Patent classifications
F16H61/433
Control device for hydraulic traveling device
A travel control device is provided with hydraulic pumps of a variable capacity type that are driven by an engine; hydraulic motors that are driven by discharged oil from the hydraulic pumps; traveling devices that are rotation-driven by the hydraulic motors; a travel operation lever that is operated so as to instruct a traveling operation; a first control valve for generating a charged hydraulic pressure by adjusting the discharged oil from a charge pump and a second control valve for generating a capacity control hydraulic pressure in accordance with the operation of the travel operation lever. The first control valve is designed to pressure-adjust and generate a charged hydraulic pressure in accordance with the rotation speed of the engine, and the hydraulic pump is subjected to a variable capacity control process by a capacity control hydraulic pressure that is pressure-adjusted and generated by the second control valve.
Control device for hydraulic traveling device
A travel control device is provided with hydraulic pumps of a variable capacity type that are driven by an engine; hydraulic motors that are driven by discharged oil from the hydraulic pumps; traveling devices that are rotation-driven by the hydraulic motors; a travel operation lever that is operated so as to instruct a traveling operation; a first control valve for generating a charged hydraulic pressure by adjusting the discharged oil from a charge pump and a second control valve for generating a capacity control hydraulic pressure in accordance with the operation of the travel operation lever. The first control valve is designed to pressure-adjust and generate a charged hydraulic pressure in accordance with the rotation speed of the engine, and the hydraulic pump is subjected to a variable capacity control process by a capacity control hydraulic pressure that is pressure-adjusted and generated by the second control valve.
HYDRAULIC SYSTEM IN WORK MACHINE
A hydraulic system in of a work machine includes a hydraulic pump to supply pilot hydraulic oil in a hydraulic oil reservoir. A travel pump is to drive a travel motor according to a pilot pressure of the pilot hydraulic oil. A target pilot pressure of the pilot hydraulic oil is input through a travel operation device to control, according to the target pilot pressure, the pilot pressure supplied from the hydraulic pump to the travel pump. A pilot oil path connects the travel operation device and the travel pump to supply the pilot pressure to the travel pump. A drain oil path is divided from the pilot oil path. A pressure adjustment valve is provided in the drain oil path to adjust the pilot pressure to be less than the target pilot pressure when a condition is satisfied.
WORK VEHICLE COLLECTIVE SWITCH APPARATUS AND WORK VEHICLE EQUIPPED WITH COLLECTIVE SWITCH APPARATUS
A work vehicle collective switch apparatus includes: a switch operation unit including a plurality of switches; a network side signal output unit that outputs a switch state signal to an in-vehicle network side connected to the collective switch apparatus; a drive signal output unit that outputs a drive signal to a direct-coupled device connected to the collective switch apparatus, and a control unit that outputs a command signal corresponding to switch operation on a basis of switch assignment information that assigns in advance as to whether the drive signal is to be output from the drive signal output unit or the switch state signal is to be output from the network side signal output unit in accordance with switch operation of any of the plurality of switches
A TRANSMISSION SYSTEM
A transmission system includes a power take-off for driving an implement and a hydrostatic unit for transmitting power from the engine to the power take-off. The hydrostatic unit includes a first hydraulic power unit having a first connection line and a second connection line, and a second hydraulic power unit having a first connection line and a second connection line. The hydrostatic unit also includes a valve for connecting the first hydraulic power unit and the second hydraulic power unit, the valve being positionable at least in a first position, in a second position and in a neutral position.
A TRANSMISSION SYSTEM
A transmission system includes a power take-off for driving an implement and a hydrostatic unit for transmitting power from the engine to the power take-off. The hydrostatic unit includes a first hydraulic power unit having a first connection line and a second connection line, and a second hydraulic power unit having a first connection line and a second connection line. The hydrostatic unit also includes a valve for connecting the first hydraulic power unit and the second hydraulic power unit, the valve being positionable at least in a first position, in a second position and in a neutral position.
Work Vehicle
The work vehicle includes: a clutch device including a forward-travel clutch and a backward-travel clutch configured to cause, when being in an engagement state, the work vehicle to travel in a forward travel direction and a backward travel direction; a forward-backward travel instruction device configured to instruct the work vehicle to travel in the forward travel direction or the backward travel direction; a clutch state detection device configured to detect whether the forward-travel clutch and the backward-travel clutch are each in the engagement state; and a torque restriction section configured to restrict a maximum absorbing torque of the hydraulic pump to be low when a restriction condition holds, the restriction condition including a condition that a traveling direction of the work vehicle, which corresponds to an engagement state of the clutch device, and a traveling direction of the work vehicle, which is instructed by the forward-backward travel instruction device are opposite to each other.
LOAD CANCELLING HYDROSTATIC SYSTEM
A load cancelling hydrostatic system is disclosed comprising at least two hydrostatic modules coupled in parallel. Each hydrostatic module comprises input and output hydraulic piston drive units, each of which is coupled to its respective unit in the other module by common drive shafts. The pistons in a hydraulic piston drive unit of one module are coupled together with those in the respective unit of the other module with a timing angle of about 0. The design advantageously cancels any axial imbalances and allows for use of radial drive shaft bearings which support an essentially purely radial load. In turn, greater power density and system efficiency can be obtained.
LOAD CANCELLING HYDROSTATIC SYSTEM
A load cancelling hydrostatic system is disclosed comprising at least two hydrostatic modules coupled in parallel. Each hydrostatic module comprises input and output hydraulic piston drive units, each of which is coupled to its respective unit in the other module by common drive shafts. The pistons in a hydraulic piston drive unit of one module are coupled together with those in the respective unit of the other module with a timing angle of about 0. The design advantageously cancels any axial imbalances and allows for use of radial drive shaft bearings which support an essentially purely radial load. In turn, greater power density and system efficiency can be obtained.
HYDROSTATIC TRANSMISSION AND METHOD FOR BRAKING USING THE SAME
A hydrostatic transmission is configured to realize a braking operation in which at least one adjustable traction motor, which acts as a pump, is supported via a closed circuit on an adjustable axial piston pump, which acts as a motor, and which in turn is supported on an internal combustion engine. Since overspeeding of the latter should be avoided, a control unit adjusts the pivot angle of the pump in accordance with a characteristic map which represents a relationship between a setting force and a pressure difference of two working lines of a closed circuit, a pump rotational speed, and the pivot angle. Thus, characteristic-map-based pilot control of the pivot angle of the pump is possible and feedback of the present pivot angle is omitted.