Robust Optimization Design And Research Of High - Speed Machine

This thesis deals with the screw gas pressure elevating equilibrator and hydro-pneumatic elevating equilibrator of howitzer, analyze and optimize the performance characteristics and their key components, based on the modern mechanical design theory and methods.The temperature is indeterminate, when the elevating equilibrator of a howitzer is working, it can’t be controlled, and has an influence on the hand wheel force. The conventional optimization design method does not consider the uncertain factors such as temperature, etc. In order to increase the equilibrator’s stability and reliability, and reduce the temperature fluctuation’s influence on hand wheel force, the optimization model of the elevating equilibrator is acquired through 6σ robust optimization method and setting the temperature as a variable factor. The optimum results show that, the hand wheel force fluctuation is reduced when the temperature fluctuation amplitude is fixed, which means that the optimization reduces the elevating equilibrator’s insensitive of hand wheel force to the temperature fluctuation and enhances the elevating equilibrator’s stability.Seal rings are the key parts of elevating equilibrator with hydraulic control, using high-pressure gas as elastic medium. In the process of adjusting the angle of elevation, the friction of seal ring has a great impact on the balance of performance and hand wheel force. The thesis analyzes the friction of seal ring with the method of FEA, based on the constitutive relation of NBR, and provides the basis of the optimization for the elevating equilibrator and seal ring.In this thesis, the structural parameters mathematic model of the elevating equilibrator has been constructed, based on the analysis of the hydro-pneumatic elevating equilibrator. The maximum unbalanced moment is the optimization objective of the model, MIGA algorithm is used to solve the optimization model. The result shows that the unbalanced moment has been controlled in the operational range, achieving the optimal goal.Due to the hydraulic oil’s elastic modulus, hydraulic oil will produce compression when the hydro-pneumatic elevating equilibrator receives an impact load. Therefore the thesis derives the formula of the hydraulic oil column’s stiffness, and calculates its stiffness with the finite element model including the elevating equilibrator and the hydraulic oil. The results verify the correctness of the theoretical formula, and provided the basis of howitzer dynamic analysis.