Groove parameters were determined to maximize the stability of herringbone-grooved journal bearings. Parameters optimized were groove depth, width, length, and angle Optimization was performed by using a small-eccentricity, infinite-groove analysis in conjunction with (1) a previously developed Newton-Raphson procedure for bearings with the smooth member rotating or with the grooved member rotating at low compressibility numbers and (2) a newly developed vector technique for bearings with the grooved member rotating at high compressibil¬ity number s. The design curves in this report enable one to choose the optimum bearing for a wide range of operating conditions. These include (1) compressibility numbers from 0 (incom¬pressible) to 80, (2) length-to-diameter ratios from 1/4 to 2, and (3) rotation of the smooth or grooved member. Compared with bearings optimized to maximize load capacity, bearings optimized for stability (1) allow a thousandfold increase in bearing-supported mass in some cases before onset of instability (the most pronounced increases are for bearings with small length-to-diameter ratios operating at high compressibility numbers) and (2) lose no more than 77 percent of their load capacity in any case studied. Stability is much greater when the grooved member rotates.
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