Exhaust gas turbo charger

The exhaust gas turbocharger comprises a rotor block arranged in the interior of the housing shell with an inner bearing housing (30). A shaft (3) is rotatably mounted in the inner bearing housing. A radial gap (85) running along the circumference is provided in the transition area of two flow channels (82,83) between the inner bearing housing and a gas outlet housing (52). A blocking air duct (35) is provided in the inner bearing housing of the rotor block for sealing the radial gap, which originates on the compressor side of the inner bearing housing and opens into the radial gap.