Mazda Motor Corporation

Seiji Esaki

Kazuhiko Ueda

Osamu Sado

Shinya Kamada

Tatsutoshi Mizobe

Junichi Doi

Norio Iwashita

Tokimori Saka

Takamichi Teraoka

Naohiro Sakaue

Yoshihiko Fujita

Satoshi Komori

Seiji Terauchi

Tatsuhiko Iwasaki

Hidetoshi Nobumoto

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

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).

Automatic transmission

A hybrid drive system comprises an oil pump for forcing an operating oil to a transmission, an engine operationally connected to the oil-operated transmission through a first clutch, a battery-operated traction motor operationally connected to the transmission, a battery-operated auxiliary motor operationally connected to the engine through a second clutch so as to start the engine, an oil pump for forcing an operating oil to at least the transmission, and alteration means for selectively operationally connecting the oil pump to either one of the traction motor and the auxiliary motor which rotates at a speed of rotation higher than the other.

Hybrid drive system

A power transmission system for a vehicle has a first power transmission path having a forward-reverse shift mechanism and a reduction gear, a second power transmission path having an infinitely variable gear, and a path switching mechanism which switches the power transmission path between the first and second power transmission paths according to the running condition of the vehicle. The infinitely variable gear is a toroidal speed change mechanism having an output disk fixed to the output shaft of the power transmission system, an input disk which can be displaced in the axial direction of the output shaft and a roller which is in contact with both the input and output disks to rotate about an axis in response to rotation of the input disk and transmit rotation of the input disk to the output disk, the transmission ratio of the toroidal speed change mechanism being changed by changing the inclination of the axis about which the roller rotates.

Power transmission system for vehicle

A power transmission device for a vehicle comprises a first power transmitting path for transmitting engine output to a wheel side via a reduction gear, a second power transmitting path for transmitting engine output to the wheel side via a stepless speed change gear mechanism, a path switching clutch for switching between the paths to transmit by one of the paths, a switch-over control part for controlling switch-over operation of the clutch according to a driving condition of the vehicle, and a rotational condition abrupt change restraining part for restraining an abrupt change of a rotational condition of an engine output shaft at switch-over between the paths. The restraining part adjusts to conform rotating speeds of the input and output sides of the clutch to each other at switch-over of the clutch, or conform output torque to the wheel side between before and after switch-over of the clutch. Thus, an abrupt change of rotation of the engine output shaft is restrained to prevent a shock owing to switch-over, and the durability of a friction element is enhanced.

Power transmission device for vehicle

A hydraulically operated stepless transmission has a first power flow path established so as to include a torque converter and a reverse and reduction gear and a second power flow path established so as to include a stepless transmission gear. The first and second flow paths are selectively available. A hydraulic control circuit, including at least one oil pump, causes a decrease in quantity of a lubrication oil delivered to the stepless transmission gear while the first power flow path is established, and causes a decrease in quantity of a working oil delivered to the torque converter while the second power flow path is established.

Stepless transmission for vehicles

A differential gear is to be interposed between an input shaft and first and second output shafts in an automotive vehicle. The differential gear includes a carrier rotatable together with the input shaft, a pair of first and second pinions disposed on one side of the carrier and rotatably supported on the carrier, a pair of third and fourth pinions disposed on the other side of the carrier and rotatably supported on the carrier, a first internal gear rotatable together with the first output shaft and having common rotational axis with the carrier, and a second internal gear rotatable together with the second output shaft and having a common rotational axis with the carrier. The first and second pinions are placed symmetrically with respect to the rotational axis of the carrier. Likewise, the third and fourth pinions are placed symmetrically with respect to the rotational axis of the carrier. The first and second internal gears are in mesh with the first and second pinions and the third and fourth pinions, respectively. On each side of the carrier, the set of one internal gear and two pinions constitutes two gear pumps.

Differential gear for use in an automotive vehicle

A differential for use in a car includes a case rotatable around an axis, an input gear fixed to the case, coaxial with the axis of the case, a pair of output shafts which are rotatably supported by the case coaxially with the axis of the case and protrude from opposite ends of the case, a pair of intermeshing first gears disposed in the case at opposite sides of the axis of the case and rotatably supported by the case, a pair of second gears disposed in the case, a pair of third gears disposed in the case coaxially with the axis of the case, and at least one gear pump defined by at least one of the pairs of intermeshing gears. The differential restricts a flow of an operation oil of the gear pump so as to generate a load on the gear pump. One of the second gears is located at one side of and coaxial with one of the first gears and rotates integrally with this first gear. The other of the second gears is located at the other side of and coaxial with the other one of the first gears and rotates integrally with this first gear. One of the third gears rotates integrally with one of the output shafts and meshes with one of the second gears. The other of the third gears rotates integrally with the other of the output shafts and intermeshes with the other of the second gears. The gear pump has two chambers one of which operates as an inlet chamber. The other chamber operates as an outlet chamber in response to the direction of the rotation of the gears. The gear pump and the restricted flow of the operation oil of the gear pump combine a restrict a differential motion of the differential.

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Hiroshima, Japan

Seiji Esaki