GB642636A - Improved means for damping torsional vibration in rotary shafts - Google Patents

Abstract

642,636. Torsional vibration-dampers. BARCLAY, CURLE, & CO., Ltd., McNEE, J. B. July 29, 1948, No. 20219. [Class 108(iii)] In a power transmis sion of the kind ir which a rotary shaft is connected to at least two bodies due to which torsional vibration is set up in the shaft, a torsional vibration damper comprises a vaned component secured to the rotary shaft and a heavy vaned component that is freely rotatable in relation to the shaft, the damper containing hydraulic fluid and the components being so associated that each in turn acts on the fluid as an impeller, while the other serves as a follower. In the arrangement shown, as applied to a marine propulsion unit an extension 23 at the free end of a crankshaft 14 carries an external vaned component 25, 26 which is rigid with the extension 23 and within which is housed a freely rotatable double vaned weighted component 28. Hydraulic fluid such as oil is admitted to the damper through inlet ports (not shown) on the external component 25, 26. In a modification, (Fig. 3, not shown), the external component, which is weighted and freely rotatable relative to the shaft is provided with a single set of vanes which cooperate' with similar vanes on an internal component rigid with the shaft: The external component is journalled on the shaft extension which is hollow, and on an extension of the internal component, into which hydraulic fluid is admitted through a port or ports communicating with a part of the hollow extension. Fluid is supplied to the hollow extension through a central duct in the shaft.