Patent GB-961522-A (GB)
Title: Bearing assembly
Inventor: ROBINSON NORMAN ROBERT
IPC: F01D25/18
Filed: 1963-01-09
Abstract: 961,522. Gas turbine plant. ROLLS-ROYCE Ltd. April 4, 1963 [Jan. 9, 1963], No. 1087/63. Heading FIG. [Also in Division F2] A bearing assembly comprises an outer race mounted in a first member; an inner race mounted within said outer race and spaced therefrom by balls or rollers; a second member mounted in the inner race, said first and second members being relatively rotatable; first duct means through which lubricant may pass to cool the inner and outer races; second duct means through which lubricant may pass to the balls or rollers to effect lubrication thereof; and means for supplying the first and second duct means with lubricant from a common source. In an embodiment, a gas turbine engine has a shaft 10 having a compressor and turbine, (not shown) mounted thereon and having a shaft 11 concentrically mounted therein. The shaft 11 has a low pressure compressor and a low pressure turbine (not shown) mounted thereon. The shaft 10 is mounted in a ball bearing 13, having races 12 and 15, the outer race 15 of which is mounted within annular members 16, 17, which are secured to each other and to a fixed structure 20. The shaft 11 has a lubricant supply pipe 21 therein which supplies, by means of centrifugal force and a passage 23, a space 22 located between the shafts 10, 11. A sleeve 24, Fig. 3, having a number of angularly spaced apart pockets 25 therein, is mounted within the shaft 10 so that the lubricant can pass from the space 22, through the pockets 25 and drillings 26 to passages 27 which lead to axially-extending grooves 30 which serve to cool the inner race 12. The outer ends of the grooves 30 communicate by means of drillings 32 with annular chambers 33, 34. The annular members 16, 17 have slotted portions 35, 36, Fig. 2, having slots 37 therein so as to meter the flow of lubricant from the drillings 32 to ducts 40 which lead to the ball bearing 13. Lubricant passes from the bearing 13, through ducts 41 and through drillings 42, 43 in the members 16, 17 respectively, and into the chambers 33, 34 respectively, from where it passes directly to a scavenge passage 44 from the chamber 34 and via a passage 45 from the chamber 33. The outer race 15 of the bearing 13 has grooves 47 therein which are supplied with lubricant from a conduit 50 by way of conduits 51-54 so as to cool the outer race. The lubricant is conveyed from the grooves 47 to the scavenge passage 44 via drillings 43a and the chamber 34. The shaft 11 is mounted in a sleeve 56 which constitutes an inner race of ball bearings 57, 58 having outer races 60, 61 mounted in a sleeve 62, the latter being mounted in the shaft 10. The sleeve 62 carries a frusto-conical member 63, Fig. 4, having holes 66 therein and lubricant is passed from the interior of the shaft 11, to the member 63 via drillings 64 in the shaft 11 which communicate with the pipe 21 by means not shown. The member 63 is formed with scoops 65 which direct a portion of the lubricant to the bearings 57, 58, after which the lubricant passes through drillings 74 in the shaft 10 to the chamber 33 and finally via the passage 45 to the scavenge passage 44. Some of the lubricant which has passed through the drillings 64 is centrifuged up the member 63, through the holes 66 and into an annular chamber 70 from where it passes via drillings 71 to groove 72 to cool the outer race 60 and then through grooves 73 to cool the outer race 61. The lubricant then passes in the chamber 33 via drillings 74 in the shaft 10. In a modification, the slotted portions 35, 36 of the members 16, 17 are omitted.