BACKGROUND OF THE INVENTION
Field of the invention
The present invention relates to the field of magnetic
materials in general and more specifically regards a component having a composite
structure, including composite magnetic material, as well as new magnetic devices
that make use of one or more of said magnetic components, which can be used, for
example, for making spring devices, linear and rotary suspension devices, shock
absorbers, damping and suspension devices; systems for opening and closing doors,
pumps, compressors, lifts and elevators, valves, injectors, and linear or rotary
stepper actuators of various types, and units for imparting a movement on a driven
Magnetic materials in general can be classified according
to their magnetic susceptibility (&khgr;=M/H) and relative permeability
+1)) in different categories: ferromagnetic, ferrimagnetic, antiferromagnetic,
paramagnetic, diamagnetic, and superconductive materials.
Ferromagnetic materials have a high relative permeability,
which amplifies small magnetic fields into large flux densities and renders them
suitable for microsensors. Their high saturation magnetization can generate large
fluxes, which is useful for making microactuators.
Ferromagnetic materials can be magnetized, demagnetized,
and remagnetized. They exhibit a hysteretic behaviour (see Figure 1A of the annexed
plate of drawings). Important characteristics that are frequently cited, displayed
by the diagrams of the type appearing in Figure 1A, are the saturation magnetization
Ms, the remanent magnetization Mr, the coercivity Hc
and the saturation field Hs. According to said parameters, ferromagnetic
materials can be divided into the so-called "soft" magnetic materials, i.e., ones
with low coercivity (having a diagram of the type illustrated in Figure 1C), and
"hard" magnetic materials, i.e., ones with high coercivity (having a diagram of
the type illustrated in Figure 1B).
The magnetic materials most commonly used in miniaturized
devices are the so-called soft ferromagnetic materials, such as NiFe alloys (i.e.,
permalloy, which typically contains 81% Fe and 19% Ni). The combination of relatively
high saturation flux densities, low hysteresis losses and magnetostriction close
to zero (i.e., the stresses in the device do not affect its magnetic performance)
has meant that these materials are widely used for macroscopic and microscopic sensors
and actuators. The production and the construction of magnetic microactuators have
in general reproduced those of their macroscopic equivalents.
Even though soft magnetic materials can be used for making
high-power actuators and for sensitive magnetometers, hard magnetic materials or
permanent magnetic materials would be more appropriate in certain cases. For example,
hard magnetic materials with high remanent magnetization Mr can be advantageously
used in bidirectional microactuators. In addition, microactuators controlled by
coils can be activated with weaker fields and consequently with lower power levels
if a hard magnetic material is used instead of a soft magnetic material. It is possible
to prepare a wide range of hard magnetic materials by means of metallurgical processes
(for example, by sintering, pressure joining, injection moulding, casting, extrusion,
and calendering) by means of vacuum processes (for example, evaporation, sputtering,
molecular-beam epitaxy or MBE, and chemical vapour deposition or CVD), and by means
of electrochemical processes (for example, non-electrical deposition and electrodeposition).
The table below lists typical values of the coercivity
and hence of the degree of hardness of some magnetic materials, such as NdFeB and
SmCo V and of others, such as alnico V and ferrite.
Originally, the majority of hard magnetic materials were
based upon cobalt alloys, on account of the high crystal anisotropy of said material.
So far cobalt-based alloys have been deposited with P, As, Sb, Bi, W, Cr, Mo, Pd,
Pt, Ni, Fe, Cu, Mn, O, and H. The elements bound in the cobalt tend to concentrate
on the boundaries of the grains. There should result therefrom isolated magnetic
cobalt particles, surrounded by non-magnetic and weakly magnetic layers. Said formations
create microscopic energy barriers that increase the coercivity Hc of
the film, thus rendering it magnetically harder.
Ever since 1983, the production of neodymium-ferro-boron
(NdFeB) magnets using processes of sintering or of melt spinning has led to their
use in many commercial products. NdFeB alloys in the bulk state represent a new
promising type of hard magnetic material in so far as they do not contain costly
and rare elements, such as cobalt, and enable production of a product of maximum
energy of up to 50 Mgauss Oe (0.4 MJ/m3). A nanocomposite structure of
NdFeB alloys improves the remanent magnetization Mr, maintaining at the
same time high the coercivity Hc and renders NdFeB the material for making
the most powerful rare-earth magnets amongst the ones available.
Figure 2 of the annexed plate of drawings shows the development
of the magnetic materials.
As third generation of rare-earth-based permanent magnets,
NdFeB-based products are less brittle than SmCo and are used in a wide range of
applications. NdFeB-based magnets can replace SmCo-based magnets in the majority
of cases, especially where the operating temperature is lower than 80°C. The
stability in temperature of NdFeB is not as good as that of SmCo-based magnets.
The magnetic performance of NdFeB magnets deteriorates rapidly at temperatures above
180°C. As compared to SmCo-based magnets, the resistance to corrosion and to
oxidation of NdFeB is relatively low.
Sintered NdFeB-based permanent magnets are obtained via
successive steps. First of all, an NdFeB alloy is formulated on the basis of the
properties of the final permanent magnets that it is desired to obtain. The alloy
is produced in a vacuum oven. The alloy is then pulverized. Sintered NdFeB-based
permanent magnets are formed by means of a metallurgical process of treatment of
the powders. Said magnets can be formed in a mould or isostatically. During the
process of pressing there are applied magnetic fields with the assistance of equipment
purposely designed for aligning the magnetic domains and optimizing the magnetic
performance of said magnets. The pressed magnets are then put into an oven in a
protected atmosphere for sintering. After sintering, the shape of the magnet is
rough and requires machining and grinding in order to achieve the desired shape
and dimensions. Usually, a cladding surface is applied on NdFeB magnets. Commonly
used as protective layer is zinc or nickel. For said purpose, other materials can
also be used, such as cadmium chromate, aluminium chromate, tin, or (epoxy) polymers.
The NdFeB alloy magnets are obtained by binding NdFeB powders
via fast quenching. The powder is mixed with resin so as to form a magnet by means
of compression moulding with epoxy resin or by means of injection moulding with
nylon. The latter technique is particularly effective for large-scale production
even though the magnetic value of the products is inferior to that obtained with
compression moulding on account of their relatively lower density. It is possible
to produce various shapes with a high dimensional accuracy without any further treatment.
The surface is treated with epoxy coating or nickel plating to prevent corrosion.
In order to obtain different magnetic properties, hybrid magnets can be made.
With different ratios of additives to the NdFeB powder,
the magnetic properties of hybrid NdFeB magnets can be modulated within a wide range.
Once the ratio is fixed, the fluctuation of the magnetic property can still be limited
within a narrow range. Some of the properties are presented in the table below.
max Maximum energy produced
The properties appearing in the table above are typical
at room temperature (23°C) for specimens without any cladding. Figure 3 gives
an example of a demagnetization curve for an alloy magnet to NB12.
In addition to the class of the multidomain composite magnetic
materials, the present patent also regards composites the magnetic characteristics
of which, as will be seen, are derived from the collective behaviour of an organized
multitude of elementary magnets that can present in the form of single domains,
of complex molecules, or more in general of molecular clusters. Since these are
of microscopic or nanoscopic dimensions, they present the peculiarity of having
a high surface/volume ratio, which is very advantageous in terms of the magnetic
characteristics that can generally be defined starting from the distribution of
the magnetic domains on the surface.
PURPOSES OF THE INVENTION
A first purpose of the present invention is to provide
a type of composite magnetic material of a new conception which can be advantageously
used for making devices of various kinds, such as spring devices, active or passive
damping devices, pumps or compressors, electrically controlled active closing and
opening devices, and, more in general, actuators of various types and units for
imparting movement on a driven member.
A particular purpose of the invention is to provide a class
of magnetic devices, for example in the form of support to magnetic suspensions,
which use the aforesaid composite magnetic material.
A further purpose of the invention is to provide a class
of magnetic actuators which uses the aforesaid composite magnetic material.
Yet another purpose of the invention is to provide an articulated
and jointed moving system in which every single element made of the composite magnetic
material takes part in the overall motion.
Yet a further purpose of the invention is to provide a
system of a large number of magnets set in a chamber with elements in motion so
as to guarantee fluid tightness and to act as valve, pressure regulator, or pump-compressor.
With a view to achieving the above and further purposes,
the subject of the invention is a type of composite magnetic materials which can
be used, for example, for the development of a component comprising a body made
of non-magnetic material having two main plane faces or in general surfaces of an
arbitrary shape, hence even not perfectly parallel, and opposite to one another
and of any geometrical shape. The composite magnetic material consists of a plurality
of elementary magnetic elements of a pre-defined shape, which are set at a distance
from one another and are englobed in a body made of non-magnetic material and have
their polarities oriented and aligned according to the shape of the main faces of
the body and of the shape of the elementary magnets themselves.
In the composite magnetic component according to the invention,
the magnetic elements are arranged in three-dimensional space in a discrete way
and in such a way that the resulting magnetic field produced is the vector superposition
of the fields produced by the individual magnetic elements. The resultant field
produced by the composite structure of the component according to the invention
in this way presents, around the poles, a magnetic field the lines of force of which,
in contrast with the case of a conventional magnet, can be determined and defined
via: the composition and shape of the elementary magnets; the position of the elementary
magnets in the matrix; and the peripheral geometry of the composite. In the proximity
of the poles, the composite magnet can be designed so as to present magnetic equipotential
lines more orthogonal to the direction of magnetization and more parallel to one
another as compared to the ones produced by a conventional magnet in the corresponding
areas. This results in a magnetic force which is more aligned in the direction of
magnetization of the magnet itself. The force of interaction between opposed magnets
in the repulsion configuration or attraction configuration proves in this way to
be more uniformly distributed over a larger area than what can obtained with a massive
Given the same magnetic mass, as compared to a conventional
magnet the composite magnet can be designed for the purpose of exerting an attractive/repulsive
force which is more uniform and in general according to a pre-set distribution of
the intensity of the field in the space of interest. Said behaviour is an effect
due to the geometrical distribution of the elementary magnets as well as to their
composition and shape.
The distribution of the elementary magnets in the organized
composite matrix is such that the lines of force of the field can be controlled
as regards their paths and their intensity.
The main peculiarity of the present invention is the possibility
of defining a priori the distribution and intensity of the lines of field
via the combined control of the overall geometry of the composite, of the geometry
of the elementary magnets, of the distribution or relative spacing or orientation
of the elementary magnets, and of the choice of the material that constitutes the
elementary magnet, with the elementary magnet that can present in the form of a
single-domain or multidomain ferromagnetic particle, of a complex molecule, or,
more in general, of a molecular cluster.
The composite magnetic component according to the invention
can be provided with a cladding along its perimetral wall consisting of a material
with a high magnetic permeability designed to confine and concentrate the lines
of magnetic flux generated by the magnetic elements inside it or in a desired area
of space. Said material with high magnetic permeability can also mask part of the
polar surfaces of the body of the magnet.
Said material with high permeability can also be a material
with a permeability that is not uniform in space, for example a heterostructure
with gradient or with modulation of the magnetic permeability. A material with gradient
or with modulation of the permeability can be a variable-stoichiometry alloy. Said
element can be integrated with the device so as to enable a full control of the
individual lines of magnetic field and of the magnetic equipotential lines throughout
Said material with high permeability can be a multilayer
made of materials with different physical characteristics. As a particular case,
an intermediate layer may be constituted by air.
Composite magnetic materials for example with polymeric
or ceramic matrices have already been known for some decades. This type of materials
finds extensive use whenever it is possible to accept a reduction in the magnetic
properties to the advantage of a lower cost and a lower weight, associated to a
great flexibility of the possible shapes. In effect, the final component may, for
example, be injection-moulded or hot-press moulded. During the process of forming,
the magnetic inclusions are usually magnetized in a pre-defined direction in the
composite, via the application of an external magnetic field. The magnetic inclusions,
which are usually in the form of a micrometric powder, are mixed in the "paste"
with the polymeric or ceramic matrix in such a way that their distribution density
per unit volume will be as uniform as possible throughout the composite. The lines
of force of the magnetic field of such a composite are similar to those of a bulk
material but are characterized by a lower intensity.
The characteristic of the composites according to the present
invention is the one whereby, through the shape and spatial organization of the
elementary magnets defined analytically, it is possible to generate magnetic components
that produce fields with lines of force defined beforehand.
The non-magnetic material constituting the body has a specific
weight lower than that of the material of the magnetic elements, and is preferably
a synthetic material, in particular a polymeric material, even though it is also
possible, for example, to use a light non-magnetic metal, e.g., aluminium, copper,
gold, etc., but also a dielectric one, a porous one with heterogeneous porosity
or orderly porosity, a ceramic one, a composite and elastic one, or, in general,
a material chosen on account of peculiar physical properties, such as, for example,
thermal and electrical conductivity. The elementary magnetic elements are arranged
in a matrix or according to any orderly reticular geometry. The use of a protective
layer with high thermal conductivity enables dissipation of heat in the case where
the component is subjected to extreme thermal conditions that may limit the characteristics
of the elementary magnets.
The composite magnetic material can be characterized also
as regards the magnetic properties of the individual constituent elementary magnets
(B-H curves); in particular, they can differ in shape and be made of materials with
different magnetic properties. The possibility of distributing elementary magnets
with different magnetic properties in a regular way constitutes a further degree
of freedom for characterizing the magnetic properties of the resulting composite
and for rendering the cycles of magnetization and remagnetization faster and more
The regularity of the magnets can be of the type with a
periodic structure or with a structure in which the elementary magnets are arranged
in the body of the polymeric matrix according to pre-set analytical functions. In
particular, in the case of bistable composites, the elementary magnets (whether
soft or hard, whether in the form of nanoparticles or in the form of single-domain
or multidomain molecular clusters) will be arranged in the field generated by the
coil and uniformly distributed throughout the entire composite, according to spatial
co-ordinates and orientation such that the reversal of polarity in the current of
the coil will induce simultaneous reversal of polarity in all the elementary magnets
of the matrix.
Also the shape of each individual magnetic element in the
matrix, as likewise that of the composite magnetic element, can be arbitrary in
order to bestow the desired magnetic properties on said elements. In particular,
an appropriate shape of the composite material enables orientation of the lines
of magnetic field, the lines of the resultant forces, and the equipotential lines,
The elementary magnet forming the composite can be a single-crystal
magnet, single-domain ferromagnetic microparticles or nanoparticles, a molecule
or a complex of magnetic molecules, a magnetic molecular cluster, etc.
In the particular case where the magnetic characteristics
of the individual elementary magnets are markedly dependent upon the temperature,
the material that includes them, whether it is of an organic or inorganic type,
will have the function of maintaining the magnetic characteristics unaltered over
a wider range of temperatures.
According to a first simplified embodiment, the subject
of the invention is also a magnetic device, for example having the function of a
spring or shock absorber, comprising a plurality of composite magnetic components
of the type indicated above, set on top of one another and slidably mounted within
a tubular guide column with their polarities alternately oriented in one direction
and in the other, in such a way as to repel one another.
Linear or rotational magnetic suspensions, i.e., of a bearing
type, enable a contactless support. They consequently differ substantially from
the mechanical suspensions or bearings or from mechanical shock absorbers, which
require a shaft and some form of lubrication.
In passive magnetic suspensions, the field is generated
by permanent magnets or by constant-field electromagnets. These are very similar
to the mechanical ones in so far as they do not require active control for their
operation. Generally, the body to be suspended is partially or totally made of ferromagnetic
material. The main disadvantage of passive magnetic suspensions is their low rigidity
and their low capacity for damping, which is only in part compensated for by the
new powerful rare-earth-based permanent magnetic materials such as NdFeB.
Magnetic suspensions, and more in general magnetic devices,
present various advantages as compared to hydraulic mechanical ones, such as:
- easier microscale fabrication;
- higher reliability;
- different non-linear characteristics and possibility of modifying them via an
appropriate composition of the magnetic composite;
- greater scalability (generalizability) of a design from the microscale to the
macroscale, and vice versa.
In a preferred embodiment of the invention, the composite
magnetic components described above are used for making a device with functions
that are superior to those of the simple conventional magnetic-spring or magnetic-suspension
device made with materials of the massive bulk type. In said preferred embodiment,
the magnetic device according to the invention comprises a plurality of magnetic
components, preferably composite magnetic components of the type indicated above,
slidably mounted within a longitudinal guide. The slidable magnetic elements can
be shaped appropriately so as to run along a rail made on the internal surface of
the runner guide. The guide can be a tubular element or a simple wire or rod or
a set of runner rods, as will be illustrated in detail in what follows. The magnetic
components are alternately formed by permanent magnets typically consisting of hard
elementary magnets and by bistable magnetic elements consisting of soft or hard
elementary magnets, and coil-type winding means for reversing the polarity of the
bistable composite magnetic components for the purpose of controlling the passage
of the device between a condition of operation in which the composite magnetic components
repel one another (push operation), corresponding to the value of current I >
Ic, and a condition of operation in which the composite elements attract
one another (pull operation), corresponding to a current I = 0 in the coil, where
Ic is the electric current to be supplied to the winding for reversing
the magnetization of the composite core.
The push-pull system forming the subject of the invention
can operate with just two elements as illustrated in Figures 15a and 15b. The first
element will consist of a bistable composite, for example made with soft elementary
magnets, and the second element will be made with hard elementary magnets.
The system forming the subject of the invention, however,
preferably consists of a minimum of three magnetic elements interacting as represented
in Figures 14, 15, and 16. In a particular configuration illustrated in Figures
16b and 16c, the bistable component, made, for example, with soft magnets, is perforated
or else is of smaller size in order to enable connection of the two composite hard
magnets to one another with rods. The bistable magnet is constrained to the structure
or else is momentarily clamped via jaws described hereinafter. The polarities of
the two hard permanent magnets with high intensity are opposite. In this way, the
bistable magnet attracts one of them and repels the other. The reversal of polarity
of the bistable composite magnet, preferably with a high remanent magnetization,
causes the system of the two hard magnets connected to one another to perform a
reciprocating motion downwards or upwards. In the present description and in the
ensuing claims, magnetic materials capable of reversing their magnetization following
upon application of an external magnetic field are considered as bistable composite
magnetic materials. The composite may be obtained with soft or hard elementary magnets
or in general with elementary magnets having a pre-set degree of remanent magnetization
and, in particular, with magnetic microparticles or nanoparticles or with magnetic-cluster-based
In the preferred embodiment, the device described above
is an actuator device of a push-pull type, in which a magnetic component is set
at the end of the series of magnetic components and is operatively connected to
a driven member.
The aforesaid means for reversing the polarity of the bistable
magnetic components, for instance of a soft type, are formed by windings, which
are arranged around the portions of the tubular guide that are traversed in operation
by said magnetic components, or else are arranged along the entire tubular guide,
or else are fixedly mounted around the soft magnet within the guide, as will also
be illustrated in detail in what follows. In this latter case, the winding is preferably
supplied in one of the two following ways: by means of a battery fixed to the winding
fixed to the soft magnet or by means of sliding contacts (in which case two electrical
paths inside the tubular guide are provided). The battery solution can also include
a unit for generation or conversion of energy and a wireless unit for communication
with the outside world.
A plurality of independent elements of the bistable-composite
type set adjacent to or on top of one another, each equipped with its own winding,
can be used to form a single multistage element. The latter, according to the currents
applied to the individual windings, may be configured in a multitude of levels of
intensity of the field generated in one of the two polarities.
In an alternative embodiment, the non-magnetic part of
the composite element mentioned above is made of elastic material and is, consequently,
compressible and expandable. Said element possesses within it an element that can
expand radially for clamping as required the position of the element itself in a
definite position of the cylindrical guide. By appropriately clamping first one
and then the other element, or pairs (or any multiplicity) of elements, it is possible
to move the entire chain along the tubular guide. All the aforesaid embodiments
will be described in detail in what follows.
Each individual element can be clamped by a clamping unit,
which is in turn formed by a pair, or by any multiplicity of (soft and hard) magnetic
sub-elements, which together form a jaw that can be opened (clamping by expansion)
and closed (element free to move) upon command.
As a particular case, one of the elements of the chain
may consist of a material of a superconductive type.
The clamping unit can be integrated both in the elements
with permanent polarity and in bistable ones and in general in one or more elements
of the chain. Also in this case, each sub-element made of bistable magnetic material
constituting the clamping unit is equipped with a coil fixed thereto, which is able
to magnetize the sub-element to which it is coupled in one direction or in the other.
Also in this latter case, the magnetic sub-element can be equipped with a battery
for self-supply of the coil, a unit for generating or converting energy, and a wireless
port for remote communication.
In a configuration of stepper actuator in the condition
of rest the magnets of the jaws are preferably arranged in positions such as repel
one another, i.e., in the position of actuator clamped. At the moment of application
of the current in the winding, the jaws come closer to one another, releasing the
elements of the actuator so that they can move one at a time or simultaneously on
In a configuration of a spring actuator or of a configuration
the shock-absorber/suspension type, the jaws at rest are preferably released, whereas
they open for clamping or for slowing down movement of the mobile parts once the
polarity of the bistable composite, made, for example, of soft elementary magnets,
Between the mobile elements it is possible to insert elastic
polymeric spacer elements, or plastic spacer elements, or non-magnetic-metal spacer
elements designed to prevent direct contact between the components. In the case
where the spacer is elastic, it will also have the function of facilitating passage
from the condition in which two components attract one another to the condition
in which they repel one another. The energy necessary (i.e., the impulse) for triggering
actuation will be in this case lower.
The push-pull system can be fixed on one side.
In a particular embodiment, the push-pull system is used
as valve, pressure regulator or compressor.
The mobile elements can in general move within any fluid
(even a lubricant).
A particular application of the magnetic composite forming
the subject of the present patent is in transformers. In this case, the ease in
reversing the polarity and the spatial organization of the elementary magnets enables
both a marked reduction in the parasitic currents and a major reduction in the complexity
typical of lamellar systems.
Further preferred characteristics of the invention are
specified in the annexed dependent claims.
BRIEF DESCRIPTION OF THE PLATE OF DRAWINGS
DETAILED DESCRIPTION OF SOME EMBODIMENTS
- Figures 1A, 1B and 1C and Figures 2 and 3 illustrate the diagrams corresponding
to the magnetic materials which have already been discussed above.
- Figure 4 is a schematic plan view of an example of a composite magnetic component
according to the invention, in which the elementary magnets are arranged according
to a pre-set order.
- Figure 5 is a partially sectioned perspective view of the magnetic component
of Figure 4.
- Figures 6, 7, 8, 9, and 10 are perspective views of further embodiments of the
magnetic component according to the invention, which represent possible variants
with respect to the example illustrated in Figure 5.
- in particular, Figure 8 illustrates a case where the composite component has
curved surfaces and a composite multilayer perimetral cladding with high magnetic
permeability, which is used for confining the field in the component.
- Figure 9 illustrates the case of a composite in which the elementary magnets
are magnetic molecules derived from the salts:
- (tcnq = 7, 7, 8, 8-tetracyanoquinodimethane;
- [Fe2(&eegr;-C5Me5) 2 (µ-SEt)
- tcne = tetracyanoethylene) [Fe2(&eegr;-C5Me5)
2(µ-SEt) 2(CO) 2] [tcne].
- Figure 10 illustrates the case of a composite in which the elementary magnets
are magnetic molecules of the ferrous type.
- Figure 11a shows the lines of field generated by a massive bulk magnetic component,
whilst Figure 11b shows a magnetic component according to the invention in which
the lines of field and the resulting forces are defined by the distribution of the
elementary magnets, by the perimetral shape, and by the type of elementary magnets
- Figure 12 is a cross-sectional view of two conventional magnetic elements set
adjacent to one another in the repulsion configuration, i.e., with the same polarities
facing one another, which shows the lines of the magnetic flux (Figure 12b) and
the equipotential lines (Figure 12a) generated thereby.
- Figure 13 is a cross-sectional view of two conventional magnetic elements set
adjacent to one another in the attraction configuration, i.e., with different polarities
facing one another, which shows the lines of the magnetic flux (Figure 13b) and
the equipotential lines (Figure 13a) generated thereby.
- Figure 14 is a view similar to that of Figure 8, which shows how the lines of
magnetic flux are modified in the case where the magnetic component according to
the invention is provided with an external cladding for containment of the lines
of magnetic flux.
- Figure 15 is a schematic perspective view which illustrates a first elementary
example of application of magnetic components according to the invention, designed
for example to function as spring-shock absorber-suspension. The system consists
of two composite magnetic elements. The bistable element, for example consisting
of soft elementary magnets, is fixed on one side, whilst the permanent magnetic
element, constituted for example by elementary magnets with high coercivity, is
repelled (Figure 15a) or attracted (Figure 15b) according to the current (I) applied
to the winding.
- Figure 16 is a schematic perspective view illustrating a preferred example of
embodiment with three elements, in which the composite magnetic components according
to the invention are used for making an actuator device that can have various applications.
- Figures 17 and 18 are schematic views illustrating the principles of operation
of the device of Figure 16.
- Figure 19 is a plan view that illustrates an alternative embodiment of the means
for guiding the axial movement of the magnetic components illustrated in Figures
15, 16 and 17, according to the invention.
- Figure 20 illustrates a further embodiment, in which the components are guided
- Figures 21a and 21b illustrate a variant of the embodiment with three elements,
in which the bistable component is perforated or else is of a smaller size in order
to enable the two composites with permanent magnetization to be connected to one
another by rods. The bistable magnet, for example consisting of soft elementary
magnets, but preferably consisting of elementary magnets with high remanent magnetization,
is constrained to the structure or else is momentarily clamped via jaws, as will
be illustrated in detail in what follows. The polarities of the two permanent magnets
are opposite. In this way, the bistable magnet attracts one permanent magnet and
repels the other. Reversal of the polarity of the bistable composite magnet causes
the rigid system of the two hard magnets connected to one another to perform a definite
movement downwards or upwards. The device can be used as stepper motor, the total
stroke of which depends only upon the length of the guide. The particularly advantageous
use of this type of actuator is in lifts and elevators, which in this way do not
require a number of cables or racks. In the case where the actuator system were
to operate at high frequency, the bistable components implemented in the configuration
of composite with inclusions of elementary magnets will present the further peculiarity
of limiting the dissipation of Foucault currents (eddy currents).
- Figures 22 and 23 illustrate two types of supply of the winding of the bistable
composite element. In Figure 22 the supply of the winding is provided by a battery
supply integrated in the component itself, whilst in Figure 23 the supply of the
winding occurs by contact on conductive paths set on the guide.
- Figures 24 and 25 illustrate two different conditions of operation of a jaw
device used in the device of Figures 22 and 23. In particular, in Figure 24 the
clamping mechanism is closed, whereas in Figure 25, with the application of the
current to the winding, the clamping mechanism is operative.
- Figures 26 and 27 illustrate the two different operating conditions of a clamping
and releasing device with two elements, which constitutes a variant to the one illustrated
in Figures 24 and 25.
- Figures 28 and 29 illustrate the two operating conditions of a clamping mechanism
with four elements.
- Figure 30 illustrates a further example of embodiment of the multielement invention.
- Figures 31a, 31b and 31c illustrate types of embodiment in which either rigid
or elastic polymeric non-magnetic separation means or metallic non-magnetic separation
means are arranged on the components for preventing their direct contact and facilitating
passage between the condition of repulsion and that of attraction.
- Figure 32 is a schematic illustration of the various operating steps of a compressor
system with flexure valves or valves of an electrical type for controlling intake
and pumping of air, gas or liquid.
- Figures 33a, 33b and 33c illustrate a multistage component consisting of a plurality
of independent bistable composite elements set adjacent to or on top of one another.
Each element can be equipped with its own winding. Consequently, the multistage
component, according to the currents applied to the windings, may be configured
in a multitude of levels of intensity of the resultant generated field in one of
the two polarities.
- Figures 34a and 34b illustrate an open/close valve for regulating flow of a
gas, for instance natural gas, or propane, or hydrogen, or a liquid or gaseous fuel
- Figures 35a and 35b illustrate a valve for selection between two fluids.
- Figure 36 illustrates a valve for deviating the flow of a fluid.
Figures 4 and 5 are a plan view and a partially sectioned
perspective view of a first example of embodiment of the composite magnetic component
according to the invention. The composite magnetic component, designated as a whole
by the reference number 1, comprises a body made of non-magnetic material 2 having
any desired conformation. The example illustrated in Figures 4 and 5 relates to
the case of a cylindrical conformation, in the form of a circular disk, with two
main opposite faces 3. Figures 6 and 7 illustrate variants in which the body has
a parallellepipedal conformation. The component can in any case assume, as has been
said, any other conformation, including, for example, an annular conformation. In
the body made of non-magnetic material 2 a number of elementary magnetic elements
4 are englobed, having their N-S polarities all oriented in the same way, in a direction
orthogonal to the faces 3. In the example illustrated, each elementary magnetic
element 4 has a cylindrical conformation with a circular cross section. In a plan
view (Figure 4), the magnetic elements 4 have a diameter ϕ and are arranged
in a matrix array with a pitch dx in a first direction and a pitch dy in a second
direction orthogonal thereto; the discretization is extended in the direction orthogonal
to the plane defined by the first and second directions, with a pitch dz, as further
represented in Figure 7.
Also in the case of the individual magnetic elements 4,
it is, however, possible to adopt any conformation both as regards their cross section
and as regards their general geometry. The dimensional parameters specified above
are pre-determined so as to optimize the operating results that will be described
in detail in what follows.
The non-magnetic material constituting the disk 2 is preferably
a material having a specific weight lower than that of the material constituting
the magnetic elements 4. Still more preferably, said material is a synthetic material,
for example a polymeric material, or a non-magnetic light metal, for example aluminium,
or a dielectric or porous composite material, or again an elastic material.
In the case of the variant of Figure 6, the conformation
of the magnetic component 1 is parallelepipedal, to be precise cubic, and the elementary
magnetic elements 4 assume the shape of blades or layers englobed in the matrix
2 and each extending throughout the cross section of the body. Figure 7 illustrates
once again the case of a parallelepipedal body 2, englobed in which is a matrix
arrangement, similar to that of Figure 5, with a number of planes, set on top of
one another, of elementary magnetic elements 4 with parallelepipedal conformation.
Figure 8 illustrates the advantages of the present invention
in an embodiment in which the spatial organization of the individual elementary
magnets in the composite allows the conformation of the lines of field (the equipotential
lines are illustrated). These, via the combined use of a composite multilayer perimetral
cladding with high magnetic permeability HPC, can moreover be confined in the component
itself. This configuration is particularly advantageous when the device is not required
to interact with sensors or other surrounding electronic components.
Figure 9 illustrates the case of a composite in which the
elementary magnets are magnetic molecules derived from the salts (tcnq = 7, 7, 8,
(CO)2]2[tcnq] and derived from the salts tcne = tetracyanoethylene)
whilst Figure 10 illustrates the case of a composite in which the elementary magnets
are magnetic molecules derived from ferracene, manganocene, chromocene, Mn12Ac,
V15, Mn6Rad6, Fe8, Fe10,
These molecules are complex agglomerates with atomic weights
of the order of 103 atomic units. The properties are due to the presence
in the molecule of magnetic ions of Mn, Fe, V, etc. coupled to one another by strong
exchange interactions (of the order of 106 Oe).
More in general, the present invention claims the inclusion,
according to a spatial order pre-established by an analytical function, of bistable
elementary magnets of the high-spin-molecular type (which characterizes their magnetic
properties) in organic or inorganic matrices of a polymeric, ceramic, or metallic
nature, or of other nature, which also have the function of thermal stabilization
of the magnetic characteristics of the elementary magnets.
Magnetic microparticles and nanoparticles, or magnetic
molecules of large dimensions, of different size and chemical nature can be combined
with polymers or in general be included chemically or physically or mechanically
or again via techniques of a microelectronic type in non-magnetic matrices of orderly
structure, for example of a photonic-crystal type.
An important peculiarity of single-domain elementary magnets,
in the form of microparticles or nanoparticles or complex molecules or molecular
clusters, is that of presenting a marked magnetic anisotropy or a high coercivity
in one direction, which can be exploited for the fabrication of regular compounds
forming the subject of the present patent.
Another peculiarity of interest for the present patent
lies in the fact that the magnetic behaviour of an agglomerate of said molecules
is the result of the phenomenon of magnetic co-operativity between the individual
Figure 12 illustrates the condition of two magnetic elements
M of a massive bulk type, set one above the other in the repulsion configuration,
which have their same polarities set facing one another. The lines S appearing in
Figure 12b are magnetic equipotential lines, i.e., lines that join points having
the same value of the magnetic field. Since the forces exchanged between the two
magnetic elements are locally orthogonal to the equipotential lines S, they appear,
as may be seen in Figure 12a, relatively open in a fan-like fashion with respect
to the direction of alignment of the two magnetic elements M.
Figure 13 illustrates the condition of two magnetic elements
M of a massive bulk type, set one above the other in the configuration of attraction,
which have their opposed polarities facing one another. The lines S indicated in
Figure 13b are magnetic equipotential lines, i.e., lines that join points having
the same value of the magnetic field. The forces exchanged between the two magnetic
elements are locally orthogonal to the equipotential lines S. The lines of force
of the field coming out of a magnet, as is shown in Figure 13a, partially close
on the adjacent magnet.
Figure 11a illustrates the lines of flux m of a single
conventional massive bulk magnet. Figure 11b illustrates the same situation with
a magnetic component made in conformance with the teachings of the invention. In
this case, then, the magnetic component 1 has a plurality of elementary magnetic
elements 4 arranged in a matrix within a body made of non-magnetic material. Following
upon the geometrical arrangement of the elementary magnetic elements 4, the resulting
global magnetic field has equipotential lines S, which, in the proximity of the
poles of the magnetic component 1 are markedly close to being orthogonal to the
direction of magnetization. Consequently, the forces F that the magnetic component
1 can exchange with a second similar component facing it are more oriented in the
direction of magnetization of the components themselves.
Said phenomenon may be noted even more clearly in Figure
14, which shows the geometrical arrangement of the magnetic elements 4 seen in a
cross-sectional plane orthogonal to the opposite faces of the composite magnetic
component. Figure 14 shows the lines of flux t of the global magnetic field generated
by the sum of the magnetic fields of the multitude of elementary magnets 4. The
resulting magnetic field produced is the vector superposition of the fields produced
by the individual elementary magnets. As may be seen, thanks to the geometrical
arrangement of the magnetic elements, the resulting magnetic field is more uniform
and directed, in the proximity of the poles, along the axis of magnetization. Once
again in the proximity of the poles, the magnetic equipotential lines are more orthogonal
to the direction of magnetization and more parallel to one another as compared to
the ones produced by a conventional magnet in the corresponding areas.
Consequently, the composite magnetic component according
to the invention is not only lighter than a traditional magnetic element given the
same volume, but also and above all gives rise to a magnetic effect which is much
more effective for the purposes of the uses that will be described in detail in
what follows. As compared to a conventional magnet, the composite magnet exerts
a more controlled attractive/repulsive force in a specified direction of magnetization.
Said behaviour, as has been seen, is an effect due to the type of the elementary
magnets and to their geometrical distribution in the component itself.
The composite magnetic component according to the invention
can be provided with a cladding 5 along its perimetral wall, consisting of a material
with a high magnetic permeability, which tends to confine inside it the lines of
magnetic flux generated by the magnetic elements 4. In this way, with reference
to Figure 14, the lines of magnetic flux of the component, generated by the sum
of the individual magnetic elements 4, become the ones designated by r in Figure
14, instead of the lines t already described above.
In a first simplified example of use of composite magnetic
components made according to the present invention, a magnetic device may be envisaged,
which functions as a spring or passive or active shock absorber with a minimum of
two elements (Figure 15) or with a higher number of elements (Figure 16). Provided
in said device is a plurality of magnetic components 1 according to the invention,
set on top of one another and oriented so as to present alternately their polarities
reversed (see the arrows in Figures 17 and 18). The various magnetic components
1 are slidably mounted within a guide 6. The magnetic component 1, set at one end
of the row, can be operatively connected to a fixed member, whilst the magnetic
component 1 set at the opposite end can be connected to a member that is able to
move in the direction of the axis of the device in order to achieve an effect of
elastic and/or damping suspension of said element.
It should be noted that, in general, the production of
suspension or damping devices, with magnetic elements set on top of one another,
is in itself known for example from the patent No. US-6 147 422. Not known, instead,
are devices of this type which use magnetic elements that assume the form of the
composite magnetic component according to the invention. The use of a component
of this type affords a wide range of advantages. Above all, the adoption of a composite
structure enables a reduction in the weight of the component and, at the same time,
the best characteristics of operation thanks to an appropriate choice of the optimal
dimensions of the magnetic elements englobed in the body of the non-magnetic material
and of the distance between said elements in the two directions of the matrix.
In the case of the present invention, the organized discretization
of the elementary magnets in the form of microparticles and nanoparticles and in
particular of magnetic molecular clusters enables the use of a bistable component
for which it is possible to reverse the polarity with a low level of electric power
applied to the winding means, whilst maintaining an intense total magnetic field
for both conditions of polarity.
A further important characteristic lies in the fact that,
thanks to the organized arrangement of the magnetic elements 4, a better control
of the lines of magnetic flux is rendered possible, with a consequent increase in
the efficiency of the device, as has been illustrated above with reference to Figures
11, 12, 13, and 14.
A further advantage of the use of the structure described
above for each magnetic component of the device lies in the fact that the force
of repulsion between each component and the adjacent one is a function of the degree
of alignment between the magnetic elements of the two components, said force being
maximum when the magnetic elements of each component are perfectly aligned with
the magnetic elements of the adjacent component. For this purpose, Figure 19 illustrates
a configuration in which the magnetic components are forced to move according to
paths defined for example by a tubular guide designated by 6 and shaped in such
a way as not to enable any rotation or translation of the components. The tubular
guide designated by 6 can also be replaced for example by a simple wire or rod 6a
(Figure 20) or by a set of runner rods.
The preferred use of the magnetic component according to
the invention is in any case represented by a magnetic actuator device of the active
push-pull type, an example of embodiment of which is illustrated in what follows
with reference to Figures 15, 16 and 17. In the case of said embodiment, an important
difference with respect to the case of the simple passive spring or shock-absorber
device lies in the fact that at least one component is equipped with windings that
enable bistability, i.e., control of the state of magnetization and hence of the
polarity. In the case of a simple spring or passive actuator, the components are
necessarily composites with a state of permanent magnetization with polarities of
the same type facing one another, i.e., arranged in the repulsion configuration.
In the active configuration, the magnetic components 1
set on top of one another in the device are alternately permanent magnets MP and
bistable magnets MB, where the latter are equipped with elementary magnets 4 made
of hard or soft magnetic material, according to the meaning that has been defined
above. In the case of Figures 16, 17 and 18, the two magnetic components at the
ends of the device, where the arrows indicate that their polarities are oriented
upwards, have permanent magnetic elements of high intensity made of massive or bulk
material or in general are formed by composites the elementary magnets of which
have a high coercivity. The magnetic component 1 that is, instead, in an intermediate
position englobes magnetic elements that are, instead, formed by elementary magnets,
the polarities of which can be easily reversed by a magnetic field generated for
example by windings. The elementary magnets preferably have a high remanent magnetization,
but, according to the application, may also be made of soft magnetic material.
Furthermore, as may be seen from Figures 15 and 16, a winding
7 is provided around the portion of the tubular guide 6 that is traversed by the
central component 1. The winding 7 is supplied with electric current alternately
in one direction and in the other to enable successive reversal of the polarity
of the bistable magnetic component MB, for example having soft elementary magnets.
The electric current can also be supplied or modulated via PWM and PDM so as to
produce effective fields and consequently effective mechanical forces. By reversing
the polarity of the bistable component, it is thus possible to pass from a condition
in which the components of the device of Figures 15 and 16 attract one another (see
Figure 15b and Figure 17, where the arrows M indicate the direction of polarization,
and the arrows F indicate attraction forces) to a condition in which the components
repel one another (Figures 15a and 18). Consequently, if for instance the component
1 that is at the base of the column is kept clamped, the component 1 that is at
the opposite end of the column is alternately pulled (Figures 15b and 17) and pushed
(Figures 15a and 18). If the component located in a higher position is connected
to a driven member, it is thus possible to obtain accordingly a reciprocating movement
of said member with a push-pull effect, following upon the successive reversal in
polarity of the bistable component.
Also in this case, the effect is maximum in the case where
the magnetic elements of the composite magnetic components are aligned to one another
as previously illustrated in Figures 19 and 20. In addition, the number of magnetic
components can be any whatsoever. It is on the other hand possible to envisage a
guide column in the form of a tube having a non-rectilinear development, in which
case the magnetic components arranged within the tube can may have a curved configuration,
to adapt to the bends of the guide tube.
Figures 21a and 21b illustrate a variant embodiment with
three elements, in which the bistable component is perforated or else has a smaller
size in order to enable the two composites with permanent magnetization to be connected
to one another with rods. The bistable magnet, for example consisting of soft elementary
magnets, but preferably consisting of elementary magnets with high remanent magnetization,
is constrained to the structure or else is momentarily clamped via jaws. The polarities
of the two permanent magnets are opposite. In his way, the bistable magnet attracts
one permanent magnet and repels the other. The reversal of the polarities of the
bistable composite magnets causes the rigid system of the two permanent magnets
connected to one another to perform a reciprocating motion downwards or upwards.
This configuration of a push-pull system is particularly efficient in so far as
the permanent magnets act not only in the same direction but also in the same sense.
In the embodiment illustrated in Figures 21a and 21b, the
composite magnets can also be formed by a succession of a multiplicity (at least
two) of ferromagnetic or antiferromagnetic (FeMn, IrMn) layers coupled by means
of layer-layer interaction of exchange. In said composites, a first layer with high
coercivity and low saturation magnetization (e.g., SmCo, Co, NixFexCox
alloys, etc.) forces the magnetization of a second adjacent layer with low coercivity
and high saturation (e.g., Fe, NixFex alloys, etc.) in a desired
direction. The composite material thus obtained has a high product of energy (for
square cycles of hysteresis, this is defined as the product of the coercive field
and the saturation magnetization), which means a high saturation and at the same
time a high coercivity.
The embodiment represented in Figure 21 can be made entirely
using conventional magnets (bulk massive ones), or else can have both conventional
magnets (bulk massive ones) and composite magnetic components, one or more of the
latter possibly being of the type referred to above with interacting layers.
The means for obtaining reversal of the bistable magnetic
components can be formed by windings, which are arranged around the portions of
the tubular guide and are traversed in operation by the bistable magnetic components,
as already illustrated above, or else by windings arranged along the entire tubular
guide. An alternative embodiment is one which envisages prearranging a winding around
each bistable magnetic component within the tubular guide (Figures 22 and 23). In
the example of Figure 22, the winding 7 is supplied by means of a battery 8 rigidly
connected to the body of the component 1. In this case, there are also preferably
envisaged: a unit for energy generation or conversion 9, designed for example to
generate energy starting from the vibrations of the component; a supply device 10;
an electronic control unit 11; and a wireless-communication unit 12. Alternatively,
as illustrated in Figure 23, the winding can be provided with sliding contacts 7a,
which co-operate with electrical-supply paths 7b arranged longitudinally within
the tubular guide 6.
Figures 24 and 25 illustrate an alternative embodiment,
in which the non-magnetic body of each composite magnetic component 1 consists of
elastically deformable material and in particular a material that can be dilated
from the undeformed condition illustrated in Figure 24 to the enlarged condition
illustrated in Figure 25. The enlargement can be determined by means of an internal
actuator element 9, which can be brought from a condition of rest (Figures 24, 26
and 28) to an enlarged operating condition (Figures 25, 27 and 29).
In the dilated condition of the body of the magnetic component
1, illustrated in Figure 25, said body is pressed against the internal surface of
the guide 6 and is consequently blocked in position by friction along the guide
Thanks to the solution illustrated in Figures 24 and 25,
it is consequently possible to provide one or more magnetic components in such a
way that they can be clamped at any desired instant along the guide. Said functionality
enables new possibilities for exploiting the device according to the invention,
as will be described in detail in what follows.
Figures 26 and 27 illustrate a first example of embodiment
of the internal actuator element 9 designed to cause expansion of the body of the
composite magnetic component 1 illustrated in Figures 24 and 25. In this case, an
actuator member 9 in the form of a jaw is provided, having a substantially annular
conformation formed by two sectors 9A, 9B, each of which is, in turn, a magnetic
element with a direction of magnetization in its circumferential direction. Associated
to one of the two sectors, 9A, is an element 70. Said sector is made of bistable
magnetic material so that, if the winding 70 is supplied with a current alternately
in one direction and in the other, it is possible to reverse the magnetization of
said element so as to cause alternately attraction or repulsion thereof with respect
to the other sector 9B. In the condition of attraction, the member 9 assumes its
configuration of minimum encumbrance, corresponding to the resting condition illustrated
in Figure 24, whereas, in the condition of repulsion, the member 9 assumes the enlarged
configuration corresponding to that of Figure 25. Also in the case of the solution
illustrated in Figures 26 and 27, a battery supply can be associated to the winding
70, together with a unit for generating or converting energy and a wireless port
for communication and remote actuation.
Figures 28 and 29 illustrate a variant of the solution
of Figures 26 and 27, where the member 9 consists of four sectors, two of which,
set diametrally opposite to one another, are provided with a winding 70, which can
be supplied for generating a condition of repulsion that brings the member 9 from
the condition of rest illustrated in Figure 24 to the expanded operating condition
illustrated in Figure 25.
The actuation of the embodiment illustrated in Figures
24 and 25 or of any other solution designed to enable clamping in position of a
magnetic component along the guide enables a movement by successive steps to be
performed without any limits in the distance travelled or enables in general a worm-like
movement of a series of magnetic components according to the invention along a flexible
or rigid guide, for example a tubular guide, as illustrated in Figure 30. In said
figure, the sections 1-10 illustrate ten successive operating steps of a system
comprising a guide 6, set along which is a row of magnetic components according
to the invention, alternately designated by HM (hard magnets or permanent magnets)
and SM (bistable magnets, for example having elementary soft magnets). In other
words, according to the solution of Figure 16, there is provided a series of magnetic
components according to the invention, which are alternately equipped with high-intensity
permanent magnetic elements and with bistable elements, preferably formed by elementary
magnets with a high remanent magnetization. In the case of the solution illustrated
in Figure 30, each bistable magnetic component is of the type illustrated in Figures
22 and 23, i.e., equipped with a winding 7 of its own that controls magnetization.
In addition, the permanent magnetic components are each pre-arranged according to
the embodiment illustrated in Figures 24 and 25 (except as regards the absence of
the winding 7) in such a way that each of said components can be clamped on the
guide. In the drawings of Figure 30, the horizontal arrows associated to each magnetic
component indicate the direction of magnetization thereof, whilst the clamped condition
of a magnetic component on the guide has been indicated symbolically by a small
square in a position corresponding to the clamped component. Said representation
is purely symbolical, since clamping is obtained, as has been said, in the way illustrated
in Figures 24 and 25. As may be seen, in the condition 30(1) the magnetic component
furthest to the left is in a clamped condition. All the permanent magnetic components
are permanently magnetized with a direction of magnetization oriented towards the
right, as viewed in the figure. In the condition 30(1), the two bistable magnetic
components are in a neutral condition, since their windings are not supplied. The
condition 30(2) describes a subsequent step in which the bistable magnetic components
are magnetized with a direction of magnetization identical to that of the permanent
magnetic components. As a result of said magnetization, a force of attraction is
created between all the magnetic components, which leads the latter to pack against
the magnetic component set at the left-hand end, which is clamped in position (Figure
30(4)). At this point, the magnetic component at the left-hand end is released,
and the magnetic component at the right-hand end is clamped (Figure 30(5)). In the
subsequent step 30(6), the magnetization of the bistable magnetic components is
reversed (arrow pointing to the left) so that the magnetic components repel one
another, this bringing about advance towards the left, as viewed in the figure,
of all the magnetic components, except the one on the extreme right, which is clamped
(Figure 30(7)). Once said condition has been reached, the magnetic component on
the extreme right is released, and the component on the extreme left is clamped,
after which the magnetization of the bistable magnetic components is reversed so
as to bring about a movement of attraction that causes packing of all the magnetic
components against the clamped magnetic component, on the extreme left (Figures
30(9) and 30(10)). Once said condition has been reached, the element on the extreme
left is released, and the element on the extreme right is clamped, and the cycle
is repeated, so obtaining a stepwise advance of the series of magnetic components
towards the left, as viewed in the drawing.
Thanks to the aforesaid arrangement, it is consequently
possible to obtain movement of any driven member along a guide, which of course
may even be non-rectilinear.
Figures 31a, 31b and 31c illustrate types of actuation
in which either rigid or elastic polymeric non-magnetic means of separation or metallic
non-magnetic means of separation MS are arranged on the components for preventing
their direct contact and facilitating the passage between the condition of repulsion
and that of attraction.
Figures 32a and 32b are schematic illustrations of the
two operating steps of intake and pumping of a compressor system with valves VI,
VO of a flexure type or of the electrical type for control of intake and pumping
of air, gas or liquid. There are provided inlet and outlet openings for the fluid
and seal rings S on the components 4.
Figure 33 illustrates a multistage component consisting
of a plurality of independent bistable composite elements set adjacent to one another
or set on top of one another. Each element is equipped with its own winding. Consequently,
the multistage component, according to the currents applied to the windings, may
be configured in a multitude of levels of intensity of the resultant generated field
in one of the two polarities.
Figure 33a is a view from above of the multistage component,
in which a multitude of composites, according to the present invention, of the column
type are supplied by independent windings. In Figure 33b, the case is considered
where the overall composite along the axis z consists of portions with elementary
magnets made of different materials, and where control of each of these portions
can be made through windings that require different currents in order to act on
the polarity of the individual portion of composite. Figure 33c illustrates the
case where the coils associated to the portions of composite can be supplied with
alternating current with a modulation of the PDM or else PWM type.
Figures 34a and 34b illustrate a valve for regulation of
the flow of a gaseous or liquid fluid, which can operate indifferently with two
or three composite magnetic elements. In this case, the separation means between
the magnetic composites are preferably O-rings S made of elastic material, with
high resistance to wear and with low porosity to prevent leakages.
Figures 35a and 35b illustrate the case of a selector or
mixer for fluids, which can also be implemented indifferently with two or three
composite magnetic elements. As for the case of Figure 34, the separation means
between the magnetic composites are preferably rings made of elastic material, with
a high resistance to wear and with low porosity to prevent leakages.
Figure 36 illustrates a two-way deviator for fluids, whether
liquids or gases.
Likewise not excluded is an application of the magnetic
components according to the invention in a device that operates in the opposite
direction, for recovering electrical energy within a winding, following upon a movement
of a magnetic component according to the invention within the winding. A further
embodiment can envisage a hybrid use, in which an active system of the spring, shock-absorber,
damper or suspension type can act alternatively also as system for recovering the
energy generated by the movement of the magnetic elements in the winding means.
Of course, without prejudice to the principle of the invention,
the details of construction and the embodiments may vary widely with respect to
what is described and illustrated herein purely by way of example, without thereby
departing from the scope of the present invention.