Patent ID: 9353864
Filing Date: 2016-05-31
CPC Classification: F16J

Claim Text:
1. An oil ring for an internal combustion engine in which at least part of a surface of the oil ring has a surface roughness Ra of 0.005 μm to 0.4 μm and is coated with a metal coating having a thickness of 0.1 to 10 μm, wherein: the metal coating has a surface roughness Ra of the metal coating within a range of 0.005 μm to 0.4 μm; a surface of the metal coating has a surface free energy at 60° C. of 40 mJ/m the metal coating contains a material selected from the group consisting of Ni, Cu, and alloys containing one of Ni and Cu; the oil ring for an internal combustion engine comprises an oil ring body that includes a pair of axially disposed upper and lower rail portions and a web connecting the rail portions, the oil ring body having an end gap, and a coil expander that is attached to an inner peripheral groove of the oil ring body; and the oil ring for an internal combustion engine comprises a spacer expander, and a pair of upper and lower side rails supported by the spacer expander.