Patent ID: 7771120

Claim:
A plain bearing for internal combustion engines, which comprises a back metal layer and a bearing alloy layer made of an aluminum-base bearing alloy formed over the back metal layer, wherein the bearing alloy layer has a Vickers hardness (Hv) of from not less than 40 to not more than 160, and wherein the bearing alloy layer comprises a lubricative surfacial sub-layer containing a solid lubricant, which sub-layer is produced by shooting particles of the solid lubricant having a particle size of a most 10 μm, to collide against the surface of the bearing alloy layer, the sub-layer being a part of said bearing alloy layer and having a thickness of not more than 10 μm extending from the surface of the bearing alloy layer into the bearing alloy layer, wherein a concentration of an element contained in the solid lubricant decreases from the outermost part of the lubricative surfacial sub-layer toward the depth throughout the lubractive surfacial sub-layer, and the maximum concentration of such an element is not less than 5 mass % at the outermost part of the lubricative surfacial sub-layer, wherein the outermost part of the lubricative surfacial sub-layer of the bearing alloy layer has a surface roughness of not more than 3 μm in terms of the maximum height (Rz), and wherein there is provided a coating layer having a thickness of 0.01 to 10 μm on the bearing alloy layer, the coating layer consisting of a solid lubricant material.