Patent ID: 7914415
Filing Date: 2011-03-29
Classification: F16H

Abstract:
1. An automatic transmission comprising: an input shaft; an output shaft; a first planetary gear unit including a first sun gear that is always fixed, a first carrier supporting a first pinion in meshed engagement with the first sun gear and a first ring gear in meshed engagement with the first pinion; a second planetary gear unit including a second sun gear, a second carrier supporting the second pinion in meshed engagement with the second sun gear and a second ring gear in meshed engagement with the second pinion, with the first carrier and the second ring gear being connected to form a rotating member; a third planetary gear unit including a third sun gear that is always connected to the input shaft, a third carrier supporting a third pinion in meshed engagement with the third sun gear and that is always connected to the output shaft and a third ring gear in meshed engagement with the third pinion; a first friction element arranged to selectively stop rotation of the second carrier; a second friction element arranged to selectively connect the second sun gear and the third carrier; a third friction element arranged to selectively connect the second carrier and a first rotating member formed by the first and third ring gears being connected rotate together as a unit; a fourth friction element arranged to selectively connect the second sun gear and the third sun gear; and a fifth friction element arranged to selectively connect the second carrier and the third sun gear, the first to fifth friction elements being operatively arranged with respect to the first, second and third planetary gear units to selectively establish at least seven forward speeds and one reverse speed by combining simultaneous engagement of two out of the first to fifth friction elements for transmitting torque from the input shaft to the output shaft.