HOLE ROD PUMP Russian patent published in 2008 - IPC F04B47/00 

FIELD: engines and pump.

SUBSTANCE: pump is intended for forcing liquid media from holes and incorporates a cylinder, a plunger with a discharge valve and suction valve made up of a seat with ball. The said suction valve is furnished with a formation fluid feed device representing two-stage cylinder with one open end provided with external thread and a cylindrical coaxial smooth recess at its bottom accommodating a hollow con-rod of the spring-loaded small-piston. The said small piston is furnished with a hollow pusher arranged on free end and rigidly attached thereto, the said pusher being provided with two through radial bores communicating with the pusher inner space. An inclined channel is made on the small piston ends face, wherein the said hollow pusher is located, communicating with the said pusher space. On the small piston other side, a similar channel is made to communicate with the hollow con-rod space. A blind threaded recess is arranged under the plunger end face extending below on the suction valve seat lower end face, the said threaded recess being aligned with the smooth recess made on the top part accommodating the small piston hollow pusher for it to move axially. The said two-stage cylinder is screwed in the aforesaid threaded recess.

EFFECT: higher pump capacity.

4 dwg