Analysis of Dynamic Contact and Carrying Capacity Factors for Super-Modulus Pinion and Rack

Abstract

Jack-up platform jacking system which undertakes the weight of the platform and working load is very important during the lifting, and its performance exerts a direct influence on the safety and application effect of the whole platform. The super-modulus pinion and rack of jack-up platform jacking system are most likely to damage by fracture and fatigue pitting, which are due to the hostile environments. As a result of dynamic load, the analysis of dynamic contact has important engineering significance in an actual project. For strengthening the carrying capacity of pinion and shortening the design period, the research of carrying capacity factors is very meaningful. In this paper, the changing of stresses on the pinion and rack are gained by FEM, and main parameters that influence the carrying capacity of the pinion in a jacking system are analyzed according to the calculation method in GB standard. The study results shows the contact stresses and bending stress are higher throughout the meshing process, which implies the dangerous position of the pinion. In single meshing period, the trend of bending stress in the compression side of pinion and rack is opposite, while the bending stress in the tension side of both rack and pinion are minimum near the pitch circle. The carrying capacity of pinion can be strengthened by changing the main parameters, such as tooth width, normal modulus, pressure angle, modification coefficient, but the influence degree of each parameter is different.