Research On The Key Technology Of Non-circular Gear's Parametric Design

Gear is the most widely used transmission component of machine and instrument.The cylindrical gear is widely used in industry.It can achieve a fixed drive ratio,it is difficult to realize the variable transmission ratio drive.Non-circular gear can be used to realize the function of variable gear ratio transmission or reproduction of some independent functions.Non-circular gear transmission can realize transmission of cam,and can realize the precise gear transmission and high overload balance,so the non-circular gear is a kind of integrated mechanical components.The purpose of this paper is to use computer technology to solve non-circular gear design problem,to better achieve the noncircular gear application.The main research contents are as follows:In the basic theory aspect: First of all make a comprehensive survey of the development of the non-circular gear,introduce the development and present situation of design and machining in the domestic and foreign,the application of computer technology and numerical control technology in the design and manufacturing of non-circular gear.This paper expounds the research background,purpose and main content,and then introduces the basic theory of design of non-circular gear pitch curve and tooth profile,pitch curve parametric design mathematical model and parameter verification conditions are derived,and lay the foundation for the development of parameters modeling Program.In the parametric design: use the MATLAB as programming tool,program for non-circular gear pitch curve design and tooth profile,developed parametric programs for human-computer interaction in GUIDE environment.Solved the design parameters problem for common types of non-circular gear pitch curve,improve the design efficiency and accuracy of non-circular gear.The pitch curve parameterized module is for the section curve commonly used,according to different requirements of the design parameters quick and convenient realize of generating the pitch curve and calibrating parameters.Includes three types: realize the reproduction function,according to the given transmission ratio function,known driving gear pitch curve.In each case,according to the actual requirement of the design develop different programs,make calibration of convexity,undercut and pressure angle and other parameters,make the teeth uniformly distributed on the pitch curve,adjust which does not meet the requirements of the design parameters,for the assurance of meeting the correct meshing requirements;on the basis of these drawing pressure angle graphics,transmission ratio graphics and section curve mesh graphics.The elliptic gear is the key of the research,the dynamic meshing simulation of the pitch curve may predict the correctness and effectively of design results.Propose a method of modifying undercutting,by revising undercutting the short axis of the new curve and the original curve is equal length.The tooth profile curve design module,modeling by analytical method and convert gear number method,using MATLAB programmes to solve noncircular gear tooth profile by the tooth profile equation,through programming in section curve gear,determine the important point of tooth profile curve,so as to design the whole tooth profile curve,and draws it out.By examples to verify the feasibility of this program.In processing: analyse and compare principles and characteristics of several noncircular gear machining method,introduce the wire cutting and 3B instruction programming,deduce the model of NC gear hobbing technology,as the noncircular gear machining schemes used.Finally,the summary of this thesis,summarizes the achievements,also pointed out theshortcomings and the needed of this paper for further research.