CONNECTION FOR PUMP RODS (VERSIONS) AND PROCEDURE FOR THEIR ASSEMBLY Russian patent published in 2011 - IPC E21B17/42 F16L15/00 

FIELD: mining engineering.

SUBSTANCE: connection for pump rods consists of conic enveloped and enveloping elements with multitude of trapezoid threads. The enveloped element is screwed by thread into the enveloping element. Also, both sides of each thread turn on the enveloped element contact sides of thread on the enveloping element forming diametre tightness between the elements. The enveloping element is equipped with a collar, surface of which is perpendicular to lengthwise axis of the said element and which is positioned at an end of turns; while the enveloping element has a collar located on front surface of the said element also perpendicular to its axis. At assembly both collars contact each other facilitating accurate specified diametre tightness between turns of thread of the enveloped and enveloping elements. Notably, axial tightness between the said elements is considerably decreased.

EFFECT: increased fatigue resistance of threaded connection.

17 cl, 24 dwg