Driving Rod For The Piston Of A Reciprocating Compressor

Abstract

A driving rod for the piston of a reciprocating compressor of the type that comprises: a cylinder block defining a compression chamber; a piston reciprocating within the compression chamber; a driving means to apply reciprocating forces to the piston; and a driving rod disposed between the piston and the driving means and comprising a number, greater than 1, of rods disposed side by side along the axis of the driving rod and each presenting a cross-section that is dimensioned and configured to impart to the driving rod, jointly with the other rods, a required axial rigidity and a flexibility, in at least one direction transversal to the axis of the driving rod, sufficient to absorb, at least substantially, the forces exerted on the piston by the driving rod and by the driving means.

1 . A driving rod for the piston of a reciprocating compressor of the type that comprises: a cylinder block defining, therewithin, a compression chamber; a piston axially reciprocating within the compression chamber according to the axis of the latter; a driving means mounted in the cylinder block to apply reciprocating forces to the piston; and a driving rod coupled to the piston and to the driving means, wherein the driving rod comprises a bundle of “n” rods disposed side by side along the axis of the driving rod, each rod presenting a cross-section that is dimensioned and configured to impart to the driving rod, jointly with the other rods an axial rigidity sufficient to transmit the reciprocating forces to be applied to the piston, as well as a flexibility, in at least one direction transversal to the axis of the driving rod, which is sufficient to absorb, at least substantially, the forces exerted on the piston, in said transversal direction, by the driving rod and by the driving means in the region of the compression chamber. 
   
   
       2 . The driving rod as set forth in clam  1 , wherein each one of the rods present a cross-section area corresponding to 1/n the cross-section area needed to impart to the driving rod the sufficient axial rigidity, the cross-section of the rods being dimensioned and configured so that the sum of the moments of inertia of the rods, in said transversal direction is a fraction of the moment of inertia, in said transversal direction, of a single-piece rod having a cross-section area corresponding to the sum of the cross-section areas of the rod. 
   
   
       3 . The driving rod as set forth in  claim 2 , wherein the sum of the moments of inertia of the rods corresponds to a fraction “n” of the moment of inertia of a single-piece driving rod with a cross-section area corresponding to the sum of the cross-section areas of the rods. 
   
   
       4 . The driving rod as set forth in  claim 2 , wherein the sum of the moments of inertia of the rods corresponds to a fraction “n 2 ” of the moment of inertia of a single-piece driving rod with a cross-section area corresponding to the sum of the cross-section areas of rods. 
   
   
       5 . The driving rod as set forth in  claim 2 , wherein the rods are symmetrically disposed around the displacement axis of the piston and laterally seated to each other. 
   
   
       6 . The driving rod as set forth in  claim 5 , wherein the rods are rectilinear and parallel to each other. 
   
   
       7 . The driving rod as set forth in  claim 5 , wherein the rods are disposed in a helical arrangement. 
   
   
       8 . The driving rod as set forth in  claim 5 , wherein the rods present a circular cross-section with equal flexibility in any transversal direction. 
   
   
       9 . The driving rod as set forth in  claim 5 , wherein the rods are rectilinear, parallel and laterally seated to each other, each rod having a rectangular cross-section with a dimension corresponding to a dimension (L) of the rectangular cross-section of a single-piece driving rod, and with the other dimension (h) corresponding to the fraction “n” of the other dimension (H) of the cross-section of said single-piece driving rod, the cross-section of the latter corresponding to the sum of the cross-section areas of the “n” rods of the driving rod with multiple rods. 
   
   
       10 . The driving rod as set forth in  claim 2 , wherein the rods are jointly and medianly surrounded by at least one sleeve occupying part of the longitudinal extension of the driving rod. 
   
   
       11 . The driving, rod as set forth in  claim 10 , wherein the sleeve is defined by an elastic ring pressing the rods against each other. 
   
   
       12 . The driving rod as set forth in  claim 10 , wherein the sleeve is defined by a helical spring tightly mounted around the rods of the driving rod. 
   
   
       13 . The driving rod as set forth in  claim 10 , wherein the sleeve is defined by a tube extension mounted with a small clearance around the rods of the driving rod. 
   
   
       14 . The driving rod as set forth in  claim 2 , wherein the rods present opposite ends defining the ends of the driving rod, said rods having each of the opposite ends jointly affixed to a terminal block. 
   
   
       15 . The driving rod as set forth in  claim 14 , wherein each terminal block comprises a tubular body incorporating an enlarged end head turned to the rods and presenting, internally, a housing axially defined through the enlarged end head and through at least part of the extension of the tubular body. 
   
   
       16 . The driving rod as set forth in  claim 15 , wherein the tubular body is externally threaded, the enlarged end header being in the form of a hexagonal nut. 
   
   
       17 . The driving rod as set forth in  claim 14 , wherein the opposite ends of the rods are laterally curved, defining an anchorage deformation, each terminal block being rolled over one of the opposite ends of the rods. 
   
   
       18 . The driving rod as set forth in  claim 17 , in wherein each terminal block comprises an elongated body incorporating an enlarged end head turned to the rods. 
   
   
       19 . The driving rod as set forth in  claim 18 , wherein the elongated body is externally threaded, the enlarged end head being in the form of a hexagonal nut. 
   
   
       20 . The driving rod as set forth in  claim 14 , wherein the terminal blocks are each formed by a pair of plates to be affixed to each other, sandwiching a respective end of the rods. 
   
   
       21 . The driving rod as set forth in  claim 14 , wherein the terminal blocks are defined by eyes of a driving rod in the form of a connecting rod of a reciprocating compressor.