EFFECT ANALYSIS OF DIMENSIONAL TOLERANCES ON THE DYNAMIC CHARACTERISTICS OF HYDRODYNAMIC JOURNAL BEARING SYSTEM

According to the exist of dimensional tolerances on hydrodynamic journal bearing system, a nonlinear oil film force model was developed, emphasis on the different dimensional tolerances in the system, the tolerances of dynamic viscosity, bearing width, bearing diameter and journal diameter along with its interaction effect to the dynamics characteristics of the hydrodynamic journal bearing system were analyzed. By using the eccentricity corresponding to the stability threshold velocity, the effects of the stiffness and damping coefficients, carrying capacity, system stability and friction power loss brought by the dimensional tolerances of the dynamic viscosity, bearing width, bearing diameter and journal diameter was quantitative analyzed. The results show that in contrast to the impacts of the tolerances in bearing diameter, dynamic viscosity and bearing width, the journal diameter tolerance would lead to a negative effect, and the dimensional tolerances have different degrees of impacts on the journal bearing system. The energy decreased as the eccentricity increased, when the eccentricity is 0.6948 the friction energy reach to a minimum. It provides a theoretical basis to select reasonable parameter, find the best solution and control varieties of nonlinear dynamical behavior.