• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.117-124
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• 2007

The pressure ripple in most hydraulic systems is the root cause of their noise and vibration. This paper reduced the pressure ripple using side branch hose for an axial piston pump applied to small excavator. First, in calculating open area, a new method using groove area of valve plate is proposed. Simulation model in AMESim environment is developed to verify proposed method, find effective length and diameter of branch hose. Finally, the comparisons with experiment results show that the proposed method is more effective than previous method in reducing the pressure ripple.

• Transactions of The Korea Fluid Power Systems Society
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• v.6 no.1
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• pp.1-9
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• 2009

This study presents an analytical model of an automotive steering hose containing tuner(flexible spiral metal tube) to reduce the ripple pressure induced by steering vane pump. The double-wall side branch composed in a steering hose containing tuner was analogically considered as a filter in a conduit. Specialized test equipment was manufactured for the estimation of speed of sound in a conduit and measurement of amplitude ratio between the propagated ripple pressures of inlet and outlet of the steering hose. Experimental data of entire frequency ranges can be obtained through the test once in short time. The results of three points' measurement method and cross-correlation method to estimate the speeds of sound in a hose, tuner, and side branch respectively reveal that cross-correlation method can be used practically. The results of simulation and experiment were so close, especially in the range of engine idling speed, that the proposed analytical model in this study was validated. Sensitivity analyses and experiments show that longer tuner is preferable, and that the positive-positive composition of the steering hoses containing tuner is superior to others to attenuate ripple pressure.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.297-302
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• 2007

Discharge variations of perforated hose and drip irrigation systems were examined to evaluate irrigation uniformity at different pressures and length of branch line. Evaluation using statistical uniformity indicated that button drippers performed at excellent level but drip tapes and drip hoses were a little lower level. Nominal discharge of drip irrigation systems showed at the high side within the range of regulating pressure provided by the manufacturer. It is desirable that the length of branch line for drip hose, drip tape, and button dripper should be limited to 50 m, 70 m, and 100 m, respectively. Irrigation uniformity of perforated hoses showed very low level. So it is recommended that the length of branch line for perforated hoses should be limited to $30{\sim}35m$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.101-102
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• 2006

The purpose of this paper is pulsation-analysis of the swash plate type axial piston pump for excavator and the method of side branch hose application, which is used normally in construction equipments. In this paper, draw the mathematical modeling for pressure pulsation mechanism of the swash plate type axial piston pump for excavator, expression the flow pulsation in the pipelines by transfer matrix method, programmed simulation for pulsation by AMEsim software, and the reliability of that was verified by the comparison with the experimental results.