SYSTEM AND METHOD USING INTERNAL CANCELLATION MAGNETS TO CONTROL MAGNETIC WHEEL ADHESION

A system and method control magnetic adhesion of a wheel to a surface using internal cancellation magnets. An inner annular disc of the wheel comprises a non-magnetic material and has first and second apertures which retain magnets while an outer annular disc comprises a ferromagnetic material and is disposed on a side of the inner annular disc and has a non-magnetic isolator ring which extends in a serpentine manner. In one configuration, the curves of the serpentine isolator ring isolate the first magnets from the second magnets. In another configuration, the outer annular disc rotates relative to the inner annular disc to dispose the curves of the serpentine isolator ring in a second position to allow magnetic interaction between the first and second magnets to generate a second magnetic flux between the second magnets and the ferromagnetic surface to thereby decrease the adhesion of the wheel to the ferromagnetic surface.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to magnetized wheels, and, more particularly, to a system and method using internal cancellation magnets to control magnetic adhesion of a wheel to a ferromagnetic surface.

BACKGROUND OF THE DISCLOSURE

Magnetic wheels enable vehicles to climb and drive on ferromagnetic structures. For example, an unmanned aerial vehicle (UAV) can fly to a point on a ferromagnetic structure, perch at that point, and utilize magnetic wheels to adhere to the ferromagnetic structure. The magnetic adhesion is the result of magnetic flux passing through the surface from the magnet north pole to the magnetic south pole of a magnet in the wheel. Having a strong magnetic grip to the ferromagnetic surface is essential to prevent the vehicle from disengaging inadvertently and from falling from the ferromagnetic surface. However, a strong pulling force is required to overcome the magnetic adhesion to disengage the vehicle from the ferromagnetic surface. In order to enable vehicles to obtain a strong magnetic grip as well as easy disengagement, incorporation of a magnetic switch into the wheel is desirable.

SUMMARY OF THE DISCLOSURE

According to an embodiment consistent with the present disclosure, a system and method using internal cancellation magnets to control magnetic adhesion of a wheel to a ferromagnetic surface.

In an embodiment, a wheel configured to adhere magnetically to a ferromagnetic surface, comprising an inner annular disc and a pair of outer annular discs. The inner annular disc is composed of a non-magnetic material and has a first outer circumferential periphery, a first central axial bore, a first plurality of apertures, and a second plurality of apertures. The first central axial bore is configured to retain an axle. The first plurality of apertures is disposed adjacent to the first central axial bore and configured to retain a first plurality of magnets. The second plurality of apertures disposed adjacent to the outer circumferential periphery and configured to retain a second plurality of magnets.

The pair of outer annular discs are composed of a ferromagnetic material and are disposed on either side of the inner annular disc. Each outer annular disc has a second outer circumferential periphery, a second central axial bore, an inner circumferential periphery, and an isolator ring. The second central axial bore is configured to retain an axle. The inner circumferential periphery is disposed adjacent to the second central axial bore. The isolator ring is composed of a non-magnetic material and defines a plurality of curves extending in a serpentine manner circumferentially around the inner circumferential periphery intermediate of the second outer circumferential periphery and the second central axial bore, with the curves of the serpentine isolator ring disposed between the inner circumferential periphery and the second outer circumferential periphery. In a first configuration, the curves of the serpentine isolator ring are disposed in a first position relative to the second plurality of magnets to isolate the first plurality of magnets from the second plurality of magnets, thereby generating a first magnetic flux between the second plurality of magnets and the ferromagnetic surface to increase the adhesion of the wheel to the ferromagnetic surface. In a second configuration, at least one outer annular disc is rotated about the axle relative to the inner annular disc to dispose the curves of the serpentine isolator ring in a second position relative to the second plurality of magnets to allow magnetic interaction between the first plurality of magnets and the second plurality of magnets, thereby generating a second magnetic flux between the second plurality of magnets and the ferromagnetic surface to decrease the adhesion of the wheel to the ferromagnetic surface. The second magnetic flux is less than the first magnetic flux.

Each of the first plurality of magnets has a first polarity, and each of the second plurality of magnets has a second polarity opposite to the first polarity. In the second configuration, the first plurality of magnets at least partially cancels the magnetic flux of the second plurality of magnets. The first plurality of magnets are permanent magnets. The second plurality of magnets are permanent magnets. The first and second pluralities of apertures are cylindrical. The first and second pluralities of magnets are cylindrical.

In another embodiment, a wheel is configured to adhere magnetically to a ferromagnetic surface, and comprises a first annular disc and a second annular disc. The first annular disc is composed of a non-magnetic material and has a first outer circumferential periphery, a first central axial bore, a first plurality of apertures, and a second plurality of apertures. The first central axial bore is configured to retain an axle. The first plurality of apertures are disposed adjacent to the first central axial bore and are configured to retain a first plurality of magnets. The second plurality of apertures are disposed adjacent to the outer circumferential periphery and are configured to retain a second plurality of magnets.

The second annular disc is composed of a ferromagnetic material and is disposed on one side of the first annular disc, with the outer annular disc having a second outer circumferential periphery, a second central axial bore, an inner circumferential periphery, and an isolator ring. The second central axial bore is configured to retain an axle. The inner circumferential periphery is disposed adjacent to the second central axial bore. The isolator ring is composed of a non-magnetic material and defines a plurality of curves extending in a serpentine manner circumferentially around the inner circumferential periphery intermediate of the second outer circumferential periphery and the second central axial bore, with the curves of the serpentine isolator ring disposed between the inner circumferential periphery and the second outer circumferential periphery. In a first configuration, the curves of the serpentine isolator ring are disposed in a first position relative to the second plurality of magnets to isolate the first plurality of magnets from the second plurality of magnets, thereby generating a first magnetic flux between the second plurality of magnets and the ferromagnetic surface to increase the adhesion of the wheel to the ferromagnetic surface. In a second configuration, the second annular disc is rotated about the axle relative to the first annular disc to dispose the curves of the serpentine isolator ring in a second position relative to the second plurality of magnets to allow magnetic interaction between the first plurality of magnets and the second plurality of magnets, thereby generating a second magnetic flux between the second plurality of magnets and the ferromagnetic surface to decrease the adhesion of the wheel to the ferromagnetic surface. The second magnetic flux is less than the first magnetic flux.

Each of the first plurality of magnets has a first polarity, and each of the second plurality of magnets has a second polarity opposite to the first polarity. In the second configuration, the first plurality of magnets at least partially cancels the magnetic flux of the second plurality of magnets. The first plurality of magnets are permanent magnets. The second plurality of magnets are permanent magnets. The first and second pluralities of apertures are cylindrical. The first and second pluralities of magnets are cylindrical.

In a further embodiment, a method of adhering a wheel magnetically to a ferromagnetic surface comprises providing a wheel having a first annular disc and a second annular disc, wherein the first annular disc is composed of a non-magnetic material and has a first outer circumferential periphery, a first central axial bore, a first plurality of apertures, and a second plurality of apertures. The first central axial bore is configured to retain an axle. The first plurality of apertures are disposed adjacent to the first central axial bore and are configured to retain a first plurality of magnets. A second plurality of apertures is disposed adjacent to the outer circumferential periphery and is configured to retain a second plurality of magnets. The second annular disc is composed of a ferromagnetic material and is disposed on one side of the first annular disc, with the outer annular disc having a second outer circumferential periphery, a second central axial bore, an inner circumferential periphery, and an isolator ring. The second central axial bore is configured to retain an axle. The inner circumferential periphery is disposed adjacent to the second central axial bore. The isolator ring is composed of a non-magnetic material and defines a plurality of curves extending in a serpentine manner circumferentially around the inner circumferential periphery intermediate of the second outer circumferential periphery and the second central axial bore, with the curves of the serpentine isolator ring disposed between the inner circumferential periphery and the second outer circumferential periphery.

The method also comprises disposing the first and second annular discs in a first configuration wherein the curves of the serpentine isolator ring are disposed in a first position relative to the second plurality of magnets, isolating the first plurality of magnets magnetically from the second plurality of magnets, and generating a first magnetic flux between the second plurality of magnets and the ferromagnetic surface thereby increasing the adhesion of the wheel to the ferromagnetic surface.

The method further comprises disposing the first and second annular discs in a second configuration, wherein the second annular disc is rotated about the axle relative to the first annular disc, disposing the curves of the serpentine isolator ring in a second position relative to the second plurality of magnets, allowing magnetic interaction between the first plurality of magnets and the second plurality of magnets, and generating a second magnetic flux between the second plurality of magnets and the ferromagnetic surface to decrease the adhesion of the wheel to the ferromagnetic surface, wherein the second magnetic flux is less than the first magnetic flux.

Each of the first plurality of magnets has a first polarity, and each of the second plurality of magnets has a second polarity opposite to the first polarity. The first plurality of magnets are permanent magnets. The second plurality of magnets are permanent magnets. The first and second pluralities of apertures are cylindrical.

It is noted that the drawings are illustrative and are not necessarily to scale.

Example embodiments consistent with the teachings included in the present disclosure are directed to a system and method using internal cancellation magnets to control magnetic adhesion of a wheel to a ferromagnetic surface.

Referring toFIGS.1-9, the wheel10is configured to roll on a surface12. Using the system and method described below, when the surface12is ferromagnetic, a magnetic flux generated by the wheel10can be controlled to increase or decrease magnetic adhesion of the wheel10to the ferromagnetic surface12. As shown inFIGS.1-2, the wheel10has an inner disc14having a pair of planar sides16. The inner disc14is composed of a non-magnetic material. For example, the inner disc14can be composed of plastic. The inner disc14is generally annular with a central axial bore18partially surrounded by a disc retainer20,22extending perpendicularly from at least one of the planar sides16. The central axial bore18is configured to receive an axle to roll the wheel10about the axle on the surface12. A plurality of apertures24,26extend perpendicularly and at least partially into at least one of the planar sides16. A first plurality of apertures24are disposed adjacent to the first central axial bore and configured to retain a first plurality of magnets28as inner magnets. A second plurality of apertures26are disposed adjacent to the outer circumferential periphery and configured to retain a second plurality of magnets30as outer magnets. The magnets28,30are sized and dimensioned to be retained in the respective apertures24,26. In an example embodiment, the apertures24,26are cylindrical, and the magnets28,30are also cylindrical.

The wheel10also has at least one outer disc32,34disposed adjacent to a respective planar side of the inner disc14. Each outer disc32,34is composed of a ferromagnetic material. For example, each outer disc32,34can be composed of steel. Alternatively, each outer disc32,34can be composed of nickel. In another alternative embodiment, each outer disc32,34can be composed of cobalt. The outer disc32,34can also be composed of other ferromagnetic materials. Each outer disc32,34has a central axial bore36configured to receive a respective disc retainer20,22through which an axle passes. The central axial bore36of each outer disc32,34has a rotation stopper38for engaging radial sides40,42of a respective disc retainer20,22. The radial sides40,42limit the rotation of each outer disc32,34relative to the inner disc14to a predetermined angle. The predetermined angle is equal to 180°/(the number of outer magnets on an outer circumferential periphery of the inner disc). For example, in an embodiment with eight outer magnets, the predetermined angle can be about 180°/8, which is about 22.5°. Using a different number of outer magnets would change the predetermined angle. For example, for ten outer magnets, the rotation angle can be about 180°/10, which is about 18°. It is also understood that other sizes and dimensions of the outer diameters of the discs as well as the aperture sizes are contemplated.

Referring again toFIGS.1-2, each outer disc32,34has an outer circumferential periphery44and an inner circumferential periphery46disposed adjacent to the central axial bore36. An isolator ring48composed of a non-magnetic material and defining a plurality of curves extends in a serpentine manner circumferentially around the inner circumferential periphery46intermediate of the outer circumferential periphery44and the central axial bore36, with the curves of the serpentine isolator ring48disposed between the inner circumferential periphery46and the outer circumferential periphery44. The isolator ring48can be composed of plastic.

As described above, rotation of each outer disc32,34can be performed relative to the inner disc14to within a predetermined angle.FIG.3illustrates outer discs32,34of the wheel10rotating in a common direction relative to the inner disc14. As shown inFIG.3, the inner disc14can be motionless as the outer discs32,34rotate in a common direction.FIG.4illustrates the outer discs32,34of the wheel10rotating in opposite directions relative to the inner disc14. As shown inFIG.4, the inner disc14can be motionless as the outer discs32,34rotate in opposite directions.FIG.5illustrates the inner disc14of the wheel10rotating relative to both of the outer discs32,34. As shown inFIG.5, the inner disc14can be rotated as the outer discs32,34remain motionless.

Regardless of the absolute motion of the inner disc14and the outer discs32,34, the relative motion of the discs14,32,34changes the wheel10from a first configuration, as shown inFIGS.6-7, to a second configuration, as shown inFIG.8-9. In the first configuration, the curves of the serpentine isolator ring48are disposed in a first position relative to the second plurality of magnets30to isolate the first plurality of magnets28from the second plurality of magnets30, thereby generating a first magnetic flux50between the second plurality of magnets and the ferromagnetic surface12to increase the adhesion of the wheel to the ferromagnetic surface12. A weaker magnetic flux52is also generated. An air gap54is formed between the inner disc14and the ferromagnetic surface12.

In the second configuration, at least one outer annular disc32,34is rotated about the axle relative to the inner annular disc14to dispose the curves of the serpentine isolator ring48in a second position relative to the second plurality of magnets30to allow magnetic interaction between the first plurality of magnets28and the second plurality of magnets30, thereby generating a second magnetic flux56between the second plurality of magnets30and the ferromagnetic surface12to decrease the adhesion of the wheel10to the ferromagnetic surface12. A stronger magnetic flux58is also generated between the magnets28,30. However, the second magnetic flux56is less than the first magnetic flux50shown inFIG.7, so there is less adhesion of the wheel10to the ferromagnetic surface12.

As shown inFIG.10, a method100includes the step of providing the wheel10in step110, with the wheel10having a first annular disc retaining first and second magnets, and having a second annular disc with a serpentine isolator ring. The method100then disposes the first and second annular discs in a first configuration in step120with curves of the serpentine isolator ring in a first position relative to the magnets. The method100then isolates the first magnets from the second magnets in step130, and generates a first magnetic flux between the second magnets and a ferromagnetic surface in step140to increase the adhesion of the wheel to the ferromagnetic surface. The method100then rotates the second annular disc relative to the first annular disc to be in a second configuration in step150, and disposes the curves of the serpentine isolator ring in a second position in step160. The method100then allows magnetic interaction between the first and second magnets in step170, and generates a second magnetic flux between the second magnets and the ferromagnetic surface in step180, with the second magnetic flux being less than the first magnetic flux. The method100then decreases the adhesion of the wheel to the ferromagnetic surface in step190.

Portions of the methods described herein can be performed by software or firmware in machine readable form on a tangible (e.g., non-transitory) storage medium. For example, the software or firmware can be in the form of a computer program including computer program code adapted to cause the system to perform various actions described herein when the program is run on a computer or suitable hardware device, and where the computer program can be embodied on a computer readable medium. Examples of tangible storage media include computer storage devices having computer-readable media such as disks, thumb drives, flash memory, and the like, and do not include propagated signals. Propagated signals can be present in a tangible storage media. The software can be suitable for execution on a parallel processor or a serial processor such that various actions described herein can be carried out in any suitable order, or simultaneously.

It is to be further understood that like or similar numerals in the drawings represent like or similar elements through the several figures, and that not all components or steps described and illustrated with reference to the figures are required for all embodiments or arrangements.

Terms of orientation are used herein merely for purposes of convention and referencing and are not to be construed as limiting. However, it is recognized these terms could be used with reference to an operator or user. Accordingly, no limitations are implied or to be inferred. In addition, the use of ordinal numbers (e.g., first, second, third) is for distinction and not counting. For example, the use of “third” does not imply there is a corresponding “first” or “second.” Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

While the disclosure has described several exemplary embodiments, it will be understood by those skilled in the art that various changes can be made, and equivalents can be substituted for elements thereof, without departing from the spirit and scope of the invention. In addition, many modifications will be appreciated by those skilled in the art to adapt a particular instrument, situation, or material to embodiments of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, or to the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.