Analysis and Verification of Design Concepts for a 7000-hp Ring Gear Driven Mill - Part II

Torsional steady-state and transient analysis and field test data relationships are discussed as applied to a 7000-hp dual-pinion ring gear drive system. Topics include estimates of frequencies, mode shapes, and modal damping parameters. Good agreement was obtained between predictions and test data when the motor air-gap stiffness was included in the analysis and 30 percent of the total charge inertia was taken as the effective charge inertia. Lifter excitation clearly did not contribute to dynamic torque.