Abstract
The present disclosure relates to impellers with removable and replaceable vanes, and methods of constructing such impellers. According to aspects of the present disclosure, a plurality of impeller back plates are provided with differently configured slots to receive removable vanes. In addition, a plurality of differently configured vanes are disclosed which may be connected to the plurality of impeller back plates. As a result, the desired performance characteristics of a pump based upon end use applications may be efficiently and quickly achieved by combining appropriately configured vanes and back plate into a desired impeller providing the desired characteristics, together with a particular pump casing and motor.
Claims
1. A pump impeller, comprising: a. a first plate having a first surface, a second surface and a perimeter edge disposed between the first and second surfaces; b. an aperture at the center of the plate extending through the plate and configured to receive a shaft for rotating the impeller; c. a plurality of slots extending through the plate between the first and second surfaces, the slots extending from a first position proximate the aperture to a second position proximate the perimeter edge; d. a plurality of removable vanes, wherein each vane extends into at least a single slot when secured to the first plate, and wherein each vane is removable from the at least a single slot; e. a second plate having a first surface and a second surface and a perimeter edge disposed between the first and second surfaces; f. a second aperture at the center of the second plate extending through the second plate and configured to receive the shaft; and g. a plurality of slots disposed in the second plate, and wherein the second plate is disposed at a distance from the first plate and each vane engages a slot formed in the second plate such that the vanes extend between the first and second plates.
2. The impeller of claim 1, wherein at least one vane is removably secured in a plurality of slots.
3. (canceled)
4. The impeller of claim 2, wherein the vanes extend through the first and second plates and in both axial directions away from the first surface of the first plate and away from the second surface of the second plate.
5. The impeller of claim 1, wherein each slot of the plurality of slots is curved.
6. The impeller of claim 1, wherein each vane is oriented perpendicular to at least one of the first and second plates.
7. The impeller of claim 1, wherein each vane has a length extending between the first position and the second position, and wherein at least one vane is curved along its length.
8. The impeller of claim 1, wherein each vane comprises a first surface and a second surface, and wherein the first surface is oriented at an acute angle relative to at least the first plate and the second surface is oriented at an obtuse angle relative to at least the first plate.
9. The impeller of claim 1, wherein a radial direction is defined as extending outwardly away from the shaft, and wherein at least some of the plurality of vanes are curved in the radial direction.
10. The impeller of claim 1, wherein at least some of the plurality of removable vanes comprise a vane with a curvature in three dimensions.
11. The impeller of claim 1, wherein each vane comprises a composite fiber material, and the fibers are substantially oriented in the axial direction.
12. The impeller of claim 1, wherein at least one of the first and second plates is substantially flat.
13. The impeller of claim 1, further comprising ribs disposed on at least one surface of at least one of the first and second plates.
14. The impeller of claim 1, wherein the first surface of at least one of the first and second plates is curved.
15. The impeller of claim 14, wherein at least one of the first and second plates has a convex shape.
16. (canceled)
17. The impeller of claim 1, wherein each vane comprises a body having a first edge with a plurality of cutouts positioned along the edge and configured to engage the first or second plate.
18. The impeller of claim 17, wherein the body of each vane comprises a first end and a second end, and further comprises a tab extending from the first end, the tab configured to engage a hub configured to secure the impeller to the shaft.
19. The impeller of claim 18, wherein the hub comprises a first member and a second member, and wherein the first member of the hub and the second member of the hub are secured to each other.
20. (canceled)
21. (canceled)
22. (canceled)
23. (canceled)
24. (canceled)
25. (canceled)
26. (canceled)
27. The impeller of claim 1, wherein the plurality of slots are elongate.
28. (canceled)
29. The impeller of claim 17, wherein each cutout comprises a plurality of surfaces and at least three surfaces of each cutout engage a surface of the plate.
30. An impeller and expleller, comprising: a. a single plate having a first surface, a second surface and a perimeter edge disposed between the first and second surfaces; b. an aperture at the center of the plate extending through the plate and configured to receive a shaft for rotating the impeller; c. a plurality of slots extending through the plate between the first and second surfaces; and d. a plurality of removeable vanes, wherein at least one vane extends through a plurality of slots when secured to the first plate and extends axially outwardly from the first surface to form the impeller and from the second surface to form the expeller.
31. The impeller and expeller of claim 30, wherein each vane is removably secured in a plurality of slots.
32. The impeller and expleller of claim 30, wherein at least one vane is curved along its length.
33. The impeller and expleller of claim 30, wherein the first surface of the plate is curved.
34. The impeller and expleller of claim 30, wherein each vane comprises a composite fiber material, and the fibers are substantially oriented in the axial direction.
35. The impeller and expleller of claim 30, wherein the portion of each vane positioned within the at least one slot comprises a majority of the radial length of each vane.
36. The impeller and expleller of claim 30, wherein at least some of the plurality of removable vanes comprise a vane with a curvature in three dimensions.
37. The impeller and expleller of claim 33, wherein the second surface of the plate is curved.
38. The pump impeller of claim 40, wherein each vane comprises a composite fiber material, and the fibers are substantially oriented in the axial direction.
39. The impeller of claim 30, wherein each vane comprises a first surface and a second surface, and wherein the first surface is oriented at an acute angle relative to the plate and the second surface is oriented at an obtuse angle relative to the plate.
40. A pump impeller, comprising: a. a plate having a first surface, a second surface and a perimeter edge disposed between the first and second surfaces; b. an aperture at the center of the plate extending through the plate and configured to receive a shaft for rotating the impeller, wherein the shaft defines an axial direction; c. a plurality of slots extending through the plate between the first and second surfaces, the slots extending from a first position proximate the aperture to a second position proximate the perimeter edge; d. a plurality of vanes, wherein the vanes extend in an axial direction away from the first surface, wherein each vanes comprises an axially inner edge and at least one cutout is disposed proximate the axially inner edge, wherein each vane extends through at least a single slot when secured to the plate and extends axially outwardly from the first surface to form an impeller and wherein the at least one cutout comprises an axially extending channel configured to allow repositioning of each vane relative to the plate in the axial direction while the plate is rotating.
41. The pump impeller of claim 40, wherein each cutout comprises a plurality of surfaces and at least three surfaces of each cutout engage a surface of the plate.
42. The pump impeller of claim 40, wherein at least one vane is curved along its length.
43. The pump impeller of claim 40, wherein at least some of the plurality of removable vanes comprise a vane with a curvature in three dimensions.
44. A centrifugal pump, comprising: a. a casing defining an interior chamber; b. a shaft having a first end and a second end and defining an axial direction along its length, the second end extending into the chamber; c. an impeller comprising: i. a single plate having a first surface, a second surface and a perimeter edge disposed between the first and second surfaces, an aperture at the center of the plate extending through the plate and configured to receive the shaft; ii. a plurality of slots extending through the plate between the first and second surfaces; and iii. a plurality of removable vanes, wherein each vane comprises a body having a radial inner end and a radial outer end spaced from the radial inner end and defining the radial length of the body, wherein a portion of each vane is positioned within at least one slot and each vane is removably secured within the at least one slot, wherein the portion of each vane positioned within the at least one slot comprises a majority of the radial length of each vane, wherein each vane extends axially away from the first surface of the plate and away from the second surface of the plate to form an expeller.
45. (canceled)
46. The centrifugal pump of claim 44, wherein the first surface of the plate is curved.
47. The centrifugal pump of claim 44, wherein each slot of the plurality of slots is curved.
48. The centrifugal pump of claim 44, wherein each vane comprises a first end and a second end, and further comprises a tab extending from the first end, the tab configured to engage a hub configured used to secure the impeller to the shaft.
49. The centrifugal pump of claim 44, wherein each vane comprises a first surface and a second surface, and wherein the first surface is oriented at an acute angle relative to the plate and the second surface is oriented at an obtuse angle relative to the plate.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of these inventions.
[0023] FIG. 1 is a perspective view of a centrifugal pump with a portion of the casing removed.
[0024] FIG. 2A is a perspective of an impeller with removable vanes according to one aspect of the present disclosure.
[0025] FIG. 2B is a top plan view of the impeller of FIG. 2A.
[0026] FIG. 3A is a perspective view of an impeller made according to one aspect of the present disclosure.
[0027] FIG. 3B is a top plan view of the impeller of FIG. 3A.
[0028] FIG. 4 is a perspective of an impeller made according to one aspect of the present disclosure.
[0029] FIG. 5 is a partial exploded perspective view of the impeller of FIG. 4.
[0030] FIG. 6A is an exploded cross-sectional plan view of an impeller and removable vane according to aspects of the present disclosure.
[0031] FIG. 6B is a partially assembled view of the impeller of FIG. 6A.
[0032] FIG. 6C is a fully assembled view of the impeller of FIG. 6A.
[0033] FIG. 6D is an enlarged plan view of an exemplary cutout as illustrated in FIG. 6A.
[0034] FIG. 7A is a top plan view of an optional secondary back plate according to one aspect of the present disclosure.
[0035] FIG. 7B is a top plan view of an impeller incorporating the optional back plate of FIG. 7A.
[0036] FIG. 8A is a top plan view of an optional secondary back plate according to aspects of the present disclosure.
[0037] FIG. 8B is a top plan view of an impeller incorporating the optional back plate of FIG. 8A.
[0038] FIG. 9 is an exploded plan view of an impeller assembly incorporating two optional secondary back plates according to one aspect of the present disclosure.
[0039] FIG. 10 is a plan view of a partially assembled impeller according to one aspect of the present disclosure with a single removable vane secured relative to a back plate.
[0040] FIG. 11 is a cross-sectional view of an impeller assembled within a pump casing according to aspects of the present disclosure.
[0041] FIG. 12A is a plan view of an impeller according to aspects of the present disclosure.
[0042] FIG. 12B is a plan view of an impeller according to aspects of the present disclosure.
[0043] FIG. 12C is a plan view of an impeller according to aspects of the present disclosure.
[0044] FIG. 13A is a top plan view of a removable impeller vane according to aspects of the present disclosure.
[0045] FIG. 13B is an elevational plan view of the removable vane of FIG. 13A.
[0046] FIG. 13C is a top plan view of a removable impeller vane according to aspects of the present disclosure.
[0047] FIG. 13D is an elevational plan view of the removable vane of FIG. 13C.
[0048] FIG. 13E is a top plan view of a removable impeller vane according to aspects of the present disclosure.
[0049] FIG. 13F is an elevational plan view of the removable vane of FIG. 13E.
[0050] FIG. 14A is a plan view of an impeller back plate and vane according to aspects of the present disclosure.
[0051] FIG. 14B is a plan view of an impeller back plate and vane according to aspects of the present disclosure.
[0052] FIG. 14C is a plan view of an impeller back plate and vane according to aspects of the present disclosure.
[0053] FIG. 14D is a partial elevation view of an impeller back plate and vane according to aspects of the present disclosure.
[0054] FIG. 14E is a perspective view of an impeller made according to aspects of the present disclosure.
[0055] FIG. 14F is a top plan view of an impeller made according to aspects of the present disclosure.
[0056] FIG. 14G is a partial elevation view of an impeller back plate and vane according to aspects of the present disclosure.
[0057] FIG. 15 is a plan view of a composite vane made according to aspects of the present disclosure.
[0058] FIG. 16A is a top plan view of an impeller made according to aspects of the present disclosure.
[0059] FIG. 16B is a partial elevation view of the impeller of FIG. 16A, taken along ling 16B-16B.
[0060] FIG. 17A is a plan view of an impeller made according to aspects of the present disclosure.
[0061] FIG. 17B is a plan view of an impeller made according to aspects of the present disclosure.
[0062] FIG. 18A is a plan view of an impeller made according to aspects of the present disclosure.
[0063] FIG. 18B is a perspective view of the impeller of FIG. 18A.
[0064] FIG. 19A is a top plan view of an impeller according to aspects of the present disclosure.
[0065] FIG. 19B is a cross sectional view of the impeller of FIG. 19A taken along line 19B-19B.
[0066] FIG. 20 is a top plan view of an impeller back plate according to aspects of the present disclosure.
[0067] FIG. 21A is a cross sectional view of an impeller installed within a pump casing according to aspects of the present disclosure.
[0068] FIG. 21B is an enlarged partial view of an exemplary cutout as illustrated in FIG. 21A.
[0069] FIG. 22A is a cross sectional view of an impeller in a first state according to aspects of the present disclosure.
[0070] FIG. 22B is a cross sectional view of the impeller of FIG. 22A in a second state according to aspects of the present disclosure.
[0071] While the following disclosure describes the invention in connection with those aspects presented, one should understand that the invention is not strictly limited to these aspects. Furthermore, one should understand that the drawings are not necessarily to scale, and that in certain instances, the disclosure may not include details which are not necessary for an understanding of the present invention, such as conventional details of fabrication and assembly.
DETAILED DESCRIPTION
[0072] Turning to FIG. 1, one embodiment of a centrifugal pump 10 is illustrated with a portion of the casing 12 removed to reveal internal structures. The casing has a first opening 14 to receive a rotary shaft 16. The shaft is rotated by a motor (not shown) and supported by bearings 20. An impeller 22 is affixed to the end of the shaft 16 and is positioned in an interior chamber 24 of the casing 12. The casing further includes an intake opening 26 that is in fluid communication with the chamber 24 and a discharge port 28 which is also in fluid communication with the chamber 24. In operation, the motor rotates the shaft 16 and impeller 22. Rotation of the impeller 22 causes fluid to be drawn into the chamber 24 through the intake opening 26 and expelled out of the discharge port 28.
[0073] FIGS. 2A and 2B illustrate one embodiment of an impeller made according to aspects of the present disclosure. The impeller comprises a back plate 30 and three curved vanes 32a-32c. The vanes 32a-32c are removable from the back plate 30. A multi-sided aperture 34 is formed in the center of the plate 30 for connecting to the shaft 16. Here the aperture 34 has five sides. The vanes have a curved profile and a height that decreases as the vane moves from an inner radial location to an outer radial location on the back plate 30. As illustrated, the vanes are oriented generally perpendicular to the back plate 30.
[0074] A second embodiment of an impeller made according to aspects of the present disclosure is shown in FIGS. 3A and 3B. Here, the impeller has six removable vanes 32a-32f . The curvature of the vanes 32 may be the same as or different from the curvature of the vanes shown in FIGS. 2A and 2B. In addition, the varying height profile of the vanes 32a-32f may be the same as or different from that illustrated in FIGS. 2A and 2B.
[0075] FIG. 4 illustrates another impeller made according to aspects of the present disclosure. Here, five removable vanes 32a-32e are utilized.
[0076] Turning to FIG. 5, a back plate 30 is shown having slots 36 formed through the entire thickness of the back plate 30. The slots are designed to receive and secure vanes 32. As illustrated in this embodiment, three slot segments 36a, 36b and 36c, form a discontinuous slot 36 interrupted by portions 18 of the back plate. The vane 32 may have a pre-set curvature that matches the orientation of the slot segments 36a, 36b and 36c, or the vane may be made from a flexible material that allows it to be bent or curved during installation to fit within the slots 36. An individual slot 36 may comprise one or more slot segments. The vane has a radial inner edge 38 and a radial outer edge 40. Here, the use of the term “radial” is in reference to a position relative to the back plate 30. Thus, a radial inner position is closer to the aperture 34 than a radial outer position. A radial outer position is closer to the perimeter edge 42 of the back plate 30. Each vane 32 also has an axial outer edge 44 and an axial inner edge 46. Here, the term “axial” is in reference to the orientation of the pump shaft 16. The axial outer edge 44 is typically located closer to the intake opening 26 and a further distance from the back plate 30 than the axial inner edge 46. The axial inner edge 46 of a vane 32 is located farther from the intake opening 26 and closer to the back plate 30.
[0077] With reference to FIGS. 5 and 6A, 6B and 6C, an explanation of how a vane 32 is interconnected to a back plate 30 according to one aspect of the invention will be described. A tab 48 extends from the radial inner edge 38 of the vane 32. The tab 48 is spaced axially outwardly from the axial inner edge 46 by a distance d.sub.1 that is the same or substantially the same as the thickness of the back plate 30. The tab 48 has an axially outer edge 50 and an axial inner edge 52. Two “L”-shaped cutouts 54 are formed along the axial inner edge 46 of the vane 32. A similarly shaped cutout 56 is formed at the intersection of the radial outer edge 40 and axial inner edge 46 of the vane 32. As shown in FIG. 6D, each of the cutouts form an axial channel 58, a radial channel 60 and a tab 62. Each of the tabs 62 have an axial length Li equal to or substantially the same as distance d.sub.1. The radial channel 60 has a radial inner most surface 66.
[0078] As seen by the sequence provided by FIGS. 6A-6C, a vane 32 is aligned over the slot segments 36a, 36b and 36c in the back plate 30. FIG. 6A is a cross-section of the back plate 30 taken through and including slot segments 36a, 36b and 36c. Although the slot segments are depicted in FIG. 5 as being curved, it should be appreciated that slot segments 36a, 36b and 36c may be in the form of a differently shaped curved line or a straight line. The vane may be pre-curved to fit into the slot segments or may be bent in place to fit into the slot segments. The vane is inserted into and through the slots as shown in FIG. 6B, and then moved to the left as shown in FIG. 6C. As a result, the back plate is captured between the tabs 62 and the axial outer edge 64 of the L-shaped cutouts 54 and 56. The axial outer edge 68 of the tabs 62 engage the lower surface 70 of the back plate 30, and the axial outer edge 64 of the cutouts 54 and 56 engage the upper surface 72 of the back plate 30. As shown in FIG. 6C, the hub 74 has a first portion 76 that is secured to the shaft 16 and is configured to receive the second portion 78. When the first portion is joined to the second portion, the tab 48 and back plate 30 are captured between the first portion 76 and second portion 78 to secure radial inner edge 38 of the vane 32.
[0079] When the pump is operating and the impellers rotating about the shaft, a centrifugal force will also act on the vanes 32 and assist in securing each vane relative to the back plate. More specifically, with reference to FIG. 6C, the vane 32 will be forced to the left such that the back plate 30 will be secured between surfaces 64, 66 and 68 of the radial channel 60. For added securement, the back plate may include grooves (not shown) that capture and secure the edges of the vane proximate surfaces 64, 66 and 68.
[0080] Also for enhanced securement, secondary or additional back plates 80 and 82 may optionally be included for securing the vanes 32 relative to the back plate 30. FIGS. 7A and 7B show optional additional back plate 80 which would be positioned on the axial outer surface 72 of the back plate 30, and FIGS. 8A and 8B show the optional additional back plate 82 which would engage the inner axial surface 70 of the back plate 30. Additional back plate 80 is formed with shoulders 84 to abut the radial inner edge 38 of each of the vanes 32, as well as overlap tab 48 of the vane 32. Secondary or additional back plate 82 includes outwardly extending radial arms 86 separated by channels 88. The axial inner edge 46 of the vanes fit in the channels 88, and the radial arms 86 lie in the space between adjacent vanes 32.
[0081] An exploded view of an impeller assembly according to one aspect of the present disclosure is illustrated in FIG. 9. It should be appreciated that the additional back plate 80 could also be positioned on the opposite side of the back plate 30, and additionally back plate 82 could also be used on both sides of the back plate 30. Further still, the additional back plate 30 could be differently configured. For example, the arms 86 could have a different length or could vary in length on a single back plate.
[0082] FIG. 10 further illustrates the relative position of optional additional back plates 80 and 82 relative to a single vane 32 and hub 74. The back plate 30 is omitted for clarity. The tab 48 is captured and secured by the additional back plates 80 and 82, together with the first and second portions 76 and 78 of the hub 74.
[0083] FIG. 11 is a cross-sectional view of a fully assembled impeller 22 positioned in the chamber 24 of a pump casing 12 according to one aspect of the present disclosure. As illustrated, a portion of each vane 32 extends axially outwardly from the back plate 30 such that the axial outer edge 44 of the vane is positioned adjacent the inner surface 84 of the chamber 24. A second portion of each vane 32 extends axially inward from the back plate 30 and forms the expeller portion 90 of the impeller 10. It should be appreciated that the vanes 32 may be configured and built to orient at different positions relative to the back plate 30 according to different embodiments of the present invention. More specifically, for a given internal chamber 24, the vanes 32 may be designed to provide different impeller vane depths and expeller vane depths using the same back plate to vary the performance specifications of a specific pump casing. FIG. 12A illustrates an embodiment in which the majority of the axial length of the vanes 32 is positioned on the axial outer side of the back plate 30 and a relatively small portion of the vanes 30, forming the expeller, are positioned on the axial inward side of the back plate 30. FIG. 12B shows more of the vanes 32 extending through the back plate 30 to enhance the expeller portion 90. FIG. 12C shows even more of the axial length of the vanes 32 extending through the back plate 30 and forming the expeller portion 90.
[0084] FIGS. 13A-13F show variety of vane curvatures. FIGS. 13A and 13B show a vane having a significantly curved profile. FIGS. 13C and 13D show a vane 32 having a less curved profile. FIGS. 13E and 13F show a straight vane. It should be appreciated by those of skill in the art that the embodiments of the present invention allow for vanes of an infinite range of curvatures from flat to significantly curved, and of constant radial curvature or complex curvatures as may be required to meet pump operating conditions. It is contemplated by the embodiments of the present application that for any given internal chamber of a specific casing, different back plates 30 may be made to operate in association with the existing shaft to provide a wide variety of different numbers of vanes and a different number of vane configurations, including but not limited to vane impeller and expeller depths, vane curvatures, vane profile, and angular orientation relative to the back plate.
[0085] According to aspects of the present disclosure, the configuration of the vanes 32 may also vary to achieve desired performance characteristics. FIGS. 14A, 14B and 14C illustrate the principal that the replaceable impeller vanes may vary in the axial direction. FIG. 14A illustrates a vane 32 with an axial outer edge 44 with a large degree of slope in the radial direction. FIG. 14B shows an impeller vane 32 with an axial outer edge 44 with a moderate degree of slope in the radial direction. FIG. 14C shows an impeller vane 32 with an axial outer edge 44 that has a flat or no slope. Although the vanes 32 depicted in FIGS. 14A-14C are straight, they may also have a two dimensional curve in the radial direction and/or have a more complex three dimensional curvature. More specifically, the vanes 32 are curved in the radial direction, from inner radial edge 38 to outer radial edge 40, and in the axial direction as illustrated by the sloped vane shape along the outer axial edge 44. It should be further appreciated that all of the edges of a vane, the axial outer edge 44, the axial inner edge 46, the radial inner edge 38 and radial outer edge 40 may vary in slope or profile, wherein the shape may include cutouts or other non-uniformities that alter fluid flow.
[0086] Examples of vanes 32 with a complex configuration or curvature are illustrated in FIGS. 14D-14G. FIG. 14D illustrates an aspect of the present disclosure where the slot 36 is formed at an angle relative to the back plate 30 such that one surface 32a is positioned at an acute angle relative to the back plate and a second surface 32b is positioned at an obtuse angle relative to the back plate. FIG. 14E illustrates an impeller with a three dimensional complex shape, where the vanes 32 are curved radially and axially. For example, the axial outer edges 44 are laid over or “dog eared.” Also, two differently configured sets of vanes 32′ and 32″ alternate on the back plate. The radial length of one set of vanes 32′ is staggered relative to the length of the second set of vanes 32″. FIG. 14F illustrates a top plan view of an impeller where the vanes 32 are identical, but each vane has a complex configuration. Complex in this context means the vane has curvature in three dimensions, not just two dimensions as illustrated in FIGS. 13A and 13C. Complex vanes provide further performance alternatives.
[0087] It should also be appreciated that the shape or configuration of the replaceable vanes 32 may vary from the profiles as shown in the accompanying Figures. The reasons to alter vane profiles are for performance and efficiency of a particular pump, and to accommodate different pumpages. Thus, a single back plate may be utilized with different sized and shaped vanes in different chambers of different casings or one of a variety of back plates may be selected and combined with a variety of vane styles to meet end use applications.
[0088] In another aspect of the invention, the replaceable vanes may be made from metal, composite materials or plastic. Vanes may also be made thicker or thinner. A vane 32 having increased thickness is shown in FIG. 14G. Vanes may also be made with varying surface smoothness or roughness, and may include grooves or other surface effects to assist in moving the pumpage. If made from composite materials, according to one aspect of the present disclosure, the primary fibers of the composite material may be aligned in the axial direction. With the primary fibers so aligned, the vane will have desirable stiffness in the axial direction, yet will have flexibility in the radial direction along the length of the vane. FIG. 15 illustrates this concept. In this manner, the vanes will be sufficiently pliable to adapt to more than one curved configuration such that a single vane may be utilized with multiple back plates having differently configured slots. It should also be appreciated that the composite fibers may be differently oriented to achieve different results in vane characteristics.
[0089] FIGS. 16A and 16B illustrate a further aspect of the present disclosure. Here, the back plate 30 may be made from thinner material, or from plastic or composites as the end application allows. Ribs 94 are formed in the back plate to add rigidity. The ribs 94 may be oriented radially straight as illustrated in FIG. 16A, or they may follow the curvature of the vanes 32 or some other curvature. The ribs 94 may also be formed on one or both surfaces 70 and 72 of the back plate.
[0090] All of the impellers described thus far are open impeller designs. FIGS. 17A and 17B show further aspects of the present disclosure. In FIG. 17A, the configuration of impeller 10 utilizes dual back plates 30 and 30′. Dual back plates provide added support and rigidity to the impeller by providing support to the vanes 32 at multiple locations along the axial length of the vanes. By providing increased support, the individual back plates 30 and 30′ may be constructed using less material, and the individual vanes 32 may also be constructed using less material or have a thinner profile, made from less expensive material or less rigid metals or carbon fibers, thereby saving cost while maintaining performance. FIG. 17B shows an alternative design with the back plates 30 and 30′ spaced further apart. Also, the expeller vanes 90 are deeper compared to FIG. 17A. The configuration illustrated in FIG. 17B, and to a lesser extent in FIG. 17A, is a hybrid design. In other words, these configurations combine performance characteristics of both open and close impeller designs.
[0091] Impellers according to the present disclosure can also be made with a closed impeller design such as shown in FIGS. 18A-18B. Here, an end plate 96 is configured to enclose the axial outer edges 44 of the vanes 32 to provide a closed impeller configuration. The end plate 96 includes a central aperture 98 to allow intake of fluids. The end plate 96 may be configured so as to connect to the end of shaft 16 utilizing an internal hub, or alternatively may be configured to attach to the axial outer edge 44 of the vanes 32 themselves, such as by the locking arrangements shown in FIGS. 6A-6C.
[0092] FIGS. 19A and 19B illustrate a further aspect of the present disclosure. As shown, the back plate 30 has a curved or concave profile. The curved profile provides additional structural rigidity to the back plate, allowing it to be made from less rigid or thinner materials, resulting in potential cost savings. Also, the perimeter edge 42 of the back plate 30 need not be circular. For example, a scalloped perimeter edge where cutouts are formed along the perimeter edge may reduce axial thrust by reducing surface area of the back plate.
[0093] FIG. 20 shows a further aspect of the present disclosure. As illustrated, the aperture 34′ is a “D”-shape rather than the pentagon shape shown in other embodiments. It should be appreciated by those of skill in the art that the center aperture can have a variety of configurations sufficient for securement to the shaft 16. According to another aspect of the present disclosure, the vanes 32 may be designed to float or move relative to a back plate 30. FIG. 21A is a cross-sectional view of such an embodiment. A vane 32 is positioned within the chamber 24. Cutouts 100 are formed along the axial inner edge 102. Here, as more clearly shown in FIG. 21B, the cutouts 100 are generally “S” or “Z” shaped to engage and secure the back plate 30. The cutouts 100 include an axially oriented channel 104 having an axial length that allows the vane 32 to move relative to the back plate 30 in the axial direction. FIGS. 22A and 22B illustrate the concept that over time the axial outer edge 106 of the vane 32 wears against the inner surface 108 of the chamber 24. Over time the vane 32 will decrease in axial length due to the wear, but the vane will automatically reposition itself relative to the back plate 30 such that the outer axial edge 106 remains in contact with the interior surface of the chamber while the axial inner edge 102 increasingly separates from the inner surface of the chamber 24 to form a gap 110. As also illustrated, the hub 112 is configured with an inner notch 114 to fixedly secure the perimeter edge 42 of the back plate and an axially extended outer notch 116 to allow the tab 118 at the inner radial edge 120 of the vane 32 to float relative to the hub 112. The hub 112 may comprise multiple component pieces interconnected during assembly in order to secure the vane and back plate. In this manner, the vane is allowed to float and maintain contact with the inner surface of the chamber to provide a best case for efficiency and permit longer life for the impeller vanes 32.
[0094] In view of the foregoing, it will be appreciated that one may dismantle and existing pump and change the vanes to thereby transform an existing pump into something better. However, the ability to design and produce quickly the a more perfect impeller for a given application is an equally if not more important benefit. The more perfect impeller design being the design that achieves the desired flow and head at the lowest power draw or highest efficiency and at the lowest part cost. For a given pump application, the more perfect impeller may be designed and manufactured more quickly and effectively, giving the end user or customer significantly improved if not optimal performance and service
[0095] The foregoing discussion of the invention has been presented for purposes of illustration and description. The foregoing is not intended to limit the invention to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the invention.
[0096] While various embodiments of the safety system present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention. In addition, it should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein. Other modifications or uses for the present invention will also occur to those of skill in the art after reading the present disclosure. Such modifications or uses are deemed to be within the scope of the present invention.
