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 construction machine is provided which is capable of warming up without an additional hydraulic device. A hydraulic excavator includes a cooling oil line connected to an arm control valve for leading hydraulic oil discharged from the arm control valve to a tank through an oil cooler when the arm control valve is shifted to an extension position, and a non-cooling oil line connected to the arm control valve for leading hydraulic fluid discharged from the arm control valve to the tank running away from the oil cooler when the arm control valve is shifted to a neutral position. The arm control valve includes a guide passage provided at the neutral position for leading hydraulic fluid discharged from a hydraulic pump to the non-cooling oil line.

A mobile hydraulic system includes a hydraulic actuator coupled to a load, and a control unit coupled to the load and/or to the hydraulic actuator. The control unit is adapted to anticipate an over-center transition of the load relative to a gravity vector prior to the over-center transition through the use of sensors configured with accelerometers, gyroscopes and magnetometers. In some examples, the over-center transition is from an overrunning driving of the load to a passive driving of the load. In some examples, the over-center transition is from a passive driving of the load to an overrunning driving of the load. In some examples, the control unit is adapted to control change in a metered flow through one or more ports of the associated actuator to minimize and/or prevent one or more hydraulic effects of the anticipated over-center transition. In some examples, the control unit controls the metered flow by causing one or more actuators (e.g., a solenoid) to shift one or more valve positions to change the flow through one or more ports of the associated actuator.

An excavator includes at least one gyro sensor for sensing the incline of equipment; a swing motor for rotating an upper body of the excavator; a first pressure sensor for sensing an operating pressure value applied to the swing motor; a swing joystick for driving the swing motor; a second pressure sensor for sensing a manipulation value inputted into the swing joystick; and a controller, wherein the controller receives pieces of information sensed by the gym sensors, the first pressure sensor, and the second pressure sensor, and detects the operating pressure value of the swing motor, sensed through the first pressure sensor, so as to notify a worker of the time at which lubricating oil is added if a maximum manipulation value is inputted into the swing joystick for a minimum measuring time or more in a swing friction force measurement mode.

A construction machine includes an image capturing device configured to capture an image of the surroundings, an image display part mounted in an operator's cab and configured to display a menu screen showing an operating condition and various settings, or the captured image captured with the image capturing device, an operation part including a menu switch to cause the menu screen to be displayed on the image display part, and a detector configured to detect whether a work element is enabled or disabled. The image display part is configured to display a warning in response to the menu switch being operated while the work element is enabled.

An hydraulic system for a working machine, the system comprising an engine, and an engine speed sensor configured to detect the engine speed; a travel pump configured to actuate a travel actuator, and a travel pump pressure sensor configured to detect the travel pump pressure; a service pump configured to actuate a service actuator, and a service pump pressure sensor configured to detect the service pump pressure; and a micro-controller unit configured to receive input values from each sensor, and configured to determine whether each input value is within a predetermined range where the engine will not stall. The micro-controller unit is configured to provide an output when at least one input value is outside the predetermined range.

A hydraulic control device includes: a recovery oil passage; a regenerative motor that rotates an output shaft of an engine in response to a supply of the hydraulic fluid and is driven to rotate by rotation of the output shaft of the engine; a regenerative oil passage for guiding return oil from a boom cylinder to the regenerative motor without passing the return oil through the recovery oil passage; a coupling oil passage that couples the recovery oil passage and the regenerative oil passage to each other; and a regeneration-side check valve that is provided on the coupling oil passage, and allows the hydraulic fluid to flow from the recovery oil passage toward the regenerative motor, and moreover restricts the hydraulic fluid from flowing from the regenerative motor toward the recovery oil passage.

A hydraulic system includes: hydraulic actuators; a control valve for controlling the hydraulic actuators; a tank for storing a hydraulic operation fluid; a variable displacement pump for supplying the hydraulic operation fluid to the hydraulic actuators; a regulator for controlling the variable displacement pump; a pilot pump for discharging a hydraulic pilot fluid; a load sensing system for maintaining a differential pressure to be a constant pressure, the differential pressure being obtained by subtracting a second signal pressure from a first signal pressure that is the discharge pressure of the variable displacement pump, the second signal pressure being the maximum one of the load pressures generated in the hydraulic actuators; a signal tube for sending the second signal pressure to the regulator; a throttle provided on the signal tube; and a warm-up circuit for supplying the hydraulic pilot fluid to a downstream side of the throttle.

A control system for a machine is disclosed. The control system may have a bypass passage situated to allow fluid to bypass an actuator, and a warmup valve disposed within the bypass passage that is movable between flow-passing and-blocking positions. A controller is configured to move the warmup valve to the flow-passing position, fix a displacement position of the pump, compare the pressure of the fluid of the actuator with a threshold, and move the warmup valve to the flow-blocking position and reduce a pump outlet pressure when the pressure of the fluid is greater than the threshold. The controller may be configured to move the warmup valve to the flow-passing position, fix a displacement position of the pump, and adjust an input speed of the pump in response to the signal.

A hydraulic fluid tank arrangement for a working machine is provided, the arrangement including a hydraulic fluid tank; an inlet portion for receiving hydraulic fluid into the hydraulic fluid tank; and an oil filter arranged in fluid communication with the inlet portion; wherein the hydraulic fluid tank arrangement further includes a gas removal device arranged in fluid communication with the oil filter downstream the inlet portion and upstream the oil filter for removing gas from the hydraulic fluid before the hydraulic fluid reaches the oil filter. A method for removing gas from hydraulic fluid contained in a hydraulic fluid tank arrangement is also provided.