Patent Application
20180245586
The present disclosure relates to pumps, and more particularly, to a positive displacement pump having rotary, intermeshing impellers.
Positive displacement pumps are more useful to pump liquids than other types of pumps, such as centrifugal pumps. A positive displacement pump may be more efficient, may have less variable output flow rates, and may provide still other advantages compared to other types of pumps.
As with all pumps, positive displacement pumps will require maintenance and repairs over time. This is not necessarily easy to accomplish. For example, pump impellers and drive gears may need to be pressed from shafts, and shafts may need to be press fit to supporting structure within the pump. This may require the services of a special facility, such as a machine shop. Where positive displacement pumps are used far from such facilities, repair becomes more time consuming and expensive.
There exists a need to simplify assembly and disassembly operations to facilitate repair, maintenance, and other operations performed on positive displacement pumps.
The disclosed concepts address the above stated situation by providing in exemplary embodiments a positive displacement pump wherein a pump housing includes a central member having throughbores for supporting impeller shafts, wherein the central member is formed in plural, manually separable sections. This may facilitate disassembly of the pump. Where joints between adjacent ones of the manually separable sections extend through the throughbores, impeller shafts may be released from engagement merely by manually pulling away one or both of the manually separable sections at each end of the central member.
The nature of the disclosed concepts will become readily apparent upon further review of the following specification and drawings.
Various objects, features, and attendant advantages of the disclosed concepts will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
Referring first to
Although 100 has been illustrated as having four vanes 116 or 126 for first and second rotary impellers 108, 118, more or fewer vanes 116 or 126 could be used.
Unless otherwise indicated, the terms “first”, “second”, etc., are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the times to which these terms refer. Moreover, reference to, e.g., a “second” item does not either require or preclude the existence of, e.g., a “first” or lower-numbered item, and/or, e.g., a “third” or higher-numbered item.
A first gear 128 is secured to first shaft 110, and a second gear 130 is secured to second shaft 120. First gear 128 meshes with second gear 130 and synchronizes rotation of first and second rotary impellers 108, 118 to ensure that vanes 116 of first shaft 110 do not contact vanes 126 of second shaft 120 during rotation.
As shown in the Figures, pump housing 102 comprises three major parts including a first part (a gear cover section 138) enclosing first gear 128 and second gear 130, a second part comprising a dividing wall 136, and a third part (a pumping chamber cover 140) enclosing a pumping chamber 132. Each of the first part, the second part, and the third part has a surface exposed to the exterior of pump housing 102 when the first part, the second part, and the third part are assembled together. These surfaces may occupy a common curved plane as depicted, or alternatively, any of the first part, the second part, and the third part may project to different degrees from pump housing 102 (this option is not shown).
It would be possible to configure rotary, self-priming, positive displacement pump 100 such that dividing wall 136 comprises two rather than three sections (this option is not shown). For example, dividing wall 136 could be divided along an axis perpendicular to ribs 152 and grooves 154, with the axis of division extending through first and second shafts 110, 120 of respective first and second rotary impellers 108, 118. Removal of either of the two sections would free both the first and second rotary impellers 108, 118 for removal.
It would be possible to configure rotary, self-priming, positive displacement pump 100 to have dividing wall 136 be internal to pump housing 102, rather than to have a surface exposed to the exterior of pump housing 102. It would also be possible to configure rotary, self-priming, positive displacement pump 100 such that dividing wall 136 is partially internal and partially exposed to the exterior of pump housing 102.
Pumping chamber 132 (
Fluid inlet and outlet 104, 106 may project from pump housing 102 as shown in
First shaft end 112 may be journaled within a boss 142 which is part of gear cover 138. First shaft end 114 may be journaled within a bore (not shown) similar to a bore or blind hole 144 (
First shaft 110 may be driven via a non-circular enlarged head 148. Although depicted as generally triangular, non-circular head 148 may be no greater in transverse dimension than its associated first shaft 110 if desired. Non-circular head 148 may take configurations other than generally triangular.
First shaft 110 and second shaft 120 each extend through dividing wall 136 between adjacent ones (e.g., 136a and 136b, or 136b and 136c) of abutting manually separable sections 136a, 136b, 136c. Removal of at least outermost ones (136a, 136c) of abutting manually separable sections 136a, 136b, 136c enables removal of first shaft 110 and second shaft 120 from pump housing 102 after exposing first end 112 and second end 114 of first shaft 110 and first end 122 and second end 124 of second shaft 120. Exposing the first and second ends 112, 114, 122, 124 of first and second shafts 110, 120 signifies that pump housing 102 has been disassembled.
Dividing wall 136 may be formed in three manually separable sections including first end separable section 136a, central separable section 136b, and second end separable section 136c. Central separable section 136b is between first end separable section 136a and second end separable section 136c. First end separable section 136a contacts first shaft 110. Central separable section 136b contacts first shaft 110 and second shaft 120. Second end separable section 136c contacts second shaft 120.
Once abutting manually separable sections 136a and 136c have been pulled away from remaining abutting manually separable section 136b, first and second rotary impellers 108, 118 may be easily pulled free for service, inspection, replacement, etc. Referring particularly to
In prior art pumps (not shown), this may require using a mechanical pump, which may require bringing the prior art pump to a machine shop or other service facility. Because first and second rotary impellers 108, 118 can be manually removed, many repairs formerly requiring special service facilities may be performed in the field.
At least two of abutting manually separable sections 136a, 136b, 136c each have a complementing interfitting element constraining the two abutting manually separable sections 136a, 136b or 136b, 136c against mutual movement in at least one axis by interference fit. Referring specifically to
It should be noted at this point that orientational terms such as vertical refer to the subject drawing as viewed by an observer. The drawing figures depict their subject matter in orientations of normal use, which could obviously change. Therefore, orientational terms must be understood to provide semantic basis for purposes of description only, and do not imply that their subject matter can be used only in one position or orientation.
This arrangement constrains any of abutting manually separable sections 136a, 136b or 136b, 136c against movement in the vertical direction as depicted in
Manually separable sections 136a, 136b, 136c may be sealed against leaks by gasket, application of a tacky substance, or in any other suitable way.
Pump housing 102 may be secured as a unit by threaded fasteners such as screws, bolts, or studs. To this end, there may be provided a plurality of through holes 156 extending through at least two of gear cover section 138, dividing wall 136, and pumping chamber cover 140. This enables the threaded fastener to be passed through the at least two of gear cover section 138, dividing wall 136, and pumping chamber cover 140 when inserted into any one of through holes 156. It would be possible to have a threaded fastener pass entirely through gear cover section 138, dividing wall 136, and pumping chamber cover 140. Alternatively, a stud may be embedded within gear cover section 138 or pumping chamber cover 140, and would need to pass through only two of the remaining major components of pump housing 102. As depicted in
Turning now to
Depending upon pumping chamber design, impeller design, clogs, and possibly other variables, orderly operation of rotary, self-priming, positive displacement pump 100 may be compromised by excessive pressure developing in pressure zones in pumping chamber 132. To forestall such an occurrence, rotary, self-priming, positive displacement pump 100 may be provided with a pressure relief feature comprising, for example, recesses or channels (none shown the above referenced copending application may be consulted for further details on pressure relief) formed in the underside of dividing wall 136 or in the floor or lateral wall of pumping chamber cover 140. These recesses or channels communicate among potential pressure zones to conduct fluid pressure from one zone of high pressure to a zone of lesser pressure. Although pressures may not be rendered equal in all zones of pumping chamber 132, peak pressures may be attenuated to the point that 100 operates satisfactorily.
In the preceding description, numerous specific details are set forth in order to provide an understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. The specific details may be varied from and still be contemplated to be within the spirit and scope of the present disclosure. Many modifications of examples set forth herein will come to mind to one skilled in the art to which the present disclosure pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.
This written description uses examples of the subject matter disclosed to enable any person skilled in the art to practice the same, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the subject matter is defined by the claims, and can include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims.
The above-described embodiments are intended to be illustrative in all respects, rather than restrictive, of the embodiments. Thus, the embodiments are capable of many variations in detailed implementation that can be derived from the description contained herein by a person skilled in the art. No element, act, or instruction used in the description of the present application should be construed as critical or essential to the embodiments unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Therefore, it is to be understood that the present disclosure is not to be limited to the specific examples presented and that modifications and other examples are intended to be included within the scope of the appended claims. Moreover, although the foregoing description and the associated drawings describe examples of the present disclosure in the context of certain illustrative combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative implementations without departing from the scope of the appended claims.
This application claims priority of U.S. patent application Ser. No. 10/963,071, filed Oct. 12, 2004, which is incorporated by reference in its entirety, and is related to my copending application entitled “Positive Displacement Pump With Pressure Relief”, filed concurrently with the present application.
