The Research On Evaluation Method Of Tooth Surface Topographic Deviation For Spiral Bevel Gear

The spiral bevel gear (SBG) is a critical component of machinery transmission, which not only transfers movement and power, changes transmission direction, but also features high carrying ability, good movement stability and so on. So it is widely used in lots of industrial equipment such as aviation, spaceflight, automobile, precision mechanism and petroleum drilling. But the SBG has the complicated tooth surface structure, which makes its manufacturing and measurement more complicated than those of ordinary cylindrical gear. Meanwhile, it is an exploring phase to analyze and diagnose SBG's process errors. Based on the conception of gear global deviations, starting with the related factors influencing SBG's deviations, the paper has explored the quantitative evaluation of topographic deviation for SBG by means of mathematical method in combination with measurement principle, and has developed the software of SBG's deviation evaluation. The paper establishes a certain foundation to deepen the study of deviation theory of SBG.The two key factors, machining methods and machine-setting parameters of SBG, which are related with the generation of theoretical tooth surface and topographic deviation for SBG, are analyzed in details. After building the machine-tool mathematical model and computing the tooth surface parameters, using the given conditions and mesh equation, the coordinates of the theoretical tooth surface of SBG can be computed, and, then, the theoretical tooth surface model of SBG is derived. The causes of formation of global form errors for SBG and its separation method are analyzed theoretically. The tooth surface deviation and pitch deviations resulted from tooth surface distortion are separated and derived.Difference surface in combination with the least square method is employed for the evaluation of topographic deviation for SBG. Geometrical and physical meanings of difference surface are presented, and the parameters of tooth surface topographic deviations are derived. In addition, the complete mathematical formulae of the 0th, the 1st, 2nd order form deviations is proposed, and diagnostic parameters of each order form deviation is gotten by the least square method, which lead to evaluate the tooth surface topographic deviation quantificationally.Finally, the evaluation software of topographic deviations, for the example of spiral bevel gear, is programmed by VC++6.0 and Matlab. Inputting the certain module, pressure angle, helix angle and...