| 摘要 |
A turbine engine having interior cavity (73) sealed by a thermally controlled valve (80) is disclosed. The cavity (73) is defined by at least one cylindrical wall portion (74). The valve comprises an opening (82) in the cylindrical wall portion and a cylindrical band (83), coaxial and interior to the wall portion. The cylindrical (83) band is made of material having a higher thermal coefficient of expansion than the wall portion. As the temperature of the engine increases, the band (83) expands at a higher rate than the wall (74), thereby sealing the valve. As the temperature decreases, the band contracts thereby opening the valve. The valve may be used to permit a cavity to be pressurized at low temperatures. The pressure in the cavity may exert a forward load on a thrust bearing, suspending the engine shaft.
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