Engine with exhaust energy recovery device and generator device for use with the engine.

摘要

An engine is composed of an exhaust turbine rotatable by the exhaust energy of an exhaust gas discharged from the engine, a generator coupled to the exhaust turbine, and a motor drivable by the generator. The energy recovered from the exhaust gas by the exhaust turbine is fed back to an output shaft of the engine through the generator and the motor. The engine may have a second exhaust turbine located downstream of the first-mentioned exhaust turbine in an exhaust passage for driving an intake air compressor. The exhaust gas may be introduced directly into the second exhaust turbine by a bypass passage. In a generator device used with the engine, the generator includes a rotor shaft coupled coaxially with a turbine wheel shaft of the exhaust turbine. The turbine wheel, the wheel shaft, and the rotor shaft are constructed of ceramics preferably as an intergral structure. The rotor shaft is rotatably supported by oil floating bearings. On the rotor shaft, there is mounted a magnet rotor of a rare earth metal kept in position by holder plates held against opposite axial ends of the magnet rotor. A carbon wire is coiled around the magnet rotor. Alternatively, a magnet housing is mounted on the rotor shaft and comprises a plurality of housing members held axially together, and a magnet of a rare earth metal is accommodated in recesses in each pair of housing members.