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Precision gear grinding machining There are many techniques, such as quenching, carburizing, tooth surface high-frequency induction heating quenching, intensive benchmark, finishing precision gear grinding machining process analysis, benchmark selection for the gear grinding machining datum often due to the choice of different structural shapes of gears vary. With gears mainly apex hole location; for the hollow shaft, the hole drilled in the center, with both ends of the opening of the bevel position; aperture large cone block is used. Apex high positioning accuracy, and can be done benchmarks coincide and unity. With holes in the gear tooth surface machining is often used in two for positioning and clamping manner.Within this hole and face orientation is targeting workpiece hole location to determine position location, and then to the end face as an axial positioning reference, and against the end face of the clamp. This allows the positioning reference, the reference design, assembly and measurement reference datum coincide, high positioning accuracy, suitable for mass production. But for the manufacture of high precision jig. Outside the circle and face orientation when the workpiece spindle with a large and increasing gap, the use of a dial indicator to determine the correction cylindrical central location, and the end face axial location from the other end face of the clamp.This positioning because each workpiece to be corrected, so the productivity is low, while the internal gear blanks, cylindrical coaxial requirements, while the fixture less precision, it applies to a single piece, small batch production.