Research On Design And Meshing Characteristics Of Involute Internal Beveloid Gear Transmission

The involute internal beveloid gear transmission with parallel axis is composed of external gear and internal gear,the tooth profile has different profile shift coefficient along the direction of tooth width and the addendum has a certain taper.Involute internal beveloid gear transmission has the advantages of small volume,big contact ratio,high strength and so on.Through adjusting the axial displacement,the backlash can be reduced and high transmission accuracy can be achieved.So it is widely used in the field of precision gear drive,such as precision robots,packaging machines,etc.However,due to the different profile shift coefficient along the direction of tooth width,the geometric design,interference calculation,manufacture and mesh characteristics are complicated.Aiming at the above problems,the involute internal beveloid gear transmission is selected as the research object.The design of the geometric parameters,machining method and the mesh characteristics are studied,which can provide theoretical basis of internal beveloid gear transmission with parallel axis for industrialization promotion and has great academic significance and engineering application value.The main contents of this dissertation are shown as follows:(1)A method based on the limiting chart for the design of geometric parameters of involute internal beveloid gear transmission with parallel axis is presented,the mathematical model of limiting chart for geometry design of involute internal gear with parallel axis is derived,and the electronic limiting chart is drawn.The influence of the meshing angle of the gear pair and the polar radius value of the top endpoint at the shaper cutter involute profile on the shape of electronic limiting chart are studied.On the basis of this,the influence law of the range of the modification coefficient of the beveloid gear pair is studied and the parameter design of involute internal gear with parallel axis is conducted.(2)Based on spatial meshing theory,a new method which the cutting motions are represented using three degrees of freedom that are the rotation along its axes,translations along the axial and radial directions for manufacturing the internal beveloid gear pair with parallel axes between the shaper and the gear blank is proposed.The manufacturing coordinate system of the internal and external beveloid gear are established,respectively.The mathematical model of tooth surface of the internal and external straight beveloid gear are derived,respectively.The generating procedure of internal beveled gear is programmed and the 3D solid model of the internal beveled gear is created.(3)The internal bevoloid gear pair finite element analysis model with parallel axis is established and the loaded contact characteristic of the internal bevoloid gear pair is conducted.The tooth surface contact form,tooth bending stress,influence of the load case and the pitch cone angle on the mesh characteristics of internal beveloid gear are studied.(4)The error of the axial parallelism of the internal beveloid gear pair with parallel axes is defined,and the influence of the axis error of the X direction and the Y direction on the instantaneous contact line,contact pattern,mesh force,transmission error and mesh stiffness are investigated.