Research On Design Method, CAD And Applications Of Pitch Curves Of Non-circular Gears

First of all, this paper summarizes the development history of non-circular gears. They have been used more and more because of their special transmission character in kinematics and geometry, and they can satisfy different varied transmission ratio.This paper mainly studies three aspects: design method of pitch curves of non-circular gears, computer-aided design and applications.Author has summed up and put forward two kinds of practical design method of pitch curves of non-circular gears. In the first method, r1(θ1)(or r2(θ1)) has been created by radius vector function q(θ1) of initial pitch curves. This method can be used for designing identical pitch curves of non-circular gears; in the second method, pitch curves of non-circular gears have been created by transmission ratio i12 (or i21). As an example, author has put forward a quick return mechanism incorporating non-circular gears. The output part can get uniform velocity in the work area, and also has a better quick return character.Author has also studied how to design, calculate, create and optimize pitch curves of non-circular gears by computer. All the datum and figures in this paper have been calculated or drawn by computer. The program languages used in this paper are FORTRAN and MATLAB. Drawing software are MATLAB and AUTOCAD. Moreover, author studies the movement combination and optimum of oval gears and sine mechanism.Application is the ultima thule of study. Two applications have been studied in this paper. The first application is non-circular gears are used in press. Non-circular gears are used as the leading mechanism of slider-crank mechanism, and they can optimize the kinetic characteristic and dynamic characteristic of sliding block; thesecond application is non-circular gears are used in steering mechanism of four-wheeled carrier. This steering mechanism has the capability of turning a carrier with a small radius.