Family of multi-speed transmission mechanisms with three planetary gear sets and a stationary member

摘要

The family of transmissions has a plurality of members that can be utilized in powertrains to provide at least seven forward speed ratios and one reverse speed ratio. The transmission family members include three planetary gear sets having six torque-transmitting mechanisms and two fixed interconnections. Also, one planetary gear member is continuously connected with the transmission housing. The powertrain includes an engine and torque converter that is not continuously connected to any of the planetary gear members and an output member that is continuously connected with at least one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members and with the input shaft, output shaft, and transmission housing, and are operated in combinations of three to establish at least seven forward speed ratios and one reverse speed ratio.