US20050254972A1

US20050254972A1 - Bench top pump

Info

Publication number: US20050254972A1
Application number: US11/129,235
Authority: US
Inventors: Rodney Baker; Keith Grayson
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-05-14
Filing date: 2005-05-13
Publication date: 2005-11-17

Abstract

A modular, expandable, no-tools pump assembly having precise computer control for controlling dispensing volumes and flow characteristics of the dispensed fluid.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application is based upon and claims benefit of copending and co-owned U.S. Provisional Patent Application Ser. No. 60/571,327 entitled “Bench Top Pump,” filed with the U.S. Patent and Trademark Office on May 14, 2004 by the inventors herein, the specification of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention
This invention relates to fluid dispensing apparatus, and more particularly to a modular, expandable, no-tools pump assembly having precise computer control for regulating dispensing volumes and flow characteristics of the dispensed fluid.

SUMMARY OF THE INVENTION

Disclosed is a modular product delivery system capable of dispensing aqueous materials of various viscosities. The pump assembly described herein is capable of dispensing fluids with extremely high accuracy, in turn enabling a wider range of fill volumes to be satisfied for a given pump size. The modular construction enables a single drive unit to be used with pump assemblies of varying sizes and configurations, valves of various sizes and configurations, and even a variety of automated actuating systems. The pump assembly described herein in suitable for use in automatic, semi-automatic, and stand-alone operations. A programmable controller is provided, allowing a user to input at least dispense volumes and dispense profiles through a user interface giving control of the product flow characteristics and process functions. Quick-connect fasteners interconnect the modular components of the assembly, such that no tools are required for cleanup and there are no married pump parts. All parts for a given pump size are interchangeable with any other pump of the same size. The pump assembly may be manufactured from a variety of materials, thus making it compatible with a wide range of products. Moreover, the controller of the pump assembly is preferably capable of working numerous peripheral devices.
The various features of novelty that characterize the invention will be pointed out with particularity in the claims of this application.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features, aspects, and advantages of the present invention are considered in more detail, in relation to the following description of embodiments thereof shown in the accompanying drawings, in which:
FIG. 1 is an exemplary drive unit for a fluid product delivery system according to a first embodiment of the present invention.
FIG. 2 is an elevational side view of a drive assembly according to a first embodiment of the present invention.
FIG. 2(a) is an elevational end view of a drive assembly according to a first embodiment of the present invention.
FIG. 3 shows a piston pump assembly according to the present invention.
FIG. 4 shows a diaphragm pump assembly according to the present invention.

DETAILED DESCRIPTION

The invention summarized above and defined by the enumerated claims may be better understood by referring to the following description, which should be read in conjunction with the accompanying drawings. This description of an embodiment, set out below to enable one to build and use an implementation of the invention, is not intended to limit the invention, but to serve as a particular example thereof. Those skilled in the art should appreciate that they may readily use the conception and specific embodiments disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent assemblies do not depart from the spirit and scope of the invention in its broadest form.
As shown in the front, top, and side sectional views of FIG. 1, an exemplary drive unit for a fluid product delivery system according to a first embodiment of the invention includes a pump housing 10, a linearly extending drive rod 20 configured for generally horizontal movement out of and into housing 10, and a programmable controller 30 in communication with a drive motor 40, the drive motor 40 being mechanically connected to drive rod 20 through a drive assembly so as to execute linear displacement of drive rod 20 as desired.
As shown more particularly in the cross-sectional view of FIG. 2, drive rod 20 comprises a rigid, hollow shaft extending between a drive plate 21 and a front face 11 of housing 10. In FIG. 2, drive rod 20 is particularly depicted at a rear-most “home” position. Extending through drive rod 20 is a screw member 50 rotatably mounted within housing 10. A rear end of screw member 50 is attached to a drive pulley 60, such that rotation of drive pulley 60 in turn causes rotation of screw member 50. Positioned to ride along screw member 50 is internally threaded drive member 51, preferably in the form of a ball nut. As will be explained, the angular orientation of drive member 51 is fixed with regard to housing 10, such that rotation of screw member 50 causes linear displacement of drive member 51 along screw member 50 in a direction determined by the direction of rotation of screw member 50.
A guide member 70 is mounted to front face 11 of housing 10, and is provided a central bore therein allowing drive rod 20 to pass therethrough. As the position of guide member 70 is fixed with regard to front face 11 of housing 10, it provides a guide for the front end of drive rod 20 as it moves linearly into and out of housing 10. A seal member 71 is provided external to guide member 70 positioned within a circular groove in the front face of faceplate 75. Seal member 71, preferably in the form of a spring loaded cup seal, has an inner diameter and an outer diameter with a thickness corresponding to a groove in front face 11. The inner diameter of seal member 71 is such that it forms a closed circle around drive rod 20 closing off any path that liquid could pass by seal member 71, serving to prevent residual liquid from entering housing 10 through front face 11 during cleanup. The outer diameter of seal member 71 fits tightly in the groove of front face 11, thus securing seal member 71 so that linear movement of drive rod 20 does not displace seal member 71. A spring located between the inner and outer diameter of seal member 71 adds additional squeeze pressure against the inner diameter of seal member 71. The seal member 71 is preferably made of Teflon, creating a low friction surface allowing drive rod 20 virtually unrestricted linear movement while maintaining a liquid tight seal.
Referring to both FIGS. 2 and 2 a, drive plate 21 is rigidly affixed to a guide plate 22. Guide plate 22 is provided a plurality of channels through which guide rods 23 pass. Guide rods 23 are likewise rigidly connected to housing 10, preferably via threaded connectors or similarly fashioned fasteners 23 a joining a front end of guide rods 23 to front face 11, and back end of guide rods 23 to a support plate 25 positioned near the back of drive unit enclosure 10. Optionally, a bearing 23 b may be provided in each such channel surrounding the respective guide rod 23 to assist linear movement of guide plate 22 along guide rods 23. Screw member 50 likewise extends through support plate 25, and is likewise optionally supported therein by one or more bearings 50 a.
Guide plate 22 and guide rods 23 help assure precise, strictly linear movement of drive rod 20 out of and into housing 10 when motor 40 is actuated. Drive member 51 is rigidly attached to drive plate 21, guide plate 22, and drive rod 20 through trantorque 17. The trantorque 17 is comprised of 5 pieces, nut 202, inner race 201 and 3 outer races 200. The nut 202 has a hexagonal outer form to accept a standard English wrench. The hex allows for tightening in order to secure the drive rod 20 to guide plate 22. The nut 202 has internal thread and the inner race 201 has mating external threads. The inner race 201 is also tapered on the upper outside half such that rotating the nut 202, while engaged with the threads of the inner race 201, pulls the inner race 201 up towards the top of nut 202, forcing the taper to move inside the 3 outer races 200. As the taper contacts outer races 200, they are forced outward, against guide plate 22. The inner race 201 has slots to allow for compressing as the outer races 200 engage the guide plate 22. When the outer races 200 engage the guide plate 22, it compresses the inner race 201 thus engaging the drive rod 20. The nut 202 is continually rotated until inner race 201 and outer races 200 fill the gap between the drive rod 20 and guide plate 22. The taper on the inner race 201 creates a locking force keeping the nut 202 from rotating. With the nut 202 tightened and all gap removed between the drive rod 20 and guide plate 22, the drive rod 20 is secured to the guide plate allowing no independent movement. Because drive member 51, drive plate 21, guide plate 22, and drive rod 20 are thus all rigidly affixed to one another, they form a unitary block structure that moves as a single unit upon rotation of screw member 50, which eliminates the risk of slippage and associated inadvertent and unwanted displacement of drive rod 20. Rotation of screw member 50 in even miniscule increments causes an associated, minute linear displacement of drive plate 21 and drive rod 20, thus allowing greater control of displacement of a piston external to the drive unit, and thus greater control over dispensed volumes. With no mechanical inefficiencies in the connection point from the drive rod 20 to the drive member 51, the linear movement of the drive rod 20 with respect to the drive member is calculatingly repeatable.
In order to rotate screw member 50, motor 40 is preferably utilized to rotate a first drive pulley 45. First drive pulley 45 is operatively connected to drive pulley 60 through a drive chain member, such as drive belt 46. Optionally, drive pulleys 45 and 60 may be provided in sizes customized for a particularly desired dispensing configuration to deliver the optimum power for products being dispensed. Further, to ensure micro control of the linear displacement of drive rod 20, and thus of the volume to be dispensed, motor 40 preferably comprises a high precision servomotor. By way of example only, and not by way of limitation, motor 40 may comprise an Allen Bradley type Y series motor. Notably, any servo motor that can be given an analog or digital signal, interpret the signal into an angular displacement, and, through means of an encoder or resolver, monitor and compare the angular displacement against the input signal thus confirming that the position the motor was commanded to go to is in fact the position it has reached, will suffice, provided the resolution of the angular position and the encoder/resolver meet the precision required by the system.
As particularly shown in FIG. 2, drive rod 20 is preferably equipped with a threaded stud 24 at the end that extends outside of housing 10. As will be discussed in greater detail below, threaded stud 24 is configured to receive an internally threaded piston member for use in a modular cylinder assembly for use with the aforementioned drive unit.
Mounted to front face 11 of housing 10 is a faceplate 75 through which drive rod 20 extends and travels during its linear displacement. While not particularly shown in FIG. 2, faceplate 75 is preferably provided a plurality of externally facing threaded bores for receiving threaded members used to attach modular components to the exterior of housing 10, as will be described.
Referring again to FIG. 1, a position sensor 80 is mounted at a fixed position within drive housing 10 so as to establish a “home” reference position for the piston rod. By way of example only and not by way of limitation, position sensor 80 may comprise a proximity switch model AE1-AP-4F from Automation Direct. For instance, position sensor 80 may be mounted immediately adjacent the path of travel of guide plate 22 so as to detect the presence of guide plate 22 when it reaches its predetermined home position. As guide plate 22 is rigidly attached to drive rod 20, such home position of guide plate 22 likewise indicates home position of drive rod 20, and thus of a piston attached to drive rod 20 external to housing 10. A second sensor of the same type described above may be mounted at the full travel position of guide plate 22. This sensor may be used to initiate a stop condition should the guide plate 22 travel past its stop limit position.
A significant advantage of the construction of the fluid product delivery system of the instant invention is its modular construction enabling the quick-connect assembly and disassembly of pump members from the drive unit. Such quick connect assembly and disassembly provides a pump construction having no married parts, thus easing adaptability to various pumping requirements and easing maintenance by allowing separate pump cylinder, piston, and valve assemblies to be quickly removed for cleaning, maintenance, and replacement.
As shown in FIG. 3, a preferably machined cylinder 100 is provided. Cylinder 100 is preferably machined to allow, if required, the ability to modify the dimensions of the pump for custom fit applications and/or future enhancements. The base of cylinder 100 is preferably provided a skirt 110 having a plurality of boreholes 111 extending therethrough. Skirt 110 is sized so as to fit on face plate 75 mounted to front face 11 of housing 10, with bore holes 111 aligned with threaded bores on the external surface of face plate 75. A plurality of hand-tightening screws (not shown) are provided, the threaded shafts of which extend through bore holes 111 in skirt 110 and into the threaded bores on the external surface of face plate 75, such that mere hand tightening of such screws is sufficient to clamp cylinder 100 to drive housing 10. Cylinder 100 is provided an internal chamber 120 through which a preferably multilayer piston 130 travels. Piston 130 is provided a central threaded bore configured to receive threaded post 24 on the end of drive rod 20. The layers of piston 130 preferably comprise multiple layers of rubber and plastic so as to allow easy assembly and cleaning as well as an ability to accept various types of seal materials so that the seals will be compatible with the product being dispensed. A generally cup-shaped cap 140 is provided on an outside end of cylinder 100. Cap 140 is provided at least two boreholes 141 to allow fluid access into and out of cylinder 100 when fully assembled. Preferably press-fit into boreholes 141 are channel members 150. Press fit is preferred so that no other type of material comes in contact with the channel members 150 and cap 140, providing purity at the connection point. However, the channel members 150 may be welded and chemically treated to an acceptable purity level. The latter welding and treatment process though, increases the number of operations required to fabricate the cap 140 making it more costly. Attached to channel members 150 are fluid inlet and outlet connectors 142 and 143, respectively. One-directional valves of typical construction, such as those manufactured by Intellitech, part # 200-00000009, utilizing umbrella style seals that open in the direction of applied pressure, are preferably situated on each inlet and outlet so as to allow one directional flow of fluid into and out of internal chamber 120.
As mentioned above, an important advantage of such assembly is its modular construction. Using a single drive unit, cylinders having various diameters but a uniform skirt 110 may be provided for different pumping applications. Likewise, different caps 140 may be provided. Channel members 150 and inlet and outlet connectors 142 and 143, respectively, of varying geometries may be provided to suit particular dispensing needs. As the system is modular in construction and enables quick connect and disconnect of such components, the system may be readily adapted to varying dispensing requirements. To effect such quick connect and disconnect function, manually operable quick connect clamps 160 are provided, for example, clamps commercially available from VNE as type 102-HDC-.50, to attach cap 140 to cylinder 100, and to connect each of inlet connector 142 and outlet connector 143 to their respective channel members 150. Preferably, compressible sealing members, such as O-ring seals 165, are provided at the connection point between cap 140 and cylinder 100, and between each inlet and outlet connector 142 and 143 and their respective channel members 150.
As an alternative to the piston pump shown in FIG. 3, a diaphragm pump assembly may likewise be provided as shown in FIG. 4. Once again, a piston 130 is provided having a threaded opening configured to receive threaded stud member 24. A flexible diaphragm assembly of traditional construction (shown generally at 170) is provided, mounted between cap 140 and cylinder 100. Such diaphragm pump assembly is particularly advantageous in pumping applications in which particulate is not acceptable in the product being dispensed. The diaphragm is moved back and forth by a piston 130 located outside the product contact area of the diaphragm. The diaphragm does not rub against the walls of the cylinder 100 or the cap 140, thus eliminating friction that could cause particles to separate from the diaphragm and mix with the product. As with the assembly of FIG. 3, the base of cylinder 100 is preferably provided a skirt 110 having a plurality of bore holes 111 extending therethrough. Skirt 110 is again sized so as to fit on face plate 75 mounted to outside face 11 of housing 10, with bore holes 111 aligned with threaded bores on the external surface of face plate 75. A plurality of hand-tightening screws (not shown) are provided, the threaded shafts of which extend through bore holes 111 in skirt 110 and into the threaded bores on the external surface of face plate 75, such that mere hand tightening of such screws is sufficient to clamp cylinder 100 to drive housing 10. Once again, cap 140 is provided at least two channel members 150 to allow fluid access into and out of cylinder 100. Attached to channel members 150 are fluid inlet and outlet connectors 142 and 143, respectively. One-directional valves of typical construction are again preferably situated on each inlet and outlet so as to allow one directional flow of fluid into and out of internal chamber 120. The diaphragm pump assembly likewise maintains the above-described quick connect and quick disconnect functionality, including manually operable quick connect clamps 160 to attach cap 140 to cylinder 100, and to connect each of inlet connector 142 and outlet connector 143 to their respective channel members 150. Once again, compressible sealing members, such as O-ring seals 165, are preferably provided at the connection point between cap 140 and cylinder 100, and between each inlet and outlet connector 142 and 143 and their respective channel members 150.
The above-described construction has been found to provide significant benefit over prior known dispensing apparatuses, in that it provides for a modular assembly lacking married pump parts that complicate even routine maintenance. The modular structure described above with quick connect clamps allows the system to be readily adapted to particularly dispensing operations, and enables easy disassembly of components that come in contact with the working fluid to ease maintenance. Further, the linear ball screw drive construction provides for significantly improved control over linear displacement of the piston external to the pump housing 10.
Of course, in order to move drive rod 20 to any extent, servomotor 40 must be operated to rotate screw member 50. Programmable controller 30 is provided to precisely control such activation.
More particularly, the controller 30 allows a user to program instructions to the motor 40 to control fluid intake and fluid discharge entirely independent of one another, thus providing the user unlimited ability to control the flow characteristics of the product being dispensed, and more particularly allowing the user to customize such operation for the particular delivery system and collection device in use. For both intake and discharge, a user may input a desired acceleration value (i.e., the acceleration of piston 130 as it travels through cylinder 100), a desired deceleration value, and a velocity value for when the piston is at speed. In addition to these values, an operator is likewise prompted to input pump size, dispense volume, and optionally other parameters that may affect motion or overall cycle of the piston 130. An appropriate scaling factor is applied to the parameters input by the user to translate the desired dispensing volumes and acceleration, deceleration, and velocity settings to specific instructions configured for driving the motor, based upon the screw pitch of screw member 50, the gear ratio between the motor 40 and the screw member 50, and the amount of fluid that will be displaced by a given linear movement of the piston 130 as a result of a given rotation of screw member 50 (as determined by the geometry of the modular components attached to the drive housing 10). Of course, such scaling factor is a matter of geometry, and thus the particular value of such scaling factor may be readily determined once based on the geometry of the above-described elements.
In some embodiments, programmable controller 30 may comprise a touch sensitive key pad, as illustrated. In some embodiments, the controller 30 may comprise a remote personal computer having data storage capability to record information concerning operation of the drive unit and attached pump components.
Such programmable control of motor 40 enables precise control of dispensing volumes and of overall flow characteristics of the fluid being dispensed. For instance, if a product delivery system is located below the pump described herein, an operator may adjust acceleration, velocity, and deceleration on the intake stroke to accommodate for the need to pull product into the pump. Likewise, if the product is located above the pump, an operator may again adjust acceleration, velocity, and deceleration on the intake stroke to compensate for the resulting in-feed pressure. Similarly, a user may vary discharge fluid flow characteristics based on the container into which the fluid is to be dispensed. For instance, if a container has a wide base that funnels down to a narrow neck and opening area, the user may reduce velocity and deceleration as the product enters the neck, thus reducing the opportunity of overflow of the product.
Again, each of the flow characteristics input by the user may effect actual movement of the piston 130 by translating those characteristics into a drive signal that is sent to motor 40. Given the pitch of screw member 50, the gear ratio between motor 40 and screw member 50, and the resolution of a motor feedback device (i.e., any device capable of generating an accurate electronic pulse representing a distance mark that can be interpreted by the controller), the exact displacement of drive rod 20 may be determined for a given rotation of the motor 40. More particularly, such control is accomplished by an encoder mounted to the motor. An encoder sends out pulses as it rotates. Depending on the resolution of the encoder, i.e., the number of pulse segments per revolution, one may determine the angular position of the motor shaft by dividing one revolution by the encoder resolution. For example, assuming an encoder has a resolution of 1000, one revolution of the motor feeds back 1000 pulses or counts. If the ball nut of drive member 51 has a 10 mm pitch, and the belt drive has a 1 to 1 ratio, then for every revolution, or 1000 pulses, the piston rod mounted to the drive member 51 will move 10 mm, thus enabling exact determination of the displacement of drive rod 20 for a given motor rotation. By controlling motor 40, displacement of drive rod 20, and thus of piston 130, is likewise controlled. Based, in turn, on the geometry of the pump housing (cylinder 100, cap 140, etc.), a user may readily determine the precise volume of fluid that will be dispensed for a given angular displacement of motor 40 (and ensuing linear displacement of drive rod 20). Based on this mathematical analysis, an appropriate scaling factor, as discussed above, may readily be determined for varying pump configurations. By providing a control system that adapts dispensing characteristics based upon geometry of the drive and pump elements and the desired fluid flow characteristics of the product to be dispensed, a user may accurately determine and control the volume dispensed by a pump and maintain a repeatable accuracy level, and likewise utilize a single pump assembly for dispensing products of highly varying viscosities and other characteristics.
By way of example, in order to dispense protein product, it is typically desirable to begin moving product slowly, keep it moving at a steady velocity, and slow it down to a controlled stop, so as to keep the shear effect on the fluid at an acceptable minimum and thus prevent damage to the protein in the fluid. Using a system in accordance with the instant invention, during intake, fluid is pulled into chamber 120 until the stroke of drive rod 20 stops. The rearward movement of drive rod 20, and resulting rearward movement of piston 130 within chamber 120, creates a vacuum in the fluid tubing causing the fluid to begin moving in the direction of the vacuum source. If such intake proceeds too quickly, the shear forces created by so moving the fluid could damage the protein material and cause the fluid to cavitate, in turn leaving holes in the fluid path and causing an inaccurate amount of fluid to accumulate in the pump chamber, resulting in an inaccurate volume of fluid being dispensed. A user may, through controller 30, input an appropriate acceleration that will gradually begin moving the fluid, thereby reducing the shear effect and cavitation. The user may also input a velocity value to maintain a constant flow rate once the fluid starts moving. As the pump reaches the end of its intake cycle, it is desirable not to abruptly stop the fluid motion, as this will also affect the shear properties of the fluid being dispensed. Moreover, because the flow path changes as the product enters the pump chamber 120, it is again desirable to change the rate of flow to decrease the shear effect. Accordingly, the user may also input a deceleration value to slow the flow of fluid as it enters pump chamber 120, until piston 130 stops its intake stroke. With regard to dispensing such a protein product, it remains desirable to start moving the fluid slowly as it is dispensed from chamber 120, keep it moving at a steady velocity, and slow it down to a controlled stop, so as to keep the shear effect on the fluid at an acceptable minimum so as to not damage protein in the fluid. Moreover, excessive speed in dispensing fluid from chamber 120 may result in the fluid hitting the collection container with enough force to splash out of the container, in turn causing an inaccurate fill, as well as spilled product. The user is prompted, before beginning the dispensing operation, to input an acceptable acceleration that will gradually begin moving the fluid, thereby reducing the shear effect and dispensing force. The user likewise inputs a velocity value to establish a constant flow rate during dispensing of the fluid. Still further, the user may input a deceleration value such that, as the piston reaches the end of its discharge cycle, it does not abruptly stop the fluid motion and result in excess shear stress on the fluid. Such versatility and control of fluid flow characteristics enables a single system constructed pursuant to the invention herein to be used for dispensing fluids of highly varied viscosities without requiring substitution of the pump or drive assembly.
The invention has been described with references to a preferred embodiment. While specific values, relationships, materials and steps have been set forth for purposes of describing concepts of the invention, it will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the basic concepts and operating principles of the invention as broadly described. It should be recognized that, in the light of the above teachings, those skilled in the art can modify those specifics without departing from the invention taught herein. Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with such underlying concept. It is intended to include all such modifications, alternatives and other embodiments insofar as they come within the scope of the appended claims or equivalents thereof. It should be understood, therefore, that the invention may be practiced otherwise than as specifically set forth herein. Consequently, the present embodiments are to be considered in all respects as illustrative and not restrictive.

Claims

1. A drive unit, comprising:

a housing;

a hollow drive rod;

a motor;

a screw member extending through said hollow drive rod and operationally attached to said motor; and

an internally threaded drive member attached to said drive rod and operationally attached to said screw member such that rotation of said screw member causes linear displacement of said drive rod.

2. The drive unit according to claim 1, further comprising:

at least one guide member mounted to the front of said housing, said at least one guide member having a central bore therein to allow said drive rod to pass therethrough.

3. The drive unit according to claim 2, said at least one guide member further comprising:

a low friction seal member to form a seal around said drive rod.

4. The drive unit according to claim 1, further comprising:

a drive plate attached to an end of said drive rod.

5. The drive unit according to claim 4, further comprising:

a guide plate rigidly attached to said drive plate;

a plurality of guide rods connected to said housing, said guide plate having a plurality of channels to enable said plurality of guide rods to pass therethrough.

6. The drive unit according to claim 5, wherein said drive member is rigidly attached to said drive plate, said guide plate, and said drive rod through a trantourque, said trantourque comprising:

an inner race;

a plurality of outer races; and

a plurality of fasteners;

wherein said inner race is tapered on its upper outside half; said plurality of fasteners enables tightening of said drive rod to said guide plate, such that said fasteners draw said inner race into said plurality of outer races to engage said guide plate and engage said inner race to said drive rod.

7. The drive unit according to claim 1, wherein said drive member comprises a ball nut.

8. The drive unit according to claim 1, wherein said screw member is operationally connected to said motor by a pulley system.

9. The drive unit according to claim 1, wherein said motor comprises a high precision servomotor.

10. The drive unit according to claim 1, further comprising a controller to operate said motor.

11. A fluid product delivery system, comprising:

a housing;

a hollow drive rod;

a motor;

a screw member extending through said hollow drive rod and operationally attached to said motor;

an internally threaded drive member attached to said drive rod and operationally attached to said screw member such that rotation of said screw member causes linear displacement of said drive rod; and

a piston assembly operationally attached to said drive rod, wherein linear displacement of said drive rod causes linear displacement of said piston.

12. The fluid product delivery system according to claim 11, further comprising:

13. The fluid product delivery system according to claim 12, said at least one guide member further comprising:

a low friction seal member to form a seal around said drive rod.

14. The fluid product delivery system according to claim 11, further comprising:

a drive plate attached to an end of said drive rod.

15. The fluid product delivery system according to claim 14, further comprising:

a guide plate rigidly attached to said drive plate;

16. The fluid product delivery system according to claim 15, wherein said drive member is rigidly attached to said drive plate, said guide plate, and said drive rod through a trantourque, said trantourque comprising:

an inner race;

a plurality of outer races; and

a plurality of fasteners;

17. The fluid product delivery system according to claim 11, wherein said drive member comprises a ball nut.

18. The fluid product delivery system according to claim 11, said piston assembly further comprising:

a pump enclosure releasably mounted to said housing and a pump selected from the group consisting of:

piston pumps; and

diaphragm pumps.

19. The fluid product delivery system according to claim 18, wherein said pump enclosure comprises a modular component enabling quick-connect assembly to said enclosure.

20. The fluid product delivery system according to claim 11, further comprising a controller to operate said motor.