Accurate Meshing Theory And Application Technology Research On Small Module Spiral Bevel Gear

For its advantages of steady transmission and high strength, the spiral bevel gearplayed an irreplaceable part in the intersection shaft motion of the high speed andheavy loads. However, the small module spiral bevel gears were generated normallyby duplex, whose meshing quality on their surface could not be controlled, so theimprovement of the transmission property was restricted.To make the production status of the small module spiral bevel gear better, a newgenerating combination method was posed in this article: the pinion was generated bytraditional duplex, while the gear was generated by single-side method to control thetwo sides of the gear and pinion to match, which could improve the meshing quality ontheir surface. Against the above generating combination, the processing parameters ofthe favorable meshing surface were designed, and the modeling techniques based onthese processing parameters and the molding generating application techniques of thesmall module spiral bevel gear were studied, such as powder metallurgy, precisionforging and injection so on. The main contents and conclusions about this article wereshowed as follow:Firstly, the meshing theory on the surface and the designing techniques of theprocessing parameters were researched when the small module spiral bevel gears weregenerated. Based on the conventional methods, local conjugated principle and localsynthesis, their meshing theory and generating techniques were studied by the newmethod, and the theoretical basis for precision transmission was obtained. Taking apair of gears as an example, the basic geometric parameters of the gear were defined.According to the generating theory of the gear, the processing parameters that wereverified by TCA were designed to meet the meshing property and surface contact. Atthe same time, the surface contact situations were studied with numerical simulation.According to their simulated results, the preset parameters, calculated by the localsynthesis, were adjusted to realize the pre-controlling of the contact zone. Secondly, the three-dimensional modeling techniques of the small module spiralbevel gears were studied. According to the processing parameters, the tooth judgmentthat was suitable for the gear de-molding and the geometric calculation procedureswere developed, and the calculation procedures of the tooth points’ coordinate valueswere obtained. Under UG, the mathematical models of the milling teeth generatingwere built with the points’ coordinate values to realize the model building of the gear.Thirdly, the tooth contact analysis techniques based on the three-dimensionalmodeling techniques were researched. And the tooth shape situation, including theundercutting, interference, addendum sharper and tooth taper so on. The contact shapeof the gear was examined, and the stress distributions of the contact zone wereanalyzed with simulation techniques.In the end, the modeling, generating and shaping techniques of the molding diewere studied. The precision model of the gear molding was built based on theprocessing parameters of the gear. When it was difficult to mill the molding cavity inthe CNC center, the appropriate situations were studied by adopting spark erosiontechnique. Because its cone angle of the small module spiral bevel gear was big, themachining techniques that the molding cavity was milled directly by the ball mill inCNC machine, which realized the precision machining of the gear molding. Then,because the molding machining needed to be shaped repeatedly, the new processingparameters were obtained by re-adjusting the contact zone to shape the mold. So themold teeth was re-built and the shaping of the contact zone was realized.