TURBINE GENERATOR ARRANGEMENT

Description

Technical field

[0001] The present invention relates to an assembly which forms part of a turbogenerator and is intended for use in an electricity generation or energy cogeneration apparatus. Prior art

[0002] Known electricity production or energy cogeneration devices comprise a combustion device supplying combustion gas to a turbine mechanically coupled to a compressor compressing air injected into the combustion device. Such a device is for example described in document WO2022089822A1.

[0003] The mechanical coupling between the turbine and the compressor is provided by a central element. Document DE 10 2014 210 451 A1 discloses an example of such a configuration. The central element may be rotatably supported by radial bearings. Documents US 6,305,169 B1, US 2003 / 223892 A1 and DE 20 2006 004 975 U1 disclose such mechanical couplings. The proper positioning of these bearings is essential to achieve excellent stability, particularly at high rotational speeds.

[0004] In this context, a motor-generator can be mechanically coupled to the turbine and compressor via the central element. In this case, sufficient air circulation must be provided between the rotor and stator of the motor-generator, particularly for cooling purposes. In addition, a rotor of limited length is preferable to ensure the rotor stability of the device.

[0005] These technical constraints discourage, or at least complicate, the integration of means contributing to the control and / or monitoring of the device during its operation. In the technically distinct context of a hybrid motor for a motor vehicle, document FR 3 027 103 A1 discloses the use of an angular position sensor mounted on a stator of the motor to detect a movement of blades present on a target of a rotor of the motor. Statement of the invention

[0006] The object of the invention is to provide a turbogenerator assembly according to claim 1.

[0007] For this purpose, the invention proposes an assembly for a turbogenerator comprising: a turbine configured to be supplied with combustion gas by a combustion device; a compressor mechanically coupled to the turbine by a central element; and a motor-generator axially offset from the compressor and mechanically coupled to the turbine and the compressor by the central element; comprising an angular position detector of the central element, which comprises: a target fixed to one end of the central element, and an inductive sensor fixed relative to a stator of the motor-generator.

[0008] The detector makes it possible to determine an angular position of the central element simply, taking into account the technical constraints of the assembly, so that this data can be used for the control and / or monitoring of the assembly during its operation, for example, by controlling in a closed loop the rotation of the rotor part of the assembly. In this way, control is possible, which makes it possible to avoid the assembly becoming unstuck.

[0009] The use of a target fixed at the end of the central element and an inductive sensor associated with the target is advantageous. The target can cover the end of the central element, on the one hand without obstructing the air circulation in the assembly, and on the other hand without requiring substantial axial extension of the rotor part of the assembly, therefore with limited space requirement. In addition, the inductive sensor, by being arranged fixedly relative to and / or at the level of and / or on the stator, can be positioned in the immediate vicinity of the target by taking advantage of the rotation of the central element (and therefore of the target) to generate the currents useful for detecting the angular position of the central element.

[0010] These advantages are reinforced in the case of a motor-generator with a rotor fixed to the central element provided with a rotor magnetic device arranged in or around the central element from its end. Indeed, in this case, to limit the rotor in length, the rotor magnetic device is arranged at the stator; typically, the latter surrounds the rotor magnetic device. As the target is simply fixed at the end of the central element, it is thus preferably also arranged at the stator, like the inductive sensor. An additional axial space or an axial extension of the rotor and / or the central element is therefore not necessary for the detector because the detector is at the stator, as illustrated in figures 4 And 6 hereinafter introduced.

[0011] A limitation of the length of the rotor and / or the central element is beneficial for the stability and dynamism of the assembly, in particular in the case of a rigid central element with a radially measured diameter between 15 and 40 mm subject to a high first natural frequency.

[0012] The detector of the assembly according to the invention also allows a determination of the angular position of the central element independent of the electromagnetic noise and the temperature that it is likely to undergo within a turbogenerator.

[0013] The rotor part of the assembly is preferably designed to rotate at a speed of at least 80,000 revolutions per minute, more preferably at least 100,000 revolutions per minute. It may, for example, be designed to rotate at a speed between 90,000 and 150,000 revolutions per minute.

[0014] As known to a person skilled in the art, the "motor-generator" operates as a motor when supplied with electrical energy and provides energy in the form of motion, and as a generator when supplied with energy in the form of motion and provides electrical energy. Alternatively, the term "motor-generator" may be substituted in this document by "motor and / or generator". The motor-generator is an electric motor-generator comprising a rotor and a stator.

[0015] The rotor of the motor-generator is typically formed of a portion of the central element on which a rotor magnetic device is attached. The rotor magnetic device comprises one or more magnets which are preferably permanent.

[0016] The angular position sensor preferably also makes it possible to determine the rotational speed of the central element.

[0017] The target is preferably arranged in (and / or according to) a radial plane at the end of the central element. The inductive sensor is preferably aligned axially (i.e. "on the" main extension axis of the assembly, in particular of the central element) on the target, facing it, or in other words, opposite it. This arrangement is advantageously simple to set up in a very small space, at the very level of the stator of the generator motor.

[0018] The inductive sensor then also extends along a radial plane parallel to the plane along which the target extends, the target and the inductive sensor facing each other at a small distance, which allows noise-free determination of the angular position of the central element (and therefore, if applicable, of the rotor of the motor-generator). The distance between the target and the inductive sensor is preferably between 0.5 and 2.0 mm, more preferably between 1.0 and 1.5 mm, for example, approximately (i.e., within 10%) 1.0 mm. A distance greater than 2.0 mm makes the determination of the angular position uncertain in this technical environment, while a sufficient safety distance of at least 0.5 mm must be ensured between the target and the inductive sensor.

[0019] According to the present invention, the inductive sensor is connected to an electronic device axially aligned with the inductive sensor and comprising a card for acquiring angular positions (and / or, where appropriate, rotational speeds) of the central element. The electronic device axially extends the inductive sensor, without projecting radially relative to the latter.

[0020] Since the electronic device is axially aligned with the inductive sensor, it is housed in the axial extension of the inductive sensor and does not obstruct the circulation of air between the stator and the rotor of the motor-generator. This is an advantageous effect compared to similar electronic devices of the prior art which are arranged in the same plane as the inductive sensor. Preferably, the electronic device, or at least the acquisition card, extends along a plane (carried axially and) perpendicular to the radial plane along which the inductive sensor extends, as illustrated in figure 7 hereinafter introduced.

[0021] The electronic device makes it possible to acquire and, preferably, to process and / or exploit the angular position data (and / or rotation speed where appropriate) from the detector. Preferably, it comprises or is connected to a processor or any similar means for carrying out such processing and / or such exploitation, with the aim of monitoring and / or controlling (for example, in a closed loop) the rotational operation of the assembly, which makes it possible to avoid any possible detachment of the assembly according to the invention.

[0022] The electronic device is preferably supported by a bullet-shaped housing axially extending the inductive sensor. In this case, the housing is preferably also fixed relative to the stator of the motor-generator. The housing allows the electronic device and the inductive sensor to be fixedly supported. Its bullet shape (in particular, as shown in figures 4 And 6hereinafter introduced) plays an advantageous aerodynamic role in contributing to the circulation of air between the rotor and the stator of the motor-generator without obstructing it.

[0023] Preferably, the housing comprises internal notches for placing and holding the electronic device and the inductive sensor, typically along two perpendicular planes as described above.

[0024] In short, according to several embodiments, the inductive sensor is connected to an electronic device supported by a bullet-shaped housing.

[0025] According to a preferred embodiment of the target, it comprises, and more preferably consists of, an insulating surface and a metallic radial element. The metallic radial element, by its nature, then becomes a reference point of the inductive sensor, in particular for the purposes of determining the angular position of the central element. This embodiment is particularly simple and inexpensive to set up in a limited space.

[0026] An easy and effective embodiment of the target is to partially cover the insulating surface with the metallic radial element, for example by fixing it on it, for example by gluing it or screwing it on. In this way, the metallic radial element is arranged axially between the inductive sensor and the insulating surface. It is seen directly by the inductive sensor which easily distinguishes, during rotation, the metallic radial element from the rest of the insulating surface.

[0027] For example, the insulating surface may have an axial thickness of 2.0 to 3.0 mm, e.g., 2.4 mm, while the metallic radial element is very thin axially, e.g., with an axial thickness of only a few µm, e.g., between 20 and 60 µm, e.g., 35 µm.

[0028] The metallic radial element is preferably made of copper (Cu). The insulating surface is for example made of " printed circuit board » (PCB), preferably of a fiberglass reinforced epoxy resin composite material (known as FR-4). Advantageously, this same substrate can be used for the design of the inductive sensor and / or electronic device where appropriate. It has the advantage of being light weight and good resistance to centrifugal force, which is particularly relevant in the case of the target.

[0029] The insulating surface (and preferably the target as a whole) and the inductive sensor preferably extend along two parallel discs. The insulating surface preferably has an annular shape while the inductive sensor is preferably in the shape of a disc of the same external radius.

[0030] In other words, the target and the inductive sensor each preferably have a circular edge of the same radius.

[0031] This geometry aims to best fit the assembly, for example because the target is fixed to the end of the central element (and rotor) which typically has a disc-shaped end of the same radius. Thus, the target and the inductive sensor are completely integrated into the assembly (without protruding radially) preferably at the stator of the motor-generator, in very little space and without obstructing the air circulation between the stator and the rotor of the motor-generator.

[0032] The insulating surface may include a visual cue, such as a dot or radial line mark, useful for testing the assembly at low rotational speed.

[0033] The metallic radial element can take various radial shapes which depend on assembly constraints, for example the number of poles of a rotor magnetic device as mentioned above. It is preferably a metallic surface which partially covers the insulating surface. This embodiment is preferred because it allows easy detection while being simple to design. For example, the metallic radial element is a single-piece surface and takes for example the shape of a semicircle or a half-moon, and / or covers approximately (to within 10%) half of the insulating surface. This embodiment is particularly suitable for detection when the rotor magnetic device is bipolar. Those skilled in the art will understand that other embodiments, for example, with two portions of metallic surfaces covering two opposite quarters of the insulating surface, or another number of such portions, are possible.

[0034] Preferably, the target comprises an axial hole. This is particularly the case when the insulating surface is annular in shape as described above. The axial hole makes it possible to include elements for fixing the target to the end of the central element. Preferably, the hole is chamfered. In particular, the hole has a flared shape on the face of the target opposite the end of the central element. This embodiment is advantageous because it makes it possible to fix the target by a screw, for example of suitable geometry, without the head of the screw protruding axially beyond the target. Thus, the inductive sensor can be arranged as close as possible to the target, as described above, without having to provide an additional distance for the screw head (or any other fixing element).

[0035] In particular, preferably, a fixing part, for example a screw, is then arranged in the chamfered axial hole to fix the target to the end of the central element.

[0036] An embodiment of the target not detailed at present and alternative to the above description may consist of a partly machined metal extension of the central element (and / or the motor-generator rotor). Thus, the difference in axial length of the central element (and / or the rotor) between its machined part and its non-machined part may be detected by the inductive sensor to deduce the angular position of the central element (and / or the rotor).

[0037] In particular, preferably, a fixing part, for example a screw, is then arranged in the chamfered axial hole to fix the target to the end of the central element.

[0038] According to an achievement of the visible target in figure 8hereinafter introduced, the target extends into a ring comprising a plurality of axial orifices. These are preferably oriented away from the central element. The inductive sensor faces the target preferably without extending parallel to the ring, so that it does not contribute to the determination of the angular position of the central element.

[0039] The holes can then be advantageously used to balance the assembly in situ of the assembly, for example by inserting a spot weld into one or more of the holes.

[0040] As mentioned in the prior art, the assembly is preferably provided with one or more radial bearings provided to guide the central element in rotation. According to one embodiment within the framework of the present invention, the bearings comprise: a first radial bearing located axially between the turbine and the compressor, and a second radial bearing located axially between the compressor and the motor-generator.

[0041] The radial bearings are then located axially on either side of the compressor: the first bearing is located between the turbine and the compressor, and the second bearing is located between the compressor and the motor-generator. Such a distribution of the radial bearings makes it possible to absorb the force moments particularly efficiently because these torques come from the masses of the turbine, the compressor and the rotor of the motor-generator (the latter being particularly heavy). Consequently, it makes it possible to limit the number of radial bearings.

[0042] Furthermore, the position of the second bearing, on the other side of the compressor from the turbine, makes it possible to reduce the distance between the turbine and the compressor, to better ventilate the region between the turbine and the compressor which is very hot, and therefore to improve the stability of the system.

[0043] For the purposes of this document, a "radial" bearing is a bearing preventing movement perpendicular to the axis of rotation, and an "axial" bearing is a bearing preventing movement parallel to the axis of rotation. The terms "radial" and "axial" more generally refer to directions respectively perpendicular and parallel to the axis of rotation. The assembly, and in particular the central element and / or the rotor, preferably extend along this axis and rotate around it. The radial bearings may be separated, radially, from the central element by another rotating element and fixed to the central element.

[0044] For the purposes of this document, a radial bearing is an aerodynamic bearing. Thus, during rotation, the central element is levitated, separated from the bearing by a layer of air that supports the bearing by a lift effect. It is therefore not a rolling bearing. It does not require lubrication.

[0045] In one embodiment, the first radial bearing and the second radial bearing are foil bearings. Foil bearings allow the use of a larger diameter center member than would be possible with other bearings, for example ball bearings. This increases the first bending natural frequency, which improves stability and high-speed operation.

[0046] According to one embodiment, the assembly comprises an air duct opening onto the compressor, the air duct being located between the compressor and the second radial bearing and having a radial component.

[0047] In fact, instead of an axial air duct located between the rotor and the stator, it is preferred that the air duct is between the second radial bearing and the compressor and is not parallel to the axis (in other words, it has a radial component). This allows the distance between the rotor and the stator to be particularly small, which improves the electro-magneto-mechanical stability of the system and reduces the reactive power, while improving the angular phase shift (cosine ϕ). The air duct may include one or more turns, include a radial section and / or include an inlet volute that takes the air from the side, and makes it spiral at a specific angle.

[0048] According to one embodiment, the central element is made of a single piece or a plurality of pieces fixed together so as to rotate integrally.

[0049] The central element, which extends from the turbine to the motor-generator via the compressor, therefore has a rotational speed that is identical throughout its entire extent. A central element of one piece or made of integrally fixed parts simplifies the balancing procedure, which is particularly delicate in a turbine generator assembly such as that of the invention.

[0050] According to one embodiment, the first radial bearing is the only radial bearing between the turbine and the compressor. There is therefore no other radial bearing than the first radial bearing between the turbine and the compressor. This makes it possible to reduce the distance between the turbine and the compressor, and therefore to improve the stability of the system.

[0051] According to one embodiment, the first radial bearing and the second radial bearing are the only radial bearings. There is therefore no other radial bearing, neither beyond the motor-generator relative to the compressor, nor between the motor-generator and the turbine, nor beyond the turbine relative to the compressor. Since the turbogenerator assembly according to the invention rotates particularly quickly, the question of concentricity is important. However, the lower the number of bearings, the easier it is for them all to be concentric. Having two bearings is an interesting compromise between the constraints of stability and concentricity.

[0052] According to one embodiment, the turbine generator assembly comprises a thrust bearing and an axial bearing configured to prevent axial movement of the thrust bearing. The thrust bearing, which may be referred to as an axial thrust bearing, is preferably located between the turbine and the compressor. It is attached directly or indirectly to the central element.

[0053] According to one embodiment, the turbine generator assembly comprises a shaft attached to the central element in a detachable manner and such that the shaft and the central element rotate together, the thrust bearing being part of the shaft. The shaft could also be called a "rotating element". The presence of the shaft, forming a separate part from the central element, allows the radial bearings, the compressor and the turbine to be fitted onto the central element.

[0054] According to one embodiment, the motor-generator comprises a rotor fixed to the central element and comprising a bipole rotor magnetic device, preferably with permanent magnet(s). In other words, the rotor magnetic device has only one south pole and one north pole. Given the very high rotation speed, the assembly is easier to straighten than with a quadrupole or with more magnetic poles. This can be a single permanent magnet.

[0055] According to one embodiment, the motor-generator comprises a rotor fixed to the central element and comprising a rotor magnetic device located inside the central element. This allows the rotor magnetic device, which is particularly heavy, to be close to the axis. It is however possible, while remaining within the scope of the invention, for the rotor magnetic device to be fixed outside the central element, for example shrunk onto the central element.

[0056] According to one embodiment, the central element comprises a cavity having an opening in a radial plane and located at one end of the central element, the rotor magnetic device being located in the cavity. The opening makes it possible to introduce the rotor magnetic device into the central element by centering it in a particularly precise manner.

[0057] According to one embodiment, the central element has a diameter greater than 15 mm and less than 40 mm. This diameter is naturally measured radially. The diameter of the central element may vary depending on the position along the axis, but preferably it is nowhere less than 15 mm or greater than 40 mm. A small diameter reduces the value of the first bending natural frequency, which deteriorates stability and high-speed operation. A large diameter reduces the efficiency of the turbine generator assembly. The aforementioned interval allows a compromise between these two constraints.

[0058] The invention also provides an apparatus for producing electricity or cogeneration of energy comprising a turbogenerator assembly according to the invention. Preferably, the only radial bearings are the first radial bearing and the second radial bearing. Brief description of the figures

[0059] Other characteristics and advantages of the 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: there figure 1 schematizes an electricity production or energy cogeneration device; figure 2 is an axial section of part of a turbogenerator assembly, the figure 3 is an axial section of a part of another turbine generator assembly, the figure 4 is an axial section of the partially illustrated turbogenerator assembly figure 2 , there Figure 5 is a front view of a target, the figure 6 is a partial axial section of the partially illustrated turbine generator assembly figure 2 , reproducing part of the figure 4 with more details, the figure 7 is a three-dimensional view of an inductive sensor connected to an electronic device, the figure 8is a front view of a target other than that of the Figure 5 . Embodiments of the invention

[0060] The present invention is described with particular embodiments and references to figures but the invention is not limited by them. The drawings or figures described are only schematic and are not limiting. Furthermore, the functions described may be performed by structures other than those described herein.

[0061] In the figures, identical or similar elements may have the same references. The reference numbers in the claims do not limit their scope.

[0062] In this document, the terms "first" and "second" serve to differentiate between the different elements and do not imply an order between these elements. In this document, the use of the verbs "comprendre", "include", "comprendre", or any other variant, as well as their conjugations, cannot exclude the presence of elements other than those mentioned. Similarly, in this document, the use of an indefinite article "un", "une", and / or a definite article "le", "la" or "l'", to introduce an element does not exclude the presence of a plurality of these elements.

[0063] There figure 1schematically illustrates different elements of an electricity production or energy cogeneration device 2. The device 2 comprises a combustion device 90, a turbine 30, a compressor 20 and a motor-generator 70. The combustion device 90 transmits combustion gases, (i.e. resulting from combustion) to the turbine 30 via a first conduit 91. The turbine 30, the compressor 20 and the motor-generator 70 are mechanically coupled via a central element 10. Air compressed by the compressor 20 is sent to the combustion device 90 via a second conduit 92 and a recuperator 93 which preheats the compressed air before injection into the combustion device 90. The compressor 20 is preferably shrunk onto the central element 10.

[0064] In the context of this document, a turbogenerator assembly 1 comprises the turbine 30, the compressor 20, the motor-generator 70 and the central element 10 which are aligned to rotate around the axis 5 (axis of rotation). It is connected to the combustion device 90. The turbine 30, the compressor 20, the motor-generator 70 are arranged, axially, in the following order: turbine 30, compressor 20, motor-generator 70, so as to be axially spaced from each other.

[0065] There figure 2 illustrates parts of an assembly for a turbogenerator 1. It notably shows the blades 31 of the turbine 30, the blades 21 of the compressor 20, and a rotor magnetic device 72 of the rotor 71 of the motor-generator 70.

[0066] In this embodiment, the turbine 30 and the compressor 20 are separated, axially, by a first radial bearing 50, which radially surrounds the central element 10. The first radial bearing 50 is, preferably, the only radial bearing between the turbine 30 and the compressor 20.

[0067] In this embodiment, the compressor 20 and the motor-generator 70 are also separated, axially, by a second radial bearing 60, which radially surrounds the central element 10. In particular, the second radial bearing 60 axially separates the compressor from the rotor magnetic device 72. The second radial bearing 60 is, preferably, the only radial bearing between the compressor 20 and the motor-generator 70.

[0068] The first radial bearing 50 and the second radial bearing 60 are preferably foil bearings. The first radial bearing 50 and the second radial bearing 60 are preferably the only radial bearings of the turbine generator assembly 1 and of the electricity production or energy cogeneration apparatus 2.

[0069] Preferably, the central element 10 is made of a single piece or a plurality of pieces fixed together so as to all rotate at the same angular speed, as if they were of a single piece.

[0070] Preferably, the radial diameter 15 of the central element, regardless of the position along the axis 5, is greater than 15 mm and / or is less than 40 mm.

[0071] Preferably, the central element 10 is fixed to a shaft 40 which surrounds it radially, and the first radial bearing 50 surrounds the shaft 40 radially. The shaft 40 is located, axially, between the turbine 30 and the compressor 20. The shaft 40 comprises an axial stop 41 held by an axial bearing 81 (visible in figure 4 ). The stop 41 is such that the diameter 15 of the central element 10, at all points, is smaller than the diameter of the stop 41.

[0072] The rotor magnetic device 72 is preferably a bipole, for example a magnet. In the embodiment of the figure 2 , it is located in a cavity 11 inside the central element 10. The cavity 11 preferably comprises an opening opening axially onto the end 12 of the central element 10.

[0073] In the embodiment of the figure 3, the rotor magnetic device 72 is alternately fixed to the outside of the central element 10, so as to surround it radially.

[0074] THE figures 2 And 3 further illustrate a target 111 fixed to one end 12 of the central element 10 which is at the heart of the present invention as described in the disclosure of the invention. This same target is commented on below with regard to the figures 4 , 5 And 6 .

[0075] There figure 4 illustrates parts of a turbogenerator assembly 1. The turbogenerator assembly 1 comprises an air duct 25 supplying air to the compressor 20. The air duct 25 is preferably located between the compressor 20 and the second radial bearing 60. It has a radial component, that is to say that the path of the air in this air duct 25 is not only axial.

[0076] The turbogenerator assembly 1 preferably comprises a first bearing support 51 around the first radial bearing 50 and a second bearing support 61 around the second radial bearing 60. The first 51 and the second 61 bearing supports are fixed relative to each other and are concentric. The first 51 and the second 61 bearing supports are fixed relative to a stator 73 of the motor-generator 70.

[0077] In the context of this invention, the turbogenerator assembly 1 is provided with a detector 110 making it possible to determine the angular position of the central element 10 and preferably the angular speed of the central element 10.

[0078] The detector 110 comprises a target 111 fixed to the end 12 of the central element 10 in a radial plane. It rotates with the central element 10 while remaining in the same plane. The detector 110 also comprises an inductive sensor 115 axially aligned with the target 111, and fixed relative to the stator 73 of the motor-generator 70. As is apparent from the figure 6 , the detector is connected to an electronic device 118 comprising an angular speed and / or position acquisition card which is supported by a bullet-shaped housing 116. Based on measurements of angular positions and / or angular speeds of the detector 110, the electronic device 118 typically makes it possible to control and / or monitor the turbogenerator assembly 1, which makes it possible to prevent it from stalling.

[0079] The target 111 and the inductive sensor 115 preferably have a similar geometry as shown in the figures 5 to 8. They are inscribed in two discs of the same radius, extending along two parallel radial planes, so that they face each other at a distance D of approximately 1 mm. They both have a circular edge d of the same radius, corresponding approximately to the radius of a radial section at the end 12 of the central element 10. The target 111 is configured to cooperate electromagnetically with the inductive sensor 115.

[0080] The inductive sensor 115 is more precisely visible in figure 7. It is designed for example from a PCB body on which are arranged different metal coils, for example copper, and connection points. This type of device is known to those skilled in the art. It comprises for example, a transmitting coil and two receiving coils for the signal from the target. The electronic device 118, or at least the acquisition card, is formed of a printed circuit for example on a material of the same PCB. It is connected to the inductive sensor 115 by a plurality of solder points between the coils and the electronic circuits, so as to extend along a plane perpendicular to the radial plane along which the inductive sensor 115 extends, so as to be in its axial extension and not to protrude radially relative to the inductive sensor 115.

[0081] There Figure 5illustrates the target 111 in one embodiment of the invention. It consists of an insulating surface 112 and a metallic radial element 113. The latter is illustrated in the form of a radial metallic surface fixed in or on the insulating surface 112. The target 111 is pierced with a hole 114, preferably chamfered and axial as can be seen from the section of the figures 2 , 3 , 4 And 6 This hole 114 makes it possible to fix the target 111 on the central element 10 by means of a screw 117 with a countersunk head and / or with a suitable geometry without the screw head protruding axially from the target 111, as illustrated in figure 6 .

[0082] There figure 8illustrates another target 111 which is suitable for carrying out the present invention. The metallic radial element 113 is in the form of a half-moon, more precisely a half-ring covering approximately half of the insulating surface 112. In this embodiment, the target 111 extends into a ring comprising a plurality of axial orifices 119 which can be used for balancing in situ of the turbine generator assembly 1 by inserting weights, for example from molten metal deposits. The ring is arranged beyond the edge d so that it does not contribute to or interfere with detection by the inductive sensor. The ring and the half-moon radial element are two independent features although illustrated in the same figure.

[0083] The target 111 and the inductive sensor 115 can be designed from the same body (the insulating surface 112 for the target 111 and the support of the copper coils for the inductive sensor 115) made of PCB materials as described in the disclosure of the invention.

[0084] In brief, the invention relates to a turbogenerator assembly 1 for an energy production or cogeneration apparatus comprising a turbine 30, a compressor 20 and a motor-generator 70 mechanically coupled together by a central element 10. The assembly comprises an angular position detector 110 of the central element 10 in the form of a target 111 fixed at the end 12 of the central element 10 and an inductive sensor 115 fixed relative to a stator 73 of the motor-generator 70 arranged to cooperate (electromagnetically) with the target 111.

[0085] The present invention has been described in relation to specific embodiments, which are for illustrative purposes only and should not be considered limiting. It will be readily apparent to those skilled in the art that the invention is not limited to the examples illustrated or described above, and that its scope is more broadly defined by the claims introduced below.

Claims

1. A turbine generator assembly (1) comprising: • a turbine (30) configured to be supplied with combustion gases by a combustion device (90); • a compressor (20) mechanically coupled to the turbine (30) by a central element (10); and • a motor-generator (70) axially offset from the compressor (20) and mechanically coupled to the turbine (30) and the compressor (20) by the central element (10); characterized in that the turbine generator assembly (1) comprises an angular position detector (110) for the central element (10) comprising: - a target (111) attached to one end (12) of the central element (10), and - an inductive sensor (115) stationary relative to a stator (73) of the motor-generator (70), wherein the inductive sensor (115) is connected to an electronic device (118) which comprises an angular position acquisition card and which axially extends and is aligned with the inductive sensor (115), without projecting radially with respect to the latter.

2. The turbine generator assembly according to claim 1, wherein: - the target (111) is arranged in a radial plane at the end (12) of the central element (10), and - the inductive sensor (115) is axially aligned with, and faces, the target (111).

3. The turbine generator assembly according to claim 1 or 2, wherein a distance separating the target (111) and the inductive sensor (115) is between 0.5 and 2.0 mm.

4. The turbine generator assembly according to any of the preceding claims, wherein the electronic device (118) is supported by an ogive-shaped casing (116) axially extending the inductive sensor (115).

5. The turbine generator assembly according to any of the preceding claims, in which the target (111) consists of an insulating surface (112) and a metallic radial element (113).

6. The turbine generator assembly according to claim 5, wherein the metallic radial element (113) partially covers the insulating surface (112) so that it is arranged axially between the inductive sensor (115) and the insulating surface (112).

7. The turbine generator assembly according to any of the preceding claims, wherein the target (111) comprises a chamfered axial hole (114).

8. Turbine generator assembly according to any of the preceding claims, wherein the target (111) and the inductive sensor (115) each have a circular edge (d) of the same radius.

9. The turbine generator assembly according to any of the preceding claims, wherein the target (111) extends into a ring comprising a plurality of axial orifices (119).

10. The turbine generator assembly according to any one of claims 1 to 9, wherein the motor-generator (70) comprises a rotor (71) attached to the central element (10), and comprising a bipolar rotor magnet device (72).

11. The turbine generator assembly according to any one of claims 1 to 9, wherein the motor-generator (70) comprises a rotor (71) attached to the central element (10), and comprising a rotor magnet device (72) located inside the central element (10).

12. The turbine generator assembly according to any of the preceding claims, further comprising: • a first radial bearing (50) located axially between the turbine (30) and the compressor (20) and designed to guide the central element (10) in rotation; and • a second radial bearing (60), located axially between the compressor (20) and the motor-generator (70), and designed to guide the central element (10) in rotation.

13. The turbine generator assembly according to claim 12, in which the first (50) and second (60) radial bearings are the only radial bearings.

14. The turbine generator assembly according to claim 12 or 13, comprising an air pipe (25) leading to the compressor (20), the air pipe (25) being located between the compressor (20) and the second radial bearing (60) and having a radial component.

15. A power generation or energy cogeneration unit (2) comprising a turbine generator assembly (1) according to any of the preceding claims.