Tribological performance of dimpled thrust bearings with phyllotactic patterns

• Phyllotactic pattern is introduced to position dimples on thrust bearing.
• Dimple thrust bearing presents better lubricating effect in friction experiments.
• Optimizing dimples area can improve frictional performance of thrust bearing.

This study explored a novel method of arranging lubricating dimples on the working surface of thrust bearings. Because these dimples influence the frictional performance of the thrust bearing, we performed experiments to measure the friction coefficient under various dimple arrangements and phyllotactic coefficients. The surface of the experimental thrust bearing was designed to hold CuZn25Al6Mn4 material, and dimples were positioned on the bearing surface in different patterns via mask electrolysis. For friction experiments, L-AN46(GB/T7631.13-1995) lubricant with kinematic viscosity of 41.4–50.6 mm2/s, −10 °C congealing point, and 180 °C flash point was used as the media. Low friction coefficient was achieved under reasonable phyllotactic parameters – a 27% maximum reduction in friction was achieved under optimal dimple pattern and phyllotactic parameters. We also compared the measured friction coefficients of our dimpled thrust bearing setup against those conventional linear patterns, and found that the proposed phyllotactic pattern showed better lubricating effect in the dimpled thrust bearing under normal load and normal frictional shaft rotation speed. Under various normal forces, average reductions of 16.8% and 15.7% in friction are achieved for the tested parameters at phyllotactic pattern.