Arrangement of engine, motor-generator and planet gears

摘要

The invention provides an arrangement of an internal combustion engine and an electrical machine 10 which can operate both as a motor driving the engine to rotate and as an electrical power generator receiving drive from the internal combustion engine. The arrangement comprises an epicyclic transmission 13 via which drive is transmitted. The transmission has a first operating mode in which drive is transmitted from the electrical machine 10 to the internal combustion engine and a second operating mode in which drive is transmitted from the internal combustion engine to the electrical machine 10. Two different gear ratios are provided, one for each mode of operation. The arrangement typically has two one-way clutches C1, C2 and two rings of planet gears, one ring being of inner planet gears (21 see fig 2) which mesh with outer planet gears (22 see fig 2). This epicyclic arrangement may be for a vehicle and may provide a reduction ratio of 5:1 to allow for the relatively high speed of the electric machine 10.