Studying the Axial Balance of External Gear Pumps

In this paper some design aspects related to externalgear pumps balancing surfaces are studied, and someuseful guidelines for designing bearing blocksbalancing surfaces are suggested. In order to studybearing blocks axial balance, a numerical procedurefor the determination of the pressure distribution insidethe clearance bounded by gears sides and bearingblocks internal surfaces is firstly presented andapplied. After, the influence of bearing blocksgeometry and pump operating conditions on thewidening thrust is highlighted, considering bothconstant and variable lateral clearance heights. Then,the computations are performed to evaluate thewidening thrust variation as a function of bearingblocks relative tilt with respect to gears lateral sides,and both positive and negative bearing blocks tilts areevidenced and discussed. Finally, the numericalprocedure is validated through a comprehensivecomparison of its results with experimental data(coming from some bibliographic sources), and someuseful guidelines in designing external gear pumpsbalancing surfaces are defined.