FIGURE 1 Brake and gear train schematic. Moments of inertia I

In summary, the kinetic energy to be dissipated from a geared system may be written as

(2-4)

for moments of inertia Ii rotating at speeds ratios ni1 relative to shaft 1, where the brake is located.

For simplicity the moment of inertia of most rotating mechanical components is often given in terms of the radius of gyration rg, which is defined by

(2-5)

where m=W/g in terms of the weight of the component and the acceleration due to gravity, usually taken as 32.2 ft/sec2 or 9.81 m/sec2.