Research Of Transition Curve At Transition Zone Of Hydraulic Cylinder Flange

Hydraulic machine as an important forging equipment in machinery manufacturing industry occupies an important position, Hydraulic cylinder is one of the key components. Hydraulic cylinder of the flange surface to the bearing is an ordinary structure used up to the hydraulic machine. Its bottom and flange are under moment, in particular the stress concentration in flange transition zone is shown to be obvious. The failure mode of hydraulic cylinder is fatigue damage, which is fatigue crack in flange transition zone. Of course, the manufacture, installation and use of misconduct are main cause, But as a designer, the quality of transition curve is a key.In this paper, transition-curve of flange transition zone in the hydraulic cylinder will be optimized. Firstly, through researching the causes of damage of hydraulic cylinder, analyzing the transition curve of flange transition zone, the author studied methods of reducing stress concentration in the flange transition zone. Based on above research, the new two transition curve that are the curve of the inner bias and arc and the curve of the double arc were introduced. Secondly, depending the elasticity theory and the method of ring and shell combination, calculation program of the stress of bearing flange cylinder has been designed. The curve of single arc and the curve of outer bias and arc had been analyzed. The curve of the inner bias and arc and the curve of the double arc had been designed in geometric analysis. Through the application of elasticity theory and the method of ring and shell combination, above four curve of transition zone had been compared and analyzed. The researching proved that the curve of the inner bias and arc and the curve of the double arc were better than the curve of single arc and the curve of outer bias and arc. Third, the authors used finite element analysis software ANSYS to simulate and analyze the t four hydraulic cylinder. In the process of being analyzed, three-dimensional isoparametric element Solid186 and axisymmetric elements Plane82 were used. Finite element analysis showed that Von Mises stress of two new curve transition hydraulic cylinder was smaller, Stress concentration is correspondingly decreased, and the stress distribution is superior to the other existing transition curve of hydraulic cylinder. Fourth, in the Design Opt module of ANSYS software, the total volume of hydraulic cylinder was objective function, geometric parameters of transition zone were design variables, the largest Von Mises stress of the hydraulic cylinder were state variables. the optimal solution were found by a series of optimization. Through the optimization analysis, the authors listed the the main parameters value of transition curve. After analysis and comparison to the optimal solution, the result once again shows that the curve of the inner bias and arc and the curve of the double arc were better than the curve of single arc and the curve of outer bias and arc. Finally, using the Fatigue module of ANSYS software, hydraulic cylinder was loaded fatigue and durability analysis. The results show that two new curves of the transition zone had a good performance in fatigue durability and was suitable for the actual works.