Method and apparatus for cooling a high pressure compressor of a gas turbine engine

Claim 1

A gas turbine jet engine comprising a high pressure compressor including a rotor and a plurality of rotor discs secured for rotation with the rotor, each disc having an outer periphery and a plurality of rotor blades secured thereto, said blades having respective feet secured in said disc at said periphery thereof, said rotor comprising a hollow shaft including a conical section downstream of the last rotor disc of the high pressure compressor and means for cooling the high pressure compressor by supplying cooling air from a low pressure compressor, characterized as follows: (a) a conical heat shield surrounding said conical section of the rotor to define a hollow, annular space therebetween, said heat shield having an upstream end connected to the last rotor disc of the compressor radially outwards of the conical section, (b) said hollow shaft being provided with circumferentially distributed holes through which cooling air coming from the low pressure compressor can flow into said hollow annular space; (c) said last rotor disc of the high pressure compressor being provided with holes proximate the outer periphery of the disc through which cooling air in said hollow space can flow; (d) said annular heat shield covering the entire region at which the feet of the blades ar o secured in the last rotor disc said heat shield including a portion which extends radially outwards of the feet of the blades.

Claim 9

A method of cooling the downstream rotor discs of a multistage high pressure compressor comprising supplying cooling air to a high pressure compressor in a direction headed downstream of successive rotor discs of the compressor, reversing the direction of flow of a portion of the cooling air leaving the compressor so that the reversal portion flows upstream towards the last rotor disc of the compressor, conveying the reversed portion of the cooling air in an enclosed annular region surrounding a conical portion of a shaft of the rotor secured to the last rotor disc, said reversed portion of the cooling air flowing radially outwards towards the periphery of the last rotor disc, and conveying the flowing cooling air through holes formed in said last rotor disc along a circulating path between the last rotor disc and the next rotor disc adjacent thereto to combine with fresh cooling air supplied to the compressor.

Claim 10

A method of cooling the downstream rotor discs of a multistage high pressure compressor comprising supplying cooling air to a high pressure compressor in a direction headed downstream of successive rotor discs of the compressor, reversing the direction of flow of a portion of the cooling air leaving the compressor so that the reversal portion flows upstream towards the last rotor disc of the compressor, conveying the reversed portion of the cooling air in an enclosed annular region surrounding a conical portion of a shaft of the rotor secured to the last rotor disc, said reversed portion of the cooling air flowing radially outwards towards the periphery of the last rotor disc, and conveying the flowing cooling air through holes formed in said last rotor disc along a circulating path between the last rotor disc and the next rotor disc adjacent thereto to combine with fresh cooling air supplied to the compressor.