Patent ID: 8083630
Filing Date: 2011-12-27
Classification: F16H

Abstract:
1. A multi-speed transmission comprising: first, second, third and fourth planetary gear trains each having at least three members including a ring gear, at least one carrier, and a sun gear; a housing; an input shaft fixedly coupled to the carrier of the second planetary gear train and the ring gear of the first planetary gear train; an output shaft fixedly coupled to the carrier of the fourth planetary gear train and the ring gear of the third planetary gear train; a first link fixedly coupled to the carrier of the first planetary gear train and the carrier of the third planetary gear train; a second link and a third link fixedly coupled to the ring gear of the second planetary gear train and the sun gears of the third and fourth planetary gear trains; and six torque-transmitting mechanisms, each said torque-transmitting mechanism for selectively interconnecting at least one member of one of the planetary gear trains with at least one of the housing or other members of the planetary gear trains, the six torque-transmitting mechanisms being engaged in combinations of two to establish at least seven forward speed ratios and at least one reverse speed ratio between the input shaft and the output shaft.