Study On Multi-objective Optimization Design Of A New Planetary Gearbox Based On The Fuzzy Reliability

Planetary gear drive is widely applied in petroleum, mines, engineering machinery, automobiles and many industrial production fields because of its high transmission efficiency, small volume, smooth movement and strong ability of resistance to impact and vibration.Use of routine design methods or past designers experiences could be meet the requirements. But along with the development of society, the user put higher request with the reliability of gearbox, transmission efficiency and vibration noise.For the structure of planetary gear train is complex, and the planet carrier is an irregular entity, its deformation will impact the whole planet gear train. The conventional reliability design assumptions components is completely normal or failure, trying to accurate description of the state of components, but there are a lot of fuzzy, random phenomenon in actual condition. In order to accurately calculating the reliability of the products, we combined the conventional reliability design with fuzzy mathematics. Application of modern design method integrated optimizing design and finite element analysis in order to improve the transmission efficiency and increasing the planetary system reliability and try our best to reduce the weight, through the linear weighted function method to establish the objective function.Adopt the method of design variables normalization to determine the weighting factors, based on the fuzzy mathematics theory of reliability constraints and geometric constraint. Then, the optimal design is conducted by using optimization toolbox in MATLAB. To ensure the optimal parameter to meet the the global optimal solution of objective function, stack calculation the three local optimal solution. The optimization results show that using multi-objective optimization method of fuzzy reliability design, the transfer efficiency and stability of the system improved, the weight of the planet gear train also reduced. For the weight of planetary gear train decreased 2.43%, Coincidence degree and the meshing efficiency improved 2.70% and 2.84% respectively. This indicates the fuzzy reliability of multi-objective design not only reflect the real situation of product design and operation in the design phase, and guarantee the reliability of the products, it is a kind of more scientific and more accord with the objective facts design method.Its has wide application in engineering practice. Based on the results obtained from the fuzzy reliability multi-objective optimization, than establish the 3d models of whole planet gear train.In the product design phase assembly interference and guarantee the parts design calculation is correct.In planetary gear transmission planet carrier is the main parts to transfer force and torque, its deformation affects the meshing gears of entire gear train. After Design completed we must check the gear stress. To get planet shelf stress and deformation we must do finite element analysis with planet carrier. Using finite element contact analysis to calculation how the deformation of planet carrier influence of the gearing force of the planet to sun gear. The planet wheel rotation speed is higher, in order to prevent the resonance of planetary gear train in rotating process, it is necessary to do modal analysis of the planet gear. Through the design, checking, analysis, to ensure the reliability of the product.