Fuel cell comprising fluid compressor

Abstract

The present invention relates to a fuel cell comprising a two-stage fluid compressor, the compressor comprising: a housing having a fluid inlet and a compressed fluid outlet and housing a shaft rotatably mounted about a longitudinal axis; the first compression wheel and the second compression wheel are mounted on the shaft in a back-to-back manner; and a motor. The housing comprises a through inner housing extending coaxially with the longitudinal axis and inside which at least the electric motor is arranged, the inner wall of said inner housing being arranged to form, together with the electric motor, a channel at least between said inner wall and the electric motor, allowing the electric motor to be cooled when in contact with the fluid to be compressed flowing in the channel. Furthermore, the housing comprises, at its surface, at least one cavity forming at least one integrated housing arranged to receive at least one electronic component of the compressor, said integrated housing extending towards the inner wall to allow said electronic component to be cooled by the fluid to be compressed flowing in the channel by means of the inner wall.

Description

[0001] This application is a divisional application of an application with a filing date of April 19, 2019, application number 201910317313.2, and invention name “Fuel Cell Including Fluid Compressor”. Technical Field

[0002] The present invention relates to a fuel cell comprising a two-stage high-speed fluid compressor, the compressor comprising: a housing having a fluid inlet and a compressed fluid outlet and accommodating a shaft rotatably mounted about a longitudinal axis; a first compression wheel and a second compression wheel mounted back to back on the shaft, the first compression wheel forming a first compression stage and the second compression wheel forming a second compression stage; and an electric motor, preferably a synchronous electric motor, located between the first compression wheel and the second compression wheel and arranged to rotate the shaft. Background Art

[0003] Such fluid compressors are often called turbo compressors or centrifugal compressors. They are provided with a stator and a rotor, which form a permanent magnet synchronous motor (brushless motor). This type of compressor can reach very high speeds, for example 100,000 to 500,000 revolutions per minute. The motor drives the compression wheel at high speed, and the compression wheel compresses the fluid. The fluid used here is air. Using two compression wheels allows the fluid to be compressed twice.

[0004] These compressors usually comprise a first flow circuit for the fluid to be compressed and a second flow circuit for a cooling liquid used to cool the compressor, more specifically the electric motor and the bearings supporting the motor shaft on the one hand and the electronic components on the other hand. In practice, the high speed of rotation of the electric motor causes very high heating, making it necessary to cool the compressor elements to avoid damage. At least as far as the cooling circuits are concerned, these circuits are usually arranged outside the actual compressor.

[0005] Therefore, these compressors are very bulky and cannot be integrated in confined environments.

[0006] Furthermore, the heat recovered by the coolant is wasted, which constitutes a considerable waste of energy. Summary of the invention

[0007] It is an object of the present invention to overcome the various disadvantages of known fuel cells comprising a high speed compressor.

[0008] More specifically, it is an object of the present invention to provide a fuel cell comprising a very compact two-stage high-speed fluid compressor.

[0009] Another object of the present invention is to provide a fuel cell comprising a two-stage high-speed fluid compressor having a high rotation speed, a high compression ratio and an optimal energy efficiency but occupying a small volume.

[0010] To this end, the present invention relates to a fuel cell comprising a two-stage fluid compressor, the compressor comprising: a housing having a fluid inlet and a compressed fluid outlet and accommodating a shaft rotatably mounted about a longitudinal axis; a first compression wheel and a second compression wheel mounted back to back on the shaft, the first compression wheel forming a first compression stage and the second compression wheel forming a second compression stage; and an electric motor located between the first compression wheel and the second compression wheel and arranged to rotate the shaft.

[0011] According to the invention, the housing comprises a through inner housing extending coaxially with the longitudinal axis and at least the motor is arranged inside the housing, the inner housing having an inner wall arranged to form a channel together with the motor at least between the inner wall and the motor, the channel extending between the first compression stage and the second compression stage to cool the motor in contact with the fluid to be compressed flowing in the channel. In addition, the housing comprises at least one cavity at its surface, the cavity forming at least one integrated housing arranged to receive at least one electronic component of the compressor, the integrated housing extending towards the inner wall to allow the electronic component to be cooled by the fluid to be compressed flowing in the channel through the inner wall.

[0012] The fuel cell according to the invention therefore comprises a compressor which uses the same fluid both for compression and for cooling the compressor. The arrangement of the channels for both circulating the fluid to be compressed and for cooling the various compressor elements makes it possible to obtain a very compact compressor and therefore a very compact fuel cell. In particular, a configuration in which the electronic components are cooled via the inner wall has several advantages over a configuration in which the electronic components are cooled directly by the fluid. All electronic components can be arranged without special seals. The electronic components can be operated without draining the fluid, which is a complex and expensive operation. Furthermore, fixing the electronic components in an integrated housing in the housing saves space.

[0013] Furthermore, the fuel cell according to the invention comprises a compressor capable of recovering all heat losses in the motor, the bearings supporting the motor shaft and the electronic components to convert said losses into useful work. Thus, the fuel cell according to the invention comprises a compressor having a high rotation speed, a high compression ratio and an optimal energy efficiency, but occupying a small volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The objects, advantages and features of the present invention will appear more clearly from the following detailed description of embodiments of the invention given by way of non-limiting example only and illustrated by the accompanying drawings, in which:

[0015] - Figure 1 A schematic diagram of a fuel cell according to the invention shown in perspective view comprising a high-speed compressor is shown.

[0016] - Figure 2 Shows Figure 1 Exploded view of the compressor along the longitudinal axis.

[0017] - Figure 3 Shown as seen from above Figure 1 A partially exploded perspective view of a compressor.

[0018] - Figure 4 yes Figure 1 Longitudinal cross-sectional view of a compressor.

[0019] - Figure 5 It is along Figure 4 Cross-sectional view of the CC line.

[0020] - Figure 6 is a perspective view of the shaft carrying the compression wheel and rotor.

[0021] - Figure 7 This is an enlarged cross-sectional view of the compressor around the bearing.

[0022] - Figure 8 is a perspective view of the board carrying the electronic components. DETAILED DESCRIPTION

[0023] Reference Figure 1 , schematically shows a fuel cell 100 according to the present invention, which includes a two-stage high-speed fluid compressor 1 of the turbo compressor or centrifugal compressor type. In the following description, the term "fluid" refers to air. Except for the compressor described below, the elements constituting the fuel cell are known and do not require any specific description here.

[0024] The compressor 1 comprises a housing 2 made of aluminum, whose upper surface 2a is closed by an upper cover 3a and whose front surface 2b and rear surface 2c are closed by front cover 3b and rear cover 3c, respectively. The side surfaces 2d of the housing are joined at their base to form a bottom 2e having a U-shaped cross section.

[0025] The upper cover 3a is located on the side of the electronic components 4 of the compressor, as will be seen below. Therefore, as will be seen below, the electronic components 4 integrated in the compressor are easily accessible thanks to access through the upper cover 3a. The front cover 3b and the rear cover 3c are used to access the interior of the compressor (motor, rotor, bearings, etc.). A sealing gasket 20 is inserted between the upper surface 2a of the housing 2 and the upper cover 3a. This gasket 20 protects the electronic components 4 from dust and moisture.

[0026] The housing 2 has an inlet 5 for the fluid to be compressed, arranged on the front cover 3 b , and a tangential compressed fluid outlet 6 arranged on one of the side faces 2 d of the housing 2 .

[0027] Reference Figure 4 The housing 2 houses a ceramic shaft 7 rotatably mounted around a longitudinal axis AA passing through a front surface 2b and a rear surface 2c, a first centrifugal compression wheel 8 and a second centrifugal compression wheel 10 mounted back to back at each end of the shaft 7, wherein the first compression wheel 8 forms a first compression stage and the second compression wheel 10 forms a second compression stage. More specifically, the shaft 7 is hollow and includes a screw 11, and one of the compression wheels 8, 10 is screwed at each end of the screw 11, which allows easy assembly and disassembly of the compression wheels. Therefore, the two compression wheels 8 and 10 are driven on the same shaft 7, which provides better energy efficiency and avoids the use of reduction gears. The rear of the compression wheels 8 and 10 includes a labyrinth seal to control the pressure in the compressor and balance the axial forces.

[0028] The housing 2 also accommodates a synchronous motor 12 located between the first compression wheel 8 and the second compression wheel 10 and arranged to rotate the shaft 7. The motor 12 comprises a stator 14 and a rotor, which interact to form a permanent magnet synchronous motor (brushless motor). More specifically, the stator 14 is formed by a coil 14a and two ferrite elements 14b fixedly mounted relative to the housing 2. The rotor comprises a magnet 16a made integrally with the shaft 7, for example by bonding, and is covered with a carbon fiber sheath 16b. A titanium flange 16c is fixed (for example by bonding) to the side end and ensures the resistance of the rotor to high-speed centrifugal forces.

[0029] The shaft 7 is rotatably mounted on the housing 2 about its longitudinal axis AA by means of at least a front radial bearing 18, a rear radial bearing 22 and an axial bearing 24. The compressor comprises a front radial bearing support 26 for supporting the front radial bearing 18, a rear radial bearing support 28 for supporting the rear radial bearing 22, which are arranged to be positioned around the shaft 7 at the front and rear of the motor 16, respectively. At the rear, a volute 29 is also provided between the rear radial bearing support and the rear cover 3c. The volute 29 comprises an orifice leading to the tangential fluid outlet 6 after compression. An axial bearing support 30 for supporting the axial bearing 24 is also provided, which is arranged to be positioned around the shaft 7 between the first compression wheel 8 and the front radial bearing support 26. Obviously, the axial bearing can be arranged at the rear of the motor.

[0030] The bearings are non-contact and aerodynamic to produce limited friction. They require no lubrication and require very little maintenance. More specifically, refer to Figure 6 The axial bearing 24 is an aerodynamic bearing and is formed by a disk which comprises on at least one face thereof a first preferably spiral groove 24a arranged to form an air film. The front radial bearing 18 and the rear radial bearing 22 are aerodynamic bearings, and the shaft 7 has a second groove 32 facing the front radial bearing 18 and the rear radial bearing 22, which is arranged to form an air film.

[0031] Reference Figure 7 The front radial bearing support 26 includes at least a first groove 34, the first groove 34 is positioned to face a second groove 36 provided on the front radial bearing 18, and the first groove 34 and the second groove 36 are arranged to receive a front bearing O-ring joint 38. Figure 7 In the embodiment of the invention, two sets of grooves 34, 36 are provided. Similarly, the rear radial bearing support 28 comprises at least a third groove, which is positioned facing a fourth groove provided on the rear radial bearing 22, and the third groove and the fourth groove are provided to receive the rear bearing O-ring joint. The grooves provided on the front radial bearing 18 and the rear radial bearing 22 have rounded bottoms. The radial bearings 18, 22 are axially and radially retained only by the corresponding O-ring joints. The O-ring joints ensure the centering of the radial bearings 18, 22, compensate for radial play, dampen vibrations and maintain their axial position. In addition, the assembly saves space, thereby further increasing the compactness of the compressor.

[0032] By means of a joint 39 mounted in a groove provided on the threaded rod 11 (see Figure 4 ) to achieve radial retention and centering of the screw 11 carrying the two compression wheels 8 and 10 at the center of the shaft 7.

[0033] Furthermore, the front radial bearing support 26 comprises a fifth groove 40 provided for the passage of air. Likewise, the rear radial bearing support 28 comprises a sixth groove provided for the passage of air. These fifth and sixth grooves and the holes communicating between each important point of the bearing make it possible to balance the pressure throughout the compressor, in particular between the O-ring joints. This makes it possible to avoid misaligning the joints.

[0034] Reference Figure 2 , 4 5, the housing 2 includes a through inner housing 50, which extends coaxially with the longitudinal axis AA between the front surface 2b and the rear surface 2c of the housing 2 and receives the front radial bearing support 26 and the front radial bearing 18, the motor 12 and its shaft 7, the rear radial bearing support 28 and the rear radial bearing 22, the second compression wheel 10 and the volute 29. On the front surface 2b side, the inner housing 50 is closed by the front cover 3b, which combines the first compression wheel 8, the axial bearing support 30 and the axial bearing 24. On the rear surface 2c side, the inner housing 50 is closed by the rear cover 3c.

[0035] The inner housing 50 has an inner wall 52 which is arranged to form, together with the electric motor 12, at least between said inner wall 52 and the electric motor 12, a channel 54 which extends between the first compression stage and the second compression stage, allowing the electric motor 12 to be cooled when in contact with the fluid to be compressed flowing in the channel 54. More specifically, in the variant shown here, the inner wall 52 of the inner housing 50 has a circular cross section and the two ferrite elements 14 b of the stator 14 of the electric motor 12 have, on their outer surface, longitudinal recesses 55 extending along the longitudinal axis AA (see Figure 5 ) so that the motor has a roughly polygonal cross-section (here a dodecagon), so that the recess 55 or the surface of the ferrite element 14b of the motor 12 that is not in contact with the inner wall 52 forms together with the inner wall 52 the channel 54 for the flow of the fluid to be compressed.

[0036] More generally, all the parts of the compressor located along the longitudinal axis between the first and second compression stages are dimensioned and arranged to form said flow channel 54 for the fluid to be compressed extending between the first and second compression stages. Thus, the channel 54 is formed between the front cover 3b and the axial bearing support 30, between the front radial bearing support 26 and the inner wall 52 (for this purpose, the shoulder 56 of the front radial bearing support 26 resting on the inlet of the housing 50 has a groove 58 arranged corresponding to the compressed fluid flow channel 54), between the ferrite element 14b of the motor 12 as described above and the inner wall 52, between the rear radial bearing support 28 and the inner wall 52, between the volute 29 and the inner wall 52, and between the rear cover 3c and the volute 29. These channels 54 are designed to avoid turbulence inside the compressor.

[0037] Furthermore, at least one opening (e.g. Figure 4 57a in the figure), which is arranged to allow the fluid to be compressed flowing in the passage 54 to enter the motor 12 and flow between the stator 14 and the rotor 16; and at least one orifice (e.g. Figure 4 The passage 54 is provided at a point 57b in the figure, which is arranged to allow the fluid to be compressed to leave the motor 12 and flow back into the passage 54 after cooling the motor 12.

[0038] Likewise, at least one orifice (e.g. Figure 4 59a in the figure), which is arranged to allow the fluid to be compressed flowing in the channel 54 to flow near the axial bearing 24, the front radial bearing 18 and the rear radial bearing 22; and at least one orifice (for example corresponding to Figure 4 The same point as 57b in the figure), which is arranged to allow the fluid to be compressed to flow back into the channel 54 after cooling the axial bearing 24, the front radial bearing 18 and the rear radial bearing 22.

[0039] Thus, after entering the first compression stage through the inlet 5, the fluid to be compressed enters the channel 54 through the compressor component located between the first and second compression stages along the longitudinal axis and flows back into the second compression stage. Thus, when it passes between the inner wall 52 and the ferrite element 14b of the motor, the fluid to be compressed cools the motor and recovers the heat lost by the motor to improve its efficiency before entering the second compression stage. In addition, the orifices 57a, 57b, 59A allow a slight deviation of the flow so that the fluid to be compressed also flows between the stator 14 and the rotor 16 and in the bearings to cool these elements and recover the heat losses in the motor and the heat losses caused by friction in the bearings.

[0040] In addition, reference Figure 3 and 5 The housing 2 comprises at least one cavity 60a, 60b at its surface, the cavities 60a, 60b forming at least one integrated shell arranged to receive at least one electronic component of the compressor, the integrated shell extending towards the inner wall 52, as close as possible to the channel 54, to allow the electronic component to be cooled by the fluid to be compressed flowing in the channel 54 with the aid of the inner wall 52, the inner wall 52 itself being in contact with the fluid to be compressed flowing in the channel 54.

[0041] Advantageously, the housing 2 comprises a plurality of cavities 60a, 60b on the same surface defining its upper inner surface 62, each cavity forming an integrated housing arranged to receive the electronic components of the compressor, said cavities 60a, 60b being arranged at least above and on at least one side, preferably both sides, of the inner wall 52 of the inner housing 50 of the housing 2. Therefore, the integrated housings and therefore the electronic components placed in these integrated housings are arranged as close as possible to the fluid to be compressed flowing in the channel 54 in contact with the inner wall 52, so that the fluid to be compressed can recover the heat emitted by the electronic components by means of the inner wall 52.

[0042] Preferably, at least one of the cavities 60a, 60b extends longitudinally at least partially along the flow channel 54 for the fluid to be compressed, so as to form an integrated housing extending longitudinally on at least a portion of the upper inner surface 62 of the housing 2. The integrated housing thus follows the channel 54 so as to provide a maximum heat exchange area between the electronic components arranged in the integrated housing and the fluid to be compressed by means of the inner wall 52.

[0043] Advantageously, and with reference to Figure 8The compressor comprises at least one plate 64 arranged to receive the compressor electronics 4, said plate 64 carrying on its lower surface at least the electronic components 4a, 4b extending longitudinally along the longitudinal axis AA, said plate 64 being located above the upper inner surface 62 of the housing 2, so that said electronic components 4a, 4b extending longitudinally across the lower surface of the plate 64 are respectively received in their integrated housings, said integrated housings extending longitudinally at least partially along the flow channel 54 for the fluid to be compressed. On the upper surface of the plate 64 are arranged other electronic components 4c arranged to be received in the upper cover 3a.

[0044] For example, the electronic components 4a are transistors arranged longitudinally on both sides of the plate and perpendicular to the plate 64, so as to have as large a contact surface as possible with the housing and to be as close as possible to the fluid to be compressed by means of the inner walls 52 on both sides of the motor 12. Obviously, if there is enough space, the transistors can all be placed on the same side of the motor.

[0045] In addition, the integrated housing, in particular a longitudinally extending integrated housing, may include a strip spring 66 at least partially along the flow channel 54 for the fluid to be compressed, which is preferably arranged longitudinally and is arranged to keep the electronic component 4a arranged in the integrated housing resting on the wall of the integrated housing in the direction of the inner wall 52.

[0046] The electronic component 4b is, for example, a tubular capacitor of circular cross section and is arranged longitudinally on the lower surface of the plate 64 so as to be received in a cavity 60b provided at a corresponding rounded bottom above the motor 12, so as to have the largest possible contact surface with the housing and to be as close as possible to the fluid to be compressed by means of the inner wall 52 above the motor 12. A thermally conductive paste may be provided at the bottom of the cavity 60b for better contact between the capacitor and the housing 2.

[0047] Thus, the fluid to be compressed flowing in the channel 54 also recovers heat losses from the electronic components of the compressor, which are arranged as close as possible to the fluid to be compressed. In addition, the interior of the compressor is optimized, in particular the upper surface of the housing is cut so as to accommodate the electronic components of the compressor in a small volume, which makes it possible to manufacture a very compact compressor.

[0048] Advantageously, the upper inner surface 62 of the housing 2 has a hole 68 arranged to allow the passage of a cable between the motor 12 and the electronic component 4, the hole 38 being sealed so that the fluid to be compressed does not leak. To this end, resin is poured into the hole 68 and the cable element is inserted into the resin when the resin is poured. The other cable elements connected to the motor 12 and the electronic component 4, respectively, are then welded to the cable elements cast in the resin in the hole 68. Other sealed cable passages 70 and 72 are provided on the back side 2c of the housing 2, for example for the control cable outlet and the power cable outlet, which provide a safe connection.

[0049] Preferably, the compressor comprises a pressure and temperature sensor 74 between the two compression stages, which allows self-regulation of the compressor.

[0050] The fluid compressor used in the present invention can reach very high speeds, between 100,000rpm and 500,000rpm. It allows the fluid compressed in the first compression stage to move substantially through the entire system to recover all lost heat, especially the heat lost in the motor, bearings and electronic components, so as to improve its efficiency before entering the second compression stage (as the temperature of the fluid to be compressed increases, its pressure also increases). In addition, only the fluid to be compressed is used to cool the compressor without the aid of an additional cooling circuit and the electronic components inside the compressor are arranged so that the electronic devices are integrated in the housing so that a very compact compressor can be obtained. Therefore, the fuel cell according to the present invention including the above-mentioned compressor has a high speed and a high compression ratio while occupying a small volume. For example, the compressor used in the present invention has a compression ratio greater than 3 and has a power of about 4kW, and the dimensions are as follows: for a weight of only 1.5kg, the length × width × height is about 14 × 8 × 11cm.

Claims

1. A fuel cell (100), comprising a two-stage fluid compressor (1), the compressor comprising: a housing (2) having a fluid inlet (5) and a compressed fluid outlet (6) and housing a shaft (7) rotatably mounted about a longitudinal axis (AA); a first compression wheel (8) and a second compression wheel (10) mounted back-to-back on the shaft (7), the first compression wheel (8) forming a first compression stage and the second compression wheel (10) forming a second compression stage; and An electric motor (12), which is located between the first compression wheel (8) and the second compression wheel (10) and is arranged to rotate the shaft (7), characterized in that The housing (2) comprises a through inner housing (50), the inner housing extending coaxially with the longitudinal axis (AA) and at least the motor (12) being arranged inside the inner housing (50), the inner housing (50) having an inner wall (52), the inner wall (52) being arranged to form, together with the motor (12), at least a channel (54) between the inner wall (52) and the motor (12), the channel (54) extending between the first compression stage and the second compression stage, allowing the motor (12) to be cooled when in contact with the fluid to be compressed flowing in the channel (54) after the fluid to be compressed has been compressed by the first compression stage, and the housing (2) comprising at least one cavity (60a, 60b) at its surface forming at least one integrated housing arranged to receive at least one electronic component (4) of the compressor, the integrated housing extending towards the inner wall (52) to allow the electronic component (4) to be cooled by the fluid to be compressed flowing in the channel (54) by means of the inner wall (52), The motor (12) comprises a stator (14) and a rotor (16), and is provided with at least one orifice (57a), the at least one orifice (57a) being arranged to allow the fluid to be compressed flowing in the passage (54) to enter the motor (12) and flow between the stator (14) and the rotor (16) to cool the motor (12) and recover heat loss in the motor (12), and the motor is provided with at least one orifice (57b) being arranged to allow the fluid to be compressed to leave the motor (12) after cooling the motor (12) and flow back into the passage (54) to flow back into the second compression stage.

2. The fuel cell according to claim 1, characterized in that The inner wall (52) of the inner housing (50) has a circular cross section, and the motor (12) has a recessed portion (55) on its outer surface, the recessed portion (55) together with the inner wall (52) forming the passage (54) for the fluid to be compressed to flow.

3. The fuel cell according to claim 1, characterized in that The housing (2) includes a plurality of cavities (60a, 60b) on the same surface defining its upper inner surface (62), each of the cavities forming an integrated housing, the integrated housing being arranged to receive the electronic components (4a, 4b) of the compressor, the cavities (60a, 60b) being arranged at least above the inner wall (52) of the housing (2) and at least on one side of the inner wall (52) of the housing (2).

4. The fuel cell according to claim 1, characterized in that The cavities (60a, 60b) extend longitudinally at least partially along the passage (54) for the fluid to be compressed to form a longitudinally extending integrated housing.

5. The fuel cell according to claim 4, characterized in that The fluid compressor comprises at least one plate (64) arranged to receive the electronic components (4) of the compressor, the plate (64) carrying at least longitudinally extending electronic components (4a, 4b) on its lower surface, the plate (64) being located above the upper inner surface (62) of the housing (2), so that the longitudinally extending electronic components (4a, 4b) on the lower surface of the plate (64) are respectively received in their integrated housings, the integrated housings at least partially extending longitudinally along the flow channel (54) for the fluid to be compressed.

6. The fuel cell according to claim 1, characterized in that The integrated housing comprises a strip spring (66) arranged to hold an electronic component (4a) arranged in the integrated housing against a wall of the integrated housing in the direction of the inner wall (52).

7. The fuel cell according to claim 1, characterized in that The fluid compressor (1) comprises an upper cover (3a) for closing the upper surface (2a) of the housing (2), and the upper cover (3a) is located on the side of the electronic component (4).

8. The fuel cell according to claim 1, characterized in that The shaft (7) is rotatably mounted on the housing (2) by means of at least a front radial bearing (18), a rear radial bearing (22) and an axial bearing (24).

9. The fuel cell according to claim 8, characterized in that At least one orifice (59a) is provided, and the orifice (59a) is arranged to allow the fluid to be compressed flowing in the channel (54) to flow near the front radial bearing (18), the rear radial bearing (22) and the axial bearing (24), respectively, and at least one orifice (57b) is provided to allow the fluid to be compressed to flow back into the channel (54) after cooling the front radial bearing (18), the rear radial bearing (22) and the axial bearing (24).

10. The fuel cell according to claim 8, characterized in that The axial bearing (24) is an aerodynamic bearing, and on at least one face thereof, the bearing has a first groove (24a) arranged to form an air film.

11. The fuel cell according to claim 8, characterized in that The front radial bearing (18) and the rear radial bearing (22) are aerodynamic bearings, and the shaft (7) has a second groove (32) facing the front radial bearing (18) and the rear radial bearing (22), the second groove (32) being arranged to generate an air film.

12. The fuel cell according to claim 8, characterized in that The fluid compressor (1) comprises a front radial bearing support (26) and a rear radial bearing support (28), which are arranged to be positioned around the shaft (7) at the front and rear of the motor (12), respectively, and the front radial bearing support (26) comprises at least a first groove (34) positioned facing a second groove (36) provided on the front radial bearing (18), the first groove (34) and the second groove (36) being arranged to receive a front bearing O-ring joint (38), and the rear radial bearing support (28) comprises at least a third groove, the third groove being positioned facing a fourth groove provided on the rear radial bearing (22), the third groove and the fourth groove being arranged to receive a rear bearing O-ring joint.

13. The fuel cell according to claim 12, characterized in that The front radial bearing support (26) includes a fifth slot (40) configured to allow air to pass through, and the rear radial bearing support (28) includes a sixth slot configured to allow air to pass through.

14. The fuel cell according to claim 1, characterized in that The housing (2) has a hole (68) arranged to allow a cable to pass between the motor (12) and the electronic component (4), the hole (68) being sealed.

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