Inner bearing block of an exhaust gas turbocharger

The passages (44, 45, 46) for all operating media, such as cooling air, lubricating oil or cooling water from the external bearing housing (30) to the rotor block of an exhaust gas turbocharger are oriented axially and advantageously executed within an interface. This reduces the risk of incorrect assembly compared to radially separated passages. If all passages are realized within an interface (A), the time required for assembly of the rotor block is reduced compared to passages distributed across multiple interfaces.