Patent Description:
This disclosure relates to positive displacement pumps and more particularly to a cooling system for positive displacement pumps.

Positive displacement pumps discharge a process fluid at a selected flow rate. In a typical positive displacement pump, a fluid displacer, usually a piston or diaphragm, pumps the process fluid. Some positive displacement pumps are double displacement pumps that employ two fluid displacers that pump the process fluid.

Fluid-operated double displacement pumps typically employ diaphragms as the fluid displacers and air or hydraulic fluid as a working fluid to drive the fluid displacers. The two diaphragms are joined by a shaft. In an air operated double displacement pump compressed air is the working fluid and is alternatingly provided to drive chambers of each diaphragm to drive displacement of the diaphragms. In a hydraulically-operated double displacement pump, hydraulic fluid, such as non-compressible hydraulic oil, is the working fluid that is alternatingly provided to first and second chambers to displace the fluid displacers.

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

The document <CIT> relates to an air compressor suitable for producing compressed air which is required in order to drive, for instance, a pneumatic tool. The air compressor is capable of cooling heat generating units such as a circuit board, a motor, a compressor, and the like, while the circuit board contains inverter control means.

The document <CIT> relates to a package-type compressor with improved cooling performance for cooling a body unit and a control panel. The package-type compressor includes: a cooling fan accommodated in a fan duct to induce a flow of cooling air taken in through inlets and discharged through an outlet; a machine chamber that causes the cooling air taken in at the inlet to flow along a body unit; and a cooling duct that causes the cooling air taken in at the inlet to flow along the control panel.

The document <CIT> relates to a pump system and to a method for cooling a vacuum pump of a pump system.

The document <CIT> relates to a device for sealing and inflating inflatable objects, in particular a motor vehicle tire.

The present invention relates to a displacement pump according to independent claim <NUM>, wherein further developments of the inventive displacement pump are provided in the sub-claims, respectively.

According to one aspect of the disclosure, a displacement pump for pumping a fluid includes an electric motor including a stator and a rotor; a fluid displacer configured to pump fluid by linear reciprocation of the fluid displacer; a cooling circuit including a flowpath about an exterior of a motor housing that houses the electric motor; and a fan assembly configured to blow air through the cooling circuit.

According to an additional or alternative aspect of the disclosure, a displacement pump for pumping a fluid includes an electric motor at least partially disposed in a motor housing and including a stator and a rotor; a first fluid displacer connected to the rotor such that a rotational output from the rotor provides a driving input to the first fluid displacer; and a cooling circuit extending about an exterior of the motor housing that houses the electric motor.

According to another additional or alternative aspect of the disclosure, a displacement pump for pumping a fluid includes an electric motor at least partially disposed in a motor housing and including a stator and a rotor; a controller operatively connected to the electric motor, the controller disposed in a control housing extending from the motor housing; a first fluid displacer connected to the rotor such that a rotational output from the rotor provides a driving input to the first fluid displacer to cause pumping by the first fluid displacer; and a cooling circuit having a flowpath extending between the motor housing and the control housing.

According to yet another additional or alternative aspect of the disclosure, a displacement pump for pumping a fluid includes an electric motor including a stator and a rotor; a fluid displacer configured to pump fluid and connected to the rotor to be driven by the rotor; a cooling circuit including a flowpath about an exterior of a motor housing that houses the electric motor; and a fan assembly configured to blow air into a portion of the flowpath disposed between a first thermally conductive wall of the motor housing and a second thermally conductive wall of a control housing in which electrical control components of the displacement pump are disposed, such that an output from the fan assembly contacts both the first thermally conductive wall and the second thermally conductive wall.

According to yet another additional or alternative aspect of the disclosure, a displacement pump for pumping a fluid includes an electric motor including a stator and a rotor; a fluid displacer configured to pump fluid and connected to the rotor to be driven by the rotor; a cooling circuit including a flowpath about a curved exterior of a motor housing that houses the electric motor; and a fan assembly configured to blow air through the cooling circuit.

According to yet another additional or alternative aspect of the disclosure, a displacement pump for pumping a fluid includes an electric motor including a stator and a rotor; a fluid displacer configured to pump fluid and connected to the rotor to be driven by the rotor; a cooling circuit including a flowpath about an exterior of a motor housing that houses the electric motor; and a fan assembly configured to blow air through the cooling circuit, an inlet of the fan assembly is oriented to receive the air axially along a fan axis that an impeller of the fan assembly rotates on, and an outlet of the fan assembly is oriented to output the air transverse to the fan axis.

According to yet another additional or alternative aspect of the disclosure, a displacement pump for pumping a fluid includes an electric motor including a stator and a rotor; a motor housing that houses the electric motor, the motor housing including a housing body and a plurality of heat sinks projecting from the housing body; a fluid displacer configured to pump fluid and connected to the rotor to be driven by the rotor; a cooling circuit including a flowpath about an exterior of the motor housing; and a fan assembly configured to blow air through the cooling circuit.

According to yet another additional or alternative aspect of the disclosure, a displacement pump for pumping a fluid includes an electric motor including a stator and a rotor; a fluid displacer configured to pump fluid and connected to the rotor to be driven by the rotor; a cooling circuit including a flowpath about an exterior of a motor housing that houses the electric motor; and a fan assembly configured to blow air through the cooling circuit. The flowpath extends at least <NUM>-degrees about the motor housing.

This disclosure relates to cooling of electrically operated pumps. The electrically operated pumps include an electric motor that provides driving force to a fluid displacement member of the pump. The electric motor and electrical control components, such as those mounted on circuit boards, etc., generate heat during operation. Those components requiring cooling to dissipate the heat. According to the present disclosure, the electric motor and, in some examples, the control components are actively cooled by a cooling assembly that blows cooling air over the housings of such components to wick heat from those heat generating components. The housings of the motor and control components can be formed from thermally conductive material that is exposed directly to the cooling flow generated by the cooling assembly. Such a configuration facilitates cooling of both the electric motor and the control components by a single cooling flow.

<FIG> is a first block schematic diagram of electrically operated pump <NUM>. <FIG> is a second block schematic diagram of electrically operated pump <NUM>. <FIG> will be discussed together. Motor <NUM>, fluid displacer <NUM>, driver <NUM>, cooling assembly <NUM>, and controller <NUM>. Motor <NUM> includes motor components 6a, 6b. Motor <NUM> is at least partially disposed in motor housing <NUM>. Controller <NUM> is at least partially disposed in control housing <NUM>.

Motor <NUM> is disposed within a motor housing <NUM> and is configured to drive displacement of fluid displacer <NUM>. Motor <NUM> includes motor components 6a, 6b, one of which is formed as a stator is configured to electromagnetically drive rotation of the other one of motor components 6a, 6b that is formed as a rotor. The rotor rotates on the motor axis MA. For example, motor component 6a can be a stator and motor component 6b can be a rotor in an inner rotator example, with the rotor radially within the stator. In other examples, motor component 6b can be a stator and motor component 6a can be a rotor in an outer rotator example, with the stator radially within the rotor.

The rotor is configured to rotate on a rotational axis in response to current (such as a direct current (DC) signals and/or alternating current (AC) signals) through the stator. The motor <NUM> can be a reversible motor in that the stator can cause the rotor to rotate in either of two rotational directions (e.g., alternating between clockwise and counterclockwise). The rotor is connected to the fluid displacer <NUM> via driver <NUM>. Driver <NUM> can receive a rotational output from the rotor to drive displacement of fluid displacer <NUM>.

It is understood that fluid displacer <NUM> can be configured to reciprocate along an axis, rotate on an axis, or be otherwise displaced to pump the fluid. In some examples, driver <NUM> can be configured to receive a rotary output from the rotor and provide a linear, reciprocating input to fluid displacer <NUM>. In other examples, the fluid displacer <NUM> can be a rotor configured to rotate within or about a stationary member. Fluid displacers <NUM> can be of any type suitable for pumping fluid. For example, fluid displacers <NUM> can be configured as diaphragms or pistons in reciprocating examples, or configured as rotating elements in rotational pump configurations. Pump <NUM> can be configured as a progressive cavity pump, impeller pump, peristaltic pump, among other options. In examples where the pump <NUM> includes a rotating fluid displacer <NUM>, it is understood that the fluid displacer <NUM> can be directly connected to the rotor. For example, driver <NUM> can be formed as a component of the rotor, such as integrally with the rotor. In the example shown, pump <NUM> includes a single fluid displacer <NUM>, but it is understood that pump <NUM> can include one, two, or more fluid displacers <NUM> operatively connected to the motor <NUM> to be driven by the motor <NUM>. It is understood that fluid displacer <NUM> can be configured to reciprocate or rotate on an axis coaxial with the motor axis MA or misaligned with the motor axis MA. For example, the motor <NUM> can be connected to the fluid displacer <NUM> by an eccentric driver such that the motor axis MA and the axis of reciprocation of the fluid displacer <NUM> are not coaxial.

Controller <NUM> is operatively connected to motor <NUM> to control operation of motor <NUM>. Controller <NUM> can further be operatively connected to cooling assembly <NUM> to control operation of the active components of cooling assembly <NUM> (e.g., the impeller of the cooling assembly <NUM>). The controller <NUM> is configured to store software, implement functionality, and/or process instructions. The controller <NUM> can include memory and control circuitry configured to implement functionality and/or process instructions. For example, the control circuitry can be capable of processing instructions stored in the memory. Examples of the control circuitry can include one or more of a processor, a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other equivalent discrete or integrated logic circuitry. The controller <NUM> can be of any suitable configuration for gathering data, processing data, etc. The controller <NUM> can receive inputs, provide outputs, generate commands for controlling operation of motor <NUM>, etc. The controller <NUM> can be configured to receive inputs and/or provide outputs via a user interface. The controller <NUM> can include hardware, firmware, and/or stored software. The controller <NUM> can be entirely or partially mounted on one or more circuit boards.

Cooling assembly <NUM> is configured to actively cool the heat generating components of pump <NUM>, such as motor <NUM> and controller <NUM>. Cooling assembly <NUM> can include a fan that draws a cooling airflow AF in and blows a cooling airflow AF out. The intake cooling airflow can flow over motor housing <NUM> of motor <NUM> and, in some examples, over control housing <NUM> of controller <NUM>. The output cooling airflow from cooling assembly <NUM> can flow over both the motor housing <NUM> and the control housing <NUM>. As shown in <FIG>, the cooling assembly <NUM> can be configured to output the cooling airflow into a passage disposed directly between and defined at least partially by the motor housing <NUM> and the control housing <NUM>. The motor housing <NUM> and control housing <NUM> can thus define the passage that the cooling airflow flows through, such that the cooling airflow can wick heat from both the control components and motor components. At least the portions of the motor housing <NUM> and the control housing <NUM> exposed to the cooling airflow AF can be formed by thermally conductive material to facilitate efficient heat transfer. In some examples, heat sinks extend from one or both of motor housing <NUM> and control housing <NUM> and be exposed to the cooling airflow AF to increase the surface area of the respective housing and facilitate more efficient heat transfer.

Pump <NUM> provides significant advantages. Cooling assembly <NUM> actively blows cooling air over the main heat sources of the pump <NUM>, providing efficient heat transfer relative to a passive cooling arrangement. The housings <NUM>, <NUM> of those heat generating components can be formed from thermally conductive material to facilitate efficient heat transfer. Cooling assembly <NUM> actively blowing the cooling flow over the housings of the heat generating components, actively exchanging the heated air for cool air providing for more efficient cooling. The cooling configuration of pump <NUM> facilitates longer operation and continuous operation of pump <NUM> at higher speeds and greater flowrates without overheating. The cooling configuration allows for more efficient pumping and fluid transfer.

<FIG> is a front isometric view of electrically operated pump <NUM>. <FIG> is a rear isometric view of pump <NUM>. <FIG> is a block schematic diagram of pump <NUM>. <FIG> will be discussed together. Pump <NUM> is substantially similar to pump <NUM> shown in <FIG>. Pump <NUM> includes inlet manifold <NUM>, outlet manifold <NUM>, pump body <NUM>, fluid covers 18a, 18b (collectively herein "fluid cover <NUM>" or "fluid covers <NUM>"), fluid displacers 20a, 20b (collectively herein "fluid displacer <NUM>" or "fluid displacers <NUM>"), motor <NUM>, driver <NUM>, and controller <NUM>. Motor <NUM> includes stator <NUM> and rotor <NUM>. Pump body <NUM> is disposed between fluid covers 18a, 18b. Motor <NUM> is disposed within pump body <NUM> and is configured to drive displacement of fluid displacers <NUM>. While motor <NUM> shown as disposed on the pump axis PA such that a rotational axis of rotor <NUM> is coaxial with the pump axis PA, it is understood that not all examples are so limited. For example, the motor <NUM> can be connected to the fluid displacer <NUM> by an eccentric driver and such that the rotational axis and pump axis PA are not coaxial in such a case. The rotational axis can be transverse to the pump axis PA. In some examples, the rotational axis can be orthogonal to the pump axis PA.

In the example shown, motor <NUM> is disposed coaxial with fluid displacers <NUM>, through it is understood that not all examples are so limited. Motor <NUM> is an electric motor having stator <NUM> and rotor <NUM>. Stator <NUM> includes armature windings and rotor <NUM> includes permanent magnets. Rotor <NUM> is configured to rotate on a rotational axis in response to current (such as a direct current (DC) signals and/or alternating current (AC) signals) through stator <NUM>. Motor <NUM> is a reversible motor in that stator <NUM> can cause rotor <NUM> to rotate in either of two rotational directions (e.g., alternating between clockwise and counterclockwise). Rotor <NUM> is connected to the fluid displacers <NUM> via driver <NUM>. In the example shown, driver <NUM> is configured to receive a rotary output from rotor <NUM> and provide a linear, reciprocating input to fluid displacers <NUM>. It is understood that, while fluid displacers <NUM> are described as linearly reciprocating, some examples of pump <NUM> includes a fluid displacer <NUM> that is configured to rotate to pump the fluid. For example, the fluid displacer can be a rotor configured to rotate within or about a stationary member. For example, pump <NUM> can be configured as a progressive cavity pump, impeller pump, peristaltic pump, among other options. In examples where the pump <NUM> includes a rotating fluid displacer <NUM>, it is understood that the fluid displacer <NUM> can be directly connected to the rotor <NUM> without an intermediate driver <NUM>.

Fluid displacers <NUM> can be of any type suitable for pumping fluid from inlet manifold <NUM> to outlet manifold <NUM>. For example, fluid displacers <NUM> can be configured as diaphragms or pistons in reciprocating examples, or configured as rotating elements in rotational pump configurations. While pump <NUM> is shown as including two fluid displacers <NUM>, it is understood that some examples of pump <NUM> include a single fluid displacer <NUM>. It is understood that the teachings discussed herein can apply equally to displacement pumps having any desired number of fluid displacers <NUM> and the fluid displacers <NUM> can be formed in any desired manner, such as diaphragms or pistons. Pump <NUM> can be referred to as a diaphragm pump when fluid displacers <NUM> are formed by one or more diaphragms. Pump <NUM> can be referred to as a piston pump when fluid displacers <NUM> are formed by one or more pistons.

Controller <NUM> is operatively connected to motor <NUM> to control operation of motor <NUM>. The controller <NUM> is configured to store software, implement functionality, and/or process instructions. The controller <NUM> can include memory and control circuitry configured to implement functionality and/or process instructions. For example, the control circuitry can be capable of processing instructions stored in the memory. Examples of the control circuitry can include one or more of a processor, a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other equivalent discrete or integrated logic circuitry. The controller <NUM> can be of any suitable configuration for gathering data, processing data, etc. The controller <NUM> can receive inputs, provide outputs, generate commands for controlling operation of motor <NUM>, etc. The controller <NUM> can be configured to receive inputs and/or provide outputs via user interface <NUM>. The controller <NUM> can include hardware, firmware, and/or stored software. The controller <NUM> can be entirely or partially mounted on one or more circuit boards.

User interface <NUM> of controller <NUM> is shown. The user can provide inputs to controller <NUM> via user interface <NUM> to control operation of pump <NUM>. During operation, control signals are provided to stator <NUM> to cause stator <NUM> to drive rotation of rotor <NUM>. Driver <NUM> receives the rotational output from rotor <NUM> as an input and converts that rotational input into a linear output to drive reciprocation of fluid displacers <NUM>. In some examples, rotor <NUM> rotates in the first rotational direction to drive fluid displacers <NUM> in a first axial direction and rotates in the second rotational direction opposite the first rotational direction to drive fluid displacers <NUM> in a second axial direction opposite the first axial direction.

In the example shown, driver <NUM> causes fluid displacers <NUM> to reciprocate along pump axis PA through alternating suction and pumping strokes. During the suction stroke, the fluid displacer <NUM> draws process fluid from inlet manifold <NUM> into a process fluid chamber defined, at least in part, by fluid covers <NUM> and fluid displacers <NUM>. During the pumping stroke, the fluid displacer <NUM> drives process fluid from the process fluid chamber to outlet manifold <NUM>. Typically, depending on the arrangement of check valves, the two fluid displacers <NUM> are operated <NUM>-degrees out of phase, such that a first fluid displacer <NUM> is driven through a pumping stroke (e.g., driving process fluid downstream from the pump) while a second fluid displacer <NUM> is driven through a suction stroke (e.g., drawing process fluid from upstream and into the pump). In the example shown, pump <NUM> includes two fluid displacers <NUM> that can simultaneously changeover (e.g., transition between the pumping stroke and the suction stroke), but <NUM>-degrees out of phase with respect to each other.

Driver <NUM> is directly connected to rotor <NUM> and fluid displacers <NUM> are directly driven by driver <NUM>. As such, motor <NUM> directly drives fluid displacers <NUM> without the presence of intermediate gearing, such as speed reduction gearing. Power cord <NUM> extends from pump <NUM> and is configured to provide electric power to the electronic components of pump <NUM>. Power cord <NUM> can connect to a wall socket.

It is understood that, in some examples, the pump <NUM> is configured with a single fluid displacer <NUM>. Such a pump <NUM> can be either a single displacement pump, which outputs the process fluid during the pumping stroke but not the suction stroke, or a doble displacement pump, which outputs the process fluid during both the pumping stroke and the suction stroke. For example, the single fluid displacement member <NUM> can be a piston for a double displacement pump that reciprocates within a cylinder. The piston includes an internal flowpath through the piston between an upstream pump chamber and a downstream pump chamber that are separated by the piston interfacing with the cylinder. The outlet check valve is disposed within the piston itself to reciprocate with the piston. During a first stroke, the piston reduces the size of the upstream chamber, opens the outlet valve in the piston, closes an inlet valve on an opposite side of the upstream chamber from the piston, and causes the process fluid to flow through the piston and downstream from the cylinder. During a second stroke, the piston reduces the size of the downstream chamber and increases the size of the upstream chamber, closes the outlet valve, opens the inlet valve, outputs process fluid from the downstream chamber, and draws process fluid into the upstream chamber through the inlet valve.

<FIG> is an exploded front isometric view of pump <NUM>. Pump <NUM> includes inlet manifold <NUM>, outlet manifold <NUM>, pump body <NUM>, fluid covers 18a, 18b (collectively herein "fluid cover <NUM>" or "fluid covers <NUM>"), fluid displacers 20a, 20b (collectively herein "fluid displacer <NUM>" or "fluid displacers <NUM>"), motor <NUM>, driver <NUM>, bearings 54a, 54b (collectively herein "bearing <NUM>" or "bearings <NUM>"), motor nut <NUM>, pump check valves <NUM>, grease caps 60a, 60b (collectively herein "grease cap <NUM>" or "grease caps <NUM>"), position sensor <NUM>, and housing fasteners <NUM>.

Pump body <NUM> includes central portion <NUM> and end caps 68a, 68b (collectively herein "end cap <NUM>" or "end caps <NUM>"). Central portion <NUM> includes motor housing <NUM>, control housing <NUM>, and heat sinks <NUM>. Fluid displacers 20a, 20b are configured as diaphragms in the example shown and respectively include inner plates 78a, 78b (collectively herein "inner plate <NUM>" or "inner plates <NUM>"); outer plates 80a, 80b (collectively herein "outer plate <NUM>" or "outer plates <NUM>"); membranes 82a, 82b (collectively herein "membrane <NUM>" or "membranes <NUM>"), and fasteners 84a, 84b. Motor <NUM> includes stator <NUM> and rotor <NUM>. Rotor <NUM> includes permanent magnet array <NUM> and rotor body <NUM>. Drive nut <NUM> and screw <NUM> of driver <NUM> are shown.

End caps 68a, 68b are disposed on opposite lateral sides of central portion <NUM> and are attached to central portion <NUM> to form pump body <NUM>. Housing fasteners <NUM> extend through end caps <NUM> into pump body <NUM> to secure end caps <NUM> to pump body <NUM>. Specifically, housing fasteners <NUM> extend through end caps <NUM> and into fastener openings formed in body flanges <NUM> formed on motor housing <NUM> of pump body <NUM>. Heat sinks <NUM> are formed on central portion <NUM>. In the example shown, heat sinks <NUM> are formed by fins, but it is understood that heat sinks can be of any configuration suitable for increasing the surface area of pump body <NUM> to facilitate heat exchange to cool the heat generating components of pump <NUM>, such as motor <NUM> and controller <NUM>.

Fluid covers 18a, 18b are connected to end caps 68a, 68b, respectively. Housing fasteners <NUM> secure fluid covers <NUM> to end caps <NUM>. Inlet manifold <NUM> is connected to each fluid cover <NUM>. Inlet ones of pump checks <NUM> are disposed between inlet manifold <NUM> and fluid covers 18a, 18b. The inlet ones of pump checks <NUM> are one-way valves configured to allow the process fluid to flow into process fluid chambers formed by a fluid displacement member <NUM> and fluid cover <NUM> and prevent retrograde flow from the process fluid chambers to inlet manifold <NUM>. Outlet manifold <NUM> is connected to each fluid cover <NUM>. Outlet ones of pump checks <NUM> are disposed between outlet manifold <NUM> and fluid covers 18a, 18b. The outlet ones of pump checks <NUM> are one-way valves configured to allow the process fluid to flow out of the process fluid chambers to outlet manifold <NUM> and to prevent retrograde flow from outlet manifold <NUM> to the process fluid chambers.

Motor <NUM> is disposed within motor housing <NUM> between end caps <NUM>. Control housing <NUM> is connected to and extends from motor housing <NUM>. Motor housing <NUM> can be substantially similar to motor housing <NUM> (<FIG>). Control housing <NUM> can be substantially similar to control housing <NUM> (<FIG>). Control housing <NUM> is configured to house control elements of pump <NUM>, such as controller <NUM> (<FIG> and <FIG>). Stator <NUM> surrounds rotor <NUM> and drives rotation of rotor <NUM>. As such, motor <NUM> can be considered to be an inner rotator motor. Rotor <NUM> rotates on a rotational axis, coaxial with pump axis PA in the example shown, and is disposed coaxially with driver <NUM> and fluid displacers <NUM>. Permanent magnet array <NUM> is disposed on rotor body <NUM>.

Drive nut <NUM> is disposed within and connected to rotor body <NUM>. Drive nut <NUM> can be attached to rotor body <NUM> via fasteners (e.g., bolts), adhesive, or press-fitting, among other options. Drive nut <NUM> rotates with rotor body <NUM>. Drive nut <NUM> is mounted to bearings 54a, 54b at opposite axial ends of drive nut <NUM>. Bearings <NUM> are configured to support both axial and radial forces. In some examples, bearings <NUM> comprise tapered roller bearings. Screw <NUM> extends through drive nut <NUM> and is connected to each fluid displacer <NUM>. Screw <NUM> reciprocates along pump axis PA to drive fluid displacers <NUM> through respective pumping and suction strokes. Rolling elements (not shown), such as balls or elongate rollers among other options, can be disposed between drive nut <NUM> and screw <NUM> to support screw <NUM> relative to drive nut <NUM>. As such, screw <NUM> may not directly contact drive nut <NUM>. Instead, the rolling elements engage the thread of screw <NUM>, receive the rotational input from drive nut <NUM>, and drive axial displacement of screw <NUM>.

Motor nut <NUM> connects to a portion of pump body <NUM> housing stator <NUM>. Motor nut <NUM> can be considered to connect to a stator housing of pump <NUM>, which stator housing can be formed by the motor housing <NUM> and end caps 68a, 68b. In the example shown, motor nut <NUM> connects to end cap 68a and secures bearings <NUM> within pump body <NUM>. Motor nut <NUM> preloads bearings <NUM>. Screw <NUM> can reciprocate through motor nut <NUM> during operation. Grease cap 60a is supported by motor nut <NUM> and motor nut <NUM> aligns grease cap 60a relative to bearing 54a. Grease cap 60b is disposed adjacent bearing 54b. Grease caps <NUM> prevent contaminants from entering bearings <NUM> and retain any grease that may liquify during operation.

Fluid displacer 20a is connected to first end of screw <NUM>. Membrane 82a is captured between inner plate 78a and outer plate 80a. Fastener 84a extends through each of inner plate 78a, outer plate 80a, and membrane 82a and into screw <NUM> to connect fluid displacer 20a to driver <NUM>. An outer circumferential edge of membrane 82a is captured between fluid cover 18a and end cap 68a. Fluid displacer 20b is connected to an opposite axial end of screw <NUM> from fluid displacer 20a. In the example shown, membrane 82b is overmolded onto outer plate 80b. Fastener 84b extends from outer plate 80b through the inner plate 78b and into screw <NUM> to connect fluid displacer 20b to driver <NUM>. An outer circumferential edge of membrane 82b is captured between fluid cover 18b and end cap 68b. While fluid displacers 20a, 20b are described as having different configurations, it is understood that pump <NUM> can include fluid displacers 20a, 20b having the same or differing configurations. It is further understood that fluid displacers <NUM> can be configured as pistons connected to the opposite axial ends of screw <NUM>, among other options.

During operation, current signals are provided to stator <NUM> to electromagnetically drive rotation of rotor <NUM>. Position sensor <NUM> is disposed proximate rotor <NUM>, as discussed in more detail below, and generates position data regarding the rotational position of rotor <NUM> relative to stator <NUM>. For example, position sensor <NUM> can include an array of Hall-effect sensors responsive to the polarity of the permanent magnets in permanent magnet array <NUM>. Controller <NUM> can utilize the position data to commutate motor <NUM>.

Driver <NUM> converts rotational motion from rotor <NUM> into linear motion of fluid displacers <NUM>. Rotor body <NUM> rotates about pump axis PA, in the example shown, and drives rotation of drive nut <NUM>. Drive nut <NUM> drives screw <NUM> axially along pump axis PA, such as by engagement of rolling elements disposed between drive nut <NUM> and screw <NUM> and that support drive nut <NUM> relative to screw <NUM>. The rolling elements support drive nut <NUM> relative screw <NUM> such that drive nut <NUM> does not contact screw <NUM> during operation. The rolling elements translate the rotation of drive nut <NUM> into linear movement of screw <NUM>. Screw <NUM> drives fluid displacers <NUM> through respective pumping and suction strokes. In some examples, rotor <NUM> is rotated in a first rotational direction to cause screw <NUM> to displace in a first axial direction and rotor <NUM> is rotated in a second rotational direction opposite the first rotational direction to cause screw <NUM> to displace in a second axial direction opposite the first axial direction.

Motor <NUM> is axially aligned with fluid displacers <NUM> and drives reciprocation of fluid displacers <NUM>. Rotor <NUM> rotates on a rotational axis and fluid displacers <NUM> reciprocate on pump axis PA, in the example shown. In the example shown the rotational axis is coaxial with pump axis PA, but it is understood that not all examples are so limited. Pump <NUM> provides significant advantages. Motor <NUM> being axially aligned with fluid displacers <NUM> facilitates a compact pump arrangement providing a smaller package relative to other mechanically-driven and electrically-driven pumps. In addition, motor <NUM> does not include gearing, such as reduction gears, between motor <NUM> and fluid displacers <NUM>. Eliminating that gearing provides a more reliable, simpler pump by reducing the count of moving parts. Eliminating the gearing also provides a quieter pump operation.

<FIG> is a rear isometric view of electrically operated pump <NUM>. <FIG> is a rear isometric view of pump <NUM> with housing cover <NUM> removed. <FIG> is an isometric view of pump body <NUM> of pump <NUM>. <FIG> is a cross-sectional view taken along line D-D in <FIG>. <FIG> is a cross-sectional view taken along line E-E in <FIG>. <FIG> will be discussed together. Pump <NUM> is substantially similar to pump <NUM> shown in <FIG>. Pump <NUM> includes inlet manifold <NUM>, outlet manifold <NUM>, pump body <NUM>, fluid covers 18a, 18b (collectively herein "fluid cover <NUM>" or "fluid covers <NUM>"), fluid displacers 20a, 20b (collectively herein "fluid displacer <NUM>" or "fluid displacers <NUM>"), motor <NUM>, driver <NUM>, controller <NUM>, fan assembly <NUM>, and housing cover <NUM>. Motor <NUM> includes stator <NUM> and rotor <NUM>. Fan assembly <NUM> includes impeller <NUM> and fan motor <NUM>. The cooling configuration shown in <FIG> is substantially similar to the cooling configuration shown in <FIG>.

Pump body <NUM> includes central portion <NUM> and end caps 68a, 68b (collectively herein "end cap <NUM>" or "end caps <NUM>"). Central portion <NUM> includes motor housing <NUM>, control housing <NUM>, and heat sinks <NUM>. Control housing <NUM> includes control housing block <NUM> and control cover <NUM>. Rotor <NUM> includes permanent magnet array <NUM> and rotor body <NUM>. Drive nut <NUM> and screw <NUM> of driver <NUM> are shown.

End caps 68a, 68b are disposed on opposite lateral sides of central portion <NUM> and are attached to central portion <NUM> to form pump body <NUM>. Fluid covers 18a, 18b are respectively connected to end caps 68a, 68b. Inlet manifold <NUM> is connected to each fluid cover <NUM> to provide the pumped fluid to the process fluid chambers. Outlet manifold <NUM> is connected to each fluid cover <NUM> to receive fluid from the process fluid chambers.

Motor <NUM> and control elements <NUM> (such as controller <NUM> (<FIG> and <FIG>), one or more circuit boards, etc.) are supported by pump body <NUM>. More specifically, motor <NUM> and control elements <NUM> are supported by central portion <NUM> of pump body <NUM>. Motor <NUM> is disposed within motor housing <NUM> between end caps <NUM>. A body of motor housing <NUM> extends circumferentially around motor <NUM>, relative to the rotational axis RA of the rotor <NUM>, and circumferentially encloses the motor <NUM>. The body of motor housing <NUM> curves away from control housing wall <NUM> of the control housing <NUM>. The body of motor housing <NUM> can be considered to be convex towards the control housing <NUM>. Stator <NUM> surrounds rotor <NUM> and drives rotation of rotor <NUM>, such that motor <NUM> can be considered to be an inner rotator motor. Rotor <NUM> rotates on a rotational axis RA. Rotor <NUM> rotates about pump axis PA and is disposed coaxially with driver <NUM> and fluid displacers <NUM>, in the example shown. Permanent magnet array <NUM> is disposed on rotor body <NUM>.

Control housing <NUM> is connected to and extends from motor housing <NUM>. In the example shown, portions of control housing <NUM> and motor housing <NUM> are integrally formed as a single housing component (e. g, by casting among other options). Control housing <NUM> is configured to house control elements <NUM> of pump <NUM>, such as controller <NUM>. In the example shown, control housing block <NUM> is integrally formed with motor housing <NUM>. Control cover <NUM> is mounted to control housing block <NUM>, such as by fasteners. In some examples, control cover <NUM> can be removably connected to control housing block <NUM> to provide access to the internal components within control housing <NUM>.

Heat sinks <NUM> are formed on central portion <NUM>. In the example shown, heat sinks <NUM> are formed in multiple configurations and include projections <NUM> and fins <NUM>. Fins <NUM> are elongate about the rotational axis RA of rotor <NUM> and wrap at least partially around motor housing <NUM>. While heat sinks <NUM> are shown as multiple configurations, it is understood that heat sinks <NUM> can be of any configuration suitable for increasing the surface area of pump body <NUM> to facilitate heat exchange to cool the heat generating components of pump <NUM>. In the example shown, at least some of heat sinks <NUM> define flow passages forming a cooling fluid circuit CF for pump <NUM>. The cooling circuit CF is an outer cooling fluid circuit in that cooling circuit CF extends about the exterior of motor housing <NUM>. In the example shown, the cooling fluid circuit CF is disposed axially between the fluid displacers <NUM>. In the example shown, the cooling fluid circuit CF does not radially overlap with a fluid displacer <NUM> relative to pump axis PA. The cooling fluid circuit CF is fully between the fluid displacers <NUM> axially along the pump axis PA.

In the example shown, support sinks <NUM> extend between and connect control housing <NUM> and motor housing <NUM>, as best seen in <FIG>. The support sinks <NUM> are formed by one or more heat sinks <NUM> that extend between and connect the control housing block <NUM> and motor housing <NUM>. The support sinks <NUM> can be integrally formed with both the control housing block <NUM> and motor housing <NUM>. The support sinks <NUM> at least partially define the cooling fluid circuit CF. More specifically, the support sinks <NUM> at least partially define the channels <NUM> of the intermediate passage <NUM> of the cooling fluid circuit CF. The support sinks <NUM> structurally connect control housing block <NUM> and motor housing <NUM> and facilitate heat transfer from the heat generating components of pump <NUM>. Support sinks <NUM> can be exposed to the cooling flow through the cooling fluid circuit CF on both axial sides of the support sinks <NUM> relative to the rotational axis RA, which is also relative to the pump axis PA in the example shown.

Housing cover <NUM> is mounted to pump body <NUM> and at least partially defines flow passages of the cooling fluid circuit CF. Cooling fluid circuit CF is at least partially enclosed by the housing cover <NUM>. Inlet openings <NUM> and outlet openings <NUM> are formed through housing cover <NUM>. In some examples, housing cover <NUM> is formed as an exhaust cover <NUM> connected to pump body <NUM> on an upper side of central portion <NUM> (e.g., between outlet manifold <NUM> and central portion <NUM> in the example shown), and as intake cover <NUM> connected to pump body <NUM> on a lower side of central portion <NUM> (e.g., between inlet manifold <NUM> and central portion <NUM> in the example shown). As such, housing cover <NUM> can be formed from multiple discrete components assembled to pump <NUM> to at least partially define cooling fluid circuit CF. It is understood, however, that housing cover <NUM> can be formed by as many or as few components as desired. In some examples, housing cover <NUM> is disposed on only one side of central portion, such as by housing cover <NUM> including exhaust cover <NUM> and not intake cover <NUM>.

The main heat sources of pump <NUM> include controller <NUM>, stator <NUM>, and driver <NUM>. Cooling fluid circuit CF directs cooling air through passages proximate the heat generating components to effect heat exchange between the flow of cooling air through cooling fluid circuit CF and the heat sources to thereby cool pump <NUM>. Cooling fluid circuit CF is configured to direct cooling air around motor housing <NUM>. Cooling fluid circuit CF directs cooling air circumferentially around the rotational axis RA of rotor <NUM>. Cooling fluid circuit CF is configured to direct cooling air to provide cooling to elements in both motor housing <NUM> and control housing <NUM>. A cooling assembly, similar to cooling assembly <NUM> (<FIG>), actively blows cooling airflow through the cooling fluid circuit CF to facilitate cooling of the heat generating components of pump <NUM>. In the example shown, the cooling assembly can be considered to include at least fan assembly <NUM>. The cooling assembly can be considered to further include flow directing components, such as housing cover <NUM>.

The flowpath of cooling fluid circuit CF extends directly between the thermally conductive body of the motor housing <NUM> and the thermally conductive control housing wall <NUM>. The flowpath of the cooling air in cooling fluid circuit CF wraps at least partially around the motor housing <NUM>. In some examples, the flowpath can be curved greater than or equal to <NUM>-degrees around the motor housing <NUM> between an inlet and an outlet. In some examples, the flowpath can be curved greater than or equal to <NUM>-degrees around the motor housing <NUM> between an inlet and an outlet. In some examples, the flowpath can be curved greater than or equal to <NUM>-degress around the motor housing <NUM> between an inlet and an outlet. The flowpath of the cooling fluid circuit CF extending about the motor housing <NUM> exposes a large portion of the motor housing <NUM> to the cooling air moved by the fan assembly <NUM>, facilitating heat exchange and cooling of motor <NUM>. The flowpath of the cooling fluid circuit CF extends circumferentially about the rotational axis RA of the rotor <NUM> disposed within motor housing <NUM>. As best seen in <FIG>, the flowpath of the cooling fluid circuit CF is in a plane orthogonal to the axis RA of rotation of the rotor <NUM>, which can also be referred to as the motor axis. The flowpath does not extend through the axis of rotation RA of the rotor <NUM>, but is instead offset from and flows around the axis of rotation RA of the rotor <NUM>.

The flowpath of the cooling fluid circuit CF can be at least partially disposed between the fluid displacers 20a, 20b, such as along the axes of reciprocation of the fluid displacers 20a, 20b. In some examples, at least a portion of the flowpath of the cooling fluid circuit CF is disposed directly between the fluid displacers 20a, 20b. In such an example, a line parallel to the axis of rotation RA of the rotor <NUM> can extend through fluid displacer 20a, fluid displacer 20b, and the flowpath of the cooling fluid circuit CF. Such an axial line can extend through one or more heat sinks <NUM>, such that the heat sinks <NUM> are disposed directly between the fluid displacers 20a, 20b. In some examples, as shown in <FIG>, a portion of the flowpath is disposed radially outside of an area directly between the fluid displacer 20a and the fluid displacer 20b and a second portion of the flowpath is disposed within the area. Disposing a portion of the flowpath directly between the fluid displacers 20a, 20b provides a compact pump arrangement and facilitates forming the flowpath close to the motor <NUM> to further facilitate heat transfer.

In the example shown, cooling fluid circuit CF includes intake passage <NUM>, intermediate passage <NUM>, and exhaust passage <NUM>. In the example shown, there is no valving in cooling fluid circuit CF to direct flow. Instead, fan assembly <NUM> is configured to actively drive cooling air through cooling fluid circuit CF. Fan assembly <NUM> is supported by pump body <NUM>. More specifically, fan assembly <NUM> is supported by control housing wall <NUM> of control housing <NUM>. Impeller <NUM> is disposed within cooling fluid circuit CF. In the example shown, impeller <NUM> is disposed at an intersection between intake passage <NUM> and intermediate passage <NUM>. It is understood, however, that fan assembly <NUM> can be disposed at any desired location relative to the cooling fluid circuit CF. For example, the fan assembly <NUM> can be disposed at an intersection between intermediate passage <NUM> and exhaust passage <NUM>, within intermediate passage <NUM>, among other location options. Blades <NUM> extend from the body of impeller <NUM> and drive the cooling fluid through cooling fluid circuit CF. In the example shown, blades <NUM> extend straight between a root connected to the body of impeller <NUM> and a tip opposite the root.

In the example shown, fan assembly <NUM> is at least partially disposed within the cooling fluid circuit CF, but it is understood that not all examples are so limited. More specifically, impeller <NUM> is disposed in the flowpath between an inlet of cooling fluid circuit CF and an outlet of cooling fluid circuit CF. In the example shown, impeller <NUM> is unshrouded, except by intake cover <NUM>, but it is understood that impeller <NUM> can be shrouded in other examples. Fan motor <NUM> is disposed in control housing <NUM>. Fan motor <NUM>, which can be an electric motor, is isolated from the environment surrounding stator <NUM> by control housing wall <NUM> of control housing block <NUM>, such that the cooling arrangement shown is suitable for use in hazardous locations. Fan shaft <NUM> extends through control housing wall <NUM> to connect impeller <NUM> and fan motor <NUM>.

Impeller <NUM> rotates on fan axis FA to blow the cooling air through the cooling fluid circuit CF. The main flow vector of the cooling air exiting the fan assembly <NUM> is perpendicular to the fan axis FA and is directed directly between the motor <NUM> and control elements <NUM>. More specifically, the air existing the fan assembly <NUM> flows directly between the thermally conductive body of motor housing <NUM> and the thermally conductive control housing wall <NUM>. The main flow vector of the cooling air exiting the fan assembly <NUM> is directed directly between the motor housing <NUM> and the control housing <NUM>. Impeller <NUM> is configured to output airflow radially relative to fan axis FA. In the example shown, impeller <NUM> is disposed axially between the motor housing <NUM> and the control housing <NUM> along the fan axis FA. In the example shown, the impeller <NUM> does not radially overlap with either the motor housing <NUM> or the control housing <NUM> relative to the fan axis FA. As such, a radial line extending from the fan axis FA that passes through the impeller <NUM> does not also pass through either of the motor housing <NUM> or the control housing <NUM>. The fan assembly <NUM> is disposed such that the fan axis FA is disposed in an orientation perpendicular to, but offset from, the axis of rotation RA of the rotor <NUM>.

Intake passage <NUM> is defined between motor housing <NUM> and housing cover <NUM>. Specifically, intake passage <NUM> is defined between motor housing <NUM> and intake cover <NUM>. In the example shown, intake passage <NUM> includes multiple individual channels <NUM> that are at least partially defined by heat sinks <NUM>. The individual channels <NUM> of intake passage <NUM> extend arcuately around motor housing <NUM>. The axial sides of the individual flow channels <NUM>, along rotational axis RA of rotor <NUM>, can be formed by heat sinks <NUM>. As such, at least some of the individual channels <NUM> can be axially bracketed by heat sinks <NUM> relative to the rotational axis RA of rotor <NUM>. In the example shown, at least some of heat sinks <NUM> can extend circumferentially, but not axially, on motor housing <NUM> and about the rotor axis RA of rotor <NUM>, which is also circumferentially about the pump axis PA in the example shown. It is understood, however, that heat sinks <NUM> of intake passage <NUM> can, in some examples, be canted to extend both circumferentially about the rotational axis RA of rotor <NUM> and axially relative to the rotational axis RA of rotor <NUM>. In the example shown, the individual channels <NUM> of intake passage <NUM> include at least three sides at least partially formed by thermally conductive material (e.g., the motor housing <NUM> and heat sinks <NUM>). The body of motor housing <NUM> at least partially defines intake passage <NUM>. Motor housing <NUM> is thereby directly exposed to the cooling flow through cooling fluid circuit CF. Motor housing <NUM> is disposed directly between stator <NUM> and intake passage <NUM> to provide efficient heat transfer from stator <NUM> and driver <NUM> to the cooling flow through cooling fluid circuit CF.

Intermediate passage <NUM> is disposed between control housing <NUM> and motor housing <NUM>. More specifically, intermediate passage <NUM> is disposed between control housing block <NUM> and motor housing <NUM>. Control housing wall <NUM> at least partially defines intermediate passage <NUM>. One or more of the heat generating elements in control housing <NUM> can be mounted to control housing wall <NUM>. The heat generating elements are thereby mounted to the control housing wall <NUM> that is also directly in contact with the cooling air flowing through cooling fluid circuit CF. As such, the heat generating elements are mounted to thermally conductive material (e.g., control housing wall <NUM> can be metallic) that is also exposed to a cooling air flow. Mounting the heat generating elements to control housing wall <NUM> facilitates efficient heat transfer from those components to the cooling flow through cooling fluid circuit CF.

Intermediate passage <NUM> is at least partially defined by the body of motor housing <NUM>. Motor housing <NUM> is thereby directly exposed to the cooling flow through cooling fluid circuit CF. Motor housing <NUM> is disposed directly between stator <NUM> and intermediate passage <NUM> to provide efficient heat transfer from stator <NUM> to the cooling flow through cooling fluid circuit CF. In the example shown, at least one heat sink <NUM> extends between and connects control housing <NUM> and motor housing <NUM>. Specifically, support sinks <NUM> extend between and connect control housing block <NUM> and motor housing <NUM>. The support sinks <NUM> at least partially define intermediate passage <NUM> and directly contact both control housing <NUM> and motor housing <NUM>. Such heat sinks <NUM> facilitate heat transfer from heat generating components disposed within control housing <NUM> and within motor housing <NUM>. Intermediate passage <NUM> includes multiple individual channels <NUM> through which the cooling air flows.

Exhaust passage <NUM> is defined between motor housing <NUM> and housing cover <NUM>. Specifically, exhaust passage <NUM> is formed between motor housing <NUM> and exhaust cover <NUM>. In the example shown, exhaust passage <NUM> includes multiple individual channels <NUM> at least partially defined by heat sinks <NUM>. The individual channels <NUM> of exhaust passage <NUM> extend arcuately around motor housing <NUM>. An axial side, relative to the rotational axis RA of rotor <NUM>, of each of the individual channels <NUM> of exhaust passage <NUM> is formed by a heat sink <NUM>. In the example shown, at least some of heat sinks <NUM> can extend circumferentially, but not axially, on motor housing <NUM> and about the rotational axis RA of rotor <NUM>. It is understood, however, that heat sinks <NUM> of exhaust passage <NUM> can, in some examples, be canted to extend both circumferentially about rotational axis RA of rotor <NUM> and axially relative to the rotational axis RA of rotor <NUM>. In the example shown, the channels <NUM> of exhaust passage <NUM> include at least three sides that are at least partially formed by thermally conductive material (e.g., the motor housing <NUM> and heat sinks <NUM>). The body of motor housing <NUM> at least partially defines exhaust passage <NUM>. Motor housing <NUM> is thereby directly exposed to the cooling flow through cooling fluid circuit CF. Motor housing <NUM> is disposed directly between stator <NUM> and exhaust passage <NUM> to provide efficient heat transfer from stator <NUM> to the cooling flow through cooling fluid circuit CF.

During operation, fan motor <NUM> is powered to drive rotation of impeller <NUM>. Fan assembly <NUM> draws air into cooling fluid circuit CF through inlet openings <NUM>. Inlet openings <NUM> provide locations for air to enter into cooling fluid circuit CF and are in fluid communication with the surrounding environment. As such, the ambient air in the environment of pump <NUM> can form the cooling fluid of cooling fluid circuit CF. While multiple inlet openings <NUM> are shown, it is understood that cooling fluid circuit CF can include any desired number of inlet openings <NUM>, such as one or more. Inlet openings <NUM> can also be spaced circumferentially along intake passage <NUM> relative to the rotational axis RA of rotor <NUM>. For example, one or more additional or alternative inlet openings <NUM> can be formed at circumferential locations along housing cover <NUM> between the location currently shown and the position of fan <NUM>. For example, one or more of the inlet openings <NUM> can be disposed between the inlet manifold <NUM> and motor housing <NUM>.

Impeller <NUM> draws intake air (shown by arrow IA) through intake passage <NUM> and over motor housing <NUM> and heat sinks <NUM>. The flow of cooling air (shown by arrows AF in <FIG>) passes over heat sinks <NUM> and motor housing <NUM> and draws heat from those elements to effect cooling of those elements. Impeller <NUM> blows the air downstream through intermediate passage <NUM> and exhaust passage <NUM>. The cooling air blown by the impeller <NUM> initially flows through the channels <NUM> of intermediate passage <NUM>. The air flowing through intermediate passage <NUM> contacts both control housing <NUM> and motor housing <NUM> to transfer heat from both the heat generating components in control housing <NUM> (e.g., controller <NUM> among others) and from the heat generating components of in motor housing <NUM> (e.g., stator <NUM> and driver <NUM>). At least a portion of the flow through cooling fluid circuit CF flows directly between the motor <NUM> and an electric component <NUM> mounted to housing wall <NUM>. A radial line extending from the rotational axis RA of rotor <NUM> can extend through driver <NUM>, stator <NUM>, a passage through cooling fluid circuit CF and an electric component <NUM> mounted to housing wall <NUM>. Such a configuration facilitates efficient cooling of the heat generating components by wicking heat from heat generating components disposed on opposite sides of and bracketing the cooling fluid circuit CF.

At least a portion of cooling fluid circuit CF is radially bracketed, relative to the rotational axis RA of rotor <NUM>, by two unique heat sources. Specifically, intermediate passage <NUM> is exposed to thermally conductive element on both radial sides of intermediate passage <NUM> relative to the rotational axis RA of rotor <NUM>. The electric elements within control housing <NUM> form a first heat source cooled by the flow through cooling fluid circuit CF and the stator <NUM> and driver <NUM> within motor housing <NUM> form a second heat source cooled by the flow through cooling fluid circuit CF. Intermediate passage <NUM> is adjacent to the fan assembly <NUM>. Intermediate passage <NUM> is disposed directly downstream from impeller <NUM>, in the example shown. The air entering and then flowing through intermediate passage <NUM> has the greatest velocity of the flow through cooling fluid circuit CF. The high velocity facilitates quick air exchange and decreases residence time, providing enhanced cooling efficiency in the portion of cooling fluid circuit CF exposed to two independent heat sources disposed on opposite sides of the cooling fluid circuit CF.

Impeller <NUM> blows the cooling air downstream through intermediate passage <NUM>. The cooling air flows through intermediate passage <NUM> and flows through exhaust passage <NUM>. The cooling air further cools pump <NUM> as the air flows through exhaust passage <NUM> to outlet openings <NUM>. The cooling air exits cooling fluid circuit CF through outlet openings <NUM> as exhaust air (shown by arrow EA). In some examples, pump <NUM> includes deflectors and/or contouring to direct heated exhaust air exiting outlet openings <NUM> away from inlet openings <NUM>. In some examples, pump <NUM> includes deflectors and/or contouring such that an air intake is oriented away from outlet openings <NUM> to avoid intake of hot exhaust air. In the example shown, the flowpath of the cooling fluid circuit CF extends about the motor housing <NUM> such that one or more inlet locations, through which intake air IA is drawn, and one or more outlet locations, through which exhaust air EA is emitted, are on the same side of the motor <NUM>. For example, inlet air IA can be drawn into intake passage <NUM> at a location proximate blocker wall <NUM> and exhaust air EA can be emitted from exhaust passage <NUM> at a location proximate blocker wall <NUM> but on an opposite circumferential side of blocker wall <NUM> from the inlet location. For example, the inlet locations and the outlet locations can be on the same side of a radial line extending through the rotational axis RA of rotor <NUM>. In the example shown, the inlet locations and outlet locations are disposed on the same lateral side of a vertical radial line through the rotational axis RA of the rotor <NUM>. The inlet and outlet locations are on an opposite side of motor <NUM> from control housing <NUM>.

Blocker wall <NUM> extends radially from motor housing <NUM> relative to the rotational axis RA of the rotor <NUM>. Blocker wall <NUM> is disposed circumferentially between intake passage <NUM> and exhaust passage <NUM> relative to the rotational axis RA of the rotor <NUM>. Blocker wall <NUM> prevents cool intake air entering intake passage <NUM> from crossing into exhaust passage <NUM> and prevents heated exhaust air from exhaust passage <NUM> from crossing into intake passage <NUM>. Blocker wall <NUM> can further act as a heat sink to conduct heat away from stator <NUM> and driver <NUM>.

One or more of heat sinks <NUM> can be formed as a continuous projection extending through multiple portions of the cooling fluid flowpath CF. For example, a single heat sink <NUM> can extend from blocker wall <NUM>, through intake passage <NUM>, through intermediate passage <NUM>, and through exhaust passage <NUM> and back to blocker wall <NUM>. As such, one or more of heat sinks <NUM> can extend fully circumferentially about motor <NUM> relative to the rotational axis RA of the rotor <NUM> and between a common connection point (e.g., blocker wall <NUM>).

The cooling air flow AF is drawn into cooling fluid circuit CF by fan assembly <NUM> and blown through cooling fluid circuit CF. The cooling air flow AF flows between two independent heat sources contained in control housing <NUM> and motor housing <NUM> and downstream out of cooling fluid circuit CF. The cooling air flow AF is routed circumferentially about motor housing <NUM> and the rotational axis RA of the rotor <NUM>. The cooling fluid circuit CF can be considered to extend arcuately about the rotational axis RA of the rotor <NUM>. The cooling air flow AF flows around both the axis of rotation RA of rotor <NUM> and the axis of reciprocation of fluid displacers <NUM>. In the example shown, the cooling air flow AF contacts motor housing <NUM> about a full circumferential length of the cooling fluid circuit CF. The cooling air flow AF contacts control housing <NUM> along a portion of the length of the cooling fluid circuit CF.

The cooling configuration of pump <NUM> provides significant advantages. Cooling fluid circuit CF draws cooling air from the environment surrounding pump <NUM>, providing an unlimited source of cooling air. Fan assembly <NUM> actively pulls the cooling fluid into cooling fluid circuit CF and blows the cooling fluid downstream through cooling fluid circuit CF to the outlet. Fan assembly <NUM> actively blows the air through cooling fluid circuit CF, facilitating greater flow and more efficient cooling. Cooling fluid circuit CF provides cooling to both the heat generating elements in control housing <NUM> and the heat generating elements in motor housing <NUM>. By cooling multiple distinct heat sources, cooling fluid circuit CF simplifies the arrangement of pump <NUM> and provides for a more compact, efficient pumping assembly. Cooling fluid circuit CF routes the cooling air circumferentially around motor housing <NUM>, maximizing the heat transfer area between motor housing <NUM> and the cooling air flow AF.

<FIG> is a first isometric view of a pump <NUM>. <FIG> is a second isometric view of the pump <NUM>. <FIG> is an isometric view of central portion <NUM>'. <FIG> is a cross-sectional view taken along line <NUM>-<NUM> in <FIG>. <FIG> will be discussed together. Central portion <NUM>' and end caps <NUM> of pump body <NUM>', motor <NUM>, driver <NUM>, control elements <NUM>, fan assembly <NUM>', and housing cover <NUM>' of pump <NUM> are shown. Pump <NUM> is substantially similar to pump <NUM> shown in <FIG>. Central portion <NUM>' includes motor housing <NUM>', control housing <NUM>', and heat sinks <NUM>'. Control housing <NUM>' includes control housing block <NUM>' and control cover <NUM>'. Motor <NUM> includes stator <NUM> and rotor <NUM>. Driver <NUM> includes drive nut <NUM> and screw <NUM>. Fan assembly <NUM>' includes impeller <NUM>', fan motor <NUM>', and shroud <NUM>. Housing cover <NUM>' includes exhaust cover <NUM>' and baffle <NUM>.

The cooling configuration shown in <FIG> is substantially similar to the cooling configuration shown in <FIG>. The cooling configuration shown in <FIG> is substantially similar to the cooling configuration shown in <FIG>. Cooling air is drawn into the cooling fluid circuit by a fan assembly and routed circumferentially about the motor housing <NUM>', relative to the rotational axis RA of the rotor <NUM>, to provide active cooling to the heat generating components of the pump <NUM>. Components in <FIG> that are similar to components in <FIG> are indicated with a prime (e.g., motor housing <NUM> in <FIG> and motor housing <NUM>' in <FIG>).

Central portion <NUM>' of pump body <NUM>' houses motor <NUM> and control elements <NUM> that are connected to motor <NUM>, electrically and/or communicatively, to control operation of motor <NUM> and thus control pumping by pump <NUM>. Motor <NUM> is disposed within motor housing <NUM>'. Motor housing <NUM>' can be substantially similar to motor housing <NUM> (<FIG>). More specifically, motor <NUM> is disposed within the body of motor housing <NUM>'. The body of motor housing <NUM>' forms a wall that extends fully about the motor <NUM> and the rotational axis RA to enclose the motor <NUM> within the motor housing <NUM>'. The body of motor housing <NUM>' can be considered to form an annular wall that is exposed to the cooling fluid circuit CF. The body of motor housing <NUM>' curves away from control block wall <NUM>' of control housing <NUM>'. The body of motor housing <NUM>' can be considered to be convex towards control block wall <NUM>' of control housing <NUM>'. In the example shown, motor <NUM> is disposed within motor housing <NUM>' and between end caps <NUM>. End caps <NUM> are mounted to opposite axial sides of motor housing <NUM>' along the rotational axis RA. Stator <NUM> surrounds rotor <NUM> and drives rotation of rotor <NUM>, such that motor <NUM> can be considered to be an inner rotator motor. Rotor <NUM> rotates about the rotational axis RA and is disposed coaxially with driver <NUM> and fluid displacers <NUM> (not shown in <FIG>). Permanent magnet array <NUM> is disposed on rotor body <NUM>. It is understood that the rotational axis RA can be coaxial with the pump axis along which the fluid displacers reciprocate.

Control housing <NUM>' is connected to and extends from motor housing <NUM>'. Control housing <NUM>' can be substantially similar to control housing <NUM> (<FIG>). In the example shown, portions of control housing <NUM>' and motor housing <NUM>' are integrally formed as a single component (e.g., by casting, among other options). Control housing <NUM>' is configured to house control elements <NUM> of pump <NUM>, such as controller <NUM>. In the example shown, control housing block <NUM>' is integrally formed with motor housing <NUM>'. Control housing <NUM>' is mounted to control housing block <NUM>', such as by fasteners. In some examples, control housing <NUM>' can be removably connected to control housing block <NUM>' to provide access to the internal components within control housing <NUM>'. In some examples, a width of the control housing <NUM>' is greater than a width of the motor <NUM> taken perpendicular to the rotational axis RA. The control housing <NUM>' extends both above and below the motor <NUM> such that the motor <NUM> can be considered to be fully within a vertical footprint of the control housing <NUM>'. In the example shown, a height H1 of the control housing <NUM>' is greater than a height H2 of the body of the motor housing <NUM>'.

Heat sinks <NUM>' are formed on central portion <NUM>'. In the example shown, heat sinks <NUM>' are formed in multiple configurations and include projections <NUM>' and fins <NUM>', but it is understood that heat sinks <NUM>' can be of any configuration suitable for increasing the surface area of pump body <NUM> to facilitate heat exchange to cool the heat generating components of pump <NUM>. Projections <NUM>' are aligned with fastener openings through the axial ends of motor housing <NUM>'. Projections <NUM>' define portions of the fastener bores and receive the fasteners, such as the fasteners <NUM> that secure end caps <NUM> to central portion <NUM>'.

In the example shown, at least some of heat sinks <NUM>' define flow passages forming a cooling fluid circuit CF for pump <NUM>. The cooling fluid circuit CF is an outer cooling fluid circuit in that cooling fluid circuit CF extends about the exterior of motor housing <NUM>'. In the example shown, the cooling fluid circuit CF is disposed axially between the fluid displacers <NUM>. In the example shown, the cooling fluid circuit CF does not radially overlap with a fluid displacer <NUM> relative to the rotational axis RA. In the example shown, support sink <NUM>' extends between and connects control housing <NUM>' and motor housing <NUM>'. The support sink <NUM>' is formed by one or more heat sinks <NUM>' that extend between and connect the control housing block <NUM>' and motor housing <NUM>'. The support sink <NUM>' can be integrally formed with both the control housing block <NUM>' and motor housing <NUM>'. The support sink <NUM>' at least partially defines a portion of the cooling fluid circuit CF. In the example shown, a single support sink <NUM>' extends between motor housing <NUM>' and control housing <NUM>' within the cooling fluid circuit CF such that that support sink <NUM>' is exposed to the cooling airflow on both axial sides of the support sink <NUM>' relative to the rotational axis RA. Such a configuration provides relatively large cooling channels <NUM>' through the intermediate passage <NUM>' of cooling fluid circuit CF, which intermediate passage <NUM>' is disposed between control housing <NUM>' and motor housing <NUM>'. The single support sink <NUM>' within the flowpath of the cooling air provides less restriction than multiple support sinks <NUM>' fully in the flowpath, thereby facilitating laminar flow and decreasing residence time.

Housing cover <NUM>' is mounted to pump body <NUM> and at least partially defines flow passages of the cooling fluid circuit CF. Housing cover <NUM>' at least partially encloses the cooling fluid circuit CF. In the example shown, pump <NUM> is configured such that the intake passage <NUM>' of the cooling fluid circuit CF is unshrouded and at least a portion of the exhaust passage <NUM>' of the cooling fluid circuit CF is shrouded. In particular, exhaust cover <NUM>' of housing cover <NUM>' is mounted to pump <NUM> on an upper side of central portion <NUM>' (e.g., between an outlet manifold <NUM> and central portion <NUM>'). Specifically, exhaust cover <NUM>' is fixed to control housing <NUM>' by bolts extending through exhaust cover <NUM>' and into control housing <NUM>'. Baffle <NUM> (shown in <FIG>) is a portion of housing cover <NUM>' disposed between fan assembly <NUM>' and exhaust cover <NUM>'.

Baffle <NUM> includes curved surface <NUM> configured to redirect the cooling air as the air flows from intermediate passage <NUM>' to exhaust passage <NUM>'. Baffle <NUM> can be mounted on heat sinks <NUM>' and is enclosed within cooling fluid circuit CF by exhaust cover <NUM>' of housing cover <NUM>'. In the example shown, baffle <NUM> is separately formed from exhaust cover <NUM>'. As such, housing cover <NUM>' can be formed from multiple discrete components assembled to pump <NUM> to at least partially define cooling fluid circuit CF. It is understood, however, that housing cover <NUM>' can be formed by as many or as few components as desired. For example, exhaust cover <NUM>' and baffle <NUM> can be integrally formed as a single component. In some examples, housing cover <NUM>' further includes an exhaust cover, similar to housing cover <NUM> (best seen in <FIG> and <FIG>), that at least partially defines intake passage <NUM>' of cooling fluid circuit CF.

Housing cover <NUM>' at least partially defines exhaust passage <NUM>' of cooling fluid circuit CF. In the example shown, housing cover <NUM>' includes cover body <NUM> and contoured end <NUM>. Cover body <NUM> extends between body flanges <NUM> disposed at the axial ends of motor housing <NUM>' along the rotational axis RA. Contoured end <NUM> extends from cover body <NUM> and is disposed at an end of cover body <NUM> opposite the end adjacent control housing <NUM>'. Contoured end <NUM> narrows axially, relative to the rotational axis RA, as the contoured end <NUM> extends away from cover body <NUM>. Housing cover <NUM>' both directs airflow through exhaust passage <NUM>' of cooling fluid circuit CF and protects components of pump <NUM> from moisture. In the example shown, the full width cover body <NUM> extends at least to the top dead center TDC radial location of motor housing <NUM>'. Cover body <NUM> extending to the top dead center TDC location fully encloses those portions of motor housing <NUM>' extending circumferentially towards control housing <NUM>' from the top dead center TDC location. Cover body <NUM> prevents liquid from flowing into the intermediate passage <NUM>' of the cooling fluid circuit CF. If any liquid falls on central portion <NUM>', the cover body <NUM> prevents that liquid from flowing into intermediate passage <NUM>', and any liquid that does fall on motor housing <NUM>' (e.g., the portion extending circumferentially from the top dead center TDC location and away from control housing <NUM>') flows away from intermediate passage <NUM>' and thus away from the electronic components within control housing <NUM>'. Such a configuration facilitates quick cleaning of pump <NUM> during washdown as housing cover <NUM>' prevents water ingress into intermediate passage <NUM>'.

Housing cover <NUM>' is spaced radially relative to the rotational axis RA from heat sinks <NUM>' by gap <NUM>. Gap <NUM> is formed such that the individual channels <NUM>' between axially adjacent heat sinks <NUM>', relative to the rotational axis RA, are fluidly connected. The gap <NUM> allows the cooling air flow to flow over the outer edges of the heat sinks <NUM>' between the individual channels <NUM>'. Such a configuration facilitates efficient cooling by providing larger cooling passages and allowing flow between the adjacent passages.

The main heat sources of pump <NUM> include controller <NUM>, stator <NUM>, and driver <NUM>. Cooling fluid circuit CF directs cooling air through passages proximate the heat generating components to effect heat exchange between the flow of cooling air through cooling fluid circuit CF and the heat sources to thereby cool pump <NUM>. Cooling fluid circuit CF is configured to direct cooling air around motor housing <NUM>'. Cooling fluid circuit CF directs cooling air circumferentially around the rotational axis RA. Cooling fluid circuit CF extends arcuately about motor housing <NUM>'. Cooling fluid circuit CF is configured to direct cooling air to provide cooling to the heat generating elements in both motor housing <NUM>' and control housing <NUM>'. A cooling assembly, similar to cooling assembly <NUM> (<FIG>), actively blows cooling airflow through the cooling fluid circuit CF to facilitate cooling of the heat generating components of pump <NUM>. In the example shown, the cooling assembly can be considered to include at least fan assembly <NUM>'. The cooling assembly can be considered to further include flow directing components, such as baffle <NUM> and housing cover <NUM>'.

In the example shown, cooling fluid circuit CF includes intake passage <NUM>', intermediate passage <NUM>', and exhaust passage <NUM>'. In the example shown, there is no valving in cooling fluid circuit CF to direct flow. Instead, fan assembly <NUM>' is configured to actively drive cooling air through cooling fluid circuit CF. The flowpath of cooling fluid circuit CF extends about motor housing <NUM>'. The flowpath of cooling fluid circuit CF curves at least <NUM>-degrees about the motor housing <NUM>'. The annular wall of the motor housing body collects heat generated by motor <NUM> and is exposed to the flowpath of the cooling fluid circuit CF to effect cooling of the motor <NUM> and other heat generating elements within the motor housing <NUM>'.

Fan assembly <NUM>' is supported by pump body <NUM>. More specifically, fan assembly <NUM>' is supported by a control housing wall <NUM>' of control housing <NUM>'. Impeller <NUM>' is disposed within cooling fluid circuit CF. In the example shown, impeller <NUM>' is disposed at an intersection between intake passage <NUM>' and intermediate passage <NUM>'. It is understood, however, that fan assembly <NUM>' can be disposed at any desired location along the cooling fluid flowpath CF. For example, fan assembly <NUM>' can be disposed proximate an intersection between intermediate passage <NUM>' and exhaust passage <NUM>'. In some examples, fan assembly <NUM>' can be mounted within intermediate passage <NUM>' and between intake passage <NUM>' and exhaust passage <NUM>'. In such an example, both the inlet and outlet of fan assembly <NUM>' can be oriented vertically such that fan assembly <NUM>' is an axial blower. Fan assembly <NUM>' is at least partially disposed within the cooling fluid circuit CF in the example shown, but it is understood that not all examples are so limited. More specifically, impeller <NUM>' is disposed in the flowpath between an inlet of cooling fluid circuit CF and an outlet of cooling fluid circuit CF. In the example shown, at least a portion of fan assembly <NUM>' is disposed directly between motor <NUM> and the control elements <NUM> disposed within control housing <NUM>'.

Shroud <NUM> is mounted to pump body <NUM>'. Impeller <NUM>' is at least partially disposed within shroud <NUM>. Impeller <NUM>' is disposed in impeller chamber <NUM> defined by shroud <NUM> and pump body <NUM>'. In the example shown, fan assembly <NUM>' includes primary inlet <NUM> and secondary inlet <NUM>. Primary inlet <NUM> is oriented towards intake passage <NUM>'. Secondary inlet <NUM> is oriented towards control housing <NUM>'. A housing passage <NUM> is at least partially defined by control housing <NUM>' and provides a flowpath for cooling air to flow to secondary inlet <NUM>. In the example shown, primary inlet <NUM> and secondary inlet <NUM> are disposed coaxially on a fan axis FA on which impeller <NUM>' rotates. Fan motor <NUM>' is disposed in control housing <NUM>'. Fan motor <NUM>', which can be an electric motor, is isolated from the environment surrounding stator <NUM> by control housing wall <NUM>' of control housing block <NUM>', such that the cooling arrangement shown is suitable for use in hazardous locations. Fan shaft <NUM>' extends through control housing wall <NUM>' to connect fan motor <NUM>' and impeller <NUM>'.

Impeller <NUM>' is configured to draw cooling fluid into shroud through both primary inlet <NUM> and secondary inlet <NUM>. Impeller <NUM>' blows the cooling air downstream out of fan outlet <NUM>. In the example shown, the fan outlet <NUM> is disposed directly between the motor housing <NUM>' and the control housing <NUM>' such that a line parallel to the fan axis FA can pass through each of the motor housing <NUM>', the shroud <NUM>, and the control housing <NUM>', In the example shown, the fan assembly <NUM>' is configured such that a line parallel to the fan axis FA can pass through each of the motor housing <NUM>', shroud <NUM>, impeller <NUM>', and control housing wall <NUM>'. As such, those components can be considered to axially overlap relative to fan axis FA.

The main flow vector of the cooling air exiting the fan assembly <NUM>' is perpendicular to the fan axis FA and is directed directly between the motor <NUM> and control elements <NUM>. More specifically, the air existing the fan assembly <NUM>' flows directly between the thermally conductive body of motor housing <NUM>' and the thermally conductive control housing wall <NUM>'. The main flow vector of the cooling air exiting the fan assembly <NUM>' is directed directly between the motor housing <NUM>' and the control housing <NUM>'. Impeller <NUM> is configured to output airflow radially relative to fan axis FA. In the example shown, impeller <NUM> is disposed axially between the motor housing <NUM> and the control housing <NUM> along the fan axis FA. In the example shown, at least a portion of the impeller <NUM> does not radially overlap with either the motor housing <NUM> or the control housing <NUM> relative to the fan axis FA. As such, a radial line extending from the fan axis FA that passes through the impeller <NUM> does not also pass through either of the motor housing <NUM> or the control housing <NUM>. The fan assembly <NUM> is disposed such that the fan axis FA is disposed in an orientation perpendicular to, but offset from, the axis of rotation RA of the rotor <NUM>.

Impeller <NUM>' includes blades <NUM>' that include primary blade projection <NUM> and secondary blade projection <NUM>. Blades <NUM>' are supported by the body of impeller <NUM>' and blow the cooling fluid through cooling fluid circuit CF. Primary blade projections <NUM> extend from a first side of impeller body <NUM> and away from control housing <NUM>'. Secondary blade projections160 extend from a second side of impeller body <NUM>, opposite the first side, and towards control housing <NUM>'. Primary blade projections <NUM> have a length L1 and secondary blade projections <NUM> have a length L2. The length L1 is larger than the length L2. For example, a length ratio of the length L1 to the length L2 can be <NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM>, or any other desired length ratio. The longer primary blade projections <NUM> facilitate greater flow of the cooling fluid through primary inlet <NUM> than through secondary inlet <NUM> to facilitate efficient cooling.

Intake passage <NUM>' of cooling fluid circuit CF is unshrouded in the example shown. Intake passage <NUM>' is formed on an opposite radial side of motor housing <NUM>' from exhaust passage <NUM>' relative to the rotational axis RA. Intake passage <NUM>' includes multiple individual channels <NUM>' that are each at least partially defined by heat sinks <NUM>'. Intake passage <NUM>' is disposed upstream of primary inlet <NUM> of fan assembly <NUM>'. The individual channels <NUM>' of intake passage <NUM>' extend arcuately around motor housing <NUM>'. One or both of the axial sides of the individual channels <NUM>', along the rotational axis RA, can be formed by a heat sink <NUM>. As such, at least some of the individual channels <NUM>' can be axially bracketed by heat sinks <NUM>' relative to the rotational axis RA. In the example shown, at least some of heat sinks <NUM>' can extend circumferentially, but not axially, on motor housing <NUM>' and about the rotational axis RA. It is understood, however, that heat sinks <NUM>' of intake passage <NUM>' can, in some examples, be canted to extend both circumferentially about the rotational axis RA and axially relative to the rotational axis RA.

In the example shown, the individual channels <NUM>' of intake passage <NUM>' include at least three sides that are each at least partially formed by thermally conductive material (e.g., the motor housing <NUM>' and heat sinks <NUM>'). The body of motor housing <NUM>' at least partially defines intake passage <NUM>'. Motor housing <NUM>' is thereby directly exposed to the cooling flow through cooling fluid circuit CF. Motor housing <NUM>' is disposed directly between stator <NUM> and intake passage <NUM>' to provide efficient heat transfer from stator <NUM> to the cooling flow through cooling fluid circuit CF. In the example shown, the upstream intake passage <NUM>' is unshrouded such that cooling air can be drawn into fan assembly from multiple different points about the rotational axis RA. As impeller <NUM>' rotates, the cooling air is drawn into shroud <NUM> through both primary inlet <NUM> and secondary inlet <NUM> and is blown downstream through intermediate passage <NUM>' and then to downstream exhaust passage <NUM>'. Specifically, a first portion of the cooling air is drawn into primary inlet <NUM> from intake passage <NUM>' and a second portion of the cooling air is drawn into secondary inlet <NUM> through housing passage <NUM>.

Intermediate passage <NUM>' is disposed between control housing <NUM>' and motor housing <NUM>'. More specifically, intermediate passage <NUM>' is disposed between control housing block <NUM>' and motor housing <NUM>'. Control housing wall <NUM>' at least partially defines intermediate passage <NUM>'. One or more of the heat generating elements in control housing <NUM>' can be mounted to control housing wall <NUM>'. The heat generating elements are thereby mounted to a thermally conductive part of control housing <NUM>', formed by control housing wall <NUM>', that is also directly in contact with the cooling air flowing through cooling fluid circuit CF. At least some of the heat generating control elements <NUM> are mounted directly to thermally conductive material that is also exposed directly to the cooling air flow, which thermally conductive material is formed by control housing wall <NUM>' in the example shown. The control housing wall <NUM>' is configured to collect heat from the control elements <NUM> and is also exposed to the cooling flow through the cooling fluid circuit CF. As best seen in <FIG>, the control elements <NUM> extend both above and below the motor <NUM> such that the motor <NUM> can be considered to be within a footprint of the control elements <NUM>. Mounting the heat generating elements to control housing wall <NUM>' facilitates efficient heat transfer from those components to the cooling flow through cooling fluid circuit CF.

Intermediate passage <NUM>' is at least partially defined by the body of motor housing <NUM>'. Motor housing <NUM>' is thereby directly exposed to the cooling flow through cooling fluid circuit CF. Motor housing <NUM>' is disposed directly between stator <NUM> and intermediate passage <NUM>' to provide efficient heat transfer from stator <NUM> to the cooling flow through cooling fluid circuit CF. In the example shown, at least one heat sink <NUM>' extends between and connects control housing <NUM>' and motor housing <NUM>'. Specifically, support sinks <NUM>' extend between and connect control housing block <NUM>' and motor housing <NUM>'. The support sinks <NUM>' at least partially define intermediate passage <NUM>' and directly contact both control housing <NUM>' and motor housing <NUM>'. The support sinks <NUM>' define the channels <NUM>' of intermediate passage <NUM>'. Such heat sinks <NUM>' facilitate efficient heat transfer from both control housing <NUM>' and motor housing <NUM>'. In the example shown, central portion <NUM>' includes a single support sink <NUM>' fully within the intermediate passage <NUM>'. Such a configuration encourages flow through intermediate passage <NUM>' downstream from fan assembly <NUM>' by limiting the restrictions within the intermediate passage <NUM>' of cooling fluid circuit CF.

Exhaust passage <NUM>' extends downstream from intermediate passage <NUM>'. Exhaust passage <NUM>' is at least partially defined between motor housing <NUM>' and housing cover <NUM>'. Baffle <NUM> is mounted to redirected the flow of cooling air from the intermediate passage <NUM>' to the exhaust passage <NUM>'. Curved surface <NUM> of baffle <NUM> provides a smoothly contoured surface at a downstream end of intermediate passage <NUM>' such that the cooling airflow is redirected without encountering a <NUM>-degree corner. Redirecting the cooling flow by the curved surface <NUM> encourages continuous flow and decreases the residence time of the cooling air within cooling flowpath CF. Baffle <NUM> redirecting the flow of the cooling airflow facilitates efficient cooling.

In the example shown, a first portion of exhaust passage <NUM>' extends from intermediate passage <NUM>' and is at disposed between motor housing <NUM>' and exhaust cover <NUM>'. A second portion of exhaust passage <NUM>' extends from the first portion and can be considered to be unshrouded. The portions of the heat sinks <NUM>' in the unshrouded portion of the exhaust passage <NUM>' are directly exposed to the atmosphere, which is also the source of the cooling air, providing passive heat transfer to those portions of the exhaust passage <NUM>'.

In the example shown, exhaust passage <NUM>' includes multiple individual channels <NUM>' at least partially defined by heat sinks <NUM>'. The individual channels <NUM>' of exhaust passage <NUM>' extend arcuately around motor housing <NUM>'. An axial side, relative to the rotational axis RA, of each channel <NUM>' is formed by a heat sink <NUM>. In the example shown, at least some of heat sinks <NUM>' can extend circumferentially, but not axially, on motor housing <NUM>' and about the rotational axis RA. It is understood, however, that heat sinks <NUM>' of exhaust passage <NUM>' can, in some examples, be canted to extend both circumferentially about the rotational axis RA and axially along the rotational axis RA. In the example shown, each of the individual channels <NUM>' can include at least three sides at least partially formed by thermally conductive material (e.g., the motor housing <NUM>' and heat sinks <NUM>'). The body of motor housing <NUM>' at least partially defines the exhaust passage <NUM>'. Motor housing <NUM>' is thereby directly exposed to the cooling flow through cooling fluid circuit CF. Motor housing <NUM>' is disposed directly between stator <NUM> and exhaust passage <NUM>' to provide efficient heat transfer from stator <NUM> to the cooling airflow through cooling fluid circuit CF.

During operation, fan motor <NUM>' is powered to drive rotation of impeller <NUM>'. Fan assembly <NUM>' draws air into cooling fluid circuit CF through intake passage <NUM>'. The cooling air can enter into the cooling fluid circuit CF at any point circumferentially along the intake passage <NUM>' about the rotational axis RA. The intake passage <NUM>' is in fluid communication with the surrounding environment. The portions of the heat sinks <NUM>' in the intake passage <NUM>' are exposed to the ambient air in the environment. The ambient air in the environment of pump <NUM> forms the cooling fluid drawn into cooling fluid circuit CF by fan assembly <NUM>'.

Fan assembly <NUM>' draws a first portion of intake air (shown by arrows IA1) through primary inlet <NUM> in shroud <NUM>. Fan assembly <NUM>' draws the intake air IA1 from multiple locations separated circumferentially about the motor <NUM>. The various flows forming the intake air IA1 can flow over the motor housing <NUM>' and heat sinks <NUM>' to conduct heat from those thermally conductive components. Fan assembly <NUM>' also draws a second portion of intake air (shown by arrow IA2) into the shroud <NUM> through secondary inlet <NUM>. The second portion of intake air IA2 contacts control housing block <NUM>' prior to entering shroud <NUM> such that the second portion of intake air IA2 can provide cooling to control housing <NUM>' at locations upstream of shroud <NUM>.

The flow of cooling air (shown by arrows AF in <FIG>) passes over heat sinks <NUM>', control housing <NUM>', and motor housing <NUM>' and draws heat from those elements to effect cooling of those elements. Fan assembly <NUM>' blows the air downstream through intermediate passage <NUM>' and exhaust passage <NUM>'. The cooling airflow generated by fan assembly <NUM>' initially flows through intermediate passage <NUM>' after exiting from shroud <NUM>. The air flowing through intermediate passage <NUM>' contacts both control housing <NUM>' and motor housing <NUM>' to transfer heat from both the heat generating components in control housing <NUM>' (e.g., control elements <NUM> among others) and from the heat generating components of in motor housing <NUM>' (e.g., stator <NUM> and driver <NUM>). At least a portion of the flow through cooling fluid circuit CF flows directly between the motor <NUM> and a control component <NUM> mounted to control housing wall <NUM>'. A radial line extending from the rotational axis RA can extend through driver <NUM>, stator <NUM>, a passage through cooling fluid circuit CF, and a control component <NUM> mounted to control housing wall <NUM>'. Such a configuration facilitates a compact pump and efficient cooling of heat generating components on opposite sides of the cooling fluid circuit CF.

At least a portion of cooling fluid circuit CF is bracketed by two unique heat sources. Specifically, intermediate passage <NUM>' is exposed to thermally conductive elements on both radial sides of intermediate passage <NUM>' relative to the rotational axis RA. The electric control elements <NUM> within control housing <NUM>' form a first heat source cooled by the flow through cooling fluid circuit CF and the stator <NUM> and driver <NUM> within motor housing <NUM>' form a second heat source cooled by the flow through cooling fluid circuit CF. In the example shown, intermediate passage <NUM>' is disposed directly downstream from impeller <NUM>'. As such, the air entering and then flowing through intermediate passage <NUM>' has the greatest velocity of the flow through cooling fluid circuit CF. The high velocity facilitates quick air exchange within the cooling fluid circuit CF and decreases residence time, providing enhanced cooling efficiency in the portion of cooling fluid circuit CF exposed to two independent heat sources disposed on opposite sides of the cooling fluid circuit CF.

In the example shown, fan assembly <NUM>' blows the air downstream through intermediate passage <NUM>'. As discussed above, it is understood that some examples include a fan assembly <NUM>' mounted at the downstream end of intermediate passage <NUM>', within intermediate passage <NUM>', or at any other desired location within the cooling fluid circuit CF. In such an example, fan assembly <NUM>' can be considered to draw the air downstream through intermediate passage <NUM>'. The air flow exits intermediate passage <NUM>' and flows through exhaust passage <NUM>'. The air further cools pump <NUM> as the air flows through exhaust passage <NUM>'. The air is exhausted from cooling fluid circuit CF as exhaust air (shown by arrow EA). In the example shown, the exhaust air is directed through outlets <NUM>. The outlets <NUM> can be considered to be formed between the housing cover <NUM>' and the pump body <NUM>'. In the example shown, the outlets <NUM> are formed radially between the contoured end <NUM> of exhaust cover <NUM>' and motor housing <NUM>' relative to the rotational axis RA. Contoured end <NUM> of exhaust cover <NUM>' curves around motor housing <NUM>'. The curved contoured end <NUM> directs the exhaust air to flow within the individual channels <NUM>' between the heat sinks <NUM>' even after passing out from under housing cover <NUM>', further facilitating cooling. In the example shown, the flowpath of the cooling fluid circuit CF extends about the motor housing <NUM>' such that one or more inlet locations, through which intake air IA1 is drawn, and one or more outlet locations, through which exhaust air EA is emitted, are on the same side of the motor <NUM>. For example, inlet air IA1 can be drawn into intake passage <NUM>' at a location proximate blocker wall <NUM>' and exhaust air EA can be emitted from exhaust passage <NUM>' at a location proximate blocker wall <NUM>' but on an opposite circumferential side of blocker wall <NUM>' from the inlet location. For example, the inlet locations and the outlet locations can be on the same side of a radial line extending through the rotational axis RA. In the example shown, the inlet locations and outlet locations are disposed on the same lateral side of a vertical line extending radially through the rotational axis RA of the rotor <NUM>.

Blocker wall <NUM>' extends radially from motor housing <NUM>' relative to the rotational axis RA. Blocker wall <NUM>' is disposed circumferentially between intake passage <NUM>' and exhaust passage <NUM>' on an opposite side of motor <NUM> from control housing <NUM>'. Blocker wall <NUM>' prevents heated exhaust air from crossing into intake passage <NUM>' and being recirculated. Blocker wall <NUM>' can further act as a heat sink to conduct heat away from stator <NUM> and driver <NUM>.

One or more of heat sinks <NUM>' can be formed as a continuous projection extending through multiple portions of the cooling fluid flowpath CF. For example, a single heat sink <NUM> can extend from blocker wall <NUM>', through intake passage <NUM>', through intermediate passage <NUM>', and through exhaust passage <NUM>', and back to blocker wall <NUM>'. As such, one or more of heat sinks <NUM>' can extend fully circumferentially about motor <NUM> between a common connection point (e.g., blocker wall <NUM>').

The cooling air flow AF is drawn into cooling fluid circuit CF by fan assembly <NUM>' and flows between two independent heat sources contained in control housing <NUM>' and motor housing <NUM>' and downstream out of cooling fluid circuit CF. The cooling air flow AF is routed circumferentially about motor housing <NUM>' and the rotational axis RA. The cooling air flow AF thereby flows around both the axis of rotation of rotor <NUM> and the axis of reciprocation of fluid displacers <NUM>, in the example shown. In the example shown, the cooling air flow AF can contact motor housing <NUM>' about a full circumferential length of the cooling fluid circuit CF. The cooling air flow AF contacts control housing <NUM>' along a portion of the length of the cooling fluid circuit CF.

The cooling configuration of pump <NUM> provides significant advantages. Cooling fluid circuit CF draws cooling air from the environment surrounding pump <NUM>, providing an unlimited source of cooling air. Fan assembly <NUM>' actively pulls the cooling fluid into cooling fluid circuit CF and blows the cooling fluid downstream through cooling fluid circuit CF to the outlet. Fan assembly <NUM>' actively blows the air through cooling fluid circuit CF, facilitating greater flow and more efficient cooling. Cooling fluid circuit CF provides cooling to both the heat generating elements in control housing <NUM>' and the heat generating elements in motor housing <NUM>'. By cooling multiple distinct heat sources, cooling fluid circuit CF simplifies the arrangement of pump <NUM> and provides for a more compact, efficient pumping assembly. Cooling fluid circuit CF routes the cooling air circumferentially around motor housing <NUM>', maximizing the heat transfer area between motor housing <NUM>' and the cooling air flow AF.

<FIG> is a cross-sectional view taken along line 6A-6A in <FIG>. <FIG> is a cross-sectional view taken along line 6B-6B in <FIG>. <FIG> and <FIG> will be discussed together. Central portion <NUM>' of pump body <NUM>', fan assembly <NUM>', and housing cover <NUM>' of pump <NUM> are shown. Motor housing <NUM>', control housing <NUM>', and heat sinks <NUM>' of central portion <NUM>' are shown. Impeller <NUM>' and impeller shroud <NUM> of fan assembly <NUM>' are shown. Primary inlet <NUM> and shroud body <NUM> of impeller shroud <NUM> are shown. Blades <NUM>' and impeller body <NUM> of impeller <NUM>' are shown. Each blade <NUM>' includes a pressure side <NUM> and a suction side <NUM>. Exhaust cover <NUM>' and baffle <NUM> of housing cover <NUM>' are shown. Grooves <NUM> of baffle <NUM> are shown.

Fan assembly <NUM>' is mounted to pump body <NUM>' to blow cooling air through the cooling fluid circuit CF (best seen in <FIG>). Impeller <NUM>' is supported by fan shaft <NUM>' (<FIG>) that extends through control housing wall <NUM>' between the fan motor <NUM>' (<FIG>) disposed within control housing <NUM>' and the impeller <NUM>'. The impeller <NUM>' is mounted within the impeller chamber <NUM> and rotates within the impeller chamber <NUM>. Shroud <NUM> at least partially defines impeller chamber <NUM>. Impeller chamber <NUM> is further defined by pump body <NUM>'.

Impeller chamber <NUM> includes chamber wall <NUM> that extends about impeller <NUM>'. Chamber wall <NUM> is partially formed by shroud <NUM> and partially formed by pump body <NUM>'. Chamber wall <NUM> is formed as an involute curve in the example shown. The portions of chamber wall <NUM> formed by pump body <NUM>' and shroud <NUM> form a smooth curve that encourages flow of the cooling air through fan outlet <NUM>. The smooth curvature of the chamber wall <NUM> includes wall portion 178a formed by pump body <NUM>', wall portion 178b formed by shroud <NUM>, and wall portion 178c formed by pump body <NUM>'. As such, the smoothly curved chamber wall <NUM> can be formed by portions of the pump body <NUM>' bracketing the shroud <NUM> about the fan axis FA.

Impeller <NUM>' rotates within impeller chamber <NUM>. Impeller <NUM>' draws cooling air into impeller chamber <NUM> through primary inlet <NUM> and secondary inlet <NUM> (<FIG>). The cooling air is blown radially outward relative to fan axis FA by blades <NUM>' and is ejected from impeller chamber <NUM> through fan outlet <NUM>. Fan outlet <NUM> is oriented vertically into the intermediate passage <NUM>' of cooling fluid circuit CF. The cooling air can be ejected from the impeller chamber <NUM> through intermediate passage <NUM>' and towards baffle <NUM>. In the example shown, the cooling air is ejected vertically upward, though it is understood that the configuration can vary depending on the orientation of pump <NUM>. As shown in <FIG>, a radially inner portion of each blade <NUM>', relative to fan axis FA, is exposed through the primary inlet <NUM>. Impeller body <NUM> includes openings <NUM> such that cooling air can flow through the impeller body <NUM>. As such, the primary inlet <NUM> and secondary inlet <NUM> are not fluidly isolated.

Blades <NUM>' are formed on impeller <NUM>' and move the cooling air. The pressure side <NUM> of each blade <NUM>' is concave and the suction side <NUM> of each blade <NUM>' is convex. Both the primary blade projection <NUM> and secondary blade projection <NUM> of each blade <NUM>' can be curved. In some examples, the primary blade projection <NUM> and secondary blade projection <NUM> are curved in the same manner such that blades <NUM>' can be considered to have a common profile across the blade body from the tip of the secondary blade projection <NUM> to the tip of the primary blade projection <NUM>. Impeller <NUM>' is configured to rotate towards the pressure side <NUM> (e.g., in the rotational direction R1 shown in <FIG>).

Baffle <NUM> is mounted on heat sinks <NUM>'. Baffle <NUM> is formed with grooves <NUM> that are disposed over the heat sinks <NUM>' and receive the heat sinks <NUM>'. The heat sinks <NUM>' extending into the grooves <NUM> locates the baffle <NUM> on pump body <NUM>'. Baffle <NUM> is formed such that curved surface <NUM> of baffle <NUM> is in a direct flowpath of the cooling air exiting from fan assembly <NUM>'. The curved surface <NUM> smoothly redirects the cooling airflow through the cooling fluid circuit CF.

<FIG> is an isometric cross-sectional view taken along line <NUM>-<NUM> in <FIG>. <FIG> is a plan cross-sectional view taken along line <NUM>-<NUM> in <FIG>. <FIG> and <FIG> will be discussed together. Central portion <NUM>' and end caps <NUM> of pump body <NUM>', motor <NUM>, driver <NUM>, and control elements <NUM> of pump <NUM> are shown. Central portion <NUM>' includes motor housing <NUM>', control housing <NUM>', and heat sinks <NUM>'. Control housing <NUM>' includes control housing block <NUM>' and control cover <NUM>'. Motor <NUM> includes stator <NUM> and rotor <NUM>. Driver <NUM> includes drive nut <NUM> and screw <NUM>.

Intermediate passage <NUM>' of cooling fluid circuit CF is shown. Heat sinks <NUM>' are formed on and project from both control housing <NUM>' and motor housing <NUM>' of pump body <NUM>'. As shown, a single support sink <NUM>' is disposed within the intermediate passage <NUM>' of the cooling fluid circuit CF. The support sink <NUM>' divides the intermediate passage <NUM>' into multiple cooling channels <NUM>'. The support sink <NUM>' is connected to both the control housing <NUM>' and the motor housing <NUM>' such that the support sink <NUM>' can dissipate heat from the heat generating components within the control housing <NUM>' and within the motor housing <NUM>'. Others of the heat sinks <NUM>' project into the intermediate passage <NUM>' but do not span the intermediate passage <NUM>'. In the example shown, motor sinks <NUM> extend from motor housing <NUM>' and control sinks <NUM> extend from control housing <NUM>'. The motor sinks <NUM> increase the surface area of motor housing <NUM>' to effect cooling of the heat generating components within motor housing <NUM>'. The control sinks <NUM> increase the surface area of control housing <NUM>' to increase the surface area of control housing <NUM>' to effect cooling of the heat generating components within control housing <NUM>'. Such partial-width heat sinks <NUM>' increase the surface areas of the control housing <NUM>' and the motor housing <NUM>', facilitating effective heat transfer, but without the restriction that occurs from a full width heat sink. As such, heat sinks <NUM>' can be disposed in an external portion of the flowpath of cooling fluid circuit CF (e.g., in exhaust passage <NUM>' proximate blocker wall <NUM>') and heat sinks <NUM>' can be disposed in an internal portion of the flowpath of cooling fluid circuit CF (e.g., in intermediate passage <NUM>'). The individual channels <NUM>' within the intermediate passage <NUM>' provide the cooling air to the individual channels <NUM>' within the exhaust passage <NUM>' (best seen in <FIG>) of the cooling flowpath CF.

In the example shown, intermediate passage <NUM>' can be considered to include dual channels <NUM>' extending through the intermediate passage <NUM>' and divided by the support sink <NUM>'. In some examples, the exhaust passage <NUM>' has a larger number of individual channels <NUM>' than the intermediate passage <NUM>' includes individual channels <NUM>'. As such, the cooling flow in an individual channel <NUM>' within the intermediate passage <NUM>' can flow into multiple individual channels <NUM>' within the exhaust passage <NUM>'. Multiple individual channels <NUM>' of the intake passage <NUM>' can feed fan assembly <NUM>' and then be blown into the individual channels <NUM>' of the intermediate passage <NUM>'.

The cooling configuration of pump <NUM> provides significant advantages. Cooling fluid circuit CF draws cooling air from the environment surrounding pump <NUM> and drives the cooling air around the exterior of motor housing <NUM>'. Fan assembly <NUM>' actively pulls the cooling fluid into cooling fluid circuit CF and blows the cooling fluid downstream through cooling fluid circuit CF to the outlet. Intermediate passage <NUM>' has a small number of individual channels <NUM>' to facilitate efficient air flow through cooling fluid circuit CF. Fan assembly <NUM>' actively blows the air through cooling fluid circuit CF. Cooling fluid circuit CF provides cooling to both the heat generating elements in control housing <NUM>' and the heat generating elements in motor housing <NUM>'. By cooling multiple distinct heat sources, cooling fluid circuit CF simplifies the arrangement of pump <NUM> and provides for a more compact, efficient pumping assembly.

Claim 1:
A displacement pump (<NUM>) for pumping a fluid, the displacement pump (<NUM>) comprising:
- an electric motor (<NUM>) including a stator (<NUM>) and a rotor (<NUM>);
- a first fluid displacer (<NUM>) and a second fluid displacer (<NUM>) configured to pump fluid and connected to the rotor (<NUM>) to be driven by the rotor (<NUM>);
- a cooling circuit (CF) including a flowpath about an exterior of a motor housing (<NUM>) that houses the electric motor (<NUM>), wherein the flowpath is disposed between the first fluid displacer (<NUM>) and the second fluid displacer (<NUM>); and
- a fan assembly (<NUM>) configured to blow air through the cooling circuit (CF).