An electric discharge machining apparatus includes a tool electrode that performs electric discharge machining to a workpiece, a housing in which the tool electrode is inserted, a compressed gas supplying device for supplying compressed gas into a mist generating region which is provided between an inner wall of the housing and the tool electrode, a first flow path through which the compressed gas flows and connecting the compressed gas supplying device with the mist generating region, a pressurized working fluid supplying device for supplying pressurized working fluid into the mist generating region, and a second flow path through which the pressurized working fluid flows and connecting the pressurized working fluid supplying device with the mist generating region.

This disclosure provides a system, method, and resulting workpiece combining liquid guided laser and electrical discharge machining to create a common feature. The workpiece is positioned in a liquid guided laser cutting path and machined by the liquid guided laser device to create an intermediate feature in the workpiece. The work piece is then positioned in an electrical discharge machining (EDM) device so that an electrode of the EDM device is operatively positioned proximate the intermediate feature and machined using the EDM device to modify the intermediate feature in the workpiece to create the finished common feature in the workpiece.

A grip unit including holding units in each of which an upper plate is placed on a lower plate to form a V-shaped groove, a grip unit control device that can change a distance between the holding unit in a range between a distance equal to or longer than a diameter of an electrode holder with an electrode feeding mechanism and a distance equal to a diameter of an electrode, a grip unit control device moving-shaft motor that can change a height of the grip unit in a range between a height at which the holding unit are placed lower than an electrode holder brim of an electrode holder having an electrode feeding mechanism attached to an electric holder gripping device and a height to which the holding units lift up the electrode holder brim of the electrode holder having an electrode feeding mechanism attached to the electric holder gripping device, and an electrode gripping device that can grip the electrode on a lower side of the grip unit are included. In one of the pair of holding units, a portion of the upper plate which forms the V-shaped groove is placed on a front side and a portion of the lower plate is placed on a rear side so as to overlap with each other. In the other one of the pair of holding unit, a portion of the lower plate which forms the V-shaped groove is placed on the front side and the upper plate is placed on the rear side so as to overlap with each other.

An electric discharge machining apparatus includes a tool electrode that performs electric discharge machining to a workpiece, a tubular extended guide in which the tool electrode is inserted, a long nozzle in which the tool electrode is inserted with a tip protruded, and provided along an outer wall surface of the extended guide so as to provide mist generating space between the extended guide and the long nozzle, a compressed gas supplying device supplying compressed gas into the mist generating space, and a pressurized working fluid supplying device supplying pressurized working fluid into working fluid filling space between the tool electrode and the extended guide.

An electrical discharge machining (EDM) assembly includes a mounting device that is configured to support an EDM electrode relative to a work piece. The electrode includes an axial opening that extends between opposed ends of the electrode, a first portion that includes one end and a second portion that includes the opposed end. The flexibility of the first portion is greater than that of the second portion. For example, the first portion may be a helical spring and the second portion may be a rigid tube. The mounting device includes a back plate, an upright portion that protrudes from the back plate and a curved sleeve disposed in a through hole that extends through the back plate and the upright portion. The electrode is movably disposed in the sleeve.

To provide a turbine blade, a manufacturing method for a turbine blade, and a gas turbine. In the turbine blade including a cooling passage provided along a blade height direction, the cooling passage includes: a first cooling hole including one end opening toward a front end, and having an inner diameter that is constant along the blade height direction; and a second cooling hole including one end communicating with the other end of the first cooling hole without a level difference, and having an inner diameter that is increased toward a base end. A length from the one end of the first cooling hole to a position where the first cooling hole and the second cooling hole are communicated with is 40% to 60% of a length from the one end of the first cooling hole to a gas path surface on the base end.

EDM assemblies mount on a machining surface and discharge rotating sub-electrodes against the surface. The sub-electrodes can also revolve about another shared axis while discharging. Rotation and revolution may be achieved with planetary gears fixed with the sub-electrodes and meshing with a stationary sun gear. Several sub-electrodes can be used in a single assembly. Downward movement of the sub-electrodes from a central shaft on the mount allows several inches of the surface to be machined. Assemblies are usable in a nuclear reactor during a maintenance period to machine a hole for a replacement manway cover underwater in the flooded reactor. The differing rotational movements and vertical movement can be independently controlled with separate motors in the assembly. Power and controls may be provided remotely through an underwater connection.

EDM assemblies mount on a machining surface and discharge rotating sub-electrodes against the surface. The sub-electrodes can also revolve about another shared axis while discharging. Rotation and revolution may be achieved with planetary gears fixed with the sub-electrodes and meshing with a stationary sun gear. Several sub-electrodes can be used in a single assembly. Downward movement of the sub-electrodes from a central shaft on the mount allows several inches of the surface to be machined. Assemblies are usable in a nuclear reactor during a maintenance period to machine a hole for a replacement manway cover underwater in the flooded reactor. The differing rotational movements and vertical movement can be independently controlled with separate motors in the assembly. Power and controls may be provided remotely through an underwater connection.

A system for forming features within composite components includes a tubular electrode extending along a longitudinal direction from a proximal end to a distal end. The distal end is, in turn, configured to be positioned relative to a machining surface of the composite component such that a spark gap is defined between the distal end and the machining surface. Furthermore, the tubular electrode further extends in a radial direction between an inner surface and an outer surface, with the inner surface defining a central passage configured to supply a dielectric fluid to the machining surface. The outer surface of the tubular electrode includes at least one a channel defined therein or a non-circular cross-sectional shape.

A method for manufacturing a stage of a steam turbine comprising the steps of milling a block of material to define a sector having a plurality of blades, each blade having an external surface; machining an opening in the external surface of at least one of the blades; machining a cavity in fluid communication with the opening; the step of machining the cavity being performed by wire electric discharge machining.