Toyota Jidosha Kabushiki Kaisha

Aisin Aw Co., Ltd.

Katsuhisa Ishii

Atsushi Honda

Kazutoshi Nozaki

Hirofumi Ota

Minoru Todo

Takuya Nakajima

Mikio Iwase

Masato Nakano

Masafumi Kinoshita

Naoya Okada

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

A piston operating a first clutch is disposed between a first drum accommodating the first clutch and a second drum accommodating a second clutch, and an oil reservoir storing lubricating oil that has lubricated the first clutch is provided on an inner cylindrical surface of a skirt portion of the piston. Barriers having different inner diameters are provided to the axial front and rear of the oil reservoir. When the second clutch is disengaged such that the amount of lubricating oil supplied to the oil reservoir increases, the lubricating oil overflows the barrier having the smaller inner diameter, and thus flows to the second clutch.

Automatic transmission with lubricating structure

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.

Automatic transmission

Growing community of inventors

Okazaki, Japan

Katsuhisa Ishii