Applications of a Computer Model in the Design and Development of a Quiet Vane Pump

In hydraulic pumps the combined effects of compressibility and of segment and port compression mismatch results in high levels of fluid flow ripple. However, the introduction of resistive flow paths allows correct segment compression by providing adequate leakage from the ports. A computer model has been developed for a novel pump with twin abutments and independently retractable radial vanes. The model computes the flow and pressure histories for the segment and ports, based on compressibility, leakage and geometry effects, and these have been found to correlate well with actual measurements. Using the model, silencing grooves have been shown to be effective in reducing the amplitudes of flow ripples over a wide range of operating conditions. In the pump tested, reductions of 5.4 dB were achieved. Further simulations have shown that lower noise levels could be achieved under optimum conditions.