Abstract:

Based on the theoretical analysis of axial piston pump, a simulation model of variable displacement pump model is established by software platform AMEsim. Under the same load pressure condition, the pressure fluctuation of pump is simulated and tested by changing rotating speed and pump displacement. The result shows that the experiment curve and the simulation curve are perfectly fitted, which verifies accuracy of the model. On this basis, according to the simulation and experiment data, the pressure pulsation characteristics are compared and analyzed with different combination of displacement and rotating speed in the same loading and different loading conditions. The result shows that the pressure fluctuating amplitude is enlarged with the displacement or the rotation speed increasing. In independent control and same flow output condition, the amplitude in displacement control is larger than in rotating speed control. In the compound control condition, the minimum amplitude and maximum power occurred in high rotating speed and low displacement. Furthermore, from the noise point of view, the varying tendency of the system noise in changing the rotating speed and the displacement respectively is consistent with the pressure pulsation, while in the hydraulic system with the same load and same flow, the changing rule of noise is contrary to pressure pulsation in rotating speed and displacement compound control condition. According to the analysis of the simulation and experimental data, the conclusion is drawn that under the same load, the pressure fluctuation is smaller in the combination of high motor speed and low pump displacement while the motor input power is smaller and the system noise is lower in the combination of low motor speed and high pump displacement. Based on above analysis, it provided technical support for the variable speed and variable displacement compound controlling theory and engineering applications.

Key words: compound control, noise, variable displacement pump, pressure pulsation