Research And Design Of Double-compound Gear Pump

Double-compound gear pump is a new hydraulic component which is designed on the basis of the compound-gear pump and double gear pump designed, so it has many advantages of compound gear pump such as large displacement, good flow characteristic, stable transmission, small noise and the balanced radial force on the center wheel. while it meets the needs of different power as well. As to the demand for low-power, there is no throttle so as to reduce energy consumption and achieve"a double pump"function.For designing and researching the double-compound gear pump, this paper studies it from the following four aspects:First, Commmon gear pump is analyzed. On the basis of the principal of common gear pump, displacement and transient flow equations are given while the influence of the structural parameters of gear pump over flow characteristic and the radial force gear pump suffered is analyzed.Secondly, it studies the basic structure and working principle for the double- compound gear pump, gives displacement and the unit volume displacement formulae, and analyzes the influencing factors of unit volume dislacement. On the basis of transient flow, through derivation of the displacement equation of meshing, it concludes the equations of transient flow and pulsation coefficient flow rate , when center wheel's toothnumber of the double-compound is differen. The flow curves under different conditions are obtained by editing the MATLAB language program.Again, in order to make the volume of double-compound gear pump smallest, the optimization model for the pump is established. Meanwhile, in order to avoid generating undercutting, the optimization model for selecting modification coefficient is established and the modification coefficient is optimized.Finally, double-compound gear pump is designed parametrically. According to the gear parameters optimized, 3d parametric models of gear and axial are designed. By studying the oil flow of double-compund gear pump, the structure of metered flow plate is determined and the models of them are designed. On the basis of gear axials and meter flow paltes, other parametric models of the pump are still designed and all of models are assembled.