Cylinders or tubes assembled by means of a new method for eliminating interference

Abstract

The present invention relates to a method for interference-joining concentric cylinders, where the smaller cylinder ( 102 ) does not fit into the larger cylinder ( 101 ), involving the use of auxiliary cylinders inside an assembly chamber ( 301 ), such that the interference is momentarily eliminated by means of isostatic pressure, and one cylinder is fitted into the other, yielding an interference-joined thicker cylinder. The pressure is released, and it is removed from the assembly chamber ( 301 ) finally leaving only the two interference-joined cylinders. It is possible to assemble 3 or 10 and more cylinders in the same way, assembling a thick cylinder, pre-compressed on the inside and pre-stressed on the outside. Several interference-joined cylinders exert the same stress when the cylinder withstands the maximum pressure, such that it withstands a greater pressure than a single cylinder with the same total wall thickness, which always reduces the stress from a maximum at the inside of the wall to a lower percentage at the outer edge.

1 . Method for joining two or more concentric cylinders ( 101 ,  102 ) by isostatic-pressure interference, being one or two of said cylinders already interference-joined; auxiliary cylindrical tubes ( 201 ,  202 ), caps ( 211 ,  212 ,  213 ,  214 ) and assembly chamber ( 301 ) of high pressure to be used as tools of the process for joining by isostatic-pressure interference; elastic and structural guides to push one cylinder into another, being inside the assembly chamber ( 301 ); wherein each pair or set of concentric cylinders ( 101 ,  201 ) and ( 102 ,  202 ) is prepared with the respective caps ( 211 ,  212 ), ( 213 ,  214 ) welded or glued forming auxiliary or tubular chambers such that they are subjected to pressure within the assembly chamber ( 301 ) with liquid or gas, taking into consideration that no pressure enters the interior of the tubular chambers through the caps, where both consecutive tubular chambers must be so assembled with a gadget and small guides, such that when the pressure rises and the interference disappears—as the pressure increases the diameter of the cylinder ( 101 ) of the larger tubular chamber and decreases the diameter of the cylinder ( 102 ) of the smaller tubular chamber, it is in conditions then to fit, slide and put the smaller tubular chamber into the larger tubular chamber through the guide that was made for such effect, thus fitting as the mechanism for such effect is activated, where said mechanism can go on the interior of the tubes of smaller radius or on the outside; after the sliding or adjustment is produced, the pressure of the assembly chamber ( 301 ) is released from the already fitted cylinders, variation in the diameters is produced and the tubes that are joined by interference ( 101  and  102 ) tend to return to the initial diameter; the auxiliary cylinders are removed and only both cylinders are left joined by interference. 
     
     
         2 . The method according to  claim 1 , wherein a pair of cylindrical tubes ( 101  and  201 ) with caps is prepared, another tube ( 102 ) with circular caps or without caps is also prepared, and the interference takes place between the tubes ( 101 ,  102 ); analogously to the case of  claim 1 , the pressure in the assembly chamber ( 301 ) removes the interference, and then a cylindrical tube ( 102 ) slides into the other ( 101 ), the pressure in the assembly chamber is lowered and the auxiliary cylinder and the caps are disassembled, being the cylinders finally joined by the interference. 
     
     
         3 . The method according to  claim 1 , wherein a pair of cylindrical tubes ( 102  and  202 ) with caps is prepared, another tube  101  without caps is also prepared; the interference also takes place in tubes  101  and  102 : analogously to the previous case, the pressure removes the interference and then a cylindrical tube ( 102 ) slides into the other ( 101 ); the pressure in the assembly chamber ( 301 ) is lowered and the auxiliary cylinder and the caps are disassembled, being the cylinders finally joined by the interference. 
     
     
         4 . The method according to  claim 1 , wherein a cylindrical tube  102  with circular caps is prepared, another tube  101  without caps is also prepared; the pressure removes the interference and then a cylindrical tube ( 102 ) is slid into the other ( 101 ); the pressure in the assembly chamber ( 301 ) is lowered and the caps are disassembled, being the cylinders finally joined by the interference.