Abstract:
A pump of the rotor/stator type for wet cementitious material includes a suction housing for receiving and directing the material into a rotor/stator combination for delivery to the location of use. The suction housing is in the form of a rectangular closed structure having a material receiving flange and enclosing coupling between a drive shaft and an end of a rotor. The housing includes top, bottom and side panels, one of which includes the aforementioned material receiving flange. Each of the panels is easily removed from the suction housing to facilitate cleaning and removal of material residue after use, as well as maintenance and repair of the pump. Cementitious material may be introduced through either the top, bottom or either of the side panels by appropriate positioning of the material receiving flange. The pump further includes a lubricant reservoir for lubricating the drive shaft to extend pump operating lifetime.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates generally to pumps of the rotor/stator type such as used for cementitious material and is particularly directed to an improved suction housing and other improvements for use in a rotor/stator-type pump.  
       BACKGROUND OF THE INVENTION  
       [0002]     Pumps are commonly used for directing cementitious material, such as of the grouting type, to the location of use of the material. The cementitious material is typically transported and injected under pressure by means of a progressing cavity-type pump comprised of a helical rotor rotating within an elongated, contoured stator which is internally lined with an elastomer. A relatively compact, closed chamber known as a suction housing is disposed between and connects the input end of the rotor/stator combination with a conventional drive arrangement incorporating a motor with a rotationally displaced drive shaft. The closed suction housing is adapted to receive the wet cementitious material such as under a hydrostatic head and deliver it to the input end of the rotor/stator combination in a manner which eliminates the possibility of foreign material entering the pump during the pumping process. Pumps used for these applications are known as “closed throat” type pumps, and are available from various manufacturers. Pumps of this type direct the cementitious material to the location of application which frequently affords only limited accessibility.  
         [0003]     Referring to  FIG. 1 , there is shown a partially cutaway perspective view of a prior art rotor/stator pump  10  which the present invention provides various improvements over. The rotor/stator pump  10  is generally in the form of an elongated, hollow tube and includes an inlet/drive stage  14  and a pumping stage  17 . The inlet/drive stage  14  and pumping stage  17  are connected to various mounting/support brackets  11   a ,  11   b  and  11   c  which provide stable positioning for the rotor/stator pump  10  and allow it to be connected such as by bolts to a support structure which is not shown in the figure for simplicity. The inlet/drive stage  14  is comprised of a bearing housing  15  and a suction housing  19  which in the arrangement shown in  FIG. 1  is formed as a single cast piece preferably comprised of aluminum. Disposed within and extending from the bearing housing  15  is a drive shaft  18  which is connected to a source of rotary power which also is not shown in the figure for simplicity. Disposed about and engaging the drive shaft  18  within the bearing housing  15  is the combination of a thrust bearing  20  and a radial ball bearing  22  to facilitate rotational displacement of the drive shaft. Also disposed about and engaging the drive shaft  18  and located generally within the suction housing  19  is the combination of a packing gland  24 , packing  26  and a lantern ring  28  which form a seal between the suction housing and inlet/drive stage  14 . Other conventional components are disposed within bearing housing  15 , but are not discussed herein as these components are well known to those skilled in the relevant arts.  
         [0004]     Attached to the suction housing  19  is an apertured inlet flange, or collar,  16  through which a wet cementitious material is deposited into the suction housing for introduction into a stator frame, or transport tube,  12 . Cementitious material introduced into the suction housing  19  via inlet flange  16  typically flows under the influence of a hydrostatic head arising from the weight of the cementitious material. Drive shaft  18  is connected to an inner end hub of a rotor  32  within the suction housing  19  by means of a connecting rod  30 . Opposed ends of the connecting rod  30  are pivotally coupled to the drive shaft  18  and the inner end hub of rotor  32  in a pivoting manner which allows the rotor hub to follow an elliptical path as it is rotated by the drive shaft  18 . Connecting rod  30  thus imparts rotation to rotor  32 , while allowing the rotor hub to follow an elliptical path above the axis of rotation. As rotor  32  is rotationally displaced, cementitious material is drawn out of the suction housing  19  and into the space between the rotor  32  and stator  34  and is displaced along the rotor/stator combination for discharge through an aperture  36  in the distal end  12   a  of the stator frame  12 . A bolt  23  disposed in a lower portion of the suction housing  18 , when removed, allows for discharge during cleaning of residue remaining within the rotor/stator pump  10  following use. Cleaning of the rotor/stator pump  10  after each use is essential for continued pump operation because of the cementitious composition of the material introduced into and displaced by the pump, but is very difficult to carry out in this prior art pump.  
         [0005]     These types of pumps suffer from three basic recurrent problems. The problems arise from the limited access afforded by the pump&#39;s closed suction housing. First, pumps of this type are difficult to clean and maintain, as well as to disassemble for inspection or repair. For example, when the rotor is turning, its hub describes an elliptical path. Thus, a connection between the rotor&#39;s hub and an input drive shaft requires that this type of motion be accommodated. In the standard pump design, this is accomplished by means of a connecting rod disposed within a tubular drive shaft, one end of which is pinned to an end of the tubular drive shaft, while a second opposed end of the connecting rod is pinned to an end of the rotor hub. The connecting rod imparts rotation to the rotor, while also describing the elliptical path of the rotor hub. The standard design leaves the end of the drive shaft open and exposed to the product being pumped. This allows some of the product deposited in the suction housing to enter an end of the drive shaft. Because the product is a cementitious material, it often forms a solid mass within the drive shaft. This renders the connecting rod immobile resulting in excessive stator wear, and makes disassembly of the pump for inspection and/or maintenance difficult, if not impossible. This unfortunate situation also invariably results in reduced pump operating lifetime.  
         [0006]     The present invention addresses the aforementioned limitations of the prior art by providing an improved suction housing for a rotor/stator pump used with cementitious materials which is easily disassembled to facilitate cleaning, inspection and repair of the pump. This invention also contemplates additional improvements which increase the reliability and prolong the operating lifetime of these types of pumps.  
       OBJECTS AND SUMMARY OF THE INVENTION  
       [0007]     Accordingly, it is an object of the present invention to provide an improved pump for cementitious material which is easily cleaned and repaired, has an increased operating lifetime, and is of simplified design and construction.  
         [0008]     It is another object of the present invention to provide a suction housing for a rotor/stator pump which is easily disassembled to provide access to a drive shaft/rotor combination to facilitate pump cleaning and repair.  
         [0009]     Yet another object of the present invention is to provide lubrication for the moving parts of a rotor/stator pump for increasing pump reliability and extending its operating lifetime.  
         [0010]     A still further object of the present invention is to provide increased operating flexibility for a rotor/stator pump such as for cementitious materials for use in a wide range of operating environments.  
         [0011]     This invention contemplates an improved suction housing for use in a progressing cavity pump of the rotor/stator type having removable panels which facilitates cleaning and maintenance of the pump as well repair or replacement of worn or damaged pump components. This invention further contemplates lubricating the pump&#39;s drive shaft for improved pump reliability and longevity, while allowing cementitious material to be delivered to the location of application with greater positioning flexibility than heretofore available. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The appended claims set forth those novel features which characterize the invention. However, the invention itself, as well as further objects and advantages thereof, will best be understood by reference to the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings, where like reference characters identify like elements throughout the various figures, in which:  
         [0013]      FIG. 1  is a partially cutaway perspective view of a prior art rotor/stator pump;  
         [0014]      FIG. 2  is a partially cutaway and exploded perspective view of a rotor/stator pump in accordance with the principles of the present invention;  
         [0015]      FIG. 3  is a longitudinal sectional view of the inventive rotor/stator pump shown in  FIG. 2 ;  
         [0016]      FIG. 4  is an upper perspective view of a suction housing for use in a rotor/stator pump in accordance with one aspect of the present invention, where one of the suction housing&#39;s cover plates has been removed to illustrate additional details of the invention;  
         [0017]      FIG. 5  is a partial sectional view of the inventive rotor/stator pump illustrating details of the manner in which a sealed connection is provided between the pump&#39;s drive shaft and the rotor&#39;s hub; and  
         [0018]      FIG. 6  is a sectional view shown partially in phantom of the suction housing contemplated for use in a rotor/stator pump in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]     Referring to  FIG. 2 , there is shown a partially cutaway and exploded perspective view of a rotor/stator pump  50  in accordance with the principles of the present invention.  FIG. 3  is a longitudinal sectional view of the inventive rotor/stator pump  50  shown in  FIG. 2 , while  FIG. 4  is a perspective view of the inventive rotor/stator pump illustrating additional details of its suction housing  56  and lubricant reservoir  66 .  
         [0020]     As in the previously described prior art approach, rotor/stator pump  50  includes a stator frame  52  and a bearing housing  60 . The rotor/stator pump  50  includes plural pump mounting/support brackets  58 , although only one such bracket is shown in  FIG. 2  for simplicity. The pump mounting/support bracket  58  is attached to the bearing housing  60  by conventional means such as a clamping structure with attaching bolts as shown in  FIG. 2 . Disposed between and attached to the stator frame  52  and bearing housing  60  is a suction housing  56 . Suction housing  56  is attached to a first input end of the stator frame  52  by means of a threaded end portion  52   a  on the stator frame. Suction housing  56  is further connected to an end of the bearing housing  60  by means of a coupling flange  82  as described in detail below.  
         [0021]     Stator frame  52  and bearing housing  60  and the contents thereof are conventional in design and operation. Thus, stator frame  52  has an inner surface in the form of a stator  52   b  incorporating an elastomer and a rotor  54  disposed within the stator frame and extending the length thereof. Bearing housing  60  has disposed therein and extending the length thereof a drive shaft  64 . Attached to one end of drive shaft  64  is an adapter  62  for facilitating attachment of the drive shaft to conventional rotary drive means such as an electric, gas or hydraulic motor. Disposed within the bearing housing  60  and engaging the drive shaft  64  are various conventional components to facilitate rotational displacement of the drive shaft within the bearing housing such as previously described with regard to the prior art rotor/stator pump  10  of  FIG. 1  as well as a shaft collar  94  and a packing gland  96  as shown in  FIG. 2 .  
         [0022]     Suction housing  56  includes a front panel  70   a  and a back panel  70   b  having attached thereto the aforementioned coupling flange  82  as shown in  FIG. 4 . Coupling flange  82  is securely connected in a sealed manner to an end of the bearing housing  60  by conventional means such as plural nut and bolt combinations, where only three such combinations are shown in the figures as elements  98 ,  100  and  102 . Suction housing  56  further includes first and second side panels  72   a  and  72   b , and top and bottom panels, where the top panel is shown as element  74   a . Suction housing  56  is generally rectangular in shape, with each of the first and second side panels  72   a ,  72   b  and top and bottom panels including a respective generally circular aperture therein. Thus, as shown in  FIGS. 2 and 3 , the first side panel  72   a  includes aperture  76 , while as shown in  FIG. 4  top panel  74   a  includes aperture  78 . Each of the aforementioned panel apertures allows for access to the inner portion of the suction housing  56  and the various components disposed therein to facilitate cleaning of the rotor/stator pump  50  and/or repairing or replacing pump components when needed. Each of the first and second side panels  72   a ,  72   b  and top and bottom panels includes plural threaded pins therein for attaching a cover plate to the panel. Thus, as shown in  FIGS. 2 and 3 , the first side panel  72   a  includes four threaded mounting pins  80   a - 80   d . Similarly, as shown in  FIG. 4 , the top panel  74   a  includes four threaded mounting pins  79   a - 79   d . Each of the aforementioned sets of threaded mounting pins on a respective panel allows a cover plate to be attached to the panel so as to cover the generally circular aperture in the panel and render the suction housing  56  fully enclosed and sealed. Thus, each of four apertures within a first side cover plate  84   a  is adapted to receive one of the respective mounting pins  80   a - 80   d  for positioning the cover plate on the panel. First through fourth threaded connectors  88   a - 88   d  are respectively adapted to engage the first through fourth mounting pins  80   a - 80   d  for securely attaching the first cover plate  84   a  on the first side panel  72   a  in a sealed manner. Similarly, four threaded mounted pins  79   a - 79   d  disposed on the top panel  74   a  are adapted for insertion within respective apertures in a top cover plate  86   a  for secure attachment to the top panel by means of four threaded connectors  90   a - 90   d . A second side cover plate  84   b  and a bottom cover plate  86   b  are similarly adapted for attachment to the second side panel  72   b  and the bottom panel, respectively, in a sealed manner.  
         [0023]     Referring to  FIG. 5 , there is shown additional details of the manner in which an intermediate portion of a drive shaft  124  is connected to the hub  126   a  of a rotor  126  in a sealed manner in accordance with another aspect of the present invention.  FIG. 5  is a sectional view of the suction housing  120  taken along the longitudinal center axis A-A′ shown in  FIG. 3  of the rotor/stator pump within which the suction housing is disposed. Shown in  FIG. 5  is a suction housing  120  in accordance with another aspect of the present invention having an inlet tube  122  attached to a lower portion of the housing to facilitate introduction of cementitious material in the suction housing. Suction housing  120  also includes a side panel  132  having a generally circular aperture  132   a  therein. The intermediate portion of drive shaft  124  is connected to rotor hub  126   a  located on the end of rotor  126  by means of the combination of a connecting rod  130  and a connecting rod  128 . Connecting rod  128  is also connected to the end of intermediate portion of drive shaft  124  by means of a second connecting pin  136  shown in the figure in dotted line form. As described above, as the rotor turns, the rotor&#39;s hub  126   a  moves in an elliptical path in a plane transverse to the longitudinal axis of the rotor/stator pump. This dual connecting pin coupling arrangement between the rotor&#39;s hub  126   a , connecting rod  130  and the intermediate portion of drive shaft  124  allows for elliptical displacement of the rotor&#39;s hub. The off-axis positioning of the connection between the intermediate portion of the drive shaft  124  and the rotor&#39;s hub  126   a  is shown in  FIG. 3 , where the connecting pin  112  between the rotor&#39;s hub and the connecting rod  30  is shown disposed below the longitudinal axis center A-A′ of the rotor/stator pump.  
         [0024]     Also in accordance with the present invention, there is shown in  FIG. 5 a  shaft sealing gasket  134  disposed about adjacent portions of the rotor&#39;s hub  126   a  and the intermediate portion of drive shaft  124 . The end of the shaft sealing gasket  134  is securely positioned over a drive shaft slot  138  within the suction housing  120  and enclosing the intermediate portion of drive shaft  124 . Shaft sealing gasket  134  prevents cementitious material deposited in the suction housing  120  from entering an end slot  126   b  within the rotor&#39;s hub  126   a  and from coming in contact with various pump components such as connecting pin  130  and connecting rod  128  connecting the intermediate portion of drive shaft  124  to the rotor&#39;s hub. Thus, this connection between the intermediate portion of drive shaft  124  and the rotor&#39;s hub  126   a  does not have to be cleaned out after each use of the rotor/stator pump. This sealed arrangement for the aforementioned drive components of the rotor/stator pump also increases the reliability and prolongs the operating lifetime of the rotor/stator pump.  
         [0025]     Referring to  FIG. 6 , there is shown a sectional view of suction housing  140  in accordance with the present invention illustrating additional features of the suction housing. Suction housing  140  includes a side panel  142  having a generally circular aperture  142   a  therein as previously described. Each of the top and bottom as well as the two lateral surfaces of the suction housing  140  are provided with four threaded slots for receiving threaded mounting pins for attaching a respective cover plate to each of these outer surfaces of the suction housing. Four of these threaded slots  146   a - 146   d  are shown in dotted line form in the sectional view of  FIG. 6 . Also, a front portion of the suction housing  140  is provided with an enlarged threaded aperture  144  for receiving a threaded end of the stator frame which is not shown in the figure for simplicity.  
         [0026]     Disposed on an aft portion of suction housing  140  is a coupling flange  150  for connecting the suction housing to a bearing housing also as previously described. Plural threaded slots  152   a ,  152   b  and  152   c  are provided in the coupling flange  150  for connecting the suction housing  140  to the bearing housing (not shown for simplicity). A fourth threaded slot is provided in the coupling flange  150  for this purpose, but is not shown in  FIG. 6  for simplicity. Also disposed within the coupling flange  150  is a larger, generally circular slot  156 , within which the drive shaft is disposed and which is adapted for also receiving aforementioned conventional components such as a lantern ring and packing rings for forming a seal between the suction housing  140  and a bearing housing to which it is attached. To facilitate rotation of a drive shaft extending through these various sealing components within the coupling flange&#39;s circular slot  156 , a lubricant reservoir  160  is connected to the coupling flange  150  by means of a threaded connection. Lubricant reservoir  160  includes a connecting tube  160   a  having a threaded distal end to facilitate connection to a lubricant slot  154   a  within the coupling flange  150 . Three additional lubricant slots are provided for within the coupling flange  150  to accommodate various orientations of the suction housing  140  during operation, where two of these additional lubricant slots are shown as elements  154   b  and  154   c  in  FIG. 6 . Lubricant reservoir  160  is disposed on an upper portion of the coupling flange  150  to allow lubricant to flow into the coupling flange&#39;s circular slot  156  during pump operation. Lubricant reservoir  160  provided lubricant to the aforementioned sealing components such as the lantern and packing rings to facilitate rotation of the drive shaft within the suction housing&#39;s coupling flange  150 . Elongated, linear slots  158  in the coupling flange  150  are each aligned with a respective lubricant slot to permit lubricant to be distributed over the full width of the lantern ring and plural adjacent packing rings. Finally, a threaded member such as a bolt is inserted in each of the lubricant slots not connected to the lubricant reservoir  160 , as shown for the case of threaded member  162  connected to lubricant slot  154   b , to prevent leakage of lubricant from the suction housing&#39;s coupling flange  150 .  
         [0027]     While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the relevant arts that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.