An exemplary embodiment suggested in the present specification provides an apparatus and a method of controlling a voltage of a direct current terminal of construction machinery equipped with a motor, which are capable of improving energy efficiency of a power conversion apparatus, such as an inverter and a converter by changing a voltage of the direct current terminal to an optimum voltage size in consideration of operation conditions of a swing motor, an engine auxiliary motor, and an energy storage apparatus.

Provided is a hybrid-type construction machine including a swing device of the hydraulic-electric combined swing type and by which, in a work for which accurate swing operability is demanded like, for example, a crane work, a swing body is driven alone by the electric motor. The hybrid-type construction machine includes an engine, a hydraulic pump driven by the engine, a swing body, an electric motor for driving the swing body, and a hydraulic motor driven by the hydraulic pump for driving the swing body. The swing body is swung by simultaneous drive by the electric motor and the hydraulic motor. The hybrid-type construction machine includes a control apparatus having a work mode changeover unit by which an operator changes over a mode in response to an aspect of a work and an electric alone swing controlling unit configured to control the swing body to be swung by the electric motor alone. When a work in which position accuracy is demanded is selected by the work mode changeover unit, the swing body is swung by the electric alone swing controlling unit.

The invention relates to a construction machine such as a road paver with an electric generator. The construction machine comprises a hydraulic oil system for hydraulic functions that also cools the generator.

An upper slewing body 3 includes: a bottom plate rotatably attached to a lower traveling body; supporting frames and standing on the bottom plate; an engine supported on the bottom plate by the supporting frames; a generator motor connected to the engine; and a terminal box including a terminal, which is electrically connected to the generator motor and allows a cable to be connected, and a box main body housing the terminal and being attached to the generator motor. The generator motor includes a facing section facing the bottom plate at a position separated from the supporting frames in a plan view. The terminal box is arranged between the facing section of the generator motor and the bottom plate.

A road working machine includes an operator's station that is adapted to be occupied by an operator of the road working machine. The road working machine also includes a controller and a safety light circuit that is operatively attached to the controller. The safety light circuit includes a plurality of downwardly directed safety lights that are located so as to provide lighted egress from the operator's station.

A debris accumulation control system is provided for usage within a work vehicle including an operator station and a work vehicle compartment. In embodiments, the work vehicle debris accumulation control system includes a display device located in the operator station of the work vehicle, a three dimensional (3D) imaging device having a field of view (FOV) encompassing a debris-gathering region of the work vehicle compartment, and a controller operably coupled to the display device and to the 3D imaging device. The controller is configured to: (i) utilize 3D imaging data provided by the 3D imaging device to estimate a debris accumulation risk level within the work vehicle compartment; and (ii) generate a first visual alert on the display device when the debris accumulation risk level surpasses a first predetermined threshold.

A hydraulic system includes a first electric machine connected to a first hydraulic machine and a second electric machine connected to a second hydraulic machine. An output side of the second hydraulic machine is connected to an input side of the first hydraulic machine. A hydraulic consumer is hydraulically coupled to an output side of the first hydraulic machine via a supply line and is powered by the first hydraulic machine. A return line hydraulically couples the hydraulic consumer to an input side of the first hydraulic machine. The second hydraulic machine provides a flow of hydraulic fluid to the input side of the first hydraulic machine if a requested flow from the first hydraulic machine exceeds a flow of the return line and recuperates energy if the requested flow from the first hydraulic machine is lower than the flow of the return line.

The invention includes a vehicle main body, a boom, a first actuator connecting the boom and the vehicle main body and configured to rotate the boom with respect to the vehicle main body about a first central axis, a first electric motor connected to the first actuator and that operates the first actuator. The boom includes a pair of boom lateral plates disposed to face each other in a direction of the first central axis, and a boom bottom plate connecting the boom lateral plates to each other, the first electric motor being disposed in a boom internal space surrounded by the pair of boom lateral plates and the boom bottom plate.

Method for controlling a hydraulic system for a working machine, the system including a first electric machine connected to a first hydraulic machine the first hydraulic machine including an input side and an output side a second electric machine connected to a second hydraulic machine the second hydraulic machine including a high-pressure side and a low-pressure side the high-pressure side connected to the input side; a hydraulic consumer coupled to the output side via a supply line and configured to be powered by the first hydraulic machine; a first return line hydraulically coupling the hydraulic consumer to the input side and to the high-pressure side; wherein the method includes detecting a return flow from the hydraulic consumer through the first return line; and controlling the second hydraulic machine to maintain a pressure in the first return line at a pressure level higher than a predetermined minimum pressure level.

A device for emergency supply of a high voltage onboard network, in particular for the emergency load lowering of a work machine such as a crane or a cable excavator, comprising a high voltage onboard network having an electrical drive unit and a primary DC energy source for supplying the electrical drive unit with energy; a low voltage onboard network, preferably a 12 V, 24 V, or 48 V onboard network, having a low voltage rechargeable battery for taking up and outputting energy, wherein the high voltage onboard network and the low voltage onboard network are connected via a DC/DC converter to allow an energy flow from the high voltage onboard network in the direction of the low voltage onboard network. The DC/DC converter is preferably a bidirectional DC/DC converter to permit an energy flow from the low voltage onboard network in the direction of the high voltage onboard network.