Tooth Contact Analysis Of Double Circular Arc Spiral Bevel Gear

Double circular arc spiral bevel gear is a new technology which applied double arc tooth on spiral bevel gear, compared with the spiral bevel gear, which has the advantages of high load capacity, long service life, high coincidence degree, high contact strength and bending strength. For the theoretical study is still immature, this limits its application in our country.In the gear transmission, the location, size, shape of the gear contact area may influence the gear drive quality, efficiency, dynamic performance, carrying capacity. Therefore, the effective analysis and correction of the contact area can ensure gear transmission reliability and stability. This thesis focuses on the contact performance analysis of double-arc tooth on spiral bevel gear, based on the principle of TCA, the contact area without load and the influence of installation error on contact area are simulated by MATLAB software. Based on this, the LTCA is made, and the contact area with load, the force distribution of contact ellipse and the transmission error curve are gained, in addition, the 3-d model is build by the virtual machining principle, the non-linear contact analysis is made by FEM software to get the contact area change of different meshing moment. The main research contents are as follows:1) According to the conjugate gear tooth surface forming principle and gear processing principle, shaping gear tooth surface equation, the meshing equation, instantaneous contact line equation, the tooth surface equation of pinion and wheel are deduced.2) According to the meshing principle, the TCA is carried on to expound the contact trajectory, contact ellipse and transmission error curve and study the influence of installation error on contact area, at last,the output of contact trajectory, contact ellipse and transmission error curve are realized by MATLAB.3) On the basis of TCA, the loading contact analysis is made. Based on finite element theory, the gear clearance before loading and the elastic deformation are calculated, then the displacements compatibility equation and force balance equation are listed, force distribution of the single contact ellipse is calculated by solving nonlinear equation. At last, simulation analysis is made by MATLAB on the FSH bevel gear with given concrete parameters.4) Based on spiral bevel gear engagement principle and processing principle, the spiral bevel gear machine model, plane milling cutter model, bevel gear tooth billet model are established in Pro/E software, three-dimensional models of a pair of meshing gear is established applying the CNC virtual machining principle.5) The FEM analysis is carried on the meshing gear pairs, first the finite element mesh of the meshing gear pair is established by Hypermesh software, then FEM contact analysis is carried on MSC. Patran/Marc, the static contact analysis and the dynamic engagement simulation analysis with low-speed are carried on, the contact area changes of different moment are gained. At last, by comparing the calculation result with the numerical analysis result, the reliability is proved.