R&D And Analysis Of Coaxial Planetary Gear Transmission With Dual Power Output

The planetary gear transmission are widely applied in modern industries, such as machines, electron, textile, metallurgy, mining, automobile, spaceflight, navigation and so on because of its small size, light weight, high transmission ratio and great bearing capacity. Meantime, the researchers lay an emphasis on the coaxial planetary gear transmission with dual power output now due to the unique structural style. The technical requirement and economic indicator of the planetary gear transmission are becoming even higher according to the high development of modern industrial technology. Therefore, it brings the strong challenge to the structure design. Not only the optimization is a necessary part of design, but also the prediction of the dynamic performance is very significant for the planetary gearboxes.This research subject comes from the cooperation of my school and the affiliate factory. In order to improve the performance of equipment owned by the Qingping machine factory of Chinese Ship Heavy Industry Corporation, a coaxial planetary gear reducer with dual power output is designed, and the finite element (FE) analysis, optimization design and kinematical simulation are fulfilled. These researches furnish a theory basis for the design of high reliability, light weight and low noise gearbox.The research work and results presented in this dissertation can be summarized as follows:1) According to the design demands of the coaxial planetary gear transmission with dual power output, the closed and differential drive schemes are proposed. Using the software of Solid Edge, the solid and assembly models of the planetary reducer are completed. The kinematical calculation and power flow analysis prove that the both drive schemes don't have closed power flow in transmission. The results of load analysis, strength check and efficiency calculation indicate that the gears and output shafts have enough strength and the transmission efficiency satisfies to the design demands of the differential planetary reducer. Meantime, the preliminary tests of specimen machine verify the validity of movement.2) The contact stress of tooth profile and the bending stress of gear root in the external and internal meshing gears are calculated by using the elastic contact FE method. These stresses are approximately equal with the results obtained by analytic formulas. The FE software of ANSYS is used to analyze the stress and strain of the shell parts and planet carrier parts of planetary reducer under non-uniform load. The results prove that the reducer has enough strength and stiffness.3) Using the ANSYS parametric design language (APDL), the command stream based program is compiled to establish the parameter model, generate mesh, determine the boundary condition and complete optimization analysis of the shell and planet carrier parts. The zero order method is used to implement the optimization design under the conditions of enough strength and stiffness.4) The dynamic FE model of coaxial planetary gear transmission with dual power output is established in the software of I-DEAS, and then the intrinsic properties including the mode of vibration and the nature frequency are obtained. The results indicate that the nature frequencies are not agreed with the rotation frequencies of the shafts and the meshing frequencies of gears.5) The internal dynamic excitations of the transmission system including the meshing stiffness excitation, error excitation and impact excitation are calculated, and the dynamic response and the structure-borne noise of the coaxial planetary gear transmission with dual power output are simulated and predicted by using the software of I-DEAS.