Patent ID: 7556864
Filing Date: 2009-07-07
Classification: B22F,F16H,Y10T

Abstract:
1. A sintered gear composed of a sintered alloy having a metal matrix and pores, comprising: a first densified layer that is formed on a tooth surface with a thickness of 500 to 1,000 microns and porosity of 10% or less; and a second densified layer that is formed on a bottom land with a thickness of 10 to 300 microns and porosity of 10% or less, in which a boundary of the first densified layer being continuous with a boundary of the second densified layer without a substantial level difference, wherein the porosity of the sintered alloy is 10 to 15%, and the difference in porosity between the sintered alloy and an outermost surface of each of the first densified layer and the second densified layer is respectively 7% or more by volume.