| 摘要 |
PROBLEM TO BE SOLVED: To suppress generation of a clearance between end parts, and prevent the damage of a rubber like elastic body made ring by arranging a displacement absorbing part on an end part which abuts on a cut part formed on one part on the circumference of a resin ring. SOLUTION: A packing 1 is mounted in an installing groove 4 formed on an outer periphery of a piston 3, and seals between a cylinder 2 and a piston 3 while being brought into slidably contact with an inner circumferential surface of the cylinder 2. The packing 1 is formed by assembling a rubber like elastic body made back ring 5 and a resin ring 6, is provided with a cut part 7 on one part, and is provided with a bellows part 9 set as a displacement absorbing part. The diameter of the packing 1 is formed larger than that of a groove, the packing 1 is mounted without a clearance against the groove by displacing and contracting the bellows part 9 so as to absorb the tolerance at the time of molding. Even at the time of a high temperature, tensile strength generated by a difference between heat expansion coefficients of the cylinder 2 and the seal ring 6 is absorbed by the bellows part 9 so as to suppress creep. |
