Kanzaki Kokyukoki Mfg. Co., Ltd.

Yanmar Co., Ltd.

Minoru Kamada

Koji Iwaki

Jun Matsuura

Tomoyuki Ebihara

Kengo Sasahara

Nobuhiko Ichinose

Toshifumi Yasuda

Fumitoshi Ishino

Kazunari Koga

Hideki Kanenobu

Takashi Nishizawa

Daisuke Murashima

Tomoyuki Tsuji

Akifumi Kuroda

Shinichi Hirose

Koji Sakata

Takeshi Oouchida

Tadao Hirai

Masaya Itou

Keiichirou Yuzaki

Masaaki Inoue

Ryota Iwaibara

An HST control mechanism includes a rotary member, a servo unit, a telescopic member, and a biasing device. The rotary member for controlling a displacement of a hydrostatic transmission (HST) is pivoted outside of a casing incorporating the HST. The servo unit includes a telescopically movable actuator and a valve controlling the telescopic movement of the actuator. The actuator is interlockingly connected to the rotary member. The servo unit is pivotally supported on the casing via a first pivot. The servo unit rotates centered on the first pivot as the rotary member rotates according to the telescopic movement of the actuator hydraulically controlled by the valve. The telescopic member is pivotally supported on the casing via a second pivot. The telescopic member is provided with the biasing device that biases the telescopic member and the rotary member toward a position corresponding to a neutral state of the HST.

Actuator unit for controlling hydraulic pump

A hydrostatic stepless transmission ('HST') includes a center casing into which a plunger block of a hydraulic pump and a plunger block of a hydraulic motor are inserted. Plunger ports are open and aligned peripherally on an outer peripheral surface of each plunger block. A pair of main fluid passages of a closed fluid circuit fluidly connecting the hydraulic pump to the hydraulic motor are formed in opposite side portions of the center casing. Each of the main fluid passage includes peripheral grooves formed on an inner peripheral surface of the center casing so as to face the plunger ports of the respective plunger blocks, and includes an axial fluid duct formed to be interposed between the peripheral grooves. A bearing gap is provided between the inner peripheral surface of the center casing and the outer peripheral surface of the plunger block so as to cause a dynamic pressure action of fluid.

Hydrostatic stepless transmission

A continuously variable transmission control system includes a continuously variable transmission device having an electricity-driven actuator that changes an width between a moveable sheave and a fixed sheave in at least one pulley of a drive pulley and a driven pulley, and a control device that controls driving of the electricity-driven actuator. The control device selects, from a plurality of speed relationships, each of which is a relationship between an input shaft rotational speed of the drive pulley and an output shaft rotational speed of the driven pulley, one speed relationship according to an input of a switch command signal or a drive state of the vehicle, and changes the width between the moveable sheave and the fixed sheave based on the selected speed relationship and detected values of the input shaft rotational speed and the output shaft rotational speed.

Continuously variable transmission control system for vehicle and work vehicle

A travel control unit of a working vehicle includes an HST which is a hydraulic continuously variable transmission having a hydraulic pump and a hydraulic motor, a pedal sensor which is an operator sensor which detects a position of an acceleration pedal which is an acceleration operator, and a controller which changes a displacement of the hydraulic pump based on the position of the acceleration pedal. The controller increases the displacement of the hydraulic motor as the displacement of the hydraulic pump is reduced due to a displacement of the acceleration pedal to a low-velocity side.

Travel control unit of working vehicle

At least one of first and second hydraulic motor units that drive first and second wheels is of a variable displacement. A volume adjusting mechanism thereof is operated by an electric motor in accordance with manual operation or automatic operation based on difference in turning radius between the first and second wheels. A control device that controls the electric motor includes normal mode that operates the electric motor in accordance with the manual operation or the automatic operation and torque-up mode that fixes the variable displacement hydraulic motor to a first volume larger than a standard volume, and activates the torque-up mode at idling state in which a power source is in operating state and a pump-side volume adjusting mechanism is in neutral state and shifts the torque-up mode to the normal mode when a traveling speed reaches a first speed.

Hydraulic four-wheel-drive work vehicle

In a working vehicle, there is dissolved a risk that a black smoke is discharged, a knocking is generated and an engine stall is caused, if a lot of load is applied to a rotary tiller during various works while traveling at a low speed. In the working vehicle provided with an engine which is mounted to a travel machine body, a common rail type fuel injection device which injects fuel to the engine, and a continuously variable transmission which shifts power from the engine, an engine driving point Q (Q&#x2192;Q) relating to a rotating speed N and a torque T of the engine is changed in such a manner that the rotation speed come to a high speed side rotating speed Ndissolving an overload, and a change gear ratio of the continuously variable transmission is modified and regulates in such a manner that a vehicle speed V of the travel machine body does not change in the case that the overload acts on the engine of having a low speed Nin the rotating speed N.

Drive system control device for working vehicle

Provided an electrically-operated hydraulic actuator unit that includes an electrically-operated motor controlled by a control apparatus and actuating a volume adjusting mechanism through driving-side and driven-side arms, and a clutch mechanism in which the driven-side arm presses a contact member against a clutch case so that the driven-side arm is locked when a force from the volume adjusting mechanism is applied to the driven-side arm. The control apparatus can set duties of first to fourth drive signals to be output to the electrically-operated motor in a neutral-side start period, a neutral-side ordinary actuation period, a higher-volume-side start period and a higher-volume-side ordinary actuation period. The duties of the first and fourth drive signals are larger than that of the second drive signal, the duty of the third drive signal is larger than that of the fourth drive signal, and an integrated ON-time of the third drive signal is larger than that of the first drive signal.

Electrically-operated hydraulic actuator unit and hydraulic four-wheel-drive work vehicle

A hydraulic actuator unit includes a first electric motor assembly formed by mounting one of a pair of electric motors to one of a pair of electric motor covers, wherein the first electric motor assembly is detachably mounted to a pump case so as to rotate a first control shaft around its axis line, and a second electric motor assembly formed by mounting the other one of the pair of electric motors to the other one of the pair of electric motor covers, wherein the second electric motor assembly is detachably mounted to the pump case so as to rotate a second control shaft around its axis line.

Hydraulic actuator unit

Growing community of inventors

Amagasaki, Japan

Minoru Kamada