A pivot control apparatus of construction equipment is provided for reaching a desired swing angle by controlling the brake torque of a swing motor during a loading operation using an excavator, along with a control method therefor. The swing control apparatus of construction equipment according to one embodiment of the present invention includes first and second hydraulic pumps and a pilot pump; a boom cylinder, an arm cylinder, and a bucket cylinder which are driven by the hydraulic fluid of the first and second hydraulic pumps; an operation apparatus control valve for controlling the hydraulic fluid which is supplied from the first and second hydraulic pumps to the boom cylinder, the arm cylinder and the bucket cylinder; a swing motor Which is driven by the hydraulic fluid of any one of the first and second hydraulic pumps to swing an upper swinging, body; a swing control valve; a swing operation lever, a direction control valve which applies a pilot pressure to the swing control valve according to the swing operation lever or a semi-automatic swing mode selection; electronic proportional variable relief valves capable of variably adjusting the relief setup pressure of the swing motor; and a controller which, when a semi-automatic swing mode is selected and the operation apparatus is actuated at the time of swing return, applies an electric signal to the variable relief valve at the outlet side, from among the electronic proportional variable relief valves, so as to increase or decrease the relief setup pressure.

A base assembly for a working machine. The base assembly comprising a ground engaging structure, an undercarriage connected to the ground engaging structure, and a connector for connecting the undercarriage to a superstructure that mounts a working arm. A drive arrangement is provided for moving the ground engaging structure to propel, in use, the base assembly and a connected superstructure. The drive arrangement includes a prime mover and a transmission and the drive arrangement is housed within the undercarriage. An electronic control unit (ECU) is provided for controlling the drive arrangement and/or the ground engaging structure.

At least some embodiments of the present disclosure are directed to distributed pump architectures used in control systems for multifunctional machines. In some cases, a control system for a multifunctional machine includes three or more control circuits. At least two of the control circuits each has a hydraulic fluid pump and each of the pumps is controlled by a different control circuit. At least two of the hydraulic fluid pump have different flow rates.

An energy recovery system for a machine having a movable work tool, a swing motor to swing the work tool about a vertical axis, a pump providing pressurized fluid to the swing motor, a power source outputting power to drive the pump, and a controller. The energy recovery system may include a first accumulator, a swing charge valve selectively connecting the swing motor to the first accumulator, an assist motor operatively connected to the power source, and a discharge selectively connecting the first accumulator to the assist motor. The swing charge valve may fluidly connect the swing motor to the first accumulator when fluid pressure from the swing motor is greater than a charge set pressure. The controller may cause the discharge valve to fluidly connect the first accumulator with the assist motor when the power demand on the power source is greater than a minimum assisted power demand.

A hydraulic system including an accumulator and a hydraulic transformer is disclosed. The hydraulic transformer includes first and second variable displacement pump/motor units mounted on a rotatable shaft. The rotatable shaft has an end adapted for connection to an external load. The first variable displacement pump/motor unit includes a first side that fluidly connects to a pump and a second side that fluidly connects to a tank. The second variable displacement pump/motor unit includes a first side that fluidly connects to the accumulator and a second side that fluidly connects with the tank.

Provided is a construction machine on which a hydraulic closed circuit for driving a single rod-type hydraulic cylinder and a swing hydraulic motor is mounted and that has good swing deceleration responsiveness. In this construction machine that drives each of a single rod-type hydraulic cylinder and a swing hydraulic motor in a closed circuit, a minimum passage area from a second flushing valve to a tank in a case the second flushing valve is fully open is smaller than a minimum passage area from a first flushing valve to the tank in a case the first flushing valve is fully open.

A bi-directional pump connected to a motor by a pair of supply/discharge lines; a regulator changes the bi-directional pump tilting angle; and a controller controls the regulator based on a turning signal outputted from a turning operation valve. At the turning acceleration, at which the signal increases, the controller calculates a motor flow rate passing through the motor and an instruction flow rate determined based on the turning signal. If the instruction flow rate is greater than a reference flow rate obtained by adding a predetermined value to the motor flow rate, the controller controls the regulator so the bi-directional pump tilting angle is adjusted to a tilting angle realizing the reference flow rate. If the instruction flow rate is not greater than the reference flow rate, the controller controls the regulator so the bi-directional pump tilting angle is adjusted to a tilting angle realizing the instruction flow rate.

The invention relates to a drive mechanism (1) for rotatably coupling a first system part or machine part, preferably an assembly (A), to a base, pedestal or frame or to another system part or machine part, for example for rotary positioning during the processing of large workpieces or during the moving of loads, which drive mechanism comprises two ring-shaped connecting elements (3, 4) each having at least one planar connecting surface (5, 6) and fastening means (7, 8) that are arranged distributed in a crown shape therein and effect connection to different system parts or machine parts or the like, said two connecting elements (3, 4) being arranged concentrically with each other and radially one inside the other with a gap-shaped interspace (9) in which are disposed one or more rows of rolling elements (14, 15, 16), each row whereof rolls between two respective raceways (17, 18) on the two connecting elements (3, 4), thus enabling same to rotate relative to each other, at least one connecting surface (5, 6) and at least one raceway (17, 18) being formed by machining or shaping a common base body. The invention is characterized in that at least one fully circumferentially extending row of magnets (40) is arranged inside the gap (9) on one connecting element (3, 4) and at least one fully circumferentially extending row of coils (38) is arranged directly opposite said magnets on the other connecting element (4, 3). According to the invention, at least one fully circumferentially extending row of magnets is arranged inside the gap on one connecting element and at least one fully circumferentially extending row of coils is arranged directly opposite said magnets on the other connecting element.

A work machine is adapted for reduced fuel consumption in regions where swinging by a hydraulic motor is prone to deterioration in efficiency, such as when the operating stroke of the swinging is small. The work machine includes an engine, a hydraulic pump, a swing structure, an electric motor for driving the swing structure, and a hydraulic motor for driving the swing structure, the hydraulic motor being driven by the hydraulic pump, and includes a swing control lever device that commands the swing structure to be driven. A control device operates in either an electric swing mode in which the swing structure is driven mainly by torque of the electric motor or a hydraulic swing mode in which the swing structure is driven mainly by torque of the hydraulic motor, depending on an operating stroke of the control lever device and/or a swing speed of the swing structure.

A construction machine, comprising a hydraulic pump, a swing hydraulic motor, a swing electric motor, a delivery capacity regulating device, and a control unit which controls the driving/braking of the swing structure, is configured to comprise an operation amount detection device for detecting the operation amount of the swing control lever and a speed detection device for detecting the speed of the swing electric motor. The control unit includes a hydraulic pump output reduction control unit which takes in an operation amount signal representing the operation amount of the swing control lever detected by the operation amount detection device and a speed signal representing the speed of the swing electric motor detected by the speed detection device and controls the delivery capacity regulating device by calculating a reduction rate of the output of the hydraulic pump based on the detection signals.