Aisin Aw Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Aisin Seiki Kabushiki Kaisha

Takuya Nakajima

Naoya Jinnai

Minoru Todo

Hiroshi Kato

Atsushi Honda

Mikio Iwase

Kazutoshi Nozaki

Hirofumi Ota

Masahiro Otake

Katsuhisa Ishii

Masanori Murakami

Shota Ikeda

Satoru Kasuya

Nobutada Sugiura

Masato Nakano

Natsuki Sada

Toshihiko Aoki

Masafumi Kinoshita

Hideki Nakamura

Takashi Morimoto

Hiroshi Yoshikawa

Hideaki Niimi

Keita Suwa

Tsuyoshi Fukaya

In an automatic transmission, an engagement oil chamber and a centrifugal oil pressure cancel chamber of a clutch corresponding to a third ring gear of a Ravigneaux type planetary gear mechanism are defined by a drum member, a piston, and a cancel plate that rotate integrally with the third ring gear. An engagement oil chamber and a centrifugal oil pressure cancel chamber of a clutch corresponding to a third sun gear of the Ravigneaux type planetary gear mechanism are defined by a shaft portion, a piston, and an oil-chamber defining member that rotate integrally with the third sun gear.

Multi-stage transmission

A clutch that includes a friction plate; a separator plate; a clutch hub; and a piston that presses the friction plate and the separator plate, wherein the clutch hub includes a hub on which an inner peripheral portion of the friction plate or the separator plate is fitted, a tubular shaft that movably supports the piston, and an engagement oil chamber defining wall that together with the piston defines an engagement oil chamber to which an engagement oil pressure is supplied, the hub is spline-fitted on a gear of a planetary gear so as to rotate with the gear, and the tubular shaft is rotatably supported by a central shaft and is fitted by a spigot joint in the gear.

Clutch and speed change device including the same

A brake of an automatic transmission includes: first and second recessed portions and formed in a center support; a first piston having a first pressure-receiving portion that is disposed in the first recessed portion and defines a first engagement oil chamber and having a plate-pressing portion that presses friction plates and separator plates; a second piston having a second pressure-receiving portion that is disposed in the second recessed portion and defines a second engagement oil chamber and a piston-pressing portion that presses the first piston by supply of oil pressure to the second engagement oil chamber; and a return spring that biases the first piston so that the first piston moves away from the friction plates and the separator plates.

A multi-stage transmission that includes a case including an annular support that extends radially inward from an inner peripheral surface of the case; a first planetary gear mechanism that includes a plurality of rotating elements and to which power is transmitted from the input member; a second planetary gear mechanism that is disposed on an opposite side of the support of the case from the first planetary gear mechanism; a clutch that interconnects any one of the rotating elements of the first planetary gear mechanism with an element to be connected which is included in the second planetary gear mechanism and releases this interconnection; and a brake that connects the element to be connected to the case to hold this element stationary and releases this connection.

A brake of an automatic transmission holds a second ring gear of a second planetary gear stationary, and includes: friction plates and separator plates; and a drum member as a brake hub that is continuously coupled to the second ring gear and is rotatably supported by an inner tubular portion of a center support between the friction plates, for example, and the second planetary gear. The drum member and the second ring gear are coupled together via a spline.

A first planetary gear and a clutch are placed between a second carrier of a second planetary gear and an output shaft in the axial direction. A transmission case has a small diameter tubular portion that rotatably supports an output shaft, an annular wall portion extended radially outward from the small diameter tubular portion, and a large diameter tubular portion extended in the axial direction from the outer periphery of the annular wall portion such that the first planetary gear and the clutch are partially surrounded. A mount is fixed to a vehicle body of a vehicle so as to at least partially overlap the small diameter tubular portion, the annular wall portion, and the large diameter tubular portion as viewed in the radial direction. A parking gear of a parking lock device is coupled to the outer periphery of the second carrier.

Power transmission device

The automatic transmission which includes a third brake element formed by a support member including a first cylindrical portion having a first sliding surface at an outer peripheral surface thereof, a second cylindrical portion having a second sliding surface at an inner peripheral surface thereof and a third cylindrical portion having a third sliding surface at an inner peripheral surface thereof, an inner side piston, inner edge portion of which is in contact with the first sliding surface and an outer edge portion of which is in contact with the second sliding surface and an outer side piston which includes a first piston cylindrical portion, outer edge of which is in contact with the second sliding surface over an entire periphery thereof and a second piston cylindrical portion, outer edge portion of which is in contact with the third sliding surface over an entire periphery thereof.

Automatic transmission

A transmission device, wherein the compound planetary gear mechanism increases the speed of the power transmitted to the input element and transmits the resultant power to the first and the second output elements when the fixable element is non-rotatably held stationary by the first brake; and the first and the second clutches are disposed on a side closer in the axial direction to the compound planetary gear mechanism than the first and the second planetary gear mechanisms.

Transmission device

A hydraulic servo for a brake in an automatic transmission has a piston secured against rotation without provision of a protrusion on the piston engaging the transmission casing. The piston of the hydraulic servo has an inner cylindrical surface configured to grasp, along their lengths, return springs compressed between the piston and a return plate to which the return springs are fixed. The return plate is bolted to a bulkhead portion of the transmission case and, thus, the piston member is fixed to the bulkhead portion and thereby prevented from rotating.

Hydraulic servo for a brake in an automatic transmission

The present invention provides an automatic transmission having a main bearing disposed between the inner surface of a boss portion of a first drum and the outer surface of a cylindrical support, for rotatably supporting the first drum. An auxiliary bearing is press-fit into one end of the interior of the boss portion of the first drum and surrounds the cylindrical support with an annular gap therebetween. The auxiliary bearing contacts the cylindrical support only when the first drum tilts relative to the central axis of the transmission, and has a shorter axial length than that of the main bearing.

Growing community of inventors

Toyota, Japan

Takuya Nakajima