Mazda Motor Corporation

Masamichi Fujikawa

Masanori Sasaki

Kensuke Ueda

Yasuo Miura

Takeyuki Tanaka

Hirokazu Kouno

Shinya Kamada

Toshihisa Marusue

Kyosei Nakashima

Kazuhiro Yamada

Takashi Miyamoto

Shinya Okumura

Kazuyuki Shiino

Masashi Morihiro

Yuya Takemura

Sayaka Katayama

Ryohei Hanamure

Siyuan Tao

A power transmission device in an automatic transmission includes a friction tightening element (a second brake) having a drum member, and a transmission path constituent member (a third ring gear) coupled to the drum member via a coupling part extending circumferentially along the drum member, the drum member having low-rigidity parts (long holes) provided at a plurality of circumferential positions on the drum member in at least one of portions radially outside and inside the coupling part.

Automatic transmission power transmission device

A friction engagement device of an automatic transmission is provided, which includes a rotational member comprised of at least one of a drum member and a hub member including a spline part engaged with a friction plate to be movable in axial directions of the automatic transmission, and a drive force transmitting part for exchanging a drive force with another rotational element. The drive force transmitting part of the rotational member is made of a ferrous metal. A part of the rotational member other than the drive force transmitting part is made of a clad material containing a first material that is easily joined to the ferrous metal and a second material that is less easily joined to the ferrous metal compared to the first material and weighs less than the ferrous metal.

Friction engagement device of automatic transmission

Automatic transmissionincludes second friction platesconnecting a second drumto a second hub, a second engagement hydraulic chamber, a second centrifugal balance chamber, and a second pistonengaging and disengaging the second friction plates. The second centrifugal balance chamberoverlaps the second friction platesin the axial direction in the automatic transmission. The automatic transmissionfurther includes a second oil passagefor discharging hydraulic oil in the second centrifugal balance chamberto a position not overlapping the second friction platesin the axial direction.

Automatic transmission

A first piston () that presses friction plates () is fitted in a second piston () in such a manner as to be movable together with the second piston and relatively movable with respect to the second piston. An A-chamber () and a B-chamber () each configured to move a respective one of the first piston () and the second piston () by a stroke toward a side close to the friction plates, a return spring () biasing the second piston () on a side away from the friction plates, and a stopper member () configured to prevent a stroke of the second piston () toward the side close to the friction plates from becoming greater than a given value (W) are provided. Engagement responsiveness of a L-R brake () does not deteriorate even when a clearance (V) in the friction plates () increases.

Brake element for transmission and control system therefor

Growing community of inventors

Hatsukaichi, Japan

Masamichi Fujikawa