Externally mountable spiral adaptor

Abstract

An adaptor that can be used with rotary fluid equipment will protect mechanical seals and/or packing material adjacent a seal cavity ( 18 ) of the equipment. The adaptor includes an annular body ( 30 ) with a central bore ( 32 ) adapted to receive a shaft ( 12 ) of the equipment. When used with mechanical seals the adaptor is receivable in the cavity at the entrance thereto and it has a portion which surface which effects contact with a complementary surface of the seal. When used with packing the adaptor fits within the cavity and defines an outboard extension in which the packing can be received. The bore defines two portions, one of which is close to the shaft ( 52 ) and another portion ( 54 ) which flares outwardly from the one portion towards the outboard end of the adaptor. Each bore portion has a spiral groove ( 56,58 ) therein, which groove serves to redirect contaminant material contained in fluids surrounding the shaft away from the seal cavity.

1 . A spiral adaptor for location at an entrance to an annular seal cavity of rotating equipment, such seal cavity being defined by a outer cylindrical surface of a rotatable shaft of such equipment and a shaft housing surrounding at least a portion of said shaft, said cavity having a bottom end, an entrance end and an outer cylindrical surface, said equipment including a mechanical seal positioned outboard of said shaft housing adjacent said entrance to said seal cavity, said adaptor comprising: an annular adaptor body having a central bore therethrough; said adaptor body including a first annular portion receivable within said seal cavity at said entrance thereto and a second annular portion of greater diameter than said first annular portion, said second annular portion having an inboard radial surface adapted for contact with a complementary face of said shaft housing and an outboard radial surface adapted for contact with a complementary face of said mechanical seal; said bore including a first portion defining an annular gap with said shaft outer cylindrical surface when said adaptor is in its operating position and a second portion which flares outwardly from said first bore portion towards said outboard radial surface, said first and second bore portions each including a spiral groove formed therein, the hand thereof being in the same direction as the rotation of said shaft, said groove serving to redirect contaminant material contained in fluids surrounding said shaft away from said seal cavity.  
   
   
       2 . The spiral adaptor of  claim 1  wherein said first annular portion of said adaptor body has an outer cylindrical surface adapted for a tight fit within said seal cavity, said outer cylindrical surface including a circumferential groove therein for reception of an annular seal member adapted for sealing engagement with said outer cylindrical surface of said seal cavity.  
   
   
       3 . The spiral adaptor of  claim 1  wherein said first annular portion of said adaptor body acts as a locating boss for positioning said spiral adaptor at said cavity entrance  
   
   
       4 . The spiral adaptor of  claim 1  wherein said first annular portion of said adaptor body has an outer cylindrical surface adapted for a tight fit within said seal cavity, said outer cylindrical surface including at least a pair of axially spaced apart circumferential grooves therein, each for reception of an annular seal member adapted for sealing engagement with said outer cylindrical surface of said seal cavity.  
   
   
       5 . The spiral adaptor of  claim 1  wherein said inboard radial surface of said adaptor body second annular portion has a ribbed gasket surface formed integrally therewith for sealing engagement with said complementary face of said shaft housing.  
   
   
       6 . The spiral adaptor of  claim 1  wherein said inboard radial surface of said adaptor body second annular portion has an annular groove formed therein for reception of an annular sealing member for sealing engagement with said complementary face of said shaft housing.  
   
   
       7 . The spiral adaptor of  claim 1  wherein the axial extent of said adaptor body first portion may be greater than, lesser than or equal to the axial extent of said adaptor body second portion.  
   
   
       8 . The spiral adaptor of  claim 1  including a shutoff mechanism contained therein, said shutoff mechanism comprising a circumferential groove formed in said first bore portion, a flexible sealing ring contained within said circumferential, and a passage in said annular body communicating a source of pressurized fluid with said circumferential groove for pressing said flexible ring against said shaft.  
   
   
       9 . The spiral adaptor of  claim 1  in combination with an insert positionable within said seal cavity adjacent the bottom end thereof, said insert comprising an annular insert body receivable within said seal cavity and having a central bore therethrough; said central bore including a first portion defining an annular gap with said shaft outer cylindrical surface when said insert is in its operating position and a second portion which flares outwardly from said first bore portion towards an outboard end of said insert, said first and second bore portions each including a spiral groove formed therein, the hand thereof being in the same direction as the rotation of said shaft, said groove serving to redirect contaminant material contained in fluids within said seal cavity towards said spiral adaptor.  
   
   
       10 . A spiral adaptor for location at an entrance to an annular seal cavity of rotating equipment, such seal cavity being defined by a outer cylindrical surface of a rotatable shaft of such equipment and a shaft housing surrounding at least a portion of said shaft, said cavity having a bottom end, an entrance end and an outer cylindrical surface, said equipment including a mechanical seal positioned outboard of said shaft housing adjacent said entrance to said seal cavity, said adaptor comprising: an annular adaptor body receivable within said seal cavity at said entrance thereto and having a central bore therethrough; said adaptor body including an outboard radial surface adapted for contact with a complementary face of said mechanical seal; said bore including a first portion defining an annular gap with said shaft outer cylindrical surface when said adaptor is in its operating position and a second portion which flares outwardly from said first bore portion towards said outboard radial surface, said first and second bore portions each including a spiral groove formed therein, the hand thereof being in the same direction as the rotation of said shaft, said groove serving to redirect contaminant material contained in fluids surrounding said shaft away from said seal cavity.  
   
   
       11 . The spiral adaptor of  claim 10  wherein said adaptor body has an outer cylindrical surface adapted for a tight fit within said cavity, said outer cylindrical surface including at least one circumferential groove therein for reception of an annular seal member adapted for sealing engagement with said outer cylindrical surface of said seal cavity.  
   
   
       12 . The spiral adaptor of  claim 1  wherein said spiral groove formed in said adaptor body bore first portion leads smoothly into said spiral groove formed in said adaptor body bore second portion.  
   
   
       13 . The spiral adaptor of  claim 1  wherein said spiral groove has radial and non-radial surface portions, the non-radial portion extending into the adaptor body from the adaptor body bore and the radial portion extending generally radially from the inner end of the non-radial portion back towards the adaptor body bore.  
   
   
       14 . The spiral adaptor of  claim 1  wherein said adaptor body bore includes an intermediate portion between said first and second portions and of diameter greater than that of said first portion, there being a flared transition section between said first and intermediate portions, said intermediate and flared transition portions each having a spiral groove formed therein.  
   
   
       15 . A spiral adaptor for location within an annular seal cavity of rotating equipment, such seal cavity being defined by a outer cylindrical surface of a rotatable shaft of such equipment and a shaft housing surrounding at least a portion of said shaft, said cavity having a bottom end, an entrance end and an outer cylindrical surface, said adaptor comprising: an annular adaptor body receivable within said seal cavity and having a central bore therethrough; said adaptor body including a first annular body portion positionable at said bottom end of said seal cavity and a second annular body portion outboard of said first body portion; said bore including a first portion defining an annular gap with said shaft outer cylindrical surface when said adaptor is in its operating position and a second portion which flares outwardly from said first bore portion towards a radially inwardly tapering central portion, said first, second and central bore portions each including a spiral groove formed therein, the hand thereof being in the same direction as the rotation of said shaft, said groove serving to redirect contaminant material contained in fluids surrounding said shaft away from said seal cavity; and said adaptor also including an annular extension portion extending from said second annular portion to an outboard end of said adaptor, said extension portion including a blind bore therein which, with said shaft outer cylindrical surface defines an annular cavity for reception of one or more packing rings.  
   
   
       16 . The spiral adaptor of  claim 15  wherein said second annular portion includes an outer circumferential groove therein for communication with a source of flushing fluid, and at least one passage leading from said circumferential groove through said adaptor body to said bore central portion.  
   
   
       17 . The spiral adaptor of  claim 15  wherein each of said first annular portion and said extension portion includes at least one outer circumferential groove therein for reception of an annular sealing member.  
   
   
       18 . The spiral adaptor of  claim 15  wherein said extension portion terminates at its outboard end at a radially outwardly extending flange.  
   
   
       19 . The spiral adaptor of  claim 10  wherein said spiral groove has radial and non-radial surface portions, the non-radial portion extending into the adaptor body from the adaptor body bore and the radial portion extending generally radially from the inner end of the non-radial portion back towards the adaptor body bore.  
   
   
       20 . The spiral adaptor of  claim 10  wherein said adaptor body bore includes an intermediate portion between said first and second portions and of diameter greater than that of said first portion, there being a flared transition section between said first and intermediate portions, said intermediate and flared transition portions each having a spiral groove formed therein.