Research On Optimal Design Of Marine Enclosed Epicyclic Gear

With the ship-building industry fast developing, the demand of marine gear-box is increasing greatly. At present, the ship gear-box is developing in the direction toward increasing power density, reducing the weight, improving the transmission efficiency, accelerating the development speed etc. With the characteristics of compact structure, higher transmission efficiency and power-flow shut type, the enclosed epicyclic gear train makes great concern. Under this background, the optimization of marine enclosed epicyclic gear reducer is carried out in this paper. The model which optimal targets are volume and efficiency is put on pocus and the selection of optimized algorithm are put forward.Combining the structure feature of enclosed epicyclic gear, the power-flow type and the loads of gears are analyzed. And the simplified method of stress calculation is discussed. Including the objective functions of minimum volume and maximum efficiency, the optimum variables of tooth numbers, modulus, tooth width coefficient, planetary gear numbers and helix angle, and the constraints of contact ratio, strength conditions, the radial direction sizes of two adjacent levels etc, an accurate mathematic model of marine enclosed epicyclic gear transmission train is established.The optimal model has these properties:the non-linear objective and constraint functions, the discrete and continuous variables, the Genetic Algorithm (GA) is selected as optimization algorithm. The genetic operators are modified by distance measurement. By absorbing rhombus-thinking and elitist preservation method, the advanced adaptive GA with real number code is achieved.Based on Visual C++ platform and Access database, the gear-strength verification procedure of ABS2008, the ordinary material database and the Human-Computer Interaction of optimization procedure of marine enclosed epicyclic gear reducer are compiled by C++. An example was calculated and examined. The optimum result and conventional design result are compared with each other. The analysis shows that the volume is reduced effectively and the efficiency is increased by using improved genetic algorithm. The weight is reduced significantly and the gear-strength maintains well.