Komatsu Corporation

Takehiro Komatsu

Hikosaburo Hiraki

Shunsuke Miyamoto

Noboru Kanayama

Yasuo Fujiwara

Shu Takeda

Shinichi Naito

Kyousuke Moriguchi

A transmission includes an input shaft, an output shaft, a first planetary gear mechanism, a second planetary gear mechanism, and a first variable device. The first planetary gear mechanism includes a first carrier connected to the input shaft, a first planetary gear connected to the first carrier, a first sun gear connected to the first planetary gear, and a ring gear connected to the first planetary gear. The second planetary gear mechanism includes a second sun gear connected to the first carrier, a second planetary gear connected to the second sun gear, and a second ring gear connected to the second planetary gear and connected to the first ring gear. The first variable device is connected to the first ring gear and the second ring gear to continuously change a speed ratio of the output shaft to the input shaft.

Transmission and work vehicle

A work vehicle includes a control unit having a motor switch control unit and a motor command determining unit. The motor switch control unit controls a motor switching mechanism so that a third motor connects to a first motor when a first rotation speed is less than a second rotation speed. The first rotation speed is the rotation speed of the first motor corresponding to that of a rotating shaft of the third motor. The second rotation speed is the rotation speed of the second motor corresponding to that of a rotating shaft of the third motor. When the third motor is connected to the first motor, the motor command determining unit determines a command torque for the first motor and the third motor so that the command torque for the third motor is no more than the command torque for the first motor.

Work vehicle and control method for same

A fuel consumption saving control device for a work vehicle includes: a vehicle speed detectorfor detecting whether the vehicle is traveling; an accelerator operation detectorfor detecting whether an accelerator operating member is not operated; a boom operating leverfor detecting whether a command to carry out operation to lift a boom which performs cargo carrying work has been issued; and a controllerfor carrying out control for increasing a speed reducing ratio of a travel transmissionwhen the vehicle speed detectordetects that the vehicle is traveling, the accelerator operation detectordetects that the accelerator operating member is not operated, and also the boom operating leverdetects that the command to lift the boom has been issued.

Fuel consumption saving control device for work vehicle and fuel consumption saving method for work vehicle

A sun gear of a first planetary gear train is connected to an input shaft. A carrier of the first planetary gear train is connected to a sun gear of a second planetary gear train and to a first pump/motor. A ring gear of the first planetary gear train is connected to a second pump/motor, and a ring gear of the second planetary gear train is connected to an output shaft. A first clutch is provided for engaging and disengaging a carrier of the second planetary gear train and the ring gear of the first planetary gear train with and from each other, and a second clutch is provided for engaging and disengaging the carrier of the second planetary gear train and a fixed end with and from each other.

Transmission system

A sun gear of a first planetary gear train is connected to an input shaft. A carrierof the first planetary gear train is connected to a sun gear of a second planetary gear train and to a first pump/motor. A ring gear of the first planetary gear train is connected to a second pump/motor, and a ring gear of the second planetary gear train is connected to an output shaft. A first clutch is provided for engaging and disengaging a carrier of the second planetary gear train and the ring gear of the first planetary gear train with and from each other, and a second clutch is provided for engaging and disengaging the carrier of the second planetary gear train and a fixed end with and from each other.

To provide a transmission capable of using pump/motors or generator/motors of smaller maximum torque and of small size. The transmission includes input shaft (), output shaft (), a mechanical transmission part interposed between input shaft () and output shaft () including planetary gear mechanisms (), (), and a hydrostatic transmission part interposed between input shaft () and output shaft () including three pump/motors (), (), (). A rotating shaft of first pump/motor () and a rotating shaft of second pump/motor () are coupled to the mechanical transmission part. Clutches (), (), () are provided for coupling a rotating shaft of third pump/motor () to at least one of the rotating shaft of first pump/motor () and the rotating shaft of second pump/motor ().

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Hiratsuka, Japan

Takehiro Komatsu