Electrical energy recovery device using mechanical energy conversion

Abstract

Title: Electrical Energy Recovery Device by Mechanical Energy Conversion The proposed recovery device comprises a stator 11, a slide 12, return means 13, a support platform 14, a frame 15, and an electrical pulse integration circuit 16. It is a magnetically bistable device which, by design, ensures that the amount of energy collected by integrating each electrical pulse it generates is controlled and substantially constant. It offers higher performance than previous solutions, is easily adaptable in size, and has a sufficiently low manufacturing and maintenance cost to allow for industrial production and widespread deployment. Figure for the abstract: Fig. 2

Description

Title of the invention: Device for recovering electrical energy by converting mechanical energy technical field

[0001] The present invention relates to the field of mechanical energy conversion and electrical energy recovery, and more particularly to the field of electrical energy recovery devices that convert mechanical energy. The present invention has applications in numerous fields, including energy recovery from road infrastructure through vehicle traffic. STATE OF THE ART

[0002] Several systems exist for converting mechanical energy into electrical energy of the impulsive type. In this respect, these systems differ from oscillating systems, which are discussed below. Some of these impulsive systems are based on traditional electromagnetic couplings and have, as their main drawbacks, a lack of compactness and high maintenance costs. Some of these impulsive systems based on traditional electromagnetic couplings also involve gear devices and have, as their main drawbacks, a significant size, low reliability, difficult integration of the generated electrical power, and a lack of techno-economic viability, which explains why they have often remained at the prototype stage and have never been significantly deployed.Other impulsive systems are based on the use of piezoelectric materials and have, as their main disadvantages, their low performance, although they are compact and inexpensive, and require little or no maintenance.

[0003] There are also electrical energy recovery systems that convert mechanical energy, which, unlike impulsive systems, are oscillating and can potentially operate with small displacements and in the absence of rotating parts. Such systems are described, for example, in patent documents referenced WO 2021 / 260711 A1, US 2020 / 0119619 A1, US 2015 / 0188389 A1 and US 2008 / 0164701 A1

[0004] Some of these systems may include a stator, a slider, return means, a support platform, a chassis and an electrical power integration circuit: a. The stator being fixedly mounted on the chassis and comprising a first part and a second part superimposed and separated from each other in a direction defined by an axis of excitation of the return means, b. The slider, integral with the support platform, being mounted to move in translation, relative to the stator, along the direction defined by the axis of excitation of the return means and between a so-called rest position and a position of excitation of the return means, and c. The slider and the stator having electromagnetic properties such that each translation of the slider between its rest position and its position of activation of the return means generates an electrical surge which the electrical surge integration circuit is configured to integrate.

[0005] These systems aim to convert the mechanical energy generated by any translational movement of the slider in the stator, regardless of the amplitude and speed of oscillation of the slider.

[0006] While these oscillating systems can be considered as offering an advantageous compromise between the main drawbacks of traditional electromagnetically coupled impulsive systems and the main drawbacks of impulsive systems based on the use of piezoelectric materials, their limited deployment shows that it is still desirable to develop other solutions, particularly more environmentally friendly, less expensive, more robust and efficient solutions, and above all, solutions that allow for higher electrical energy production values. The present invention aims to provide such a solution, and in particular an even more advantageous compromise.

[0007] More particularly, the present invention aims to provide an electrical energy recovery device by mechanical energy conversion exhibiting higher performance than prior solutions.

[0008] Another objective of the present invention is to propose a device for recovering electrical energy by converting mechanical energy easily adaptable to different scales, and in particular from the macroscopic scale (on the order of the cubic decimeter) to the microscopic scale (on the order of the cubic micrometer).

[0009] Another objective of the present invention is to propose a device for recovering electrical energy by converting mechanical energy whose size remains moderate and / or whose manufacturing and maintenance cost remains sufficiently low, to allow their industrial production and their wide deployment, while preferably presenting higher performance than previous solutions. SUMMARY

[0010] To achieve this objective, according to a first aspect, a device for recovering electrical energy by converting mechanical energy is provided, conforming to the preamble above, and is essentially such that: a. One of the slider and each of the first and second parts of the stator comprises a permanent magnet and two extension elements made of a ferromagnetic material, the two extension elements extending respectively on either side of the permanent magnet in a direction substantially perpendicular to the axis of excitation of the return means, b. The first and second parts of the stator define, between them, a suitable housing, with an air gap, the slider, c. So that, when a mechanical force exceeding a predetermined threshold is exerted on the support platform: i. The slider leaves its rest position, generating an electrical current in the first and second parts of the stator from which the slider is moving, and ii. the slide approaches its position for engaging the return means, generating at least one electrical current in the first and second parts of the stator that the slide approaches, and d. So that, when the mechanical force is no longer exerted on the support platform: i. the slide leaves its position of activation of the return means by release of the return means, generating at least one electrical current in the first and second parts of the stator from which the slide moves away, and ii. the slide returns to its rest position, generating at least one electrical current in the first and second parts of the stator that the slide approaches.

[0011] Thus, four electrical power sources are integrated by the integration circuit at each round trip of the slider, that is to say at each passage of the slider from its rest position to its position of activation of the return means and, conversely, from its position of activation of the return means to its rest position.

[0012] More specifically, the permanent magnet of the slide creates, when the slide is close to either of the first and second parts of the stator, a magnetic field circulating through the slide and the part of the stator to which the slide is close; moving the slide away from either part of the stator disturbs the magnetic field circulating in the part of the stator from which the slide is moving away and generates an integrable magnetic field, and, conversely, moving the slide closer to either part of the stator disturbs the magnetic field circulating in the part of the stator toward which the slide is approaching and generates a magnetic field. Built-in electric.

[0013] Thus, it appears that the proposed recovery device exploits, four times per back-and-forth movement of the slider, the reluctance variation of each of the magnetic circuits formed alternately by the slider and one of the two parts of the stator. Each generated electrical surge corresponds to a quantity of energy, so that the integration of each electrical surge can, for example, induce the storage of a quantity of energy corresponding to the electrical surge.

[0014] Furthermore, it is understood from the foregoing that the proposed recovery device is a magnetically bistable device, and that, in this respect, it differs from oscillating devices for recovering electrical energy by converting mechanical energy, which aim in particular to recover all quantities of energy induced by any forces exerted on the support platform, including the smallest or even the slowest. Unlike such oscillating devices, the recovery device proposed here makes it possible, by design, to ensure that the quantity of energy collected by integrating each generated electrical surge is controlled and substantially constant.Furthermore, the proposed device can be configured so that each of the four electrical pulses generated by the back-and-forth movement of the slider is controlled and substantially identical to the other three; consequently, the integration of any one of the four electrical pulses can be achieved by a simple integration circuit, relative to the integration circuit implemented by certain oscillating devices, and an amount of energy substantially equal to that generated by the other three pulses can be stored.

[0015] More specifically, the amount of energy collected by integrating each generated electrical pulse depends on the various characteristics that define the energy recovery device, and not on the amplitude or speed of the slider's oscillations. This is achieved through a constraint: the pressure force on the platform must exceed a threshold to drive the slider in translation. The value of this threshold is determined by various characteristics that define the energy recovery device. Consequently, the threshold value defines, at least in part, the amount of energy collected by integrating each generated electrical pulse.

[0016] A second aspect of the invention relates to an electrical energy recovery system by conversion of mechanical energy comprising at least one recovery device as introduced above and at least one piece of furniture, for example urban, intended to be fixed on a site of installation of the system and having at least one housing adapted to accommodate at least one recovery device as introduced above. BRIEF DESCRIPTION OF THE FIGURES

[0017] The aims, objects, features and advantages of the invention will become clearer from the detailed description of an embodiment thereof, which is illustrated by the following accompanying drawings in which:

[0018] [Fig-1] Fig. 1 represents a schematic view of one embodiment of the recovery device according to the first aspect of the invention.

[0019] [Fig.2] Fig.2 represents a perspective view of an internal part of the recovery device according to a first embodiment of the first aspect of the invention.

[0020] [Fig.2A] [Fig.2A] represents a perspective view of an internal part of the recovery device according to a variant of the first embodiment illustrated in [Fig.2],

[0021] [Fig.3] [Fig.3] represents a perspective view from the outside of a part of the recovery device according to the embodiment illustrated in [Fig.2].

[0022] [Fig.4A] Fig.4A schematically represents an exploded view of an embodiment of the connections implemented to functionally link together the electrical feeds of different induction sub-coils of the recovery device according to an embodiment of the first aspect of the invention by means of an electrical connection pin.

[0023] [Fig.4B] [Fig.4B] schematically represents different ways of connecting the induction sub-coils illustrated on [Fig.4A]; the implementation of the series and parallel electrical configurations of the induction sub-coils of the recovery device is illustrated by the two superimposed boxes on the left of [Fig.4B].

[0024] [Fig.5] Figure 5 substantially represents the perspective view illustrated in Figure 2 and graphically illustrates an example of the relationship between the external force Fexl to be exerted on the support platform to move the slider and the magnetic force of attraction Fma between the slider and the part of the stator to which it is closest, this relationship being arbitrated in particular by the stiffness kspr of the return means so as to substantially optimize the recovery device according to the first aspect of the invention.

[0025] [Fig.6A] Fig.6A illustrates an embodiment of an integration circuit of the recovery device according to an embodiment of the first aspect of the invention.

[0026] [Fig.6B] The [Fig.6B] illustrates an embodiment of a test circuit of the recovery device according to an embodiment of the first aspect of the invention.

[0027] [Fig.7] [Fig.7] illustrates a perspective view of an exploded part of the recovery device according to the embodiment illustrated in [Fig.3].

[0028] [Fig. 8A] Figures 8A and 8B each illustrate an alternative with regard to the shape taken by the slider and that taken by the parts of the stator of a recovery device according to an embodiment of the first aspect of the invention.

[0029] [Fig.8B]

[0030] [Fig.9] Fig.9 represents a partial schematic perspective view of the stator and of the slide of the recovery device according to the embodiment illustrated in [Fig.8A] and illustrate the different dimensions of interest with regard to the dimensioning of these parts of the device in relation to each other.

[0031] [Fig. 10] The [Fig. 10] is a schematic front view of each part of the stator, the slider and the support platform of the recovery device according to the embodiment illustrated in the [Fig.8A].

[0032] [Fig. 11 A] The [Fig. 11 A] illustrates the closed magnetic field formed by the slider with the upper part of the stator, when these two elements of the recovery device are in direct contact with each other.

[0033] [Fig. 1 IB] The [Fig. 1 IB] illustrates the closed magnetic field formed by the slider with the lower part of the stator, when these two elements of the recovery device are in direct contact with each other.

[0034] [Fig.12A] Figures 12A to 12E illustrate the deformation of the magnetic field at different stages of a forward translational movement of the slider, from the configuration illustrated on [Fig.1A], to the configuration illustrated on [Fig.1B].

[0035] [Fig.12B]

[0036] [Fig.12C]

[0037] [Fig.12D]

[0038] [Fig.12E]

[0039] [Fig.13A] Figures 13A to 13D are schematic front views of the stator and slider of the recovery device according to an embodiment of the first aspect of the invention, at different stages of the back-and-forth translation movement of the slider.

[0040] [Fig.l3B]

[0041] [Fig.13C]

[0042] [Fig.13D]

[0043] [Fig. 14] Fig. 14 is to be read in superposition of figures 13A to 13D. It illustrates the moments during the back-and-forth translational movement of the slider during each of which an electrical surge is generated, this illustration taking the form of two electrograms superimposed on each other, the upper electrogram being related to the electrical surges generated in the upper part of the stator and the lower electrogram being related to the electrical surges generated in the lower part of the stator.

[0044] [Fig. 15] [Fig. 15] illustrates an electrogram resulting from the addition of the two electrograms illustrated in [Fig. 14], after rectification of one of the two sources electrical currents generated in each part of the stator, said rectification being obtained for example by implementing a diode bridge as illustrated in [Fig.6A].

[0045] [Fig.10A] Figure 16A is a graph illustrating the evolution of the instantaneous power produced (in Watts), the power density (in Watts per square meter and milliwatts per cubic centimeter), the energy converted (in Joules) and the efficiency (in percentage) as a function of the value of the resistance Rext of an electrical characterization circuit of a prototype of the device according to the first embodiment of the invention; each evolution illustrated corresponds to an arrangement in parallel and / or in series of three induction sub-coils wound around the ferromagnetic core of each of the parts of the stator. The characterized prototype has dimensions of 73x108x93 mm3= 0.733 dm3, an Nd2Fel4B magnet (hm — / ,,,=15 mm, H=50 mm), coils of inductance Lcoi(s=2x2.5 Henry (in series) and springs of stiffness kspr =4x90 N / mm.This device is activated by an external force F„w=900 N by traveling a displacement of xmav=2.5rnm (for a mechanical energy: £,„=2.25 J), producing in non-optimized conditions an electrical energy £,^=0.25 J. .

[0046] [Fig.10B] Figure 16B is a graph illustrating the evolution of a voltage peak (in Volts) across the resistor Rext of the electrical characterization circuit of the prototype device according to the first embodiment of the invention as a function of the value of the resistor Rext, each evolution illustrated corresponds to one of the parallel and / or series arrangements of three induction sub-coils wound around the ferromagnetic core of each of the parts of the stator which are considered on [Fig.10A].

[0047] [Fig.10C] Figure 16C is a graph illustrating the evolution of the electric current (in Amperes) across the resistor Rext of the electrical characterization circuit of the prototype device according to the first embodiment of the invention as a function of the value of the resistor Rext; each evolution illustrated corresponds to one of the parallel and / or series arrangements of three induction sub-coils wound around the ferromagnetic core of each of the parts of the stator which are considered on [Fig.10A].

[0048] [Fig. 17A] The [Fig. 17A] is a graph showing the time evolution of the voltage (in volts) across the diodes of a diode bridge forming part of the integration circuit of the recovery device according to the first aspect of the invention and the time evolution of the voltage (in volts) accumulated across a capacitor forming part of the integration circuit of the recovery device according to the first aspect of the invention.

[0049] [Fig. 17B] [Fig. 17B] and a graph showing the evolution of the stored energy as a function of the capacitance value of the integration circuits of the recovery device according to the first aspect of the invention for a given configuration of the connections between sub-coils constituting the induction coil of each of the two parts of the stator of the recovery device according to the first aspect of the invention.

[0050] [Fig. 18A] [Fig. 18A] represents a perspective view of part of a system recovery according to an embodiment of the second aspect of the invention.

[0051] [Fig.18B] [Fig.18B] represents an exploded view of the part of the recovery system according to the embodiment illustrated in [Fig. 18A].

[0052] [Fig.19A] [Fig.19A] represents a perspective view of part of a recovery system according to another embodiment of the second aspect of the invention than that illustrated in [Fig. 18A].

[0053] [Fig.l9B] [Fig.l9B] represents an exploded view of the part of the recovery system according to the embodiment illustrated in [Fig.l9A].

[0054] The drawings are given by way of example and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate understanding of the invention and are not necessarily to scale with practical applications. DETAILED DESCRIPTION

[0055] Before proceeding to a detailed review of embodiments of the invention, optional features that may be used in combination or alternatively are listed below:

[0056] According to one example, the first part of the stator and the second part of the stator can be fixed in position relative to each other.

[0057] According to one example, the slide and the support platform can be mechanically connected to the chassis via the return means.

[0058] According to one example, the return means may include at least one spring, for example helical.

[0059] According to one example, the slider in either of its rest position and / or its position when the return means are engaged can form, with the part of the stator to which it is closest, a support for a closed magnetic field induced by the permanent magnet. Preferably, said support has a substantially constant cross-section.

[0060] According to one example, at least one of the rest and activation positions of the return means can be a contact position, direct or indirect, between the two extension elements of the slide and one corresponding of the first and second parts of the stator.

[0061] In addition to or as an alternative to the preceding example, the recovery device may further include a stop arranged to oppose contact between the The magnetic attraction force Fma between the slide and the part of the stator near which the slide is located when the slide is in its rest position, and therefore the support force Fext required to move the slide, can be reduced in a controlled manner.

[0062] According to one example, the threshold beyond which the mechanical force exerted on the support platform induces displacement of the slide can be determined proportionally to an electromagnetic attractive force between the slide in its rest position and the part of the stator near which the slide is located when the slide is in its rest position. In addition, the return means can be parameterized so that they do not generate a return force on the slide towards the rest position of the return means before the slide has moved a non-zero distance from the rest position of the return means.

[0063] According to one example, the stiffness of the return means can be parameterized to apply, on the slider in its position of stressing the return means, a return force towards its rest position greater than an electromagnetic attraction force between the slider and the part of the stator to which the slider is close when it is in its position of stressing the return means.

[0064] According to one example, the slide comprising the permanent magnet and the two extension elements made of a ferromagnetic material, each part of the stator may include a ferromagnetic core and at least one induction coil wound around a central portion of the ferromagnetic core, each electrical current generated in a part of the stator taking the form of an electric current flowing in each induction coil of that part of the stator. More particularly, each ferromagnetic core of each part of the stator may have a U-shape, and the ends of the U-shape of one of the first and second parts of the stator face those of the U-shape of the other of the first and second parts of the stator.Alternatively or in addition, the slider may have an H-shape comprising side bars joined together by a central bar, the permanent magnet of the slider forming part of the central bar of the H-shape and the two extension elements forming the side bars of the H-shape and completing the central bar of the H-shape. The number of turns and the cross-section of the conductor wire of each induction coil can be parameterized so as to adapt its impedance.

[0065] According to one example, the extension elements can extend from the permanent magnet through faces of the permanent magnet which are opposite to each other along a direction of magnetization of the permanent magnet, the latter being substantially perpendicular to the axis of excitation of the return means.

[0066] According to one example, the slide comprising the permanent magnet and the two extension elements in a ferromagnetic material, the slide and the first and second parts of the stator can be configured so that the permanent magnet of the slide does not come into contact with one of the first and second parts of the stator, regardless of the position of the slide.

[0067] According to one example, the electrical power source integration circuit may include a diode bridge and a capacitor, the diode bridge being configured, downstream of the capacitor, so that all the electrical power sources have the same orientation and the capacitor being suitable for storing an amount of energy corresponding to each generated electrical power source.

[0068] According to one example, the chassis can be configured to allow the device to be fixed to an installation site or to furniture, for example urban furniture, intended to be fixed to an installation site.

[0069] According to one example, the recovery device may be free of at least one of the following: a. a piezoelectric component, b. a rotating part, c. a self-centering device for the slide relative to the stator, and d. a device for transmitting motion from a driving shaft to a driven shaft.

[0070] The term "returning means" refers to an elastic element, for example made of steel, capable of deforming under tension and / or compression, storing energy in potential form and releasing it by returning to its initial shape. The returning means are typically such that their deformation occurs along a predetermined axis of stress. For example, when the returning means comprise a helical spring, the axis of stress is typically defined by the axis of the spring.

[0071] The term “closed magnetic circuit” means a magnetic circuit comprising ferromagnetic parts which channel the magnetic flux in this circuit.

[0072] With reference to [Fig. 1], the electrical energy recovery device 1, which converts mechanical energy according to the first aspect of the invention, comprises a stator 11, a slide 12, return means 13, a support platform 14, a frame 15, and an electrical power integration circuit 16. In the other accompanying figures, parts of the recovery device 1 according to the first aspect of the invention are often shown. When only the electrical power integration circuit 16 is missing, the illustrated parts of the recovery device 1 according to the first aspect of the invention are collectively referenced by the numeral 1', as in [Fig. 1]. These remaining parts 1' are notably included in the device as partially illustrated in [Fig. 3], this illustration not leaving However, it may appear that part of the support plate 14 and the frame 15 is visible; the stator 11, the slide 12 and the return means 13 are concealed by the support plate 14 and the frame 15. By way of non-limiting example, [Fig.7] shows an exploded view of part of the assembly of elements 1' of the recovery device 1 which illustrates one way in which the stator 11, the slide 12 and the return means 13 can be arranged in the frame 15 and relative to the support plate 14 and.

[0073] With reference to [Fig. 10], the stator 11, composed of two parts referenced 111 and 112, is fixedly mounted on the frame 15. A first part 111 of the stator 11 and a second part 112 of the stator 11 are superimposed and separated from each other in a direction (illustrated by the double arrow) defined by the axis of excitation of the return means 13. The slide 12 is fixed to the support platform 14 and is mounted to move in translation, relative to the stator 11, in the direction defined by the axis of excitation of the return means 13. In [Fig. 10], the slide 12 is in a so-called rest position of the return means 13; the slide 12 is then close to, or even in contact with, the first, upper part 111 of the stator 11.When the slide 12 is brought, according to its translational movement, into a position close to, or even in contact with, the second, lower part 112 of the stator 11, the slide 12 is in a position called the excitation of the return means 13; the latter then tend to push the slide 12 back into the rest position of the return means 13.

[0074] The stator 11 and the slide 12 have electromagnetic properties such that each translation of the slide 11 between its rest position and its position of activation of the return means 13 generates at least one electrical surge which the electrical surge integration circuit 16 is configured to integrate.

[0075] With reference to [Fig.2], and according to a preferred embodiment of the invention, the slider 12 may include a permanent magnet 121, for example based on neodymium (for example of formula Nd2Fei4B) and two extension elements 122 and 123 in a ferromagnetic material (or ferrimagnetic, these two compositions being able where appropriate to be grouped under the name "soft magnetic material"). The two extension elements 122 and 123 of the slide 12 extend respectively on either side of the permanent magnet 121 in a direction substantially perpendicular to the axis of excitation of the return means 13. The first and second parts 111 and 112 of the stator 11 define, between them, a housing accommodating, with an air gap 110, the permanent magnet 121 and the two extension elements 122 and 123 of the slide 12.

[0076] With further reference to [Fig. 2], each ferromagnetic part 111, 112 of the stator 11 comprises a ferromagnetic core 1111, 1121 and at least one induction coil 1112, 1122 wound around a central portion of the ferromagnetic core Magnetic 1111, 1121. Each electrical current generated in a ferromagnetic part 111, 112 of the stator 11 takes the form of an electric current flowing in each induction coil 1112, 1122 of this ferromagnetic part 111, 112 of the stator 11. The ferromagnetic cores are, for example, made of soft magnetic cast iron. The coils are, for example, made of a winding of copper wire, for example having a diameter approximately equal to 80 µm.

[0077] Figure 2A illustrates an embodiment of the stator 11 and the slide 12 which is an alternative to that illustrated in Figure 2. This alternative shows that the thickness w (Cf. [Fig.9]) over which the stator 11 and the slide 12 extend can vary to the point of changing the aspect ratio of the assembly, without rendering the recovery device 1 dysfunctional according to the first aspect of the invention.

[0078] The embodiment illustrated in [Fig. 2] corresponds substantially to that illustrated in [Fig. 8A]; in the latter, a helical spring as a return means 13 and a bearing 14' on the helical spring are further shown, this bearing 14' being seen as a schematic representation of the support platform 14 to which it is considered to be integral. According to the embodiment illustrated in [Fig. 8A], each ferromagnetic core 1111, 1121 of each part 111, 112 of the stator 11 has a U-shape and the ends of the U-shape of the first part 111 of the stator 11 face those of the U-shape of the second part 112 of the stator 11. Alternatively, and as illustrated in [Fig.[8B], the slide 12 can have an H-shape comprising lateral bars joined together by a central bar, the permanent magnet 121 of the slide 12 forming part of the central bar of the H-shape and the two extension elements 122 and 123 forming the lateral bars of the H-shape and completing the central bar of the H-shape. Note here that these alternatives can be combined with each other.

[0079] It is clear from the various figures already detailed that the extension elements 122 and 123 of the slide 12 extend, regardless of the embodiment envisaged, from the permanent magnet 121 by means of faces of the permanent magnet 121 that are opposite to each other along a magnetization direction of the permanent magnet 121 (defined by the arrow drawn on the permanent magnet 121 illustrated in Figures 2, 2A, 8A, 8B and 9). The magnetization direction of the permanent magnet 121 is substantially perpendicular to the axis of excitation of the return means 13.It also appears from the various figures already detailed that the permanent magnet 121, the extension elements 122 and 123, and the first and second parts 111 and 112 of the stator 11 can advantageously be configured so that the permanent magnet 121 of the slide 12 does not come into contact with one of the first and second parts 111 and 112 of the stator 11, whatever the position of the slide 12; if this can lead to the loss of magnetic field lines, and consequently significantly reduce the per. Formances of the recovery device 1, this on the other hand provides a simple method to reduce the external force required for the operation of the device.

[0080] Figure 9 illustrates the various parameters characterizing the stator 11 and the slider 12 constituting part of the recovery device 1 according to its embodiment illustrated in Figure 2, or in Figure 2A. These various parameters were fixed as follows to produce a functional prototype of the recovery device 1 according to the first aspect of the invention: a. xmax = e = 2.5 mm; b. a, — at — au = ad = hm— 15 mm; c. lm = 15 mm; d. w — 50 mm; e. ha = 4.5 mm; f. hs = 57 mm; g. ls— 51mm.

[0081] For these dimensions of the stator 11 and the slider 12, which are fixed here to be able to recover the energy produced by the passage of a bicycle over the recovery device 1: a. The magnetic attraction force F = F11 ! = F112 exerted by each part of the stator on the slide 12 when they are in contact with each other is approximately equal to 900 N (where, as illustrated in Figure 11 A, p^ is the magnetic attraction force exerted between the first part 111 of the stator 11 and the slide 12 in the rest position of the return means, due to the permanent magnet 121 of the slide 12, and where, as illustrated in Figure 1 IB, p^ is the magnetic attraction force exerted between the second part 112 of the stator 11 and the slide 12 in the excitation position of the return means, due to the permanent magnet 121 of the slide 12), and b. The so-called mechanical input energy Ein of the device amounts to approximately 2.25 J.

[0082] Furthermore, the inductance coils of the stator 11 are parameterized so as to have an inductance satisfying s, in particular in terms of the number of windings, Lcoils = 2 x 2.5 H

[0083] Moreover, for these dimensions of the stator 11 and the slider 12, the return means 13 of the prototype advantageously take the form of 4 helical springs each having a stiffness kspr substantially equal to 90 N / mm.

[0084] A speed equivalent to the passage of a vehicle of Ve <idef ~ ~2-5 km / h a été utilisée pour les tests en laboratoire, en donnant des performances comparables aux tests with cars passing at up to 20 km / h in a parking lot.

[0085] In particular, due to the various arrangements mentioned above of the recovery device 1 according to the first aspect of the invention, and with reference to Figures 13A to 13D and to [Fig. 14]: a. when a mechanical force, or external force Fext, greater than a determined threshold, for example the value of the threshold being equal to that of the magnetic attraction force p^ exerted by the first part 111 of the stator on the slide 12 when they are in contact with each other, is exerted on the support platform 14: i. The slider 11 leaves its rest position (see Figure 13A), generating an electrical current 21 (see Figure 14) in the first part 111 of the stator 12, that is, the part of the stator 11 from which the slider 12 moves away, and ii. The slide 11 approaches its position for activating the return means 13 (see Figure 13B), generating an electrical current 22 (see Figure 14) in the second part 112 of the stator 11, that is, the part of the stator 11 that the slide 12 approaches; then b. when the mechanical force, or external force Fexb, is no longer exerted on the support platform 14: i. The slide 12 leaves its position of excitation of the return means 13 (see Figure 13C) by release of the return means 13, generating an electrical current 23 (see Figure 14) in the second part 112 of the stator 11, that is to say the part of the stator 11 from which the slide 12 moves away, and ii. the slider 12 returns to the rest position of the return means 13 (See figure 13D), generating an electrical draw 24 (See figure 14) in the first part 111 of the stator 11, that is to say the part of the stator 11 which the slider 12 approaches.

[0086] Note here that the time between the generation of the electric pump 23 and the generation of the electric pump 24 illustrated in [Fig. 14] is potentially directly proportional to the stiffness of the return means 13 alone. On the contrary, the time between the generation of the electric pump 21 and the generation of the electric pump 22 illustrated in [Fig. 14] depends on the value of the support force exerted on the support platform 14.

[0087] As illustrated in Figures 11A and 11B, the slide 12 in each of the rest position and the position of activation of the return means 13 forms, with that of the first and second parts 111 and 112 of the stator 11 to which it is closest, a support for a closed magnetic field 31 and 32 induced by the magnet permanent 121 of the slide 12. Preferably, said support has a substantially constant cross-section, so as to avoid magnetic field line leakage. Figures 13A to 13D illustrate how the magnetic field lines are deformed when passing from the closed magnetic field 31 shown in [Fig. 11A] to the closed magnetic field 32 shown in [Fig. 11B], at different stages of a translational movement of the slide 12 from the rest position of the return means 13 to the actuated position of the return means 13.

[0088] If, in Figures 11A and 11B, each of the rest and activation positions of the return means 13 is a position of direct contact between the two extension elements 122 and 123 of the slide 12 and a corresponding position of the first and second parts 111 and 112 of the stator 11, this example is not limiting to the recovery device 1 according to the first aspect of the invention. In particular, and with reference to Figure 9, the latter may further comprise a stop 17 arranged to prevent direct contact between the two extension elements 122 and 123 of the slide 12 and the first part 111 of the stator 11.It is thus possible to provide a physical gap between the slide 12 and the first part 111 of the stator 11 so that the magnetic attraction force Fma between the slide 12 and the first part 111 of the stator 11, and therefore the support force Fext required to move the slide 12, can, if necessary, be adjusted, and in particular reduced, in a controlled manner.

[0089] With reference to Figure 5, the threshold beyond which the mechanical force Fext exerted on the support platform 14 induces the displacement of the slide 12 can be determined from the electromagnetic attraction force (see also Figure 11 A) between the slide 12 in the rest position of the return means 13 and the first part 111 of the stator 11. More particularly, the recovery device 1 according to the first aspect of the invention can be parameterized so that it is not necessary to oppose a force that the return means 13 would exert on the slide 12 in the rest position of the return means 13.To do this, by denoting Xmax the aforementioned air gap 110, the return means 13 can be advantageously parameterized so that they do not generate, on the slide 12, a return force towards the rest position of the return means 13, before the slide 12 has moved a non-zero distance preferably less than half of the air gap 110, i.e. less than . .

[0090] Alternatively or in addition, the stiffness of the return means 13 can be parameterized to apply, on the slide 12 in its position of excitation of the return means 13, a return force towards its rest position greater than an electromagnetic attraction force p^p (See [Fig. IIB]) between the slide 12 and the second part 112 of the stator 11 when it is in its position of excitation of the means of recall 13.

[0091] The stiffness of the return means 13 can therefore be advantageously parameterized so as to optimize the conversion which the recovery device 1 allows according to the first aspect of the invention, by not artificially increasing the threshold beyond which the mechanical force Fext exerted on the support platform 14 induces the displacement of the slide 12, and while allowing the return of the slide 12 to the rest position of the return means 13 from the position of stress of the return means 13 solely due to the return force exerted on the slide 12 by the return means 13.

[0092] To be recovered, the four energy pulses generated with each back-and-forth movement of the slider 12 must be integrated. For this purpose, the integration circuit 16 of the electrical energy pulses 21, 22, 23, and 24 is provided; however, as can be seen from the electrical energy pulses 21, 22, 23, and 24 illustrated in [Fig. 14], each generated energy pulse has the same shape and therefore corresponds to the same quantity of energy, which simplifies the design of the integration circuit 16 to be implemented to recover the energy produced by the recovery device according to the first aspect of the invention, particularly in comparison to the oscillating recovery devices mentioned in the introduction. More specifically, the integration circuit 16 can take the form of the circuit illustrated in [Fig. 6A] and thus comprise a diode bridge 162 and a capacitor 163.The diode bridge 162 is then preferably arranged to rectify the two generated electrical sources 21 and 23, which have an orientation opposite to the orientation of the two electrical sources 22 and 24, and to obtain the two electrical sources 21' and 23' as illustrated in [Fig. 15]. In this way, the capacitor 163 receives a rectified signal as illustrated in [Fig. 15], so as to be able to advantageously integrate the four electrical draws 21', 22, 23' and 24 generated by the recovery device 1 at each back-and-forth movement of the slider 12. The result of this integration is illustrated in [Fig. 17A] which shows the accumulation of the quantities of energy that each generated electrical draw represents in the capacitor 163 of the integration circuit 16. Note here that the choice of the value of the capacitor 163 can influence the quantity of energy stored, in particular in the way illustrated in [Fig. 17B].This parameter, the value of capacitance 163, must therefore be adjusted on a case-by-case basis, in a manner considered to be known to those skilled in the art, to optimize recovery. It should be noted here that [Fig. 17A] was obtained for a specific case in which the induction coil 1112, 1122 of each part 111, 112 of the stator 11 is actually made up of three sub-induction coils connected in series, and in which the induction coil 1112 of the first part 111 of the stator 11 and the induction coil 1122 of the first part 112 of the stator 11 are connected in parallel. Furthermore, it should be noted, from the graph in [Fig. 17B], that the efficiency of the prototyped device is directly proportional to . the energy stored in the capacity of the integration device 16 and that it is envisaged that the recovery device 1, once optimized, will allow to achieve efficiencies greater than 6%.

[0093] It thus appears that, as illustrated in Figures 4A and 4B, each induction coil 1112, 1122 can be made up of a plurality of sub-coils which, according to the intended application, can be connected together in series (see [Fig. 4B]). Furthermore, note in [Fig. 4A] that the electrical connection pin then comprises at least as many electrical connections as the sub-coils have ends. [Fig. 4A] illustrates, in this case, a possible arrangement of the sub-coils constituting each of the induction coils of each part 111, 112 of the stator 11 relative to each of the ferromagnetic cores 1111 and 1121 of the stator 11.

[0094] Performance tests were carried out on the prototype described above, the results of which are illustrated in Figures 16A to 16C, at least for each of the four electrical connection configurations between sub-coils shown in Figure 4B. More specifically, these tests were carried out by simulation or by measurement of the electric current and voltage reaching an external resistance Rext, as illustrated in [Fig. 6B], connected to the aforementioned remaining parts 1' of the prototyped recovery device in place of the integration circuit 16 illustrated in [Fig. 6A].

[0095] Figures 16B and 16C show that the recovery device 1 according to the first aspect of the invention can operate in a so-called electrical current recovery mode when the value of the external resistance Rexl is relatively low, and typically less than 1000 Q for the prototype considered, or can operate in a so-called electrical voltage recovery mode when the value of the external resistance RexJ is relatively high, and typically greater than 10,000 Q for the prototype considered. It can also be seen that the recovered current and voltage have different values ​​depending on the different connection configurations of the sub-coils of each part 111, 112 of the stator 11; thus, these different possible configurations offer those skilled in the art the ability to adapt to the intended or encountered application.It should be noted that, as illustrated by the graph in Figure 16A, the instantaneous power generated by the prototype reaches, depending on the value of the external resistance Rext, more or less equivalent values ​​for the different envisaged configurations of connection between the sub-coils of each part 111, 112 of the stator 11. .

[0096] It will be noted that the recovery device 1 according to the first aspect of the invention is advantageously free of at least one of the following: a. a piezoelectric component, even though the size of the device The proposed recovery method remains limited compared to existing solutions that do not include piezoelectric components. b. a rotating part, which explains in particular the absence of a need for lubrication of the proposed recovery device, c. a self-centering device for the slide relative to the stator, which contributes to the robustness of the proposed recovery device, and d. a device for transmitting movement from a drive shaft to a driven shaft, which again explains the absence of a need for lubrication of the proposed recovery device.

[0097] Finally, it should be noted that the proposed energy recovery device, as well as the associated system, offers, for a given power density gain, a more environmentally friendly energy recovery solution than some existing solutions. In order to reduce the cost of electricity production, it is even conceivable to choose a less expensive permanent magnet 121, which is less efficient but has a lower environmental impact, while still allowing the same amount of energy to be recovered with an increase in its dimensions, thus retaining the advantage of the architecture in terms of power density.

[0098] As mentioned in the introduction, the present invention also relates, according to a second aspect of the invention, to an electrical energy recovery system comprising a recovery device according to the first aspect of the invention, the chassis 15 of the recovery device 1 being configurable to allow the recovery device 1 to be fixed either directly to an installation site or to a piece of furniture, for example, street furniture, intended to be fixed to said installation site. It is understood that more than one recovery device 1 can be arranged on the same installation site and possibly via the same piece of furniture 10. It is then possible to mount several recovery devices in series, in parallel, or in a mixed configuration.

[0099] Figures 18A and 18B illustrate a first embodiment of the recovery system 0 according to the second aspect of the invention, in which a piece of furniture 10 has a housing 100 adapted to accommodate a recovery device 1 according to the first aspect of the invention. This first embodiment is particularly suited to being embedded in a span of a roadway, for example, for motor vehicles, bicycles, or pedestrians, the surface of the furniture 10 partially constituting the roadway surface. Another embodiment is illustrated in Figures 19A and 19B, which is more specifically designed to form a protrusion relative to a roadway on which it is intended to be installed. In this way, the recovery system 1 can also act as a speed bump.

[0100] The proposed recovery device 1, and in particular the one that was prototyped to demonstrate the feasibility and the interest of the proposed device, are still the case While further optimization is needed, as demonstrated above, they are already promising. Indeed, although not yet optimized, they are already competitive with traditional recovery systems and emerging technologies. Cost-effective and highly robust, the proposed recovery device is advantageously customizable or modular, particularly in terms of the size of the surfaces and other volumes involved (ranging from at least cubic micrometers to cubic decimeters), depending on the intended application.

[0101] The integration of the recovery system 0 is easy regardless of the environment, particularly urban (road, railway, cycle path, playground, sports center, etc.) of its installation. Its use can also be repurposed, for example, to measure traffic flow on a road, and / or to measure at least one of the following: the weight and / or the speed of vehicles traveling over the recovery device 1.

[0102] It is further apparent from the foregoing that the recovery device 1 according to the first aspect of the invention offers high performance for a relatively small dimension and small deformations, or more particularly small displacements (over the distance constituted by the air gap 110), compared to the recovery device known in the prior art.

[0103] The invention is not limited to the embodiments or applications described above and potentially extends to other embodiments or applications. For example, on a larger scale, the device can be used with or without springs in applications where the source is impulsive or oscillatory. For example, each fixed part of the device (each of the first and second parts of the stator) and the moving part of the device (the slider) assume, in the preceding description, a configuration that can be interchanged with the other part without altering the operation and performance of the recovery device in any way.Potentially, only the position of the spring contact would need to be adapted to allow the aforementioned permutation, where the elements described above as constituting each part of the stator would be mobile and the elements described above as constituting the slide would be fixed.

Claims

Claims

1. Device (1) for recovering electrical energy by converting mechanical energy, the device comprising at least one stator (11), a slider (12), return means (13), a support platform (14), a chassis (15) and an integration circuit (16) of electrical pulses (2): • The stator (11) being fixedly mounted on the chassis (15) and comprising a first part (111) and a second part (112) superimposed and spaced apart from each other in a direction defined by a stress axis of the return means (13), • The slide (12), integral with the support platform (14), being mounted to move in translation, relative to the stator (11), in the direction defined by the axis of stress of the return means (13) and between a so-called rest position and a position of stress of the return means (13), and • The stator (11) and the slider (12) having electromagnetic properties such that each translation of the slider (11) between its rest position and its position of stressing the return means (13) generates an electric pulse (2) that the integration circuit (16) of electric pulses (2) is configured to integrate, The device (1) being characterized in that: • One of the slide (12) and each of the first and second parts (111, 112) of the stator (11) comprises a permanent magnet (121) and two extension elements (122, 123) made of a ferromagnetic material, the two extension elements (122, 123) extending respectively on either side of the permanent magnet (121) in a direction substantially perpendicular to the axis of stress of the return means (13), • The first and second parts (111, 112) of the stator (11) define, between them, an accommodating housing, with an air gap, the slider (12), • So that, when a mechanical force greater than a determined threshold is exerted on the support platform (14): i. the slide (11) leaves its rest position, generating at least one electrical pulse (21) in that (111) of the first and second parts (111, 112) of the stator (12) from which the slide (11) moves away, and ii. the slide (11) approaches its stress position citing the return means (13), generating an electrical pulse (22) in that (112) of the first and second parts (111, 112) of the stator (11) from which the slide (11) approaches, and • So that, when the mechanical force is no longer exerted on the support platform (14): i. the slider (12) leaves its position of stressing the return means (13) by relaxing the return means (13), generating an electrical pulse (23) in that (112) of the first and second parts (111, 112) of the stator (11) from which the slider (12) moves away, and ii.the slider (12) returns to its rest position, generating an electrical pulse (24) in that (111) of the first and second parts (111, 112) of the stator (11) which the slider (12) approaches.

2. Device (1) according to the preceding claim, in which the slide (12) in one and / or the other of its rest position and its position of stressing the return means (13) forms, with that of the first and second parts (111, 112) (111, 112) of the stator (11) to which it is closest, a support for a closed magnetic field (31, 32) induced by the permanent magnet (121).

3. Device (1) according to the preceding claim, wherein said support is of a substantially constant section.

4. Device (1) according to any one of the preceding claims, in which at least one of the rest and biasing positions of the return means (13) is a contact position between the two extension elements (122, 123) of the slide (12) and a corresponding one of the first and second parts (111, 112) of the stator (11).

5. Device (1) according to any one of the preceding claims, further comprising a stop (17) arranged so as to oppose a direct contact between the slider (12) and the part (111) of the stator (11) to which the slider (12) is close when the slider (12) is in its rest position.

6. Device (1) according to any one of the preceding claims, in which the threshold beyond which the mechanical force exerted on the support platform (14) induces the movement of the slider (12) is determined from an electromagnetic attraction force p^ between the slider (12) in its rest position and the part (111) of the stator (11) to which the slider (12) is close when the slider (12) is in its rest position.

7. Device (1) according to the preceding claim, in which the return means (13) are configured so that they do not generate, on the slide (12), a return force towards the rest position of the return means (13), before the slide (12) has moved a non-zero distance XsPr from the rest position of the return means (13).

8. Device (1) according to any one of the preceding claims, in which the stiffness of the return means (13) is configured to apply, on the slide (12) in its position of stressing the return means (13), a return force towards its rest position greater than an electromagnetic attraction force p^ between the slide (12) and the part (112) of the stator (11) to which the slide (12) is close when it is in its position of stressing the return means (13).

9. Device (1) according to any one of the preceding claims, wherein, the slider (12) comprising the permanent magnet (121) and the two extension elements (122, 123) made of a ferromagnetic material, each part (111, 112) of the stator (11) comprises a ferromagnetic core (1111, 1121) and at least one induction coil (1112, 1122) wound around a central portion of the ferromagnetic core (1111, 1121), each electrical pulse (21, 22, 23, 24) generated in a part (111, 112) of the stator (11) taking the form of an electric current flowing in each induction coil (1112, 1122) of this part (111, 112) of the stator (11).

10. Device (1) according to any one of the preceding claims, wherein the extension elements (122,123) extend from the permanent magnet (121) by faces of the permanent magnet (121) which are opposed to each other according to a direction of magnetization of the permanent magnet (121), the latter being substantially perpendicular to the axis of stress of the return means (13).

11. Device (1) according to any one of the three preceding claims, wherein, the slider (12) comprising the permanent magnet (121) and the two extension elements (122,123) made of a ferromagnetic material, the slider (12) and the first and second parts (111,112) of the stator (11) are configured so that the permanent magnet (121) of the slider (12) does not come into contact with one of the first and second parts (111,112) of the stator (11), whatever the position of the slider (12).

12. Device (1) according to any one of the preceding claims, in which the integration circuit (16) of the electrical pulses (21, 22, 23, 24) comprises a diode bridge (162) and a capacitor (163), the diode bridge (162) being configured, downstream of the capacitor (163), so that all the electrical pulses (21, 22, 23, 24) are rectified in the same direction and the capacitor (163) being capable of storing an energy density corresponding to each electrical pulse (21', 22, 23', 24) generated and, where appropriate, rectified.

13. Device (1) according to any one of the preceding claims, in which the frame (15) is configured to allow the device (1) to be fixed to an installation site or to furniture, for example urban furniture, intended to be fixed to an installation site.

14. Device (1) according to any one of the preceding claims, free from at least one of: • a piezoelectric component, • a rotating part, • a device for self-centering the slide relative to the stator, and • a device for transmitting movement from a motor shaft to a receiving shaft.

15. System for recovering (0) electrical energy by converting mechanical energy comprising at least one recovery device (1) according to any one of the preceding claims and at least one piece of furniture (10), for example urban furniture, intended to be fixed to a site for installing the system (0) and having at least one housing (100) adapted to house at least one recovery device (1) according to any one of the preceding claims.

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