A NOVEL DESIGN FOR HIGH-PERFORMANCE DRIVE SCREW SYSTEMS

Drive screw systems are used as linear actuators in a wide variety of machines. For traditional design of drive screw systems, critical spee d vibrations limit the maximum output stroke (overall length of travel ) attainable for a given screw pitch, diameter and required output spe ed. 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 o f nested mobile supports to minimize the critical speed vibrations. Th e mobile supports are rigidly connected in pairs, and are automaticall y positioned in proper locations to minimize the effective unsupported length of the drive screw. This in turn, reduces the drive screw vibr ation amplitudes. The solution method presented will theoretically per mit operation of a drive screw system under any combination of diamete r, length, and rotational velocity, without restriction due to critica l speed vibrations. The proposed solution has been tested and has prov en effective in an industrial setting.