Research On The Design Theory Of Worm Face Gear Drive And Machining By Flying Cutter

Worm face gear transmission consists of worm and worm face gear,which is also known as curved tooth face gear.In this paper,the worm face gear drive is taken as the research object.Based on the tooth surface equation of Archimedes worm,the theoretical model of worm-face gear is solved and the relevant theoretical analysis is carried out.In addition,a new processing method of worm-face gear,named flying cutter machining method,is proposed.The feasibility of this method is verified by theoretical analysis and machining experiments.Firstly,based on the gear engagement principle,the tooth surface equation of worm-face gear is solved combined with the process of the worm rolling the face gear.On this basis,the influence of the pressure angle of worm on the undercutting of worm-face gear is studied and the critical pressure angle is solved.Besides,the influence of the assembly parameters on the normal addendum thickness of worm-face gear is studied and the reasonable value of each assembly parameter is determined.Secondly,the flying cutter machining method of worm-face gear is proposed.Taking the Archimedes worm as an example,the profile of the axial section of the worm is solved,which is used as the cutting edge of the flying cutter.Then the trajectory of the cutting edge of the flying cutter during the machining process is solved.And the relationship between the spindle angle,the workpiece shaft rotation angle and the feed amount of the flying cutter is determined.Thirdly,two modes of implementation of the flying cutter method are proposed:the axial feed machining method and the radial feed machining method.The corresponding NC programs are programmed and simulated in VEIRCUT.The comparison of the cutting and theory model of worm-face gear verifies the feasibility of the two processing methods above.Finally,the structure of the flying cutter is designed in detail.A pull pin structure is proposed,which can not only fix the cutter on the arbor stably,but also can adjust its tilt angle when needed.The trial cutting experiment is carried out on the CNC machine tool.By measuring the coordinates of the discrete points on the surface of the gear and comparing them with the theoretical ones,the tooth surface machining error is obtained,which proves the correctness of the flying cutter processing method.