Electric diaphragm pump with offset slider crank

Abstract

A diaphragm pump has a crankshaft rotatable about a rotation axis and coupled to a piston. The piston is displaceable reciprocally within a piston cylinder along a motion axis between a suction stroke and a discharge stroke. A diaphragm housing coupled to the piston cylinder at least partially defines a pumping chamber through which fluid is pumped upon reciprocation of the piston. The motion axis intersecting the connection between the piston and the connecting rod can not intersect the rotation axis of the crankshaft such that, relative to an arrangement in which the motion axis intersects the rotation axis, a peak of a piston side load force is reduced during the discharge stroke and a peak of the piston side load force is increased during the suction stroke in order to obtain an improved balance between the peaks of the piston side load force of the discharge stroke and the suction stroke.

Description

[0001] This application is a continuation-in-part of patent application number 202010161297.5, filed March 10, 2020, entitled “Electric Diaphragm Pump with Offset Slider Crank.”

[0002] Cross Reference to Related Applications

[0003] This application claims the benefit of U.S. Provisional Patent Application Serial No. 62 / 816,732, filed March 11, 2019, and incorporated herein by reference in its entirety. TECHNICAL FIELD

[0004] The present disclosure relates to positive displacement pumps for moving liquids and slurries. More particularly, but not exclusively, the present disclosure relates to diaphragm pumps having electric motors for actuating one or more diaphragms of the pump. BACKGROUND

[0005] Pumps can be used to facilitate the transfer of fluids, including but not limited to liquids, slurries, and mixtures. Accordingly, pumps such as, for example, positive displacement pumps, can be designed to handle a range of fluid viscosities, including fluids containing relatively significant solids content, and to pump relatively harsh chemicals.

[0006] Positive displacement pumps can take a variety of different forms, including, for example, positive displacement pumps that utilize a diaphragm or piston in connection with the intake and subsequent discharge of fluid from a chamber of the pump. For example, with respect to positive displacement pumps that are diaphragm pumps, such pumps typically include a pair of opposing diaphragms that reciprocate relative to one another along a common axis. Conventionally, these “double diaphragm” pumps are pneumatically driven with high pressure air. Such designs can allow the pressure generated by the pump to be controlled by the pressure of air in the system. Moreover, because pneumatic drives can generally prevent the generation of sparks, such air-operated diaphragm pumps are often suitable for operation in potentially explosive environments.

[0007] However, air-operated diaphragm pumps (AODPs) have their drawbacks. For example, the high pressure air of AODPs is typically generated by an air compressor, which can be an additional piece of equipment required for the system and has associated costs. Additionally, reliance on pneumatic technology can result in poor net operational energy usage due to relatively significant losses of energy in the generation, delivery, and conversion of high pressure gas to mechanical work.

[0008] Accordingly, there remains an opportunity to create a pump that includes the typical advantages of diaphragm pumps and improves upon them, while providing an alternative to the inefficiencies of pneumatically driven pumps. SUMMARY

[0009] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the DETAILED DESCRIPTION. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0010] An aspect of embodiments of the present disclosure is a diaphragm pump that can include a crankcase and a crankshaft positioned at least partially within the crankcase and rotatable about a rotational axis. The diaphragm pump can include a piston coupled to the crankshaft by a connecting rod, the piston being reciprocally displaceable within a piston cylinder and along a motion axis between a suction stroke and a discharge stroke, the motion axis intersecting the connection between the piston and the connecting rod. A diaphragm housing can be coupled to an end of the piston cylinder and can be configured to at least partially define a pumping chamber through which a pumping fluid is pumped as the piston reciprocates. The motion axis can not intersect the rotational axis of the crankshaft such that, relative to an arrangement in which the motion axis intersects the rotational axis, a peak of a piston side load force encountered during the discharge stroke is reduced and a peak of the piston side load force encountered during the suction stroke is increased to achieve a closer balance between the peaks of the piston side load forces of the discharge and suction strokes.

[0011] Another aspect of embodiments of the present disclosure is a diaphragm pump system that can include a crankcase and a crankshaft positioned at least partially within the crankcase and coupled to an electric motor. Further, the crankshaft can be rotatable about a rotational axis. At least three pistons can be arranged radially about the crankcase, each of the at least three pistons being coupled to a crank web of the crankshaft by a connecting rod. Additionally, each of the pistons can be reciprocally displaceable within a piston cylinder and along a motion axis between a suction stroke and a discharge stroke, the motion axis of each of the at least three pistons intersecting the connection between the piston and the connecting rod. The diaphragm pump system can further include at least three diaphragm housings each coupled to an end of the piston cylinder and configured to at least partially define a pumping chamber through which a pumping fluid is pumped as the piston reciprocates. Further, the motion axis of each of the at least three pistons can not intersect the rotational axis of the crankshaft such that, relative to an arrangement in which the motion axis intersects the rotational axis, a peak of a piston side load force encountered during the discharge stroke is reduced and a peak of the piston side load force encountered during the suction stroke is increased such that a closer balance is achieved between the piston side load forces of the discharge and suction strokes.

[0012] Additionally, an aspect of embodiments of this disclosure is a diaphragm pump that may include a crankcase and a crankshaft, the crankshaft being at least partially located within the crankcase and rotatable about an axis of rotation. The diaphragm pump may include a piston connected to the crankshaft via a connecting rod, the piston being reciprocally displaced within a piston cylinder between intake and exhaust strokes. A diaphragm housing may be coupled to an end of the piston cylinder and configured to at least partially define a pumping chamber through which pumped fluid passes during piston reciprocation. The piston cylinder may extend about a central longitudinal cylinder axis intersecting the axis of rotation. Furthermore, the piston may be pivotally connected to the connecting rod via a piston pin positioned along a central longitudinal axis parallel to and linearly offset from the central longitudinal cylinder axis, such that, relative to an arrangement where the piston pin is not linearly offset from the central longitudinal cylinder axis, the peak value of the piston-side load force encountered during the exhaust stroke is reduced, and the peak value of the piston-side load force encountered during the intake stroke is increased, in order to achieve a closer balance between the piston-side load forces of the exhaust and intake strokes.

[0013] These and other aspects of this disclosure will be better understood in conjunction with the accompanying drawings and the following detailed description. Attached Figure Description

[0014] The description herein refers to the accompanying drawings, which are shown throughout several views, and similar reference numerals refer to similar parts.

[0015] Figure 1 A diaphragm pump system according to an embodiment shown in this disclosure is illustrated.

[0016] Figure 2 A perspective side view of a diaphragm pump according to an embodiment shown in this disclosure is presented.

[0017] Figure 3 Show along Figure 2 The cross-sectional view of the diaphragm pump is shown in line 3-3.

[0018] Figure 4 Show along Figure 2 The cross-sectional view of the diaphragm pump is shown in line 4-4.

[0019] Figure 5 An exploded view of a diaphragm pump system and associated support according to an embodiment of the present disclosure is shown.

[0020] Figure 6 A side view of a diaphragm pump system and associated support according to an embodiment of the present disclosure is shown.

[0021] Figure 7 A side perspective view of the crankcase and piston assembly of a diaphragm pump according to an illustrated embodiment of the present disclosure is shown.

[0022] Figure 8 A side view of a crankcase, an inner diaphragm housing, and certain piston members of a diaphragm pump according to the illustrated embodiment of the present disclosure is shown.

[0023] Figure 9 A graph showing outlet pressure at a common outlet of an electric diaphragm pump having three diaphragm housings as a function of crank angle according to the illustrated embodiment of the present disclosure is shown.

[0024] Figure 10 A graph showing outlet pressure in a prior art dual diaphragm pump as a function of pump cycle is shown.

[0025] Figure 11A A cross-sectional view of a portion of an electric diaphragm pump having a linear offset slider crank mechanism according to the illustrated embodiment of the subject disclosure is shown.

[0026] Figure 11B An enlarged view from Figure 11A block 11 depicting a linear offset centerline of a piston cylinder of an offset slider crank mechanism according to the illustrated embodiment of the subject disclosure is shown.

[0027] Figure 12 A graph depicting an example of the effect of an offset design of a slider crank mechanism on piston side loading as a function of crank angle is shown.

[0028] Figure 13 A graph depicting an example of the effect of an offset design of a slider crank mechanism on pump outlet pressure as a function of crank angle is shown.

[0029] Figure 14 A piston pin housed in a piston pin cavity in a piston that is linearly offset from the corresponding cylinder axis is shown.

[0030] Figure 15A An enlarged view of a portion of a pump and an associated piston of a slider crank mechanism having an offset axis of motion and whose reciprocating displacement is guided by linear guides is shown.

[0031] Figure 15B A front perspective view of a portion of a pump having a piston that is slidably coupled to a piston cylinder by linear guides is shown.

[0032] Figure 16 An enlarged view of a portion of a diaphragm pump in which the axis of motion is angularly offset relative to at least the axis of rotation is shown.

[0033] The foregoing SUMMARY, as well as certain embodiments of the present disclosure, will be better understood when read in conjunction with the following detailed description and with reference to the drawings, in which: DETAILED DESCRIPTION

[0034] Certain terminology is used in the foregoing description for convenience and is not intended to be limiting. Words such as "upper," "lower," "top," "bottom," "first" and "second" describe the orientation in the drawings to which reference is made and are used in connection with the extreme ends of the components to which they refer. This terminology includes the words specifically mentioned above, derivatives thereof and words of similar import. Additionally, the words "a" and "one" are defined to mean one or more of the items it describes, unless specifically stated otherwise. The phrases "at least one of' and "one or more of' followed by a list of two or more items, such as "A, B, or C," mean any individual one of A, B or C, as well as any combination thereof.

[0035] Figure 1 A diaphragm pump system 50 according to the illustrated embodiment of the present disclosure is shown. The diaphragm pump system 50 can include, among other things, a diaphragm pump 10 that is operably coupled to a control system 12 and a driver 14. While the embodiments discussed herein are discussed in terms of diaphragm pump systems that include electrically powered diaphragm pump systems, at least certain features can also be applicable to various other types of pump systems, including but not limited to other types of pumps and positive displacement pumps, including but not limited to positive displacement pumps that utilize pistons rather than diaphragms to move fluid into / out of a pumping chamber of the pump. Additionally, at least certain features of the diaphragm pump systems discussed herein can provide relatively significant advantages when compared to at least pneumatically powered diaphragm pump systems, including but not limited to increased energy efficiency in net operating energy usage.

[0036] According to certain embodiments, the control system 12 can include, among other things, an external embedded controller 11 that is communicatively coupled to a human machine interface 13. The external controller 11 can be configured to automate the operation of the diaphragm pump 10 at least for batching or dosing purposes. The external controller 11 can also be configured to add other cycle counting functionality to the system 50. Additionally, the external controller 11 can be configured to correlate the speed of the driver 14, such as, for example, the motor speed, to the flow rate of the process fluid being pumped by the diaphragm pump. The external controller 11 can also include an override for stall events for extended periods of time. Further, the control system 12 can be optional to supplement the motor drive, such as a variable frequency drive (VFD) 15 that is configured to operate the driver 14.

[0037] As at least Figure 1As shown, the diaphragm pump 10 is mechanically coupled to the drive 14. While various types of drives 14 can be used, including but not limited to various different types of engines and motors, according to the illustrated embodiment, the drive 14 is an electric motor. Additionally, the drive 14 can be operatively coupled to the crankshaft 40 of the diaphragm pump system 50. Figure 4 This allows the operation of the drive 14 to facilitate at least the crankshaft 40 about the crankshaft axis (or "axis of rotation") 100 ( Figure 4 The rotational displacement of ). Furthermore, such as at least Figure 1 As shown, according to some embodiments, such an operable connection between the drive 14 and the crankshaft 40 may include a gearbox 16, which may be configured to regulate and / or control the relative speed and torque transmitted from the drive 14 to the crankshaft 40.

[0038] Such as at least Figures 1-5 As shown, according to some embodiments, the diaphragm pump 10 may include, in addition to other components, a crankcase 17, a plurality of diaphragm housings 18, and a common inlet manifold 20. Figure 5 ), public exit manifold 38 and slider-crank mechanism 21 ( Figure 3 Furthermore, such as by at least Figure 2 As shown, crankcase 17 may include a lower crankcase 26 and an upper crankcase 28. For example, at least... Figure 4 As shown, the lower crankcase 26 provides a lower crankcase cavity 86. Additionally, the crankshaft 40 protrudes from the crankcase 17 for operable connection with the drive 14, as previously described.

[0039] While the number of diaphragm housings 18 may vary for different embodiments, the inventors of the disclosed subject matter have determined that an odd number of diaphragm housings (more than one) is preferred. Therefore, the illustrated embodiments depict, but are not limited to, a diaphragm pump 10 having three diaphragm assemblies 18. Furthermore, each diaphragm housing 18 may be coupled to an adjacent piston 68 of a slider-crank mechanism 21, such as, for example… Figure 3 As shown. In addition to multiple pistons 68 that can reciprocate within their respective piston cylinders 60, the shown slider-crank mechanism 21 may also include a cam 82 (also referred to as a crank) of the crankshaft 40 and a connecting rod 62, such as, for example... Figure 4 As shown.

[0040] Additionally, according to at least certain embodiments, each of the diaphragm housings 18 can have generally similar components. Similarly, at least certain components of the slider crank mechanisms 21 associated with a particular diaphragm housing 18 can have the same construction as other similar components of the slider crank mechanisms 21 associated with another diaphragm housing 18. Thus, for example, each of the pistons 68, piston cylinders 60, and / or connecting rods 62 of the slider crank mechanisms 21 used with a particular diaphragm housing 18 can have similar construction and features as similar components used with another diaphragm housing 18. Thus, it should be understood that, unless otherwise noted, parallel elements and associated features for such elements can exist for each of the diaphragm assemblies 18 and associated slider crank mechanisms 21, whether such parallel elements and features are actually visible in certain figures of the present disclosure, or whether they are explicitly discussed separately herein.

[0041] Each of the diaphragm housings 18 can include an outer housing 42, which can also be referred to as a fluid cap, and an inner housing 44. As shown at least Figure 3 At least an inner portion of the outer housing 42 can generally define at least a portion of a pumping chamber 46 of the diaphragm housing 18. The pumping chamber 46 can be in fluid communication with the inlet 22 and outlet 24 of the diaphragm housing 18. Thus, according to the illustrated embodiment, at least a portion of the process fluid entering the common inlet manifold 20 of the diaphragm pump 10 can enter the pumping chamber 46 of the diaphragm housing 18 through the inlet 22. Further, such process fluid can exit the pumping chamber 46 through the outlet 24 of the diaphragm housing 18, and continue on to the common outlet manifold 38 of the diaphragm pump 10.

[0042] Additionally, as Figure 5 shown, according to certain embodiments, a one-way check valve 48 can be functionally positioned proximate both the inlet 22 and outlet 24 of each of the diaphragm housings 18. While a variety of types of one-way check valves can be used, according to certain embodiments, the one-way check valves 48 are ball valves. Additionally, according to certain embodiments, such ball valves can be gravity operated, and thus do not include a biasing mechanism, such as, for example, a spring. Alternatively, however, according to other embodiments, the one-way check valves 48 can include a biasing element, such as, for example, a spring, in addition to other forms of biasing elements.

[0043] Figure 3 shown along Figure 2FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. Diaphragm housing 18 includes diaphragm 80, which can be used to vary the volume, and thus the pressure, within pumping chamber 46. Operation of diaphragm 80 can be used to draw process fluid into pumping chamber 46 through inlet 22, such as, for example, by displacing or flexing at least a portion of diaphragm 80 in a first direction to increase the volume within pumping chamber 46, and thereby decrease the pressure. Further, displacement or flexing of diaphragm 80 in an opposite, second direction can decrease the volume of pumping chamber 46, and thereby provide a pressure that can force at least a portion of the process fluid out of pumping chamber 46 through outlet 24.

[0044] While a variety of types of diaphragms can be used, according to certain embodiments, diaphragm 80 is a conventional flexible diaphragm. Additionally and optionally, according to certain embodiments, diaphragm 80 can be positioned in an opposite orientation between inner housing 44 and outer housing 42 as compared to the use of a diaphragm in a conventional AODP. According to certain embodiments, such as at least the embodiment shown in FIGS. 2 and 3, diaphragm 80 can be positioned such that the arcuate shape of annular flexible portion 83 of diaphragm 80 is disposed in a direction generally away from pumping chamber 46, and instead toward the general direction of containment cavity 81 of diaphragm housing 18. Figure 3 and Figure 4 According to certain embodiments, such as at least the embodiment shown in FIGS. 2 and 3, diaphragm 80 can be positioned such that the arcuate shape of annular flexible portion 83 of diaphragm 80 is disposed in a direction generally away from pumping chamber 46, and instead toward the general direction of containment cavity 81 of diaphragm housing 18.

[0045] Diaphragm 80 within diaphragm housing 18 can be designed as a replaceable wear component. For example, in the illustrated embodiment, diaphragm 80 is mechanically coupled to second end 94 of associated piston 68 via removable mechanical fasteners 74, such as, for example, bolts. Further, according to certain embodiments, mechanical fasteners 74 can extend through inner gasket 76 and outer gasket 78, which are positioned on and support opposite sides of diaphragm 80. For example, as shown at least in FIG. 3, a radially inner portion of diaphragm 80 can be secured between inner gasket 76 and outer gasket 78. Inner gasket 76 and outer gasket 78 can be configured to provide at least stable and rigid support to adjacent portions of diaphragm 80. Additionally, a radially outward portion of diaphragm 80 can be securely fitted between opposing sealing surfaces of inner housing 44 and outer housing 42. Further, according to certain embodiments, outer gasket 78 can be integrated into diaphragm 80 such that outer gasket 78 and diaphragm 80 together have a unitary structure. Figure 3

[0046] ​Further, as described below, the diaphragm housing 18 can be configured to minimize or avoid contamination of process fluid that can leak past the diaphragm 80, such as, for example, due to the diaphragm 80 being damaged or worn. Such minimization or prevention of leakage past the diaphragm 80 can also minimize interruptions in and / or damage to the diaphragm 80 and thus the diaphragm pump 10 in operation. Additionally, the diaphragm pump 10 can similarly be designed to minimize or avoid contamination of process fluid that can leak through the diaphragm 80.

[0047] More particularly, as can be seen in at least Figure 3 More particularly, as can be seen in at least

[0048] Additionally, prior art diaphragm pumps typically use a high pressure working fluid, such as hydraulic fluid, that is stored behind the diaphragm to exert fluid pressure on the back of the diaphragm that assists or fully drives the diaphragm. However, with such designs, leakage through the diaphragm can cause the working fluid to flow from the back of the diaphragm and into the process fluid, thereby contaminating the process fluid. However, unlike such designs, the containment cavity 81 of the diaphragm housing 18 disclosed herein can only contain low pressure air because the diaphragm 80 is substantially fully mechanically actuated, such as, for example, by the corresponding piston 68 and the components associated with the mechanical coupling of the piston 68 to the diaphragm 80. Thus, according to certain embodiments of the subject disclosure, unlike prior designs that at least partially, if not entirely, rely on high pressure working fluid to drive the diaphragm, the annular flexible portion 83 of the diaphragm 80 is not driven by working fluid, but instead can be substantially fully mechanically actuated.

[0049] The containment cavity 81 can also be substantially sealed from a lubricant sump that can be within at least a portion of the crankcase 17, such as, for example, lubricant within the crankcase cavity 86 that is used to reduce wear and distribute heat of the crankshaft 40 and connecting rods 62. For example, the seal assembly 72 (Figure 3 ) can be supported against an outer surface of the piston 68. The seal assembly 72 can include, for example, one or more oil-facing seals and one or more cavity-facing seals, including but not limited to bellows seals and double seals. According to certain embodiments, the cavity-facing seal can be a bellows design (not shown) that spans between the second end 94 of the piston 68 and the piston cylinder 60. The seal assembly 72 can be constructed and positioned to prevent the mixing of lubricant with process fluid, even if process fluid were to leak past the diaphragm 80 and to the containment cavity 81.

[0050] Additionally, during at least maintenance operations, the containment cavity 81 can be restricted from process fluid to minimize downtime of the diaphragm pump 10. For example, by simple removal of the outer housing 42 of the diaphragm housing 18 and the mechanical fasteners 74, as at least Figure 4 shown, the diaphragm 80, as well as the inner gasket 76 and the outer gasket 78, can be removed, and the containment cavity 81 can be easily and thoroughly cleaned.

[0051] With respect to operation of the slider-crank mechanism 21, the piston 68 reciprocates along a piston axis that extends through the bore 59 of the piston cylinder 60 that is positioned between the crankcase 17 and the diaphragm housing 18. The piston 68 extends between a first end 92 and a second end 94 of the piston 68. The portion of the piston 68 proximate the crankcase 17 (i.e., the first end 92 of the piston 68) can include a piston pin cavity in which the piston pin 64 is positioned, the piston pin 64 attaching the piston 68 to the connecting rod 62.

[0052] The piston cylinder 60 can be removably mounted to the lower crankcase 26. As at least Figure 3 and Figure 4 shown, according to certain embodiments, the piston cylinder 60 can be aligned with the aperture 88 of the lower crankcase 26 such that a portion of the piston cylinder 60 extends through the aperture 88 and toward the crankcase cavity 86. The piston cylinder 60 can also mate with an inner surface of the aperture 88. Such an arrangement can provide increased stability to the piston cylinder 60 during operation of the pump 10. Additionally, such a construction can reduce the radial dimension of the pump 10 via such positioning of the piston cylinder 60, and thus, the piston 68, the diaphragm 80, and the outer housing 42 can be at a reduced radial position(s) from the crankshaft 40. Additionally, as at least Figure 8 shown, the piston cylinder 60 can further include a shoulder 61 that can be attached to a flat surface 138 of the crankcase 17, thereby providing increased stability to the piston cylinder 60 during operation of the pump 10, and improving ease of access and disassembly.

[0053] According to certain embodiments, the piston 68 and the piston cylinder 60 can be designed for controlled metal-to-metal sliding contact. In addition, one or both of the piston 68 and the piston cylinder 60 can be surface treated, such as with a diamond coating, in order to control wear of one or both of the piston 68 and the piston cylinder 60. In other embodiments, rolling contact can be provided between the piston 68 and the piston cylinder 60, such as, for example, via a rolling element bearing that is a recirculating ball track.

[0054] Additionally or alternatively, a sleeve or rider band 70 Figure 7 ) can be positioned circumferentially around a portion of the piston 68, which can minimize or prevent metal-to-metal contact between adjacent portions of the piston 68 and the piston cylinder 60. The sleeve 70, which can be replaceable as a wear part, can be made of a variety of materials, including, for example, a polymer, a ceramic, or a metal. Exemplary polymers that can provide suitable wear properties over a range of necessary pressures and speeds of the piston 68 can include, among other materials, a polyester reinforced resin and a bronze-filled polytetrafluoroethylene (PTFE).

[0055] For example, among other features, Figure 7 A sleeve 70 is shown attached to a first piston 68, as well as another second piston 68 prior to attachment of the sleeve to the piston 68. With respect to the second piston 68, as seen, the outer surface of the piston 68 includes a sleeve recess 150 formed into the piston 68, the sleeve recess 150 configured for seating of the sleeve onto the piston 68. As also seen, according to certain embodiments, the sleeve recess 150 can be a portion of the outer surface of the piston 68 that has a size, such as, for example, a diameter, that is different, such as, for example, smaller, than a corresponding size of other adjacent portions of the piston 68. In addition, while the sleeve recess 150 can be positioned at a variety of locations along the piston 68, as shown, according to certain embodiments, the sleeve recess 150 can be located at a location where the sleeve 70, which is then attached to the piston 68, will cover the piston pin 64 that attaches the piston 68 to an associated connecting rod. Figure 7

[0056] As previously mentioned, and as at least Figure 4 ​​As shown, the crankshaft 40 is rotatable about the axis of rotation 100. Similarly, a cam 82, offset relative to the crankshaft 40, includes a central axis 102 that may be parallel to and offset from the axis of rotation 100. According to some embodiments, the crankshaft 40 may include a two-part shaft. Furthermore, the cam 82 may be integrated with a first portion 41 of the crankshaft 40, while a second portion 43 of the crankshaft 40 may form a seat 108. The seat 108 may be secured in the lower crankcase 26 by a first bearing assembly 110, and a second bearing assembly 112 may secure the crankshaft 40 in the upper crankcase 28. Additionally, the upper crankcase 28 may include a seal 114 extending around a portion of the crankshaft 40.

[0057] like Figure 4 As shown in the middle portion, connecting rod 62 extends from its connection to piston 68 as previously described to its connection to cam 82 of crankshaft 40. While connecting rod 62 can be connected to cam 82 in various different ways, according to the illustrated embodiment, connecting rod 62 is connected to cam 82 via a bearing ring or journal bearing 84. While bearing ring 84 can be connected to connecting rod 62 in various ways, such as by at least... Figure 4 As shown, however, according to the illustrated embodiment, the bearing ring 84 may be positioned within an orifice in the connecting rod 62. The bearing ring 84 may also be configured to facilitate sliding movement between the connecting rod 62 and the cam 82 of the crankshaft 40. Additionally, according to the illustrated embodiment, each bearing ring 84 may be vertically displaced along the cam 82 relative to each other and centered on the central axis 102 of the cam 82.

[0058] Such as at least Figure 3 and Figure 4 As shown, extending through each piston cylinder 60 is the corresponding central longitudinal cylinder axis l16. Additionally, according to some embodiments, each piston 68 shares its central axis with its corresponding cylinder axis 116. Furthermore, according to some embodiments, the piston pin 64 may also be positioned on the cylinder axis 116. Alternatively, according to other embodiments, the piston pin 64 may be linearly offset from the cylinder axis 116, which provides an offset feature to the slider-crank mechanism 21 that improves the balance of piston-side load forces and stresses encountered during the discharge and intake strokes of the diaphragm housing 18, as described below.

[0059] For example Figure 3 and Figure 4 As partially shown, the diaphragm housing 18 can similarly be oriented about the cylinder axis 116 of the associated piston cylinder 60. Additionally, the bearing ring 84, connecting rod 62, piston cylinder 60, and piston 68 can be centered on a horizontal plane that, together with similar horizontal planes for the other diaphragm housings 18, can be vertically displaced along the cam 82.

[0060] Additionally, according to certain embodiments, each cylinder axis 116 for a diaphragm housing 18 is perpendicular to the rotational axis 100 of the crankshaft 40. Moreover, according to certain embodiments, the cylinder axes 116 of the diaphragm housings 18 can also be substantially equally radially spaced about the rotational axis 100. For example, with respect to Figure 3 According to certain embodiments in which the diaphragm pump 10 includes three diaphragm housings 18, each cylinder axis 116 is disposed 120 degrees from another cylinder axis 116. Because all three connecting rods 62 of the diaphragm housings 18 are disposed on the same cam 82 and equally spaced about the rotational axis 100, the reciprocating motion of the respective pistons 68 are 120 degrees out of phase with one another. Thus, if the piston 68 of a first diaphragm housing 18 is at 0 degrees in its reciprocating cycle, the piston 68 of a second diaphragm housing 18 is at 120 degrees in its respective reciprocating cycle, and the piston 68 of a third diaphragm housing 18 is at 240 degrees in its respective reciprocating cycle. Similarly, for certain embodiments including five diaphragm housings, each piston can be disposed approximately 72 degrees from its adjacent pistons.

[0061] Figure 5 An exploded view of an exemplary diaphragm pump 10 and associated stand 30 according to the illustrated embodiments of the present disclosure is shown. As Figure 5 As shown in the embodiments depicted in FIGS. 1-3, the diaphragm pump 10 can include a driver 14 and a gear box 16 in a vertical orientation relative to the crankcase 17 and stand 30, with the drive shaft 19 of the driver 14 oriented to be directly or indirectly coupled coaxially with the crankshaft 40. Figure 5 Also shown in FIG. 4 is an exploded view of the diaphragm housing 18, which, as previously mentioned, can each include at least an outer housing 42, an inner housing 44, a diaphragm 80, and a mechanical fastener 74. Also shown are the common inlet manifold 20 and common outlet manifold 38, as well as the one-way check valves 48 in operable communication with the common inlet manifold 20 and common outlet manifold 38, respectively. Additionally, Figure 5 A three-legged stand 30 is shown, with individual legs of the stand 30 disposed about the crankcase 17 at locations between adjacent diaphragm housings 18. Such legs of the stand 30 can secure the pump 10 on a horizontal work surface with minimal work surface footprint.

[0062] Figure 6 A side view of a diaphragm pump 10 mounted to an alternative stand 30' according to at least one embodiment of the subject disclosure is shown. Figure 6 The stand 30' depicted in FIG. 5 differs from the stand 30 of FIG. 4 in that the stand 30' includes a single leg 32' that is disposed about the crankcase 17 at a location between adjacent diaphragm housings 18. Figure 5The bracket 30 may include an upper bracket portion 31, a lower bracket portion 32, a bracket base 34, and a plurality of support members 36. The diaphragm pump 10 may be attached to the bracket 30' at the upper bracket portion 31 and / or the lower bracket portion 32. The bracket base 34 may be used to secure the diaphragm pump 10 to a work surface or floor other than another surface. Additionally, the bracket base 34 may be configured for relatively easy picking and moving by forklifts or other handcarts.

[0063] As at least Figure 5 and Figure 6 As indicated, the diaphragm pump 10 can be configured to be supported by supports 30, 30' in a substantially vertical orientation. Therefore, the rotation axis 100 of the crankshaft 40 ( Figure 5 The drive shaft 19 of the actuator 14 can also be positioned in a generally vertical direction. Furthermore, this orientation accommodates the drive shaft 19 of the actuator 14, which is substantially coaxial with the axis of rotation 100 of the crankshaft 40. This vertical orientation of the diaphragm pump 10 offers numerous advantages, including, for example, a significantly reduced workplace footprint and horizontal proximity to the pump 10 (which is relatively independent of other pumping equipment), which can benefit the ability to maintain the pump 10, including replacement, repair, and / or cleaning of the pump 10 and / or its components. Additionally, this vertical orientation of the diaphragm pump 10 allows the one-way check valve 48 to operate based on gravity, which can potentially reduce the number of components in the check valve 48, including, for example, avoiding the use of springs to bias the ball within the check valve 48. However, although... Figure 1 , Figure 5 and Figure 6 The driver 14 depicted is shown mounted in a vertical orientation, but the driver 14 and other components of the diaphragm pump system 50 may be mounted in a variety of other orientations.

[0064] Figure 7 A side perspective view of the crankcase 17 and piston 68 of a diaphragm pump 10 according to an illustrated embodiment of the present disclosure is shown. Furthermore, Figure 7 At least the lower crankcase 26 and the upper crankcase 28 are depicted, in which two of the pistons 68 protruding from the lower crankcase 26 and the upper crankcase 28 can be seen.

[0065] like Figure 7As seen in FIG. 1, according to the illustrated embodiment, the upper crankcase 28 can include a recessed section 130, and a first plurality of connector holes 132 for connecting portions of the upper crankcase 28 to the lower crankcase 26 at locations proximate to a curved surface 140 of the crankcase 17. The upper crankcase 28 can also include a second plurality of connector holes 134 for connecting portions of the upper crankcase 28 to the lower crankcase 26 at locations proximate to a flat surface 138 of the crankcase 17. The lower crankcase 26 can include a third plurality of connector holes 136 for connecting the shoulder 61 of the piston cylinder 60 to the adjacent flat surface 138 of the crankcase 17. Additionally, the lower crankcase 26 can also include an outer wall 148, the flat surface 138, the curved surface 140, a first circulation port 142, and a second circulation port 144.

[0066] As Figure 8 As seen in FIG. 1, the connector 160 can be positioned in at least the second plurality of connector holes 134 Figure 7 ) for connecting the upper crankcase 28 to the lower crankcase 26 at locations proximate to the flat surface 138 of the crankcase 17. Additionally, the first circulation fitting 178 can be secured in the first circulation port 142 Figure 7 ) and the second circulation fitting 180 can be secured in the second circulation port 144 Figure 7 ).

[0067] Having described the structure of the diaphragm pump 10, the operation will now be further described. In one exemplary embodiment, the driver 14 is an electric motor driven by an electric current, which can be controlled by the control system 12, for example. In response to receiving the electric current, the driver 14 can facilitate rotation of the drive shaft 19, which is operably connected to the crankshaft 40 (with or without the optional gear box 16). Due to the offset between the rotational axis 100 and the central axis 102 of the cam 82, rotation of the crankshaft 40 will generate reciprocating axial motion of each piston 68 along its respective piston cylinder 60 bore 59. As described above, by using a single cam 82 to drive each of the at least three pistons 68, in combination with the 120 degree spacing of the pistons 68 about the crankshaft axis 100 in this example, the motion of each piston 68 and the intake / exhaust cycle of each diaphragm 80 is 120 degrees or 240 degrees out of phase with the other pistons 68 and their associated diaphragms 80.

[0068] In certain embodiments, the electric diaphragm pump 10 is configured to provide flow rates in the range of about 0 gallons per minute to about 300 gallons per minute at pressures in the range of about 0 pounds per square inch (psi) to about 500 psi through inlet and outlet ports ranging from about ¼ inch to about 6 inches in diameter. Embodiments of the present disclosure are also configured to provide a dry stroke of at least 15 feet. According to certain embodiments, the electric diaphragm pump is capable of performing a wet stroke of at least about 20 feet and preferably at least about 30 feet.

[0069] Figure 9 A graph is shown that displays outlet pressure (dashed line) at the common outlet of an exemplary diaphragm pump 10 having three diaphragm housings 18 as a function of crank angle. As shown, using three diaphragms 80 with out-of-phase suction / discharge cycles can generate a pressure profile that results in six outlet maximum pressure peaks (P1-P6) per revolution of the crankshaft 40. As shown, these six maximum pressure peaks per 360 degree cycle of the diaphragm pump 10 are fairly level, with the maximum pressure of the peaks differing only slightly from the median pressure, as indicated by the solid line extending through the graph, and the minimum outlet pressure (M1-M4) at the common outlet also differing only slightly from the median pressure, as shown.

[0070] Figure 10 A graph is shown that displays outlet pressure as a function of pump cycle in a prior art dual diaphragm pump. As shown, the prior art dual diaphragm pump can generate only two maximum pressure peaks per 360 degree cycle of the dual diaphragm pump. In addition, the difference between the peak outlet pressure and the minimum outlet pressure per cycle of the prior art dual diaphragm pump is greater than the difference between the maximum outlet pressure and the minimum outlet pressure that can be obtained using the electric diaphragm pump 10 of the subject disclosure having three diaphragm housings 18. Figure 10

[0071] Figure 9 A comparison of the pressure profiles of Figure 10 shows significant improvements in reduced pressure pulsation and increased average pressure that can be obtained with embodiments of the subject disclosed pump 10 that include three diaphragm housings 18 as compared to conventional dual diaphragm pumps. In addition, the subject disclosed triple diaphragm pump 10 embodiments can reduce the magnitude of the force on the system 50 by spreading the load over three diaphragm assemblies 18 as compared to conventional dual diaphragm designs.

[0072] ​Additionally, the diaphragm pump 10 can be designed to avoid pressure buildup when the diaphragm pump 10 faces a stall condition. Furthermore, diaphragm pumps are often used in industrial processes that require or otherwise result in temporary flow interruptions. Such flow interruptions can be intentional, such as for example via an operator closing a valve to a nozzle, or unintentional, such as resulting from an unexpected blockage in the flow path. In a typical air-operated diaphragm pump, the air motor is designed such that total flow interruption, commonly referred to as stalling, avoids the buildup of pressure in the process fluid (as air continues to be delivered to the pump).

[0073] With respect to the subject disclosed diaphragm pump system 50, for example, the drive 14 of the diaphragm pump 10, such as for example an electric motor, can be designed and controlled to slow down, and even stop, when back pressure builds during a stall event. For example, according to certain embodiments in which the drive 14 is an electric motor, the drive 14 can have a pulse width modulation (PWM) based VFD controller 15, and can be capable of a constant torque mode, a constant speed mode, or a combination thereof. By programming the VFD controller 15 to operate at a desired or predetermined torque across a range of motor speeds, the drive 14 can be designed to vary its speed to maintain the desired torque, including running at very slow speeds. When faced with a stall event, the motor torque required by the drive 14 to drive the piston 68 typically increases as the discharge flow backs up to the outlet of the pump 14. The drive 14 using torque control can advantageously be used for the control system of the drive 14 to reduce the revolutions per minute (rpm) of the drive 14 so as not to exceed a predetermined threshold torque placed on the drive 14. By using this control, the rpm of the drive 14 can be reduced, and in fact stopped, as long as the system places a torque on the drive 14 that exceeds the threshold. Thus, dangerous high back pressure in the discharge line from the diaphragm pump 10 can be avoided.

[0074] Additionally, according to certain embodiments, the drive 14 can be designed to maintain a constant speed until a threshold torque. Thus, the drive 14 can be designed to maintain a selected speed even as back pressure changes, below the threshold torque, which can otherwise affect the amount of torque on the drive 14. The constant speed of the drive 14 can be designed or selected to substantially maintain a selected flow rate of the diaphragm pump 10. Above the threshold torque, the drive 14 can be controlled to maintain the torque at the threshold by reducing the speed until the drive shaft 19 of the drive 14 rotates relatively very slowly, or stops, in a stall condition, so as to maintain pressure in the system, but not build up pressure.

[0075] In such embodiments, because the driver 14 is designed or configured to maintain pressure in the system 50 by maintaining torque at or below a selected threshold at the end of a stall event, when the stall condition is removed, such as for example via opening a valve or flow in a discharge line, the pressure of the pumped fluid is substantially immediately available. Further, the torque required by the driver 14 will drop below the selected torque threshold, the control system will actuate increased rpm of the driver 14, and the discharge flow can advance from zero to the target flow rate. In other embodiments, if the stall event persists beyond a predetermined time limit, such as for example a one hour time limit, the control system 12 can override and shut down the VFD controller 15 of the driver 14.

[0076] Embodiments of the present disclosure can also exhibit relatively significant energy utilization efficiency. For example, with respect to electrical water efficiency (and more specifically, the amount of electrical energy used to operate the driver 14 to the amount of kinetic energy delivered by the diaphragm pump 10 to the process fluid exiting the diaphragm pump 10), certain embodiments can achieve efficiencies greater than 50% over a substantial portion of the designed operating range of the diaphragm pump 10. Further, according to certain embodiments, such efficiencies can be greater than 60%, and in some embodiments, efficiencies of about 65% can be achieved.

[0077] Embodiments of the present disclosure can also provide significantly reduced acoustic or noise profiles relative to those associated with many double diaphragm pumps. Because the crankshaft 40 of the diaphragm pump 10 is continuously rotated in one direction during operation (without stall events), and the diaphragm 80 is coupled to the cam 82 by a substantially rigid connection, the movement of the components of the pump 10, and in particular the diaphragm 80, is substantially smooth without intermittent sudden movements and accompanying acoustic impacts that are typically characteristic of the operation of double diaphragm pumps. Such design of embodiments of the subject disclosure can also minimize or eliminate noisy inefficient motion connections and generated impact noise. Further, the noise associated with the operation of the driver 14, such as for example an electric motor, is generally quieter than the drive noise from compressed air and AODP air motors. Thus, the operating acoustic profile of embodiments of the present disclosure can provide a significant advantage over conventional designs in terms of operating and work environment arrangements.

[0078] Additionally, the extent of the forces acting on the diaphragm pump 10 during the suction stroke can be very different from those acting on the diaphragm pump 10 during the compression stroke during operation. For example, at least certain components of the diaphragm pump 10 used in the displacement of the diaphragm 80 can experience a relatively significantly higher level of load forces on the discharge stroke than the forces encountered by those components during the return / suction stroke. Thus, such components can experience a higher rate of wear on the discharge portion of the stroke, and increased mechanical integrity is required for the discharge portion of the stroke.

[0079] Referring toFigure 11A and Figure 11B According to certain embodiments, the slider-crank mechanism 221 can have one or more pistons 68 that are displaced in a reciprocating manner along a motion axis 216 within a corresponding piston cylinder 60, the motion axis 216 being offset from the rotational axis 100 of the crankshaft 40 and thus lying out of its plane. According to certain embodiments, the motion axis 216 intersects the corresponding connection of the piston 68 at the piston pin 64 to the connecting rod 62. Thus, according to at least certain embodiments, the motion axis 216 extends through both the position in which the center of the piston pin 64 is located when the piston 68 completes a discharge stroke and the position in which the center of the piston pin 64 is located when the piston 68 completes an intake stroke. Moreover, the positions of the center of the piston pin 64 when the piston 68 completes the discharge and intake strokes can be located on a central axis of the piston pin 68 that is generally located along or shared by the motion axis 216. According to certain embodiments, the degree of offset between the motion axis 216 and the rotational axis 100 of the crankshaft 40 can be at least the distance between the motion axis 216 and the rotational axis 100 of the crankshaft 40. Moreover, while Figure 11A and Figure 11B The slider-crank mechanism 221 is depicted as having three pistons 68 as well as three associated piston cylinders 60 and connecting rods 62, but for different disclosures the number of pistons 68 and associated components used with the slider-crank mechanism 221 can vary.

[0080] The offset of the motion axis 216 relative to the rotational axis 100 of the crankshaft 40 can be achieved in a number of different ways. For example, Figure 11A and Figure 11B The depicted slider-crank mechanism 221 is configured such that the motion axis 216 along which the associated pistons 68 are displaced in a reciprocating manner is linearly offset from the rotational axis 100 of the crankshaft 40. For example, such linear offset can be achieved by linearly adjusting the position of the motion axis 216 such that the motion axis 216 does not intersect the rotational axis 100 of the crankshaft 40 and is offset therefrom. For example, and at least for the purposes of discussion, the motion axis 216 associated with the third piston 68 shown in FIG. 3 is linearly offset in the generally horizontal direction (as indicated by the direction “x” in FIG. 3) such that the motion axis 216 is not intersected by the rotational axis 100 of the crankshaft 40 but is offset to the right of the rotational axis 100. Figure 11B The generally vertical orientation of the motion axis 216 associated with the third piston 68 shown in FIG. 3 is offset in the generally horizontal direction (as indicated by the direction “x” in FIG. 3) such that the motion axis 216 is not intersected by the rotational axis 100 of the crankshaft 40 but is offset to the right of the rotational axis 100. Figure 11B

[0081] ​Such linear offset of the axis of motion 216 of the slider-crank mechanism 221 can be accomplished in a variety of different ways. For example, according to certain embodiments, the cylinder bore 59 can be positioned or oriented such that the central longitudinal axis 218 of the cylinder bore 59 is linearly offset from the rotational axis 100 of the crankshaft 40. Since the axis of motion 216 associated with the reciprocating displacement of the piston 68 within the cylinder bore 59 can be coplanar with the central longitudinal axis 218 of the cylinder bore 59, the offset of the central longitudinal axis 218 relative to the rotational axis 100 of the crankshaft 40 can result in a similar offset of the axis of motion 216 relative to the rotational axis 100 of the crankshaft 40. Thus, according to such embodiments, the central longitudinal axis 218 of the cylinder bore 59 and the corresponding axis of motion 216 can be offset from the rotational axis 100 of the crankshaft 40 by substantially the same distance or magnitude, and in the same direction.

[0082] Alternatively, as previously mentioned, and as shown at least in Figure 11A FIG. 6, the lower crankcase 26 can include one or more apertures 88 each sized and positioned to receive or otherwise couple to at least a portion of the piston cylinder 60. Such apertures 88 can be positioned and / or oriented such that a central longitudinal axis 217 of the aperture 88 is linearly offset from the rotational axis 100 of the crankshaft 40. Moreover, according to certain embodiments, such central longitudinal axis 217 of the aperture 88 can be positioned such that, when the piston cylinder 60 is attached to the lower crankcase 26 and the slider-crank mechanism 221 is assembled, the axis of motion 216 of the associated piston 68 is coplanar with the central longitudinal axis 217 of the aperture 88, and the central longitudinal axis 217 of the aperture 88 and the corresponding axis of motion 216 are thus offset from the rotational axis 100 of the crankshaft 40 by substantially the same distance or magnitude.

[0083] As shown at least in Figure 11B FIG. 6, according to the illustrated embodiment in which the slider-crank mechanism 221 includes at least three pistons 68, the axis of motion 216 for each of the pistons 68 can be offset from the rotational axis 100 of the crankshaft 40. Moreover, each axis of motion 216 can thus be oriented such that all three axes of motion 216 do not all intersect at any common point.

[0084] Additionally, the magnitude of the offset between the axis of motion 216 and the rotational axis 100 of the crankshaft can be based on a variety of criteria, including, for example, but not limited to, the stroke length. For example, according to certain embodiments, the axis of motion 216 can be offset from the rotational axis 100 of the crankshaft 40 by a distance of 0.1 inches to about 0.5 inches, and more particularly, by about 0.157 inches, among other distances.

[0085] The offset feature of the slider crank mechanism 221 can be configured to increase the duration of the discharge stroke during displacement of the piston 68 and associated operation of the diaphragm housing 118. As the degree of force and stress encountered on the discharge stroke can typically be higher than those encountered on the intake stroke, increasing the amount of time spent on the discharge stroke can improve the balance between the piston side load forces and stresses that can be encountered during the discharge and intake strokes. Thus, the offset feature of the slider crank mechanism 221 can reduce the maximum forces and stresses experienced by at least certain components of the slider crank mechanism 221 and / or the diaphragm housing 118. Such reduction in maximum forces and stresses can eliminate or reduce at least any need to over-design the offset slider crank mechanism 221 and / or the diaphragm housing 118 of the pump 10, which can provide cost savings. Moreover, such improved balance of forces can facilitate better balancing of expected wear on the diaphragm 80, as well as wear between at least the piston cylinder 60 and associated piston 68, the sleeve or support band 70 and / or associated linear guide assembly Figure 15A and Figure 15B ) and thereby extend the useful life of such components.

[0086] For example, Figure 12 A chart depicting an example of piston side load as a function of crank angle of the slider crank mechanism 221 of the diaphragm pump 10 is provided, with three levels of offset distance of the axis of motion 216 from the rotational axis 100. With respect to a slider crank mechanism without an offset feature (e.g., “Offset = 0 inches”), such as the slider crank 21 of Figure 3 as depicted by Figure 12As shown in the graph, during the intake stroke, the illustrated piston-side load force drops to a minimum of approximately -80 lbf and reaches a maximum of approximately 600 lbf during the exhaust stroke. In other words, in this example, without the offset feature, the maximum piston-side load during the exhaust stroke is approximately 7.5 times the maximum piston-side load experienced during the intake stroke. However, for the offset slider crank 221, when the motion axis 216 is offset by 0.2 inches from the rotation axis 100 in this example, an improved balance between the piston-side load forces during the intake and exhaust strokes is shown, as indicated by the piston-side load force reaching approximately -130 lbf during the intake stroke and the maximum piston-side load force of approximately 450 lbf during the exhaust stroke. Therefore, in this example, with a 0.2-inch offset between the motion axis 216 and the rotation axis 100, the maximum piston-side load force during the exhaust stroke decreases to approximately 3.5 times the maximum piston-side load force during the intake stroke. As can be further seen in this example, increasing the offset distance to 0.4 inches further enhances this balance of piston-side load forces between the exhaust and intake strokes. Furthermore, with an offset distance of 0.4 inches, the maximum piston-side load forces in this example are approximately 200 lbf and 300 lbf, respectively, during the intake and exhaust strokes. Therefore, with an offset distance of 0.4 inches, the maximum piston-side load force during the exhaust stroke decreases to approximately 1.5 times that of the maximum piston-side load force during the intake stroke. Thus, the change in offset distance reduces the peak piston-side load force encountered during the exhaust stroke while increasing the peak piston-side load force encountered during the intake stroke. Therefore, a closer balance can be achieved between the piston-side load forces encountered during the exhaust and intake strokes.

[0087] Therefore, as from Figure 12 The example shown demonstrates that by providing a slider-crank mechanism 221 with offset characteristics, the diaphragm pump 10 can be designed and constructed using components capable of withstanding lower levels of force. Furthermore, refer to... Figure 12 Based on the data shown, the diaphragm pump 10 could be modified to withstand a maximum piston-side load force of at least approximately 300 lbf (as shown by the exemplary slider-crank mechanism 221 with a 0.4-inch offset), instead of constructing a diaphragm pump 10 that can withstand a maximum piston-side load force of at least approximately 600 lbf (as shown by the exemplary slider-crank mechanism 221 without the offset feature). Therefore, such a reduction in the maximum force and maximum stress by incorporating the offset feature into the slider-crank mechanism 221 reduces (if not eliminates) any need for over-designing at least the components of the slider-crank mechanism 221 (such as making them excessively large), which can provide cost and size advantages in the composition and manufacture of the diaphragm pump.

[0088] Incorporation of the offset feature into the slider crank mechanism 221 can provide associated improved balancing of the piston side load forces and stresses encountered during the discharge stroke and the intake stroke without significantly altering the total outlet pressure of the diaphragm pump 10. For example, Figure 13 A chart depicting an example of the pump outlet pressure measured in pounds per square inch (psi) as a function of the crank angle of the slider crank mechanism 21, 221 of the diaphragm pump 10 having three offset levels of Figure 12 the same three offset levels depicted in FIG. 6. Figure 13 The illustrated outlet pressure can be a combined pressure effect of the diaphragm pump 10 having three diaphragm housings 118 and thus three corresponding pistons 68. As Figure 13 illustrated, the total outlet pressure of the diaphragm pump 10 generally remains the same for each of the three offset levels. Moreover, in Figure 12 and Figure 13 The extent to which the maximum piston side load force and the maximum / minimum pressure occur at different crank angles can be attributed at least to the variation in the duration of the intake stroke and the discharge stroke, as previously described.

[0089] Additionally, similar to Figure 9 , Figure 13 It is also demonstrated that using an odd number of diaphragm housings 118 increases the number of pressure peaks that occur in each operating cycle. Moreover, with respect to a diaphragm pump 10 having an odd number of diaphragm housings 118, the number of pressure peaks can be equal to twice the number of diaphragm housings 118. Thus, as Figure 13 depicted, the data corresponds to an exemplary diaphragm pump 10 having three diaphragm housings 118 and the number of pressure peaks occurring in each cycle is six, with three pressure peaks generally being about 115 psi and the other three pressure peaks generally being about 102 psi. In contrast, with respect to a diaphragm pump having an even number of diaphragm housings, the number of pressure peaks is typically equal to the number of diaphragm housings, as each diaphragm has only one pressure peak. The additional pressure peaks provided by using an odd number of diaphragm housings 118 can be a product of the increased duration of the overlap period in which multiple diaphragm housings 118 are subjected to the discharge stroke. Moreover, by increasing the duration of the discharge stroke of each diaphragm housing 118 via the offset feature of the slider crank mechanism 221 of the subject disclosure, the duration in which multiple diaphragm housings 118 are simultaneously subjected to the discharge stroke can also be increased. Moreover, as previously described, the increase in the number of pressure peaks per cycle can enhance the loading shared by the diaphragms 80 of the pump 10 and improve the average pressure that can be obtained by the pump 10.

[0090] While the foregoing examples are discussed in terms of a linear offset of the axis of motion 216 of the slider-crank mechanism 221 relative to the axis of rotation 100 of the crankshaft 40, the offset feature of the slider-crank mechanism 221 can be provided in a variety of other ways. For example, according to certain embodiments, the piston pin 64 can be linearly offset from the corresponding cylinder axis 116, rather than offsetting the axis of motion 216. For example, Figure 14 A piston pin 64 is shown housed in a piston pin cavity 65 in a piston 68, the piston pin 64 being attached to a connecting rod 62 coupled to a cam 82. As shown, a cylinder axis 116 of a corresponding piston cylinder 60 (not shown) is positioned to intersect the axis of rotation 100, where the axis of rotation 100 is not positioned at the center of the cam 82, the cylinder axis 116 can also serve as an axis of motion along which the piston 68 reciprocates. However, a central longitudinal axis 67 of the piston pin 64 is positioned on the piston 68 at a location that is linearly offset from the cylinder axis 116, as indicated by the distance "X" in Figure 14 According to the illustrated embodiment, this linear distance can be based on a distance from the central longitudinal axis 67 of the piston pin 64 and / or the piston pin cavity 65 in a direction generally orthogonal to the cylinder axis 116. Further, such an offset of the piston pin 64 and / or the piston pin cavity 65 can provide an adjusted angle of attack of the connecting rod 62 relative to the piston 68, which can at least increase the duration of the exhaust stroke, which again can be beneficial to improve the balance of forces experienced by the piston 68 during the intake and exhaust strokes.

[0091] Referring to Figure 16According to other embodiments, instead of a linear offset, the pump 10 can include a slider-crank mechanism 221 in which the axis of motion 216 of each diaphragm housing 18 is angularly offset relative to at least the rotational axis 100 of the crankshaft 40 such that the axis of motion 216 does not intersect the rotational axis 100. According to certain embodiments, such an angular offset of the axis of motion 216 can be achieved by angularly offsetting the central longitudinal axis 218 of the bore 59 of the piston cylinder 60 relative to at least the rotational axis 100 of the crankshaft 40. Such an angular offset of the axis of motion 216 and the central longitudinal axis 218 of the bore 59 relative to at least the rotational axis 100 can be achieved in a variety of ways. For example, according to certain embodiments, the bore 59 can be formed in the piston cylinder 60 such that the central longitudinal axis 218 of the bore 59 is angularly offset relative to the central longitudinal axis 63 of the piston cylinder 60. According to such embodiments, the central longitudinal axis 63 of the piston cylinder 60, rather than the central longitudinal axis 218 of the bore 59, can be positioned and oriented to intersect the rotational axis 100. According to such embodiments, since the axis of motion 216 can extend along the central longitudinal axis 218 of the bore 59, the axis of motion 216 can also be offset relative to the rotational axis 100. Additionally, according to such embodiments, the piston pin 64 can be positioned along the central longitudinal axis 67 of the piston pin 64, which is parallel to, but linearly offset from, the axis of motion 216, as seen in FIG. 3. Figure 16

[0092] Alternatively, according to other embodiments in which the central longitudinal axis 218 of the bore 59, and thus the axis of motion 216, both extend along the central longitudinal axis 63 of the piston cylinder 60, the piston cylinder 60 can be mounted to the lower crankcase 26 via the aperture 88 in a manner that angularly offsets each of the central longitudinal axis 63 of the piston cylinder 60, the central longitudinal axis 218 of the bore 59, and the axis of motion 216 from the rotational axis 100 without intersecting the rotational axis 100.

[0093] Figure 15A A magnified view of a portion of the pump 10 and the associated piston 68 of the slider-crank mechanism 221 is shown, in which the reciprocating displacement of the piston 68 is guided by a linear guide or bearing assembly 202. According to the illustrated embodiment, the linear guide assembly 202 can include a bearing block 204, a plurality of balls or rollers (not shown), and a track 206. The plurality of balls or rollers, which can act as bearings, can be positioned between the bearing block 204 and the track 206 such that the balls or rollers rotate as the bearing block 204 linearly displaces along the track 206, thereby facilitating the linear displacement of the bearing block 204 along the track 206. Furthermore, the bearing block 204 and the track 206 can have matching shapes so as to facilitate the bearing block 204 remaining engaged with the track 206 and at least to facilitate the plurality of balls or rollers remaining in operable position between the bearing block 204 and the track 206. ​

[0094] like Figure 15A and Figure 15B As shown, according to the illustrated embodiment, the track 204 may be secured to the inner wall 208 of the piston cylinder 60, such as by one or more mechanical fasteners, including but not limited to one or more bolts. Furthermore, according to some embodiments, at least a portion of the track 206 may be recessed into a groove in the inner wall 208 of the piston cylinder 60. Similarly, the bearing seat 204 may be secured to the piston 68 such that the bearing seat 204 linearly displaces as the piston 68 moves. Thus, as the piston 68 linearly displaces, such displacement of the piston 68 can be guided at least in a linear direction by the linear movement of the bearing seat 204 along the track 206. Furthermore, according to some embodiments, the linear guide assembly 202 may provide a rolling interface between the piston 68 and the piston cylinder 60. Furthermore, according to some embodiments, at least a portion of the piston 68 may have a shape and / or size adaptable to the placement of at least a portion of the linear guide assembly 202 within the piston cylinder 60.

[0095] Additionally, similar to the above regarding Figure 14 The embodiments discussed, Figure 15A An embodiment is also shown in which the cylinder axis 216 of the corresponding piston cylinder 60 is positioned to intersect the rotation axis 100 of the crankshaft 40, wherein the rotation axis 100 is not positioned at the center of the cam 82, and the cylinder axis 216 can also serve as the axis of motion for the piston 68 to reciprocate along it. However, similar to the above regarding... Figure 14 In the discussed embodiment, the central longitudinal axis 67 of the piston pin 64 may be parallel to the axis of motion 116, but offset linearly from it, as by Figure 15A The distance “X” is indicated in the figure. Such offset of piston pin 64 can also provide connecting rod 62 with an adjusted angle of attack relative to piston 68, which can at least increase the duration of the exhaust stroke, and can also contribute to a better balance of piston-side load forces experienced during the intake and exhaust strokes.

[0096] Although the linear guide component 202 is mentioned above regarding having at least Figure 14 The slider-crank mechanism 221 with offset features shown in the examples is discussed in conjunction with other slider-crank mechanisms that may have other types of offset features or configurations. Additionally, the linear guide assembly 202 may also be used with slider-crank mechanisms that do not utilize offset features.

[0097] While the examples above are discussed in relation to a single piston cylinder and piston and its associated axis of motion, similar offset features can be incorporated into any (if not all) of other piston cylinders, pistons and their associated axes of motion and / or associated diaphragm housings.

[0098] While the application has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the application is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. Furthermore, it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that certain features are considered to be more desirable, but not required, any embodiment not possessing these features is nevertheless to be considered as being within the scope of the application, which scope is to be accorded the broadest interpretation of the claims appended hereto. In reading the claims, it is intended that when words such as "a," "an," "at least one," and "at least one portion" are used, there is no intention to limit the claims to only one item unless specifically recited in the claims. Further, when the language is used "at least one portion" and / or "a portion," an item can comprise a portion and / or the whole, unless specifically recited otherwise.

Claims

1. An apparatus comprising: A diaphragm pump (10) having a plurality of diaphragms (80) that at least partially define a plurality of pumping chambers (46), each diaphragm (80) being configured to reciprocate between a first position and a second position to pump fluid, the diaphragm pump (10) comprising: A crankcase (17) and a crankshaft (40) at least partially disposed within the crankcase (17); A bracket (30) configured to support the crankcase (17), the bracket (30) being configured to contact a horizontal support surface; The crankshaft (40) has a crankshaft axis oriented vertically by the bracket (30), and the crankshaft is operatively connected to a motor such that the motor provides power during operation to rotate the crankshaft (40). At least one cam (82) configured to rotate together with the crankshaft (40) to cause the reciprocating motion of the plurality of diaphragms (80), each of the plurality of diaphragms (80) being oriented to reciprocate along a cylinder axis (116) orthogonal to the crankshaft axis; The diaphragm pump (10) includes at least three diaphragms (80) and at least three pumping chambers (46), wherein the at least three pumping chambers (46) are evenly distributed around the crankshaft axis (100) such that the angles formed between adjacent cylinder axes (116) are substantially the same. A cylinder (60) for each of the at least three diaphragms (80), each cylinder (60) being arranged along a corresponding cylinder axis (116), and a piston (68) disposed within the cylinder (60), the piston (68) being connected to the crankshaft (40) via a connecting rod. The feature is that a corresponding cavity (81) is positioned between the surface of each of the at least three diaphragms (80) and the surface of the corresponding cylinder (60), wherein each diaphragm (80) fluidly separates the corresponding cavity (81) from the corresponding pumping chamber (46), each corresponding cavity (81) includes low-pressure air, and at least two of the corresponding cavities (81) are configured such that the low-pressure air passes between each other to avoid pressure buildup in the corresponding cavity (81) during the reciprocating motion of the at least three diaphragms (80).

2. The device according to claim 1, characterized in that, The cylinder axis (116) of the plurality of diaphragms (80) is vertically displaced relative to each other.

3. The device according to claim 1 or claim 2, characterized in that, Each of the at least three diaphragms (80) reciprocates via a single cam (82).

4. The device according to any one of the preceding claims, characterized in that, The motor (14) is an electric motor having a rotatable rotor that is in power communication with the crankshaft (40) and is capable of rotating about a rotor axis parallel to the crankshaft axis; optionally, the motor is configured to drive to reduce the speed of the crankshaft (40) and maintain torque in the event of a flow interruption event.

5. The device according to any one of the preceding claims, characterized in that, The bracket (30) includes a plurality of legs extending from the crankcase (17).

6. The device according to any one of the preceding claims, characterized in that, Each of the cylinder axis (116) is offset from the crankshaft axis (100).

7. The device according to claim 6, characterized in that, Each of the pistons (68) is configured to move the corresponding diaphragm (80) directly between the first position and the second position; optionally, the reciprocating displacement of each of the pistons (68) along the cylinder axis (116) is guided by a rolling element bearing between the piston (68) and the cylinder (60).

8. The device according to claim 7, characterized in that, A seal is disposed between the piston (68) and the cylinder (60) to prevent lubricant from reaching the cavity (81), which is opposite the diaphragm (80) to the pumping chamber (46); optionally, the seal includes a lubricant-facing seal and a cavity-facing seal, wherein the cavity-facing seal is a bellows seal.

9. The device according to any one of claims 6-8, characterized in that, The diaphragms are oriented such that the arcuate shape of the annular flexible portion (83) of each diaphragm (81) is positioned in a direction generally away from the pumping chamber (46).

10. The device according to claim 6, characterized in that, Each of the pistons includes a support band circumferentially positioned around at least a portion of the respective piston.

11. A method comprising: A crankshaft (40) is at least partially inserted into the crankcase (17) of a diaphragm pump (10), the crankshaft (40) having at least one cam (82) and a crankshaft axis; characterized in that the diaphragm pump (10) comprises at least three diaphragms (80) and at least three pumping chambers (46); An electric motor (14) is connected to the crankcase, and the electric motor (14) is in power communication with the crankshaft (40); The bracket (30) is connected to the crankcase (17) such that when the crankcase (17) is supported by the bracket (30), the crankshaft axis is vertically oriented; The cylinder axis (116) of each of at least three diaphragm pump cylinders (60) is oriented relative to the crankshaft (40) such that each of the respective cylinder axis (116) forms a right angle with the crankshaft axis when viewed from a side transverse to the respective cylinder axis (116) and the crankshaft axis. The at least three diaphragm pump cylinders (60) are attached to the crankcase (17), the diaphragm pump cylinders (60) being spaced at equal angles around the crankshaft axis (100); and At least two corresponding low-pressure air cavities (81) are interconnected, each cavity (81) being positioned behind a corresponding diaphragm (80) to allow low-pressure air to pass between the cavities (81) to avoid pressure buildup in the cavities (81) during the reciprocating motion of the diaphragm (80).

12. The method according to claim 11, characterized in that, It also includes orienting the bracket (30) such that the respective cylinder axis (116) of the at least three diaphragm pump cylinders is horizontal.

13. The method according to claim 11 or claim 12, characterized in that, It also includes positioning a piston (68) in each of the respective plurality of diaphragm pump cylinders (60) and connecting a diaphragm (68) in each respective cylinder (60) to the respective piston (68); optionally, it also includes attaching a connecting rod (62) between each piston (68) and the cam (82).

14. The method according to any one of claims 11-13, characterized in that, Orienting the cylinder axis (116) includes offsetting the cylinder axis (116) from the crankshaft axis (100).

15. The method according to any one of claims 11-14, characterized in that, It also includes a rolling element bearing connecting each piston (68) and each cylinder (60); it also includes an oil-facing seal and a seal facing the cavity (81); and / or includes a support band (70) circumferentially attached around at least a portion of each piston (68).

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