WO2008020419A1

WO2008020419A1 - A collector rotor and a related airplane tyre

Info

Publication number: WO2008020419A1
Application number: PCT/IB2007/053288
Authority: WO
Inventors: Danny Patrick Holton
Original assignee: Danny Patrick Holton
Priority date: 2006-08-18
Filing date: 2007-08-17
Publication date: 2008-02-21

Abstract

This invention relates to a collector rotor (10) and to a related airplane tyre (116.1). The collector rotor (10) is for harvesting energy from fluid flow, e.g. airflow or water flow. The rotor includes an arrangement of fluid flow barriers (16.1), typically flaps (20), around its rotational axis. The configuration of the barriers is such that, in use of the rotor, fluid flow transverse to the axis alternately forces each barrier into a first, high drag configuration when the barrier is displaced against fluid flow during rotation of the rotor and into a second, low drag configuration when the barrier is displaced along with the flow. The invention extends to a method of using the collector rotor for energy harvesting for electricity generation. The collector rotor may be provided as part of an airplane tyre (116.1) to provide for operatively rotationally accelerating the tyre for landing, upon being exposed to airflow.

Description

A COLLECTOR ROTOR AND A RELATED AIRPLANE TYRE

THIS INVENTION relates to a collector rotor and to a related airplane tyre.

It is an aim of the invention to provide a collector rotor which can be provided in different embodiments suitable for harvesting energy from fluid flow, e.g. wind, wave action, and so forth, for different purposes.

Insofar as the invention relates to an airplane tyre, the following background applies. It is known that, immediately before touchdown of a tyre of a wheel of an airplane on a runway, with the wheel rotationally stationary, a differential speed equal to the ground speed of the airplane exists between the underside of the tyre and the runway. Upon touchdown, a shear force between the underside of the tyre at any given instant and the runway causes the wheel to rapidly rotationally accelerate until the differential speed has been eliminated. The shear force causes wear on the tyre and one aim of the invention is to reduce such wear significantly.

According to a first aspect of the invention, there is provided a collector rotor which defines a forward direction of rotation, which includes an arrangement of fluid flow barriers, and in which the fluid flow barriers are arranged around the rotational axis of the rotor and each fluid flow barrier defines a forward direction, being the direction relative to the rotational axis in which the barrier is displaced during forward rotation of the rotor, and an opposite reverse direction; and each fluid flow barrier is displaceable between a first and a second configuration under action of fluid flow, the barrier particularly being configured so that fluid flow in its forward direction will urge it towards its first configuration, in which it defines a larger cross-section swept path and presents higher drag resistance against fluid flow, and so that opposite fluid flow will urge it towards its second configuration, in which it defines a smaller cross-section swept path and presents lower drag resistance against fluid flow. For understanding the operation of the collector rotor, consider a plane which includes the rotational axis of the rotor and the fluid flowing parallel to the plane and perpendicular to the rotational axis. Generally speaking, the fluid flow barriers on a first side of the plane are displaced into their first configurations and present high drag resistance to the fluid flow. The fluid flow barriers on a second side of the plane, opposite to the first, are displaced into their second configurations and present low drag resistance to the fluid flow. The forces exerted by the fluid flow on the fluid flow barriers on opposite sides of the plane are thus unbalanced, resulting in a torque on the rotor, urging it to rotate in the direction in which the fluid flow barriers on the first side are displaced downstream with respect to the fluid flow. During such rotation of the rotor, each fluid flow barrier thus alternates between the first and the second side of the plane and is accordingly alternately displaced, under action of the fluid flow, into its first and its second configuration, respectively.

Certain embodiments of collector rotors, in accordance with the first aspect of the invention, will each operatively be rotatably mounted on a suitable support and typically will be connected to a device which generates electricity, thereby to convert rotation of the rotor into electricity.

The collector rotor of the first aspect of the invention may include at least one carrier wheel carrying its fluid flow barriers, the wheel being disposed transverse to the rotational axis of the rotor and the fluid flow barriers being displaceable laterally with respect to the carrier wheel between their first and second configurations. The carrier wheel may be in the form of a disc. The carrier wheel may particularly carry an arrangement of fluid flow barriers, as defined, on each side thereof.

In a particular type of collector rotor, in accordance with the first aspect of the invention, each fluid flow barrier includes a flap of which a leading end is pivotally mounted on the carrier wheel, the pivot axis being at least substantially radially disposed with respect to the rotor; and the flap is pivotally displaceable about the pivot axis between a first and a second position, corresponding to the first and second configuration, respectively, of the fluid flow barrier.

In a collector rotor of this type, for increasing its drag resistance against fluid flow when in its first position, the flap may be provided with two opposite collapsible gussets.

In another particular type of collector rotor, in accordance with the first aspect of the invention, the fluid flow barriers are resiliently flexible bristles defining a brush-like formation; and each bristle is secured at a root end thereof to the carrier wheel in a configuration in which it is biased under its own resilience towards a rest position thereof in which the root end is its leading end and its free end is its trailing end according to the forward direction of rotation of the rotor.

In the case of the collector rotor of the first aspect of the invention including a carrier wheel, as defined, it may include an axle and a series of such carrier wheels, spaced apart along the axle.

Further in accordance with the first aspect of the invention, there is provided a collector rotor, which forms a part of an airplane tyre, including opposite side walls, and in which the rotational axis of the rotor coincides with the rotational axis of the tyre; the fluid flow barriers of the rotor are airflow barriers provided on at least one of the side walls of the tyre; the forward direction of rotation operatively corresponds to the direction of operative rotation of the tyre upon landing of an airplane on which it is mounted; and each airflow barrier is operatively displaceable between its first and second configurations under action of fluid flow in the form of airflow past the airplane upon approach to a runway for landing. The airflow barriers may be flaps. Each flap may be secured at a root end thereof to a side wall of the tyre.

In a particular type of the collector rotor which forms a part of an airplane tyre, each flap is secured at a root end thereof to a side wall of the tyre by having the root end integrally formed with the side wall; airflow in the reverse direction of the flap urges the flap towards the side wall, towards the second configuration of the flap, so that the flap presents low drag resistance; and airflow in the forward direction of the flap urges the flap away from the side wall, towards the first configuration of the flap, so that the flap presents high drag resistance.

In this type of collector rotor, the flaps may define a scale-like arrangement and overlap each other. Alternatively or additionally, the flaps may be resiliently flexible and each biased under its own resilience towards its second configuration.

In the case of the collector rotor which forms a part of an airplane tyre and includes flaps, each flap may be hingedly connected to a side wall of the tyre. In this case, each flap may be so connected via an elastic formation defining a resiliently flexible hinge, resiliently biasing the flap towards its second configuration.

Further in accordance with the first aspect of the invention, there is provided a collector rotor, which is an accessory for an airplane tyre, the accessory including an annular base wall and the airflow barriers of the rotor are provided on the base wall; the base wall is securable to a side wall of an airplane tyre in a configuration in which the rotational axis of the rotor coincides with the rotational axis of the tyre; the forward direction of rotation operatively corresponds to the direction of forward rotation of the tyre; and each airflow barrier is operatively displaceable between its first and second configurations under action of fluid flow in the form of airflow past the airplane upon approach to a runway for landing.

In this type of collector rotor, the base wall may be securable to a side wall of an airplane tyre via a suitable adhesive. Alternatively, in the case of the collector rotor being made of rubber, it may be securable to a side wall of an airplane tyre through vulcanizing.

Insofar as further features of the collector rotor of the first aspect of the invention which is an accessory for an airplane tyre may be analogous to features of the collector rotor forming a part of an airplane tyre, they do not warrant repetition here.

The applicant submits that the collector rotor of the first aspect of the invention, insofar as it relates to airplane tyres, may, in use, effect significantly reduced wear on airplane tyres, thus reducing costs relating to the replacement of airplane tyres and the removal of rubber from runways.

According to a second aspect of the invention, there is provided an airplane tyre including a suitable collector rotor, in accordance with the first aspect of the invention, as defined above.

According to a third aspect of the invention, there is provided a method of harvesting wind energy, which includes mounting a suitable collector rotor, in accordance with the first aspect of the invention, in a location in which it is exposed to wind and driving an electricity generating device via the rotor.

In this case, the rotor may be mounted with its rotational axis at least substantially vertical.

According to a fourth aspect of the invention, there is provided a method of harvesting energy from water currents, which includes mounting a suitable collector rotor, in accordance with the first aspect of the invention on a suitable support and submerged in waters characterized by a current, with its rotational axis transverse to the direction of the current; and driving an electricity generating device via the rotor.

According to a fifth aspect of the invention, there is provided a method of harvesting energy from sea wave action, which includes mounting a suitable collector rotor, in accordance with the first aspect of the invention, on a suitable support in a wave region with its rotational axis disposed horizontally, transverse with respect to the direction of wave travel, and at a level permitting the waves to act on the upper fluid flow barriers and reverse current to act on the lower fluid flow barriers; and driving an electricity generating device via the rotor.

According to a sixth aspect of the invention, there is provided a method of harvesting energy from airflow caused by forward motion of a vehicle, which includes mounting a suitable collector rotor, in accordance with the first aspect of the invention, in a location on a vehicle in which it is exposed to airflow caused by forward motion of the vehicle; and driving an electricity generating device via the rotor.

In this case, the method may include using energy generated by the device in powering a drive motor of the vehicle.

The method may include providing ducting, defining a frontal air intake, for channelling the airflow to one side of the rotor for optimally driving the rotor.

According to a seventh aspect of the invention, there is provided a method of harvesting energy from water flow caused by forward motion of a water craft, which includes mounting a suitable collector rotor, in accordance with the first aspect of the invention, in a location on a water craft in which it is exposed to water flow caused by forward motion of the craft; and driving an electricity generating device via the rotor.

In this case, the method may include using energy generated by the device in powering a drive motor of the craft.

Further features of the invention will become apparent from the following description of non-limiting examples of embodiments of the invention in its respective aspects, with reference to and as illustrated in the accompanying diagrammatic drawings. In the drawings: Figure 1 shows an end view of a first embodiment of a collector rotor, in accordance with the first aspect of the invention;

Figure 2 shows a side view of an axle acarrier wheels the rotor of Figure 1 , in the direction of arrows N-Il of Figure 1 ;

Figure 3 shows a cross-section of a part of a disc-like carrier wheel and a fluid flow barrier of the rotor of Figure 1 , along the line Ill-Ill of Figure 1 , the fluid flow barrier being in a second configuration;

Figure 4 shows the view IV-IV of Figure 3;

Figure 5 shows a view corresponding to Figure 3, but with the fluid flow barrier in a first configuration; Figure 6 shows a side elevation of a wind powered electricity generation system incorporating a collector rotor of a type similar to that shown in Figures 1 and 2, for generating electricity in accordance with the method of the third aspect of the invention; Figure 7 shows a sectional view of a part of an electricity generation system in a motor vehicle, incorporating a collector rotor of a type similar to that shown in Figures 1 and 2, for generating electricity in accordance with the method of the sixth or seventh aspect of the invention;

Figure 8 shows a side elevation of an arrangement forming a part of an electricity generation system and incorporating a further embodiment of a collector rotor, in accordance with the first aspect of the invention, mounted on a support on a sea bed with a wave about to travel over the rotor, for generating electricity in accordance with the method of the fifth aspect of the invention;

Figure 9 shows a perspective view of the arrangement of Figure 8; Figure 10 shows an enlarged detail of a part of Figure 9; Figure 1 1 shows a perspective view of a flap of the collector rotor of Figure 8;

Figure 12 shows a side elevation of a part of an electricity generation system incorporating a collector rotor similar to that shown in Figure 8, mounted on a support on a sea bed and submerged in water characterized by tidal currents, for generating electricity in accordance with the method of the fourth aspect of the invention;

Figure 13 shows a part section through a carrier wheel of a further embodiment of a collector rotor, in accordance with the first aspect of the invention, carrying a brush formation comprised of resiliently flexible bristles, the plane of the section being tangential to an imaginary round cylinder that is concentric with the rotational axis of the rotor, the bristles being shown in a second configuration;

Figure 14 shows the part section of Figure 13, but with the bristles in a first configuration;

Figure 15 shows an operative front view of a part of an undercarriage of an airplane, including a pair of wheels, each including a tyre, in accordance with the second aspect of the invention, including two collector rotors, in accordance with the first aspect of the invention;

Figure 16 shows a diagrammatic side elevation of one of the wheels of Figure 15, in the direction of arrows XVI-XVI of Figure 15;

Figure 17 shows a diagrammatic cross-section of a part of a side wall of the tyre of Figure 16 and flaps provided on the side wall, along the line XVII-XVII of Figure 16, the flaps being in a second configuration;

Figure 18 shows a diagrammatic cross-section of another part of the side wall of Figure 17 and flaps provided on the side wall, along the line XVIII-XVIII of Figure 16, the flaps being in a first configuration; Figure 19 shows a diagrammatic side elevation of a further embodiment of an airplane tyre, in accordance with the second aspect of the invention;

Figure 20 shows a diagrammatic face-on view of an embodiment of a collector rotor, in accordance with the first aspect of the invention, being an accessory for an airplane tyre; and Figures 21 and 22 show cross-sections equivalent to those shown in Figures 17 and 18, respectively, but showing flaps of an alternative type to those shown in the latter two drawings. Materials suitable for use in each of the collector rotor embodiments described and illustrated below can be ascertained by those skilled in the art and, as such, are generally not discussed herein.

In Figures 1 and 2, an embodiment of a collector rotor, in accordance with the first aspect of the invention, is designated generally by the reference numeral 10.

The collector rotor 10 includes an axle 12 and a series of nine identical fluid flow barrier carrier wheels 14, the carrier wheels being disc-like and disposed transversely with respect to the axle and at equal spacing along the axle. In other embodiments (not shown), the number of carrier wheels may be different and the rotor may include a single carrier wheel.

Each carrier wheel 14 carries on each of its opposite faces an arrangement of fluid flow barriers 16 (see Figure 1 ). For the sake of simplicity, these fluid flow barriers are not shown in Figure 2. The collector rotor 10 defines a forward direction of rotation, indicated in Figure 1 by an arrow 18. The fluid flow barriers 16 are all identical and similarly mounted on the respective carrier wheels 14. As such, by way of example, the details of only one of these fluid flow barriers, designated 16.1 , will now be described.

With reference particularly to Figures 3 and 4, the fluid flow barrier 16.1 includes a rectangular flap 20, which defines a leading end 22 and a trailing end 24 of the fluid flow barrier, in accordance with forward rotation of the carrier wheel 14.9 (see arrow 18 in Figure 1 ). In another embodiment of the collector rotor of the invention (not shown), such a flap may have a non-rectangular shape. It may, e.g., have a shape similar to that of a fish scale. Along its leading end 22, the flap 20 is pivotally mounted on the carrier wheel 14.9 to pivot about a pivot axis 26 (see Figure 1 also) which is substantially radially disposed with respect to the rotor 10.

The fluid flow barrier 16.1 includes two opposite flexible gussets 30, each secured along opposite edges thereof to the flap 20 and the wheel 14.9, respectively. The material of the gussets must be suitably selected or developed and the applicant suggests a trial of materials such as rubber, synthetic plastics, or Nylon. In an alternative embodiment (not shown), such gussets may be omitted.

With reference particularly to Figure 3, under fluid flow in the plane of the carrier wheel 14.9 in the direction of arrow 34, i.e. in the reverse direction of the fluid flow barrier 16.1 , the flap 20 is pivotally displaced by the fluid flow into a second position, as shown, which constitutes the second configuration of the barrier, in which it presents low drag resistance against the fluid flow. The cross-section of the path swept by the fluid flow barrier 16.1 during rotation of the carrier wheel 14.9 has a small area. The flap 20 is disposed to pierce the fluid stream, minimizing drag resistance. The gussets 30 are collapsed.

With reference particularly to Figure 5, under fluid flow in the plane of the carrier wheel 14.9 in the direction of arrow 36, i.e. in the forward direction of the fluid flow barrier 16.1 , the flap 20 is pivotally displaced by the fluid flow into a first position, as shown, which constitutes the first configuration of the barrier, in which it presents high drag resistance against the fluid flow. The cross-section of the path swept by the fluid flow barrier 16.1 during rotation of the carrier wheel 14.9 has a large area. The flap 20 and gussets 30 are disposed to define a pocket 37 between them and the carrier wheel 14.9, maximizing drag. The gussets 30 are extended.

With reference particularly to Figure 1 , consider fluid flowing in the plane of the carrier wheel 14.9 in the direction of arrow 38, parallel to a plane 40 which includes the rotational axis of the rotor 10. A number of the fluid flow barriers 16 on a first side 41 of the plane 40, including the fluid flow barriers 16.1 , 16.2, and 16.3, will be displaced by the fluid flow into their first configurations, similar to that shown in Figure 5. A number of the fluid flow barriers 16 on the opposite, second side 42 of the plane 40, including the fluid flow barriers 16.4, 16.5, and 16.6, will be displaced into their second configurations, similar to that shown in Figure 3. Clearly, due to the higher drag resistance presented by the fluid flow barriers on the side 41 compared to those on the side 42, a torque will be exerted by the fluid flow on the carrier wheel 14.9, urging it to rotate in the direction of arrow 18. Clearly, the arrangement of the fluid flow barriers on the wheels 14 is highly variable and they may even overlap or be otherwise layered. The arrangement illustrated is clearly for example purposes only.

The shape and configuration of the fluid flow barriers of the collector rotor of the invention clearly are highly variable and the fluid flow barriers 16 are thus illustrated by way of example only. Many mechanical equivalents are possible. It will thus be appreciated that the invention extends to any collector rotor including the essential features of the collector rotor of the invention as defined herein, irrespective of the shape and configuration of its fluid flow barriers.

Figure 6 shows an electricity generation system 43, for generating electricity in accordance with the method of the third aspect of the invention, including a rotor 44, similar to the rotor 10 of Figures 1 and 2 and mounted with its rotational axis vertically disposed; an electricity generator unit 46 on which the rotor 44 is mounted; and a conical cap 48 mounted on top of the rotor 44

With wind of sufficient strength acting on the rotor 44 in any horizontal direction, it will be caused to rotate. Energy from the wind can thus be harvested and converted into electrical energy via the generator unit 46. The conical cap 48 serves to make the system 43 more closely resemble a bush or a tree, to enhance its aesthetic properties. In an alternative embodiment (not shown) of the collector rotor of the invention, such a cap may be provided with fluid flow barriers similar to the barriers 16, for enhancing the performance of the rotor. At least one such rotor may be provided for harvesting wind energy and a "forest" of such rotors may even be provided.

Figure 7 shows a part of an electricity generation system 49, for generating electricity in accordance with the method of the sixth or seventh aspect of the invention, in a land motor vehicle or water craft which includes an electric drive motor (not shown). The system 49 includes a collector rotor 50, which is similar to the rotor 10 of Figures 1 and 2 and which has been mounted with its rotational axis transverse with respect to the motor vehicle or craft. The direction of the forward motion of the motor vehicle or craft is indicated by the arrow 52. The system 49 includes a fluid duct 54 defining a frontal intake 56 which is exposed to fluid flow from the front of the vehicle or craft, during forward motion of the vehicle or craft. Such fluid flow entering the duct 54 is indicated by the arrows 58.

The motor vehicle may be a land vehicle, in which case the fluid flow is airflow. It may, alternatively, be a water craft, in which case the fluid flow may be water flow, the intake 56 being mounted below water level. The example will be proceeded with for a land vehicle, the water craft case being analogous and being reverted to briefly after the land vehicle example.

The duct 54 is tapered to direct air flow into the top half only of the rotor 50. Clearly, the effective cross-sectional area of the passage defined in the duct 54 in the vicinity of the rotor 49 is smaller than the area of the inlet 56. As such, the duct 54 converges the airflow towards one side of the rotor 50. The rotor 50 is orientated so that such air flow will induce rotation of the rotor in its forward direction of rotation, indicated again by an arrow 18. The rotor 50 is linked to a generator unit (not shown) of the system 49, which can generate electricity for powering the electric drive motor of the vehicle, either directly or via batteries. The Applicant envisages that an electricity generation system such as the system 49 may harvest energy from air flow relative to a motor vehicle to assist in powering the vehicle.

A variation of this system may be adapted for use with water craft, in which variation the ducting defines a water intake, operatively submerged in water on which the craft travels, and the rotor is driven by water flow.

In Figures 8 and 9, a further embodiment of a collector rotor, in accordance with the invention, is designated generally by the reference numeral 62. The collector rotor 62 has been mounted, via a base structure 64, on a sea bed 66.

With reference particularly to Figures 9 and 10, the collector rotor 62 includes an axle 68 and four identical fluid flow barrier carrier wheels 70 mounted on the axle. Each wheel 70 includes a hub 72, a rim 73, and eleven pairs of spokes 74, the spokes extending radially from the hub 72 and carrying the rim 73. The collector rotor 62 includes also eleven pairs of fluid flow barriers on each wheel 70, each in the form of a flap 76, the flaps being mounted on the respective spokes 74 of the relevant wheel.

One of the flaps 76 is shown in detail in Figure 1 1 . The flap 76 includes a flap formation 78, two passage defining formations 80, spaced apart along an edge of the flap formation 78 and defining therethrough aligned passages 82, and two stop formations 84, projecting from the passage defining formations 80.

With the flap 76 mounted on a wheel 70, as shown in Figure 10, a spoke 74 of a pair of spokes is disposed through the passages 82 of the flap so that the flap is pivotally displaceable with respect to the wheel between a first position, substantially perpendicular to the wheel, and a second position, substantially in the plane of the wheel.

In Figure 9, the flaps 76 at the top of the rotor 62 are in their first positions, the flaps 76 at the bottom of the rotor 62 in their second positions, and intermediate flaps in intermediate positions. In the first position of a flap 76, its stop formations 84 (see Figure 1 1 ) abut against the spoke 74 paired to the spoke on which the flap is pivotally mounted, thus preventing pivotal displacement of the flap beyond the first position.

With reference now again to Figure 8, the rotor 62 is particularly mounted with its rotational axis disposed transverse to the direction of travel of waves, one of which is shown and designated by the reference numeral 86, and substantially at the water level 88 in between waves. Forward motion of the wave 86 will constitute fluid flow which will act on the top half of the rotor 62, urging it to rotate it in its forward direction of rotation (see arrow 18). Backwash, indicated by an arrow 90, will act on the bottom half of the rotor 62, also urging it to rotate in its forward direction of rotation. The collector rotor 62 drives a generator unit (not shown), and the combination thus defines an electricity generation system for generating electricity in accordance with the method of the fifth aspect of the invention. In Figure 12, a collector rotor 92, similar to the collector rotor 62 of Figure

8, has been mounted, via a base structure 93, on a sea bed 94. The rotor 92 is submerged in water associated with tidal currents 96 which alternate with opposite tidal currents 98. The rotational axis of the rotor 92 is disposed horizontally and transverse to the direction of the tidal currents 96 and 98. A tidal current in either direction will induce rotation of the rotor 92 in its forward direction of rotation, as indicated again by an arrow

18. The collector rotor 92 drives a generator unit (not shown), and the combination thus defines an electricity generation system, for generating electricity in accordance with the method of the fourth aspect of the invention. Such a system may also be used in waters characterized by currents other than tidal currents, e.g. other types of sea currents.

In Figures 13 and 14, a further embodiment of a collector rotor (only a small part being shown), in accordance with the first aspect of the invention, is designated generally by the reference numeral 100. The collector rotor 100 is similar to the rotor 10 of Figures 1 and 2 in that it includes a similar axle and a similar arrangement of carrier wheels. As such, a particular carrier wheel of the rotor 100 is again designated by the reference numeral 14.9. Only a small part of this wheel is shown in section, the plane of the section being tangential to an imaginary round cylinder that is concentric with the rotational axis of the rotor 100. Instead of having flaps, as was the case with the rotor 10, each carrier wheel of the rotor 100 is covered on each of its opposite faces by an arrangement of fluid flow barriers in the form of resiliently flexible bristles 102, comprising a brush formation on each face of the wheel.

Using the wheel 14.9 as an example, each bristle 102 is secured at a root end thereof to the carrier wheel 14.9. With no fluid flow acting on the wheel 14.9, each bristle is in a rest position thereof (not shown) in which it is straight and in which its root end is its leading end and its free end its trailing end in relation to the direction of rotation of the rotor 100.

With reference to Figure 13, with fluid flow in the plane of the wheel 14.9 in the direction of arrow 104, generally in the reverse direction of the bristles 100 that are shown, the bristles are deflected towards the wheel, presenting low drag resistance. This is the second configuration of the bristles 102, as defined herein. With reference to Figure 14, with fluid flow in the plane of the wheel 14.9 in the direction of arrow 106, generally in the forward direction of the bristles 100 that are shown, the bristles are deflected away from the wheel, presenting high drag resistance. This is the first configuration of the bristles 100, as defined herein.

It will be understood that under fluid flow in the plane of the wheel 14.9, the bristles 102 on one side of a plane, parallel to the fluid flow and including the rotational axis of the rotor 100, will tend towards their first configurations, presenting high drag, and those on the other side of the plane will tend towards their second configurations, presenting low drag. A torque is thus exerted by the fluid flow on the wheel 14.9, urging the rotor 100 to rotate. The same applies to the other wheels.

Insofar as possible applications of the collector rotor 100 correspond to those of the collector rotor 10, they will not be repeated here.

In Figure 15, a part of a retractable wing-mounted undercarriage of an airplane is designated generally by the reference numeral 1 10. The part 1 10 includes suspension components 1 12 and two wheels 1 14.1 and 1 14.2 mounted on the suspension components. The wheels 1 14.1 and 1 14.2 include tyres 1 16.1 and 1 16.2, respectively, in accordance with the second aspect of the invention. The tyres 1 16.1 and 1 16.2 are identical and, as such, only the one tyre 1 16.1 will now be described in detail.

With reference particularly to Figure 16, the tyre 1 16.1 includes two opposite side walls of which only one, designated by the reference numeral 1 18.1 , is shown. The side wall 1 18.1 has an arrangement of fluid, particularly air, flow barriers in the form of flaps 120 provided on it, arranged in three concentric circles around the rotational axis of the wheel 1 16.1 . For the sake of simplicity, only the uppermost and lowermost flap 120 in each circle is shown in Figure 15, and then in outline only. It will be noted that the three flaps 120 at the bottom are shown to project further from the wheel 1 16.1 than the flaps 120 at the top and the reason for this will become apparent from the remainder of this description. The part of the tyre 1 16.1 comprising both the side wall 1 18.1 and the arrangement of flaps 120 is a further embodiment of a collector rotor, in accordance with the first aspect of the invention.

With reference now particularly to Figure 17, each flap 120 is particularly secured to the side wall 1 18.1 by being integrally formed, at a root end 122 thereof, with the side wall. The flaps 120 are made of reinforced rubber, as is the case with the side wall 1 18.1 , and are resiliently flexible. In alternative embodiments, such flaps may be made of another suitable material, e.g. possibly one of nylon, plastics, and so forth.

Each flap 120 is shown here in a second configuration, closely spaced to the side wall 1 18.1 . Each flap 120 is displaceable between this configuration and a first configuration, as shown in Figure 18, in which a free end 124 opposite to its root end 122 is displaced way from the side wall 1 18.1 . Each flap 120 is biased under its own resilience towards its second configuration.

With reference again particularly to Figure 16, the wheel 1 14.1 defines a forward rotational direction, indicated by an arrow 126. Each flap 122 defines a forward direction, being the direction in which it will be displaced relative to the rotational axis of the wheel 1 14.1 during forward rotation of the wheel, and an opposite reverse direction. By way of example, the forward directions of some of the flaps 120 are indicated by arrows 128 and the reverse directions of some by arrows 130.

Consider the airplane flying in the direction of an arrow 132 at a particular airspeed. The wheel 1 14.1 experiences airflow in the opposite direction, this direction being indicated by an arrow 134, of a magnitude equal to the airspeed. Consider now a plane 136 which includes the rotational axis of the wheel 1 14.1 and which is parallel to the arrows 132 and 134. The airflow in the direction of the arrow 134 urges at least some of the flaps 120 above the plane 136, i.e. on the upper half of the tyre 1 16.1 , at any instant, into their second configurations, as shown in Figure 17. Conversely, such airflow urges at least some of the flaps 120 below the plane 136, at any instant, i.e. on the lower half of the tyre 1 16.1 , into their first configurations, as shown in Figure 18. Clearly, the magnitude of the resultant of the drag forces exerted by the airflow on the flaps 120 above the plane 136 is smaller than that on the flaps 120 below the plane 136. A torque is thus exerted on the wheel 1 14.1 , urging it to rotationally accelerate in the direction of the arrow 126.

The tyre 1 16.1 has an arrangement of flaps 138 (see Figure 15), defining a mirror image of the arrangement of flaps 120, on its opposite side wall. These flaps 138 are optional, i.e. they may be omitted in other embodiments of the airplane tyre of the second aspect of the invention.

In the design of the tyre 1 16.1 , particularly that of its arrangements of flaps 120 and 138, an aim would be to achieve a minimal differential speed between the underside of the tyre and a runway upon touchdown, in use of the tyre. As such, wear of the tyre upon touchdown will be minimized.

In Figure 19, a further embodiment of an airplane tyre, in accordance with the second aspect of the invention, is designated generally by the reference numeral 140. The tyre 140 includes an arrangement of flaps 142, arranged in a single circle. This arrangement is identical to the outer circle of the arrangement of flaps 120 shown in Figures 15 and 16 and described above and, as such, is not described separately.

The tyre 140 may optionally include a similar arrangement of flaps on its opposite side wall.

In Figure 20, an embodiment of a collector rotor, in accordance with the first aspect of the invention, in the form of an accessory for an airplane tyre, is designated generally by the reference numeral 144. The accessory 144 includes an annular reinforced rubber base wall 146, which has an arrangement of flaps 148 integrally formed therewith.

Insofar as the properties of the arrangement of flaps 148 are substantially identical to those of the arrangement of flaps 120 of Figures 15 to 18, as described above, they will not be described separately. The base wall 146, in use of the accessory 144, is secured to a side wall of a conventional airplane tyre via a suitable method, e.g. adhesion via suitable adhesive or vulcanizing. With the accessory 144 operatively adhered to a side wall of a tyre of an airplane wheel, the accessory will serve to rotationally accelerate the wheel, as was the case with the tyre 1 16.1 described above. The accessory 144 may thus be used to convert a conventional airplane tyre into a mechanical equivalent of an airplane tyre such as the tyre 1 16.1 of Figures 15 and 16.

Figures 21 and 22 merely show alternative configuration flaps, designated by the reference numeral 150, which may serve in lieu of flaps such as the flaps 120 of Figures 13 to 16. The flaps 150 may, for example, be provided in an arrangement such as that of the flaps 120 in Figure 16 or the flaps 142 in Figure 19. The meaning of arrows 128, 130, and 134 in Figures 21 and 22 are the same as that of the corresponding arrows in Figures 17 and 18, as described above.

With reference particularly to Figure 21 , each flap 150 is secured to the side wall 152 of an airplane tyre via a resiliently elastic hinge formation 154. At the hinge formation 154, a groove 156 is defined between two opposite stop surfaces 158.

Under airflow in the direction of arrow 134 occurring in the reverse direction of a particular flap 150, the flap is biased by both the resilience of its hinge formation 154 and the airflow into its second configuration, as shown here, in which it presents low drag resistance.

With reference particularly to Figure 22, under airflow in the direction of arrow 134 occurring in the forward direction 128 of a particular flap 150, the flap is hingedly displaced into its first configuration, as shown here, in which it presents high drag resistance. Such displacement occurs against the resilience of the hinge formation 154. The limit position of such displacement is determined by the stop surfaces 158 abutting against each other. Insofar as the operation of an airplane tyre having been provided with the arrangement of flaps 150 would be similar to that of the airplane tyre 1 16.1 of Figures 15 to 18, as described above, it will not be described separately. Such an arrangement of flaps 150 may clearly form a part of either an airplane tyre or an accessory for an airplane tyre, as envisaged herein.

Preferably, all tyres on an airplane will be provided with arrangements of flaps, as envisaged herein, to operatively rotationally accelerate them before touchdown on a runway, with a view to minimizing wear of the tyres.

Claims

CLAIMS:

1 . A collector rotor which defines a forward direction of rotation, which includes an arrangement of fluid flow barriers, and in which the fluid flow barriers are arranged around the rotational axis of the rotor and each fluid flow barrier defines a forward direction, being the direction relative to the rotational axis in which the barrier is displaced during forward rotation of the rotor, and an opposite reverse direction; and each fluid flow barrier is displaceable between a first and a second configuration under action of fluid flow, the barrier particularly being configured so that fluid flow in its forward direction will urge it towards its first configuration, in which it defines a larger cross-section swept path and presents higher drag resistance against fluid flow, and so that opposite fluid flow will urge it towards its second configuration, in which it defines a smaller cross-section swept path and presents lower drag resistance against the fluid flow.

2. A collector rotor as claimed in claim 1 , which includes at least one carrier wheel carrying its fluid flow barriers and in which the wheel is disposed transverse to the rotational axis of the rotor and the fluid flow barriers are displaceable laterally with respect to the carrier wheel between their first and second configurations.

3. A collector rotor as claimed in claim 2, in which the carrier wheel carries an arrangement of fluid flow barriers, as defined in claim 1 , on each side thereof.

4. A collector rotor as claimed in any one of claims 2 and 3, in which each fluid flow barrier includes a flap of which a leading end is pivotally mounted on the carrier wheel, the pivot axis being at least substantially radially disposed with respect to the rotor; and the flap is pivotally displaceable about the pivot axis between a first and a second position, corresponding to the first and second configuration, respectively, of the fluid flow barrier.

5. A collector rotor as claimed in claim 4, in which, for increasing its drag resistance against fluid flow when in its first position, the flap is provided with two opposite collapsible gussets.

6. A collector rotor as claimed in any one of claims 2 and 3, in which the fluid flow barriers are resiliently flexible bristles defining a brush-like formation; and each bristle is secured at a root end thereof to the carrier wheel in a configuration in which it is biased under its own resilience towards a rest position thereof in which the root end is its leading end and its free end is its trailing end, according to the forward direction of rotation of the rotor.

7. A collector rotor as claimed in any one of claims 2 to 5, which includes an axle and a series of carrier wheels, as defined, spaced apart along the axle.

8. A collector rotor as claimed in claim 1 , which forms a part of an airplane tyre, including opposite side walls, and in which the rotational axis of the rotor coincides with the rotational axis of the tyre; the fluid flow barriers of the rotor are airflow barriers provided on at least one of the side walls of the tyre; the forward direction of rotation operatively corresponds to the direction of operative rotation of the tyre upon landing of an airplane on which it is mounted; and each airflow barrier is operatively displaceable between its first and second configurations under action of fluid flow in the form of airflow past the airplane upon approach to a runway for landing.

9. A collector rotor as claimed in claim 8, in which the airflow barriers are flaps.

10. A collector rotor as claimed in claim 9, in which each flap is secured at a root end thereof to a side wall of the tyre.

1 1 . A collector rotor as claimed in any one of claims 9 and 10, in which each flap is secured at a root end thereof to a side wall of the tyre by having the root end integrally formed with the side wall; airflow in the reverse direction of the flap urges the flap towards the side wall, towards the second configuration of the flap, so that the flap presents low drag resistance; and airflow in the forward direction of the flap urges the flap away from the side wall, towards the first configuration of the flap, so that the flap presents high drag resistance.

12. A collector rotor as claimed in claim 1 1 , in which the flaps define a scale-like arrangement and overlap each other.

13. A collector rotor as claimed in any one of claims 1 1 and 12, in which the flaps are resiliently flexible and each biased under its own resilience towards its second configuration.

14. A collector rotor as claimed in any one of claims 1 1 to 13, in which each flap is hingedly connected to a side wall of the tyre.

15. A collector rotor as claimed in 14, in which each flap is so connected via an elastic formation defining a resiliently flexible hinge, resiliently biasing the flap towards its second configuration.

16. A collector rotor as claimed in claim 1 , which is an accessory for an airplane tyre, the accessory including an annular base wall; the airflow barriers of the rotor are provided on the base wall; the base wall is securable to a side wall of an airplane tyre in a configuration in which the rotational axis of the rotor coincides with the rotational axis of the tyre, the forward direction of rotation operatively corresponds to the direction of operative rotation of the tyre to which the rotor is secured upon landing of an airplane on which the tyre is mounted; and each airflow barrier is operatively displaceable between its first and second configurations under action of fluid flow in the form of airflow past the airplane upon approach to a runway for landing.

17. A collector rotor as claimed in claim 16, in which the base wall is securable to a side wall of an airplane tyre via a suitable adhesive.

18. A collector rotor as claimed in claim 16, in which the base wall is made of rubber and securable to a side wall of an airplane tyre through vulcanizing.

19. An airplane tyre including a collector rotor as claimed in any one of claims 8 to 15.

20. A method of harvesting wind energy, which includes mounting a collector rotor, as claimed in any one of claims 1 to 7, in a location in which it is exposed to wind and driving an electricity generating device via the rotor.

21 . A method as claimed in claim 20, in which the rotor is mounted with its rotational axis at least substantially vertical.

22. A method of harvesting energy from water currents, which includes mounting a collector rotor, as claimed in any one of claims 1 to 7, on a suitable support and submerged in waters characterized by current, with its rotational axis transverse to the direction of the current; and driving an electricity generating device via the rotor.

23. A method of harvesting energy from sea wave action, which includes mounting a collector rotor, as claimed in any one of claims 1 to 7, on a suitable support in a wave region with its rotational axis disposed horizontally, transverse with respect to the direction of wave travel, and at a level permitting the waves to act on the upper fluid flow barriers and reverse current to act on the lower fluid flow barriers; and driving an electricity generating device via the rotor.

24. A method of harvesting energy from air flow caused by forward motion of a vehicle, which includes mounting a collector rotor, as claimed in any one of claims 1 to 7, in a location on a vehicle in which it is exposed to airflow caused by forward motion of the vehicle; and driving an electricity generating device via the rotor.

25. A method as claimed in claim 24, which includes using energy generated by the device in powering a drive motor of the vehicle.

26. A method as claimed in claim 24 or in claim 25, which includes providing ducting, defining a frontal air intake, for channelling the air flow to one side of the rotor for optimal driving of the rotor.

27. A method of harvesting energy from water flow caused by forward motion of a water craft, which includes mounting a collector rotor, as claimed in any one of claims 1 to 8, in a location on a water craft in which it is exposed to water flow caused by forward motion of the craft; and driving an electricity generating device via the rotor.

28. A method as claimed in claim 27, which includes using energy generated by the device in powering a drive motor of the craft.

29. A collector rotor as claimed in claim 1 , substantially as herein described with reference to and as illustrated in the accompanying diagrammatic drawings.

30. An airplane tyre as claimed in claim 19, substantially as herein described with reference to and as illustrated in the accompanying diagrammatic drawings.

31 . A method as claimed in any one of claims 20, 22, 23, 24, and 27, substantially as herein described with reference to and as illustrated in the accompanying diagrammatic drawings.