US Patent 7798936 8-speed transmissions

The transmission has a plurality of members that can be utilized in powertrains to provide eight forward speed ratios and one reverse speed ratio. The transmission includes three planetary gear sets having six torque-transmitting mechanisms, one fixed interconnection and a grounded member. The powertrain includes an engine and torque converter that is continuously connected to one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members, and the transmission housing, and are operated in combinations of three to establish eight forward speed ratios and one reverse speed ratio.