NOVELTY - The apparatus (1) has an air compression system (2) with a vaned-rotor (11), an electric motor (3) driving the vaned-rotor, an air bearing assembly (17) guiding a shaft (12) of the motor, and an air thrust assembly (18) placed on the shaft. A fan (4) is placed at a side of the shaft and against the shaft on which the system is placed, where the fan has a vaned-rotor (26) placed in a reversed manner relative to the vaned-rotor (11). Transporting and evacuation conduits (5, 7) and transporting passages (6) distribute pressurized air generated by the fan towards the assemblies and the motor.    USE - Gas compression apparatus i.e. turbomachine, for use as a pressurized air supply source for a fuel cell or as a pressurized air generator in a ventilation system of an aircraft, and for driving a turbocharger assembly of the aircraft.    ADVANTAGE - The transporting and evacuation conduits and the transporting passages distribute pressurized air generated by the fan towards the air bearing assembly, air thrust assembly and the motor, thus offering optimal cooling of the apparatus, permitting cooling air to be at a temperature lower than that of the apparatus, and eliminating the need for an external air cooling unit, and hence permitting the apparatus to be simple in structure and presenting the apparatus with a reduced encumbrance, a reduced cost and improved reliability. The vaned-rotor of the fan is placed in the reversed manner relative to the vaned-rotor of the air compression system, thus counter-balancing a part of the axial thrust exerted on the shaft by the vaned-rotor of the air compression system, and hence reducing demands relative to the air thrust assembly and reducing overheating of the air thrust assembly. The apparatus has improved utilization and improved performance, and permits the air thrust assembly to be subjected to less axial effort.    DESCRIPTION OF DRAWING(S) - The drawing shows a longitudinal sectional view of a gas compression apparatus passing around an axis of a shaft of an electric motor.    Gas compression apparatus (1)    Air compression system (2)    Electric motor (3)    Fan (4)    Transporting conduit (5)    Transporting passage (6)    Evacuation conduit (7)    Vaned-rotors (11, 26)    Shaft (12)    Air bearing assembly (17)    Air thrust assembly (18)