Bearings

Bearing Life

Rolling-bearing rating life per ISO 281 / ABMA 9 and 11 as presented in Shigley's Mechanical Engineering Design, Chapter 11: the equivalent radial load from the radial and axial loads (Table 11-1 factors interpolated for ball bearings, catalogue X, Y, e for tapered and spherical rollers, the Timken induced-thrust rules for a tapered-roller pair, or the cubic-mean load of a duty cycle), the basic rating life L10 in revolutions and hours, the Weibull reliability adjustment (life at the design reliability, median life, reliability at a chosen life), the catalogue rating C10 required for a design life and reliability with an application factor, the reliability and life of a two-bearing system, and the ISO 281:2007 modified rating life from the viscosity ratio, the contamination factor and the fatigue load limit. The default case is Shigley's Example 11-3, the SKF 6210 angular-contact bearing under 500 lbf radial and 400 lbf axial load at 720 rev/min, whose printed F_e = 890.8 lbf and L10 = 16 150 h the page reproduces.

1 worked example reproduced, listed on the tool page.

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Shafts · Gears · Springs · Fasteners and Power Screws · Pressure Vessels · Tolerances · Mass Properties · Vibration · Acoustics · Brakes, Clutches and Belts · Machining and Manufacturing · Lubrication and Wear