Patent ID: 7904993

Claim:
A spherical bearing for a lock gate door, interposed between a door body and a lock gate such that the door body which has a rotational axis inclined with respect to a vertical axis is rotatably supported around the rotational axis by the lock gate, said spherical bearing comprising: a convex curved body made of stainless steel and having a spherical surface, and a concave curved seat made of copper alloy and disposed above the convex curved body, said concave curved seat having toroidal curved surface which slidably contacts said spherical surface of said convex curved body, said toroidal curved surface having a center of curvature located on a circle which has as its center a position spaced apart a predetermined distance from a spherical center of the spherical surface in an axial direction passing through the spherical center of the spherical surface, and which is located in a plane perpendicular to the axial direction, said spherical surface of said convex curved body having a radius of curvature smaller than a radius of curvature of said toroidal curved surface of the concave curved seat, said toroidal curved surface is formed so as to slidably contact said spherical surface at a portion intersecting lines which pass through the center of the curvature of the toroidal curved surface and are inclined at a range of angles ranging from 30 degrees to 45 degrees with respect to an axis extending in the axial direction.