A fluid supply system supplying multiple fluid consumers of a vehicle with fluid, the fluid supply system including: a first pump supplying a first fluid consumer, arranged in a first supply circulation of the vehicle, with fluid; a second pump supplying a second fluid consumer, arranged in a second supply circulation of the vehicle, with fluid; and a directional control valve adjustable between a first valve position and at least one other, second valve position and preferably includes an electromagnetic device for adjusting. The directional control valve allows the fluid to be delivered from the second pump into the first supply circulation in the first valve position and separates the first supply circulation from the second pump, or allows the fluid to be delivered from the second pump into the first supply circulation only to a restricted extent as compared to the first valve position, in the second valve position.

This hydraulic drive device for a work vehicle includes a main pump (1) of a variable displacement type or a fixed displacement type discharging pressure oil, a main flow passage (F1) for supplying pressure oil of the main pump to an actuator, a sub-pump (5) of a fixed displacement type discharging pressure oil, a sub-flow passage (F2) for making pressure oil of the sub-pump merge with the main flow passage and supplying the pressure oil to the actuator (2), a merging directional valve (6A) for connecting or cutting off the main flow passage and the sub-flow passage, a controller (30) for controlling operation of the merging directional valve, and a relief valve (7A) arranged in the sub-flow passage, in which the relief valve has a pressure override characteristic having a tendency that the relief pressure increases from a cracking pressure to a set pressure as a relief flow rate increases.

A hydraulic system for a transmission of a motor vehicle, the system having first and second pumps for conveying hydraulic fluid into primary and/or system-pressure circuits so that an intended pressure prevails in the circuits. The system further including liquid retention means preventing a flow of hydraulic fluid conveyed by the second pump from being conducted through the first pump when the first pump is not conveying and the second pump is conveying, and preventing a flow of hydraulic fluid conveyed by the first pump from being conducted through the second pump when the second pump is not conveying and the first pump is conveying. The system additionally including a sailing-mode lubricating valve for controlling, by an open-loop system, a flow rate of hydraulic fluid conveyed by the second pump into the primary and/or secondary system-pressure circuits such that the intended pressure is set in the system-pressure circuits.

A hydraulic flushing valve arrangement includes a flushing valve having a housing, flushing piston, and at least one spring. The housing includes a valve bore, two circular housing control edges, two inlet channels fluidically connected to the bore, and an outlet channel opening into the bore between the inlet channels. The piston includes two control collars, a piston neck, and piston control edges that delimit the collars from the neck, and that have circular shapes with a recess. The recess has a portion that, in a cross-sectional plane perpendicular to an axis of the piston, is constant and sized such that a flushing quantity is reduced when the portion of the recess is situated in a region of a corresponding housing control edge relative to a quantity when the piston is in an end position. The collars guide the piston so as to be longitudinally displaceable in the bore, and are spaced apart by the neck. The piston and control edges are configured to control the fluidic connections between the bore, the inlet channels, and the outlet channel. The spring preloads the piston in a middle position whereat the outlet channel is blocked from the inlet channels. The piston is configured to move out of the middle position in response to a specific difference between pressures of the two inlet channels. The control collars are respectively configured to open the fluidic connection between a corresponding inlet channel in which a lower pressure prevails and the outlet channel. Such a flushing valve arrangement is usable in hydrostatic travel drives in which two hydromachines are operated in a closed hydraulic circuit.

A portable hydraulic power unit includes a fluid tank supported on a frame, a first pump configured to draw hydraulic fluid from the tank and a second pump configured to draw hydraulic fluid from the tank. The portable hydraulic power unit further includes a two-way valve disposed on a high-flow line extending from an output of the second pump, the two-way valve movable between an open state and a closed state. The two-way valve is electrically-actuated and configured to shift to the open state based on a hydraulic fluid pressure in a combined flow line downstream of the first pump and the second pump exceeding a threshold pressure level. The two-way valve directs the output of the second pump back to the fluid tank when the two-way valve is in the open state.

A trigger guard for a pendant for controlling a hydraulic power unit includes a first prong extending from a front side of a handle of the pendant; a second prong extending from the front side of the handle; a groove disposed between the first prong and the second prong, the groove defined by the first prong, the second prong, and the handle; a first gap disposed between the first prong and a head of the pendant; and a second gap disposed between the second prong and the head. The trigger is disposed between the first prong and the second prong such that the trigger is accessible through the groove, the first gap, and the second gap.

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.

A hydraulic flushing valve arrangement includes a flushing valve having a housing, flushing piston, and at least one spring. The housing includes a valve bore, two circular housing control edges, two inlet channels fluidically connected to the bore, and an outlet channel opening into the bore between the inlet channels. The piston includes two control collars, a piston neck, and piston control edges that delimit the collars from the neck, and that have circular shapes with a recess. The recess has a portion that, in a cross-sectional plane perpendicular to an axis of the piston, is constant and sized such that a flushing quantity is reduced when the portion of the recess is situated in a region of a corresponding housing control edge relative to a quantity when the piston is in an end position. The collars guide the piston so as to be longitudinally displaceable in the bore, and are spaced apart by the neck. The piston and control edges are configured to control the fluidic connections between the bore, the inlet channels, and the outlet channel. The spring preloads the piston in a middle position whereat the outlet channel is blocked from the inlet channels. The piston is configured to move out of the middle position in response to a specific difference between pressures of the two inlet channels. The control collars are respectively configured to open the fluidic connection between a corresponding inlet channel in which a lower pressure prevails and the outlet channel. Such a flushing valve arrangement is usable in hydrostatic travel drives in which two hydromachines are operated in a closed hydraulic circuit.

The present disclosure provides a hydraulic system for a material handling vehicle. The hydraulic system includes a reservoir tank, a pump configured to draw fluid from the reservoir tank, and an auxiliary circuit having an auxiliary filter. The auxiliary circuit is in fluid communication with one or more auxiliary functions that are configured to receive fluid from the pump and return fluid to the reservoir tank. When the one of the one or more auxiliary functions is commanded, fluid flow is provided from the pump to the reservoir tank through the auxiliary filter.

A hydraulic system, a mobile mining machine and to a method of controlling a hydraulic actuator is provided. The hydraulic system includes two hydraulic pumps (P1, P2) for generating hydraulic power for a hydraulic actuator. The pumps are powered by means of a common electric motor. Operation of the actuator is controlled by controlling speed and direction of the motor, whereby hydraulic lines (19a, 19b) may be without actively controlled control valves.