AUTOMATIC TRANSMISSION FOR VEHICLE

摘要

PROBLEM TO BE SOLVED: To provide a miniaturizable automatic transmission for a vehicle which can prevent the increase of the relative rotation between transmission elements. SOLUTION: A planetary gear unit 5 comprises a sun gear S1 with the rotation of an input shaft inputted therein, a lockable carrier CR1, and a ring gear R1 which outputs the rotation with reduced number compared with the number of the input rotation to a planetary gear set 9. A clutch C-3 is intermittently engaged to appropriately connect/disconnect the input shaft to/from the sun gear S1, and the carrier CR1 is appropriately locked/unlocked by a brake B-1 and a one-way clutch F-1 to prevent the extreme increase of the relative rotation between the transmission elements of the gear unit 5 not involved in the transmission operation. When the clutch C-3 is provided between the input shaft 2 and the sun gear S1, the capacity of the clutch C-3 can be smaller than that when the clutch is provided between the gear unit 5 and the gear set 9, and the size of the automatic transmission can be reduced using the compact clutch.