Automatic transmission and speed change control method.

摘要

Herein disclosed is an automatic transmission which comprises a plurality of frictional engagement means and agear train including a plurality of rotary members and adapted to be set to a plurality of speeds of different gear ratios in accordance with the engagement/disengagement statuses of the frictional engagement means. The gear train has a plurality of kinds of combination patterns of engagement/disengagement of the frictional engagement means for setting a predetermined speed and has the number of revolutions of any of its rotary members increased or decreased according to any of the engagement/disengagement patterns. Speed control means is provided for selecting one of the combination patterns of the frictional engagement means for setting the predetermined speed so as to decrease the fluctuating number of revolutions of any of the rotary members.