| It is the important component part of automobile and engineering machine transmission system that Gleason helical bevel gear including spiral bevel gear and hypoid gear, its operating characteristic has the most important influence for entire transmission system. Along with the raising of automobile speed and power, automobile spiral bevel gear and hypoid gear transmission are developing toward high speed and heavy load, The issues relating to its dynamics behavior have brought a great concern to scholars all over the world. Since the vibration and noise of the automobile gear of our country is generally more serious than foreign product, therefore the research of coupled nonlinear dynamics behavior of the automobile spiral gear is one of the most important topics that must be resolved urgently in the engineering application.The gearing mesh is bound to have some backlash, which may be designed to provide better lubrication and installation or due to manufacturing, machining and installation error and wear during gear transmission. Taking into account of the time variant of the meshing stiffness, spiral bevel gear and hypoid gear transmission system will be a non-linear system with backlash, which has parametric excitation and the variant of the meshing stiffness. Researching on the coupling non-linear vibration property of spiral bevel gear and hypoid gear transmission system will be given rise to not only important practical value but also important theoretical meaning for the dynamical design of automobile Gleason helical bevel gear.This thesis based on the national fund project of natural science "3-D multipoint impact contact dynamic simulation and physical analogue of the automobile high speed transmission "( Authorize number: 50075088). The focus of this thesis is on the coupling nonlinear dynamics problem of the automobile Gleason helical bevel gear. Some progress and accomplishment have been made on the key issues such as coupling vibration of spiral bevel gear and hypoid gear, 3-D dynamic contact-impact and the non-linear vibration behavior with time-varying stiffness and backlash. The major works of this thesis are listed as follow: 1. The finite element model of the spiral bevel gear and hypoid gear tooth is established, the dynamic meshing property is analyzed combining with the mixed finite element method for contact problems. 2. The coupled Lateral-torsional-axial-pendulant vibration dynamics model and nalysis model with multiple degrees of freedom of the spiral bevel gear and hypoid gear are established. Elastic deformation of the shaft and bearing, and the excitation of the time-varying stiffness, deviation and meshing impact are considered in the model. The analysis model of the integrity gear system including the gear transmission system and the structure system is established and the dynamic response of the gear system is analyzed using the numerical simulation method. 3. The finite element kinematical differential equation relating to the dynamic contact-impact problem is derived from Hamilton theory. The finite element program of 3-D dynamic contact-impact problem is developed making use of the mixed finite element method, and used to analyze the 3-D dynamic contact-impact characteristic of the spiral bevel gear and hypoid gear. 4. The 3-D dynamic contact-impact numerical simulation method is used to simulate non-linear characteristics of the spiral bevel gear and hypoid gear with backlash. Then the influence of the backlash to the impact force is analyzed either the initial speed or the sudden load is applied to driving gear. The changing rule of the contact-impact force is also by this numerical method. 5. The non-linear dynamics model with backlash is established and the multi-degree- of-freedom differential equations with variable parameter, translational-torsional coupling and multi-element non-linear function also are gotten. In term of coordination transform, a new set of uniform non-linear dimensionless differential equations of the gear system is constructed. So all of the elastic res... |
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