GB1215300A - Improvements in rotor discs for bladed rotors - Google Patents

Abstract

1,215,300. Turbines; centrifugal and axial flow compressors. ROLLS-ROYCE Ltd. Oct.17, 1968 [July 19, 1967], No.33243/67. Headings F1C and F1T. A rotor disc for a turbine, fan or compressor comprises an annular axially extending slotted rim 12, Fig. 1, to which blades 2 are attached, and at least two webs 8, 10 extending radially inwardly from the rim to resist centrifugal loads. In the arrangement shown, the blades 2 are fan blades of a gas turbine ducted fan engine and each blade has a dovetail root 4 engaging an axial slot 13 in the rim 12, a lug 24 retaining the blade axially. The rotor disc is supported by an integral annular member 18 bolted at 16 to frusto-conical members 14, 34, the latter being bolted at 15 to an intermediate compressor. The webs 8, 10 may diverge slightly towards the rotor axis. In a modification, Fig.3 (not shown), the webs are thickened at their inner edges (26, 28), whilst in Fig. 5 (not shown), the webs are connected at their inner edges by an annular member (33) to form a closed box section. In a further modification, Fig.4, three webs 8b, 9b, 10b are provided, the webs being aligned with the centres of mass of portions of the blade of mass proportional to the thickness of the respective web, as indicated by dividing planes X-X, Y-Y. Four webs may be provided. As well as the axial flow machines described, the construction can also be applied to a centrifugal compressor. (For Figures see next page)