The Research On High-pressure Technologies Of Straight Line Conjugate Internal Meshing Gear Pump

Straight line conjugate internal meshing gear pumps are widely used in various types of engineering machinery. Because of their virtues, such as compact structure, small flow pulsation, high pressure, low noise, good self-priming performance, smooth operation, not sensitive to medium pollution etc. The high-pressure is an inexorable trend.This study takes the QX53-40R straight line conjugate internal meshing gear pump as a research object. Analyzing the key technologies effecting high-pressure of internal gear pump from its operating principle and the geometrical structure, it provides theoretical basis for further research on straight line conjugate internal meshing gear pump.Two factors that affect the pressure level of gear pump are radial force and clearance. This article discussed the two aspects.The radial force is the sum of hydraulic pressure and meshing force, it increases as the pump pressure increases, and various problems going to be occurred, such as friction between moving parts, clearance leakage, the deformation of main component increases etc, so the force analysis of pump is the basic work. The pressure of pump acted by the external wall of internal gear is large, it will cause veneering failure by the increased friction between annular gear and pump casing. According to the failure forms of the annular gear, proposed the static pressure supporting measures, the key parameters such as the position and angle range of the hydrostatic support’s channel were computed by theoretical analysis and FLUENT numerical simulation. The structure of static pressure supporting groove can improve the problem of unbalance radical force and availably prevent veneering failure.Besides the way of balance radical force, enhance the bearing capacity of components is a good way to solve the problems caused by radical force, such as improving the capacity of sliding bearing, reinforcing the strength, rigidity and stabilities of drive shaft etc. The capacity of bearing and resisting deform have been calibrated through finite element method. Checking whether the shaft resonated in working condition through modal analysis. Finally, discussing the way to improving the vibration proof performance of shaft by the harmonic response analysis.As a result of fixed clearance structure, the gear pump exists the problem of leakage, this paper discussed the axial clearance. Set up the mathematical model on internal leakage flow of pump, and utilized the theory of optimum calculated the best clearance value in gear pump. Calculated the pre-stressing force and preload torque of bolts, which connected pump body and pump cover. Calculated axial clearance value in different bolt pre-tightening force by FEM, got the relations between axial clearance and pre-tightening force.