Patent Description:
A generator or an electric generator is an electric machine that converts mechanical kinetic energy or motion energy in ortho-radial manner to electric current.

A generator comprises a rotor, a number of magnetic elements or magnets and a number of inductance coils. The magnetic element and the inductance coils may be arranged in the generator in different ways but the basic principle of the operation of the generator is that at least one of the at least one magnetic element and the at least one inductance coil are rotated relative to each other whereby electromotive force, i.e., voltage, is induced in the at least one inductance coil in response to the rotation of the at least one inductance coil in the magnetic field provided by the at least one magnetic element when the rotor rotates. The voltage induced in the at least one inductance coil causes the electric current in response for connecting the at least one inductance coil to a closed electric circuit.

<CIT> discloses a magnetic-drive axial-flow fluid displacement pump and turbine.

An object of the present invention is to provide a novel ortho-radial induction generator.

The invention is characterized by the features of the independent claim.

The invention is based on the idea of using a fluid flow to directly operate a rotor of a generator, the rotor being arranged to rotate relative to the flow channel unit in a floating bearing manner.

An advantage of the invention is a high coefficient of the efficiency of the generator because of converting the kinetic energy of the fluid flow straight to a rotational movement of the rotor in the generator with minimal losses of energy due to very low coefficient of friction of the solution.

Some embodiments of the invention are disclosed in the dependent claims.

For the sake of clarity, the figures show some embodiments of the invention in a simplified manner. Like reference numerals identify like elements in the figures.

<FIG> is a schematic side view of a generator <NUM>, <FIG> is a schematic top view of the generator <NUM> of <FIG>, <FIG> is a schematic cross sectional side view of the generator <NUM> of <FIG> along the line A - A in <FIG> and <FIG> is a schematic cross-sectional top view of the generator <NUM> of <FIG> along the line B - B in <FIG>. <FIG> disclose only one possible embodiment of the generator <NUM>, other embodiments of the generator <NUM>, however, being possible according to the disclosed solution. It is notified herein that any possible term referring to a "top" of the generator <NUM> or any part thereof, a "bottom" of the generator <NUM> or any part thereof and a "side" of the generator <NUM> or any part thereof refers only to the position or attitude of the generator <NUM> or any part thereof in the attached drawings. The actual position of the generator <NUM> in use may be selected freely.

The generator <NUM> has an axial direction X and in the axial direction X a first end 10a and a second end 10b. The axial direction X denotes also a centre axis of the generator <NUM>. A radial direction R of the generator <NUM> is a direction substantially transverse to the axial direction X. The generator <NUM> comprises a frame <NUM> and a power generating unit <NUM> supported to the frame <NUM>. The power generating unit <NUM> is intended to convert a kinetic energy of at least one fluid flow supplied into the generator <NUM> to the electric energy.

The frame <NUM> has an axial direction that substantially coincides with the axial direction X of the generator <NUM>. Therefore, the axial direction of the frame <NUM> and a centre axis of the frame <NUM> may also be denoted with the reference sign X. The frame <NUM> comprises a first end plate <NUM> at the first end 10a of the generator <NUM> and a second end plate <NUM> at the second end 10b of the generator <NUM>, the second end plate <NUM> thus being at a distance from the first end plate <NUM> in the axial direction X of generator <NUM>. The first end plate <NUM> provides a first end 20a of the frame <NUM> that in the embodiment of the generator <NUM> in the Figures provides the first end 10a of the generator <NUM>, and the second end plate <NUM> provides a second end 20b of the frame <NUM> that in the embodiment of the generator <NUM> in the Figures provides the second end 10b of the generator <NUM>.

The frame <NUM> further may comprise a number of support rods <NUM>, in the embodiment of the Figures altogether four support rods <NUM>, running substantially parallel to the axial direction X between the first end plate <NUM> and the second end plate <NUM>. The support rods <NUM> fastens the first end plate <NUM> and the second end plate <NUM> to each other such that a space <NUM> for accommodating the power generating unit <NUM> is provided by the first end plate <NUM>, the second end plate <NUM> and the support rods <NUM>.

The power generating unit <NUM> has an axial direction that substantially coincides with the axial direction X of the generator <NUM>. Therefore, the axial direction of the power generating unit <NUM> and a centre axis of the power generating unit <NUM> may also be denoted with the reference sign X. The power generating unit <NUM> has, in the axial direction X thereof, a first end 30a facing towards the first end 10a of the generator <NUM> and a second end 30b facing towards the second end 10b of the generator <NUM>. A radial direction R of the power generating unit <NUM> is a direction substantially transverse to the axial direction X.

The power generating unit <NUM> has a stationary flow channel unit <NUM>, a rotatable rotor <NUM> provided with a number of magnetic bridging element(s) <NUM> and at least one, i.e., one or more stationary inductance units <NUM>, wherein the flow channel unit <NUM> and the rotor <NUM> are arranged substantially consecutively to each other in the axial direction X of the power generating unit <NUM>, and wherein the rotor <NUM> is, in the embodiment of the Figures, arranged at least partly around the flow channel unit <NUM>. Other embodiments, wherein the rotor <NUM> is not at least partly arranged around the flow channel unit <NUM> are, however, possible. The flow channel unit <NUM> is arranged to convey at least one fluid flow to the rotor <NUM> for causing the rotor <NUM> to operate, i.e., to rotate. In response to a rotation of the rotor <NUM>, the at least one magnetic bridging element <NUM> arranged to the rotor <NUM> also rotates along at least one respective circumferential path about the centre axis X of the power generating unit <NUM>. The rotation of the at least one magnetic bridging element <NUM> along with the rotating rotor <NUM> is arranged to provide a magnetic field rotating in respect of the at least one stationary inductance unit <NUM>, thus causing electromotive force, i.e., voltage, being induced in the inductance unit <NUM>. The magnetic bridging element <NUM> is a magnetic element comprising or being composed of magnetic material, such as ferromagnetic material or any other material or composite having magnetic properties. Preferably the magnetic bridging element <NUM> is a piece of iron or a piece of other ferromagnetic material or composite comprising ferromagnetic material.

An example of the inductance unit <NUM> is depicted in <FIG>, wherein two inductance coils 61a are connected to each other with a magnetic element 61b and placed within at an area of an influence G2 of the magnetic bridging element <NUM>. The magnetic element 61b is a magnetic element comprising or being composed of magnetic material, such as ferromagnetic material or any other material or composite having magnetic properties. Preferably the magnetic element 61b is a piece of iron or a piece of other ferromagnetic material or composite comprising ferromagnetic material. The magnetic bridging element <NUM> is thus mounted on the rotating (moving) structure of the power generating unit <NUM>, and the inductance unit <NUM> is mounted in the stationary part of the power generating unit <NUM>. The magnetic bridging element <NUM> and the inductance unit <NUM> need to be placed within an area of influence G2 from each other so that the magnetic bridging element <NUM> rotating with the rotating structure, i.e., with the rotor <NUM>, can induce the electromotive force in the induction unit <NUM> in response to the movement of the magnetic bridging element <NUM> relative to the induction unit <NUM>. Some alternative examples of placement of magnetic bridging elements are shown with reference signs <NUM>' in <FIG>. Key feature herein is that these magnetic bridging elements <NUM> are in the rotating part of the generator, within close proximity G2 of the inductance unit <NUM>.

It is notified herein that in the embodiment of <FIG> the inductance unit <NUM> is substantially next to the rotor <NUM>, at a distance from the rotor <NUM>, but in the embodiment of <FIG>, the inductance unit <NUM> is in the axial direction of the generator <NUM> at a distance from a second end 50b of the rotor <NUM>.

The power generating unit <NUM> is fastened to the first end plate <NUM> of the frame <NUM> of the generator <NUM> by fastening bolts <NUM> (e.g., <FIG>) inserted into respective fastening openings <NUM> in the flow channel unit <NUM> (e.g., <FIG> and <FIG>). Other fastening means may also be provided. The flow channel unit <NUM> is thus fixed to the frame <NUM> of the generator <NUM> such that the flow channel unit <NUM> is stationary. The inductance unit <NUM> is mounted to the frame <NUM> in such a way that the inductance unit <NUM> is stationary. The rotor <NUM>, that is arranged to be operated in response to fluid flow flowing to the rotor <NUM>, is thus the only rotating part in the power generating unit <NUM>. The power generating unit <NUM> thus consists of three main parts, i.e., the flow channel unit <NUM>, the rotor <NUM>, wherein the at least one magnetic bridging element <NUM> is arranged to, and the stationary frame <NUM> with inductance unit <NUM> fixed thereto. Of these parts two parts, i.e., the flow channel unit <NUM> and the frame <NUM>, with the inductance unit <NUM>, are stationary and only one part, i.e., the rotor <NUM>, is a rotating part. The construction of the flow channel unit <NUM>, the rotor <NUM> and frame <NUM> with the fixed inductance unit <NUM> and the operation of the power generating unit <NUM> are disclosed in more detail next.

<FIG> is a schematic bottom view of the flow channel unit <NUM> of the power generating unit <NUM> of <FIG>, <FIG> is a schematic side view of the flow channel unit <NUM> of <FIG> is a schematic cross-sectional side view of the flow channel unit <NUM> of <FIG> along the line C - C in <FIG> shows schematically the flow channel unit <NUM> of <FIG> as seen obliquely from above. The flow channel unit <NUM> has an axial direction that substantially coincides with the axial direction X of the generator <NUM> and of the power generating unit <NUM>. Therefore, the axial direction of the flow channel unit <NUM> and a centre axis of the flow channel unit <NUM> may also be denoted with the reference sign X. A radial direction R of the flow channel unit <NUM> is a direction substantially transverse to the axial direction X.

The flow channel unit <NUM> has, in the axial direction X thereof, a first end 40a intended to face towards the first end 10a of the generator <NUM> or the first end plate <NUM> of the frame <NUM> of the generator <NUM>, the first end 40a of the flow channel unit <NUM> providing the first end 30a of the power generating unit <NUM>. Furthermore, the flow channel unit <NUM> has, in the axial direction X thereof, a second end 40b intended to face towards the second end 30a of the power generating unit <NUM> or towards the rotor <NUM>.

At the second end 40b of the flow channel unit <NUM> there is a chamber <NUM> having a shape of a truncated cone extending towards the first end 40a of the flow channel unit <NUM>, a first end 42a of the chamber <NUM> having a smaller diameter and being directed towards the first end 40a of the flow channel unit <NUM> and a second end 42b of the chamber <NUM> having a larger diameter and being directed towards the second end 40b of the flow channel unit <NUM> or towards the rotor <NUM>. The first end 42a of the chamber <NUM> is a substantially planar circular plate the centre of which substantially coincides with the centre axis X of the flow channel unit <NUM>. The second end 42b of the chamber <NUM> is substantially open circle facing towards the second end 40b of the flow channel unit <NUM>, i.e., towards the rotor <NUM>, a centre of the second end 42b of the chamber <NUM> substantially coinciding with the centre axis X of the flow channel unit <NUM>.

The flow channel unit <NUM> comprises a channel system intended to direct at least one fluid flow received by the flow channel unit <NUM> towards the rotor <NUM> to operate the rotor <NUM>. The channel system of the flow channel unit <NUM> of <FIG> comprises substantially at the first end 40a of the flow channel unit <NUM> at least one first inlet flow channel <NUM> and at least one second inlet flow channel <NUM> that is, in the radial direction R of the flow channel unit <NUM>, farther away from a centre of the flow channel unit <NUM> than the at least one first inlet flow channel <NUM>. The at least one first inlet flow channel <NUM> and the at least one second inlet flow channel <NUM> are intended to receive into the flow channel unit <NUM> at least one fluid flow for operating the rotor <NUM>. In the embodiment of the Figures there is one first inlet flow channel <NUM> and six pieces of second inlet channels <NUM> arranged to surround the first inlet flow channel <NUM>.

The channel system of the flow channel unit <NUM> comprises a set of first sub-channels <NUM> (e.g., <FIG>) extending from the first inlet flow channel <NUM> up to the chamber <NUM>, each first sub-channel <NUM> having an inlet opening 44a at the first inlet flow channel <NUM> and an outlet opening 44b at the first end 42a of the chamber <NUM>, the outlet opening 44b extending through the plate providing the first end 42a of the chamber <NUM>. The number of the first sub-channels <NUM> in the embodiment of the Figures is seven but this number may vary from one to more depending on for example the size or nominal power of the power generating unit <NUM>. The fluid flow provided through the first sub-channels <NUM> is intended to provide a small gap G1 or clearance (<FIG>) between the flow channel unit <NUM> and the rotor <NUM> to allow the rotor <NUM> to float in the fluid flow and to rotate substantially freely, i.e., almost friction-free or at very low total efficient of the friction, relative to the flow channel unit <NUM> as explained in more detail later.

The channel system of the flow channel unit <NUM> further comprises a set of second sub-channels <NUM> (e.g. <FIG>, <FIG>) extending from the second inlet flow channels <NUM> up to the outer circumference of the flow channel unit <NUM> substantially at the second end 40b of the flow channel unit <NUM>, each second sub-channel <NUM> having an inlet opening 46a at the second inlet flow channel <NUM> and an outlet opening 46b at the outer circumference of the flow channel unit <NUM> substantially at the second end 40b of the flow channel unit <NUM>, in the axial direction X of the flow channel unit <NUM>, at a position of the flow channel unit <NUM> to be surrounded by the rotor <NUM>. In the embodiment of the Figures the second sub-channels <NUM> are thus arranged to extend in at least partly radial direction R such that the outlet openings 46b of the second sub-channels <NUM> are arranged at an outer periphery of the flow channel unit <NUM>, substantially at the position of the rotor <NUM>, in the axial direction X of the flow channel unit <NUM>.

The number of the second sub-channels <NUM> in the embodiment of the Figures is six, corresponding to the number of the second inlet flow channels <NUM>, but this number may vary from one to more depending on for example the size or nominal power of the power generating unit <NUM>. The fluid flow provided through the second sub-channels <NUM> is intended to cause the rotor <NUM> to rotate around its rotation axis, i.e., around the centre axis X of the rotor <NUM>.

<FIG> and the description above disclose only one possible embodiment of the flow channel unit <NUM>, other embodiments of the flow channel unit <NUM>, however, being possible.

<FIG> shows schematically a side view of the rotor <NUM>. <FIG> shows schematically a cross-sectional side view of the rotor of <FIG> along the line D - D in <FIG>. The magnetic bridging element <NUM> shown in <FIG> are omitted in <FIG>. The rotor <NUM> has an axial direction that substantially coincides with the axial direction X of the generator <NUM> and of the power generating unit <NUM>. Therefore, the axial direction of the rotor <NUM> and a centre axis of the rotor <NUM>, providing a fictitious rotating axis of the rotor <NUM>, may also be denoted with the reference sign X. A radial direction R of the rotor <NUM> is a direction substantially transverse to the axial direction X.

The rotor <NUM> has, in the axial direction X thereof, a first end plate <NUM> forming a first end 50a of the rotor <NUM>, the first end 50a of the rotor <NUM> facing towards the first end 30a of the power generating unit <NUM> and the first end 40a of the flow channel unit <NUM>. Furthermore, the rotor <NUM> has, in the axial direction X thereof, a second end plate <NUM> forming a second end 50b of the rotor <NUM> facing towards the second end 30b of the power generating unit <NUM>.

The first end plate <NUM> of the rotor <NUM> comprises an opening <NUM> at a centre area of the first end plate <NUM>. The second end plate <NUM> of the rotor <NUM> comprises, at a centre area of the second end plate <NUM>, an extension <NUM> internal in the rotor <NUM> and having a shape of a truncated cone extending from the second end plate <NUM>, i.e., from the second end 50b of the rotor <NUM>, towards the opening <NUM> in the first end plate <NUM>, i.e., towards the first end 50a of the rotor <NUM>. The extension <NUM> has a first end 55a with a smaller diameter and being directed towards the flow channel unit <NUM> and a second end 55b with larger diameter and being directed away from the flow channel unit <NUM>, i.e., towards the second end of the rotor <NUM> or the inductance unit <NUM>.

The first end 55a of the extension <NUM> is a substantially planar, circular, solid plate the centre of which substantially coincides with the centre axis X of the rotor <NUM>. The second end 55b of the extension <NUM> is substantially closed part of the second end plate <NUM> of the rotor <NUM>, a centre of the second end 55b of the extension <NUM> substantially coinciding with the centre axis X of the rotor <NUM>.

The shape and dimensions of the extension <NUM> in the rotor <NUM> is arranged such that it provides a counterpart with the chamber <NUM> in the flow channel unit <NUM>, whereby the chamber <NUM> in the flow channel unit <NUM> can at least partly receive or accommodate the extension <NUM> in the rotor <NUM>. The first end 55a of the extension <NUM> in the rotor <NUM> provides a counterpart surface for the first end 42a of the chamber <NUM> in the flow channel unit <NUM>. Around the extension <NUM> in the rotor <NUM> there is an open space <NUM> which is intended to receive or accommodate the upper part of the outer circumference of the flow channel unit <NUM> when the power generating unit <NUM> is assembled.

The rotor <NUM> further comprises a number of wings <NUM> (e.g., <FIG>) providing a wing ring <NUM>, the wing ring <NUM> thus being provided by a number of wings <NUM> following to each other at a distance from each other in the circumferential direction of the rotor <NUM>. The wing ring <NUM> has an inner circumference 58a being substantially defined by an outer circumference of the open space <NUM> surrounding the extension <NUM>, and an outer circumference 58b being substantially defined by an outer circumference of the rotor <NUM>. The wings <NUM> are arranged to extend in a radial direction of the rotor <NUM>, i.e., in the direction that is substantially transverse to the axial direction X of the rotor <NUM>, in a curved manner from the inner circumference 58a of the wing ring <NUM> towards the outer circumference 58b of the wing ring <NUM>.

The neighbouring wings <NUM> in the circumferential direction of the wing ring <NUM> define therebetween a number of rotor flow channels <NUM> extending from the direction of the inner circumference 58a of the wing ring <NUM> towards the outer circumference 58b of the wing ring <NUM> in a curved manner. Each flow channel <NUM> has an inlet opening 59a substantially at the inner circumference 58a of the wing ring <NUM> and an outlet opening 59b substantially at the outer circumference 58b of the wing ring <NUM>. The number of the rotor flow channels <NUM> in the embodiment of the Figure is eight but may vary depending on for example the size or nominal power of the power generating unit <NUM> or on the type and viscosity of the fluid.

The inductance unit <NUM> is arranged and fixed in the power generating unit <NUM> in such a way that the inductance unit <NUM> is at an area of an influence of the magnetic bridging element <NUM> rotating with the rotor <NUM> but at a small distance apart from the magnetic bridging element <NUM> in the rotor <NUM> such that the magnetic bridging element <NUM> can freely rotate relative to the stationary inductance unit <NUM>. In other words, there is a small gap G2 or clearance between the inductance unit <NUM> and the magnetic bridging element <NUM>. In response to the magnetic bridging element <NUM> rotating relative to the inductance unit <NUM> electromotive force, i.e., voltage, is induced in the inductance unit <NUM>.

When the electrical power outputs are connected to provide closed electric circuit (not shown for the sake of clarity), the voltage induced in the inductance unit <NUM> provides the electric current output from the generator <NUM>. The number of the inductance units <NUM> in the embodiment may vary from one to more depending on for example the size or nominal power of the power generating unit <NUM>.

Figures and the description above disclose only two possible embodiments of creating and mounting the inductance unit <NUM>, other embodiments, however, being possible.

The generator <NUM> and the power generating unit <NUM> of the Figures may be assembled, in the position shown in the Figures, as follows. The rotor <NUM> is set on top of the flow channel unit <NUM> such that the chamber <NUM> in the flow channel unit <NUM> receives the extension <NUM> in the rotor <NUM>, and the first end 42a of the chamber <NUM> in the flow channel unit <NUM> and the first end 55a of the extension <NUM> in the rotor <NUM> set substantially opposite to each other. The rotor <NUM> is therefore arranged at least partly around the second end 40a of the flow channel unit <NUM> such that the inlet openings 59a of the rotor flow channels <NUM> coincide in the axial direction X of the power generating unit <NUM> with the outlet openings 46b of the second sub-channels <NUM> in the flow channel unit <NUM>. Thereafter the flow channel unit <NUM> together with the rotor <NUM> is fastened to the first end plate <NUM> of the frame <NUM> of the generator <NUM> for example by fastening bolts <NUM>, and the support rods <NUM> are also fastened to the first end plate <NUM> of the frame <NUM>. The assembly may be continued by fastening the inductance unit <NUM> to the second end plate <NUM> of the frame <NUM> of the generator <NUM> and thereafter by fastening the inductance unit <NUM> with the second end plate <NUM> of the frame <NUM> to the support rods <NUM> such that a small gap G2 (<FIG>) is left in the axial direction X of the power generating unit <NUM> between the magnetic bridging element <NUM> in the rotor <NUM> and the inductance unit <NUM>. Other assembling orders are, however, possible.

The operation of the generator <NUM> of the Figures is as follows.

The fluid flow, shown schematically in <FIG> with arrows denoted with reference sign F, is conveyed into the flow channel unit <NUM> at the first end 40a of the flow channel unit <NUM> through an opening <NUM> in the first end plate <NUM> of the frame <NUM> indicated schematically with broken lines. In the flow channel unit <NUM> a portion of the fluid flow F will flow into the first sub-channels <NUM> through the inlet openings 44a of the first sub-channels <NUM> and further through the first sub-channels <NUM> into the chamber <NUM> through the outlet openings 44b of the first sub-channels <NUM>. The portion of the fluid flow flowing through the first sub-channels <NUM> into the chamber <NUM>, as shown schematically in <FIG> with an arrow denoted with the reference sign F44, is arranged to provide in the chamber <NUM> a pressure effect between the first end 42a of the chamber <NUM> in the flow channel unit <NUM> and the first end 55a of the extension <NUM> in the rotor <NUM>. This pressure effect causes the rotor <NUM> in the axial direction X to move a little bit or a small distance away from the flow channel unit <NUM> such that a small gap G1, the position of which is denoted schematically in <FIG> with an arrow G1, will appear between the flow channel unit <NUM> and the rotor <NUM>. This pressure effect thus causes the rotor <NUM> to remain, i.e., to float, at a small distance from the flow channel unit <NUM> in the axial direction X of the power generating unit <NUM>.

In the flow channel unit <NUM> a portion of the fluid flow F will flow into the second sub-channels <NUM> through the inlet openings 46a, and through the second sub-channels <NUM> and the outlet openings 46b thereof tangentially further into the rotor flow channels <NUM> in the rotor <NUM> through the inlet openings 59a of the rotor flow channels <NUM>, as shown schematically in <FIG> with an arrow denoted with the reference sign F46. Furthermore, the fluid flow F46 flows through the rotor flow channels <NUM> and the outlet openings 59b of the rotor flow channels <NUM> out of the rotor <NUM>, in a substantially radial direction R of the rotor, causing the rotor <NUM> to rotate due to the interaction between the pressure of the fluid flow F46 and the wings <NUM> in the rotor <NUM>. The positioning of the outlet openings 46b of the second sub-channels <NUM> on the outer circumference of the flow channel unit <NUM> and the number of the second sub-channels <NUM> in the flow channel unit <NUM> and the number of the rotor flow channels <NUM> is selected such that even if in the power generating unit <NUM> the number of the second sub-channels <NUM> in the flow channel unit <NUM> and the number of the rotor flow channels <NUM> may deviate from each other, there is always, during the operation of the power generating unit <NUM>, at least some second sub-channels <NUM> in the flow channel unit <NUM> that are in flow contact with at least some rotor flow channels <NUM> in the rotor <NUM>, thus providing a constant rotation of the rotor <NUM>.

In the power generating unit <NUM> disclosed above the same fluid flow is utilized both to provide the pressure effect between the flow channel unit <NUM> and rotor <NUM> causing the rotor <NUM> to remain, i.e., to float, at a small distance from the flow channel unit <NUM> in the axial direction X of the power generating unit <NUM>, as well as to rotate the rotor <NUM>. The pressure effect between the flow channel unit <NUM> and rotor <NUM> causing the rotor <NUM> to remain, i.e., to float, at a small distance from the flow channel unit <NUM> in the axial direction X of the power generating unit <NUM> decreases friction between the flow channel unit <NUM> and the rotor <NUM>, allowing the rotor <NUM> to rotate substantially or almost friction-free, i.e., at very low total coefficient of friction, about the flow channel unit <NUM>. This solution thus provides a so-called floating bearing solution in the generator <NUM>. This increases the coefficient of the efficiency in respect of traditional bearing solutions utilized in prior art generators, the operation and construction being, however, simple.

When the rotor <NUM> rotates, the magnetic bridging element <NUM> rotates in response to the rotation of the rotor <NUM>, the magnetic bridging element <NUM> thereby rotating relative to the inductance unit <NUM> and causing electromotive force, i.e. voltage, being induced in the inductance unit <NUM>. When the electrical power outputs for the inductance unit <NUM> are connected to provide closed electric circuit (not shown for the sake of clarity), the voltage, induced in the inductance unit <NUM> provides the electric current output from the generator <NUM>.

According to an embodiment the inductance unit <NUM> may be equipped with a servo motor arrangement comprising at least one servomotor so as to control the size of the gap G2 between the magnetic bridging element <NUM> and the inductance unit <NUM>, and thereby indirectly also to control the size of the gap G1 between the flow control unit <NUM> and the rotor <NUM>, based on the electromagnetic forces affecting between the magnetic bridging element <NUM> and the inductance unit <NUM> when the power generating unit <NUM> is operating. Additionally, or alternatively, the size of the gap G1 between the flow control unit <NUM> and the rotor <NUM> may take place by controlling the fluid rate and/or pressure intended to cause the rotor <NUM> to float. <FIG>, for example, discloses schematically control means <NUM>, <NUM> intended to control the fluid rates and/or pressures of the fluid flows causing the rotor to float and rotate. The control of the size of the gap G2 between the magnetic bridging element <NUM> and the inductance unit <NUM>, and thereby indirectly also the control of the size of the gap G1 between the flow control unit <NUM> and the rotor <NUM>, or vice versa, and other possible controls applied in the generator, may take place by computer-aided means.

The fluid flow F may for example be, but not limited to, an air flow, a steam flow, an exhaust gas flow or liquid flow with a sufficient pressure, or a pressurized flow of at least one of the air flow, the steam flow, the exhaust gas flow and the liquid flow. The fluid flow F may thus also be a mixture of at least one of the air flow, the steam flow, the exhaust gas flow and the liquid flow. The fluid flow F may take place gaseous, supercritical or heterogeneous fluid phase. In the case of the fluid flow F being the air flow, the air flow may be an air flow due to a wind, whereby the generator <NUM> may be utilized in the wind turbines, for example. The air flow may also be a pressurized air flow in an industrial pressurized air system, for example. In the case of the fluid flow F being the steam flow, the steam flow may originate from an engine or a system generating the steam flow. In the case of the fluid flow F being the exhaust gas flow, the exhaust gas flow may originate from an engine or a system generating the exhaust gas. In the case of the fluid flow F not having a pressure high enough for properly operating the power generating unit <NUM>, a pressure increasing arrangement, comprising for example a number of adjustable jet nozzles, for increasing the pressure of the fluid flow F may be arranged at the inlet of the flow channel unit <NUM>. A typical pressure of the fluid flow F to be supplied into the generator <NUM> may for example be, but not limited to, <NUM> to <NUM> bars.

A nominal power of the generator <NUM> disclosed may vary for example, but not limited to, between <NUM> kW and <NUM> MW. A typical rotation speed of the rotor <NUM> may for example be, but not limited to, <NUM> - <NUM> rpm.

In the embodiment disclosed above, the same fluid flow in same fluid phase is used both to cause the rotor to float as well as to rotate the rotor. However, the fluid flows causing the rotor to float and to rotate may be different fluid flows in same fluid phase or in different fluid phases or same fluid flow in different fluid phases. Furthermore, in the embodiment disclosed above, the supply directions of the fluid flows causing the rotor to float and to rotate the rotor are same but the supply directions of the fluid flows causing the rotor to float and to rotate the rotor may also be different.

Furthermore, in the embodiment disclosed above, the rotor does not comprise any specific rotor shaft, but the rotor could also comprise a shaft, which may also be hollow in order to provide at least one flow channel and/or which may take part in centralization of the rotor in the power generating unit.

Furthermore, in the embodiment disclosed above, the generator comprises only one rotor and one flow channel unit. However, the number of rotors and flow channel units in the generator may vary. Additionally, for example, the size of the rotors in a generator comprising at least two rotors may vary for example to provide an optimized size in view of the nominal power of the generator. The generator may thus comprise a rotor system comprising at least two rotors.

It will be obvious to a person skilled in the art that this novel solution may also be used in reverse mode, meaning that the almost friction free structure disclosed may be used to generate flow of fluids when electrical power is applied to the inductance units. The benefits or intended end uses of operation in reverse mode are numerous, ranging from clean air transfer to fluid transportation, especially in tasks where presence of shaft lubrication, bearings or other potential sources of impurities are present.

Claim 1:
An electric generator (<NUM>) comprising
at least one rotor (<NUM>),
at least one magnetic bridging element (<NUM>) arranged to rotate about a rotation axis (X) of the rotor (<NUM>) in response to the rotation of the rotor (<NUM>),
at least one inductance unit (<NUM>) comprising an inductance coil (61a) and a magnetic element (61b) at an area of an influence (G2) of the moving magnetic bridging element (<NUM>) for inducing electromotive force in response to the movement of the magnetic bridging element (<NUM>) relative to the inductance unit (<NUM>), and
at least one flow channel unit (<NUM>) for conveying a fluid flow to the rotor (<NUM>) for operating the rotor (<NUM>), wherein the rotor (<NUM>) is arranged to rotate relative to the flow channel unit (<NUM>) in a floating bearing manner,
characterized in that
the flow channel unit (<NUM>) comprises at least one channel (<NUM>) for conveying at least one fluid flow between the flow channel unit (<NUM>) and the rotor (<NUM>) to create a pressure effect between the flow channel unit (<NUM>) and the rotor (<NUM>) to push, in the axial direction (X) of the flow channel unit (<NUM>) and the rotor (<NUM>), the rotor (<NUM>) away from the flow channel unit (<NUM>) such that a gap (G1) is arranged between the flow channel unit (<NUM>) and the rotor (<NUM>) for allowing the rotor (<NUM>) to rotate relative to the flow channel unit (<NUM>) substantially friction-free, and that
the flow channel unit (<NUM>) comprises at least one channel (<NUM>) for conveying at least one fluid flow to the rotor (<NUM>) for rotating the rotor (<NUM>).