GB876862A - Improvements in or relating to bearing lubrication - Google Patents

Abstract

876,862. Lubricators. ROLLS-ROYCE Ltd. March 11, 1960 [March 11, 1959], No. 8497/59. Class 12 (3). A bearing lubrication system for a gasturbine engine in which the lubricating fluid is contained in a first chamber formed within the rotatable structure of the engine and discharged from the chamber upon rotation of said structure so as to pass through the bearing into a second rotatable chamber, said lubricating fluid passing from said second chamber into said first chamber when the rotatable structure becomes stationary. The first chamber is located below the second chamber and the second chamber is located below the bearing. Mounted within a compressor rotor shaft 14 is a hollow tube 23 supported at portions 14a, 14b of the shaft 14. The tube 23 has apertures 23a, 23b, the former being connected to an annular chamber 13a via radial holes 14d and the latter being connected to the second chamber 24c via radial holes 14f and apertures 24d. The lower end of the tube 23 is mounted by a radially-spaced tube 26 to form an annular passage 27 extending into a chamber 27a, and is closed by an end wall 26a. The chamber 27a is connected to a lower bearing 21 via radial holes 14g and an annular space 29 formed between a shaft 20 and a sleeve 30. The shaft 20 has radial holes 20b connected to the inside of the tube 23 via ports 14h in the portion 14b and ducts 26c and connected to an annular chamber 31 by ports 31a. An oil inlet tube 32 is mounted in the end wall 26a of the tube 26 and forms the first chamber 33. To lubricate the bearings 13, 21, oil is injected through the tube 32 prior to the starting of the engine and it flows down the tube 23 into the chamber 33. The engine is then started, the shafts 14, 20 rotate and the oil is centrifugally-forced up the tube 23 and up the annular space 27. The oil passes through the apertures 23a the radial holes 14d into the annular chamber 13a and then through the bearing 13, after which the oil is collected in the chamber 24c where it is centrifuged on to the wall 24b thereof. The oil flowing up the annular space 27 passes to the bearings 21 via the chamber 27a, the radial hole 14g, the annular space 29 and a space between the sleeve 30 and the shaft 20. The oil is collected in the chamber 31 and is held therein by centrifugal force. When the engine is stopped the oil returns to the first chamber 33, a conical baffle 23c deflecting the oil towards the wall of the tube 23. The tubes 23, 26 are tapered upwardly and outwardly to permit centrifugal forcing of the oil therethrough, alternatively an Archimedean screw may be used.