Kanzaki Kokyukoki Mfg. Co., Ltd.

Yanmar Co., Ltd.

Kazuhiro Owada

Koji Iwaki

Kengo Sasahara

Yasuhisa Mochizuki

Hidekazu Niu

Koji Sakata

Kohei Ogura

Ryo Motooka

Keishi Yamanaka

Takumi Takahashi

Kensuke Kaneda

In a transmission of the present invention, a transmission case has a peripheral wall with an opening sized to allow an HST to be other than a main plate of the HST. The HST has the main plate and a sub-plate sandwiching members out of a center section, a pump-side holder and a motor-side holder that face to each other with the pump main body and the motor main body being arranged between the members. The sub-plate has an engaging portion, and the transmission case has a mounting seat with which the engaging portion is engaged in a slidable manner so that the HST is guided until an installation position.

HST and transmission

In a transmission structure according to this invention, speed change ratios of input side first and second transmission mechanisms are set so that the rotational speed of a planetary second element is the same when an HST output is set to a second HST speed in either a first transmission state or a second transmission state, and the rotational speed of a planetary first element is the same when the HST output is set to the second HST speed in either the second transmission state or the first transmission state. The speed change ratios of an output side first and second transmission mechanisms are set so that the rotational speed developed in a speed change output shaft when the HST output is set to the second HST speed is the same in either the first or second transmission states.

Transmission structure and working vehicle

An HST of the present invention includes a main plate and a sub-plate supporting a center section, a pump-side swash plate holder and a motor-side swash plate holder by their inner surfaces facing each other. The main plate is provided with an extended region that extends farther outward in a planar direction of the main plate than an installation space of the center section, the pump-side swash plate holder and the motor-side swash plate holder and than the sub-plate as viewed along a direction in which the main plate and the sub-plate face each other.

HST and transmission device

A transmission structure of the present invention changes capacity of pump body so that vehicle speed detected by vehicle speed sensor increases and reduces according to speed-increasing and speed-reducing operations of speed-change operating member while fixing capacity of motor body at a low-speed motor capacity when the vehicle speed is equal to or lower than a switching speed that is realized by setting motor body to the low-speed motor capacity and setting the pump body to a predetermined pump switching capacity, and changes capacity of motor body so that vehicle speed increases and reduces in accordance with speed-increasing and speed-reducing operations of speed-change operating member while fixing capacity of the pump body at the pump switching capacity when vehicle speed is higher than the switching speed.

Transmission structure

A transmission structure of the present invention causes, during a period from a time point when a rotational speed of a drive rotational power reaches a predetermined first/second speed stage shift-up start speed until a first/second speed stage shift-up end time point, one of an input-side clutch mechanism pair and an output-side clutch mechanism pair to be in a double transmitting state, and causes, in the double transmitting state, a first clutch mechanism and a second clutch mechanism of the other one of the input-side clutch mechanism pair and the output-side clutch mechanism pair to be shifted to a disengagement sate and an engagement state, respectively, while having frictional plate slid.

A working vehicle of this invention includes a main speed change structure that includes a continuously variable speed change structure such as an HMT structure and a multi-speed speed change structure capable of switching between a first power transmission state with a first gear ratio and a second power transmission state with a second gear ratio providing a higher speed than the first gear ratio. A control device causes the continuously variable speed change structure to be accelerated to a forward travel side in accordance with an accelerating operation of a speed change operation member in a forward travel direction, and causes the multi-speed speed change structure to be changed from a first power transmission state to a second power transmission state when the rotational speed of the speed change output shaft reaches a switching speed set to exceed a work speed range.

Working vehicle

The hydraulic apparatus is set so that the ratio of the pressure-receiving area of the respective bottom oil chambers of the boom cylinder, the arm cylinder and the bucket cylinder to the pressure-receiving area of the respective rod oil chambers matches the ratio of the extruded volume drawn into or discharged from the bottom oil chambers per single rotation by the respective extrusion members of the first hydraulic pump motor, the second hydraulic pump motor and the third hydraulic pump motor to the volume discharged from or drawn into the rod oil chambers.

Hydraulic apparatus

There is provided a hydrostatic transmission (HST) in which a hydraulic pump unit operatively driven by a driving power source and a hydraulic motor unit arranged spaced apart from the hydraulic pump unit and operatively driving a driving-wheel are fluidly connected by way of operation fluid lines so as to form a closed circuit. The hydraulic motor unit is provided with motor-side operation fluid passages forming one part of the operation fluid lines. A motor-side charge fluid passage having a first end opened to an outside to form a motor-side charge port and a second end fluidly connected to at least one of the motor-side operation fluid passages is also included. A check valve is interposed in the motor-side charge fluid passage so as to allow the fluid to flow from the motor-side charge port to one motor-side operation fluid passage while preventing reverse flow.

Growing community of inventors

Amagasaki, Japan

Kazuhiro Owada