COMPRESSION RING

WIPO Patent Application WO/2022/168668

A1

An outer peripheral surface of this compression ring includes a barrel curved surface, wherein: if L1 is a width of the outer peripheral surface in an axial direction of the compression ring, the condition 0.2 mm<1/2×L1 is satisfied; and if d1 is a distance in the radial direction of the compression ring between an outer peripheral vertex and each of two points on the barrel curved surface separated by 0.1 mm from the outer peripheral vertex in the axial direction of the compression ring, and d2 is a distance in the radial direction of the compression ring between the outer peripheral vertex and each of two points on the barrel curved surface separated by 1/4×L1 from the outer peripheral vertex in the axial direction of the compression ring, the condition d1