"=T=+¦¦" 57 BOREHOLE PUMP Russian patent published in 2015 - IPC F04B47/00 

FIELD: engines and pumps.

SUBSTANCE: invention relates to borehole oil pumps to surface a thick oil. Claimed pump comprises plunger chamber shaped to a hollow cylinder coupled at its top part with flow string with ID larger than that of said plunger chamber. Said cylindrical plunger is coupled with said flow string and fits in plunger chamber diameter. Pressure valve slides over said flow string between the flow string thrust and said plunger. Section valve is communicated with bore clearance and arranged in plunger chamber plunger end. Drain valve is communicated with bore clearance and arranged in plunger chamber rod end. Pressure valve stroke limiter is composed by a collet fitted in said flow string above said plunger chamber. Additionally, claimed pump incorporates the centraliser fitted at flow string above said pressure valve and composed of a cylindrical body with side inclined bores made at its outer surface. Pressure valve is composed of cylindrical body with mid part of smaller diameter with a smooth transition to top and bottom parts. Pressure valve stroke limiter collet can embrace the valve mix part. Said centraliser features diameter corresponding to that of the pressure valve top part.

EFFECT: higher reliability.

1 dwg