Background art The invention comprises a development of rotors which are disclosed in Australian Patent 694679 (AU-B-62946/96) and International Patent Application PCT/AU00/01438 (WO 01/38697) which comprise a rotor which has a configuration which conforms generally to the curve of a logarithmic configuration substantially conforming to an equiangular spiral of the Golden Section which is also known as the Phi ratio. The contents of Australian patent 694679 and WO 01/38697 are incorporated herein by reference.

Rotors such as impellors, propellers turbine blades and fan blades have scarcely changed over the years and are relatively inefficient. In addition, it is a common characteristic of such fan blades that their use results in the generation of a considerable amount of noise and in turbulence. Furthermore, where rotors are used in a liquid environment, if the rotors are caused to rotate too fast, this can result in cavitation on the surface and tips of the rotor which not only reduces the operational efficiency of the rotor but can result in destructive influences on the rotor

and the surrounding housing associated with the rotor. Typically, rotors force fluids into centrifugal moments, flinging the fluid to the extremities. This is used to advantage in centrifugal pumps, but also results in inefficiencies.

It is an object of this invention to provide a single or multi-bladed rotor which can react to or induce a fluid flow and whereby the usage of that rotor results in a reduction of the degree of extraneous turbulence and tip vortices exerted on the fluid in its passage past the rotor with the resultant energy loss and noise generation when compared to conventional rotors which are currently in use. Typically rotors according to the invention cause fluids to flow centripetally rather than centrifugally and subsequently are able to exploit associated efficiency.

The preceding discussion of the background to the invention is intended only to facilitate an understanding of the present invention. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge in Australia or elsewhere as at the priority date of the application.

Disclosure of the Invention Accordingly, the invention resides in a rotor comprising a hub supporting a blade, the blade having an axial extent and extending transversely outwardly from the hub to define a first and second face of substantially corresponding configuration which conform to at least one logarithmic curve conforming to the Golden Section.

According to a preferred feature of the invention, the transverse cross sectional configuration of the faces is curved in conformity with the Golden Section.

According to a preferred feature of the invention, the extent of the blade which is transverse to the longitudinal axes varies along the length of the rotor accordance with a logarithmic curve conforming to the Golden Section.

According to a further preferred feature of the invention, fluid flow relative to the rotor is centripetal.

According to a preferred embodiment, the blade defines a helical vane having the configuration of a whorl.

According to a preferred embodiment, the blade has a shell-like configuration where the transverse displacement of the surfaces at an intermediate location along the length of the rotor is greater than the transverse displacement at either end.

According to a preferred feature of the invention, one end of the blade co-operates with the hub to define an open, generally axially directed opening, the other end being closed wherein the hub provides for fluid flow longitudinally through the rotor.

According to a embodiment, a single blade is mounted to the hub and the hub is provided with a counterweight positioned to balance the rotor in use.

According to a preferred feature of the invention at least two blades are mounted to the hub said blades being spaced angularly equidistant around the hub.

According to a preferred embodiment, the curvature of the faces are of substantially equivalent form.

According to a further preferred feature of the invention, the curvatures of the reactive surfaces are uni-dimensional. According to one embodiment the curvature of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially radial to the axis. According to another embodiment the curvature of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially tangential to the rotation path about said axis. According to another embodiment the curvature of the faces according to the logarithmic curve

substantially conforming to the Golden Section is about an axis which is substantially coaxial with or substantially parallel with said axis.

According to a further preferred feature of the invention, the curvatures of the reactive faces are bi-dimensional. According to one embodiment the curvature of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially radial to the rotation path of that point about said axis and an axis which is substantially tangential to the rotation path about said axis. According to another embodiment the curvatures of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially radial to the axis and an axis which is substantially coaxial with or substantially parallel with said axis. According to another embodiment the curvature of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially tangential to the rotation path about said axis and an axis which is substantially coaxial with or substantially parallel with said axis.

According to a further preferred feature of the invention, the curvatures of the faces is three dimensional. According to one embodiment the curvature of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially radial to the rotation path, an axis which is substantially tangential to the rotation path about said axis and an axis which is substantially coaxial with or substantially parallel with said axis.

According a preferred feature of the invention, the rotor comprises a fan blade which is intended to induce or react to a gaseous flow past the rotor.

According to an alternative embodiment of the invention, the rotor comprises an aircraft propeller.

According to an alternative embodiment of the invention, the rotor comprises a watercraft propeller.

According to an alternative embodiment of the invention, the rotor comprises a marine jet pump impeller.

According to an alternative embodiment of the invention, the rotor comprises a pump rotor.

According to an alternative embodiment of the invention, the rotor comprises a turbine rotor.

According to an alternative embodiment of the invention, the rotor comprises a mixer rotor.

The invention will be more fully understood in the light of the following description of several specific embodiments.

Brief Description of the Drawings The description is made with reference to the accompanying drawings of which : Figure 1 is an isometric view of a rotor according to the first embodiment; Figure 2 is a side elevation of the rotor according to the first embodiment; Figure 3 is a plan view of the rotor according to the first embodiment; Figure 4 is an inverted end view of the rotor according to the first embodiment as shown at Figure 3;

Figure 5 is a schematic isometric view of the first embodiment illustrating the fluid flow that it is believed is generated by the rotation of the rotor Detailed Description of Several Embodiments Each of the embodiments of the invention comprises a rotor having a hub supporting at least one blade. While embodiments having single blades are capable of operating satisfactorily, additional balancing would be required to enable satisfactory operation. it is envisaged that multi-bladed embodiments would generally be preferred to avoid the difficulties in balancing a single bladed rotor.

The rotors of the embodiments differ from prior art rotors by virtue of the blade or blades extending from the hub in an axial direction as well as extending transversely outwardly. Each blade defines a first and second surface of substantially corresponding configuration which conforms to at least one logarithmic curve conforming to the Golden Section.

The first embodiment shown in Figures 1 to 4 of the drawings comprises a rotor which has particular application as a propeller for a water craft. Alternatively, the rotor can be used as a fan, turbine, propeller, pump or mixer.

As shown at Figures 1 to 4, the rotor comprises a hub (112) which supports a set of two blades (111) extending both radially and axially from the hub. The hub (112) is formed with a central shaft or tube which is adapted to be mounted to a rotatable shaft or tube which comprises, in the case of a fan blade intended to induce fluid flow, a drive shaft driven from a suitable motor. Each of the blades are formed with an internal reactive face (114) which is of a concave configuration and which has a three dimensional curvature whereby the curvature in each dimension is about an axis which is radial to the central axis of the rotor, an axis which is tangential to the central axis of the rotor and an axis which is coincidental or parallel to the central axis of the rotor. In each case the curvature is in accordance with a logarithmic

curve conforming to the Golden Section. As a result, the blades (111) jointly define a generally concave internal face of the rotor.

In addition, each blade has a remote reactive face (115) which is remote from the reactive face (114) and which also has a three dimensional curvature of a convex nature whereby the curvature in each dimension conforms with a logarithmic curve according to the Golden Section, and whereby the curvature in each dimension is of the same form as the curvature of the reactive face (114) in each dimension. As a result, the remote faces (115) jointly define a generally convex surface of the rotor.

As a result of this blade arrangement, the transverse displacement of the surfaces at an intermediated location along the length of the rotor is greater than the transverse displacement at either end.

It may be seen that the general appearance of the embodiment as shown at Figure 1 generally takes the form of pairs of shells of the phylum Mollusca, classes Gastropoda and Cephalopoda.

It has been found that the rotation of the rotor induces a fluid flow which is centripetal rather than centrifugal and subsequently are able to exploit associated efficiencies.

It is a particular characteristic which results from the configuration of the blades of the rotor as described above, that fluid flowing relative to the blades will be directed centripetally, that is inwardly towards the axis. This surprising effect which follows from the vortical motion of the fluid provides a number of advantages. In particular, it is found that when a rotor according to the embodiment is used as a propeller for a water craft, it is not necessary to use a shroud or the extent of shrouding required is significantly reduced.

The rotor according to the first embodiment is suitable for use in many applications such as pumping of liquids or gases, whereby with rotation of the rotor blade such

that the one edge (116) forms the leading edge of each blade, fluid flow will be induced past the fan blade from the convex face to the concave face. Alternatively, the other edge (117) may form the leading edge for opposite rotation. Because of the curvature of the reactive face of each of the radial blades of the embodiment, the fan blade induces a vortical fluid flow in the fluid medium as it both approaches the rotor and as it exhausts from the rotor as illustrated at Figure 5.

It has been found that in use of the first embodiment the rotation of the rotor generates a fluid flow through the rotor in which the flowing fluid maintains its own inertia and if the rotor is stopped the fluid flow will continue through the rotor for a period of time because of such inertia. It is believed that this is at least in part due to the circumstance that the use of the rotor of the first embodiment results in the generation of a fluid flow in which the pathway for the fluid flow though the rotor (as distinct from conventional rotors) is constant in its geometry from a position in advance of the entry to the rotor to a position beyond the exit from the rotor.

The second embodiment shown in Figures 6 to 9 of the drawings comprises a rotor which also has application as a propeller for a water craft. Again it may also be used as a fan, pump, turbine, pond circulator or mixer.

As shown in the drawings, the rotor of the second embodiment has a very different appearance from that of the first embodiment. Nevertheless, the blades have a configuration which conform in most respects to the configuration described in relation to the first embodiment. To clarify the similarities, in identifying the features of the embodiment as shown in the drawings, like numerals are used to denote like parts.

The rotor of the second embodiment also comprises a hub (12) which supports a set of two blades (11) extending both radially and axially from the hub. The hub (12) is formed with a central shaft or tube which is adapted to be mounted to a rotatable shaft or tube which comprises, in the case of a fan blade intended to induce fluid

flow, a drive shaft driven from a suitable motor. Each of the blades are formed with an internal reactive face (14) which is of a concave configuration and which has a three dimensional curvature whereby the curvature in each dimension is about an axis which is radial to the central axis of the rotor, an axis which is tangential to the central axis of the rotor and an axis which is coincidental or parallel to the central axis of the rotor. In each case the curvature is in accordance with a logarithmic curve conforming to the Golden Section. As a result, the blades (11) jointly define a generally concave intemal face of the rotor.

In addition, each blade has a remote reactive face (15) which is remote from the intemal reactive face (14) and which also has a three dimensional curvature of a convex nature whereby the curvature in each dimension conforms with a logarithmic curve according to the Golden Section, and whereby the curvature in each dimension is of the same form as the curvature of the reactive face (14) in each dimension. As a result, the remote faces (15) jointly define a generally convex surface of the rotor.

While these features are identical to those of the first embodiment, the blades of the second embodiment have the configuration of a whorl. It will be seen from the drawings that the blades provided a maximum diameter near to the hub but the diameter then diminishes further from the hub. Figure 10 illustrates the vortical flow induced by the rotor.

According to a third embodiment of the invention a rotor of a similar form to that of the first or second embodiment is used as the impeller of a fluid mixer, pond circulator or bioreactor.

According to a fourth embodiment of the invention a rotor of a similar form to that of the first or second embodiment is used as the impeller of a fluid pump.

According to a fifth embodiment of the invention a rotor of a similar form to that of the first or second embodiment is used as the impeller of a compressor.

According to a sixth embodiment of the invention a rotor of a similar form to that of the first or second embodiment is used as the turbine blade of a turbine.

It should be appreciated that the scope of the present invention need not be limited to the particular scope described above.

Throughout the specification, unless the context requires otherwise, the word "comprise"or variations such as"comprises"or"comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.