Oil pumping device

An oil pumping device comprising an oil storage tank;

• the oil storage tank being installed with an upper cover and a lower cover, a pump being installed between the upper cover an lower cover, the upper cover and lower cover sealing a top and a bottom of the pump, respectively, the pump being installed with a piston;
• the piston having a handle installed out of the upper cover;
• an interior of the lower cover having a unidirectional pressure relief valve with respect to the pump;
• an outer side of the pump of the oil storage tank being defined with a oil storage space, characterized in that:
• a top of the oil storage tank has an annular positioning wall extending upwards with a predetermined height;
• and a top of the pump is inserted into an interior of the positioning wall;
• and
• an outer peripheral surface of the pump has at least one recess;
• one section of the recess is enclosed by the positioning wall;
• another portion of the pump protrudes from the positioning wall to extend to the lower side of the positioning wall;
• the recess has an air inlet hole having a radial hollowed portion, thereby, the recess being communicated with the interior of the pump;
• and a unidirectional air inlet valve configured with respect to the air inlet hole is installed in an interior of the pump.