Improved wave energy generator

Abstract

An energy generator assembly for installation in an aqueous environment, the generator assembly comprising: a hollow and elongate impeller extending between two ends, the impeller comprising a cylindrical impeller body having an outer surface and an inner surface, the inner surface defining an internal volume, the internal volume comprising a central, hollow region radially, to allow fluid to flow between the two ends, wherein the inner surface comprises a plurality of fluid flow guide vanes extending axially along the length of the inner surface, the vanes projecting radially towards the central, hollow region, wherein the vanes are arranged to induce rotation of the impeller during flow of fluid between the two ends of the hollow impeller.

Description

Technical Field

[0001] This invention relates to an improved wave energy generator for generating electricity through the flow of water. More specifically... Background Technology

[0002] Any reference to existing methods, equipment, or documents shall not be considered as evidence or acknowledgment that they form or constitute part of common general knowledge.

[0003] As fossil fuels on Earth dwindle, the demand for energy from renewable sources continues to increase. Furthermore, there is a desire to generate electricity from clean energy sources that do not contribute to global warming.

[0004] A common renewable energy source is hydropower, which generates electricity by utilizing the potential energy head of a fluid, such as water. A typical hydropower system requires a water source, such as a river where a dam is built at a high point to create a head that stores potential energy. Pipes extend from the dam to a lower point. A turbine generator is installed at the end of the pipe, allowing water discharged from the higher point to flow through the turbine. The water drives the turbine, which in turn drives the generator, which produces electricity. A problem with dam-based hydropower installations is that the floods caused by the dam have negative impacts on the local environment. Floods damage the natural landscape and force nearby residents to relocate.

[0005] In light of the above, there will be a need for energy generation systems that can utilize smaller bodies of water, where water flows at relatively low speeds. Small-scale energy generation systems suitable for generating energy using gravity-fed municipal water distribution pipelines will also be required. Summary of the Invention

[0006] In one aspect, the present invention provides an energy generator assembly installed in an aquatic environment, the generator assembly comprising: a hollow and elongated impeller extending between two ends, the impeller comprising a cylindrical impeller body having an outer surface and an inner surface, the inner surface defining an internal volume including a radially oriented central hollow region to allow fluid flow between the two ends, wherein the inner surface includes a plurality of fluid flow guide vanes extending axially along the length of the inner surface, the vanes projecting radially toward the central hollow region, wherein the vanes are arranged to cause rotation of the impeller during fluid flow between the two ends of the hollow impeller, wherein the diameter of the central hollow region is at least 1 / 3 of the diameter of the impeller.

[0007] In this implementation, multiple flow guide vanes are integrally formed with the impeller body.

[0008] In one embodiment, one or more of the flow guide vanes extend in a spiral shape relative to the central region of the cylindrical impeller body.

[0009] In one embodiment, each flow guide vane includes a corresponding edge portion extending along the longitudinal axis of the impeller body, the corresponding edge portion defining the central hollow region of the impeller body.

[0010] In one implementation, a pair of adjacently positioned blades define corresponding helical flow paths to allow fluid to flow between the ends.

[0011] In one embodiment, each pair of adjacent blades forms a radially arranged helical flow path within the hollow impeller body, wherein during the flow of fluid between the two ends of the hollow impeller, the fluid flow through the radially arranged flow path causes the hollow impeller body to rotate.

[0012] In one embodiment, the energy generator further includes one or more radial bearing assemblies for surrounding and supporting one or more sections of the elongated impeller body.

[0013] In one embodiment, a radial bearing assembly is positioned to surround and support one end of the impeller body, and a second radial bearing assembly of the radial bearing assembly is positioned to surround and support the other end of the impeller body.

[0014] In one embodiment, the outer surface of the impeller body includes a plurality of magnetic elements arranged on the outer surface, such that the rotation of the impeller body caused by the flow of fluid through the hollow impeller body causes the magnetic elements to move.

[0015] Preferably, the outer surface includes a plurality of recessed cavities configured to receive and securely engage the respective magnetic element.

[0016] In one embodiment, the energy generator further includes a stator assembly comprising an elongated and hollow stator body, the stator body including a stator channel extending through the stator body, the stator channel being sized to accommodate an impeller body within the stator channel, wherein the stator body includes stator windings positioned such that rotation of the impeller body and magnetic elements on the impeller body relative to the stator body results in the generation of a current in the stator windings of the stator assembly.

[0017] In the first embodiment, the stator assembly includes a plurality of stator slots (Ns), and wherein the magnetic elements on the outer surface are provided with a plurality of rotor poles (N). M ), such that when the outer diameter of the rotor is greater than 1000 mm and the inner diameter of the stator is greater than 1000 mm and the axial length of the rotor and stator is greater than 3000 mm, Ns / NM The ratio is greater than 4 and preferably greater than 5.

[0018] In an alternative embodiment, the stator assembly includes a plurality of stator slots (Ns), and wherein magnetic elements on the outer surface are provided with a plurality of rotor poles (N). M ), such that when the outer diameter of the rotor is less than 500 mm and the inner diameter of the stator is greater than 500 mm and the axial length of the rotor and stator is less than 500 mm, Ns / N M The ratio is less than 2.

[0019] In one embodiment, the stator body extends between a first end and a second end, such that a recessed channel for receiving a bearing assembly is also included at the first end and / or the second end.

[0020] In one embodiment, the energy generator further includes a housing subassembly that at least partially houses the stator assembly and the impeller body received within a passageway in the stator body.

[0021] In this implementation, the housing sub-assembly includes:

[0022] a. An inlet housing portion including an inlet for receiving flowing water, the inlet housing portion for conveying the received water to one end of the hollow impeller body; and

[0023] b. An outlet housing portion including an outlet for discharging water from the housing, the outlet housing being fluidly connected to another end of the hollow impeller body to receive water from the other end of the impeller body and deliver the received water to the outlet, thereby achieving the discharge of water from the housing.

[0024] In one embodiment, the inlet housing portion includes a diverging configuration to allow the received water flow to diverge toward one of the ends of the hollow impeller body.

[0025] In one embodiment, the outlet housing portion includes a converging configuration to allow water flowing from the other end of the impeller body to converge toward the outlet.

[0026] In one embodiment, the housing subassembly further includes an intermediate housing portion adapted to be positioned between the inlet housing portion and the outlet housing portion, wherein the intermediate housing portion includes an internal volume to substantially accommodate the stator assembly and the impeller body received within a passage of the stator body of the stator assembly. Attached Figure Description

[0027] Preferred features, embodiments, and variations of the present invention will become apparent from the following detailed description, which provides sufficient information for those skilled in the art to perform the invention. This detailed description should not be construed as limiting the scope of the foregoing summary of the invention in any way. The detailed description will be referenced to the following figures:

[0028] Figure 1 This is a top perspective view of the energy generation system 1000 according to a preferred embodiment.

[0029] Figure 2 This is a cross-sectional view of the energy generation system 1000.

[0030] Figure 3 This is a top perspective view of the impeller assembly 100, which is part of the energy generation system 1000.

[0031] Figure 4 This is a top perspective view of the stator assembly 200, which is part of the energy generation system 1000.

[0032] Figure 5 and Figure 6 The illustration shows a perspective view of the impeller assembly 100.

[0033] Figure 7 and Figure 8 The illustration shows a perspective view of the stator assembly 200.

[0034] Figure 9 and Figure 10 The figure shows an end-view perspective view of the energy generation component 2000 utilizing the energy generation system 1000.

[0035] Figure 11 and Figure 12 The diagram shows a cross-sectional view of the energy generation component 2000.

[0036] Figure 13 The illustration shows a top perspective view of the energy generation component 3000 utilizing the energy generation system 1000.

[0037] Figure 14 The illustration shows a side view of the energy generation component 3000.

[0038] Figure 15 and Figure 16 The illustration shows an end view of the energy generation component 3000.

[0039] Figure 17 This is a cross-sectional view of the energy generation component 3000.

[0040] Figures 18 to 24 The illustration shows a combination of a small stator 200A and a small rotor 100A according to a first alternative embodiment.

[0041] Figures 25 to 31 The illustration shows a combination of a large stator 200B and a large rotor 100B according to a second alternative embodiment. Detailed Implementation

[0042] Figures 1 to 8 The diagram illustrates an energy generation system 1000, which includes a hollow, elongated impeller assembly 100 rotatably mounted within a stator assembly 200. As will become apparent from the preceding sections, the operating principle of the energy generation system involves water flowing through the hollow impeller assembly, causing rotation of the impeller body 110, which in turn generates an electric current in the stator assembly 120.

[0043] Impeller assembly 100 includes a hollow, elongated cylindrical impeller body 110 extending between two ends 112 and 114. The impeller body 110 includes an outer surface 116 and an inner surface 118, the inner surface 118 defining an internal volume that allows water or any other fluid to flow between the two ends 112 and 114. The internal volume includes a radially centrally hollow and continuous region 111 extending between the two ends 112 and 114 to allow fluid flow between the two ends. The inner surface 118 of the impeller body includes a plurality of fluid flow guide blades 113 extending axially along the length of the inner surface 118. Each of these blades 113 projects radially toward the central, hollow region 111. The blades are arranged to cause rotation of the impeller during fluid flow between the two ends of the hollow impeller.

[0044] Flow guide vanes 113 extend helically relative to the central hollow region 111 of the cylindrical impeller body 110. These helically oriented vanes 113 include helically oriented edges that extend between ends 112 and 114 to define the central hollow region 111 of the impeller body 110. Each pair of adjacently positioned helically oriented vanes 113 forms a helically oriented flow path defined along the inner surface 118 of the impeller body 110. Each pair of adjacently positioned vanes 113 forms a radially arranged helically oriented flow path within the hollow impeller body 110. During use, as fluid flows between the two ends (112 and 114) of the hollow impeller body 110, the fluid flow through the radially arranged flow path causes the hollow impeller body 110 to rotate. Each of the ends 112 and 114 of the impeller body is supported by a corresponding bearing assembly 300, which enables the cylindrical and hollow impeller body 110 to rotate as fluid flows through the helical flow path of the impeller body 110, thereby causing the impeller body 110 to rotate. During use, the flow rate or velocity of the fluid flowing into the impeller body 110 determines the rotational speed of the impeller body 110. Each bearing assembly of the bearing assembly 300 is generally annular and configured to surround and support the two ends 112 and 114 of the hollow and cylindrical impeller body 110.

[0045] The outer surface 116 of the impeller body 110 includes a plurality of magnetic elements (not shown) embedded in small, recessed cavities extending across the entire outer surface of the impeller body 110. During operation, fluid flow through the helical flow path and central region 110 causes the impeller body 110 to rotate. As the impeller body 110 rotates, the magnetic elements on the outer surface 116 also rotate, resulting in a continuous change in magnetic flux. The effect of the magnetic elements will become apparent in the preceding sections.

[0046] A hollow impeller 100 is located within the stator assembly 200, such that during rotation of the hollow impeller body 110, a changing magnetic flux causes the generation of electricity in the stator coils, which form part of the stator assembly 200. The stator assembly 200 includes an elongated and hollow stator body 210, which includes a stator channel 211 extending through the stator body 210. The stator channel 211 is sized to accommodate the impeller body 110. As previously described, the stator body 210 includes stator windings (not shown) positioned along the length of the cylindrical stator body 210 such that rotation of magnetic elements on the outer surface of the impeller body 110 relative to the stator body 210 causes the generation of current in the stator windings of the stator assembly. Each of the two ends 212 and 214 of the stator body 210 includes a corresponding recessed channel for receiving and substantially supporting each bearing assembly in the bearing assembly 300, which enables the impeller body 110 to rotate as fluid flows through the hollow impeller body 110.

[0047] The energy generation system 1000 can be used in a variety of ways to generate electricity using a low-speed water flow. Figures 9 to 12 A first alternative embodiment of an energy generation assembly 2000 is illustrated, which utilizes the energy generation system 1000 described in the preceding sections. The energy generation assembly 2000 is particularly suitable for utilizing low-velocity water. The housing assembly 400 includes an inlet housing portion 410, which includes an inlet 402 for receiving flowing water. The inlet housing portion 410 includes a converging configuration to receive a low-velocity flow through the inlet opening 402. The converging configuration increases the velocity of the water as it is conveyed through the converging configuration of the inlet housing portion 410 (due to the Venturi effect), after which the increased-velocity water enters a first end 112 of the impeller body 110, which in turn causes the impeller body 110 to rotate to generate electricity. The housing assembly 400 also includes an outlet housing 420 for discharging water from the outlet housing portion 420. The outlet housing portion 420 is fluidly connected to the second end 114 of the hollow impeller body 110 to receive water from the second end 114 of the impeller body 110 and deliver the received water to the outlet 414, thereby enabling water to be discharged from the housing. The energy generation system 1000 is housed within an intermediate housing portion 415 located between the inlet housing portion 410 and the outlet housing portion 420.

[0048] Figures 13 to 17A second alternative embodiment of the energy generation assembly 3000 is illustrated, which utilizes the energy generation system 1000 described in the preceding sections. The energy generation assembly 3000 is particularly suitable for use with conduits (e.g., municipal pipelines) where water flows at a low velocity under gravity. The housing assembly 500 includes an inlet housing portion 510 with an inlet 502 having a fluid connection for receiving flowing water from a conduit connected to the inlet 502. The inlet housing portion 510 includes an inlet channel having a slightly divergent configuration to receive the low-velocity flow via the inlet opening 502. Water is conveyed through the inlet housing portion 510 and then enters a first end 112 of the impeller body 110, which in turn causes the impeller body 110 to rotate to generate electricity. The housing assembly 400 also includes an outlet housing 520 for discharging water from the outlet housing portion 520. The outlet housing portion 520 is fluidly connected to the second end 114 of the hollow impeller body 110 to receive water from the second end 114 of the impeller body 110 and deliver the received water to the outlet 514, thereby enabling water to be discharged from the housing into the pipe via the fluid connection associated with the outlet 514.

[0049] During the development of the energy generation system described herein, the inventors have surprisingly recognized that the size and proportions of the device, i.e., the rotor, can play a significant role in the design of the stator assembly 200. The following paragraphs relate to two alternative embodiments 200A and 200B of the stator assembly 200.

[0050] See Figures 18 to 23 This illustrates a first alternative embodiment of the stator assembly 200A. The stator assembly 200A is a small stator, which is particularly suitable for use in conjunction with a small rotor 100A.

[0051] The stator 200A shown in the figure has an outer diameter of 225 mm and an inner diameter of 171.4 mm. The rotor 100A has an outer diameter of 164.4 mm and an inner diameter of 149.4 mm. The air gap length is 3.5 mm, and the axial length of both the rotor 100A and stator 200A is 455 mm. The stator 200A, combined with the rotor 100A, is particularly suitable for use with water pipes with a diameter of approximately 100 mm.

[0052] The optimization of a small permanent magnet generator was analyzed using 2D and 3D simulations, highlighting key performance differences. 2D simulation results show a peak cogging torque of 5.1 Nm, which is less than 1% of the rated torque of 666 Nm. The no-load voltage peaks at 530.1 V at 200 rpm, 1590.2 V at 600 rpm, and 3180.3 V at 1200 rpm, demonstrating a linear increase with speed. Under full load conditions, the generator provides 666 Nm of torque, with peak voltages of 1189.3 V at 200 rpm, 3595 V at 600 rpm, and 7189.9 V at 1200 rpm.

[0053] In contrast, the 3D simulation results show a reduced peak cogging torque of 3.8 Nm. The full-load torque is slightly lower at 626 Nm, with peak full-load voltages of 960 V at 200 rpm, 2950 V at 600 rpm, and 5610 V at 1200 rpm. The combined 2D simulation estimates the power output at 13.9 kW at 200 rpm, 41.9 kW at 600 rpm, and 83.7 kW at 1200 rpm. Meanwhile, the 3D simulation predicts slightly lower power outputs of 13.1 kW, 39.3 kW, and 78.6 kW at the same corresponding speeds.

[0054] Generator design exhibits a linear relationship with axial length. For different axial lengths, the optimal choice of dimensions will not change. Several changes occur when the generator's axial length is modified. Increasing the axial length generally improves power output and torque generation because the volume of the machine's active material increases, allowing it to handle more magnetic flux and generate higher electromagnetic forces.

[0055] The three-phase stator 200A can benefit from simplified winding layout by having a number of slots divisible by 6. Therefore, slot numbers of 18, 24, 30, 36, and 48 are potential stator slot numbers (or tooth numbers). Considering size and to ensure a minimum tooth width of 5mm or more, the tooth number needs to be below 36, as thinner teeth present manufacturing challenges. Therefore, 36 teeth were chosen as a suitable value for this design. Table 1

[0056] The highlighted rows have high least common multiple values, resulting in low cogging torque.

[0057] Twenty-six rotor poles were chosen because this design achieves less than 1% cogging torque. Higher numbers of rotor poles, such as 34 or 38, would likely produce lower cogging torque, but would increase the fundamental frequency.

[0058] The design of a 36-slot, 26-pole permanent magnet generator shows a peak cogging torque of 5.1 Nm. The no-load peak voltage is 520.5 V, 1561.4 V, and 3123 V at 200 rpm, 600 rpm, and 1200 rpm, respectively, demonstrating a linear increase with speed. Under full load, the torque is 203.5 Nm, with peak voltages of 556.8 V, 1688.7 V, and 3377.8 V at the same speeds. Table 2

[0059] In summary, it has been observed that stator designs for smaller stators with an outer diameter less than 500 mm, and more preferably less than 200 m, and an axial length less than 500 mm, should have a stator slot to pole ratio (Ns / N) of less than 2. M N s N represents the number of stator slots and M This indicates the number of poles used for optimal operation.

[0060] Figures 24 to 31 The diagram illustrates a combination of a large stator assembly 200B and a large rotor 100B. The stator 200B shown has an outer diameter of 3000 mm and an inner diameter of 2285 mm. The rotor 100B has an outer diameter of 2225 mm and an inner diameter of 1000 mm. The air gap length is 30 mm, and the axial length of both the rotor 100B and stator 200B is 6200 mm. The combination of stator 200B and rotor 100B is particularly suitable for large-scale operations, as will be evident from some preliminary simulation studies already conducted.

[0061] The results of 2D and 3D simulations of the generator design highlight the differences in performance metrics. The peak cogging torque in the 3D simulation (13.5 kNm) is significantly higher than that in the 2D simulation (5.4 kNm), demonstrating the effectiveness of 3D modeling and more accurate magnetic force modeling. The full-load torque is almost identical, at 4550 kNm for 2D and 4500 kNm for 3D, indicating that size has a minimal impact on torque output. The peak voltage per phase under no-load conditions at different speeds (200 rpm, 600 rpm, 1200 rpm) shows a slight difference between 2D and 3D, with the 3D simulation consistently showing a difference of approximately 0.1 kV to 0.6 kV. Similarly, the peak voltage per phase under full-load conditions is also slightly lower in the 3D simulation. Power output at different speeds follows the same trend, with the 3D simulation showing a slightly lower value, reflecting more accurate losses and the effectiveness of 3D modeling.

[0062] To achieve a simplified winding configuration, the number of slots per phase per pole is kept to an integer, resulting in an integer-slot motor. Therefore, a 180-slot / 30-pole motor was selected as a suitable candidate for large motors. The selected 180-slot 30-pole motor has a winding with a coil span of 5 and a slot per phase per pole (SPP) of 2, meaning each pole pair spans 6 slots. With a coil span of 5, each coil spans 5 slots, so if the start of the coil is in slot n, the end will be in slot n+5. The winding layout ensures a 120° electrical phase difference between phases, repeating every 6 slots to maintain three-phase symmetry and minimize harmonics.

[0063] This summary shows that 2D simulations estimate power output at 95.3 MW at 200 rpm, 285.9 MW at 600 rpm, and 571.8 MW at 1200 rpm. Meanwhile, 3D simulations predict slightly lower power outputs of 94.2 MW, 282.7 MW, and 565.5 kW at the same corresponding speeds. The generator design exhibits a linear relationship with axial length. For different axial lengths, the optimal choice of dimensions will not change. Several changes occur when the generator's axial length is modified. Increasing the axial length generally improves power output and torque generation because the volume of the machine's active material increases, allowing it to handle more magnetic flux and generate higher electromagnetic forces. Table 3

[0064] The selection of slot / pole combinations for large motors is primarily influenced by the simplicity of the winding configuration. Compared to small motors, due to their larger size and higher torque generation, cogging torque is relatively low, i.e., a low percentage of the rated torque. Therefore, finding the least common multiple between the number of slots and poles seems irrelevant. Furthermore, a low pole number makes it difficult to use rectangular magnet components. Therefore, a rotor pole number around 24 to 36 seems suitable. To achieve a simplified winding configuration, the number of slots per phase per pole is kept to an integer, resulting in an integer-slot machine. Therefore, a 180-slot / 30-pole motor is selected as a suitable candidate for large motors.

[0065] The selected 180-slot, 30-pole motor has windings with a coil span of 5 and a slot per phase per pole (SPP) of 2, meaning each pole pair spans 6 slots. With a coil span of 5, each coil spans 5 slots, so if the start of a coil is in slot n, the end will be in slot n+5. The winding layout ensures a 120° electrical phase difference between phases, repeating every 6 slots to maintain three-phase symmetry and minimize harmonics.

[0066] In summary, it has been observed that for larger stators with an outer diameter greater than 1000 mm, and more preferably greater than 1500 mm, and an axial length less than 3000 mm, the stator design should have a stator slot to pole ratio greater than 4 (Ns / N). M Ns represents the number of stator slots, and N M This indicates the number of poles used for optimal operation.

[0067] In accordance with regulations, the invention has been described in language that is more or less specific to structural or methodological features. The terms “comprising” and variations thereof, such as “including” or “containing,” are always used in an inclusive sense without excluding any additional features.

[0068] It should be understood that the present invention is not limited to the specific features shown or described, as the methods described herein include preferred forms that enable the invention to take effect.

[0069] Therefore, the present invention is claimed in any form or modification thereof within the proper scope of the appended claims as properly interpreted by those skilled in the art.

Claims

1. An energy generator assembly for installation in an aquatic environment, the generator assembly comprising: A hollow and elongated impeller extending between two ends, the impeller comprising a cylindrical impeller body having an outer surface and an inner surface, the inner surface defining an internal volume including a radially central hollow region to allow fluid flow between the two ends, wherein the inner surface includes a plurality of fluid flow guide vanes extending along the length axis of the inner surface, the vanes projecting radially toward the central hollow region, wherein the vanes are arranged to cause rotation of the impeller during fluid flow between the two ends of the hollow impeller, wherein the diameter of the central hollow region is at least 1 / 3 of the diameter of the impeller; One or more radial bearing assemblies for surrounding and supporting one or more segments of the elongated impeller body, wherein a first bearing assembly of the radial bearing assemblies is positioned to surround and support one end of the impeller body, and a second bearing assembly of the radial bearing assemblies is positioned to surround and support the other end of the impeller body. The plurality of flow guide vanes are integrally formed with the impeller body; and the entire outer surface of the impeller body includes a plurality of magnetic elements disposed on the outer surface, the plurality of magnetic elements extending between the ends of the impeller body, such that rotation of the impeller body caused by fluid flow through the hollow impeller body causes movement of the magnetic elements, wherein the outer surface includes a plurality of recessed cavities configured to receive and securely engage the respective magnetic elements; A stator assembly comprising an elongated and hollow stator body, the stator body including a stator channel extending through the stator body, the stator channel being sized to accommodate an impeller body within the stator channel, wherein the stator body includes a stator winding positioned such that rotation of the impeller body and the magnetic elements on the impeller body relative to the stator body causes a current to be generated in the stator winding of the stator assembly, wherein the stator body extends between a first end and a second end, such that it further includes a recessed channel at the first end and / or the second end for accommodating the bearing assembly.

2. The energy generator according to claim 1, wherein, One or more of the flow guide vanes extend in a spiral shape relative to the central region of the cylindrical impeller body.

3. The energy generator according to claim 1 or claim 2, wherein, Each flow guide vane includes a corresponding edge portion extending along the longitudinal axis of the impeller body, the corresponding edge portion defining the central hollow region of the impeller body.

4. The energy generator according to claim 3, wherein, A pair of adjacent blades define a corresponding helical flow path to allow fluid to flow between the ends.

5. The energy generator according to claim 4, wherein, Each pair of adjacent blades forms a radially arranged helical flow path within the hollow impeller body, wherein, during fluid flow between the two ends of the hollow impeller, the fluid flow through the radially arranged flow path causes the hollow impeller body to rotate.

6. The energy generator according to any one of the preceding claims, wherein, The stator assembly includes a plurality of stator slots (Ns), and wherein the magnetic elements on the outer surface are provided with a plurality of rotor poles (N). M ), such that when the outer diameter of the rotor is greater than 1000 mm and the inner diameter of the stator is greater than 1000 mm and the axial length of the rotor and the stator is greater than 3000 mm, Ns / N M The ratio is greater than 4 and preferably greater than 5.

7. The energy generator according to any one of the preceding claims, wherein, The stator assembly includes a plurality of stator slots (Ns), and wherein the magnetic elements on the outer surface are provided with a plurality of rotor poles (N). M ), such that when the outer diameter of the rotor is less than 500 mm and the inner diameter of the stator is greater than 500 mm and the axial length of the rotor and the stator is less than 500 mm, Ns / N M The ratio is less than 2.

8. The energy generator according to any one of the preceding claims further includes a housing subassembly that at least partially houses the stator assembly and the impeller body received within the passage of the stator body.

9. The energy generator according to claim 8, wherein, The housing sub-assembly includes: a. An inlet housing portion, the inlet housing portion including an inlet for receiving flowing water, the inlet housing portion for conveying the received water to one end of the hollow impeller body; and b. An outlet housing portion, the outlet housing portion including an outlet for discharging water from the housing, the outlet housing being fluidly connected to another end of the hollow impeller body to receive water from the other end of the impeller body and deliver the received water to the outlet, thereby enabling the water to be discharged from the housing.

10. The energy generator according to claim 9, wherein, The inlet housing portion includes a converging configuration to allow the received water flow to converge toward one of the ends of the hollow impeller body.

11. The energy generator according to claim 9 or claim 10, wherein, The outlet housing portion includes a diverging configuration to allow water flowing from the other end of the impeller body to diverge toward the outlet.

12. The energy generator according to any one of claims 9 to 11, wherein, The housing subassembly further includes an intermediate housing portion adapted to be positioned between the inlet housing portion and the outlet housing portion, wherein the intermediate housing portion includes an internal volume to substantially accommodate the stator assembly and the impeller body received within a passage of the stator body of the stator assembly.

Images