Patent Publication Number: US-9429019-B2

Title: High pressure device for fluid media

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority under 35 U.S.C. §119 of Austrian Patent Application No. A 280/2012 filed Mar. 5, 2012, the disclosure of which is expressly incorporated by reference herein in its entirety. 
     BACKGROUND OF THE EMBODIMENTS 
     1. Field of the Invention 
     Embodiments of the invention relate to a high pressure device for fluid media. 
     In particular, embodiments are directed to a cylinder unit of a high pressure pump for a fluid with a pressure of greater than 2,000 bars. The cylinder unit includes a cylinder formed by shrink connection of at least two concentric, tubular components, and the cylinder unit is detachably connected on one side to a flange part with a sealing system, in which a plunger is axially moveable back and forth, and is connected on another side to a valve body. 
     2. Discussion of Background Information 
     Components of high pressure devices, in particular a wall of a cylinder of high pressure pumps, are exposed during operation to considerable tensile stresses, which are possibly of an unsteady nature or act in a pulsating manner, due to an internal pressure of over 2,000 bars. 
     The tensile stresses can thereby approach the yielding point of the materials in sections of the cylinder wall, but at least cause a long-duration flow of the material, which is constantly diminished in a logarithmic tempo at a given tension. 
     It is known to a person skilled in the art to provide tubular component parts with concentric, thermally shrunk-on parts for high internal pressures or to reinforce fluid-conducting pipes with shrunk-on outer components or outer pipes. 
     Via pipe body of this type formed by a shrinking method from multiple concentric components, it is possible to embody the tensions in the parts of the pipe wall for a high pressure operation such that the most uniform material stresses possible occur over the cross section or that the tensile stress concentrations in the part, which could cause a plastic deformation of the material, are avoided. 
     Cylinder units or pipe bodies made from a compound of at least two components formed by a shrinking-on of an outer part have however among other things a disadvantage, namely that the inner component in the pipe compound can be axially moved and/or stretched under pulsating or possibly alternating stress. This can, in the flange region of the plunger device and/or in the valve body connection region, lead to problems in the system of a sealing of the high pressure fluid. 
     SUMMARY OF THE EMBODIMENTS 
     In embodiments, the invention provides a remedy to the deficiencies in the prior art and creates a class-conforming cylinder unit for a high pressure pump of the type named at the outset. According to embodiments, during heavy continuous operation of the high pressure pump, a tightness of the connection of the cylinder unit to a flange part in the plunger region and to a flange part in the region of the valve body is ensured. 
     According to the embodiments of the invention, a cylinder unit includes a cylinder formed by a shrink connection of at least two concentric, tubular components with grooves on the connection surface. The cylinder is detachably connected on one side to a flange part with a sealing system, in which a plunger is axially moveable back and forth, and on another side to a valve body. A bearing bushing of the sealing system and a radially outermost component of the cylinder bear against the flange part and form intermediately a gap, in which a tensioned, disk-shaped spring device is supported distally on an outer component of the cylinder and proximally on an outside of the bearing bushing to face the flange part. Axially opposite the flange part, the tubular components of the cylinder in the region of a surface bearing against the valve body have a metallic connection, in particular a welded connection. 
     In an advantageous embodiment of the invention, the grooves on the connection surface of the tubular components are essentially semicircularly embodied or formed in cross section with a depth of up to 2 mm. 
     Embodiments of the invention are directed to a cylinder unit of a high pressure pump for a fluid. The cylinder unit includes a cylinder formed by at least two concentric tubular components coupled by a shrink connection. A flange part with a sealing system is detachably connected on one side of the cylinder, and the sealing system has a plunger movable back and forth and a bearing bushing. A valve body is connected on an other side of the cylinder. The bearing bushing and a radially outermost component of the cylinder are arranged to bear against the flange part to form an intermediate gap, a spring device has a distal portion supported on the outermost component of the cylinder and a proximal portion on an outside of the bearing bushing facing the flange part, and a valve body against which an other side of the cylinder bears are included. The tubular components have a metallic connection in a region of a surface bearing between the valve body and the cylinder. 
     According to embodiments, the high pressure pump can be structured and arranged for water with a maximum pressure of greater than 2,000 bars. 
     In accordance with other embodiments of the invention, the metallic connection between the tubular components may be a welded connection. 
     In embodiments, at least one connection surface between the two concentric tubular components can have grooves. The grooves on the at least one connection surface can be formed with a depth of up to 2 mm. The grooves can generally be semicircularly formed on the at least one connection surface. 
     According to still other embodiments of the instant invention, a recess can be formed in an end of the one side of the cylinder. At least part of the recess may be formed in the outermost component. 
     In still further embodiments of the invention, the spring device can be structured and arranged to allow limited axial movement of an inner component. The spring device may limit the axial movement of the inner component to less than 1 mm. Further, the spring device can limit the axial movement of the inner component to up to 0.95 mm. 
     In accordance with still yet other embodiments of the present invention, the spring device can include a tensioned, disk-shaped spring. 
     Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein: 
         FIG. 1  shows a cylinder unit in a high pressure pump. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice. 
     In principle, a cylinder unit Z of a high pressure pump is illustrated in  FIG. 1 . As shown in the FIGURE, one axial side of cylinder unit Z is detachably connected to a sealing system  3  for a plunger piston P and the other axial side of cylinder unit Z is connected, and preferably detachably connected, to a valve body  6 . Sealing systems for plunger pistons are described in European Patent Nos. EP 0 505 352 B1 and EP 1 845 290 B1, the disclosures of which are expressly incorporated by reference herein in their entireties. 
     A cylinder unit  1  according to the invention is formed by an inner component  12  with at least one outer component  11  shrunk thereon. Further, grooves  15  are formed on at least one of the connection surfaces of the tubular components  12 ,  11  by recesses. 
     Sealing system  3  for plunger piston P has, in a manner known per se, a bearing bushing  31  supported in an axial direction by a flange part  2 . An outer region of an outermost component  11  of cylinder  1  is supported on flange part  2  and a recess is formed in the flange part  2  supported end of cylinder  1  in a radial direction up to bearing bushing  31 . 
     A spring device  5 , such as a disk spring, is located in the recess, as shown in  FIG. 1 . A distal portion of spring device  5  is supported on outermost component  11  of the cylinder  1  and a proximal part of spring device  5  is arranged to apply pressure, via its prestress, on an outside of bearing bushing  31 . Further, bearing bushing  31  is axially retained by flange part  2 . 
     Between spring device  5  and inner component  12  of cylinder  1 , a gap  4  is embodied or formed, which allows for axial movement of inner component  12  up to 0.95 mm and thus, at least ensures a tightness of the connection. 
     On an end of cylinder  1  axially opposite sealing system  3  of plunger P, i.e., in a region of a valve body  6  of cylinder  1 , components  11 ,  12  are metallically connected or welded to one another and bear against an opposite surface on valve body  6  in a sealing manner with their worked faces  14 . 
     For the hindrance or prevention of a movement of components  11 ,  12  of cylinder  1  for a high pressure pump, it can be advantageous if grooves  15  in the region of the connection surface are essentially semicircularly embodied or formed in cross section with a depth of up to 2 mm and possibly run spirally in an axial direction. 
     It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.