Patent ID: 7285069
Filing Date: 2007-10-23
Classification: F16H

Abstract:
1. A powertrain having a multi-speed transmission comprising: an input shaft; an output shaft; a transmission housing; a first planetary gearset having first, second and third members; a second planetary gearset having first, second and third members; a third planetary gearset having first, second and third members; a fourth planetary gearset having first, second and third members; seven torque-transmitting mechanisms; said first member of said first planetary gearset being continuously connected with said transmission housing; said second member of said first planetary gearset being connected with a first of said torque-transmitting mechanisms; said third member of said first planetary gearset being continuously interconnected with said input shaft and with said first member of said second planetary gearset; said second member of said second planetary gearset being selectively connectible with said second member of said first planetary gearset through said first torque-transmitting mechanism and selectively connectible with said input shaft through a second of said torque-transmitting mechanisms and continuously connected with said first member of said fourth planetary gearset; said third member of said second planetary gearset being selectively connectible with said housing through a third of said torque-transmitting mechanisms; said first member of said third planetary gearset being continuously connected with said second member of said fourth planetary gearset and selectively connectible with said transmission housing through a fourth of said torque-transmitting mechanisms; said second member of said third planetary gearset being continuously connected with said output shaft; said third member of said third planetary gearset being continuously connected with said third member of said fourth planetary gearset and selectively connectible with said input shaft through a fifth of said torque-transmitting mechanisms, and selectively connectible with said transmission housing through a sixth of said torque-transmitting mechanisms; said second member of said second planetary gearset and said first member of said fourth planetary gearset being selectively connectible with said transmission housing through a seventh of said torque-transmitting mechanisms; and said torque-transmitting mechanisms being selectively connectible in combinations of two to establish a reverse speed ratio and eight forward speed ratios between said input shaft and said output shaft.