Blade attachment

Claim 1

A high speed rotor comprising a small rotor disk and a plurality of small blades, said disk having an outer surface with a pair of spaced annular radial flanges extending therefrom, said annular radial flanges being a continuous circumferential extension from each side of the disk, each blade having a blade platform, each blade having a bottom surface below said platform with a pair of spaced root fingers extending therefrom, said root fingers having a flat surface overlapping and being bonded to a flat surface on said radial flanges, said platform extending forwardly and rearwardly over the annular radial flanges, said flanges and said root fingers being of such length that the bottom surface of the blade is spaced from the outer surface of the rotor disk a distance not less than about half the length of the blade, a circumferential passage being formed between the bottom surface of the blade and the outer surface of the rotor disk and the flanges and root fingers, said passage being sized to act as an insulator to restrict heat conduction from the blades to the disk, means for supplying a coolant through said passage, the length of said blades being approximately one inch or less, the root fingers being thin and tapered inwardly from said bottom surface and said radial flanges being thin and tapered inwardly as they extend from said outer surface, said thin flanges and fingers prOviding for axial deflection in response to growth due to the blades operating at a much higher temperature than the main body of the disk and reducing the heat flow into the disk.