A hydraulic excavator as an electric work machine includes a lower traveling body, an upper swivel body located above the lower traveling body and provided to be swivelable with respect to the lower traveling body, an electric motor arranged in the upper swivel body, a hydraulic pump arranged in the upper swivel body and driven by the electric motor, a battery unit arranged in the upper swivel body and storing electric power to drive the electric motor, and a hydraulic actuator driven by hydraulic oil supplied from the hydraulic pump. The upper swivel body has a swivel frame at a bottom portion thereof. The battery unit is arranged on the swivel frame. The electric motor and the hydraulic pump are arranged on the swivel frame, side by side in a left-right direction of the upper swivel body.

A power system may include a high-speed flywheel connected to an engine of a machine; a battery; a motor-generator unit (MGU) connected to the engine and the battery; and a turbocharger connected to the engine. One or more of the high-speed flywheel, the battery and the MGU, or the turbocharger may be configured to provide supplemental power to power provided by the engine to operate the machine, or provide replacement power when no power is provided by the engine to operate the machine.

An excavator includes a lower traveling body; an upper turning body turnably mounted to the lower traveling body; an actuator configured to drive a driven part including the lower traveling body and the upper turning body; and a power storage device mounted in the upper turning body and configured to serve as an energy source for driving the actuator. The power storage device includes a plurality of power storage modules stacked in a vertical direction, each of the plurality of power storage modules including a power storage part and a housing configured to house the power storage part. The housings of power storage modules among the plurality of power storage modules that are adjacent to each other in the vertical direction, are coupled to each other.

A power system for a working machine, including a prime mover drivingly connectable to a main shaft; a planetary gear set including a rotatable first member drivingly connected to the main shaft, a rotatable second member and a rotatable third member for propulsion of the working machine; a hydraulic system including at least one hydraulic actuator for performing a working function of the working machine; an electric energy storage system; a first hydraulic machine mechanically coupled to the main shaft and hydraulically coupled to the hydraulic system; a first electric machine mechanically coupled to the main shaft; a second electric machine mechanically coupled to the rotatable second member, wherein the electric energy storage system is electrically connected to the first and second electric machines, and wherein the power system further includes a second hydraulic machine mechanically coupled to the rotatable second member and hydraulically coupled to the hydraulic system.

A mobile apparatus includes a main frame, an operating arm connected to the main frame, drive means configured to drive displacing means of the mobile apparatus, such as one or more wheels or tracks, drive means configured to drive the operating arm and a control system, connected to operating instruments for a driver, for controlling the drive means. The drive means for the displacing means includes an electric motor such that the drive of the displacing means is substantially electrical.

A control device for a power machine can be configured to determine an operating temperature of a power machine and to derate one or more electrical actuators of the power machine to limit regenerative charging to the electrical power source. A method of operating a power machine can include controlling one or more electrical actuators, with a control device, to cause an implement of a power machine to fluctuate in orientation over a plurality of cycles, based on receiving an operator input that initiates the fluctuation or detecting an operational condition of the power machine.

A drive control system includes an electric motor, a capacitor, a revolution sensor, a driving device, and a control device. The driving device causes the capacitor to supply electric power to the electric motor to operate the electric motor and causes the capacitor to store the electric power, generated by the electric motor, to brake a turning body. The driving device configured as above is driven by driving electric power supplied from the capacitor. When a charging stop condition is satisfied, the control device stops the driving electric power supplied from the capacitor to the driving device. The charging stop condition is a condition that a turning speed detected by the revolution sensor is a predetermined speed or less while the turning body is decelerating.

A working vehicle includes an electric storage device; a traction motor configured to propel the working vehicle and to generate electrical energy when braking; a hydraulic system including a hydraulic pump driven by a load motor, a hydraulic actuator and a control valve; and a control system. The control system is configured to determine a state of charge of the electric storage device; induce additional load on the hydraulic system by directing the load motor to drive the hydraulic pump and actuating the control valve to direct flow of hydraulic fluid to the hydraulic actuator when the state of charge is at or above a predetermined threshold.

A pump that supplies hydraulic oil to a boom cylinder and a turning hydraulic motor; a regenerative hydraulic motor is coupled to the pump and to which the hydraulic oil discharged from the boom cylinder at a time of boom lowering and/or the hydraulic oil discharged from the turning hydraulic motor at a time of turning deceleration is/are led; an engine drives the pump; an alternator mounted to the engine and operable to rotate an output shaft of the engine when electric power is supplied to the alternator; an electrical storage device connected to the alternator; a power converter interposed between the alternator and the electrical storage device; and a controller that switches the power converter to either a servo-on state or a servo-off state and that controls the power converter either in a charging mode or in a discharging mode when switching the power converter to the servo-on state.

A control system of a hybrid construction machine includes fluid pressure pumps, a regeneration motor, a rotating electric motor coupled to the regeneration motor, a storage battery configured to store electric power generated by the rotating electric motor, an assist pump provided coaxially to the regeneration motor to be driven by the rotating electric motor, the assist pump being configured to supply a working fluid to a fluid pressure actuator, and load adjusting units configured to change a load of the assist pump in accordance with a state of the storage battery.