摘要 |
The bob system for alternating pumps comprises a pyramidal tower (8) (fig. 1) with a truncated summit (5 and 6) (fig. 1) wherein a single acting hydraulic cylinder (2) (fig. 1) can rest, which are installed at the vertical of a water or oil well (16) (fig. 1). The piston (3) (fig. 1) of the hydraulic cylinder (2) (fig. 2) has a prolongation with holes (19) (fig. 2) which, during its down stroke, is introduced inside the support tube thereby producing a choking effect and forcing the oil to pass through the holes and slowing down gently the rod (10) (fig. 2) at the end of its down stroke. In the up stroke of the rod (10) (fig. 2) the contrary occurs, that is an acceleration up to the freeing of the piston extension (19) (fig. 2) inside the support tube (4) (fig. 2) thereby creating an overpressure which is compensated by an accumulator (23) (fig. 3). <IMAGE> |