An electric machine and method for powering the electric machine using interchangeable power modules that are configured to be interchangeably placed within power bays of the electric machine is disclosed. The electric machine includes an electrical module that is configured to receive power from one or more of the power modules placed in the power bays and transform, such as from DC to multi-phase alternating current (AC), and provide the power to one or more motors of the electric machine. The power modules may be of the same dimensions, same electrical interfaces, and/or same power output (e.g., type, magnitude) as each other to enable the interchangeability of the power modules. The power modules may be ones that generate power or ones that store energy. In some cases, the generating power modules may charge the energy storage power modules, while the energy storage power modules power the electric machine.

To reduce an increase in the electric power consumption of an electric motor according to the state of an electric power source at the start of driving of an actuator, and make it possible to use devices in an appropriate state in an electrically driven hydraulic construction machine including a driving system that drives a hydraulic pump by using the electric motor. For this purpose, a controller 50 sets a target relief pressure of a relief valve 3 to a normal relief pressure Pn (first relief pressure) when an operation lever device 44 is not being operated and a storage amount SOC(t) of a battery 62 (the state quantity of an electric power source) is equal to or larger than a threshold S1, and sets the target relief pressure to a reduced relief pressure Pr(t) (second relief pressure) lower than the normal relief pressure Pn (first relief pressure) when the operation lever device 44 is not being operated, and the storage amount SOC(t) of the battery 62 (the state quantity of the electric power source) is smaller than the threshold S1.

A prime mover and hydraulic actuators, a hydraulic machine having a rotatable shaft engaged with the prime mover and having a plurality of working chambers, a hydraulic circuit extending between a group of working chambers of the hydraulic machine and the hydraulic actuators, each working chamber of the hydraulic machine having a low-pressure and a high-pressure valve regulating the flow of hydraulic fluid between the working chamber and a corresponding low-pressure manifold and a high-pressure manifold. The hydraulic machine controlling the low-pressure valves of the group of working chambers to select the net displacement of hydraulic fluid by each working chamber on each cycle of working chamber volume, and thereby the net displacement of hydraulic fluid by the group of working chambers, responsive to a demand signal, the apparatus further having a controller calculating the demand signal responsive to a measured property of the hydraulic circuit or an actuator.

A hydraulic excavator as an electric working machine includes: a lower traveling body; an upper turning body that is positioned above the lower traveling body and provided to be turnable with respect to the lower traveling body; an electric motor that is arranged in the upper turning body; and a battery unit that is arranged in the upper turning body and stores electric power for driving the electric motor. The upper turning body includes a turning frame at a bottom. The battery unit is arranged on the turning frame. The electric motor is arranged above the battery unit.

A prime mover and a plurality of hydraulic actuators, a hydraulic machine having a rotatable shaft in driven engagement with the prime mover and comprising a plurality of working chambers, a hydraulic circuit extending between a group of one or more working chambers of the hydraulic machine and one or more of the hydraulic actuators, each working chamber of the hydraulic machine comprising a low-pressure valve which regulates the flow of hydraulic fluid between the working chamber and a low-pressure manifold and a high-pressure valve which regulates the flow of hydraulic fluid between the working chamber and a high-pressure manifold. The hydraulic machine being configured to actively control at least the low-pressure valves of the group of one or more working chambers to select the net displacement of hydraulic fluid by each working chamber on each cycle of working chamber volume, and thereby the net displacement of hydraulic fluid by the group of one or more working chambers, responsive to a demand signal, wherein the apparatus further comprises a controller configured to calculate the demand signal in response to a measured property of the hydraulic circuit or one or more actuators.

A battery-operated work machine is provided which can perform a work while avoiding such a situation that the work machine cannot reach charging equipment. When the remaining capacity of a battery becomes lower than a first threshold value set in advance, a controller controls an inverter such that the revolution speed of an electric motor is kept at a target revolution speed and controls a first notification device to operate, and besides switches a traveling motor to a travel first speed side, in which the displacement volume is a large volume, irrespective of an input from a traveling mode instruction device, when the remaining capacity of the battery becomes lower than a first threshold value set in advance.

Construction machine including: an inverter; a battery; a battery controller; a main controller controlling the inverter based on limited power modes prescribed; and a display device displaying a remaining battery electric power. The main controller calculates open circuit voltage and battery resistance values of the battery at the state of energy of the battery based on the specification information about the battery and state of energy of the battery which are input from the battery controller, calculates an amount of electric power stored in the battery in each of the limited power modes based on the open circuit voltage value and battery resistance value of the battery as well as limited power and operating voltage prescribed for each of the limited power modes, and outputs a display signal for displaying the amount of electric power stored in the battery in each of the limited power.

A machine is adapted for operation powered by any one of a plurality of interchangeable power sources. The machine may include an undercarriage configured for supporting ground engagement members that propel the machine and an upper structure rotatably supported on the undercarriage. The upper structure may include a swing frame, with the swing frame supporting an operator cab, any one of the plurality of interchangeable power sources, hydraulic components, electrical components, and a counterweight disposed at a first end of the swing frame. The counterweight may include a hollowed out portion facing toward the swing frame. The hollowed out portion of the counterweight may be centrally aligned with a center core portion of the swing frame configured for supporting any one of the plurality of interchangeable power sources, with the one power source being partially accommodated within the hollowed out portion of the counterweight.

The invention concerns a portable power supply system (30) intended to supply a remotely controlled, electrically driven work machine (1) with electrical power, where the work machine is of the type that demonstrates a propulsion means that includes continuous tracks (8b) and is equipped with a maneuverable arm (10) intended to carry a tool at its free end, and electric motor (19) that is connected to a hydraulic pump (20) and is intended to supply the operating means (8c, 10a) of the machine with a hydraulic medium, whereby the work machine is intended to be connected under normal operation to a primary source of power (30a) via an electrical cable (2′), which primary source of power includes a fixed alternating current electricity distribution grid at the location. In order to be able to supply the current that is required it comprises a DC energy-storage arrangement (29) that, including a secondary source of power (30b), can store energy and, when necessary, supply energy in electrical form; a coupling arrangement (31, 33, 34, 34′) that makes it possible to choose between connecting the primary (30a) or the secondary (30b) source of power to the electric motor in order to drive the same.

A prime mover and a plurality of hydraulic actuators, a hydraulic machine having a rotatable shaft in driven engagement with the prime mover and comprising a plurality of working chambers, a hydraulic circuit extending between a group of one or more working chambers of the hydraulic machine and one or more of the hydraulic actuators, each working chamber of the hydraulic machine comprising a low-pressure valve which regulates the flow of hydraulic fluid between the working chamber and a low-pressure manifold and a high-pressure valve which regulates the flow of hydraulic fluid between the working chamber and a high-pressure manifold. The hydraulic machine being configured to actively control at least the low-pressure valves of the group of one or more working chambers to select the net displacement of hydraulic fluid by each working chamber on each cycle of working chamber volume, and thereby the net displacement of hydraulic fluid by the group of one or more working chambers, responsive to a demand signal, wherein the apparatus further comprises a controller configured to calculate the demand signal in response to a measured property of the hydraulic circuit or one or more actuators.