INSTALLATION OF A HYDRAULIC KILN DRIVE TO ELIMINATE A RESONANT VIBRATION PROBLEM

Large, dual electromechanical drive systems have been shown to often e xperience vibration problems due to the high inertia of the components of these systems and the large number of resonant frequencies experie nced by these drives, Hydraulic drives, by comparison, are extremely l ow inertia drives that have fewer resonant frequencies and benefit fro m the damping characteristic of the hydraulic oil used to transmit pow er. Reducer Additional benefits include the ability to isolate compone nts while operating the drive and smooth speed control starting at ext remely low speeds and full rated torque, This paper outlines the vibra tion problems that were experienced in the dual drive of a 655-ft long with 52-ft and 19-ft diameter section rotary cement kiln between 1979 and 1993. A number of analytical and empirical studies were performed , and various modifications were made or considered, to reduce the vib ration in the drive train, Finally, in 1994 when the existing drive re ached the end of its life, it was replaced with a hydraulic system. Th e methods used and considered to reduce the vibration are discussed, a s web as the critical elements in deciding on a hydraulic drive, and t he design issues encountered including questions of drive efficiency, reliability, maintenance, and control Results to date of the hydraulic drive are discussed, including the elimination of the vibration probl em and added flexibility in speed control.