Improvements in cooling means for a multi-stage turbine

836,952. Cooling turbine rotors. GENERAL ELECTRIC CO. Jan. 31, 1958, No. 3251/58. Class 110 (3). A multi-stage turbine comprises at least two rotor discs carried by a shaft member, the rotor discs being interconnected at their peripheries by a spacer ring, a disc member being disposed between the rotor discs and carrying radially- and axially-extending vanes, coolant fluid being introduced into the space between adjacent rotor discs at one side of the vane-supporting disc and withdrawn at the other side. The turbine shown comprises three discs 12, the two upstream discs being mounted on shaft 10 for rotation therewith. The two downstream discs are interconnected adjacent their inner peripheries by a ring member 25 secured to the discs. A core member 11 is supported within the shaft 10 and ring 25 by means of baffle members 14. The rotor discs 12 are interconnected adjacent their outer peripheries by spacer rings 16. Disc members 21 are supported in the spaces between adjacent rotor discs 12, each disc having four radially- and axially-extending vanes 22 secured at its upstream side and similar vanes 28 secured at its downstream side. Cooling fluid such as air from a compressor is supplied through hollow shaft 10 and enters the space between the first two rotor discs through ports 19 in shaft 10 and discharges therefrom through ports 20, the flow of cooling air in the space being as indicated by arrows. The cooling fluid then enters the space between the second and third rotor discs through ports 26 in the ring member 25 and discharges therefrom through ports 29. The inner faces of the spacer rings 16 are formed with axially-extending fins 27, and the outer surfaces with circumferentially-extending ribs 18 which with stator parts form labyrinth seals. The vanes 22 are connected to the first stage rotor disc 12 by links 24.