A hydraulic system includes a hydraulic pump to output an operation fluid, first and second hydraulic devices to be operated by the operation fluid, first and second control valves to control the first and second hydraulic device, respectively, first and second communication tubes connecting the first hydraulic device to the first control valve, a supply fluid tube connecting the first control valve to the second control valve, the supply fluid tube being configured to supply the return fluid to the second control valve, first and second connection fluid tubes disposed on the first control valve, a discharge fluid tube connected to the first control valve, first and second branching fluid tubes branched from the first and second connection fluid tubes, respectively, first and second throttles disposed on the first and second branching fluid tubes, respectively, the second throttle being smaller than the first throttle.

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.

A manifold structure for a fluid reclamation apparatus incorporated into a hydraulic system having inner and outer fluid lines and with annular containment space between the inner and outer fluid lines for capturing fluid leaking from the inner fluid line, the manifold structure being connected to least one end the inner and outer fluid lines and contains a chamber for receiving leaked fluid from the annular space and including a manifold inner sleeve to which the inner fluid line is coupled, the inner sleeve being retained within a manifold outer sleeve to which the outer fluid line is coupled and having a lateral bore extending from the chamber and through the outer sleeve for delivering leaked fluid into a reclamation line and back into the hydraulic system, the inner sleeve being rotatably mounted within the outer sleeve by at least one O-ring seated in a groove around the inner sleeve and sealingly abutting the inner surface of the outer sleeve.

A manifold structure for a fluid reclamation apparatus incorporated into a hydraulic system having inner and outer fluid lines and with annular containment space between the inner and outer fluid lines for capturing fluid leaking from the inner fluid line, the manifold structure being connected to least one end the inner and outer fluid lines and contains a chamber for receiving leaked fluid from the annular space and including a manifold inner sleeve to which the inner fluid line is coupled, the inner sleeve being retained within a manifold outer sleeve to which the outer fluid line is coupled and having a lateral bore extending from the chamber and through the outer sleeve for delivering leaked fluid into a reclamation line and back into the hydraulic system, the inner sleeve being rotatably mounted within the outer sleeve by at least one O-ring seated in a groove around the inner sleeve and sealingly abutting the inner surface of the outer sleeve.

Hydraulic fluid flushing valve for hydrostatic units usable in closed hydraulic circuit propel applications, having a flushing valve housing with a first inlet port connected to a first working line, a second inlet port connected to a second working line, and a discharge port for draining hydraulic fluid. A two-sided flushing valve flushing valve spool which can be shifted is mounted within the flushing valve housing in a cylindrical valve bore, which, in a shifted position, enables a fluid flow from one of the first or the second inlet port at which the lower hydraulic pressure is present, to the discharge port. The flushing valve spool includes on each side a pressure surface each of which is connected to one of the two inlet ports. At each side of the flushing valve spool a flushing valve spring is located in the flushing valve housing in such a manner that, when the flushing valve spool is in its centre, non-shifted position, at each side of the flushing valve spool a distance between a spring contact surface on the flushing valve spool and a spring support surface in the flushing valve housing is greater than the axial length of the corresponding flushing valve spring.

A working machine includes a prime mover, a hydraulic pump driven by power of the prime mover, a cooler including a cooling fan rotated by either the power of the prime mover or hydraulic fluid delivered from the hydraulic pump, and a controller configured or programmed to perform a reduction control for reducing a target fan rotation speed that is a target rotation speed of the cooling fan in response to reduction of an actual prime mover rotation speed that is an actual rotation speed of the prime mover, and to perform, after the reduction control, a restoration control for restoring the target fan rotation speed. The controller is configured or programmed to make a difference between a reduction rate of the target fan rotation speed in the reduction control and an increase rate of the target fan rotation speed in the restoration control.

A system uses a two-stage electrohydraulic servo valve that includes an additional control port that commands a fail-fixed valve to lock the position of a device in the last commanded position. The additional port is modulated by an existing land on the EHSV valve element, adding little to no complexity. Major technical benefits of the disclosed system are that it adds little to no cost, complexity, size, or weight the device being controlled. The disclosed configuration allows for the use of a relatively small and simple fail-fixed valve, and the control ports on the controlled device keep “drift” to a minimum, when transitioning between normal operating mode and fail-fixed operating mode.

A load sensing valve maintains a differential pressure at a set pressure by controlling a regulator in accordance with a differential pressure between a discharge pressure of a hydraulic pump and a load pressure of hydraulic actuators. A set pressure control device controls the set pressure. A controller controls the set pressure control device to reduce the set pressure more than when the work implement is being operated, when a predetermined determination condition that includes the work implement not being operated is satisfied.

A work machine including a prime mover, an electric motor, an electric motor fluid circuit, a transmission fluid circuit, a hydraulic circuit, a cooling circuit, a pump, and a controller. The electric motor may supply a portion of power of the prime mover. The electric motor fluid circuit may be adapted to remove waste heat from the electric motor. The transmission fluid circuit may be adapted to lubricate a moving part of a transmission powered by the prime mover. The hydraulic circuit may be adapted to transmit power from the prime mover to a moving component of the work machine. The cooling circuit may be absorbing waste heat from one or more of the electric motor fluid circuit, the transmission fluid circuit, and the hydraulic circuit. The control may be adapted to control diversion of a portion of waste heat from the cooling circuit to a portion of the cab.

A work machine including a prime mover, an electric motor, an electric motor fluid circuit, a transmission fluid circuit, a hydraulic circuit, a cooling circuit, a pump, and a controller. The electric motor may supply a portion of power of the prime mover. The electric motor fluid circuit may be adapted to remove waste heat from the electric motor. The transmission fluid circuit may be adapted to lubricate a moving part of a transmission powered by the prime mover. The hydraulic circuit may be adapted to transmit power from the prime mover to a moving component of the work machine. The cooling circuit may be absorbing waste heat from one or more of the electric motor fluid circuit, the transmission fluid circuit, and the hydraulic circuit. The control may be adapted to control diversion of a portion of waste heat from the cooling circuit to a portion of the cab.