Kubota Corporation

Tetsu Fukui

Shigekazu Hasegawa

Yoshimi Oota

Takeshi Ura

Tetsuo Yamaguchi

Toshihiko Takemura

Susumu Umemoto

Takashi Yoshii

Satoshi Machida

Hidetoshi Hana

Yoshifumi Horiuchi

Akio Hattori

Hiroyuki Miki

Isamu Kawai

Mikio Kinoshita

Takashi Yasumi

A transmission control apparatus includes transmission lines disposed between a pair of transmission shafts and a hydraulic multiple disc transmission clutch disposed on one side of the transmission lines. Power from an engine is transmitted via one of the transmission lines to a traveling unit. Each of the transmission lines has a friction clutch. A first gear mechanism operated by a first actuator is disposed between one of the transmission shafts and the first transmission line. A second gear mechanism operated by a second actuator is disposed between one of the transmission shafts and the second transmission line. When the first transmission line is powered, a first system operates the second gear mechanism into a speed position; the first clutch to a non-transmitting state and the second clutch to a transmitting state, thereby providing a progressive shifting of the transmission clutch from a transmitting state to a semi-transmitting state.

Control apparatus for transmission

A transmission system having a first clutch for receiving engine drive, a second clutch disposed downstream of the first clutch with respect to a direction of drive transmission, change speed gearing disused between the first clutch and second clutch, a first transmission shaft for transmitting drive from the first clutch to the change speed gearing, a second transmission shaft for transmitting drive in varied speeds from the change speed gearing to the second clutch, a third transmission shaft for transmitting drive from the second clutch to drive wheels, and a third clutch for transmitting drive at a low speed to the first transmission shaft. The first clutch and second clutch are disengageable upon start of a shifting operation of the change speed gearing, and re-engageable upon completion of the shifting operation. To obtain matching between rotating rates of an input line and an output line of the change speed gearing, the third clutch transmits the low speed drive to the first transmission shaft upon disengagement of the first clutch and second clutch, and breaks the drive upon completion of the shifting operation of the change speed gearing.

Transmission system for transmitting engine drive in varied speeds to

A control system for controlling change speed gearing (A) of a vehicle for transmitting output of an engine (1) in varied speeds to wheels. This system has a first clutch mechanism mounted in a drive transmitting line between the engine and the change speed gearing, the first clutch mechanism including two hydraulically operable clutches (5, 6) for forward drive and backward drive, and a backward-forward changeover valve (32) for selectively operating the two clutches; a second clutch mechanism mounted in a drive transmitting line between the change speed gearing and the wheels, the second clutch mechanism including a quick operating clutch (19) for quickly making and breaking drive transmission, and a clutch control valve (26) for controlling the quick operating clutch; actuators (T1, T2) for shifting the change speed gearing; and a control unit (30) operatively connected to the backward-forward changeover valve, clutch control valve and actuators. In response to start of a shifting operation of the actuators, the quick operating clutch is disengaged and an engaged one of the hydraulically operable clutches of the first clutch mechanism is reduced to a predetermined low pressure. In response to completion of the shifting operation of the actuators, the quick operating clutch is engaged and the clutch of the first clutch mechanism is gradually raised from the predetermined low pressure.

Propelling transmission structure for a working vehicle

A four wheel drive working vehicle having transmission clutches separately operable for driving right and left rear wheels. Power for driving right and left front wheels is transmitted thereto from a change speed device through a front differential, while power for driving the rear wheels is transmitted thereto from the change speed device through the transmission clutches, respectively. When the front wheels are steered from a straight running position beyond a predetermined angle in order to turn the vehicle, the transmission clutch corresponding to the rear wheel lying on the inside of the turn is disengaged while the transmission clutch corresponding to the outside rear wheel remains engaged. Consequently, the rear wheel lying on the inside of the turn and describing the smallest turning radius is placed in free rotation state. The working vehicle can change running directions and make small, sharp turns smoothly without a rear differential.

Four wheel drive working vehicle having transmission clutches separately

A rolling clutch apparatus having two one-way transmission mechanisms arranged axially of a drive shaft and a driven shaft. Each transmission mechanism includes an inner ring defining a conical outside surface, an outer ring disposed coaxially with the inner ring and defining a conical inside surface, and tapered rollers arranged between the conical surfaces of the inner and outer rings. The transmission mechanisms are shiftable at the same time so that the rollers in one of the transmission mechanisms are displaced axilly to be pressed between the conical surfaces of the inner and outer rings whereby the inner and outer rings rotate together to transmit drive.

Conical roller type clutch apparatus

A power transmission comprising a drive shaft and a driven shaft connected to each other to be relatively rotatable within a predetermined range. The connection between the two shafts includes a cam member axially slidable on the driven shaft. The driven shaft carries a brake device interlocked with the cam member. When an accelerating force is transmitted from ground wheels to the driven shaft, the cam member slides axially of the driven shaft. This sliding movement causes the brake device to brake the driven shaft.

Power transmission

A propelling drive control apparatus for a working vehicle comprising hydraulically operable friction clutches, a first clutch control valve for selecting between the friction clutches, and a second clutch control valve connected in series to the first clutch control valve. The second clutch control valve is manually switchable to a declutching position for disengaging the friction clutches, a first clutch engaging position for engaging one of the friction clutches, and a second clutch engaging position intermediate between the declutching position the first clutch engaging position. In this second clutch engaging position one of the friction clutches is operable under a lower hydraulic pressure than in the first clutch engaging position.

Propelling drive control apparatus for working vehicle

A grass cutting system for use on a walking operator type or a riding type lawn mower as mounted between front and rear wheels. This grass cutting system comprises a cutting blade rotatable on a vertical axis, a grass catcher disposed above the cutting blade and defining a top opening, and a housing surrounding the grass catcher. A cylindrical space is defined between the grass catcher and the housing, through which grass clippings are fed with air currents from the cutting blade to the grass catcher.

Grass cutting system having a grass catcher

A hydraulic construction for a working vehicle comprising a transmission case housing a hydraulic clutch and defining a lateral opening, and hydraulic control device mounted on an inner face of a cover attached to the transmission case to close the opening, the hydraulic control device acting to control oil flows to the hydraulic clutch. The hydraulic control device is hydraulically connectable to oil passage device connected to the hydraulic clutch when the cover is attached to the transmission case.

Transmission casing including a hydraulic clutch

A four-wheel driven vehicle including a front wheel high/low speed changeover device adapted to be set to the high speed side upon detection of at least one condition out of three conditions, i.e. an excessive turning angle of the front wheel over a predetermined angle, a low vehicle speed below a predetermined speed and actuation of either rear wheel brake.

Four-wheel driven vehicles

A drive apparatus for a work vehicle such as a tractor is disclosed, with an engine, an input shaft coupled to the engine, a change-speed mechanism, a hydraulic clutch, an auxiliary change-speed mechanism and a reduction mechanism housed in a common transmission case. Power from the reduction mechanism is transmitted to the rear wheels through a rear differential and to the front wheels through a drive shaft and a front differential.

Drive apparatus

The invention provides a speed changing apparatus for a working vehicle comprising branched transmission lines between an input shaft and an output shaft. Each of the transmission lines includes one or more synchromesh type change speed gear mechanisms and one hydraulically operated clutch.

Speed changing apparatus for a working vehicle

A transmission for agricultural tractors in which a front wheel speed increasing transmission part (12) is disposed forwardly of a main transmission part (8). An input shaft (13) and an output shaft (15) of the speed increasing transmission part (12) are arranged coaxial with a front wheel drive output shaft (14a) of the main transmission part (8).

Growing community of inventors

Sakai, Japan

Tetsu Fukui