Patent GB-547316-A (GB)
Title: Improvements in hydraulic pumping systems
IPC: F04B47/04
Filed: 1941-08-14
Abstract: 547,316. Well-pumps: fluid-pressure engines. VICKERS, Inc., TWYMAN, L. R., MOSER, J. R., and ROSE, H. E. Aug. 14, 1941, No. 10329. [Class 102 (i)] [Also in Group XXIX] A hydraulic counterbalanced pumping system for wells of the kind in which air pressure is used as the counter-balancing medium is constructed so that the air pressure is of a comparatively low order and so that the hydraulic circuit and the air circuit are continuously replenished An adjustable connection between the hydraulic ram and the sucker rod 50 attached to the pump plunger 18 is also provided. This ram comprises a piston 48 arranged in a cylinder 46 attached to a casing 34 arranged above the pump outlet 26, and on the cylinder 46 are mounted projecting closure members 52, 54, in the lower of which are a pair of doors which permit of access to an adjustable clamp 78 on the rod 50 when adjustment for depth is required. The clamp 78 normally rests on a sleeve 76, Fig. 3, extending from the piston 46, and when the clamp is to be adjusted the rod 50 is supported temporarily by a safety clamp 80 and a U-shaped support mounted on the access doors.. A column of liquid below the piston 48 is connected by a pipe 96 with liquid above a piston 86 in a cylinder 84 which is supported by the pressure of air admitted by pipe 98 from a bottle 100, the pressure in which is automatically maintained at a predetermined pressure of about 400 lb. per square inch, and this is arranged to balance the pressure due to the weight of the rod 50 upon the piston 48. To actuate the pump the piston 86 is reciprocated by a hydraulic motor comprising a cylinder 104 and a piston 102 connected to a rod 98 attached to the piston 86. The motor is supplied with pressure liquid by a unidirectional pump contained in a casing 120 and driven by an electric motor, 164. Pipes 112, 114 direct the liquid alternately to opposite ends of the cylinder 104 under control of a piston valve which is actuated by fluid pressure supplied by a pilot valve operated by a lever 122 actuated by tappet mechanism from the piston rod 88. The driven pump also by-passes a controlled amount of liquid to a pipe 204 which replenishes the liquid in the pipe 96 of the counterbalanced circuit. The piston 86 forces liquid into this pipe past a velocity control valve 94 which closes at a predetermined pressure, and the liquid also enters the cylinder 46 via a velocity control valve 44. Near this valve are arranged a spring-loaded relief valve 40 and a check valve 42 which permits free flow into chamber 38 when the piston 46 is below the normal inlet. When the piston 48 reaches the top of its stroke valves 72 arranged as shown in Fig. 3 open to relieve the pressure, and escaping liquid returns to tank 120 via pipes 55, 60. Any leakage past the packing for rod 50 above the outlet 26 can pass to pipe 60. The air pressure in the bottle 100 is maintained by a compressor 142 which is actuated by the piston rod 86. The rod is fitted at its end with a spring-plunger which operates the compressor when it needs replenishing but yields when this pressure is reached.