Patent ID: 7686731
Filing Date: 2010-03-30
Classification: F16H

Abstract:
1. A multi-speed transmission comprising: an input shaft; an output shaft; first, second, third and fourth planetary gear sets each having first, second and third members; said input shaft being continuously interconnected with at least one member of said planetary gear sets, and said output shaft being continuously interconnected with another member of said planetary gear sets; a first interconnecting member continuously connecting said first member of said first planetary gear set with said first member of said second planetary gear set, said first member of said third planetary gear set and said first member of said fourth planetary gear set; a second interconnecting member continuously connecting said second member of said first planetary gear set with said second member of said second planetary gear set; a third interconnecting member continuously connecting said third member of said second planetary gear set with said second member of said fourth planetary gear set; a first torque-transmitting mechanism selectively connecting a member of said third planetary gear set with a member of said first, second, third or fourth planetary gear set which is continuously connected with said input member; a second torque-transmitting mechanism selectively connecting a member of said second planetary gear set with a member of said third planetary gear set; a third torque-transmitting mechanism selectively connecting said second interconnecting member with a stationary member; a fourth torque-transmitting mechanism selectively connecting said first interconnecting member with said stationary member; a fifth torque-transmitting mechanism selectively connecting said third interconnecting member with said stationary member; a sixth torque-transmitting mechanism selectively connecting a member of said third planetary gear set with said stationary member; a seventh torque-transmitting mechanism selectively connecting a member of said fourth planetary gear set with said stationary member; said torque-transmitting mechanisms being engaged in combinations of two to establish at least eight forward speed ratios and at least one reverse speed ratio between said input shaft and said output shaft.