Pump with high torque driver

Abstract

A fluid moving apparatus (12) includes an electric motor (24) having a rotor (42) and a stator (44) and a fluid displacement member (34). The rotor (42) rotates relative to the stator (44) on a common axis (CA) to produce a rotational output. The rotational output is provided to the fluid displacement member (34) to power the fluid displacement member (34) to perform one of linearly moving along the common axis and rotating about the common axis. The stator (44) includes a plurality of coils (52) configured to power the rotation of the rotor (42). The plurality of coils (52) are arranged along the common axis (CA).

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 003,021, filed on March 31, 2020, entitled "Pump with High Torque Drive," the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to pump systems. More specifically, this disclosure relates to drives for fluid moving equipment (e.g., pump equipment) used in a variety of applications. Background Technology

[0004] Typically, the fluid being pumped is pressurized by a positive displacement pump. In coating applications, the pump pressurizes the paint and delivers it under pressure through a flexible hose. A spray gun is used to dispense the paint, and it is connected to the end of the hose opposite to the pump. Positive displacement pumps are typically mounted on a drive housing and driven by an electric motor. A pump rod is attached to a reciprocating drive that drives the pump rod to reciprocate, thereby drawing fluid from the container into the pump and then driving the fluid downstream from the pump. In some cases, an electric motor can power the pump. The electric motor is connected to the pump via a gear reduction system that increases the torque generated by the electric motor. Summary of the Invention

[0005] According to one aspect of this disclosure, a pumping device for pumping fluid includes: an electric motor configured to generate a rotary output; a driver configured to convert the rotary output from the electric motor into a linear reciprocating output; and a device configured to receive the linear reciprocating output from the driver to linearly reciprocate along a common axis to pump fluid. The electric motor includes: a rotor configured to rotate about the common axis, the rotor including a plurality of magnets, each magnet being elongated and extending parallel to the common axis, the plurality of magnets being arranged annularly around the common axis; and a stator configured to be energized to generate a magnetic flux that rotates the rotor. The stator includes a plurality of coils arranged along the common axis, each of the plurality of coils being coaxial with the common axis; and a plurality of circular spike arrays arranged along the common axis, each of the plurality of circular spike arrays including a plurality of spikes arranged in a circle coaxial with the common axis, all spikes of the plurality of circular spike arrays being configured to be simultaneously polarized by the coils of the plurality of coils to generate a magnetic flux, causing the rotor to rotate relative to the stator.

[0006] According to an additional or alternative aspect of the present disclosure, a pump apparatus includes: an electric motor including a stator and a rotor rotating coaxially about a common axis, the stator including a plurality of coils arranged along the common axis; a fluid displacement member configured to reciprocate linearly along the common axis to pump fluid; and a drive mechanism axially between the electric motor and the piston that converts a rotational output from the electric motor to a linear reciprocating output that drives the fluid displacement member. The drive mechanism is configured such that the electric motor turns a first number of complete revolutions, the fluid displacement member travels one inch, wherein the first number is in a range of 0.9-3.0 turns, inclusive.

[0007] According to another additional or alternative aspect of the present disclosure, a pump apparatus includes: an electric motor including a stator and a rotor rotating about a common axis, the stator including a plurality of coils arranged along the common axis; a fluid displacement member configured to reciprocate linearly along the common axis CA to pump fluid; and a drive mechanism between the electric motor and the piston that converts a rotational output of the electric motor to a linear reciprocating output that drives the piston. The drive mechanism is configured such that the electric motor turns an X number of complete revolutions, the fluid displacement member completes one pump stroke, wherein X is in a range of 1-3, inclusive.

[0008] According to yet another additional or alternative aspect of the present disclosure, a pump apparatus includes: an electric motor including a stator and a rotor rotating about a common axis, the stator including a plurality of coils arranged along the common axis, each coil surrounding and extending along and coaxial with the common axis; a cylindrical piston coaxial with the common axis, the piston configured to reciprocate linearly along the common axis to pump fluid; and a drive mechanism between the electric motor and the piston that converts a rotational output of the electric motor to a linear reciprocating output that drives the piston.

[0009] According to yet another additional or alternative aspect of the present disclosure, an apparatus for moving a liquid includes a motor configured to produce a rotational output and a fluid displacement member configured to be moved by the output of the motor to move the liquid. The motor includes a rotor configured to rotate about a common axis, the rotor including a plurality of magnets each elongated and extending parallel to the common axis, the plurality of magnets annularly arranged about the common axis, and a stator configured to be energized to produce a magnetic flux that rotates the rotor. The stator includes a plurality of coils arranged along the common axis, each of the plurality of coils coaxial with the common axis, a plurality of circular spur arrays arranged along the common axis, each of the plurality of circular spur arrays including a plurality of spurs arranged in a circle coaxial with the common axis, the plurality of circular spurs configured to be simultaneously polarized by a coil of the plurality of coils to produce the magnetic flux to rotate the rotor relative to the stator.

[0010] According to yet another additional or alternative aspect of the present disclosure, an apparatus for moving a liquid includes a motor configured to produce a rotational output and a fluid displacement member configured to be moved by the output of the motor to move the liquid. The motor includes a rotor configured to rotate about a common axis, the rotor including a plurality of magnets each elongated and extending parallel to the common axis, the plurality of magnets annularly arranged about the common axis, and a stator configured to be energized to produce a magnetic flux that rotates the rotor. The stator includes a plurality of coils arranged along the common axis, each of the plurality of coils coaxial with the common axis. A plurality of circular spur arrays are arranged along the common axis, each of the plurality of circular spur arrays including a plurality of spurs arranged in a circle coaxial with the common axis, the plurality of circular spurs configured to be simultaneously polarized by a coil of the plurality of coils to produce the magnetic flux to rotate the rotor relative to the stator. At least one spur of the stator is closer to the fluid displacement member than any one of the plurality of coils. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1A is a front view schematic block diagram of a pump apparatus.

[0012] Figure 1B is Figure 1A a side view schematic block diagram of the pump apparatus of

[0013] Figure 2 is a schematic block diagram of a pump apparatus.

[0014] Figure 3A is a perspective view of a pump assembly used in the pump system of Figure 1A and Figure 1B ​

[0015] Figure 3B is a perspective cut view taken along line B-B in Figure 3A

[0016] Figure 3C is a first front cut view taken along line B-B in Figure 3A

[0017] Figure 4A is a perspective view showing a portion of the electric motor in isolation.

[0018] Figure 4B is a perspective view of the stator of the electric motor shown in Figure 4A

[0019] Figure 5A is a perspective view of a phase assembly of the stator shown in Figure 4B

[0020] Figure 5B is a perspective view of the phase assembly shown in Figure 5A

[0021] Figure 6A is an enlarged cut view showing the current flow through the phase assembly.

[0022] Figure 6B is an enlarged cut view showing the current flow in opposition to that shown in Figure 6A

[0023] Figure 6C is an enlarged end view showing the magnetic polarity of components of the rotor portion of the electric motor.

[0024] Figure 7 is a schematic block diagram of a pump apparatus.

[0025] Figure 8 is a schematic block diagram of a pump apparatus.

[0026] Figure 9 is a schematic block diagram of a pump apparatus.

[0027] Figure 10 is a schematic block diagram of a pump apparatus.

[0028] Figure 11 is a schematic block diagram of a pump apparatus.

[0029] Figure 12A is a schematic block diagram of a prior art pump apparatus.

[0030] Figure 12B is an end view of a prior art electric motor. DETAILED DESCRIPTION

[0031] ​​​​​​The present disclosure relates to a pump apparatus having an electric motor rotating about a common axis and a pumping member reciprocating along the common axis. The electric motor and the pumping member are coaxial on the common axis. The electric motor includes a rotor rotating about the common axis and a stator energized to generate a magnetic flux that rotates the rotor. The stator includes one or more coils, each of which is coaxial with the common axis.

[0032] Figure 1A is a front view schematic diagram of the pump system 10. Figure 1B is a side view schematic diagram of the pump system 10. Together with Figure 1A and Figure 1B In this embodiment, the pump system 10 is set up as a spray system, for example, for spraying paint or other liquids, however, the pump system 10 can be set up for other pumping and fluid handling applications, for example, position transfer, loading and unloading, spraying, metering, coating, etc. The pump apparatus 12, support 14, spray gun 16, supply line 18, and reservoir 20 are shown. The pump apparatus 12 includes a pump frame 22, electric motor 24, drive 26, displacement pump 28, and controller 29. The support 14 includes a support frame 30 and wheels 32. A fluid displacement member 34 and pump body 36 of the displacement pump 28 are shown. The spray gun 16 includes a handle 38 and trigger 40.

[0033] The pump system 10 in this embodiment is a system for applying a spray of various fluids to a substrate, examples of which include paint, water, oil, stain, finish material, aggregate, covering material, and solvent, among other choices. The pump apparatus 12 can produce high fluid pumping pressures, for example, about 3.4-69 MegaPascals (MPa) (about 500-10,000 pounds per square inch (psi)) or even lower and / or higher. In some examples, the pumping pressure is in the range of about 20.7-34.5 MPa (about 2,000-4,000 psi). High fluid pumping pressures are useful for atomizing a fluid into a spray to apply the fluid to a surface. While the pump apparatus 12 is described with respect to a spray system version of the pump system 10, it should be understood that the pump apparatus 12 can be used for pumping in any desired system. For example, the pump apparatus 12 can be used as a delivery pump to deliver a fluid; can be used in a multi-component spray system, for example, to feed component fluids to a proportioning pump; in a proportioning pump; for loading and unloading; for metering; for coating, etc.

[0034] The pump apparatus 12 is configured to draw spray fluid from the reservoir 20 and pump the fluid downstream to the spray gun 16 for application onto a substrate. The support 14 is connected to the pump apparatus 12 and supports the pump apparatus 12 relative to the reservoir 20. The support frame 30 is connected to the pump frame 22. Wheels 32 are connected to the support frame 30 to facilitate movement between and within a worksite. While the pump apparatus 12 is described as being supported by the support 14, it should be understood that the pump apparatus 12 can be mounted to draw fluid in any desired manner. For example, the pump apparatus 12 can be mounted on a lid of the reservoir 20 such that the reservoir 20 supports the pump apparatus 12. The pump apparatus 12 can be mounted directly to the reservoir 20. For example, the reservoir can be a drum, such as a 55 gallon drum and other options, and the pump apparatus 12 can be mounted directly to the drum. In such examples, the pump apparatus 12 can be referred to as a drum pump.

[0035] The pump frame 22 supports other components of the pump apparatus 12. The motor 24 and the positive displacement pump 28 are connected to the pump frame 22. The motor 24 is an electric motor having a stator and a rotor. The rotor is configured to rotate about a rotational axis in response to current through the stator. The rotational axis is coaxial with the common axis CA of the illustration. The motor 24 produces a rotational output that is coaxial with the common axis CA.

[0036] The term “radial” or “radially” as used herein means orthogonal to the common axis CA, unless otherwise specified. The term “axial” or “axially” as used herein means parallel to the common axis CA, unless otherwise specified. The term “circumferential” or “circumferentially” as used herein means about the common axis CA, unless otherwise specified.

[0037] The controller 29 is operably connected to the motor 24, electrically and / or communicatively, to control operation of the motor 24. The controller 29 thereby controls pumping of the volumetric pump 28. The controller 29 can have any desired configuration for controlling pumping of the volumetric pump 28 and can include control circuitry and memory. The controller 29 is configured to store executable code, implement functions, and / or process instructions. The controller 29 is configured to perform any of the functions discussed herein, including receiving output from any of the sensors mentioned herein, detecting any of the conditions or events mentioned herein, and controlling operation of any of the components mentioned herein. The controller 29 can have any suitable configuration for controlling operation of the pump apparatus 12, collecting data, processing data, etc. The controller 29 can include hardware, firmware, and / or stored software. The controller 29 can be of any type suitable to operate in accordance with the techniques described herein. While the controller 29 is shown as a single unit, it can be appreciated that the controller 29 can be disposed, in whole or in part, on one or more circuit boards. In some examples, the controller 29 can be implemented as a plurality of discrete circuit subassemblies.

[0038] The drive 26 is connected to the motor 24 to be driven by the motor 24. The drive 26 receives a rotational output from the motor 24 and converts the rotational output from the motor 24 to a linear input along the common axis CA. The drive 26 is connected (directly or indirectly) to the fluid displacement member 34 to drive the fluid displacement member 34 to reciprocate along the common axis CA. In some examples, the motor 24, the drive 26, and the fluid displacement member 34 are coaxially disposed on the common axis CA. As such, a rotational axis of the motor 24 and a reciprocation axis of the fluid displacement member 34 are coaxial. The fluid displacement member 34 reciprocates within the pump body 36 to pump the spray fluid from the reservoir 20 through the supply line 18 to the spray gun 16. The fluid displacement member 34 can be cylindrical, elongated along the common axis CA, and coaxial with the common axis CA. In some examples, the fluid displacement member 34 can be a piston, which can be elongated along the common axis CA and coaxial with the common axis CA. In some examples, the fluid displacement member 34 can be a diaphragm, in which a central line linearly reciprocates while a circular outer periphery of the diaphragm remains in place. The diaphragm can be coaxial with the common axis CA such that a center of the diaphragm is on and linearly reciprocates along the common axis CA.

[0039] During operation, a user can maneuver the pump apparatus 12 into a desired position relative to a target substrate, or other pumping application, by moving the support 14. For example, a user can maneuver the pump apparatus 12 by tilting the support frame 30 on the wheels 32 and rolling the pump apparatus 12 to the desired position. The pump apparatus 12 can be hand-held, meaning that a person can move the pump apparatus 12 with a hand onto and around a work site. In some embodiments, the pump apparatus 12 is light enough that it can be picked up (e.g., less than about 31.8 kilograms (kg) (less than about 70 pounds (lbs.)) and carried. In some cases, the pump apparatus 12 is wheeled to allow transport, as described above. In some cases, the pump apparatus 12 can weigh less than about 45.4 kg (about 100 lbs.), or in some cases can weigh less than about 68.0 kg (about 150 lbs.), or in some cases can weigh less than about 90.7 kg (about 200 lbs.).

[0040] The positive displacement pump 28 can extend into the reservoir 20. The motor 24 provides a rotational input to the driver 26, and the driver 26 provides a linear input to the fluid displacement member 34 to cause reciprocating motion of the fluid displacement member 34. A rotor of the motor 24 rotates on a common axis CA to produce a rotational output. The rotational output from the motor 24 is provided as a rotational input to the driver 26, which converts the rotational input from the motor 24 to a linear output, which is provided as a linear input to the fluid displacement member 34. The linear input to the fluid displacement member 34 from the driver 26 causes linear displacement of the fluid displacement member 34 on the common axis CA. The fluid displacement member 34 draws fluid from the reservoir 20, pressurizes the fluid, and drives the fluid downstream through the supply line 18 to the spray gun 16. A user can maneuver the spray gun 16 by, for example, grasping the handle 38 with a single hand of the user. The user causes spraying by actuating the trigger 40. In some examples, the pressure generated by the pump apparatus 12 atomizes the fluid exiting the spray gun 16 to produce a fluid spray. In some examples, the spray gun 16 is a gasless sprayer, meaning that pressure generated by the pump apparatus 12 acts alone on the fluid and pushes and atomizes the fluid into a spray, without a gas flow used to push and atomize the fluid into a spray.

[0041] Figure 2 is a schematic block diagram of the pump apparatus 12. The pump apparatus 12 includes the motor 24, the driver 26, and the positive displacement pump 28. It shows a rotor 42 and a stator 44 of the motor 24. The rotor 42 includes an array of permanent magnets 46 and a rotor body 48. The stator 44 includes phase assemblies 50, each of which includes a coil 52. The driver 26 includes a drive nut 54 and a screw 56. The positive displacement pump 28 includes the pump body 36, the fluid displacement member 34, and check valves 58a, 58b.

[0042] The motor 24 is an electric motor. The rotor 42 is configured to rotate relative to the stator 44 and on the rotational axis AR. The stator 44 is disposed coaxially with the rotor 42 on the rotational axis AR. The rotational axis AR is coaxial with the common axis CA. The rotor 42 includes an array of permanent magnets 46 oriented toward the stator 44. In the illustrated example, the rotor 42 is disposed around the stator 44 and the array of permanent magnets 46 is disposed on a radially inner side of a rotor body 48. An air gap 60 is formed between the stator 44 and the rotor 42 such that the stator 44 and the rotor 42 do not directly contact. More specifically, the air gap is formed radially between the stator 44 and the array of permanent magnets 46. Thus, the electric motor 24 can be considered to include an external rotor. However, it should be appreciated that in various other examples, the rotor 42 is disposed within the stator 44 to rotate within the stator 44 such that the electric motor 24 can be considered to include an internal rotor. In such examples, the array of permanent magnets 46 can be disposed on an outer radial surface of the rotor body 48.

[0043] The stator 44 includes phase assemblies 50 arranged along and around the rotational axis AR. Each phase assembly 50 includes a coil 52 extending circumferentially about the common axis CA. The phase assembly 50 includes a metal component formed on each axial side of the coil 52 of the phase assembly 50. The metal component can be formed in whole or in part from a stack of laminations. The laminations can be formed from a material that is very susceptible to being polarized by a field generated by the coil 52. Such a material is typically ferromagnetic. The ferromagnetic material can be a metal, such as iron or an iron alloy, such as steel. More specifically, the laminations can be made of silicon steel, among other options. The ferromagnetic material can be a ceramic doped or embedded with a ferromagnetic element.

[0044] The coil 52 is formed as a wire wrap extending circumferentially about the common axis CA. Thus, the coil 52 is coaxial with the common axis CA. Each coil 52 is discrete relative to the other coils 52. Each coil 52 is a winding of wire, typically copper, about the common axis CA. Thus, each coil 52 can be a continuous winding of 20, 30, 40, 50, 100, or fewer or more turns about the common axis CA. In some embodiments, a ribbon is wrapped instead of wire. Each coil 52 has two terminal wires representing circuit ends of each coil 52 for running an AC signal through the coil 52, which can be electrically connected with the controller 29 Figure 1A and Figure 1B .

[0045] The coils 52 do not overlap or cross each other in the radial direction. No portion of any one coil 52 is disposed at the same axial location along the common axis CA as any other coil 52. Thus, no coil 52 overlaps any other coil 52 in the radial direction. There is an axial gap between each coil 52 of the motor 24. Thus, the coils 52 are at separate and distinct axial locations along the common axis CA. Each coil 52 is made of a circular coil. The common axis CA extends through each loop of each coil 52. The coils 52 do not include loops through which the common axis CA does not extend. The wires of the loops do not extend axially, but rather circumferentially around the common axis CA.

[0046] The volumetric pump 28 is disposed at an axial end of the pump apparatus 12 opposite the motor 24. The fluid displacement member 34, such as a piston or diaphragm among other options, is configured to reciprocate on a reciprocation axis RA. The reciprocation axis RA is coaxial with the common axis CA. The reciprocation axis RA is also coaxial with the rotation axis AR. The fluid displacement member 34 reciprocates within a pump body 36 to pump fluid. Both the pump body 36 and the fluid displacement member 34 can be coaxial with the common axis CA. In some examples, the pump body 36 is a cylinder. For example, the pump body 36 can be a cylinder, the fluid displacement member 34 can be a piston elongated axially along the reciprocation axis RA, both disposed coaxially on the common axis CA with the rotor 42 and the stator 44.

[0047] The drive 26 extends between and connects the motor 24 and the fluid displacement member 34. In the illustrated example, the drive 26 includes a screw 56 and a drive nut 54. The elongated screw 56 is coaxial with the common axis CA, and thus the reciprocation axis RA and the rotation axis AR. Depending on the mechanical design of the pump apparatus 12, the elongated screw 56 can be one of either rotating on the common axis CA without linear reciprocation, or reciprocating linearly along the common axis CA without rotation. The drive nut 54 is coaxial with the common axis CA, and thus the reciprocation axis RA and the rotation axis AR. The drive nut 54 can be one of either rotating on the common axis CA in embodiments in which the screw 56 reciprocates linearly, or reciprocating along the common axis CA in embodiments in which the screw 56 rotates on the common axis CA without linear reciprocation.

[0048] The rotating component of driver 26 (e.g., the first of drive nut 54 and screw 56) is connected to rotor 42 to receive rotational output from motor 24. The reciprocating component of driver 26 (e.g., the other of drive nut 54 and screw 56) is connected to fluid displacement member 34 to provide linear input to fluid displacement member 34 to drive axial reciprocation of fluid displacement member 34.

[0049] While at least a portion of driver 26 is disposed axially between motor 24 and volumetric pump 28, it should be appreciated that one or more components of driver 26 can radially overlap one or more components of motor 24. Components can be considered to radially overlap when they are arranged at a common axial location along common axis CA. A radial line extending from common axis CA would extend through each radially overlapping component. For example, drive nut 54 can be radially inward of rotor 42 (particularly in embodiments where rotor 42 is located within stator 44 and rotates within stator 44) to linearly drive screw 56. In some examples, screw 56 is at least partially disposed within a hollow core of motor 24 (the hollow core extending through rotor 42 and coaxial with rotor 42 and common axis CA). In some examples, the amount of overlap between linear displacement elements of motor 24 and driver 26 can vary during operation. For example, the axial ends of screw 56 can be disposed within motor 24 and moved axially relative to motor 24 along common axis CA such that the amount of overlap increases and decreases. Thus, at least a portion of the reciprocation region of the reciprocating component (i.e., the region along common axis between the distal ends of the linear travel range of the reciprocating component) can be both coaxial with and co-located with at least a portion of the rotor region of the rotational axis (i.e., the region along the rotational axis where rotor 42 is located).

[0050] During operation, power is provided to coils 52 and phase assemblies 50 generate electromagnetic fields that interact with permanent magnet array 46 to drive rotor 42 to rotate. The illustrated embodiment of motor 24 includes three phases, which correspond to three phase assemblies 50 and coils 52 therein, with three sinusoidal AC signals (offset by 120 degrees electrically) passed through coils 52. If there are two phase assemblies 50 and two coils 52, then two sinusoidal AC signals would be 180 degrees apart, or 90 degrees apart for a set of four phase assemblies 50, etc.

[0051] The rotor 42 rotates about the common axis CA and produces a rotational output. The rotational output is provided to the driver 26, which converts the rotational motion to linear motion along the common axis CA. The linear output produced by the driver 26 is provided to the fluid displacement member 34 to linearly displace the fluid displacement member 34 on the common axis CA. In some examples, the motor 24 is a reversible motor such that the rotor 42 is driven in a first rotational direction (e.g., one of the clockwise and counterclockwise directions) to move the fluid displacement member 34 in a first axial direction AD1 and the rotor 42 is driven in a second rotational direction (e.g., the other of the clockwise and counterclockwise directions) to move the fluid displacement member 34 in a second axial direction AD2.

[0052] In the illustrated example, the positive displacement pump 28 is a double- displacement pump configured to output fluid when the fluid displacement member 34 is driven in the first axial direction AD1 and when the fluid displacement member 34 is driven in the second axial direction AD2. In the illustrated example, the fluid displacement member 34 is a piston and a check valve 58b is mounted to the piston to axially travel with the piston. As the fluid displacement member 34 moves in the second axial direction AD2, the check valve 58a opens and the check valve 58b closes. Fluid is drawn through the check valve 58a into an upstream chamber of the pump body 36 that is axially disposed between the check valve 58a and the check valve 58b. Fluid in a downstream chamber located on an axial side of the check valve 58b opposite the upstream chamber is driven downstream from the positive displacement pump 28. As the fluid displacement member 34 moves in the first axial direction AD1, the check valve 58a closes and the check valve 58b opens. The closed check valve 58a prevents backflow out of the upstream chamber. Fluid is driven from the upstream chamber, through the check valve 58b, and into the downstream chamber. Fluid is also driven out of the downstream chamber downstream from the positive displacement pump 28. Thus, the positive displacement pump 28 can output fluid during each stroke of the fluid displacement member 34.

[0053] Conventional AC induction motors use a plurality of discrete coils that extend axially and form an array of coils that extend circumferentially around a rotational axis of the rotor (see Figure 10 A- Figure 10 B). Each coil represents a potential pole that acts on a magnet. In conventional AC induction motors, the discrete coils arranged circumferentially around the rotational axis are out of phase with each other. The resulting potential torque is proportional to the number of poles. The number of poles in such motors is limited by the ability to install discrete coils circumferentially around the rotational axis within the motor.

[0054] The coil 52 extending circumferentially all the way around the common axis CA allows for more magnetic poles than a traditional AC induction motor, and more magnetic poles allow for the force to be produced more evenly distributed around the circumference of the rotor 42 to minimize or eliminate non-productive portions of the eccentric force. Co-locating the rotational axis AR of the rotor 42 with the reciprocating motion axis RA of the displacement member 34 on the common axis CA further minimizes the eccentric force. The high pole count eliminates or reduces the need for reduction gearing, further reducing the eccentric force as well as weight and friction, allowing for a more compact arrangement of the pump apparatus 12. The design of the present motor 24 is advantageous for high torque (which produces high fluid pressure) even at low pumping speeds, with little or no reduction gearing, again reducing cost, weight, friction, and package size. Co-axializing (e.g., along the common axis CA) the rotational axes of the rotor 42, the elongated screw 56, and the displacement member 34 relative to one another allows for a compact and efficient pump design.

[0055] There is no mechanical amplification (mechanically reducing speed to increase torque) between the rotational output of the motor 24 and the linear reciprocating input to the piston pump 28. While the motor 24 can produce high torque at low speeds (unlike a traditional AC induction motor), the present motor 24 can also produce high torque at high speeds. Thus, a single pump apparatus 12 can achieve many performance points (e.g., pressure versus volume pumped) within one performance range that would otherwise require several different models of conventional motor-driven pumps, each with a specific gear reduction ratio specific to a sub-portion of the same performance range. The pump apparatus 12 thereby provides a wide range of possible operating conditions that would require multiple conventional pumps (each with a different driver) to achieve the same range.

[0056] Figure 3A is a perspective view of the pump apparatus 12. Figure 3B is a perspective view of the pump apparatus 12 taken along line B-B in Figure 3A is a perspective cross-sectional view of the pump apparatus 12 taken along line B-B in Figure 3C is a perspective view of the pump apparatus 12 taken along line B-B in Figure 3A is an elevation cross-sectional view taken along line B-B in Figures 3A-3C will be discussed together. The pump frame 22, the motor 24, the driver 26, the displacement pump 28, the rotor shaft 62, the bearing assembly 64, the sensor 66, the pump shaft 68, and the timing member 70 are shown. The pump frame 22 includes a main body 72, a connector 74, and a frame end 76. The main body 72 includes a first portion 78, a second portion 80, a third portion 82, a mounting flange 84, a post 86, and a side opening 88. The frame end 76 includes a radial protrusion 90.

[0057] The motor 24 includes a rotor 42, a stator 44, motor bearings 92, an axle 94, a first motor end 96, a second motor end 98, and a power connector 100. The rotor 42 includes a rotor body 48 and an array of permanent magnets 46. The internal details of the stator 44 and the rotor 42 will be discussed further herein. The axle 94 includes an outer end 102.

[0058] The driver 26 includes a drive nut 54, a screw rod 56, and a rolling element 104 Figure 2 B). The drive nut 54 includes a nut mounting protrusion 106, a nut shoulder 108, and an axial extension 110. The screw rod 56 includes a first screw rod end 112, a second screw rod end 114, a thread 116, and a bore 118. The rotor axle 62 includes a first axle end 120 and a second axle end 122.

[0059] The positive displacement pump 28 includes the fluid displacement member 34, the pump body 36, and the check valves 58a, 58b. The fluid displacement member 34 includes the connector 108. The sensor 66 includes a first transducer component 126 and a second transducer component 128.

[0060] The motor 24 is disposed at a first axial end of the pump apparatus 12, and the positive displacement pump 38 is disposed at a second axial end of the pump apparatus 12. The pump frame 22 supports other components of the pump apparatus 12. The motor 24 is disposed axially between the frame end 76 and the body 72. The motor 24 is an electric motor 24. The stator 44 includes the coil 52 (as shown in Figure 2 and 4A - Figure 9 The rotor 42 includes the array of permanent magnets 46. The stator 44 and the rotor 42 are coaxially disposed on a common axis CA. The rotor 42 is configured to rotate about the common axis CA in response to an electric current through the stator 44. The motor 24 is a reversible motor because the stator 44 can cause the rotor 42 to rotate alternately in two rotational directions (e.g., clockwise or counterclockwise) about the common axis CA to cause the fluid displacement member 34 to linearly travel in a forward or backward direction alternately along the common axis CA (e.g., in the axial direction AD1 and the axial direction AD2). For example, the rotor 42 can rotate in one of the clockwise and counterclockwise directions to drive the fluid displacement member 34 to make a downstroke in the axial direction AD1 and away from the motor 24, and then the rotor 42 can rotate in the other of the clockwise and counterclockwise directions to pull the fluid displacement member 34 toward the motor 24 by making an upstroke in the second axial direction AD2.

[0061] In the example shown, rotor 42 is arranged around stator 44 such that motor 24 includes an outer rotor. In various other embodiments, rotor 42 is arranged within stator 44 such that motor 24 includes an inner rotor, which still conforms to the principles of this disclosure. Permanent magnet array 46 faces stator 44 and is spaced from stator 44 by air gap 60 (preferably in...). Figure 2 (See shown in the image). In the example shown, the permanent magnet array 46 is disposed on the inner circumferential surface of the rotor body 48 because the rotor 42 is the outer rotor. The permanent magnet array 46 is arranged circumferentially around a common axis CA. The permanent magnet array 46 forms a ring array coaxially disposed on the common axis CA with the rotor 42 and the stator 44. The rotor body 48 can be formed from a single component or from multiple components fixed together.

[0062] The stator 44 is fixed to the shaft 94. The shaft 94 extends along and is coaxially arranged with the common axis CA. The outer end portion 102 of the shaft 94 extends beyond the axial end of the stator 44 in a second axial direction AD2. The outer end portion 102 of the shaft 94 extends beyond the axial end of the rotor 42 in the second axial direction AD2. The outer end portion 102 axially protrudes beyond the second motor end 98. The outer end portion 102 of the shaft 94 is open, thereby providing power to the motor 24 through the second motor end 98. In the example shown, the power connector 100 may be an electrical plug configured to connect to a socket (e.g., a wall socket), which is connected to the stator 44 by a cable extending through the opening in the outer end portion 102 and connected to the coil 52 of the stator 44. Thus, the motor 24 can receive power through the second motor end 98 and provide rotational output through the first motor end 96. The motor bearing 92 supports the rotor 42 relative to the stator 44. The motor bearing 92 facilitates the rotation of the rotor 42 relative to the stator 44. Shaft 94 extends through motor bearing 92 located at the second motor end 98 of motor 24, such that motor bearing 92 is located at the second motor end 98 between rotor body 48 and shaft 94.

[0063] The pump frame 22 supports the motor 24. The body 72 extends in the axial direction AD1 relative to the motor 24. In the example shown, the body 72 is axially spaced apart from the first motor end 96. The body 72 is spaced apart from the first motor end 96 in the first axial direction AD1. The body 72 is disposed coaxially with the common axis CA. As such, the body 72 is disposed coaxially with the motor 24 and the fluid displacement member 34 on the common axis CA. The body 72 includes a first portion 78 axially nearest the motor 24, a second portion 80 connected to and extending from the first portion 78 in the first axial direction AD1, and a third portion 82 connected to and extending from the second portion 80 in the first axial direction AD1. While the body 72 is shown as being formed from three portions, it should be understood that the body 72 can be formed from as many or as few portions as desired. In the example shown, the width of each portion of the body 72 that is orthogonal to the common axis CA decreases as the body 72 extends away from the motor 24 and toward the positive displacement pump 28. In the example shown, the width of the first portion 78 is greater than the width of the second portion 80. The width of the second portion 80 is greater than the width of the third portion 82, and the width of the third portion 82 is greater than the width of the pump body 36. The post portions 86 and the side openings 88 are formed in an end of the third portion 82 opposite the second portion 80. The side openings 88 are formed between the post portions 86. The side openings 88 provide access to the connection between the fluid displacement member 34 and the pump shaft 68 to facilitate installation and removal of the positive displacement pump 28.

[0064] The body 72 formed from multiple portions facilitates efficient assembly and service of the pump apparatus 12. The body 72 can be disassembled to provide access to various components of the pump apparatus 12, including dynamic, moving components. For example, the second portion 80 can be removed from the first portion 78 to facilitate lubrication of the driver 26. It should be understood that, in some examples, the driver 26 can be accessed and serviced without disassembling the body 72. The bumper 130b is disposed in the third frame body 62 on a side of the pump shaft 68 opposite the drive nut 54. The bumper 130b can be compressible and can interface with the pump shaft 68 in the event of overtravel.

[0065] The frame end 56 is disposed on an axial side of the motor 24 opposite the body 72. The frame end 76 is disposed proximate the second motor end 98. The frame end 76 is fixed to the outer end 102 of the shaft 94. With the connection of the shaft 94 and the frame end 76, the motor 24 is statically connected to the pump frame 22. The pump frame 22 fixes the motor 24 in an axial position along the common axis CA and prevents movement of the stator 44 relative to the common axis CA with the connection of the pump frame 22 and the shaft 94.

[0066] The connector 74 extends between the body 72 and the frame end 76 and secures the body 72 and the frame end 76 together to prevent relative motion between the frame end 76 and the body 72. In the example shown, the connector 74 is secured to the radial protrusion 90 of the frame end 76 and is connected to the mounting flange 84 of the body 72. The connector 74 secures the body 72 and the frame end 76 together to prevent unwanted relative motion between these components and unwanted motion of these components relative to the common axis CA. While the pump frame 22 is described as being formed from multiple components, it should be appreciated that the pump frame 22 functions as a single component to support the motor 24 and the positive displacement pump 28 and to react loads experienced during pumping, as discussed in more detail below. The pump frame 22 can be formed from as many or as few individual components as desired.

[0067] The connector 74 is radially spaced from the rotor 42 and extends axially between the frame end 76 and the body 72. The rotor 42 rotates within an area defined by the connector 74, the body 72, and the frame end 76. While the connector 74 is shown as being formed from multiple connecting members that are spaced circumferentially around the rotor 42, it should be appreciated that in some examples the connector 74 can completely enclose the rotor 42. For example, one or more connectors 74 can form a housing in which the rotor 42 rotates. In the example shown, the connecting members 74 include a plurality of tie rods that extend between and connect the frame end 76 and the body 72.

[0068] The rotor 42 and the rotor shaft 62 serve as a rotational output component of the motor 24 that the drive 26 provides power to. The rotor shaft 62 is fixed to the rotor 42 to rotate with the rotor 42. The rotor shaft 62 rotates on the rotational axis of the rotor 42 and thus on the common axis CA. The rotor shaft 62 extends to the interior of the body 72 such that at least a portion of the rotor shaft 62 radially overlaps at least a portion of the body 72. In some examples, the rotor shaft 62 can be removably connected to the rotor 42, for example, by fasteners. It should be appreciated that in other examples, the rotor shaft 62 can be integrally formed with the rotor body 48. The rotor shaft 62 extends axially from the rotor 42 along the common axis CA and along the first axial direction AD1. The rotor shaft 62 is elongate along an axis that is coaxial with the common axis CA. The rotor shaft 62 is coaxially disposed with the stator 44, the rotor 42, the drive 26, and the fluid displacement member 34. In the illustrated example, the rotor shaft 62 includes an open first axial end 102 and a closed second axial end 104. The closed end is disposed at the interface between the rotor shaft 62 and the rotor 42. A bumper 130a is disposed in the rotor shaft 62 at the closed end of the rotor shaft 62. The bumper 130a can be compressible and can engage the second screw end 114 in the event of over travel to prevent damage to the screw 56.

[0069] The bearing assembly 64 is radially disposed between the rotor shaft 62 and the pump frame 22. More specifically, the bearing assembly 64 is radially disposed between the rotor shaft 62 and the body 72. The bearing assembly 64 is axially disposed between the drive nut 54 and the motor 24. The bearing assembly 64 supports the motor 24 relative to the pump frame 22 and facilitates rotation of the rotor shaft 62 relative to the pump frame 22. As such, the bearing assembly 64 forms a dynamic connection between the motor 24 and the pump frame 22. The bearing assembly 64 is configured to support rotational and axial loads generated during pumping. The bearing assembly 64 supports axial loads to isolate the motor 24 from axial loads generated by the positive displacement pump 28. The bearing assembly 64 can be referred to as a thrust bearing.

[0070] The bearing assembly 64 can have any configuration suitable to support axial loads generated during pumping. In some examples, the bearing assembly 64 can include a single bearing element configured to support axial loads in each of the first axial direction AD1 and the second axial direction AD2, such as a double row angular contact bearing, among others. In some examples, the bearing assembly 64 can be formed from multiple bearing elements to support axial loads in each of the first axial direction AD1 and the second axial direction AD2. For example, the bearing assembly 64 can be formed from a first tapered roller bearing configured to support axial loads in the first axial direction AD1 and a second tapered roller bearing configured to support axial loads in the second axial direction AD2.

[0071] The driver 26 is coaxial with the common axis CA and operably connected to the rotor shaft 62. The driver 26 is disposed at an axial end of the rotor shaft 62 opposite the rotor 42. The driver 26 receives rotational output from the rotor 42 through the rotor shaft 62. The driver 26 is supported by the pump frame 22 through a bearing assembly 64. The driver 26 is axially located directly between the motor 24 and the positive displacement pump 28.

[0072] The drive nut 54 of the driver 26 is connected to the rotor shaft 62 for driving by the rotor shaft 62 for rotation on the common axis CA. The drive nut 54 can be attached to the rotor shaft 62 by fasteners such as bolts, adhesives, or press fits, among other options. In the example shown, a nut mounting protrusion 106 facilitates mounting the drive nut 54 onto the rotor shaft 62. Fasteners can extend into the rotor shaft 62 through the nut mounting protrusion 106. A first axial end 120 engages a nut shoulder 108 formed on the drive nut 54. The nut shoulder 108 is formed between the nut mounting protrusion 106 and an axial extension 110 that extends into and radially overlaps the rotor shaft 62. The screw 56 is disposed radially within the drive nut 54. The screw 56 and the drive nut 54 are disposed coaxially with the common axis CA.

[0073] The rolling elements 104 are disposed between the screw 56 and the drive nut 54 and support the screw 56 relative to the drive nut 54. The rolling elements 104 are aligned about and along an axis that is coaxial with the common axis CA. The rolling elements 104 circumferentially define a receiving area within which a portion of the screw 56 is disposed throughout operation. The screw 56 extends axially out of both ends of the receiving area. The receiving area can be cylindrical and coaxial with the common axis CA as well as the axis of reciprocation of the fluid displacement member 34 and the axis of rotation of the rotor 42. The rolling elements 104 support the screw 56 within the drive nut 54 such that a radial gap 132 is formed between the screw 56 and the drive nut 54 and is maintained by the rolling elements 104 rolling therebetween. Maintaining the gap 132 prevents the screw 56 and the drive nut 54 from directly contacting one another. The rolling elements 104 engage the threads 116 of the screw 56 to exert an axial driving force on the screw 56 to axially translate the screw 56 along the common axis CA. The rolling elements 104 can have any suitable configuration for supporting the drive nut 54 relative to the screw 56 and driving the screw 56 linearly due to rotation of the drive nut 54. For example, the rolling elements 104 can be balls or axially elongated rollers. The balls can engage threads of the nut 54 and the threads 116. The axially elongated rollers can include threaded shafts that engage the threads 116 to drive the screw 56. The rolling elements 104 are circumferentially aligned about the common axis CA.

[0074] In the illustrated example, the screw 56 is configured to reciprocate along the common axis CA during operation. Rotation of the drive nut 54 causes the rolling element 104 to exert an axial drive force on the screw 56 to linearly drive the screw 56 along the common axis CA. The screw 56 provides a linear output from the driver 26 to the displacement pump 28. While the screw 56 is described as reciprocating along the common axis CA, it should be understood that in some examples the screw 56 is configured to rotate on the common axis CA to drive displacement of the linear fluid displacement member 34. For example, a nut can be connected to the screw 56 to linearly displace along the screw 56 due to rotation of the screw 56. In such examples, the screw 56 can be directly connected to or formed as part of the rotor shaft 62. Further, while the screw 56 is shown external to the motor 24 in the present embodiment, in some embodiments the screw 56 can translate into the motor 24. For example, the drive nut 54 and rolling element 104 can be radially internal to the rotor 42 (particularly in embodiments where the rotor 42 resides within and rotates within the stator 44) to drive the screw 56 to extend through a hollow core of the motor 24 (the hollow core extending through and coaxial with the rotor 42 and the common axis CA). In another embodiment, while the drive nut 54 and rolling element 104 do not radially overlap the rotor 42, the screw 56 extends into the hollow core of the motor 24 (e.g., the end of the screw is retracted into, and translates through, and is within the hollow core of the motor 24). Thus, in some examples, the linear displacement element of the driver 26 (e.g., the screw 56) radially overlaps the motor 24 during at least a portion of the pump cycle, while the rotational component of the driver (e.g., the nut 54) does not radially overlap the motor 24. In each case, the hollow core and the screw 56 are coaxial with the common axis CA.

[0075] The pump shaft 68 is connected to the screw 56 and the fluid displacement member 34. The pump shaft 68 is disposed coaxially with the motor 24 and the fluid displacement member 34 on the common axis CA. The pump shaft 68 is disposed coaxially with the screw 56, the driver 54, and the rotor shaft 62 on the common axis CA. The pump shaft 68 is connected to the screw 56 to reciprocate along the common axis CA. In the illustrated example, the pump shaft 68 reciprocates with the screw 56. It should be understood that in examples where the screw 56 rotates rather than reciprocates, the pump shaft 68 can be connected to the screw 56 to reciprocate along the screw 56.

[0076] The pump shaft 68 is connected to the fluid displacement member 34 to drive the reciprocating motion of the fluid displacement member 34. Thus, the screw 56 and the pump shaft 68 can be considered to form a linear displacement element of the driver 26. The pump shaft 68 extends into the bore 118 within the screw 56. The pump shaft 68 can be connected to the screw 56 in any desired manner, such as by interface threads, a pin, a press fit, an adhesive, or a spring lock, among other options. While the pump shaft 68 and the screw 56 are described as being formed separately, it will be appreciated that the screw 56 and the pump shaft 68 can be formed as a single component. In some examples, the fluid displacement member 34 can be directly connected to the screw 56 and the timing member 70 can also be mounted to the screw 56.

[0077] The timing member 70 is disposed on and supported by the pump shaft 68. The pump shaft 68 and the timing member 70 can be considered to form a timing assembly to prevent the linear displacement element of the driver 26 from rotating about the common axis CA. In the illustrated example, the timing assembly prevents the screw 56 from rotating to cause the screw 56 to instead displace linearly. The pump shaft 68 forms a support for the timing assembly, as the pump shaft 68 supports the timing member 70. The timing member 70 reciprocates with the screw 56 and the pump shaft 68. The timing member 70 is timed and engaged with the body 72, thereby preventing the timing assembly from rotating about the common axis CA. For example, a protrusion formed on one of the timing member 70 and the body 72 can be engaged with a groove formed on the other of the timing member 70 and the body 72. In this way, the timing member 70 prevents the screw 56 from rotating about the common axis CA, thereby facilitating translation of the screw 56 along the common axis CA. In some examples, an outer surface of the timing member 70 is closely fitted with the body 72 to provide a sliding seal at the interface between the timing member 70 and the body 72. The sliding seal interface prevents dust and other contaminants from migrating through the body 72 in examples in which the screw 56 rotates about the common axis CA. The timing member 70 can be associated with a nut that is configured to translate along the screw 56 to prevent the nut from rotating about the common axis CA, in some examples.

[0078] The sensor 66 is configured to sense the end of a pump stroke in the first axial direction AD1 and / or the linear and / or rotational position of the moving element of the pump apparatus 12. The first transducer component 126 can be mounted in a bore of the pump frame 22 and the second transducer component 128 can be mounted in a bore of the pump shaft 68, among other options. The sensor 66 can generate data based on the position of the linear and / or rotational displacement element and provide the data to the controller 29 of the motor 24. In the illustrated example, the sensor 66 is configured to generate a date indicating when the linear displacement element is at the downstroke end, which can be associated with a home position. In some examples, the motor 24 is homed upon power up. For example, the rotor 42 can be driven in a first rotational direction associated with the downstroke until the first transducer component 126 senses the second transducer component 128, indicating the end of the downstroke. The rotor 42 can then be controlled to rotate a set number of revolutions associated with the stroke to cause a subsequent upstroke and downstroke. In some examples, the motor 24 is re-homed during operation to prevent creep, for example, after a predetermined number of pump cycles or pump strokes. In some examples, a sensor can be integrated into the motor 24 to sense the angular position of the rotor 42 for control and signal timing purposes. For example, a second sensor associated with the motor 24 can generate data regarding the rotation of the rotor 42 and provide the data to the controller 29. The first and second transducer components 126, 128 can have any desired configuration. For example, one of the first and second transducer components 126, 128 can be a magnet and the other of the first and second transducer components 126, 128 can be a reed switch sensitive to a magnetic field generated by the magnet. The magnet component can be mounted to either of the pump frame 22 and the pump shaft 68 and the magnetic field sensor can be mounted to the other component.

[0079] The positive displacement pump 28 is mounted on the pump frame 22 and disposed on the common axis CA. More specifically, the pump body 36 is mounted on an end of the pump frame 22 opposite the motor 24. The pump body 36 is fixedly mounted on the pump frame 22. The pump body 36 is fixed to the pump frame 22 such that the pump body 36 remains stationary during operation and does not move relative to the common axis CA. The pump body 36 can be cylindrical about an axis coaxial with the common axis CA. As such, the pump body 36 can be elongated along an axis coaxial with the axis of rotation of the rotor 42.

[0080] The fluid displacement member 34 is at least partially disposed within the pump body 36. In the example shown, the fluid displacement member 34 is elongated along an axis that is coaxial with the common axis CA. In the example shown, the fluid displacement member 34 is a piston configured to pump fluid by reciprocating motion along the common axis CA. However, it should be understood that the fluid displacement member 34 can have any desired configuration suitable for pumping while being disposed coaxially with the common axis CA. For example, the fluid displacement member 34 can be a diaphragm having a center that is disposed and configured to reciprocate along the common axis CA. While the fluid displacement member 34 is described as reciprocating along the common axis CA in this example, it should be understood that some examples of the fluid displacement member 34 can rotate on the common axis CA without reciprocating.

[0081] The fluid displacement member 34 is axially elongated between a first end 134 and a second end 136. The first end 134 of the fluid displacement member 34 is connected to the linear displacement drive element of the pump apparatus 12. In the example shown, the first end 134 of the fluid displacement member 34 is directly connected to the axial end of the pump shaft 68 opposite the screw 56. In the example shown, the first end 134 of the fluid displacement member 34 extends into the pump shaft 68. The first end 134 is fixed to the pump shaft 68 such that the fluid displacement member 34 reciprocates with the screw 56 and the pump shaft 68 along the common axis CA. The first end 134 and the pump shaft 68 can be connected in any desired manner. For example, a pin can extend through the first axial end 134 and through the pump shaft 68 to fix the fluid displacement member 34 to the pump shaft 68. While the fluid displacement member 34 is described as being directly connected to the pump shaft 68, it should be understood that the fluid displacement member 34 can be directly connected to other linear displacement elements of the drive 26. In some examples, the fluid displacement element 34 can be directly connected to the screw 56.

[0082] The displacement pump 28 is statically connected to the pump frame 22 through the connection between the pump body 36 and the main body 72. The static connection holds the pump body 36 in a set position along the common axis CA. The static connection prevents movement of the pump body 36 relative to the common axis CA. For example, the static connection prevents linear motion along the common axis CA or rotational motion about the common axis CA. The displacement pump 28 is dynamically connected to the motor 24 through the connection between the fluid displacement member 34 and the drive 26. The dynamic connection causes movement of the fluid displacement member 34 relative to the common axis CA. For example, the dynamic connection causes linear motion along the common axis CA or rotational motion about the common axis CA, depending on the configuration of the displacement pump 28.

[0083] Check valve 58a is a one-way valve supported by pump body 36. Check valve 58b is a one-way valve disposed in fluid displacement member 34 so as to reciprocate with fluid displacement member 34. In the illustrated example, check valve 58b is disposed at second axial end 136 of fluid displacement member 34. Second volume pump 28 can be a double volume pump in that fluid is output by volume pump 28 during both the upstroke in second axial direction AD2 and the downstroke in first axial direction AD1. Check valve 58a can be coaxial with common axis CA. More specifically, both the ball and the annular seat of check valve 58a can be coaxial with common axis CA. Check valve 58b can be coaxial with common axis CA. More specifically, both the ball and the annular seat of check valve 58b can be coaxial with common axis CA.

[0084] Dynamic seal 124a divides the interior of pump body 36 into an upstream chamber and a downstream chamber. Dynamic seal 124a can be mounted to fluid displacement member 34 to move with fluid displacement member 34 or can be stationary relative to pump body 36 such that fluid displacement member 34 moves relative to dynamic seal 124a. In the illustrated example, fluid displacement member 34 exits pump body 36 through dynamic seal 124b. Dynamic seal 124b is supported by pump body 36 and remains stationary relative to pump body 36 such that fluid displacement member 34 moves relative to dynamic seal 124b. Dynamic seals 124a, 124b can be formed by a stack of sealing rings. Dynamic seals 124a, 124b are coaxially disposed on common axis CA, and thus coaxial with the rotational axis of rotor 42 and the reciprocating axis of fluid displacement member 34.

[0085] An example pump cycle including a downstroke and an upstroke is discussed by way of example. During operation, power is provided to stator 44 to drive rotor 42 to rotate about common axis CA. Rotor 42 rotates in a first rotational direction (e.g., one of the clockwise and counterclockwise directions) about common axis CA and rotor shaft 62 is simultaneously rotated due to the connection between rotor 42 and rotor shaft 62. Rotor shaft 62 rotates on common axis CA and powers driver 26 due to the connection between rotor shaft 62 and drive nut 54.

[0086] The drive nut 54 is rotated on the common axis CA, causing the rolling elements 104 to exert an axial driving force on the screw 56 in the second axial direction AD2, thereby driving the screw 56 linearly along the common axis CA. The screw 56 is driven linearly in the second axial direction AD2 and toward the motor 24. In some examples, a portion of the screw 56 extends into and axially overlaps a portion of the motor 24. In such examples, as the screw 56 is displaced in the second axial direction AD2, the amount of axial overlap increases. The screw 56 pulls the fluid displacement member 34 through an upstroke along the common axis CA and the second axial direction AD2. During the upstroke, the check valve 58a is open and the check valve 58b is closed. The volume of an upstream chamber formed between the fluid displacement member 34 and the check valve 58a increases, and the volume of a downstream chamber on an axial side of a dynamic interface between the fluid displacement member 34 and the dynamic seal 124a opposite the upstream chamber decreases. Fluid is drawn into the upstream chamber through the check valve 58a while being driven downstream from the downstream chamber of the displacement pump 28.

[0087] After the upstroke is completed, the rotor 42 is driven in a second rotational direction opposite the first rotational direction (e.g., the other of the clockwise and counterclockwise directions). The rotor 42 drives rotation of the rotor shaft 62, which drives rotation of the drive nut 54. The rolling elements 104 exert an axial driving force on the screw 56 in the first axial direction AD1 to drive the screw 56 linearly along the common axis CA. The screw 56 drives the pump shaft 68 and thus the fluid displacement member 34 through a downstroke along the common axis CA and the first axial direction AD1. During the downstroke, the check valve 58a is closed and the check valve 58b is open. Fluid is driven from the upstream chamber to the downstream chamber through the check valve 58b. Fluid is driven downstream from the displacement pump 28. The sensor 66 can sense the end of the downstroke and provide that data to the controller 29. In the illustrated example, the displacement pump 28 outputs fluid during both the upstroke and the downstroke.

[0088] Axial forces are generated and experienced during pumping. The bearing assembly 64 allows rotational motion from the motor 24 to be transmitted within the driver 26 while preventing some or all of the axial forces generated by the positive displacement pump 28 from being transmitted to the rotor 42. The fluid displacement member 34 moves in a reciprocating linear manner along the common axis CA and is subject to axial forces generated due to fluid resistance during the reciprocating motion. Specifically, the fluid displacement member 34 experiences a downward reaction force when moving through the upstroke and an upward reaction force when moving through the downstroke. Both the upward and downward reaction forces are transmitted through the driver 26 to the bearing assembly 64. The coaxial nature of the motor 24, the fluid displacement member 34, and the bearing assembly 64 facilitates efficient force transmission to protect the motor 24 from the reaction forces. The bearing assembly 64 is disposed coaxially with the reciprocating axis of the fluid displacement member 34 such that the forces provided to the bearing assembly 64 are balanced about the common axis CA. The bearing assembly 64 transmits such forces to the pump frame 22 to isolate the motor 24. The coaxial nature facilitates a compact, efficient bearing arrangement.

[0089] In examples using an elongate roller, the lead on the screw 56, the drive nut 54, and possibly the rolling element 104 determines the ratio of rotor 42 rotation to linear travel of the fluid displacement member 34. The rotor 42 and driver 26 are sized to provide a desired ratio of rotations to travel. In some examples, the rotor 42 and driver 26 are sized such that one revolution of the rotor 42 results in a full stroke of the fluid displacement member 34 in one of the first and second axial directions AD1, AD2. A full revolution in the opposite rotational direction results in a full stroke of the fluid displacement member 34 in the opposite axial direction. Thus, two revolutions in opposite directions can provide a full pump cycle of the fluid displacement member 34, each pump cycle including one stroke in each axial direction (e.g., an upstroke and a downstroke). As such, the pump apparatus 12 can provide a 1 : 1 ratio between rotations of the rotor 42 and pump travel.

[0090] However, it is understood that the rotor 42 and driver 26 can be sized to provide any desired ratio of rotations to travel. The pump apparatus 12 can be configured to provide any desired ratio of rotations to travel. In some examples, the pump apparatus 12 provides a ratio of rotations to travel of up to about 4: 1. It is understood that other maximum ratios of rotations to travel are possible, such as about 1 : 1, 2: 1, 3: 1, or 5: 1, among other options. In some examples, the pump apparatus 12 can provide a ratio of rotations to travel of between about 0.25: 1 and 7: 1. It is understood that any range discussed can be a range that includes the end values such that the boundary values are included in the range. It is also understood that each of the ranges discussed can be different from the specified range while still falling within the scope of the present disclosure.

[0091] It should also be appreciated that the controller 29 can control operation of the motor 24 such that the actual stroke length is dynamic and can vary during operation. The controller 29 can vary the stroke length between a downstroke and an upstroke. In some examples, the controller 29 is configured to control operation of the motor 24 between a maximum stroke length and a minimum stroke length.

[0092] The motor 24 and drive 26 can be configured to displace the fluid displacement member 34 at least about 6.35 mm (about 0.25 inch) per revolution of the rotor 42. The rotor 42 is about 8.9-30.5 mm (about 0.35-1.2 inch) per revolution. In some examples, the motor 24 and drive 26 are configured to move the fluid displacement member 34 between about 8.9-11.4 mm (about 0.35-0.45 inch). In some examples, the motor 24 and drive 26 are configured to move the fluid displacement member 34 between about 19-21.6 mm (about 0.75-0.85 inch). In some examples, the motor 24 and drive 26 are configured to move the fluid displacement member 34 between about 24.1-26.7 mm (about 0.95-1.05 inch). The axial displacement per revolution of the rotor 42 provided by the pump apparatus 12 facilitates precise control and fast response during pumping. The axial displacement per revolution of the rotor 42 facilitates fast switching between pump strokes, minimizes time when the fluid displacement member 34 is not moving, and provides more efficient pumping while reducing wear on components of the pump apparatus 12.

[0093] Pump apparatus 12 is configured to pump according to a ratio of revolutions to displacement. More specifically, motor 24 and driver 26 are configured to provide a desired ratio of revolutions to displacement between the number of revolutions of rotor 42 and the linear travel distance of fluid displacement member 34 for each revolution of rotor 42, as measured in inches. In some examples, the ratio of revolutions to displacement (rev / in) is less than about 4: 1. In some examples, the ratio of revolutions to displacement is between about 0.85: 1 and 3.25: 1. In some examples, the ratio of revolutions to displacement is between about 1 : 1 - 3: 1. In some examples, the ratio of revolutions to displacement is between about 1 : 1 - 2.75: 1. In some examples, the ratio of revolutions to displacement is about 1 : 1 - 2.55: 1. In some examples, the ratio of revolutions to displacement is between about 1 : 1 - 1.3: 1. In some examples, the ratio of revolutions to displacement is between about 0.9: 1 - 1.1 : 1. In some examples, the ratio of revolutions to displacement is between about 2.4: 1 - 2.6: 1. The lower ratio of revolutions to displacement provided by pump apparatus 12 is advantageous for more efficient pumping, produces less wear, and provides a quick response for changing stroke direction relative to other electric pumps, such as crank drive pumps that require a reduction gear to produce sufficient pumping torque and typically have a ratio of revolutions to displacement of about 8: 1 or higher. Rotor 42 can be driven at a lower rotational speed to produce the same linear speed, resulting in less heat generated during operation.

[0094] Pump apparatus 12 provides significant advantages. Motor 24 and fluid displacement member 34 are coaxially disposed on common axis CA, facilitating a compact, lightweight pumping arrangement. The coaxial motor 24 and fluid displacement member 34 allow for quick response and control compared to pump arrangements that include a gear reduction. Motor 24 can produce high torque at low speeds and does not require a reduction gear to drive displacement of fluid displacement member 34. Motor 24 provides rotational power directly to driver 26 and driver 26 provides linear power directly to fluid displacement member 34. The rotational and reciprocating motions are facilitated by components that are coaxially disposed on common axis CA for efficient force transfer, even loading on common axis CA, preventing wear, and increasing the useful life of pump apparatus 12.

[0095] Each rotational component of pump apparatus 12 (e.g., rotor 42, rotor shaft 62, and drive nut 54) is connected together to rotate together at a common rotational speed. Each axial displacement component of pump apparatus 12 (e.g., screw 56, pump shaft 68, and fluid displacement member 34) is connected together to linearly displace at a common axial speed. This common speed facilitates quick response and reversal because the rotational output does not have to be accelerated or otherwise changed through a reduction gear train. As such, pump apparatus 12 provides a compact, lightweight assembly suitable for pumping fluids at high pressures.

[0096] Figure 4A is a perspective view of the components of motor 24 shown individually and in perspective. Figure 4B is a perspective view of stator 44. Stator 44 and rotor 42 will be discussed together Figure 4A and Figure 4B . Motor 24 includes stator 44 surrounded by rotor 42. Array of permanent magnets 46 of rotor 42 is shown. Array of permanent magnets 46 includes magnets 138 and concentrators 140. Stator 44 includes phase assemblies 50a-50c (collectively referred to herein as "phase assemblies 50" or "a plurality of phase assemblies 50"). Phase assembly 50a includes a pair of flux rings 142a, 142b; an axial return 144; and a coil 52. Phase assembly 50b includes a pair of flux rings 142c, 142d; an axial return 144; and a coil 52. Phase assembly 50c includes a pair of flux rings 142e, 142f; an axial return 144; and a coil 52. Each flux ring 142a-142f (collectively referred to herein as "flux rings 142" or "a plurality of flux rings 142") includes a circular array of prongs 146a-146f (collectively referred to herein as "circular array of prongs 146" or "a plurality of circular arrays of prongs 146"), respectively. Each flux ring 142a-142f includes a laminated piece 148, a branch 150, a stem 152, a hoop 154, and a plurality of prongs 156.

[0097] Motor 24 is positioned along a common axis CA. More specifically, motor 24 has a cylindrical profile that is coaxial with common axis CA. Each of stator 44 and rotor 42 also has a cylindrical profile that is coaxial with common axis CA. Rotor 42 is driven by stator 44 to rotate coaxially about common axis CA. While in the present embodiment, rotor 42 is around stator 44 such that rotor 42 rotates circumferentially about stator 44 on common axis CA, in alternative embodiments, rotor 42 can instead be inside stator 44. Regardless of whether rotor 42 is around stator 44 or inside stator 44, the principles of operation of motor 24 and the structure of rotor 42 and stator 44 can be similar. So, while the discussion below refers to an embodiment in which rotor 42 rotates around stator 44, the teachings are equally applicable to an embodiment in which rotor 42 rotates inside stator 44.

[0098] In the illustrated embodiment, rotor 42 includes array of permanent magnets 46. Array of permanent magnets 46 includes a plurality of magnets 138. The plurality of magnets 138 is annularly arranged about common axis CA. More specifically, the tubular array of the plurality of magnets 138 is coaxial with common axis CA. The plurality of magnets 138 is circumferentially arranged about common axis CA. The plurality of magnets 138 is circumferentially arranged about stator 44.

[0099] As Figure 4AAs shown, each magnet 138 has a long axis, long axis LA, that is axially oriented (parallel to the common axis CA). Each magnet 138 has a short axis SA that is orthogonal to the long axis LA and that is tangential to the rotor 42. The short axis SA of each magnet 138 can be tangential to a circle centered on the common axis CA. Each magnet 138 has a north pole and a south pole that are circumferentially oriented. More specifically, each magnet 138 has a north pole at one end of the short axis SA and a south pole at the opposite end of the short axis SA. Each of the north and south poles extends the length of the long axis LA such that the north and south poles are separated by an axial interface along the long axis LA. The north and south poles of each magnet 138 are not axially oriented in the manner that magnets are typically split into north and south poles at opposite ends of their long axis LA. In the illustrated embodiment, although the plurality of magnets 138 are annularly arranged around the stator 44, as described previously, the plurality of magnets 138 can be annularly arranged within the stator 44. The stator 44 can not include any permanent magnets, but rather electromagnets that, as described further herein, generate a magnetic field when energized by the coils 52. Likewise, the rotor 42 can include only permanent magnets and not any electromagnets. Figure 4A As shown, the short axis SA is orthogonal to the long axis LA and is tangential to the rotor 42. The short axis SA of each magnet 138 can be tangential to a circle centered on the common axis CA. Each magnet 138 has a north pole and a south pole that are circumferentially oriented. More specifically, each magnet 138 has a north pole at one end of the short axis SA and a south pole at the opposite end of the short axis SA. Each of the north and south poles extends the length of the long axis LA such that the north and south poles are separated by an axial interface along the long axis LA. The north and south poles of each magnet 138 are not axially oriented in the manner that magnets are typically split into north and south poles at opposite ends of their long axis LA. In the illustrated embodiment, although the plurality of magnets 138 are annularly arranged around the stator 44, as described previously, the plurality of magnets 138 can be annularly arranged within the stator 44. The stator 44 can not include any permanent magnets, but rather electromagnets that, as described further herein, generate a magnetic field when energized by the coils 52. Likewise, the rotor 42 can include only permanent magnets and not any electromagnets.

[0100] The rotor 42 also includes a plurality of concentrators 140. The plurality of concentrators 140 are interleaved with the plurality of magnets 138. As such, no magnet 138 physically contacts another magnet 138, and no magnet 138 is physically contiguous with another. However, the magnets 138 are physically secured by the plurality of concentrators 140. The plurality of concentrators 140 are axially oriented such that a long axis of each concentrator 140 is parallel to the common axis CA. The long axis of each concentrator 140 is parallel to the long axis LA of each magnet 138. Each concentrator 140 can be formed from a stack of laminations. The long axis of each lamination is parallel to the common axis CA. Thus, the grain of the stack of laminations is axially oriented.

[0101] Each magnet 138 extends parallel to the common axis. Each magnet 138 can span and magnetically interact with a plurality of phases of the stator 44. For example, each magnet 138 can radially overlap a plurality of coils 52 and a plurality of annular arrays of prongs 156. Each concentrator 140 extends parallel to the common axis. Each concentrator 140 can span and magnetically interact with a plurality of phases of the stator 44. For example, each concentrator 140 can radially overlap a plurality of coils 52 and an annular array of prongs 156.

[0102] The stack can be made of a material that is very easily polarizable under the action of the magnetic field generated by the coil. Such a material is typically ferromagnetic. The ferromagnetic material can be a metal such as iron or an iron alloy such as steel. More specifically, the stack can be made of silicon steel, among other options. The ferromagnetic material can be a ceramic doped or embedded with ferromagnetic elements.

[0103] The stator 44 includes a plurality of spikes 156. Each spike 156 projects toward the rotor 42. For example, each spike 156 projects radially (orthogonally) relative to the common axis CA toward the rotor 42. In the present embodiment, each spike 156 is a structure that narrows toward the rotor 42 to concentrate magnetic flux toward a limited portion of the rotor 42. More specifically, the circumferential width of each spike 156 narrows as the spike 156 extends radially relative to the stator 44 and toward the rotor 42. In some embodiments, magnetic flux can be concentrated toward the rotor 42 even though the spikes 156 can not narrow toward the rotor 42. In the present embodiment, the spikes 156 project outward from the common axis CA because the rotor 42 is positioned radially outward from the stator 44. However, in alternative embodiments with an inner rotor 42, the spikes 156 project inward toward such a rotor 42 and toward the common axis CA. The plurality of spikes 156 are arranged to have a tubular profile. More specifically, the plurality of spikes 156 are annularly arranged around the common axis CA and axially arranged along the common axis CA. As such, the stator 44 includes a plurality of circular spike arrays 146a-146f. Figure 4B The present embodiment shows six circular spike arrays 146a-146f that are arranged along the common axis CA. The plurality of circular spike arrays 146a-146f are arranged along the common axis CA. Each circular spike array 146a-146f is coaxial with the common axis CA. The plurality of circular spike arrays 146a-146f define a cylinder coaxial with the common axis CA. The spikes 156 do not necessarily project into the air gap away from other physical components of the stator 44. Rather, the spikes 156 can be partially or completely embedded in a potting compound such as epoxy. For example, the stator 156 can have a cylindrical outer portion with the spikes 156 located inside and / or exposed on the cylindrical outer surface, but the spikes 156 still function to concentrate electromagnetic flux relative to the surrounding potting material.

[0104] In the present embodiment, the circular arrays of prongs 146a-146f are part of a plurality of flux rings 142a-146f, respectively. Each flux ring 142 supports all of the prongs 156 of the respective circular array of prongs 146 of that flux ring 142. For example, flux ring 142a supports all of the prongs 156 of circular array of prongs 146a. The flux rings 142 are each at least partially formed from a laminate. Each flux ring 142a-146f can be a continuous laminate piece or formed from a plurality of laminate pieces arranged about a common axis CA. In the present embodiment, each flux ring 142a-146f includes a collar 154, a plurality of stems 152 extending radially relative to the collar 154, and a plurality of branches 150 supported by the plurality of stems 152.

[0105] For each flux ring 142, the collar 154 extends completely around the common axis CA as a ring. The stems 152 extend radially from the collar 154 and toward the rotor 42. In the example shown, the stems 152 extend radially away from the common axis CA because the motor 24 is an external rotor. The branches 150 are supported by the stems 152. The branches 150 are disposed at a radial end of the stems 152 opposite the collar 154. The branches 150 extend circumferentially from the stems 152 in a first circumferential direction about the common axis CA (e.g., one of clockwise and counterclockwise) and in a second circumferential direction about the common axis CA (e.g., the other of clockwise and counterclockwise). The prongs 156 are formed on the radial side of the branches 150 opposite the stems 152.

[0106] In some other embodiments, the flux rings 142 do not include the collars 154 and / or the stems 152, in which case the branches 150 are directly connected and / or supported by other structures, such as by an epoxy or other potting compound. In some embodiments, a plurality of laminate pieces are assembled together to form each circular flux ring 142 and / or circular array of prongs 146, such as by a plurality of arc-shaped portions assembled together.

[0107] Each ferrule 154 is coaxial with the common axis CA. Whether assembled from discrete laminate pieces that each support a plurality but not all of the prongs 156 of the circular array of prongs 146, or formed from a continuous laminate that supports all of the prongs 156 of the circular array of prongs 146, the circular arrays of prongs 146a-146f are supported by flux rings 142a-142f that allow flux to flow between circumferentially adjacent prongs 156. The plurality of flux rings 142a-142f are arranged along and around the common axis CA. Each flux ring 142a-142f is coaxial with the common axis CA. The laminates 148 from which the flux rings 142a-142f are formed form at least a portion of the prongs 156. The prongs 156 in this embodiment, as further described herein, include a prong body 158 formed from a laminate and a powder metal tip 160 formed from a powder metal. However, it should be appreciated that in various other embodiments, the laminates 148 can form the prongs 156 entirely.

[0108] In this embodiment, each prong 156 includes a powder metal tip 160, which can be desirable in some embodiments (due to the lack of directional grain in powder metal), but various embodiments are not so limited and each prong 156 can not include a powder metal component. Thus, each prong 156 can be formed partially or entirely from a laminate, such as the laminate piece 148 of its associated flux ring 142. As shown, a plurality of circumferentially adjacent prongs 156 belonging to a common flux ring 142 are formed from a single common laminate piece 148. More specifically, in the illustrated embodiment, the prong bodies 158 of a plurality of circumferentially adjacent prongs 156 of the same flux ring 142 are formed from a single laminate piece 148.

[0109] Each prong 156 can be contiguous with the branch 150, stem 152, and / or ferrule 154 of its flux ring 142. As such, the prongs 156, branches 150, stems 152, and / or ferrules 154 of a single flux ring 142 can be formed from a single laminate piece or a plurality of laminate pieces. Each prong 156 of the array of prongs 146 can thus be formed from a common laminate piece. In the illustrated embodiment, the laminate pieces 148 that form the flux rings 142a-142f are contiguous pieces. As such, the laminate portions of each flux ring 142a-142f are formed from contiguous laminates. The prongs 156, branches 150, stems 152, and / or ferrules 154 can have a laminate grain that extends (e.g., orthogonally) radially relative to the common axis CA. Such a laminate grain can be oriented radially only.

[0110] As Figure 4BAs shown, the stator 44 is formed from an array of phase assemblies 50a-50c. The phase assemblies 50a-50c are aligned along a common axis CA. Each phase assembly 50a-50c includes a pair of circular prong arrays 146a-146b, 146c-146d, 146e-146f, respectively. Thus, the phase assembly 50a includes a pair of circular prong arrays 146a, 146b; the phase assembly 50b includes a pair of circular prong arrays 146c, 146d; and the phase assembly 50c includes a pair of circular prong arrays 146e, 146f. In the present embodiment, each phase assembly 50a-50c includes a pair of flux rings 142a-142b, 142c-142d, 142e-142f, respectively. Each pair of circular prong arrays 146a-146b, 146c-146d, 146e-146f is connected by an axial return 144. Each pair of flux rings 142a-142b, 142c-142d, 142e-142f is connected by an axial return 144.

[0111] Each phase assembly 50 includes a coil 52 axially disposed between the pair of flux rings 142 of the phase assembly 50. The coil 52 extends circumferentially around the common axis CA such that the common axis CA extends through a loop formed by each coil 52. The coil 52 is axially disposed between the laminated portions of each phase assembly 50. Each coil 52 is thereby enclosed by the laminated stack.

[0112] The axial returns 144 extend between and connect the pair of flux rings 142 to form the phase assembly 50. The axial returns 144 are arranged around the common axis CA and form a circular array of axial returns 144 for each phase assembly 50. The axial returns 144 are arranged on a radially opposite side of the coil 52 from the rotor 42. The axial returns 144 are disposed on a radially opposite side of the coil 52 from the permanent magnet array 46. The array of axial returns 144 defines a cylinder through which the common axis CA extends. The axial returns 144 are disposed on a radially opposite side of the limb 150 from the prong 156. The axial returns 144 can be in direct contact with the laminations of each flux ring 142 of the phase assembly 50. For example, each axial return 144 can be in direct contact with a radially opposite side of each limb 150 from the prong 156. In the example shown, the axial returns 144 are in direct contact with a radially inner side of each limb 150, as the motor 24 is of the external rotor type.

[0113] Each axial return portion 144 is formed by a stack of layers having an axial (i.e., parallel to the common axis CA) texture orientation. The texture of the stack of axial return portions 144 may be axial only. Thus, the texture of the stack of axial return portions 144 may be orthogonal to the texture of the stack forming the flux loops 142. Therefore, the motor 24 may include one or more axially oriented arrays of stacks arranged around the common axis CA. One or more axially oriented arrays of stacks define cylinders coaxial with and therefore coaxial with each other to the common axis CA. As further explained herein, the axial return portions 144 conduct electromagnetic flux between each of the pair of flux loops 142 forming the phase assembly 50. In the example shown, the first array of the axial return section 144 conducts electromagnetic flux between pairs of flux rings 142a-142b; the second array of the axial return section 144 conducts electromagnetic flux between pairs of flux rings 142c-142d; and the third array of the axial return section conducts electromagnetic flux between pairs of flux rings 142e-142f. The axial return section 144 conducts electromagnetic flux between pairs of flux rings 142 in each phase assembly 50. Similarly, the axial return section 144 conducts electromagnetic flux between each pair of circular spike arrays 146a-146b, 146c-146d, and 146e-146f. Also, the axial return section 144 conducts electromagnetic flux between axially adjacent branches 150 of the pairs of flux rings 142. As further explained herein, the spikes 156 of the paired flux loops 142a-142b, 142c-142d, 142e-142f and thus the paired array of circular spikes 146a-146b, 146c-146d, 146d-146f form multiple flux loops through the stator 44, which magnetically act on the magnets 138 of the rotor 42 to cause the rotor 34 to rotate relative to the stator 44.

[0114] The flux loop 142 and / or stack 148 and / or spike 156 (or other stacked structures that guide magnetic flux to magnet 138) closest to the displacement member 34 (and the pumping chamber(s) of the positive displacement pump 28, and the body 36 of the positive displacement pump 28) along the common axis CA are axially closer than the coil 52 closest along the common axis CA. This is partly because the coils do not have end turns extending axially relative to the motor 24, as discussed in more detail below.

[0115] Figure 5A This is a 3D view of phase component 50a. Figure 5B This is a perspective view of phase component 50a, in which the flux ring 142a has been removed for clarity. It will be discussed together. Figure 5A and Figure 5B Although phase component 50a is shown and discussed in more detail, it should be understood that other phase components 50b, 50c (in...) Figure 4BThe phase assemblies 50a-50c can be identical in structure and function, with the only difference being that the signals passed through the coils 52 of the phase assemblies 50a-50c are out of phase with respect to each other. In addition, the phase assemblies 50a-50c can be rotated with respect to each other about a common axis CA to form the stator 44. The flux ring 142a includes a circular array of prongs 146a, a branch 150a, a stem 152a, a collar 154a, and prongs 156a. The flux ring 142b includes a circular array of prongs 146b, a branch 150b, a stem 152b, a collar 154b, and prongs 156b.

[0116] The phase assembly 50a is formed from a pair of flux rings 142a, 142b, with the coils 52 axially sandwiched between the pair of flux rings 142a-142b. Each coil 52 is a winding of wire (typically copper) about the common axis CA. Thus, each coil 52 can be a continuous winding having 20, 30, 40, 50, 100, or fewer or more turns about the common axis CA. In some embodiments, tape is wound instead of wire. Each coil 52 has two terminal wires 162a, 162b, which represent the ends of the electrical circuit of each coil 52. Figure 5B The wire ends 162a, 162b of the coils 52, which are best shown for passing the AC signal through the coils 52, can be electrically connected with the controller 29.

[0117] The coils 52 radially overlap the prongs 156a, 156b of the phase assembly 50a, as a portion of each of the prongs 156a, 156b axially protrudes along the common axis CA. Thus, a radial line extending from the common axis CA can pass through each of the coils 52 and a portion of the prongs 156 of the phase assembly 50. The radial line can extend through the axial return 144, the coil 52, and a portion of the prong 156. In the example shown, a powder metal end 160 axially extends over the coil 52. Thus, a radial line extending from the common axis CA can extend through a laminate (e.g., of the axial return 144), a wire (e.g., of the coil 52), and a powder metal (e.g., of the powder metal of the powder metal end 160). In some other embodiments, the prongs 156 do not axially protrude but only radially protrude (toward or away from the common axis CA).

[0118] Coil 52 is disposed directly between the pair of flux rings 142a, 142b. Coil 52 is disposed in an axial gap formed between the pair of flux rings 142a, 142b. More specifically, coil 52 is located directly between the stack forming flux ring 142a and the stack forming flux ring 142b. At least a portion of coil 52 is located directly between opposing limbs 150a, 150b of the pair of flux rings 142a, 142b. At least a portion of coil 52 is located directly between portions of each pair of spikes 156a, 156b of the pair of circular spike arrays 146a, 146b (e.g., spikes 156a of spike array 146a and spikes 156b of spike array 146b). Coil 52 is located directly axially between portions of the pair of circular spike arrays 146a, 146b formed by the stacks. Thus, coil 52 is axially supported / enclosed by the stacks.

[0119] Coil 52 radially overlaps axial return 144. In this particular embodiment, coil 52 is radially sandwiched between axial return 144 and portions of spikes 156a, 156b, as spikes 156a, 156b each have an axially protruding portion. Thus, coil 52 is disposed in an annular chamber that is coaxial with common axis CA and is defined by axial return 144 and flux rings 142a, 142b. In the example shown, three of the four sides of the annular chamber (e.g., two axial sides and one radial side) are formed by the stacks. In the example shown, one of the four sides of the annular chamber is formed by a powder metal component (e.g., powder metal end portion 160 of spikes 156a, 156b). However, it should be appreciated that some examples include an annular chamber having all four sides defined by stacks. In some examples, the annular chamber can have three sides, for example, where spikes 156a, 156b do not include axially extending components.

[0120] Figure 6A And Figure 6B It is shown how a magnetic flux loop is formed by those of spikes 156a, 156b that are flux pairing. Figure 6C A detailed view of flux pairing spikes 156a, 156b of phase assembly 50a interacting with permanent magnet array 46 of rotor 42 is shown. It will be discussed together with Figures 6A-6C . Flux pairing spikes refer to respective nearest pairs of spikes 156 of opposing circular spike arrays 146 of phase assembly 50 (e.g., nearest pairs of spikes 156a, 156b of opposing circular spike arrays 146a, 146b of phase assembly 50a). While spikes 156a, 156b are in Figures 6A-6CThe middle prongs are shown as flux-paired prongs, but it should be understood that these are examples, and all prongs 156a, 156b of the flux rings 142a, 142b similarly flux-pair through the circular prong arrays 146a, 146b.

[0121] Each prong 156a is part of a similar flux loop with its corresponding flux-paired prong 156b. The flux-paired prongs 156a, 156b generally flux-pair axially with prongs 156a, 156b of the opposite circular prong array 146a, 146b, rather than circumferentially with adjacent prongs 156a, 156b of the same circular prong array 146a, 146b, because all prongs 156a of a circular prong array 146a will have the same polarity at any given time, while all prongs 156b of the opposite circular prong array 146b of the same phase assembly 50a will have opposite polarity at any given time. More specifically, each prong 156a of a circular prong array 146a flux-pairs with the nearest prong 156b of the circular prong array 156b on the other axial side of the coil 52. As Figure 6A and Figure 6B As shown, a flux loop is formed by the flux-paired prongs 156a, 156b such that the prongs 156a, 156b are polarized— north and south, respectively.

[0122] Flux is generated by the coils 52. Specifically, an AC signal is passed through each coil 52, which quickly establishes and destroys a magnetic field as the current through the coil 52 reverses. As shown, flux concentrating material of the flux rings 142a, 142b and the axial return 144 surrounds at least three sides of the coils 52. In Figure 6A and Figure 6B The lamination texture of the flux concentrating material is shown in FIGS. 15 and 16. Generally, flux flows along the lamination direction with the texture because flux will generally flow along the path of highest permeability, and there is significant resistance to flux jumping from one lamination to another. The lamination texture of the limbs 150a, 150b (including the prongs 156a, 156b in addition to the powder metal end portions 160) is radially oriented, while the lamination texture of the axial return 144 is axially oriented. Thus, flux flows U-shaped axially through the axial return 144 and radially through the limbs 150a, 150b and prongs 156a, 156b toward the rotor 42, with the bottom of the U on the side of the coil 52 opposite the rotor 42, and the U legs toward the rotor 42. Figure 6A and Figure 6B Indicates the reversal of the AC signal and how the poles of the flux-paired prongs 156a, 156b switch.

[0123] The flux-paired prongs 156a, 156b are circumferentially offset from one another such that the prongs 156a are not axially aligned with the prongs 156b. The ends of the flux-paired prongs 156a, 156b are not axially aligned because the prongs 156a are circumferentially offset from the prongs 156b, so the flux loop travels circumferentially between the flux-paired prongs 156a, 156b at least a limited distance. Thus, the cumulative flux loop including the plurality of flux-paired prongs 156a, 156b can flow circumferentially through the prongs 156a, 156b and the axial return 144 in a spiral pattern. Note that while most of the magnetic flux flows between the flux-paired prongs 156a, 156b, the limbs 150a, 150b allow the magnetic flux between the prongs 156a, 156b of the same limb 150a, 150b to flow, so that a limited amount of magnetic flux can flow to the next prong 156a, 156b of the same limb 150a, 150b, skipping the flux-paired prongs 156a, 156b.

[0124] Figure 6C A detailed view showing the flux-paired prongs 156a, 156b of the stator 44 interacting with the concentrators 140 and the magnets 138 of the rotor 42. The AC signal flowing through the coils 52 rapidly changes the direction of current and thus rapidly changes the north-south polarity of the flux-paired prongs 156a, 156b. Figure 6C An example is shown in which all of the prongs 156a of the circular prong array 146a have a north pole and all of the prongs 156b of the circular prong array 146b have a south pole. Again in this case, the prongs 156a, 156b are aligned with the concentrators 140 disposed circumferentially between the magnets 138. The stack of concentrators 140 does not have an inherent polarity, but due to the fixed position of the concentrators 140 between the magnetic poles, the concentrators 140 effectively exhibit a permanent polarization as shown. Each concentrator 140 contacts two magnets 138. Each concentrator 140 contacts the same pole of both magnets 138. For example, a concentrator 140 will contact two south poles or two north poles. Depending on the polarity adjacent to the concentrator 140, the concentrator 140 exhibits an alternating north and south pole on opposite sides of each magnet 138. As shown, each magnet 138 is permanently polarized into a north pole and a south pole on opposite sides of its minor axis. The interleaved arrangement of the magnets 138 and the concentrators 140 produces oppositely polarized concentrator 140 and magnet 138 poles.

[0125] The concentrators 140 direct the magnetic flux from the magnets 138 toward the stator 126. The magnetic flux loop is completed across the air gap 60 between the stator 44 and the rotor 42. The magnetic flux from the rotor 42 (specifically the magnets 138) and the magnetic flux from the coils 52 (through the prongs 156a, 156b) interact in the air gap 152, and the resulting magnetic flux shear forces urge the rotor 42 to rotate. The magnetic flux of this motor 24 has an orientation that is transverse to the axis of rotation (which is coaxial with the common axis CA). This is different from the radial magnetic flux direction of conventional AC and DC brushless motors.

[0126] The magnetic flux generated by the stator 44 and acting on the rotor 42 is constantly changing, both due to the changing position of the magnets 138 and the concentrators 140 due to the rotation of the rotor 42, and due to the changing polarity of the prongs 156a, 156b due to the changing AC signal through the coils 52. Thus, the AC signal through the coils 52 is synchronized with the rotation of the rotor 42 to produce through the prongs 156a, 156b a magnetic field that timely corresponds to the concentrators 140 (which are approaching and receding from the prongs 156a, 156b) to simultaneously push and pull the magnets 138 of the rotor 42 to provide a force that rotates the rotor 42. More specifically, the N-N and S-S interfaces repel while the N-S attracts when aligned to approach and recede.

[0127] The respective AC signals (e.g., sinusoidal or trapezoidal) are out of phase with respect to each other. In this way, the magnets 138 (along their lengths) have a magnetic flux peak acting on them more frequently than with a synchronized sinusoidal AC signal to obtain a smoother torque distribution acting on the rotor 42 along the axis of rotation of the rotor 42 (which is also the common axis CA). Figure 2 、 Figure 4A and Figure 4B The embodiment of the motor 24 shown includes three phases, which correspond to three phase assemblies 50a-50c and coils 52 therein, with three 120-degree electrically offset sinusoidal AC signals being delivered through the coils 52. If there are two phase assemblies 50 and two coils 52, then two sinusoidal AC signals would be 180 degrees apart, or 90 degrees apart for a set of four phase assemblies 50.

[0128] Because the magnets 138 are elongated and radially overlap multiple coils 52, each magnet 138 is electromagnetically acted upon by multiple coils 52. More specifically, in the example shown, each magnet 138 can be simultaneously electromagnetically acted upon by three coils 52 along the length of the magnet 142. Thus, multiple different coils 52 can simultaneously electromagnetically act on each magnet 138. Furthermore, each magnet 138 can be electromagnetically acted upon by only three coils 52 (or only two coils 52 in a two-phase motor 24 embodiment, or only four coils 52 in a four-phase motor 24 embodiment, etc.) at all times throughout operation. This is unlike a conventional AC induction motor, in which each magnet would interact with all of the windings of a conventional annular winding array around the rotational axis of the rotor. Because each magnet 138 is symmetric along its long axis, the motor 24 has multiple stator phases but continuous rotor phases.

[0129] Conventional AC induction motors use multiple discrete coils that form an array of coils extending circumferentially around the rotational axis of the rotor (see Figure 10 A and Figure 10 B). Each coil represents a potential pole acting on a magnet. In a conventional AC induction motor, the discrete coils arranged circumferentially around the rotational axis are out of phase with each other. In any given instance, a discrete coil can interact with a small subset of magnets. The resulting potential torque is proportional to the number of poles. The number of poles in such a motor is limited by the ability to install discrete coils circumferentially around the rotational axis within the motor. Coil windings can be made smaller, and the diameter of the stator can be made larger to accommodate more coils to support more magnetic poles, but this increases the size, weight, and cost of the motor, and is still limited. Power can also be increased when the rotor is rotating at a relatively high rate, so that more coil-magnet passes can occur per unit of time. However, this power increase requires the motor to operate at a relatively high speed, while certain applications can require low speed output. Providing a reduction drive mechanism to reduce the speed and increase the torque to the high torque and low speed required increases cost, weight, size, and friction.

[0130] The motor 24 according to the present disclosure differs from conventional AC and DC brushless motors. One aspect of the motor 24 is that it contains relatively few coils 52, in the illustrated embodiment only three. Unlike conventional AC and DC brushless motors, the coils 52 are formed from wire loops that extend entirely around the rotational axis (and common axis CA) of the rotor 42. The rotational axis (and common axis CA) of the rotor 42 extends through each loop (e.g., the center of each loop). Each coil 52 is looped, and the loop of each coil 52 is likewise looped, and the circular planar profile of the coils 52 and loops are orthogonal to the common axis CA. The wire of each coil 52 forms a single wire hoop having multiple loops that overlap and contact one another to form a single wire hoop assembly. The coils 52 do not include loops that create magnetic flux that causes the rotor 42 to rotate, the common axis CA does not extend through which. Unlike conventional AC induction motors, where a coil is added for each magnetic pole, the limb 150 and axial return 144 around the single coil 52 direct magnetic flux to the plurality of prongs 156 that are flux paired across the limb 150 to create a plurality of magnetic poles. In the illustrated example, for each phase assembly 50, one coil 52 supports thirty magnetic poles, as the example flux ring 142 each includes thirty prongs 156, but fewer and more poles can be created depending on the number of prongs 156 of the circular prong array 138. Thus, activating one coil 52 will activate many poles, whereas in some conventional AC and DC brushless motors activating one coil activates only one pole. In some examples, each coil 52 can interact with each magnet 138 in a given situation. Further, the plurality of coils 52 are arranged along the rotational axis of the rotor 42 as part of the plurality of phase assemblies 50, thereby multiplying the number of poles.

[0131] The high number of poles eliminates or reduces the need for a reduction gear, and further reduces eccentric forces as well as weight and friction, allowing for a more compact arrangement of the pump apparatus 12. The high number of poles allowed by the present motor 24 design, due to the fact that pumping applications are typically performed at low speeds, means that high fluid pressure can be generated with high torque even at low pumping speeds, with little or no transmission reduction, which again reduces cost, weight, friction, and packaging size. For at least these reasons, the motor 24 of the present disclosure can generate high torque in a small packaging size, even at the low speeds at which pumps typically operate. As a result, transmission reduction of the drive can be minimized or completely eliminated, thereby saving cost, size, weight, and friction.

[0132] Figure 7is a schematic view of a pump apparatus 12'. Pump apparatus 12' includes a motor 24', a driver 26, and a positive displacement pump 28'. Motor 24' is an inner rotor type having a rotor 42' disposed within a stator 44'. Rotor 42' rotates within stator 44'. Stator 44' is substantially similar to stator 44 (best as shown in Figure 5A Figure 2 and Figure 5A

[0133] In the example shown, positive displacement pump 28' includes an inlet check valve 58a and an outlet check valve 58c, which can be any desired form of one-way valve, such as ball and seat valves and other options. Each of inlet check valve 58a and outlet check valve 58c is stationary relative to common axis CA. A pumping chamber 164 is fluidly connected to each of inlet check valve 58a and outlet check valve 58c. The volume of pumping chamber 164 increases as fluid displacement member 34 is drawn axially toward motor 24', and the volume of pumping chamber 164 decreases as fluid displacement member 34 is driven axially away from motor 24'. In the example shown, positive displacement pump 28' is a single- volume pump that drives fluid downstream only during one of the pump strokes. However, it will be appreciated that positive displacement pump 28' can be a double- volume pump similar to positive displacement pump 28 Figures 1A-3C

[0134] Magnetic flux rings 142 and / or laminations 148 and / or prongs 156 (or other lamination structure that directs magnetic flux to magnets 138) that are closest to displacement member 34 (and pumping chamber 164) along common axis CA are positioned at an axial location closer to positive displacement pump 28' (and pumping chamber 164) than the axially closest coil 52. This is in part because coil 52 does not have axially extending end turns. As such, pump apparatus 12' provides a compact, efficient pumping device.

[0135] Figure 8 is a schematic block diagram of a pump apparatus 12". While various other embodiments referenced herein can have a fluid displacement member 34 that moves linearly in a reciprocating manner, fluid displacement member 34' of this embodiment, and various other embodiments, rotates and can or can not reciprocate. Figure 8 ​​​The pump apparatus 12” of FIG. 1 1 includes a motor 24 having a rotor 42 that rotates inside or outside of a stator 44. The stator 44 includes a plurality of coils 52 (three in this embodiment, but more or fewer numbers can be provided in various other embodiments) that generate a magnetic field. Magnetic flux passes through the stator 44 to drive the rotor 42. The rotor 42 rotates coaxially with a common axis CA. The positive displacement pump 28” includes a rotating fluid displacement member 34’. The fluid displacement member 34’ can be elongate along the common axis CA. The fluid displacement member 34’ can be coaxial with the common axis CA. The fluid displacement member 34’ can rotate coaxially with respect to the common axis CA. Rotation of the fluid displacement member 34’ can pump fluid. An axis of rotation AR of the rotor 42 can be coaxial with an axis of rotation AR2 of the fluid displacement member 34’.

[0136] Figure 8 The positive displacement pump 28” of FIG. 1 1 can be a progressive cavity pump, a vane pump, an impeller pump, or a peristaltic pump, among other options. There can be no mechanical amplification between the rotor 42 and the rotating fluid displacement member 34’. For example, there can be no gearing between the rotor 42 and the rotating fluid displacement member 34’, or there can be no gearing at all on the pump apparatus 12”. The rotor 42 and the rotating fluid displacement member 34’ can be fixed such that one revolution of the rotor 42 results in one revolution of the rotating fluid displacement member 34’.

[0137] In the case of a peristaltic pump, the rotating fluid displacement member 34’ can be a rotor type that rotates within a housing that contains a flexible tube. The rotor that forms the fluid displacement member 34’ moves along to progressively and repeatedly squeeze the flexible tube against the interior of the housing along a portion of the length of the flexible tube; as the rotating fluid displacement member 34’ rotates, the rotor repeatedly starts and releases its squeezing of the flexible tube along the length of the tube.

[0138] In the case of a vane pump, the rotating fluid displacement member 34’ can be a rotor that rotates within a housing. Two vanes can protrude in opposite directions from the rotor that forms the fluid displacement member 34” within the housing. The vanes can be supported on one or more springs to allow the vanes to move in and out of the rotor to accommodate the shape of the interior of the housing. The housing can be coaxial with the common axis CA. The rotor can rotate about an axis of rotation that is coaxial with the common axis CA.

[0139] Figure 9is a schematic block diagram showing volumetric pump 28" as a progressive cavity pump. Internal rotor motor 24' is connected to fluid displacement member 34' to cause pumping of volumetric pump 28". In this embodiment, rotating fluid displacement member 34' is a helical rotor 166. Helical rotor 166 rotates within a progressive cavity stator housing 168. Helical rotor 166 can include fins, as shown, for propelling or otherwise moving a liquid, for example as water. An elastomer on the inside of progressive cavity stator housing 168 forms a series of cavities including lobes into which helical rotor 166 enters and exits to move a plurality of corresponding pockets from one end of the pump to the other, fluid moving under pressure through the cavities. Helical rotor 166 can rotate about a common axis CA. Helical rotor 166 can rotate coaxially with respect to common axis CA. In some embodiments, helical rotor 166 can be disposed inside a tube having a cylindrical interior profile (e.g., not a progressive cavity), or helical rotor 166 can be completely exposed to the liquid medium being moved without a sleeve around helical rotor 166.

[0140] As discussed herein, devices according to the present disclosure can have various advantages. One advantage can be to reduce canting of the fluid displacement member, which would otherwise cause side loading and premature failure. Figure 10 A schematic diagram is shown showing motor 24 operably connected to pump 28. In particular, magnetic flux ring 142 is shown. As previously described and shown, annular array of spikes 156 (not shown in Figure 10 ) is simultaneously polarized to the same polarity by coil (not shown in Figure 10 ) completely surrounding magnetic flux ring 142. This is denoted by the "+" symbol with respect to magnetic flux ring 142, however depending on the portion of the phase cycle, it can also be "-". Figure 10Further shown are phase assemblies 50 of motor 24. Phase assemblies 50 are labeled A, B, and C, representing the three phases, operating with 120 degrees of electrical offset. As such, the phases run along a common axis. As shown, each phase assembly 50 includes a first flux ring 142A and a second flux ring 142B. The prongs of each flux pair of first flux ring 142A and second flux ring 142B are of opposite polarity, shown as “+” and “-”. Each pole of flux rings 142A, 142B is simultaneously polarized with either a positive or negative pole 360 degrees around the common axis CA. The direction of opposite polarization between first flux ring 142A and second flux ring 142B of each phase assembly 50 varies with the sinusoidal input signal of the respective coil of phase assembly 50. Since first flux ring 142A and second flux ring 142B are axially aligned and oppositely loaded, an axial force can be generated between them and the rotor’s magnets, except that this axial force is balanced and cancelled due to the two oppositely polarized first flux ring 142A and second flux ring 142B. Each ring 142A, 142B is polarized completely around the common axis CA, balancing the load. Over time, wear can reduce the normal functioning of any motor, and this degradation can cause an imbalance between first flux ring 142A and second flux ring 142B with respect to the magnets (e.g., due to wear or defects in materials such as the coils), which, due to the axially oriented phases, will only push motor 24 axially along the common axis, and thus driver 26 and fluid displacement member 34. This undesirable force does not cause a problem because pump 28 is configured to move fluid displacement member 34 axially. Thus, motor 24 prevents unwanted lateral loading on fluid displacement member 34.

[0141] Figure 11 A schematic of a pump 28”’ operated by a conventional radial flux electric motor 24” is shown, in which the coils are aligned around the common axis, rather than along the common axis. As such, phases A, B, C are aligned around the common axis. Pump 28”’ can be substantially similar to any of pumps 28, 28’, 28”. Not only can fewer poles be used to evenly distribute force around the common axis, but phase imbalances due to wear will also generate a torque on the rotor, as shown by the downward force. This is in contrast to Figure 10The discussed unbalance to create axial forces. Such a misdirected force on motor 24" would cause motor 24" to rotate about driver 26', which can be substantially similar to driver 26', in which any degree of play exists, thereby pushing fluid displacement member 34" off the common axis and loading the sides of fluid displacement member 34", which can cause fluid displacement member 34" to prematurely wear, especially if it is relied upon to provide a dynamic sealing surface, such as in the case of it being a piston. The radial force D in motor 24" can cause a radial reaction force E in pump 28"'. Thus, a motor according to the present disclosure has advantages over conventional radial flux motors in operating pumps and similar fluid moving devices.

[0142] Figure 12A is a schematic block diagram of a prior art pump apparatus 200. Figure 12B is a prior art schematic end view of a conventional AC induction motor 202. As shown, end turns 210 of coil 212 extend closer to fluid displacement member 34 than do steel laminations 214 and magnets 216. These end turns 210 serve little purpose other than to return the loop of coil 212 to overlap steel laminations 214. Without such end turns 210, as in motors 24, 24', the length of the motor is reduced and the weight and cost associated with such end turns 210 is eliminated.

[0143] Prior art pump apparatus 200 includes a driver 218 formed by a reduction gear 220 that increases torque and reduces the speed of the output of motor 202. Reduction gear 220 connects pump 222, and in particular fluid displacement member 224, to motor 202. Fluid displacement member 224 reciprocates on an axis that is not aligned with the axis of rotation of the rotor of motor 202. In the example shown the axis is transverse. Gear arrangement 220 adds offset and additional structure, resulting in the axis of fluid displacement member 224 being misaligned with the axis of motor 202.

[0144] While the pumping assemblies of the present disclosure and claims are discussed in the context of a spray system, it should be understood that the pumping assemblies and control devices can be used in a variety of fluid moving contexts and systems and are not limited to those discussed. Any one or more of the pumping assemblies discussed can be used alone or with one or more additional pumps to move fluid for any desired purpose, such as position transfer, spraying, metering, application, propulsion, etc.

[0145] While the application has been described with reference to example embodiments, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the application. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the application without departing from the essential scope thereof. Therefore, it is intended that the application not be limited to the particular embodiment disclosed, but that the application will include all embodiments falling within the scope of the appended claims.

Claims

1. A pumping device for pumping fluid, the pumping device comprising: An electric motor configured to produce a rotational output, the electric motor comprising: A rotor configured to rotate about a common axis, the rotor comprising a plurality of magnets, each magnet being elongated and extending parallel to the common axis, the plurality of magnets being arranged in a ring around the common axis; and A stator configured to be energized to generate a magnetic flux that rotates the rotor, the stator comprising: Multiple coils, arranged along a common axis, each coil being coaxial with the common axis; and Multiple circular spike arrays arranged along the common axis, each of the multiple circular spike arrays comprising: Multiple spikes are arranged in a circle coaxial with the common axis, and all spikes are configured to be simultaneously polarized by the coils of the multiple coils to generate a magnetic flux that causes the rotor to rotate relative to the stator. A driver configured to convert the rotary output from the electric motor into a linear reciprocating output; and A fluid displacement member, configured to receive a linear reciprocating output from the driver, to reciprocate linearly along the common axis to pump fluid. The plurality of coils are arranged along the common axis such that each coil does not overlap radially with any other coil among the plurality of coils, and Among the plurality of protrusions, the protrusion closest to the common axis is closer to the fluid displacement member than the closest coil among one or more coils.

2. The pump device according to claim 1, wherein, For each circular spike array, each of the plurality of spikes protrudes radially toward the rotor relative to the common axis to focus the concentrated magnetic flux toward the rotor.

3. The pump device according to claim 2, wherein, The circumferential width of each of the plurality of spikes narrows as the spike extends toward the rotor.

4. The pump device according to any one of claims 1-3, wherein, Each of the plurality of spikes comprises metal.

5. The pump device according to any one of claims 1-3, wherein, Each of the plurality of spikes comprises a stack of metal layers.

6. The pump device according to any one of claims 1-3, wherein, Each of the plurality of spikes comprises a powdered metal component.

7. The pump device according to any one of claims 1-3, wherein, Each of the plurality of circular spike arrays comprises at least 25 spikes.

8. The pump device according to any one of claims 1-3, wherein, The plurality of circular spike arrays are arranged into multiple pairs of circular spike arrays, each pair having a first circular spike array and a second circular spike array, and the one or more coils comprising a corresponding coil located between each pair of circular spike arrays.

9. The pump device according to claim 8, wherein, Each pair of circular spike arrays includes multiple axial return sections extending between the first and second circular spike arrays to allow the flux loop to polarize the spike pairs on the first and second circular spike arrays.

10. The pump device according to any one of claims 1-3, wherein, The motor does not include a coil with end turns that extend along the common axis beyond all the spikes.

11. The pump device according to claim 1, wherein, The stator includes at least one phase assembly, the at least one phase assembly including a first coil of the one or more coils, the first coil being axially disposed between a first flux loop of the at least one phase assembly and a second flux loop of the at least one phase assembly.

12. The pump device according to claim 11, wherein, The first flux loop includes a plurality of branches, each branch extending radially relative to the common axis, and the plurality of spikes of the first flux loop are correspondingly supported by the plurality of branches, such that each branch supports at least three corresponding spikes of the plurality of spikes of the first flux loop.

13. The pump device according to any one of claims 1-3, wherein, The rotor includes a plurality of magnets, each having a major axis and a minor axis orthogonal to its major axis, the major axis of each magnet extending parallel to the common axis, and each magnet being permanently magnetically polarized to have a north pole and a south pole at the ends of the minor axis, respectively.

14. The pump device according to claim 13, wherein, One or more coils include three coils arranged along the common axis, wherein none of the three coils overlaps with each other circumferentially, and wherein each of the three coils generates a corresponding magnetic field that interacts with each of the plurality of magnets to rotate the rotor.

15. The pump device according to any one of claims 1-3, wherein, The stator is configured to generate magnetic flux based on one or more AC sinusoidal signals to rotate the rotor, the one or more AC sinusoidal signals being provided through the one or more coils respectively.

16. The pump device according to any one of claims 1-3, wherein, Each of the one or more coils is positioned such that the common axis extends through each coil and such that the motor does not include a coil through which the common axis does not extend.

17. The pump device according to any one of claims 1-3, wherein, The motor does not include coils located at a common axial position along the common axis and arranged circumferentially around the common axis.

18. The pump device according to any one of claims 1-3, wherein, The one or more coils include three coils arranged along the common axis, each of the three coils being coaxial with the common axis.

19. The pump device according to any one of claims 1-3, wherein, Compared to any metal stack of the stator that concentrates magnetic flux into the magnet of the motor, none of the one or more coils extend closer to the fluid displacement member.

20. The pump device according to any one of claims 1-3, wherein, The actuator includes: an elongated screw coaxial with the common axis, the screw being driven by the rotational output such that the screw either rotates about the common axis or reciprocates linearly along the common axis; and a nut connected to the elongated screw to either rotate about the common axis or reciprocate linearly along the common axis.

21. The pump device according to claim 20, wherein, The actuator also includes a nut that engages the screw, such that one of the screw and the nut rotates and the other of the screw and the nut translates linearly.

22. The pump device according to any one of claims 1-3, wherein, The fluid displacement component is a piston.

23. The pump device according to claim 1, wherein, The stator includes: One or more phase components are arranged along the common axis, each of the one or more phase components including a coil of the one or more coils, the coils being axially arranged between a first flux loop and a second flux loop of the phase component.

24. The pump device according to claim 23, wherein, Both the first and second flux rings are made of metal.

25. The pump device according to claim 23, wherein, Each of the one or more phase components further includes a plurality of axial return portions extending between and connecting the first flux loop and the second flux loop.

26. The pump device according to claim 25, wherein, Each of the plurality of axial return sections is made of metal.

27. The pump device according to claim 25, wherein, The coil is disposed in an annular chamber coaxial with the common axis and defined by the first flux ring, the second flux ring and the plurality of axial return sections.

28. The pump device according to claim 27, wherein, The coil is radially disposed between the plurality of axial return sections and the rotor.

29. The pump device according to claim 27, wherein, The first flux ring includes a plurality of first spikes that protrude radially toward the rotor, and the second flux ring includes a plurality of second spikes that protrude radially toward the rotor.

30. The pump device according to claim 29, wherein, The plurality of first protrusions extend axially above the coil, such that at least a portion of each of the plurality of first protrusions is radially disposed between the coil and the rotor.

31. The pump device according to claim 1, wherein The actuator is configured such that: for every first number of full revolutions of the motor, the fluid displacement member travels one inch, wherein... The first quantity is in the range of 0.9-3.0 revolutions, including the end value.

32. The pump device according to claim 31, wherein, The rotor is arranged radially outside the stator.

33. The pump device according to claim 31, wherein, The rotor is arranged radially inside the stator.

34. The pump device according to claim 1, wherein, The driver is configured such that the fluid displacement member completes one pump stroke for every X number of full revolutions of the motor, wherein X is in the range of 1-3, including the extreme value.

35. The pump device according to claim 1, wherein, The fluid displacement member includes a cylindrical piston coaxial with the common axis, and the piston is configured to reciprocate linearly along the common axis to pump fluid.

36. The pump device according to claim 35, wherein, Each of the plurality of coils is axially positioned between the first metal component and the second metal component.

37. The pump device according to claim 36, wherein, Each of the plurality of coils is radially disposed between the third metal component and the rotor.

38. A sprayer comprising a pump device according to any one of the preceding claims.

39. The sprayer according to claim 38, wherein, The sprayer is handheld.

40. A drum-shaped component unloading machine, comprising a pump device according to any one of claims 1-37.

41. An apparatus for moving a liquid, the apparatus comprising: An electric motor configured to produce a rotary output, the electric motor comprising: A rotor configured to rotate about a common axis, the rotor comprising a plurality of magnets, each magnet being elongated and extending parallel to the common axis, the plurality of magnets being arranged in a ring around the common axis; and A stator configured to be energized to generate a magnetic flux that rotates the rotor, the stator comprising: Multiple coils, arranged along a common axis, each coil being coaxial with the common axis; and Multiple circular spike arrays arranged along the common axis, each of the multiple circular spike arrays comprising: A plurality of spikes arranged in a circle coaxial with the common axis, all spikes being configured to be simultaneously polarized by coils of a plurality of coils to generate magnetic flux, thereby causing the rotor to rotate relative to the stator; and A fluid displacement member configured to rotate about the common axis via the rotor to move liquid; The stator includes a first phase assembly, which comprises a first circular spike array, a second circular spike array, and a first coil, which is axially disposed directly between the first and second circular spike arrays. The motor does not include a coil with end turns that extend along the common axis beyond all the spikes.

42. The device according to claim 41, wherein, The fluid displacement component rotates coaxially with respect to the common axis.

43. The device according to claim 41, wherein, There is no transmission device between the fluid displacement component and the rotor.

44. The device according to any one of claims 41-43, wherein, The fluid displacement component is one of the rotors of a progressive cavitation pump, a vane pump, and a peristaltic pump.

45. The device according to claim 41, wherein, The fluid displacement component includes a helical rotor that rotates within a progressive cavity stator housing.

46. ​​The device according to claim 45, wherein, One or both of the helical rotor and the progressive cavity stator housing are coaxial with the common axis.

47. The device according to claim 45, wherein, The helical rotor rotates coaxially with the common axis.

48. The device according to any one of claims 41-43, wherein, The plurality of circular spike arrays are arranged into multiple pairs of circular spike arrays, each pair having a first circular spike array and a second circular spike array, and the plurality of coils including corresponding coils located between each pair of circular spike arrays.

49. The device according to any one of claims 41-43, wherein, Each of the plurality of magnets overlaps radially with each of the plurality of coils.

50. The device according to any one of claims 41-43, wherein, The motor does not include a coil with an end turn positioned closer to the fluid displacement member than any of the spikes.

51. An apparatus for moving a liquid, the apparatus comprising: An electric motor configured to produce a rotary output, the electric motor comprising: A rotor configured to rotate about a common axis, the rotor comprising a plurality of magnets, each magnet being elongated and extending parallel to the common axis, the plurality of magnets being arranged in a ring around the common axis; and A stator, configured to be energized to generate magnetic flux that rotates the rotor, the stator comprising: A plurality of phase components, the plurality of phase components being arranged along the common axis, each of the plurality of phase components comprising: A coil, the coil extending along the common axis, the coil being coaxially arranged with the common axis; and A first circular spike array, comprising: a first plurality of spikes arranged in a circle coaxial with the common axis; The second circular spike array includes a second plurality of spikes arranged in a circle coaxial with the common axis; Wherein, all the protrusions of the first plurality of protrusions and all the protrusions of the second plurality of protrusions are configured to be simultaneously polarized by the coils disposed axially directly between the first circular protrusion array and the second circular protrusion array to generate magnetic flux, so as to rotate the rotor relative to the stator; and a fluid displacement member is configured to be moved by the output of the electric motor, wherein at least one protrusion of the plurality of phase components of the stator is arranged to be closer to the fluid displacement member than any coil of the plurality of phase components.

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