Fluid pumping device

A fluid pumping device, including:

• a barrel body, including a first end portion and a second end portion located at an opposite side thereof from the first end portion, the first end portion and the second end portion being aligned along an axial direction, the first end portion being formed with a flow hole, the second end portion having an opening, the barrel body further including a cavity communicating the flow hole and the opening respectively;
• a piston mechanism, including a piston member, a first annular plug, and a second annular plug, the piston member being arranged through the opening and movably extending into the cavity, the piston member having two annular grooves, the first annular plug and the second annular plug being disposed in the two annular grooves respectively, the first annular plug being structurally same with the second annular plug, each of the first annular plug and the second annular plug having an annular base section and an annular protrusion section, the annular protrusion section having a first outer annular abutting face, the annular base section having an outer annular base face, the first outer annular abutting face traversing the outer annular base face, the first outer annular abutting face abutting against an inner wall of the cavity to block the cavity, the annular base section of the first annular plug being closer to the second end portion than the annular protrusion section of the first annular plug is, the annular protrusion section of the second annular plug being closer to the second end portion than the annular base section of the second annular plug is;
• wherein the annular protrusion section further includes a compression portion and an outer annular arm corresponding to the compression portion, the outer annular arm is radially swingable toward the compression portion, the outer annular arm has the first outer annular abutting face;
• wherein the annular protrusion section further includes an inner annular arm, the inner annular arm includes an inner annular surface which abuts, in parallel, against a bottom of one of the annular grooves, the compression portion is arranged between the inner annular arm and the outer annular arm, the outer annular arm is thicker than the inner annular arm;
• wherein each of the annular grooves has two lateral walk opposite to each other, the two lateral walls face the axial direction, one of two lateral walls in each groove has a guiding face which is non-perpendicular to the axial direction and non-perpendicular to the two lateral walls.