An electrical machining device is provided for machining a surface of a workpiece. The electrical machining device includes a nozzle connectable to an electrolyte reservoir, the nozzle configured to dispense electrolyte towards a surface of a workpiece, in use, and an electrolyte flow path for conveying electrolyte from an electrolyte reservoir to the nozzle. The electrolyte flow path has a gas inlet therealong and the electrical machining device is configured to inject a gas into electrolyte flowing along the electrolyte flow path via the gas inlet, in use, so as to form gas bubbles in said electrolyte.

An electrical machining device is provided for machining a surface of a workpiece. The electrical machining device includes a nozzle connectable to an electrolyte reservoir, the nozzle configured to dispense electrolyte towards a surface of a workpiece, in use, and an electrolyte flow path for conveying electrolyte from an electrolyte reservoir to the nozzle. The electrolyte flow path has a gas inlet therealong and the electrical machining device is configured to inject a gas into electrolyte flowing along the electrolyte flow path via the gas inlet, in use, so as to form gas bubbles in said electrolyte.

A herringbone gear includes a cylindrical body having a circumferential face having a width. A first helical gear tooth on the circumferential face has a first configuration, a second helical gear tooth on the circumferential face has a second configuration, and a transition on the circumferential face extends between the first helical gear tooth and the second helical gear tooth. An involute form taken within a transverse plane of the circumferential face remains constant over the width.

A herringbone gear includes a cylindrical body having a circumferential face having a width. A first helical gear tooth on the circumferential face has a first configuration, a second helical gear tooth on the circumferential face has a second configuration, and a transition on the circumferential face extends between the first helical gear tooth and the second helical gear tooth. An involute form taken within a transverse plane of the circumferential face remains constant over the width.

A method of performing hybrid electrochemical and abrasive fluid polishing is provided. The method comprised disposing (202) a workpiece to be polished and a cathode in a flow of polishing fluid, wherein the polishing fluid comprises at least one electrolyte and at least one abrasive medium. The method further comprises connecting (204) the workpiece and the cathode to an electrical power supply. An apparatus (100) is also provided for hybrid electrochemical and abrasive fluid polishing. The apparatus comprises a vessel (102) comprising an inlet (103a) and an outlet (103b) to allow a flow of fluid through the vessel. The apparatus further comprises one or more mounts (104) configured to hold a workpiece (108) to be polished in the vessel between the inlet and the outlet. The apparatus also comprises one or more connectors (106) configured to connect the workpiece and a cathode (110) to an electrical power supply.

A method of performing hybrid electrochemical and abrasive fluid polishing is provided. The method comprised disposing (202) a workpiece to be polished and a cathode in a flow of polishing fluid, wherein the polishing fluid comprises at least one electrolyte and at least one abrasive medium. The method further comprises connecting (204) the workpiece and the cathode to an electrical power supply. An apparatus (100) is also provided for hybrid electrochemical and abrasive fluid polishing. The apparatus comprises a vessel (102) comprising an inlet (103a) and an outlet (103b) to allow a flow of fluid through the vessel. The apparatus further comprises one or more mounts (104) configured to hold a workpiece (108) to be polished in the vessel between the inlet and the outlet. The apparatus also comprises one or more connectors (106) configured to connect the workpiece and a cathode (110) to an electrical power supply.

A downhole tool, for removing sections of metal tubing, said downhole tool comprising at least one conductive element being arranged to corrode a section of metal tubing using an electrolytic process, said conductive element being made of electric conductive material, an apparatus to establish a connection to the metal tubing, and a source of electrical power.

A downhole tool, for removing sections of metal tubing, said downhole tool comprising at least one conductive element being arranged to corrode a section of metal tubing using an electrolytic process, said conductive element being made of electric conductive material, an apparatus to establish a connection to the metal tubing, and a source of electrical power.

The present invention relates to a grind machining apparatus, which comprises a grinding wheel and an electrochemical processing module. The grinding wheel has a grinding surface on the surface. The electrochemical processing modules is disposed at the grinding wheel. The processing surface of the electrochemical processing module faces the direction away from an axle of the grinding wheel and is located lower than the grinding surface. By using the above grind machining apparatus, alternate compound machining including electrochemical oxidation processing and mechanical grind machining can be performed.

A machine for machining a workpiece having a first central longitudinal axis passing through a workpiece plane that is disposed orthogonally relative to the first central longitudinal axis is provided. The machine includes a chuck or fixture on which the workpiece is disposable, a grinding spindle having a body, a wheel supporting an abrasive and an insulator electrically isolating the wheel from the body, the wheel being operable to remove material from the workpiece, the grinding spindle having a second central longitudinal axis about which the grinding spindle rotates, the second central longitudinal axis of the grinding spindle passing through the workpiece in the workpiece plane so as to create a continuous gear tooth on the workpiece and an electrochemical grinding (ECG) element configured to execute ECG processing on the grinding spindle and the workpiece to soften the workpiece as the gear tooth is being created by the grinding spindle.