Research On Helicopter Main Reducer Design Method Based On The Axiomatic Design Theory

The performance of a helicopter is deeply affected by its main reducer, for its complex structure and high demands on performance, so the common mechanical design method can not provide main reducer a complete, standardized and effective design guide. Axiomatic design theory is a scientific,rigorous and effective engineering design theory, which provides an integrated design frame, guidance and help during design process. In this paper, axiomatic design theory is studied as the research object,the design frame and design axiom is studied in-depth and applied on a typical helicopter main reducer, which is the combination of theory and practice.At first, axiomatic design theory is studied, summarized and enriched, including the design of function domain, the zigzag mapping process, the standard describe of function trees and structure trees. The “black box” method is introduced to analyze the function, axiomatic constraint is studied and classified, zigzag mapping is also analyzed and applied on the typical helicopter main reducer to conduct its axiomatic function-structure analysis and map.Then, the theory of function-coupling is developed, the method of uncoupling and the optimization of the axiomatic information quantity is also studied. The function-transition method and sequential-conversion method is utilized separately to uncouple the coupling Caused by the function-structure zigzagging and function temporal relationship. The methods of uncoupling,reducing design stiffness and DPS integration are also studied and applied in the helicopter main reducer's axiomatic information optimization.Then, the evaluation system of the helicopter main reducer is designed based on the information axiom of the axiomatic design theory. The information quantity equations of the evaluation indexes,main reducer's weight, transmission efficiency, life and dry running ability, are determined. The weight calculation method based on entropy weight method is studied, finally obtaining the information decision-making system.Finally, axiomatic design theory is applied systematically on the typical helicopter main reducer,verifying its reasonability and effectiveness. The application software, containing the requirement analysis module and axiomatic analysis module, is developed, providing designer an available basic tool for axiomatic design.