Study About The Optimum Value Of External Spur Pump Gear And Its CAD

Pump gears are the key part of gear pump. The performance of gear pump depends greatly on the correct and optimum parameters selection for pump gear.After thoroughly analyzing the influence of each pump parameters on the gear pump performance, the paper developes the criterion for optimum gear parameters, which can be utilizied in practice easily for gear manufacturing using normal involute gear hob with two-fillet type. The conclutions studied by the paper are:1. Both the addendum coefficient and the deddendum coefficient of the pump gear should be 1.125.2. The long-addendum coefficient of pump gear must make the gear in the condition of undercut.Base on these conclusions, the basic parameters of pump gear are optimum. The paper derives a new calculation formula for contact ratio of pump gear, provides a C language program as well, which make the pump gear optimum design convieniently.The paper describes an approach based on preferences for drawing pump gear by Visual Lisp language and for designing dialog-box. Gear form is precisely, plotted by portray point.For friendly user interface, the dialog-box is given, using DCL language to compile dialog box program.Because the given program can not only output all the optimum basic parameters of pump gear, but also simulate the meshing process of a pair of pump gears, gear pump can be designed and manufactured economically.