GB736808A - Improvements in or relating to vibration dampers - Google Patents

Abstract

736,808. Torsional-vibration dampers. CROSET, L. P. Oct. 7, 1953 [Oct. 8, 1952; March 25, 1953], Nos. 25181/52 and 8161/53. Class 108 (3). A vibration damper for rotary shafts comprises a casing A formed by two portions 12, 13 (Fig. 1) united by two submerged circular butt welds 14, 15, an annular flywheel 11 being located in the casing which is filled with a silicone damping fluid, the casing having a reservoir 13g associated therewith and formed at least partially within a part of one of the portions 12, 13 which is nearer to the centre of rotation of the damper than the inner periphery of the flywheel. In Fig. 1, the reservoir 13g is formed by a groove turned in the casing, and it is connected by a restricted passage or passages 13m with the interior of the casing A. The reservoir 13g may however open directly into the casing A (Figs. 2 and 4, not shown). The member 13 has an inwardly directed mounting flange 13i. Lips of a thickness of a quarter to a third of the thickness of the radial portions of the members 12, 13, are formed on the member 12, at 12a, and on the member 13, at 13a. These lips distort during welding and prevent distortion of the operative part of the casing A. In a modification (Fig. 2, not shown), the outer face of the flange 13i, is coplanar with the outer axial face of the member 12. The lip 13a is then provided by turning a groove in the outer face of the flange 13i. The member 12 may be an annular disc (Fig. 4, not shown) which closes an annular cavity of channelshaped cross section provided by the member 13. A filling aperture 17 is provided at diametrically opposed positions (one only shown in Fig. 1). The aperture is sealed by welding 18. The flywheel 11 has bearing engagement at its inner periphery 11i, and at axially-projecting annular portions 11f. In the construction shown in Fig. 6, the bearing engagement is provided by bronze rings 16 rigid with the flywheel. The reservoir is provided at 13g, and a small volume is provided by the centre portion 11c of the inner periphery of the flywheel 11 being disposed slightly radially outwards of the bearing surfaces of the rings 16. A circumferential groove 11g, 16g is formed in the axial face of the flywheel 11 at the junction of each of the rings 16 and the flywheel 11 (Fig. 7). This groove is connected by peripherally-spaced radial grooves 16h with grooves 16k axially disposed in the peripheral bearing surfaces of the rings 16. These grooves are shaped to assist the drainage of salts when the flywheel 11 is lifted from an electrolytic zinc-plating bath. All the working surfaces of the casing A are also zinc plated. The casing may alternatively be secured together by nuts and bolts. The flywheel may be forged, flame cut, rolled, or centrifugally cast. The casing components may be steel pressings, stampings, or drop forgings, or may be steel or whitehart malleable iron, castings. For non-magnetic dampers, the flywheel may be of bronze, and the casing of aluminium. Specification 636,881 is referred to.