AIR SUPPLY UNIT FOR A FUEL CELL

摘要

The invention relates to an air supply unit (14) for a fuel cell (2), comprising a compressor (16), an electric drive unit (17) for driving the compressor (16) and a turbine (27). Said compressor (16) comprises a compressor wheel (21) and the electric drive unit (17) comprises a housing (24) in which a rotor (23) is rotationally mounted by means of a bearing unit (25). The turbine (27) comprises a turbine wheel (33) and the compressor wheel (21), the rotor (23) and the turbine wheel (33) are connected together in a rotationally fixed manner. According to the invention, the compressor (16), the rotor (23), the turbine (27) and the bearing unit (25) are designed in such a manner that a rotational characterisitic RoK defined according to formula (I) wherein vv = speed characteristic of the compressor; vT = speed characteristic of the turbine; DKR = speed characteristic of the bearing unit and VRV = speed characteristic of the rotor in the nominal point of air supply unit (14) lies in a defined range.