| 摘要 |
<p>The improved pump drive head (1, 2) has an integrated stuffing box (9) and comprises: a power transmission (3, 4) coupled to the rotating pump driveshaft (8) within a crude oil well; a stuffing box (9) to retain the pressure; a thrust assembly (6) adapted to take the tensile force exerted on said pump shaft; wherein said power transmission comprises a tube (5, 16) arranged to be rotated coaxially with the shaft (8) and having at least two different diameters; the rotating seals (20, 50) fit over the small outside diameter of the tube to establish fluid-tightness between said tube and the body (19) of the stuffing box, the working diameter (51) of the seals (20; 50) being smaller than the large outside diameter of said tube (5, 16); and static seals (17) are provided between the tube and the shaft (8); thereby on disassembling, the rotating (20; 30) and static (17) seals come away along with said tube and the seal retainer ring (22). Advantageously, an improved clamp (10) for locking the rotating pump driveshaft (8) of the pump down a crude oil well is associated with said head and comprises a jaw pair (35, 36), of which one (35) is a pull jaw and the other (36) a push jaw, both operated through a screw (38) arranged to act with its end on one jaw (35) and to engage in a threaded hole formed in the other jaw (36).</p> |
