Method for forming a tubular body, undulating tubular body and use of same

Abstract

A method for forming a tubular body, comprising the following steps: making available a tubular body having a first and a second tube end, filling the tubular body with a liquid, closing the tubular body, and forming the tubular body.

1 . A method for forming a tubular body, the method comprising:
 filling a tubular body with a liquid, the tubular body having a first end, a second tube end, and a cross-sectional shape;   closing the tubular body, and   forming the tubular body, wherein forming the tubular body includes changing the cross-sectional shape of at least a portion of the tubular body.   
     
     
         2 . The method according to  claim 1 , comprising pressurizing the liquid in the tubular body before forming the tubular body. 
     
     
         3 . The method according to  claim 2 , wherein the liquid is subjected to a pressure of 20 bar or more. 
     
     
         4 . The method according to  claim 1 , wherein forming comprises introducing one or more bending radii into the tubular body. 
     
     
         5 . The method according to  claim 4 , wherein the one or more bending radii is less than three times a diameter of the tubular body. 
     
     
         6 . (canceled) 
     
     
         7 . The method according to  claim 1 , wherein changing the cross-sectional shape includes placing the tubular body in a die and forming the tubular body to match the die by applying force to the tubular body. 
     
     
         8 . The method according to  claim 1  further comprises:
 bending the tubular body into a meandering shape, wherein the meandering shape has one or more substantially uncurved tube segments, each of the one or more substantially uncurved tube segments adjoin one or more of the bending radii. 
 
     
     
         9 . The method according to  claim 1 , comprising:
 discharging the liquid from the tubular body when the pressure exceeds a predetermined value during forming.   
     
     
         10 . The method according to  claim 1 , comprising monitoring the liquid pressure during forming. 
     
     
         11 . The method according to  claim 1 , wherein the tubular body is a steel material. 
     
     
         12 . A meandering tubular body produced by a method according to  claim 1 , the meandering tubular body comprising:
 a plurality of bending radii with a bending radius of less than three times the tube diameter, and   a plurality of substantially uncurved segments that adjoin the bending radii,   wherein at least one of the uncurved segments has a substantially polygonal cross section.   
     
     
         13 . The meandering tubular body according to  claim 12  in a generator, wherein the generator is configured to produce an electric current in a multi-pole synchronous generator of a wind power plant, wherein:
 the generator has a plurality of grooves, in which a winding is arranged, 
 the tubular body has a plurality of substantially uncurved tube segments having a substantially polygonal cross section, wherein the substantially uncurved segments of the tubular body are arranged in the grooves, the tubular body including a cooling liquid flowing through said segments. 
 
     
     
         14 . The meandering tubular body according to  claim 12 , wherein a stator of the generator has the plurality of grooves and the winding is a stator winding. 
     
     
         15 . The method according to  claim 1 , wherein changing the cross-sectional shape of at least the portion of the tubular body includes changing the cross-sectional shape of at least the portion of the tubular body to a substantially polygonal cross-sectional shape. 
     
     
         16 . The method according to  claim 15 , wherein the polygonal cross-sectional shape is a substantially rectangular cross-sectional shape. 
     
     
         17 . The method according to  claim 7 , wherein applying force to the tubular body includes using a punch or a roll. 
     
     
         18 . The method according to  claim 9  wherein discharging the liquid from the tubular body comprises using a pressure relief valve, if the pressure exceeds a predetermined value during forming.