Split mechanical face seal

A mechanical face seal assembly for creating a seal between a stuffing box housing and a shaft which projects outwardly of the stuffing box housing and is rotatable relative thereto about its longitudinal axis, said face seal assembly comprising:

• a rotor assembly mountable on the shaft in sealed and nonrotatable relationship therewith including a sleeve-type collar which is nonrotatably and sealingly mountable on the shaft and a first face ring which is mounted on and carried by the collar, said first face ring defining a first annular sealing face thereon which is disposed on an axially outwardly facing end surface of said first face ring;
• a stator assembly disposed in surrounding relationship to the shaft and nonrotatably mountable to the stuffing box housing, the stator assembly including an annular gland member which surrounds the shaft and is nonrotatably mountable on the stuffing box housing, and a second face ring which is nonrotatably carried on the gland housing in surrounding relationship to the shaft and defines a second annular sealing face on an axially outwardly facing end surface thereof so that said first and second sealing faces are disposed in axially opposed relationship to one another;
• one of said stator and rotor assemblies having a pushing device cooperating with the face ring of said one assembly for urging the face ring of said one assembly axially toward the face ring of the other assembly so as to normally maintain the opposed first and second sealing faces in abutting contact with one another;
• said rotor assembly including a substantially annular bore which opens axially inwardly from one end of said collar and terminates in a substantially flat bottom wall which extends transversely with respect to a longitudinal axis of the collar, said first face ring having an axially extending rear annular part which terminates at a substantially rear flat end face which extends substantially perpendicularly relative to a longitudinal axis of the first face ring, said rear annular part being disposed within the annular bore of the collar so that the rear flat end face of the first face ring abuts the bottom wall on the collar, a first annular elastomeric seal member disposed within the annular bore of the collar and in circling relationship to said rear annular part of said first face ring, said first elastomeric seal member being maintained in sealing engagement with both said collar and said first face ring, said first elastomeric sealing member being axially abutted against a shoulder on the collar which prevents the first face ring from moving axially outwardly of the annular bore, said first elastomeric seal member also being axially abutted against a shoulder on the rear annular part when the first face ring is seated against said bottom surface so as to retain the first face ring axially within the annular bore;
• said rotor assembly also including a drive pin arrangement cooperating between said collar and said first face ring for preventing relative rotation there between, said drive pin arrangement including at least two drive pins fixed to said collar in angularly spaced relationship from one another and projecting axially therefrom into respective recesses which open axially inwardly of said first face ring, each said recess having a radially outer wall which is disposed in close proximity to an opposed side surface of the respective drive pin so as to restrain said first face ring from radially inward movement relative to the respective drive pin;
• said rotor assembly being axially split in its entirety into two substantially similar rotor subassemblies each having a substantially semi-cylindrical configuration with the axial splitting of said rotor assemblies causing each of the collar, first face ring and first elastomeric seal member to be axially split into two substantially semi-cylindrical segments, one of said drive pins being associated with each of said rotor subassemblies with said drive pin being angularly spaced from opposite arcuate ends of the respective rotor subassembly so that the respective drive pin radially retains the face ring segment within the respective collar segment while the elastomeric member segment axially retains the face ring segment within the respective collar segment, whereby the rotor subassemblies can be preassembled and handled as a unitized arrangement and;
• removable fastening means cooperating between opposed ends of the collar segments for permitting the opposed collar segments to be fixedly secured in an annular configuration in surrounding relationship to said shaft.

A mechanical seal assembly for creating a sealed engagement between an annular stuffing box housing and a shaft which projects concentrically out of the stuffing box housing and is rotatable about its longitudinal axis, said mechanical seal assembly comprising:

• a rotor assembly which includes an annular collar which is mountable in sealed and nonrotatable engagement with the shaft in concentric surrounding relationship therewith, a first annular face ring which is sealingly and concentrically mounted within said collar and has an axially exposed end which defines thereon an axially facing first annular seal face, and a first annular elastomeric seal ring disposed between and sealingly engaged with annular walls on said collar and said face ring;
• an annular stator assembly nonrotatably mountable on the stuffing box housing in generally concentric and surrounding relationship to the shaft and including an annular gland member which sealingly engages and nonrotatably mounts to the stuffing box housing, a second annular face ring which is mounted generally concentrically within said gland member, said second face ring defining a second generally flat annular seal face on an inner axial end thereof so that said second seal face is disposed in axially opposed relation to said first annular seal face, and a second elastomeric seal ring disposed between and sealingly engaged with annular surfaces on said gland member and said second face ring;
• said rotor assembly being split axially along a substantially diametral plane into two substantially semi-cylindrical rotor subassemblies with said split as it extends along said diametral plane splitting each of said collar, said first elastomeric seal ring and said first face ring into substantially semicircular segments;
• each said rotor subassembly having adjacent and opposed stop surfaces defined on the segments of said collar and said first face ring and an axially protruding drive pin for drivingly coupling each segment of the first face ring to the respective segment of the collar to both axially and radially restrain said first face ring segment relative to the respective collar segment to prevent separation therebetween, whereby the respective segments of the collar, first face ring and first elastomeric seal ring of each rotor subassembly are preassembled to define a unitized subassembly prior to mounting thereof on the shaft;
• said stator assembly being axially split along a substantially diametral plane into two substantially semi-cylindrical stator subassemblies with said split along said diametrical plane splitting each of the gland member, said second face ring and said second elastomeric seal ring into substantially semicircular segments;
• and
• each said stator subassembly having adjacent and opposed stop surfaces cooperating between said gland member and said second face ring segments to both axially and radially restrain said second face ring segment relative to said respective gland member segment to prevent separation therebetween, whereby the respective segments of the gland member, second face ring and second elastomeric seal ring of each stator subassembly can be preassembled to define a unitized subassembly prior to mounting thereof on the shaft.

A mechanical seal assembly for creating a sealed engagement between a stuffing box housing and a shaft which projects out of the stuffing box housing and is rotatable about its longitudinal axis, said mechanical seal assembly comprising:

• a rotor assembly which includes an annular collar which is mountable in sealed and nonrotatable engagement with the shaft in concentric surrounding relationship therewith, a first annular face ring which is sealingly and conentrically mounted within said collar and which defines thereon an axially facing first annular seal face, and a first annular elastomeric seal ring disposed between and sealingly engaged with annular walls on said collar and said face ring;
• an annular stator assembly nonrotatably mountable on the stuffing box housing in surrounding relationship to the shaft and including an annular gland member which sealingly engages and nonrotatably mounts to the stuffing box housing, a second annular face ring which is mounted generally concentrically within said gland member, said second face ring defining thereon an axially facing second annular seal face disposed in axially opposed relation to said first annular seal face, and a second elastomeric seal ring disposed between and sealingly engaged with annular sufaces on said gland member and said second face ring;
• said rotor assembly being split axially into only two rotor subassemblies with said split splitting each of said collar, said first elastomeric seal ring and said first face ring into arcuate segments;
• each said rotor subassembly being configured to axially and radially retain said first face ring segment relative to the respective collar segment with the respective elastomeric seal ring segment retained therebetween, the respective segments of the collar, first face ring and first elastomeric seal ring of each rotor subassembly being preassembled to define a unitized subassembly prior to mounting thereof on the shaft;
• said stator assembly being split axially into only two stator subassemblies with said split splitting each of said gland member, said second face ring and said second elastomeric seal ring into substantially arcuate segments;
• each said stator subassembly being configured to axially and radially retain said second face ring segment relative to said respective gland member segment with the respective elastomeric seal ring segment retained therebetween, the respective segments of the gland member, second face ring and second elastomeric seal ring of each stator subassembly being preassembled to define a unitized subassembly prior to mounting thereof on the shaft;
• said rotor and stator subassemblies being separate and independent unitized subassemblies;
• and
• the collar segments at each end thereof having aligned openings which extend therethrough in generally intersecting relationship to opposed end surfaces of the collar segments, the centerlines of said openings defining a securing plane which extends generally perpendicular to the axis of the shaft, and a pair of removable threaded fasteners each being positioned in the aligned openings at one end of the collar segments for fixedly securing the collar segments together in a substantially endless annular configuration, and each of said collar segments also having a threaded opening extending radially therethrough and having a set screw provided therein for engaging a surface of the shaft to fix the collar thereto, said set screw opening having the axis thereof disposed generally within said securing plane.

A mechanical seal assembly for creating a sealed engagement between a stuffing box housing and a shaft which projects out of the stuffing box housing and is rotatable about its longitudinal axis, said mechanical seal assembly comprising:

• a rotor assembly which includes an annular collar which is mountable in sealed and nonrotatable engagement with the shaft in concentric surrounding relationship therewith, a first annular face ring which is sealingly and concentrically mounted within said collar and which defines thereon an axially facing first annular seal face, a first annular elastomeric seal ring disposed between and sealingly engaged with annular walls on said collar and said face ring;
• an annular stator assembly nonrotatably mountable on the stuffing box housing in surrounding relationship to the shaft and including an annular gland member which sealingly engages and nonrotatably mounts to the stuffing box housing, a second annular face ring which is mounted generally concentrically within said gland member, said second face ring defining an axially facing second annular seal face disposed in axially opposed relation to said first annular seal face, and a second elastomeric seal ring disposed between and sealingly engaged with annular sufaces on said gland member and said second face ring;
• said first face ring having an axially facing rear surface which is directly and substantially rigidly seated against an opposed support surface on said collr;
• said first face ring having a second axially facing rear surface which is separated from said first rear surface by said first seal ring and which is exposed to fluid in the stuffing box in surrounding relation to the seal assembly for exerting a fluid-created unbalanced force on the first face ring in a direction away from said support surface;
• said rotor assembly being split axially along a plane into two rotor subassemblies with said split splitting each of said collar, said first elastomeric seal ring and said first face ring into substantially arcuate segments;
• and
• each said rotor subassembly having adjacent and opposed stop surfaces defined on the segments of said collar and said first face ring to axially and radially retain said first face ring segment relative to the respective collar segment to prevent separation therebetween, the respective segments of the collar, first face ring and first elastomeric seal ring of each rotor subassembly being preassembled to define a unitized subassembly prior to mounting thereof on the shaft.