MAGNETIC GEARBOX

Abstract

A magnetic gearbox (1) comprising: a driving rotor (6); a driven rotor (2) coaxial with the driving rotor; and a modulator (4), interposed between the driving rotor (6) and the driven rotor (2) and coaxial with the driving rotor (6) and the driven rotor (2), the modulator (4) comprising at least one ferromagnetic component. The driving rotor (6) and the driven rotor (2) each comprise a plurality of magnetic sectors (8) whose polarity is controlled to form a first determined number of magnetic poles on the driving rotor (6) and a second determined number of magnetic poles on the driven rotor (2). Figure to be published with the abbreviation: Fig. 1

Description

Title of the invention: MAGNETIC GEARBOX technical field

[0001] The invention relates to the field of magnetic gearboxes. STATE OF PRIOR ART

[0002] In a known manner, a mechanical reducer is a gear system with a transmission ratio less than one. A reducer typically comprises at least two gears, an input shaft, and an output shaft. A rotational motion is applied to the input shaft, with a given input torque and input speed. Typically, the reducer allows for an output torque and output speed that differ from the input torque and input speed. Thus, a reducer can typically increase the output torque relative to the input torque, or increase the output speed relative to the input speed.

[0003] In a known manner, a mechanical gearbox is a system comprising a plurality of mechanical reducers, the gearbox allowing the choice between several reduction ratios.

[0004] Mechanical gearboxes are old and well-known systems known for their robustness. However, mechanical gearboxes can be quite bulky due to the size of the gears they contain. In addition, the rotation of the various gears can be noisy. To address these problems, magnetic gearboxes have been developed. Typically, a magnetic gearbox comprises:

[0005] - An external rotor consisting of a ferromagnetic ring and a given number magnets deposited on its internal surface.

[0006] - A driving rotor consisting of a ferromagnetic ring and a number the number of magnets differs from the number of magnets in the driven rotor, the magnets being deposited on the external surface of the ring.

[0007] - Modulators made of ferromagnetic parts. Their number is determined by combining the number of poles of the driving rotor and the number of poles of the driven rotor.

[0008] In a conventional way, the choice of the number of magnets (and therefore of magnetic poles) on the outer ring and on the inner ring, and the choice of the number of ferromagnetic parts of the modulators, make it possible to determine a reduction ratio of the reducer (just as the choice of the number of teeth and the diameter makes it possible to determine the reduction ratio of a mechanical reducer).

[0009] Such magnetic reducers are particularly efficient and can be They are less bulky and quieter than mechanical reducers. However, the known architecture of magnetic reducers does not allow for a gearbox system that would allow for varying the reduction ratio.

[0010] Thus, in this context, it is necessary to provide a magnetic gearbox that allows for varying a reduction ratio, while being quieter and less bulky than prior art mechanical gearboxes. Description of the invention

[0011] To this end, according to a first aspect, a magnetic gearbox is proposed comprising: (i) a driving rotor;

[0012] (ii) a driven rotor coaxial with the driving rotor; and

[0013] (iii) a modulator, interposed between the driving rotor and the driven rotor and coaxial with the driving rotor and the driven rotor, the modulator comprising at least one ferromagnetic part. In addition, the driving rotor and the driven rotor each comprise a plurality of magnetic sectors whose polarity is controlled to form a first determined number of magnetic poles on the driving rotor and a second determined number of magnetic poles on the driven rotor.

[0014] Thus, a magnetic gearbox is proposed that allows for varying the reduction ratio, while being quieter and more compact than prior art mechanical gearboxes. Indeed, controlling the polarity of the magnetic sectors allows for modifying the gearbox's reduction ratio. Furthermore, the ingenious use of magnetic sectors with controlled polarity allows for a reduced number of rotors, thereby reducing the gearbox's size compared to a mechanical gearbox. Finally, the magnetic gearbox operates more quietly than a known geared gearbox.

[0015] According to a particular arrangement, each rotor comprises a first ferromagnetic ring having a plurality of radial slats, each radial slat being adapted to receive a magnet or an electromagnet to form a magnetic sector.

[0016] According to a particular arrangement, at least one magnetic sector includes a magnet fixed on a radial strip.

[0017] According to a particular arrangement, at least one magnetic sector comprises an electromagnet having a coil wound around a radial strip having a magnet, the polarity of the magnetic sector being controlled by changing one direction of flow of a current in the electromagnet.

[0018] According to a particular arrangement, at least one of the rotors comprises at least two coaxial ferromagnetic rings, the first ferromagnetic ring comprising a first series of magnets arranged radially around the first ferromagnetic ring and the second ferromagnetic ring comprising a second series of magnets arranged radially around the second ferromagnetic ring, the first ferromagnetic ring and the second ferromagnetic ring pivot relative to each other to change the alignment of the magnets of the second series with the magnets of the first series, the alignment of a magnet of the second series with a magnet of the first series forming a magnetic sector and a change in the alignment of the magnets of the second series with the magnets of the first series allowing the polarity of the magnetic sectors to be changed.

[0019] According to a particular arrangement, the gearbox includes an intermediate ring made of ferromagnetic material, disposed between the first ring and the second ring, coaxial with the first and second rings, and having a third series of magnets, the second ferromagnetic ring and the intermediate ring pivot relative to each other to change the alignment of the magnets of the second series with the magnets of the third series, the alignment of a magnet of the second series with a magnet of the third series forming a magnetic sector and a change in the alignment of the magnets of the second series with the magnets of the third series allowing the polarity of the magnetic sectors to be changed.

[0020] According to a particular arrangement, the first ring and the second ring are concentric.

[0021] According to a particular arrangement, the intermediate ring is concentric with the first ring and the second ring.

[0022] According to a particular arrangement, the modulator is fixed relative to the gearbox.

[0023] According to a particular arrangement, the modulator is free to rotate relative to the gearbox.

[0024] According to a particular arrangement, the driving rotor, the driven rotor and the modulator are concentric. Brief description of the drawings

[0025] The features of the invention mentioned above, as well as others, will become clearer upon reading the following description of at least one exemplary embodiment, said description being made in relation to the accompanying drawings, among which:

[0026] [Fig. 1] schematically illustrates a gearbox according to one embodiment of the invention;

[0027] [Fig.2] schematically illustrates a rotor according to an embodiment of the invention

[0028] [Fig.3] schematically illustrates a first ring of a rotor according to a mode of realization of the invention;

[0029] [Fig.4] schematically illustrates a second ring of a rotor according to a mode realization of the invention;

[0030] [Fig. 5] schematically illustrates an intermediate ring of a rotor according to a method of implementing the invention;

[0031] [Fig.6] illustrates magnetic sectors according to a second embodiment of the invention;

[0032] [Fig.7] illustrates a gearbox according to an embodiment of the invention;

[0033] [Fig.8] schematically illustrates a first ring of a rotor according to an embodiment of the invention;

[0034] [Fig.9] schematically illustrates a second ring of a rotor according to a mode realization of the invention;

[0035] [Fig. 10] schematically illustrates an intermediate ring of a rotor according to an embodiment of the invention.

[0036] DETAILED DESCRIPTION OF IMPROVEMENTS

[0037] Magnetic gearbox

[0038] With reference to [Fig. 1], according to a first aspect, a gearbox is proposed 1 magnetic item including: (i) a driving rotor 6; (ii) a driven rotor 2 coaxial with the driving rotor 6; and (iii) a modulator 4, interposed between the driving rotor 6 and the driven rotor 2 and coaxial with the driving rotor 6 and the driven rotor 2, the modulator 4 comprising at least one ferromagnetic part.

[0039] Furthermore, the driving rotor 6 and the driven rotor 2 each comprise a plurality of magnetic sectors 8, which will be described below. The polarity of each magnetic sector 8 is controlled to form a first determined number of magnetic poles on the driving rotor 6 and a second determined number of magnetic poles on the driven rotor 2.

[0040] It is specified that in this document, polarity control means the ability to change a polarity between a south polarity and a north polarity.

[0041] Thus, in other words, controlling the polarity of each magnetic sector 8 allows the number of magnetic poles on each rotor 2 and 6 to be varied, which in turn allows the reduction ratio of the gearbox 1 to be modified. Indeed, schematically, the number of magnetic poles 8 of each rotor 2 and 6 of the Gearbox 1 can be compared to the number of teeth on a gear in a gear system. Therefore, changing the number of magnetic poles allows for a change in the reduction ratio of gearbox 1.

[0042] More specifically, the mathematical rules known for calculating a reduction ratio of a gear system apply by extension to the magnetic gearbox 1 by replacing the expression for the number of teeth with the number of magnetic poles. However, compared to a conventional mechanical gearbox with a limited number of reduction ratios (due to the volume constraints of the gears), the gearbox 1 according to the invention offers a large number of possible reduction ratios. Indeed, depending on the polarity chosen for each magnetic sector 8 and depending on the polarity chosen for neighboring magnetic sectors 8, it is possible to have a magnetic pole comprising more or fewer magnetic sectors 8. In other words, several magnetic sectors 8 can be grouped together to form a single magnetic pole.This technical arrangement therefore allows the number of magnetic poles of each rotor 2 and 6 to be varied, without changing the dimensions of each rotor 2 and 6.

[0043] In addition, the use of magnetic sectors 8 with controlled polarity allows for quieter gear ratio changes than with a gear system, and generally, the magnetic gearbox 1 according to the invention operates more quietly than a known mechanical gearbox 1. Furthermore, controlling the polarity of the magnetic sectors 8 advantageously allows for obtaining a plurality of reduction ratios using only two rotors 2 and 6. This technical arrangement allows the gearbox 1 according to the invention to be much more compact than a prior art gear gearbox.

[0044] However, it is specified that it would be possible to have more than two coaxial rotors 2 and 6.

[0045] As schematically shown in [Fig.2], each rotor 2 or 6 comprises a first ferromagnetic ring 10 having a plurality of radial slats, each radial slat being adapted to receive a magnet or an electromagnet to form a magnetic sector 8.

[0046] Furthermore, each magnetic sector 8 comprises a magnet fixed to the radial strip.

[0047] First embodiment of a magnetic sector

[0048] According to a first embodiment, schematically shown in Figures 2 to 5, at least one of the rotors comprises three coaxial rings 10, 12 and 14 (as will be specified below, in addition to being coaxial, the rings 10, 12 and 14 may be concentric) made of ferromagnetic material: the first ring 10, a second ring 14 and an intermediate ring 12.

[0049] As schematically represented in [Fig. 3], the first ferromagnetic ring 10 comprises a first series of magnets 16 arranged radially around the first ferromagnetic ring 10. According to the embodiment presented here, the magnets 16 of the first series are oriented according to a first polarity.

[0050] As schematically shown in [Fig. 5], the second ring 14 comprises a second series of magnets 20 arranged radially around the second ferromagnetic ring 14. According to the embodiment presented here, the magnets 20 of the second ring 14 have different polarities, alternating. In the example shown here, several consecutive magnets have the same polarity, in a defined interval. In other words, on the second ring 14, the polarities alternate in a defined interval.

[0051] As schematically represented in [Fig.4], the intermediate ring 12 comprises a third series of magnets 18 arranged radially around the intermediate ring 12. According to the embodiment presented here, the magnets 18 of the third series are oriented according to a second polarity different from the polarity of the magnets 16 of the first series.

[0052] It is specified that according to another arrangement, not shown, it would be possible to have only two rings. According to this arrangement, the first ring 10 then presents an alternation of polarities.

[0053] Aligning a magnet 20 of the second series with a magnet 16 of the first series, or 18 of the third series, forms a magnetic sector 8 and a modification of the alignment of the magnets 20 of the second series with the magnets 16 of the first series, or 18 of the third series, allows the polarity of the magnetic sectors to be changed.

[0054] It is specified that, according to one embodiment, the intermediate ring 12 and the second ring 14 are made of grain-oriented ferromagnetic material. According to the same embodiment, the first ring 10 is made of grain-unoriented ferromagnetic material.

[0055] Second embodiment of a magnetic sector

[0056] According to a second embodiment, schematically shown in [Fig.6], each magnetic sector 8 further comprises an electromagnet 22 having a coil wound around the radial strip having a magnet, the polarity of the magnetic sector 8 being controlled by changing the direction of flow of an electric current in the electromagnet.

[0057] According to a particular arrangement, the coil of the electromagnet 22 is not continuously energized. In this embodiment, the coil of the electromagnet 22 provides a pulsed current that changes the polarity of the magnet it surrounds.

[0058] Concentric rotors and rings

[0059] According to the embodiment shown in particular in Figs. 2 to 5, the rotors 2 and 6 are concentric. Furthermore, according to this same embodiment, the rings 10, 12 and 14 are also concentric.

[0060] This embodiment very advantageously allows for a thin structure along the direction of the axis of revolution of the rotors 2 and 6.

[0061] Coaxial rotors and crowns

[0062] According to the embodiment shown in particular in Figs. 7 to 10, the rotors 2 and 6 are coaxial. According to this embodiment, the rotors 2 and 6 and the rings 10, 12 and 14 of each rotor 2 or 6 are juxtaposed along the same axis of revolution. According to this embodiment, the gearbox 1 has a compact structure in a radial direction.

[0063] Thus, according to one embodiment, the rotors 2 and 6 and the rings 10, 12 and 14 are juxtaposed concentrically (and therefore coaxially). According to another embodiment, the rotors 2 and 6 and the rings 10, 12 and 14 are juxtaposed coaxially without being concentric.

[0064] Modulator

[0065] As previously stated, the gearbox includes a modulator 4 interposed between the driving rotor 6 and the driven rotor 2. The modulator 4 is a ring made of ferromagnetic material (according to a particular arrangement, the modulator 4 is not entirely made of ferromagnetic material). According to a particular arrangement, the modulator 4 is fixed relative to the driving rotor 6 and the driven rotor 2. In other words, according to this technical arrangement, the modulator 4 is fixed relative to a frame of the gearbox 1 (i.e., the modulator 4 is not free to rotate). According to this arrangement, with the modulator 4 fixed, the driving rotor 6 and the driven rotor 2 rotate in opposite directions.

[0066] According to another particular arrangement, the modulator 4 is rotationally movable relative to the driving rotor 6 and the driven rotor 2. In other words, according to this technical arrangement, the modulator 4 rotates within the gearbox 1. According to this arrangement, since the modulator 4 is rotationally movable, the driving rotor 6 and the driven rotor 2 each rotate in the same direction.

[0067] Operation

[0068] In operation, each rotor 2 and 6 can be connected to a shaft. One of the rotors 2 or 6 is driving and the other is driven in rotation.

[0069] As detailed previously, the polarity of each magnetic sector 8 is controlled to define a reduction ratio. Depending on the requirements during the operation of the gearbox 1, the polarity of the magnetic sectors 8 is controlled to, for example, increase or decrease the number of magnetic poles on each rotor 2 and 6. In a particularly advantageous way, the change in ratio of reduction can be carried out at standstill or when rotors 2 and 6 are rotating, without the need to use a clutch system.

Claims

Demands

1. A magnetic gearbox (1) comprising: (i) a driving rotor (6); (ii) a driven rotor (2) coaxial with the driving rotor; and (iii) a modulator (4), interposed between the driving rotor (6) and the driven rotor (2) and coaxial with the driving rotor (6) and the driven rotor (2), the modulator (4) comprising at least one ferromagnetic component; the gearbox (1) being characterized in that the driving rotor (6) and the driven rotor (2) each comprise a plurality of magnetic sectors (8) whose polarity is controlled to form a first determinate number of magnetic poles on the driving rotor (6) and a second determinate number of magnetic poles on the driven rotor (2), at least one magnetic sector (8) comprises a magnet fixed to a radial strip and at least one of the rotors (2, 6) comprises at least two coaxial ferromagnetic rings,the first ferromagnetic ring (10) comprising a first series of magnets (16) arranged radially around the first ferromagnetic ring (10) and the second ferromagnetic ring (14) comprising a second series of magnets (20) arranged radially around the second ferromagnetic ring (14), the first ferromagnetic ring (10) and the second ferromagnetic ring (14) pivot relative to each other to modify the alignment of the magnets (20) of the second series with the magnets (16) of the first series, the alignment of a magnet (20) of the second series with a magnet (16) of the first series forming a magnetic sector (8) and a modification of the alignment of the magnets (20) of the second series with the magnets (16) of the first series allowing the polarity of the magnetic sectors (8) to be modified.

2. Gearbox (1) according to claim 1, in which each rotor (2, 6) comprises a first ferromagnetic ring (10) having a plurality of radial slats, each radial slat being adapted to receive a magnet or electromagnet to form a magnetic sector (8).

3. A gearbox (1) according to any one of the preceding claims, wherein at least one magnetic sector (8) comprises an electromagnet (22) having a coil wound around a radial strip having a magnet, the polarity of the magnetic sector being controlled by

4.

5.

6.

7.

8.

9. changing the direction of current flow in the electromagnet (22). Gearbox (1) according to claim 1 comprising an intermediate ring (12) of ferromagnetic material, disposed between the first ring (10) and the second ring (14), coaxial with the first ring (10) and the second ring (14), and having a third series of magnets (18), the second ferromagnetic ring (14) and the intermediate ring (12) pivot relative to each other to modify the alignment of the magnets (20) of the second series with the magnets (18) of the third series, the alignment of a magnet (20) of the second series with a magnet (18) of the third series forming a magnetic sector (8) and a modification of the alignment of the magnets (20) of the second series with the magnets (18) of the third series allowing the polarity of the magnetic sectors (8) to be modified. Gearbox (1) according to claim 1, in which the first ring (10) and the second ring (14) are concentric. Gearbox (1) according to claims 4 and 5 in combination, wherein the intermediate ring (12) is concentric with the first ring (10) and the second ring (14). Gearbox (1) according to any one of the preceding claims, wherein the modulator (4) is fixed relative to the gearbox (1). Gearbox (1) according to any one of the preceding claims, wherein the modulator (4) is free to rotate relative to the gearbox (1). Gearbox (1) according to any one of the preceding claims, wherein the driving rotor (6), the driven rotor (2) and the modulator (4) are concentric.

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