Patent ID: 8262291

Claim:
A coreless seal arranged between a rotation shaft and a shell-type outer ring, the coreless seal having an inner diameter surface opposed to an outer diameter surface of said rotation shaft with a space for preventing leakage of fluid, wherein the shell-type outer ring has a flange bent inwardly, and further wherein an outer diameter and an inner diameter of said coreless seal are dimensions obtained by adding interference for an amount of shrinkage; and still further wherein the coreless seal has a lip part which projects inwardly and toward the flange of the shell-type outer ring; a surface of the outer diameter being flat when viewed in cross section; and an end surface of the coreless seal which is in contact with the flange of the shell-type outer ring in an axial direction is flat; wherein when it is assumed that said dimension obtained by adding interference for an amount of thermal shrinkage in a radial direction is A, and an outer diameter dimension of said coreless seal in a free state at room temperature is B, the following relation is satisfied, 0.005 B≦A≦ 0.030 B ; and when it is assumed that an outer diameter dimension of said coreless seal in a free state at room temperature is B, and an inner diameter dimension of said outer ring is C, the following relation is satisfied, 0.950 B≦C≦ 0.985 B , and when it is assumed that said dimension obtained by adding interference for an amount of thermal shrinkage in a radial direction is A, an inner diameter dimension of said coreless seal in a free state at room temperature is D, and an outer diameter dimension of said rotation shaft is E, the following relation is satisfied, E<D<E+ 2 A.