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Piston for automatic transmission

A technology for automatic transmissions and pistons, which is applied in fluid-driven clutches, mechanical-driven clutches, and non-mechanical-driven clutches, etc., and can solve problems such as mutual frictional contact, decreased durability of pistons and frictional engagement elements, and increased power loss in automatic transmissions. Achieve the effects of reducing stress, improving durability, and improving operating efficiency

Inactive Publication Date: 2007-07-04
TOYOTA JIDOSHA KK +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, the first piston part tends to have axial looseness, creating a risk of unnecessary abutment contact of the first piston part with one of the outermost of the friction engagement elements, which may cause unnecessary frictional contact of the friction engagement elements with each other, resulting in So-called "dragging" of clutches or brakes, resulting in reduced durability of pistons and frictional engagement elements, and increased power loss of automatic transmissions due to dragging

Method used

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  • Piston for automatic transmission
  • Piston for automatic transmission
  • Piston for automatic transmission

Examples

Experimental program
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Embodiment Construction

[0028] Referring first to FIG. 1 , a side view in section, there is shown a portion of an automatic transmission 8 provided with a clutch arrangement 10 comprising a piston in the form of a radially outer piston 18 constructed in accordance with one embodiment of the invention.

[0029] The clutch device 10 is of a dual-clutch configuration, and includes: a clutch drum 16 supporting the first set of frictional engagement elements 12 and the second set of frictional engagement elements 14; an outward piston 18 ; and a radially inward piston 20 arranged radially inwardly of the clutch drum 16 .

[0030] The automatic transmission 8 has a housing 24 and an input shaft 22 rotatably supported by the housing 24 at its end 22a. The input shaft 22 has a flange portion 22b located near the end portion 22a in an axial position. The flange portion 22 b extends radially outward perpendicular to the axis of the input shaft 22 . The input shaft 22 is a turbine shaft of a torque converter ...

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PUM

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Abstract

A piston (18; 80) for an automatic transmission (8), including a first piston member (46) forming a cylindrical portion and a second piston member (48; 82) forming a bottom portion, wherein the first piston member has a plurality of engaging grooves (76) having a radial surface (76a) extending in a radial direction of the first piston member, and the second piston member (48; 82) has a plurality of elongate claws (70) having a free end portion and a fixed end portion, and being bent in an axial direction of the second piston member such that the free end portion is spaced from the fixed end portion in the axial direction toward an open end of the piston, each elongate claw having a first engaging lug (72) which is held in engagement with the corresponding engaging groove and in pressing contact with the radial end face of the corresponding engaging groove.

Description

technical field [0001] The present invention generally relates to pistons operable to force frictional engagement elements of a clutch or brake provided in an automatic transmission against each other to place the clutch or brake in an engaged state. Background technique [0002] A known automatic transmission includes clutches and brakes each provided with friction engaging elements in the form of a plurality of friction plates so that the automatic transmission automatically shifts gears by selectively engaging and disengaging the clutches and brakes. Each clutch or brake is placed into engagement by pistons forcing the frictional engagement elements against each other. JP-9-32919A discloses an example of such a piston consisting of two parts, a first piston part forming a cylindrical portion of the piston and a second piston part forming a bottom of the piston. In the piston disclosed in JP-9-32919A, the first piston part (cylindrical part) has a slit, and the second pis...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): F16D25/12F16D25/0638
CPCF16D25/0638F16D25/12F16D25/126F16D13/70F16D25/10
Inventor 大西博文安田勇治喜来达夫桝田雅史大前浩二
Owner TOYOTA JIDOSHA KK
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