Numerical Study of the Sensitivity of Tilting-Pad Journal Bearing Performance Characteristics to Manufacturing Tolerances: Dynamic Analysis

In engineering practice, the predictions of bearing steady state and the dynamic characteristics are based on the bearing nominal dimensions. However, as the authors showed in a previous study (Fillon, et al. (1) Fillon, M., Dmochowski, W. and Dadouche, A. 2007. Sensitivity of Tilting Pad Journal Bearing Performance Characteristics to Manufacturing Tolerances. Trib. Transactions, 50: 387–400. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]), manufacturing tolerances related to the bearing geometry (e.g., bearing clearances or angular pivot position) can significantly affect the steady-state characteristics such as the operating temperature, the minimum film thickness, and the power loss. This paper investigates changes to the bearing dynamic properties due to variations of the design parameters within the manufacturing tolerances. The dynamic properties of the tilting-pad journal bearings are represented by eight linear coefficients of stiffness and damping.

The study presents results obtained for realistic variations of bearing clearance, preload, pivot offset, as well as the pad angular extension. As an example, five-pad tilting-pad journal bearings with a diameter of 76.2 mm (3 in.) and three different L/d ratios have been used.