Patent ID: 7963876
Filing Date: 2011-06-21
Classification: F16H

Abstract:
1. A multi-speed transmission comprising: an input member and an output member; a first planetary gear set having a first, a second, and a third member; a second, a third, and a fourth planetary gear set having a fourth, a fifth, a sixth, a seventh, and an eighth member which rotate in fixed relation to one another; wherein at least two of the second, third and fourth planetary gear sets intermesh as a compound planetary gear set; wherein the first member is continuously grounded to a stationary member; wherein the third member is continuously connected for common rotation with the input member; wherein the seventh member is continuously connected for common rotation with the output member; and six torque-transmitting mechanisms selectively engagable in different combinations to establish at least seven forward speed ratios and a reverse speed ratio between the input member and the output member; wherein said at least seven forward speed ratios include a first, a second, a third, a fourth, a fifth, a sixth, and a seventh forward speed ratio from highest to lowest numerical speed ratio; and wherein one of said six torque-transmitting mechanisms is selectively engagable to ground the fifth member to the stationary member and is engaged only in the seventh of said first, said second, said third, said fourth, said fifth, said sixth, and said seventh forward speed ratios.