Abstract: Disclosed is a hydraulic circuit for construction equipment, having a floating function for ground leveling work, which can be implemented by a main control valve.

Abstract: A subsea blowout preventer (BOP) hydraulic control system to reduce water hammer that includes a hydraulic fluid source. The system further includes a fluid supply conduit in fluid communication with the hydraulic fluid source at an upstream end, and with a BOP function at a downstream end. The system further includes a supply valve in the fluid supply conduit that controls the amount of fluid flow through the fluid supply conduit to the BOP function, the supply valve having an open state and a closed state. The supply valve has a choke that controls movement of the supply valve between the open state and the closed state and vice versa so that such movement is retarded when the supply valve state approaches the fully open or the fully closed state to reduce pressure spikes in the fluid of the fluid supply conduit.

Abstract: A hydraulic cylinder includes a rod inner passage that is formed in a piston rod along an axial direction and communicates a fluid pressure source and an interior of a cylinder tube; a plug that is inserted from an open end that opens to the interior of the cylinder tube of the rod inner passage; a lateral hole that is formed in the piston rod along a radial direction and extends so as to cross the rod inner passage; and a pin that is inserted into the lateral hole. In the piston rod, an inner-circumference screw portion is formed on an inner circumference of the rod inner passage, and on the plug, an outer-circumference screw portion that is screwed into the inner-circumference screw portion and an engagement portion that is engaged with the pin and locks rotation of the plug are formed.

Abstract: An illustrative embodiment of a safety block may include an actuator bracket pivotally engaged with a pivot arm. The actuator bracket may be configured to engage a master actuator having a first end moveable with respect to a second end. A secondary actuator may have a first end engaged with the actuator bracket and a second end engaged with the pivot arm such the secondary actuator may cause the pivot arm to move between a first position, in which first position the pivot arm prevents the master actuator from retracting, and a second position, in which second position the pivot arm allows the master actuator to retract.

Abstract: A cooling and lubricating device for a transmission for a wind turbine includes a transmission oil tank for storing transmission oil for the transmission, a transmission oil line system for carrying the transmission oil between the transmission oil tank and the transmission, a hydraulic oil tank for storing hydraulic oil, a hydraulic oil line system for carrying the hydraulic oil, a hydraulic oil conveying device for conveying the hydraulic oil through the hydraulic oil line system, an energy accumulator for at least temporarily maintaining a pressure within the hydraulic oil line system, the energy accumulator chargeable using the hydraulic oil conveyed by the hydraulic oil conveying device; and a transmission oil conveying device coupled to the hydraulic oil line system and to the transmission oil line system and configured to be driven by the hydraulic oil in order to convey the transmission oil to the transmission.

Abstract: An electro-hydraulic actuation system includes a regeneration valve in fluid communication with a first fluid chamber and a second fluid chamber of a hydraulic actuator, and a dump valve is in fluid communication with the second fluid chamber and a fluid reservoir. A pump provides a flow of fluid to the first and second fluid chambers, a displacement of the pump controlling a velocity of the actuator during motion in the retraction and extension directions. An electric motor drives the pump, and a controller controls a state of the regeneration valve and the dump valve. At least one feedback device senses a system condition and provides a respective feedback signal indicative of the sensed system condition to the controller, the controller responsive to the feedback signal to determine an occurrence of an over-center load condition and control a state of the regeneration valve and the dump valve in response to the occurrence to maintain the velocity of the actuator.

Abstract: A redundant accumulator system for delivery of pressurized hydraulic fluid to blowout preventers (“BOPs”) and other well equipment during coiled tubing and wirelining operations that has sufficient reserve fluid capacity to simultaneously operate a plurality of BOPs and other well equipment and to hold a plurality of BOPs closed in the event of a hydraulic fluid leak, and is appropriately sized for use aboard an offshore vessel or platform or for use in close proximity to an inland wellhead. The accumulator system includes a hydraulic fluid capacity that is at least twice the capacity of the accumulators, a plurality of pneumatically operated pumps in parallel, each having the maximum inlets and outlets for their size to maximize the charging capacity of the accumulator system and allow the system to be charged to operational pressure in less than thirty minutes.

Abstract: A vacuum suction and pressure regulation cylinder includes a pneumatic cylinder, in which a fixed division plate is arranged. A piston assembly is slidably arranged in the fixed division plate and includes an airtight piston mounted to a middle portion thereof and including a flowrate regulation screw and an end of the piston assembly is provided with a second airtight piston so as to define, in an interior space of the pneumatic cylinder, a first air chamber, a second air chamber, and a third air chamber, which are in communication with a prosthesis sleeve. When the piston assembly moves, air flow induced in the pneumatic cylinder varies the sizes of the air chambers for regulation of the spaces thereof. Further, the variation of the air chambers helps evacuate the sleeve so as to make a stump and the prosthesis tightly coupled to each other through suction.

Abstract: Disclosed are a control device for confluence flow rate of a working device and a control method therefor, the control device being capable of minutely operating a working device when a flow rate supplied to the working device is merged or blocked.

Abstract: A hydrostatic automatic flight servo system is provided. The automatic flight servo system includes a manifold that defines a first fluid chamber, and a hydraulic fluid is received in the first fluid chamber. The first fluid chamber includes a first bellows and a second bellows. The automatic flight servo system includes a stick received at least partially within the manifold and pivotally coupled to the manifold. The stick includes a control arm fixedly coupled to the first bellows, and the stick is to receive an input. The automatic flight servo system includes a flight output system pivotally coupled to the manifold. The flight output system includes a second control arm received at least partially within the manifold and coupled to the second bellows such that the pivotal movement of the stick pivots the flight output system relative to the manifold.

Abstract: The present disclosure relates to a load-sense system such as a load-sense steering system that operates in a static load-sense mode for low flows and operates in a dynamic load-sense mode for high flows.

Abstract: A ram air turbine (RAT) stowing system includes a closed loop hydraulic circuit configured to hold a quantity of a hydraulic fluid to be utilized only by the RAT stowing system and a RAT actuator disposed in fluid communication with the closed loop hydraulic circuit. A pump system is connected to the hydraulic circuit to selectively pump the hydraulic fluid to a stow reservoir portion of the RAT actuator to move the RAT actuator from a deployed position to a stowed position. A control valve is connected to the hydraulic circuit between the RAT actuator and the pump to selectively allow the hydraulic fluid to be drained from the stow reservoir portion of the RAT actuator in a drain state and to allow the hydraulic fluid to be pumped into the stow reservoir portion of the RAT actuator in a pump state.

Abstract: In one aspect, a system for controlling the supply of hydraulic fluid to an implement may include a pump, a control valve coupled to the pump and first and second fluid lines provided in flow communication with output ports of the control valve. The system may also include a pressure control valve configured to regulate a pressure of the hydraulic fluid being supplied to the control valve such that the hydraulic fluid is supplied to the control valve at a first pressure for raising at least one ground-engaging component of the implement and a second pressure for lowering the ground-engaging component(s). Moreover, the system may include a bypass line in fluid communication with the pressure control valve such that fluid diverted through the bypass line actuates the pressure control valve to adjust the fluid pressure of the hydraulic fluid supplied to the control valve between the first and second pressures.

Abstract: A piston-cylinder unit (40) for hydraulic actuation of a clutch in a vehicle, including a piston (42), a cylinder (41) and a sealing element (43). The piston cylinder unit is fluidically linked to a fluid circuit (44), the piston (42) is axially displaceable in the cylinder, and the sealing element is arranged sealingly between the piston and the cylinder, characterized in that a sensor is arranged in or on the piston-cylinder unit, by which sensor a pressure can be measured in the interior of the piston-cylinder unit and/or in the fluidically linked fluid circuit. A method for operating the piston-cylinder unit is also provided.

Abstract: A piston configuration is provided, the configuration including a piston having a ring seat and a piston ring disposed within the ring seat. The piston ring is configured to form a sealing surface between a surface of the piston ring and a surface of the ring seat. The sealing surface is formed when a first pressure on a first side of the piston ring is greater than a second pressure on a second side of the piston ring. At least one fluid channel is configured to increase a surface area on the piston ring that is subject to the second pressure.

Abstract: A hydraulic system (1) is disclosed comprising a pressure source (2), at least a hydraulic consumer (12, 13), and a pressure booster (16) arranged between the pressure source (2) and the hydraulic consumer (12, 13), wherein inactivating means (17) are provided inactivating or activating said pressure booster (16), said pressure booster (16) and said inactivating means (17) being part of a booster module (11). The operational possibilities of such a hydraulic system (1) should be extended. To this end the booster module (11) is part of a valve block (3), said valve block (3) comprising said booster module (11) and at least one valve module (9, 10) controlling said hydraulic consumer (12, 13).

Abstract: A piston unit includes a piston which has a rolling element seat configured to rotatably support a rolling element. The rolling element seat has a bearing surface with a surface coating composed of a polymer compound or with a ceramic surface coating.

Abstract: Respective outer peripheral surfaces (33, 35) of opening-side end portions (30, 31) of a front cover (12) and a pump shell (7), which have been shaped by pressing, are formed by slimming such that the outside diameters of the slimmed outer peripheral surfaces are equal to each other. With the opening-side end portions abutting against each other, a high-energy beam such as a laser beam (R) is radiated toward the abutment surfaces (30, 31) from the radially outer side to weld the abutment surfaces to each other. Consequently, it is possible to perform welding accurately through easy processing in order to easily manufacture a fluid coupling with high precision that facilitates post-processing.

Abstract: A hydrodynamic machine contains a bladed primary wheel driven by a rotary shaft and a bladed secondary wheel, which together form a work chamber filled with a working medium. The machine has a pressure pump for delivering a working medium from the work chamber. The pressure pump has a first inlet, which projects into the work chamber, and has a first inlet opening which is aligned with the rotary shaft in the circumferential direction. The pressure pump has a second inlet which projects into the work chamber and has a second inlet opening which is aligned to the rotary shaft in the circumferential direction opposite to the first inlet opening. The first and second inlets are joined to a common working medium channel behind the two inlet openings. The first and second inlets extend adjacent to each other in the same flow direction separated by a separation wall.

Abstract: A hydraulic system and method for using the same are provided. The hydraulic system includes a pump, a first actuator having a first head chamber and a first rod chamber, and a second actuator having a second head chamber and a second rod chamber. The hydraulic system further includes a first control valve and a second control valve. The second control valve to selectively provide regeneration fluid flow from the first rod chamber to the first head chamber in response to a first function command is less than a first function command limit, a second function command is greater than a second function command limit, and a second function load is greater than a second function load limit.