Patent ID: 7291086
Filing Date: 2007-11-06
Classification: F16H

Abstract:
1. A six-speed powertrain of an automatic transmission, comprising: a first planetary gearset having operational elements of a first sun gear, a first ring gear, and a first carrier; a second planetary gearset having operational elements of a second sun gear, a second ring gear, and a second carrier; a third planetary gearset having operational elements of a third sun gear, a third ring gear, and a third carrier; a fourth planetary gearset having operational elements of a fourth sun gear, a fourth ring gear, and a fourth carrier; an input shaft; an output gear; and a transmission case, wherein: the first ring gear is fixedly connected to the third carrier and the fourth ring gear; the first carrier is fixedly connected to the fourth carrier; the second carrier is fixedly connected to the third ring gear; the second ring gear is always stationary by being fixedly connected to the transmission case; the third sun gear always acts as an input element by being fixedly connected to the input shaft; the third carrier always acts as an output element by being fixedly connected to the output gear; the fourth sun gear is variably connected to the input shaft via a first clutch; at least one of the fixedly connected first and fourth carriers is variably connected to the input shaft via a second clutch; the first sun gear is variably connected to the second sun gear via a third clutch; at least one of the fixedly connected first and fourth carriers is variably connected to the transmission case via a first brake and is subject to a stopping operation of the first brake; and the first sun gear is variably connected to the transmission case via a second brake and is subject to a stopping operation of the second brake.