MOTOR VEHICLE COMPRISING A TURBOMACHINE EQUIPPED WITH A GENERATOR AND A REDUCTION GEAR AND PROCESS BASED ON SUCH A VEHICLE

Abstract

The invention relates to a motor vehicle comprising a turbomachine which includes: - at least one turbine and / or at least one compressor, arranged on a working shaft, - an electric generator rotationally coupled to the working shaft, characterized in that the turbomachine further includes a reduction gear on the working shaft. The invention also relates to a manufacturing method based on such a vehicle. Figure 1

Description

Title of the invention: AUTOMOBILE VEHICLE COMPRISING A TURBOMACHINE EQUIPPED WITH A GENERATOR AND A REDUCER GEAR AND A METHOD BASED ON SUCH A VEHICLE

[0001] The invention relates to the field of gas turbine cycle type turbogenerator devices and systems, integrated into a vehicle.

[0002] Gas turbine-type power converters are currently being extensively studied as range extenders in production hybrid vehicles. This converter can operate in APU (Auxiliary Power Unit) mode, where its role is to recharge the batteries of an electric vehicle. It is thus mechanically decoupled from the powertrain and operates at its maximum efficiency point.

[0003] Several cycles are under investigation, including simple regenerative cycles (RGT for Regenerative Gas Turbine), but also regenerative cycles with a cooler (IRGT) and cycles with a cooler, recuperator and reheat or "Intercooled Regenerative Reheat Gas Turbine" in English.

[0004] The gas turbine cycle with cooler, recuperator and reheater (IRReGT) is a cycle with high potential for automotive applications. This cycle makes it possible to achieve high efficiency but also high power density (high specific net work).

[0005] Integrating the turbogenerator into an electric vehicle presents difficulties. Indeed, the engine speed of turbomachines is generally very high, often exceeding 100,000 RPM. To convert the rotation of the turbomachine into electrical energy, a specific electric machine is required.

[0006] In addition, this integration requires the use of a specific power electronic system, not readily available, to process high frequency and achieve a ripple at a voltage acceptable to the vehicle's battery.

[0007] Thus, one objective of the invention is to remedy the defects of the prior art and to propose a solution enabling the use of a conventional electrical machine on a turbine of a turbocharger so as to convert the energy of the rotations of the turbine into electrical energy.

[0008] To achieve this objective, the invention proposes a motor vehicle comprising a turbomachine which includes: - at least one turbine and / or at least one compressor, arranged on a working axis, - an electric generator rotationally coupled to the working axis, characterized in that the turbomachine further comprises a reducer on the working axis.

[0009] Advantageously, the invention provides a turbogenerator with a high-speed friction reduction system. This reduction gear is integrated into the turbogenerator at the turbomachinery level, which makes it possible to reduce the rotational speed and consequently use a conventional electrical machine and, above all, expensive conventional power electronics.

[0010] The invention also applies to other technical fields where a high-speed reducer is required.

[0011] In addition, the invention makes it possible to reduce the output speed of the turbomachine and to couple it to a low-speed electric machine.

[0012] This proposal is valid for all turbomachines regardless of their architecture: GT (simple Gas Turbine), RGT (Recuperative Gas Turbine), IRGT (Intercooled Recuperative Gas Turbine), IRReGT (Intercooled Recuperative Reheat Gas Turbine), etc...

[0013] According to one variant, said reducer is disposed between the generator and the turbine or compressor.

[0014] This allows the operating speed of the working axis to be reduced directly in the vicinity of the generator.

[0015] According to one variant, said reducer is a planetary reducer.

[0016] This makes it possible to limit the size of the assembly.

[0017] According to one variant, said reducer comprises a frame, a conical sun gear, a spherical planet gear, a transmission shaft, and a conical gear wheel.

[0018] This allows for a fully functional reduction system.

[0019] According to one variant, said reducer includes a first adjustable locking screw controlling the slip and stresses between the contact points at the level of the gear wheel, and the planetary gear, the first locking screw acting on the gear wheel through a tension / force sensor, and through a lever, a helical spring and a pressure piston.

[0020] This allows for easy control of said slippage and said stresses. Furthermore, it reduces sensitivity to perfect non-coaxiality (misalignment error) of the gears.

[0021] According to one variant, said reducer includes a second locking screw controlling the slip and stresses at the level of the solar gear and the planetary gear, the second locking screw acting on the solar gear through a tension / force sensor, a specific lever and a bearing.

[0022] This makes it easy to control said sliding and said stresses.

[0023] According to one variant, said bearing is of the spindle bearing type.

[0024] According to one variant, the solar gear operating at high speed transmits the power and torque, through the transmission axis of the planetary gear, the gear wheel being fixed to the frame through a dog clutch, and being movable along the axial direction following the working axis.

[0025] The invention further relates to a method for manufacturing a turbocharger for a motor vehicle according to the invention, characterized in that it comprises the following steps: - install at least one turbine and / or at least one compressor, arranged on the working axis, - an electric generator rotatably coupled to the working axis, - to rotatably couple an electric generator to the working axis, - to further couple a reducer to the working axis.

[0026] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: - [Fig.l] illustrates an internal diagram of a reducer for a turbomachine of a vehicle according to a preferred embodiment; - [Fig.2] schematically illustrates a view in space of the reducer of [Fig.1]; - [Fig. 3] schematically illustrates a first example of a turbomachine implemented in the invention; and - [Fig.4] schematically illustrates a first example of a turbomachine implemented in the invention.

[0027] The invention provides a high-speed planetary friction reducer for a turbogenerator shaft, enabling the reduction of the rotational speed of an output shaft. This planetary friction reducer is intended to reduce the rotational speed of a turbomachine shaft rotating at very high speeds.

[0028] We seek to propose a reduction device which makes it possible to reduce the rotational speed of a shaft rotating at very high speed, in particular a shaft of a turbomachine.

[0029] Turbomachinery operating at high speed requires specific electrical machines and dedicated power electronics; said power electronics has the role of processing the high-frequency signal to obtain a signal compatible with the correct voltage required at the output level.

[0030] This device is compatible with a turbomachine; said turbomachine can be installed in an electric vehicle to supply electricity to the vehicle, or in a combustion engine vehicle, or in other applications. Possible types include electric generators or auxiliary power units (APUs), particularly for aircraft, boats, buses, etc.

[0031] Thus the objective of the invention is to propose this device which makes it possible to reduce the complexity of the manufacture of the turbomachine and consequently that of the vehicle.

[0032] This proposed device can be coupled to any type of turbomachine. The turbomachine may be a single or booster compressor, a two-stage compressor, a twin compressor, two or more compressors coupled on the same shaft, a single turbine, a single or multi-stage turbine, or two or more turbines coupled together. The turbomachine may also be a simple turbocharger consisting of a compressor and a turbine, a two-stage compressor coupled to a turbine, a single compressor coupled to a twin turbine, or any variant formed by assembling a compressor and a turbine.

[0033] Compressors and turbines can be of radial or axial technology.

[0034] Said reducer can be coupled to the turbine side (referred to as the hot side) or to the compressor side (referred to as the cold side). The coupling of the device can be to the compressor side with a double compression stage, or to the compressor side with a double expansion stage.

[0035] The friction planetary reducer comprises a frame 1, a sun gear 2 (or "sun gear" in English) with a conical shape, at least one planet gear 3 (or "planet gear" in English) with a spherical shape, a transmission shaft 4 (or "carrier shaft" in English), and a ring gear 5 (or "ring gear" in English) with a conical shape.

[0036] The choice of contact geometries (spherical vs conical) offers a solution which makes it possible to reduce the sensitivity for the perfect non-coaxiality (alignment error) of the gears.

[0037] The frictional contact between the sun gear 2 and the planetary gears 3 (in the preferred embodiment, there are three planetary gears 3), and between the planetary gears 3 and the gear wheel 5, are different and independent. In the illustrated embodiment, the friction angles and Hertzian pressures can be optimized independently (choice of materials, radii of curvature). Similarly, cooling can be improved.

[0038] The slippage (and stresses) between the contact points at the level of the gear wheel 5 and the planetary gears 3 are controlled by an adjustable screw 7 which acts on the gear wheel 5 through a tension / force sensor 8, and through a lever 9, a helical spring 10 and a pressure piston 11.

[0039] Furthermore, the slippage (and stresses) at the level of the solar gear 2 and the planetary gears 3 are controlled by a screw which acts on the solar gear 2 through a tension / force sensor, a specific lever and a bearing 12, said bearing 12 being of the spindle bearing type.

[0040] The reducer can operate dry or lubricated.

[0041] In the case of operation in reduction mode, the power (torque) is transmitted from the solar gear 2, operating at high speed, through the planetary gears 3 of the transmission shaft 4. The gear wheel 5 does not rotate, it is fixed to the frame of the reducer through a kind of dog teeth connection / spline; it is movable along the axial direction.

[0042] In the architecture presented, the reduction ratio is 10 (for a slip ratio of 0). The friction contacts can be created and controlled using an active or passive system (for example, an electric, mechanical, hydraulic, magnetic, or other actuator). This allows the friction to be adapted at any given moment according to the input-output torques (or power). The mechanism proposed in this architecture is equipped with a passive control mechanism.

[0043] The conical arm is fixed by a radial bearing on one side and suspended by three friction contacts with the planetary gears on the other side. It is possible to use magnetic bearings (as solid segments) instead of mechanical contacts to eliminate friction (power dissipation through heating). This significantly increases the mechanical efficiency of the device.

[0044] The technical advantages are as follows: - Reduction in the cost of power electronics due to the use of a low-speed electrical machine; - the device allows the friction rate to be adapted during normal operation and according to the transmitted torque, which makes it possible to increase mechanical efficiency by controlling friction at all times; - the device is compatible with magnetic transmissions; - the device makes it possible to achieve very high reduction ratios, by adapting the diameters of the gears, preferably non-toothed.

[0045] The proposal is compatible with all thermodynamic architectures of turbochargers using a recuperator. Below is a non-exhaustive list of these architectures: - Recuperative gas turbine architecture (RGT for "Recuperative gas turbine" in English); - Intercooled Recuperative Gas Turbine (IRGT) architecture; - gas turbine architecture with cooled compression, regenerator and reheat during expansion (RReGT - for "Recuperative Reheat Gas Turbine" in English); - gas turbine architecture with cooled compression, regenerator and reheat during expansion (IRReGT - for "Intercooled Regenerative Reheat Gas Turbine" in English).

[0046] Besides the automotive field, the turbogenerator of the invention can be applied to various non-automotive applications.

Claims

Demands

1. A motor vehicle comprising a turbomachine which includes: - at least one turbine (Tl) and / or at least one compressor (Cl), disposed on a working shaft, - an electric generator (Gl) rotationally coupled to the working shaft, characterized in that the turbomachine further comprises a reduction gear (R) on the working shaft (A), this reduction gear (R) being a planetary reduction gear comprising a frame (1), a bevel gear (2), a spherical planetary gear (3), a transmission shaft (4), a bevel gear (5) and a first adjustable locking screw (7) controlling the slip and stresses between the contact points at the gear wheel (5) and the planetary gear (3), the first locking screw (7) acting on the gear wheel (5) through a tension / force sensor (8), and through a lever (9), a helical spring (10) and a pressure piston (11).

2. Motor vehicle according to claim 1, characterized in that said reducer is disposed between the generator (Gl) and the turbine (Tl) or the compressor (Cl).

3. Motor vehicle according to any one of claims 1 to 2, characterized in that said reducer (R) comprises a second locking screw controlling the slip and stresses at the level of the solar gear and the planetary gear, the second locking screw acting on the solar gear through a tension / force sensor, a specific lever and a bearing (12),

4. Motor vehicle according to claim 3, characterized in that said bearing (12) is of the spindle bearing type.

5. Motor vehicle according to any one of claims 1 to 3, characterized in that the high-speed solar gear transmits power and torque through the transmission shaft of the planetary gear, the gear wheel being fixed to the frame through a dog clutch, and being movable along the axial direction along the working axis.

6. A method for manufacturing a turbocharger for a motor vehicle according to any one of claims 1 to 5, characterized in that it comprises the following steps: - install at least one turbine (Tl) and / or at least one compressor (Cl), positioned on the working axis, - an electric generator (Gl) rotationally coupled to the working axis, - to rotaryly couple an electric generator (Gl) to the working axis, - furthermore, couple a reducer to the working axis (A).

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