Seal ring

摘要

Sandwiching of a foreign matter between a seal ring and a housing is suppressed, and abrasion of the housing and the seal ring is suppressed. The size of the diameter of a second seal portion 3 is set to be larger than the size d2 of the diameter of an inner peripheral face 81 so that the difference in diameter size between the second seal portion 3 and an inner peripheral face 81 of a housing 80 becomes 1.0 mm or less in a state before the ring body is provided in the annular gap.

主权项

1. A method for setting a seal ring, the seal ring being attached to an annual groove provided in a shaft member to be assembled in a shaft hole in a housing, the seal ring including a first seal portion which comes into close contact with a sidewall face on a side of a fluid which is not to be sealed of the annular groove, and a second seal portion which comes into close contact with an inner peripheral face of the housing, the seal ring for sealing an annular gap between the shaft member and the housing, the seal ring having a separation portion provided in one place in the circumferential direction of a ring body of the seal ring, the separation portion provided with, at one separation end, a circular projection which projects in the circumferential direction and, at the other separation end, a circular recess which engages with the circular projection, the circular projection and the circular recess being provided with mating faces which enable relative movement in the circumferential direction, and the seal ring being capable of absorbing a change in circumferential length of the ring body by the relative movement in the circumferential direction between the circular projection and the circular recess, the method comprising:
forming the ring body by injection molding molten plastic in a cavity such that, in a state after the molten plastic is cooled and before the ring body is provided in the annular gap, a diameter of the second seal portion is larger than a diameter of the inner peripheral face of the housing by 5 to 10%; after forming the ring body, adjusting the diameter of the molded ring body to be smaller than the diameter of the inner peripheral face by 1.0 mm or less by heating the ring body in a hot die and performing a shaping process; and after adjusting the ring body, installing the ring body in the annular groove within the shaft and within the shaft hole and expanding the ring body by executing a pre-conditioning interim heating, and making the ring body expand and come into close contact with the inner peripheral face.