A Novel Design for High Performance Drive Screw Systems

Abstract

Drive screw systems are used as linear actuators in a wide variety of machines. For traditional design of drive screw systems, critical speed vibrations limit the maximum output stroke (overall length of travel) attainable for a given screw pitch, diameter and required output speed. This paper discusses a new design and presents performance results of a working apparatus to overcome the critical speed limitations in drive screw systems. The solution approach utilizes a series of sets of nested mobile supports to minimize the critical speed vibrations. The mobile supports are rigidly connected in pairs, and are automatically positioned in proper locations to minimize the effective unsupported length of the drive screw. This in turn, reduces the drive screw vibration amplitudes. The solution method presented will theoretically permit operation of a drive screw system under any combination of diameter, length, and rotational velocity, without restriction due to critical speed vibrations. The proposed solution has been tested and has proven effective in an industrial setting.