油圧ポンプの音響放射パワーのFEM解析による推定 Estimation of Sound Radiation Power of Hydraulic Fluid Power Pump by FEM Analysis
The sound power radiated from a hydraulic fluid power pump under real operating conditions is investigated using FEM analysis so as to develop a computer simulation program for reducing the pump audible noise level by the vibration control technique. A variable-displacement, swash-plate type of axial piston pump, is examined as the test pump. The author's devised a new method replacing the real moving exciting force with the virtual stationary forces applied on the three node points of the FEM model, which enables one to analyze the forced vibration of pump structure with the FEM, is used for the estimation of air-vibration power level on the entire surface of the pump structure. The measurements of the sound radiation power are also taken by the sound intensity method based on the ISO 9614 in order to investigate the appropriateness and industrial availability of the present FEM analysis. The value of the sound radiation efficiency necessary for the estimation of sound power by the FEM is experimentally determined by comparing the air-vibration power predicted from the measured vibration acceleration at 190 points on the pump's surface with the measured sound radiation power.<BR>The harmonic amplitudes of sound radiation power estimated by the FEM analysis agrees well with the measured values with an accuracy sufficient for practical usage for its complex structure for almost all harmonics up to around 3 kHz except the frequency ranges around some resonances and anti-resonances. It is also shown that the effects of improvement of valve-plate design on the noise reduction can be predicted by the proposed FEM simulation analysis within an accuracy of around 3dB in an over-all RMS of sound power.
日本油空圧学会論文集 30(6), 163-169, 1999-09-15
The Japan Fluid Power System Society