Abstract:
A replaceable motor module for a groundwater sampling device including an inner housing defined by a cylindrical shape and having a first alignment pin. A DC-operated electric motor is positionable within the inner housing, and includes a first set of electrical input terminals, an output shaft capable of downwardly extending through a sealed hole in the inner housing, and a first alignment groove for mating with the first alignment pin of the inner housing. An inner housing cap includes a second set of electrical input terminals and electrical output terminals, and is pressingly engageable with the inner housing.

Description:
FIELD OF THE INVENTION 
     The present invention relates to sampling devices and pumps for the gathering or recovery of liquid samples from groundwater or other liquid bodies. 
     BACKGROUND OF THE INVENTION 
     Submersible pumps, supported by electrical leads and one or more conduits for fluid flow, may be descended into a pre-established well or other water source. The electrical leads provide a means to control the submersible pump, and the liquid conduit provides means to transfer the liquid from the source to the surface for removal or further analysis. A submersible pump of this type is described in U.S. Pat. No. 7,584,785 to Intelisano, the contents of which patent are hereby incorporated by reference. 
     One known use of submersible pumps is the testing for, and removal of, contaminants found in liquid bodies. The removal of subsurface contaminants that exist in aquifers and other water sources remains a high national priority. Contaminants of concern span various man-made volatile organic compounds such as chlorinated hydrocarbons and chlorinated olefins (i.e., tetrachloroethylene, trichloroethylene, cis 1,2-dichloroethane and vinyl chloride). Other compounds of interest include, e.g., aromatic or polyaromatic ring compounds such as benzene, toluene, methylbenzene, xylenes, and naphthalene. 
     Submersible pumps are subject to potential mechanical failure due to design inefficiencies (e.g., overheating failures related to an inability to effectively dissipate pump heat generation), as well as due to the harsh environmental conditions encountered in subterranean atmospheres (e.g., system strain due to significant turbidity). Maintenance or replacement of the submersible pump assembly can be disruptive as it may cause significant downtime. Moreover, replacement of the entire pumping assembly, typically required upon failure of the pump motor, may be costly. 
     Accordingly, there exists a need for a submersible pump for, e.g., groundwater sampling, which is readily serviceable by the quick and convenient removal and replacement of the motor contained therein and for enhanced flow and cooling characteristics around the motor for extended life. 
     SUMMARY OF THE INVENTION 
     Aspects of the present invention relate to submersible pumps for withdrawing water from a water source. 
     In accordance with one aspect of the present invention, a replaceable motor module for a groundwater sampling device is disclosed. The replaceable motor module includes an inner housing. The inner housing is defined by a cylindrical shape and has a first alignment pin. A DC-operated electric motor is positionable within the inner housing. The DC-operated electric motor includes a first set of electrical input terminals, an output shaft capable of downwardly extending through a sealed hole in the inner housing, and a first alignment groove capable of mating with the first alignment pin. An inner housing cap including electrical output terminals and a second set of electrical input terminals is pressibly engageable with the inner housing. 
     In an exemplary embodiment, a method of assembling a groundwater sampling device is provided. The method includes aligning an alignment groove of an inner housing comprising a DC-operated electric motor within said inner housing, the motor including a first set of electrical input terminals and an output shaft downwardly extending through a sealed hole in the inner housing, with an alignment pin of an inner housing cap comprising a second set of electrical input terminals and electrical output terminals. The method further includes fixedly securing the inner housing to the inner housing cap. 
     In another embodiment, a motor module cap for a replaceable motor module for a groundwater sampling device is provided. The motor module cap includes an output cap having a fluid conduit, a first set of lead bores for receiving electrical leads and a first plurality of holes for receiving an equal number of fasteners. A compression disc is substantially annular in shape, and includes a second set of lead bores for receiving electrical leads and a second plurality of holes for affixing the compression disk to the output cap, the second set of lead bores having a diameter equal to or less than the diameter of the first set of lead bores. The compression disc is affixed to the output cap such that the first set of lead bores is in alignment with the second set of lead bores and the first plurality of holes is in alignment with the second plurality of holes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is best understood from the following detailed description when read in connection with the accompanying drawings, with like elements having the same reference numerals. When a plurality of similar elements are present, a single reference numeral may be assigned to the plurality of similar elements with a small letter designation referring to specific elements. When referring to the elements collectively or to a non-specific one or more of the elements, the small letter designation may be dropped. This emphasizes that according to common practice, the various features of the drawings are not drawn to scale unless otherwise indicated. On the contrary, the dimensions of the various features may be expanded or reduced for clarity. Included in the drawings are the following figures: 
         FIG. 1  is a simplified pictorial view of the system of the invention; 
         FIG. 2  is a perspective view of a groundwater sampling device and the associated above-ground electrical conduit reel apparatus; 
         FIG. 3  is a perspective view of the power booster/controller of the system; 
         FIG. 4  is a three dimensional exploded view of an exemplary groundwater sampling device in accordance with aspects of the present invention; 
         FIG. 5  is a three dimensional view of a motor module cap for a replaceable motor module for a groundwater sampling device in accordance with aspects of the present invention; 
         FIG. 6  is a three dimensional view of a motor module cap for a replaceable motor module for a groundwater sampling device in accordance with aspects of the present invention; 
         FIGS. 7A and 7B  are three dimensional perspective views of a contact block for a groundwater sampling device in accordance with aspects of the present invention; and 
         FIG. 8  is a cross-sectional view of an exemplary groundwater sampling device in accordance with aspects of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The various aspects of the present invention relate generally to a replaceable motor module for a groundwater sampling device. Referring now to the drawings,  FIGS. 1, 2, and 3  illustrate the basic characteristics of the inventive system, which includes water sampling device  100  in the form of a submersible groundwater pump, an electrical conduit reel apparatus  14  which interconnects a voltage controller/booster device  16  to the water sampling device  100 , and further includes a sample vial  18  into which the groundwater is pumped out of a pre-established well W through water conduit  22  for collection. 
     The device  100  is described in more detail below and is positionable within the well W formed into the ground below grade level G. The depth of device  100  is controlled primarily by the feeding of the electrical conduit  20  from reel apparatus  14 . The system voltage/current controller/booster  16  includes a connection to electrical conduit  20  through the attachment of the fitting  32  to the mating fitting  28  connected to reel apparatus  14 . Electrical contacts  34 , which are attachable to the terminals of a low voltage d.c. electrical power source such as a 12-volt battery, provide the power input into controller  16 . By the adjustment of the variable voltage adjuster  36 , which is monitored by the liquid crystal display  38 , voltage output from controller  16  into the motor module contained within device  100  is provided. 
     Controller  16  inputs direct current from the 12-volt battery and produces an output voltage to run device  100  within specified parameters. Controller  16  boosts the voltage up to 40 volts and then, using a buck converter, puts out a selected fixed voltage to the pump to operate device  100  at the selected parameters. Consideration is given to the effective wire loss to maximize water output or pressure head that can be pumped. 
     When device  100  is activated, groundwater is forced upwardly through flexible conduit  22 , through a disposable valve  24  for dispensing a controlled volume of groundwater into a VOA vial  18 . Alternatively, the system  10  may be used to simply evacuate groundwater from a pre-established well W, in which case the upper end of conduit  22  is directed to discharge the groundwater into, e.g., a suitable container or an above-ground basin. Embodiments of system  10  are currently available commercially through Proactive Environmental Products of Bradenton, Fla. 
     Turning next to  FIG. 4 , an exemplary groundwater sampling device  100  is provided in more detail. Unless otherwise provided, the components of device  100  are generally formed (e.g., machined and/or molded) of substantially non-corrosive material, such as PVC, polyethylene, polypropylene, ABS, TEFLON® or stainless steel. An outer cylindrical housing  102  formed of such material and having thin walls and a hollow interior includes threads for mating with bottom portion  104 . The mating of outer housing  102  and bottom portion  104  is made water-tight through the incorporation of an o-ring  108 , which is seated on bottom portion  104 . Bottom portion  104  may be formed as a segment sphere (or it may be flat) and includes, at the distal end of bottom portion  104 , a filter screen  106 , which includes one or more inlet ports arranged as shown or in other configurations as would be apparent to one of ordinary skill in the art. Filter screen  106  leads to an interior chamber  110  into which groundwater is drawn. 
     Interior chamber  110  is defined by a circumferential ridge  107  on bottom portion  104 . Grooves  105  are arranged on the proximal most edge of circumferential ridge  107 . Circumferential ridge  107  of bottom portion  104  abuts the base  114  of the inner housing  112 . As will be described in greater detail below, grooves  105  permit the flow of fluid from the interior chamber  110  to a clearance gap  125  between inner housing  112  and outer housing  102 . 
     Seated within the hollow interior of outer housing  102  is inner housing  112  having a cylindrical tubular shape (i.e., having a hollow interior similar to outer housing  102 ). Base  114  of inner housing  112  includes an opening containing an annular seal  116 . Annular seal  116  receives an output shaft  118  of a d.c. motor  120  upon placement of d.c. motor  120  within inner housing  112 . A water impeller  122  is attached to output shaft  118  and resides, upon assembly, within or above interior chamber  110  and above filter screen  106 . A clearance gap  125  is established between the inner diameter of outer housing  102  and the outer diameter of inner housing  112  to define a water passageway or “jacket” through which fluid can upwardly travel towards an output cap  170  containing a fluid conduit  172 . 
     The top of motor  120  includes two electrical input terminals  124  which receive d.c. current and voltage from controller  16  through electrical conduit  20  as will be described in more detail below. A thin plastic disc  127  is fastened to motor  120  by electrical input terminals  124  and acts as a quality control device which indicates tampering with motor  120 . Thin plastic disc  127  also eliminates electrical interference between motor  120  and the output contact blocks  142 . 
     Referring back to  FIG. 4 , output shaft  118  passes through an annular spacer  126 , which is positioned below the bottom of motor  120  and inside of inner housing  112 . Annular spacer  126  further contains an opening  130  for receiving an alignment pin  128 . Turning briefly to  FIG. 8 , alignment pin  128  is fixedly attached to base  114  of inner housing  112 , passes through opening of annular sparer  126 , and is received by an aperture  132  of motor  120 . Alignment pin  128  establishes the proper rotational alignment and immobilization between motor  120  and inner housing  112 . In one embodiment, springs  134  may exert an upward force upon annular spacer  126  to further stabilize motor  120  and to keep electrical inputs  124  in contact with the d.c. power source. 
     An inner housing cap  136  may include one or more o-rings  135  (three are shown in  FIG. 4 ) positioned at the base (i.e. proximal) portion  138  of inner housing cap  136 . Inner housing cap  136 , forms a water-tight seal with inner housing  112  by way of o-rings  135  after base  138  is inserted into inner housing  112 . Preferably, a proper rotational alignment is established between inner housing cap  136  and inner housing  112  in order to align protrusions  137  on inner housing with receiving gaps  141 . In one embodiment, upon the mating of protrusions  137  with receiving gaps  141 , an inward force applied to protrusions  137 , such as provided by a pneumatic press, engages protrusions  137  with receiving gaps  141 , thereby fixedly attaching inner housing cap  136  to inner housing  112 . Alternatively, protrusions  137  can extend radially towards the longitudinal axis of inner housing  112  such that protrusions  137  snap into receiving gaps  141 . 
     The proper rotational alignment between inner housing cap  136  and inner housing  112  may also be established by way of a cap alignment pin  139 , which may be located on base portion  138 , and an inner housing notch  140 , located at the top of inner housing  112 . In one embodiment, cap alignment pin  139  mates with inner housing notch  140 . One of ordinary skill in the art will understand that other arrangements may be used to establish alignment and connection between inner housing  112  and inner housing cap  136  (such as, e.g., reversing the above described embodiment by providing a notch on inner housing cap  136  and an alignment pin at the top of inner housing  112 ). 
     Proper rotational alignment permits mechanical and electrical contact between electrical input terminals  124  of d.c. motor  120  and two output contact blocks  142 . Output contact blocks  142  may be seated within slots formed into a non-conductive accurately configured spacer  144 , which itself is held in position inside of base portion  138  by threaded fasteners  143 . 
     Input contact blocks  146  may be similarly seated into slots formed into a non-conductive spacer  148  which, as shown in  FIG. 4 , may be positioned inside the distal portion of inner housing cap  136 . Electrical and mechanical contact may be established between input contact blocks  146  and output contact blocks  142  by way of an electrical conduit, shown in  FIG. 4  as two wire portions  150 . 
     Output cap  170 , also formed of machined material, includes outwardly extending pins  174  which lockably engage into L-shaped slots  152  formed into inner housing cap  136 . Following axial movement together with the pins  174  properly aligned with the longitudinal portions of these L-shaped slots  152 , a simple twisting action seals and locks output cap  170  into engagement with the upper end of inner housing cap  136 . Upon reading the teachings contained herein, other manners of attaching output cap  170  and inner housing cap  136  will become apparent to those having ordinary skill in the art. 
     Output cap  170  further includes, at a base portion  175 , a plurality of o-rings  177  that allow a water-tight seal between output cap  170  and inner housing cap  136  upon lockably engaging these two components. Within base portion  175 , output contact blocks  176  may be seated within slots formed into a non-conductive accurately configured spacer  178 . Configured spacer  178  is held in position inside of base portion  175  by threaded fasteners  179 . Electrical and mechanical contact between output contact blocks  176  and input contact blocks  146  is established as a result of lockably engaging output cap  170  and inner housing cap  136 . 
     At distal portion of output cap  170 , a fluid output passage  184  is a longitudinal passage within output cap  170  which is in fluid communication with fluid conduit  172 . In one embodiment, fluid conduit  172  radially extends from the base of fluid output passage  184  (i.e., fluid flows into fluid conduit  172  in a radial direction towards fluid output passage  184 , at which point the fluid flow is re-directed longitudinally upwards towards the distal portion of output cap  170 ). In  FIG. 4 , fluid conduit  172  includes a series of radial passageways which intersect with fluid output passage  184 . Turning briefly to  FIG. 5 , an alternative embodiment is shown in which fluid conduit  272  penetrates completely through output cap  270 , forming an “hour glass” shape in which the circumference of the fluid passage (on both sides of output cap  270 ) is gradually restricted until intersecting with fluid output passage  284  at the center point of the hour glass. The hour glass configuration, which is incorporated in, e.g., the SS Mega-Typhoon® and the SS Mini-Monsoon®, available commercially from Proactive Environmental Products of Bradenton, Fla., provides increased head pressure and, accordingly, an increased flow rate. Additionally, this configuration facilitates cleaning this region. 
     Returning to  FIG. 4 , also at distal portion of output cap  170 , two longitudinal bores  188  provide access to output contact blocks  176 . Electrical conduit  20 , shown specifically in this case as electrical leads  186 , passes through longitudinal bores  188 . Preferably, the ends of electrical leads  186  are stripped of insulation to expose the conductive interior wiring and then affixed (e.g., clamped, soldered, or otherwise mechanically attached) within mating holes formed into output contact blocks  176 . In one embodiment, additional deterrence of fluid flow into bores  188  is accomplished through the use of one or more o-rings positioned around electrical leads  186 . As shown, a configuration having an o-ring  190  above a spacer  192 , which is above a second o-ring  194 , is employed for each lead  186 . Preferably, o-ring  190 , spacer  192 , and second o-ring  194  surround each lead  186  within bores  188 . 
     Further ensuring against fluid access to interior electrical components via bores  188 , each contact block (i.e. output contact blocks  176 , input contact blocks  146 , and output contact blocks  142 ) may be machined such that only a partial bore is created for receiving the electrical conduit and for receiving fasteners. That is, in this alternative embodiment of the invention, no contact block contains a bore which passes completely through the contact block. An exemplary contact block incorporating these “partial” bores is shown in  FIGS. 7A and 7B . Partial bore  701  receives a lead, which is fastened into place via, e.g., spot welding or a threaded fastener which biases the lead at partial bore  703 . Partial bore  705  receives a threaded fastener (such as, e.g., threaded fastener  143 ), which secures contact block  700  to the overall structure. 
     Returning to  FIG. 4 , an annular compression disc  196  is fastened to the distal portion of output cap  170  by way of one or more fasteners  195  which penetrate through compression disc  196  and into output cap  170 . Compression disc  196  further includes two longitudinal bores  198 , which have a relatively smaller circumference than longitudinal bores  188 . By this smaller circumference, compression disc  196  compresses o-ring  190 , spacer  192 , and second o-ring  194  within bores  188 . While not intending to be limited to a single theory, it is believed that this arrangement provides a uniform distribution of downward pressure upon d.c. motor  120 , thereby acting as a harmonic balancer by minimizing resonance from the operation of d.c. motor  120 . 
     A conduit nipple  199  passes through the annular portion of compression disc  196  and into output cap  170 , threadably mating with threads contained therein. An extension conduit in the form of flexible tubing (not shown) may then be mounted on conduit nipple  199 , thereby obtaining access to fluid output passage  184 . In one embodiment, conduit nipple  199  comprises a single “mushroom head” configuration in which a single circumferential protrusion  201  allows easy removal and fitting of the flexible tubing fluid conduit. Other configurations of conduit nipple  199  are within the grasp of the ordinarily skilled artisan, such as, e.g., multiple circumferential protrusions  201 (known as a “barb” tip). 
     The completed device  100  is assembled, upon locking together output cap  170  and inner housing cap  136  (i.e., after inner housing cap  136  is fixedly attached to inner housing  112  as described above), by threadably engaging threads  180  on output cap  170  with mating threads  103  formed into the upper end of outer housing  102 . One of ordinary skill will appreciate that other means exist to securing output cap  170  to outer housing  102 , including an adaptation of the locking configuration described above for locking output cap  170  to housing cap  136 . One or more o-rings  182  placed on the outer periphery of output cap  170  (e.g., proximal to threads  180 ) creates a water-tight seal with outer housing  102 . By this arrangement, electrical power flows from controller  16  through electrical conduit  20  to output contact blocks  176 , input contact blocks  146 , output contact blocks  142  and, finally, to input terminals  124 , which provides power directly to d.c. motor  120 . 
     Fluid passes through filter screen  106  into inner chamber  110  of bottom portion  104 , drawn into the groundwater sampling device by water impeller  122  upon rotation of output shaft  118  by motor  120 . From the inner chamber  110 , fluid passes through grooves  105 , advantageously increasing the pressure of the fluid stream, and into a clearance gap  125 . Clearance gap  125  is established by diameter selection between the inner diameter of outer housing  102  and the outer diameter of inner housing  112 . Clearance gap  125  defines a water passage which upwardly receives groundwater in the direction of the arrows towards output cap  170  and fluid conduit  172 . Water drawn in this fashion will proceed through conduit nipple  199  to attached flexible tubing leading to the surface (not shown). 
     Simple replacement of d.c. motor  120  may be accomplished by: a) unscrewing output cap  170  from outer housing  102 ; b) removing impeller  122  from output shaft  118 ; c) unlocking (by twisting, and then pulling) output cap  170  from inner housing cap  136 ; and d) the disposable sub-assembly includes inner housing cap  136  fixedly attached to inner housing  112  (which includes, inter alia, the spent d.c. motor  120 ). The procedure is reversed to install the new sub-assembly containing a new d.c. motor  120 . 
     Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.