A work vehicle includes a work implement. A control system for the work vehicle includes an operating device that outputs an operation signal indicative of an operation by an operator, and a controller that communicates with the operating device and controls the work implement. The controller determines a target design topography indicative of a target topography. The controller generates a command signal to operate the work implement in accordance with the target design topography. When a tilt angle of the work implement is changed with an operation of the operating device, the controller corrects the tilt angle of the work implement in accordance with the changed tilt angle.

A transmission system includes a transmission assembly having clutches to transmit power from an input shaft to an output shaft at a plurality of gear ratios. A traction motor drives the input shaft and propels the work vehicle, while a controller controls operation of the transmission assembly and the traction motor. A hydraulic circuit controls actuation of the clutches responsive to commands from the controller. The hydraulic circuit includes a hydraulic pump driven by the traction motor, an accumulator connected to the hydraulic pump and that holds hydraulic fluid therein under pressure, and an unloading valve positioned in a secondary fluid path running from an outlet of the hydraulic pump to a sump. The unloading valve operates in a closed state to direct hydraulic fluid from the hydraulic pump to the accumulator and operates in an open state to direct hydraulic fluid from the hydraulic pump to the sump.

An excavator or other work machine includes a tilting bucket operated by a hydraulic actuator controlled by a bucket control valve responsive to control signals including a bucket shake control signal, which causes the bucket to move repeatedly in the rack and dump directions to shake debris from the bucket in a bucket shake operation. The actuator is powered by pressure from a hydraulic pump, and a control system includes an unloader valve to relieve pressure from the supply line to unload the pump when there is no demand for power. The control system is arranged to maintain a constant pressure signal in a load sensing line, to maintain the unloader valve constantly in a closed condition, for the duration of the bucket shake operation. This may be achieved by pressurising an actuator of a quick coupler to lock the bucket to the machine.

A hydraulic excavator drive system includes: a first pump connected to a head-side chamber of a boom cylinder; and a second pump that supplies hydraulic oil to one of, or both, an arm cylinder and a bucket cylinder. The first pump is driven by an electric motor. The drive system further includes a switching valve that is in a first position at a boom raising operation and in a second position at a vehicle body lifting operation. The first position is a position in which the switching valve brings a rod-side chamber of the boom cylinder into communication with a tank, and the second position is a position in which the switching valve brings the rod-side chamber into communication with the second pump.

An electric machine and method for powering the electric machine using interchangeable power modules that are configured to be interchangeably placed within power bays of the electric machine is disclosed. The electric machine includes an electrical module that is configured to receive power from one or more of the power modules placed in the power bays and transform, such as from DC to multi-phase alternating current (AC), and provide the power to one or more motors of the electric machine. The power modules may be of the same dimensions, same electrical interfaces, and/or same power output (e.g., type, magnitude) as each other to enable the interchangeability of the power modules. The power modules may be ones that generate power or ones that store energy. In some cases, the generating power modules may charge the energy storage power modules, while the energy storage power modules power the electric machine.

To provide a driving device capable of improving the operability of a plurality of single rod hydraulic cylinders. The present invention takes a construction provided with a closed circuit A in which first and third hydraulic pumps 12, 14 and a boom cylinder 1 are connected through selector valves 43a, 45a in a closed-circuit fashion, a plurality of open circuits E, F provided with second and fourth hydraulic pumps 13, 15 and selector valves 44a, 46a that switch the supply destinations of hydraulic oils flowing out from the second and fourth hydraulic pumps 13, 15, and a connection passage 301 connected to sides of the selector valves 44a, 46a from which sides hydraulic oil flows out, and connected to the closed circuit A.

An inspection device for hydraulic equipment includes a hydraulic circuit having a branch valve, an optical detection section, a pump configured to supply oil to the hydraulic circuit, and a controller. The optical detection section includes an inspection oil passage connected to the branch valve. The inspection oil passage includes a filter arranged to collect foreign matter. The controller operates the branch valve to supply oil to the inspection oil passage. The optical detection section includes first and second foreign matter detection sections arranged on upstream and downstream sides of the filter to detect foreign matter. A work vehicle includes the inspection device. An inspection system includes the inspection device. An inspection method includes supplying oil to an inspection oil passage by operating a branch valve of a hydraulic circuit, and detecting foreign matter on upstream and downstream sides of a filter arranged on the inspection oil passage.

The present disclosure relates to a grader and a blade control method. The grader includes: a blade mechanism including a blade; a blade adjusting mechanism including a plurality of adjusting means respectively corresponding to at least two degrees of freedom of the blade, and configured to adjust a spatial position and/or angle of the blade; a blade position detecting mechanism configured to detect a slope parameter for characterizing a spatial position of the blade; a motion trajectory library configured to store motion functions of the plurality of adjusting means respectively when different operation conditions and/or different grades are switched; a controller configured to call a corresponding motion function in the motion trajectory library according to a set operation condition and a required slope, and control at least one of the plurality of adjusting means according to a position parameter of the blade and the motion function.

Disclosed is an apparatus for improving excavating operation characteristic and grading operation characteristic of an excavator. The apparatus includes a solenoid valve group and a hydraulically controlled selector valve. An oil controlling output A1 of the solenoid valve group is configured in series with oil controlling input a1 of the hydraulic control valve. An oil controlling output A2 of the solenoid valve group is configured in series with a pilot control end XBa2 of a multi-port valve group. An oil return port T1 of the solenoid valve group is connected to the hydraulic oil tank. An oil controlling output b1 of the hydraulically controlled selector valve is connected to a pilot control end XAb2 of the multiplexer valve group, and an oil return port T2 of the hydraulically controlled selector valve is connected with the hydraulic oil tank. The apparatus improves operational efficiency and control comfortability.

Each of left and right direction switching valves includes: a pump port connected to a pump; a first compensation port connected to an upstream side of a corresponding pressure compensation valve; a second compensation port connected to a downstream side of the corresponding pressure compensation valve; a pair of supply/discharge ports connected to a corresponding travel motor; and a communication port. The communication ports of the left and right direction switching valves are connected by a communication line. When a spool shifts from a neutral position by the travel operation device, the pump port communicates with the first compensation port and the second compensation port communicates with one of the supply/discharge ports and the communication port. Each direction switching valve is configured wherein a degree of communication between the second compensation port and communication port increases in a shifting amount of the spool from the neutral position.