Study On Dynamic Performance Of High-power Single Unit Commonwealth Eight-axle Locomotive

This paper mainly studies on dynamic performance of the eight-axis locomotive from the perspective of locomotive dynamics, preparing for theoretical basis to develop eight-axle locomotive. As the eight-axis locomotive driving shafts are many, with the axle arrangement different and the different patterns of locomotive traction, resulting in the structure of the eight-axle locomotive bogie various form. Selecting a good project of the bogie structure ensures that the bogie structural design is reasonable and ensures the locomotive fully exerts characteristics of the height of locomotive adhesion load, and ensures the locomotive is running with stability and smooth on the straight line and through the curve. The commonwealth bogie structure project with excellent dynamic performance is selected by analysis of inside and outside four-axis bogie and the experience of overseas operating instance.Mechanism analysis shows the mechanism of commonwealth bogie has sex degree of freedom in fact. Yawing and Lateral play of the wheel are closely correlation with lateral and longitudinal stiffness of guide post, primary suspension distance and primary lateral suspension stiffness etc. Locomotive adhesion load is the most influenced by traction height and the best adhesion load utility factor is up to 94.32%. The locomotive can fully exert characteristics of the height of locomotive adhesion load by designing rational draw gear. Dynamics emulation analysis indicates commonwealth locomotive is provided with upper stability, and non-linearity critical speed is up to 375km/h, and dynamic performance of locomotive running on the straight line and through the curve fulfils dynamic criterion. Studying on the influence of instructure parameters on dynamic performance makes chear commonwealth locomotive dynamic performance is greatly affected by lateral and longitudinal stiffness of guide post and primary lateral suspension stiffness. But whether primary longitudinal suspension stiffness is in gear or not, which is not fateful to dynamic performance, thereby achieving separate between primary longitudinal and lateral suspension stiffness and matching primary suspension parameters logically. Primary lateral suspension stiffness and primary suspension distance influence locomotive dynamic performance definitely, especially the effect of guide post to distribute wheel guiding effort. The smaller Primary lateral suspension stiffness and primary suspension distance, the guiding effort on two wheels is more well-proportioned.The investigation of this thesis indicates guide post play an important role in the commonwealth locomotive, which meets locomotion relation between bogie and guide post, and fills upper dynamic demand as well. Therefore the key is to design guide post for the commonwealth locomotive.