PLUNGER OF SUCKER-ROD PUMP Russian patent published in 2020 - IPC F04B47/00 F04B53/14 

FIELD: machine building.

SUBSTANCE: invention relates to oil machine building, particularly, to sucker rod pump plunger designs. Plunger consists of hollow bushings connected to each other by thread, provided with thrust ledges, on which there is a sealing element, consisting of cylindrical helical spiral spring, between coils of which there arranged are seal turns. Hollow bushings with sealing elements form sections with right and left rotation of seal spiral. Sections with sealing elements are separated by hollow bushings with centralisers. Upper section is threaded for connection to pump rod string, lower section is equipped with internal thread for connection of pressure valve. In each section, sealing element is pressed from above by lock washer, having limited axial movement. When the plunger moves upwards, the hydrostatic pressure of the formation fluid column is received by the lock washer and the seal body. Formation fluid along helical spiral channel, arranged by outer surface of cylindrical helical spiral spring and inner surface of cylinder with right rotation of flow, flows into annular gap between centraliser and cylinder, with supply to helical spiral channel of next section, with change of rotation of flow to opposite, which creates powerful hydraulic resistance and prevents overflow of formation fluid into cavity under plunger. Number of sections with sealing elements can be different and depends on depth of well and installation site of sucker-rod pump.

EFFECT: movement of lock washer and cylindrical helical spiral spring promotes squeezing of each section seals to ensure contact with inner surface of the cylinder.

1 cl, 3 dwg