Optimum Design Of Vane Pump Used In Engineering Equipment For Noise Controlling

The noise source of construction machinery comesmainly from the diesel engine and the hydraulic pump. Theperformance research for diesel engine has developedadequately and its results have been applied to actual productssuccessfully. In this case, the noise problem of hydraulic pumpbecomes more and more conspicuous in constructionmachinery.The optimum design for the vane pump′noise controlis discussed in this paper. The present theoretic researchsituation, the developing direction and practical methods onvane pump′noise control are introduced here.The causes on vane pump ′ noise is analyzedtheoretically. The vane pump′noise can be divided into twoparts: one is machinery noise , the other is fluid noise. Themachinery noise is generated by bumping between the vanesand the stator. The fluid noise comes mainly from output flowpulse, which is mainly caused by the instantaneous highpressure returning flow generated when big arc pressure shiftswithin sealed volume. To some extent the curve performancewithin stator, output flow pulse, the selection of fittingclearances , the top profile of the vane, the rigidity of statorand the housing have effects on the noise value of the vanepump, which are analyzed respectively. Depending on thespectrum analysis on the noise signal of one kind of vanepump checked on site and pump housing vibration spectrumand noise spectrum cohesence testing results, the conclusionsare obtained that the main noise of vane pump is mechanicalnoise, while the curve profile of the stator influences on thevane pump ′ noise obviously .In addition, the clearancebetween vanes and vane slot of rotor, axial clearance and topprofile of vane have effects on the pump noise value to someextent.On the basis of a series of single factor tests have beenmade, such as test of changing stator, test of changing rotor,axial clearance test and run-in test etc. Thus, the conclusion isdrawn that the machinery noise caused by bumping betweenvane and stator inner surface is the main cause that the vanepump noise is beyond the standard. In addition, axialclearance, the clearance between vane and vane slot of rotoralso influence on noise value of implement vane pump, whichrequires optimization. Therefore, the improving proposals aremade as follows:1) The curve of power eight is used within stator and theoptimization control theory is used to carry outoptimization design;2) Optimize the axial clearance and the clearance between thevane and vane slot of rotor;3) The original arc is designed to be curve of power sevenwhich has pre-compressing function;4) The top profile of the vane is optimum designed to be arcsharp;5) Rigidity design is improvedThe adequate stator inner curve is very important toconstrain the impacting vibration between the vane and therotor and decrease the noise value of the implement pump.The common inner curve characteristics of stator is analyzedin the paper, and curve of power five, non-symmetry curve ofpower six, complete non-impacting low noise curve of powereight and optimum curve of power eight are analyzed todetermine the best optimization curve of power eight.Based on the optimization analysis for axial clearanceand the effects of oil viscosity changing , the optimizationaxial clearance is determined and the research result is appliedinto actual assembling, which indicates that the noise value isdecreased obviously.The common vane is introduced briefly, and one kind ofround arc vane with high bearing capacity is proposed in thepaper. The noise value of this type of vane pump is decreasedand the service life of vane pump is increased dramatically.Practice shows that the comprehensive application of thestator inner curve with pre-compressing and throttlepressurization mode can decrease the flow noise of implementvane pump efficiently.Extending rotor curve in oil pressing area andpre-compressing the seal volume when shifting from lowpressure to high pressure and decreasing high returning flowof the fluid will decrease the flow noise. The adequatemodification of V-sharp slot of oil pan and throttlepressurization eliminate the shortage of pre-compressing.Increasing the rigidity of elastic body can increase theoriginal frequency to avoid resonating with noise.Through above mentioned improvement design, thepump noise performance gains better improvement. Some ofthe measures have been taken and the noise value is reducedgenerally, thus ideal results are obtained.