Patent Publication Number: US-9845799-B2

Title: Sealed diaphragm pump

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a pump; and more particularly relates to a diaphragm pump. 
     2. Brief Description of Related Art 
     Current diaphragm pump designs use two endbells and a sealing arrangement that includes a combination of an O-ring, gasket, etc. on each end for sealing the motor to prevent intrusion of fluids.  FIG. 1  shows an example of one such current diaphragm pump design. In particular, a rear endbell and an intermediate housing portion on one end are sealed with one O-ring seal that forms one leak path, and a front endbell and the intermediate housing portion on another end are sealed with another O-ring seal that forms another leak path. There are also other leak paths, e.g., including a grommet/wire leak path, through the rear endbell on one end, as well as a front endbell and diaphragm support assembly leak path on the other end. With the current prior art technique, there are too many undesirable leak paths that allow fluids to enter the motor. In view of this, there is a need in the marketplace for an improved pump that overcomes these shortcomings. 
     SUMMARY OF THE INVENTION 
     The present invention provides apparatus in the form a pump, a diaphragm pump, or an encapsulated diaphragm pump, according to some embodiments of the present invention. 
     By way of example, the pump may include a molded housing in combination with an upper housing. 
     The molded housing may be configured with a rear endbell portion to receive an armature and bearing, an intermediate motor portion to receive a motor shell and magnets arranged around the armature, and a front endbell portion to receive a diaphragm assembly having a diaphragm support plate supporting a diaphragm. The rear endbell portion, the intermediate motor portion and the front endbell portion may be configured as an integrated molded housing unit. 
     The upper housing may be assembled and coupled to the molded housing so as to form a circumferential fluid-tight sealing arrangement that is configured between the front endbell portion and the upper housing on only one end of the encapsulated diaphragm pump. 
     According to some embodiments of the present invention, the diaphragm may be configured with two circumferential diaphragm sealing surfaces; and the upper housing may include a circumferential upper housing portion configured to cause at least part of a circumferential fluid-tight seal between the two circumferential diaphragm sealing surfaces and corresponding sealing surfaces of the check valve assembly and the diaphragm support plate when the front endbell is assembled and coupled to the upper housing. 
     According to some embodiments of the present invention, the two circumferential diaphragm sealing surfaces may include a first circumferential diaphragm sealing surface on a first side configured to make sealing contact with a corresponding circumferential sealing surface of a check valve assembly, and may also include a second circumferential diaphragm sealing surface on a second side configured to make sealing contact with a circumferential support plate sealing surface of the support plate. 
     According to some embodiments of the present invention, the encapsulated diaphragm pump may include one or more of the following features: 
     The circumferential upper housing portion may be configured as, or take the form of, a circumferential rim. 
     The first circumferential diaphragm sealing surface may be configured to receive, engage and interlock with the corresponding circumferential sealing surface of the check valve assembly. 
     The first circumferential diaphragm sealing surface may be configured with inner and outer circumferential diaphragm sealing rims so as to form a U-shaped circumferential diaphragm sealing channel. 
     The corresponding circumferential sealing portion of the check valve assembly may be configured with corresponding inner and outer circumferential sealing rims so as to form a corresponding U-shaped circumferential sealing channel. 
     The U-shaped circumferential diaphragm sealing channel may be configured to receive the outer circumferential sealing rim of the check valve assembly in an interlocking manner, and the corresponding U-shaped circumferential sealing channel of the check valve assembly may be configured to receive the inner circumferential diaphragm sealing rim in a corresponding interlocking manner. 
     The outer circumferential diaphragm sealing rim may be configured to contact the corresponding outer circumferential sealing rim of the check valve assembly, and the corresponding inner circumferential sealing rim of the check valve assembly may be configured to contact the inner circumferential diaphragm sealing rim. 
     The circumferential extended rim portion of the upper housing may be configured to engage or contact the outer circumferential diaphragm sealing rim. 
     The circumferential fluid-tight seal may be configured as, or take the form of, a circumferential interlocking seal about and between respective sealing surfaces of the diaphragm and check valve assembly, corresponding to where the molded housing and the upper housing come in contact and meet. 
     The front endbell portion may be configured to receive the diaphragm support plate and a wobble plate assembly. 
     The molded housing may be molded around the motor shell. 
     The rear endbell portion may be configured to form a cavity portion dimensioned to receive a tolerance ring to fit the bearing in the cavity. 
     The intermediate motor portion may have a substantially cylindrical shape and the front endbell portion may have a flared-out shape so as to spread outwardly from the intermediate motor portion. 
     The upper housing may have a corresponding flared-out shape for mating with the front endbell. 
     The pump may include a further circumferential seal or sealing arrangement configured between a circumferential portion of the front endbell portion and a corresponding circumferential portion of the diaphragm support plate, so as to form another part of the circumferential fluid-tight seal between the front endbell portion and the upper housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The drawing, which are not necessarily drawn to scale, includes the following Figures: 
         FIG. 1  is a side view of a diaphragm pump that is known in the prior art. 
         FIG. 2  shows an encapsulated diaphragm pump that is fully assembled, according to some embodiments of the present invention. 
         FIGS. 2 a  to 2 f   ′ show a series of steps for assembling the encapsulated diaphragm pump shown in  FIG. 2 . 
         FIG. 2 a    is a side cross-sectional view of a mold having a motor shell inserted therein, and  FIG. 2   a′  is a perspective view of the motor shell shown in  FIG. 2   a.    
         FIG. 2 b    is a side cross-sectional view of a housing having the mold with the motor shell shown in  FIG. 2 a    inserted therein, and  FIG. 2 b   ′ is a perspective view of the housing shown in  FIG. 2   b.    
         FIG. 2 c    is a side cross-sectional view of the housing shown in  FIGS. 2 b  and 2 b   ′ having an armature with bearings, a front end bell and a brushcard installed therein, and  FIG. 2 c   ′ is a perspective view of the housing shown in  FIG. 2   c.    
         FIG. 2 d    is a side cross-sectional view of the housing shown in  FIGS. 2 c  and 2 c   ′ having a diaphragm support plate and wobble plate assembly installed therein, and  FIG. 2 d   ′ is a perspective view of the housing shown in  FIG. 2   d.    
         FIG. 2 e    is a side cross-sectional view of the housing shown in  FIGS. 2 d  and 2 d   ′ having a check valve assembly installed to a diaphragm shown in  FIG. 2 d   , and  FIG. 2 e   ′ is a perspective view of the housing shown in  FIG. 2   e.    
         FIG. 2 f    is a side cross-sectional view of the housing shown in  FIGS. 2 e  and 2 e   ′ having an upper housing installed thereto, and  FIG. 2   f′  is a perspective view of the housing and upper housing shown in  FIG. 2   f.    
         FIG. 2 g    is a partial side cross-sectional view of the housing and the upper housing shown in  FIG. 2 f    showing an enlarged view of a seal provided by the diaphragm shown in  FIGS. 2 d  and 2 d   ′ between the housing and the upper housing shown in  FIG. 2   f.    
         FIG. 2 h    is a partial side cross-sectional view of the housing and the upper housing shown in  FIG. 2 f    showing an enlarged view of a tolerance ring arranged between the armature and bearing and the housing, shown on the left side of  FIG. 2   c.    
         FIG. 3  includes  FIGS. 3 a  and 3 b    that show side-by-side comparisons of the existing design known in the prior art and the encapsulation design according to some embodiments of the present invention, where  FIG. 3 a    is a top front perspective view of one side-by-side comparison, and  FIG. 3 b    is a top back perspective view of the side-by-side comparison in  FIG. 3   a.    
     
    
    
     Figures in the drawing are populated with lead lines and reference numerals so as to read consistent with the specification. However, for the sake of reducing clutter in the drawing as a whole, each Figures does not contain every lead line and reference numeral from every other figure. 
     DETAILED DESCRIPTION OF THE INVENTION 
     By way of example,  FIG. 2  shows a new and unique encapsulation diaphragm pump design generally indicated as  10 , according to some embodiments of the present invention. In  FIG. 2 , the encapsulation diaphragm pump  10  is shown fully assembled with parts and components identified with lead lines and reference numerals.  FIGS. 2 a    through  2   f′  show a series of steps indicating how the diaphragm pump  10  is assembled so as to form the encapsulation diaphragm pump  10  according to the some embodiment of the present invention. The fully assembled encapsulation diaphragm pump  10  shown in  FIG. 2  is an enlarged view of the pump shown in  FIG. 2 f   , with the exception that  FIG. 2 f    does not include many of the lead lines and reference numeral shown in  FIG. 2 . 
     In  FIG. 2 , the encapsulation diaphragm pump design  10  features a two-part housing arrangement having a molded housing  12  in combination with an upper housing  14 . Consistent with that described below, at least part of a circumferential fluid-tight seal may be configured between surfaces or portions of a diaphragm  13  and corresponding surfaces or portions of a check valve assembly generally indicated as  15  and a diaphragm support plate  28  when the molded housing  12  and the upper housing  14  are assembled or coupled together. 
     In particular, the molded housing  12  may be configured with a rear endbell portion  16  to receive an armature and bearings combination  18 , an intermediate motor portion  20  to receive a motor shell  22   a  and magnets  22   b  generally indicated as  22  (see  FIG. 2 a   ) arranged around an armature portion  18   a  of the combination  18 , and a front endbell portion  24  to receive a diaphragm assembly having the diaphragm support plate  28  supporting the diaphragm  13 . The rear endbell portion  16 , the intermediate motor portion  20  and the front endbell portion  24  are configured as part of an integrated molded housing unit  12 . The diaphragm  13  has two sides  13   a ,  13   b , each having a respective circumferential diaphragm sealing surface or portion  32 ,  32 ′. 
     By way of example, on the one side  13   a  the diaphragm  13  may include a first circumferential diaphragm sealing surface or portion  32  configured to make sealing contact with a corresponding circumferential sealing surface  33  of the check valve assembly  15 , so as to form at least part of the circumferential fluid-tight seal. In particular, as shown in  FIGS. 2 and 2   g , the circumferential diaphragm sealing surface or portion  32  may be configured to receive and interlock with the corresponding circumferential sealing surface or portion  33  of the check valve assembly  15 . For example, the circumferential diaphragm sealing surface or portion  32  may be configured with inner and outer circumferential diaphragm sealing rims  32   a  and  32   b  so as to form a U-shaped circumferential diaphragm sealing channel  32   c . The corresponding circumferential sealing portion  33  of the check valve assembly  15  may be similarly configured with corresponding inner and outer circumferential sealing rims  33   a  and  33   b  so as to form a corresponding U-shaped circumferential sealing channel  33   c . As best shown in  FIGS. 2, 2   f  and  2   g , the U-shaped circumferential diaphragm sealing channel  32   c  of the diaphragm  13  may be configured to receive, engage and interlock in a sealing manner with the outer circumferential sealing rim  33   b  of the check valve assembly  15 , and the corresponding U-shaped circumferential sealing channel  33   c  of the check valve assembly  15  may be configured to receive, engage and interlock in a corresponding sealing manner with the inner circumferential diaphragm sealing rim  32   a . The outer circumferential diaphragm sealing rim  32   b  of the diaphragm  13  may be configured to contact and engage the corresponding outer circumferential sealing rim  33   b  of the check valve assembly  15 , and the corresponding inner circumferential sealing rim  33   a  of the check valve assembly  15  may be configured to contact and engage the inner circumferential diaphragm sealing rim  32   a  of the diaphragm  13 . The sealing engagement between the surface or portion  32  of the diaphragm  13  and the corresponding surface or portion  33  of the check valve assembly  15  combine to form at least part of the circumferential fluid-tight seal when the molded housing  12  and the upper housing  14  are assembled or coupled together. The scope of the invention is not intended to be limited to the specific engagement and interlocking between the surface or portion  32  of the diaphragm  13  and the corresponding surface or portion  33  of the check valve assembly  15  disclosed herein; and embodiments are envisioned having other types or kind of engagement and/or interlocking between other types or kinds of surfaces or portions of the diaphragm  13  and other types or kinds of corresponding surfaces or portions of the check valve assembly  15  both now known and later developed in the future, e.g., including corresponding convex and concave surfaces or portions, or corresponding saw-toothed surfaces or portions. 
     The upper housing  14  may be configured to assemble or couple to the molded housing  12 . By way of example, the upper housing  14  may include a circumferential rim portion  14   a  configured to cause at least part of the circumferential fluid-tight seal between the two circumferential diaphragm sealing surfaces and corresponding sealing surfaces of the check valve assembly  15  and the diaphragm support plate  28 , when the upper housing  14  is assembled and coupled to the molded housing  12 , consistent with that disclosed herein. 
     Further, by way of example, on the other side  13   b  the diaphragm  13  may be configured with another circumferential sealing surface or portion  32 ′ to make corresponding circumferential sealing contact with a corresponding circumferential sealing surface or portion  33 ′ of the diaphragm support plate  28  so as to form at least part of the circumferential fluid-tight seal, as best shown in  FIGS. 2 and 2   g.    
     Furthermore, by way of example, the pump  10  may also include a further circumferential seal or sealing arrangement  35  configured between the front endbell portion  24  and the diaphragm support plate  28 , so as to form another part of the circumferential fluid-tight seal between the molded housing  12  and the upper housing  14 . In particular, the further circumferential seal or sealing arrangement  35  may be configured between an inner circumferential front endbell portion  24   a  of the front endbell portion  24  and a corresponding circumferential flanged portion  28   a  of the diaphragm support plate  28 , so as to form the other part of the circumferential fluid-tight seal. The further circumferential seal or sealing arrangement may also take the form of a gasket or an O-ring between corresponding surfaces or portions of the front endbell portion  24  and the diaphragm support plate  28  However, and in spite of this, the scope of the invention is intended to include other types or kinds of further circumferential seal or sealing arrangements between the front endbell portion  24  and the diaphragm support plate  28   c  within the spirit of the underlying invention. 
     Moreover, the upper housing  14  may also include a circumferential extended rim portion  14   b  configured to engage the outer circumferential diaphragm sealing rim  32   b  of the diaphragm  13  resting against the corresponding outer circumferential sealing rim  33   b  of the check valve assembly  15 . As shown in  FIGS. 2 and 2   g , this part of the circumferential fluid-tight seal may take the form of a circumferential interlocking sealing engagement about and between the respective sealing portions  32  and  33  of the diaphragm  13  and check valve assembly  15 , corresponding to where the molded housing  12  and the upper housing  14  come in contact and meet, consistent with that disclosed herein. One advantage of the present invention is that this substantially fluid-tight seal reduces the number of undesirable leak paths that allow fluids to enter the motor that plagued the prior art pump design, including eliminating any leak path between the rear endbell portion  16  and the intermediate housing portion  20 . 
     This part of the circumferential fluid-tight seal may be formed by, or the result of, the molded housing  12  and the upper housing  14  being assembled or coupled together using one or more screws or bolts  70  (see  FIG. 3 a   ), consistent with that disclosed herein, so as to cause, e.g., a compressive sealing force between the surface or portion of the diaphragm  13  and the corresponding surface or portion of the check valve assembly  15  and the diaphragm support plate  28 . The scope of the invention is not intended to be limited to the specific manner in which the molded housing  12  and the upper housing  14  are assembled or coupled together. For example, embodiments are envisioned having other types or kind of techniques for assembling and coupling the molded housing  12  and the upper housing  14  together, including using a hinge and latching technique, as well as other types or kinds of assembly or coupling techniques both now known and later developed in the future. 
     As shown in  FIG. 2 b   , the molded housing  12  may be molded around the motor shell  22 . As shown in  FIG. 2 d   , the front endbell portion  24  may be configured to receive the diaphragm support plate  28  and a wobble plate assembly  50 . As shown in  FIG. 2 h   , the rear endbell portion  16  may be configured to form a cavity portion  52  dimensioned to receive a tolerance ring  54  to fit a bearing portion  18   b  of the combination  18  in the cavity portion  52 . The intermediate motor portion  20  may have a substantially cylindrical shape, and the front endbell portion  24  may have a flared-out shape so as to spread outwardly from intermediate motor portion  20 , as shown, and the upper housing  14  may have a corresponding flared-out shape for mating with the front endbell  24 . 
     By integrating the rear end bell  16  and diaphragm assembly  26  into one piece, the pump can be assembled with only the need to seal the front section, consistent with that shown in  FIGS. 2 and 2   a  through  2   g.    
     FIGS.  2   a  to  2   h    
       FIGS. 2 a  to 2 h    set forth a series of steps showing how the diaphragm pump according to the present invention is assembled. 
     In  FIGS. 2 a  and 2 a   ′, the motor shell and magnets generally indicated in combination as  22  in  FIG. 2 a   ′ is configured and dimensioned so as to be inserted in a mold  22   a  as shown in  FIG. 2   a.    
     In  FIGS. 2 b  and 2 b   ′, the mold housing  12  is molded around the motor shell and magnets  22 . 
     In  FIGS. 2 c  and 2 c   ′, the armature and bearings  18  and the front end bell portion  24  and a brushcard  60  may be installed using the tolerance ring  54  in the rear endbell portion  16  of the molded motor housing  12 . Suitable wiring for providing power may be also routed through the front endbell portion  24  and out through, e.g., a grommet (not shown). 
     In  FIGS. 2 d  and 2 d   ′, the diaphragm support plate  28  and wobble plate assembly  50  may be installed, as shown. 
     In  FIGS. 2 e  and 2 e   ′, the check valve assembly  34  may be installed to the diaphragm  13 . 
     In  FIGS. 2 f  and 2 f   ′, the upper housing  14  may be installed to the molded housing  12 . 
       FIG. 2 g    shows that the pump unit is sealed between the upper housing  14  and the diaphragm support plate  28  using the diaphragm  13 . 
       FIG. 2 h    shows how the tolerance ring  54  is used to make the bearing portion  18   b  of the combination  18  fit into the molded housing  12 . 
     LIST POSSIBLE APPLICATIONS 
     By way of example, possible applications of some embodiments of the present invention include any application that requires a diaphragm pump. 
     THE SCOPE OF THE INVENTION 
     Further still, the embodiments shown and described in detail herein are provided by way of example only; and the scope of the invention is not intended to be limited to the particular configurations, dimensionalities, and/or design details of these parts or elements included herein. In other words, a person skilled in the art would appreciate that design changes to these embodiments may be made and such that the resulting embodiments would be different than the embodiments disclosed herein, but would still be within the overall spirit of the present invention. 
     It should be understood that, unless stated otherwise herein, any of the features, characteristics, alternatives or modifications described regarding a particular embodiment herein may also be applied, used, or incorporated with any other embodiment described herein. Also, the drawings herein are not drawn to scale. 
     Although the invention has been described and illustrated with respect to exemplary embodiments thereof, the foregoing and various other additions and omissions may be made therein and thereto without departing from the spirit and scope of the present invention.