GB677490A - Oil supply and scavenge system - Google Patents

Abstract

677,490. Gas turbine plant. MARCHANT, L. E. Aug. 9, 1950 [Aug. 19, 1949], No. 19825/50. Class 110(iii) [Also in Group XXXIV] In a lubricating system for the main shaft 10 of a gas turbine, an oil tank 1 is connected by a pipe 8 to a source of air pressure, such as a stage in the main engine compressor, and oil is fed by pipes 3 to the bearing housing 4 and is directed on to the bearings. A disc 13 having radial grooves, or alternatively radial corrugations, therein is secured to the shaft 10 between the bearings and projects between lips 15 into an annular space 16. The disc and annular space constitute a centrifugal pump returning the oil through a pipe 5 to the tank 1, oil circulation being maintained by the pressure difference between the tank 1 and the space 16, which difference remains substantially constant irrespective of engine speed. A non-return valve 18 in the pipe line 5 prevents air from the tank 1 escaping to the bearing housing when starting the engine, when the disc 13 is rotating as an unprimed pump. A non- return valve may also be inserted in the pipe 8 to prevent oil entering the compressor under conditions of negative G, and to maintain an oil supply under such conditions a stack-pipe (not shown) is provided extending from the outlet 2 into the upper part of the tank, a gravity-operated valve adjacent the outlet 2 by-passing the stack-pipe under positive G conditions.