Field of the Invention

[0001] The present invention relates to fluid turbines (fluids include liquids, vapors and gases) and is particularly concerned with turbines capable of variable volume.

Background of the Invention

[0002] Conventional rotary vane pumps and motors present some notable inconveniences:

it is relatively delicate to maintain the lean of the vanes against the stator's wall. Generally, the vanes are abutting the wall due to the centrifugal force which requires relatively high rotational speed and often must be enhanced with springs;

the moment arm of the thrust exerted on the vanes by the fluid, as gas pressure or liquid head, may reduce their ability to slide sigmficantly;

the limited capacity of the rotary vanes, which need to rotate at high speed to obtain sufficient centrifugal force without being affected by the moment arm; and

the friction and heat resulting from the high rotary speeds requires lubrication and filter systems.

[0003] Fluid turbines disclosed herein obviate or mitigate at least some of the aforementioned disadvantages,

Summary of the Invention

[0004] An object of the present invention is to provide an improved fluid turbine.

[0005] The present invention includes rotary curved paddles (also called blades or sails) mounted to a possibly floating rotor that spin inside a stator cavity, wherein the centers (axes) of these two parts may be offset causing eccentricity, representing:

a variable displacement rotary engine which may be exploited as a motor/turbine that extracts energy from a fluid flow and converts it into useful work, or a rotary pump/compressor, which may be classified as a positive displacement device, trapping a volume of fluid and forcing (displacing) it into a discharge pipe.

r [0006] In accordance with an aspect of the present invention there is provided a fluid turbine comprising a stator having a track alongside its cavity, a floating rotor rotatable in this cavity upon an axis which is positioned to create eccentricity relative to the stator axis, and a plurality of curved paddles, each paddle pivotally coupled to the rotor at a first end and coupled to the stator' s track at a second end.

[0007] Fluid turbines usually have a stator casing around the paddles that contains and controls the working fluid. But they may be mounted without a casing when exploited as windmills or water wheels, where the stator is only made of a frame for guiding the motion of the paddles. [0008] Fluid turbines are radial flow devices: the fluid enters along the axial plane, interacts ^■ with the paddles and exits at right angles to the rotor's shaft (radially). Radial flow devices can operate with a larger range of pressures (or head differentials) and flow volumes more easily than axial and mixed flow devices.

[0009] Whereas for an axial turbine the rotor is 'impacted' by the fluid flow, for a radial turbine, the flow is orientated smoothly and perpendicular to the paddles, thereby driving the turbine in the same way that water drives a watermill. The result is less mechanical and thermal stress which enables a radial turbine to be simpler, more robust and more efficient than axial turbines in a similar power range. Only when mere is a much higher power range where the radial turbine needs a heavy and expensive rotor does the efficiency become similar to that of the axial turbines.

[0010] Radial turbines are preferable for slow devices. They are submitted to lower mechanical stresses because they are not required to spin as fast as axial turbines to produce similar work, and can handle sufficient pressure differentials with only a single stage of compression and expansion. [0011] As a result, the radial turbine does not need to be cooled, which means that all the fluid entering the device is used only to drive the turbine. This gives the radial design several advantages: - it is better suited for gas compression, co-generation and electric generation applications,

- its power and efficiency remain almost constant during the lifetime of the radial turbine whereas an axial gas turbine needs to be checked often to maintain ISO performance standards,

- the bearings are placed on both ends of the rotor's shaft, outside the casing and in a cold part, so no lubrication is needed, and no thermal losses occur due to lubrication of hot parts of the rotor, and

- in most embodiments, the fluid turbine does not require lubrication and an oil filtering system which enable exploitation of gases that are not allowed to be mixed with other chemicals,

[0012] Fluid Turbine's Benefits & Enhancements:

multiple potential applications, as a motor, pump, turbine, compressor or clutch without departing from the nominal design,

a simple but efficient variable displacement solution which enables the engine to vaiy its capacity, by shifting the rotor's axis more or less distant from the stator's central axis, even while turning (the centerline distance from the eccentric rotor to the stator is used to determine the fluid displacement),

an excellent tightness between the sliding paddles and the stator's wall, without the need for seals, with only a little resistance force resulting from limited sliding friction,

comparable performances regardless of the nature of the fluid (gaseous or liquid), enables very slow rotation (from 1 RPM) and with minimal centrifugal force and no spring for the paddles to press against the stator's wall, thereby achieving a constant efficiency,

- 'chambers' with significantly larger volume, offering capacities of hundreds of litres per rotation,

very important potential working pressure or head differential,

significant inertia stabilizing the rotary motion,

closed but also open casing appliances. Brief Description of the Drawings

[0013] The present invention will be further understood from the following detailed description with reference to the drawings in which:

Fig. 1 illustrates a fluid turbine in accordance with an embodiment of the present invention, showing the main components;

Fig. 2 illustrates a fluid turbine in accordance with an embodiment of the present invention configured as a pump/compressor;

Fig. 3 illustrates a fluid turbine in accordance with the present invention configured as a motor/turbine; Figs. 4a-4d illustrates the pump of Fig. 2 with various offsets;

Figs. 5-8 illustrates a fluid turbine with inlet and outlet pipes oriented differently;

Fig. 9 illustrates in a perspective view a partially assembled fluid turbine in accordance with an embodiment of the present invention;

Fig. 10 illustrates a perspective view of a paddle for a fluid turbine in accordance with an embodiment of the present invention;

Fig. 11 illustrates in a perspective view a partially assembled fluid turbine in accordance with another embodiment of the present invention;

Fig. 12 illustrates a fluid turbine in accordance with the present invention configured as a pump/compressor, equipped with an anti-cavitation space; Fig. 13 illustrates a concept diagram of a fluid turbine in accordance with another embodiment of the present invention, configured as a motor/turbine without a casing for use in a fluid flow;

Fig. 14 illustrates in a perspective view, a fluid turbine in accordance with another embodiment of the present invention, configured as a motor/turbine without a casing for use in a fluid flow; and

Fig. 15 illustrates a concept diagram of a fluid turbine in accordance with another embodiment of the present invention, configured as a motor/turbine without a casing for use in a fluid flow, equipped with a deflector.

Detailed Description of the Preferred Embodiment

[0014] The fluid turbine provides:

- as a pump/compressor, from a rotating energy source, collected as a torque actuating the rotor, kinetic energy in the form of a high volume fluid flow, trapped from the inlet pipe into the chambers and then expelled in the discharge pipe,

- as a motor/turbine, from a kinetic energy source, collected by the paddles as a high volume fluid flow, a torque exerted on the rotor making its shaft rotate.

[00151 Referring to Fig. 1 there is illustrated a fluid turbine 10 in accordance with an embodiment of the present invention. The cavity of the stator's body 40 includes a floating rotor 12 having paddles 14 which separates the cavity space in chambers 46. The rotor 12 has a central axis 18 which is moveable along a line 20. The paddles 14 are pivotally attached 22 to the rotor 12 and have a slide 24 in a track 16 which is positioned alongside the wall of the stator 40. [0016] In operation, the fluid turbine can act as either a pump or a motor depending upon whether its function is to drive fluid or be driven by fluid. In the simplified example of Fig. 1 , if the fluid turbine were immersed in fluid, a rotation 26 in the clockwise direction would result in a net fluid flow 28 due to the larger surface area presented to the fluid by the paddles in the upper position. In this situation the fluid turbine 10 functions as a pump. Conversely, if the fluid were moving in a direction 30, the rotor 12 would be driven with a rotation 32 in the counter clockwise direction due to the pressure differential resulting from the upper paddles having a greater surface area exposed to the fluid than the lower paddles. In this situation the fluid turbine 10 functions as a motor. [0017] Movement of the axis 18 of rotor 12 along line 20 can be used to vary the relative volumes of the upper and lower chambers thereby controlling the output of the fluid turbine when used as a pump or the torque generated when acting as a motor.

[0018] Referring to Fig. 2, there is illustrated a fluid turbine in accordance with an embodiment of the present invention configured as a pump/compressor. The fluid turbine includes a stator 40 forming inlet and outlet 42 and 44, respectively.

[0019] In operation, the rotor 12 is actuated to spin inside the stator 40, whereas the centers of these two parts are offset along line 20 causing eccentricity. Between the stator 40, the rotor 12, and paddles 14 several chambers 46 are formed where fluid is successively trapped on the inlet side 42 and expelled on the outlet side 44 during rotation of the rotor 12. [0020] Each paddle 14, on one end, is mounted on a swiveling shaft 22 positioned on the external wall of the rotor 12. During the rotation of the rotor 12, this enables the paddle 14 to swivel and to vary the angle it forms with the rotor 12. On the other end, the paddle 14 is equipped with a sliding shaft 24, which is guided alongside the stator 40, e.g. using a slot 16 (track), for enabling the paddle 14 to slide against, while varying the angle it forms with, the stator 40.

[0021] By varying the offset along line 20 and having the axis of the rotor 60 closer to the axis of the stator 62, the fluid turbine may adapt the volumes of both trapping chambers 46 and shrink chambers 48, which enables the adjustment of the flow trapped by the device and expelled in the discharge pipe versus the flow returned to the inlet pipe through the shrinkable side, thereby increasing the efficiency ratio of both motor or pump functions.

[0022] Referring to Fig, 3, there is illustrated a fluid turbine in accordance with the present invention configured as a motor/turbine. The fluid turbine includes the stator 40 forming inlet and outlet 50 and 52, respectively.

[0023] In operation, fluid passing from the inlet 50 to the outlet 52 causes the rotor 12 to rotate inside the stator 40, whereas the centers of these two parts are offset along line 20 causing eccentricity. Between the stator 40, the rotor 12, and paddles 14 several chambers 46 - 4? are formed where fluid is successively trapped on the inlet side 50 and expelled on the outlet side 52 causing rotation of the rotor 12 due to the greater surface area exposed to the upper paddles 14.

[0024] The paddles 14 act as surface seals on all edges of the stator and the rotor, thereby creating chambers 46 - 48 that do the pump/motor work. [0025] On the intake side of the fluid turbine, the trapping chambers 46 present a large volume, almost constant while transferring the fluid from the inlet to the outlet side. The trapping chambers 46 are filled with fluid forced in by the inlet pressure. As a pump (Fig. 2), this inlet pressure is generally nothing more than pressure from the atmosphere. As a motor (Fig. 3), the inlet pressure determines the thrust exerted on the paddle's surface and consequently corresponds to the power of the rotor's actuator.

[0026] On the discharge side of the fluid turbine, the chambers 48 are decreasing in volume while becoming shrink chambers, therefore expelling and forcing the fluid out of the stator's cavity. However some fluid remains captured by the shrink chambers, due to the design of the paddles which do not lean on the rotor's body and is thereby returned to the intake side. [0027] Therefore the action of each paddle drives out a volume of fluid equivalent to its respective trapping chamber capacity and each complete rotation of the rotor transports a total volume equal to the volume of the trapping chamber multiplied by the number of paddles.

[0028] Referring to Figs. 4a to 4d, there is illustrated the pump of Fig. 2 with various offsets. By modifying the offset (the centerline distance from the eccentric rotor to the stator), the respective capacities of the trapping 46 and shrink chambers 48 can be varied, thereby changing the ratio of their compared volumes, which determines the efficiency of the fluid turbine. As the capacity of the trapping and shrink chambers may vary from about 5% to 95%, by displacing the rotor alongside the centerline, it will represent a ratio comprised between about 90% to -90%, whereas the turbine: Fig 4a. 95%-5% = works at its maximum capacity,

Fig 4b.66%-33% = one half of the flow returns to the inlet, Fig 4c. 50%-50% = no work is done,

Fig 4d.5%-95% = works at its maximum capacity, but swapping direction of use or function. [0029] This aspect of the design enhances the invention with a complementary function of "clutch" and means that it gives to the device the benefit of excluding any risk of overcharge. For example, two fluid turbines may be coupled to enable double clutching of two rotor's shafts rotating at different speeds,

(0030] Therefore, as a variable displacement turbine, it may be used as an energy savings device, and favorably replace traditional rotary vanes devices which have been used in many applications, including automotive transmissions and clutches, for over 30 years.

[0031] The inlet and outlet pipes may be oriented differently, according to the application, from 0° to 270° (see Figs 5, 6, 7 and 8) without departing from the efficiency of the fluid turbine. [0032] Referring to Fig. 9 there is illustrated in a perspective view a partially assembled fluid turbine in accordance with an embodiment of the present invention. Inside the perimeter of the rotor's body 12 are provided a plurality of partially cylindrical channels 90, to receive the swiveling shafts 22 of the paddles 14. The height of the rotor equals the height of the paddles, which is computed to offei a microscopic gap between the rotor/paddles assembly and the upper/lower walls 92 of the stator 40 so that the rotor 12 will float and spin inside the stator 40 with minimal lean, thereby enabling a sufficient tightness without notable friction.

[0033] Referring to Fig, 10 there is illustrated in a perspective view a paddle for a fluid turbine in accordance with an embodiment of the present invention. A plurality of curved paddles 14 (also called 'blades') are installed between the rotor 12 and the stator 40, thereby separating the space into a plurality of chambers. The design of the paddles, that is the curvature, thickness and shafts and material are specifically adapted to the shape, direction and dimensions of the inlet/outlet pipes as well as to the nature of the fluid (gas or liquid) and pressures involved.

[0034] With a cylindrical stator's cavity, the radius of the paddle's curvature is computed to represent about 75 % of the radius of the stator's wall. But again, this may vary with the design parameters of a particular application.

[0035] Each curved paddle 14 ends by a swiveling shaft 22 which pivotally couples to the rotor's perimeter, where slots are hollowed to receive the said shafts 22, according to the motion of the rotor 12 relative to the stator and the resulting angle that the paddles 14 form.

[0036] At the other end, the paddle 14 is shaped as a half-cylinder to form a sliding shaft 24 that can be maintained abutted against the stator's wall (not shown in Fig. 10). The guiding slots may use, for example, balls or any other guiding system mounted on the sliding shaft to maintain the paddle 14 abutted to the stator's wall with a constant distance of preferably about 0.01 mm, so that the paddle will slide with about no friction. Also, the rotor being floating between the upper and lower walls of the stator, there are 2 pastilles or balls placed on the top/bottom of the swivelling shaft to maintain the spin of the rotor between the said upper and lower walls, Because of their small dimensions the faction can be reduced to a minimum and there is minimal heating phenomenon or deformation due to friction. For maintenance, only the sliding pastilles (or balls) should be replaced from time to time. This ensures a long lifespan to the turbine and makes possible to avoid any seals while forming chambers with satisfactory tightness without need for lubrication.

[0037] Referring to Fig. 11 there is illustrated in a perspective view a partially assembled fluid turbine in accordance with another embodiment of the present invention. With liquids, which are non-compressible fluids, the swiveling shaft 22 of the paddle 14 is combined with a hydro-pneumatic amortizer 110 to avoid cavitation concerns that may occur when the volume of the trapping or shrink chambers varies while spinning. This enables part of the trapped liquid to compress/depress a pneumatic chamber. The amortizer 110 may be simply a piston in a cylinder, a rubber capsule or a silicon balloon inserted in the swiveling shaft of the paddle, shaped as an open tube.

[0038] Referring to Fig. 12, there is illustrated a fluid turbine in accordance with the present invention configured as a pump/compressor. With liquids, some system for avoiding cavitation problems may also be adapted on the stator, by opening apertures to an anti- cavitation space 120 between the inlet pipe 42 and a shriπJk point 122. This is done to enable some liquid to fill/empty the 'shrink chamber' between the limit of the pipe edge and the shrink point. This solution works as an alternative of the above described amortizing system. With such a design the position of the paddles 14 forming the trapping chamber must be computed such that their motion places the sliding shaft alongside the edges of the inlet and outlet In this way, the chamber does not change the volume of the trapped liquid, in which case the amortizer may not be necessary.

[0039] Referring to Figs, 13 and 14, there is illustrated a fluid turbine in accordance with another embodiment of the present invention configured as a motor/turbine without a casing for use in a fluid flow. The fluid turbine is directly immerged into the fluid The stator 205 and the rotor 210 are only made of frames without edges. For example, a fluid turbine of this configuration could be used in water stream as a water wheel or in wind as a wind turbine. The design of Open Fluid Turbines' is similar to the 'Cased Fluid Turbines', except that stators aad rotors are not made of a solid body but simply of a frame guiding the rotation of the paddles, in this case generally called "sails", and i.e. using rollers 215 to do so.

[0040] Referring to Fig. 14, there is illustrated a fluid turbine in accordance with another embodiment of the present invention configured as a motor/turbine without a casing for use in a fluid flow causing the fluid turbine mainly to function as a wind or water turbine, vertically or horizontally positioned.

[0041] The stator's frame is fixed. It works like a guiding circle for the paddles to slide along, while they swivel at the rotor's perimeter during rotation, thereby creating open chambers submitted to the thrust of the fluid flow.

[0042] Fig, 15 shows how an open casing turbine operates, resting vertically on the ground. The thrust, which is exerted by the fluid on the first paddle 152, is naturally redirected, through the open rotor 150, to the secondary paddles 154, 156, 158 like a Savonius Rotor, thereby improving recovery of the overall fluid flow's energy. [0043] Because fluid turbines are radial flow devices, the power of such engine is directly related to the thrust (drag forces) exercised by the fluid flow on the paddles (therefore depending on the mass and the flow speed of the fluid), the combined foil surface of the paddles and their angle of attack (as opposed to the flow direction).

[0044] Conversely to axial blade turbines, the fluid turbine is optimized to enable slow but high torques rather than to target certain rotary speeds for the propeller. In this way, "Wind/Hydro Turbines" exploit the drag forces rather than the lift effect Therefore the sails preferably should be shaped as arc of cylinders or spheres to enhance their drag coefficient.

[0045] By using a deflector 160, in front of the paddles 156 and 158 spinning back to the fluid source, it is possible to reduce significantly any negative drag by redirecting all of the flow to the positive drag area of the turbine where paddles 152 and 154 are directly submitted to the fluid flow. [0046] Because of the offset, the sails present less effective surface area and are over a shorter period of time, subjected to the negative drag (e.g. sails are spinning over three times faster from position D to A than from A to D). Therefore the thrust of the fluid flow on the sails is 75% more effective in the positive drag area, which enables the fluid turbine to collect about four times more power than conventional blade turbines for the same foil surface (i.e. for wind turbines: about 1 kW/m2 versus 250 W/m2 with a wind speed of 12 ΓΛ/S). The deflector 160 would enhance the efficiency of the uncased fluid turbine by shielding the lower paddles and by creating back eddies that would help to offset the negating pressure on the lower paddles. The deflector 160 can be a static structure or it could be dynamic where its position would depend upon the offset of the rotor relative to the stator track.

[0047] Common uses of the fluid turbine include:

high, mid-range, low-pressure and vacuum pump applications, hydraulic or pneumatic, for uses in mechanics, air conditioning, laboratory, physics, and the like;

- hydraulic or pneumatic high and slow torque motors/turbmes for uses in automotive, transmission or electricity generation and similar applications;

gas expander or compressor, achieving larger pressure and temperature differentials than other devices,

simple or double hydraulic clutches,

- fluid kinetic energy and pressure collection, and

in certain applications gas and oil may be mixed within the fluid turbine (but separated externally), as well as saturated vapors or steam.

[0048] Therefore the areas of application are more flexible than comparative industrial motors/turbines/pumps/compressors in a number of areas including but not limited to the following examples:

Thermal, Wind and Hydraulic Power generation,

Gas compression,

Thermo-electrical generators (see separate patent),

Construction, Air conditioning,

Automotive,

Single or double clutching,

Regenerative braking)

- Leverage,

Mining,

Petrochemicals,

Beverage,

Pharmaceutical,

- Laboratory,

Mechanics, and

Physics.

(0049] Numerous modifications, variations and adaptations may be made to the particular embodiments described above without departing from the scope patent disclosure, which is defined in the claims.