Patent Publication Number: US-2023160397-A1

Title: Self-priming assembly for use in a multi-stage pump

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/773,110 filed on Jan. 27, 2020, which claims priority under 35 U.S.C. § 119 to U.S. Provisional Application No. 62/796,743 filed on Jan. 25, 2019, the entire disclosures of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     In many fluid pumping applications it may be useful to have a self-priming multistage pump. Present approaches to priming a multi-stage pump incorporate secondary equipment. For instance, a separate diaphragm pump or a compressed air powered venturi/vacuum pump can be employed to prime the multi-stage pump. However, these types of systems not only require additional components, but can be costly and complex. Therefore, a self-priming pump that engages in the pumping action when called upon without requiring extensive secondary equipment or intervention by an operator to prime the pump is a more efficient approach to establishing prime and engaging the pumping action. 
     SUMMARY 
     The invention relates to multi-stage pumps and methods. Specifically, the invention relates to a self-priming assembly for use in multi-stage pumps. 
     Some embodiments provide a self-priming assembly for a multi-stage pump. The self-priming assembly includes a first diffuser with a first central portion, a first diffuser axis, a first arcuate channel within the first central portion, and a first arcuate passage extending through the first central portion and a first peripheral portion having a first ledge. The self-priming assembly also includes a second diffuser with a second central portion, a second diffuser axis, a second arcuate channel within the second central portion, a second arcuate passage extending through the second central portion, and a second peripheral portion having a second ledge. The first ledge abuts the second ledge. Further, the self-priming assembly includes an impeller with an impeller axis. The first diffuser and the second diffuser are configured to be combined and to receive the impeller therebetween with the first diffuser axis, the second diffuser axis, and the impeller axis aligned. 
     In some forms, the first peripheral portion extends along and defines a circumference of the first diffuser and the second peripheral portion extends along and defines a circumference of the second diffuser. The first peripheral portion has a first width dimension and a second width dimension and the difference of the first width dimension and the second width dimension defines the first ledge. The second peripheral portion has a third width dimension and a fourth width dimension, and the difference of the third width dimension and the fourth width dimension defines the second ledge. In some forms, the first ledge and the second ledge are at least partially perpendicular to the impeller axis such that the abutment of the first ledge and the second ledge prevents rotation of the first diffuser and the second diffuser relative to each other as torque is created by the rotation of the impeller. 
     Some embodiments include a multi-stage pump comprising an inlet member; an outlet member; a plurality of pump stage assemblies assembled along a pump axis and a self-priming assembly. The self-priming assembly includes a first diffuser with a first diffuser axis and a first peripheral portion having a first ledge, a second diffuser with a second diffuser axis and a second peripheral portion having a second ledge, and the first ledge abuts the second ledge. The self-priming assembly also includes an impeller with an impeller axis, and the impeller is positioned between the first diffuser and the second diffuser, the impeller axis being aligned with the first diffuser axis and the second diffuser axis. The self-priming assembly is coupled to the plurality of pump stage assemblies and axially aligned with the pump axis. The plurality of pump stage assemblies and the self-priming assembly are positioned between the inlet member and the outlet member. 
     These and other features of the disclosure will become more apparent from the following description of the illustrative embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an isometric view of a multi-stage pump with a cover removed therefrom and exposing multiple pump stage assemblies and a self-priming assembly integrated therewith according to one embodiment; 
         FIG.  2    is a front isometric exploded view of the self-priming assembly of the multi-stage pump shown in  FIG.  1   ; 
         FIG.  3    is a rear isometric exploded view of the self-priming assembly of the multi-stage pump shown in  FIG.  1   ; 
         FIG.  4    is a front elevational view of a diffuser plate of the multi-stage pump of  FIG.  1    according to one embodiment; 
         FIG.  5    is a rear elevational view of the diffuser plate shown in  FIG.  4   ; 
         FIG.  6    is a front elevational view of an impeller of the multi-stage pump of  FIG.  1   , according to one embodiment; 
         FIG.  7    is a front isometric view of the self-priming assembly of the multi-stage pump shown in  FIG.  1   ; and 
         FIG.  8    is a rear isometric view of the self-priming assembly of the multi-stage pump shown in  FIG.  1   . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the disclosure, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the embodiments of the disclosure. 
     DETAILED DESCRIPTION 
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
     The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of embodiments of the invention. 
     Some of the disclosure below describes a multi-stage pump with a self-priming assembly configured to prime the multi-stage pump upon activation of the multi-stage pump. The context and particulars of this discussion are presented as examples only. For example, embodiments of the disclosed invention can be configured in various ways, including different placement and more, fewer, and/or different parts within the multi-stage pump than are expressly presented below, such as a self-priming assembly positioned at any location among the plurality of pump stage assemblies, including before, after, or in-between. As another example, the self-priming assembly can be combined with one or multiple pump stage assemblies. As a further example, a plurality of self-priming assemblies can be incorporated within a multi-stage pump. 
       FIG.  1    illustrates an example multi-stage pump  10  incorporating an embodiment of a self-priming assembly  100  according to one embodiment of the invention. The multi-stage pump  10  includes an inlet member  12 , an outlet member  14 , and a plurality of pump stage assemblies  16  provided therebeteween. The plurality of pump stage assemblies  16  each generally contain an impeller and a diffuser assembly  18  that are axially aligned along a pump axis  20 . Each of the plurality of pump stage assemblies  16  is configured to direct a fluid to the outermost portion of the diffuser  18  through the rotation of the impeller and the inertia of the fluid. Pressure within the multi-stage pump  10  progressively increases as the fluid travels through the plurality of pump stage assemblies  16  from the inlet member  12  to the outlet member  14 . 
     As shown in  FIG.  1   , the self-priming assembly  100  is positioned between the ultimate (i.e., final or last) pump stage assembly  16 A of the plurality of pump stage assemblies  16  and the outlet member  14  and is axially aligned with the plurality of pump stage assemblies  16  along the pump axis  20 . However, as stated previously, in other embodiments the self-priming assembly  100  can also be positioned between the inlet member  12  and the plurality of pump stage assemblies  16  or in-between any two pump stage assemblies  16 . In still other embodiments, multiple self-priming assemblies  100  can be incorporated and positioned at various locations throughout the multistage pump  10  (e.g., one positioned closest to the inlet member  12  and another positioned closest to the outlet member  14 , two or more adjacent to the others and positioned at any stage position within the multi-stage pump  10 , etc.). 
     Turning now to  FIGS.  2  and  3   , the self-priming assembly  100  is shown in exploded form from various angles. The self-priming assembly  100  includes a first diffuser  110 , a second diffuser  210 , and an impeller  180  positioned between and within the first and second diffusers  110 ,  210 . The first diffuser  110  and the second diffuser  210  can be substantially similar in every regard, including shape, size, and configuration, wherein like reference numbers represent like elements. This relationship not only simplifies the manufacturing process but also aids in assembly and functionality. 
     With further reference to  FIGS.  4  and  5   , the first diffuser  110  is shown. As stated above, the second diffuser  210  is substantially similar to the first diffuser  110 ; therefore, for the sake of brevity the first and second diffusers  110 ,  210  will be described together. 
     The first and second diffusers  110 ,  210  are defined by bodies  120 ,  220  that are substantially disc-shaped with a depth that extends along first and second diffuser axes  176 .  276 . Each of the bodies  120 ,  220  have a peripheral portion  130 ,  230  and a central portion  150 ,  250 . The peripheral portions  130 ,  230  extend along and define the circumference of the bodies  120 ,  220  and have a first width  132 ,  232  for half of the circumference, a second width  134 ,  234  for the remaining half of the circumference, and an inner diameter  136 ,  236 . The first width dimensions  132 ,  232  are each greater than the second width dimensions  134 ,  234 , respectively, whereby the difference defines a first ledge  138 ,  238  and a second ledge  140 ,  240  along mating surfaces  142 ,  242 . 
     The central portions  150 ,  250  are adjacent to and bounded by the peripheral portions  130 ,  230  and have a central portion surface  152 ,  252  defining a central portion plane that is substantially perpendicular to the first and second diffuser axes  176 ,  276 . The central portion surfaces  152 ,  252  are positioned inwards from the mating surface  142 ,  242  along the first and second diffuser axes  176 ,  276  a distance  174 ,  274  from the internal mating surface  142 ,  242  at the portion of the peripheral portion  130 ,  230  with the first width dimensions  132 ,  232 . Further, through-holes  154 ,  254  are provided in the central portions  150 ,  250  and centered on the first and second diffuser axes  176 ,  276 . 
     An arcuate channel  156 ,  256  is provided in the central portions  150 ,  250  between the through-hole  154 ,  254  and the peripheral portion  130 ,  230  and is substantially concentric, or concentric with both. The channels  156 ,  256  extend approximately 5π/3 radians, or approximately 300 degrees, around the central portion surfaces  152 ,  252  and define channel lengths  160 ,  260  at a radial distances  172 ,  272  from the first and second diffuser axes  176 ,  276 . 
     The channels  156 ,  256  are continuous along the channel lengths  160 ,  260  and have a first portion  162 ,  262  adjacent to a second portion  164 ,  264 , which is adjacent to a third portion  166   266 . The channels  156 ,  256  each have a first depth dimension and a first width dimension at the first portion  162 ,  262 , which both increase in depth and width as the channels  156 ,  256  extend from the first portion  162 ,  272  to the second portion  164 ,  264 . The channels  156 ,  256  include a planar base surface  157 ,  257  with flared sidewalls  159 ,  259  and  161 ,  261  that extend away from the base surface  157 ,  257  in radially outer and inner directions respectively. The second depth dimension and second width dimension of the channels  156 ,  256  are maintained through the second portion  164 ,  264 . The depth dimension and the width dimension of the channels  156 ,  256  gradually decrease back to approximately the first depth dimension and the first width dimension as the channels  156 ,  256  extend from the second portion  164 ,  264  the third portion  166 ,  266 . While the example channels  156 ,  256  are illustrated with generally planar surfaces having linear or constant curvatures, the channels  156 ,  256  may define a variety of other form factors to impart application-specific flow dynamics. 
     The passages  168 ,  268  are defined by an arcuate ellipse-like shape and extend through the central portion  150 ,  250 . The passages  168 ,  268  are radially spaced between the first portion  162 ,  262  of the channels  156 ,  256  and the through-holes  154 ,  254 , and are substantially concentric with both. The passages  168 ,  268  each extend along the central portions  150 ,  250  for approximately the same radians as the first portion  162 ,  262  of the channels  156 ,  256  (e.g., approximately 2π/3 radians or 120 degrees), and define a passage length  170 ,  270 . At transitions  158 ,  258 , the radially inner sidewalls  161 ,  261  transition toward the base surface  157 ,  257  and into the passage  168 ,  268  proximate the first portion  162 ,  262  of the channel  156 ,  256 . 
     The impeller  180  is shown in  FIGS.  2 ,  3 , and  6   . The impeller  180  is defined by an impeller body having an impeller depth  182 , an impeller diameter  194 , and a plurality of chambers  184  extending radially outward from and radially spaced around a hub  186 . The hub  186  has an axle  188  extending axially outwardly from the hub  186  along an impeller axis  192 . The axle  188  is configured to be received within the through-holes  154 ,  254  of the first and second diffusers  110 ,  210 , respectively, when the self-priming assembly  10  is assembled. 
     The impeller depth  182  is substantially similar to and preferably slightly less than an axial distance defined between the central portions  150 ,  250  when the respective first and second diffusers  110 ,  210  are coupled (shown in  FIGS.  7  and  8   ). The impeller diameter  194  is preferably slightly less than the inner diameters  136 ,  236  of the peripheral portions  130 ,  230  of the first and second diffusers  110 ,  210 . The impeller  180  is configured to be retained within and between the first and second diffusers  110 ,  210 . 
     The plurality of chambers  184  is wedge-shaped and is radially spaced around the hub  186 . The axle  188  has an aperture  190  sized and configured to receive a drive shaft of the multi-stage pump  10 . The plurality of chambers  184  are equally sized, with each chamber having an angular measurement of approximately π/6 radians, or 30 degrees. A plurality of planar spokes  191  extend radially outward from the hub  186 . In other forms, the spokes  191  can define arcuate blades of varying cross-section and orientation to accommodate application-specific pumping performance. 
     In use, when the multi-stage pump  10  is activated, the impeller  180  rotates due to the engagement between the driveshaft of the multi-stage pump  10  and the axle  188  of the impeller  180 . As shown in  FIG.  7    the rotation of the impeller  180  is clockwise in the direction of arrow A and in  FIG.  8    the impeller  180  is viewed as rotating counter-clockwise in the direction of arrow B. Fluid generally moves through the multi-stage pump  10  into the passage  168  in the first diffuser  110  and into at least one of the plurality of chambers  184  in the impeller  180 . Because the first diffuser  110  and the second diffuser  210  are identical, when they are coupled together, as shown in  FIGS.  7  and  8   , the first portion  162  of the first diffuser  110  aligns with the third portion  266  of the second diffuser  210 . Similarly, the third portion  166  of the first diffuser  110  aligns with the first portion  262  of the second diffuser  210 . Accordingly, when fluid enters the self-priming assembly  100  through the passage  168 , the fluid subsequently flows into the first portion  162  of the first diffuser  110  and the third portion  266  of the second diffuser  210 . The rotation of the impeller  180  urges the fluid to the outermost portion of the plurality of chambers  184  and into the channels  156 ,  256  of the first and second diffusers  110 ,  210 . 
     The movement of fluid from the passage  168  in the first diffuser  110  to the outermost portion of the plurality of chambers  184  creates a low pressure to urge more fluid into the self-priming assembly  100 . This action causes the fluid to displace the air in the pump cavity and carry the air along with the fluid, which creates a vacuum. The fluid then travels along the second portions  164 ,  264  of the channels  156 ,  256  which comprise the deepest portions of channels  156 ,  256  and where the fluid is inhibited from entering or exiting the channels  156 ,  256 . Through continued rotation of the impeller  180 , the fluid then enters the third portion  166  of channel  156  and the first portion  262  of channel  256 , which are each more shallow in depth than the respective second portion  164 ,  264 . As discussed above, the first portion  262  of channel  256  is where the transition  258  is located and the radially inner sidewall  261  tapers toward the passage  268 . Thus, fluid is directed toward and out of the passage  268  of the second diffuser  210 , and eventually out of the outlet member  14  of the multi-stage pump  10 . 
     When assembled, the first and second ledges  138 ,  140  of the first diffuser  110  abut the first and second ledges  238 ,  240  of the second diffuser  210 , respectively. During use, this arrangement prevents the first and second diffusers  110 ,  210  from rotating relative to each other as the self-priming assembly  100  experiences torque created by the rotation of the impeller  180  and movement of fluid through the self-priming assembly  100 . Various alternative interlocking arrangements can be employed to rotationally couple the first and second diffusers  110 ,  210 , such as external tabs that mate with a fixed external collar or housing. 
     It is preferable that at least the self-priming assembly  100  contains fluid upon activation of the multi-stage pump  10  (e.g., such as via an elbow or trap in fluid communication with the outlet member  14 ). Fluid in the plurality of chambers  184  aids in creating and maintaining a vacuum within the self-priming assembly  100  when the impeller  180  is initially rotated. The vacuum draws fluid through the plurality of pump stage assemblies  16  of the multi-stage pump  10  toward and through the self-priming assembly  100  and out the outlet member  14 . 
     It will be appreciated by those skilled in the art that while the invention has been described above in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication were individually incorporated by reference herein. Various features and advantages of the invention are set forth in the following claims.