Hydraulic system for work machine and work machine
AssigneeKubota Corporation
InventorsYuji Fukuda, Kazuyoshi Arii, Hiroaki Nakagawa
Life of this patent
Estimating the term…
Abstract
A hydraulic system for a work machine includes a tank to store an operation fluid, a hydraulic device to be operated by the operation fluid, a control valve to control the hydraulic device, a first fluid tube connecting the hydraulic device and the control valve, the first fluid tube being to supply the operation fluid from the control valve to the hydraulic device, a second fluid tube branching from the first fluid tube and connected to the tank, a switch valve provided to the second fluid tube, the switch valve being to control a flow rate of the operation fluid, and an oil cooler provided to the second fluid tube between the switch valve and the tank.
Claims11
A hydraulic system for a work machine comprising:
- a tank to store an operation fluid;
- a hydraulic device to be operated by the operation fluid;
- a travel motor to be operated by the operation fluid;
- a control valve to control the hydraulic device;
- a first fluid tube including:
- a first supply-discharge fluid tube and a second supply-discharge fluid tube, both of the first supply-discharge fluid tube and the second supply-discharge fluid tube connecting the hydraulic device and the control valve and being configured to supply the operation fluid from the control valve to the hydraulic device;
- a second fluid tube branching from the first supply-discharge fluid tube and connected to the tank;
- a switch valve provided to the second fluid tube, the switch valve being to control a flow rate of the operation fluid;
- an oil cooler provided to the second fluid tube between the switch valve and the tank;
- a sixth fluid tube to supply the operation fluid into the oil cooler, the operation fluid being applied to the travel motor;
- and
- a second check valve provided to the second fluid tube, the second check valve being to block the operation fluid flowing from the oil cooler to the switch valve.
A hydraulic system for a work machine comprising:
- a working hydraulic pump to output an operation fluid;
- an extending hydraulic pump to output the operation fluid;
- a hydraulic device to be operated by the operation fluid;
- a control valve to control the hydraulic device;
- a first fluid tube including:
- a first supply-discharge fluid tube and a second supply-discharge fluid tube, both of the first supply-discharge fluid tube and the second supply-discharge fluid tube connecting the hydraulic device and the control valve and being configured to supply the operation fluid from the control valve to the hydraulic device;
- a second fluid tube connected to the second supply-discharge fluid tube, the second fluid tube being capable of draining the operation fluid of the second supply-discharge fluid tube;
- an eighth fluid tube branching from the first supply-discharge fluid tube and connected to the extending hydraulic pump;
- a first operation valve including a pressure-receiving portion to receive a pressure of a pilot fluid that is the operation fluid, the first operation valve being provided to the second fluid tube and configured to change an aperture of the first operation valve in accordance with the pressure of the pilot fluid applied to the pressure-receiving portion;
- a third operation valve including a pressure-receiving portion to receive the pressure of the pilot fluid, the third operation valve being provided to the eighth fluid tube and configured to change an aperture of the third operation valve;
- a seventh fluid tube connecting the pressure-receiving portion of the first operation valve and the pressure-receiving portion of the third operation valve;
- a second operation valve provided to the seventh fluid tube;
- and
- a ninth fluid tube branched from the seventh fluid tube and connected to a pressure-receiving portion of the control valve.
Dependencies are inferred from the claim text.