Mazda Motor Corporation

Tatsutoshi Mizobe

Shinya Kamada

Tatsuhiko Iwasaki

Takuji Fujiwara

Toshihisa Marusue

Junichi Doi

Norio Iwashita

Kazunori Enokido

Hidehiko Mishima

Naohiro Sakaue

Tokimori Saka

Takamichi Teraoka

Yoshihiko Fujita

Fumiaki Baba

Kozo Ishii

Koichiro Takeuchi

Kaori Sako

Kazuhiko Ueda

Tadashi Saito

Tomotaka Ishizaka

Manabu Sasahara

Hideo Toyota

Yutaro Fukuda

Masahito Kitada

Tomohiro Kubo

Shigeru Nagayama

Seiji Esaki

Hiroaki Yokota

Akihiro Mitani

Akio Matsumoto

Keiichiro Sueshige

Keiichi Nakamura

Satoshi Komori

Kazuo Sasaki

Minoru Kuriyama

Koshiro Saji

Kazuo Takemoto

Yuzo Ohkawa

Shotaro Nagai

Takayuki Sumimoto

Hiroshi Shinozuka

Kensuke Ueda

Takahiro Kimura

Takenori Kawano

Shinya Yamamoto

Osamu Watanabe

Masahiro Kaji

Esaki Seiji

The automatic transmission has, on an axis of a power transmission shaft: a one-side clutch including a plurality of friction plates; and an other-side clutch including a plurality of friction plate. A pressing section of a piston of the one-side clutch and a pressing section of a piston of the other-side clutch are arranged to overlap each other in an axial direction. On one side in the axial direction of the plurality of friction plates of the one-side clutch, a radial section of the piston of the one-side clutch and a radial section of the piston of the other-side clutch are arranged in parallel in the axial direction. Pressure-receiving sections of the pistons of the one-side clutch and the other-side clutch and bearing sections of the pistons of the one-side clutch and the other-side clutch are aggregated and arranged on a radially inner side.

Automatic transmission

An automatic transmission has a one-side clutch and an other-side clutch in an axial direction, the one-side clutch and the other-side clutch being aligned in the axial direction on an axis of a power transmission shaft. These clutches respectively include: drum sections; hub sections; friction plates that are engaged in an axially slidable manner between the drum sections and the hub sections; and pistons that press the friction plates. The friction plates in the one-side and other-side clutches are arranged in parallel in the axial direction. The pistons in the one-side clutch and the other-side clutch are arranged on one sides in the axial direction of the friction plates and are arranged such that axial positions thereof overlap. The piston in the other-side clutch penetrates the friction plate in the one-side clutch in the axial direction.

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.

A brake device of a transmission according to the present invention includes: a rotary-side holding member including an inner peripheral surface having a cylindrical surface shape about an axis extending in a forward/rearward direction and configured to hold a rotary-side friction plate on the inner peripheral surface; a fixed-side holding member including an outer peripheral surface having a cylindrical surface shape about the axis extending in the forward/rearward direction and configured to hold a fixed-side friction plate on the outer peripheral surface; and a lubricating oil supply portion supplying lubricating oil to the fixed-side friction plate and the rotary-side friction plate. The fixed-side holding member is provided in a transmission casing so as not to rotate. The rotary-side holding member is provided in the transmission casing at a radially outer side of the fixed-side holding member and is rotatable about a central axis of the inner peripheral surface.

Brake device of transmission

An automatic transmission is provided with a brake device provided with a rotatable rotation-side friction plate and a non-rotatable fixed-side friction plate; a transmission case which accommodates the brake device; a lubrication oil supply section which supplies lubrication oil introduced into the transmission case to an upper portion of the brake device; and a lubrication oil discharge section disposed below the brake device, and configured to discharge lubrication oil supplied from the lubrication oil supply section to the brake device.

There is provided, in one aspect of the present description, an automatic transmission. In one example, the automatic transmission comprises a transmission case, a valve body which is arranged in the transmission case, a control valve mechanism which controls oil pressures in parts of the automatic transmission and is installed in the valve body, and a solenoid valve which is attached to the valve body and is arranged at a first side of the valve body and in the transmission case. The automatic transmission further comprises an electronic control unit which controls the solenoid valve, is attached to the valve body, and is arranged at a second side of the valve body that is opposite to the first side across the valve body.

Control apparatus for automatic transmission

An automatic transmission has first, second and third gear sets, first and second clutches, and first, second and third brakes. First, second and third sun gears, and a first carrier are interconnected with a second sun gear, a second carrier, a third carrier, an input shaft and an output gear, respectively. The first clutch selectively connects the first sun gear and the second sun gear to the input shaft, and the second clutch selectively connects the first ring gear and the second carrier to the input shaft. The first brake selectively connects the first ring gear and the second carrier to a casing. The second brake selectively connects the second ring gear and the third carrier to the casing, and the third brake selectively connects the third ring gear to the casing.

An automatic transmission is provided. One embodiment of the automatic transmission may include a valve body including control valves for hydraulically controlling a friction engaging element provided within said transmission. The automatic transmission may further include an electric control unit located on said valve body for controlling gear shifting of said automatic transmission. The automatic transmission may further include a transmission case having a peripheral wall for at least partially enclosing a gear shift mechanism and an outer wall provided adjacent to said peripheral wall, wherein said electric control unit is located within a containing space surrounded by said peripheral wall, said outer wall and said valve body.

Each of first and second multi-plate clutches comprises a clutch outer cylinder portion provided to be coaxial with the input shaft and connected with a first or second rotational element, a clutch inner cylinder portion provided to be coaxial with an input shaft, plural clutch plates provided between these cylinder portions to slide in an axial direction of the input shaft within the clutch outer or inner cylinder portion, and a clutch piston provided to slide in the axial direction and press the clutch plates for connecting the clutch outer cylinder portion with the clutch inner cylinder portion. The clutch outer and inner cylinder portions of each of the first and second multi-plate clutches are provided in the axial direction, and there is provided a support wall portion that is connected with the input shaft and supports the clutch inner cylinder portion of each of the multi-plate clutches.

There is provided an automatic transmission comprising a first shaft capable of receiving torque from an engine, and four planetary gear sets arranged coaxially on the first shaft and in series in an axial direction of the first shaft. Each of the four planetary gear sets has a single sun gear and a single ring gear. Further, the automatic transmission comprises an output wheel arranged coaxially on the first shaft, and capable of outputting torque transmitted from the engine through some of the four planetary gear sets. The output wheel is arranged between two of the four planetary gear sets. Accordingly, the noise or vibration from the planetary gear sets in the automatic transmission may be reduced, while the overall length of the first shaft may be made shorter, and the overall size of the automatic transmission may be made smaller.

Automatic transmission for automotive vehicles

On an input shaft are provided in order from a side of an engine a torque converter with a lock-up clutch, a first planetary gear set as a multiplying mechanism, a counter drive gear outputting a rotational drive force to a countershaft, a second planetary gear set as a speed-change element, a third planetary gear set as a speed-change element. Accordingly, there can be provided an automatic transmission for six forward speeds with plural planetary gear sets, clutches and brakes that can properly reduce a clutch capacity and restrain gear noises with its compact and light-weighted structure.

In an automatic transmission (AT) in which an input shaft (Input) and an output gear (Output) are disposed on the same axis and three clutches (C-C) and two brakes (B, B) are selectively operated to provide six forward speeds, first and second planetary gear sets (GS, GS) are configured to consistently reduce the speed of input rotation and output the speed-reduced rotation, thereby enabling downsizing of them. The first and second planetary gear sets (GS, GS) are arranged in a transmission case at both the axial ends thereof. Third and fourth planetary gear sets (GS, GS) are connected to each other to have four rotation elements in combination, thereby constituting a Simpson planetary gear train. One of the four rotation elements (a fourth carrier (PC) in an illustrated example) is connected to the output gear (Output). Rotations input and reduced in speed by the first and second planetary gear sets (GS, GS) are input to sun gears (S, S) of the third and fourth planetary gear sets (GS, GS), respectively. First to third clutches (C-C) and a first brake (B) are arranged to surround the first and second planetary gear sets (GS, GS).

A control system of an automatic transmission includes a torque converter, a lock-up clutch for directly connecting input and output members of the torque converter, a pressure control valve which changes a hydraulic pressure to control an engaging force of the lock-up clutch, and a pressure regulator, disposed in an engaging passage, which supplies hydraulic pressure to engage a frictional element. The pressure regulator adjusts a primary pressure and produces an output hydraulic pressure corresponding to a control pressure introduced into a control port of the pressure regulator. A control pressure supply device is provided for introducing the control pressure, controlled by the pressure control valve, into the control port of the pressure regulator. The number of parts can be reduced without producing any inconvenience.

Control system of automatic transmission

A hydraulic control system of an automatic transmission during a shift operation wherein a control pressure is controlled to selectively engage and release a plurality of frictional elements to establish a desirable shift stage comprising inertia phase detecting device for detecting a starting point of an inertia phase of the shift operation from one shift stage to another, and control pressure reducing device for gradually reducing the control pressure introduced to a frictional element to be engaged after the inertia phase is detected. The torque shock in the shift operation can be effectively reduced.

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Hiroshima, Japan

Tatsutoshi Mizobe