The difficulties involved in measuring a pump fluid-borne noise rating are discussed. A new test method is described for measuring the source flow ripple and source impedance of positive displacement hydraulic pumps. This is called the ‘secondary source’ method, and is based on the analysis of the wave propagation characteristics in a circuit which includes the pump under test and an additional source of fluid-borne noise.
Get full access to this article
View all access options for this article.
References
1.
TilleyD. G.ButlerM. D.The generation and transmission of fluid borne pressure ripple in hydraulic systems. Seminar on Quieter oil hydraulics, London, October 1980 (Institution of Mechanical Engineers).
2.
BownsD. E.McCandlishD.Pressure ripple propagation. Conference on Quiet oil hydraulic systems, London, November 1977, pp. 93–102 (Institution of Mechanical Engineers).
3.
EdgeK. A.TilleyD. G.The use of plane wave theory in the modelling of pressure ripple in hydraulic systems. Trans. Inst. M.C., 1983, 5(4), 171–178.
4.
UnruhD. R.Outlet pressure ripple measurement of positive displacement hydraulic pumps. National Conference on Fluid power, Chicago, October 1975.
5.
SzerlagS. F.Rating pump fluidborne noise. SAE paper 750830, September 1975.
6.
BownsD. E.EdgeK. A.McCandlishD.Factors affecting the choice of a standard method for the determination of pump pressure ripple. Seminar on Quieter oil hydraulics, London, October 1980, pp. 1–6 (Institution of Mechanical Engineers).
7.
BownsD. E.EdgeK. A.TilleyD. G.The assessment of pump fluid borne noise. Conference on Quiet oil hydraulics systems, London, November 1977, pp. 115–125 (Institution of Mechanical Engineers).
8.
BS 6335: 1983 Methods for determining pressure ripple levels generated in hydraulic fluid power systems and components. Part 1—High impedance method for pumps, British Standards Institution, London, 1983.
9.
EdgeK. A.WingT. J.The measurement of the fluid borne pressure ripple characteristics of hydraulic components. Proc. Instn. Mech. Engrs, Part B, November 1983, 197, 247–254.
10.
SteckiJ. S.DavisD. C.Fluid transmission lines—distributed parameter models. Part 1—A review of the state of the art. Proc. Instn. Mech. Engrs, Part A, 1986, 200(A4), 215–228.
11.
FosterK.ParkerG. A.Transmission of power by sinusoidal wave motion through hydraulic oil in a uniform pipe. Proc. Instn Mech. Engrs, 1964–5, 179, pt 1 (19), 599–612.
12.
MargolisD. L.BrownF. T.Measurement of the propagation of long-wavelength disturbances through turbulent flow in tubes. Trans. ASME, J. Fluids Engng, March 1976, 70–78.
13.
JohnstonD. N.Measurement and prediction of the fluid borne noise characteristics of hydraulic components and systems. PhD thesis, 1987, University of Bath.
14.
EdgeK. A.JohnstonD. N.A new method for evaluating the fluid borne noise characteristics of positive displacement pumps. Seventh International Symposium on Fluid power, Bath, September 1986, pp. 253–260.
15.
EdgeK. A.The theoretical prediction of the impedance of positive displacement pumps. Seminar on Quieter oil hydraulics, London, October 1980, pp. 95–103 (Institution of Mechanical Engineers).
16.
DavidsonL. C.The internal impedance of centrifugal and positive displacement pumps. Conference on Noise and Fluids Engineering, Atlanta, Georgia, November–December 1977, pp. 225–231 (ASME).
