Abstract: Provided is a diaphragm type actuator that drives an operation rod in an axial direction of the operation rod, including: a diaphragm which is connected to the operation rod; a low pressure chamber which is adjacent to one end side of the diaphragm in the axial direction; a high pressure chamber which is adjacent to the other end side of the diaphragm in the axial direction; a return spring which is provided in the low pressure chamber and urges the diaphragm toward the high pressure chamber; and a retainer which is provided on a surface near the high pressure chamber in the diaphragm. An elastic member is disposed inside the high pressure chamber and the elastic member is disposed between a retainer and a wall surface facing the retainer in the axial direction.

Abstract: A method for detecting and isolation a leak in a hydraulic system having a supply pump serving at least one control valve is disclosed. In one embodiment, the control valve has multiple work sections. In step of the method, the hydraulic system is activated. In another step, an actuation command for at least one of the work sections is received, for example from a human-to-machine interface. Subsequently, the method may include generating a flow demand for the work sections for which an actuation command has been received. The method also includes the step of implementing at least one of a first, second, third, and fourth leak detection and isolation protocol to detect and isolate a leak between the pump and the control valve assembly, a leak between the reservoir and the control valve assembly and a leak between the at least one work circuit and the control valve assembly.

Abstract: A hydraulic drive unit of a hydraulic excavator is configured to include a first hydraulic pump (P1) that discharges a hydraulic oil for activating a boom cylinder (36) and the like, a first electric motor (M1) that drives the first hydraulic pump (P1), a hydraulic pump for revolution (P2) that discharges a hydraulic oil for activating a revolution motor (26), a second electric motor (M2) that drives the hydraulic pump for revolution (P2), and a motor control device (150) that controls the rotation of the first electric motor (M1) and that of the second electric motor (M2). The motor control device (150) is configured such that when the revolution of the revolving body is not activated by the revolution motor (26), control to deactivate the second electric motor (M2) is performed.

Abstract: A piston seal for a reciprocating piston is disclosed having the shape of split ring comprising a first end segment and a second end segment overlapping along a split surface that extends from the inner circumferential surface to the outer circumferential surface of the seal and is transverse to the direction in which the 5 piston moves when reciprocating in a cylinder bore. The split surface is spaced further from the leading lateral surface of the seal that faces a compression chamber associated with the piston than it is spaced from said trailing lateral surface of the seal that is opposite to the leading lateral surface.

Abstract: An auxiliary flow adjustment system and method are disclosed for controlling an auxiliary hydraulic function on a machine in accordance with commands from an operator. The auxiliary flow adjustment system includes operator controls that control a hydraulic control valve. The control valve controls flow rate and flow direction to the auxiliary hydraulic function. When the auxiliary flow adjustment system is activated, the operator can use the operator controls to select a desired flow rate and flow direction for the auxiliary function and maintain the desired flow rate and direction without further use of the operator controls. When the flow adjustment system is activated while a non-zero flow rate is selected, the desired flow rate and direction can be set to the current settings. A resume control can retrieve and command the previously stored desired flow rate and direction. Controls can be used to increase and decrease the set flow rate.

Abstract: A piston rod assembly includes a piston rod having a first end configured to contact fluid, a packing retainer through which the piston rod extends, and one or more packing rings. The packing retainer includes one or more leakage ports forming passageways between an inner surface and an outer surface of the packing retainer. The one or more packing rings surround the piston rod, are adjacent the inner surface of the packing retainer, and are positioned between the one or more leakage ports and a bottom end of the packing retainer. The one or more leakage ports are positioned so that fluid that leaks past the one or more packing rings will flow through the one or more leakage ports.

Abstract: An actuator assembly includes an actuation member, a release member, and a source of pressurized gas, wherein during a normal mode of operation, the actuation member and the release member are engaged to move in unison, and wherein during an emergency mode of operation, pressurized gas automatically decouples the actuation member from the release member to move separately. In accordance with yet other aspects of the present disclosure, an electro-mechanical actuator includes an electro-mechanical drive system and an integrated backup system operated by a gas generator, wherein when the backup system is activated, the electro-mechanical drive system is decoupled and the actuator moves to a predetermined position and mechanically locks in place.

Abstract: A housing for a motor or compressor has an elongate crankcase with two end surfaces. At least one cylinder chamber is provided in which a piston is caused to perform a movement by rotation of the crankshaft. The internal diameter of the crankcase narrows monotonously from the first end surface to the second end surface. A crankcase shaped in this way can be manufactured particularly easily by virtue of the casting being performed around a shaping mandrel. A shaping mandrel of this type must likewise narrow monotonously in order that, after the casting has been performed around it, the shaping mandrel can be pulled out of the housing at a first end. By way of the shaping of the crankcase, it is possible for the housing to be of unipartite and at the same time very compact construction.

Abstract: The present disclosure relates to an adjustment system a method for compensating for temperature variations in a spool valve. The spool valve and adjustment system may be parts in a duplex hydraulic actuator. The adjustment device comprises a spring, a pivot point, and a shape memory alloy (SMA) device. The spring and SMA device are disposed on either side of the pivot point to hold the pivot point in a first position. The SMA device is configured to change size in response to a temperature change so as move the pivot point to a second location. This may eliminate force fight in the duplex hydraulic actuator by preventing asynchronous activation of the spool valves due to thermal expansion within the spool valves.

Abstract: A hydraulic system of a work machine includes a first oil path which is connected to a hydraulic pump and though which hydraulic oil is to flow from the hydraulic pump. An operation valve is connected to the first oil path. An operation lever is to control the operation valve to control pressure of the hydraulic oil in accordance with an operation of the operation member. A hydraulic instrument is to be actuated by the hydraulic oil output from the operation valve. A second oil path connects the operation valve and the hydraulic instrument. The hydraulic oil in the second oil path is discharged through a discharge oil path. An actuation valve is provided in the discharge oil path. An actuation valve controller is to control the actuation valve to be opened and closed according to a temperature of hydraulic oil detected by a first sensor.

Abstract: A pump assembly. The pump assembly may comprise a motor portion for driving a fluid pumping portion via a piston. The motor portion may comprise: a spool and a spool housing assembly having a spool chamber. The spool may be disposed within the spool chamber. The spool may comprise an upper portion and a lower portion, wherein the diameter of the lower portion is larger than the diameter of the upper portion. The spool may also comprise: (1) two support groove portions for cradling two slide valves and (2) two spool bores, which are in fluid communication with the two slide valves. The piston of the pump assembly may comprise a valve stem having a valve stem bore and valve stem openings. The valve stem openings may be funnel-shaped or may inwardly slope into the valve stem bore to prevent or minimize cutting or shredding of a blown seal.

Abstract: An operation device includes: an operating unit; a pilot valve that outputs a pilot pressure corresponding to an operating amount of the operating unit; an operating amount detection sensor that outputs an operating amount signal corresponding to the operating amount of the operating unit; a first bar code provided on the pilot valve and containing pilot pressure actual measurement information indicating a relationship between the operating amount of the operating unit and an actual measurement value of the pilot pressure outputted from the pilot valve; and a second bar code provided on the pilot valve and containing operating amount signal actual measurement information indicating a relationship between the operating amount of the operating unit and an actual measurement value of the operating amount signal outputted from the operating amount detection sensor.

Abstract: A triplex pneumatic architecture system is disclosed having first, second, and third pneumatic subsystems where triplex redundancy may be accomplished by measuring only one particular node in each system, such as a measured current of the servo valve. Each of the first, second, and third pneumatic subsystems are configured to control a separate redundant pneumatic actuation assembly. Each subsystem may comprise a current sensor to measure a control current from a servo driver to a servo valve that controls the pneumatic actuation assembly to output a measured current value, and a dump valve coupled to a relay. Each processor is configured to generate a termination signal to actuate the first relay to open the first dump valve. The triplex pneumatic architecture system further includes a communication bus to communicatively couple each of the first, second, and third pneumatic subsystems.

Abstract: The invention relates to a device (10) for controlling the displacement of a machine (20) with axial pistons comprising a case (23) that houses a control unit comprising a displacement control spool (110) adapted to be switched between two positions by a control pressure (Ps) according to an axis of sliding (?): a working position wherein the control spool (110) provides a connection between at least one inlet (103, 104) that receives a supply pressure and an outlet (105, 106) connected to a cylinder for adjusting the inclination of said machine (31a, 31b), and an idle position wherein the control spool (110) interrupts the connection between said inlet (102, 104) and said outlet (101, 103), and comprising means for switching adapted to vary the position of the adjusting cylinder (31a, 31b), a spring (140), characterised in that: said means of communication comprise a second switching spool (130), coaxial to the control spool (110), a switching pressure (Pm) exerts an axial force on the second spool (130) in

Abstract: A hydraulic controller for a vehicle gearbox is provided. The controller includes a hydraulic actuator which has an oil supply port, a high-pressure hydraulic pump for providing a feed to a high-pressure line, a low-pressure hydraulic pump for providing a feed to a low-pressure line, a hydraulic reservoir for receiving the hydraulic medium from a return line, and a hydraulic control valve. The control valve includes at least three control positions and at least four valve ports. In a first control position, the high-pressure line is fluidly connected to the oil supply port for the regulation of the actuating force of the hydraulic actuator. In a second control position, the low-pressure line is fluidly connected to the oil supply port for the pre-charging of the hydraulic actuator. In a third control position, the hydraulic actuator is fluidly connected to the return line for the return of the hydraulic medium.

Abstract: An example tool includes a hydraulic actuator cylinder; a piston slidably accommodated within the hydraulic actuator cylinder, where the piston includes a piston head and a piston rod extending from the piston head along a central axis direction of the hydraulic actuator cylinder, the piston head divides an inside of the hydraulic actuator cylinder into a first chamber and a second chamber, and the piston rod is disposed in the first chamber and configured to move one or more jaws of the tool; a pump configured to provide pressurized fluid; and a sequence valve configured to block the pressurized fluid from flowing into the second chamber of the hydraulic actuator cylinder until pressure of the pressurized fluid exceeds a threshold pressure value.

Abstract: Methods, systems and apparatuses including systems and methods that can be used for operating a wind turbine including in power generation and regeneration modes are disclosed.

Abstract: A method is disclosed wherein two sheets of a flexible, inelastic substance are sealed along a periphery thereof, creating an interior reservoir preferably containing two or more elongate chambers, organized normal to an axis of traction. The disclosed axis of traction is an axis along which the disclosed device reduces length as a compressed medium is introduced into the reservoir. Further disclosed is a method by which one or more bladders of flexible, inelastic substance are woven through two or more preferably parallel strips or strings. The bladders are adapted to receive a preferably gaseous or liquid compressed medium. As the compressed medium is moved into the bladders, the flexible strips or stings are deformed to cause the strips or strings to have a reduced length along the axis of traction.

Abstract: An actuator main body (11) is formed by a plurality of artificial muscles (12). Each artificial muscle (12) includes an elastic tube (13) and a braided tube (15) covering an outside of the elastic tube (13). A first outside cylindrical body (21) is attached to one end portion of the actuator main body (11), and a second outside cylindrical body (22) is attached to the other end portion of the actuator main body (11). Bonding portions (23, 24) are respectively provided in the first and second outside cylindrical bodies (21, 22). The bonding portions (23, 24) are used to bond the elastic tube (13) to the braided tube (15), to bond the outside cylindrical body (21) to the artificial muscles (12), and to bond the outside cylindrical body (22) to the artificial muscles (12).

Abstract: An object of the present invention is to facilitate discharge of foreign matter present around a valve member, while inhibiting degradation of seal performance of the valve member. A shock absorber includes a cylinder portion containing a liquid, a piston valve partitioning a space in the cylinder portion into a first oil chamber and a second oil chamber which contain oil, a piston rod connected to the piston valve and moving in an axial direction of the cylinder portion, a piston nut 43 (cylinder portion 433) forming a channel for the liquid between the first oil chamber and the second oil chamber, and a float valve 52 deformed or displaced depending on the pressure of oil in the channel in the piston nut 43 to open and close the channel. The float valve 52 for the channel member includes a projecting portion 52P and a recessed portion 52M so that, with the position of the float valve 52 adjusted, a gap is formed between the float valve 52 and the piston nut 43 (cylinder portion 433).