BE1026475B1 - Magnetic coupling drive system - Google Patents

Abstract

The invention relates to a drive system (1) by magnetic coupling comprising: - an input member (2) comprising a toothed wheel of a gearbox (4) of an aircraft turbomachine; - an output member (3) comprising a shaft of a lubrication group (5) of the aircraft turbomachine.

Description

Magnetic coupling drive system

Technical area

The present invention relates to a magnetic coupling drive system.

Prior art

Generally, an lubrication group of an aircraft turbomachine includes one or more pumps and hoses for circulating oil, among other things, from an oil tank to the turbomachine. The lubrication group plays a central role in the lubrication of the turbomachine. In particular, it pumps oil into the oil tank to spray it onto the bearings of the turbomachine, before redirecting it to the oil tank.

The lubrication groups and other equipment of an aircraft turbomachine are usually mounted on gearboxes and driven by drive systems.

In particular, each of these drive systems allows a transmission of a torque between an input member, for example, a gear of a gearbox, and an output member, for example, a shaft of a lubrication group. Such a drive system is made mechanically by means of several mechanical elements.

A disadvantage of such a drive system lies in its complex implementation and its high cost. This can be understood by a potentially high number of aforementioned elements, the constraints, tolerances and quality controls induced by their manufacture, the need to maintain and lubricate them, as well as the need to replace some of these elements in the event of mechanical wear.

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- 2 Summary of the invention

An object of the invention is to provide a drive system for a lubrication group of an aircraft turbomachine which is simpler and less costly to implement.

To this end, the invention proposes a drive system for a lubrication group of an aircraft turbomachine comprising:

an input member comprising a toothed wheel of a transmission box of an aircraft turbomachine capable of being rotated;

- An output member comprising a shaft of a lubrication group of the aircraft turbomachine capable of being rotated;

one of a first part of the input member and a second part of the output member comprising at least one emitting element arranged to generate a magnetic field, another among the first part and the second part comprising at least one element receiver capable of being magnetically coupled to the transmitter element, so as to allow transmission without mechanical contact of a torque from the input member to the output member.

The drive system according to the invention is simpler and less expensive to implement than the drive systems for a lubrication group of a known aircraft turbomachine.

In fact, the drive system is produced by means of a magnetic coupling between the first and second parts, therefore, between the input member and the output member. This magnetic coupling is achieved by the presence of the emitting element of at least one of these parts to generate the magnetic field inducing a force of attraction and / or repulsion between these parts, thanks to the receiving element of the other part magnetically coupled to the transmitting element. Thus, the output member is rotated from the movements of the member

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- 3 input, without mechanical contact between the first and second parts. The transmission of the torque between the members therefore takes place without mechanical contact, by magnetic forces.

This drive system is particularly simple. In particular, it does not require splines of the shaft, nor of keel in which these splines are fitted, and capable of comprising itself other splines fitting into a toothed wheel, possibly by means of a sleeve, and this to correct any misalignment. The costs of production, quality control, maintenance, and lubrication of such mechanical elements are therefore reduced or zero.

This drive system is also simple because it does not include a gearbox protection system, such as a shaft groove capable of breaking if the torque is too great. In fact, if the torque is too large, the shaft is magnetically cut out from the first part, so as to disengage the lubrication group without damaging any mechanical parts. In this sense, the aforementioned magnetic coupling acts as a non-destructive fuse.

Thanks to the drive system according to the invention, the risks of damage to mechanical parts in the event of overtorque are greatly reduced, as are the associated costs.

Another advantage of the drive system according to the invention is that it allows the transmission of a torque between the input and output members without wear of the mechanical parts comprising it. The costs of maintenance and replacement of such parts are therefore reduced.

The drive system according to the invention also has the advantage of transmitting this torque without energy supply and in a silent manner.

Another advantage of the drive system according to the invention is that it can be carried out through a wall separating two media, the input member being in one of these media and the output member in

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- 4 the other of these media, one of these media can be sanitized or, conversely, contaminated with toxic agents. In particular, and advantageously, the invention allows complete sealing between the gearbox and the lubrication group.

According to a preferred embodiment of the invention, the gearbox comprises a set of meshing gear wheels (usually and technically called "Accessory Gearbox") for driving accessories of the turbomachine, these accessories include at least a part of the lubrication group, and / or a hydraulic pump, and / or a generator.

According to a preferred embodiment of the invention, the gearbox comprises a set of meshing gear wheels (usually and technically called "Propeller Gearbox") for driving at least one propeller.

According to a preferred embodiment of the invention, at least one of said receiver and transmitter elements comprises at least one of:

- a permanent magnet;

- an electromagnet.

The latter are advantageously very simple and inexpensive. Their physical functioning is also well known. An embodiment of the magnetic coupling by means of permanent magnets is known to a person skilled in the art. Another type of element can be used to carry out the invention and generate the magnetic field and the magnetic coupling, without departing from the scope of the invention. In particular, the magnetic coupling can also be carried out by variable reluctance coupler and / or by hysteresis coupler.

Preferably, each of the receiver and transmitter elements comprises at least one of:

- a permanent magnet;

- an electromagnet.

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- 5 According to a preferred embodiment of the invention, the first part comprises a first permanent magnet extending over a first portion facing the first part, the second part comprises a second permanent magnet extending over a second portion from the front of the second part, the first and second permanent magnets facing each other and being separated by a strictly positive distance.

In a first more preferred sub-embodiment, the first and second face portions preferably comprise, essentially flat bases of the inlet and outlet members.

The first and second parts are then preferably end portions of the inlet and outlet members respectively, comprising a base of these members, these bases facing each other, each provided with at least one permanent magnet. The magnetic coupling associated with this embodiment is said to be axial. It is done by attraction and / or magnetic repulsion along straight lines two by two and perpendicular to the bases.

Preferably, the first and second parts are arranged essentially symmetrically with respect to a plane situated between the input and output members, and the transmitter and receiver elements are arranged in a manner that is essentially symmetrical with respect to this plane. More preferably, the transmitter and receiver elements comprise the first and second permanent magnets respectively.

In a second more preferred sub-embodiment, the first and second face portions consist of portions of coaxial cylinders.

The first and second parts are then preferably cylindrical parts of the inlet and outlet members respectively, at least partially overlapping one another along a common axis. The magnetic coupling associated with this embodiment is

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- 6 called radial. It is done by magnetic attraction and / or repulsion along lines perpendicular to the axis.

Preferably, the toothed wheel and the shaft are capable of being rotated about the same axis of rotation. More preferably, the first and second parts are arranged in a manner essentially symmetrical with respect to the axis, and the emitter and receiver elements are arranged in a manner that is essentially symmetrical with respect to the axis. Preferably, the transmitter and receiver elements comprise the first and second permanent magnets respectively.

The production of an essentially radial magnetic coupling can be obtained more generally according to an embodiment of the invention for which the first part comprises a recess configured to receive at least partially, preferably completely, the second part.

According to a preferred embodiment of the invention, at least one of the first and second parts comprises a ferromagnetic material.

Preferably, the receiving element comprises at least a portion of the other part made of a ferromagnetic material. More preferably, the emitting element comprises a permanent magnet and is capable of generating a magnetic field acting on the ferromagnetic material of the portion of the other part.

The present invention also provides a kit of elements comprising:

- the drive system according to the invention;

- the associated gearbox and lubrication group.

The present invention also provides an aircraft turbomachine comprising the drive system according to the invention.

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- 7 All of the preferred embodiments as well as all of the advantages of the system according to the invention transpose mutatis mutandis to the present kit and to the present turbomachine.

Brief description of the figures

Other characteristics and advantages of the present invention will appear on reading the detailed description which follows for the understanding of which reference will be made to the appended figures among which:

- Figure 1 illustrates a schematic representation of a drive system according to an embodiment of the invention;

- Figure 2 illustrates a schematic representation of a drive system according to another embodiment of the invention.

The drawings of the figures are not to scale. Generally, similar elements are denoted by similar references in the figures. In the context of this document, identical or analogous elements may have the same references. In addition, the presence of reference numbers or letters in the drawings cannot be considered as limiting, including when these numbers or letters are indicated in the claims.

Detailed description of particular embodiments of the invention

The present invention is described with particular embodiments and references to figures, but the invention is not limited by these. The drawings or figures described are only schematic and are not limiting.

In the context of the present document, by “drive by magnetic coupling”, it is understood the transmission of a torque and / or of a movement, from an input member to an output member, by means of magnetic forces. , without energy input, and without this

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- 8 transmission is due to mechanical contact. Magnetic radial and / or axial couplings are introduced in the summary of the invention.

Each of Figures 1 and 2 illustrates a schematic representation of a drive system 1 by magnetic coupling according to an embodiment of the invention.

The system 1 comprises an input member 2 comprising a gear wheel of a gear of a transmission box 4 of an aircraft turbomachine, and an output member 3 comprising a shaft of a lubrication group 5 of said aircraft turbomachine. The gearbox 4 comprises a set of toothed wheels meshing for driving at least one propeller 6 and / or accessories of the turbomachine. The input and output members are arranged to rotate for about the same Z axis, along which the output member is elongated

3. A first part 21 of the input member 2 and a second part 31 of the output member 3 are adjacent and respectively comprise a transmitter element and a receiver element. These consist of permanent magnets to generate magnetic fields interacting with each other, so that the emitting and receiving elements are magnetically coupled and allow a contactless transmission of a couple around the Z axis. from the input member 2 to the output member 3. The permanent magnets of the transmitter element extend over a first face portion 22 of the first part 21. The permanent magnets of the receiver element are extend over a second face portion 32 of the second part 31. The permanent magnets which extend over the face portions 22 and 32 face each other and are separated by a strictly positive distance, preferably between zero and one centimeter.

In the representation of FIG. 1, the face portions 22 and 32 consist of coaxial truncated cylindrical surfaces, arranged

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- 9 symmetrically with respect to the axis Z. The first part 21 comprises a recess 23 to receive the second part 31. The face portion 22 consists of a lateral surface of the recess. The face portion 32 consists of a lateral surface of the second part 31. A magnetic force of attraction and / or repulsion perpendicular to the axis Z is exerted on the permanent magnets extending symmetrically with respect to the axis Z, so that a rotational movement of the toothed wheel of the input member 2 around the axis Z generates a rotational movement of the shaft of the output member 3 around the Z axis.

In the representation of FIG. 2, the face portions 22 and 32 consist of essentially flat surfaces, arranged symmetrically with respect to a plane P. The latter is represented by a straight line in FIG. 2 taking into account the fact that the representation is illustrated in a plane perpendicular to the plane P. The first part 21 and the second part 31 are arranged symmetrically on either side of this plane P. The face portion 22 consists of an essentially plane surface constituting a face of the first part 21, and a base of the input member 2. The face portion 22 consists of an essentially planar surface constituting one face of the second part 31, and a base of the output member 3. A magnetic force of attraction and / or repulsion perpendicular to the plane P is exerted on the permanent magnets extending on the face portions 22 and 32, parallel to the plane P, so that a rotational movement of the toothed wheel e of the input member 2 around the axis Z generates a rotational movement of the shaft of the output member 3 around the axis Z.

In summary, the invention relates to a drive system 1 by magnetic coupling comprising:

- An input member 2 comprising a toothed wheel of a transmission box 4 of an aircraft turbomachine;

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- 10 - an output member 3 comprising a shaft of a lubrication group 5 of the aircraft turbomachine.

The present invention has been described in relation to specific embodiments, which have a purely illustrative value and should not be considered as limiting. In general, it will be obvious to a person skilled in the art that the present invention is not limited to the examples illustrated and / or described above. The invention each includes new features and all of their combinations.

In the context of this document, the terms "first", "second", "third" and "fourth" serve only to differentiate between the different elements and do not imply an order between them. The use of the verbs "to understand", "to include", "to include", or any other variant, as well as their conjugations, cannot in any way exclude the presence of elements other than those mentioned. The use of the indefinite article "a", "an", or of the definite article "the", "the" or "the", to introduce an element does not exclude the presence of a plurality of these elements.

Claims (15)

Claims 1. Drive system (1) for a lubrication group of an aircraft turbomachine comprising: - An input member (2) comprising a toothed wheel of a transmission box (4) of an aircraft turbomachine capable of being rotated; - An output member (3) comprising a shaft of a lubrication group (5) of said aircraft turbomachine capable of being rotated; one of a first part (21) of said input member (2) and a second part (31) of said output member (3) comprising at least one emitter element arranged to generate a magnetic field, the other of said first part (21) and said second part (31) comprising at least one receiving element capable of being magnetically coupled to said emitting element, so as to allow transmission without mechanical contact of a torque from said input member (2) to said output member (3). 2. System (1) according to the preceding claim, characterized in that said transmission box (4) comprises a set of toothed wheels meshing for driving accessories of said turbomachine, said accessories comprising at least one part of said lubrication group (5), and / or a hydraulic pump, and / or a generator. 3. System (1) according to any one of the preceding claims, characterized in that said gearbox (4) comprises a set of toothed wheels meshing for driving at least one propeller (6). BE2018 / 5515 4. System (1) according to any one of the preceding claims, characterized in that said first part (21) comprises a recess (23) configured to at least partially accommodate said second part (31). 5. System (1) according to any one of the preceding claims, characterized in that at least one of said receiver and transmitter elements comprises at least one of: - a permanent magnet; - an electromagnet. 6. System (1) according to the preceding claim, characterized in that each of said receiver and transmitter elements comprises at least one of: - a permanent magnet; - an electromagnet. 7. System (1) according to any one of the preceding claims, characterized in that said first part (21) comprises a first permanent magnet extending over a first face portion (22) of said first part (21), in that said second part (31) comprises a second permanent magnet extending over a second face portion (32) of said second part (31), said first and second permanent magnets facing each other and being separated by a distance strictly positive. 8. System (1) according to claim 7, characterized in that said first (22) and second (32) face portions comprise BE2018 / 5515 - 13 essentially flat bases of said input and output members (2, 3). 9. System (1) according to the preceding claim, characterized in that: - The first (21) and second (31) parts are arranged essentially symmetrically with respect to a plane (P) located between the inlet (2) and outlet (3) members; and in that - the transmitter and receiver elements are arranged essentially symmetrically with respect to said plane (P). 10. System (1) according to claim 7, characterized in that said first (22) and second (32) face portions consist of portions of coaxial cylinders. 11. System (1) according to the preceding claim, characterized in that the toothed wheel and the shaft are capable of being rotated about the same axis of rotation (Z). 12. System (1) according to the preceding claim, characterized in that in that - The first (21) and second parts (31) are arranged essentially symmetrically with respect to said axis (Z); and in that - the transmitter and receiver elements are arranged essentially symmetrically with respect to said axis (Z). BE2018 / 5515 13. System (1) according to any one of the preceding claims, characterized in that at least one of said first (21) and second (31) parts comprises a ferromagnetic material. 5 14. Kit of elements including: - the drive system (1) according to any one of the preceding claims; - said transmission box (4); - said lubrication group (5). 15. An aircraft turbomachine comprising the drive system (1) according to any one of claims 1 to 13.