Research On A Gear Geometric Modeling Method Taking Account Into Eccentric Error And Parametric Design

CNC turret is mounted on the CNC machine tools, which is the important functional part for CNC machining, and its performance affects the cutting performance and efficiency of the whole machine directly. Therefore, CNC turret marks the pros and cons of CNC machine tools in the design and manufacturing standards. For high-speed, high-precision power servo turret, the study to its transmission system and access to an effective way to improve the turret turning positioning accuracy and reduce the transmission noise and vibration has important theoretical significance and practical value.This paper is associated with Key National Science & Technology Special Project on "High-Grade CNC Machine Tools and Basic Manufacturing Equipments"—"dynamic relia-bility and reliability sensitivity of the power servo turret design and test technology", and it presents a research on a power servo turret made by Shenyang Machine Tool Group. It's mainly about establishment of precise involute cylindrical gear model, and the gear plug-ins is de-signed based on NX. So, we can generate standard gear model or gear model with eccentricity error model quickly and accurately for the subsequent work of the kinematics analysis, dynamic analysis and transmission accuracy analysis as support of theories and models. The main works as follows:(1) Improve modeling method of involute cylindrical gear in NXIn the condition of rack-type tool with a double fillet machining involute gear, we deduce theoretical formula of involute gear tooth profile. Meanwhile, we carry out further research about undercut point M of undercut gear, and deduce the location parameters of undercut point M and the undercut amount. We use these results to compare with the penalty function method and empirical formula, and improve the theoretical formula of gear tooth profile. In the basis of the improved theoretical formula, we establish gear model in NX software.(2) Put forward modeling method of gear with eccentric error and measurement of radial displacementAccording to the machining process, this paper puts forward modeling method of gear with geometric eccentric. We can establish gear model with geometric eccentric to help simu- lation analysis in the subsequent works. Because of the radial displacement caused by geome-tric eccentric, we put forward selection criteria of amount of stick (ball) diameter and provide the basis for the more accurate measurement of the actual gear.(3) Based on NX5.0 software platform to develop involute gear plug-inUse NX5.0 software secondary development function modules, combined with VC++6.0 to design involute cylindrical gear plug-in. We use two plug-in design methods:The first me-thod is based on a template graphic design of a gear plug-in; the second method is based entirely on the API function to design gear plug-in.