Visualizing simulation of flow field in the large displacement gear pump based on two-module gears

Flow,pressure characteristics of dual-mode combination tooth gear pump were studied.By overlaying the different modulus,the lord,driven gear of double modulus tooth form were designed to increase the amount of volume changes in meshing process of the gear,and gear pump displacement was improved.The inside water hydraulic flow field of the external gear pump was simulated by using the software of Fluent.Flow field pressure imagery、velocity contours and velocity vector imaging were obtained under the start and steady states of gear pump,and gear pump flow pattern of the flow field was analyzed.The results show that with the same volume,output flow rate of the two-module gear pump is 1.6-3.3 times than that of ordinary gear pump.The large teeth of gear pump separate flow field into different pressure region,and the large teeth's both sides have larger pressure difference.The flow speed in tip clearance liquid is faster.All above explain that the radial leakage of the two-module gear pump is more serious.The phenomenon of vortex exists in the entrance of the pump,and it will produce pressure impact,and affect the life of the tooth surface.