In recent years, the automotive industry has been demanding high-precision and
high-efficiency processing of internal gears (ring gears) used for planetary gear devices in terms of
improvement of fuel efficiency and reduction of noise. To achieve these, manufacturers are
developing a skiving cutting system expected to realize high precision and high efficiency.
However, the conventional skiving cutting system using a gear shaper cutter (skiving cutting) has
not come into practical use because, in principle, its cutting load is large and, therefore, tool life is
shortened and production costs are increased. Against such a background, Mitsubishi Heavy
Industries, Ltd. (MHI) has established a process technology with similar accuracy to the skiving
cutting while exceeding it in efficiency and tool life. This paper presents the process technology.
