Kanzaki Kokyukoki Mfg. Co., Ltd.

Other

Shinya Sakakura

Shigenori Sakikawa

Yoshitaka Ishimaru

Ryota Ohashi

Koji Iwaki

Hideki Kanenobu

Takeshi Okazaki

Masaru Iida

Tsuyoshi Kita

A hydraulic transaxle comprises a transaxle housing, an axle, a hydraulic pump, a hydraulic motor, a hydraulic circuit, and a pair of auxiliary pumps. The transaxle housing defines a fluid sump therein. The axle is supported by the transaxle housing. The hydraulic motor is disposed in the transaxle housing so as to drive the axle. The hydraulic pump is disposed in the transaxle housing so as to supply hydraulic fluid to the hydraulic motor. The hydraulic circuit is disposed in the transaxle housing so as to fluidly connect the hydraulic pump to the hydraulic motor. The pair of auxiliary pumps are disposed in the transaxle housing so as to supply fluid from the fluid sump to outside of the transaxle housing.

Hydraulic transaxle

A hydraulic transmission system for a zero-turn vehicle, comprises first and second transaxles each of which includes an axle, a casing supporting the axle, a fluid sump provided in the casing, first and second ports provided on the casing and opened outward from the casing, an HST circuit, a charge pump disposed in the casing, and a charge passage disposed in the casing to supply the HST circuit with fluid delivered from the charge pump. A first pipe connects the first ports of the transaxles, thereby making the flow of fluid from the charge pump of the first transaxle to the fluid sump of the second transaxle. A second pipe connects the second ports of the transaxles, whereby overflowing fluid of the fluid sump of the second transaxle is released to the fluid sump of the first transaxle via the second pipe.

Hydraulic transmission system for zero-turn vehicle

A hydraulic transaxle has an axle casing and a pair of hydraulic motors disposed in the axle casing. The hydraulic motors have respective motor shafts and respective moveable swash plates. An axis of tilt of each moveable swash plate is offset with respect to a longitudinal axis of the respective motor shaft, and the moveable swash plates are operatively engaged to a steering operation device.

A hydrostatic transaxle is provided for a vehicle having a first axle and a second axle. The hydrostatic transaxle comprises: a hydraulic pump; a first hydraulic motor drivingly connected to the first axle; a closed circuit fluidly connecting the hydraulic pump to the first hydraulic motor; and a fluid-supply switching device shifted between a supply position for supplying fluid from the closed fluid circuit to a second hydraulic motor, which is disposed on the outside of the hydraulic transaxle and is drivingly connected to the second axle, and a supply-stop position for stopping the supply of fluid from the closed fluid circuit to the second hydraulic motor. The first hydraulic motor is variable in displacement, and the hydrostatic transaxle further comprises a linkage system for associating the switching of the fluid-supply switching device between the supply position and the supply-stop position with an operation for changing the displacement of the first hydraulic motor.

Hydrostatic transaxle

A hydrostatic transmission for vehicle interposed in a drive-power transmission path between a driving power source and a driving axle for non-stepwisely changing the speed of the vehicle includes an HST housing; a hydraulic pump unit having a pump shaft with first and second ends extending in a fore-aft direction of the vehicle away from each other; a hydraulic motor unit having a motor shaft for outputting the drive power from the motor shaft whose speed is non-stepwisely varied in cooperation with the hydraulic pump unit; a PTO unit having a PTO shaft extending in the fore-aft direction of the vehicle, the PTO shaft being operatively connected to the pump shaft; a charge pump unit for replenishing pressurized hydraulic fluid to a hydraulic circuit, the hydraulic circuit hydraulically connecting the hydraulic pump unit with the hydraulic motor unit, the charge pump unit including a charge pump body, and a charge pump case connected to the HST housing through its wall closer to the driving axle for supporting the charge pump body; the PTO shaft having an one end closer to the driving axle, the one end extending outwardly through the HST housing to have an outer extension positioned outside of the HST housing; and the charge pump case being designed so as to bearing-support the outer extension of the PTO shaft.

Hydrostatic transmission and power train for vehicle

A hydrostatic transmission constructed so that a check valve and a relief valve are made as compact as possible to supply oil to a closed circuit for connecting a hydraulic pump and a hydraulic motor, and to regulate maximum pressure in the closed circuit. A check valve and a relief valve are contained in a valve casing. A valve body of the relief valve is disposed opposite to a valve body of the check valve. A relief spring of the relief valve is retained by a cover detachably mounted to an open end of the valve casing, thereby facilitating pressure setting of the relief valve. The valve body of the relief valve is contained in a relief valve casing slidably disposed in the valve casing. A plunger, capable of urging the check valve in the opening direction via the relief valve casing, is provided in the cover, thereby enabling the check valve to be manually opened.

Hydrostatic Transmission

A variable displacement hydraulic system contains a housing, a cylinder block provided with a plurality of pistons movable in reciprocation, and a swash plate for controlling reciprocation of each of the pistons so that the swash plate is slantwise rotatable along a slidable contact surface of arcuate shape. A thrust metal is mounted to an arcuate contact surface of the housing. Arcuate plates having smooth surfaces of high sliding efficiency are fixed onto outwardly curved portions formed at the rear surface of the swash plate, which is in contact with the thrust metal. Alternatively, a smooth surface layer having a high sliding efficiency is formed on the swash plate by applying chemical processes, thereby reducing the sliding resistance of the swash plate and improving the ease with which the swash plate is restored to the neutral position.

Variable displacement hydraulic system

Hydrostatic transmission

In a valve mechanism for controlling oil pressure in an oil path (13) connecting between a hydraulic pump (11) and motor (12) of a hydrostatic transmission (10), a differential piston (23) serving as a relief valve member for gradually increasing the oil pressure has a larger pressure-applied surface area at the side opposite to the oil path than at the side of this path. A throttled oil passage (24) is provided for conducting oil pressure in the path to the larger surface area. The piston is biased by a valve spring (25) through a control piston (26). A receiving member (27) for the spring and a stopper member (28) for the control piston are provided such that they are adjustable in position independently of each other. By this, the manner of increasing the oil pressure may be adjusted in a large variety. The valve mechanism also serves as a relief valve for excluding a possible, excessively high pressure.

Growing community of inventors

Amagasaki, Japan

Shinya Sakakura