Patent ID: 6035627
Filing Date: 2000-03-14
Classification: F02C,F04D

Abstract:
A turbine engine comprising a casing; a compressor section within the casing having a centrifugal impeller including an impeller tip and a diffuser surrounding the impeller tip, whereby P3 pressurized air exits from the diffuser; a turbine section; a shaft mounted for rotation about a central longitudinal axis connecting the impeller to the turbine section; a central bearing mounted to the casing downstream of the impeller and supporting the shaft; the impeller defining a rear cavity between the impeller and the turbine section and a cavity wall surrounding the rear cavity in the central bearing; means diverting a first stream of air from the impeller tip into the rear cavity; means for diverting a second stream of P3 air through a heat exchanger for cooling the second stream of P3 air; and means for passing the cooled P3 air from the heat exchanger to the rear cavity to mix with the first stream of air, whereby the temperature of the resulting mixed P3 air in the rear cavity is reduced at least to the point of improving the hub life of the impeller and eliminating the requirement of bearing seals for the central thrust bearing.