PRIOR ART It has long been known to attempt to gain electrical energy from oscillating movements.

It is previously known from EP 1 100 189, for example, to generate electricity by transforming vibrations that are produced by means of wind, waves and human activity.

Yet in EP 1 100 189 piezoelectric elements are used to achieve this transformation.

Piezoelectric elements consist of ceramic material, which gives rise to strength problems. In addition, piezoelectric elements are sensitive with regard to temperature variations, meaning among other things that such systems suffer from cooling problems.

It is known from US 3 753 058 to transform electrical energy into mechanical energy by means of magnetostrictive actuators. Although it is indicated in the description that magnetostrictive actuators could be used in principle instead of piezoelectric elements, with the aim of being able to extract electrical energy from oscillating movements, no specific solution is demonstrated, rather all solutions shown are directed towards the contrary, namely transforming electrical energy into mechanical. In addition, the proposal exhibits the disadvantage that at least two coils have to be used to obtain a functional unit, which is not desirable from the energy viewpoint, since it results in impaired efficiency. There are problems/disadvantages for other design reasons also that mean that the concept has not resulted in actual practical application. A concept according to similar principles and with the same type of problems is known from EP 443 873.

Furthermore, a method for using a magnetorestrictive transformer intended to be used as a power source in environments that are hard for electronics is previously known from Lundgren, A. et al.,"A magnetostrictive electric generator" ; IEEE Transactions on Magnetics, Vol. 29, No. 6, November 1993. In this case, however, only very low power output could be demonstrated, namely a small output of 5 watts when using quite a large magnetoelectric body. Since magnetoelectric material is very expensive, this known method appears entirely unacceptable commercially.

There is thus no effective method or device today for being able to transform vibration energy into useful electrical energy, above all not with regard to vibrations with a frequency exceeding 5 Hz, still less when they exceed 50 Hz. In connection with combustion engines, for example, there is and has long been a great effort to increase efficiency. It is the case for a combustion engine that only around 30-40 % of the energy content in the fuel can be converted into directly useful energy according to current technology. Approx. 15 % of the energy not utilized consists of vibration energy, i. e. approx. 50 % of the energy that can be utilized directly in a vehicle. It is perceived therefore that it would be extremely valuable, not least for environmental reasons, if a portion of said vibration energy could be utilized.

BACKGROUND TO THE INVENTION One object of the present invention is to eliminate or at least minimize one or some of the aforementioned problems, which is achieved by a method for increasing efficiency when using a combustion engine that generates vibrations during operation, a portion of said vibrations being converted into electrical energy in a mechanoelectrical transformer, in accordance with what is defined in the claims.

Thanks to the invention, previously wasted and often actually harmful vibration energy can thus be utilized, since it is possible thanks to the invention to obtain sufficient energy density by means of a magnetoelectric body to be able to utilize vibration energy commercially. This is advantageous above all in connection with boats/vehicles in which the energy utilized can advantageously be reused directly in their own system.

It should be pointed out that the solution according to the invention must appear surprising against the background of what is previously known from Lundgren, A et al. , in which a power output of a modest 5 watts is presented, meaning that the magnetoelastic body (Terfenol) only exhibits a very small energy density, i. e. it can only produce a very small amount of energy per unit of volume. The explanation appears to lie in the fact that, prior to the invention, the basic principles for being able to obtain efficient operation of a magnetoelectric body were not fully realized. Thus it was not understood that to be able to turn the dipoles in the magnetoelectric body within an effective operating range, the braking force arising from the H-field induced had to be taken into account as well as the purely mechanical elastic pressure component. In Lundgren et al. , it is evident that one is in a stress range with pressure variations that are less than 2 MPa during a work cycle, which is not sufficient to compensate for the braking force from the induced H-field.

According to further aspects of the invention, it is the case that : - said magnetic prestress is achieved at least in part by means of permanent magnets, - said magnetic prestress in said body is between 0.05-1. 5 Tesla, preferably between 0. 1-1. 0 Tesla, more preferredly approx. 0.5 Tesla, - said body operates cyclically under the influence of said vibrations and the body is thereby exposed to a mechanical stress cycle in the range +70 MPa, which consists preferably chiefly of compressive strains, said stress cycle more preferredly chiefly lying in the range 0-100 MPa, - said electrical energy is returned at least partly to a system of which said engine forms a part, - said vibrations are within a range of 5-50000 Hz, preferably over 10 Hz, and more preferredly over 50 Hz, - said mechanical prestress is achieved by means of a housing unit inside which said body is prestressed, - said housing unit has an ellipsoid shape and said body is arranged so that its longitudinal axis coincides with the longitudinal axis of the housing unit.

The invention also relates to a system unit comprising at least one vibration-generating unit, characterized in that a mechanoelectrical transformer is disposed in said system unit for receiving at least a portion of the vibrations that are produced by said vibration- generating unit, and that said mechanoelectrical transformer has a coil with at least one output that is connected directly or indirectly to at least one electricity-consuming, electricity-storing or electricity-transforming unit.

According to further aspects of said system unit it is the case that: -said mechanoelectrical transformer comprises a body with a magnetoelastic coupling factor k33 of between 0.1-1. 0, preferably greater than 0.4 and more preferredly greater than 0.6, - the Curie temperature of said body is between 150-1000°C, preferably at least 200°C and more preferredly at least 250°C, - said body is formed as a bar around which said coil is arranged and that at least two permanent magnets are arranged by said body, said magnets preferably being provided in the form of bars that extend essentially parallel to the longitudinal axis of the body, - said permanent magnet generates between 10-100 kA/m, preferably 30-70 kAlm, more preferredly around 50 kA/m, - said body is provided with a prestress in the form of compressive force,

- the system is a boat, - said vibration-generating unit consists of a combustion engine, - said body is placed in a device that at least partly also fulfils the function of an engine mounting, - said bar is arranged inside a housing unit, - said housing unit has a greater extension in at least one direction in a longitudinal plane that is arranged perpendicularly in relation to a cross-direction, and said bar is arranged parallel to said longitudinal plane, - said prestress is provided in an axial direction to said body, - said prestress is applied in a radial direction to said body, - said prestress is applied in both an axial and a radial direction to said body, - said radial prestress is provided by means of an elastic organ that is placed around the body, - said elastic organ comprises some form of wire/fibre that extends chiefly in a circumferential direction around the body, - said elastic organ comprises a type of sleeve that is placed onto the body by means of shrinking and/or joining, - said radial prestress is provided by means of a fluid, preferably hydraulically.

According to a preferred specific embodiment, the invention can be used instead of, or as a complement to, a generator, due to which the advantage is also obtained that a longer life and thereby lower maintenance costs are achieved.

BRIEF DESCRIPTION OF FIGURES The invention will be described in greater detail below with reference to the enclosed figures, in which: Fig. 1 shows an outline diagram of a preferred embodiment according to the invention, Fig. 2A shows a diagram that illustrates the properties of a magnetoelastic bar made of a preferred material, a plurality of isobar curves showing the change in length of the bar depending on an external magnetic field, the H-field, Fig. 2B shows the influence of the magnetic field, the B-field, in a coil around a bar according to Fig. 2A with parameters corresponding to Fig. 2A, Fig. 2C shows a selected part of the diagram 2B and illustrates the change in permeability of a given bar according to the invention that is exposed to the same force in different H-fields,

Figs. 2D, 2E show the same diagram as in Fig. 2A and 2B, including a work cycle for a bar that is influenced in a displacement-driven system, Figs. 2F, 2G show the same diagram as in Fig. 2A and 2B, including a work cycle for a bar that is influenced in a force-driven system, Fig. 3 shows an alternative execution according to the invention, Fig. 4 shows the principles of a specific application of the invention, Fig. 5 shows a modified application according to Fig. 3, Fig. 6 shows another conceivable application area for the invention, Fig. 7 shows another conceivable application area for the invention, Fig. 8 shows a modification according to Fig. 6, Fig. 9 shows a specific preferred application in a vehicle according to the invention, Fig. 10 shows a modified embodiment of an execution according to Fig. 3, Fig. 11 shows a conceivable specific execution of an application according to the invention, Fig. 12 shows a modified execution of an application according to Fig. 11, Fig. 13 shows a modified embodiment of a bar according to the invention, Fig. 14 shows a diagram that illustrates the possibilities with an execution according to Fig. 13, Fig. 15 shows a modified embodiment of an execution according to Fig. 13, Fig. 16 shows another modified embodiment of an execution according to Fig.

13, Fig. 17 shows another modified embodiment according to the principles of the execution according to Fig. 13 and Fig. 18 shows a modified embodiment of the arrangement of permanent magnets by a bar according to the invention.

DETAILED DESCRIPTION OF FIGURES Fig. 1 shows an outline diagram of a device according to the invention. This device consists of a magnetostrictive bar 1 with a wire 2 of conductive material (e. g. copper) forming a coil 2A wound around it. The wire ends 2B, 2C of the coil 2A are connected to a load/device 8, which in the present case is exemplified by a charge regulator 8, which is coupled to a battery 22. Attached to each end of the bar 1 is a permanent magnet 4,5, which is positioned in a selected way to"turn the magnetic moments"to the best position in the bar 1. This can also be popularly expressed as achieving a magnetic prestress in the bar by means of the permanent magnets 4,5 and their positioning. It is expedient, but not necessary, for there to be no electrical contact

between bar and magnets, since this can have a certain negative effect on the efficiency, due to eddy current losses. The bar 1, coil 2A and magnets 4,5 form a unit, which is termed the base unit 3 below. The base unit 3 is mounted fixedly at one end 5A in a "fixed point 6", for example a chassis in a vehicle. The other end 5B of the bar 1 is fixedly mounted against the body 7 that is to influence the base unit 3 with an oscillating mechanical force Fv. According to a preferred embodiment, the base unit 3 is also mechanically prestressed between the fixed point 6 and the oscillating body 7 with a certain force, so that the mechanical stress variations of the bar 1 will lie in an optimum working range. One of the reasons for advantageously providing a mechanical prestress according to the invention in certain cases is that preferred materials for the bar more often than not have a good capacity for absorbing and handling compressive stress but a limited capacity for absorbing tensile stress.

The force Fv that influences the compressive stress in the bar 1 results in a change taking place in the magnetic properties in the bar 1, as described below. When the magnetic flux that is produced by the permanent magnets 4,5 and passes through the coil 2A varies, a voltage U is induced between the ends 2B, 2C of the coil, meaning that electrical energy can be taken out of the device 8.

The invention utilizes several phenomena and shows how a material with magnetoelastic properties can be used to convert mechanical energy, e. g. in the form of vibrations, into electrical energy.

The fundamental physical phenomenon that is utilized is that when a magnet oscillates inside a coil executed from electrically conductive material, e. g. copper, an alternating voltage is produced between the ends of this coil, which voltage can be utilized to drive electrical energy when a load is connected to both ends of the coil.

According to the invention, the magnetostrictive bar 1 acts together with the permanent magnets 4,5 as the oscillating magnet according to the above, since its characteristic is such that the bar 1 achieves a magnetic field change when it is exposed to a force Fv.

The force Fv generates a pressure effect in the bar, which pressure effect corresponds metaphorically to changing the position of a magnet in a coil according to the description above. The job of the permanent magnets 4,5 in this context is to apply a magnetic field around the bar.

The magnetostrictive bar 1 according to the preferred case is executed from an. alloy of rare earths among other things, in this example TERFENOL-D (the name TERFENOL- D derives from terbium, iron, dysprosium and"Naval Ordnance Laboratory", where it was developed), which has a high magnetoelasticity in a temperature range suitable for many applications (including combustion engines). Magnetostriction is a phenomenon found in ferromagnetic materials causing them to change their shape in a magnetic field, the magnetic domains of the material orienting themselves according to field lines in the magnetic field and any mechanical force applied. The phenomenon is based on atomic forces and thus takes place incredibly fast and is thus very strong. TERFENOL-D has magnetoelastic properties that are approx. 1000 times better than e. g. iron. The so-called coupling factor $33=approx. 0.7) for Terfenol is tremendously high compared with iron.

The invention utilizes the fact that the magnetostrictive phenomenon can be applied"in reverse", i. e. that a change of shape of the material (e. g. a bar) produces a change in the magnetic properties (of the bar).

When the bar 1 is exposed to a change in mechanical stress (compressed and drawn apart respectively), the permeability of the bar (material parameter that influences the magnetic properties) will be changed, due to which the magnetic field will also be changed and thus the magnetic flux.

The voltage U, which is an alternating voltage, is"proportional to"or"dependent on" physical dimensions, the speed/frequency of the force Fv that acts on the bar 1, the magnetostrictive material in the bar 1, the amplitude of the influencing force Fv (the pressure change in the bar), temperature and the material (conductive capacity), thickness and number of windings of the coil 2A.

In the event of a vibration, the bar will be compressed/decompressed at the same vibration frequency as the vibration. The bar will thereby be exposed to a mechanical stress change. This results in a change in the bar's permeability and thereby in the magnetic field and the magnetic flux. Due to the fact that the magnetic flux is changed over time (d/dt), a voltage is thus produced, which can be expressed as follows: <BR> <BR> do-dur dB do<BR> <BR> <BR> <BR> <BR> <BR> <BR> Vibrationenergyt------&num ------&num ----&num U&num electricalenergy dt dt dt dt This alternating voltage, U, will thus depend on the frequency and amplitude of the vibrations as well as the magnetic system.

When the magnetic flux is changed, an alternating voltage U will be generated in the coil 2A that has been placed around the bar 1. In the load/device 8 that is attached between the two ends 2B, 2C of the coil, the voltage produced thus drives a current that can be used in various ways, at best following adaptation. Preferably the power taken out via the load is increased when the frequency increases and is reduced when the frequency reduces respectively. If the load is a charge regulator for a battery, the increase in the load takes place automatically since the regulator manages to drive a higher direct current to the battery at a higher frequency. In certain applications, it can be advantageous to have two or more batteries 22,22'coupled to a unit 3 via a charge regulator with automatic control system, which e. g. distributes the charging current according to a certain order of priority, e. g. with the aim of first obtaining a full charge in a primary battery, following which the charging current can be distributed to secondary sources.

To utilize the base unit 3 optimally, it is advantageous in certain oscillating systems for the prestress on the magnetostrictive bar 1 to correspond roughly to half the maximum amplitude for the oscillating part by which the base unit 3 is arranged, so that at maximum amplitude the bar oscillates between an upper O position where it is largely unloaded axially and a lower maximally compressed position.

Furthermore, the magnetic bias that is applied to the permanent magnets should be in the range 10-100 kA/m, preferably in the interval 40-80 kA/m and most preferredly approx. 50 kA/m.

In addition, it is advantageous if the electric load is increased as the frequency of the oscillating force increases, since the increasing voltage in this case increases the capacity for maintaining the same current with a higher resistance in the circuit.

Figs. 2A and 2B show in greater detail the result of experiments carried out in a trial system. The system thus comprises a magnetostrictive bar (called the bar) that is. executed in the Terfenol material and is otherwise arranged in accordance with what is shown in Fig. 1. In the experiments, the bar has been statically prestressed (mechanically) at ten different levels (1,6. 5,12, 19,26. 5,34. 5,42. 5,50, 57.5 and 65 MPa respectively) so that each curve represents a certain mechanical prestress, with the upper curve in Fig. 2B showing an example with only 1 MPa (in the form of compressive stress) and the lowest curve showing an example of only 65 MPa.

The quantities included and shown in Figures 2A and 2B are: B = magnetic flux density (induction, in Teslas), H = magnetic field strength (in kOe) and AM = relative change in length of the bar.

Fig. 2A shows a diagram that illustrates properties of a magnetoelastic bar made of a preferred material, a plurality of isobar curves showing the change in length of the bar depending on an external magnetic field, H-field.

Point a in Figs. 2A and 2B is represented, by a bar that has a prestress of 1 MPa and where an external magnetic field of approx. 40 kA/m has been applied to the bar 1 by means of permanent magnets. By increasing the H-field from 0 to 40 kA/m, a certain change in length will occur, which manifests itself in that the isobar 1 MPa follows a bent curve up to the right of the picture, with (after approx. 10 kA/m) a decreasing derivative. The bar is thus lengthened by a certain amount, Ax, in this case.

Furthermore, Figs. 2A and 2B show that a Terfenol bar that operates in a non-closed electric circuit acts like a magnetoelastic spring, i. e. the changes will follow a vertical line L in the diagram 2A and 2B respectively from a-b when the load is increased, such that the pressure increases successively in the bar when an external load is applied, energy being stored in both the magnetic and elastic system of the bar without any change of the external applied H-field.

Fig. 2C shows a simplification of the right half of the curves in Fig. 2B. Only a selected part of the upper right corner of Fig. 2B is reproduced in Fig. 2C, namely the upper pressure curve P1 (1 MPa) on the one hand and the lower pressure curve P10 (65 MPa) from Fig. 2B. Three different areas, 1-3, have been marked above these in Fig. 2C.

Above each of these areas are figures that illustrate diagrammatically how the magnetic dipoles in the Terfenol bar are oriented inside the respective area. The force F that is shown to act on the respective figure (i. e. the bar) should be regarded in this case as being constant. In area 1 it is clear that for the applied force F the magnetic dipoles in the material will be completely compressed. In this area the Terfenol bar will therefore act in principle like a completely rigid Hook's spring. In area 2, on the other hand, the greater H-field has caused the magnetic dipoles to turn to an oblique position, meaning that the bar no longer only acts as a pure Hook's spring. The increased H-field has thus influenced the dipoles so that they can counteract the applied force F sufficiently to remain oblique. In the third area, the case is illustrated that the H-field is sufficiently great to turn the magnetic dipoles completely in line with the H-field. A type of rigid

Hook's spring is also obtained thereby, as in area 1, since the magnetic dipole does not allow itself to be influenced by the force applied. The H-field should thus be adapted so that the bar works in area 2.

The elastic properties of the bar are thus both magnetic and mechanical. The"magnetic spring", however, is much softer than a pure Hook's spring and depends on the relationship between the magnetic reaction force and the mechanical load (dimensional change in the material). The higher the external pressure applied to the system (the bar), the higher the magnetic field strength required to turn the magnetic dipoles to an optimum sphere of influence. Like many technical systems, it is capable of being used to show the transformation of energy in the form of a work cycle. In Figs. 2D, 2E and 2F, 2G respectively, different forms of work cycles are shown for a bar according to the invention.

Figs. 2D and 2E show the work cycle for a Terfenol mechanoelectrical generator that can be described as displacement-driven. The principles of electric current induction in the coil for the Terfenol generator are the same as in the secondary winding for a transformer, i. e. nature opposes changes. A change in the mechanical stress results in a linked change in the magnetic induction B. To counteract changes in the B-field, an electric current will be induced in the coil that generates an H-field, which contributes to maintaining the B-field intact. This is symbolized by the movement from point a-b in the work cycle in Figs. 2D and 2E. This change is instantaneous in principle. Thereafter the bar will be compressed, in which case energy will be taken out of the mechanical system in the form of electrical energy. A braking force is created by the displacement of the induced H-field. At the same time, the H-field introduced produces a change in the magnetic energy that will be released to the load that is connected to the coil in the system, e. g. a charge regulator. As in the case with a loaded secondary coil in a transformer, the voltage in the loaded circuit in the Terfenol generator will be reduced due to the induced current that counteracts the change in the B-field, which leads to a reduction in the counterinduced current and thus a reduction in the braking force in the compression and a reduction in the energy output, i. e. a reduction in dB/dt. Thus the bar will be compressed, which is illustrated in the diagram by section b-c in diagrams 2D and 2E.

As is clear from the diagram, this change takes place at a higher pressure level in the bar than when the bar is exposed to corresponding loading in a non-loaded, non-closed coil (then the bar thus moves along a vertical line, L, in the figure). When point c is reached,

i. e. the downward movement has been completed, a momentary pressure relief will occur in the bar, which is illustrated by the change from c-d in Figs. 2D and 2E. The bar will then be influenced by an opposed movement to return to the position of its original length, which means a move along the line d-a.

As is evident from the diagram, the bar is normally influenced by a lower force when moving in a decompressing direction (along d-a) than when it is compressed (along b- c). This property of a system unit according to the invention results in an advantage in many situations, since many magnetoelastic materials tolerate compressive force better than tensile force. Thus more work is normally carried out when the bar is compressed and less work is carried out when the bar is decompressed.

As already mentioned earlier, the work cycle that is illustrated in Fig. 2D and 2E is to be described as a displacement-driven work cycle, the opposing force from the Terfenol generator being marginal in relation to the driving force. This should be regarded as being the most reasonable analogy when using a very powerful engine of e. g. 500 kW with a corresponding vibration loss of approx. 75 kW, a 500 watt Terfenol generator not being able to be regarded as representing any notable opposing force. It should be observed over and above this that the work cycle that is shown in Fig. 2D and 2E has been approximated to be ideal.

In Fig. 2F and 2G, a work cycle is shown in a system in which the Terfenol element is force-driven instead, i. e. in which the force that influences the Terfenol bar is constant in principle during the compression phase. In this case the work cycle is changed somewhat, since during the phase when the actual work is carried out from b-c the work cycle follows a certain isobar. An isobar will be followed in this case in the return movement also, along d-a. As is evident from Fig. 2G, it is the case that at the same time as the H-field increases when the pressure on the bar increases, a certain reduction of the B-field will take place. This occurs as a result of the load-induced current in the coil being partly consumed in the load that is connected. The work has thus been utilized as electrical energy in e. g. a charging unit.

Fig. 3 shows the principles of a preferred application according to the invention, the base unit 3 being fitted on a vehicle to drive a charge regulator 8, which can supply a current of not insignificant magnitude. The charge regulator 8 can consist advantageously of a conventional unit that is currently known in itself. It is evident from the figure that the base unit 3 is fixed inside an elliptically shaped housing 9. Arranged.

centrally on each longitudinal side of the housing 9 are attachment organs 9A, 9B, so that the device 3,9 can be installed between the chassis 6'and engine 7'. The unit 3, 9 is best used in exchange for a conventional engine mounting. The unit 3,9 thereby fulfils not only the function of current generator but also the function of vibration damper, which is a major advantage of the invention. Furthermore, it is shown diagrammatically according to the figure that the fixing devices 10A, 10B are arranged between the ends 5A, 4A of the base unit 3 and the short inner ends of the housing.

According to a preferred embodiment, these fixing devices 9A, 9B are formed with such dimensions that the bar 1 is exposed to a certain compression (compressive stresses) in a non-influenced position of the housing 9. As is clear from the figure, the bar 1 will be positioned across the direction of movement for the substantial portion of the vibration forces. The vibration forces will thus first be propagated down into the housing 9 and influence this to be compressed or elongated respectively, due to which a change in the length of the housing occurs in the direction in which the bar 1 extends. Due to this, the same phenomenon for current generation will occur as described above with reference to Fig. 1. It is expedient if a prestress of the bar l is selected that is also adequate in relation to the static force with which the engine 7'influences the device 3,9 in a position of rest. The bar 1 is thereby exposed prior to fitting in the vehicle to a greater compressive stress than after it has been fitted, since the weight of the engine will compress the housing 9 somewhat and thereby produce a certain reduction in the compressive force. This embodiment is therefore advantageous from several viewpoints, including from the strength point of view.

It is advantageous to use precisely an ellipsoid shape for the housing 9. The ellipsoid namely results in the great advantage that a movement that is propagated across the longitudinal sides (in the same direction as the vibration movement, Fv) is reduced to roughly a third with regard to the movement in the perpendicular direction. This thus means that the movement in the longitudinal direction of the bar is roughly a third at the same time as the force is roughly three times as great. This is advantageous since a. bar of a preferred material according to the invention should preferably not be exposed to amplitudes that are too great. To obtain sufficient power from a Terfenol bar, often a movement of some tenths of a mm is enough to obtain sufficient power.

According to an example of how the device according to Fig. 3 can function as a generator, it holds good (as an approximation) that the frequency of the vibration is approx. 500 Hz. If acceleration that acts on an engine of normal size is assumed to be approx. 25 g (g=9.8 m/s), this means that an estimated power of approx. 500 watts can

be obtained. If a charge regulator 8 is assumed to charge a 12 V battery, thus a current of approx. 30 A is obtained. In the example, the base unit 3 consists of a bar manufactured from TERFENOL-D that is 80 mm long and 20 mm in diameter. The "absorbing"coil 2A consists of copper with a diameter of 2 mm and with 100-150 turns.

The permanent magnets 4,5 are in the order of magnitude of 50 kA/m.

The bar 1 has been prestressed with a force that corresponds to the force that is applied from the oscillating body, i. e. the maximum amplitude.

Fig. 4 shows an alternative application according to the invention, according to the same basic principles as described in connection with Fig. 1. Here, however, an application is shown in which a stationary engine 7"is arranged on a floor 6". Arranged between the fixing devices 7"A, 7"B and the floor 6"are at least two current-generating units 3"A, 3"B, which each supply a charge regulator 8"A, 8"B.

Fig. 5 shows diagrammatically in principle the same type of application as in Fig. 3, but the base units 3 are enclosed in the housing 9 in accordance with Fig. 2.

Fig. 6 shows that a base unit 3 according to the invention can be arranged advantageously between different engine parts to damp vibrations and/or to produce electrical energy. Furthermore, the figure shows that a number (five in the present case) of base units 3 that drive a common device 8 can advantageously be coupled in parallel.

According to the figure, this is exemplified by having the base units 3 arranged between the engine block 11 and cylinder head 12.

Fig. 7 shows that a base unit 3 according to the invention can be used to transform a certain portion of the movement energy of a rotating shaft 13 into electrical energy in e. g. a charge regulator 8. The unit 3 is arranged in this case between a foundation 6 and a non-round device 14 that is fixed to the shaft 13. On rotation the non-round device 14 acts on a bearing 15 arranged at the upper end 4A of the base unit, so that the base unit 3 will oscillate. The base unit 3 is suitably provided at the bottom with a spring package 16 between the foundation 6 and the lower end 5A of the base unit, with the aim of avoiding the base unit 3 being exposed to forces above a certain limit. A unit of this kind, or if applicable several, can advantageously replace a conventional generator. A significant disadvantage of current generators is that they have a limited life dependent on many moving parts, which suffer wear. For a lorry it is not unusual for the generator to have to be replaced three times during its lifetime. By using a device according to the

invention instead, a charging unit is obtained that never needs to be changed during the lifetime of the vehicle.

Fig. 8 shows an arrangement similar in principle to Fig. 7, but a base unit 3 enclosed in a housing 9 is used instead according to the principles described in connection with Fig.

3.

Fig. 9 shows a specific application according to the invention for being able to damp vibrations and produce energy from the wheel suspension of a vehicle. A chassis 6 is shown on which a wheel 17, a shock absorber 18 and a spring strut 19 are arranged.

Inside the central space for the spring strut 19, a base unit 3 according to the invention has been arranged by attaching the upper end 4A of the unit to the chassis 6 and its lower end 5A in contact with a spring 16, the lower end of which is fixed to the wheel 17 or a slewing bracket (not shown) for the wheel 17. Precisely as in accordance with Fig. 6 and 7, the task of the spring 16 is to protect the base unit 3 from being exposed to great forces. Thanks to the device according to the application shown, vibrations that occur when a vehicle is driven on an uneven base can thus be converted to electrical energy in a charge regulator 8 or used in another load. According to an alternative execution for being able to damp vibrations and produce energy from the wheel suspension of a vehicle, a device according to Fig. 8 can be applied to the chassis 6 with the change that the shaft 13 is driven/rotated by means of the movement of the wheel 17, e. g. by providing a rack (not shown) that moves up and down with the wheel 17, which drives a cog wheel (not shown) on the shaft 13.

Fig. 10 shows a modification of a device according to the principle described in Fig. 2.

A view from above is shown of a housing 9 that is ellipse-shaped from the side. It is clear that the housing in the view from above is essentially circular and that three base units 3A-3C are arranged symmetrically with regard to a centre device 9C through the housing 9. The three base units are connected in parallel so that they drive the same load 8. Several units 3 can hereby be driven via one and the same central device 9fixing point, e. g. in an engine mounting. Certain flexibility is thus obtained from the range/production viewpoint. A varying number and/or different types of base units 3 can then be installed in the same type of module unit 9, so that different types of properties can be obtained. It is also possible hereby to create devices with several interacting arrays of base units 3, such as a unit 9 that includes 6 base units, for example, only three base units being active up to a certain amplitude range and all 6 base units being active when the amplitude exceeds said range.

Fig. 11 shows a further application according to the invention. A base 6 is shown, e. g. a chassis, which is exposed to vibrations. Arranged above this is a housing 7 that is fastened to the base by means of e. g. a screw 27. Arranged inside the housing 7 and between its central part and the base 6 is a bar-shaped device 3 according to the invention. The bar-shaped device 3 has the coil 2 connected to a charge regulator 8, which charges a battery 22. The battery 22 drives a circuit board 25 and is connected via a shorter lead 24B to a sensor unit 23. In the bottom of the housing 7 is a sealing cover 26, which encloses the unit 3 together with the housing. The sensor 23 can in principle be any sensor whatsoever, e. g. a temperature sensor or a pressure sensor. As soon as the base 6 vibrates (i. e. when the engine is operating, for example, if a vehicle is involved), the unit 3 will start to generate an alternating voltage in accordance with what was described earlier. The charge regulator 8 will then ensure that the battery 22 is charged continuously. The circuit board 25 hereby obtains the current required to be able to be active. In addition, the required current is conveyed to the sensor unit 23 by the contact 24A and lead 24B so that this is also activated. Via the same connection 24 the sensor will send measured values back to the circuit board 25. Arranged on top of the housing 7 is an aerial/transmitter unit 29, which is also driven by the battery unit 22 and which emits signals to a control centre/regulating unit 28. Thanks to this arrangement,. cabling can thus be completely avoided between the sensor unit 23 and the control unit 28. In the case of large fixed diesel engines, for example, there can often be over a hundred temperature sensors. Operating problems occur not infrequently on such engines due to erroneous indication by one or some of the sensors, which erroneous indication is often shown to be due to problems with the cabling. A solution according to the invention thus means that e. g. problems of this nature can be solved effectively. Cabling is undesirable in many other contexts also, since it is expensive and means a risk of malfunction that is relatively difficult/lengthy to diagnose. In a vehicle it would therefore be a great advantage to provide units according to the principles described above, so that cabling can largely be eliminated.

Fig. 12 shows a modified execution of a device according to Fig. 11. The unit is of the same sort in principle as described with reference to Fig. 11. However, the difference is that there is no lead/cabling between the sensor unit 23 and the housing 7. There is instead a receiver/transmitter unit 29'arranged by the sensor unit 23, which receiver/transmitter unit 29'sends measuring information to the transmitter/receiver unit 29 by the housing 7. The receiver/transmitter unit 28 is driven according to the same principles as the receiver/transmitter unit 29 by the housing, i. e. by means of a dedicated voltage-generating unit 3'that supplies a charge regulator and battery for the

circuit board 25'that is arranged by the sensor unit 23. This voltage-generating unit 3' also drives the sub-elements forming part of the sensor unit 23. Thus all units are fully self-supplying and cabling is completely avoided.

According to an adjustment according to the invention, an axial mechanical prestressing load can advantageously be balanced with a radial mechanical prestress and/or an axial displacement magnetization with the aim of maximizing the change in magnetization in the bar element in relation to the mechanical stress cycle. An optimal magnetoelastic working point can be retained by way of this measure in a considerably larger range of mechanical load situations.

Through a radial prestress more electrical energy can also be extracted during the half- period of the mechanical work cycle in which the bar element should actually be driven by an axial tensile stress (which is considerably more difficult to apply and due to the ordinarily low tensile strength in the bar element less suitable). The radial prestress can be achieved for example by winding a wire, fibre or the like around the bar element, this being applied under an adequate tensile stress. A further advantage of spinning a winding over the bar element is that its mechanical integrity is increased and the risk of delamination in connection with laminated bar elements is considerably reduced.

Fig. 13 shows an execution of a bar 1 according to the invention that has been provided with a winding 41 that has the task of acting as a radial prestressing unit 40. The material in the winding is best executed in a material with a high modulus of elasticity that is non-conducting, e. g. a composite material containing kevlar fibres.

Thanks to this radial prestress, the optimal working range for a bar can be moved, which is illustrated in Fig. 14 ? which shows the B-field on the y-axis and the axial force that acts on the bar on the x-axis. The curve a shows that the optimal working range 0., for a non-radially prestressed bar ends up in a lower axial force range compared with a radially prestressed bar, which is represented by the curve B, where the optimal working range Op for the bar lies at a considerably higher force level with regard to the axial force Fv that acts on the bar. This can popularly be expressed as forcing up the magnetic dipoles from area 1 in Fig. 2C to area 2 in Fig. 2C by means of the radial prestress. It is thus possible to adapt the bar/system to be suitable for a certain working operation by means of the radial prestress.

Fig. 15. shows an alternative execution for achieving radial prestressing. Here it is demonstrated that a clamp sleeve is used consisting of two halves 42,43, which are clamped by means of threaded joints 44. An elastomer 45 is best used between the sleeve joint 42,43 and the bar 1 with the aim of obtaining optimal elasticity in the radial prestress. A spring element 44A is preferably also used in the threaded joint to obtain optimal elasticity in the radial prestress.

Fig. 16 shows a further alternative of a radially prestressed bar 1, in which a sleeve 46 of suitable material is formed with a through cavity adapted to the outer diameter 1 of the bar. To obtain adequate prestressing, the bar 1 is cooled down before it is inserted into the adapted cavity 46A, following which the desired radial prestress is achieved when the bar has expanded following heating to working temperature. It can also be advantageous in connection with positioning of the bar in the cavity 46A to have turned the magnetic dipoles to area 3 according to Fig. 2C, so that the magnetic dipoles also contribute to a reduction in the diameter prior to introduction into the cavity, which further increases the radial prestress.

Fig. 17 shows another execution with the aim of being able to obtain radial prestress. It is shown that the bar 1 is arranged inside a cavity 50, which is filled with a fluid that can be compressed, suitably oil. The fluid is enclosed by a housing 51 and a cover 52. When the bar 1 is compressed, its diameter will be widened somewhat, which leads to an increased pressure p in the fluid in the cavity 50. A radial counterpressure is thus obtained automatically hereby, according to the desired radial prestressing principle. In addition, the system makes it possible for an external pressure to be applied momentarily with the aim of further strengthening the radial prestress by means of the fluid.

Fig. 18 shows a preferred execution of a unit 3 according to the invention. It is shown that the bar 1 is provided with a plurality of magnets 4,5 that consist of bar-shaped elements. In the example shown, six bar-shaped permanent magnets 4,5 are. used that are arranged embedded in a housing 47 symmetrically with regard to the longitudinal axis of the bar 1. All bars are arranged with the same pole in the same direction, so that . an evenly distributed magnetic field is created in and around the bar 1. The unit 3 is also suitably provided with some form of magnetic-flux-equalizing"cover" (not shown) for the purpose of further equalizing the magnetic flux in and around the bar 1. It is perceived that the number of bars can be varied within wide boundaries, just as different

combinations of different types of bars can be used with the aim of obtaining an evenly distributed field.

The invention is not limited to what has been indicated above, but can be varied in the scope of the following claims. It is perceived inter alia that when it is intended to achieve a power supply to e. g. electronic equipment of various types, which is placed in such a position (or for another reason) that it is not wanted to use cabling, this invention can come in very handy. The device can be adapted within wide limits to utilize mechanically oscillating movements of very different types, making it very usable.

The device can be used advantageously to charge rechargeable batteries. It should therefore be advantageously possible to provide a large quantity of devices of varying types in a vehicle for different types of work/function.

The device can be used advantageously for example where it is difficult to lay cable for supplying power and/or communication (e. g. exchange of measuring information). For communication it is possible for example to use Bluetooth to send measuring signals to a central location (e. g. in a car) or to other units that must have the information (machine to machine communication). A Bluetooth circuit requires namely relatively little power to function, which means that even small vibrations can suffice to drive such a circuit by means of the invention. If on the other hand the device is fitted where large mechanical forces occur, e. g. in a shock absorber or between an engine and a chassis, a large current/voltage can be utilized from the device, so that it (one or more) can then replace a conventional generator.

It is also perceived that other materials with corresponding good magnetoelastic properties (depending on what is to be achieved) can be used as a"bar"in the device.

Furthermore, it is perceived that shapes other than bars can be used to utilize the invention. In addition, it is perceived that amorphous material can advantageously be used as a bar in certain situations, including when very small oscillations are present.

It is also perceived that several"tapping points" (different numbers of turns) can be used to get a desired voltage from a device. It is perceived that the invention is not limited by what has been stated above. Thus it is perceived that a device according to the invention can advantageously be used in mobile units other than terrestrial vehicles.

For example, in aircraft, where many vibrations occur, there is great potential for being able to derive major advantages from the invention. It is also perceived that it does not

necessarily have to be a resistive load 8 that is used, but that also a capacitive and/or inductive load can be used. It is also perceived that even if permanent magnets are a preferred solution for the magnetic prestress in the bar 1, a coil can advantageously be combined, e. g. by having a coil that is only driven/connected in the event of forces above a certain level, with the aim thereby of optimizing the unit further. It is also perceived that many of the advantages of the invention can be obtained entirely without using permanent magnets, i. e. only by using electromagnetism to create the H-field.