Load-carrying Capacity of the HB〓340 (Hardened and Tempered) Gears : 2nd Report, Surface Durabilities of the Leaded Free-cutting Steel Hobbed Gears and Honed Gears

抄録

The surface durability of the H_B≈340 hobbed gears made of a leaded free-cutting steel was investigated by using a power circulating-type gear tester. And, the surface durability of the honed gears was studied. It is found that the hobbed gears made of a leaded free-cutting steel are longer in pitting life than ones of a usual steel, and that the honed gears have a much longer pitting life. The main reason for these results is that the initial tooth surface of leaded free-cutting steel gears is smoother than that of usual steel gears under the same hobbing conditions, and that the honed gears have a much smoother surface. Therefore, these gear tests show that the surface durability of the H_B≈340 steel is improved by the smoother surface, and this confirms the results obtained in the roller tests in the previous paper (1st report)⁽¹⁾.