Mazda Motor Corporation

Mazda Motor Corporat Ion

Tomotaka Ishizaka

Tatsuhiko Iwasaki

Shota Yamakawa

Norio Iwashita

Tadashi Saito

Manabu Sasahara

Koshiro Saji

Shinya Kamada

Tatsutoshi Mizobe

Yutaro Fukuda

Tomohiro Kubo

Masanori Sasaki

Yuki Tsuchitori

Kaori Sako

Kensuke Ueda

Narifumi Domen

Kotaro Suzuki

Atsushi Abe

Kenta Fukuchi

Masahiro Kaji

Takashi Nishioka

An automatic transmission includes a brake including a fixed-side cylindrical member spline-coupled to a transmission case, a rotation-side cylindrical member coupled to a given rotating member, a plurality of friction plates disposed between the fixed-side cylindrical member and the rotation-side cylindrical member, and including a fixed-side friction plate configured to be spline-engaged with the fixed-side cylindrical member and a rotation-side friction plate configured to be spline-engaged with the rotation-side cylindrical member, and a piston configured to engage the plurality of friction plates. The automatic transmission further includes a shock absorbing member disposed between a spline part of the transmission case and a spline part of the fixed-side cylindrical member and configured to absorb impact when the fixed-side cylindrical member rotates relative to the transmission case.

Automatic transmission

An automatic transmission is provided, which includes a transmission case having a vertical wall part, a clutch disposed on a first side of the vertical wall part in an axial direction, a given component disposed on the second side of the vertical wall part, and a sleeve having a cylindrical body and a flange part coupled to the second side of the vertical wall part and disposed radially inward of the given component. The hydraulic fluid is supplied to the clutch from radially inward of the clutch through the vertical wall part. An oil supply passage is configured to supply the hydraulic fluid to the radially inward of the clutch through a first oil passage extending in the axial direction via a coupling part between the vertical wall part and the flange part, a second oil passage inside the flange part, and a third oil passage inside the cylindrical body.

Provided is an automatic transmission with a compact arrangement that prevents rotation of a hub member, and efficiently supplies lubrication hydraulic oil to the friction plates. The automatic transmission comprises a brake in which a plurality of friction plates are arranged between the hub member and a drum member, wherein a biasing member, an engagement hydraulic pressure chamber, and a disengagement hydraulic pressure chamber are arranged radially inward of the friction plates at positions radially overlapping each other. The hub member comprises: a first hub member comprising a cylindrical portion having a splined region with which the friction plates are spline-engaged, wherein the first hub member s spline-engaged with a transmission casing; and a second hub member formed with a part of a lubrication oil supply passage, wherein the second hub member is fittingly engaged with the transmission casing such that it is connected to a valve body.

An automatic transmission with a brake is provided, the brake including a hub member coupled to a transmission case. The hub member includes a first hub member having a cylindrical part spline-engaged with friction plates and the transmission case, and forming a disengagement hydraulic chamber, a second hub member disposed at one side of the first hub member in the axial direction, fitted into the transmission case, and coupled to the one side of the first hub member in the axial direction by a first coupling member, and a third hub member disposed at the other side of the first hub member in the axial direction, coupled to the other side of the first hub member in the axial direction by a second coupling member, and forming an engagement hydraulic chamber. The first coupling member and the second coupling member are disposed radially inward of the disengagement hydraulic chamber.

An automatic transmission is provided, which includes a friction engaging element. The friction engaging element includes a plurality of friction plates disposed inside a transmission case, a piston configured to cause the plurality of friction plates to be engaged with each other, a spring configured to bias the piston, and a hydraulic chamber to which hydraulic fluid is supplied, the hydraulic fluid biasing the piston. The hydraulic chamber is disposed so as to overlap with the spring in a radially internal and external relationship.

An automatic transmission is provided, which includes a friction engaging element. The friction engaging element includes a plurality of friction plates disposed inside a transmission case, a piston configured to cause the plurality of friction plates to be engaged with each other, and a spring configured to bias the piston. The spring includes a first spring and a second spring with a longer free length than the first spring, and the first spring and the second spring are aligned in circumferential directions of the transmission case.

An automatic transmission is provided with a friction engaging element having a hub member, a drum member, friction plates disposed between the hub member and the drum member, and a piston configured to engage the friction plates. The hub member includes a first hub member made of ferrous material and having a cylindrical part provided with a spline part, the friction plates being spline-engaged with the spline part, and a second hub member made of aluminum-based material, disposed at a side part of the first hub member, and having a feed part for lubrication provided with a supply oil channel configured to supply hydraulic fluid for lubrication to the friction plates. A notch for lubrication is formed by circumferentially cutting the cylindrical part of the first hub member corresponding to the feed part of the second hub member. The feed part supplies the hydraulic fluid for lubrication through the notch.

An automatic transmission is provided, which includes a brake including a hub member which is coupled to a transmission case and includes first and second hub members, a drum member coupled to a given rotary member, friction plates, a piston configured to engage the friction plates, and a valve body disposed in a lower part of the transmission case. The first hub member includes a radially outer circumferential part formed with a first spline part spline-engaged with the transmission case, and a cylindrical part provided at a radially inner circumferential side and formed with a second spline part with which the friction plates are spline-engaged. The second hub member is disposed at a side part of the first hub member, is provided by fitting a radially outer circumferential part of the second hub member to the transmission case, and has a feed part for lubrication.

A frictional engagement element includes: a first piston, a second piston, a first urging member for urging the first piston in a direction of releasing a friction plate, and a second urging member for urging the second piston in the direction of releasing the friction plate with an urging force larger than the urging force of the first urging member. One of the first and second pistons has a communicating hole for connecting an engaging hydraulic chamber with an opposite hydraulic chamber and the other of the first and second pistons has a valve part for closing the communicating hole. The difference in travel distance between the first and second pistons in motion due to the different urging forces of the first and second urging members causes the valve part to open the communicating hole.

Automatic transmission and frictional engagement element

An automatic transmission includes a piston movable in an axial direction, a plurality of friction plates disposed on a side of a first surface of the piston, a fastening hydraulic chamber applying a hydraulic pressure to a second surface of the piston to move the piston to a fastening position where the friction plates are pressed to be fastened to each other, a release hydraulic chamber applying a hydraulic pressure to the first surface of the piston to move the piston to a release position where the friction plates are released, and a hydraulic pressure control valve that supplies and discharges the hydraulic pressure to and from each of the fastening hydraulic chamber and the release hydraulic chamber. An area of the second surface of the piston for receiving the hydraulic pressure is set to be larger than an area of the first surface for receiving the hydraulic pressure.

In a brake device of a transmission, rotation side friction plates are engaged with a cylindrical part of a rotation side holding member, and fixed side friction plates are engaged with a spline part that is provided on an outer peripheral surface of an inner cylindrical part of a fixed side holding member opposed to a cylindrical part of the rotation side holding member. The fixed side holding member includes an inflow oil passage that supplies lubricating oil from the outside to the inside of the radial direction thereof. An annular space communicating with an inflow oil passage is provided on the inside of the cylindrical part of the fixed side holding member. Oil discharge holes supplying lubricating oil, which was flowed into the annular space, to the rotation side and fixed side friction plates are provided on the cylindrical part of the fixed side holding member.

Brake device of transmission

An automatic transmission is provided, which includes a brake and an oil channel forming member. The brake includes an inner stationary member coupled to a transmission case, an outer rotary member, a plurality of friction plates, a piston configured to cause the friction plates to be engaged, and a hydraulic chamber for engagement. The oil channel forming member forms a supply oil channel for engagement. The piston includes a pressing part, a hydraulic chamber forming part, and a coupling part. The oil channel forming member includes a bonding part, a hydraulic chamber forming part, and a coupling part. The bonding part and the coupling part of the oil channel forming member are disposed in a cutoff part formed in the coupling part of the piston, and are disposed to overlap with the coupling part of the piston in circumferential directions.

An automatic transmission is provided with a brake including a hub member coupled to a transmission case, a drum member coupled to a given rotary member, friction plates, a piston configured to engage the friction plates, and a hydraulic chamber for engagement disposed radially inward of the hub member and to which hydraulic fluid for biasing the piston in an engaging direction is supplied. The piston includes a pressing part configured to press the friction plates, a hydraulic chamber for engagement forming part, and a coupling part coupling the pressing part to the hydraulic chamber for engagement and extending radially. The hub member includes spline parts with which the friction plates are spline-engaged. Notches are formed by cutting the coupling part of the piston so as to be spaced apart from each other in circumferential directions, and end parts of the spline parts in axial directions enter into the notches.

Provided is a frictional engagement element including: a plurality of friction plates; a piston movable between a releasing position and an engaging position; and a first urging mechanism and a second urging mechanism configured to urge the piston in an engaging direction from the releasing position toward the engaging position. Urging forces of both of the first urging mechanism and the second urging mechanism act on the piston from the releasing position to a first position in the engaging direction. The urging force of the first urging mechanism acts on the piston from the first position to a second position closer to the engaging position than the first position. The first position is a predetermined position where the piston does not abut against the friction plates, and the second position is a position where the piston abuts against the friction plates and the clearances are reduced.

Frictional engagement element and automatic transmission

Provided is an automatic transmission including: an input section to which power generated by a drive source is input; an output section configured to output a drive force; and a gear shifting mechanism configured to change a gear ratio. The power is input to the input section without intervention of a hydraulic power transmission device. The gear shifting mechanism includes a predetermined frictional engagement element for achieving a starting gear ratio of a vehicle. The frictional engagement element includes: a plurality of friction plates arranged with clearances therebetween; a piston movable between a releasing position where the friction plates are brought into a released state, and an engaging position where the friction plates are brought into an engaged state by pressing the friction plates; and an urging mechanism configured to urge the piston so that the piston abuts against the friction plates and the clearances are reduced.

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Hiroshima, Japan

Tomotaka Ishizaka