motor hydraulic transmission systems, flow pulsation exists inevitably due to the periodic oil suction and discharge of pump and motor. When the pulsation frequency of the pump approaches that of the motor, the pressure beat vibration will occur in the system. In this paper, the mathematical model of the pump-motor transmission system was established for pressure pulsation analysis. The characteristics of period and amplitude of the pressure beat vibration was analyzed theoretically. Simulation model of the pump-motor transmission system was built by using centralized parameter method. The pattern of system pressure beat vibration was analyzed through the simulation and experiment. The results indicate that the pressure beat vibration happens when the pulsation frequencies of the pump and the motor are close each other, and the amplitude of the beat vibration increases with increasing the proximity of the pulsation frequencies of the pump and the motor. Based on the mechanism analysis of the pressure beat vibration, it is suggested that reasonable selection of transmission ratio and the number of pistons can effectively inhibit the pressure beat vibration of the system.