Patent ID: 8226088

Claim:
A floating seal comprising a pair of housings, which are relatively rotatable on a common axis, wherein each housing supports a floating ring with an elastic ring in between, the floating rings being slidably sealed together by the elasticity of the elastic rings, the floating seal further comprising, at a contact portion between each floating ring and the corresponding elastic ring and at least at a portion of each floating ring that is located closer to a sealing side, tight contact means arranged in at least one of the floating ring and the elastic ring, the tight contact means maintaining the contact portion in a tight contact state, wherein a rough surface is formed on each of a contact surface of the floating ring that faces the elastic ring and a contact surface of the housing that faces elastic ring to prevent the elastic ring and the floating ring as well as the elastic ring and the housing from sliding with respect to each other and wherein the rough surface is located further from the sealing side of the floating ring than the tight contact means, wherein, at the contact portion between each housing and the corresponding elastic ring and at least at the portion of each floating ring that is located closer to the sealing side, additional tight contact means is arranged in the housing, the additional tight contact means maintaining the contact portion in a tight contact state, wherein the additional tight means is an elastic layer secured to each housing.