| 摘要 |
<p>Petroleum Pumping Unit A petroleum pumping unit which is especially suitable for use in remote oil fields and under unpredictable pumping conditions is disclosed. The petroleum pumping unit of the present invention, which is easily movable between a folded, collapsed position for storage and shipment and an erect position for pumping operations, includes a horizontal support platform on which is pivotally mounted a mast assembly including a pair of masts spaced outwardly from the centrally positioned well polish rod. The polish rod is engaged by a notch in a horizontal, vertically movable bridle and is powered by at least one pair of flexibly mounted hydraulic cylinders and associated piston rods attached to the bridle and positioned between the polish rod and the masts and parallel thereto. Vertical movement of the bridle and, therefore, the stroke of the polish rod is defined by upper and lower limit switches which are actuated by actuating means on the bridle. A counterweight support box which surrounds the masts and is vertically movable thereon is provided to assist the cylinders in powering the polish rod. Tapered weight brackets including diagonal projecting ridges engage notched counterweights which are held in place by gravity and prevented from contacting the mast by weight guards. The counterweight box may be eliminated and a plurality of spaced cylinders employed to power the polish rod.</p> |
