抄録
All positive displacement pumps generate a flow ripple, which interacts with the characteristics of the circuit connected to produce a fluid-borne vibration. This may be the major source of the overall system noise level as well as the major cause of vibration of the system components. Consequently, to predict accurately the fluid-borne vibration generated in a system during the design stage, and to reduce it and produce quieter systems, it is necessary first to understand and quantify the fluid-borne vibration characteristics of positive displacement pumps as well as the wave propagation characteristics of pressure ripple in system components.
In this paper, the measuring procedure referred to as the “2 pressures/2 systems” method has been newly devised for experimental determination of the fluid-borne vibration characteristics of hydraulic pumps. This method has great merit in that the flow ripple and source impedance of the pump can be evaluated just by the analysis of the wave propagation characteristics of pressure ripple in the reference pipe alone, which is just a part of the discharge line adjacent to pump exit, i.e., there is no necessity for evaluating the characteristics of any piping elements other than the reference pipe. Thus, not only the hydraulic test circuit and calculation procedure become very simple compared to the former methods (in which the characteristics of all piping elements have to be evaluated or predicted analytically in advance) but also the tests can be performed very quickly.
