MAGNETICALLY LEVITATED AXLELESS WHEEL SYSTEM

SYSTEME DE ROUE SANS MOYEU A SUSTENTATION MAGNETIQUE

English Abstract

A magnetically levitated axleless wheel system provides
infinite degrees of freedom in horizontal movement. The
spherical rotor assembly comprises a plurality of permanent
magnets which are arranged so as to expose the same polarity on
the entire surface of the rotor assembly facing the stator
assembly. The concave stator assembly comprises permanent or
electro-magnets which are arranged so as to expose the same
polarity on the entire surface of the stator assembly facing the
rotor assembly. The magnetic repulsion force between the rotor
assembly and the stator assembly produces an air-gap which permits
omni-directional horizontal movement of the axleless wheel system.
This invention relates to magnetic levitation, and the principal
use of the invention is for friction-less transport, cushion and
suspension devices.

French Abstract

Roue sans essieu à suspension magnétique fournissant un mouvement horizontal d'une grande liberté. Le rotor sphérique comprend de nombreux aimants permanents qui sont placés afin d'exposer la même polarité sur toute la surface du rotor qui fait face au stator. Le stator concave comprend des aimants permanents ou des électro-aimants qui sont placés de façon à exposer la même polarité sur toute la surface du stator qui fait face au rotor. La force de répulsion magnétique entre le rotor et le stator produit un espace d'air qui permet un mouvement horizontal omnidirectionnel de la roue sans essieu. L'invention inclut la suspension magnétique et sert principalement dans les dispositifs d'amortissement, de suspension et de transport sans friction.

Claims

Claims
The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:
1. A magnetic levitation system for supporting a body for
movement, comprising in combination:
a spherical rotor assembly having an exterior surface and
an interior void, the spherical rotor comprising a plurality of
permanent magnetic units so as to expose only one polarity on the
exterior surface, the spherical rotor having a plurality of gaps
between the permanent magnetic units in order to provide return
paths of magnetic flux lines from the exterior surface of the
spherical rotor to the interior void of the spherical rotor; and
a concave stator assembly in the form of a rod having one
end defining a concave hole, longitudinally magnetised on the
exterior surface so as to expose one polarity on one end of the
rod;
positioned to exert repulsive force upon one another, the concave
stator assembly partly enveloping the spherical rotor assembly
permitting friction-free rotation in an axleless configuration.
2. A magnetic levitation system as defined in claim 1, in which
the rotor assembly is positioned below the stator assembly to
touch a floor in order to support a mass connected to the stator
assembly, permitting the translational movement of the magnetic
levitation system in any horizontal direction.
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3. A magnetic levitation system as defined in claim 2, in which
a means for braking, comprising a hole at the centre of the stator
assembly and a rod made of non-magnetic material inserted into the
hole, is provided to permit a slow-down of the speed of rotation
of the rotor assembly by surface friction.
4. A magnetic levitation system as defined in claim 1, in which
the rotor assembly has a shaft at the top securely connected to
the rotor, arranged so that the stator assembly is positioned
below the rotor assembly in order to support a mass connected to
the rotor assembly.
5. A magnetic levitation system as defined in claim 1, in which
the stator assembly has a hole at the bottom, and the rotor
assembly has a wire at the bottom securely connected to the rotor,
arranged so that the stator assembly is positioned below the rotor
assembly in order to support a mass connected to the rotor
assembly.
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Description

CA 02190298 2001-03-14
Description
Title
Magnetically Levitated Axleless Wheel Systems
Technical Field
This invention relates to magnetic levitation, more
particularly to a magnetically levitated wheel system..
Background Art
There are many instances where it would be desirable to be
able to move a body with a minimum amount of friction.
A large number of patents disclose magnetic levitation
systems for transportation and magnetic bearing systems for
industrial applications in order to support essentially
friction-free translational or rotational movement.
These prior art arrangements have either flat or cylindrical
configuration. Such support systems provide no resting position,
or require a guard-rail to keep the movable body in position,
restricting the movement to pre-determined translation or
rotation. In addition, the magnetically levitated system of flat
configuration requires stationary magnets embedded in a track.
Description of the Invention
It is a primary object of the invention to provide an
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CA 02190298 2001-03-14
axleless wheel system that provides a support for mass and
friction-free translational movement with infinite degrees of
freedom in horizontal direction by means of magnetic levitation.
It is another object of the invention to provide cushion and
suspension by inverting the axleless wheel arrangement.
One aspect of the invention provides a magnetically levitated
axleless wheel system comprising a spherical rotor assembly and a
hemispherical stator assembly. The spherical rotor assembly
comprises a plurality of permanent magnets which are arranged so
as to expose the same polarity on the entire surface of the rotor
assembly facing the stator assembly. The concave stator assembly
comprises permanent or electro-magnets which are arranged so as to
expose the same polarity on the entire surface of the stator
assembly facing the rotor assembly. The magnetic repulsion force
between the rotor assembly and the stator assembly produces an
air-gap which permits omni-directional horizontal movement of the
axleless wheel system.
Preferably, the spherical rotor assembly comprises a
plurality of magnetic units made of rare earth elements such as
neodymium, for example, embedded in a non-magnetic material such
as plastic or rubber, and the concave stator assembly comprises a
monolithic permanent or electro-magnet in the form of a rod with a
hollow cavity on one end. Alternatively, the stator assembly may
comprise a plurality of magnetic units substantially greater than
those on the spherical rotor assembly arranged in segments of
different size from those on the rotor assembly so that the
magnetic flux lines in the stator assembly do not align with the
magnetic flux lines in the rotor assembly.
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CA 02190298 2001-03-14
Another aspect of the invention provides an inverted
configuration of the axleless wheel system in which the spherical
rotor assembly is positioned above the stator assembly to form a
cushion or suspension device in order to support the mass
connected to the spherical rotor assembly.
Brief Description of the Figures in the Drawings
In drawings which illustrate embodiments of the invention:
Figure 1 is a perspective view of one embodiment of the
magnetically levitated axleless wheel system according to the
invention;
Figure 2 is a sectional view of this embodiment along the
line I - I of Figure 1;
Figure 3 is a perspective view of a device having the
embodiment of the invention shown in Figure 1 and Figure 2;
Figure 4 is a perspective view of another embodiment of the
magnetically levitated axleless wheel system according to the
invention;
Figure 5 is a sectional view of this embodiment along the
line I I - I I of Figure 4 ;
Figure 6 is a perspective view of a device having the
embodiment of the invention shown in Figure 4 and Figure 5;
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CA 02190298 2001-03-14
Figure 7 is a perspective view of an additional embodiment of
the magnetically levitated axleless wheel system according to the
invention;
Figure 8 is a sectional view of this embodiment along the
line I I i - I I I of Figure 7 ; and
Figure 9 is a perspective view of a device having the
embodiment of the invention shown in Figure 7 and Figure 8.
Modes for Carrying Out the Invention
In one embodiment of the invention shown in Figure 1 and
Figure 2, the axleless wheel system comprises a spherical rotor
assembly 1 and a concave stator assembly 2. The magnetic
repulsion force between the magnetic units in the rotor assembly
1 and the magnetic units in the stator assembly 2 produces a
hemispherical air-gap 3, permitting essentially friction-free
rotational movement of the rotor assembly 1.
In this configuration, the rotor assembly 1 is positioned
below the floating stator assembly 2 without any axle. The
rotor assembly 1 is placed on the floor, and supports the weight
of the floating stator assembly 2 and the mass attached to the
stator assembly 2.
The spherical rotor assembly 1 comprises a plurality of
closely-spaced permanent magnets in the form of a soccer-ball
segment or a disc, preferably made of rare earth elements such as
neodymium. The magnetic units are embedded in and covered with a
non-magnetic material such as plastic or rubber to form a rigid
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CA 02190298 2001-03-14
rotor assembly. The magnetic units are arranged so that the
entire surface of the rotor assembly 1 exposes the same polarity.
This configuration provides return magnetic flux lines to the
opposite magnetic pole through substantially narrow gaps between
the magnetic units in the rotor assembly 1.
The concave stator assembly 2 may comprise a single permanent
or electro-magnet in the form of a monolithic rod with a hollow
cavity on one end. Alternatively, the stator assembly may also
comprise a plurality of permanent or electro-magnets which are
arranged so as to expose the same polarity as that of the rotor
assembly 1 on the entire surface of the stator assembly 2. In the
latter configuration, the magnetic units on the stator assembly 2
should be substantially greater than those on the spherical rotor
assembly 1, and be arranged asymmetrically so that the magnetic
flux lines in the stator assembly 2 do not align with the magnetic
flux lines in the rotor assembly 1.
If desired, the stator assembly 2 may include a vertical hole
4 at the top in order to accommodate a brake shaft 5 made of a
non-magnetic material such as plastic or rubber. The surface
friction between the rotor assembly 1 and the brake shaft 5
provides a braking action in order to control the speed of the
rotation.
The diameter of the hole 3 at the bottom of the concave
stator assembly Z is slightly greater than that of the spherical
rotor assembly 1 in order to be able to insert the rotor
assembly 1. The hollow cavity of the concave stator assembly 2
envelopes more than one half of the rotor assembly 1 in order to
form a repulsion force strong enough to support the weight of the
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rotor assembly 1 when the axleless wheel system is lifted.
Stability is achieved when at least 3 axleless wheel systems
are employed in a device. The example shown in Figure 3 is a
device for transport, incorporating the embodiment shown in Figure
1 and Figure 2. The device comprises 4 axleless wheel systems 6
mounted at the bottom of a light rectangular cart 7, which is made
of non-magnetic materials. When a force is exerted at the handle
8, the cart moves horizontally along the direction of the
corresponding force, as indicated by the arrows.
In another embodiment of the invention shown in Figure 4 and
Figure 5, the axleless wheel system configuration shown in Figure
1 and Figure 2 is inverted.
In this configuration, the stator assembly 2 is positioned
below the floating rotor assembly 1 without any axle. The stator
assembly 2 is placed on the floor, and supports the weight of the
floating rotor assembly 1 and the mass attached to the rotor
assembly 2 with a shaft 9. The shaft 9 is made of a non-magnetic
material, and is securely connected to the floating rotor assembly
1.
Stability is achieved when at least 3 axleless wheel systems
are employed in a device. The example shown in Figure 6 is a
device for cushion, incorporating the embodiment shown in Figure 4
and Figure 5. The device comprises 3 inverted axleless wheel
systems 10 mounted at the bottom of a light triangular platform
11, which is made of non-magnetic materials. When a force is
exerted at the top of the platform 11, the self-centering cushion
absorbs the vibration, as indicated by the arrows. In a
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configuration with an electro-magnet stator, the strength of the
cushion may be controlled by varying the voltage to the
electro-magnet.
In additional embodiment of the invention shown in Figure 7
and Figure 8, the axleless wheel system configuration shown in
Figure 1 and Figure 2 is inverted.
In this configuration, the stator assembly 2 is positioned
below the floating rotor assembly 1 without any axle. The stator
assembly 2 is attached to the ceiling, and supports the weight of
the floating rotor assembly 1 and the mass 13 attached to the
rotor assembly 2 with a wire 12. The wire 1 2 is made of a
non-magnetic material, and is securely connected to the floating
rotor assembly 1 through a vertical hole 4 in the stator assembly
2. The mass 13 swings around the centre-line IV.
The example shown in Figure 9 is a device for suspension,
incorporating the embodiment shown in Figure 7 and Figure 8. The
device comprises 2 inverted axleless wheel systems 1 4 mounted at
the top of a light wire 12 and a mass 1 3, both of which are made
of non-magnetic materials. When a force is exerted at the mass
13, the suspension provides a swing movement around the
centre-line IV, as indicated by the arrows. The suspension uses
no hinge, and causes no mechanical stress.

Representative Drawing