Structural Scheme Design And Machining Simulation Of Planar Enveloping Hourglass Worm NC Grinding Machine

Compared with common worm pairs,the Plane double-enveloping worm gear pair has many advantages,such as multi-line contact,large contact line and comprehensive curvature radius.These advantages has a broad application prospect in various types of machinery.Due to the complexity of the shape of the tooth surface and difficult to machine,it has caused a greater restrictions of researching machining equipment and high production costs,which is difficult to meet the needs of a wide range of market.Therefore,the development and research of the plane double-enveloping hourglass worm(hereinafter referred to as "plane enveloping hourglass worm")machining equipment has become a very important condition for the popularization and application of the plane double-enveloping worm gear pair.To deal with the plane enveloping hourglass worm tooth surface precision grinding,some enterprises and research institutions have been working to research and develop planar enveloping hourglass worm machining method and equipment,and has developed such NC grinding machine.In this paper,preliminary research and development were analyzed,combined with the development trend of modern complex surface NC grinding machine,put forward a kind of kinematic configuration and structure program of new high automation and high precision four-axis-linkage NC grinding machine,completed plane enveloping hourglass worm tooth surface precision grinding with high efficiency and low cost.Our study has important significance and practical value in the popularization and application of plane double-enveloping hourglass worm.Firstly,this paper analyzes the problems of traditional machining and virtual center distance machining in machining precision and range of plane enveloping hourglass worm.Then,we puts forward motion and structure configuration of new four-axis-linkage machining program,and has carried on the kinematic analysis and machining range demonstration.According to the motion and structure configuration of new worm grinding machine,combined with plane enveloping hourglass worm gear pair meshing theory and homogeneous coordinate transformation principle,we constructed a mathematical model of virtual center distance machining principle,and established the theory mathematical model of worm and grinding wheel generating surface.To obtain accurate worm tooth surface,we analyzed and calculated the plane enveloping worm parameters under computer-aided,in combination with mathematical model of the hourglass worm tooth surface and grinding wheel generating surface,conducted the mathematical modeling and simulation for worm tooth surface,grinding wheel contact line,and A class / II boundary curve curve by using MATLAB software,which verified the feasibility of virtual center distance machining principle used in the new grinding machine.Not only does it completed the machining and motion configuration,structure configuration,and structural scheme design of new grinding machine,but also conducted the motion distribution of each axis,made the preliminary design of the main components structure program,and established the three-dimensional model of motion and structure program of the grinding machine.In addition,this paper researched the parametric 3D modeling of the hourglass worm tooth surface,and constructed accurate 3D model of the worm tooth surface.Combined with 3D model of grinding machine structure and worm,established the machining model of virtual plane enveloping hourglass worm NC grinding machine by using VERICUT software.Moreover,according to the process of hourglass worm tooth surface NC machining process,we simulate the machining movement process of hourglass worm tooth surface by using new grinding machine to test the accuracy of worm tooth surface and optimized the NC program,and the feasibility and accuracy of structure scheme of the new plane enveloping hourglass worm NC grinding machine in this paper has been verified.