Theoretical and Experimental Study on the Axial Oil Film Stiffness of Tilting Pad Thrust Bearings

Abstract

ABSTRACTTilting pad thrust bearings are a key component of marine propulsion shaft systems. The dynamic performance of thrust bearings has a significant influence on the propeller vibration. To investigate the axial oil film stiffness of tilting pad thrust bearings, a two-dimensional thermohydrodynamic model incorporating the vibration frequency is developed. The test apparatus and experimental identification model are also constructed. The axial oil film stiffness is experimentally identified at different speeds, loads, and temperature employing the hammer impulse excitation. The axial oil film stiffness between theoretical and experimental results is compared. The discrepancies are not more than 7% for 30 kN operation cases but increase with axial static load. This is partially because the influence of the pivot stiffness becomes obvious with the axial static load increase and cannot be ignored. The results indicate that axial oil film stiffness is at a magnitude of 109 N·m−1. Compared to foundation stiffness of the thrust bearing system, the influence of axial oil film stiffness needs to be considered for bearing–rotor system design of marine propulsion systems in engineering practice.