Hypoid Gear Tooth Surface Based On Digital Initiative To Design Methods And Key Technology Research

The hypoid gear is one sort of the special bevel gears. It gets comparatively extensive application in aircraft industry, automotive industry and tractor industry. Compared with the ordinary bevel gear, its overlapping coefficient is bigger, specific pressure of the tooth face is lower. Therefore, the hypoid gear has advantage of stability at transmission, lower impact and noise, higher carrying capacity and longer life. But the tooth face of traditional hypoid gear can only have the several kinds of finite modes of tooth face, and can't be to carrying on valid control in the whole meshing performance which is exposed to the course of the transmission according to the practical function demand. At the same time, according as current maufacture method of the hypoid gear, the maufacture of conjugate tooth profiles need repeated revision the tooth, the cycle of adjusting machine tool is longer, and it is very difficult to assure manufacture quality.If the limit of the complexity and limitation of the hypoid gear design and manufacture is broken through, the design & manufacture level must be rapidly hightened. The active design technique of hypoid gear tooth face provides a kind of fresh method of the hypoid gear design. The active design method startes from real function demand (such as being reliable, steady and durable drive that be required, etc.), according to the known tooth face ∑(1) (that is the bigger gear tooth face) characteristic parameter (parametric equation of tooth face, trajectory of contact point, etc.) and concrete require at transmission (such as instantaneous transmitting ratio), designs the qualified meshing tooth face ∑(2). The Digitization of the Tooth face is an inevitable demand of design, manufacture, and measureing technology of the hypoid gear, the uniform mathematical model that oriented deisgn, manufacture and measuring of tooth face is an important technical basis of hypoid gear's study.In the thesis, the way of obtaining disperse points of tooth face is discussed, a program of emulation of tooth face's manufacture is compiled, a series of accurate disperse points of tooth face are gained, and the hypoid gear tooth face is figured byNURBS method. The method of constructing NURBS model of tooth face based on disperse points of tooth face is the same with the process of design, manufactue and measureing of the hypoid gear. It is a kind of method that has broad applicability. Depended on the above method, it can be constructed that NURBS model of tooth face at the basis of known data come from design, manufacture and measureing, so that it is realized that unification of mathematical model of the hypoid gear.Secondly, at the basis of realizing the hypoid gear tooth face's NURBS expression, according to the active design method, faced special circs of tooth face's NURBS expression, it is deduced that all equations that must be required when realized the actice design of digitization tooth face. At the same time, it is detailedly designed that program of solution, and the above theory and method is validated by real example.In conclusion, it is studied that method of contructing mathematical model of the hypoid gear oriented design, manufacture and measuring process. It is realized that unification of tooth face model by NURBS expression. It is completed that the study of the active design method of NURBS tooth face, the way of tooth face expression and design is provided. Besides, the designed emulation manufacture program can expediently and rapidly analyze manufacture process of the hypoid gear through computer simulation, passes over traditional process of trial cutting, repeat rolling test and modifying, not only reduces the design difficulty, but also decreases the rejection ratio of manufacture. Therefore, the above method has very good favorable practicability.