On the Use of Taguchi Method in the Analysis of the Dynamic Response of Variable Bearing Design under Impact Load

Abstract

Optimizing the bearing design is an essential step to maintain safe operation and extend the bearing life. Taguchi method is one of the powerful methods in this direction, which can be used to assess the geometrical design parameters under shaft deviation. Shaft deviation is unavoidable in the industrial applications of journal bearing. It results from installation and manufacturing errors, bearing deformation, asymmetric loading, and many other sources. This work investigates the use of three bearing profiles with a wide range of geometrical characteristics to minimize the deviation negative effects. These designs modified the inner bearing surface in a linear, parabolic, or cubic shape. A general 3D deviation representation is considered in the analysis where the deviations in the horizontal and vertical directions are taken into consideration. The analysis is performed for a finite-length journal bearing using the Taguchi method to determine the optimal design characteristics. This analysis is achieved in terms of the rotor critical speed and the film thickness of the lubricant. Furthermore, the system response to an impact load is analyzed. The finite difference method is used in the analysis to solve the governing equations of the hydrodynamic problem, and the 4th-order Range Kutta solution is considered to solve the motion equations of the rotor under the impact load. Results show that using the suggested designs enhances the system’s critical speed, elevates the thickness of the lubricant layer, and extends the safe operation limits under impact load. The parabolic profile gives the most effective outcome where the shaft trajectory under impact excitation is very close to the ideal journal-bearing case. The suggested design reduces the maximum pressure by 17.07%, increases the minimum film thickness by 175.04%, and increases the critical speed by 23.42%.