Method of producing a spherical bearing

A method of manufacturing a spherical bearing, comprising the steps of:

• preparing a spherical bearing element assembly including an outer ring having a cylindrical inner peripheral surface, an inner ring having a spherical outer peripheral surface arranged in face-to-face relation with the inner peripheral surface of said outer ring, and a flexible lubricating sheet of a hollow cylindrical shape disposed between the inner peripheral surface of said outer ring and the spherical outer peripheral surface of said inner ring and having a metallic net-like member as a base material, a synthetic resin composition exhibiting lubricity being filled in meshes of said base material and coated on a surface of said base material;
• preparing a pair of caulking dies respectively provided with annular projections with a substantially triangular cross section on the surfaces thereof;
• placing said spherical bearing element assembly on one of said caulking dies in such a manner that the annular projection of said one caulking die abuts against said outer ring on an outer side of one annular end of the inner peripheral surface of said outer ring;
• placing another of said caulking dies on said spherical bearing element assembly in such a manner that the annular projection of said another caulking die abuts against said outer ring on an outer side of another annular end of the inner peripheral surface of said outer ring;
• and
• pressing one of said caulking dies towards another of said caulking dies so as to form annular recesses generally complementary to the annular projections of said caulking dies on respective outer sides of both the annular ends of the inner peripheral surface of said outer ring and to deform outer surrounding portions of both annular ends of the inner peripheral surface of said outer ring toward the center of said spherical bearing element assembly, by means of said annular projections of said caulking dies, respectively, whereby respective portions of said flexible lubricating sheet which are offset from central portions of respective annular areas of said flexible lubricating sheet in an axial direction of said outer ring toward respective annular ends of the inner peripheral surface of said outer ring are made to undergo plastic flow by means of said deformed outer surrounding portions of both annular ends of the inner peripheral surface of said outer ring, said annular areas of said flexible lubricating sheet being respectively defined between a center of said outer ring in the axial direction and one annular end of the inner peripheral surface of said outer ring and between the center of said outer ring in the axial direction and another annular end of the inner peripheral surface of said outer ring.