Method of electrochemical machining bladed rotors

Abstract

In electrochemically machining individual oversize blades of an integral bladed gas turbine engine rotor, opposed cathodes are initially offset in an electrolyte chamber relative to a selected machining position with the rotor outside the chamber skewed at an angle relative to the final position of the cathodes in the electrolyte chamber. The rotor and electrolyte chamber are then relatively moved in a vertical direction to position an individual blade to be machined in a workpart machining position in the chamber and concurrently one cathode is moved in a direction toward one side of the blade and the other cathode is moved in two other different directions, one toward the blade from the opposite side of the blade and the other transverse thereto, to position the cathodes in aligned relation on opposite sides of the blade at the machining position with blades adjacent the individual blade to be machined received in pockets in the cathodes without contact. The cathode on the convex side of the blade is initially offset laterally and is moved bi- directionally whereas the other cathode on the concave side is moved in one direction toward the blade to be machined. The cathodes are advanced toward the respective side of the blade and toward one another from a cathode start machining position to a cathode finish position with electrolyte and electrical current flow between the cathodes and blade to effect machining and with the adjacent blades received in the cathode pockets out of contact. During this advance, the cathodes are releasably clamped against movement in directions transverse to cathode advancement.