Finite Element Analysis Of The Spline Coupling And The Drive Gear Pair Of The Shield Machine

Shield machine is a large and high-tech equipment widely used in tunnel excavation engineering,and the cutter drive device is the key components.However,due to the fact that we started to study shield machine late and the core technology is monopolized by developed countries such as Germany,Japan and France,in the current stage we still do not master the key technologies.Some of the core components have to be imported.Therefore,thorough study of the manufacturing technology of the spline fuse shaft and multi-gear parallel transmission system will not only build up theoretical basis for further experimental research of core technologies of shield machine,but also have positive impact on revitalizing our equipment manufacturing industry and raise independent research and development capability of domestic technology.This paper takes the spline fuse shaft and the multi-gear parallel drive reduction unit of the shield machine disk drive system as the research object.The stress change rule in the meshing process has been deeply studied,and the detailed optimization schemes has been put forward.The design of shield involute spline fuse shaft connection and pinion gear and large gear reduction unit have been completed according to the design requirements.According to the conventional theory,the strength is calculated according to the national standard.The 3D model is build up precisely by use of the three-dimensional modeling software Creo.spline pairs and gear pairs have been assembled according to the relationship of connection and transmission and the installation condition of the driving gear of shield machine has been tested.Based on the results of simulation analysis,the problem of stress concentration caused by edge effects has been studied deeply.Meanwhile various modification schemes have been proposed for the spline teeth to reduce or avoid stress concentration.Finally,the modification effect has been analyzed and verified by the finite element method.By selection of several characteristic positions of cutter drive pinion and the ring gear in meshing period,the maximum contact stress has been calculated by use of Hertz formula.And the simulated analysis has also been conducted in detail by use of the finite element method to observe variation rule of stress.And the results have been compared with those of the Hertz formula.The research results of this paper show that the stress value is much larger than the theoretical value as the load distribution on the tooth surface of the spline fuse shaft is uneven and the stress concentration is obvious at the contact edge.Modification scheme has been proposed to improve this situation.Meanwhile the stress change rule of the special position of the driving gear in the meshing process has been also found out,which provides a theoretical basis for the further research of the shield technology in China.