Side-channel compressor for a fuel cell system for conveying and / or compressing a gaseous medium, and fuel cell system

Abstract

The invention relates to a side-channel compressor (1) for a fuel cell system (2) for compressing a gaseous medium, having a housing with a first housing part (3) and a second housing part (4). The first housing part (3) has a bearing journal (5) extending along a rotational axis (R); at least one bearing inner ring (8) of a bearing device (9) is provided on the bearing journal (5); the bearing device (9) comprises at least one bearing (19, 20), the at least one bearing (19, 20) having at least one respective sealing disc (21) which encapsulates the bearing interior (27); and a compressor wheel assembly (10) having a compressor wheel (34) is provided within the housing on a bearing outer ring (11) of the bearing device (9) so as to be rotatable about the rotational axis (R) and can be driven via a drive (37). According to the invention, the compressor wheel assembly (10) has at least one water-repelling disc (23b), the water-repelling disc (23b) consisting of a hydrophobic material (22), in particular polytetrafluoroethylene (PTFE) (22), and / or having a hydrophobic coating (22). The invention also relates to a fuel cell system (2) comprising a side-channel compressor (1) according to the invention.

Description

[0001] R. 412933

[0002] - 1 -

[0003] Description

[0004] title

[0005] Side channel compressor for a fuel cell system for conveying and / or compressing a gaseous medium, fuel cell system

[0006] The present invention relates to a side channel compressor for a fuel cell system for conveying and / or compressing a gaseous medium, in particular hydrogen, which is intended in particular for use in vehicles with a fuel cell drive. Furthermore, the invention relates to a fuel cell system with a side channel compressor according to the invention.

[0007] In the automotive sector, gaseous fuels will play an increasingly important role alongside liquid fuels in the future. Particularly in vehicles with fuel cell propulsion, hydrogen gas flows must be controlled. Unlike liquid fuel injection, where gas flows are controlled discontinuously, the gaseous medium is drawn from at least one high-pressure tank and fed via a supply line of a medium-pressure line system to an ejector unit. This ejector unit then directs the gaseous medium via a connecting line of a low-pressure line system to a fuel cell. After the gaseous medium has flowed through the fuel cell, it is returned to the ejector unit via a return line. A side-channel compressor can be integrated into this process to improve the flow and efficiency of the gas recirculation.Furthermore, side-channel compressors are used to assist flow development in fuel cell propulsion systems, particularly during a (cold) start of the vehicle after a period of inactivity. These side-channel compressors are typically driven by electric motors, which, when operating in vehicles, are powered by the vehicle battery.

[0008] From DE 10 2022 206 578 A1, a side channel compressor for a fuel cell system for conveying and / or compressing a gaseous medium, in particular hydrogen, is disclosed, comprising a housing with a first housing part and a second housing part, wherein the first housing part has a [R. 412933]

[0009] - 2 - has a bearing journal extending about an axis of rotation R, wherein at least one inner bearing ring of a bearing device is arranged on the bearing journal, wherein the bearing device has at least one bearing, wherein the at least one bearing has at least one sealing disc which encapsulates the bearing channel space, wherein a compressor wheel assembly with a compressor wheel is arranged rotatably inside the housing on an outer bearing ring of the bearing device about the axis of rotation R and can be driven by a drive.

[0010] The side-channel blower known from DE 10 2022 206 578 A1 can have certain disadvantages. Liquids and / or water can accumulate in the area of ​​the sealing disc and / or on the face of the respective bearing. Due to the high rotational speeds of the side-channel blower, this can lead to high stress on the sealing system and increased wear between the friction partners, the sealing disc and the inner bearing ring. Furthermore, centrifugal forces generated by rotation act on the sealing disc and any optional sealing lip. This can cause water or other liquids to penetrate the bearing between the sealing disc and the inner bearing ring, negatively affecting the lubricating properties of the grease and ultimately leading to bearing failure. This reduces the service life of the bearing and, consequently, of the side-channel blower.

[0011] Disclosure of the invention

[0012] The present invention relates to a side-channel compressor for a fuel cell system for compressing a fluid, comprising the features of independent claim 1, and to a fuel cell system comprising a side-channel compressor comprising the features of dependent claim 9. Further features and details of the invention will become apparent from the dependent claims, the description, and the drawings. Features and details described in connection with the side-channel compressor according to the invention naturally also apply in connection with the fuel cell system according to the invention, and vice versa, so that the disclosure of the individual aspects of the invention always makes, or can make, reciprocal references. R. 412933

[0013] - 3 -

[0014] According to a first aspect of the invention, a side-channel compressor for a fuel cell system is provided for compressing a gaseous medium. The side-channel compressor has a housing with a first housing part and a second housing part, the first housing part having a bearing journal extending along an axis of rotation R. An inner bearing ring of a bearing assembly is arranged on the main section of the journal. The bearing assembly has at least one bearing, the bearing having at least one sealing disc that fluidically encapsulates a bearing interior, and a compressor wheel assembly with a compressor wheel is rotatably arranged inside the housing on an outer bearing ring of the bearing assembly about the axis of rotation R and can be driven by a drive.

[0015] According to the invention, it may be provided, but is not absolutely necessary, that the first housing part and / or the second housing part comprise further housing parts, which may be designed in particular as a housing cover, housing wall, or the like. Preferably, the first housing part defines a pre-assembled assembly of the side channel blower, which includes the bearing device and the compressor wheel assembly. The housing, preferably through the interaction of the first housing part with the second housing part, forms a working space for the compressor wheel assembly.

[0016] The working chamber is preferably designed to be fluid-tight, apart from a working chamber inlet and a working chamber outlet. Within the scope of the invention, "fluid-tight" also means that the tightness is maintained even at a higher operating pressure of the silk channel compressor than the ambient pressure. To ensure tightness, sealing devices, such as sealing rings, in particular elastomers made of EPDM and FKM, or the like, are preferably provided between the first housing part and the second housing part. The first housing part is preferably made essentially or predominantly of aluminum. The second housing part is preferably made essentially or predominantly of aluminum.

[0017] The bearing journal is formed as a partial area of ​​the first housing part and extends away from an inner wall of the first housing part. According to the invention, the bearing journal is formed monolithically with the first housing part. Alternatively, the bearing journal can also be formed by a material bond, R. 412933

[0018] - 4 - for example, by welding, or by frictional connection, for example, by bolting or pressing, on the first housing part. The bearing journal extends from the inner wall of the first housing part from the journal root section, through the journal main section, to the journal end section. The journal end section includes the journal clamping section. Preferably, the journal end section is designed as a journal clamping section.

[0019] The bearing assembly comprises an inner bearing ring and an outer bearing ring. Preferably, several rolling elements, such as balls, rollers, barrels, or the like, are arranged between the inner and outer bearing rings to support the outer bearing ring on the inner bearing ring with minimal play and to ensure relative rotation between the inner and outer bearing rings.

[0020] The inner bearing ring of the bearing assembly is arranged on the main journal section, preferably in a loose fit. Several inner bearing rings can also be arranged on the main journal section, preferably each in a loose fit. The loose fit is preferably designed such that, when the clamping force is released, the bearing assembly can be easily moved on the journal, for example manually, and tilting of the inner bearing ring on the journal is prevented.

[0021] The compressor wheel assembly is arranged on the outer bearing ring of the bearing assembly, preferably in an interference fit. The interference fit is preferably designed such that displacement of the compressor wheel assembly on the bearing assembly is prevented by frictional engagement. Alternatively, the compressor wheel assembly can be arranged on the outer bearing ring in a loose fit and secured against axial slippage from the bearing assembly by retaining means.

[0022] Referring to claim 1, the side-channel blower is configured such that the blower wheel assembly has at least one water-repellent disc, wherein the water-repellent disc comprises a hydrophobic material, in particular polytetrafluoroethylene (PTFE), and / or a hydrophobic coating. In this way, the advantage can be achieved that water or other liquids penetrating from the environment of the side-channel blower to the blower wheel assembly, in particular to the sealing disc and / or R. 412933

[0023] - 5 - the water deflector disc, from the hydrophobic properties of the water deflector disc in this area. Thus, when the side channel blower is at rest, water is prevented from penetrating the area between the water deflector disc and the respective bearing and / or the respective sealing disc, thereby preventing damage to the respective bearing from penetrating water. Furthermore, this also reduces the risk of water wetting the surface of the respective water deflector disc, especially the surface facing the respective bearing, and utilizes an inhomogeneous capillary effect. In this way, the service life of the bearings and / or the water deflector discs and / or the surrounding components can be increased. Thus, the probability of failure of the entire side channel blower can be reduced and its service life extended.

[0024] The measures listed in the dependent claims enable advantageous further developments of the side channel blower specified in claim 1. The dependent claims relate to preferred further developments of the invention.

[0025] According to an advantageous embodiment of the side-channel compressor, the at least one sealing disc of the compressor wheel assembly comprises the hydrophilic material and / or the hydrophilic coating, wherein the sealing disc has the hydrophilic coating particularly on its first end face facing the water deflector disc. In this way, the advantage can be achieved that water entering a water ingress gap between the sealing disc and the water deflector disc from the environment is accelerated by the rotating sealing disc, particularly in an operating side-channel compressor, and flung outwards away from the axis of rotation R by centrifugal force. This allows the water and / or liquid to be moved away from the area of ​​a sealing lip between the sealing disc and the inner bearing ring, so that the water and / or liquid cannot penetrate into the bearing interior.In this way, the probability of bearing failure due to water or liquid ingress can be reduced, thereby increasing the service life of the side channel blower. R. 412933.

[0026] - 6 -

[0027] According to a particularly advantageous embodiment of the side channel compressor, the water deflector disc is arranged in the direction of the axis of rotation R on a first end face of the compressor wheel assembly, such that the respective water ingress gap is formed between the water deflector disc and the respective sealing disc and / or the respective inner bearing ring.In this way, the advantage can be achieved that the water and / or liquid cannot penetrate into the respective bearing, since it cannot reach the first end face of the sealing disc due to the water-repellent disc and the respective water ingress gap, whereby the water and / or the respective liquid cannot penetrate, in particular, into the area where a seal and / or frictional contact exists between the sealing disc and the bearing inner ring. In addition, due to the formed water ingress gap, the advantage can be achieved that the hydrophobic properties of the water-repellent disc can be used in such a way that water and / or liquid are prevented from penetrating into the water ingress gap, since they cannot pass through the hydrophobic surface of the water-repellent disc.This reduces the probability of bearing failure due to reduced lubricating properties of the bearing grease and / or bearing oil caused by water and / or other fluid ingress and / or contamination. This, in turn, extends the service life of the entire side channel blower.

[0028] According to a particularly advantageous embodiment of the side-channel blower, the water deflector disc is positively and / or frictionally and / or materially bonded to the bearing journal and is thus rotationally fixed to the bearing assembly and / or the respective sealing disc. The sealing disc is positively and / or frictionally and / or materially bonded to the outer bearing ring and is rotatably arranged with it about the axis of rotation R. Water and / or liquid from the environment can thus enter the water ingress gap between the sealing disc and the water deflector disc, especially when the side-channel blower is at rest and the compressor wheel and / or compressor wheel assembly is not rotating. This is made possible in particular by the hydrophilic properties of the sealing disc.When the side channel compressor is started, in which the compressor wheel with the bearing outer ring and the sealing disc is set into a rotational movement, the advantage can now be achieved that the water and / or liquid is drawn through the rotating sealing disc. R. 412933.

[0029] - 7 - The disc is accelerated and, due to centrifugal force, is moved outwards away from the axis of rotation R and thus guided out of the water ingress gap. This only occurs if the rotating sealing disc has hydrophilic properties, i.e., it attracts water, and the rotationally fixed water deflector disc has hydrophobic properties, i.e., it repels water. This prevents water and / or liquid from penetrating the respective bearing and damaging it, thereby reducing the probability of failure of the side channel blower. Furthermore, the inventive design of the side channel blower allows for a compact design of the blower wheel assembly and / or the side channel blower.

[0030] According to a particularly advantageous embodiment of the side-channel compressor, the respective sealing disc has at least one sealing lip extending around the axis of rotation, in particular a plastic sealing lip, which provides at least partial encapsulation of the bearing interior, wherein the sealing lip is in frictional and / or sliding contact with the inner bearing ring. This achieves the advantage of a sealing function between the sealing disc and the inner bearing ring in a cost-effective manner. Furthermore, a compact design of the compressor wheel assembly and / or the side-channel compressor can be achieved.

[0031] According to a particularly advantageous embodiment of the side-channel blower, the water deflector disc has a first outer diameter D1, and the respective sealing disc has a second outer diameter D2. The second outer diameter D2 is larger than the first outer diameter D1, but the water deflector disc covers a large portion of the first end face orthogonally to the axis of rotation R. This allows for a compact design of the blower wheel assembly and / or the side-channel blower. Furthermore, at least partial fluidic encapsulation of the respective bearing interior and / or the inner area of ​​the blower wheel assembly can be achieved by forming the respective water penetration gap, through which water and / or other liquids from the environment cannot penetrate due to their surface tension. R. 412933

[0032] - 8 - can only pass through with difficulty. This increases the service life of the respective bearing and thus of the entire side channel blower.

[0033] According to an advantageous embodiment of the side-channel compressor, the respective water ingress gap has a gap dimension of less than 1 mm. This increases the effectiveness of the water ingress gap to such an extent that water penetrating from the surrounding environment cannot pass through it, thus creating an encapsulating effect. This prevents the water from penetrating into the inner area of ​​the compressor wheel assembly and the bearing interior. Furthermore, this also reduces the risk of water wetting the surface of the respective water deflector disc, particularly the surface facing the bearing, and thus mitigates the risk of inhomogeneous capillary action. In this way, the service life of the bearings, the water deflector discs, and / or the surrounding components can be extended.This reduces the probability of failure of the entire side channel blower and increases the service life of the side channel blower.

[0034] According to an advantageous embodiment of the side-channel compressor, the sealing discs located at the respective water inlet gap form several flow wedges on their end face facing the water inlet gap, extending at least approximately orthogonally to the axis of rotation R. This achieves the advantage that, during operation of the side-channel compressor, in which the sealing disc rotates with the outer bearing ring, the flow wedges perform a rotational movement around the axis of rotation with the sealing disc. The water, which is located in the area of ​​the respective water inlet gap, is thereby set into a rotational movement around the axis of rotation by the rotating wedges. This generates centrifugal forces on the medium, which are directed away from the axis of rotation and / or the inner bearing ring.This allows water to be drained away from the compressor wheel assembly, preventing damage to the bearing and reducing the probability of bearing failure due to water damage. This can reduce the failure rate of the side channel blower and / or increase the service life of the bearing and / or the side channel blower. R. 412933.

[0035] - 9 -

[0036] The fuel cell system according to the invention offers all the advantages already described for a side-channel blower according to the first aspect of the invention. Accordingly, the fuel cell system according to the invention has the advantage over conventional fuel cell systems that improved encapsulation of the bearings, in particular of the respective bearing interior, can be achieved with simple means. In this way, the stress and damage to the respective bearings and / or the bearing assembly caused by water ingress can be reduced, and the service life of the bearing assembly can thus be significantly extended compared to conventional side-channel blowers. Furthermore, the fuel cell system according to the invention features particularly easy assembly and disassembly of the side-channel blower and is therefore cost-effective to install and very easy to maintain.

[0037] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, within the scope specified by the claims, a multitude of modifications are possible that fall within the bounds of what is considered skilled in the art.

[0038] R. 412933

[0039] - 10 -

[0040] Brief description of the drawing

[0041] The invention is described in more detail below with reference to the drawing.

[0042] It shows:

[0043] Figure 1 shows a sectional view of a side channel blower according to the prior art.

[0044] Figure 2 shows a sectional view of a section of the side channel compressor, labelled II in Fig. 1, with a compressor wheel assembly according to the prior art.

[0045] Figure 3 shows a sectional view of a section of the side channel compressor according to the invention, designated II in Fig. 1, with a compressor wheel assembly according to the invention.

[0046] Figure 4 shows a sectional view of a section of the side channel compressor according to the invention, designated III in Fig. 3, with a water deflector disc and a sealing disc according to the invention.

[0047] Elements with the same function and mode of operation are each provided with the same reference symbols in Figures 1 to 4.

[0048] Figure 1 shows a schematic sectional view of a side channel blower 1 according to the prior art. The side channel blower 1 has a housing with a first housing part 3 and a second housing part 4.

[0049] The first housing part 3 has a bearing journal 5 extending towards the second housing part 4 and a bearing assembly 9 arranged on the bearing journal 5 with two rolling bearings 19, 20. A first bearing 19 and a second bearing 20 of the bearing assembly 9 are arranged side by side in the direction of an axis of rotation R. Furthermore, a spacer 15 is located between the rolling bearings 19, 20, wherein in particular each bearing R. 412933

[0050] - 11 -

[0051] The outer ring 11 a, b is in axial contact with the spacer 15 relative to the axis of rotation R. Inner bearing rings 8 of the bearing assembly 9 are arranged on the bearing journal 5. A hub 16 with a compressor wheel 34 is arranged on the outer bearing rings 11 a, b of the bearing assembly 9. Furthermore, the side-channel compressor 1 has a compressor chamber 36 extending circumferentially around the axis of rotation R, which has at least one circumferential side channel 35.

[0052] As shown in Fig. 1, the bearing journal 5 has a recess with an internal thread in which a fastening screw 28 is arranged. The bearings 19, 20 are at least indirectly clamped to the first housing part 3 and a bearing washer 12 via the fastening screw 28, with the first housing part 3 being at least indirectly clamped to the bearing assembly 9 via the fastening screw 28. In an exemplary embodiment, a spring element 14 can also be located between the housing and a compressor wheel assembly 10, which is additionally clamped by means of the fastening screw 28. A stop washer 12 can be arranged in the direction of the axis of rotation R between the fastening screw 28, in particular an enlarged screw head, and the bearing journal 5 and / or the respective inner bearing ring 8. The compressor wheel 34 is arranged to rotate about the axis of rotation R in the housing and can be driven by a drive 37.Furthermore, the first housing part 3 is at least indirectly clamped to the bearing device 9 via the fastening screw 28.

[0053] Furthermore, Fig. 1 shows that by screwing in the fastening screw 28, a preload force 39 acting parallel to the axis of rotation R is applied to the bearing device 9. It is also shown that four axial gaps 33a, b, c, d are located in the direction of the axis of rotation R in the area between the compressor wheel assembly 10 and the respective housing part 3, 4, wherein the axial gaps 33a, b, c, d enclose the compressor chamber 36. The compressed gaseous medium can then be conveyed from the compressor chamber 36 of the side channel compressor 1 to a fuel cell 26 of a fuel cell system 2. The side channel compressor 1 can be arranged in an anode circuit of the fuel cell system 2.The drive 37 can be designed as an axial field electric motor 37, which has a stator 37, wherein a magnetic field is generated by energizing the stator 37, which acts on a segment magnet of the compressor wheel assembly 10 such that the compressor wheel assembly 10 is set into a rotary motion. R. 412933.

[0054] - 12 -

[0055] Fig. 2 shows a sectional view of a section of the side-channel compressor 1, labelled II in Fig. 1, with a compressor wheel assembly 10 according to the prior art. It is shown that the at least one bearing 19 comprises the outer bearing ring 11 and the inner bearing ring 8. The side-channel compressor 1 has a housing with the first housing part 3 and the second housing part 4 (shown in Fig. 1), wherein the first housing part 3 has the bearing journal 5 extending along the axis of rotation R, and at least one inner bearing ring 8 of the bearing assembly 9 is arranged on the bearing journal 5.

[0056] Furthermore, Fig. 2 shows that, according to the prior art, a water-repellent disc 23a is located on the bearing journal 5 and, in the direction of the axis of rotation R, on the inner bearing ring 8 of the bearing 19. In the prior art, the water-repellent disc 23a covers only the inner bearing ring 8 perpendicular to the axis of rotation R, but is not in contact with or in contact with it, so that a water ingress gap 43 forms exclusively between the inner bearing ring 8 and the water-repellent disc 23a. It is also shown that the respective sealing disc 21 has at least one sealing lip 13 extending around the axis of rotation R, in particular a plastic sealing lip 13, which in particular causes at least partial encapsulation of the bearing interior 27, wherein the sealing lip 13 is in frictional and / or sliding contact with the inner bearing ring 8.

[0057] Fig. 3 shows a sectional view of a section of the side channel compressor 1 according to the invention, designated II in Fig. 1, with a compressor wheel assembly 10 according to the invention. It is shown that the side channel compressor 1 and / or the compressor wheel assembly 10 have the water deflector disc 23ab according to the invention, wherein the water deflector disc 23b has a larger diameter compared to the water deflector disc 23b from the prior art. The water-deflecting disc 23b, designed according to the invention, covers not only the inner bearing ring 8, but also at least almost completely the sealing disc 21, orthogonally to the axis of rotation R. The water-deflecting disc 23b is arranged in the direction of the axis of rotation R on a first end face 30 of the compressor wheel assembly 10 such that the respective water ingress gap 43 is located between the water-deflecting disc 23b and the respective sealing disc 21 and / or the respective R. 412933

[0058] - 13 -

[0059] The inner bearing ring 8 forms a water ingress gap. In an exemplary embodiment, this respective water ingress gap 43 can have a gap dimension of less than 1 mm.

[0060] Furthermore, Fig. 3 shows that the water-repellent disc 23b designed according to the invention is positively and / or frictionally and / or materially bonded to the bearing journal 5 and is thus arranged in a rotationally fixed manner on the bearing assembly 9 and / or the compressor wheel assembly 10 and / or the respective sealing disc 21, wherein the respective sealing disc 21 is positively and / or frictionally and / or materially bonded to the respective bearing outer ring 11 and is arranged to rotate with it about the axis of rotation R. This makes it more difficult for the fluid 17 from the environment 29 to penetrate into the area of ​​the water ingress gap 43 and to the sealing lip 13, since this area is covered by the water-repellent disc 23b with its enlarged diameter.The water 17, which from the surroundings 29 reaches the area of ​​the water ingress gap 43 between the sealing disc 21 and the water deflector disc 23b, is accelerated away from the axis of rotation R by the rotating sealing disc 21, particularly in the case of a side-channel compressor in operation, and flung outwards by centrifugal force. This separation of the water from the water ingress gap 43 only succeeds if the rotating sealing disc 21 has hydrophilic properties, i.e., is water-attracting, and the stationary water deflector disc 23b, which is particularly fixed to rotation on the pin 5, has hydrophobic properties, i.e., is water-repellent.If the rotationally fixed water deflector disc 23b does not have hydrophobic properties, as is the case in the prior art, the capillary forces will dominate and the water 17 can penetrate through the water penetration gap 43 to the area of ​​the sealing lip 13 and, in the event of wear of the sealing lip 13, penetrate into the respective bearing 19, 20 and damage it.

[0061] Fig. 4 shows a sectional view of a section of the side-channel compressor 1 according to the invention, designated III in Fig. 3, with the water-repellent disc 23b and the sealing disc 21 according to the invention. It is shown that the compressor wheel assembly 10 has at least one water-repellent disc 23b, wherein the water-repellent disc 23b comprises a hydrophobic material 22, in particular polytetrafluoroethylene (PTFE) 22, and / or a hydrophobic coating 22. This hydrophobic material and / or this R. 412933

[0062] - 14 - Hydrophobic coatings cause water to bead up on the water-repellent disc 23b and / or be directed away from it. The at least one sealing disc 21 of the compressor wheel assembly 10 can have a hydrophilic material 24 and / or a hydrophilic coating 24, wherein the sealing disc 21 has the hydrophilic coating 24 particularly on its first end face 30 facing the water-repellent disc 23b.

[0063] Furthermore, Fig. 4 shows that the water deflector disc 23b has a first outer diameter D1 and the respective sealing disc 21 has a second outer diameter D2, wherein the second outer diameter D2 is larger than the first outer diameter D1, but the water deflector disc 23b covers a large part of the first end face 30 orthogonally to the axis of rotation R. In this way, the water ingress gap 43 can form between the compressor wheel assembly 10 and / or the respective bearing 19, 20 and / or the respective sealing disc 21, which extends almost over the majority of the first end face 30 of the sealing disc 21. The water-repellent disc 23b has a second end face 32 which has at least almost the entire length the hydrophobic coating 22, and wherein the second end face 32 runs opposite the first end face 30 of the sealing disc 21 in the direction of the axis of rotation R.In an exemplary embodiment of the side-channel compressor 1, the sealing disc 21 located at the respective water inlet gap 43 can form several flow wedges on its first end face 30, which extend at least approximately orthogonally to the axis of rotation R. During operation of the side-channel compressor 1, the outer bearing ring 11 rotates with the sealing disc 21 and, through centrifugal forces at the flow wedges, generates an outward centrifugal flow of the water, thereby conveying the water away from the axis of rotation R during operation.

Claims

R. 412933 - 15 - Claims 1. Side channel compressor (1) for a fuel cell system (2) for compressing a gaseous medium, comprising a housing with a first housing part (3) and a second housing part (4), wherein the first housing part (3) has a bearing journal (5) extending along an axis of rotation (R), wherein at least one inner bearing ring (8) of a bearing device (9) is arranged on the bearing journal (5), wherein the bearing device (9) has at least one bearing (19, 20), wherein the at least one bearing (19, 20) each has at least one sealing disc (21) encapsulating the bearing channel space (27), wherein a compressor wheel assembly (10) with a compressor wheel (34) is rotatably arranged inside the housing on a bearing outer ring (11) of the bearing device (9) about the axis of rotation (R) and is driveable via a drive (37), characterized in that the compressor wheel assembly (10) has at least one water-repellent disc (23b) has,wherein the water-repellent disc (23b) comprises a hydrophobic material (22), in particular polytetrafluoroethylene (PTFE) (22), and / or a hydrophobic coating (22).

2. Side channel compressor (1) according to claim 1 , characterized in that the at least one sealing disc (21) of the compressor wheel assembly (10) has a hydrophilic material (24) and / or a hydrophilic coating (24), wherein the sealing disc (21) has the hydrophilic coating (24) in particular on a first end face (30) facing the water deflector disc (23b).

3. Side channel compressor (1) according to claim 1 or 2, characterized in that the water deflector disc (23b) is arranged in the direction of the axis of rotation (R) on the first end face (30) of the compressor wheel assembly (10) such that a respective water ingress gap (43) is formed between the water deflector disc (23b) and the respective sealing disc (21) and / or the respective bearing inner ring (8). R. 412933 - 16 - 4. Side channel blower (1) according to one of the preceding claims, characterized in that the water deflector disc (23b) is positively and / or force-fit and / or materially bonded to the bearing journal (5) and is thus arranged in a rotationally fixed manner on the bearing device (9) and / or the respective sealing disc (21), wherein the sealing disc (21) is positively and / or force-fit and / or materially bonded to the bearing outer ring (11) and is arranged rotatably with it about the axis of rotation (R).

5. Side channel compressor (1) according to one of the preceding claims, characterized in that the respective sealing disc (21) has at least one sealing lip (13) extending around the axis of rotation (R), in particular a plastic sealing lip (13), which in particular provides at least partial encapsulation of the bearing interior (27), wherein the sealing lip (13) is in frictional contact and / or sliding contact with the bearing inner ring (8).

6. Side channel blower (1) according to one of the preceding claims, characterized in that the water deflector disc (23b) has a first outer diameter (D1) and the respective sealing disc (21) has a second outer diameter (D2), wherein the second outer diameter (D2) is larger than the first outer diameter (D1), but wherein the water deflector disc (23b) covers a large part of the first end face (30) orthogonal to the axis of rotation (R).

7. Side channel compressor (1) according to one of claims 2 to 6 , characterized in that the respective water ingress gap (43) has a gap dimension of less than 1 mm.

8. Side channel compressor (1) according to one of the preceding claims, characterized in that the sealing discs (21) located at the respective water ingress gap (43) form several flow wedges at least approximately orthogonal to the axis of rotation (R) on their first end face (30). R. 412933 - 17 - 9. Fuel cell system (2) with a side channel compressor (1) according to one of claims 1 to 8, wherein the side channel compressor (1) is arranged in an anode circuit of the fuel cell system (2).

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