Abstract: A pair of opposed spindleheads are rigidly mounted on a bed for holding a crankshaft to be machined between a pair of chucks on the ends of indexing spindles. One or more, preferably two, cutter assemblies are provided between the spindleheads for movement therebetween. Each cutter assembly includes a carriage slidable along a guideway on the bed and itself having slidably mounted thereon a slide which is reciprocable in a direction normal to the axis of the crankshaft. Mounted to the slide for rotation about an axis parallel to the axis of the crankshaft is a disklike tool holder carrying a annular, rotary cutting tool in an eccentric position thereon. The cutting tool has an annular row of internal cutting edges surrounding with clearance a desired part of the crankshaft to be machined.

Abstract: A crankshaft milling machine comprising a bed, a pair of rails fixedly secured to the bed, a spindle fixedly mounted on the bed, a chuck mounted for rotation on one end of the spindle, a first motor for imparting a rotation to the chuck, a tool guide slidably mounted on the rails, the tool guide being inverted U-shape in cross-section, a tool support movably accommodated within the tool guide, the tool support being reciprocally movable in a vertical plane, and a second motor for causing a reciprocal movement of the tool support. An internal tooth cutter is rotatably supported by the tool support and a third motor is installed for rotating the internal tooth cutter. A numerical control device is provided for controlling the relative movement of the chuck and the tool support in such a way that the rotation of the chuck is synchronized with the reciprocal movement of the tool support.