Patent ID: 8714556

Claim:
A mechanical seal for mounting between a pump bore of a pump and a rotatable shaft extending axially therethrough, said mechanical seal comprising: a thin-walled, metal support shell having an annular outer shell wall defining an outer shell surface configured for a press fit into the pump bore and an inner shell surface defining an interior chamber which opens axially from an open end of said outer shell wall, said outer shell wall having a wall portion with a radial wall thickness defined between said outer and inner shell surfaces and a radial shell diameter defined relative to a pump bore such that press fitting engagement of said wall portion of said support shell with a pump bore smaller than said radial shell diameter effects limited radial distortion of the outer shell wall radially inwardly upon axial pressing of the support shell into the pump bore, said wall portion defining a maximum radial dimension for said radial shell diameter and said inner shell surface defining an inner shell circumference which is circumferentially continuous, said outer shell wall having a metal radial flange at said open end which projects radially outwardly of said radial shell diameter and defines a flange face which faces axially; a stationary seal ring which has an annular shape and is mounted in stationary engagement with said support shell; a drive ring which has an annular shape having a radial ring thickness defined by an outer ring surface and an inner ring surface and having an axial length defined between opposite, axially-facing ring end faces wherein said radial ring thickness is thicker than said radial wall thickness along said axial length and defines a radial stiffness of said drive ring along said axial length which has a greater rigidity than said outer shell wall, said drive ring being inserted with an interference fit into said interior chamber of said support shell in fixed non-movable engagement therewith wherein an outer one of said ring end faces is substantially coplanar with said flange end face, and said outer ring surface is in substantially continuous contact with said inner shell surface along said inner shell circumference, said inner ring surface and said stationary seal ring being interfitted in said fixed non-movable engagement to prevent circumferential movement of said stationary drive ring relative to said support shell, said drive ring being disposed directly radially inwardly of said wall portion to be subjected to said limited radial distortion of said outer shell wall by a pump bore and said greater rigidity providing radial support to said support shell along said axial length and about said inner shell circumference when said support shell is press fit into a pump bore; and a rotatable seal ring supportable on a rotating shaft by a shaft sleeve, wherein said stationary and rotatable seal rings have opposed seal faces which are disposed in sealing engagement with each other.