Multi-step planetary reduction gearbox for motor vehicle, has planetary gear trains selectively engaged with shafts so that various transmission ratios are produced between drive and driven shafts to realize forward and reverse gears

摘要

The gearbox has planetary gears (P1-P4), rotatable shafts (1-9) and shift elements comprising brakes (03,04) and clutches (15,28,57,79). The planetary gear trains are selectively engaged with respective shafts over brakes and clutches so that various transmission ratios are produced between drive and driven shafts (1,2) to realize seven forward and reverse gears. The sun and ring gears of planetary gear trains (P1,P4) are connected to respective shafts (3,4,5,6). The sun and ring gears of planetary gear trains (P2,P3) are connected to respective shafts (3,7,9,5).