Gear Contact Stress And Optimal Design Of Gear Pump On Tractor

Tractor as the power machinery not be replaced in the procession of agriculturalproduction, plays an important role in modern agriculture. Gear pump as the pressurizedcomponents in tractor hydraulic system, its working state and performance directly influencesthe working performance of the tractor.In this paper, the subject of gear pump on tractor is the object of study, combined withCAD/CAE modern design methods, optimal design and finite element analysis to the existinggear pump on tractor.(1)First treat the existing gear pump through the reverse design, through themeasurement and calculation, get the three-dimensional size of gear pump, using thethree-dimensional designing software Pro/E of its parametric modeling capabilities toestablish all parts of the three-dimensional model and the assembly model of gear pump,checking the interference of the assembly model.(2)Simplifying the gear contact model, with the flexible body and flexible body contactmodel, analyzing the non-linear gear contact stress on the simplified model of gear pump bythe finite element analysis software ANSYS, gained the cloud pictures of equivalent contactstress and equivalent contact strain, and The magnitude and the distribution of maximumstress and maximum strain, comparing the result of finite element method with the calculationof Hertz theory, verifying the conservative result gained by the traditional formula and thereliability of finite element analysis.(3)Building the simplified flow field model of gear pump, simulation and analysis offlow field inside the gear pump by the fluid analysis software FLEENT, gained the contoursof velocity magnitude and contours of pressure, from the chart of velocity we can see that theflow field is prone to vortex motion, through the chart of pressure we estimate the magnitudeand direction of radial unbalance force of gear shaft.(4)Finishing prestressed mode analysis of the simplified gear shaft model, gained thefirst ten order natural frequencies and corresponding mode shapes of gear shaft under the action of centrifugal force, the vibration type mainly for bending vibration, radial vibration,axial vibration of gear shaft and torsion vibration, fold vibration of gear, all the results aremuch higher than the working frequency of gear shaft, so it is impossible to cause resonance.(5)Take the basic gear parameters of gear pump as the optimization variables, theminimum volume of gear pump and the minimum radial unbalance force of gear shaft as theobjective function, establish the multi objective optimization model, constraint conditions arealso considered according to its structural characteristics, using the optimization toolbox ofMATLAB to carry on the optimization calculation, gained a better structure parameters ofgear pump, providing some references to improve the performance of gear pump.