An electrically powered hydraulic system for a working machine includes: an electric motor to power a working hydraulic pump. A flow of hydraulic fluid generated by the hydraulic pump is controlled by the operation rotational speed of the electric motor. An electronic control unit is configured to: when an operator input device is in a first operating range, maintain the electric motor at a constant rotational speed, and control a variation in flow of hydraulic fluid to the hydraulic function with an electronically controlled control valve, and when the operator input device is in a second operating range, control a variation in flow of hydraulic fluid by varying the electric motor rotational speed and by controlling the control valve, according to displacement of the operator input device.

A work vehicle has a chassis, and a member connected to the chassis for movement with respect to the chassis. An actuator is connected to the chassis and to the member to move the member with respect to the chassis. A hydraulic circuit is connected to the actuator and a pump pressurizes fluid in the hydraulic circuit. An adjustable quarter wave tuner is connected to the hydraulic circuit. The adjustable quarter wave tuner has a length that is adjustable within a range of lengths to thereby reduce noise caused by the pump across a corresponding range of frequencies. In some embodiments, the member is a linear actuator, such as a hydraulic cylinder. In other embodiments, the member is a rotary actuator, such as a hydraulic motor.

An apparatus for installing a land anchor of a foundation in an earthen surface includes an articulated arm assembly including a first linear actuator and a drill configured to releasably couple to a helical member, and a control system coupled to the articulated arm assembly and configured to operate the first linear actuator in a free-floating mode configured to maintain an installation angle between the drill and the earthen surface as the helical member is drilled into the earthen surface.

A slewing hydraulic work machine includes a slewing control device performing a slewing control in accordance with an applied slewing command operation, a boom control device performing a boom-raising control in accordance with an applied boom-raising command operation, a boom angle detector, and a capacity control section. The capacity control section calculates a command motor capacity based on a boom angle, generates a capacity command signal corresponding to the command motor capacity and inputs the signal to a slewing motor. During the performance of slewing and boom-raising operation, the capacity control section sets the command motor capacity to a value equal to or less than a base capacity when the boom angle is equal to or less than a slewing priority angle and sets the command motor capacity to a value greater than the base capacity when the boom angle is greater than the slewing priority angle.

A working machine comprising a hydraulic fluid circuit an operator structure and a thermal management system. The thermal management system connects an operator structure heater and a heat exchanger arranged to selectively remove heat energy from the hydraulic fluid circuit, so as to be capable transferring heat from the hydraulic fluid to the operator structure.

A working machine having a thermal management system with an energy distribution system to selectively transfer thermal energy between an operator structure and a hydraulic fluid, based on the relative values of an operator structure energy requirement and a hydraulic fluid energy requirement.

Provided are an energy regeneration device which can regenerate energy of a working fluid discharged from an actuator while controlling a flow rate of the working fluid, and a work machine including the foregoing device. The regeneration device (100) includes a boom cylinder (20), an inertial fluid container (102), an oil tank (110), an accumulator (105), a low-pressure-side opening/closing device (103), and a high-pressure-side opening/closing device (104). A calculation unit (151) calculates a duty ratio for opening/closing the low-pressure-side opening/closing device (103) and the high-pressure-side opening/closing device (104) in accordance with a desired flow rate of a working fluid discharged from the boom cylinder (20). A regeneration control unit (153) selects alternately the low-pressure-side opening/closing device (103) and the high-pressure-side opening/closing device (104) as a destination with which the inertial fluid container (102) communicates in accordance with the calculated duty ratio, and supplies a discharged working fluid to an accumulator (105).

A seal member includes: an inner circumferential surface surrounding a central axis; an upper surface connected to one end of the inner circumferential surface in an axial direction of the central axis; a lower surface connected to another end of the inner circumferential surface in the axial direction; and a protrusion that is provided continuously to the inner circumferential surface so as to surround the central axis and that includes a first portion inclined to the upper surface side toward one side in a circumferential direction of the central axis and a second portion inclined to the lower surface side toward the one side in the circumferential direction.

A hydraulic system of a construction machine includes: a pump that supplies hydraulic oil to a hydraulic actuator; a control valve on a center bypass line extending from the pump to a tank, the control valve including a bypass passage; an unloading valve on the center bypass line downstream of the control valve; and a controller that controls the unloading valve. The control valve is configured such that an opening area of the bypass passage is greater than an opening area of the unloading valve while an operation signal outputted from an operation device increases from a predetermined value to a first setting value, and such that the opening area of the bypass passage is less than or equal to of a maximum opening area of the bypass passage when the operation signal is greater than or equal to a second setting value greater than the first setting value.

Embodiments described herein provide for the control of an industrial machine dump operation by monitoring a position of the piston within a dump cylinder. The position of the piston is determined using a sensor within the dump cylinder. The sensor generates and provides an output signal to a controller. Based the output signal from the sensor, the controller is configured to limit the travel of the dump cylinder during the dump operation to reduce wear on the dump cylinder (e.g., by preventing damage caused when the dump cylinder is extending or retracting rapidly and the internal cylinder components make forceful contact with the rod or cap end).