Abstract: The disclosed invention introduces an efficient lifting mechanism for reciprocating vertically a load system, the load consisting of the aggregate weights of a cargo payload in conjunction with “dead weights” of moving parts of the lifting apparatus. The disclosed invention uses a hydro-pneumatic linear actuator to lift the load and a pressurized accumulator, acting as a force intensifier. The pressurized accumulator, acting as a self-contained stored energy source, provides to the actuator adequate power to lift the “dead weights” plus part of the cargo payload. An external power source provides to the actuator adequate power to lift the remainder of the cargo payload. The disclosed invention saves significant amounts of power and energy in applications in which the “dead weights” are sizable compared to the cargo load. The disclosed invention provides also exceptional means for accurate motion control of the cargo payload.

Abstract: The disclosed invention provides intelligent adaptive control for optimization of production output, energy efficiency and safety of a linear reciprocating long stroke hydraulic lift system, for use at the surface of oil and gas wells to extract fluids or gas after free flowing stopped due to natural decline of reservoir pressure. The hydraulic pump and its adaptive control system introduced in this invention are capable of optimizing its production capacity by varying multiple operating parameters, including its stroking length and speed characteristics continuously and instantaneously at any point. Merits and benefits of this invention include significant increase in production efficiency, improved durability and longevity of the pumping equipment, significant power consumption savings and an ability to adapt effectively to changing well conditions.

Abstract: The disclosed invention introduces an efficient lifting mechanism for reciprocating vertically a load system, the load consisting of the aggregate weights of a cargo payload in conjunction with “dead weights” of moving parts of the lifting apparatus. The disclosed invention uses a hydro-pneumatic linear actuator to lift the load and a pressurized accumulator, acting as a force intensifier. The pressurized accumulator, acting as a self-contained stored energy source, provides to the actuator adequate power to lift the “dead weights” plus part of the cargo payload. An external power source provides to the actuator adequate power to lift the remainder of the cargo payload. The disclosed invention saves significant amounts of power and energy in applications in which the “dead weights” are sizable compared to the cargo load. The disclosed invention provides also exceptional means for accurate motion control of the cargo payload.

Abstract: A port control member (80) is depressed by either a mechanical force (124) applied on it by the pilot (44), for moving it to meter pressure and flow from a supply pressure (72) to the wheel brakes (34) , or a hydraulic pressure force (128) applied following take-off, to activate the brakes (34) for stopping the wheels from spinning. The valve housing (62) defines an annular command pressure chamber (102) surrounding a portion of the port control member (80). The port control member (80) provides a larger pressure surface (128) to this chamber in the brake applying direction than it does in the opposite direction. This area differential results in pressure within the command pressure chamber (102) acting to move the port control member (80) in a brake applying direction. The command pressure chamber (102) may be connected to the wheel retract system (130) so that pressure is delivered into this chamber (102) automatically at the start of the wheel retraction operation.