Investigations of Lubrication Characteristics of Dimpled Seal-type Thrust Bearings by Experiments under Fixed Applied Load and Fixed Fluid Film Thickness Conditions

Abstract

The lubrication characteristics of seal-type thrust bearings with dimples on the lubricating surface were experimentally investigated. Circular and two types of fan-shape dimples were etched on the stationary specimen of the bearings. A plane (dimple-free) bearing were also tested for comparisons. In the experiments, the test results obtained by measurements with a fixed fluid film thickness were compared to those by the general measurements with fixed applied load, and their validities were clarified. The fluid film force, frictional torque, and fluid film thickness were measured in both types of test devices. In addition, the lubricating surface were visualized during experiments. As the results, the oil film force of the circular dimple was about three times larger than that of the fan-shaped dimples, and the frictional torque of the circular dimple was also slightly smaller. The measurement results obtained by both types of test devices were in good agreement, including with cavitation phenomena, and the validity of the measurement method with a fixed fluid film thickness was confirmed.