Design of the new gear tooth profile of the trochoidal gearing

Abstract

Methodology for selection of optimal shape of trochoidal gear tooth profile applied at gerotor pumps is presented in the paper. The first part of the paper presents the general procedure for generation of gearing with profiles described by epitrochoid equidistant and corresponding coupled envelope. Next, geometrical and kinematical conditions which should be fulfilled by profiles were defined in order to achieve proper coupling. Dependences between geometrical gearing parameters and functional characteristics of the pump were determined. In order to assess maximal contact stresses, analysis of forces and moments is conducted with application of analytical and numerical methods. The influence of the profiles with technological gaps on volumetric losses of the pump was identified through investigation of profile characteristics. In order that derived models and functional dependences for determination of output parameters may be used as flexible and reliable as possible, their generalization is conducted. Described methodology is illustrated on the example of the actual pump and the obtained solution is proposed as optimal for given conditions 1. Based on theoretical considerations, physical models of gears were made and simulation experiment performed, wherewith the results of the analysis of the functional characteristics of the pump and described methodology were entirely verified.