WO2024010798A2

WO2024010798A2 - Pump and fluid displacer for a pump

Info

Publication number: WO2024010798A2
Application number: PCT/US2023/026915
Authority: WO
Inventors: Bradley H. Hines; Brian W. KOEHN; Jacob W. MEYER; Paul W. SCHEIERL; Thomas E. ARMSTRONG; Jacob D. HIGGINS; David L. FEHR
Original assignee: Graco Minnesota Inc.
Priority date: 2022-07-08
Filing date: 2023-07-05
Publication date: 2024-01-11
Also published as: WO2024010798A3

Abstract

An electrically operated displacement pump includes an electric motor having a stator and a rotor. The rotor is connected to the fluid displacer to drive axial reciprocation of the fluid displacer. A controller controls operation of the motor based on an operating state of the motor to control pumping by the displacement pump. The controller is configured to operate the pump in a priming mode, during priming of the pump, and a pumping mode, during pumping of process fluid. The controller causes the fluid displacer to move differently in the priming mode than in the pumping mode.

Description

PUMP AND FLUID DISPLACER FOR A PUMP

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional Application No. 63/359,515 filed July 8, 2022 and entitled “PUMP,” the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND

This disclosure relates to positive displacement pumps. More particularly, this disclosure relates to control systems for positive displacement pumps. This disclosure further relates to diaphragms for positive displacement pumps.

Positive displacement pumps discharge a process fluid based on a selected discharge parameter, such as flow or pressure. In a ty pical positive displacement pump, a fluid displacement member, usually a piston or diaphragm, pumps the process fluid.

Fluid-operated double displacement pumps typically employ diaphragms as the fluid displacement members and air or hydraulic fluid as a working fluid to drive the fluid displacement members. In an air operated double displacement pump, the two diaphragms are joined by a shaft and compressed air is the working fluid. Compressed air is applied to one of two chambers associated with the respective diaphragms. The compressed air applies force to all portions of the diaphragm exposed to the air chamber that contains the compressed air. The first diaphragm is driven through a pumping stroke and pulls the second diaphragm through a suction stroke when compressed air is provided to the first chamber. The diaphragms move through a reverse stroke when compressed air is provided to the second chamber. Delivery of compressed air is controlled by an air valve, and the air valve is usually actuated mechanically by the diaphragms. One diaphragm is pulled until it causes the actuator to toggle the air valve. Toggling the air valve exhausts the compressed air from the first chamber to the atmosphere and introduces fresh compressed air to the second chamber, thereby causing reciprocation of the respective diaphragms.

Double displacement pumps can also be mechanically operated such that the pump does not require the use of working fluid. In such a case, a motor is operatively connected to the fluid displacement members to drive reciprocation. A gear train is disposed between the motor and the shaft connecting the fluid displacement members to ensure that the pump can provide sufficient torque during pumping. The motor and gear train are disposed external to the main body of the pump. SUMMARY

According to an aspect of the disclosure, a pump for pumping a fluid includes a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a pumping stroke phase, a suction stroke phase, and a changeover phase that occurs in each transition between the pumping stroke phase and the suction stroke phase in which the first fluid displacer reverses direction; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, and wherein the controller regulates the energy delivery in the priming mode such that the rotor rotates to cause the first fluid displacer to move differently in the priming mode than dunng the pumping mode.

According to an additional or alternative aspect of the disclosure, a pump for pumping a fluid includes a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a pumping stroke phase, a suction stroke phase, and a changeover phase that occurs in each transition between the pumping stroke phase and the suction stroke phase in which the first fluid displacer reverses direction; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, wherein the controller regulates the energy delivery based on a target priming speed of the first fluid displacer in the priming mode and based on a target pumping speed of the first fluid displacer in the pumping mode, the target priming speed greater than the target pumping speed. According to another additional or alternative aspect of the disclosure, a pump for pumping a fluid includes a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated along an axis and at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a first stroke in a first direction along the axis, a second stroke in a second direction along the axis, a first changeover in which the first fluid displacer reverses direction from the first stroke to the second stroke, and a second changeover in which the first fluid displacer reverses direction from the second stroke to the first stroke; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, wherein the controller regulates the energy delivery such that the first fluid displacer moves differently in the priming mode than in the pumping mode.

According to yet another additional or alternative aspect of the disclosure, a pump for pumping a fluid includes a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated along an axis and at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a first stroke in a first direction along the axis, a second stroke in a second direction along the axis, a first changeover in which the first fluid displacer reverses direction from the first stroke to the second stroke, and a second changeover in which the first fluid displacer reverses direction from the second stroke to the first stroke; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, wherein the controller regulates the energy delivery such that the first fluid displacer moves a first distance through the first stroke in the priming mode and the fluid displacer moves a second distance through the first stroke in the pumping mode, the first distance greater than the second distance.

According to yet another additional or alternative aspect of the disclosure, a pump for pumping a fluid includes a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a pumping stroke phase, a suction stroke phase, and a changeover phase that occurs in each transition between the pumping stroke phase and the suction stroke phase in which the first fluid displacer reverses direction; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, and wherein the controller regulates the energy delivery in the pnming mode such that the rotor rotates to cause the first fluid displacer such that the changeover phase during the priming mode is slower than the changeover phase during the pumping mode.

According to yet another additional or alternative aspect of the disclosure, a pump for pumping a fluid includes a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a pumping stroke phase, a suction stroke phase, and a changeover phase that occurs in each transition between the pumping stroke phase and the suction stroke phase in which the first fluid displacer reverses direction; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, and wherein the controller regulates the energy delivery in the priming mode such that the first fluid displacer pauses for a first time period during the changeover phase during the priming mode pauses for a second time period during the changeover phase in the pumping mode, the first time period longer than the second time period.

According to yet another additional or alternative aspect of the disclosure, a pump for pumping a fluid includes a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a pumping stroke phase, a suction stroke phase, and a changeover phase that occurs in each transition between the pumping stroke phase and the suction stroke phase in which the first fluid displacer reverses direction; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, and wherein the controller regulates the energy delivery in the pnming mode such that the rotor rotates to cause the first fluid displacer to move differently through the changeover phase in the priming mode than through the changeover phase in the pumping mode.

According to yet another additional or alternative aspect of the disclosure, a pump for pumping a fluid includes a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated along an axis and at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a first stroke in a first direction along the axis, a second stroke in a second direction along the axis, a first changeover in which the first fluid displacer reverses direction from the first stroke to the second stroke, and a second changeover in which the first fluid displacer reverses direction from the second stroke to the first stroke; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, wherein the controller regulates the energy delivery such that the first fluid displacer moves differently through the changeover phase in the priming mode than through the changeover phase in the pumping mode.

According to yet another additional or alternative aspect of the disclosure, a diaphragm configured to reciprocate along an axis to pump a fluid for a pump includes a first diaphragm plate; and a flexible body extending radially outward from the diaphragm plate, the flexible body having an outer side oriented in a first direction along the axis and configured to be oriented towards a pumping chamber through which the fluid is pumped and having an inner side oriented in a second direction along the axis and configured to be oriented towards a motor that drives reciprocation of the diaphragm. The flexible body includes a main membrane including a bead that is enlarged relative to a membrane body of the main membrane, the bead configured to be clamped to mount the diaphragm to the pump; and a backer formed separately from the main membrane and disposed such that the main membrane is between the backer and the outer side of the flexible body, the backer including a bead cup open in the first direction and configured to receive the bead.

According to yet another additional or alternative aspect of the disclosure, a pump for pumping a fluid includes a pump body at least partially defining a motor housing; an electric motor disposed within the motor housing and configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion along an axis; a first fluid chamber at least partially defined by a first fluid cover connected to the pump body; and a first diaphragm configured to be linearly reciprocated along the axis at least partially within the first fluid chamber by the drive to pump the fluid through the first fluid chamber. The first diaphragm includes a first diaphragm plate; and a flexible body extending radially outward from the diaphragm plate and at least partially defining the first fluid chamber, the flexible body having an outer side oriented towards the first fluid chamber and having an inner side oriented towards the electric motor. The flexible body includes a main membrane including a bead that is enlarged relative to a membrane body of the main membrane; and a backer formed separately from the main membrane and disposed such that the backer is between the main membrane and the electric motor, the backer including a bead cup configured to receive the bead, the bead cup open axially away from the electric motor The bead and bead cup are clamped together between the first fluid cover and the pump body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 A is a front isometric view of an electrically operated pump.

FIG. IB is a rear isometric view of the electrically operated pump. FIG. 1C is a block schematic diagram of the electrically operated pump.

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

FIG. 2B is an enlarged view of detail B in FIG. 2A.

FIG. 2C is a cross-sectional view taken along line C-C in FIG. 1A.

FIG. 2D is a cross-sectional view taken along line D-D in FIG. 2C.

FIG. 3 is an isometric partial cross-sectional view showing a motor and drive of an electrically operated pump.

FIG. 4 is an isometric view of a drive with a portion of the drive nut removed.

FIG. 5 is an isometric view of a drive with a portion of the drive nut removed.

FIG. 6 is an isometric view of the drive shown in FIG. 5 with the body of the drive nut removed to show the rolling elements.

FIG. 7 is a block diagram of an electrically operated pump.

FIG. 8 is a schematic diagram illustrating changeover locations for a fluid displacer of a pump.

FIG. 9A is a cross-sectional view of a pump.

FIG. 9B is an enlarged view of detail B in FIG. 9A.

FIG. 9C is a cross-sectional view showing a fluid displacer dismounted from a pump and in a partially disassembled state.

FIG. 10 is a cross-sectional view showing a fluid displacer assembled to a drive and dismounted from a pump.

DETAILED DESCRIPTION

According to aspects of the disclosure, a pump is configured to operate in a priming mode and a pumping mode. A controller regulates energy delivery to an electric motor that drives displacement of the one or more fluid displacers of the pump. The controller can cause the pump to operate in the priming mode to prime the pump and can cause the pump to operate in the pumping mode to pump process fluid. The controller can be configured such that the fluid displacer has different driving profiles during the priming mode and the pumping mode. The controller can cause the fluid displacer to move differently with the pump operating in the priming mode than with the pump operating in the pumping mode.

According to some aspects of the disclosure, the controller can cause the pump to operate such that the speed profile, acceleration profile, deceleration profile, displacement distance profile, and/or one or more other movement profiles of the fluid displacer vary between the priming mode and the pumping mode. The controller can be configured to cause the fluid displacer to move at a different speed through a stroke during priming than through a stroke during pumping. Additionally or alternatively, the controller can be configured to cause the fluid displacer to travel a different distance for a stroke during priming than for a stroke during pumping. Additionally or alternatively, the controller can be configured to cause the fluid displacer to accelerate and/or decelerate at different rates during priming than during pumping.

The controller, according to aspects of the disclosure, can be configured to control displacement of the fluid displacer such that the changeover profile of the fluid displacer in the priming mode differs from the changeover profile of the fluid displacer in the pumping mode. Changeover occurs when the fluid displacer reverses direction to change stroke direction between pump strokes. For example, the changeover can be considered to occur when the fluid displacer reverses from moving in a first direction along a reciprocation axis to an opposite second direction along the reciprocation axis. Changeover can be considered to occur based on the operating parameters of the pump or based on portions of the length of the pump stroke, among other options. In some examples, changeover can be considered to occur based on the beginning of deceleration until the fluid displacer begins moving in the opposite axial direction. In some examples, the fluid displacer can be considered to be in changeover when in the final 20%, 15%, 10%, or 5% of the end of the pump stroke, among other distance options. The controller can be configured to cause the pump to operate such that the changeover takes a different amount of time during the priming mode than during the pumping mode.

The fluid displacer necessarily pauses for at least a brief period during changeover, when the fluid displacer stops moving in the first direction along an axis and then begins moving in the second opposite direction along the axis. The controller can cause the fluid displacer to purposefully pause during changeover in the priming mode such that the fluid displacer remains stationary for a set period prior to beginning movement in the second direction. The controller can control energy delivery to the electric motor such that the fluid displacer is stationary at changeover for a greater period of time in the priming mode than in the pumping mode.

The controller can be configured to determine an operating status of the pump and control operation of the pump based on the determined operating status. The controller can receive parameter information regarding operation of pump, such as fluid parameters (e.g., pressure, flow rate, etc. of the process fluid output by the pump) and/or operating parameters (e.g., the electric current draw of the electric motor of the pump). The controller can determine if the pump requires priming based on the parameter information. The controller can cause the pump to operate in the priming mode based on the controller determining that the pump requires priming.

The controller can be configured to automatically cause the pump to exit the priming mode and operate in the pumping mode. The controller can, in some examples, cause the pump to exit the priming mode and enter the pumping mode based on a pumping threshold. For example, the pumping threshold can be based on the parameter information. The controller can compare the parameter information to one or more thresholds to determine whether the pump is primed and should operate in the pumping mode. For example, the controller can determine that the pump is primed based on current draw of the electric motor.

Additionally or alternatively, the controller can cause the pump to exit the priming mode based on a count threshold such that the controller causes the pump to switch to the pumping mode from the priming mode based on a count reaching the threshold (e.g., a time count, a count of pump strokes, a count of changeovers, a count of pump cycles, etc.). The controller can further cause the pump to enter the priming mode based on a count threshold. The controller can cause the pump to operate in the pumping mode, whether on system start up or after exiting the priming mode, for a minimum period (e.g., a minimum time period, a minimum number of pump strokes, a minimum number of changeovers, a minimum number of pump cycles, etc.) prior to entering into the priming mode.

According to aspects of the disclosure, a diaphragm for a displacement pump includes a flexible body formed by a stacked main membrane and backer. The main membrane and backer are separately formed and stacked together to form the flexible body of the diaphragm. The main membrane includes a bead that is clamped to secure the diaphragm relative to other components of the pump. The backer can be disposed adjacent to the main membrane and can cover one axial side of the main membrane. The backer is disposed on a dry side of the flexible body such that the backer is disposed on an opposite axial side of the flexible body from the side oriented towards the fluid chamber through which process fluid is pumped by the fluid displacer. The main membrane can be exposed to the process fluid within the fluid chamber during pumping. The backer is thinner than the main membrane. The backer is configured to provide stiffening and support to the body. The backer is disposed axially between the drive of the pump and the main membrane. The backer enhances stiffness of the membrane and reduces wear on the diaphragm during pumping. The backer can be formed from a different material than the main membrane or can be formed from the same material as the main membrane, depending on the configuration of the diaphragm.

FIG. 1A is a front isometric view of electrically operated pump 10. FIG. IB is a rear isometric view of pump 10. FIG. 1C is a block schematic diagram of pump 10. FIGS. 1A-1C will be discussed together. Pump 10 includes inlet manifold 12, outlet manifold 14, pump body 16, fluid covers 18a, 18b (collectively herein “fluid cover 18” or “fluid covers 18”), fluid displacers 20a, 20b (collectively herein “fluid displacer 20” or “fluid displacer 20”), motor 22, drive 24, and controller 26. Motor 22 includes stator 28 and rotor 30. Fluid chambers 34a, 34b (collectively herein “fluid chamber 34” or “fluid chambers “34”) are shown.

Pump body 16 is disposed between fluid covers 18a, 18b. Motor 22 is disposed at least partially within pump body 16. Pump body 18 can be considered to at least partially define a motor housing within which the motor 22 is disposed. In the example shown, motor 22 is coaxial with fluid displacers 20, as discussed in more detail below. A rotational axis of rotor 30 of motor 22 is disposed coaxially with a reciprocation axis of one or more of the fluid displacers 20. In the example shown, the rotational axis is coaxially with the reciprocation axis of each of the two fluid displacers 20.

Motor 22 is an electric motor having a stator 28 and rotor 30. Stator 28 includes armature windings and rotor 30 includes permanent magnets. Rotor 30 is configured to rotate about pump axis PA in response to electric current (such as a direct current (DC) signals and/or alternating current (AC) signals) through stator 28. Controller 26 is configured to regulate electric energy to the motor 22 to control operation of motor 22 and thus displacement of fluid displacers 20. Motor 22 is a reversible motor in that stator 28 can cause rotor 30 to rotate in either of two rotational directions (e.g., alternating between clockwise and counterclockwise) about the rotational axis of the rotor 30. Rotor 30 can be rotated in a first rotational direction to displace the fluid displacers 20 in a first direction along the axis PA and can be rotated in a second rotational direction opposite the first rotational direction to displace the fluid displacers 20 in a second direction along the axis PA opposite the first direction along the axis PA. Rotor 30 is connected to the fluid displacers 20 via drive 24, which receives a rotary output from rotor 30 and provides a linear, reciprocating input to fluid displacement members 20. Drive 24 is configured to convert the rotational output from the motor 22 to linear, reciprocation motion. For example, drive 24 can be a ball screw, crank, scotch yoke, among other options. Fluid displacers 20 can be of any type suitable for pumping fluid from inlet manifold 12 to outlet manifold 14, such as diaphragms or pistons. While pump 10 is shown as including two fluid displacers 20, it is understood that some examples of pump 10 include a single fluid displacer 20 or more than two fluid displacers 20. Further, while the two fluid displacers 20 are shown herein as diaphragms, they could instead be pistons in various other embodiments, and the teachings provided herein can apply to piston pumps.

Controller 26 is operatively connected, electrically and/or communicatively, to motor 22 to control operation of motor 22. User interface 27 of controller 26 is shown. During operation, power signals are provided to stator 28 to cause stator 28 to drive rotation of rotor 30. Drive 24 receives the rotational output from rotor 30 and converts that rotational output into a linear output to drive fluid displacers 20 linearly along the reciprocation axes of the fluid displacers 20, which reciprocation axis can be coaxial with pump axis PA. In some examples, rotor 30 rotates in the first rotational direction to drive fluid displacement members 20 in a first axial direction ADI along the axis and rotates in the second rotational direction to drive fluid displacement members 20 in a second axial direction AD2 along the axis. The pump 10 is shown as including pump axis PA, which is coaxial with the rotational axis of rotor 30 and reciprocation axes of fluid displacers 20 in the example shown.

Drive 24 causes fluid displacers 20 to reciprocate along pump axis PA through alternating displacement strokes. The controller 26 is configured to regulate energy delivery to the electric motor 22 to cause the fluid displacers 20 to move through pump cycles. Each pump cycle includes a first stroke in a first direction along the pump axis PA, a second stroke in a second direction along the pump axis PA, a first changeover in which the fluid displacer 20 reverses direction from the first stroke to the second stroke, and a second changeover in which the fluid displacer 20 reverses direction from the second stroke to the first stroke.

The displacement strokes can be suction strokes and pumping strokes. During the suction stroke of a fluid displacer 20, a volume of the fluid chamber 34 of that fluid displacer 20 expands due to movement of the fluid displacer 20 and during the pumping stroke a volume of the fluid chamber 34 of that fluid displacer 20 is decreased by movement of the fluid displacer 20. Each of the suction stroke and the pumping stroke can be referred to as a displacement stroke. Each pump cycle includes two displacement strokes, one of which is a suction stroke and the other of which is a pumping stroke. During the suction stroke, the fluid displacement member 20 draws process fluid from inlet manifold 12 into a process fluid chamber 34 defined, at least in part, by a fluid cover 18 and the fluid displacer 20. During the pumping stroke, the fluid displacer 20 drives process fluid from the fluid chamber 34 to outlet manifold 14. The fluid flows as shown by fluid flow lines FF from inlet manifold 12 to a process fluid chamber 34 and then from the process fluid chamber 34 to the outlet manifold 14.

Typically, depending on the arrangement of check valves 56, the two fluid displacers 20 are operated 180 degrees out of phase, such that a first fluid displacer 20 is driven through a pumping stroke (e g., driving process fluid downstream from the pump 10) while a second fluid displacer 20 is driven through a suction stroke (e.g., pulling process fluid from upstream and into the pump 10). The two fluid displacers 20 also simultaneously changeover (e.g., transition between the pumping stroke and the suction stroke) but 180- degrees out of phase with respect to each other. While the example shown includes dual fluid displacers 20, it is understood that the disclosure is not so limited. For example, pump 10 can be configured to includes a single fluid displacer 20 or more than two fluid displacers 20, such as three, four, or more fluid displacers 20.

Dnve 24, which can also be referred to as a drive mechanism, is directly connected to rotor 30 and fluid displacers 20 are directly driven by drive 24. As such, motor 22 drives fluid displacers 20 without the presence of intermediate gearing, such as speed reduction gearing. Power cord 32 extends from pump 10 and is configured to provide electric power to the electric components of pump 10. Power cord 32 can connect to a wall socket to provide the electric power to pump 10

Fluid displacer 20a is disposed between and fluidly isolates process fluid chamber 34a and motor 12. Fluid displacer 20a shifts in a first axial direction ADI to decrease the volume of process fluid chamber 34a, driving process fluid out of process fluid chamber 34a. Fluid displacer 20a shifts in a second axial direction AD2 opposite the first axial direction ADI to increase the volume of process fluid chamber 34a, drawing process fluid from inlet manifold 12 into process fluid chamber 34a. Fluid displacer 20b is substantially similarly to fluid displacer 20a. Fluid displacer 20b pumps process fluid through process fluid chamber 34b. Fluid displacer 20b is connected to fluid displacer 20a such that displacement strokes are reversed betw een the two fluid displacers 20a, 20b. As such, fluid displacer 20b moves through a pumping stroke of process fluid chamber 34b when driven in the second axial direction AD2 and proceeds through a suction stroke of process fluid chamber 34b when driven in the first axial direction ADI. During operation, fluid displacers 20 shift axially through first and second displacement strokes. During the first stroke, fluid displacer 20a shifts through a pumping stroke for process fluid chamber 34a and fluid displacer 20b shifts through a suction stroke for process fluid chamber 34b. Fluid displacers 20 changeover at the end of the first stroke and are driven in the opposite axial direction during the second stroke during which fluid displacer 20a shifts through a suction stroke for process fluid chamber 34a and fluid displacer 20b shifts through a pumping stroke for process fluid chamber 34b.

After completing the second stroke, fluid displacers 20 are driven back through the first stroke and continue to pump the process fluid. In some examples, fluid displacers 20a, 20b are disposed in parallel for pumping the process fluid. In such an example, each fluid displacer 20 is downstream of inlet manifold 12 and upstream of outlet manifold 14. Neither one of fluid displacers 20 is upstream or downstream of the other one of fluid displacers. Neither one of fluid displacers 20 receives process fluid from or provides process fluid to the other one of fluid displacers 20.

FIG. 2A is a cross-sectional view of pump 10 taken along line A-A in FIG. IB. FIG. 2B is an enlarged view of a portion of the cross-section shown in FIG. 2A. FIG. 2C is a cross-sectional view of pump 10 taken along line C-C in FIG. 1A. FIG. 2D is a cross- sectional view taken along line D-D in FIG. 2C. FIGS. 2A-2D will be discussed together. Pump body 16, fluid covers 18a, 18b, fluid displacers 20a, 20b, motor 22, drive 24, process fluid chambers 34a, 34b, bearings 54a, 54b, and motor nut 56 of pump 10 are shown.

Pump body 1 includes central portion 66 and end caps 68a, 68b (collectively herein “end cap 68” or “end caps 68”). Central portion 66 includes motor housing 70, control housing 72 and heat sinks 74. Fluid displacers 20a, 20b respectively include inner plates 78a, 78b (collectively herein “inner plate 78” or “inner plates 78”); outer plates 80a, 80b (collectively herein “outer plate 80” or “outer plates 80”); flexible bodies 82a, 82b (collectively herein “flexible body 82” or “flexible bodies 82”), and fasteners 84a, 84b.

Motor 22 includes stator 28 and rotor 30. Rotor 30 includes permanent magnet array 86 and rotor body 88. Motor 22 is disposed within motor housing 70 between end caps 68. Control housing 72 is connected to and extends from motor housing 70. Control housing 72 is configured to house control elements of pump 10, such as controller 26 (FIGS. !C and 7).

Drive 24 includes drive nut 90, screw 92, and rolling elements 98. Drive nut 90 includes nut thread 102. Screw 92 includes first screw end 104, second screw end 106, screw body 108, and screw thread 110. Bearings 54a, 54b include inner races 122a, 122b, rollers 123a, 123b, and outer races 124a, 124b, respectively.

Components can be considered to axially overlap with each other when the components are disposed at a common radial location relative to an axis such that an axial line parallel to the axis extends through each of those axially overlapping components. Similarly, components can be considered to radially overlap when the components are disposed at common axial locations such that a radial line extending from the axis passes through each of those radially overlapping components.

End caps 68a, 68b are disposed on opposite lateral sides of central portion 66 and are attached to central portion 66 to form pump body 16. Housing fasteners 64 extend through end caps 68 into pump body 16 to secure end caps 68 to pump body 16. While end caps 68a, 68b are described as removably mountable to central portion 66, it is understood that not all examples are so limited. In some examples, pump body 16 can be formed monolithically.

Heat sinks 74 are formed on central portion 66. Motor 22 is disposed within motor housing 70 between end caps 68. End caps 68 can also be referred to as end walls. While end caps 68 are shown as formed separately from and connected to central portion 66, it is understood that not all examples are so limited. For example, one or more of end caps 68 can be formed monolithically with central portion 66.

Fluid covers 18a, 18b are connected to pump body 16. In the example shown, fluid covers 18a, 18b are mounted to end caps 68a, 68b, respectively. Housing fasteners 64 secure fluid covers 18 to end caps 68. Inlet manifold 12 is connected to each fluid cover 18. Inlet ones of pump checks 58 (FIG. 1C) are disposed between inlet manifold 12 and fluid covers 18a, 18b. The inlet ones of pump checks 58 are one-way valves configured to allow flow into process fluid chambers 34a, 34b and prevent retrograde flow from process fluid chambers 34a, 34b to inlet manifold 12. Outlet manifold 14 is connected to each fluid cover 18. Outlet ones of pump checks 58 (FIG. 1C) are disposed between outlet manifold 14 and fluid covers 18a, 18b. The outlet ones of pump checks 58 are one-way valves configured to allow flow out of process fluid chambers 34a, 34b to outlet manifold 14 and to prevent retrograde flow from outlet manifold 14 to process fluid chambers 34a, 34b. The pump checks 58 can be configured as ball valves in which a ball engages with a seat to close the valve and the ball is disengaged from the seat to open the valve. In some examples, the pump checks 58 do not include biasing elements that bias the valve towards the closed state, such as a spring interfacing with the ball. In some examples, the pump checks 58 can be configured such that the valve members (e.g., the ball) seats due to gravity and/or pressure change within an associated fluid chamber 34 without the assistance of a biasing element.

Control housing 72 is connected to and extends from motor housing 70. Control housing 72 is configured to house control elements of pump 10, such as controller 26 (FIGS. 1C and 7). Stator 28 surrounds rotor 30 and drives rotation of rotor 30. Rotor 30 rotates about pump axis PA and is disposed coaxially with drive mechanism 24 and fluid displacement members 20 in the example shown. Permanent magnet array 86 is disposed on rotor body 88. Rotor 30 is disposed radially within stator 28 such that motor 22 is an inner rotating motor, though it is understood that not all examples are so limited. For example, motor 22 can be configured as an outer rotating motor in which stator 28 is disposed within rotor 30 such that rotor 30 rotates about stator 28.

Drive 24 receives a rotational output from rotor 30 and converts that rotational output into a linear input to fluid displacers 20. Motor 22 drives reciprocation of fluid displacers 20 via drive 24 without any intermediate gearing. Drive nut 90 is connected to rotor body 88 to rotate with rotor 30. Screw 92 is elongate along pump axis PA and extends through drive nut 90 coaxially with rotor 30. In some examples, permanent magnets of permanent magnet array 86 can be mounted to drive nut 90 such that drive nut 90 forms the rotor body 88. Rotor body 88 and drive nut 90 can be monolithically formed as a single block, in some examples.

Rolling elements 98 are disposed between rotor 30 and screw 92. More specifically, rolling elements 98 are disposed between drive nut 90 and screw 92. Rolling elements 98 are disposed in raceways formed by opposing nut thread 102 and screw thread 110. Rolling elements 98 engage screw thread 110 to drive linear displacement of screw 92 along pump axis PA. Rolling elements 98 can be balls or rollers among other options and as discussed in more detail below. Rolling elements 98 are disposed circumferentially about screw 92 and evenly arrayed around screw 92. Rolling elements 98 are arrayed around, and are arrayed along, an axis that is coaxial with axis PA. Rolling elements 98 separate drive nut 90 and screw 92 such that drive nut does not directly contact screw 92. Instead, both drive nut 90 and screw 92 ride on rolling elements 98 Rolling elements 98 maintain gap 99 (FIG. 3) between drive nut 90 and screw 92 to prevent contact therebetween.

Bearings 54a, 54b are disposed at opposite axial ends of rotor 30. Bearings 54 are configured to support both axial and radial forces. In some examples, bearings 54 are tapered roller bearings, though it is understood that other examples are possible. Bearing 54a is disposed at a first end of rotor 30 about drive nut 90. Bearing 54b is disposed at a second axial end of rotor 30 about drive nut 90.

Motor nut 56 is connected to pump body 16. Motor nut 56 covers at least a portion of an axial end of motor 22. In the example shown, motor nut 56 is connected to end cap 68a. Motor nut 56 and end cap 68a can be connected by interfaced threading, among other options. Motor nut 56 can compress bearings 54 to pre-load bearings 54.

Fluid displacers 20a, 20b are connected to opposite ends 104, 106, respectively, of screw 92 In the example shown, fluid displacers 20 are flexible and include a variable surface area during pumping. Fluid displacers 20 are formed as diaphragms in the example shown, including diaphragm plates 78, 80 and flexible bodies 82. The flexible bodies 82 can be formed from flexible material, such as rubber or other type of polymer. As discussed in more detail below, the flexible bodies 82 can be formed from multiple layers that are stacked axially. It is understood, however, that fluid displacers 20 can be of other configurations, such as pistons.

In the example shown, fluid displacer 20a includes inner plate 78a and outer plate 80a disposed on opposite sides of flexible body 82a. A portion of flexible body 82a is captured between the opposed diaphragm plates 78a, 80a. Fluid displacer 20a is attached to drive 24 at first screw end 104 of screw 92. Fastener 84a extends from fluid displacement member 20a into screw 92 to secure fluid displacement member 20a to screw 92. Fastener 84a extends through each outer plate 80a, flexible body 82a, and inner plate 78a and into a bore of screw 92 to connect fluid displacer 20a to drive 24.

In the example shown, fluid displacer 20b is similar to fluid displacer 20a. A portion of flexible body 82b is captured between the opposed diaphragm plates 78b, 80b. Outer plate 80b is overmolded by flexible body 82b such that that outer plate 80b is disposed at least partially within flexible body 82b. Flexible body 82b is overmolded on outer plate 80b such that outer plate 80b is not exposed to the process fluid. Fastener 84b extends from fluid displacer 20b and into screw 92 to connect fluid displacer 20b to drive 24. Fastener 84b extends from outer plate 80b, through inner plate 78b, and into a bore of screw 92 to connect fluid displacer 20b to drive 24.

While fluid displacers 20a, 20b are shown in different configurations, it is understood that not all examples are so limited. For example, pump 10 can be configured with each fluid displacer configured similar to fluid displacer 20a or with each fluid displacer configured similar to fluid displacer 20b. Drive nut 90 and rolling elements 98 exert a rotational force on screw 92 while driving screw 92 axially. As discussed above, bearings 54 are configured to support both axial and radial forces. Screw 92 is connected to fluid displacers 20 such that fluid displacers 20 prevent screw 92 from rotating about pump axis PA. Fluid displacers 20 interface with stationary components of pump 10 (e.g., by being clamped between a fluid cover 18 and pump body 16) to prevent rotation of fluid displacer 20 and screw 92 on pump axis PA.

Outer edge 128a of fluid displacer 20a is secured between fluid cover 18a and pump body 16 to provide a fluid-tight seal between wet and dry sides of fluid displacer 20a. Fluid cover 18a and fluid displacer 20a at least partially define process fluid chamber 34a. Outer edge 128a is clamped such that fluid displacer 20a does not rotate on pump axis PA. Outer edge 128a does not rotate about pump axis PA. In the example shown, outer edge 128a does not shift axially relative pump axis PA during operation. Outer edge 128a includes bead 136 seated within mounting groove 138 formed by opposing trenches of fluid cover 18a and pump body 16. Bead 136 has an enlarged thickness as compared to a portion of flexibly body 82a adjacent to bead 136.

The wet side of fluid displacer 20a is oriented towards fluid cover 18a and at least partially defines process fluid chamber 34a. Outer plate 80a and a portion of fastener 84a are exposed to the process fluid in process fluid chamber 34a in the example shown. The dry side of fluid displacer 20a is oriented towards motor 22.

Outer edge 128b of diaphragm 20b is secured between fluid cover 18b and pump body 16 to provide a fluid-tight seal between wet and dry sides of fluid displacement member 20b. Fluid cover 18b and fluid displacer 20b at least partially define process fluid chamber 34b. Outer edge 128b is clamped between pump body 16 and fluid cover 18b such that outer edge 128b remains static and does not rotate about pump axis PA. Outer edge 128b includes bead 136 seated within mounting groove 138 formed by opposing trenches formed on fluid cover 18b and pump body 16. Bead 136 has an enlarged thickness as compared to a portion of flexible body 82b adjacent to bead 136. The wet side of fluid displacer 20b is oriented towards end cap 68b and at least partially defines process fluid chamber 34b The dry side of fluid displacer 20b is oriented towards motor 22.

During operation, electric power is provided to stator 28 to drive rotation of rotor 30. Drive nut 90 is connected to rotor body 88, and in some cases forms rotor body 88 or is monolithic with rotor body 88, and rotates with rotor 30. Rolling elements 98 drive screw 92 linearly along pump axis PA. If screw 92 is initially driven in first axial direction ADI in FIG. 2A, then screw 92 pulls fluid displacer 20b through a suction stroke and pushes fluid displacer 20a through a pumping stroke. After reaching the end of the stroke in first axial direction ADI, rotor 30 is driven in an opposite rotational direction and drives screw 92 in second axial direction AD2. When screw 92 is driven in direction AD2, screw 92 pulls fluid displacer 20a through a suction stroke and pushes fluid displacer 20b through a pumping stroke. During a suction stroke, the volume of a process fluid chamber 34 increases and process fluid is drawn into process fluid chamber 34 from inlet manifold 12. During the pumping stroke, the volume of a process fluid chamber 34 decreases and fluid displacer 20 drives the process fluid downstream out of process fluid chamber 34 to outlet manifold 14. Screw 92 drives fluid displacers 20 through respective pumping and suction strokes. It is understood that rotor 30 and drive 24, 24', 24" can be sized to provide any desired revolution to stroke ratio. For example, pump 10 can have a revolution to stroke ratio of about 0.25: 1 to about 7:1. In some examples, pump 10 has a revolution to stroke ratio of about 0.5: 1 to about 3:1. In a more particular example, pump 10 has a revolution to stroke ratio of about 0.8: 1 to about 1.5: 1. A relatively larger revolution to stroke ratio facilitates greater pumping pressures. A relatively smaller revolution to stroke ratio facilitates greater flow rates. In some examples, rotor 30 and drive mechanism 24, 24', 24" are sized such that one revolution of rotor 30 results in a full stroke of screw 92 in one of first axial direction ADI and second axial direction AD2. The revolution to stroke ratio depends on the stroke length and the lead (the axial travel for a single revolution) of screw 92.

FIG. 3 is an isometric partial cross-sectional view of motor 22 and drive 24. Motor 22 includes stator 28 and rotor 30 and is mounted in motor housing 70. Rotor 30 includes permanent magnet array 86 and rotor body 88. Drive 24 includes drive nut 90, screw 92, and rolling elements 98. Gap 99 between drive nut 90 and screw 92 is shown.

Rotor 30 is disposed within stator 28 on pump axis PA. Drive nut 90 extends through rotor 30 and is disposed coaxially with rotor 30. Drive nut 90 is connected to rotor body 88 such that drive nut 90 rotates about pump axis PA with rotor 30. Nut thread 102 is formed on an inner radial surface of drive nut 90. Screw 92 extends axially through drive nut 90 and is disposed coaxially with rotor 30 and drive nut 90 Screw thread 110 is formed on an exterior of screw body 108. Rolling elements 98 are disposed in raceways formed by screw thread 110 and nut thread 102. Rolling elements 98 support screw 92 relative to drive nut 90 such that each of drive nut 90 and screw 92 ride on rolling elements 98. Rolling elements 98 support screw 92 relative to drive nut 90 such that drive nut 90 and screw 92 are not in contact during operation. Rolling elements 98 maintain gap 99 between drive nut 90 and screw 92 and prevent contact therebetween.

Drive nut 90 rotates relative to screw 92. Rolling elements 98 exert forces on screw 92 at screw thread 110 to cause axial displacement of screw 92 along pump axis PA. Rotor 30 can be driven in a first rotational direction to drive screw 92 in a first axial direction. Rotor 30 can be driven in a second rotational direction opposite the first rotational direction to drive screw 92 in a second axial direction opposite the first axial direction.

FIG. 4 is a partial cross-sectional view of drive 24'. Drive 24' includes drive nut 90', screw 92, rolling elements 98, and ball return 140.

Drive nut 90' surrounds a portion of screw 92 and rolling elements 98 are disposed between drive nut 90' and screw 92. In the example shown, rolling elements 98 are balls. As such, drive mechanism 24' can be considered to be a ball screw. Rolling elements 98 support drive nut 90' relative to screw 92 such that drive nut 90' does not contact screw 92. Rolling elements 98 are disposed in raceways formed by screw thread 110 and nut thread 102 (best seen in FIG. 3). Ball return 140 is configured to pick up rolling elements 98 and recirculate the rolling elements 98 within the raceway formed by screw thread 110 and nut thread 102. Ball return 140 can be of any type suitable for circulating rolling elements 98. In some examples, ball return 140 is an internal ball return such that rolling elements 98 that are not within raceway pass through body of drive nut 90'.

Drive nut 90' rotates relative to screw 92 and causes rolling elements 98 to exert an axial force on screw 92 to drive screw linearly. Drive 24' can thereby convert a rotational input to a linear output.

FIG. 5 is an isometric view of drive mechanism 24" with a portion of drive nut 90" removed. FIG. 6 is an isometric view of drive mechanism 24" with the body of drive nut 90" removed to show rolling elements 98'. FIGS. 5 and 6 will be discussed together. Drive 24" includes drive nut 90", screw 92, and rolling elements 98'. Drive nut 90" includes drive rings 142. Each one of rolling elements 98' includes end rollers 144 and roller shaft 146.

Drive nut 90" surrounds a portion of screw 92 and rolling elements 98' are disposed between drive nut 90" and screw 92. In the example shown, rolling elements 98' include rollers. As such, drive 24" can be considered to be a roller screw. Rolling elements 98' support drive nut 90" relative to screw 92 such that drive nut 90" does not contact screw 92. Rolling elements 98' are disposed circumferentially and symmetrically about screw 92. Roller shafts 146 extend between and connect pairs of end rollers 144. As such, each rolling element 98' can include an end roller 144 at a first end of the shaft 146 and can further include an end roller 144 at a second end of the roller shaft 146. In some examples, roller shafts 146 include threading configured to mate with screw thread 110 to exert driving force on screw 92. Each end roller 144 includes teeth. End rollers 144 extend between and engages thread 110 and drive ring 142. The teeth of end rollers 144 engage the teeth of drive ring 142.

Drive nut 90" includes a first drive ring 142 at a first end of drive nut 90" and a second drive ring 142 at a second end of drive nut 90". For each rolling element 98', a first one of the end rollers 144 engages the teeth of the drive ring 142 at the first end of drive nut 90" and the second one of the end rollers 144 engages the teeth of the drive ring 142 at the second end of drive nut 90". As drive nut 90" rotates, engagement between end rollers 144 and drive rings 142 causes each rolling element 98' to rotate about its own axis and causes the array of rolling elements 98' to rotate about pump axis PA-PA. The threads of roller shafts 146 engage and exert a driving force on screw thread 110 to linearly displace screw 92.

Drive nut 90" rotates relative to screw 92 and causes rolling elements 98' to exert an axial force on screw 92 to drive screw 92 linearly. Drive 24" thereby converts a rotational input to a linear output.

FIG. 7 is a block diagram of pump 10. Fluid displacers 20, motor 22, drive 24, controller 26, and user interface 27 are shown. Motor 22 includes stator 28 and rotor 30. Controller 26 includes control circuitry 31 and memory 33.

Motor 22 is disposed within a pump body (e g , pump body 16) and is coaxial with the fluid displacers 20 in the example shown. Controller 26 is operably connected, communicatively and/or electrically, to motor 22 to control operation of motor 22. Controller 26 is configured to regulate electric energy delivery to the electric motor 22 to control operation of and pumping by pump 10. While motor 22 and fluid displacers 20 are shown as coaxial, it is understood that, in some examples, rotor 30 can be configured to rotate on a motor axis that is not coaxial with a reciprocation axis of one or more of the fluid displacers 20. In addition, each fluid displacer 20 can be configured to reciprocate on its own reciprocation axis that is not coaxial with the reciprocation axis of the other fluid displacer 20. It is further understood that, while pump 10 is shown as including two fluid displacers 20, some examples of pump 10 can include a single fluid displacer 20 or more than two fluid displacers 20.

Position sensor 62 is configured to generate information regarding operation of pump 10 and position of fluid displacers 20. In some examples, position sensor 62 can be configured as a rotational position sensor that is configured to generate information regarding the rotational position of rotor 30. For example, position sensor 62 can be disposed proximate rotor 30 and be configured to sense rotation of rotor 30 and to generate data in response to that rotation. In some examples, position sensor 62 includes an array of Hall-effect sensors disposed proximate rotor 30 to sense the polarity of permanent magnets forming the permanent magnet array of rotor 30. Controller 26 can commutate motor 22 based on data generated by position sensor 62. Position sensor 62 can generate data regarding the permanent magnets and provide commutation information to controller 26. In some examples, position sensor 62 can be configured to directly sense the linear displacement and/or position of fluid displacers 20. For example, position sensor 62 can be configured to sense the linear displacement of fluid displacer 20 and/or screw 92.

The position sensor 62 can be configured to count the magnetic sections of rotor 30 as the permanent magnets pass by the position sensor 62, each magnet being detected as the magnetic field measured by the position sensor 62 increases above a threshold and then decreases back below the threshold, the threshold corresponding to the position sensor being proximate a magnet. The controller 26 can be configured to know what number of passing magnetic sections corresponds with what angular displacement of the rotor 30, a full turn of the rotor 30, linear displacement of the screw 92 (and fluid displacer 20), and/or portion of a pump cycle, among other options. The position sensor 62 may not provide information regarding which rotational direction the rotor 30 is spinning, but the controller 26 knows in which direction the rotor 30 is being driven. The controller 26 can then determine the position of the screw 92 and/or fluid displacer 20 along pump axis PA based on counting the number of magnets passing the position sensor 62. In some examples, the number of magnet passes is added to a running total when the rotor 30 is driven in a first direction (e.g., one of clockwise and counterclockwise) and subtracted from the running total when the rotor 30 is driven in the opposite direction (e.g., the other of clockwise and counterclockwise).

Motor 22 is a reversible motor in that stator 28 can cause rotor 30 to rotate in either of two rotational directions. Rotor 30 is connected to the fluid displacers 20 via drive 24, which receives a rotary output from rotor 30 and provides a linear input to fluid displacers 20. Drive 24 causes reciprocation of fluid displacers 20 along pump axis PA. Drive 24 can be of any desired configuration for receiving a rotational output from rotor 30 and providing a linear input to one or both of fluid displacers 20. Rotating rotor 30 in the first rotational direction causes drive 24 to displace fluid displacers 20 in a first axial direction. Rotating rotor 30 in the second rotational direction causes drive 24 to displace fluid displacers 20 in a second axial direction opposite the first axial direction. Drive 24 is directly connected to rotor 30 and fluid displacers 20 are directly driven by drive 24. As such, motor 22 directly drives fluid displacers 20 without the presence of intermediate gearing, such as speed reduction gearing.

Fluid displacers 20 can be of any type suitable for pumping fluid from inlet manifold 12 to outlet manifold 14. For example, fluid displacers 20 can include pistons, diaphragms, or be of any other type suitable for reciprocating to pump fluid. It is understood that while pump 10 is described as including multiple fluid displacers 20, some examples of pump 10 include a single fluid displacer 20 or more than two fluid displacers 20.

Controller 26 is configured to store software, implement functionality, and/or process instructions. Controller 26 is configured to perform any of the functions discussed herein, including receiving an output from any sensor referenced herein, detecting any condition or event referenced herein, and controlling operation of any components referenced herein. Controller 26 can be of any suitable configuration for controlling operation of motor 22, gathering data, processing data, etc. Controller 26 can include hardware, firmware, and/or stored software, and controller 26 can be entirely or partially mounted on one or more circuit boards. Controller 26 can be of any type suitable for operating in accordance with the techniques described herein. While controller 26 is illustrated as a single unit, it is understood that controller 26 can be disposed across one or more circuit boards. In some examples, controller 26 can be implemented as a plurality of discrete circuitry subassemblies.

Memory 33 configured to store software that, when executed by control circuitry 31, controls operation of motor 22. Control circuitry 31 can include one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other equivalent discrete or integrated logic circuitry. Memory 33, in some examples, is described as computer-readable storage media. In some examples, a computer-readable storage medium can include a non-transitory medium. The term “non-transitory” can indicate that the storage medium is not embodied in a carrier wave or a propagated signal. In certain examples, a non-transitory storage medium can store data that can, over time, change (e.g., in RAM or cache). In some examples, memory 33 is a temporary memory, meaning that a primary' purpose of memory 33 is not long-term storage. Memory 33, in some examples, is described as volatile memory. meaning that memory 33 does not maintain stored contents when power to controller 26 is turned off. Examples of volatile memories can include random access memories (RAM), dynamic random access memories (DRAM), static random access memories (SRAM), and other forms of volatile memories. Memory 33, in one example, is used by software or applications running on control circuitry 31 to temporarily store information during program execution. Memory 33, in some examples, also includes one or more computer-readable storage media. Memory 33 can further be configured for long-term storage of information. Memory 33 can be configured to store larger amounts of information than volatile memory. In some examples, memory 33 includes non-volatile storage elements. Examples of such non-volatile storage elements can include magnetic hard discs, optical discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories.

User interface 27 can be any graphical and/or mechanical interface that enables user interaction with controller 26. For example, user interface 27 can implement a graphical user interface displayed at a display device of user interface 27 for presenting information to and/or receiving input from a user. User interface 27 can include graphical navigation and control elements, such as graphical buttons or other graphical control elements presented at the display device. User interface 27, in some examples, includes physical navigation and control elements, such as physically actuated buttons, dials, switches, sliders, knobs, or other physical navigation and control elements. Tn general, user interface 27 can include any input and/or output devices and control elements that can enable user interaction with controller 26.

Pump 10 can be controlled based on any desired output parameter. In some examples, pump 10 is configured to provide a process fluid flow based on a desired pressure, flow rate, and/or any other desirable operating parameter. In some examples, pump 10 is configured such that the user can control operation of pump 10 based on an operating capacity of pump 10. For example, the user can set pump 10 to operate at 50% capacity, during which a target operating parameter, such as speed, pressure, flow rate, etc. is half of a maximum of that operating parameter. In some examples, pump 10 does not include a fluid sensor, such as a pressure sensor or flow rate sensor. In some examples, the pumping system including pump 10 does not include a fluid sensor disposed downstream of pump 10. In some examples, the pumping system does not include a fluid sensor disposed upstream of pump 10. Controller 26 controls operation of pump 10 to drive reciprocation of fluid displacers 20 at a target speed and to output fluid at a target pressure. Pump 10 can include closed-loop speed control based on data provided by one or more position sensors 62. Position sensors 62 can be configured to sense rotation of rotor 30 and a rotational speed of rotor 30 can be determined based on the data from position sensors 62. The rotational speed can provide the axial displacement speed of fluid displacers 20. As such, position sensor 62 can also be considered to form a speed sensor. The ratio of rotational speed to axial speed is known based on the configuration of the drive 24. When utilizing a drive having a screw, such as drive 24 having screw 92, axial speed is a function of the rotational speed of rotor 30 and the lead of the thread of screw 92. Controller 26 can operate pump 10 such that the actual speed does not exceed the target speed. The speed of fluid displacer 20 corresponds to the flow rate output by pump 10. As such, a higher speed provides a higher flow rate while a lower speed provides a lower flow rate.

The position of the fluid displacer 20 along the axis PA can be determined based on information generated by position sensor 62, based on directly sensing displacement/position of fluid displacer 20 or drive 24 or based on directly sensing rotational displacement/position of rotor 30. The ratio of the rotational speed of rotor 30 to the axial displacement speed of fluid displacer 20 is known, such that the speed of the fluid displacer 20 can be determined based on the rotational speed of the rotor 30. The axial displacement of the fluid displacer 20, and thus the position along the axis of the fluid displacer 20, can be determined based on a known position of fluid displacer 20 and the displacement speed of fluid displacer 20. The controller 26 can be configured to control operation of pump 10 based on the position of the fluid displacer 20 within a pump cycle, as discussed in more detail below.

Controller 26 controls the pressure output of pump 10 by controlling the delivery of electric energy to pump 10. Motor 22 can be controlled based on a maximum driving current. Controller 26 is configured to control operation of motor 22 such that the maximum driving current, which can be either the maximum operating current that motor 22 can handle or can be a target operating current associated with a target output parameter (e g., target speed, pressure, flow rate, etc ), is not exceeded. Controller 26 current-limits pump 10 such that the current applied to motor does not exceed the maximum driving current. The electric current provided to motor 22 controls the torque output by motor 22, thereby controlling the pressure and flow rate output by pump 10. In some examples, controller 26 is configured to determine the maximum driving current based on inputs to controller 26 and based on operating conditions of motor 22. For example, a target operating current can be determined based on an input voltage and target speed. In some examples, the target operating current is determined based on motor temperature in addition to input voltage and target speed. In some examples, controller 26 is configured to determine the target operating current based on a three-dimensional table in which the target operating current is determined based on each of input voltage, target speed, and motor temperature. It is understood that the target operating current can vary during operation as operating parameters of motor 22 change, such as the temperature of motor 22 varying during operation. For example, the target operating current can increase as the temperature of motor 22 increases and can decrease as the temperature of motor 22 decreases.

A target output parameter for pump 10 can be provided to controller 26 by user interface 27. For example, the user can input the target parameter via one or more interfaces of user interface 27. The user can provide an input setting to controller 26 via user interface 27 to set the target output for the pump 10. For example, the user can provide an input pressure setting to set a target output pressure, the user can provide an input flow setting to set a target output flowrate, etc. The input setting is provided to controller 26 and controller 26 controls operation of the pump 10 based on the input setting.

In some examples, the target parameter can be set by a single input to controller 26. For example, user interface 27 can include a parameter input that provides pressure and/or speed commands to controller 26. For example, user interface 27 can be or include a knob that the user can adjust to set the operating parameters of pump 10, the knob forming the parameter input. It is understood, however, that the parameter input can be of any desired configuration, including analog or digital slider, scale, button, knob, dial, etc. Adjusting the parameter input provides multiple parameter commands to controller 26 to set multiple target parameters. The parameters (e.g., pressure and speed) can be linked together to change proportionally to each other when the input is set/adjusted. For example, adjusting the parameter input to increase the target pressure can also increase the target speed, while adjusting the parameter input to decrease the target pressure can also decrease the target speed. One input can thereby results in a change to both the pressure threshold and the speed threshold. The user can thereby adjust both pressure and speed at a single instance in time by providing the single input to the controller 26 by the parameter input. During operation, controller 26 regulates electrical energy delivery to stator 28 to drive rotation of rotor 30. Controller 26 can provides up to the maximum driving cunent and drives rotation of rotor 30 up to the target operating speed. Controller 26 can control voltage to control the speed of rotor 30. The current through motor 12 determines the torque exerted on rotor 30, thereby determining the pressure output by pump 10. If the target operating speed is reached, then controller 26 continues to provide current to motor 22 to operate at the target operating speed. If the maximum driving current is reached, then motor 22 can continue to operate at that maximum driving current regardless of the actual speed.

During operation, controller 26 can axially locate one or more fluid displacers 20 and manage a stroke length of the fluid displacers 20. As discussed above, the axial displacement rate of fluid displacement members 20 is a function of rotation rate of rotor 30. In examples including screw 92, the axial displacement rate is a function of the rotation rate and the lead of the thread of screw 92. In some examples, pump 10 does not include an absolute position sensor for providing the axial location of reciprocating components. As such, controller 26 can axially locate the reciprocating components based on information other than direct sensing of the axial position. It is understood however, that in other examples the pump 10 can include a position sensor configured to directly generate information regarding the axial location of the fluid displacer 20.

On system start up, controller 26 can operate in a start-up mode. In some examples, controller 26 causes pump 10 to operate according to a priming routine on system start up. Pump 10 can initially be dry and requires priming to operate effectively. During the priming routine, controller 26 regulates the speed of pump 10 to facilitate efficient priming. For example, controller 26 can control the speed of pump 10 based on a priming speed. The priming speed can be stored in memory 274 and recalled for the priming routine. The priming speed can be based on the target speed set for pump 10 or can be disconnected from the target speed. Controller 26 causes pump 10 to operate based on the priming speed to prime pump 10. After the priming routine is complete, controller 26 exits the priming routine and resumes normal control of motor 12. For example, after exiting the priming routine controller 26 can control the speed based on the target speed rather than the priming speed. Controller 26 can be configured to exit the priming routine based on any desired parameter. For example, controller 26 can be configured to exit the priming routine based on a threshold time, number of revolutions of rotor 30, number of pump cycles or strokes, the current draw of motor 12, etc. In some examples, controller 26 can actively determine when to exit the priming routine, such as where controller 26 exits the priming routine based on the current draw to motor 12. For example, controller 26 can determine that pump 10 has been primed based on increased current draw or a spike in current, which indicates that pump 10 is pumping against pressure.

Controller 26 is configured to regulate electrical energy to motor 22 based on pump 10 operating in a priming mode and pump 10 operating in a pumping mode. The controller 26 is configured to regulate the electrical energy to motor 22 such that the fluid displacer 20 moves differently in the priming mode than in the pumping mode. The different movement profile of the fluid displacer 20 in the priming mode facilitates priming of the pump 10. The controller 26 can then exit the priming mode and enter the pumping mode to pump the process fluid once pump 10 is primed. The different movement profile during the priming mode can include different target speed, different acceleration rate, different deceleration rate, different stroke length, different movement through changeover, among other options relative to the pumping mode.

The controller 26 is configured to regulate electrical energy to the motor 22 to displace the fluid displacer 20 through pump cycles. A pump cycle can be considered to include a first stroke in a first direction along the pump axis PA, a second stroke in a second direction opposite the first direction along the pump axis PA, a first changeover in which the fluid displacer 20 reverses direction from the first stroke to the second stroke, and a second changeover in which the fluid displacer 20 reverses direction from the second stroke to the first stroke. A changeover point is the location where the fluid displacer 20 stops moving in a stroke direction and then reverses movement from that point in the other direction.

A pump cycle can additionally or alternatively be considered to include a pump stroke phase, a suction stroke phase, and a changeover phase that occurs in each transition between the pumping stroke suction stroke phases in which the fluid displacer 20 reverses direction. A changeover phase occurs in the transition from the pumping stroke phase to the suction stroke phase and in the transition from the suction stroke phase to the pumping stroke phase.

In some examples, controller 26 is configured to automatically transition between the priming mode and the pumping mode. During the priming mode, the motor 22 moves the fluid displacer 20 relatively faster through the suction and pump stroke phases but slows down and/or pauses during the changeover phase. Moreover, in the pumping mode, the motor 22 may move the fluid displacer 20 relatively slower through the suction and pump stroke phases (as compared to the velocity in the suction and pump stroke phases in the priming mode) without the slowdown or pause of the priming mode during the changeover phase, wherein such overall slower and steadier movement through the strokes in the pumping mode helps avoid unwanted pulsation of the pumped fluid.

In some examples, the changeover phase can be considered to occur from a beginning of deceleration as the fluid displacer 20 moves in a first direction along a reciprocation axis until the fluid displacer 20 begins to accelerate in a second direction opposite the first direction along the reciprocation axis. The changeover phase can thus be from the beginning of deceleration to the changeover point and until the fluid displacer 20 moves out of the changeover point to being the next, opposite stroke.

In some examples, the changeover phase can be considered to occur in a terminal portion of a stroke. For example, the changeover phase can be considered to occur in the final 20% of a stroke prior to the fluid displacer 20 stopping. In some examples, the changeover phase can be considered to occur in the final 15%, 10%, or 5% of the overall stroke distance of the stroke. The changeover phase can thus be a portion of a stroke up to the changeover point. In some such examples, the changeover phase can be considered to occur in the final portion of a stroke and until the fluid displacer is driven to move in the opposite axial direction through a subsequent stroke.

The controller 26 is configured to cause the fluid displacer 20 to move differently while operating in the priming mode as compared to the pumping mode. The different movement of the fluid displacer 20 while in the priming mode facilitates effective evacuation of air from the fluid chambers 34 to prime pump 10 with the process fluid. The different movement of the fluid displacer 20 in the priming mode can assist in evacuation of air from the fluid chamber 34 for each stroke of fluid displacer 20, can assist in seating of check valves 58 at changeover to assist in evacuation of air from the fluid chamber 34 during a subsequent stroke, etc.

During priming, only gravity closes the check valves 56 because airflow within the pump does not meaningfully move the valve members (e.g., balls) when the pump 10 is not primed, and the loss of air past a closing check valve 56 is a significant setback in attempting to prime. When the pump 10 is primed, the process fluid can more reliably close the check valves 56 such that a pause or slow down during changeover is not needed. As such, slowing or pausing during the changeover phase while priming gives the check valves 56 more time to close. In some examples, controller 26 is configured to regulate electric energy delivery to the motor 22 to slow or pause movement of the rotor 30 and consequently the fluid displacer 20 in the changeover phase while operating in the priming mode. For example, the controller 26 can be configured to cause the fluid displacer 20 to purposefully pause movement and remain in the changeover phase for a longer period of time while operating in the priming mode than while operating in the pumping mode.

In some examples, the controller 26 is configured to regulate energy delivery to the electric motor 22 to cause a changeover lag between the changeover phase during the priming mode and the changeover phase during the pumping mode. Changeover lag is the difference in time between a first time period over which the changeover phase occurs when in the priming mode and a second time period over which the changeover phase occurs when in the pumping mode. For example, if the changeover phase during the pumping mode takes two seconds and the changeover phase during the priming mode takes four seconds, then the changeover lag is equal to the two second difference between the changeover phases of the two modes. The controller 26 can regulate the energy delivery to the motor 22 such that the changeover phase takes a greater period of time dunng the priming phase than during the pumping phase.

The controller 26 can be configured to implement the changeover lag by a purposeful cessation of movement of the fluid displacer 20. Additionally or alternatively, the controller 26 can be configured to implement the changeover lag by a variation in the deceleration rate of the fluid displacer 20 as the fluid displacer 20 approaches the changeover point. For example, the controller 20 can cause the fluid displacer 20 to decelerate at a slower rate and over a greater axial distance while operating in the priming mode as compared to the pumping mode. Such a variation in deceleration rate can cause the changeover lag, whether changeover phase is determined based on a portion of the stroke or based on the beginning of deceleration.

Such a purposeful cessation of movement of the fluid displacer 20 can be particularly useful during the priming phase, as it allows the check valves 56 to more reliably close. The slower speed through the changeover phase, as indicated by the changeover lag, may be less than the speed that the controller 26 and motor 22 are capable of moving the drive 24 and fluid displacer 20 without impact or other damage. The slower speed during the changeover phase in the priming mode as compared to the pumping mode may be less than the speed that the controller 26 is programmed to move the rotor 30 and the fluid displacer 20 in the changeover phase (and/or pumping and suction phases) when in the pumping mode.

The changeover lag and/or purposeful pausing of the fluid displacer 20 provides time for the check valves 56 to close. Allowing the inlet check valve 56 to close in the changeover phase between the suction stroke phase and the pumping stroke phase prevents retrograde flow of air from the pumping chamber 34 back to the inlet manifold 12, which would inhibit priming. Allowing the outlet check valve 56 to close in the changeover phase between the pumping stroke phase and the suction stroke phase prevents retrograde flow of air from the output manifold 14 to the pumping chamber 34, which would inhibit priming.

The pause in motion may be a programmed cessation of movement of the rotor 30 for a period of time (e.g., between half a millisecond to 1000 milliseconds; or between one millisecond and 500 milliseconds; though other ranges are possible) and not an instantaneous stoppage of movement of the rotor 30 and fluid displacer 20 which may be inherent in reversing direction, such as during the pumping mode. To achieve such a pause, the motor 22 may not be energized (e.g., either at all or just not sufficiently) to drive movement or may be energized merely to hold position and resist movement due to pressure in a fluid chamber 34.

For example, during the changeover phase while not in the priming mode, the controller 26 may energize the motor 22 to spin the rotor 30 in a first direction with a first driving energy profile and then reverse the flow of energy and/or phase to urge a reverse in the direction of movement toward a second direction by delivering a second driving energy profile while the rotor 30 spins in the first direction. The controller 26 can regulate energy delivery such that the second driving energy profile continues to be provided as the rotor 30 reverses direction and then spins in the second direction. The second driving energy profile can thus cause the rotor 30 to decelerate while spinning in the first rotational direction to a stop and can then cause the rotor 30 to accelerate in the second rotational direction and out of the changeover.

Continuing with the example, during the changeover phase while in the priming mode, the controller 26 may energize the motor 22 to spin the rotor in a first direction with a first driving energy profile and then reverse the flow of energy and/or phase to urge a reverse in the direction of movement toward a second direction by delivering a second driving energy profile while the rotor spins in the first direction until the rotor nears stoppage or stops, in which state no motive energy is delivered to the motor or a third energy profile is delivered to hold the rotor 30 still. The controller 26 can then resume delivery of the second driving energy profile (or a similar motive profile) to accelerate the rotor 30 to spin in the second rotational direction and accelerate out of the changeover and into a subsequent stroke.

In some examples, when pausing during changeover in the priming mode, the controller 26 may decrease energy to the motor to allow the rotor 30 and fluid displacer 20 to float (e.g., be moved by the fluid under pressure), or the controller 26 may deliver sufficient energy to cause the rotor 30 to electromagnetically hold its position to resist backpressure during the pause.

Additionally or alternatively to implementing a slow down or pause on changeover, the controller 26 can control the displacement speed of the fluid displacer 20 in both the priming mode and the pumping mode. In some examples, the controller 26 is configured to control the displacement speed of the fluid displacer 20 during the priming and pumping modes such that the fluid displacer 20 moves differently in the priming mode as compared to the pumping mode. The controller 26 can be configured to control movement of the fluid displacer 20 based on a pumping speed setpoint while operating in the pumping mode. The pumping speed setpoint sets the desired rotational speed of the rotor 30 and thus the linear displacement speed of the fluid displacer 20 during pumping. The controller 26 is configured to accelerate the fluid displacer 20 to a speed associated with the pumping speed setpoint while moving through the pumping and suction stroke phases. The pumping speed setpoint can be set based on an input setting provided by the user at user interface 27, such as based on the user inputting a desired flow rate, pressure, etc. The controller 26 is configured to cause the rotor 30/fluid displacer 20 to accelerate to the speed associated with the pumping speed setpoint and move at that speed until decelerating to a changeover point while operating in the pumping mode.

The controller 26 can further be configured to control movement of the fluid displacer 20 based on a priming speed setpoint while operating in the priming mode. The priming speed setpoint sets the desired rotational speed of the rotor 30 and thus the linear displacement speed of the fluid displacer 20 during priming. The priming speed setpoint can be set based on the pumping speed setpoint. The priming speed setpoint can be correlated with the pumping speed setpoint (e.g., 1.1 times the pumping speed setpoint; 1.5 times the pumping speed setpoint; 2.0 times the pumping speed setpoint; etc.) such that variations in the pumping speed setpoint cause variation in the priming speed setpoint. As such, the priming speed setpoint can also be considered to be set based on the input setting provided at user interface 27.

The priming speed setpoint is associated with a higher speed than the pumping speed setpoint such that the controller 26 causes the fluid displacer 20 to move faster during the suction and pumping stroke phases during prime mode (as compared to relatively slower movement in the pumping and suction stroke phases in the pumping mode). The speed setpoint (priming or pumping) is associated with a maximum speed during the pumping stroke phase and suction stroke phase. The controller 26 can be considered to drive to a constant speed through a stroke phase, with that constant speed being greater in the priming mode than in the pumping mode. The constant speed can be the target speed that is associated with the speed setpoint. The faster speed of the fluid displacer 20 while in the priming mode enhances the compression of air during priming (whereas such compression is not a factor when pumping incompressible fluid and thus not beneficial when not priming) and thus enhances evacuation of the air from the fluid chamber 34.

In some examples, the controller 26 can be considered to implement a stroke lag between the time required to complete a stroke while operating in the pumping mode and the time required to complete a stroke in the priming mode. The time to complete a stroke can be from the beginning of acceleration in a direction along the axis PA to when the fluid displacer 20 stops moving in that direction. With the priming speed setpoint being greater than the pumping speed setpoint the fluid displacer 20 can move more quickly through a stroke while operating in the priming mode than in the pumping mode. The stroke lag is the difference in time required to complete a stroke in each of the modes. For example, if a stroke takes 1.0 second in the priming mode and takes 1.2 seconds in the pumping mode, then the stroke lag is -0.2 seconds.

Additionally or alternatively to slowing or pausing during changeover in the priming mode and moving the fluid displacer 20 at a higher speed through a stroke in the priming mode, the controller 26 can control a displacement distance of the fluid displacer 20 such that the fluid displacer 20 moves differently in the priming mode and the pumping mode. As shown in FIG. 8, the fluid displacer 20 is configured to changeover and begin moving in an opposite axial direction at changeover point CPI while operating in the pumping mode. The fluid displacer 20 is configured to changeover and begin moving in the opposite axial direction at changeover point CP2 while operating in the priming mode. The changeover points CPI and CP2 are the locations along the axis at which fluid displacement member 20 stops displacing in a first axial direction and begins displacing in a second axial direction. For example, the changeover points CPI, CP2 can be locations where fluid displacer 20 completes a pumping stroke and changes over to begin a suction stroke. The relative axial locations of changeover points CPI, CP2 along the pump axis PA can be stored in memory 33. During changeover, controller 26 causes motor 22 to begin reversing as fluid displacement member 20 approaches the changeover point CPI, CP2 to stop at the changeover point CPI, CP2 and begin accelerating in the opposite direction.

While operating in the pumping mode, the controller 20 is configured to cause the fluid displacer 20 to stop displacing in a first direction at the changeover point CPI and turnaround and begin displacing in the second direction changeover point CPI. The controller 26 is configured to alter the changeover point between the priming mode and the pumping mode such that the changeover point CP2 for the priming mode is different from the changeover point CPI for the pumping mode. As shown in FIG. 8, the changeover point CP2 is spaced axially from the changeover point CPI. In the example shown, the changeover point CP2 is further along the axis PA that the changeover point CPI by distance X. During a pumping stroke, the fluid displacer 20 changes over at a location axially closer to the fluid cover 18 while operating in the priming mode than while operating in the pumping mode. The fluid displacer 20 being axially closer to the fluid cover 18 increases a compression ratio, which is a ratio between the volume of fluid chamber 34 with fluid displacer 20 at the end of a suction stroke (when fluid chamber 34 is at a maximum volume) and the volume of fluid chamber 34 with fluid displacer 20 at the end of a pumping stroke (when fluid chamber 34 is at a minimum volume) while pumping in the priming mode as compared to pumping in the pumping mode. The compression ratio while operating in the priming mode can thus be greater than the compression ratio when operating in the pumping mode. The increased compression ratio is particularly useful when evacuating a compressible fluid, such as air, from the pumping chamber 34, which occurs during priming. As such, shifting the changeover point from the changeover point CPI to changeover point CP2 while operating in the pumping mode facilitates quicker and more efficient priming of pump 10.

As discussed above, the controller 26 can be considered to implement a stroke lag between the pumping mode and the priming mode. The difference in displacement distance between a stroke in the pumping mode and a stroke in the priming mode can reduce the stroke lag, or even negate the stroke lag, due to the fluid displacer 20 moving a greater axial distance through strokes in the priming mode than through strokes in the pumping mode in examples in which the fluid displacer 20 moves more quickly through a stroke in the priming mode than in the pumping mode.

In some examples, the controller 26 can be considered to implement a cycle lag between a pump cycle (including a full suction stroke and a full pumping stroke) in the pumping mode and a pump cycle in the priming mode. The cycle lag is the difference in time required to complete a full pump cycle in the priming mode as compared to the pumping mode.

In some examples, the cycle lag can differ (e g., be greater than or less than) from the changeover lag. For example, the cycle lag can be less than the total changeover lag for a pump cycle such as due to the increased speed of the fluid displacer 20 during the priming mode as compared to the pumping mode. A pump cycle includes two changeovers, the first from the pumping stroke to the suction stroke and the second from the suction stroke to the beginning of a pumping stroke of the next pump cycle. If the fluid displacer 20 moved the same distance and speed during both the pumping and suction strokes, then the cycle lag will equal to the total changeover lag for the pump cycle, which can be the case in some examples. In other examples, however, the cycle lag is less than the total changeover lag due to the different speeds between the pumping mode and the priming mode.

The cycle lag can be increased by the changeover lag of the pump cycle but is reduced by the increased speed of the fluid displacer 20 when moving through the strokes in the priming mode relative to the pumping mode. The cycle lag can further be increased due to the increased length of each stroke in the priming mode as compared to the pumping mode. The increased distance of the stroke length can negate the difference in speed in some examples.

In some examples, the increased distance of the stroke length can increase the cycle lag such that the cycle lag is greater than the changeover lag, such as when the speed setpoints are the same in both pumping and priming mode or when the increased speed in the priming mode does not fully compensate for the increased stroke distance in the priming mode.

In some examples, the controller 26 can implement different acceleration and/or deceleration profiles when operating in the priming mode than when operating in the pumping mode. For example, the controller 26 can cause the rotor 30 and fluid displacer 20 to accelerate more quickly while in the priming mode as compared to the pumping mode. Such acceleration can cause the fluid displacer 20 to reach a maximum speed more quickly to move through the strokes more quickly. In some examples, the fluid displacer 20 can be caused to accelerate more slowly out of changeover, providing additional time for check valves 56 to close and generating less retrograde flow in the event a check valve 6 has not fully closed prior to beginning to move out of the changeover.

In some examples, the controller 26 can cause the rotor 30 and fluid displacer 20 to decelerate differently when in the priming mode than in the pumping mode. For example, the controller 26 can cause the fluid displacer 20 to decelerate more slowly while operating in the priming mode than in the pumping mode. The slower deceleration provides a greater distance over which the fluid displacer 20 is decelerating. Such longer axial distance for deceleration can assist in driving the compressible air from the fluid chamber 34 to prime the pump 10.

The controller 26 can be configured to automatically transition between the priming mode and the pumping mode during operation of pump 10. In some examples, the controller 26 can be configured to initially operate in the priming mode on power up or other initiation of pumping. In some examples, the controller 26 can be configured to initially operate in the pumping mode on power up or other initiation of pumping and can transition to the priming mode based on the controller 26 determining that the pump 10 is not primed. For example, a state of the pump 10 as being primed and thus ready to pump in the pumping mode can be sensed, among other things, based on the current draw of the motor 22.

For example, the controller 26 can store a threshold current draw in memory 33 and can compare the actual current draw of the motor 22 to the current draw threshold to determine whether the pump 10 is primed. The threshold current draw can vary depending on the input setting from the user. For example, the threshold current draw can be greater for a relatively greater target pressure. Current draw below the threshold can indicate that the pump 10 is not primed while current draw at or above the threshold can indicate that the pump 10 is primed. In some examples, an increase in current draw while operating in the priming mode can indicate that the pump 10 is pumping against incompressible fluid instead of air, thereby indicating that the pump 10 is primed. As such, an increase in cunent draw, even without a current draw threshold, can indicate that the pump 10 is primed.

When prime is sensed, the controller 26 can transition over to operating in the pumping mode (e.g., by slower movement of the fluid displacer 20 during the suction and pumping stroke phases as compared to the speed during the priming mode; by shorter strokes in the pumping mode as compared to the priming mode; and/or shorter turnaround time at changeover in the pumping mode as compared to the priming mode, etc.). Such variations can decrease pulsation while pumping in the pumping mode.

Loss of prime can be detected by, amongst other things, a decrease in current draw through the motor 22. In which case, the controller 26 can revert back to the prime mode until prime is once again sensed in which case the controller 26 can transition back to pumping mode.

In some examples, the controller 26 is configured to exit the priming mode and operate in the pumping mode based on a parameter reaching a threshold. As discussed above, the parameter can be an operating parameter of the motor 22, such as current draw of the motor 22. In some examples, the parameter can be an output parameter of the pump 10, such as pressure or flow rate of the fluid output by the pump 10. For example, controller 26 can be configured to determine that pump 10 is primed based on a downstream fluid pressure reaching a pressure threshold.

In some examples, controller 26 is configured to switch between the priming mode and the pumping mode based on temporal parameters. The temporal parameter can be alternative to or in addition to the sensed operating parameter (e.g., current draw, pressure, flow rate, etc.). For example, controller 26 can be configured to exit the prime mode after having been in the prime mode for a certain time count. The time count can be any desired time period, such as 15 seconds, 30 seconds, 45 seconds, 60 seconds, etc. In some examples, the controller 26 can be configured to exit the prime mode based on the controller 26 detecting the pump 10 pumping against fluid (e g., based on current draw) or based on the temporal threshold being reached, whichever occurs first. The temporal threshold to exit the priming mode can be considered to form an upper limit as the temporal threshold defines a maximum amount of time for being in the priming mode.

In some examples, the controller 26 is configured to implement a cooldown period after exiting the priming mode and before reentering the priming mode. The cooldown period allows the controller 26 time to determine if the pump 10 is or has become primed. For example, the controller 26 may exit the priming mode based on the temporal threshold for being in the prime mode being reached. The controller 26 will then cause the pump 10 to operate in the pumping mode for a set period (e g , 5 seconds, 7 seconds, 10 seconds, etc.) prior to reentering the priming mode. If the controller 26 determines that the pump 10 is primed while in the pumping mode, then the controller 26 will not reenter the priming mode and will instead continue to operate in the pumping mode. The cooldown period, which is a temporal threshold, can be considered to form a lower limit as the cooldown period defines a minimum amount of time for being in the pumping mode after exiting the priming mode.

In some examples, the controller 26 exits the priming mode based on a count other than a temporal count. For example, the controller 26 can be configured to exit the priming mode based on a count of pump strokes reaching a stroke count threshold, based on a count of pump cycles reaching a pump cycle threshold, etc.

The controller 26 causes the fluid displacer 20 to move differently in the priming mode than in the pumping mode Such different movement of the fluid displacer 20 in the priming mode facilitates evacuation of air from the fluid chamber 34 for quicker and more efficient priming. The controller 26 can cause the fluid displacer 20 to purposefully pause at changeover before beginning a subsequent stroke, allowing the check valves 56 to close and preventing retrograde flow that can inhibit priming. The controller 26 can, additionally or alternatively, cause the fluid displacer 20 to move more quickly through strokes while in the priming mode, decreasing the time to prime while slower movement during pumping decreases downstream pulsation. The controller 26, additionally or alternatively, cause the fluid displacer 20 to move through strokes having a greater axial length while in the priming mode, increasing the compression ratio while in the priming mode and providing for greater evacuation of the compressible air from the fluid chamber 34 while priming.

The controller 26 can automatically enter into and exit from the priming mode during operation of pump 10. The controller 26 automatically entering into the priming mode, such as based on a sensed current draw of motor 22, facilitates priming of the pump 10 without user interaction. Instead, the controller 26 is configured to automatically prime the pump 10 when the controller 26 senses that the pump 10 is not primed. The controller 26 automatically entering into the priming mode facilitates efficient operation of pump 10 without requiring user interaction to cause priming. The controller 26 automatically exiting the priming mode, such as based on current draw or a count, also facilitates efficient operation of pump 10 without requiring user interaction. The user does not have to affirmatively switch the pump 10 to a pumping mode, but instead the controller 26 will automatically enter into the pumping mode to pump the process fluid.

FIG. 9A is a cross-sectional view of pump 10. FIG. 9B is an enlarged cross- sectional view of detail B in FIG. 9A showing the mounting of a fluid displacer 200 for pump 10. FIG. 9C is a cross-sectional view showing a fluid displacer 200 dismounted from pump 10 and in a partially disassembled state relative to drive 24. Fluid displacer 200 is substantively similar to fluid displacers 20, except that fluid displacer 200 includes a multi - part flexible body 202. Fluid displacer 200 includes flexible body 202, inner plate 204, outer plate 206, and fastener 208. Flexible body 202 includes main membrane 210 and backer 212. Main membrane 210 includes membrane body 214 and bead 216. Backer 212 includes backer body 218 and bead cup 220. Pump body 16 includes body trench 222. Fluid cover 18 includes cover trench 224. Body trench 222 and cover trench 224 together define mount groove 226.

Fluid displacer 200 is formed as a diaphragm that is configured to flex as the fluid displacer 200 moves through pumping and suction strokes. The fluid displacer 200 is configured to move along reciprocation axis RS, which can be coaxial with pump axis PA, in axial direction PS through a pumping stroke and axial direction SS through a suction stroke. Fluid displacer 200 includes outer side 228 oriented towards fluid chamber 34 and includes inner side 230 oriented towards motor 22 and drive 24. Outer side 228 can also be referred to as a fluid-facing side. Inner side 230 can also be referred to as a motor-facing side.

Flexible body 202 is configured to flex as fluid displacer 200 moves through pumping and suction strokes. Flexible body 202 is at least partially between the inner plate 204 and outer plate 206. Outer plate 206 is disposed on outer side 228 of flexible body 202 and inner plate 204 is disposed on inner side 230 of flexible body 202. Flexible body 202 can be clamped between inner plate 204 and outer plate 206. Fastener 208 extends through outer plate 206, flexible body 202, and inner plate 204 to connect fluid displacer 200 to drive 24. Tn the example shown, fastener 208 extends through fluid displacer 200 and into screw 92 of drive 24.

Main membrane 210 and backer 212 are stacked together to form flexible body 202. In the example shown, main membrane 210 and backer 212 are stacked but are not fixed to each other. No adhesive secures main membrane 210 and backer 212 together in the example shown. The main membrane 210 and backer 212 being stacked, but not fixed, together allows for disassembly of flexible body 202 and replacement of one or the other of main membrane 210 and backer 212 without replacing the other one of main membrane 210 and backer 212.

Membrane body 214 extends radially outward from reciprocation axis RA. Bead 216 is disposed at an outer radial edge of membrane body 214. It is understood that main membrane 210 can include additional portions extending radially outward from bead 216, but not all examples are so limited. The bead 216 is annular and extends about the reciprocation axis RA. Bead 216 is enlarged relative to membrane body 214. Bead 216 can be round, among other configurations. In some examples, the outer axial part (facing fluid cover 18) of the bead 216 is more fully formed than the inner axial part (facing pump body 16) of the bead 216 as the inner axial part of the bead 216 includes a recess to accommodate the backer 212. As such, bead 21 can project axially further in axial direction PS relative to the immediately adjacent portion of membrane body 214 than bead 216 projects in axial direction SS relative to the immediately adjacent portion of membrane body 214.

Backer body 218 extends radially outward from reciprocation axis RA. Bead cup 220 is disposed at an outer radial edge of backer body 218. It is understood that backer 212 can include additional portions extending radially outward from bead cup 220, but not all examples are so limited. Bead cup 220 is open to receive bead 216 within bead cup 220. In the example shown, bead cup 220 is open in axial direction PS. As such, bead cup 220 can be considered to be open away from the drive 24 and towards the fluid chamber 34. Bead cup 220 is closed towards pump body 16 and is open towards fluid cover 18 in the example shown.

Backer 212 is shown in an unflexed state in FIGS. 9B and 9C. With backer 212 in the unflexed state, backer 212 includes central portion 232 extending radially from reciprocation axis RA, trough 234 extending radially outward from central portion 232, and bead cup 220 disposed radially outward of trough 234. Central portion 232 and trough 234 form portions of the backer body 218. Trough 234 is open in axial direction SS and towards motor 22. The trough 234 and bead cup 220 are open in opposite axial directions along reciprocation axis RA. The trough 234 is an annular trough 234 that extends fully annularly about the reciprocation axis RA. The bead cup 220 and trough 234 being open in opposite axial directions facilitates mating of main membrane 210 and backer 212 even without the use of adhesives.

With main membrane 210 and backer 212 stacked together, bead 216 is disposed within bead cup 220. Bead cup 220 does not fully surround bead 216 and does not fully wrap around bead 216. Body trench 222 is an annular depression formed in pump body 16. Cover trench 224 is an annular depression formed in fluid cover 18. The body trench 222 opposes the cover trench 224 with fluid cover 18 assembled to pump body 1 such that mount groove 226 is formed between the opposed body trench 222 and cover trench 224.

Flexible body 202 is clamped between pump body 16 and fluid cover 18 with fluid displacer 200 assembled to pump 10. Bead 216 and bead cup 220 are disposed within the mount groove 226 and clamped within mount groove 226 between pump body 16 and fluid cover 18. In the example shown, the bead 216 does not directly contact the pump body 16. Instead, the bead cup 220 covers the portion of bead 216 disposed in body trench 222 such that bead cup 220 is disposed between bead 216 and pump body 16 and bead cup 220 is in contact with pump body 16.

Main membrane 210 and backer 212 are clamped together but not fixed directly to each other in the example shown. In the example shown, main membrane 210 and backer 212 are clamped together at an inner annular interface 236 and at an outer annular interface 238. The inner annular interface 236 is disposed axially between the inner plate 204 and the outer plate 206. The inner annular interface 236 clamps radially inner portions of main membrane 210 and backer 212 together. The outer annular interface 238 is disposed axially between fluid cover 18 and pump body 16. The outer annular interface 238 is disposed within mount groove 226. The flexible body 202 is configured to flex during pumping at locations radially between the inner annular interface 236 and the outer annular interface 238. Clamping main membrane 210 and backer 212 together at the radially inner annular interface 236 and at the radially outer annular interface 238 facilitates backer 212 supporting main membrane 210 at locations radially between the inner annular interface 236 and the outer annular interface 238, which locations form the flexing portions of fluid displacer 200.

Main membrane 210 is disposed axially between backer 212 and fluid chamber 34. In some examples, the main membrane 210 forms the outer side 228 of fluid displacer 200 such that main membrane 210 is exposed to and in contact with the fluid being pumped through fluid chamber 34 by fluid displacer 200. It is understood that not all examples are so limited, however. In some examples, a cover can be disposed over main membrane 210 such that the cover and not main membrane 210 is in contact with the process fluid during pumping.

Backer 212 is disposed axially between main membrane 210 and motor 22. The backer 212 is not exposed to and is not in contact with the process fluid being pumped by fluid displacer 200. The backer 212 can form the inner side 230 of fluid displacer 200. The backer 212 can be exposed to the motor cavity 240 within pump body 16 within which the motor 22 is disposed.

Main membrane 210 has thickness Tl. Thickness T1 is taken in a portion of main membrane 210 radially inwards of bead 216. Backer 212 has thickness T2. Thickness T2 is taken in a portion of backer 212 radially inwards of bead cup 220. In some examples, bead cup 220 has the same or similar thickness T2 as the backer body 218. Thickness T1 is greater than thickness T2 such that main membrane 210 is thicker than backer 212.

Backer 212 is configured to provide structural support to main membrane 210 during operation of pump 10. Backer 212 can be formed from a more resilient material than main membrane 210 and inhibits wear on main membrane 210 during operation.

In some examples, main membrane 210 is formed from a first polymer and backer 212 is formed from a second polymer. In some examples, the second polymer is different from the first polymer. For example, main membrane 210 can be formed from polytetrafluoroethylene (PTFE). Backer 212 can be formed from a thermoplastic vulcanizate (TPV). In some examples, backer 212 is formed from fully cured ethylene propylene diene monomer (EPDM) rubber particles encapsulated in a polypropylene matrix. For example, backer 212 can be formed from Santoprene® thermoplastic vulcanizate (available from Celanese) or other dynamically vulcanized alloy consisting mostly of fully cured EPDM rubber particles encapsulated in a polypropylene matrix.

In some examples, the second polymer is the same as the first polymer. For example, both main membrane 210 and backer 212 can be formed from PTFE.

Backer 212 is configured to inhibit wear of main membrane 210. As discussed above, pump 10 is configured to mechanically displace fluid displacer 200 through respective pumping and suction strokes. As fluid displacer 200 is pulled through a suction stroke (in axial direction SS) the process fluid being pulled into fluid chamber 34 acts on fluid displacer 200 and can exert force evenly across outer side 228 of fluid displacer 200.

As fluid displacer 200 is pushed through a pumping stroke (in axial direction PS) the drive 24 applies driving force to flexible body 202. The drive 24 mechanically displaces the fluid displacer 20 through the pumping stroke. The drive 24 applies driving forces on a central portion of the fluid displacer 20 while the process fluid in the pumping chamber 34 resists movement of the fluid displacer 20 and imparts forces on the outer side 228 of fluid displacer 200. Portions of fluid displacer 200 on inner side 230 that are radially outwards of inner plate 204 do not have force directly applied to those portions by the drive 24 to displace in axial direction PS. Such a mechanical driving configuration can cause the fluid displacer 200 to fold over the inner plate 204, which can cause wear on the flexible body 202. This is unlike an air operated diaphragm pump in which compressed air acts across the inner side of the diaphragm to drive the diaphragm through a pumping stroke. The compressed air in such a pump exerts forces evenly across the radial extent of the diaphragm. Backer 212 is disposed on the axially inner side 230 (closer to motor 22) of the fluid displacer 200 and, in the example shown, forms the inner side 230 of fluid displacer 200. The backer 212 is the portion of fluid displacer 200 that can fold over and contact the inner plate 204. Backer 212 provides stiffness to fluid displacer 200 and is configured to spread the forces applied by drive 24 radially outward across fluid displacer 200. The backer 212 resists the wear and prevents wear to the main membrane 210, protecting main membrane 210 and improving the lifespan of main membrane 210.

Fluid displacer 200 provides significant advantages. The flexible body 202 of fluid displacer 200 is formed in a multi-part construction with main membrane 210 and backer 212 stacked together. The stacked configuration with backer 212 on the inner side 230 of flexible body 202 facilitates backer 212 supporting main membrane 210 and reducing wear to main membrane 210. Such a configuration is particularly useful when fluid displacer 200 is mechanically displaced through pumping strokes in which the driving force is applied at a central location on fluid displacer 200. The main membrane 210 and backer 212 may not be fixed to each other, such as by adhesive, such that one or the other of the main membrane 210 and backer 212 can be removed and replaced without having to replace the other one of main membrane 210 and backer 212.

FIG. 10 is a cross-sectional view showing a fluid displacer 300 connected to a drive 24 but dismounted from the pump. Fluid displacer 300 is substantively similar to fluid displacer 200 except that main membrane 210 of fluid displacer 300 is overmolded on outer plate 206. Fluid displacer 300 further includes cover 242 that is disposed on main membrane 210, and can be fixed to main membrane 210 such as by adhesive. The cover 242 is disposed on an opposite axial side of main membrane 210 from backer 212. Cover 242 can be formed from a polymer, such as the same polymer as backer 212 or a different polymer than backer 212. Cover 242 forms the outer side 228 of flexible body 202 and is exposed to the process fluid. It is understood, however, that not all examples are so limited. For example, flexible body 202 may not include a cover 242 such that main membrane 210 that is overmolded on outer plate 206 is exposed to the process fluid. Backer 212 is shown in a flexed state in FIG. 10 in which outer plate 206 and inner plate 204 are not spaced apart but are instead fastened together to clamp the main membrane 210 and backer 212 together. In the example shown, trough 234 (FIGS. 9B and 9C) is not shown but is present when backer 212 is in the non-flexed state.

While the pumping assemblies of this disclosure and claims are discussed in the context of a double displacement pump, it is understood that the pumping assemblies and controls can be utilized in a variety of fluid handing contexts and systems and are not limited to those discussed. Any one or more of the pumping assemblies discussed can be utilized alone or in unison with one or more additional pumps to transfer fluid for any desired purpose, such as location transfer, spraying, metering, application, etc. While the invention 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 without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

CLAIMS:

1. A pump for pumping a fluid, the pump comprising: a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a pumping stroke phase, a suction stroke phase, and a changeover phase that occurs in each transition between the pumping stroke phase and the suction stroke phase in which the first fluid displacer reverses direction; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, and wherein the controller regulates the energy delivery in the priming mode such that the rotor rotates to cause the first fluid displacer to move differently through the changeover phase in the priming mode than through the changeover phase in the pumping mode.

2. The pump of claim 1, wherein the controller is configured to regulate the energy delivery to the electric motor such that the rotor rotates to cause the first fluid displacer to pause in the changeover phase in the priming mode to allow one or both of the first inlet check valve and the first outlet check valve to close.

3. The pump of claim 2, wherein the pause occurs at a point of reversing direction such that the first fluid displacer moves in a first direction along the axis, stops in place for a period of time, then moves in a second direction along the axis.

4. The pump of any one of claims 2-3, wherein the controller energizes the electric motor during the pause to hold the position of the rotor so that the first fluid displacer can resist moving due to back pressure in the first fluid chamber.

5. The pump of any preceding claim, wherein the controller is configured to cause the motor to drive the fluid displacer to a first constant speed during one of the pumping stroke phase and the suction stroke phase when operating the pump in the priming mode.

6. The pump of claim 5, wherein the controller is configured to cause the motor to drive the fluid displacer to a second constant speed during the other one of the suction stroke phase and the pumping stroke phase in the priming mode.

7. The pump of claim 6, wherein the first constant speed is the same as the second constant speed.

8. The pump of claim 5, wherein the controller is configured to cause the motor to drive the first fluid displacer to a second constant speed during the one of the pumping stroke phase and the suction stroke phase when operating the pump in the pumping mode, and wherein the first constant speed differs from the second constant speed.

9. The pump of claim 8, wherein the first constant speed is faster than the second constant speed.

10. The pump of any one of claims 1-4, wherein the controller is configured to energize the electric motor to displace the first fluid displacer through one of the pumping stroke phase and the suction stroke phase based on a first speed setpoint while in the priming mode.

11. The pump of claim 10, wherein the controller is configured to energize the electric motor to displace the first fluid displacer through the one of the pumping stroke phase and the suction stroke phase based on a second speed setpoint in the pumping mode, the second speed setpoint differing from the first speed setpoint.

12. The pump of claim 11, wherein the first speed setpoint is greater than the second speed setpoint.

13. The pump of any preceding claim, wherein the controller is configured to regulate the energy delivery to the electric motor such that the rotor rotates to cause the first fluid displacer to, in the changeover phase during the priming mode, one or both of pause and move slower as compared to the changeover phase during the pumping mode.

14. The pump of claim 1, wherein the controller is configured to regulate the energy delivery to the electric motor such that the rotor rotates to cause the first fluid displacer to move slower in the pumping and suction phases during the pumping mode as compared to when the first fluid displacer moves in the pumping and suction phases during the priming mode.

15. The pump of any preceding claim, wherein the controller is configured to exit the priming mode based on a sensed condition.

16. The pump of claim 12, wherein the sensed condition is an increase in current draw by the electric motor indicating pumping against the fluid under pressure.

17. The pump of any one of claims 1-14, wherein the controller is configured to exit the priming mode based on a parameter reaching a parameter threshold.

18. The pump of claim 17, wherein the parameter is a sensed operating parameter of the pump

19. The pump of claim 18, wherein the sensed operating parameter is a current draw of the electric motor.

20. The pump of claim 17, wherein the parameter is a temporal parameter.

21. The pump of any one of claims 17 and 20, wherein the parameter threshold is based on a time count.

22. The pump of claim 17, wherein the parameter threshold is based on a count of pump strokes.

23. The pump of claim 17, wherein the parameter threshold is based on a count of pump cycles.

24. The pump of claim 1, wherein the controller causes the first fluid displacer to move such that in the changeover phase while in the priming mode, the first fluid displacer at least one of pauses and moves slower as compared to movement of the fluid displacer during the changeover phase while in the pumping mode.

25. The pump of any preceding claim, wherein the changeover phase occurs from a beginning of deceleration in a first axial direction along the axis to a beginning of acceleration in a second axial direction along the axis, the second axial direction opposite the first axial direction.

26. The pump of any one of claims 1-24, wherein the changeover phase is up to final twenty percent of a stroke length of a displacement stroke.

27. The pump of claim 26, wherein the changeover phase is up to a final fifteen percent of the stroke length.

28. The pump of claim 27, wherein the changeover phase is up to a final ten percent of the stroke length.

29. The pump of claim 28, wherein the changeover phase is up to a final five percent of the stroke length.

30. The pump of any preceding claim, wherein the controller is configured to regulate the energy delivery to the electric motor such that the rotor rotates to cause the first fluid displacer to move at a first speed in the changeover phase as compared to each of the pumping stroke phase and the suction stroke phase, wherein the first speed is slower than a maximum speed that the electric motor could cause the first fluid displacer to move at during the changeover phase without causing an internal collision within the pump.

31. The pump of any preceding claim, wherein the controller is configured to regulate a stroke length of the first fluid displacer during the priming mode and during the pumping mode such that the first fluid displacer has a first stroke length during the priming mode and the fluid displacer has a second stroke length during the pumping mode.

32. The pump of claim 31, wherein the first stroke length differs from the second stroke length.

33. The pump of any one of claims 31 and 32, wherein the first stroke length is greater than the second stroke length.

34. The pump of any one of claims 1-33, wherein the controller is configured to control displacement of the first fluid displacer such that the first fluid chamber has a first compression ratio with the pump in the prime mode and a second compression ratio with the pump in the pumping mode, the first compression ratio differing from the second compression ratio.

35. The pump of claim 34, wherein the first compression ratio is greater than the second compression ratio.

36. The pump of any preceding claim, wherein the controller is configured to regulate the energy delivery to the electric motor such that a cycle lag occurs between the pump cycle of the first fluid displacer in the priming mode and the pump cycle of the first fluid displacer in the pumping mode.

37. The pump of claim 36, wherein the cycle lag differs from a changeover lag between changeovers during the priming mode and the pumping mode.

38. The pump of claim 37, wherein the changeovers while in the priming mode are for a longer duration than the changeovers while in the pumping mode.

39. The pump of any preceding claim, further comprising a second fluid displacer that is driven in synchrony with the first fluid displacer by the drive, the second fluid displacer linearly reciprocated at least partially within a second fluid chamber through a continuous series of second pump cycles, each second pump cycle comprising a second pumping stroke phase, a second suction stroke phase, and a second changeover phase that occurs in each transition between the second pumping stroke phase and the second suction stroke phase in which the second fluid displacer reverses direction.

40. The pump of any preceding claim, wherein the controller is configured to regulate the energy delivery to the electric motor in the changeover phase of the priming mode such that the controller energizes the motor to urge the rotor in a first direction with a first driving energy profile and then urges the rotor to spin in a second direction opposite the first direction by delivering a second driving energy profile while the rotor spins in the first direction until the rotor nears stoppage or stops, in which state the controller regulates energy delivery to the electric motor such that no motive energy is delivered to the motor or a third energy profile is delivered to hold the rotor still, and then the controller resumes delivery of the second driving energy profile to accelerate the rotor to spin in the second direction.

41. A pump for pumping a fluid, the pump comprising: a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a pumping stroke phase, a suction stroke phase, and a changeover phase that occurs in each transition between the pumping stroke phase and the suction stroke phase in which the first fluid displacer reverses direction; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, wherein the controller regulates the energy delivery based on a target priming speed of the first fluid displacer in the priming mode and based on a target pumping speed of the first fluid displacer in the pumping mode, the target priming speed greater than the target pumping speed.

42. A pump for pumping a fluid, the pump comprising: a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated along an axis and at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle compnsing a first stroke in a first direction along the axis, a second stroke in a second direction along the axis, a first changeover in which the first fluid displacer reverses direction from the first stroke to the second stroke, and a second changeover in which the first fluid displacer reverses direction from the second stroke to the first stroke; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, wherein the controller regulates the energy delivery such that the first fluid displacer moves differently through the changeover phase in the priming mode than through the changeover phase in the pumping mode.

43. The pump of claim 42, wherein the controller is configured to regulate the energy delivery to the electric motor such that the first fluid displacer moves a first distance along the axis through the first stroke in the priming mode and the first fluid displacer moves a second distance along the axis through the first stroke in the pumping mode, the first distance different than the second distance.

44. The pump of claim 43, wherein the first distance is greater than the second distance.

45. The pump of any one of claims 42-44, wherein the controller is configured to regulate the energy delivery to the electric motor such that the first fluid displacer is stationary at the first changeover for a first time period in the priming mode and the first fluid displacer is stationary at the first changeover for a second time period in the pumping mode, the first time period differing from the second time period.

46. The pump of claim 45, wherein the first time period is greater than the second time period.

47. The pump of any one of claims 42-46, wherein the controller is configured to regulate the energy delivery to the electric motor based on a first speed setpoint in the priming mode and based on a second speed setpoint in the pumping mode, the first speed setpoint differing from the second speed setpoint.

48. The pump of claim 47, wherein the first speed setpoint is associated with a higher speed than the second speed setpoint.

49. The pump of any one of claims 42-48, wherein: the first stroke includes a pumping stroke phase and a first changeover phase that occurs in a transition from the first stroke to the second stroke; the first changeover phase occurs from a beginning of deceleration in the first direction along the axis to a beginning of acceleration in the second direction along the axis; and the second stroke includes a suction stroke phase and a second changeover phase that occurs in a transition from the second stroke to the first stroke.

50. The pump of any one of claims 42-48, wherein: the first stroke includes a pumping stroke phase and a first changeover phase that occurs in a transition from the first stroke to the second stroke; the first changeover phase forms a final twenty percent of a length of the first stroke; and the second stroke includes a suction stroke phase and a second changeover phase that occurs in a transition from the second stroke to the first stroke.

51. The pump of any one of claims 42-48, wherein: the first stroke includes a pumping stroke phase and a first changeover phase that occurs in a transition from the first stroke to the second stroke; the first changeover phase forms a final fifteen percent of a length of the first stroke; and the second stroke includes a suction stroke phase and a second changeover phase that occurs in a transition from the second stroke to the first stroke.

52. The pump of any one of claims 42-48, wherein: the first stroke includes a pumping stroke phase and a first changeover phase that occurs in a transition from the first stroke to the second stroke; the first changeover phase forms a final ten percent of a length of the first stroke; and the second stroke includes a suction stroke phase and a second changeover phase that occurs in a transition from the second stroke to the first stroke.

53. The pump of any one of claims 42-48, wherein: the first stroke includes a pumping stroke phase and a first changeover phase that occurs in a transition from the first stroke to the second stroke; the first changeover phase forms a final five percent of a length of the first stroke; and the second stroke includes a suction stroke phase and a second changeover phase that occurs in a transition from the second stroke to the first stroke.

54. The pump of any one of claims 42-53, wherein the controller is configured to exit the priming mode and enter the pumping mode based on a current draw of the electric motor.

55. The pump of any one of claim 42-54, wherein the controller is configured to exit the priming mode and enter the pumping mode based on a first temporal threshold.

56. The pump of claim 55, wherein the controller is configured to reenter the priming mode from the pumping mode after having first exited the priming mode based on a second temporal threshold.

57. The pump of claim 56, wherein the first temporal threshold is an upper limit and the second temporal threshold is a lower limit.

58. The pump of any one of claims 55-57, wherein the controller is configured to reenter the priming mode from the pumping mode after having first exited the priming mode based on a threshold of a sensed parameter of the electric motor.

59. The pump of claim 58, wherein the sensed parameter of the electric motor is current draw of the electric motor.

60. The pump of any one of claims 42-53, wherein the controller is configured to automatically enter into the prime mode based on current draw of the electric motor.

61. The pump of claim 60, wherein the controller is configured to automatically enter into the prime mode based on the current draw being less than a current threshold.

62. The pump of any one of claims 42-61, wherein the controller is configured to regulate the energy delivery to the electric motor such that a pumping acceleration profile of the first fluid displacer during the pumping mode differs from a priming acceleration profile of the first fluid displacer during the priming mode.

63. The pump of any one of claims 42-62, wherein the controller is configured to regulate the energy delivery to the electric motor such that a pumping deceleration profile of the first fluid displacer during the pumping mode differs from a priming deceleration profile of the first fluid displacer during the priming mode.

64. The pump of claim 42, wherein the controller is configured to regulate the energy delivery to the electric motor such that: during the priming mode, the first fluid displacer moves a first distance through the first stroke, a maximum speed of the first fluid displacer is based on a first speed setpoint, and the first fluid displacer pauses for a first time period during changeover; during the pumping mode, the first fluid displacer moves a second distance through the first stroke, a maximum speed of the first fluid displacer is based on a second speed setpoint, and the first fluid displacer pauses for a second time period during changeover; and the first distance differs from the second distance, the first speed setpoint differs from the second speed setpoint, and the first time period differs from the second time period.

65. The pump of claim 64, wherein the first distance is greater than the second distance.

66. The pump of any one of claims 64 and 65, wherein the first speed setpoint is greater than the second speed setpoint.

67. The pump of any one of claims 64-66, wherein the first time period is longer than the second time period.

68. The pump of any one of claims 42-67, wherein the controller is configured to regulate the energy delivery to the electric motor based on a current threshold, and wherein the current threshold is based on an input voltage and a target speed.

69. The pump of claim 68, wherein the current threshold is further based on a motor temperature.

70. The pump of claim 69, wherein the current threshold is recalled from a three- dimensional table stored in a memory of the controller.

71. A pump for pumping a fluid, the pump comprising: a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated along an axis and at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a first stroke in a first direction along the axis, a second stroke in a second direction along the axis, a first changeover in which the first fluid displacer reverses direction from the first stroke to the second stroke, and a second changeover in which the first fluid displacer reverses direction from the second stroke to the first stroke; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, wherein the controller regulates the energy delivery such that the first fluid displacer moves a first distance through the first stroke in the priming mode and the fluid displacer moves a second distance through the first stroke in the pumping mode, the first distance greater than the second distance.

72. A pump for pumping a fluid, the pump comprising: a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a pumping stroke phase, a suction stroke phase, and a changeover phase that occurs in each transition between the pumping stroke phase and the suction stroke phase in which the first fluid displacer reverses direction; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, and wherein the controller regulates the energy delivery in the priming mode such that the rotor rotates to cause the first fluid displacer such that the changeover phase during the priming mode is slower than the changeover phase during the pumping mode A pump for pumping a fluid, the pump comprising: a first fluid chamber; a first inlet check valve and a first outlet check valve positioned, respectively, upstream and downstream of the first fluid chamber and which regulate flow into and out of the first fluid chamber; an electric motor comprising a stator and a rotor, the rotor configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion; a first fluid displacer configured to be linearly reciprocated at least partially within the first fluid chamber by the drive to pump the fluid, wherein the first fluid displacer is reciprocated through a continuous series of pump cycles, each pump cycle comprising a pumping stroke phase, a suction stroke phase, and a changeover phase that occurs in each transition between the pumping stroke phase and the suction stroke phase in which the first fluid displacer reverses direction; and a controller configured to regulate energy delivery to the electric motor in a priming mode during which the pump is primed and in a pumping mode, and wherein the controller regulates the energy delivery in the pnming mode such that the first fluid displacer pauses for a first time period during the changeover phase during the priming mode pauses for a second time period during the changeover phase in the pumping mode, the first time period longer than the second time period.

74. A diaphragm configured to reciprocate along an axis to pump a fluid for a pump, the diaphragm comprising: a first diaphragm plate; and a flexible body extending radially outward from the diaphragm plate, the flexible body having an outer side oriented in a first direction along the axis and configured to be oriented towards a pumping chamber through which the fluid is pumped and having an inner side oriented in a second direction along the axis and configured to be oriented towards a motor that drives reciprocation of the diaphragm, the flexible body comprising: a main membrane including a bead that is enlarged relative to a membrane body of the main membrane, the bead configured to be clamped to mount the diaphragm to the pump; and a backer formed separately from the main membrane and disposed such that the main membrane is between the backer and the outer side of the flexible body, the backer including a bead cup open in the first direction and configured to receive the bead.

75. The diaphragm of claim 74, wherein in an unflexed state the backer includes a central portion, a trough radially outward from the central portion, and the bead cup radially outward of the trough.

76. The diaphragm of claim 75, wherein the trough is annular and open in the second direction.

77. The diaphragm of any one of claims 74-76, wherein the membrane body has a first thickness, a backer body of the backer has a second thickness, and the first thickness is greater than the second thickness.

78. The diaphragm of any one of claims 74-77, wherein the main membrane is formed from a first polymer and the backer is formed from a second polymer.

79. The diaphragm of claim 78, wherein the first polymer differs from the second polymer.

80. The diaphragm of any one of claims 78 and 79, wherein the second polymer is a thermoplastic vulcanizate (TPV).

81. The diaphragm of any one of claims 78-80, wherein the second polymer includes fully cured ethylene propylene diene monomer (EPDM) rubber particles encapsulated in a polypropylene matrix.

82. The diaphragm of any one of claims 78 and 79, wherein the second polymer is polytetrafluoroethylene (PTFE).

83. The diaphragm of any one of claims 74-82, wherein the main membrane is exposed on the outer side of the flexible body.

84. The diaphragm of any one of claims 74-83, wherein the backer is exposed on the inner side of the flexible body.

85. The diaphragm of any one of claims 74-84, further comprising: a second diaphragm plate, wherein the main membrane and the backer are clamped between the first diaphragm plate and the second diaphragm plate.

86. The diaphragm of claim 85, wherein the main membrane is overmolded on the first diaphragm plate.

87. The diaphragm of any one of claims 74-86, wherein the backer is not adhered to the main membrane.

88. The diaphragm of any one of claims 74-87, wherein the flexible body does not include adhesive securing the backer to the main diaphragm.

89. A pump for pumping a fluid, the pump comprising: a pump body at least partially defining a motor housing; an electric motor disposed within the motor housing and configured to generate a rotational output; a drive that converts the rotational output from the electric motor into a linear reciprocating motion along an axis; a first fluid chamber at least partially defined by a first fluid cover connected to the pump body; and a first diaphragm configured to be linearly reciprocated along the axis at least partially within the first fluid chamber by the drive to pump the fluid through the first fluid chamber, the first diaphragm comprising: a first diaphragm plate; and a flexible body extending radially outward from the diaphragm plate and at least partially defining the first fluid chamber, the flexible body having an outer side oriented towards the first fluid chamber and having an inner side oriented towards the electric motor, the flexible body comprising: a main membrane including a bead that is enlarged relative to a membrane body of the main membrane; and a backer formed separately from the main membrane and disposed such that the backer is between the main membrane and the electric motor, the backer including a bead cup configured to receive the bead, the bead cup open axially away from the electric motor; wherein the bead and bead cup are clamped together between the first fluid cover and the pump body.

90. The pump of claim 89, wherein the backer is not fixed to the main membrane.

91. The pump of any one of claims 89 and 90, wherein the fluid cover includes a first annular trench, the pump body includes a second annular trench opposing the first annular trench, and the bead and bead cup are disposed in a mount groove formed by the first annular trench and the second annular trench.

92. The pump of any one of claims 89-91, wherein the main membrane is formed from a first polymer and the backer is formed from a second polymer.

93. The pump of claim 92, wherein the first polymer differs from the second polymer.

94. The pump of any one of claims 92 and 93, wherein the second polymer is a thermoplastic vulcanizate (TPV).

95. The pump of any one of claims 92-94, wherein the second polymer includes fully cured ethylene propylene diene monomer (EPDM) rubber particles encapsulated in a polypropylene matrix.

96. The pump of any one of claims 92 and 93, wherein the second polymer is polytetrafluoroethylene (PTFE).

97. The pump of any one of claims 89-96, wherein the main membrane is exposed to the first fluid cavity such that the main membrane contacts the fluid during pumping.

98. The pump of any one of claims 89-97, wherein the membrane body of the main membrane has a first thickness, a backer body of the backer has a second thickness, and the first thickness is greater than the second thickness.