Self aligning stuffing box for pumpjack units

An improved stuffing box of the type that can be connected to a tubing, and having a shaft received therethrough in a sealed manner therewithin and forms a tubing annulus therewith, comprising:

• said box having a longitudinal passageway extending therethrough through which said shaft can be received for either of rotational and reciprocating movement;
• said box includes means forming an upwardly opening enclosure within said box, said box has an upper end opposed to a lower end with said enclosure being spaced radially from said longitudinal passageway;
• a closure member affixed to said upper end of said means forming said enclosure;
• a seal assembly having an outer wall surface that forms an inner wall of a chamber;
• said closure member has a lower face that forms a roof of said chamber;
• said seal assembly includes a seal holder and terminates in opposed upper and lower fixtures for supporting said seal holder;
• said upper fixture slidably engages said roof of said closure member and said lower fixture slidably engages a floor of said means forming said enclosure;
• an axial passageway extending longitudinally through said seal assembly in parallel relationship respective to said longitudinal passageway of said box;
• a seal pack including seal elements mounted within said seal holder for sealingly engaging said shaft;
• said seal assembly is received within said chamber and moves radially of said longitudinal passageway to thereby align said seal pack with said shaft;
• said seal holder includes a lower end which reciprocatingly receives an upper end of said lower fixture to form a variable chamber therebetween, said variable chamber being connected to said tubing annulus whereby a pressure differential across said seal assembly effects compressive forces on said seal pack.

A stuffing box adapted for use with a pumpjack unit of the type having a polished rod reciprocatingly received through said stuffing box in a sealed manner therewithin;

• said stuffing box being attached to an upper end of a production tubing string having a pressure differential between a tubing annulus and ambient;
• the improvement comprising:
• a longitudinal passageway extending through said stuffing box through which said polished rod can be reciprocatingly received;
• said stuffing box has a roof spaced from a floor, with there being a seal assembly received therebetween;
• said seal assembly being of a size to be received for radial movement respective to said passageway;
• said seal assembly includes a seal holder, and an upper seal fixture opposed to a lower seal fixture;
• said seal holder having a seal pack therein for sealingly receiving said polished rod therethrough;
• said upper seal fixture has opposed ends with a seal pusher at one end for engaging said seal pack and a face at the other end for slidably engaging said roof;
• said seal holder having opposed ends, with one end being supported by said seal pusher with said seal pusher bearing against the seal pack;
• the other end of said seal holder being supported by said lower seal fixture;
• said lower seal fixture has opposed ends with there being a face at one end of said lower seal fixture for slidably engaging said floor and a variable chamber at the other end of said lower seal fixture which supports said other end of said seal holder;
• said seal assembly is received between said roof and said floor with said fixtures, respectively, slidably engaging said roof and said floor, respectively;
• whereby, said seal assembly can move radially of said passageway and thereby align said seal assembly with said polished rod while a pressure differential compresses said seal pack with a force proportional to fluid pressure in said tubing.