US Patent Application No. 13/495,853, Air driven hydraulic pump with pressure control
This technology is about a hydraulically driven pump with driving pressure controlled within a predetermined range. The hydraulically driven pump has a driving-fluid port fluidly coupled to a compressed air source and ambient, a driven-fluid inlet port fluidly connected to a tank, and a driven-fluid outlet port. A pressure sensor is used for providing sensing values indicative to the driving pressure in the hydraulically driven pump, and the driving pressure is controlled in closed loop by releasing and filling air through the driving-fluid port. The hydraulically driven pump has a suction stroke, in which driven fluid is refilled into the pump, and a pressing stroke, in which driven fluid is pressed out. A hydraulic buffer is used to provide driving pressure during a suction stroke and two hydraulically driven pumps can work alternately in providing continuous pressure control.
Uniqueness and benefits of this technology:
1. Strokes of a pump are electrically controlled with solenoid valves;
2. With the stroke control, fluid flow can be driven without fluctuations;
3. The air-driven nature saves driving motors in the pump and thereby lowers cost;
4. A pressure boosting structure can be further used for obtaining higher driving pressure.