Research On Error Modeling And Stress Analysis Of Gear

Gear transmission has the advantages of large range of transmission power, hightransmission efficiency, accurate transmission ratio and long service life, etc, and iswidely applied in all kinds of mechanical products. With the rapid development ofmodern industrial technology, the performance requirements of gear transmission ishigher and higher. The current research on gear are most based on the ideal model, butthe tooth profile deviation can affect the gear contact stiffness, so it is of greatsignificance to research on the tooth surface error model building method, introducetooth profile deviation into the contact analysis of the gear and analyze the tooth rootbending stress in order to ensure the strength, the working precision and the servicelife in the gear transmission process. Meanwhile，it can better guide the design andmanufacture of gear. The article main research content is as follows:Firstly, with the quantitative description of the deviation of geometric element bySmall Displacement Torsor, the tolerance modeling method based on SDT is analysed.On this basis, the error modeling method based on SDT is put forward with the pointset topology and geometry transform theory, and the error modeling analysis forcomplex surface is given.Secondly, according to the analysis of the distribution of the tooth profiledeviation and its experimental verification, it shows that it is reasonable to choose thenormal distribution as the distribution of tooth profile deviation. On the basis, withthe error modeling method of complex surface, the mathematical relationship betweenthe points of the ideal tooth surface and the specification surface model of toothsurface is established. And with the technology of surface reconstruction, the toothsurface error model with tooth profile deviation is established.Thirdly, ideal gear and gear with tooth profile deviation are researched on thestatic and dynamic contact finite element analysis. The size and the change rule ofcontact stress are obtained. In the static analysis, on the basis of related paper test data,the accuracy of gear contact analysis by finite element method in this paper is verified.Meanwhile, we find the contact stress of tooth surface has obvious increasing trendwith the tooth profile deviation increasing. In the dynamic analysis, it is concludedthat with the single and double teeth alternate meshing, the change of ideal gearcontact stress presents certain regularity, while, to some extent, the tooth profile deviation changes the rule of contact stress. Analysis results are in line with theengineering practice shows that the gear specification surface model built in the paperhas certain validity. It is of great value to guide the accuracy design and the strengthdesign of gear.Finally, the tooth root bending stress is analyzed by three kinds of methods thatare the analytical method, finite element method and experiment. It finds that theresults of the three methods are very similar, so it shows that the finite elementmethod for the analysis of the tooth root bending stress is accurate and reliable,andthe calculation result is more accurate when the load is on the upper bound point ofthe single tooth meshing, and it can be used to guide the design of the gear.