Lubricating oil for ship propulsor bearings

Abstract

The present invention has its object to provide a lubricating oil for ship propulsor bearings which is high in bearing-damaging pressure, equivalent in lubricity and anticorrosiveness to the conventional mineral oil-based lubricating oils, higher in biodegradability than in the art and miscible with seawater. The present invention provides a lubricating oil for ship propulsor bearings which comprises a water-soluble alkylene glycol and/or polyalkylene glycol (A) with a number average molecular weight of not higher than 1,000 as a base oil as well as a water-soluble thickening agent (B) and a water-soluble anticorrosive agent (C) and in which the content of (A) is 80 to 98% by weight, that of (B) is 1 to 10% by weight and that of (C) is 1 to 10% by weight, relative to the weight of the lubricating oil for ship propulsor bearings and the bearing-damaging pressure at 50° C. is not lower than 3.5 MPa.

Dependencies are inferred from the claim text.