GB871110A - Supporting structure for a gas turbine bearing - Google Patents

Abstract

871,110. Gas turbine engine bearing supports. BRISTOL SIDDELEY ENGINES Ltd. Oct. 1, 1957 [Nov. 1, 1956], No. 33348/56. Class 110(3). A gas turbine bearing support structure comprises a number of circumferentially-spaced, radially-disposed load-bearing members which are connected at their radially outer ends to the outer wall of an annular gas flow passage of the turbine, the members extending radially inwardly across the gas flow passage and through apertures in the inner wall of the gas flow passage, the radially inner ends of the members supporting the turbine bearing at points spaced inwardly from the inner wall of the gas flow passage and the members transmitting the radial loads on the bearing to the outer wall of the gas flow passage, the inner wall being secured to the members so as to be carried thereby. The invention is shown applied to the rear bearing 16 of a gas turbine engine, the rotor disc 10 of which is provided with an axial extension 17 and is mounted on a hollow shaft 15. The inner race of the bearing is secured on the extension 17 by means of a nut 18. The outer race of the bearing is located in a cap-shaped member 20 which is provided with an annular flange 21, a cap member 22 being secured by bolts to the cupshaped member. Two sealing-plates 23, 24 are sprung on to the bearing assembly to afford a chamber to which cooling medium, such as air bled from a compressor is fed through ducts 25 which communicate with the interior of the hollow shaft 15. A series of strut members 26 in the form of faired vanes are secured to the outer wall 13 of the turbine diffuser 12 and extend radially inwardly across the diffuser and pass through correspondingly-shaped openings in the inner wall 14 of the diffuser, being secured to the inner wall also by welding at 27. The inner end of each vane 26 terminates in a lug 28, the plurality of lugs lying against the annular flange 21. The flange is provided with a circumferentially-spaced series of tongues or pegs 29 which engage in a series of slots 30 formed in each of the lugs 28, the tongue and slot connections being adapted to transmit radial loads between the flange 21 and the vanes 26. The flange 21 is also secured to the lugs 28 by means of bolts passed through clearance holes, whereby they transmit only end loads on the bearing. The flange 21 functions as an intermediate supporting-member between the struts 26 and the bearing.