Effect of a biphase lubricant on half-frequency whirl in a full journal bearing

This investigation established the fact that a liquid-solid biphase lubricant can control the eccentricity of half-frequency whirl in a full journal bearing. The biphase lubricant consisted of Teflon particles of selected sizes suspended in varying concentrations in a conventional liquid lubricant. An analytical treatment of the problem yielded equations of motion which were solved numerically on a digital computer to give the orbit of the journal center relative to the bearing center. These equations of motion were obtained by equating the product of the shaft mass and the acceleration of the shaft center of gravity to the shaft forces caused by the fluid film, the shaft weight, and the crushing action of the Teflon particles. The experimental investigation obtained positive verification of the merits of a liquid-solid biphase lubricant as a whirl controlling agent. The tests were made in a shaft-and-bearing device that was constructed to isolate the whirl phenomenon. Agreement between analytical and experimental result was generally good. The overall results indicated that a liquid-solid biphase lubricant possesses an excellent whirl eccentricity control mechanism.