Automatic transmission

摘要

An automatic transmission includes a thrust bearing α disposed between a third sun gear of a third planetary gear mechanism and a second sun gear of a second planetary gear mechanism. Accordingly, transmitting a thrust load acting on the second sun gear of the second planetary gear mechanism from the thrust bearing to an input shaft via the third sun gear of the third planetary gear mechanism can avoid, as much as possible, a case where the thrust load is transmitted from the third planetary gear mechanism to the input shaft via a fourth planetary gear mechanism, and reduce friction loss of multiple thrust bearings interposed among elements or the like of the third planetary gear mechanism and the fourth planetary gear mechanism.

主权项

1. An automatic transmission, comprising:
a transmission case, an input shaft, and a plurality of planetary gear mechanisms disposed on the input shaft and housed in the transmission case, in which a gear stage is established by controlling a coupling relationship among elements of the plurality of planetary gear mechanisms, the input shaft, and the transmission case by using a plurality of clutches and a plurality of brakes, wherein said plurality of planetary gear mechanisms comprise:
a planetary gear mechanism α including a sun gear unrotatable relative to the input shaft;a planetary gear mechanism β disposed adjacent to the planetary gear mechanism α, in which elements are rotatable relative to each other; anda planetary gear mechanism γ disposed on an opposite side to the planetary gear mechanism β with the planetary gear mechanism α interposed therebetween, in which elements are rotatable relative to each other, wherein the planetary gear mechanism α and the planetary gear mechanism γ are disposed adjacent to each other, wherein the clutches comprise: a clutch α capable of coupling a ring gear of the planetary gear mechanism γ to the input shaft; wherein the automatic transmission further comprises a thrust bearing α disposed between the sun gear of the planetary gear mechanism α and a sun gear of the planetary gear mechanism β; and wherein the automatic transmission further comprises a thrust bearing β disposed between a clutch hub of the clutch α and the transmission case.