Marine bearing assembly

Abstract

A marine bearing assembly for a propeller shaft suitable for a vessel which travels in intensely cold seawater where a conventional bearing, as a result of its contraction, would seize the shaft and prevent it from rotating. The assembly includes a cylindrical body having an axial bore therein to receive the rotating shaft, the body being formed of UHMW polyethylene having a low coefficient of friction and a high coefficient of thermal contraction. To complete the assembly, the body is exposed to a temperature below the freezing point of water to cause it to contract. The contracted body is then press-fitted into a sleeve whose internal diameter matches the contracted diameter of the body, whereby at higher temperatures the body seeks to expand, but being confined within the sleeve it is held under compression. When the vessel in which the assembly is installed enters cold seawater, the UHMW body does not contract about the propeller shaft but contracts away from the sleeve in which it is confined and is therefore under reduced compression whereby the diameter of the axial bore is not significantly altered and the shaft remains free to rotate.

Dependencies are inferred from the claim text.