Patent ID: 8550794
Filing Date: 2013-10-08
Classification: F04B

Abstract:
1. A fluid pump comprising: a housing defining a first cavity and a second cavity in fluid communication with the first cavity, a linear volumetric displacement of the first cavity being smaller than a linear volumetric displacement of the second cavity, the housing having an outlet for discharging fluid out of a secondary chamber; first and second pistons fixedly mounted to a solid shaft, the first piston slideably seated within the first cavity, the second piston slideably seated within the second cavity, the first piston, second piston and the housing collectively defining the secondary chamber which increases during a compression stroke and decreases during a suction stroke, the outlet being in fluid communication with the secondary chamber, the second piston is traversable between the compression stroke and suction stroke for respectively enlarging and reducing a volume of a pumping chamber, the second piston having a one-way valve for flowing fluid from the pumping chamber to the secondary chamber during the compression stroke; wherein the one-way valve is closed during the suction stroke to discharge fluid out of the outlet by decreasing a volume of the secondary chamber and the one-way valve is opened during the compression stroke so that collectively the pumping chamber and the secondary chamber reduces in volume to discharge fluid out of the outlet; wherein the solid shaft between the first and second pistons obstructs fluid flow through the shaft, and the first piston is solid and forms a barrier with the housing to mitigate fluid flow between a tertiary chamber and the secondary chamber.