Patent Publication Number: US-2023149979-A1

Title: Spline cleaning device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from United Kingdom patent application number GB 2116563.4 filed on Nov. 17, 2021, the entire contents of which is incorporated herein by reference. 
     BACKGROUND 
     Technical Field 
     The present disclosure relates to spline cleaning devices, more specifically a device for cleaning splines formed in the inner surface of a hollow shaft, e.g. the shaft of a gas turbine engine. 
     Description of the Related Prior Art 
     Splines are ridges or grooves that form part of a component. They typically take the form of a series of uniform spaced ridges or grooves that run parallel to the axis of the component. Splines are found in a wide variety of mechanical devices including gas turbine aircraft engines. They may for example be formed within the internal surface of gas turbine engine shafts. 
     Splines can be male or female i.e. ridges or groves respectively. Female splines are typically formed to match or mate with male splines. 
     Splines can accrue debris over time. For example splines in a gas turbine engine component are typically covered by swarf or burnt oil which can cause the splines to become worn, potentially affecting performance and requiring cleaning or replacement. Excessive wearing and performance loss may even affect safe operation of the engine. 
     Cleaning splines can be difficult, firstly in achieving access to the splines, and secondly in cleaning them effectively. It is also difficult to capture debris that is removed from the splines. 
     SUMMARY 
     According to a first aspect there is provided a spline cleaning device for cleaning splines formed within a component of a gas turbine engine, the spline cleaning device comprising a central support, a central support sleeve that surrounds and is movable with respect to the central support. A scraper having protrusions, the scraper being attachable to the central support sleeve, and configured to remove surface contaminants from the splines; and a collector sump that is attachable to the central support and configured to collect the surface contaminants that have been removed from the splines. 
     In some embodiments the central support is tubular with a circular cross-section. The circular cross-section allows for the central support sleeve to be indexed around the splines without having to extract the central support sleeve completely from the central support, reducing the distance that central support sleeve has to move. A circular cross section allows for easier centralisation around the support sleeve when the scraper is in contact with the splines. 
     In some embodiments the central support sleeve surrounds at least a substantial portion of the central support. This ensures that the location of the central support sleeve in relation to the central support is maintained. 
     In some embodiments the central support sleeve and the central support comprise the same material. This will reduce any preferential wear due to the reciprocating manner of the central support sleeve with the central support to be minimised. 
     In some embodiments the scraper has a central hub and a central hole, the central hub has an internal surface that is threaded for attaching the scraper to a corresponding threaded portion on the central support sleeve. This allows for disassembly that can support storage. It also can allow for different scrapers to be attachable to the central support sleeve, allowing for different spline configurations. 
     In some embodiments the central hub has viewing apertures. This enables the operator to view through the central hub to see the splines and ensure that the protrusions of the scraper are correctly engaged with the splines. It also allows for the splines to be seen to determine if further cleaning is required during operation of the device. 
     In some embodiments the scraper has arm portions each arm portion having an external circumferential surface upon which the protrusions are formed. Arm portions reduce the overall friction that may be experienced when using the device due to the interaction between the splines and the protrusions. 
     In some embodiments the arm portions are equally spaced with respect to the central hub. Equally spaced arm portions ensure that the forces are equally distributed around the central hub, this aids the centralisation of the scraper with the central support. 
     In some embodiments the scraper has lubrication ports and lubricant passageways, the lubrication ports being configured to receive a mobilising fluid from a source of mobilising fluid, and the lubricant passageways being configured to transport the mobilising fluid from the lubrication ports to the external circumferential surface of the scraper. The mobilising fluid may react with the debris to reduce the adherence of the debris to the spline. The fluid may partially dissolve the debris. The fluid provides a means for transporting the debris from the splines to the sump. The mobilising fluid may also reduce wear on the splines as it will act as a lubricant between the scraper and the splines. 
     In some embodiments the material hardness of the protrusions is less than the material harness of the splines. This may prevent wear on the splines when the two surfaces are in contact. 
     In some embodiments the collector sump has a threaded portion that corresponds to a threaded portion of the central support. 
     In some embodiments the collector sump is shaped to collect debris from the splines that has been removed by the scraper. The collector sump may be shaped to enable the position of the engine to be in either the vertical or horizontal position. This does not restrict how the engine must be positioned. 
     In some embodiments the collector sump has a sealing lip that seals against the component of the gas turbine engine at a position adjacent the splines. The lip ensures all debris is collected in the sump and prevents loosened debris from ingress into the engine. This may prevent an additional engine clean operation. 
     In some embodiments the collector sump comprises a material that has a Shore hardness of about 70 A. This allows for the sump to be introduced into the engine past the splines and to provide an effective seal when in its final position. 
     In a second aspect there is provided a method for cleaning splines formed within a shaft of a gas turbine engine, the method comprising the steps of: providing the spline cleaning device of the first aspect; attaching the central support and the collector sump; and inserting the attached central support and the collector sump along the central axis of the engine beyond the female splines of the IPC coupling so that it covers the oil circulation holes; and attaching the scraper to the central support sleeve; and applying the central support sleeve over the central support and moving the central support sleeve in an axial direction so that the scraper engages with the female spline; and cleaning the female splines by moving the central support sleeve in an axial direction and rotating until all female splines have been cleaned. 
     The skilled person will appreciate that except where mutually exclusive, a feature or parameter described in relation to any one of the above aspects may be applied to any other aspect. Furthermore, except where mutually exclusive, any feature or parameter described herein may be applied to any aspect and/or combined with any other feature or parameter described herein. 
     The term “spline” as used herein means a series of uniform spaced ridges or grooves on a component that run parallel to the axis of the component. 
     Throughout this specification and in the claims that follow, unless the context requires otherwise, the word “comprise” or variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other stated integer or group of integers. 
     The skilled person will appreciate that except where mutually exclusive, a feature or parameter described in relation to any one of the above aspects may be applied to any other aspect. Furthermore, except where mutually exclusive, any feature or parameter described herein may be applied to any aspect and/or combined with any other feature or parameter described herein. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Embodiments will now be described by way of example only, with reference to the Figures, in which: 
         FIG.  1    is a sectional side view of a gas turbine engine, more particularly a geared turbofan aircraft engine; 
         FIG.  2    is a close-up sectional side view of an upstream portion of the gas turbine engine shown in  FIG.  1   ; 
         FIG.  3    is a partially cut-away view of a gearbox for the gas turbine engine show in  FIGS.  1  and  2   ; 
         FIG.  4    is a sectional view of gas turbine engine showing the auxiliary gearbox power offtake from the intermediate pressure compressor (IPC) coupling. 
         FIG.  5    is a close-up sectional view of the IPC coupling shown in  FIG.  4    showing the internal splines. 
         FIG.  6    is a view of the spline cleaning device of the present disclosure. 
         FIG.  7    is a sectional view of the spline cleaning device in situ with the internal splines of the IPC coupling. 
     
    
    
     The following table lists the reference numerals used in the drawings with the features to which they refer: 
     
       
         
           
               
               
               
             
               
                   
               
               
                 Ref no. 
                 Feature 
                 FIG. 
               
               
                   
               
             
            
               
                 A 
                 Core airflow 
                 1 
               
               
                 B 
                 Bypass airflow 
                 1 
               
               
                 9 
                 Principal and rotational axis (of engine) 
                 1, 2 
               
               
                 10 
                 Gas turbine engine 
                 1 
               
               
                 11 
                 Engine core 
                 1 
               
               
                 12 
                 Air intake 
                 1 
               
               
                 14 
                 Low pressure compressor 
                 1 
               
               
                 15 
                 High pressure compressor 
                 1 
               
               
                 16 
                 Combustion equipment 
                 1 
               
               
                 17 
                 High pressure turbine 
                 1 
               
               
                 18 
                 Bypass exhaust nozzle 
                 1 
               
               
                 19 
                 Low pressure turbine 
                 1 
               
               
                 20 
                 Core exhaust nozzle 
                 1 
               
               
                 21 
                 Fan nacelle 
                 1 
               
               
                 22 
                 Bypass duct 
                 1 
               
               
                 23 
                 Fan 
                 1, 2 
               
               
                 24 
                 Stationary supporting structure 
                 2 
               
               
                 26 
                 Shaft 
                 1, 2 
               
               
                 27 
                 Shaft 
                 1 
               
               
                 28 
                 Sun gear 
                 2 
               
               
                 30 
                 Epicyclic gearbox 
                 1, 2 
               
               
                 32 
                 Planet gear 
                 2 
               
               
                 34 
                 Planet carrier 
                 2 
               
               
                 36 
                 Linkage 
                 2 
               
               
                 38 
                 Ring gear 
                 2 
               
               
                 40 
                 Linkage 
                 2 
               
               
                 50 
                 Auxiliary gearbox 
                 4 
               
               
                 55 
                 Auxiliary gearbox drive shaft 
                 4 
               
               
                 60 
                 Intermediate pressure compressor (IPC) 
                 4, 5 
               
               
                   
                 coupling 
               
               
                 65 
                 Female spline 
                 5 
               
               
                 70 
                 Engine oil ways of IPC coupling 
                 5 
               
               
                 100 
                 Spline cleaning device 
                 6, 7 
               
               
                 110 
                 Central support 
                 6, 7 
               
               
                 112 
                 First end (of central support) 
                 6, 7 
               
               
                 113 
                 Threaded portion of central support 
                 6, 7 
               
               
                 114 
                 Second end (of central support) 
                 6, 7 
               
               
                 115 
                 Threaded nut 
                 6, 7 
               
               
                 120 
                 Central support sleeve 
                 6, 7 
               
               
                 122 
                 First end of central support sleeve 
                 6, 7 
               
               
                 124 
                 Second end of central support sleeve 
                 6, 7 
               
               
                 125 
                 Threaded portion of central support sleeve 
                 6, 7 
               
               
                 130 
                 Scraper 
                 6, 7 
               
               
                 132 
                 Central hub of scraper 
                 6, 7 
               
               
                 133 
                 Internal surface of central hub 
                 6, 7 
               
               
                 135 
                 Central hole of scraper 
                 6, 7 
               
               
                 137 
                 Lubrication port of scraper 
                 6 
               
               
                 140 
                 Collector sump 
                 6, 7 
               
               
                 141 
                 Sealing Lip 
                 6, 7 
               
               
                 143 
                 Threaded portion of collector sump 
                 6, 7 
               
               
                 145 
                 Central hole 
                 6, 7 
               
               
                 147 
                 Internal thread of central hole 
                 6, 7 
               
               
                 150 
                 Lubricant passageway 
                 6 
               
               
                 160 
                 Viewing aperture 
                 6 
               
               
                 180 
                 Arm portion of scraper 
                 6, 7 
               
               
                 190 
                 External circumferential surface 
                 6, 7 
               
               
                 192 
                 Protrusions 
                 6 
               
               
                   
               
            
           
         
       
     
     DETAILED DESCRIPTION 
     Aspects and embodiments of the present disclosure will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. 
     The present disclosure provides a spline cleaning device, for example, for cleaning splines formed within a shaft of a gas turbine engine.  FIGS.  1 ,  2  and  3    describe a gas turbine engine for which the spline cleaning device of the present disclosure is suitable for use, although the person skilled in the art would appreciate the spline cleaning device could be used to clean splines formed within a shaft of any gas turbine engine or indeed within a shaft of any machine or apparatus. 
     The geometry of the gas turbine engine  10 , and components thereof, is defined by a conventional axis system, comprising an axial direction (which is aligned with the rotational axis  9 ), a radial direction (in the bottom-to-top direction in  FIG.  1   ), and a circumferential direction (perpendicular to the page in the  FIG.  1    view). The axial, radial and circumferential directions are mutually perpendicular. 
       FIG.  1    illustrates a gas turbine engine  10  having a principal rotational axis  9 . The engine  10  comprises an air intake  12  and a propulsive fan  23  that generates two airflows: a core airflow A and a bypass airflow B. The gas turbine engine  10  comprises a core  11  that receives the core airflow A. The engine core  11  comprises, in axial flow series, a low pressure compressor  14 , a high-pressure compressor  15 , combustion equipment  16 , a high-pressure turbine  17 , a low pressure turbine  19  and a core exhaust nozzle  20 . A nacelle  21  surrounds the gas turbine engine  10  and defines a bypass duct  22  and a bypass exhaust nozzle  18 . The bypass airflow B flows through the bypass duct  22 . The fan  23  is attached to and driven by the low pressure turbine  19  via a shaft  26  and an epicyclic gearbox  30 . 
     In use, the core airflow A is accelerated and compressed by the low pressure compressor  14  and directed into the high pressure compressor  15  where further compression takes place. The compressed air exhausted from the high pressure compressor  15  is directed into the combustion equipment  16  where it is mixed with fuel and the mixture is combusted. The resultant hot combustion products then expand through, and thereby drive, the high pressure and low pressure turbines  17 ,  19  before being exhausted through the core exhaust nozzle  20  to provide some propulsive thrust. The high pressure turbine  17  drives the high pressure compressor  15  by a suitable interconnecting shaft  27 . The fan  23  generally provides the majority of the propulsive thrust. The epicyclic gearbox  30  is a reduction gearbox. 
     An exemplary arrangement for a geared fan gas turbine engine  10  is shown in  FIG.  2   . The low pressure turbine  19  (see  FIG.  1   ) drives the shaft  26 , which is coupled to a sun wheel, or sun gear,  28  of the epicyclic gear arrangement  30 . Radially outwardly of the sun gear  28  and intermeshing therewith is a plurality of planet gears  32  that are coupled together by a planet carrier  34 . The planet carrier  34  constrains the planet gears  32  to precess around the sun gear  28  in synchronicity whilst enabling each planet gear  32  to rotate about its own axis. The planet carrier  34  is coupled via linkages  36  to the fan  23  in order to drive its rotation about the engine axis  9 . Radially outwardly of the planet gears  32  and intermeshing therewith is an annulus or ring gear  38  that is coupled, via linkages  40 , to a stationary supporting structure  24 . 
     Note that the terms “low pressure turbine” and “low pressure compressor” as used herein may be taken to mean the lowest pressure turbine stages and lowest pressure compressor stages (i.e. not including the fan  23 ) respectively and/or the turbine and compressor stages that are connected together by the interconnecting shaft  26  with the lowest rotational speed in the engine (i.e. not including the gearbox output shaft that drives the fan  23 ). In some literature, the “low pressure turbine” and “low pressure compressor” referred to herein may alternatively be known as the “intermediate pressure turbine” and “intermediate pressure compressor”. Where such alternative nomenclature is used, the fan  23  may be referred to as a first, or lowest pressure, compression stage. 
     The epicyclic gearbox  30  is shown by way of example in greater detail in  FIG.  3   . Each of the sun gear  28 , planet gears  32  and ring gear  38  comprise teeth about their periphery to intermesh with the other gears. However, for clarity only exemplary portions of the teeth are illustrated in  FIG.  3   . There are four planet gears  32  illustrated, although it will be apparent to the skilled reader that more or fewer planet gears  32  may be provided within the scope of the claimed invention. Practical applications of a planetary epicyclic gearbox  30  generally comprise at least three planet gears  32 . 
     The epicyclic gearbox  30  illustrated by way of example in  FIGS.  2  and  3    is of the planetary type, in that the planet carrier  34  is coupled to an output shaft via linkages  36 , with the ring gear  38  fixed. However, any other suitable type of epicyclic gearbox  30  may be used. By way of further example, the epicyclic gearbox  30  may be a star arrangement, in which the planet carrier  34  is held fixed, with the ring (or annulus) gear  38  allowed to rotate. In such an arrangement the fan  23  is driven by the ring gear  38 . By way of further alternative example, the gearbox  30  may be a differential gearbox in which the ring gear  38  and the planet carrier  34  are both allowed to rotate. 
     The present disclosure concerns a spline cleaning device that is useful, for example, for cleaning splines formed in the inner surface of a gas turbine engine. 
       FIG.  4    is a cutaway view of the part of the gas turbine engine shown in  FIGS.  1 ,  2  and  3    that identifies the location of a component that has splines that can be cleaned by using the spline cleaning device of the present disclosure. That component is an IPC coupling  60 . 
       FIG.  5    is a close-up perspective view of the IPC coupling  60  shown in  FIG.  4   . It has splines  65  that can be cleaned by using the spline cleaning device of the present disclosure. 
     In operation the gas turbine engine  10  is required to provide mechanical drive to additional auxiliary components, for example fuel pump, hydraulic pumps, oil pumps. The gas turbine engine shown in  FIGS.  1  to  3    has an auxiliary gearbox  50  that provides mechanical drive to various units in the engine. The auxiliary gearbox is driven from an auxiliary gearbox drive shaft  55  that interfaces with the shaft  27  via the intermediate pressure compressor (IPC) coupling  60 . The IPC coupling  60  has female splines  65  that mate with male splines (not shown) on the shaft  27 . The IPC coupling  60  rotates with the shaft  27  and provides a mechanical drive to the auxiliary gearbox drive shaft  55  (through gears). Conversely, at engine start up the IPC coupling  60  is able to rotate the shaft  27  by driving the auxiliary gearbox through a variable frequency starter generator (VFSG). The IPC coupling  60  has oil ways  70  that allow oil to flow from the shaft to the engine. 
     During operation the female spline  65  of the IPC coupling  60  accrue debris such as swarf or burnt oil, this can result in excessive wear of the female splines  65  and the male splines as the debris acts as a grinding paste. Excessive wear may lead to the replacement of both the IPC coupling  60  and the shaft  27 . 
     In order to reduce wear of the IPC coupling  60  a method and device for cleaning debris from the female splines  65  is required that will enable the female splines to be cleaned without requiring the engine to be fully stripped. 
       FIG.  6    is a perspective view of a spline cleaning device of the present disclosure and  FIG.  7    is a sectional view of the spline cleaning device in situ within the IPC coupling  60  of the gas turbine engine  10 . 
     The spline cleaning device  100  has a central support  110 , a central support sleeve  120 , a scraper  130  and a collector sump  140 . 
     The central support  110  is elongate with a first end  112  and a second end  114 . In the embodiment shown, the central support  110  has a circular cross section and is hollow. The first end  112  of the central support has a threaded portion  113  to enable the collector sump  140  to be removably attached to the central support  110 . 
     The collector sump  140  prevents or at least minimises the ingress of debris into the engine oil ways  70  of the IPC coupling  60 . The collector sump is flexible to enable it to be introduced passed the splines into the component and to be expandable to create a seal between the collector sump and the IPC coupling. In the embodiment shown, the collector sump  140  is an ‘W’ section. This ‘W’ section allows for the use of the device to be in either of the horizontal or vertical planes. The collector sump has a central hole  145 , the central hole has an internal thread  147  by which the collector sump is attachable to the threaded portion of the first end of the shaft  112 . The collector sump can be made from any suitable material. In the embodiment shown the collector sump is produced from polyethylene. In the embodiment shown the collector sump has a Shore hardness rating of about 70 A, (the Shore A hardness scale measures the harness of flexible mold rubbers that range in hardness from very soft and flexible to hard with no flexibility. Shore hardness is measured with a Shore Durometer which is commercially available standard testing equipment). The collector sump can be made by any suitable method, for example it may be moulded. 
     The collector sump  140  is configured to be attachable to the first end  112  of the central support  110 . The collector sump  140  can be attached to the first end of the central support  110  in any suitable manner. The collector sump  140  may be permanently attached or removable attached to the central support  110  as desired. 
     In the embodiment shown, the first end  112  of the central support  110  has a threaded portion and the collector sump  140  has a corresponding threaded portion  143  and the collector sump is removably attachable to the central support  110 . This in part enables the spline cleaning device to be assembled when needed and dissembled and stored when not needed. 
     In other embodiments, a threaded nut  115  may be used to attach the collector sump  140  to the central support  110 . 
     The central support sleeve  120  has a first end  122  and a second end  124 . The central support sleeve  120  is a hollow section. In the embodiment shown, the first end  122  has a threaded portion to enable the scraper  130  to be attached to the central support sleeve  120 . The cross section of the central support sleeve  120  is the same as the central support  110 . The internal hollow section of the central support sleeve  120  is a clearance fit with the central support  110 . The clearance fit allows for the central support sleeve  120  to move relative to the central support  120  in an axial and radial direction. The central support sleeve  120  supports the scraper  130  and ensures that the scraper  130  is axially aligned with the central support  110  and the female splines  65 . 
     The scraper  130  has a central hub  132  and a central hole  135  that allows for the scraper to be positioned over the central support sleeve  120 . The scraper  130  is attachable to the first end  122  of the central support sleeve such that the scraper will move with the central support sleeve over the support shaft. The scraper  130  can be attached to the first end of the central support sleeve  120  in any suitable manner, for example the first end  122  of the central support sleeve  110  has a threaded portion ( 125 ) and the scraper  130  has a corresponding portion. The scraper  130  or at least the central hub  132  may have a circular cross-section. The scraper  130  has at least one, or ideally a plurality of protrusion  192  that extend form the external circumferential surface  190 , these protrusions  192  are configured to substantially correspond to the root and flanks of the female splines  65  of the IPC coupling  60 . The external circumferential surface is configured to substantially correspond to the face of the female splines  65 . In some embodiments, such as the one shown in  FIG.  6   , the scraper has arm portions  180  that extend from the central hub  132  and the protrusions  192  that engage the splines to be cleaned are formed at distal ends of those arm portions. The scraper  130  has at least two arm portions  180 . In the embodiment shown in  FIG.  6    the scraper has two arm portions are equally spaced around the axis of the central hub  132  such that the scrapper  130  is centralised around the axis. The equally spacing of the arm portions  180  allows for the acting forces to be equalised across the scraper helping the scraper to stay in contact with the female splines of the component and ensures that the spline cleaning device stays central to the cleaning axis. 
     The scraper  130  may have lubricant passageways  150  that extend from the central hub to the external circumferential surface  190 . The scraper  130  has lubrication ports  137  that extend into the lubricant passageways  150 . The lubricant passageways  150  are formed to receive fluid, such as a mobilising fluid e.g. acetone, and to transport the fluid to the circumferential surface. This mobilising fluid is used to aid the release of debris from the surface of the female spline  65  by partially dissolving the debris. 
     The scraper  130  may include viewing apertures  160 , these viewing apertures enable the female splines  65  to be seen when the scraper is in operation. In the embodiment shown the viewing apertures are formed in the central hub  132  of the scraper. 
     The proposed use of the spline cleaning device of the present disclosure and a method of using the spline cleaning device to clean splines of a gas turbine engine will now be described with reference to the embodiment shown in  FIGS.  6  and  7   . 
     The central support  110  and the collector sump  140  are assembled and fastened with the threaded nut  115 . Alternatively, the central support  110  and the collector sump  140  may be permanently attached. By allowing the components to be assembled allows for easy storage of the individual components. Having a permanently fixed assembly reduces time needed to assembly the components 
     The assembled central support  110  and collector sump  140  are inserted along the central axis of the gas turbine engine through the rear of the engine. 
     The collector sump  140  engages the engine beyond the spline  65  of the IPC coupling  60  and covering the oil circulation holes. 
     The scraper  130  is attached to the central support sleeve  120 . 
     The central support sleeve  120  is positioned over the central support  110 , so that the central support sleeve is free to slide and rotate around the support shaft. 
     The central support sleeve  120  is moved down the central support  110  until the protrusion  192  of the scraper engage with the female spline  65  of the IPC coupling. The central support sleeve  120  is moved with a reciprocating movement forward and aft in the axial direction through the IPC coupling  60  to remove surface debris from the female splines  65 . The central support sleeve  120  is moved to disengage with the female splines before being rotated and re-engaged with the female spline. The reciprocating and rotational movement of the central support sleeve is repeating until all female splines have been cleaned. 
     Optionally, flexible solvent pipes are inserted into the ports  137  of the scraper  130  solvent may be introduced into the flexible solvent pipes to the lubricant passageways  150 , to provide mobilising fluid to the surface of the internal splines  65   
     The central support sleeve  120  and scraper are removed along the axis of the engine. 
     Additionally, the female splines may be further swabbed to ensure that the female spines  65  are cleaned of all oil debris. Further the collector sump may be swabbed to remove oil debris prior to removal of the collector sump may be swabbed to be removed from the collector. 
     The additional steps include; 
     Attaching a swabbing head onto a secondary central support sleeve to form a swabbing head assembly. 
     Inserting the swabbing head assembly around central support  110  and passing it down the centre line. 
     Using the swab pads to clean the front and rear of the spline teeth and along the length, sides and crowns on the teeth. 
     Removing the swabbing head assembly and replacing the swabs and reinserting to continue cleaning, repeating until all debris is removed. 
     Removing the swabbing head assembly. 
     Removing the assembled central support  110  and collector sump  140 . 
     It will be understood that the invention is not limited to the embodiments above-described and various modifications and improvements can be made without departing from the concepts described herein. Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.