Pump seal

A mechanical seal for mounting between a pump bore of a pump and a rotatable shaft extending axially therethrough, said mechanical seal comprising:

• a 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, said outer shell surface having a wall portion with a size defined relative to a pump bore such that press fitting engagement of said wall portion of said support shell with a pump bore effects limited radial distortion of the outer shell wall radially inwardly upon axial pressing of the support shell into the pump bore;
• 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 thickness defined by a an outer ring surface and an inner ring surface wherein said radial thickness defines a radial stiffness of said drive ring 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, and said inner ring surface and said stationary seal ring being interfitted in said stationary 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
• 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.

A method of assembling and installing a mechanical seal between a pump bore of a pump and a rotatable shaft extending axially therethrough, said method comprising the steps of:

• providing a 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, said outer shell surface having a wall portion with a size defined relative to a pump bore adapted for press fitting of said support shell in said pump bore;
• providing a drive ring which has an annular shape having a radial thickness defined by a an outer ring surface and an inner ring surface wherein said radial thickness defines a radial stiffness of said drive ring which has a greater rigidity than said outer shell wall;
• inserting said drive ring with an interference fit into said interior chamber of said support shell in fixed non-movable engagement therewith, said drive ring being disposed directly radially inwardly of said wall portion;
• inserting a stationary seal ring in said drive ring with aid inner ring surface and said stationary seal ring being interfitted in said stationary engagement to prevent circumferential movement of said stationary drive ring relative to said support shell;
• providing 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;
• mounting said rotatable seal ring on said shaft;
• and
• press fitting said wall portion of said support shell within said pump bore which effects limited radial distortion of the outer shell wall radially inwardly in compression against said drive ring upon axial pressing of the support shell into the pump bore.