Gear ratio changing method for hybrid vehicle, involves forming traction chain by heat engine, clutch and gear box, and clutching final ratio to separate synchronizer from gear when gearbox is synchronized with rate of final ratio

摘要

The method involves forming a traction chain by a heat engine (2), a clutch (3) and a gear box (7) connected to an electrical machine (4) and a wheel drive shaft (8). Synchronization of the gearbox is not ensured by the machine when a ratio change is carried out for passing from an initial ratio to a final ratio. The initial ratio is declutched to activate one of the synchronizers (63, 64) to synchronize the gearbox with a rate of the final ratio. The final ratio is clutched to separate the synchronizer from a gear when the gearbox is synchronized with the rate of the final ratio. An independent claim is also included for a control gearbox comprising a primary shaft.