Automatic transmission

Patent metadata

Field	Value
Publication number	US-9845871-B2
Application number	US-201514677323-A
Country	US
Kind code	B2
Filing date	Apr 2, 2015
Priority date	Apr 17, 2014
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

An automatic transmission is provided. The transmission includes clutches coaxially arranged in layers in a radial direction of the transmission. The transmission includes a piston provided to each clutch, the pistons being aligned in the radial direction on a same plane perpendicular to an axis of the transmission, without overlapping with each other in an axial view. The transmission includes a common rotational member having a wall, commonly used for the clutches, and disposed at a predetermined position of the transmission in an axial direction, wherein the wall is formed along the plane. The transmission includes operational hydraulic passages parallely arranged in the wall of the common rotational member in a circumferential direction of the transmission on the same plane perpendicular to the axis, each of the operational hydraulic passages communicating with one of operational hydraulic chambers of the respective clutches.

First claim

What is claimed is:

1. An automatic transmission including a plurality of clutches coaxially arranged in layers in a radial direction of the automatic transmission, comprising:
a piston provided to each of the plurality of clutches, the pistons being aligned in the radial direction on a same first plane that is perpendicular to an axis of the automatic transmission, without overlapping with each other radially;
a common rotational member having a wall, commonly used for the plurality of clutches, and disposed at a predetermined position of the automatic transmission in an axial direction, the wall formed along a second plane perpendicular to the axis; and
a plurality of operational hydraulic passages arranged in the wall of the common rotational member spaced in a circumferential direction of the automatic transmission on the same second plane perpendicular to the axis, each of the plurality of operational hydraulic passages communicating with a respective operational hydraulic chamber of the respective clutches, the hydraulic passages arranged in the second plane separate from the first plane where the pistons are aligned,
wherein first parts of the wall of the common rotational member form thin wall parts thinner than second parts, and return springs for biasing the pistons of the clutches to their releasing sides are disposed in the thin wall parts, each of the first parts being positioned between two of the operational hydraulic passages adjacent to each other in the circumferential direction, and each of the second parts being formed with one of the operational hydraulic passages; and
wherein a subset of the return springs comprises plate springs provided on an opposite side of the common rotational member from the pistons.

2. The automatic transmission of claim 1 , wherein the plurality of clutches includes three clutches.

3. The automatic transmission of claim 2 , wherein the return springs for second and third clutches from an inner circumferential side among the three clutches are disposed in the thin wall parts of the common rotational member.

4. The automatic transmission of claim 3 , wherein the return springs and the operational hydraulic passages are alternately disposed in the circumferential direction.

5. The automatic transmission of claim 1 , wherein centrifugal balance chambers are aligned, without overlapping with each other radially, in the radial direction on a plane perpendicular to the axis, each of the centrifugal balance chambers opposing one of the operational hydraulic chambers with one of the pistons of the plurality of clutches interposed therebetween.

6. The automatic transmission of claim 1 , wherein friction plates of the plurality of clutches are aligned in the radial direction on a plane perpendicular to the axis, without overlapping with each other radially.

Assignees

• Mazda Motor

Inventors

• Iwasaki Tatsuhiko
• Kamada Shinya
• Ogauchi Yasuhiro

Classifications

• F16H3/66

  composed of a number of gear trains without drive passing from one train to another · CPC title

• F16H63/3026 Primary

  comprising friction clutches or brakes (band brake actuating mechanisms F16H63/3003) · CPC title

• F16H2200/006

  the gear ratios comprising eight forward speeds · CPC title

• F16H2200/2012

  with four sets of orbital gears · CPC title

• F16H2200/2043

  with five engaging means · CPC title