Study On Coupled Thermo-Elastic Deformation And Nonlinear Dynamic Emulate About High-Speed, Heavy-Load Gear Transmissions System

The dynamic analysis under the entire running conditions has significant effects on reducing vibration and noise in high-speed and heavy-load gear transmissions. Developing dynamics analysis theory and method for the high-speed and heavy-load gear transmissions is helpful to realize making the gear transmissions and reach international advanced level. Based on the theories of gear engagement, contact analysis, tribology, heat transfer, nonlinear dynamics, computer aided engineering, vibration, impact, a finite element model of gear transmission was established to investigate the deformation, tooth profile modification and dynamic response in the system. The corresponding analysis theory and method have been proposed. The major work is summarized as follows:With the method of material mechanics and contact finite element to investigate the meshing stiffness about the gear transmissions.Based on contact finite element model to research the heat deformations with tribology and heat transfer.Some methods have been used to assess the friction heat input and the heat transfer coefficient.The meshing stiffness of gear is the foundation of dynamic analysis. Applying formula of Ishikawa, contact finite element and coupled thermo-elastic model, the deformation and stiffness curves have been researched individually.Modification is an important means to reduce the vibration and noise in high-speed, heavy-load gear transmission. On the basis of modifying theory a new method has been proposed to acquire the modification curve according coupled thermo-elastic finite element model. Theoretical calculation and practice prove that this kind of method has good effect.A method considering thermo-elastic, time-varying meshing stiffness, movement gap, errors and tooth temperatures has been proposed to emulate the high-speed and heavy-load gear transmission under the entire running conditions.A dynamics model is developed, in which time-varying gear meshing stiffness, errors and gap are considered. By means of time-displacement diagram, phase plots, Poincaré maps and FFT spectra of numerical solution the multi-harmonic dynamic response of the system has been realized. The finite element model consist of gear pair, draft, bearings, case has been created. This model has described the dynamic property of gear system better. With I-DEAS to carry out modal analysis about the finite element model and solve the natural properties of the gear system.With harmonic balance method to solve the nonlinear dynamic differential equation. Combined with the three-dimensional finite element model to calculate the dynamic response of the case under the gear meshing stimulating and analyse the dynamic properties of the entire gear transmission system. The dynamic numerical emulatation about high-speed, heavy-load gear transmission has been finished.Have carried out the experiment research under high speed and heavy load for actual gear box. The vibration response distributions of the case surface have been gotten. It is coinciding with the calculation result and testified that the model is correct.Paper has innovation in some following aspects:With coupled thermo-elastic finite element model to acquire the deformation and stiffness curves of the high-speed and heavy-load gear transmissions. A method has been proposed to determine the gear ideal tooth profile modification curve on the basis of thermo-elastic deformation analysis.A method considering thermo-elastic, time-varying meshing stiffness, movement gap, errors and tooth temperatures has been proposed to emulate the high-speed and heavy-load gear transmission under the entire running conditions.A dynamics model is developed, in which time-varying gear meshing stiffness, errors and gap are considered. By means of time-displacement diagram, phase plots, Poincaré maps and FFT spectra of numerical solution the multi-harmonic dynamic response of the system has been realized. These will predict the dynamic behavior of the gear transmissions in designing.Have carried o...