Patent ID: 10704690

Abstract:
A piston ring may have a base with a sliding external surface, an internal surface, an upper surface, and a lower surface, the external surface having chamfered edges. The external surface, the internal surface, the upper surface, the lower surface, and the chamfered edges may have a coating provided with a nitrided first layer having a thickness of up to 2% of a nominal axial thickness of the ring when applied to the upper surface and the lower surface, and a thickness of up to 10% in relation to the thickness of the first layer applied to the upper surface and the lower surfaces when applied to the external surface and to the chamfered edges. The external surface and the chamfered edges may include a sliding layer having one of a hard chromium or ceramic chromium plated coating, the sliding layer being applied on the first layer, the sliding layer having a thickness of between 80 and 175 microns.