An electric work vehicle includes a body 3 configured to travel; a first battery 20 accommodated in the body 3; a three-point link mechanism T connected to a rear section of the body 3 in such a manner as to be swingable up and down; a drive device configured to drive the three-point link mechanism T to swing; and a second battery 60 detachably attached to the three-point link mechanism T. The second battery 60 is switchable, by swinging of the three-point link mechanism T, between a lowered state, in which the second battery 60 is in contact with a ground surface, and a raised state, in which the battery 60 is raised above the ground surface.

A hybrid work machine includes: an engine configured to drive a hydraulic pump as a hydraulic source of a hydraulic actuator; an engine-assist motor generator attached to the engine; an electric motor for use in a part of a driving system of the work machine; an electricity storage device configured to store generated power of the motor generator; a power converter disposed between the electric motor and DC buses; and a buck-boost converter disposed between the DC buses and the electricity storage device, and configured to perform power transfer between the DC buses and the electricity storage device by raising and lowering a voltage of the DC buses, the hybrid work machine, further comprises: a controller configured to temporarily raise the voltage of the DC buses when a torque required for the electric motor exceeds a torque outputtable at the voltage of the DC buses connected to the power converter.

Electro-hydraulic work vehicle system having a hydraulic lift mechanism comprising a first electric machine, a first hydraulic machine operatively connected to the first electric machine. A load holding valve is switchable between a first position in which it retains pressurized fluid in the hydraulic lift mechanism and a second position in which it enables pressurized fluid to flow between the first hydraulic machine and the hydraulic lift mechanism. A pressure relief valve is switchable between a first, initial position in which it prevents pressurized fluid from flowing from the first hydraulic machine to the hydraulic tank and a second position in which it enables pressurized fluid to flow from the first hydraulic machine to the hydraulic tank. An hydraulic energy storage is hydraulically connected between the first hydraulic machine and the relief valve, wherein in decent mode of hydraulic lift mechanism, the hydraulic system is configured to supply pressurized fluid to the hydraulic energy storage and when the load-holding valve is at its second position and the pressure relief valve is at its first position, wherein pressurized fluid from the hydraulic lift mechanism is capable of driving the first hydraulic machine which can drive the first electric machine to create electricity that can be stored in the electrical energy storage, and/or is capable of charging the hydraulic energy storage.

A control system for a hybrid construction machine includes: a first main pump and a second main pump; a regeneration motor configured to rotationally drive by returned working oil; a motor generator coupled to the regeneration motor; an assist pump coupled to the regeneration motor and the motor generator; and a controller. The controller controls the assist pump or the motor generator such that the assist pump drive force is not more than the drive force limited value when an assist pump drive force is greater than a drive force limited value.

It becomes possible to prevent deterioration of an electric storage device due to overdischarge of the electric storage device and engine stalling due to insufficient assist or disabled assist when a charge amount of the electric storage device falls, ensure that work is continuously conducted, suppress an operator from feeling discomfort in operation, and ensure favorable operability. A pump target output power computing section (21) computes present pump demanded power on the basis of work related information, limits the present pump demanded power in response to a degree of reduction of a state of charge of an electric storage device (12a) when the state of charge is lower than a preset threshold, and computes the limited present pump demanded power as present pump target output power. A pump flow rate limiting command value computing section (22) computes a pump flow rate limiting command value on the basis of the present pump target output power in such a manner that output power of a hydraulic pump (9) does not exceed the pump target output power.

The present disclosure relates to an engine control device for hybrid construction machinery, and more particularly, and an object of the present disclosure is to, in a hybrid excavator, in which a swing apparatus is electrically driven by being separated from a hydraulic power train system in the related art, satisfy a minimum rotational speed of an engine auxiliary motor which is necessary to satisfy a target charging amount required for an energy storage device, and improve fuel efficiency by removing unnecessary energy loss at low loads by controlling a rotational speed of an engine to be lower than a rotational speed of an engine determined based on a dial input and a mode input in the related art, in a case where a target power generation amount of the engine auxiliary motor is small in a low-load work situation.

An energy storage system associated with a machine having a work tool and one or more auxiliary loads includes a power source which generates mechanical power. An energy storage device supplies power to the one or more auxiliary loads. An electrical generator is operably coupled to the power source and converts at least a portion of the mechanical power into electrical power. The electrical generator supplies the electrical power to the energy storage device. A controller is communicably coupled to the power source, the work tool, the energy storage device, and the electrical generator. The controller determines a power demand of the work tool. The controller then compares whether the determined power demand exceeds a pre-determined threshold power. The controller disables the electrical generator from supplying the electrical power to the energy storage device if the power demand exceeds the pre-determined threshold power.

A work machine comprising a security system for deterring theft is disclosed. The work machine comprises a frame, a battery, a ground engaging element supporting the frame; and a security system configured to activate an at least one anti-theft deterrent when an unauthorized person is detected in a detection zone around the work machine.

The present invention relates to an electric driven hydraulic power system for heavy equipment, and more particularly, to a hydraulic power system, which includes a hydraulic pump operated by a battery and a motor, a supply line for supplying a hydraulic oil that is supplied by the hydraulic pump, a plurality of actuators, and a controller for controlling the motor and the actuators, in which electrical efficiency is significantly improved. In particular, the present invention relates to an electric driven hydraulic power system in which a plurality of motors and a plurality of hydraulic pumps corresponding to the motors, respectively, are provided, and a main control valve (MCV) for receiving a hydraulic oil from the hydraulic pumps to supply the hydraulic oil to a plurality of actuators is provided, so that efficient control is performed according to an operating load, an operating temperature, a supply flow rate, and the like to minimize power consumption of the motor, and thus electrical efficiency is improved to dramatically increase an operating time.

An excavator comprising: an electric motor having a commercial power supply and a battery as the drive power sources therefor; and a hydraulic actuator having a hydraulic pump driven by the electric motor, as the hydraulic source therefor. The excavator has: a first power supply mode in which the electric motor is driven while the battery is being charged by the commercial power supply; and a second power supply mode in which the electric motor is driven only by the battery. A power supply cable for supplying power from the commercial power supply is connected to a power supply port and, if the electric motor has stopped operating, the excavator moves from the second power supply mode to the first power supply mode.