FLEXIBLE SHAFT Russian patent published in 2019 - IPC E21B43/11 F16C1/02 F16C1/08 

FIELD: soil or rock drilling.

SUBSTANCE: invention relates to devices for well drilling, in particular to devices for perforation of cased wells and opening of productive formations as part of installation of radial penetration of formation for transfer of rotation from driving shaft of submersible motor to drilling tool during drilling. Flexible shaft comprises one end for connection with drive shaft, second end for connection with tool, flexible shell connected to both ends and consisting of successively alternating external bushings and internal links installed with possibility of their engagement by means of splines, flexible hose installed inside flexible shell. Slots are located on outer surface of middle part of each internal link. On end parts of outer bushes there are slots, width of which is greater than width of splines. On each end of the external bushing a pair of pin elements is installed. Pin elements on one end of the sleeve are located diametrically opposite to each other. Plane passing through the pair of pin elements on one end of the sleeve is perpendicular to the plane passing through the pair of pin elements on the other end of the sleeve. Ends of pin elements are installed in holes of internal links with possibility of internal links movement. Holes of internal links are elongated in axial direction.

EFFECT: higher degree of mobility of the flexible shaft while ensuring reliability of the shaft operation.

1 cl, 3 dwg