WO2011147000A1

WO2011147000A1 - Magnetic assemblies

Info

Publication number: WO2011147000A1
Application number: PCT/AU2011/000645
Authority: WO
Inventors: Andrew Boyd French; Christopher Bremner; Radu Iliuta
Original assignee: Andrew Boyd French; Christopher Bremner; Radu Iliuta
Priority date: 2010-05-28
Filing date: 2011-05-30
Publication date: 2011-12-01

Abstract

Disclosed is an apparatus for inducing drive, the apparatus comprising an inner element having an outer edge, an outer element having an inner edge adapted to be positioned around the inner element, the inner element and outer element being rotatable with respect to one another about an axis; rotation of the inner element with respect to the outer element being effected by repulsive or attractive magnetic forces between the outer edge of the inner element and the inner edge of the outer element.

Description

MAGNETIC ASSEMBLIES

Field of the Disclosure The present application relates to magnetic drive and coupling assemblies. The assemblies utilise a magnetic element or elements to induce drive in rotatable objects, to couple objects and to provide suspension. The

assemblies have broad use in drive induction applications for all manner of rotatable objects, in coupling

applications and in application requiring mechanical suspension .

Background Art

Known methods of driving rotatable objects and elements include various couplings attaching the rotatable object to a motor or engine, including pulley belts, chains, gears, discs, cogs, diaphragms and viscous fluid type couplings. There are many problems associated with mechanical couplings, such as the requirement for periodic lubrication of gears, the close alignment requirements for the mechanical couplings, particularly for disc, diaphragm and hydraulic couplings, and the limited life of elastomer and rubber element couplings. Energy losses in the form of friction and heat loss can be considerable in such apparatus .

Known methods of coupling require periodic lubrication, close alignment requirements and involve substantial wear on the couplings. Similarly, known methods of providing suspension require lubrication, close alignment of mechanical elements, and significant wear on the suspension. Further heat loss can be considerable. Summary of the Invention

Disclosed is an apparatus for inducing drive, the

apparatus comprising an inner element having an outer edge, an outer element having an inner edge adapted to be positioned around the inner element, the inner element and outer element being rotatable with respect to one another about an axis; rotation of the inner element with respect to the outer element being effected by repulsive or attractive magnetic forces between the outer edge of the inner element and the inner edge of the outer element.

In one form the inner element comprises a plurality of blades and the outer edge comprises a tip section of at least a portion of the plurality of blades.

In one form the outer edge of the inner element comprises a ring shaped magnetic array.

In one form the outer edge of the inner element and the outer element are ring shaped and are adapted to be positioned concentrically such that the inner element is positioned within the outer element.

In one form the inner element comprises an impeller.

In one form the inner element comprises a driven element and the outer element comprises a drive element, the outer element being operatively engaged with a motor to provide rotational drive. In a second aspect, disclosed is an apparatus for inducing drive in a propeller having blades, the apparatus

comprising a drive ring engaged with or integral to the blades of the propeller, such that rotation of the drive ring effects rotation of the propeller, at least one drive element, positioned such that rotation of the drive element about an axis effects rotation of the propeller by repulsive or attractive magnetic forces between the drive element and the drive ring.

In a third aspect, disclosed is apparatus for driving a wheel, the wheel having an outer circumference for contact with a surface and an inner circumference, the apparatus comprising a drive element positioned such that rotation of the drive element about an axis effects rotation of the propeller by repulsive or attractive magnetic forces between the drive element and the inner surface.

In a fourth aspect, disclosed is an apparatus for

transferring drive from a propeller to a drive shaft, the apparatus comprising a drive ring associated with the propeller such that rotation of the propeller causes the ring to rotate about a central axis and a drive element rotatable about an axis, wherein rotation of the drive ring about an axis effects rotation of the drive element by repulsive or attractive magnetic forces between the drive element and the drive ring.

One advantage of the present drive assembly over those known in the art is the minimal frictional or heat losses. Another advantage is the reduction in wear and lubrication required. Brief Description of the Drawing

Notwithstanding any other forms which may fall within the scope of the present disclosure, preferred forms will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a magnetic drive assembly of one embodiment of the present application;

Figure 2 is a cross-sectional view of the drive assembly of Figure 1;

Figure 3 is a perspective view of a second embodiment of a magnetic drive assembly;

Figure 4 is a detail view of the assembly of Figure 3;

Figure 5 is a front view of the assembly of Figure 3 ;

Figure 6 is a perspective view of a drive assembly of one embodiment of the present application;

Figure 7 is a detail view of the drive assembly of Figure 6;

Figure 8 is a detail view of the drive assembly of Figure 6; Figure 9 is an exploded view of a portion of the drive assembly of Figure 6;

Figure 10 is a drive assembly of one embodiment of the present application;

Figure 11 is a front view of the drive assembly of Figure 10;

Figure 12 is a rear perspective view of the drive assembly of Figure 10;

Figure 13 is a magnetic coupler of one form of the present application;

Figure 14 is an exploded view of the magnetic coupler of Figure 13; Figure 15 is a detail view of the coupler of Figure 13;

Figure 16 is a detail view of a second embodiment of a coupler ; Figure 17 is a perspective view of a coupler of another embodiment of the present invention;

Figure 18 is a perspective view of a suspension system of one embodiment of the present invention;

Figure 19 is a cross-sectional perspective view of the suspension system of Figure 18.

Preferred Embodiments

Referring to Figures 1 through 5, disclosed is an

apparatus for inducing drive. In this case the apparatus 1 is particularly directed towards inducing drive in an impeller 2. The impeller is adapted to rotate about an axis 3 and is specifically for use as a propeller in a submarine or other water vehicle. However, it should be noted that the drive apparatus can be adapted for use in any assembly requiring an impeller.

The drive assembly further comprises a drive element 5 which is shaped to be positioned about the impeller 2. The impeller 2 extends from the axis 3 to a tip section 4 which is engaged with a drive ring 7. In the illustrated embodiment the tip section 4 is integral to the drive ring 7. Rotary movement of the ring 7 about axis 3 results in rotation of the impeller 2 about axis 3.

The impeller 2 is shaped as a plurality of blades 8 for impelling movement of water through the assembly 1.

The assembly 1 further comprises a plurality of drive elements 10. Each drive element comprises a motor 11 engaged with a magnetic drive 12. The magnetic drive 12 is cylindrical and incorporates a plurality of magnets 14 positioned on its circumference.

The outer ring 7 of the impeller 2 incorporates a

plurality of magnets 18 in an array positioned on its outer surface. Rotation of the drive element 12 about axis 13 results in rotary movement of the drive ring 7 about axis 3. This rotation is driven by motor 10. The rotation of drive ring 7 about axis 3 effects rotation of impeller 2 about axis 3, thus resulting in propulsion of any vehicle attached with the drive assembly.

In use, the hull cavity of a vehicle is enclosed and the magnetic drive 12 and its motor 10 are positioned in the hull cavity. The pressure inside the hull cavity can be adjusted so that it matches the water pressure. The impeller 2 and drive ring 7 are positioned outside the hull.

The impeller does not have a drive shaft, but instead rotates about axis 3 on which the impeller 2 is

positioned .

The magnetic array 14 on the drive element 12 may consist of magnets polarised in varying directions as in a

Hallbach array. This concentrates the strength of the magnetic field in one direction. In this form a metal piece 15 is positioned between the magnets 18 to provide attraction to stabilise the axial load upon the drive ring 7 and to provide additional torque.

The use of multiple motors adds a redundancy in case of failure of a motor. The propeller is therefore driven by the tip region 4 of the impeller which reduces the movement of the propeller tip and therefore reduces the irregularity in the rotation of the propeller.

The drive assembly can be utilised in a windmill in which case the drive is coming from the drive ring 7 and driving the drive element 12 about axis 13. In this form, as shown in Figures 6 through 9, a drive ring 20 is engaged with the windmill blades 21.

The drive ring 20 incorporates an array of magnets 23 which interact with a complementary array 24 on generator 25. The drive ring 20 and the driven magnetic array 24 do not come in contact, rather attractive or repulsive forces between the drive ring 20 and the driven magnetic array 24 cause rotation of 24 about an axis extending through the generator 25. The magnets in the array can be polarised in one direction or can be polarised in various directions to allow for a Hallbach array.

Further generators (not illustrated) can be affixed with the stand 26 of the windmill to increase power output.

The set up allows for 90° transfer of energy, removing the need for a gearbox in the system.

Referring to Figures 10 through 12, a further example is shown where magnetic drives 30 impel tyre 31.

In this form the magnetic drives 30 include magnets 33 located on the circumference of the drive. A motor is utilised to rotate the magnetic drives 30 about a central longitudinal axis 34. The tyre 31 includes an array of magnets 35 positioned in the inner circumference of the tyre. Attractive or repulsive forces between drive magnets 33 and driven magnets 35 cause the tyre to rotate about an axis extending through its centre point upon rotation of the magnetic drives 30. Figures 13 through 16 disclose a magnetic coupler comprising a body 40 which is engaged with a plurality of magnets 41 held in place in the outer ring 41 by protrusions 43. In this form the magnets are positioned in an aluminium extrusion 44. The aluminium extrusion 44 includes magnets 45 extending therefrom and held therein by protrusions 46.

Rotation of either aluminium extrusion 44 or outer ring 40 results in rotation of the complementary ring.

In a further embodiment shown in Figure 17 is a mini- coupler magnets 60 which are wedged in a wheel shaped housing 62. The magnets 60 extend beyond the

circumference of the housing 62. A sleeve 64 is pressed over the circumference of the housing 62 such that the magnets 60 are wedged in place within the housing 62. In one form the sleeve 64 is made of stainless steel and it is fractionally smaller than the housing to press the magnets into the housing 62. The magnets are wedge-shaped to allow Morse locking, the wedge having an angle of 4-10° to lock the magnets in position. The steel sleeve 64 counteracts centrifugal forces that are created by rotation of the housing. The coupler 59 further comprises a second housing and magnet array 66 which in use is positioned to face the first housing and magnet array to allow for magnetic coupling. Figures 18 and 19 show a suspension system in which an outer ring 70 is polarised in one direction while an inner ring 71 is polarised in the opposite direction. The inner ring 71 is adapted to fit within the outer ring. Pressure on the inner ring 71 to force it into the interior cavity 72 of the outer ring 70 is resisted by the polarity of the inner member 71, creating suspension in response to pressure on the inner ring 71.

In the claims which follow and in the preceding summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", that is the features specified may be associated with further features in various embodiments of the invention. Variations and modifications may be made to the parts previously described without departing from the spirit or ambit of the invention.

Claims

1. An apparatus for inducing drive, the apparatus

comprising :

an inner element having an outer edge,

an outer element having an inner edge adapted to be positioned around the inner element, the inner element and outer element being rotatable with respect to one another about an axis;

rotation of the inner element with respect to the outer element being effected by repulsive or

attractive magnetic forces between the outer edge of the inner element and the inner edge of the outer element.

2. An apparatus as defined in claim 1, wherein the inner element comprises a plurality of blades and the outer edge comprises a tip section of at least a portion of the plurality of blades.

3. An apparatus as defined in claim 1, wherein the outer edge of the inner element comprises a ring shaped magnetic array.

4. An apparatus as defined in any of the preceding claims, wherein the outer edge of the inner element and the outer element are ring shaped and are adapted to be positioned concentrically such that the inner element is positioned within the outer element.

5. An apparatus as defined in any of the preceding claims, wherein the inner element comprises an impeller.

6. An apparatus as defined in any of the preceding claims, wherein the inner element comprises a driven element and the outer element comprises a drive element, the outer element being operatively engaged with a motor to provide rotational drive.

7. An apparatus for inducing drive in a propeller having blades, the apparatus comprising a drive ring engaged with or integral to the blades of the propeller, such that rotation of the drive ring effects rotation of the propeller, at least one drive element, positioned such that rotation of the drive element about an axis effects rotation of the propeller by repulsive or attractive magnetic forces between the drive element and the drive ring.

8. An apparatus for driving a wheel , the wheel having an outer circumference for contact with a surface and an inner circumference, the apparatus comprising a drive element positioned such that rotation of the drive element about an axis effects rotation of the propeller by repulsive or attractive magnetic forces between the drive element and the inner surface.

9. An apparatus for transferring drive from a propeller to a drive shaft, the apparatus comprising a drive ring associated with the propeller such that rotation of the propeller causes the ring to rotate about a central axis and a drive element rotatable about an axis, wherein rotation of the drive ring about an axis effects rotation of the drive element by repulsive or attractive magnetic forces between the drive element and the drive ring .