WO2024229024A1

WO2024229024A1 - Active checked multiple displacer assembly

Info

Publication number: WO2024229024A1
Application number: PCT/US2024/027053
Authority: WO
Inventors: Andrew J. Klaphake
Original assignee: Graco Minnesota Inc
Current assignee: Graco Minnesota Inc
Priority date: 2023-05-03
Filing date: 2024-04-30
Publication date: 2024-11-07
Anticipated expiration: 2025-11-03
Also published as: KR20260002804A; CN121039395A

Abstract

A multi-displacer assembly (10) comprising multiple pumps (12) having fluid displacers (34) arranged in a displacer cavity (36) of the pump. A pumping chamber (14) of one pump is connected to a displacer cavity of a second pump.

Description

ACTIVE CHECKED MULTIPLE DISPLACER ASSEMBLY

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to U.S. Provisional Application No. 63/463,715 filed May 3, 2023 and entitled “ACTIVE CHECKED MULTIPLE PISTON PUMP,” and claims priority to U.S. Provisional Application No. 63/626,707 filed January 30, 2024 and entitled “ACTIVE CHECKED MULTIPLE DISPLACER ASSEMBLY,” the disclosures of which are hereby incorporated by reference in their entireties.

BACKGROUND

The present disclosure concerns pumping. More specifically, the present disclosure concerns multiple displacer pumps.

Multiple piston pumps include multiple pistons that operate together to output a fluid flow from the pump. The pistons are driven out of phase with respect to each other. In such pumps fluid is prevented from returning to a piston cavity by the use of ball checks. Ball checks use a spring to push (bias) the ball back into the ball seat. A ball check functions relative to fluid pressure, with the ball unseating and allowing fluid to pass towards the fluid outlet as the piston downstrokes creating fluid pressure. The ball reseats at the end of the piston downstroke, when the exiting fluid pressure becomes less relative to the force exerted by ball check spring and such that the piston chamber can be refilled.

SUMMARY

According to an aspect of the disclosure, a multi-displacer pumping assembly includes first and second pumps. The first pump includes a first fluid displacer configured to reciprocate along a first pump axis within a first displacer cavity to pump fluid through a first pumping chamber. The second pump includes a second fluid displacer configured to reciprocate along a second pump axis within a second displacer cavity to pump fluid through a second pumping chamber. The first pumping chamber is fluidly connected to the second displacer cavity to receive fluid from and output fluid to the second displacer cavity.

According to an additional or alternative aspect of the disclosure, a multi-displacer pumping assembly includes a first pump having a first fluid displacer configured to reciprocate along a first pump axis within a first displacer cavity to pump fluid through a first pumping chamber; a second pump having a second fluid displacer configured to reciprocate along a second pump axis within a second displacer cavity to pump fluid through a second pumping chamber, a first fluid chamber formed in the second displacer cavity, a second fluid chamber formed in the second displacer cavity, and a common chamber formed in the second displacer cavity; a common passage extending between and fluidly connecting the first pumping chamber and the common chamber; an inlet passage fluidly connected to the first fluid chamber to provide the fluid to the first fluid chamber; and an outlet passage fluidly connected to the second fluid chamber to receive fluid from the second fluid chamber. The second fluid displacer is configured to alternatingly fluidly connect the first pump with the first fluid chamber to receive the fluid into the first pumping chamber and with the second fluid chamber to output the fluid.

According to another additional or alternative aspect of the disclosure, a method of pumping includes reciprocating a first fluid displacer on a first pump axis to pump fluid through a first pumping chamber from an intake passage to an outlet passage; reciprocating a second fluid displacer on a second pump axis to pump fluid through a second pumping chamber from the intake passage to the outlet passage; fluidly connecting the first pumping chamber with the intake passage with the second fluid displacer during a fill stroke of the first fluid displacer; and fluidly connecting the first pumping chamber with the outlet passage by the second fluid displacer during a discharge stroke of the first fluid displacer.

According to yet another additional or alternative aspect of the disclosure, a multidisplacer pumping assembly includes a first reciprocator configured to reciprocate along a first axis within a first displacer cavity to pump fluid through a first pumping chamber; and a second reciprocator configured to reciprocate along a second axis within a second displacer cavity to alternatingly fluidly connect the first pumping chamber with an inlet passage such that the first pumping chamber receives the fluid from the inlet passage and with an outlet passage such that the first pumping chamber outputs the fluid to the outlet passage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. l is a schematic diagram showing flow passages for a multi-displacer pumping assembly.

FIG. 2 is an isometric view of a multi-displacer pumping assembly.

FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2.

FIG. 4 is a cross-sectional view taken along line B-B in FIG. 2.

FIG. 5A is a cross-sectional view taken along line C-C in FIG. 2 showing a pump of the multi-displacer pumping assembly in a fill state.

FIG. 5B is a cross-sectional view taken along line C-C in FIG. 2 showing a pump of the multi-displacer pumping assembly in a transition state. FIG. 5C is a cross-sectional view taken along line C-C in FIG. 2 showing a pump of the multi-displacer pumping assembly in a dispense state.

FIG. 6A is an isometric view of a fluid distribution assembly.

FIG. 6B is a cross-sectional view taken along line B-B in FIG. 6A.

DETAILED DESCRIPTION

The present disclosure relates generally to displacement pumps. According to aspects of the present disclosure a multi-displacer pumping assembly includes multiple fluid displacers that reciprocate out of phase with respect to each other to pump a fluid. The multi-displacer pumping assembly includes multiple pumps that each include a fluid displacer that reciprocates to pump the fluid. The multi-displacer pumping assembly includes active checking in which the fluid displacers perform checking of passageways for inlet and outlet flows from the individual pumps. The fluid displacer of one pump of the assembly provides checking for directing flow into and out of another one of the pumps of the assembly.

Multi-displacer pumping assemblies according to the present disclosure do not require ball valves or other valves to regulate the inflow and outflow of fluid, unlike traditional pumps. The fluid displacers of the multiple pumps of the assembly perform the fluid checking for others of the multiple pumps. According to aspects of the present disclosure, each of the individual pumps includes a pumping chamber through which the fluid displacer of that pump pumps the fluid. The multiple pumps are fluidly connected to each other such that one pump receives fluid from and outputs fluid to another of the pumps. The pumps are fluidly connected such that one pump pumps through a displacer chamber of another pump. The pumping chamber of a first pump is fluidly connected to a second pump by fluid pathways between the first and second pumps. The fluid pathway direct fluid from a first flow chamber of the second pump to the pumping chamber of the first pump and then to a second flow chamber of the second pump. The first and second flow chambers are fluidly connected to inlet and outlet passages of the multi-displacer pumping assembly. The fluid displacer of the second pump fluidly separates the flow chambers. The fluid displacer of the second pump reciprocates to simultaneously pump fluid through the pumping chamber of the second pump and alternatingly fluidly connect the pumping chamber of the first pump to the first and second flow chambers of the second pump.

The fluid displacer of a pump of the multi-displacer pumping assembly is configured to maintain fluid separation between flow chambers of that pump. The fluid displacer can include a chamber connector configured to fluidly connect the pumping chamber of another pump with the flow chambers of the pump. The chamber connector can be formed on an exterior of the fluid displacer, within an interior of the fluid displacer, or a combination thereof.

A fluid dispensing device includes a multi-displacer pumping assembly with active checks. Active checking can be provided by the position of the fluid displacer relative to the inlet and outlet ports along the displacer cavity. The fluid displacers can have at least two diameters: (i.) a diameter narrower than the displacer cavity (allowing fluid flow to/from the displacer cavity), and (ii.) a diameter substantially similar to the coaxial diameter of the displacer cavity (i.e., a diameter that prevents fluid from the displacer cavity). The multiple fluid displacers have cross porting between select fluid displacers.

The fluid displacers of the multiple pumps of the multi-displacer pumping assembly can be driven out of phase with respect to each other. Driving the fluid displacers out of phase facilitates continuous outflow from the multi-displacer pumping assembly. According to aspects of the disclosure, the fluid displacers can be driven by drive, such as a wobble drive, a cam drive, or any suitable drivetrain that allows for phasing of the multiple fluid displacers. In some examples, the multi-displacer pumping assembly with active checks can be used for fluid metering, such as with liquid proportioning in the liquid finishing market. In some examples, the multi-displacer pumping assembly with active checks may be driven in reverse with compressed air to serve as an air motor (i.e., outputting a rotational force).

Components can be considered to radially overlap when those components are disposed at common axial locations along an axis. A radial line extending from the axis will extend through each of the radially overlapping components. Components can be considered to axially overlap when those components are disposed at common radial and circumferential locations relative to an axis such that an axial line parallel to the axis extends through the axially overlapping components. Components can be considered to circumferentially overlap when aligned about the axis, such that a circle centered on the axis passes through the circumferentially overlapping components.

FIG. 1 is a schematic diagram of a multi-displacer pumping assembly 10. The multi-piston pumping assembly includes pumps 12a-12d (collectively referred to herein as “pump 12” or “pumps 12”), inlet pathway 22, and outlet pathway 24. Each pump 12 includes pumping chamber 14, inlet chamber 16, and outlet chamber 18. Common passages 20 extend between pumps 12. Multi-displacer pumping assembly 10 is configured to pump a fluid for dispensing on a substrate. For example, multi-displacer pumping assembly 10 can be configured to dispense higher viscosity fluids (e.g., sealant, adhesive, foam, gasketing material, among other options). In some examples, the multi-piston pump 12 can be configured to produce sufficient outlet fluid pressure to create fluid atomization at a nozzle outlet, thereby allowing the system to be used in airless spraying applications, such as disclosed in United States Patent No. 9,914,141 (*141 Patent) and United States Pre-Grant Publication 2017/0165692, the disclosure of which is herein incorporated by reference in its entirety.

Multi-displacer pumping assembly 10 includes active checking in which the fluid checks are provided by a portion of the pump drivetrain, typically by a portion of a fluid displacer itself relative to a pump body. In some examples, the active checking is provided by the fluid displacer (e.g., via different diameters of the piston along select lengths of the piston) blocking the inlet port (at certain phase(s)) and the outlet port (at certain phase(s)). Active checking may provide more exact amounts of fluid dispense (e.g.., more exact doses). Active checking can also provide for smoother fluid flow by eliminating vibration generated by a ball reseating to close flowpaths in assemblies including ball check valves.

Pumps 12a-12d are fluidly connected to inlet pathway 22. Inlet pathway 22 provides flow of fluid to each of pumps 12a-12d. The pumps 12a-12d are fluidly connected to a common inlet pathway 22. In some examples, the fluid can be provided to multi-displacer pumping assembly 10 under pressure such that inlet pathway 22 provides a pressurized inflow to multi-displacer pumping assembly 10. Pumps 12a-12d are also fluidly connected to outlet pathway 24. Outlet pathway 24 receives fluid output by each of pumps 12a-12d. The pumps 12a-12d are fluidly connected to a common outlet pathway 24. The multi-displacer pumping assembly 10 can be configured to receive a common inflow and to output a common outflow. In some examples, multi-displacer pumping assembly 10 can be configured to output the pumped fluid at a pressure lower than the inlet pressure of the fluid.

Pumps 12a-12d include fluid displacers that are configured to reciprocate to pump fluid and to provide active checking for others of the pumps 12. The fluid displacers can be configured as pistons, plungers, etc. It is understood that, while fluid displacers may be referred to as pistons in this disclosure, such description is equally applicable to plunger type pumping. The fluid displacers are reciprocated through pump cycles. Each pump cycle includes a first stroke in a first direction along the reciprocation axis of the fluid displacer and a second stroke in a second direction along the reciprocation axis of the fluid displacer. The first stroke can increase a volume of the pumping chamber 14 such that fluid is drawn into the pumping chamber 14. The second stroke can decrease a volume of the pumping chamber 14 such that fluid is output from the pumping chamber 14.

Inlet chambers 16 of each pump 12a-12d are fluidly connected to inlet pathway 22. The inlet chambers 16 can be at least partially defined by a fluid displacer of the pump 12. The inlet chambers 16 can be formed within a displacer cavity of the pump 12 within which the fluid displacer of the pump 12 reciprocates. The inlet chambers 16 receive an inflow from inlet pathway 22. Outlet chambers 18 of each pump 12a-12d are fluidly connected to outlet pathway 24. The outlet chambers 18 can be at least partially defined by the fluid displacer of the pump 12. The outlet chambers 18 can be formed within the displacer cavity of the pump 12 within which the fluid displacer of the pump 12 reciprocates. Outlet chambers 18 are configured to provide an outflow to outlet pathway 24. The inlet chamber 16 and the outlet chamber 18 are maintained as fluidly separated throughout operation by the fluid displacer of the pump 12.

It is understood that multi-displacer pumping assembly 10 can be configured for dual directional flow. For example, running a drive that reciprocates the fluid displacers in a first direction can cause the inlet pathway 22 to provide the fluid to the multi-displacer pumping assembly 10 such that fluid is output through outlet pathway 24. Running the drive in a second opposite direction can cause the multi-displacer pumping assembly 10 to pump fluid from outlet pathway 24 to inlet pathway 22 such that outlet pathway 24 provides the fluid to pumps 12a-12d and inlet pathway 22 receives the fluid output by pumps 12a- 12d. The inlet pathway 22 and outlet pathway 24 can be referred to as pump pathways of the pump 12 as either of the inlet pathway 22 and the outlet pathway 24 can provide fluid to or receive fluid from pumps 12a-12d.

Pumping chambers 14 are formed in each pump 12a-12d. The fluid displacer of the pump 12a-12b reciprocates on a reciprocation axis to pump the fluid through the pumping chamber 14. The pumping chamber 14 can be at least partially defined by the fluid displacer and the displacer cavity within which the fluid displacer reciprocates.

Common passages 20 extend between and fluidly connect the various pumps 12a- 12d of the multi-piston pumping assembly 10. Common passages 20 fluidly connect the inlet chamber 16 and outlet chamber 18 of one pump 12 with the pumping chamber 14 of another pump 12. In the example shown, common passage 20a extends between the inlet chamber 16 and outlet chamber 18 of pump 12a and pumping chamber of pump 12b. Common passage 20b extends between the inlet chamber 16 and outlet chamber 18 of pump 12b and pumping chamber 14 of pump 12c. Common passage 20c extends between the inlet chamber 16 and outlet chamber 18 of pump 12c and pumping chamber 14 of pump 12d. Common passage 20d extends between the inlet chamber 16 and outlet chamber 18 of pump 12d and pumping chamber 14 of pump 12a.

In the example shown, common passages 20 are shown as branching to connect to inlet chamber 16 and outlet chamber 18. It is understood that, in some examples, the common passage 20 extends to a single port into the displacer cavity of the pump 12a-12d, the single port altematingly fluidly connected to the inlet chamber 16 and the outlet chamber 18 by the fluid displacer of the pump 12a-12d.

During operation, the pumps 12a-12d are operated out of phase such that the fluid displacers of the pumps 12 are at varying locations throughout their respective pump strokes relative to the other fluid displacers. Fluid is provided to multi-displacer pumping assembly 10 from an upstream fluid supply, which can be pressurized. The fluid flows through inlet pathway 22 and to inlet chambers 16 of the pumps 12a-12d.

For pump 12a, the fluid displacer of pump 12d fluidly connects the inlet chamber 16 of pump 12d with common passage 20 with the fluid displacer of pump 12a at or near the end of a discharge stroke in which fluid is output from pumping chamber 14 of pump 12a. The piston of pump 12a begins to move through a fill stroke and fluid flows from the inlet chamber 16 of pump 12d through the common passage 20 between pump 12d and pump 12a and into the pumping chamber of pump 12a. The piston of pump 12a turns over after the fill stroke and begins a discharge stroke. The piston of pump 12d shifts to fluidly disconnect the inlet chamber 16 of pump 12d from the pumping chamber 14 of pump 12a and to fluidly connect the outlet chamber 18 of pump 12d with the pumping chamber 14 of pump 12a. The fluid displacer of pump 12a drives the fluid out of pumping chamber 14 through common passage 20d and to outlet chamber 18 of pump 12d. The fluid is then output to outlet pathway 24. In some examples, the fluid displacer of pump 12d can be considered to form a shuttle valve for directing of fluid to the pumping chamber 14 of pump 12a.

It is understood that while operation of pump 12a is discussed above, pumps 12b- 12d can operate in the same or similar manner. In the example shown, pump 12b is configured to receive fluid from inlet chamber 16 of pump 12a and output fluid through outlet chamber 18 of pump 12a; pump 12c is configured to receive fluid from inlet chamber

configured to receive fluid from inlet chamber 16 of pump 12c and output fluid through outlet chamber 18 of pump 12c.

While multi-displacer pumping assembly 10 is described such that each pump 12 performs both fluid displacing and active checking, it is understood that not all examples are so limited. In some examples, a first subset of the pumps 12 perform fluid displacement while a second subset of the pumps 12 provide active checking for the first subset of pumps 12. For example, the reciprocator (e.g., piston, plunger, etc.) of pump 12a can be configured to pump fluid through the pumping chamber 14 of pump 12a and the reciprocator of pump 12d can be configured to provide active checking for pump 12a but without displacing fluid. Pump 12c can be configured to pump fluid through the pumping chamber 14 of pump 12c and pump 12b can be configured to provide active checking for pump 12c but without displacing fluid. In such an example, pumps 12a, 12c form the first subset that perform fluid displacement while pumps 12b, 12d perform the second subset that perform active checking.

Multi-displacer pumping assembly 10 provides significant advantages. The fluid displacers of the pumps 12 function to fluidly connect and disconnect pumping chambers 14 of others of the pumps 12 from the inlet pathway 22 and outlet pathway 24. The fluid displacers further reciprocate to pump the fluid. The fluid displacers thereby perform dual operation by both providing active checking for flow of another pump 12 and providing pumping for the pump 12 of the fluid displacer. The fluid displacers can be operated out of phase such that at least one of the pumps 12 is outputting fluid to outlet pathway 24 at any given time during operation, thereby providing a steady and continuous outflow from the multi-displacer pumping assembly 10.

Multi-displacer pumping assembly 10 can be utilized across multiple dispense operations and for multiple purposes. For example, multi- displacer pumping assembly 10 can be configured for dispensing of a high viscosity fluid (e.g., without limitation, a sealant, adhesive, foam, or gasketing material). In some examples, multi- displacer pumping assembly 10 is configured to produce sufficient outlet fluid pressure to create fluid atomization at a nozzle outlet (not shown), thereby allowing the system to be used in airless spraying applications. In some examples, multi- displacer pumping assembly 10 can be used as a meter (i.e., a dosing pump), such as the fluid meters (or dosing pumps) used with a liquid proportioner. In some examples, multi- displacer pumping assembly is not used as a fluid pump but instead as an air motor when driven in reverse direction with compressed air in order to create a rotational force (or multiple, phased linear forces if not coupled with a drive).

FIG. 2 is an isometric view of multi-piston pumping assembly 10. FIG. 3 is a cross- sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 2. FIG. 5A is a cross-sectional view taken along line 5-5 in FIG. 2 showing a pump 12 of the multi-displacer pumping assembly 10 in a fill state. FIG. 5B is a cross- sectional view taken along line 5-5 in FIG. 2 showing a pump 12 of the multi-displacer pumping assembly 10 in a transition state. FIG. 5C is a cross-sectional view taken along line 5-5 in FIG. 2 showing a pump 12 of the multi-displacer pumping assembly 10 in a dispense state. FIGS. 2-5C will be discussed together with continued reference to FIG. 1. The multi-displacer pumping assembly includes drive 26, a plurality of pumps 12, pump pathway 28a (best seen in FIG. 3A), pump pathway 28b (best seen in FIG. 3B), and assembly body 30. Pumps 12a-12d each include pumping chamber 14, flow chamber 32a, flow chamber 32b, fluid displacer 34, displacer cavity 36, pump body 38, pump cage 40, chamber cages 42a, 42b, pump seals 44a, 44b, and routing seals 46a, 46b. Common passages 20 extend between pumps 12.

Pump 12a and pump 12b and the common passage 20 therebetween are shown in FIGS. 5A-5C, but it is understood that the active checking and flowpaths can be the same as between each of the pumps 12a-12d, such as discussed above with regard to FIG. 1.

Assembly body 30 supports other components of multi-displacer pumping assembly 10. In the example shown, each pump 12 includes a distinct pump body 38 and the various pump bodies 38 are assembled together to form the assembly body 30. The pump bodies 38 can be fixed together, such as by bolts or other fasteners. It is understood, however, that assembly body 30 can be formed in any desired manner. For example, assembly body 30 can be formed monolithically, among other options.

For each pump 12, the fluid displacer 34 is at least partially disposed within the assembly body 30. The fluid displacer 34 is elongate along the reciprocation axis RA. The fluid displacers 34 can be configured as pistons, plungers, or other type of fluid mover.

The fluid displacer 34 is connected to drive 26 to receive a reciprocating input from drive 26. In the example shown, the drive 26 is formed as a wobble drive through it is understood that other configurations are possible. The rotational input for the wobble drive (or similar drive, e.g., cam) may be provided by various motors, such as described in Paragraph [0050] of United States Patent Application Publication 2017/0165692, assigned to Graco Minnesota Inc., with the disclosure of U.S. Patent Application Publication 2017/0165692 incorporated by reference in its entirety. The drive 26 is configured to drive the fluid displacers 34 of the pumps 12 out of phase relative to each other. The drive 26 can be connected to a drive shaft that provides rotational input to the drive 26. The drive 26 is configured to convert that rotational input into reciprocating linear motion that is provided to fluid displacers 34 to displace fluid displacers 34 and cause pumping by the multi-displacer pumping assembly 10.

Pump pathways 28a, 28b are formed in assembly body 30. One of pump pathways 28a, 28b provides an inlet passage (e.g., inlet pathway 22 (FIG. 1)) for multi-displacer pumping assembly 10 and the other one of pump pathways 28a, 28b provides an outlet passage (e.g., outlet pathway 24 (FIG. 1)) for multi-displacer pumping assembly 10. In the example shown, each displacer cavity 36 is fluidly connected to the both pump pathways 28a, 28b such that each pump 12 receives an inflow from a common flowpath and outputs and outflow to a common flowpath. Rotating drive 26 in a first rotational direction will cause pump 12 to intake fluid through pump pathway 28a and output fluid through pump pathway 28b. Rotating drive 26 in a second rotational direction opposite the first rotational direction will cause pump 12 to intake fluid through pump pathway 28b and output fluid through pump pathway 28a.

Pump pathway 28a is fluidly connected to the displacer cavity 36 of each pump 12a-12d. As such, pump pathway 28a can provide fluid to or receive fluid from each pump 12a-12d. Pump pathway 28a is fluidly connected to the flow chamber 32a of each pump 12. Pump pathway 28b is fluidly connected to the displacer cavity 36 of each pump 12a- 12d. As such, pump pathway 28b can provide fluid to or receive fluid from each pump 12a-12d. Pump pathway 28b is fluidly connected to the flow chamber 32b of each pump 12.

Pump cage 40 is at least partially disposed within displacer cavity 36. Pump cage 40 includes apertures therethrough that allow fluid to flow through pump cage 40. Pump cage 40 at least partially defines the pumping chamber 14. Chamber cage 42a is disposed within displacer cavity 36. Chamber cage 42a is disposed within displacer cavity 36. Chamber cage 42a includes apertures therethrough that allow fluid to flow through chamber cage 42a. Chamber cage 42a at least partially defines flow chamber 32a. Chamber cage 42b is disposed within displacer cavity 36. Chamber cage 42b includes apertures therethrough that allow fluid to flow through chamber cage 42b. Chamber cage 42b at least partially defines flow chamber 32b. The fluid displacer 34 of each pump 12 is configured to reciprocate within the displacer cavity 36 of that pump 12. The fluid displacers 34 can also be referred to as reciprocators. It is understood that in some examples, pump 12b may not include a pumping chamber 14 and may instead be configured such that the fluid displacer 34 of pump 12b reciprocates to provide active checking to pump 12a but without pumping fluid through a fluid chamber. In some such examples, pump 12a may perform fluid displacement without providing active checking, such that pump 12a may not include flow chambers 32a, 32b, common chamber 33, or corresponding sealing elements.

The fluid displacer 34 interfaces with various seals within the displacer cavity 36 to divide the displacer cavity 36 into chambers and to route fluid. In the example shown, pump seal 44a interfaces with fluid displacer 34 and at least partially defines flow chamber 32a. Pump seal 44a is configured to engage and seal against fluid displacer 34 throughout operation. Pump seal 44a is configured to prevent fluid from leaking out of pump body 38 between fluid displacer 34 and pump body 38. Pump seal 44a is a dynamic seal in that fluid displacer 34 moves relative to pump seal 44a during operation while maintaining a sealed interface with pump seal 44a.

Pump seal 44b is disposed within pump body 38. Pump seal 44b interfaces with fluid displacer 34 and at least partially defines pumping chamber 14. In the example shown, pump seal 44b also at least partially defines flow chamber 32b. Pump seal 44b is configured to engage and seal against fluid displacer 34 throughout operation. Pump seal 44b is configured to prevent fluid from leaking between the pumping chamber 14 and flow chamber 32b. Pump seal 44b is a dynamic seal in that fluid displacer 34 moves relative to pump seal 44b during operation while maintaining a sealed interface with pump seal 44b.

Each routing seal 46a, 46b is engaged with fluid displacer 34 during certain phases of operation and is disengaged from fluid displacer 34 during other phases of operation. In the example shown, at least one of routing seals 46a, 46b is in sealing engagement with fluid displacer 34 throughout operation. Routing seal 46a is disposed between flow chamber 32a and common chamber 33. Fluid displacer 34 engaging routing seal 46a fluidly isolates flow chamber 32a and common chamber 33. Routing seal 46b is disposed between flow chamber 32b and common chamber 33. Fluid displacer 34 engaging routing seal 46b fluidly isolates flow chamber 32b and common chamber 33. Pumps 12 are configured such that fluid displacer 34 moves into and out of engagement with routing seals 46a, 46b to provide the active checking for another of pumps 12. In the example shown, fluid displacer 34 is disengaged from routing seal 46a to fluidly connect flow chamber 32a and common chamber 33. Fluid displacer 34 is configured such that fluid displacer 34 is engaged with routing seal 46b to fluidly isolate flow chamber 32b and common chamber 33 when fluid displacer 34 is disengaged from routing seal 46a to fluidly connect flow chamber 32a and common chamber 33.

In the example shown, fluid displacer 34 is disengaged from routing seal 46b to fluidly connect flow chamber 32b and common chamber 33. Fluid displacer 34 is configured such that fluid displacer 34 is engaged with routing seal 46a to fluidly isolate flow chamber 32a and common chamber 33 when fluid displacer 34 is disengaged from routing seal 46b to fluidly connect flow chamber 32b and common chamber 33.

Fluid displacer 34 includes chamber connector 35 that is configured to route fluid between a flow chamber 32a, 32b and the common chamber 33. In the example shown, chamber connector 35 is formed as a reduced diameter portion of fluid displacer 34 relative to portions of fluid displacer 34 that sealingly engage with routing seals 46a, 46b.

In the example shown, chamber connector 35 is formed as an undercut on the exterior of fluid displacer 34. In the example shown, chamber connector 35 extends fully annularly around fluid displacer 34. Fluid displacer 34 has a smaller cross-sectional area orthogonal to the reciprocation axis RA of the fluid displacer 34 at locations along chamber connector 35 than at portions of fluid displacer 34 engaging with pump seals 44a, 44b or routing seals 46a, 46b. It is understood that chamber connector 35 can be of any suitable configuration for selectively fluidly connecting common chamber 33 with flow chambers 32a, 32b. For example, chamber connector 35 can be formed by one or more grooves on the exterior of piston, one or more passages at least partially formed within fluid displacer 34, a combination thereof, or can be of any other suitable configuration for selectively fluidly connecting common chamber 33 with flow chambers 32a, 32bb.

Common passage 20 extends between the displacer cavities 36 of the fluidly connected pumps 12. Common passage 20 between pumps 12a, 12b is shown in FIGS. 5A-5C. Common passage 20 fluidly connects the common chamber 33 of pump 12a with the pumping chamber 14 of pump 12b. Pump 12b is configured to receive fluid into its pumping chamber 14 through the common passage 20 and is configured to output the fluid from its pumping chamber 14 through the common passage 20.

In the example shown, the common passage 20 includes branch paths 48a, 48b and ports 50a, 50b. Port 50a opens to common chamber 33 of pump 12a. Port 50b opens to pumping chamber 14 of pump 12b. Branch paths 48a, 48b extend between and are fluidly connected to ports 50a, 50b. While common passage 20 is shown as including branch paths 48a, 48b, it is understood that common passage 20 can be configured as a single pathway without branch paths 48a, 48b.

Flow valves 52a, 52b are disposed in common passage 20 in the example shown. Flow valves 52a, 52b are formed as check valves configured to allow unidirectional flow through the flow valve 52a, 52b. Flow valve 52a is disposed in branch path 48a. Flow valve 52a is configured to facilitate unidirectional flow through branch path 48a. Flow valve 52b is disposed in branch path 48b. Flow valve 52b is configured to facilitate unidirectional flow through branch path 48b. Flow valves 52a, 52b facilitate first in-first out pumping by the pumps 12. While common passage 20 is shown as including flow valves 52a, 52b it is understood that not all examples are so limited. For example, flow valves 52a, 52b can be omitted in various examples. Flow valves 52a, 52b do not provide checking for inflow and outflow of fluid to a pumping chamber 14, but instead facilitate first in-first out flow. The fluid displacers 34 perform the checking for inflow and outflow of fluid.

A pump cycle for pump 12b is discussed in more detail. It is understood that the pump cycle of pump 12b is descriptive of the pumping by each of the pumps 12 of the multi-piston pumping assembly 10 and can be applied to any of the multiple pumps 12. A pump cycle includes fluid displacer 34 moving through a first stroke in a first axial direction ADI along the reciprocation axis RA and the fluid displacer 34 moving through a second stroke in a second axial direction AD2 along the reciprocation axis. The first stroke can also be referred to as an upstroke, fill stroke, or suction stroke. The second stroke can also be referred to as a discharge stroke, downstroke, or pressure stroke. The pump 12 is configured to intake fluid during the first stoke and output fluid during the second stroke.

Pump 12a provides active checking for pump 12b to route fluid to pumping chamber 14 of pump 12b and route fluid from pumping chamber 14 of pump 12b. The fluid displacer 34 of pump 12a both pumps fluid through the pumping chamber 14 of pump 12a and routes the fluid to and from pump 12b. Similarly, and as discussed above, the fluid displacer 34 of pump 12b both pumps fluid through pumping chamber 14 of pump 12b and routes fluid to and from pump 12c; the fluid displacer 34 of pump 12c both pumps fluid through the pumping chamber 14 of pump 12c and routes fluid to and from pump 12d; the fluid displacer 34 of pump 12d both pumps fluid through the pumping chamber 14 of pump 12d and routes fluid to and from pump 12a. The fluid displacer 34 of pump 12a can be considered to form valving for pump 12b and a fluid mover for pump 12a. As such, the fluid displacers 34 of each pump 12 both route fluid to another pump 12 of multi-displacer pumping assembly 10 and pump fluid.

For purposes of discussion, pump pathway 28a is assumed to be configured as the inlet pathway 22 through which fluid is provided to pumps 12 and pump pathway 28b is assumed to be configured as the outlet pathway 24 through which fluid is output from pumps 12. As such, flow chamber 32a forms the inlet chamber 16 and flow chamber 32b forms the outlet chamber 18 for purposes of discussion.

Pump 12b is shown in a fill state in FIG. 5A in which pump 12b is fluidly connected to the pump pathway 28a to receive an inflow of fluid. The fluid displacer 34 of pump 12b is moving in first axial direction AD 1 and through a fill stroke in FIG. 5 A. Fluid displacer 34 of pump 12a is engaged with routing seal 46b and disengaged from routing seal 46a. The chamber connector 35 of pump 12a radially overlaps with routing seal 46a such that that reduced diameter portion of the fluid displacer 34 of pump 12a is aligned with routing seal 46a. The chamber connector 35 radially overlapping with routing seal 46a forms a flowpath between the fluid displacer 34 and routing seal 46a such that fluid can flow from flow chamber 32a to common chamber 33 within displacer cavity 36 of pump 12a.

Fluid displacer 34 of pump 12a engaging with routing seal 46b fluidly isolates flow chamber 32b and common chamber 33 within pump 12a such that the pumping chamber 14 of pump 12b is fluidly disconnected from the pump pathway 28b. Fluid displacer 34 of pump 12a being disengaged from routing seal 46a fluidly connects flow chamber 32a and common chamber 33 of pump 12a such that pumping chamber 14 of pump 12b is fluidly connected to pump pathway 28a.

Fluid displacer 34 of pump 12b moves in first axial direction ADI and through the fill stroke. Fluid flows from pump pathway 28a, through the flow chamber 32a and common chamber 33 of pump 12a, and then through common passage 20 to pumping chamber 14 of pump 12b. In the example shown, check valve 62b prevents fluid from flowing into pumping chamber 14 of pump 12b through branch path 48b. The fluid instead flows through check valve 62a and branch path 48a. Such a configuration facilitates any fluid that remained in branch path 48a between check valve 62a and pumping chamber 14 being the first fluid to flow into pumping chamber 14.

Fluid displacer 34 of pump 12b continues to shift through the fill stroke until reaching the end of the fill stroke. While fluid displacer 34 of pump 12b is moving through the upstroke, the fluid displacer 34 of pump 12a has completed its fill stroke and beings to move through a discharge stroke. The fluid displacer 34 of pump 12a shifts downward in second axial direction AD2 and reengages with routing seal 46a, as shown in FIG. 5B. The pumping chamber 14 of pump 12b is fluidly isolated from both flow chamber 32a and flow chamber 32b with fluid displacer 34 of pump 12a engaged with both routing seal 46a and routing seal 46b.

Fluid displacer 34 of pump 12a engages routing seal 46a prior to disengaging from routing seal 46b to fluidly connect pump 12b to flow chamber 32b of pump 12a. Sequencing the seal engagement such that fluid displacer 34 reengages both routing seals 46a, 46b prior to disengaging from a routing seal 46a, 46b prevents cross-flow between the pump pathways 28a, 28b. The fluid displacers 34 are in sealing engagement with at least one of routing seals 46a, 46b throughout the pump stroke.

Fluid displacer 34 of pump 12a continues to shift through a discharge stroke and disengages from routing seal 46b, as shown in FIG. 5C. The chamber connector 35 of pump 12a radially overlaps with routing seal 46b such that that reduced diameter portion of the fluid displacer 34 of pump 12a is aligned with routing seal 46b. The chamber connector 35 radially overlapping with routing seal 46b forms a flowpath between the fluid displacer 34 and routing seal 46b such that fluid can flow from common chamber 33 to flow chamber 32b within displacer cavity 36 of pump 12a. Pump 12b is thus placed in an outflow state in which pump 12b is fluidly connected to pump pathway 28b forming the outlet pathway 24.

Fluid displacer 34 of pump 12a disengaging from routing seal 46b fluidly connects the common chamber 33 of pump 12a with flow chamber 32b of pump 12a. The pumping chamber 14 of pump 12b is thereby fluidly connected to flow chamber 32b and thus to pump pathway 28b. The fluid displacer 34 of pump 12b displaces in second axial direction AD2 and through a discharge stroke. The fluid displacer 34 of pump 12b drives fluid from pumping chamber 14, through common passage 20 and common chamber 33, and through flow chamber 32b to pump pathway 28b. In the example shown, check valve 62a prevents fluid from flowing from pumping chamber 14 of pump 12b to common chamber 33 of pump 12a through branch path 48a. The fluid instead flows through check valve 62b and branch path 48b. Such a configuration facilitates fluid in pumping chamber 14 being the first fluid to flow out of pumping chamber 14 and to common chamber 33, providing first in-first out flow.

The flow valves 52a, 52b facilitate first in-first out flow for the pumps 12. The flow valves 52a, 52b are configured such that fluid flows through one branch path 48a, 48b to enter into the pumping chamber 14 and flows through the other branch path 48a, 48b to exit from the pumping chamber 14. The fluid is thus routed through a circuit such that the fluid flows unidirectionally between common chamber 33 and pumping chamber 14. The unidirectional flow within each branch path 48a, 48b prevents fluid from residing within multi-piston pumping assembly 10, thereby preventing pack out and other issues that can occur due to residing fluid.

As fluid displacer 34 of pump 12b moves through the discharge stroke, the fluid displacer 34 of pump 12a completes its discharge stroke and turns over to begin a fill stroke. The fluid displacer 34 of pump 12a moves through the fill stroke and reengages with routing seal 46b. Fluid displacer 34 of pump 12a reengaging with routing seal 46b fluidly disconnects the pumping chamber 14 of pump 12b from the flow chamber 32b of pump 12a. Fluid displacer 34 of pump 12b has completed its discharge stroke and turns over to begin an upstroke. Fluid displacer 34 of pump 12a continues through its upstroke and disengages from routing seal 46a to again fluidly connect the pumping chamber 14 of pump 12b to the flow chamber 32a of pump 12a.

During operation, each fluid displacer 34 is in contact with fluid pumped both by the pump 12 of that fluid displacer 34 and by another pump. As shown in FIGS. 5A-5C, the fluid displacer 34 of pump 12a contacts fluid within the pumping chamber 14 of pump 12a to pump that fluid. The fluid displacer 34 of pump 12a is also in contact with fluid being routed to and from pump 12b. While the fluid displacer 34 of pump 12a is in contact with fluid pumped by pump 12b, the fluid displacer 34 of pump 12a does not pump that fluid. Instead, the fluid displacer 34 of pump 12a provides active checking to route the fluid to and from the pumping chamber 14 of pump 12b.

In the example shown, the pumping chamber 14, flow chambers 32a, 32bb, and common chamber 33 within a pump 12 are disposed coaxially along the reciprocation axis RA of that pump 12. The common chamber 33 is disposed axially between the flow chamber 32a and the flow chamber 32b. For a single pump 12, the common chamber 33 can be fluidly isolated from both flow chambers 32a, 32bb during certain operational phases and is fluidly connected to one or the other of flow chambers 32a, 32bb during other operational phases. For a single pump 12, the pumping chamber 14 is fluidly isolated from the flow chambers 32a, 32bb and common chamber 33 of that pump 12 throughout operation.

Multi-displacer pumping assembly 10 provides significant advantages. The fluid displacers 34 of each pump 12 both provide active checking to another one of the pumps 12 of the multi-displacer pumping assembly 10 as well as pump fluid through multidisplacer pumping assembly 10. The fluid displacers 34 providing active checking for others of the pumps 12 reduces part count by eliminating check valves that were previously required to check fluid flow to and/or from the pumping chambers 14.

The fluid displacers 34 of multi-displacer pumping assembly 10 are sequenced such that at least one of the pumps 12 of multi-displacer pumping assembly 10 is outputting fluid flow throughout operation. Multi-displacer pumping assembly 10 thereby provides a continuous outflow. The multi-displacer pumping assembly 10 provides even outflow, which is particularly advantageous for applying fluid at steady outflow rate. For example, multi-displacer pumping assembly 10 can be utilized for outputting a bead of material at a desired size, such as a bead of adhesive.

It is understood that although a four fluid displacer 34, 90-degree phased multi- displacer pumping assembly 10 is shown, other numbers of fluid displacers 34 and their corresponding phasing are possible. Multi-displacer pumping assembly 10 can include any desired number of multiple fluid displacers 34. In some examples, multi- displacer pumping assembly 10 is configured with pumps 12 in a multiple of four, such as four fluid displacers 34, eight fluid displacers 34, twelve fluid displacers 34, etc. It is understood that increasing the number of pumps 12 and corresponding fluid displacers 34 can provide for a smoother and more even fluid output. Such changes in number of fluid displacers 34 and the phasing between the pumps 12 may require changes to the relative of the pump pathways 28a, 28b and/or the lengths of the fluid displacer 34 that allow fluid movement or similarly block fluid movement.

Flow valves 52a, 52b encourage unidirectional flow through common passage 20. The common passage 20 having branch paths 48a, 48b and flow valves 52a, 52b provides for first in-first out flow from pumping chamber 14. The first in-first out flow prevents fluid residing within multi -piston pumping assembly 10, preventing pack out and other deleterious effects of such residual fluid.

FIG. 6A is a side elevational view of a fluid dispensing system 54. FIG. 6B is a cross-sectional view taken along line B-B in FIG. 6A. FIGS. 6A and 6B are discussed together. Fluid dispensing system 54 includes dispenser housing 56, motor 58, multidisplacer pumping assembly 10, and dispense assembly 60. Drive 26 and assembly body 30 of multi-displacer pumping assembly 10 are shown. Dispense assembly 60 includes valve 62. Motor 58, which can be an electric motor, such as a servo motor, among other options, is connected to drive 26. Motor 58 is configured to generate a rotational output that is provided to drive 26. Drive 26 is rotated by motor 58 to cause pumping by multidisplacer pumping assembly 10. Dispense assembly 60 is connected to multi-displacer pumping assembly 10 to receive an outflow from multi-displacer pumping assembly 10. Valve 62 is actuated between an open state, in which fluid is emitted from dispense assembly 60, and a closed state, in which fluid is prevented from being emitted from dispense assembly 60. In the example shown, fluid dispensing system 54 is configured for dispensing of a high viscosity fluid (e.g., without limitation, a sealant, adhesive, foam, or gasketing material).

While the invention(s) has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention(s) without departing from the essential scope thereof. Therefore, it is intended that the invention(s) not be limited to the particular embodiment(s) disclosed, but that the invention(s) may include all embodiments falling within the scope of the appended claims. Any single feature, or any combination of features from one embodiment show herein, may be utilized in a different embodiment independent from the other features shown in the embodiment herein. Accordingly, the scope of the invention(s) and any claims thereto are not limited to the particular to the embodiments and/or combinations of the features shown herein, but rather can include any combination of one, two, or more features shown herein.

Claims

CLAIMS:

1. A multi-displacer pumping assembly comprising: a first pump comprising: a first fluid displacer configured to reciprocate along a first pump axis within a first displacer cavity to pump fluid through a first pumping chamber; and a second pump comprising: a second fluid displacer configured to reciprocate along a second pump axis within a second displacer cavity to pump fluid through a second pumping chamber; wherein the first pumping chamber is fluidly connected to the second displacer cavity to receive fluid from and output fluid to the second displacer cavity.

2. The multi-displacer pumping assembly of claim 1 , wherein the second fluid displacer is configured to alternatingly fluidly connect the first pumping chamber to an inlet passage such that the first pumping chamber receives the fluid from the inlet passage and to an outlet passage such that the first pumping chamber outputs the fluid to the outlet passage.

3. The multi-displacer pumping assembly of claim 2, wherein the second pumping chamber is alternatingly fluidly connected to the inlet passage to receive the fluid from the inlet passage and to the outlet passage to output the fluid to the outlet passage.

4. The multi-displacer pumping assembly of claim 1, wherein: the second displacer cavity includes the second pumping chamber, a first flow chamber fluidly connected to an inlet passage, a second flow chamber fluidly connected to an outlet passage, and a common chamber; the first pumping chamber is fluidly connected to the common chamber; the second fluid displacer fluidly connects the first flow chamber and the common chamber to connect the first pumping chamber to the inlet passage; and the second fluid displacer fluidly connects the second flow chamber and the common chamber to connect the first pumping chamber to the outlet passage.

5. The multi-displacer pumping assembly of claim 4, wherein the common chamber is disposed axially between the first flow chamber and the second flow chamber.

6. The multi-displacer pumping assembly of any one of claims 4 and 5, wherein the second fluid displacer is configured to fluidly isolate the first flow chamber from the common chamber prior to fluidly connecting the second flow chamber with the common chamber.

7. The multi-displacer pumping assembly of any one of claims 4-6, wherein the second fluid displacer is configured to fluidly isolate the second flow chamber from the common chamber prior to fluidly connecting the first flow chamber with the common chamber.

8. The multi-displacer pumping assembly of any one of claims 4-7, wherein a common passage extends between the first pumping chamber and the common chamber to fluidly connect the first pumping chamber and the common chamber.

9. The multi-displacer pumping assembly of claim 8, wherein the common passage comprises a first branch path and a second branch path.

10. The multi-displacer pumping assembly of claim 9, further comprising: a first check valve disposed in the first branch path; and a second check valve disposed in the second branch path.

11. The multi-displacer pumping assembly of any one of claims 1-10, wherein the second fluid displacer is elongate along the second reciprocation axis.

12. The multi-displacer pumping assembly of claim 1, wherein the second fluid displacer includes a chamber connector formed at least one of on and in the second fluid displacer, the chamber connector configured to alternatingly connect the first pumping chamber to an inlet pathway and to an outlet pathway.

13. The multi-displacer pumping assembly of claim 12, wherein the chamber connector is formed as an undercut on an exterior of the second fluid displacer.

14. The multi-displacer pumping assembly of claim 13, wherein the undercut extends fully annularly about the second fluid displacer.

15. The multi-displacer pumping assembly of any one of claims 12-14, wherein the second pump further comprises: a first routing seal at least partially defining a first fluid chamber within the second displacer cavity; and a second routing seal at least partially defining a second fluid chamber within the second displacer cavity; wherein the second fluid displacer is sealingly engaged with the first routing seal and is disengaged from the second routing seal to fluidly connect the second routing chamber and the first pumping chamber; and wherein the second fluid displacer is sealingly engaged with the second routing seal and is disengaged from the first routing seal to fluidly connect the first routing chamber and the first pumping chamber.

16. The multi-displacer pumping assembly of claim 15, wherein a common chamber is formed between the first routing seal and the second routing seal, the common chamber fluidly connected to the first pumping chamber with the second fluid displacer engaging the first routing seal and with the second fluid displacer engaging the second routing seal.

17. The multi-displacer pumping assembly of any one of claims 1-16, further comprising: a third pump comprising: a third fluid displacer configured to reciprocate along a third pump axis within a third displacer cavity to pump fluid through a third pumping chamber; wherein the second pumping chamber is fluidly connected to the third displacer cavity to receive fluid from and output fluid to the third displacer cavity.

18. The multi-displacer pumping assembly of claim 17, further comprising: a fourth pump comprising: a fourth fluid displacer configured to reciprocate along a fourth pump axis within a fourth displacer cavity to pump fluid through a fourth pumping chamber; wherein the third pumping chamber is fluidly connected to the fourth displacer cavity to receive fluid from and output fluid to the fourth displacer cavity.

19. The multi-displacer pumping assembly of claim 18, wherein the fourth pumping chamber is fluidly connected to the first displacer cavity to receive fluid from and output fluid to the first displacer cavity.

20. The multi-displacer pumping assembly of any one of claims 1-19, wherein the first displacer cavity is formed in a first pump body, the second displacer cavity is formed in a second pump body, and the first pump body is fixed to the second pump body.

21. A multi-displacer pumping assembly comprising: a first pump comprising: a first fluid displacer configured to reciprocate along a first pump axis within a first displacer cavity to pump fluid through a first pumping chamber; a second pump comprising: a second fluid displacer configured to reciprocate along a second pump axis within a second displacer cavity to pump fluid through a second pumping chamber; a first fluid chamber formed in the second displacer cavity; a second fluid chamber formed in the second displacer cavity; and a common chamber formed in the second displacer cavity; a common passage extending between and fluidly connecting the first pumping chamber and the common chamber; an inlet passage fluidly connected to the first fluid chamber to provide the fluid to the first fluid chamber; and an outlet passage fluidly connected to the second fluid chamber to receive fluid from the second fluid chamber; wherein the second fluid displacer is configured to altematingly fluidly connect the first pump with the first fluid chamber to receive the fluid into the first pumping chamber and with the second fluid chamber to output the fluid.

22. The multi-displacer pumping assembly of claim 21, wherein the second pump further comprises: a first routing seal disposed between the first fluid chamber and the common chamber; and a second routing seal disposed between the second fluid chamber and the common chamber; wherein the second fluid displacer sealingly engages with the first routing seal to fluidly disconnect the first pumping chamber from the first fluid chamber; and wherein the second fluid displacer sealingly engages with the second routing seal to fluidly disconnect the first pumping chamber from the second fluid chamber.

23. The multi-displacer pumping assembly of claim 22, wherein the second fluid displacer is disengaged from the first routing seal to fluidly connect the first fluid chamber and the common chamber, and wherein the second fluid displacer is disengaged from the second routing seal to fluidly connect the second fluid chamber and the common chamber.

24. The multi-displacer pumping assembly of any one of claims 21-23, wherein the second pump further comprises a first pump seal at least partially defining the second pumping chamber, and wherein the second fluid displacer sealingly engages the first pump seal throughout a pump cycle of the second fluid displacer.

25. The multi-displacer pumping assembly of claim 24, wherein the first pump seal at least partially defines the second pumping chamber and one of the first fluid chamber and the second fluid chamber.

26. The multi-displacer pumping assembly of any one of claims 21-25, wherein the second fluid displacer includes a chamber connector formed on an exterior of the second fluid displacer.

27. The multi-displacer pumping assembly of any one of claims 21-26, wherein the common passage includes a plurality of branch paths.

28. The multi-displacer pumping assembly of claim 27, wherein: a first check valve is disposed in a first branch path of the plurality of branch paths, the first check valve configured to allow flow through the common passage and to the first pumping chamber; and a second check valve is disposed in a second branch path of the plurality of branch paths, the second check valve configured to allow flow through the common passage from the first pumping chamber.

29. The multi-displacer pumping assembly of any one of claims 21-28, further comprising: a drive connected to the first fluid displacer and the second fluid displacer, the drive configured to linearly reciprocate the first fluid displacer on the first pump axis and to linearly reciprocate the second fluid displacer on the second pump axis.

30. The multi-displacer pumping assembly of claim 29, wherein the drive is a wobble drive.

31. A method of pumping, the method comprising: reciprocating a first fluid displacer on a first pump axis to pump fluid through a first pumping chamber from an intake passage to an outlet passage; reciprocating a second fluid displacer on a second pump axis to pump fluid through a second pumping chamber from the intake passage to the outlet passage; fluidly connecting the first pumping chamber with the intake passage with the second fluid displacer during a fill stroke of the first fluid displacer; and fluidly connecting the first pumping chamber with the outlet passage by the second fluid displacer during a discharge stroke of the first fluid displacer.

32. The method of claim 31, wherein fluidly connecting the first pumping chamber with the intake passage with the second fluid displacer during the fill stroke of the first fluid displacer comprises: shifting the second fluid displacer such that the second fluid displacer disengages from a first routing seal to fluidly connect a first flow chamber with a common chamber, the first flow chamber fluidly connected to the intake passage and the common chamber fluidly connected to the first pumping chamber; and engaging a second routing seal with the second fluid displacer to fluidly disconnect a second flow chamber from the common chamber, the second flow chamber fluidly connected to the outlet passage.

33. The method of claim 32, wherein the second fluid displacer engages the second routing seal prior to disengaging from the first routing seal.

34. The method of any one of claims 32 and 33, wherein fluidly connecting the first pumping chamber with the outlet passage by the second fluid displacer during the discharge stroke of the first fluid displacer comprises: shifting the second fluid displacer such that the second fluid displacer disengages from the second routing seal to fluidly connect the second flow chamber with the common chamber; and engaging the first routing seal with the second fluid displacer to fluidly disconnect the first flow chamber from the common chamber.

35. The method of claim 34, wherein the second fluid displacer engages the first routing seal prior to disengaging from the second routing seal.

36. A multi-displacer pumping assembly comprising: a first reciprocator configured to reciprocate along a first axis within a first displacer cavity to pump fluid through a first pumping chamber; and a second reciprocator configured to reciprocate along a second axis within a second displacer cavity to altematingly fluidly connect the first pumping chamber with an inlet passage such that the first pumping chamber receives the fluid from the inlet passage and with an outlet passage such that the first pumping chamber outputs the fluid to the outlet passage.

37. The multi-displacer pumping assembly of claim 36, wherein the first axis is parallel to and offset from the second axis.

38. The multi-displacer pumping assembly of any one of claims 36 and 37, wherein the second reciprocator is further configured to pump fluid through a second pumping chamber.

39. The multi-displacer pumping assembly of any one of claims 36-38, wherein the first reciprocator is configured to altematingly fluidly connect a third pumping chamber with the inlet passage such that the third pumping chamber receives the fluid from the inlet passage and with the outlet passage such that the third pumping chamber outputs the fluid to the outlet passage, wherein a third reciprocator is configured to reciprocate along a third axis to pump the fluid through the third pumping chamber.

40. The multi-displacer pumping assembly of claim 39, wherein the third axis is parallel to and offset from the first axis.