Electric diaphragm pump with offset slider crank

Abstract

A diaphragm pump has a crankshaft rotatable about an axis of rotation and coupled to a piston. The piston is reciprocally displaceable within the piston cylinder along a movement 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 as the piston reciprocates. A movement axis intersecting a connection between the piston and the connecting rod may not intersect a rotation axis of the crankshaft such that a peak value of the piston-side loading force during the discharge stroke is reduced and a peak value of the piston-side loading force during the suction stroke is increased with respect to an arrangement in which the movement axis intersects the rotation axis. In order to obtain an improved balance between the peak values of the piston-side load forces of the discharge stroke and the suction stroke.

Description

[0001] This application is a divisional application of a patent application with an application date of March 10, 2020, application number 202010161297.5, and name “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 on 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 an electric motor for actuating one or more diaphragms of the pump. Background Art

[0005] Pumps can be used to facilitate the transfer of fluids, including but not limited to liquids, slurries and mixtures. Thus, 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 are designed 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 associated with the intake and subsequent discharge of a fluid from a chamber of the pump. For example, with respect to a positive displacement pump that is a diaphragm pump, such pumps typically include a pair of opposing diaphragms that reciprocate relative to each other along a common axis. Conventionally, these "double diaphragm" pumps are pneumatically driven using high pressure air. Such designs can allow the pressure generated by the pump to be controlled by the pressure of the air in the system. In addition, because pneumatic drive typically prevents the generation of sparks, such air-operated diaphragm pumps are typically suitable for operation in potentially explosive environments.

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

[0008] Thus, an opportunity still exists to create a pump that includes and improves upon the typical advantages of a diaphragm pump while providing an alternative to reliance on the inefficiencies of pneumatically driven pumps. Summary of the invention

[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 an embodiment of the present disclosure is a diaphragm pump that may include a crankcase and a crankshaft that is at least partially positioned within the crankcase and is capable of rotating around an axis of rotation. The diaphragm pump may include a piston coupled to the crankshaft by a connecting rod, the piston being capable of reciprocatingly displacing within a piston cylinder and along a motion axis between an intake stroke and an exhaust stroke, the motion axis intersecting the connection between the piston and the connecting rod. The diaphragm housing may be coupled to an end of the piston cylinder and may be configured to at least partially define a pumping chamber, and pump fluid through the pumping chamber as the piston reciprocates. The motion axis may not intersect the rotation axis of the crankshaft, so that relative to an arrangement in which the motion axis intersects the rotation 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, so as to obtain a closer balance between the peak values ​​of the piston side load forces of the exhaust stroke and the intake stroke.

[0011] Another aspect of an embodiment of the present disclosure is a diaphragm pump system, which may include a crankcase and a crankshaft, which is at least partially positioned in the crankcase and connected to the electric motor. In addition, the crankshaft may be capable of rotating around an axis of rotation. At least three pistons may be arranged radially around the crankcase, and each of the at least three pistons is connected to the crank throw of the crankshaft by a connecting rod. In addition, each piston may be reciprocally displaced within the piston cylinder and along the axis of motion between an intake stroke and a discharge stroke, and the axis of motion of each of the at least three pistons intersects the connection between the piston and the connecting rod. The diaphragm pump system may also include at least three diaphragm housings, which are each connected to the end of the piston cylinder and are configured to at least partially define a pumping chamber, and when the piston reciprocates, the pumping fluid passes through the pumping chamber. In addition, the axis of motion of each of at least three pistons may not intersect the axis of rotation of the crankshaft, so that the peak value of the piston side load force encountered during the discharge stroke is reduced, and the peak value of the piston side load force encountered during the suction stroke is increased, so that a closer balance is obtained between the piston side load forces of the discharge stroke and the suction stroke relative to the arrangement in which the axis of motion intersects the axis of rotation.

[0012] In addition, an aspect of an embodiment of the present disclosure is a diaphragm pump that may include a crankcase and a crankshaft that is at least partially positioned within the crankcase and is capable of rotating around an axis of rotation. The diaphragm pump may include a piston coupled to the crankshaft by a connecting rod, the piston being capable of reciprocatingly displacing within a piston cylinder between an intake stroke and an exhaust stroke. The diaphragm housing may be coupled to an end of the piston cylinder and may be configured to at least partially define a pumping chamber, and pump fluid through the pumping chamber as the piston reciprocates. The piston cylinder may extend around a central longitudinal cylinder axis that intersects the axis of rotation. In addition, the piston may be pivotally coupled to the connecting rod by a piston pin that is positioned along a central longitudinal axis of the piston pin that is parallel to the central longitudinal cylinder axis and linearly offset therefrom, such that relative to an arrangement in which the piston pin is not linearly offset from the central longitudinal cylinder axis, a peak value of a piston side load force encountered during a discharge stroke is reduced, and a peak value of a piston side load force encountered during an intake stroke is increased, so as to obtain a closer balance between the piston side load forces of the discharge stroke and the intake stroke.

[0013] These and other aspects of the disclosure will be better understood in view of the drawings and following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The description herein refers to the drawings, wherein like reference numerals refer to like parts throughout the several views.

[0015] Figure 1 A diaphragm pump system is shown in accordance with an illustrated embodiment of the present disclosure.

[0016] Figure 2 A perspective side view of a diaphragm pump is shown according to an illustrated embodiment of the present disclosure.

[0017] Figure 3 Shown along Figure 2 A cross-sectional view of the diaphragm pump taken along line 3-3 in FIG.

[0018] Figure 4 Shown along Figure 2 A cross-sectional view of a diaphragm pump taken along line 4-4 in FIG.

[0019] Figure 5 An exploded view of a diaphragm pump system and associated bracket is shown in accordance with an illustrated embodiment of the present disclosure.

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

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

[0022] Figure 8 A side view of a crankcase, internal diaphragm housing, and certain piston components of a diaphragm pump is shown in accordance with an illustrated embodiment of the present disclosure.

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

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

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

[0026] Fig. 11B Shown from Fig.11A An enlarged view of box 11 of the drawings depicting a linear offset centerline of a piston cylinder of an offset slider crank mechanism according to an illustrated embodiment of the subject disclosure.

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

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

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

[0030] Fig.15A An enlarged view of a portion of a pump and an associated piston of a slider crank mechanism is shown, the associated piston having an offset axis of motion and the reciprocating displacement of the piston being guided by a linear guide.

[0031] Fig. 15B A front perspective view of a portion of a pump is shown having a piston slidingly coupled to a piston cylinder via a linear guide.

[0032] Fig.16 An enlarged view of a portion of a diaphragm pump is shown, wherein the axis of movement is angularly offset relative to at least the axis of rotation.

[0033] The foregoing summary of the invention and the following detailed description of certain embodiments of the present disclosure will be better understood when read in conjunction with the accompanying drawings. In order to illustrate the present disclosure, certain embodiments are shown in the accompanying drawings. However, it should be understood that the present disclosure is not limited to the arrangements and tools shown in the accompanying drawings. In addition, similar reference numerals in the corresponding figures indicate similar or equivalent parts. DETAILED DESCRIPTION

[0034] Certain terms are used in the foregoing description for convenience and are not intended to be limiting. Words such as "upper," "lower," "top," "bottom," "first," and "second" indicate directions of reference in the accompanying drawings. The terminology includes the words specifically mentioned above, their derivatives, and words of similar meaning. In addition, the words "a" and "an" are defined to include one or more of the referenced items unless otherwise noted. The phrase "at least one of..." following a listing of two or more items (such as "A, B, or C") means any single one of A, B, or C, as well as any combination thereof.

[0035] Figure 1 A diaphragm pump system 50 is shown in accordance with an illustrated embodiment of the present disclosure. The diaphragm pump system 50 may include, among other components, a diaphragm pump 10 operably coupled to a control system 12 and a driver 14. Although the embodiments discussed herein are discussed in terms of diaphragm pump systems including electric diaphragm pump systems, at least certain features may 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 a piston rather than a diaphragm to move fluid into / out of a pumping chamber of the pump. Additionally, at least certain features of the diaphragm pump systems discussed herein may provide relatively significant advantages when compared to at least pneumatic diaphragm pump systems, including, but not limited to, improved energy efficiency in net operating energy usage.

[0036] According to certain embodiments, the control system 12 may include, for example, an external embedded controller 11, among other components, which is communicatively coupled to the human-machine interface 13. The external controller 11 may be configured to automate the operation of the diaphragm pump 10 for at least the purpose of batching or dosing. The external controller 11 may also be configured to add other cycle counting functions to the system 50. In addition, the external controller 11 may be configured to correlate the speed of the drive 14 (such as, for example, the motor speed) with the flow rate of the process fluid pumped by the diaphragm pump. The external controller 11 may also include an override for a stall event for an extended period of time. In addition, the control system 12 may be optional to supplement the motor drive, such as a variable frequency drive (VFD) 15 configured to operate the drive 14.

[0037] If at least Figure 1As shown, the diaphragm pump 10 can be mechanically coupled to a drive 14. Although a variety of types of drives 14 can be used, including but not limited to a variety of different types of engines and motors, according to the illustrated embodiment, the drive 14 is an electric motor. In addition, the drive 14 can be operably coupled to the crankshaft 40 ( Figure 4 ) such that operation of the driver 14 may facilitate rotation of at least the crankshaft 40 about a crankshaft axis (or "axis of rotation") 100 ( Figure 4 ) rotational displacement. In addition, if at least Figure 1 As shown, such an operative coupling of the driver 14 to 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 driver 14 to the crankshaft 40 , according to certain embodiments.

[0038] If at least Figures 1 to 5 As shown, according to certain embodiments, the diaphragm pump 10 may include, among other components, a crankcase 17, a plurality of diaphragm housings 18, a common inlet manifold 20 ( Figure 5 ), common outlet manifold 38 and slider crank mechanism 21 ( Figure 3 ). In addition, if at least Figure 2 As shown, the crankcase 17 may include a lower crankcase 26 and an upper crankcase 28. Figure 4 As shown, the lower crankcase 26 may provide a lower crankcase cavity 86. Additionally, the crankshaft 40 may protrude from the crankcase 17 for operable connection with the driver 14, as previously described.

[0039] Although the number of diaphragm housings 18 may vary for different embodiments, the inventors of the subject disclosure have determined that an odd number of diaphragm housings (greater than one) may be preferred. Thus, the illustrated embodiment depicts, but is not limited to, a diaphragm pump 10 having three diaphragm assemblies 18. Additionally, each diaphragm housing 18 may be coupled to an adjacent piston 68 of a slider crank mechanism 21, such as, for example, Figure 3 In addition to a plurality of pistons 68 each capable of reciprocating displacement in a corresponding piston cylinder 60, the slider crank mechanism 21 shown may also include a cam 82 (also referred to as a crank throw) of the crankshaft 40 and a connecting rod 62, such as Figure 4 shown.

[0040] In addition, according to at least some embodiments, each of the diaphragm housings 18 may have substantially similar components. Similarly, at least certain components of the slider crank mechanism 21 associated with a particular diaphragm housing 18 may have the same construction as other similar components of the slider crank mechanism 21 associated with another diaphragm housing 18. Thus, for example, each of the piston 68, piston cylinder 60, and / or connecting rod 62 of the slider crank mechanism 21 used with a particular diaphragm housing 18 may have similar construction and features as similar components used with another diaphragm housing 18. Therefore, it should be understood that, unless otherwise stated, for each of the diaphragm assemblies 18 and the associated slider crank mechanism 21, parallel elements and associated features for these elements may exist, regardless of whether such parallel elements and features are actually visible in certain figures of the present disclosure or are explicitly discussed separately herein.

[0041] Each diaphragm housing 18 may include an outer housing 42 and an inner housing 44, the outer housing 42 may also be referred to as a fluid cap. Figure 3 As shown, at least an interior 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 the outlet 24 of the diaphragm housing 18. Thus, according to the illustrated embodiment, at least a portion of the process fluid that enters 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. In addition, such process fluid can exit the pumping chamber 46 through the outlet 24 of the diaphragm housing 18 and continue to the common outlet manifold 38 of the diaphragm pump 10.

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

[0043] Figure 3 Shown along Figure 23-3 in FIG. 1 . Diaphragm housing 18 includes diaphragm 80, which can be used to change the volume, and therefore 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 reduce the pressure. Additionally, displacement or flexing of diaphragm 80 in an opposite, second direction can reduce 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] Although a variety of diaphragm types may be used, according to certain embodiments, diaphragm 80 is a conventional flexible diaphragm. Additionally and optionally, according to certain embodiments, diaphragm 80 may be positioned in an opposite orientation between inner housing 44 and outer housing 42 as compared to the use of diaphragms in conventional AODP. According to certain embodiments, such as at least Figure 3 and Figure 4 , the diaphragm 80 may be positioned such that the arcuate shape of the annular flexible portion 83 of the diaphragm 80 is disposed in a direction generally away from the pumping chamber 46 and instead in a general direction toward the receiving cavity 81 of the diaphragm housing 18 .

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

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

[0047] More specifically, if at least Figure 3 As seen in FIG. 1 , during the discharge stroke in which the diaphragm 80 is forced axially away from the rotational axis 100, the process fluid may be pumped from the pumping chamber 46 as the volume of the pumping chamber 46 is reduced. In the event that the diaphragm 80 is damaged and / or the diaphragm 80 fails, the pressure generated on the pumping fluid side of the diaphragm 80 during the discharge stroke may tend to force at least a portion of the process fluid to flow through or behind the diaphragm 80. However, in the illustrated embodiment, the containment chamber 81 may be defined on the back side of the diaphragm 80. During normal operation, the containment chamber 81 may include low-pressure air, such as, for example, air at approximately ambient pressure (including, for example, ambient air pressure of less than about 10 pounds per square inch (psi) as measured when the diaphragm pump 10 is not operating). The low-pressure air may pass within the containment chamber 81 of the separate diaphragm housing 18. Because each diaphragm 80 is at a different stage of its stroke at any one time, no significant pressure is accumulated in the containment chamber 81.

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

[0049] The containment cavity 81 may also be substantially sealed from a lubricant groove that may 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 to the crankshaft 40 and connecting rod 62). For example, the seal assembly 72 ( Figure 3 ) may bear against the outer surface of the piston 68. The seal assembly 72 may include, for example, one or more oil-facing seals and one or more housing cavity-facing seals, including but not limited to bellows seals and bidirectional seals. According to certain embodiments, the cavity-facing seal may be a bellows design (not shown) spanning between the second end 94 of the piston 68 and the piston cylinder 60. The seal assembly 72 may be constructed and positioned to prevent lubricant from mixing with the process fluid, even in the event that the process fluid will leak past the diaphragm 80 and reach the housing cavity 81.

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

[0051] With respect to operation of the slider crank mechanism 21, the piston 68 reciprocates along a piston axis that extends through a cylinder bore 59 of a piston cylinder 60 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) may 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 may be removably mounted to the lower crankcase 26. Figure 3 and Figure 4 As 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 the inner surface of the aperture 88. Such an arrangement can provide increased stability to the piston cylinder 60 during operation of the pump 10. In addition, such a configuration can reduce the radial size of the pump 10 via such positioning of the piston cylinder 60, and therefore, the piston 68, the diaphragm 80, and the outer housing 42 can be at a reduced (multiple) radial position from the crankshaft 40. In addition, as at least Figure 8 As shown, the piston cylinder 60 may further include a shoulder 61 that may be attached to the 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 removal.

[0053] According to certain embodiments, the piston 68 and the piston cylinder 60 may be designed for controlled metal-to-metal sliding contact. In addition, one or both of the piston 68 and the piston cylinder 60 may be surface treated, such as with a diamond coating, to control wear of one or both of the piston 68 and the piston cylinder 60. In other embodiments, rolling contact may 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 extending against a track.

[0054] Additionally or alternatively, a sleeve or rider band 70 ( Figure 7 ) may be positioned circumferentially around a portion of the piston 6a, which may minimize or prevent metal-to-metal contact between the piston 68 and adjacent portions of the piston cylinder 60. The sleeve 70, which may be replaceable as a wear part, may be made of a variety of materials, including, for example, polymers, ceramics, or metals. Exemplary polymers that may provide suitable wear properties within the necessary pressure and speed range of the piston 68 may include, among other materials: Polyester reinforced resin and bronze filled polytetrafluoroethylene (PTFE).

[0055] For example, among other features, Figure 7 A sleeve 70 is shown attached to a first piston 68 and another second piston 68 prior to attaching 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 being configured for seating of the sleeve onto the piston 68. As also seen, according to certain embodiments, the sleeve recess 150 may be a portion of the outer surface of the piston 68 having a dimension (such as, for example, a diameter) that is different from, such as, for example, smaller than, a corresponding dimension of other adjacent portions of the piston 68. Additionally, while the sleeve recess 150 may be positioned at multiple locations along the piston 68, such as Figure 7 As shown, however, according to certain embodiments, sleeve recess 150 may be located at a position where, subsequently to attachment of sleeve 70 to piston 6b, sleeve 70 will cover piston pin 64 attaching piston 68 to an associated connecting rod.

[0056] As mentioned above, and as at least Figure 4As shown, crankshaft 40 may rotate about rotation axis 100. Similarly, cam 82, which is offset relative to crankshaft 40, includes a central axis 102, which may be parallel to rotation axis 100 and offset from rotation axis 100. According to certain embodiments, crankshaft 40 may include a two-part shaft. In addition, cam 82 may be integrated with first portion 41 of crankshaft 40, while second portion 43 of crankshaft 40 may form seat 108. Seat 108 may be secured in lower crankcase 26 by first bearing set 110, and second bearing set 112 may secure crankshaft 40 in upper crankcase 28. In addition, upper crankcase 28 may include a seal 114 extending around a portion of crankshaft 40.

[0057] like Figure 4 As shown partially in FIG. 1 , the connecting rod 62 may extend from the connection with the piston 68 as previously described to the connection with the cam 82 of the crankshaft 40. Although the connecting rod 62 may be connected to the cam 82 in a variety of different ways, according to the illustrated embodiment, the connecting rod 62 is connected to the cam 82 via a bearing ring or journal bearing 84. Although the bearing ring 84 may be coupled to the connecting rod 62 in a variety of ways, such as by at least Figure 4 , but according to the illustrated embodiment, the bearing rings 84 may be positioned within apertures in the connecting rod 62. The bearing rings 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 displaceable relative to each other along the cam 82 and centered on the central axis 102 of the cam 82.

[0058] If at least Figure 3 and Figure 4 As shown, extending through each piston cylinder 60 is a corresponding central longitudinal cylinder axis 116. In addition, according to certain embodiments, each piston 68 shares its central axis with its corresponding cylinder axis 116. In addition, according to certain 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 may provide an offset feature to the slider crank mechanism 21, which may improve the balance of piston side load forces and stresses that may be encountered during the discharge and suction strokes of the diaphragm housing 18, as described below.

[0059] Also like Figure 3 and Figure 4 Partially shown, the diaphragm housing 18 may be similarly 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 may be centered on a horizontal plane that, along with similar horizontal planes for other diaphragm housings 18, may be vertically displaced along the cam 82.

[0060] Additionally, according to certain embodiments, each cylinder axis 116 for the diaphragm housing 18 is perpendicular to the rotational axis 100 of the crankshaft 40. Additionally, according to certain embodiments, the cylinder axes 116 of the diaphragm housing 18 may also be substantially equally spaced radially 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 at 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 are equally spaced about the axis of rotation 100, the reciprocating motion of the respective pistons 68 is 120 degrees out of phase with each other. Thus, if the piston 68 of the first diaphragm housing 18 is at 0 degrees in its reciprocating cycle, the piston 68 of the second diaphragm housing 18 is at 120 degrees of its respective reciprocating cycle, and the piston 68 of the third diaphragm housing 18 is at 240 degrees of its respective reciprocating cycle. Similarly, for certain embodiments including five diaphragm housings, each piston may be disposed at approximately 72 degrees from its adjacent piston.

[0061] Figure 5 An exploded view of an exemplary diaphragm pump 10 and associated bracket 30 is shown in accordance with an illustrated embodiment of the present disclosure. Figure 5 As shown in the embodiment depicted in , diaphragm pump 10 may include driver 14 and gearbox 16 in a vertical orientation relative to crankcase 17 and bracket 30 , with drive shaft 19 of driver 14 oriented to be coaxially coupled directly or indirectly to crankshaft 40 . Figure 5 Also shown 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 the common outlet manifold 38, and the one-way check valve 48 operably connected to the common inlet manifold 20 and the common outlet manifold 38, respectively. In addition, Figure 5 A three-legged bracket 30 is shown, wherein individual legs of the bracket 30 are disposed about the crankcase 17 at locations between adjacent diaphragm housings 18. Such legs of the bracket 30 may secure the pump 10 to a horizontal work surface with a minimal work surface footprint.

[0062] Figure 6 A side view of a diaphragm pump 10 is shown mounted on an alternative bracket 30 ′, in accordance with at least one embodiment of the subject disclosure. Figure 6 The bracket 30' depicted in FIG. Figure 5The 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, among other surfaces. Additionally, the bracket base 34 may be configured for relatively easy picking up and moving by a forklift or other cart.

[0063] If at least Figure 5 and Figure 6 As indicated, the diaphragm pump 10 may be configured to be supported by the brackets 30, 30' in a substantially vertical orientation. Figure 5 ) and the drive shaft 19 of the driver 14 may also be disposed in a generally vertical orientation. Moreover, such an orientation may accommodate the drive shaft 19 of the driver 14 being substantially coaxial with the rotational axis 100 of the crankshaft 40. Such a vertical orientation of the diaphragm pump 10 may provide a number of advantages, including, for example, a significantly reduced workplace footprint and horizontal access to the pump 10 (which may be relatively free of other pump equipment), which may be beneficial to the ability to perform maintenance on the pump 10, including replacement, repair, and / or cleaning of the pump 10 and / or components thereof. Additionally, such a vertical orientation of the diaphragm pump 10 may allow the one-way check valve 48 to operate based on gravity, which may potentially reduce the number of components of the check valve 48, including, for example, avoiding a spring for biasing the ball within the check valve 48. However, although Figure 1 , Figure 5 and Figure 6 The driver 14 depicted in FIG. 5 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 the diaphragm pump 10 is shown according to the illustrated embodiment of the present disclosure. Figure 7 At least the lower crankcase 26 and the upper crankcase 28 are depicted, wherein 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 may include a recessed section 130, and a plurality of first set of connector holes 132 for connecting a portion of the upper crankcase 28 to the lower crankcase 26 at a location proximate to a curved surface 140 of the crankcase 17. The upper crankcase 28 may also include a plurality of second set of connector holes 134 for connecting a portion of the upper crankcase 28 to the lower crankcase 26 at a location proximate to a flat surface 138 of the crankcase 17. The lower crankcase 26 may include a third set of connector holes 136 for connecting the shoulder 61 of the piston cylinder 60 to an adjacent flat surface 138 of the crankcase 17. In addition, the lower crankcase 26 may also include an outer wall 148, a flat surface 138, a curved surface 140, a first circulation port 142, and a second circulation port 144.

[0066] like Figure 8 As seen in FIG. 1 , the connector 160 may be positioned in at least the second set of connector holes 134 ( Figure 7 ), the second set of connector holes 134 is used to connect the upper crankcase 28 to the lower crankcase 26 at a position close to the flat surface 138 of the crankcase 17. In addition, the first circulation fitting 178 can be fixed to the first circulation port 142 ( Figure 7 ), and the second circulation accessory 180 can be fixed to the second circulation port 144 ( Figure 7 )middle.

[0067] Having described the structure of the diaphragm pump 10, the operation will now be further described. In an exemplary embodiment, the driver 14 is an electric motor driven by an electric current, which can be controlled, for example, by the control system 12. In response to receiving the electric current, the driver 14 can facilitate the rotation of the drive shaft 19, which is operably connected to the crankshaft 40 (with or without the optional gearbox 16). Due to the offset between the rotation axis 100 and the central axis 102 of the cam 82, the rotation of the crankshaft 40 will generate reciprocating axial movement of each piston 68 along the cylinder bore 59 of its corresponding piston cylinder 60. As described above, by using a single cam 82 to drive each of the at least three pistons 68, combined with the 120 degree spacing of the pistons 68 around the crankshaft axis 100 in this example, the movement of each piston 68 and the suction / discharge cycle of each diaphragm 80 are 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 a flow rate in the range of about 0 gallons per minute to about 300 gallons per minute at a pressure in the range of about 0 pounds per square inch (psi) to about 500 psi through inlets and outlets having diameters ranging from about 1 / 4 inch to about 6 inches. Embodiments of the present disclosure are also configured to provide a dry lift of at least 15 feet. According to certain embodiments, the electric diaphragm pump is capable of performing a wet lift of at least about 20 feet and preferably at least about 30 feet.

[0069] Fig. 9 A graph is shown showing the 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, the use of 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 for each 360 degree cycle of the diaphragm pump 10 are fairly horizontal, with the maximum pressures of these peaks only slightly different from the median pressure, as indicated by the solid line extending across the graph, and the minimum outlet pressures (M1-M4) at the common outlet also only slightly different from the median pressure, as shown.

[0070] Fig.10 A graph showing the outlet pressure of a prior art double diaphragm pump as it changes with pump cycles is shown. Fig.10 As shown, the prior art double diaphragm pump can generate only two maximum pressure peaks in each 360 degree cycle of the double diaphragm pump. In addition, the difference between the peak outlet pressure and the minimum outlet pressure of each cycle of the prior art double diaphragm pump is greater than the difference between the maximum outlet pressure and the minimum outlet pressure that can be obtained using the subject disclosed electric diaphragm pump 10 having three diaphragm housings 18.

[0071] Fig. 9 and Fig.10 A comparison of the pressure curves of 1.1 and 1.1 shows the significant improvement in reduced pressure pulsation and increased average pressure that can be achieved with embodiments of the subject disclosed pump 10 that include three diaphragm housings 18, as compared to conventional double diaphragm designs. Additionally, the subject disclosed triple diaphragm pump 10 embodiments can reduce the amount of force on the system 50 by distributing the load across three diaphragm assemblies 18, as compared to conventional double diaphragm designs.

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

[0073] With respect to the diaphragm pump system 50 disclosed in the subject matter, for example, the driver 14 of the diaphragm pump 10 (such as, for example, an electric motor) can be designed and controlled to decelerate, and even stop, when back pressure builds up during a stall event. For example, according to certain embodiments in which the driver 14 is an electric motor, the driver 14 can have a pulse width modulation (PWM) based VFD controller 15, and can have 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 within a motor speed range, the driver 14 can be designed to change its speed to maintain the desired torque, including running at a very slow speed. When faced with a stall event, the motor torque required by the driver 14 to drive the piston 68 typically increases as the discharge flow backs up to the outlet of the pump 14. Using a torque controlled driver 14 can facilitate the control system for the driver 14 to reduce the revolutions per minute (rpm) of the driver 14 so as not to exceed a predetermined threshold torque placed on the driver 14. By using this control, the rpm of the driver 14 can be reduced, and actually stopped, as long as the system places a torque exceeding the threshold on the driver 14. Thus, dangerously high back pressures in the discharge line from the diaphragm pump 10 may be avoided.

[0074] Additionally, according to certain embodiments, the driver 14 may be designed to maintain a constant speed up to a threshold torque. Thus, below a threshold torque, the driver 14 may be designed to maintain a selected speed even if the back pressure changes, which may otherwise affect the amount of torque on the driver 14. The constant speed of the driver 14 may be designed or selected to substantially maintain a selected flow rate of the diaphragm pump 10. Above the threshold torque, the driver 14 may be controlled to maintain the torque at the threshold by reducing the speed until the drive shaft 19 of the driver 14 rotates relatively very slowly, or stops in a stall condition, so as to maintain pressure in the system, but without accumulating pressure.

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

[0076] Embodiments of the present disclosure may also exhibit relatively significant energy utilization efficiencies. For example, with respect to electrical-hydraulic efficiency (and more specifically, the amount of electrical energy used to operate the drive 14 to the amount of kinetic energy transferred by the diaphragm pump 10 to the process fluid exiting the diaphragm pump 10), certain embodiments may achieve efficiencies greater than 50% over a large portion of the designed operating range of the diaphragm pump 10. Furthermore, according to certain embodiments, such efficiencies may be greater than 60%, and in some embodiments, efficiencies of approximately 65% ​​may be achieved.

[0077] Embodiments of the present disclosure can also provide significantly reduced acoustic or noise distribution relative to those distributions associated with many double diaphragm pumps. Because the crankshaft 40 of the diaphragm pump 10 rotates continuously in one direction during operation (without stall events), and the diaphragm 80 is connected to the cam 82 by a substantially rigid connection, the movement of the components of the pump 10, and in particular the movement of the diaphragm 80, is substantially smooth, without intermittent sudden movements and accompanying acoustic shocks, which are typically characteristic of the operation of a double diaphragm pump. Such designs of the embodiments disclosed in the subject matter can also minimize or eliminate noisy invalid motion connections and generated impact noise. In addition, the noise associated with the operation of the driver 14 (such as, for example, an electric motor) is generally quieter than the drive noise of the air motor from compressed air and AODP. Therefore, in terms of operation and work environment layout, the operational acoustic distribution of the embodiments of the present disclosure can provide significant advantages compared to conventional designs.

[0078] Additionally, during operation, the magnitude of forces acting on the diaphragm pump 10 during the suction stroke may be very different than those acting on the diaphragm pump 10 during the compression stroke. For example, at least certain components of the diaphragm pump 10 used in the displacement of the diaphragm 80 may experience relatively significantly higher levels of load forces on the discharge stroke than the forces encountered by those components during the return / suction stroke. As a result, such components may experience higher rates of wear on the discharge portion of the stroke and require increased mechanical integrity for the discharge portion of the stroke.

[0079] Reference Fig.11A and Fig. 11B According to some embodiments, the slider crank mechanism 221 may have one or more pistons 68 that are displaced in a reciprocating manner within a corresponding piston cylinder 60 along a motion axis 216 that is offset from the rotation axis 100 of the crankshaft 40 and is therefore located outside the plane thereof. According to some embodiments, the motion axis 216 intersects the corresponding connection to the connecting rod 62 at the piston pin 64 of the piston 68. Therefore, according to at least some embodiments, the motion axis 216 extends through both the position where the center of the piston pin 64 is located when the piston 68 completes the discharge stroke and the position where the center of the piston pin 64 is located when the piston 68 completes the intake stroke. In addition, the position of the center of the piston pin 64 when the piston 68 completes the discharge stroke and the intake stroke can be located on the central axis of the piston pin 68, which is generally located along the motion axis 216 or shared by the motion axis 216. According to certain embodiments, the degree of offset between the axis of motion 216 and the axis of rotation 100 of the crankshaft 40 may be at least the distance between the axis of motion 216 and the axis of rotation 100 of the crankshaft 40. Fig.11A and Fig. 11B The slider crank mechanism 221 is depicted as having three pistons 68 and three associated piston cylinders 60 and connecting rods 62, but the number of pistons 68 and associated components used with the slider crank mechanism 221 may vary for different disclosures.

[0080] The offset of the axis of motion 216 relative to the axis of rotation 100 of the crankshaft 40 may be achieved in a variety of different ways. For example, Fig.11A and Fig. 11B The depicted slider crank mechanism 221 is configured such that the motion axis 216 along which the associated piston 68 is displaced in a reciprocating manner is linearly offset from the rotation axis 100 of the crankshaft 40. Such linear offset may be achieved, for example, by linearly adjusting the position of the motion axis 216 so that the motion axis 216 does not intersect the rotation axis 100 of the crankshaft 40 and is offset from the rotation axis 100. For example, and at least for purposes of discussion, Fig. 11B The generally vertical orientation of the axis of motion 216 associated with the third piston 68 is shown offset in a generally horizontal direction (as indicated by Fig. 11B ), so that the movement axis 216 does not intersect with the rotation axis 100 of the crankshaft 40, but is offset to the right side of the rotation axis 100.

[0081] Such a linear offset of the axis of motion 216 of the slider crank mechanism 221 can be achieved 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. Therefore, 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 described, and as at least Fig.11A As shown, the lower crankcase 26 may include one or more apertures 88, each of which is sized and positioned to receive or otherwise couple to at least a portion of the piston cylinder 60. Such apertures 88 may 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. Further, according to certain embodiments, such a central longitudinal axis 217 of the aperture 88 may 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 therefore offset from the rotational axis 100 of the crankshaft 40 by substantially the same distance or magnitude.

[0083] If at least Fig. 11B As shown, according to the illustrated embodiment in which the slider crank mechanism 221 includes at least three pistons 68, the motion axis 216 for each of the pistons 68 can be offset from the rotation axis 100 of the crankshaft 40. In addition, each motion axis 216 can therefore be oriented so that all three motion axes 216 do not intersect at any common point.

[0084] Additionally, the magnitude of the offset between the axis of motion 216 and the axis of rotation 100 of the crankshaft may be based on a variety of criteria, including, for example, but not limited to, stroke length. For example, according to certain embodiments, the axis of motion 216 may be offset from the axis of rotation 100 of the crankshaft 40 by a distance of 0.1 inches to approximately 0.5 inches, and more specifically, by approximately 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 the displacement of the piston 68 and the associated operation of the diaphragm housing 118. Since the degree of forces and stresses encountered on the discharge stroke can generally be higher than those encountered on the suction 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 stroke and the suction stroke. Therefore, 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 a reduction in maximum forces and stresses can eliminate or reduce any need to at least over-design the offset slider crank mechanism 221 and / or the diaphragm housing 118 of the pump 10, which can provide cost savings. In addition, such improved balance of forces can facilitate better balancing the expected wear on the diaphragm 80, as well as the interface between at least the piston cylinder 60 and the associated piston 68, the sleeve or support band 70 and / or the associated linear guide assembly ( Fig.15A and Fig. 15B ) and thereby extend the service life of such components.

[0086] For example, Fig.12 A graph is provided depicting an example of piston side load as a function of crank angle for a slider-crank mechanism 221 of a diaphragm pump 10 having three levels of offset distance of the motion axis 216 from the rotation axis 100. With respect to a slider-crank mechanism without an offset feature (e.g., "offset = 0 inches"), for example Figure 3 The slider crank 21, as shown by Fig.12As shown in the graph of , during the suction stroke, the illustrated piston side load force drops to about -80 pounds of force (lbf) at its lowest point, and reaches a maximum value of about 600lbf during the discharge stroke. In other words, in this example, in the absence of an offset feature, the maximum piston side load during the discharge stroke is about 7.5 times the maximum piston side load experienced during the suction stroke. However, for the slider crank 221 with offset, when the motion axis 216 in this example is offset from the rotation axis 100 by 0.2 inches of offset distance, the improved balance between the piston side load force between the suction stroke and the discharge stroke is shown, as indicated by the piston side load force on the suction stroke reaching about -130lbf, and the maximum piston side load force during the discharge stroke being about 450lbf. Therefore, in this example, when the motion axis 216 and the rotation axis 100 are offset by 0.2 inches, the maximum piston side load force during the discharge stroke drops to about 3.5 times the maximum piston side load force on the suction stroke. As further seen in this example, by increasing the offset distance to 0.4 inches, this type of balance of the piston side load force between the discharge stroke and the suction stroke can be further enhanced. In addition, when the offset distance is 0.4 inches, the maximum piston side load forces of the suction stroke and the discharge stroke in this example are approximately 200lbf and approximately 300lbf, respectively. Therefore, when the offset distance is 0.4 inches, the maximum piston side load force of the discharge stroke drops to approximately 1.5 times the maximum piston side load force of the suction stroke. Therefore, the change in the offset distance can reduce the peak value of the piston side load force encountered during the discharge stroke, while increasing the peak value of the piston side load force encountered during the suction stroke. Therefore, a closer balance can be obtained between the piston side load forces encountered during the discharge stroke and the suction stroke.

[0087] Therefore, if Fig.12 As demonstrated by the example shown in , by providing a slider crank mechanism 221 with an offset feature, the diaphragm pump 10 can be designed and constructed using components that can withstand lower levels of force. Fig.12 , the diaphragm pump 10 may instead be constructed to withstand at least a maximum piston side load force of approximately 300 lbf (as shown as experienced by the exemplary slider-crank mechanism 221 having a 0.4 inch offset), rather than being constructed to withstand at least a maximum piston side load force of approximately 600 lbf (as shown as experienced by the exemplary slider-crank mechanism 221 without the offset feature). Thus, such a reduction in maximum force and maximum stress via incorporation of the offset feature into the slider-crank mechanism 221 may reduce (if not eliminate) any need to over-design at least the components of the slider-crank mechanism 221 (such as, for example, oversizing it), which may provide cost and size advantages in terms of the components and manufacture of the diaphragm pump.

[0088] The incorporation of an offset feature into the slider crank mechanism 221 and the associated improved balancing of piston side load forces and stresses that may be encountered during the discharge and suction strokes may be provided without significantly changing the overall outlet pressure of the diaphragm pump 10. For example, Fig.13 A graph is provided depicting an example of pump outlet pressure measured in pounds per square inch (psi) as a function of crank angle of the slider crank mechanism 21, 221 of a diaphragm pump 10 having a Fig.12 The same three offset levels depicted in . Fig.13 The outlet pressure shown may be the combined pressure effect of the diaphragm pump 10 having three diaphragm housings 118 and therefore three corresponding pistons 68. Fig.13 As shown, the total outlet pressure of the diaphragm pump 10 remains substantially the same for each of the three offset levels. Fig.12 and Fig.13 To the extent that maximum piston side load forces and maximum / minimum pressures occur at different crank angles, such differences may be attributed at least to variations in the duration of the intake and discharge strokes, as previously described.

[0089] In addition, similar to Fig. 9 , Fig.13 It has also been demonstrated that using an odd number of diaphragm housings 118 increases the number of pressure peaks that occur in each operating cycle. Furthermore, with respect to a diaphragm pump 10 having an odd number of diaphragm housings 118, the number of pressure peaks may be equal to twice the number of diaphragm housings 118. Thus, if Fig.13 The depicted 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, of which three pressure peaks are generally about 115 psi, and the other three pressure peaks are generally 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, since each diaphragm has only one pressure peak. The additional pressure peaks provided by using an odd number of diaphragm housings 118 may be a product of the increased duration of the overlapping time period in which multiple diaphragm housings 118 are subjected to a discharge stroke. In addition, by increasing the duration of the discharge stroke of each diaphragm housing 118 through the use of the offset feature of the slider crank mechanism 221 disclosed in the subject matter, the duration of multiple diaphragm housings 118 being subjected to a discharge stroke simultaneously may also be increased. In addition, as previously described, the increase in the number of pressure peaks per cycle may enhance the load shared by the diaphragms 80 of the pump 10 and increase the average pressure that may be obtained by the pump 10.

[0090] Although 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 may be provided in a variety of other ways. For example, according to certain embodiments, the piston pin 64 may be linearly offset from the corresponding cylinder axis 116, rather than offsetting the axis of motion 216. For example, Fig.14 The piston pin 64 is shown housed in the piston pin cavity 65 in the piston 68, and the piston pin 64 is attached to the connecting rod 62 coupled to the cam 82. As shown, the cylinder axis 116 of the corresponding piston cylinder 60 (not shown) is positioned to intersect the rotation axis 100, wherein the rotation axis 100 is not positioned at the center of the cam 82, and the cylinder axis 116 can also be used as the motion axis along which the piston 68 is reciprocally displaced. However, the central longitudinal axis 67 of the piston pin 64 is positioned on the piston 68 at a position linearly offset from the cylinder axis 116, as shown by Fig.14 . According to the illustrated embodiment, the linear distance may be based on a distance from a central longitudinal axis 67 of the piston pin 64 and / or the piston pin cavity 65 in a direction generally normal to the cylinder axis 116. In addition, such an offset of the piston pin 64 and / or the piston pin cavity 65 may provide the connecting rod 62 with an adjusted angle of attack relative to the piston 68, which may at least increase the duration of the discharge stroke, which again may be beneficial to improve the balance of forces experienced by the piston 68 during the intake and discharge strokes.

[0091] Reference Fig.16According to other embodiments, instead of a linear offset, the pump 10 may 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 offset of the axis of motion 216 may be achieved by angularly offsetting the central longitudinal axis 218 of the cylinder 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 cylinder bore 59 relative to at least the rotational axis 100 may be achieved in a variety of ways. For example, according to certain embodiments, the cylinder bore 59 may be formed in the piston cylinder 60 such that the central longitudinal axis 218 of the cylinder 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 cylinder bore 59, may be positioned and oriented to intersect the rotational axis 100. According to such embodiments, because the motion axis 216 can extend along the central longitudinal axis 218 of the cylinder bore 59, the motion axis 216 can also be offset relative to the rotation axis 100. In addition, 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 the motion axis 216, but linearly offset from the motion axis 216, such as in Fig.16 As seen in.

[0092] Alternatively, according to other embodiments in which the central longitudinal axis 218 of the cylinder bore 59 and therefore the movement axis 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 orifice 88 in a manner that causes each of the central longitudinal axis 63 of the piston cylinder 60, the central longitudinal axis 218 of the cylinder bore 59, and the movement axis 216 to be angularly offset from the rotation axis 100 without intersecting.

[0093] Fig.15A An enlarged view of a portion of the pump 10 and an associated piston 68 of a slider crank mechanism 221 is shown, wherein 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 may include a bearing seat 204, a plurality of balls or rollers (not shown), and a track 206. The plurality of balls or rollers, which may function as bearings, may be positioned between the bearing seat 204 and the track 206 such that the balls or rollers rotate as the bearing seat 204 is linearly displaced along the track 206, thereby facilitating the linear displacement of the bearing seat 204 along the track 206. In addition, the bearing seat 204 and the track 206 may have matching shapes to facilitate the bearing seat 204 to remain engaged with the track 206 and at least to facilitate maintaining the plurality of balls or rollers in an operable position between the bearing seat 204 and the track 206.

[0094] like Fig.15A and Fig. 15B As shown, according to the illustrated embodiment, the track 204 can be fixed to the inner wall 208 of the piston cylinder 60, such as, for example, by one or more mechanical fasteners, including but not limited to one or more bolts. In addition, according to some embodiments, at least a portion of the track 206 can be recessed in a groove in the inner wall 208 of the piston cylinder 60. Similarly, the bearing seat 204 can be fixed to the piston 68 so that the bearing seat 204 is linearly displaced as the piston 68 is displaced. Therefore, when the piston 68 is linearly displaced, 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. In addition, according to some embodiments, the linear guide assembly 202 can provide a rolling interface between the piston 68 and the piston cylinder 60. In addition, according to some embodiments, at least a portion of the piston 68 can have a shape and / or size that can accommodate the placement of at least a portion of the linear guide assembly 202 within the piston cylinder 60.

[0095] In addition, similar to the above Fig.14 The examples discussed, Fig.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 be used as the movement axis along which the piston 68 is reciprocally displaced. However, similar to the above with respect to Fig.14 In the embodiment discussed, the central longitudinal axis 67 of the piston pin 64 may be parallel to the axis of motion 116, but linearly offset therefrom, as indicated by Fig.15A Such an offset of the piston pin 64 may also provide the connecting rod 62 with an adjusted angle of attack relative to the piston 68, which may at least increase the duration of the discharge stroke, which may also facilitate an improved balance of the piston side load forces experienced during the intake and discharge strokes.

[0096] Although the linear guide assembly 202 is described above with respect to a device having at least Fig.14 The linear guide assembly 202 is discussed with a slider crank mechanism 221 having an offset feature such as those shown in FIG, but the linear guide assembly 202 can also be used with other slider crank mechanisms that can have other types of offset features or configurations. In addition, the linear guide assembly 202 can also be used with a slider crank mechanism that does not utilize an offset feature.

[0097] While the above examples are discussed with respect to a single piston cylinder and piston and its associated axis of motion, similar offset features may also be incorporated for any, if not all, of the other piston cylinders, pistons and associated axes of motion and / or associated diaphragm housings.

[0098] Although the present invention is described in conjunction with what is currently considered to be the most practical and preferred embodiment, it will be understood that the present invention is not limited to the disclosed (multiple) embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included in the spirit and scope of the appended claims, which scope will be consistent with the broadest interpretation so as to include all such modifications and equivalent structures as permitted under the law. In addition, it should be understood that although the words "preferably", "preferably" or "preferred" are used in the above description to indicate that the features described so far may be more desirable, they may not be necessary, and any embodiment lacking the feature may be conceived to be within the scope of the present invention, which scope is defined by the subsequent claims. When reading the claims, it is intended that when words such as "one", "an", "at least one" and "at least a portion" are used, it is not intended to limit the claims to only one item, unless specifically stated to the contrary in the claims. In addition, when the language "at least a portion" and / or "a portion" is used, the item may include a portion and / or the entire item, unless specifically stated to the contrary.

Claims

1. A device comprising: A diaphragm pump (10) having a plurality of diaphragms (80) at least partially defining a plurality of pump chambers (46), each diaphragm (80) being configured to reciprocate between a first position and a second position to pump a fluid, the diaphragm pump (10) comprising: A crankcase (17) and a crankshaft (40) at least partially disposed within the crankcase (17); It is characterized in that 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 in a vertical direction by the bracket (30), the crankshaft being operatively connected to a motor so that the motor provides power to rotate the crankshaft (40) during operation; at least one cam (82) configured to rotate with the crankshaft (40) to cause the reciprocating motion of the plurality of diaphragms (80), wherein each of the plurality of diaphragms (80) is oriented to reciprocate along a cylinder axis (116) orthogonal to the crankshaft axis; The diaphragm pump (10) comprises at least three diaphragms (80) and at least three pumping chambers (46), and the at least three pumping chambers (46) are evenly distributed around the crankshaft axis (100) so that the angles formed between adjacent cylinder axes (116) are substantially the same.

2. The device according to claim 1, characterized in that The cylinder axes (116) of the plurality of diaphragms (80) are 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) is reciprocated by 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, the rotatable rotor being in power communication with the crankshaft (40) and being rotatable about a rotor axis parallel to the crankshaft axis; optionally, wherein the motor is configured to be driven to reduce the speed of the crankshaft (40) and maintain torque in the event of a flow disruption 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 axes (116) is offset from the crankshaft axis (100), and wherein the diaphragm pump (10) further comprises a cylinder (60) for each of the plurality of diaphragms (80), each cylinder (60) being arranged along the cylinder axis (116), and a piston (68) being disposed in the cylinder (60), the piston (68) being connected to the crankshaft (40) via a connecting rod.

7. The device according to claim 6, characterized in that Each of the pistons (68) is configured to directly move the corresponding diaphragm (80) between the first position and the second position; optionally, wherein 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 arranged between the piston (68) and the cylinder (60) to prevent the lubricant from reaching the accommodating chamber (81), which is opposite to the pumping chamber (46) relative to the diaphragm (80); optionally, the seal includes a seal facing the lubricant and a seal facing the accommodating chamber (81), wherein the seal facing the accommodating chamber is a bellows seal.

9. The device according to any one of claims 6 to 8, characterized in that The diaphragms are oriented such that the arcuate shape of the annular flexible portion (83) of each diaphragm (81) is disposed 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 positioned circumferentially around at least a portion of the respective piston.

11. A method comprising: A crankshaft (40) having at least one cam (82) and a crankshaft axis is at least partially inserted into a crankcase (17) of a diaphragm pump (10); 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 coupled to the crankcase, wherein the electric motor (14) is in power communication with the crankshaft (40); coupling a bracket (30) to the crankcase (17) such that the crankshaft axis is oriented vertically when the crankcase (17) is supported by the bracket (30); orienting the cylinder axis (116) of each of the at least three diaphragm pump cylinders (60) relative to the crankshaft (40) so that each of the respective cylinder axes (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; and The at least three diaphragm pump cylinders (60) are attached to the crankcase (17), the diaphragm pump cylinders (60) being equally angularly spaced around the crankshaft axis (100).

12. The method according to claim 11, characterized in that Also included is orienting the support (30) so that the respective cylinder axes (116) of the at least three diaphragm pump cylinders are horizontal.

13. The method according to claim 11 or claim 12, characterized in that It also includes positioning a piston (68) within each of the corresponding plurality of diaphragm pump cylinders (60) and connecting the diaphragm (68) in each corresponding cylinder (60) to the corresponding 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 to 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 to 14, characterized in that It also includes connecting a rolling element bearing between each piston (68) and each cylinder (60); it also includes installing an oil-facing seal and a seal facing the containment cavity (81); and / or it also includes attaching a support band (70) circumferentially around at least a portion of each piston (68).

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