Abstract: A feeding device includes a tool holder, a cutter, a feeding mechanism and a mounting seat. The cutter is positioned on the tool holder. The mounting seat has at least one guiding portion. The tool holder is slidably engaged with the at least one guiding portion. The feeding mechanism includes at least two drivers. Each driver includes a forcer and a stator. The forcers are mounted in the mounting seat, the stators are fixedly positioned on the tool holder. Interactions between alternating magnetic fields produced by the forcers and magnetic fields produced by the stators drive the tool holder and the cutter to backwards and forwards under precise control along the guiding portion.

Abstract: A workpiece has non-rotary curved surface and edges. The workpiece is machined by a lathe. The lathe includes a cutter and a work table under the cutter. The worktable is configured for driving the workpiece to rotate. The non-rotary curved surface of the workpiece has a good finish because the cutter moves along a spiral cutting path on the workpiece at high speed continuously during the machining.