Patent ID: 7797829
Filing Date: 2010-09-21
Classification: F16J,Y10T

Abstract:
1. A method of manufacturing an oil ring which comprises an annular oil ring body having a pair of rail portions formed at its axially upper and lower portions and butt ends, the pair of rail portions each having an outer peripheral sliding surface, and a coil expander assembled in an inner periphery of said oil ring body, the method comprising the steps of: alternately stacking a plurality of oil ring bodies and annular spacers having a smaller diameter than said oil ring bodies, and then aligning and retaining them by using a jig such that an outer periphery of said oil ring bodies becomes a cylinder; and rotating the aligned oil ring bodies, and forming a flat region that is substantially level with respect to said outer peripheral sliding surface of the plurality of oil ring bodies and forming curved regions extending on both sides of said flat region by using a buff or an elastic grindstone.