Study And Measures Of Reduction In External Gear Pump Flow Pulsation

Hydraulic equipment is widely used in various fields of aerospace, marine andmanufacturing machinery. The hydraulic system has properties of high pressure, givesmore vigorously output per unit volume, flexible layout, easy to control, and long life.Hydraulic equipment also has its demerits such as low efficiency temperature sensitivemotors, easy to leak and fluctuations.The two most commonly used hydraulic system types are piston pump and gear pumptype. Both pump classified under displacement hydraulic pump. Displacement pumpworks: sealed volume of the cavity volume cycle changes over time, the volumechanges to high at time of absorption, the volume changes to low at time discharge ofoil, so that the cycle is completed with external supply of oil in the hydraulic system.However, this volume change over time must bring changes in the hydraulic oildischarge cycle, and thus to bring the pulse of the hydraulic system.Gear pump with a small size, quality, speed range, self-absorption and goodperformance characteristics, widely used in the hydraulic system, but the gear pumpleakage and pressure pulsation makes its limited application in the precision equipment.The gear pump using two gears meshing with each other and the gear changes thevolume of space between the conveying hydraulic oil. There are a variety of gear pumpmeshing ways which can be divided into external gear pump and internal gear pump;teeth toothed spur gear pumps, helical gear pumps and herringbone gear pump.Gear pump via a gear teeth meshing transport the liquid, the liquid output flow changesas the gear meshing angle change, so resulting in the generation of hydraulic systempulsation, the pulsation so on bring the vibration and noise of the hydraulic system andaffect the accuracy of the hydraulic system, the hydraulic system performancedegradation and even destruction of hydraulic system components Solve the hydraulicsystem pulsation can effectively improve the performance of the hydraulic system,improve the accuracy of the hydraulic output and reduce noise.This thesis is focused on the outer meshing straight gear pump analysis and theory is proposed to reduce the straight pump gear pulsation.The specific contents are:(1) Structural analysis of the external meshed straight gear pump, Identify outermeshing straight gear pumps pulsations, carry out external meshing gear pump nonuniform flow theory analysis;(2) Set up experimental platform, External gear pump system pulsation measurements,analysis of the experimental data, identify error between the theoretical andexperimental data causes outer mesh straight gear pump pulsation.(3) the outer mesh straight gear pumps pulsation reduction method verification,correctness and feasibility then summarizes the conclusions.