Gear box for motor vehicle, has shaft filled with plastic material of density lower than that of material constituting shaft, where plastic material is compatible in thermal and chemical behavior, with hot oil contained in casing

摘要

The gear box has two shafts (1) e.g. input shafts, transmitting torque. One of the shafts is hollow and filled with plastic material (17) of density lower than that of material constituting the shaft. The plastic material is compatible in thermal and chemical behavior, with hot oil contained in a casing. The shaft comprises a hollow steel body (13) defining a cavity (14) inside the shaft. The cavity is filled with the plastic material i.e. thermo-deformable material among materials of Polyamide (PA) e.g. PA6, PA66, PA46, PA6T/PA66, and PA61, and polyphthalamide or polybutylene terephthalate. An independent claim is also included for a process for manufacturing a shaft.