JP2007537383A - Reciprocating pump - Google Patents

Abstract

  A reciprocating pump (10) for delivering seawater or other fluids under high pressure. The pump (10) has a body (11) that defines an interior space (13) and an opening (18) to the interior space. A plunger (25) extends through the opening (18) and into the interior space (13). A sheath (30) closes the opening (18) and surrounds the plunger (25) inside it, whereby a pump chamber (33) is defined between the body (11) and the sheath (30). The sheath (30) is deformable in response to the reciprocating movement of the plunger (25) to cause a volume change in the pump chamber (33), and basically a first portion (31) that is not deformed; A second portion (32) surrounding the plunger (25) and extending and contracting as the plunger reciprocates. The first portion (31) defines a mounting flange (35) that is clamped by the pump body (11). The sheath (30) comprises a recess (45) adjacent to its open end, in which the reinforcing sleeve (47) is located, and there is a cavity between the reinforcing sleeve (47) and the plunger (25). It is defined. Means are provided for lubricating the contact surface between the sheath (30) and the plunger (25).

Description

  The present invention relates to a reciprocating pump.

  The present invention was made mainly for the purpose of pumping seawater at high pressure. However, it should be understood that the present invention is applicable to the pumping of various fluids other than seawater.

  International Application No. PCT / AU03 / 00813 proposes to utilize wave energy and convert the wave energy into a pressurized fluid for use in any manner. In typical applications, the fluid is seawater drawn from the marine environment in which the equipment operates, and this seawater is pumped to the coast under high pressure and used on the coast.

  There are various technical difficulties in pumping seawater at high pressures above about 70 bar using reciprocating pumps powered by wave energy (and thus often have relatively slow variable strokes). May accompany.

  Pumps used for harsh operating environments, such as seawater pumping under high pressure, require various attributes. For example, the ability to handle corrosive fluids or other aggressive fluids (such as seawater) over a long service life may be required, and may require the ability to be driven with irregular non-sinusoidal strokes. Yes (so that it can be driven by a drive train directly powered by a renewable energy source such as wave motion). Some misalignment (eg, piston shaft tilt) may need to be tolerated. The pump will be desired to be easy to maintain (e.g., easy to lubricate), and it is particularly advantageous to have low mechanical loss (i.e., high efficiency).

  The present invention seeks to provide a pump that meets at least one of the above attributes.

  According to one aspect of the invention, a body defining an interior space and an opening to the interior space, an operating element extending through the opening into the interior space, an inner portion of the operating element being closed An enclosing sheath and a pump chamber defined between the body and the sheath, wherein the sheath is deformable in response to a reciprocating motion of the operating element to cause a volume change in the pump chamber; A reciprocating pump comprising a cavity around an operating element adjacent to the open end of the sheath.

  A cavity may serve one or more purposes. The cavity may provide, for example, a reservoir for lubricant. Alternatively, the cavity may alternatively be configured to accommodate for angular misalignment of the operating element.

  Typically, the cavity is an annular cavity.

  Preferably, the cavity is defined between the periphery of the operating element and the surrounding surface.

  In one aspect, the surrounding surface may be defined by a reinforcing sleeve formed separately from the sheath and located in a recess in the sheath.

  In another aspect, the surrounding surface may be defined by the open end portion of the sheath. In such an embodiment, the open end portion of the sheath includes a stiffener to maintain the end in an open state spaced from the operating element, thereby providing a cavity between the open end portion of the sheath and the operating element. May be defined. The reinforcing material may include a reinforcing ring incorporated in the sheath.

  The cavity may be closed at its outer end by a seal such as a wiper seal.

  The operating element may be configured as a plunger.

  The open end of the sheath may be configured to provide a mounting flange.

  The sheath may include a first portion that is basically not deformed and preferably forms a mounting flange, and a second portion that surrounds the plunger and that expands and contracts as the plunger reciprocates.

  Preferably, the cavity is provided within the first portion.

  The second portion may include a surface that contacts the plunger. The surface of the second portion of the shroud that contacts the plunger may be configured to contain a lubricant.

  The configuration of the surface for containing the lubricant may include a formation on the surface. The formation may form a crack that can catch the lubricant. The formation can be in any suitable form such as a knob, ridge or other protrusion, or alternatively, a dimple.

  Lubricant is applied to any part that reduces sliding friction between the outer surface of the plunger and the inner surface of the sheath, and allows uniform sliding without tightening between the two surfaces. May be.

  As the lubricant, for example, seawater itself, silicon grease, castor oil, brake fluid, and polypropylene glycol can be used.

  A low friction material such as polytetrafluoroethylene may be applied to the outer surface of the plunger.

  You may comprise so that a lubricant may be accommodated in a sheath. The configuration may include a formation on the inner surface of the sheath. Lubricants may be supplied either under gravity or under pressure.

  In one aspect, the lubricant can be configured to be supplied to a region adjacent to the inner end of the sheath. This can be done by means of a lubricant delivery path in the operating element.

  According to a second aspect of the invention, the body defining the internal space and the opening to the internal space, the operating element extending through the opening into the internal space, the inner part of the operating element closing the opening And a pump chamber defined between the body and the sheath, wherein the sheath is deformable in response to a reciprocating motion of the operating element to cause a volume change in the pump chamber A reciprocating pump comprising a chamber, a recess in the sheath adjacent to the open end thereof, and a reinforcing sleeve located in the recess, thereby defining a cavity between the reinforcing sleeve and the operating element Provided.

  According to a third aspect of the present invention, a body defining an internal space and an opening to the internal space, a plunger extending through the opening into the internal space, and closing the opening and enclosing the inner portion of the plunger A pump chamber defined between the sheath and the body, wherein the sheath is deformable in response to a reciprocating movement of the plunger to produce a volume change in the pump chamber, And a second portion that surrounds the plunger and expands and contracts as the plunger reciprocates, and the first portion defines a mounting flange that is sandwiched and engaged with the main body. And a reciprocating pump comprising such a pump chamber.

  According to a fourth aspect of the present invention, a body defining an internal space and an opening to the internal space, a plunger extending through the opening into the internal space, and closing the opening and enclosing the inner portion of the plunger A pump chamber defined between the sheath and the body, wherein the sheath is deformable in response to a reciprocating movement of the plunger to produce a volume change in the pump chamber; A reciprocating pump is provided comprising supply means for supplying lubricant in the region between the plunger and the sheath.

  According to a fifth aspect of the present invention, a sheath comprises a first portion that defines a mounting flange, and a second portion configured to surround a plunger received within the sheath. The second portion is provided with a sheath that expands and contracts as the plunger reciprocates.

  The invention will be better understood by reference to the following description of each embodiment, as shown in the accompanying drawings.

  1-14, a reciprocating pump 10 according to a first embodiment is shown, which is particularly suitable for pumping seawater under high pressure. Since seawater is drawn from the ocean, the initial pressure corresponds to the hydrostatic pressure at the ocean depth where the seawater is taken.

  When pump 10 is powered by wave energy, it generally operates with a slow variable stroke. The pump has a structure particularly suitable for such an application.

  The pump 10 includes a main body 11 configured as a cylindrical pressure vessel that defines an internal space 13. The main body 11 includes a cylindrical side wall 15 and an end wall 17 at one end of the cylindrical side wall 15. The end wall 17 has an opening 18 therein. The other end of the cylindrical side wall 15 is closed by a base 19.

  The end wall 17 is defined by an end plate 20 removably connected to the cylindrical side wall 15, which is provided in this embodiment by fasteners such as screws.

  The pump 10 further includes an operating element 23 that includes a plunger 25 having a cylindrical side surface 26 and an end surface 27. Plunger 25 is attached to a connector 28 that is adapted to undergo reciprocating motion under the influence of, for example, a drive train powered by wave motion. In this embodiment, the connector 28 is configured as a hinge bush that engages a hinge pin 29 connected to a lever (not shown), whereby reciprocation of the lever imparts reciprocating motion to the plunger 25.

  The plunger 25 extends into the internal space 13 through the opening 18 in the end wall 17.

  The sheath 30 is attached to the body 11 around the opening 18 to surround that portion of the plunger 25 that extends into the interior space 13. The sheath 30 is made of an elastomer material, preferably rubber.

  The sheath 30 is attached to the body 11 to close the opening 18, whereby a pump chamber 33 is defined between the sheath 30 and the body 11. The sheath 30 provides a deformable boundary surface for the pump chamber 33, thereby causing a change in volume of the pump chamber 33 as the boundary surface deforms.

  The main body 11 includes an inlet 12 and an outlet 14, both of which communicate with the pump chamber 33.

  The sheath 30 includes a first portion 31 and a second portion 32, and the two portions are integrally formed. The first portion 31 is substantially rigid in the sense that it does not undergo significant deformation during operation of the pump. The second portion 32 surrounds the plunger 25 and is adapted to undergo expansion and contraction during operation of the pump.

  The first portion 31 is configured to provide a mounting flange 35. The second portion 32 is a generally tubular structure, with a tubular wall section 36 and an end section 37, the flange 35 provided by the first portion 31 is at one end of the tubular wall section 36, and the tubular wall The other end of the section is closed by an end section 37.

  The mounting flange 35 defined by the first portion 31 is fixed to the main body 11 while being sandwiched between the end wall 17 and the annular seat 38. The seat 38 is defined by a seat element 39 mounted on an annular step 40 provided inside the cylindrical side wall 15 inward of the end wall 17.

  The mounting flange 35 has an outer end surface 41 for abutting on the end wall 17 and an inner end surface 43 for abutting on a seat 38 sealingly engaged therewith.

  The first portion 31 includes an annular recess 45 that opens to the outer end surface 41. The recess 45 has a shape that can receive the reinforcing sleeve 47. The reinforcing sleeve 47 has an annular structure and has an inner surface 49 that defines a central opening having a diameter larger than the diameter of the plunger 25. With such a configuration, a gap 51 is defined between the sleeve 47 and the plunger 25.

  The reinforcing sleeve 47 is a rigid structure, and in this embodiment is made from steel. The reinforcing sleeve 47 serves to provide a reinforcing structure for the flange, and more particularly maintains the presence of the gap 51.

  The purpose of the gap 51 is to provide a cavity for containing the lubricant. The lubricant may be any liquid that reduces sliding friction between the outer surface of the plunger 25 and the inner surface of the sheath.

  Further, the gap 51 provides some clearance space to accommodate any slight misalignment of the plunger 25 relative to the body 11.

  In addition, the reinforcing sleeve 47 acts to apply an outward radial force on the flange 35 when the flange 35 is compressed by the clamp engagement between the mounting flange 35 and the seat 38, thereby causing the sheath 30 and Ensure that a high pressure seal is formed with the body 11. More specifically, the radial force exerted by the sleeve 47 acts to ensure that there is a high pressure seal established between the flange inner surface 43 and the annular support seat 38.

  The reinforcing sleeve 47 has a recess 52 on its inner surface and holds a wear band 53 for sliding contact with the outer surface of the plunger 25. Therefore, the wear band 53 protrudes beyond the inner surface of the reinforcing sleeve 47 as shown in the drawing. The wear band 53 does not completely occupy the gap 51, so that the gap 51 is available for its intended purpose.

  A wiper seal 55 is accommodated between the reinforcing sleeve 47 and the end plate 20. The wiper seal 55 is slidably engaged with the plunger 25 and is provided for the purpose of suppressing loss of lubricant when the plunger performs its reciprocating motion.

  A suitable low friction material may be applied to the outer surface of the plunger 25.

  Although not shown in the drawings, the pump 10 also includes a suitable arrangement of valves to control the direction of fluid flow through the inlet 12 into the pump chamber 33 and out of the pump chamber 33 through the outlet 14. It also has.

  Since the second portion 32 of the sheath 30 is formed along the contour of the plunger 25, sheath extension occurs primarily at its tubular wall portion 36. This results in the elastomeric material being stretched as the plunger 25 moves inward during the pump stroke, and the tubular wall portion 36 becomes thinner. The pressure generated by the seawater during the pump cycle acts almost statically when the fluid velocity around the sheath is low, so the fluid force acts to keep the sheath in contact with the plunger 25. To do. This prevents the formation of folds and stress concentrations and helps maintain the durability and service life of the sheath. The plunger 25 provides a surface that provides lateral support to the tubular wall section 36 as well as the end section 37 when they are subjected to high fluid pressure.

  When the elastomeric material forming the sheath is natural rubber and a pump is used to pump seawater as indicated above, up to 2 mm of the surface of the rubber that contacts the water is, for example, 20 years Is expected to wear over a period of time. In such cases, it is important to make the sheet thickness large enough to accommodate this reduction over the usable life of the pump.

  The sheath 30 incorporates a brazing material 61 on its inner surface in a region below the recess 45, and supplies lubricant downward from the lubricant reservoir provided by the gap 51 to other portions of the sheath under the influence of gravity. Make it possible to do. The downward flow of lubricant may also be assisted by making the inner diameter of the second portion 32 of the sheath 30 slightly larger than the outer diameter of the plunger, so that at least during the intake stroke of the pump cycle. There is some gap, in which case the pressure of the pumped fluid is not high enough to make this gap zero.

  Plunger 25 includes an axial passage 71 that extends to end surface 27 for delivering lubricant. The passage 71 receives lubricant from an external source. In this manner, the lubricant can be delivered to a region adjacent to the inner end of the sheath 30, that is, to the contact surface between the plunger end surface 27 and the sheath end section 37.

  The lubricant may flow downward along the passage 71 and then comprise a continuous flow of lubricant material (such as seawater) that flows upwardly between the cylindrical surface 26 of the plunger 25 and the tubular wall portion 36 of the sheath. Good. In this form, some excess lubricant can flow from the sheath 30 through its open end.

  In this embodiment, the lubricant contains seawater procured from high pressure seawater delivered by a pump. This is accomplished by a bypass line 75 extending from the pump outlet 14 to the axial passage 71 as best seen in FIGS. 1 and 2 of the drawings. Of course, the bypass line 75 must be flexible or structured to accommodate the movement of the plunger 25 relative to the pump body 11 in which the outlet 14 is formed. In this embodiment, the valve 77 includes a needle valve, and is connected to a bypass line 75 to restrict the supply of high-pressure seawater from the pump outlet 14 to the axial passage 71.

  Plunger 25 includes a first portion 81 that includes a head section 83 attached to connector 28 and a tube 85 extending downwardly from head section 83. The plunger 25 further comprises a second portion 87 adapted to fit into the first portion 81 to provide the cylindrical side surface 26 and end surface 27 of the plunger. The second portion 87 has a substantially cylindrical shape and has a cylindrical side wall portion 91 and an end wall portion 93. The end wall portion 93 incorporates an opening 95 in which the tube 85 is located when the second portion 87 fits into the first portion 81. The opening 95 is configured to receive the diffuser 97. The diffuser 97 engages with the tube 85 in a screwed manner. The diffuser 97 has a diffuser passage 99 that communicates with the tube 85 to receive seawater delivered along the tube and diffuse it from the plunger.

  The deflection plate 101 is incorporated in the sheath 30 and abuts against the diffuser 97. In this way, the seawater delivered through the diffuser 95 impinges on the deflector plate 101 which in turn distributes the seawater into the interface between the plunger 25 and the sheath 30.

  With reference now to FIGS. 15 and 16 of the drawings, a sheath 30 for a pump according to a second embodiment is shown. The pump according to the second embodiment is similar in many respects to the first embodiment, so that corresponding reference signs are used to identify similar parts. In this embodiment, the sheath 30 is structured in a manner similar to the sheath of the first embodiment, except that a formation 105 is provided on the inner surface 107 of the second portion 32 of the sheath and the adjacent surface of the plunger 25. 26 is different from abutment. Formation 105 is configured to define a break 111 to contain the lubricant. In this embodiment, the formation 105 comprises an array of protrusions 109, between which a space 113 is defined, which provides a break 111 for containing the lubricant. The space 113 allows the lubricant to move around the interface between the plunger 25 and the sheath 30, particularly during pump cycles where the sheath 30 is not pressed firmly to engage the abutting surface 26 of the plunger. That's right at the stage. The formation 105 cooperates at a stage where the fluid pressure in the pump chamber 33 is at a level at which the second portion 32 of the sheath 30 is firmly pressed into engagement with the abutting surface 26 of the plunger 25. A pocket or zone is formed that captures the lubricant in place, thereby ensuring that the proper amount of lubricant is retained at the interface between the second portion 32 of the sheath and the plunger 25.

  Depending on the pump application, it is possible to rely on the lubricant held by the gravity 105 from the gap 51 or by the formation 105 without having to deliver the lubricant through the plunger.

  In another embodiment not shown, the end section 37 of the second portion 32 of the sheath 30 may be attached to the end face of the plunger 25. The attachment may be provided by a fastener, and the sheath end section 37 is clamped between the end face 27 of the plunger 25 and a clamp plate through which the fastener extends for attachment to the plunger. . Such attachment ensures that the sheath 30 is always pulled with the return (outward) stroke of the plunger 25. Of course, a proper fluid seal needs to be established around the fastener, so that the integrity of the sheath is not compromised.

  As described above, the present embodiment provides a high-efficiency pump that can withstand use in a harsh environment, although it has a simple configuration. This is because the working surface of the pump exposed to seawater during the pump cycle is composed of the surface of the pump body 11 and the surface of the sheath 30 accommodated therein. With such a structure, the pump can be driven with irregular non-sinusoidal strokes generated from a drive system powered by wave energy. Further, the configuration in which the plunger 25 is supported in the pump main body 11 allows the displacement between the plunger 25 and the pump main body 11. The flexibility of the sheath 30 supports the above-described displacement absorbing structure in both the first and second portions 31, 32 thereof.

  It should be appreciated that the scope of the invention is not limited to the scope of the described embodiments. For example, although pumps according to embodiments have been described with respect to pumping seawater, pumps according to the present invention may find use in pumping various other fluid materials including liquids, gases and slurries. Good.

  Modifications and changes can be made without departing from the scope of the invention.

  Throughout this specification, unless the context requires otherwise, variations of the term “comprising” or “comprising” refer to the stated integer or group of integers. It will be understood that including, but not excluding any other integer or group of integers.

1 is a schematic perspective view of a reciprocating pump according to a first embodiment. It is a front sectional view of the pump of FIG. It is a sectional side view of the pump of FIG. It is the principal part enlarged view which illustrated the arrangement | sequence of the components between a pump plunger and a pump main body. It is a sectional elevation view of the pump body. It is a schematic perspective view of the sheath formation part of a pump. It is a side view of a sheath. It is the principal part enlarged view which illustrated the part of the sheath. It is a side view of the upper part of a pump plunger. It is a perspective view of the lower part of a pump plunger. It is an elevation sectional view of a lower plunger part. It is a principal part enlarged view which shows one end of the plunger in which the diffuser was accommodated. It is an elevation sectional view of a diffuser. It is a schematic perspective view of a diffuser. It is a schematic elevation view of the sheath for pumps by a 2nd embodiment. It is a figure which illustrates the part of the sheath of FIG.

Claims (34)

  A body defining an internal space and an opening to the internal space; an operating element extending through the opening into the internal space; a sheath closing the opening and enclosing the operating element therein; A pump chamber defined between a body and the sheath, the sheath being deformable in response to a reciprocating movement of the operating element to cause a volume change in the pump chamber; A reciprocating pump comprising a cavity around the operating element adjacent to the open end of the sheath.   The reciprocating pump according to claim 1, wherein the cavity is an annular cavity.   The reciprocating pump according to claim 1 or 2, wherein the cavity is defined between the periphery of the operating element and an surrounding surface.   The reciprocating pump of claim 3, wherein the surrounding surface is defined by a reinforcing sleeve located in a recess in the sheath.   The reciprocating pump according to claim 4, wherein the reinforcing sleeve supports a wear ring that slidably engages the operating element.   The reciprocating pump according to claim 3, wherein the surrounding surface is defined at an open end portion of the sheath.   The reciprocating pump according to claim 6, wherein a reinforcing material for maintaining an open state spaced from the operating element is incorporated in the open end portion of the sheath.   The reciprocating pump according to any one of claims 1 to 7, wherein the cavity is closed at an outer end thereof by a seal.   The reciprocating pump according to any one of claims 1 to 8, wherein the operating element is configured as a plunger.   The reciprocating pump according to any one of claims 1 to 9, wherein a mounting flange is provided at the open end of the sheath.   The said sheath is provided with the 1st part which does not deform | transform fundamentally, and the 2nd part which surrounds the said plunger and expands and contracts with the reciprocating motion of the said plunger. The reciprocating pump described in 1.   The reciprocating pump according to claim 11, wherein the mounting flange is provided in the first portion.   The reciprocating pump according to claim 11 or 12, wherein the cavity is provided within the range of the first portion.   The reciprocating pump according to claim 11, wherein the second portion includes a surface that contacts the plunger.   The reciprocating pump of claim 14, wherein the surface is configured to contain a lubricant.   The reciprocating pump according to claim 15, wherein the surface has a storage shape as a configuration for storing the lubricant on the surface.   The reciprocating pump according to any one of claims 9 to 16, wherein an outer surface of the plunger is coated with polytetrafluoroethylene or a similar low friction material.   The reciprocating pump according to any one of claims 9 to 17, further comprising a supply unit for a lubricant contained in the sheath.   19. A reciprocating pump according to claim 18, wherein the supply means is configured to deliver lubricant to a region adjacent to the inner end of the sheath.   The reciprocating pump according to claim 19, wherein the supply means includes a lubricant delivery path provided in the operating element.   A body defining an internal space and an opening to the internal space; an operating element extending through the opening into the internal space; a sheath closing the opening and enclosing the operating element therein; A pump chamber defined between a main body and the sheath; a recess provided adjacent to an open end of the sheath; and a reinforcing sleeve positioned in the recess; the sheath comprising the pump chamber A reciprocating pump that is deformable in response to a reciprocating motion of the operating element to create a volume change therein, and wherein a cavity is defined between the reinforcing sleeve and the operating element.   The reciprocating pump of claim 21, wherein the reinforcing sleeve supports a wear ring that slidably engages the operating element.   23. A reciprocating pump according to claim 21 or 22, wherein the cavity is closed at its outer end by a seal.   A body defining an interior space and an opening to the interior space; a plunger extending through the opening into the interior space; a sheath closing the opening and enclosing the plunger inside; and the body A pump chamber defined between the sheath and the sheath, the sheath being deformable in response to a reciprocating movement of the operating element in order to produce a volume change in the pump chamber; And a second portion that surrounds the plunger and that expands and contracts as the plunger reciprocates, and the first portion is sandwiched and engaged with the main body. A reciprocating pump that defines a mounting flange.   A recess is provided in the first portion of the sheath adjacent to the open end portion of the sheath, a reinforcing sleeve is located in the recess, and a cavity is defined between the reinforcing sleeve and the plunger. The reciprocating pump according to claim 24.   A body defining an interior space and an opening to the interior space; a plunger extending through the opening into the interior space; a sheath closing the opening and enclosing the plunger inside; and the body A pump chamber defined between the sheath and the sheath, the sheath being deformable in response to a reciprocating movement of the operating element to cause a volume change in the pump chamber, the plunger A reciprocating pump comprising supply means for supplying lubricant in a region between the sheath and the sheath.   27. A reciprocating pump according to claim 26, wherein the supply means is configured to deliver a lubricant to a region adjacent the inner end of the sheath.   28. The reciprocating pump according to claim 27, wherein the supply means includes a lubricant delivery path provided in the plunger.   The sheath for reciprocating pumps as described in any one of Claims 1-28.   A first portion defining a mounting flange; and a second portion configured to surround a plunger received within the sheath, the second portion being responsive to reciprocation of the plunger. A sheath that is stretchable.   31. The sheath of claim 30, wherein the second portion includes a surface that abuts the plunger, the surface configured to contain a lubricant.   32. A sheath according to claim 30 or 31, comprising a recess in the first portion adjacent to an open end, the recess being adapted to receive a reinforcing sleeve.   A reciprocating pump substantially as herein described with reference to the accompanying drawings.   A sheath substantially as herein described with reference to the accompanying drawings.

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