PCD face seal for earth-boring bit

摘要

An earth-boring bit has a mechanical face seal assembly with PCD faces. The bit has a bearing shaft 15 with a cone 16 rotatably mounted on the bearing shaft. The seal locates between the bearing shaft and the cone for sealing lubricant therein. The seal includes at least one rigid seal ring 21 having a carbide body and an annular PCD face 33 located on it. The mating face 35 may also be of a PCD material, and as shown is formed by an annular insert 23 which has a metal carbide body 36. An energizing elastomer forces the faces together and, elastomer 31 prevents the ingress of debris. Various configurations of the faces 33, 35 are disclosed, as is a method of forming the faces.