Paper 15: Experience with E.P. Turbine Oil

Abstract

This paper briefly describes early unsuccessful attempts to produce an e.p. turbine oil based on an active sulphur e.p. additive, and describes experience with a successful oil based on chlorinated paraffin wax. Anti-scuffing capacity is discussed, particularly in relation to conditions of shock loading and running time. The effect of the oil on increasing plastic flow in soft gears, and thereby on pitting, is also examined. After discussing the demulsibility of oils in service, chemical effects are described in detail; namely, staining caused by the formation of β-FeO. OH deposit formation due to overheating of bulk oil and due to the overheating in thin films exposed to air. The latter relates to severe shaft damage owing to the formation of carbonaceous matter in bearing pedestal baffles, and recommendations are made towards design. The paper concludes with experiences of the wire-wool type failure of turbine thrust bearings, and present details of the oil/steel interactions found in the course of extensive full-scale rig work on the problem.