Patent ID: 6361468
Filing Date: 2002-03-26
Classification: F16H

Abstract:
An automatic transmission for achieving a multi-stage gear change, comprising:an input shaft; a fixed reaction force element; a reduction planetary gear, coupled to the input shaft and the fixed reaction force element so as to output a reduction rotation to an output element; and a planetary gear set, that outputs a speed shift rotation with a variable speed depending on a shift position, upon input of the reduction rotation from the reduction planetary gear, wherein helical teeth of respective elements have a torsion direction set such that a direction of the thrust force of one element of the reduction planetary gear and a direction of the thrust force of one element of the planetary gear set are different from each other on a common force transmission route, in which the thrust forces generated respectively at one element of the reduction planetary gear and one element of the planetary gear set are transmitted, during driving at one of a plurality of gear speeds, and wherein the torsion direction is set such that a thrust force generated at the one element of the reduction planetary gear and a thrust force generated at the one element of the planetary gear set face with each other during driving at one of a plurality of gear speeds and further comprising: a bearing subjected to thrust forces generated at the respective elements in common is provided in the common force transmission route, and the bearing is subjected to a differential thrust force between a thrust force acting on the one element of the planetary gear set and a thrust force acting on the one element of the reduction planetary gear.