| 摘要 |
<p>A self-aligning stuffing box (12) for a pumpjack unit (18) of the type having a polished rod (19) reciprocatingly extending therethrough and downhole to a pump (20) located at the lower end of a borehole. The stuffing box has a main body (21) that terminates in a tubing adaptor (14) at the lower end thereof by which it can be mounted to the upper end of the tubing of a wellhead. The main body has an annular seal assembly (36) that includes a pressure set seal pack (40, 40', 140, 140') for sealingly engaging the polished rod. The polished rod reciprocatingly extends through the seal assembly and main body. The seal assembly moves within the main body radially of the passageway to align the polished rod with the production tubing of the wellhead. A lower end of the seal assembly includes a compression piston (80) which is moved in proportion to the well tubing pressure, and thereby compresses the seal of the seal pack so that the seal pack is always properly adjusted.</p> |
