CA3044914A1 - Valveless, toothed belt, positive displacement fluid pressure intensifier and pump - Google Patents

Abstract

A toothed belt, positive displacement type fluid pressure intensifier incorporating self-regulating pressure intensification and energy recovery means and capable of functioning without valves or other flow or pressure control means. These capabilities are provided for by one or more cooperating, hydraulic pump and motor sets wherein the greater volumetric displacement of an upstream hydraulic pump cannot be fully taken up by a synchronized, lesser volumetric displacement downstream hydraulic motor. This causes pressure intensification within that part of a fluid circuit located between the pump and motor such that a volume of permeate essentially equal to the volumetric displacement differential between the pump and motor is compelled by hydrostatic pressure to be separated from the fluid circuit, for example by passing through a semi-permeable membrane filter/separation means located within the circuit between the pump and motor.
Employment as a pump only and optional backwash capability add flexibility.

Description

1 of 32 Title Valveless, Toothed Belt, Positive Displacement Fluid Pressure Intensifier and Pump Technical field This invention relates to hydraulic pressure intensifiers employing positive displacement pumps and/or motors and which may also provide energy recovery capabilities.
Typical applications involve employment within semi-permeable membrane based fluid filtration, separation and/or concentration systems including seawater and brackish water desalination, freshwater filtration, purification, and reclamation and the concentration of sap in maple syrup production.
Background The growing and urgent global need for lower cost, more widely available potable water for drinking, food preparation, basic sanitation and, by extension, disease control is well known and documented by organizations such as the United Nations and World Health Organization, who have labelled it the single greatest challenge of the twenty-first century.
In response, the desalination of seawater and brackish water by reverse osmosis has become the primary means of addressing this crisis for those coastal regions and states having access to the significant finances and other resources required to implement it.
On a broader scale, reverse osmosis as well as other semipermeable membrane based processes such as nano-filtration, ultra-filtration and micro-filtration are increasingly being employed for expanded water filtration and purification purposes beyond desalination as well as for a growing range of fluid filtration, separation and concentration applications; for example, the concentration of maple sap to reduce the traditionally high energy usage in the maple syrup and related products industry.
Unfortunately, driven by such factors as lack of disruptive innovation, apparatus complexity and a primary focus on large scale, high rpm optimized and institutional and utility focused systems, costs remain stubbornly high, thereby seriously limiting access, often by those most in need.
Therefore, the goal of the present invention is to provide a practical, flexible and highly cost-effective means of addressing these issues and applications, whether employed in state-of-the art facilities, in the home or in remote and less developed regions including

2 of 32 where lower rpm, off-grid and small scale renewable energy converters and even manually driven devices and systems could provide major advantages and benefits.
Prior Art The following review of patent applications and grants, as well as known, commercially available devices focuses mainly on prior art that incorporates similarities of design, operating principles, function and/or application with the present invention.
Numerous, less similar examples were also reviewed but are not included here because of the major differences in the above criteria that exist.
In all of these cases, no examples were found that either employ or teach a toothed belt, positive displacement type fluid pressure intensifier, whether or not incorporating self-regulating pressure intensification and/or energy recovery means and whether or not being capable of functioning without the need for valves or other flow or pressure control means, all of which are key aspects and capabilities of the present invention. Nor do any found examples of the prior art come close to approaching the simplicity of the present invention.
In comparing the present invention to prior art, it becomes apparent that the use or lack of valves and other hydraulic flow control means offers the most useful means of comparison. Specifically, nearly all of the prior art depends on some combination of valves and/or flow control means, whether these be primary control valves, directional control valves such as check (non-return), spool, poppet or sliding valves or valve designs that are unique to the inventors. In some cases, externally controlled solenoid valves, pressure control, relief, and reducing valves and flow (volume) control valves as well as etectro hydraulic, servo, and proportional valves are used. Other non-valve, flow control means are also frequently employed.
By way of comparison, the present invention does not require the use of any of these components which, besides adding unnecessary complexity, introduce varying degrees of flow resistance, whether from turbulence, disruption or restriction, thereby leading to a loss of efficiency. Their inclusion also increases the potential for fouling related blockages, component failure due to fatigue or corrosion and leakage due to uneven wear of precision machined or polished sliding and mating surfaces. Any of these can lead to reduced life cycle, premature failure and/or more frequent maintenance and, in combination, this potential only increases. Complexity also invariably adds to manufacturing and quality

3 of 32 assurance costs and increases supply chain requirements. As shall become apparent, these significant disadvantages are addressed and overcome by the simplicity and the unique and novel aspects of the present invention. The most significant examples of the above described prior art are now listed below:
US 8,449,771 Philip David Giles; US 8,025,157 Shigeo Takita; US 2006/0,037,895 Appl.
No. 10/922,284 Scott Shumway; US 4,632,754 Robert S. Wood; US 3,369,667 George B.
Clark; US 7,828,972 B2 Young-Bog Ham; US 7,297,268 B2 Rodney E. Herrington; US

2009/0194471 Al Antonio Pares Criville; US 6,604,914 B2 Antonio Pares Criville; US
6,491,813 B2 Riccardo Verde; US 6,203,696 B1 Colin Pearson; US 6,017,200 Willard D.
Childs; US 5,628,198 Clark Permar; US 5,462,414 Clark Permar; US 4,929,347 Masaaki Imai, US 4,913,809 A lwao Sawada; US 4,534,713 & US RE 33,135 William F.
Wanner;
US 4,367,140 A Leslie P. S. Wilson; US 4,187,173 & US RE 32,144 Bowie G.
Keefer; US

4,288,326 Bowie G. Keefer (continuation in part of US 4,187,173); US 3,855,794 Kenneth H. Mayer; US 3,558,242 William Dixon Jenkyn-Thomas; US 3,234,746 Lewis T.
Cope.
Examples of commercially available, desalination specific systems that, unlike the present invention, are based on highly complex, swash plate driven rotary-reciprocating multi-piston, multi chambered pumps are US 9,416,795 B2 Friedrichsen et al.
Assignee Danfoss NS Reverse Osmosis System such as those produced under the trade name AqSep and the similar Salino/Salinnova device manufactured by KSB pumps. A
still further example is the next generation Danfoss iSave branded seawater reverse osmosis (SWRO) devices that, unlike the present invention, incorporates a booster pump as well as an isobaric type pressure exchanger similar to the commercially available PX
isobaric pressure exchanger manufactured by ERI. These systems typically also incorporate external control means.
Attention is also drawn to several prior art examples of toothed belt type positive displacement pumps that share certain physical characteristics with the apparatus of the present invention. In all cases, these have been found to be pumps only with no mention of, pressure intensification, energy recovery or employment as components of semi-permeable membrane filtration systems or otherwise incorporate the operating principles of the present invention. Nonetheless, for the sake of comparison and/or reference, those with the greatest physical similarities are now listed below:

4 of 32 US 1,445,721 S. L. Shepley; US 2,355,928 J. E. Stevens; US 2,467,641 W. 0.
West;
US 2,745,355 B. H. Mosbacher, US 3,071,078 M. M. Selby; US 4,154,560 Manfred Streicher; US 5,782,623 Dieter Brox; US 6,299,422 Timothy Charles Woodhouse;
EP 0,572,867 Al Dieter Brox.
In conclusion, it is believed that the present invention teaches a unique and highly simplified apparatus capable of providing pumping capability, hydraulic energy intensification, energy recovery and self-regulating energy use while overcoming the complexity related costs and disadvantages of the aforementioned prior art and does so in accordance with the following objectives.
Objectives of the Invention Based on the previously stated goal, the objectives of the present invention are to:
- greatly reduce the build complexity typical of the prior art;
- reduce the servicing complexity typically associated with the prior art;
- provide an apparatus which can be produced at low enough cost to be considered expendable and preferably also recyclable;
- provide an apparatus that can be powered by a range of prime movers including those operating at low rpm's in order to maximize its fitness for use in differing situations;
- provide an apparatus which better addresses local supply chain, knowledge and financial limitations in less developed regions where safe, potable water is often scarce;
- provide an apparatus which is suitable for rapid deployment and simple operation during times of natural disaster.
- provide an apparatus that is better suited than the prior art to production by emerging additive manufacturing means, also referred to as 3D printing.
Summary of the Invention The present invention offers a number of distinct advantages and benefits over the prior art, as shall become evident in the following figures and descriptions. For example, basic embodiments may be constructed such that the only significant, physical restriction or limiting factor to fluid flow is from the the apparatus' toothed belt impeller, a condition that is unavoidable with any positive displacement pump or motor. This further reduces power requirements beyond those gains made from the apparatus' self-regulating energy/

of 32 pressure demand and energy recovery capabilities. More specifically, all of the fluid conduit means incorporated into the core apparatus, whether they be channels, pipes, tubes or other equivalent means and including their inflow and outflow ports are typically unrestricted in that they do not require the direct or indirect use of valves, regulators or other flow control means in order for the apparatus and method to function. In effect, the only significant restriction to fluid flow other than from the toothed belt impeller is the unavoidable resistance, such as osmotic pressure, that is associated with fluid passing through the filtration media, that typically being one or a plurality of semi-permeable membranes. Also, because it is not a reciprocating device, the need for additional stroke reversal means such as valves are again unnecessary. This allows for a major reduction in complexity while noting that the use of various flow monitoring, regulating and/or control and cleaning/flushing means may optionally be employed in some embodiments if desired.
In terms of understanding if and how the present invention works it is helpful to point out that while it employs a number of novel and unique features, advantages and benefits, it also benefits from certain hydraulic principles that are known, well documented and successfully employed in various prior art and commercially available apparatus' that are identified in this document and so, in such cases, a highly detailed explanation of those principles would be redundant. These include, albeit in significantly more complex devices:
- The existence of a continuing volumetric displacement differential in the amount of fluid displaced by a larger displacement upstream, positive displacement hydraulic pumping means and a smaller displacement downstream positive displacement hydraulic motor means operating synchronously within the same series configured fluid circuit, this resulting in the development of a hydrostatic pressure induced pressure gradient across a cross-flow type semi-permeable membrane filtering means located within the fluid circuit between the pump and motor means. This results in the permeation of a volume of filtered fluid (permeate) through the membrane's pores equal to the volumetric displacement differential between the pump and motor thereby establishing a flow volume equilibrium that, in turn, limits further pressure increase and its associated energy demand.
- Incorporated energy recovery capability, which is achieved when the potential energy in the pressurized fluid located in the circuit between the pump and motor applies a driving force upon the motor's impeller(s) which, because the pump and motor are synchronized, 6 of 32 is transmitted as torque back to the pump's impeller(s), thereby reducing it's energy input requirements while noting that the means by which the torque is transferred back to the pump is applied in a novel fashion in a plurality of embodiments the present invention, as shall become apparent.
- An inherent capability exists to limit the amount of energy demanded of the apparatus' prime mover for building pressure to only that amount needed to reach and maintain a pressure gradient where osmotic pressure is overcome and the filtration process begins and is sustained. By extension, this allows for the use of various semi-permeable membrane classes and types without the need for any setting, pre-adjustment or control means often associated with addressing those needs by other means.
Also, for the benefit of clarity and understanding, the following observations and comments are provided:
- While the incoming stream of fluid may arrive under low but positive pressure provided by an external means, the pump portion of the apparatus typically functions as its own feed/booster pump by virtue of it's ability to draw in fluid by creating a partial vacuum.
- While the volumetric displacement of the pumps and motors differs at a fixed ratio in certain embodiments, it is understood that this ratio can be changed, for example by employing different diameter sprockets/rollers/idlers or other same acting means.
- While the cooperating pump and motor "sets" are shown as being integrated into a single module in certain embodiments described herein, these sets can also incorporated as partially or fully discrete components, as long as the novel aspects of the design as well as the arrangement of these parts is such that the volumetric displacement differential between them and the same operating principles and method are maintained.
- It is understood that for the purposes of the present invention, the terms pump and motor fit the conventional definitions, those being that a hydraulic pump has a mechanical input and a fluid output whereas a hydraulic motor has a fluid (driving) input and a mechanical output. In the case of the present invention, it is not relevant whether any given pump or motor employed is generally intended for use as one or the other or indeed classified as capable of both, only that it is capable of fulfilling the role intended by the invention. In other words two off-the-shelf pumps could be employed as long as one is 7 of 32 capable of functioning as a motor and is suitable in terms of delivering the flow and pressure requirements of the application.
Brief Description of the Drawings Figure la provides a schematic front view of a preferred embodiment of the present invention wherein the external teeth of a two-side toothed belt provide the impeller function for both a hydraulic pump and cooperating hydraulic motor located within a shared cavity that is divided into pump and motor chambers by the closing of the belt's inter-tooth gaps in those non-wrapping belt sections found between the pump and motor means and wherein this embodiment is driven by a mag-drive type direct drive electric motor.
Figure lb provides a schematic side view of the Fig. la embodiment.
Figure lc provides a schematic front view of a toothless idler that may be employed in place of the toothed idler of Fig. la.
Figure id provides a schematic front view of the toothed driving sprocket and idler of Fig. la highlighting how the volumetric displacement differential of the inter-tooth gap that occurs when the belt wraps around them diminishes as their diameter increases.
Figure 2a provides a schematic side view of a variant of Fig. 1a wherein a second pump and motor module of the same, lesser or greater volumetric output but is otherwise equivalent to that of Fig. la and wherein both modules share a common drive means.
Figure 2b provides a schematic side view of the Fig. 2a embodiment.
Figure 3a provides a schematic front view of a preferred embodiment of the present invention wherein the outward facing teeth of a single-side toothed belt rotating about a toothed drive sprocket and two differing radii rounded corners of a fixed cam provides the impeller function for each of a pump, a hybrid pump/motor and a motor such that this single-belt embodiment is capable of providing for differing pressure demands from two, independent semi-permeable membrane based filtration means.
Figure 3b provides a schematic top view of the Fig. 3a embodiment.

8 of 32 Figure 4a provides a schematic front view of a further preferred embodiment of the present invention wherein the inward facing teeth of a one-side toothed belt rotating about a toothed drive sprocket and a fixed cam provide the impeller function for a hydraulic pump and wherein a cooperating hydraulic motor of the same design but having a smaller volumetric displacement shares a common driveshaft with the pump such that the pump and motor rotate synchronously, thereby resulting in a continuing and stable volumetric displacement differential between the pump and the motor.
Figure 4b provides a schematic side view of the Fig. 4a embodiment.
Figure 4c provides a schematic side view of an embodiment similar to that of Fig. 4a but wherein the apparatus functions only as either a hydraulic pump or a hydraulic motor.
Figure 5a provides a schematic front view of a preferred embodiment of the present invention that is a variant of Fig. 4a wherein a hybrid pump/motor module is incorporated between the pump and motor modules such that it cooperates with them in a manner wherein it functions as both a motor cooperating with the first pump and as a second pump cooperating with the first motor and, therefore, such that the apparatus is capable of providing for differing pressure demands from two, independent semi-permeable membrane based filtration means.
Figure 5b provides a schematic side view of the Fig. 5a embodiment wherein it can be seen that the apparatus' three modules are driven by a shared mag-drive type direct drive electric motor such that they rotate synchronously.
Figure 6a provides a schematic front view of a preferred embodiment of the present invention similar in concept to that of Fig. 5a but wherein the toothed belt now rotates about a second fixed cam such that each module now has dual pump or motor capability.
Figure 6b provides a schematic side view of the Fig. 6a embodiment.
Figure 7a provides a schematic front view of a preferred embodiment of the present invention similar to that of Fig. 6a but wherein the cogs of a freely rotating cog wheel located within the first of two fixed cams prevents the movement of fluid via the inter-tooth 9 of 32 gaps of the sprocket that is adjacent to the base of that first cam such that a volumetric displacement differential now exists in the amount of fluid moved around the first and second cams.
Figure 7b provides a schematic side view of the Fig. 7a embodiment.
Figure 8a provides a schematic front view of another preferred embodiment of the present invention wherein the outward facing teeth of a single-side toothed belt rotating about a toothed drive sprocket and two toothless idlers provides the impeller function for a hydraulic pump and wherein a cooperating hydraulic motor of the same design and components but having a smaller volumetric displacement shares a driveshaft with the pump such that the pump and motor rotate synchronously, thereby resulting in a stable volumetric displacement differential between them.
Figure 8b provides a schematic side view of the Fig. 8a embodiment.
Figure 9 provides a schematic view of the Fig. la embodiment employed within a basic, single semi-permeable membrane based fluid filtration system.
Figure 10 provides a schematic view of the Fig. 4a embodiment employed within the same basic, single semi-permeable membrane based fluid filtration system as that of Fig. 9.
Figure 11 provides a schematic view of the interchangeable Fig. 1a and Fig. 4a embodiments employed within a basic, single semi-permeable membrane based maple sap concentration system.
Figure 12 provides a schematic view of the interchangeable Fig. la and Fig. 4a embodiments wherein fluid flows and pressures are described as they would occur during a backwashing or storage setup of a basic, semi-permeable membrane based fluid filtration system.
Figure 13 provides a schematic view of the Fig. 5a embodiment employed within a dual semi-permeable membrane based fluid filtration system.

of 32 Figure 14 provides a schematic side view of one of a plurality of ways in which a two-side toothed belt having teeth of larger volumetric displacement on one side and teeth of smaller volumetric displacement on the opposite side of the tensile member may be employed within an apparatus of the present invention.
Figure 15 provides a schematic side view of one of a plurality of ways in which a one-side toothed belt having trapezoidal teeth may be employed within an apparatus of the present invention.
Detailed Description Figure la provides a schematic front view of a preferred embodiment of the present invention whose main components include a housing 1, a larger diameter, cylindrical toothed drive sprocket 2, a smaller diameter cylindrical toothed idler 3, a two-side toothed belt 4, a fluid cavity 5, a pump intake port 6, a pump discharge port 7, a motor intake port 8, a motor discharge port 9, an adjustable width fixed cam 10 for separating the fluid cavity

5 into a pump chamber 11 and a motor chamber 12, each located within an outside portion of the fluid cavity 5 that is separated by the belt 4 from an inside portion of the cavity 5 the latter being separated into an inner chamber 5a where the idler 3 rotates and an inner chamber 5b where the drive sprocket 2 rotates. The idler 3 rotates freely on a shaft 13 that is suitably attached to the housing 1 and the drive sprocket 2 is driven by a direct drive electric motor 14 that may be enclosed within a hermetically sealed cup 15. A
cover plate (16), which is a fluid and pressure sealed integral part of the housing 1, is removed (not shown) for viewing clarity. More specifically, the two-side toothed belt 4 comprises a flexible tensile member 17, a plurality of outward facing, impeller teeth 18 and a plurality of inward facing, drive teeth 19, the latter interacting with the teeth of the drive sprocket 2 to rotate the belt 4 about the circumferences of the drive sprocket 2 and the idler 3 within the fluid cavity 5. The position of the idler 3 and the adjacent face of the cam 10 can be adjusted to install, remove and fine-tune the tightness of the belt 4 as needed.
Employing a belt 4 of suitable elasticity and which is slightly deeper than the depth of the cavity 5 allows it to be compressed in that axis by adjusting the degree of closure of the cover plate 16, understanding that the cover plate's sealing means, such as a resilient 0-ring allows for this. This expands the belt 4 along the other axes so that snugness and, 11 of 32 by extension, slip reduction and pressure handling capability can be "optimized."
In operation, the outward facing impeller teeth 18 of the belt 4 provide the impeller (fluid moving) function for both a pump section 20 and a cooperating motor section 21 of the apparatus, both being located within the shared fluid cavity 5 that is effectively divided into the pump chamber 11 and the motor chamber 12 by the closing of the belt's inter-tooth gaps in those straight, sections of the belt 4 located between the pump section 20 and motor section 21 where the belt 4 does not wrap around the circumferences of the drive sprocket 2 and the idler 3. In this case the drive sprocket 2, idler 3 and belt 4 are being driven counterclockwise as indicated by the arrows 22 while noting that the apparatus can also be driven clockwise with equal facility when called for.
More specifically, the apparatus' pump section comprises and results from interaction between the smaller diameter idler 3, the impeller teeth 18, the pump chamber 11, the pump intake port 6, the pump discharge port 7 and the fixed cam 10, all within the cavity 5 that is located within the housing 1 through which the pump intake port 6 and the pump discharge port 7 pass without the need for valves or other flow restricting components.
In the same way, the apparatus' motor section comprises and results from interaction between the larger diameter sprocket 3, the impeller teeth 18, the motor chamber 12, the motor intake port 8, the motor discharge port 9 and the fixed cam 10, all again within the same cavity 5 that is located within the housing 1 through which the the motor intake port 8 and the motor discharge port 9 pass, again without the need for valves or other flow restricting components.
It is noted that a small amount of fluid called "slip" does, in fact, pass across the barrier established by belt's 4 tensile member 17 into the inner region of fluid cavity 5 where the drive teeth are located. This condition is normal and generally unavoidable in pumps that employ sliding seal means and is actually necessary for lubrication of the area where the belt 4 is in sliding contact with the walls of the cavity 5. However, for those instances where this might be considered an issue such as when high purity needs to be maintained or buildup needs to be minimized, two drain ports 23 and 24 are located within the inner region of fluid cavity 5 such that the belt's drive teeth 19 and the toothed drive sprocket 2 continuously capture and pump this slip fluid out of the drain ports 23 and 24 rather than letting it pool and possibly stagnate or harden in place. This fluid may then be removed or, 12 of 32 if suitable, routed back into the pump intake.
In terms of operation and as can be seen in the Fig. 1 drawing, as soon as any point along the rotating belt 4 encounters the idler 3 and begins to wrap around it, the normally closed gaps between the outward facing impeller teeth 18 open up, thereby increasing the volume of the pump chamber 11 adjacent to the pump intake port 6. As is normal with positive displacement pumps, this creates a partial vacuum that draws fluid into the successively opening inter-tooth gaps, with this fluid then being carried through the pump chamber 11 as the belt 4 continues to rotate. However, as the belt 4 subsequently transitions from the curved path around the idler 3 to the straight path between the idler 3 and the drive sprocket 2, the gaps between the impeller teeth 18 then re-close, thereby decreasing the available volume in that area of the pump chamber 11 adjacent to the pump discharge port 7 and, as a result, propelling fluid out of the pump discharge port 7, again as is normal with positive displacement pumps. In the same way, as soon as any point along the rotating belt 4 encounters the drive sprocket 2 and begins to wrap around it, the normally closed gaps between the outward facing impeller teeth 18 open up to receive an intake of fluid and subsequently, as the belt 4 transitions from the curved path around the drive sprocket 2 to the straight path between the drive sprocket 2 and the idler 3 and the open gaps between the impeller teeth 18 then re-close resulting in the fluid being propelled out of the motor discharge port 9. The key difference between the pump section and the motor section lies in the amount of fluid discharged or displaced by each.
In that regard, it can be seen in the Fig. la drawing that the inter-tooth gaps and, therefore, the amount of fluid they are capable of displacing are larger as the belt 4 wraps around the smaller diameter idler 3 whereas the inter-tooth gaps and, therefore, the amount of fluid they are capable of displacing, are smaller as the belt 4 wraps around the larger diameter drive sprocket 2.
How this volumetric displacement differential is employed in terms of the operating principles and novel features and capabilities of the apparatus of the present invention when employed within a semi-permeable membrane based fluid filtration system will be taught in the descriptions of Fig's 9-13 that follow.
Figure lb provides a schematic side view of the Fig. la embodiment wherein the location 25 of a suitable prime mover such as magnetically linked direct drive electric motor 14 is 13 of 32 more clearly visible, as are the pump intake port 6 and the motor discharge port 9. In this embodiment the prime mover may itself be powered by a variety of means such as a rechargeable battery 26 as shown or any other suitable means such as electric mains supplied power or even by such means as a manually wound up spring.
Figure lc provides a schematic front view of a toothless idler 27 that may be employed in place of the toothed idler 3 (Fig. la). Advantages of using a toothless idler 27 include it being easier and less expensive to produce and that it can be infinitely sized to meet precise displacement preferences, rather than being limited to displacement steps based on limitations imposed by the drive tooth 19 size. However, a potential disadvantage is it could reduce the life of the belt 4 due to more localized loading on the drive teeth 19.
Figure 1d provides a schematic front view of the toothed driving sprocket 2 and idler 3 of Fig. la highlighting how the volumetric displacement differential of the inter-tooth gap that occurs when the belt wraps around them is conversely proportional to their diameter. As can be seen in this particular example, the larger diameter, 32 tooth drive spindle produces 11.25 degree inter-tooth gap openings whereas the smaller diameter, 16 tooth idler produces 22.5 degree inter-tooth gap openings. It is noted, however, that in all cases within this document the diameters and the number of teeth shown and/or described are arbitrary in nature and provided for the purpose of facilitating understanding.
Figure 2a provides a schematic side view of a variant of Fig. la wherein a first cooperating pump and motor module 28 and a second cooperating pump and motor module 29 are incorporated into the same apparatus and wherein the second may be of the same, lesser or greater volumetric displacement as the first but is otherwise equivalent to that of Fig. 1 and wherein both of the modules 28 and 29 share a common drive means such as a direct drive motor. Additional modules may also be incorporated if needed with the understanding that besides providing for the use of a plurality of semi-permeable membrane based filters, they may also be employed in other ways such as in series configuration for the purpose of boosting the apparatus' pressure producing capability.

14 of 32 Figure 2b provides a schematic side view of the Fig. 2a embodiment. The P1/M1 label meaning the first cooperating pump and motor module 28 and the P2/M2 label meaning a second cooperating pump and motor module 29 are applied for the benefit of clarity.
Figure 3a provides a schematic front view of a further preferred embodiment of the present invention that is similar to and functions according to the same operating principles as that of Fig la. Here, the belt 4 also bends about the drive sprocket 2.
However, in this case, the belt 4 also bends about both a first, smaller radius corner 30 and a second larger radius corner 31 of a fixed cam 10a rather than about the single idler 3 (Fig.
la). In effect, the differently radiused corners 30 and 31 of the cam 10a function in the same way as would two different diameter idlers. Therefore, in this variant of the Fig. la apparatus, the effect of having a total of three rather than two differently radiused, tooth gap opening bends of the belt 4 provides the impeller function for (a) the larger displacement pump section 20 (b) an added mid-displacement hybrid pump/motor section 32 and (c) the smaller displacement motor section 21 such that this single-belt apparatus is capable of providing for not one but two independent semi-permeable membrane based filtration means including those that may have different pressure requirements, this while employing only the single belt 4 operating within the single cavity 5. It is noted that the progressive 20, 15 and 10 degree inter-tooth gaps of the pump section 20, the hybrid pump/motor section 32 and the motor section 21 shown in the drawing will, in application, vary according to need and so are understood to be arbitrary values. It is also noted that the smaller the radius of the bend in the belt 4, the greater the included angle and, therefore, the fluid carrying and displacement capacity of the inter tooth gaps.
In this embodiment the pump intake and discharge ports 6 and 7, the motor intake and discharge ports 8 and 9 and an added set of, hybrid motor/pump 32 intake and discharge ports 33 and 34 are also made visible here as in Fig. la by extending them out from the sides of the housing, this for the sake of improved clarity. However, in practice, they could pass directly into the back of the housing 1 and feed into suitable fluid carrying conduits located there with the understanding that such conduits could simply be cavities within the solid body of the housing 1. Also, as with Fig. la, a "slip" fluid drain port 35 equivalent in purpose and function to the drain ports 23 and 24 (Fig.1) does pass directly into the back of the housing to be routed either for removal or, if suitable, back to the pump's intake 6.

15 of 32 The outer tip of the radiused corner 30 of the cam 10a can optionally be constructed to be extended outward by means of an eccentric cam 36 or other similarly acting means as a way of facilitating belt 4 removal, replacement or tightness adjustment.
Once again, as with that of Fig. 1, this embodiment employs an electric direct drive motor 14 fixed attached to the sprocket 2 as its prime mover, although a variety of other means would serve the same purpose.
As with Fig. la, how the volumetric displacement differential is employed in terms of the operating principles and novel features and capabilities of the apparatus of the present invention when employed within a semi-permeable membrane based fluid filtration system will be taught in the descriptions of Fig's 9-13 that follow.
Figure 3b provides a schematic top view of the Fig. 3a embodiment except, as was indicated in its description, the ports 6, 7, 8, 9, 33 and 34 are here understood to extend directly into the rear portion of the housing from where they continue as fluid conduits (hidden) in the form of cavities within the solid body of the housing 1 that exit in a suitable location for connection to some external system. In effect, the cavity 5 (Fig 3a) the ports 6, 7, 8, 9, 33 and 34 and the conduits they effectively extend as, are all aspects of a single, essentially unrestricted cavity. The position of the direct drive motor 14 in the context of its location within the housing 1 is also seen in this view.
As can be seen here, the addition of the hybrid motor/pump 32, its intake port 33 and its discharge port 34 and the re-positioning of physical features such as the ports 6, 7, 8, 9, 33 and 34 does not necessitate any significant structural approaches from the apparatus of Fig. la.
Figure 4a provides a schematic front view of a preferred embodiment of the present invention wherein a one-side toothed belt 37 rotates about a drive sprocket 38 and an adjacent cam 39, within a housing 40. The belt 37 and sprocket 38 both operate within a shared cavity 41 located within the housing 40, whereas the cam 39 is, in this case, simply a portion of the housing 40 that is not a cavity. The un-toothed back and two side faces of the belt 37, the front and back faces of the sprocket 38 and the top face of the cam 39 are all in fluid and pressure sealing contact with their corresponding, adjacent walls of the cavity 41 and with the inner face of at least one cover plate (42) (removed here so not 16 of 32 shown) that, when installed, is an integral part of the housing 40. An intake port 43 and a discharge port 44 pass unrestricted through the walls of the housing 40 from the cavity 41 on opposite sides of the sprocket 38 such that a pump intake chamber 45 is formed within the cavity 41 at that location where the intake port 43, the sprocket 38 and the cam 39 converge and a pump discharge chamber 46 is formed within the cavity 41 at that location where the discharge port 44, the sprocket 38 and the cam 39 converge. In this embodiment, the sprocket 38 is driven by a splined driveshaft 47 that is, in turn, driven by any suitable rotating prime mover that may be coupled to it, although, as taught in the descriptions of previous embodiments, the use of a direct drive motor would eliminate the need for the driveshaft 47. The direction of rotation of the belt 37 and sprocket 38 as well as that of the fluid carried within the open, inter-tooth gaps 48 and 49 that exist above and below the cam 39 is all clockwise, as indicated by the plurality of arrows shown in the drawing for the benefit of clarity, although it is noted that the hydraulic pump module 50 that results from this assembly can also be operated in counterclockwise or reverse mode.
To better understand the operation of the pump module 50, it is noted that the belt 37 comprises a tensile member 51 and a plurality of inward facing belt teeth 52 that mesh with a plurality of matching, outward facing sprocket teeth 53 such that no significant volume of fluid is able to be carried at those locations where and when the belt teeth 52 and sprocket teeth 53 are fully meshed. In effect, not only do the belt teeth 52 interface with the sprocket teeth 53 to provide the means by which the belt 37 is caused to rotate but they also function as the apparatus' impeller means during those times when they are in sliding contact with the cam 39 and fluid is carried within the plurality of open, inter-tooth gaps 48 that exist there.
As with conventional gear pumps, it is the rotation driven, continuous meshing and subsequent de-meshing of two sets of teeth such as occurs here between the belt teeth 52 and the sprocket teeth 53 that results first in the intake of fluid due to the expansion of the inter-tooth volumes in the pump intake chamber 45 followed by the discharge of that fluid due to the subsequent reduction of the inter-tooth volumes in the pump discharge chamber 46.
In this embodiment of the present invention, a cooperating hydraulic motor module 54 that is essentially identical to the pump module 50 except for having a smaller volumetric 17 of 32 displacement, shares the driveshaft 47 with the pump module 50 such that they must rotate synchronously, thereby resulting in a continuing and stable volumetric displacement differential between them. More specifically, the volume of fluid that enters the motor module 54 via a motor intake port 55 and is subsequently propelled through and out of the motor module 54 via a motor discharge port 56 is of a lesser volume than that which passes into, through and out of the pump module 50 and wherein the ratio of that volumetric displacement differential remains essentially stable regardless of the rotation speed of the apparatus as a whole as long as the rotation speeds of the pump module 50 and the motor module 54 remain synchronous.
Once again, how this volumetric displacement differential is employed in terms of the operating principles and novel features and capabilities of the apparatus of the present invention when employed within a semi-permeable membrane based fluid filtration system will be taught in the descriptions of Fig's 9-13 that follow.
Figure 4b provides a schematic side view of the Fig. 4a embodiment wherein it can be seen that the pump module 50 has a greater volumetric displacement than the motor module 54 due to its greater depth including that of its pumping chamber 41 (Fig. 4a) as compared to the lesser volumetric displacement of the shallower motor module 54. In this embodiment, the shared driveshaft 47 (Fig. 4a) is driven by a suitably coupled, mains 57 powered electric motor 58 such as a stepper motor.
Figure 4c provides a schematic side view of an embodiment similar to that of Fig's 4a and 4b but wherein it functions only as either a hydraulic pump 50 or a hydraulic motor 54. It is noted that a similar pump is described in US 5,782,623, Internal Toothed Belt Pump, Dieter Brox but, unlike the present invention, two guide rollers are required to ensure adequate engagement between a toothed drive pulley and a toothed belt. Also, the ratio between the number of belt teeth sliding under friction about its very large cam versus the small number of belt teeth in contact with its drive pulley's teeth creates a high resistance to rotate, thereby leading to the likelihood of premature belt wear and stretching. Also, this device offers a lesser ability to handle higher pressures compared to various embodiments of the present invention due to its small number of belt tooth and drive pulley tooth complete meshings, which allows for greater fluid slip related pressure loss.

18 of 32 Figure 5a provides a schematic front view of a preferred embodiment of the present invention that is a variant of Fig. 4a. In this case, a hybrid pump/motor module 59 is incorporated in the apparatus between the pump module 50 and the motor module 54 with all three of the modules 50, 59 and 54 being driven by a direct drive motor 14 (Fig. 3a) such that their rotation must remain synchronous.
The same design hybrid pump/motor module 59 cooperates with the pump modules and motor module 54 by functioning as both (a) a motor cooperating with the pump module 50 and (b) a pump cooperating with the motor module 54 so that, in both cases, a pre-determined, stable volumetric displacement differential exists. It is understood that although the volumetric displacements and the ratio of their differentials will vary depending on needs, the volumetric displacement of the pump module 50 will be the greatest with it's output being propelled downstream to the mid-displacement hybrid motor/
pump 59 whose output in turn is propelled downstream to the smallest displacement motor module 54.
In operation, this embodiment functions in the same manner and according to the same sequence and operating principles as the Fig. 3a embodiment. More specifically, the pump module 50 is equivalent to the pump section 20 (Fig. 3a), the hybrid motor/pump module 59 is equivalent to the hybrid motor/pump section 32 (Fig. 3a) and the motor module 54 is equivalent to the motor module 21 (Fig. 3a). Therefore, as with the Fig. 3a embodiment, this one is also capable of providing for differing pressure demands from two, independent semi-permeable membrane based filtration means.
Figure 5b provides a schematic side view of the Fig. 5a embodiment wherein it can be seen that the apparatus' three modules 50, 59 and 54 are driven by a shared direct-drive type electric motor 14 such that they rotate synchronously.
Figure 6a provides a schematic front view of an embodiment of the present invention similar in concept to that of Fig. 4a but wherein this embodiment comprises a dual pump module 60 and a dual motor module 61, both modules being driven by the shared shaft 47 such that they must rotate synchronously. They are essentially identical except that the dual pump module 60 has a larger volumetric displacement for each of its pumps 60a and 60b than the volumetric displacement of their corresponding and cooperating motors (61a) 19 of 32 and (61b) (not visible) within the dual motor module 61.
As can be seen in the front mounted dual pump module 60, the belt 37 now rotates about two fixed cams rather than one, those being the first cam 39 and a second cam 62 that is associated with the second pump 60b, its intake port 63 and its discharge port 64.
In this particular embodiment, the pumps 60a and 60b have the same volumetric displacements just as the motors 61a and 61b also have the same, albeit lesser volumetric displacements. As before, the belt 37 is also driven here by the rotating sprocket 38 but with attention being drawn to there being a lesser number of simultaneously occurring meshings between the belt teeth 52 and the sprocket teeth 53, in this case there being only two, a factor that should be considered in applications where higher pressure requirements would demand higher torque loads on the belt teeth 52 but also because there are less sets of meshed teeth in full contact at any given time that could otherwise distribute the effect of pressure differentials between the leading and trailing edges of those teeth. Nonetheless, for lower pressure applications this should not be an issue.
Just as with previous embodiments, when in operation, each of the larger volumetric displacement pumps 60a and 60b cooperates with corresponding smaller volumetric displacement pumps 61a and 61b, in this case resulting in two cooperating pump/motor sets with stable volumetric displacement differentials rather than only one, thereby providing the capability of supporting not one but two independent semi-permeable membrane based filtration means including those that may have different pressure requirements, with other configurations for this and similar embodiments anticipated. It is noted that the intake and discharge porting strategy for this design remains identical to the previously taught embodiments.
Based on previously described embodiments, it is clear that by simply changing the radius/radii of one or both of the cams 39 and 62 such that they differ, and in so doing adjusting the locations of their adjacent intake and discharge ports as needed, a volumetric displacement differential can be established within the same cavity such that one of the pumps 60a and 60b, can then function as the motor within a cooperating pump and motor set such that the second motor module 61 would no longer be required.

20 of 32 Figure 6b provides a schematic side view of the Fig. 6a embodiment highlighting the relative difference in volumetric displacement related depth between the dual pump module 60 and the dual motor module 61.
Figure 7a provides a schematic front view of an embodiment of the present invention similar to the two-cam embodiment of Fig. 6a but wherein a freely rotating, non-pumping cog wheel 65 is mounted within the first cam 39a in a manner that prevents the movement of any significant amount of fluid via the inter-tooth gaps 49 in that part of the cavity 41 located beyond where a cog 66 of the cog wheel 65 protrudes into an adjacent inter-tooth gap 49. The cog wheel 65 is non-pumping due to a clearance 67 between the cogs 66 and a cavity 68 in which the cog wheel 65 is located within the cam 39a. and a clearance 69 that exists between the intake end only of the cam 39a and the sprocket 38 The second cam 62 remains as it was in Fig. 6a, that being without the addition of a cog wheel for the purpose of restricting the flow of fluid. Therefore, fluid continues to be propelled as normal via the inter-tooth gaps 49 in that part of the cavity 41 where the sprocket 38 rotates, in this case at minimal clearance, adjacent to the cam 62.
In this way, a stable volumetric displacement differential now exists between the greater combined volume of fluid moved around the top and bottom of the one cam 62 and the lesser combined volume of fluid moved around the top and bottom of the other cam 39, such that a pump section 70 and a motor section 71 may now exist within the one shared cavity 41. In other words, the previously separated pump module 60 (Fig 6a) and motor module 61 (Fig. 6a) can now be merged into a single module containing a cooperating pump and motor set producing a stable volumetric displacement differential. It is noted, however, that this embodiment is more suitable for lower pressure applications due to the plurality of single belt 37 tooth to sprocket 38 and sprocket 38 to cam 39a meshing points that exist.
Figure 7b provides a schematic side view of the Fig. 7a embodiment for the purpose of highlighting that the pump section 70 and motor section 71 are, in this embodiment, incorporated into a single module rather than two separate modules two belts as with the Fig. 6 a/b embodiment.

21 of 32 Figure 8a provides a schematic front view of another embodiment of the present invention comprising a larger volumetric displacement pump module 72 and a smaller volumetric displacement motor module 73 within a shared housing 74 noting that there is no difference between these same acting modules other than their volumetric displacements.
Therefore, it is understood that the description and associated numbering of the visible pump module 72 is reflective of the motor module 73.
In this embodiment, a single-side toothed belt 37 such as that of Fig. 4a is driven by a sprocket 2 and direct drive motor 14 , the latter being isolated within a hermetically sealed cup 15 such as with the arrangement of Fig. la noting that because both the pump module 72 and motor module 73 are fixedly attached to and driven by the shared direct drive motor 14 they rotate synchronously, thereby resulting in a continuing and stable volumetric displacement differential between them, as with the previously taught embodiments of the present invention.
Here, the belt 37 rotates about the sprocket 2 as well as about two toothless, freely rotating idlers 75 and 76 and a raised, fixed cam 77 with all of these being located within a shared cavity 41 within the housing 74 noting that the fixed cam 77 is simply an area of a housing 74 that is not a cavity. In this embodiment, the belt teeth 52 are facing outward because the sprocket 2 is located on the outside rather than on the inside of the continuous belt 37 but the core operating principles remain the same. As with previous embodiments, not only do the belt teeth 52 mesh with the sprocket teeth 53 to provide the means by which the belt 37 is caused to rotate but they also function as the apparatus' impeller means during those times when fluid is carried within the plurality of open, inter-tooth gaps 48/49 that exist at those times when the belt teeth 52 are not meshed with the sprocket teeth 53.
As with conventional gear pumps, it is the rotation driven, continuous meshing and subsequent de-meshing of teeth such as occurs here between the belt teeth 52 and the sprocket teeth 53 that results first in the intake of fluid through the intake port 43 into the pump intake chamber 45 due to the expansion of the inter-tooth volumes as the teeth de-mesh followed by the discharge of that fluid through the discharge port 44 due to the subsequent reduction of the inter-tooth volumes in the pump discharge chamber 46 that results when the teeth re-mesh.

22 of 32 As stated, the synchronous rotation of the cooperating pump module 72 and motor module 73 set produces a continuing and stable volumetric displacement differential as with the previously described embodiments of the present invention. More specifically, the volume of fluid that passes into, through and out of the upstream pump module 72 is of a greater volume than that which passes into, through and out of the downstream motor module 73 and, because these are positive displacement types pumps/motors, the ratio of that volumetric displacement differential remains essentially stable regardless of the rotation speed of the apparatus as a whole as long as the rotation speeds of the pump module 72 and the motor module 73 remain synchronous.
Once again, how this volumetric displacement differential is employed in terms of the operating principles and novel features and capabilities of the apparatus of the present invention when employed within a semi-permeable membrane based fluid filtration system will be taught in the descriptions of Fig's 9-13 that follow.
An advantage to this embodiment lies in (a) the large number of complete tooth meshings between the sprocket 2 and the belt 37 (b) the large number of sealing interfaces between the teeth of the sprocket 2 and the inner wall of the cavity 41 and (c) the large number of sealing interfaces between the belt teeth 52 and the inner wall of the cavity 41, the combination of which allows this embodiment to handle higher working pressures than certain other previously described and anticipated embodiments.
More specifically, an advantage offered by this as well as other embodiments of these belt based devices is that pressure differentials are distributed (and dissipated/divided/spread) over a plurality of tooth meshing points rather than the typically one or two that occur with gear pumps. In other words the higher pressures on the leading sides of the impeller experience a greater number of resistance points to overcome and, in the event that a leak path develops this and other similar belt type embodiments provide secondary and more points of backup.
Figure 8b provides a schematic side view of the Fig. 8a embodiment wherein the relative position of various components including some that are not visible in Fig. 8a are better visualized. Because this is simply another view of the same Fig. 8a embodiment but wherein components of both the pump module 72 and the motor module 73 are now visible, the suffixes "p" for pump and "m" for motor are appended to the identifying 23 of 32 numerals used in Fig. 8a.
As seen by arrows representing magnetic flux, the direct drive motor 14 is magnetically coupled to both the pump sprocket 2p and the motor sprocket 2m through a shared, hermetically sealed cup 15, this being a well established and known coupling means.
Keeping in mind that the rotation speeds of the pump module 72 and motor module 73 are synchronous because of their shared drive means, it can now be seen that the greater width of the pump module's cavity depth matching belt 37p compared to the lesser width of the motor module's cavity depth matching belt 37m is what causes the apparatus' stable volumetric displacement differential when the resultant larger volumetric displacement of the upstream pump module 72 cannot be fully taken up by the smaller volumetric displacement of the speed synchronized motor module 73.
Also seen in this view, a pump cover plate 78 encloses the pump cavity such that the inner face of the pump cover plate 78 and the adjacent faces of the pump's sprocket 2p, idlers 75p and 76p (Fig. 8a), fixed cam 77p (Fig. 8a) and belt 37p are all now sealed against any significant amount of fluid passage around them other than for the normal amount of "slip" that is required to form a lubricating film. A motor cover plate 79 is employed in the same fashion.
The pump module 72 and motor module 73 each incorporate a fluid/pressure sealing means 80/81 such as an 0-rings mounted between the cover plates 78 and 79 and a shared pump/motor housing 74. All of the other circumferential and side faces of these rotating components are understood to be fluid and pressure sealed as well by any combination of suitable means, whether than be by the application of resilient coatings, the mounting of seals or simply adequately close tolerances between adjacent faces.
In that regard, it is noted that the resilient belts 37p and 37m may optionally be slightly wider than the depth of their corresponding cavities and the cover plate's seals 80 and 81 including their seating design are such that the cover plates 78 and 79 can by tightening, apply a modest, adjustable amount of compression upon the belts 37p and 37m as a means of optimizing the amount of positive sealing pressure between the belts and the surfaces against which they slide even to the degree that such intended compression of the belt's 37 p and 37m widths would result in offsetting slight expansion of their depths in order to improve sealing on two planes.

24 of 32 Referring now to Fig. 9, a schematic diagram is presented describing how the apparatus and method of present invention can be employed within a basic semi-permeable membrane based water filtration system designed to produce potable freshwater from a non-potable source. The apparatus of the present invention is shown here in simplified form but is understood to be fully representative of that taught in Fig. 1 while noting that it is fully interchangeable with the apparatus taught in Fig. 4. The system as a whole is first described in the context of tracking the intake, proc and waste fluid flows within it followed by a description of the operating principles of the apparatus and method.
In this application example, potentially or known to be unsafe raw water 82 is drawn from a source 83 such as but not limited to a river or well. It passes first through a strainer 84 into a suitable conduit 85 such as a hose or pipe and on into the unrestricted pump intake port 6 of the apparatus of the present invention ¨ that being the pressure intensifier and energy recovery module as taught in the description of Fig. 1 but hereafter referred to for convenience as a PI/ER module 86. From there it is propelled through the pump section 20 of the PI/ER module 86 and out through its pump discharge port 7 into a conduit 87 from where it continues on into a cross-flow type semi-permeable membrane based filter module 88 where it becomes separated into the two streams.
The first stream 82a comprises a typically larger volume of the raw water 82 which, having flowed across the semi-permeable membrane(s) 89 bundled, wound or otherwise distributed within the filter module 88 without permeating them, then passes out of the filter module 88 into a conduit 90 through which it then flows into the motor section 21 of the PI/
ER module 86 through its unrestricted motor intake port 8.
Upon entering the motor section 21, this first stream 82a encounters flow resistance from the motor's impeller means which, in this case, comprises the teeth 18 (Fig la) of the rotating belt 4, which does propel the first stream 82a through the motor section 21 but at a lesser flow rate than the water volume pushed to it by the pump section 20, this condition having been described previously as the volumetric displacement differential.
Finally, upon passing through the motor section 21, the still raw water of the first stream 82a is propelled out of the PI/ER module 86 through its motor discharge port 9 into a conduit 91 that carries it back to the source 83 as "brine"as in this example or potentially first to some other destination for post processing or treatment. The term brine will be taught in the 25 of 32 description that follows.
The second stream comprises of a typically smaller volume of "permeate" 92 (in this case being now filtered, potable water) that is compelled to flow through the pores of the semi-permeable membrane(s) 89 into a collection chamber 93 within the filter module 88. This occurs due to hydrostatic pressure buildup that occurs in that part of the fluid carrying circuit between the pump section 20 and motor section 21 comprising the conduits 87 and 90 and the filter module 88, this being due to the volumetric displacement differential. It is noted that this pressure increase will continue only to the point where resistance to permeation of the semi-permeable membrane, including from osmotic pressure, is overcome. At that point a volume of permeate 92 equal to the previously described volumetric displacement differential effectively passes out of the fluid carrying circuit between the pump section 20 and motor section 21 such that a volumetric equilibrium is reached and maintained. Upon passing out of the filter module 88 the permeate 92 stream which is here the product of the process, is then carried by a conduit 94 to a suitable collection means such as a reservoir 95 for storage and use.
With the flow of the raw water 82 and permeate 92 within the filtration system now described, the reader's attention is drawn to the function and operating principles of the apparatus and method of the present invention with particular attention being paid to the PI/ER module 86, it being the primary novel component of the apparatus and method. We begin by recalling that the volumetric displacement of the downstream located motor 20 is less than that of the upstream located pump 21 that the raw water 82 is propelled downstream by. Because both the pump 20 and motor 21 are of the positive displacement type, meaning that they are effectively sealed against the forward or backward leakage or slip of fluid past their impellers and because their impellers (being the teeth of the shared drive belt 4) are, therefore, connected to a shared drive means, the motor 21 can not rotate faster than the pump 20, which would need to occur in order to match their volumetric outputs within the fluid circuit between them. This means that the pump 20 pushes more raw water 82 downstream to the motor 21 than the latter can circulate. In effect, the motor 21 also functions as a flow resistor means resulting in a resistance based back pressure rather than only for propelling the fluid forward.
With that in mind and as has been well established by the previously mentioned and 26 of 32 commercially available reciprocating type, reverse osmosis based seawater desalinators such as the Spectra Watermaker, as taught in the US 5,628,198 (Clark Permar) patent and the Schenker Watermaker, as taught in US 6,491,813 B2 (Riccardo Verde) patent, as well as the commercially available KSB Salino and AQSEP/Danfoss reverse osmosis based seawater desalinators, such a volumetric displacement differential within a series circuit located between two positive displacement hydraulic pumps/motors results in a rapid pressure rise within the circuit that continues until either (a) the incoming excess fluid from the larger volumetric displacement pump can find a path of escape (b) the pump stalls because the back pressure upon it overcomes the capability of its prime mover, or (c) there is a rupture or similar failure within the fluid circuit located between the pump 20 and motor 21 or within a pump or motor itself. As with those reverse osmosis based desalinators, the apparatus and method of the present invention relies upon (a) where the incoming excess fluid finds a path of escape as the means of matching the volume of fluid circulated by the pump 20 and motor 21, thereby establishing a condition where neither continued pressure rise nor detrimental conditions such as pump/motor cavitation occur.
Because the filter module 88 is located within the closed hydraulic circuit between the pump 20 and the motor 21, this path of escape occurs the moment that the hydrostatic pressure within the filter module 88 reaches the point where osmotic pressure as well as any other incidental forms of resistance are overcome by the intensified hydrostatic pressure such that the conditions for convection are reached and the flow of fluid through the pores of the semi-permeable membrane begins, with only the amount of hydrostatic pressure needed to initiate and maintain the required pressure gradient necessary while also adapting to pressure requirement variations over time, all without the need for external input, control or other complexity, with the understanding that embodiments may be conceived and/or employed that choose to incorporate such complexity.
More specifically, a volume of filtered water equal in volume to the volumetric displacement differential between the pump 20 and the motor 21 is compelled under intensified pressure to pass through the pores of the semi-permeable membrane(s) 89 within the filter module 88 as permeate 92, the passage being represented here by the series of smaller arrows seen within the filter module 88. As previously indicated, the permeate 92, in this particular embodiment, then flows via the conduit 94 into a suitable 27 of 32 collection means such as a reservoir 95 for storage and use.
To clarify, it is the volumetric displacement differential and its resultant hydrostatic pressure induced pressure gradient that compel the permeate, in this case being almost exclusively comprised of very small water molecules, to permeate the semi-permeable membrane(s) 89 and thus become separated from the various other larger sized molecules and components as well as a significant number of water molecules that flow across but do not permeate or pass through the pores of the semi-permeable membrane(s) 89 and so remain in the larger, non-permeating first stream 82a.
This typically larger volume non-permeating first stream 82a then flows out of the filter module 88, still under increased pressure (representing potential energy) through the conduit 90 into the intake port 8 of the motor 21, whereupon it encounters and has its flow finally obstructed by the impeller(s) of the motor 21.
Referring again to that taught in the US 5,628,198 (Clark Permar) and US

6,491,813 B2 (Riccardo Verde) patents and employed by the KSB Salino and AQSEP/Danfoss desalinators; so too in the apparatus and method of the present invention is the potential energy stored in the pressurized raw water stream 82/82a that would otherwise be taken up or dissipated by rotating the motor 21 faster than the pump 20 in order to absorb the displacement differential but which cannot occur here because both the pump 20 and motor 21 are connected by the shared drive belt 4 with the result that this pressure based potential energy is instead transferred back via the shared drive belt 4 to the pump 20 as kinetic energy, thereby greatly reducing the amount of energy required for the direct drive electric motor 14 (or an equivalent prime mover) to itself drive the apparatus. With that potential energy now expended, the second stream of raw water 82a flows out of the discharge port 9 and returned via the conduit 91 to its source 83 in more concentrated form noting that where the removal of salts from the process, such as in the case of desalination of brackish water or seawater is involved, the term "brine" is used to describe this more concentrated stream.
Figure 10 provides a schematic diagram of the Fig. 4a embodiment shown here being employed within the same basic, single semi-permeable membrane based fluid filtration system as that taught in the above detailed description of Fig. 9 but which is provided here for the purpose of showing that these and, in fact, other PI/ER modules can be deemed to 28 of 32 be interchangeable in terms of the operating principles of the apparatus and method of the present invention. For this reason the numbering of various components of Fig.
4a are shown here again in Fig. 10 for the sake of comparison but are not described as it would only be a repeat of the Fig. 9 description, other than to note that the belt 4 (Fig. 9) is here replaced with the belt 37, and that the PI/ER module 86 (Fig. 9) that was taught in Fig. la is here replaced with a PI/ER module 96 that is the same as that taught in Fig. 4a. other than for the drawn location of the ports so as to allow for improved clarity in the drawing of the various conduits but such that there is no impact on the actual design or operating principles of the apparatus and method compared to the Fig. 4a drawing.
Figure 11 provide a schematic view of the Fig. 1a embodiment or the interchangeable Fig.
4a embodiment being employed within a basic, semi-permeable membrane based maple sap concentration system. For this reason the numbering of the various unchanged components are shown here again in Fig. 11 for the sake of comparison but are not described as it would only be a repeat of the previous description(s). While the apparatus and method and basic operating principles remain essentially the same here, the only significant differences in practice are that the fluid to be filtered is raw maple sap 97 and that the second or permeate 92 stream, which is essentially potable water just as it was with Fig's 9 and 10 is, in this case, the discarded component and a first stream 97a, which is now more concentrated map sap is the product.
More specifically, the raw maple sap 97 flows from the PI/ER module 96 via the conduit 87 into the filter module 88 that now contains an application specific semi-permeable membrane(s) 98. As before, the water permeate 92 flows through the conduit 94 into the collection reservoir 95, from where it is typically discarded. The non-permeating stream of concentrated but still raw sap 97a flows from the filter module 88 back to the PI/ER module 96 via the conduit 90. While the raw maple sap 97 collection means may vary, it is typically drawn from a such as a collection reservoir 99 and, upon passing out of the motor into the conduit 91, the concentrated maple sap 97a is typically fed through a dead-end type filter into an evaporator 100 for further processing.
Figure 12 yet again provide a schematic front view of the Fig. la embodiment or the inter-changeable Fig. 4a embodiment but wherein reversed fluid flows and pressures are 29 of 32 shown as they would occur during backwashing or storage setup of a basic, semi-permeable membrane based fluid filtration system. For this reason the numbering of the various unchanged components are once again shown here again in Fig. 12 for the sake of comparison but are not described as was previously stated, it would only be a repeat of the earlier description(s).
More specifically a suitable cleaning fluid 101 (or storage fluid) is drawn by the partial vacuum created by the now reversed motor 21 from a reservoir 102 that has been temporarily connected to the conduit 91. The motor 21 then propels the cleaning fluid 101 through the conduit 90 into, through and out of the filter module 88 from where the now "used" cleaning fluid 101a then flows via the conduit 87 into the pump 20 which then propels it via the conduit 85 into a suitable disposal reservoir 103. However, we are reminded that the volume of fluid demanded by the larger volumetric displacement positive displacement pump 20 is greater than the volume output by the smaller volumetric displacement motor 21, that would normally lead to a (now reversed) volumetric displacement differential. This would result in the system pulling fluid in reverse through the membrane(s) 89, however, because this can permanently damage some semi-permeable membrane types, an alternative means of providing the necessary fluid make-up must be found in order to balance the pump 20 demand to the motor 21 output. This can be accomplished in various ways such as, in this example, by temporarily connecting a "jumper" conduit 104 to suitable access points 105 and 106 that bridge the fresh cleaning fluid reservoir 102 and the conduit 87. In this or an equivalent way, the volumetric displacement differential is eliminated with the result that there is neither a positive nor a negative hydrostatic pressure differential established on the opposing sides of the membrane 89 so it is not damaged by fluid flowing in reverse through it's pores. However, the crossf low of cleaning fluid across the surfaces of the membrane allows for the flushing of deposits that typically accumulate over time and for the opportunity to inject storage fluid in the same fashion.
Figure 13 provides a schematic front view of the Fig. 5a embodiment being employed within a dual, semi-permeable membrane based fluid filtration system wherein the two filter modules are independent of each other to the degree that they may be of different types and are capable of operating at different hydrostatic pressures. Otherwise, the core 30 of 32 operating principles of the apparatus and method remain the same as the previously taught embodiments.
As before, the numbering of a plurality of unchanged components are once again shown here for the sake of comparison but are not necessarily described in all cases as it would only be a repeat of the earlier description(s). Rather, attention is focused on the revised fluid flow path associated with the integration of a second filter module into the otherwise similar, previously taught single filter system of Fig. 10.
More specifically, a PI/ER module 107 comprises a cooperating pump 50 and motor 54 set as well as a hybrid motor/pump 59, this arrangement having been taught in the description of Fig. 5a. A yet to be filtered raw fluid 108 flows or is drawn from a source 83 through a strainer 84 that is connected to a conduit 85 that feeds unrestricted into a pump intake port 43, propelled through the pump 50 by the teeth of the belt 37 (acting in its previously described impeller role), and on out through a pump discharge port 44 into a conduit 87 that delivers it to a first semi-permeable membrane based filter module 88. As before, the raw fluid 108 is propelled by the pump 50 into the filter module 88 where it is separated into a first filtered stream of raw fluid 108a that continues on out of the filter module 88 into a conduit 90 that then delivers it, in this case, into a hybrid motor/pump 59 via its intake port 109.
As previously taught, the mid volumetric displacement hybrid motor/pump 59 causes the flow resistance that produces the hydrostatic pressure needed to initiate and maintain permeation of the second stream of fluid through the pores of the membrane(s) 89 within the first filter module 88. This second, now separated stream of permeate 92 then flows via a conduit 94 into a suitable collection means such as a reservoir 95 for either use or disposal, depending upon the application. Returning now to the first, filtered stream of raw fluid 108a that entered the hybrid motor/pump 59 in its role as a motor, it now exits the hybrid motor/pump 59 in its role as a pump through a discharge port 110 and into a conduit 111 that then carries it into a second filter module 112 where the filtration process is repeated but, in this particular example, by employing a different membrane 113 type as a means of removing, separating or concentrating one or more additional and different target components from the raw fluid 108a, which having been filtered a second time, is now described as a first stream 108b. This first stream 108b then flows, under pressure for 31 of 32 the same reason as previously taught, out of the second filter module 112 and through a conduit 114 into the motor 54 through its intake port 55.
Upon passing out of the motor 54 through its discharge port 56, the first stream 108b then flows, through conduit 91 either back to its source 83 as in this example or to some other suitable collection or disposal means depending upon the application.
The second stream of permeate 92a, having passed through the pores of the membrane 113 flows out of the second filter module 112 into a conduit 115 that carries it, as with the permeate 92, into a suitable collection means such as the reservoir 95 for either use or disposal, depending upon the application. In that regard, it is noted that in this particular example the permeate streams 92 and 92a are drawn off as waste and the non-permeating streams 108a and 108b become the product. However, it is understood that in other applications of what are essentially this same or similar setups, the reverse may also be true, just as was the case when comparing the previously described water filtration and maple sap concentration processes. Finally, it is noted that any number of other components or processing means such as shown at locations 116 and 117 may also incorporated into this and other embodiments, not as necessities of the core aspects of the present invention but rather as optional or even obligatory aspects of the applications involved.
Figure 14 provides a schematic side view of one of a plurality of ways in which a two-side toothed belt 118 having larger volumetric displacement teeth 119 on one side and smaller volumetric displacement teeth 120 on the opposite side of the tensile member 121 may be employed within an apparatus of the present invention, in this case that being an embodiment incorporating a toothed drive sprocket 122 and three matching toothed idlers 123, 124 and 125 each having an associated set of intake and discharge ports 126/127, 128/129, 130/131 and 132/133, each set interacting with a shared, fixed cam 134 and wherein the tensile member 121 of the belt 118 provides the means for separation of the intake and discharge ports within an otherwise shared cavity 135.
This is not considered a preferred embodiment due to the possible pressure limitations presented by depending upon the tensile member 121 of the belt 118 to separate the various pump and/or motor chambers it incorporates. Nonetheless, the combination of having a volumetric displacement differential existing between the opposite sides of the belt 118 with having a total of four cooperating pump and motor sets, all within a single 32 of 32 cavity is seen as an advantage that could offer opportunities when employed in lower pressure applications. It is noted that this design employs the same core operating principles as previously described, more preferred embodiments.
Figure 15 provides a schematic view of one of a plurality of ways in which a one-side toothed belt 136 having trapezoidal teeth 137 rather than rectangular teeth may be employed within an apparatus of the present invention similar to that of Fig's la or 2a.
In this case, inter-tooth volumetric differences occur when areas of the belt encounter differing front side and back side bending radii leading to repeated and progressive expansion and contraction of all inter-tooth gaps such as the gaps 138a/b/c/d.
A significant difference between embodiments of this type and those taught in Fig's la and 2a relates to the need for an extra, typically small diameter idler or cam 139 that the toothed side of the belt must bend tightly around in order to cause the closing of the inter-tooth gaps such that the fluid being moved through the apparatus is essentially fully expelled on closing of the gaps, this being to necessary to separate the two pumping chambers and so that the fluid being moved does not flow between the two pumping chambers 140 and 141 in any significant amount. It is noted that in this embodiment the chambers 140 and 141 are elongated similar to those of gerotor type pumps such that they extend between the maximum expansion and maximum contraction points of the inter-tooth gaps.

Claims

1 of 1 Title Valveless, Toothed Belt, Positive Displacement Fluid Pressure Intensifier and Pump Claims To follow within the time period allowed by the Canadian Intellectual Property Office and in accordance with WIPO requirements.