being provided with an inner housing hub which is configured so as to surround the protective surface facing the protective shaft jacket said rib extends in the circumferential direction protrudes from the circumferential surface and is disposed in the zone of the circumferential surface bordering the opening that faces the turbine the rib and or the inner housing hub is are fitted with cooling fluid ducts application_number US 98870906 A description an example of a gas turbine system 1 is shown in fig1 a and 1 b in a highly schematic form the gas turbine system 1 includes two silo combustion chambers 3 a turbine 5 a compressor 7 two mixer housings 8 and an inner housing 9 the silo combustion chambers 3 serve to burn a fuel with the hot pressurized exhaust gases 2 being ducted via the mixer housings 8 and inner housing 9 to the turbine 7 in order to drive it the turbine 5 includes stationary guide vanes 10 as well as rotor blades 11 permanently connected to a shaft 12 mounted rotatably around an axis a the hot exhaust gas 2 expanding in the turbine 5 causes an impulse to be conveyed via the rotor blades 11 to the shaft 12 which is thereby made to rotate the shaft 12 can be roughly divided into three sections namely a section bearing the rotor blades 11 of the.