Multi-Cylinder Hydraulically-Driven Pump System

摘要

A hydraulically-driven pumping unit for pumping a working fluid includes a pair of double-acting hydraulic piston-cylinder (HPC) assemblies, each having a central axis, a hydraulic cylinder, a piston, and a rod coupled to the piston for axial movement relative to the first hydraulic cylinder. The pumping unit also includes a hydraulic fluid source and an exhaust path for hydraulic fluid. The two hydraulic cylinders are coupled to the hydraulic fluid source and the exhaust path such that the movements of the two pistons are synchronized. The two HPC assemblies are configured for phase-shifted operation such that when pumping unit is reciprocating the two pistons and rods, the a first pair of the pistons and rods always has a different combination of axial position and direction of travel than does a other pair of the pistons and rods. During phase-shifted operation, at least one of the two rods is moving to extend further beyond the corresponding hydraulic cylinder at all times.

主权项

1. A hydraulically-driven pumping unit for pumping a working fluid, the pumping unit comprising:
a first double-acting hydraulic piston-cylinder (HPC) assembly comprising a first central axis, a first hydraulic cylinder, a first piston, and a first rod coupled to the first piston for axial movement relative to the first hydraulic cylinder; a second double-acting hydraulic piston-cylinder (HPC) assembly comprising a second central axis, a second hydraulic cylinder, a second piston, and a second rod coupled to the second piston for axial movement relative to the second hydraulic cylinder; a hydraulic fluid source; and an exhaust path for hydraulic fluid; wherein the first and second hydraulic cylinders are coupled to the hydraulic fluid source and the exhaust path such that movements of the first and second pistons are synchronized; wherein the first and second HPC assemblies are configured for phase-shifted operation such that when pumping unit is reciprocating the two pistons and rods, the second piston and rod always have a different combination of axial position and direction of travel than do the first piston and rod, and such that at least one of the two rods is moving to extend further beyond the corresponding hydraulic cylinder at all times.