RADIALLY NOTCHED PISTON RINGS

摘要

In an annular groove (25) carried by one of a pair of reciprocally movable members (20, 22), a piston ring (30) is carried by the annular groove (25) for sealing the reciprocally movable members (20, 22) for minimizing fluid leakage between the members (20, 22). The piston ring (30) is an annular member (31) that includes an outer contact surface (42) engagable with a sidewall (23) of the other of the pair of reciprocally movable members (20, 22), an opposed inner surface (43), an end gap (45) that severs the annular member (31) and that defines spaced-apart first and second ends (46, 47) of the annular member (31), and annular member tension-relieving notches (60) formed in the inner surface (43) of the annular member (31). The notches (60) are spaced-apart along the length of the annular member (31) between the first end (46) and the second end (47), and each notch (60) has a blunt notch tip (63) for inhibiting crack propagation in the annular member (31) from the blunt notch tip (63) when the annular member (31) is tensioned.