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

FIELD: machine building.

SUBSTANCE: invention relates to machine building and is intended for use, mainly, in devices for perforation of cased wells for transfer of rotary and translational motion to cutting tool. Flexible shaft comprises shell in form of separate links contacting with each other with end parts with possibility of limited spatial displacement. Links are made with a central hole in which the core is placed. Links are made of two types: in form of cylindrical bushing and insert, which are connected to each other by means of fastening pin with possibility of restricted spatial movement relative to each other in any plane. On both end parts of the cylindrical bushing there are four cuts forming four teeth arranged in pairs opposite each other at angle of 90°. There are through holes in central part of two oppositely located teeth on one side of cylindrical bushing. In the central part of the adjacent teeth, but from the other end of the cylindrical bushing, through holes are also made. Links made in the form of an insert represent a bushing with four projections made in the form of a rectangular parallelepiped and placed in the middle part of the insert along the external surface in pairs opposite each other at angle of 90°, thus forming two end parts on the insert, on which oval-shaped through grooves are made in pairs from one end between two opposite projections and from the other end between two adjacent projections. Inner diameter of cylindrical bushing is made at both ends of sleeve stepped to make a seat for end part of insert.

EFFECT: higher reliability due to reliable connection of links to each other, broader operational capabilities due to high-quality fluid supply to the working tool.

6 cl, 3 dwg