Automatic transmission for vehicle

Abstract

An automatic transmission (1) for a vehicle, comprising a speed reduction planetary gear (DP) outputting the input rotation of an input shaft (12) after speed reduction, a first clutch (C-1) and a third clutch (C-3) capable of transmitting the speed-reduced rotation through the planetary gear (DP), a planetary gear unit (PU) having sun gears (S2) and (S3) to which the speed-reduced rotation is transmitted by the first and third clutches (C-1) and (C-3), and a fourth clutch (C-4) capable of transmitting the inputted rotation to the sun gear (S2). The fourth clutch (C-4) is connected to the sun gear (S2) of the planetary gear unit (PU) through the output side members (the clutch drum (42) and the connection member (101)) of the third clutch (C-3) to commonize the output side members. Thus, the automatic transmission (1) for the vehicle can be reduced in size.

Description

technical field [0001] The present invention relates to an automatic transmission mounted on a vehicle, and more specifically, to at least two rotational elements that freely transmit decelerated rotation to a planetary gear unit and simultaneously freely transmit input rotation to at least one of them, thereby enabling Configuration structure of automatic transmission with multi-speed shifting. Background technique [0002] In recent years, multi-speed shifting has been demanded in automatic transmissions mounted on vehicles and the like in consideration of rising fuel costs and the like. Among the technical solutions already proposed, such an automatic transmission has a planetary gear capable of outputting decelerated rotation after decelerating the input rotation input to the input shaft, and a planetary gear unit having a plurality of rotation elements, and through a clutch or the like, the The decelerated rotation from the decelerating planetary gear is freely input t...

AI Technical Summary

Problems solved by technology

On the other hand, there is a problem that miniaturization of the automatic transmission is desired from the viewpoint of mountability when the automatic transmission is mounted on the vehicle, etc.

[0004] In addition, in the hydraulic servo system of these multiple clutches, it is necessary to set up an oil passage between the relatively rotating parts to supply working oil, and it is necessary to set up a sealing ring for sealing between these relatively rotating parts, but if it is set Multiple sealing rings will cause frictional sliding between these relatively rotating parts, resulting in low efficiency and low controllability of the automatic transmission.

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