CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent App. No. 63/205,635, filed January 27, 2021, the disclosure of which is hereby incorporated by reference herein.

TECHNICAL FIELD

[0002] The present disclosure relates generally to a fluid flow meter system and method, and more particularly, to a fluid flow meter system for determining an amount of fluid flow from a fluid dispenser.

BACKGROUND

[0003] Fluid dispensing systems can be used to dispense a controlled amount of fluid from a fluid dispenser. The fluid is pumped from a holding container or tank through the dispenser and dispensed through an outlet. The amount of fluid flow through the dispenser can be measured and provided to an operator to control the fluid dispensing system as desired.

[0004] Conventional fluid dispensing systems can include fluid flow meters to measure fluid flow through the system. Fluid flow meters can include pressure sensors, piezo based volume sensors, gear heads, or other types of measurement devices, to detect parameters of the fluid flow to approximate an amount of fluid being dispensed. However, conventional flow meters can suffer from issues with accuracy because of, for example, pressure changes in the fluid flow, sedimentation in the fluid, and density changes in the fluid, and can require the use of additional devices to accurately measure and/or verify the amount of fluid dispensed. For example, measurement scales and gauges are often required to check a mass and/or volume of the dispensed fluid.

[0005] The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded subject matter by which the scope of the invention is to be bound.

SUMMARY

[0006] An improved fluid flow meter is desired to accurately measure an amount of fluid flow through a dispensing system so as to minimize the use of additional scales and gauges, to more accurately measure flow in situ, to minimize production standstill during scale measuring, and minimize waste due to offline measuring.

[0007] The disclosure relates to a flow meter configured to determine amount of fluid dispensed from a dispenser. Conventional flow metering devices suffer from inaccurate measurements due to, for example, pressure drops for measuring volumes. Scales must then be used to check the dispensed volume to confirm the amount of fluid dispensed. Other conventional systems, such as meters that include gear heads or piezo based volume sensors, cannot accurately measure small volumes and/or cannot read pastry fluids. The flow meter described herein includes a stator and a rotor that freely rotate relative to one another. The rotational displacement between the stator and the rotor can be used to determine a volume of fluid being dispensed based on cavities with defined volumes within the flow meter, without the use of additional measurement devices.

[0008] An aspect of the present disclosure provides a flow meter for measuring a flow of fluid. The flow meter comprises a housing, a stator, a rotor, a sensor, and a retention member. The stator is positioned within the housing and has an inner surface that defines a channel configured to receive the flow of fluid within. At least a portion of the inner surface is contoured. The rotor is positioned within the channel of the stator such that the contoured inner surface of the stator and an outer surface of the rotor define at least one cavity therebetween. The rotor is rotatable relative to the stator such that when the channel receives the flow of fluid a fluid force is applied to the outer surface of the rotor causing 1.) relative rotation between the rotor and the stator and 2.) the fluid to propagate the at least one cavity along a length of the channel. The sensor is adapted for detecting a rotational displacement between the rotor and the stator. The retention member coupled to the housing and to the rotor, the retention member being configured to substantially prevent axial movement between the rotor and the stator.

[0009] Another aspect of the present disclosure provides a dispensing system. The dispensing system includes a dispenser body and a flow meter. The dispenser body includes a fluid chamber and a dispensing outlet in fluid communication with the fluid chamber. The flow meter comprises a housing, a stator, a rotor, a sensor, and a retention member. The housing defines a fluid inlet in fluid communication with the fluid outlet of the dispenser body. The stator is positioned within the housing and has an inner surface that defines a channel configured to receive the flow of fluid within. At least a portion of the inner surface is contoured. The rotor is positioned within the channel of the stator such that the contoured inner surface of the stator and an outer surface of the rotor define at least one cavity therebetween. The rotor is rotatable relative to the stator such that when the channel receives the flow of fluid a fluid force is applied to the outer surface of the rotor causing 1.) relative rotation between the rotor and the stator and 2.) the fluid to propagate the at least one cavity along a length of the channel. The sensor is adapted for detecting a rotational displacement between the rotor and the stator. The retention member is coupled to the housing, and is configured to substantially prevent axial movement between the rotor and the stator.

[0010] Another aspect of the present disclosure provides a method of dispensing fluid through an outlet of a flow meter. The flow meter includes a rotor positioned within a channel of a stator. The method comprises: causing a fluid to flow within the channel, wherein the fluid applies a fluid force to an outer surface of the rotor causing relative rotation between the rotor and the stator, wherein the stator has an inner surface that defines the channel, and wherein the inner surface of the stator and an outer surface of the rotor define at least one cavity therebetween, wherein rotation of the rotor relative to the stator causes the at least one cavity to propagate along a length of the channel; detecting a rotational displacement between the rotor and the stator; and determining an amount of fluid dispensed through the outlet of the flow meter based on the detected rotational displacement.

[0011] This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. A more extensive presentation of features, details, utilities, and advantages of the present invention is provided in the following written description of various embodiments of the invention, illustrated in the accompanying drawings, and defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 illustrates a perspective view of an outer housing of a dispensing system, according to an aspect of this disclosure.

[0013] FIG. 2 illustrates a perspective view of the dispensing system shown in FIG. 1 with the outer housing removed.

[0014] FIG. 3 illustrates a cross-sectional view of the dispensing system shown in FIG. 2 taken along line 3-3 in FIG. 2.

[0015] FIG. 4 illustrates a top perspective view of a fluid flow meter, according to an aspect of this disclosure.

[0016] FIG. 5 illustrates a bottom perspective view of the fluid flow meter shown in FIG. 4. [0017] FIG. 6 illustrates an exploded perspective view of the fluid flow meter shown in FIG. 4.

[0018] FIG. 7 illustrates a perspective cross-sectional view of the fluid flow meter shown in FIG. 5 taken along line 7-7 in FIG. 5.

[0019] FIG. 8 illustrates a perspective view of a blade member, according to an aspect of this disclosure.

[0020] FIG. 9 illustrates a side cross-sectional view of the fluid flow meter shown in FIG. 5 taken along line 7-7 in FIG. 5.

DETAILED DESCRIPTION

[0021] Certain terminology used in this description is for convenience only and is not limiting. The words “top”, “bottom”, “leading”, “trailing”, “above”, “below”, “axial”, “transverse”, “circumferential,” and “radial” designate directions in the drawings to which reference is made. The term “substantially” is intended to mean considerable in extent or largely but not necessarily wholly that which is specified. All ranges disclosed herein are inclusive of the recited endpoint and independently combinable (for example, the range of “from 2 grams to 10 grams” is inclusive of the endpoints, 2 grams and 10 grams, and all the intermediate values). The terminology includes the above-listed words, derivatives thereof and words of similar import.

[0022] Referring to FIG 1., a dispensing system 10 according to an aspect of this disclosure is shown. The dispensing system 10 can comprise, for example, a jetting dispensing system or other dispensing system configured to dispense a fluid. The dispensing system 10 is capable of jetting/dispensing a plurality of droplets onto a substrate 24 so that each droplet defines a consistent volume of fluid. Furthermore, the dispensing system 10 can be configured to continue dispensing consistent volume droplets regardless of some operational parameter changes such as viscosity changes in the fluid being dispensed. In addition, the velocity profile of fluid exiting the dispensing system 10 can be maintained generally constant to avoid causing changes in fluid velocity that can damage fluid particles and/or cause rotational tumbling or blossoming of the droplet while in flight towards the substrate 24.

[0023] The dispensing system 10 includes a dispenser body 12 with a fluid chamber and a valve element 56 (see FIG. 3), and a pump 14 for feeding fluid from a fluid source 16 into the fluid chamber of the dispenser body 12. The pump can include, for example, a positivedisplacement pump, centrifugal pump, axial flow pump, progressive cavity pump, or still other pump configured to feed the fluid source 16. The pump 14 can be actuated by a controller 18 of the dispensing system 10. The controller 18 can also be configured to operate a valve actuator 20 that causes movement of the valve element 56 within the dispenser body 12 to produce dispensing cycles for sending the fluid towards the substrate 24.

[0024] It will be appreciated that different types of the dispenser bodies 12 and valve actuators 20 may be used in accordance with this disclosure. Also, the controller 18 can include two separate controller or control elements for the pump 14 and the valve actuator 20. The several aspects described in detail below are provided for exemplary purposes only, and the features thereof may be combined in any manner so long as the resulting system includes the fluid flow meter 200 configured to determine a volume of fluid dispensed by the dispensing system 10, thereby achieving the multiple functional benefits and advantages outlined throughout this disclosure.

[0025] With reference to FIGS. 1-3, the dispensing system 10 comprises a jetting dispensing system. It will be appreciated that the dispensing system 10 can comprise other dispensing systems configured to dispense fluids. The dispensing system 10 further includes a fluid module and a valve actuator 26. The fluid module and the valve actuator 26 are contained at least partially within an outer cover 26. The fluid module includes the dispenser body 12, the fluid module includes a nozzle 28, the dispenser body 12, and a fluid connection interface 30 which defines a fluid inlet 32 for the dispenser body 12. The outer cover 26 can be composed of thin sheet metal and can be fastened to a primary support structure 27 of the dispensing system 10 by conventional fasteners. The primary support structure 27 can include multiple elements serving as connection points for the various elements of the fluid module and the piezoelectric drive module, these multiple elements including at least a lower structural member 115, an upper structural member 113 and a support wall 111 that extends between and joins the upper and lower structural members 113, 115. The dispensing system 10 also includes a fluid supply assembly, which includes both the pump 14 and the fluid source 16. The fluid from the fluid supply assembly is directed to the fluid module, and the piezoelectric drive module actuates elements of the fluid module to dispense the fluid onto the substrate 24.

[0026] With reference to FIG. 3, a fluid chamber 34 is defined within the dispenser body 12, so as to communicate between the fluid inlet 32 and a dispensing outlet 36 provided proximate the nozzle 28. A first section 40 of the dispenser body 12 includes the fluid inlet 32 (at the fluid connection interface 30) and a passageway 42 defining a flow path that couples the fluid inlet 32 into communication with the fluid chamber 34. A second section 44 of the dispenser body 12 is configured to support the nozzle 28. A centering piece 46 inserted into the second section 44 aligns a dispensing outlet 36 in the nozzle 28 with a central passageway 50 extending through the second section 44 of the dispenser body 12. A valve seat 52 is positioned between the fluid inlet 32 and the dispensing outlet 36, and more specifically, between the bottom end of the fluid chamber 34 and the nozzle 28. The valve seat 52 has an opening 54 in fluid communication with the dispensing outlet 36. The centering piece 46 maintains the dispensing outlet 36 in the nozzle 28, the central passageway 50 in the second section 44 of the dispenser body 12, and the opening 54 in the valve seat 52 in a generally co-axial alignment. The second section 44 includes a shoulder at a portion of the central passageway 50, this shoulder supporting each of the centering piece 46, the nozzle 28, and the valve seat 52 in the desired positions.

[0027] A valve element 56 is located within the fluid chamber 34 so as to be positioned for movement into and out of engagement with the valve seat 52. The valve element 56 is driven by the valve actuator 20. The valve element 56 is mounted in the fluid module in a movable element 60. The movable element 60 further defines a strike plate in the form of a transverse wall 62 bounded on upper and lower sides by receptacles. One of these receptacles receives the valve element 56, and the opposite receptacle receives a tip 58a of a movable needle or drive pin 58. To this end, the tip 58a of the drive pin 58 is located adjacent to the wall 62 of the movable element 60 and on an opposite side of the wall 62 from the valve element 56. As shown in these Figures, the drive pin 58 is the element that extends out of the fluid module for connection to the valve actuator 20.

[0028] The valve actuator 20 further includes a plunger 93, an asymmetrical flexure 94, an arm 96, and a spring 96. It will be appreciated that the valve actuator 20 can include fewer or more components, such as, piezoelectric stacks, drive circuits, brackets, or still other components to facilitate the control of the valve actuator 20. The valve actuator 20 can move in a reciprocal motion to cause movement of the valve element 56 to dispense the fluid material.

[0029] The dispenser body 12 further includes a third section 66 carrying an insert 70. The third section 66 and the insert 70 elements collectively facing towards the second section 44 of the dispenser body 12 to define an opposite or top end of the fluid chamber 34. The third section 66 and insert 70 collectively define a bore 66a through which the drive pin 58 and the movable element 60 extend. A biasing element 68, such as a spring, is located between the movable element 60 and the insert 70, the biasing element 68 providing an axial force that biases the movable element 60 and the valve element 56 away from contact with valve seat 52.

[0030] A sealing ring 64 supplies a sealing engagement between the insert 70 and an exterior of the movable element 60. The sealing ring 64 may include an O-ring that flexes with movement of the movable element 60, or some other alternative seal like a dynamic seal that the movable element 60 would slide against. The part of the movable element 60 which is below the sealing ring 64 also defines a part of the boundary of the fluid chamber 34. The valve element 56 is attached to movable element 60 and is therefore located inside the fluid chamber 34 at a location between the wall 62 of the movable element 60 and the valve seat 52. The movable element 60 transfers movements of the drive pin 58 to movements of the valve element 56. Alternatively, the separate elements assembled together in this portion of the fluid module (the valve element 56 and the movable element 60) may be made as a single unified movable element.

[0031] The passageway 42 that couples the fluid inlet 32 in fluid communication with the fluid chamber 34 includes a first portion that extends completely within the first section 40 of the dispenser body 12. An annular portion of the passageway 42 communicates with this first portion, and it is created by a space provided between the first section 40 and the third section 66 of the dispenser body 12. The passageway 42 then continues from this annular portion between the insert 70 and the second section 44 down to the fluid chamber 34. The insert 70 can be provided with several grooves along an outer periphery thereof to define this final portion of the passageway 42. When the dispenser body 12 is fully assembled, a path for fluid flow is defined from the fluid inlet 32 at the fluid connection interface 30, through the passageway 42 to the fluid chamber 34, and then through the opening 54 of the valve seat 52 to the dispensing outlet 36.

[0032] With reference to FIG. 3, the fluid flow meter 200 can be connected within the passageway 42 of the dispenser body 12. The flow meter 200 is configured to measure a volume of the fluid flowing through the flow meter 200, as further described below. The flow meter 200 is configured to receive fluid flowing through the passageway 42 of the dispenser body 12 from the fluid source 16 to the dispensing outlet 36. In an aspect, the fluid flow meter 200 is positioned between the fluid source 16 and the pump 14 along the fluid flow path. Alternatively, the flow meter 200 can be connected to a different location either within or external to the dispenser body 12. For example, the flow meter can be connected to the second section 44 of the dispenser body 12. A nozzle (not shown) can be connected to a distal end of the meter 200 to dispense the fluid from the dispensing system 10. In another altemative, the flow meter 200 can be located at a remote location from the dispenser body 12. For example, fluid can be provided to the dispenser body 12 from a remote fluid reservoir. The flow meter 200 can be positioned at a remote location between the fluid reservoir and the dispenser body 12.

[0033] With reference to FIGS. 4-9, the flow meter 200 includes a body 201 (e.g. a housing) that extends from a first end 202 (e.g. proximal end) to a second end 204 (e.g. distal end). The body 201 includes an inner surface 206 (see FIG. 7) and an opposing outer surface 208. The inner surface 206 extends about a central body axis CB to define a body channel 207 that extends through the body 201 from the first end 202 to the second end 204. The central body axis CB extends through a center of the body 201 from the first end 202 to the second end 204. The body channel 207 extends from a first opening 210 at the first end 202 to second opening 212 at the second end 204. The body 201 further defines an inlet 214 that extends through the body 201 from the outer surface 208 to the inner surface 206, such that the body channel 207 is in fluid communication with an exterior of the flow meter 200 through the inlet 214. The inlet 214 is positioned between the first end 202 and the second end 204 of the body 201. The inlet 214 defines an opening that can be offset from the flow direction F by an angle of less than 90 degrees.

[0034] The outer surface 208 of the body 201 can include a first threaded portion 216 and a second threaded portion 218. The first threaded portion 216 extends from the first end 202 of the body 201 toward the second end 204. In an aspect, the first threaded portion 216 extends along the outer surface 208 to a location on the outer surface 208 between the inlet 214 and the first end 202. The second threaded portion 218 extends from the second end 204 of the body 201 toward the first end 202. The first threaded portion 216 and the second threaded portion 218 can be separated by a non-threaded portion 220, which extends along the outer surface 208 between the first and second threaded portions 216 and 218. In an alternative aspect, the first threaded portion 216 could extend along the outer surface 208 to the second threaded portion 218 such that the outer surface 208 is substantially threaded between the first and second ends 202 and 204.

[0035] The first threaded portion 216 is configured to threadedly connect with a threaded portion (not shown) of the dispenser body 12. For example, the passageway 42 can be at least partially defined by an internally threaded portion that corresponds to the first threaded portion 216 such that the first threaded portion 216 can threadedly connect to the threaded portion of the passageway 42. When the flow meter 200 is connected to the dispenser body 12, the inlet 214 of the flow meter 200 is in fluid communication with passageway 42 of the dispenser body 12.

[0036] In an aspect, the outer surface 208 of the flow meter 200 can be unthreaded, and connected to the dispenser body 12 by a method or device other than a threaded connection. For example, the flow meter 200 can be connected to the dispenser body 12 by adhesives, welding, screws, bolts, retention members, or other methods or devices configured to secure the flow meter 200 to the dispenser body 12.

[0037] The second threaded portion 218 is configured to threadedly connect with a threaded portion (not shown) of, for example, a nozzle. The nozzle could include an internal threaded portion that corresponds to the second threaded portion 218 such that the second threaded portion 218 can threadedly connect to the threaded portion of the nozzle. In an aspect, the nozzle can be integrally formed with the flow meter 200 forming a single unitary piece (e.g. monolithic structure). In alternative aspect, the flow meter 200 can be connected to the nozzle by, for example, adhesives, welding, screws, bolts, retention members, or other methods or devices configured to connect to a nozzle.

[0038] With reference to FIGS. 6 and 7, the flow meter 200 further includes a stator 222, a rotor 224, a shaft 226, a blade member 228, a seal member 230, a retention member 232, and a sensor 234. Each of the stator 222, the rotor 224, the shaft 226, the blade member 228, the seal member 230, the retention member 232, and the sensor 234 can be positioned within the body channel 207 of the body 201. It will be appreciated that one or more of the flow meter 200 components can be positioned externally from the body channel 207. The position and alignment of each of the components is such that when the fluid material enters into the inlet 214 of the body 201, the fluid material flows in a flow direction F from the inlet 214 toward the second opening 212 of the body channel 207 about the rotor 224 and through the stator 222, as further described below. The flow direction F can be substantially parallel to the central body axis CB. The flow of the fluid material through the flow meter 200 causes a rotational movement of the rotor 224 relative to the stator 222. Based on the relative rotation between the rotor 224 and the stator 222, a volume of the fluid material flowing through the flow meter 200 can be determined. For example, spacing between the rotor 224 and the stator 222 define at least one cavity 256 between them that has a defined volume. The relative rotation between the rotor 224 and the stator 222 causes a displacement of the at least one cavity 256, which can be translated into a unit of volume dispensed.

[0039] The stator 222 has an outer surface 240 and an opposing inner surface 242. When the stator 222 is positioned within the body channel 207, the outer surface 240 abuts against the inner surface 206 of the body 201. The inner surface 242 of the stator 222 defines a stator channel 246 that extends through the stator 222 from a first end 248 to a second end 250. The inner surface 242 includes a contoured portion 252. The contoured portion 252 defines an radially outermost extent of the stator channel 246. The contoured portion 252 can extend along the inner surface 242 from the first end 248 to the second end 250 of the stator 222. Alternatively, the contoured portion 252 can extend along a portion of the inner surface 242. The contoured portion 252 defines at least one undulation 254 or rolling contour when viewed in cross section (e.g. FIG. 7), and this shape is configured to engage with a corresponding contoured shape of the rotor 224 to produce the at least one fluid cavity 256. [0040] The rotor 224 is positioned within the stator 222 such that at least a portion of an outer surface 258 of the rotor 224 faces the inner surface 242 of the stator 222. The outer surface 258 of the rotor 224 can include a contoured portion 260. The contoured portion 260 can include, for example, a solid helical shape defining a twin helix shape along the outer surface 258. The contoured portion 260 can extend along at least a portion of the outer surface 258 from a first end 262 of the rotor 224 to a second end 264 of the rotor 224.

[0041] The at least one cavity 256 is defined between the respective contoured portions 252 and 260. The at least one cavity 256 can include a series of a plurality of cavities 256 with a known volume. In an aspect, a volume of each of the plurality of cavities 256 is substantially the same as a volume of each of the other plurality of cavities 256. Each cavity 256 can define a discrete cavity that is sealed and separated from each of the other cavities 256.

[0042] Each cavity 256 can be approximately helix shaped as well, with tapering ends such that a beginning of one cavity 256 overlaps an end of another cavity 256 on a radially opposite side of the rotor 224. To this end, as the rotor 224 rotates relative to the stator 222, each cavity 256 translates in the flow direction F from the first end 248 of the stator 222 to the second end 250 of the stator 222. As each one of the cavities 256 reaches the second end 250, each cavity 256 tapers down and delivers less flow to the second end 250. As one cavity 256 is tapering down, the next cavity 256 begins to open (e.g. adjacent cavities 256 overlap one another in a radial direction) during rotation of the rotor 224 to the second end 250, thereby keeping the overall flow volume and pressure generally consistent while the rotor 224 rotates relative to the stator 220. The cavities 256 can have the same size and shape, and thus contain a fixed quantity of fluid volume that does not change as the cavities 256 translate through the flow meter 200 in the flow direction F. [0043] In an alternative aspect, a single cavity 256 can be defined between the respective contoured portions 252 and 260. A cross sectional dimension of the single cavity 256 can be substantially the same along a length of the cavity 256 such that a volume of fluid flow at an inlet to the cavity 256 is substantially the same as a volume of fluid flow at an outlet of the cavity 256.

[0044] Although the elements may be formed from different types of materials, in an aspect, the stator 222 comprises a rubber or other elastomeric material, or a polymer or ceramic. The rotor 224 comprises a steel material or other rigid like material. In an aspect, the stator 222 can have a hardness of between approximately 60 and 100 Shore A hardness. Alternatively, or additionally, the stator 222 can be rigid. The rotor 224 can have an outer diameter that is slightly larger than an inner diameter of the stator 222 to define the at least one cavity 256 between the rotor 224 and the stator 222.

[0045] The first end 262 of the rotor 224 can be connected to a second end 266 of the shaft 226. The connection between the rotor 224 and the shaft 226 can include, for example, a threaded connection, a weld, an adhesive, a bolt, a screw, or still other type of connection. In an aspect, the connection between the rotor 224 and the shaft 226 comprises a rigid connection, such that rotation and axial displacement between the rotor 224 and the shaft 226 is substantially prevented. The shaft 226 extends from the first end 262 of the rotor 224 toward the first end 202 of the body 201. The first end 268 of the shaft 226, or alternatively a location on the shaft 226 between the first and second ends 268 and 266 of the shaft 226, is coupled to the retention member 232. The connection between the shaft 226 and the retention member 232 substantially axially fixes the retention member 232 to the shaft 226, and allows the shaft 226 to rotate relative to the retention member 232. In an aspect, the retention member 232 comprises a ball bearing type connection member.

[0046] The shaft 226 can include, for example, a flexishaft that is configured to at least partially axially bend when a force is applied in a direction that is substantially perpendicular to a length of the shaft 226 extending from a first end 268 of the shaft 226 to the second end 266. The shaft 226 can axially bend between the first end 262 of the rotor 224 and a connection between the shaft 226 and the blade member 228. The shaft 226 can be rigid between the first end 262 of the rotor 224 and the second end 266 of the shaft 226. The shaft 226 can also be rigid between the connection between the shaft 226 and the blade member 228 and the first end 268 of the shaft 226. The flexible shaft 226 allows for movement of the rotor 224 about axes that are offset from the central body axis CB as the rotor 224 rotates relative to the stator 222, as further described below. In alternative aspects, the shaft 226 can include constant velocity joints, universal joints, combinations thereof, or still other joints to allow for movement of the rotor 224.

[0047] The retention member 232 is positioned within the body channel 207 of the body 201. The retention member 232 is connected to the inner surface 206 of the housing 201, such that the retention member 232 is substantially rotationally and axially fixed within the housing 201. In alternative aspects, the retention member 232 can be positioned externally from the body 201. For example, the retention member 232 can be coupled to and/or extend from the first end 202 of the body 201 in a direction away from the body channel 207. The retention member 232 has an inner surface 270 that defines a retention channel 272. The retention channel 272 is configured to receive the shaft 226 within. When the shaft 226 is positioned within the retention member 232, a center of the first end 268 of the shaft 226 is aligned with the central body axis CB. AS fluid flows through the flow meter 200, the rotor 224 and the shaft 226 rotate together relative to the retention member 232. While the shaft 226 is rotating relative to the retention member 232, the center of the first end 268 of the shaft 226 substantially maintains alignment with the central body axis CB. The blade member 228 is positioned within the body channel 207 of the body 201. The blade member 228 is connected to the shaft 226, such that the blade member 228 is substantially rotationally and axially fixed to the shaft 226. The blade member 228 can be connected to a rigid portion of the shaft 226. The blade member 228 is positioned within the body channel 207 at a location between the inlet 214 and the second opening 212 of the body 201 in the flow direction F. In an aspect, the blade member 228 is positioned adjacent to the opening 214 such that as fluid enters into the flow meter 200 through the inlet 214, the fluid contacts and flows through the blade member 228. As the fluid contacts the blade member 228, a force is applied by the fluid that causes the blade member 228 to rotate within the body channel 207, which can cause the shaft 226 and the rotor 224 to rotate within the body channel 207.

[0048] With reference to Figure 8, the blade member 228 has an inner surface 280 that defines a blade channel 282. The blade channel 282 is configured to receive the shaft 226 within. The blade member 228 can include at least one aperture 284 and at least one blade portion 286. Each of the at least one apertures 284 allows the fluid to flow through in the flow direction F. Each of the at least one blade portions 286 includes a respective surface that is angularly offset from the flow direction F. As the fluid contacts each respective surface of the at least one blade portions 286, a rotational force is applied to the blade member 228 that causes the blade member 228 to rotate within the body channel 207. The rotation of the blade member 228 can facilitate the rotation of the rotor 224 and the shaft 226. In an aspect, the blade member 228 comprises a turbine blade.

[0049] The seal member 230 is positioned within the body channel 207 of the body 201. The seal member 230 can be positioned about the shaft 226 and in contact with the inner surface 206 of the body 201. The seal member 230 can be located between the inlet 214 and the first opening 210 of the body 201. The seal member 230 is configured to substantially prevent fluid from flowing between the inlet 214 and the first opening 210. In an aspect, the seal member 230 is connected to the inner surface 206 of the body 201 such that the seal member 230 is substantially rotationally and axially fixed to the body 201. In an aspect, the seal member 230 is connected to the retention member 232.

[0050] It will be appreciated that rotation of the rotor 224 relative to the stator 222 within the body channel 207 can be offset from the central body axis CB. With reference to FIG. 9, the rotor 224 extends from the first end 262 to the second end 264 along a central rotor axis CR. The central rotor axis CR extends through a center of the rotor 224. The stator 222 extends about a central stator axis Cs that extends through a center of the stator 222 from the first end 248 to the second end 250. In an aspect, the central stator axis Cs can be substantially colinear with the central body axis CB. AS the rotor 224 rotates within the body 201, the central rotor axis CR can be offset from the central body axis CB and the central stator axis Cs by a distance D. The distance D can fluctuate as the rotor 224 rotates within the stator 222. For example, during rotation of the rotor 224 within the body channel 207 the central rotor axis CR can transition between a first distance away from the central body axis CB and a second distance away from the central body axis CB, the second distance being different from the first distance. In an aspect, the central rotor axis CR is substantially parallel to the central body axis CB. In an aspect, the central rotor axis CR can rotate about the central body axis CB. A flexibility in the shaft 226 can account for the offset between the central rotor axis CR and the central body axis CB by flexibly moving with the rotor 224 during rotation. For example, a center of the second end 266 of the shaft 226 can align with a center of the first end 262 of the rotor 224 on the central rotor axis CR, while the center of the first end 268 of the shaft 226 can align with the central body axis CB.

[0051] The sensor 234 is adapted for detecting a rotational displacement between the rotor 224 and the stator 222. The sensor 234 can comprise a rotational sensor that includes, for example, an optical sensor, a magnetic sensor, infrared sensor, or other type of sensor or encoder capable of sensing rotation. The sensor 234 can be positioned within the body 201 and connected to the inner surface 207. In an aspect, the sensor 234 can be positioned about the shaft 226. The sensor 234 can be adapted for detecting a rotation of the shaft 226 within the body 201. Since the shaft 226 and the rotor 224 can be substantially rotationally and axially connected together, detecting a rotation of the shaft 226 can provide an approximate measurement for a rotation of the rotor 224. In an alternative aspect, the sensor 234 can be positioned externally from the body 201. The sensor 234 is further adapted for transmitting a signal to the controller 18 indicative of the rotational displacement between the rotor 224 and the stator 222. Based on the transmitted signal, the controller 18 can determine a volume of fluid dispensed from the flow meter 200.

[0052] With reference to FIG. 2, the controller 18 can be configured to control the pump 14 and the valve actuator 20 based on inputs and/or signals from the fluid flow meter 200 and/or the pump 14. The controller 18 may comprise any electrical control apparatus configured to control one or more variables based upon one or more inputs. The controller 18 can be implemented using at least one processor selected from microprocessors, microcontrollers, microcomputers, digital signal processors, central processing units, field programmable gate arrays, programmable logic devices, state machines, logic circuits, analog circuits, digital circuits, and/or any other devices that manipulate signals (analog and/or digital) based on operational instructions that are stored in a memory. The memory can be a single memory device or a plurality of memory devices including but not limited to random access memory (RAM), volatile memory, non-volatile memory, static random access memory (SRAM), dynamic random access memory (DRAM), flash memory, cache memory, and/or any other device capable of storing digital information. The controller 18 may also include a mass storage device of various types, and also a human machine interface for interacting with a user.

[0053] The controller 18 can be operatively connected with the sensor 234 of the fluid flow meter 200. Readings from the sensor 234 can be transmitted to the controller 18 as feedback for closed loop control of the dispensing system 10. For example, readings from the sensor 234 can be used to determine an amount of fluid that has been dispensed. After a desired amount of fluid has been dispensed, the controller 18 can send a signal to the pump 14 to halt pumping.

[0054] During operation of the dispensing system 10, the drive pin 58 and the valve element 56 jointly cooperate to dispense fluid material from the dispensing system 10. Each reciprocating cycle of the drive pin 58 and the valve element 56 can dispense the fluid material. As the fluid flows through the passageway 42 of the dispensing system 10 toward the dispensing outlet 36, the fluid enters into the flow meter 200 through the inlet 214. With reference to FIG. 7, the fluid enters into the body channel 207 from the inlet 214 and flows from the inlet 214 in the flow direction F. As the fluid flows in the fluid direction F, the fluid contacts the blade member 228 facilitating the rotation of the shaft 226 and the rotor 224 within the body 201. The fluid flows through the blade member 228 and through the body channel 207 to the stator 222. As the fluid enters into the stator channel 246, the fluid can apply a force to the outer surface 258 of the rotor 224. The force applied to the outer surface 258 of the rotor 258 further facilitates the rotation of the rotor 224 within the body 201 relative to the stator 222. As the rotor 224 rotates relative to the stator 222, the fluid enters into the at least one cavity 256 formed between the rotor 224 and stator 222. The rotation of the rotor 224 relative to the stator 222 causes the at least one cavity 256 to move in the flow direction F toward the second ends 250 and 264 of the stator 222 and the rotor 224, respectively. The fluid exits the at least one cavity 256, through the second end 250 of the stator 222, and through the second opening 212 of the body 201. After the fluid exits the body 201, the fluid continues to flow along passageway 42 toward the dispensing outlet 36. In an aspect, the flow meter 200 is connected to the dispensing outlet 36. A nozzle can be coupled to the second end 204 of the body 201, and as fluid exits the nozzle, the fluid can be applied to, for example, the substrate 24.

[0055] As the fluid flows through the fluid meter 200 and causes the rotor 224 to rotate relative to the stator 222, the sensor 234 detects the rotational displacement between the rotor 224 and the stator 222. The sensor 234 transmits a signal to the controller 18 indicative of the rotational displacement. Based on the rotational displacement between the rotor 224 and the stator 222, the controller can determine an amount of fluid that has been dispensed. For example, a volume of the at least one cavity 256 can be known and stored in a memory of the controller. As the fluid enters into the at least one cavity 256 and causes rotation of the rotor 224, a fluid displacement occurs. If the rotor 224 turns 1 degree, the 1 degree rotational displacement causes a movement of the at least one cavity 256 that can be translated into a volume displacement. Each rotational displacement can be translated into an equivalent volume displacement (e.g. amount of fluid dispensed).

[0056] The rotor 224 and the shaft 226 are free to rotate within the body 201, independent of any drive device (e.g. motor) other than the fluid flowing through the flow meter 200. The flow meter 200 may not include a brake to inhibit rotation of the rotor 224 relative to the stator 222, and therefore, there is minimal pressure buildup within the flow meter 200. For example, neither the rotor 224 nor the shaft 226 are connected to anything that substantially prevent the rotation of the rotor 224 relative to the stator 222, except for frictional forces between the rotor 224 and the stator 222, and frictional forces between the shaft 226 and the retention member 232. In an aspect, the only force causing the rotation of the rotor 224 relative to the shaft 226 is the force applied by the fluid flowing through the flow meter 200. Therefore, the pressure of the fluid at the inlet 214 of the flow meter 200 is substantially the same as the pressure of the fluid at the second opening 212 of the body 201 of the flow meter 200, which enables an accurate determination of the volume of fluid being dispensed from the flow meter 200.

[0057] One fluid that can be dispensed using the dispensing system 10 is adhesive, which typically needs to remain heated during the dispensing process. With reference to FIG. 3, a heater 76 can provided with a body 80 that operates as a heat transfer member, the heater 76 at least partially surrounding the fluid module. The heater 76 can includes pins 79 that contact respective soft, electrically conductive contacts 72 associated with an actuator body 74. At least part of the fluid module, including the second section 44 of the dispenser body 12 and the insert 70, can sit within the heater 76, and when the heater 76 is drawn against the actuator body 74 by retainer arms, the fluid module is effectively held in position by compression between the heater 76 and the actuator body 74. It will be appreciated that other fluids can be dispensed using the dispensing system 10 that may or may not require heating the fluid. In an aspect, the fluid flowing through the flow meter 200 includes a high viscosity fluid.

[0058] It will be apparent to those of ordinary skill in the art that variations and alternative embodiments may be made given the foregoing description. Such variations and alternative embodiments are accordingly considered within the scope of the present invention.

[0059] Joinder references (e.g., attached, coupled, connected, joined, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other. [0060] In some instances, components are described with reference to "ends" having a particular characteristic and/or being connected with another part. However, those skilled in the art will recognize that the present invention is not limited to components which terminate immediately beyond their points of connection with other parts. Thus, the term "end" should be interpreted broadly, in a manner that includes areas adjacent, rearward, forward of, or otherwise near the terminus of a particular element, link, component, part, member or the like. In methodologies directly or indirectly set forth herein, various steps and operations are described in one possible order of operation, but those skilled in the art will recognize that steps and operations may be rearranged, replaced, or eliminated without necessarily departing from the spirit and scope of the present invention.

[0061] The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments of the invention. Although various embodiments of the invention have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention. Other embodiments are therefore contemplated. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative only of particular embodiments and not limiting. Changes in detail or structure may be made without departing from the basic elements of the invention as defined in the following claims.