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, the side-channel compressor comprising a housing having a first housing part (3) and a second housing part (4). According to the invention, a compressor wheel assembly (10) and / or an associated bearing (19, 20) has, on its end face facing the second housing part (4), in particular on a first end face (30), a lid-shaped sealing element (13) which at least almost completely covers the bearings (19, 20) and / or a bearing device (9) orthogonally to the rotational axis (R), wherein the lid-shaped sealing element (13) is at least indirectly connected to a hub (16) such that it is possible to fluidically encapsulate an interior (27) of the hub (16) with respect to the surroundings (29) of the compressor wheel assembly (10). The invention also relates to a fuel cell system (2) comprising a side-channel compressor (1) according to the invention.

Description

[0001] Description

[0002] title

[0003] Side channel blower for a to

[0004] 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.

[0005] In the future, gaseous fuels will play an increasingly important role in the automotive sector alongside liquid fuels. Hydrogen gas flows must be controlled, particularly in fuel cell-powered vehicles. The gas flows are no longer controlled discontinuously, as with liquid fuel injection; instead, the gaseous medium is taken from at least one high-pressure tank and fed to an ejector unit via an inlet line of a medium-pressure line system. This ejector unit feeds the gaseous medium to a fuel cell via a connecting line of a low-pressure line system. After the gaseous medium has flowed through the fuel cell, it is fed back to the ejector unit via a return line. A side channel compressor can be interposed to assist the gas recirculation in terms of flow and efficiency.Side channel compressors are also used to support flow buildup in fuel cell propulsion, particularly during a (cold) start of the vehicle after a certain period of inactivity. These side channel compressors are typically powered by electric motors, which are supplied with power from the vehicle battery during operation in vehicles.

[0006] DE 10 2022 203 058 A1 discloses a side channel compressor for a fuel cell system, in which a gaseous medium, in particular hydrogen, is conveyed and / or compressed, comprising a housing and a drive, wherein the housing has an upper housing part and a lower housing part, with a compressor chamber running in the housing circumferentially about a rotational axis and having at least one circumferential side channel. Furthermore, the side channel compressor has a compressor wheel located in a housing, which is arranged so as to be rotatable about the rotational axis and is driven by the drive, wherein the compressor wheel has blades arranged on its circumference in the region of the compressor chamber and each having a gas inlet opening and a gas outlet opening formed on the housing, which are fluidically connected to one another via the compressor chamber, in particular the at least one side channel.The side channel compressor comprises at least one bearing. According to the invention, each bearing comprises at least one sealing disc, which has a plurality of flow wedges extending at least approximately orthogonally to the rotational axis on its end face, in particular the face facing away from the bearing interior. A flow opening is formed between each two flow wedges, which extends at least approximately orthogonally to the rotational axis.

[0007] The side channel compressor known from DE 10 2022 203 058 A1 can have certain disadvantages. The side channel compressor known from DE 10 2022 203 058 A1 has sealing discs located between a bearing inner ring and a bearing outer ring in order to encapsulate the bearing interior. The sealing discs can, for example, have an elastomer sealing lip on the bearing inner ring or on the bearing outer ring, which at least partially encapsulates the bearing interior by means of a sliding contact. This exemplary embodiment of the side channel compressor shown in the prior art has the disadvantage that the frictional contact leads to increased temperature development in the area of ​​the sliding contact, which damages the at least one bearing and / or other components of the side channel compressor.In addition, especially at high speeds of the side channel blower, the grease can escape from the ball bearing and / or dirt can penetrate into the bearing and this reduces the service life of the ball bearing.

[0008] Furthermore, this exemplary embodiment of the side channel compressor shown in DE 10 2022 203 058 A1 has the disadvantage that the encapsulating effect diminishes over the service life of the side channel compressor due to material wear, meaning the bearing interior is no longer sealed from the environment. This can lead to the leakage of bearing grease, which increases wear on the respective bearing and thus the probability of failure. Furthermore, if the encapsulation of the bearing interior fails, water from the compressor chamber and / or from the fuel gas-carrying components of the fuel cell can penetrate through the sealing discs into the respective bearing and damage the metallic components.In addition, water penetration can cause the bearing grease in the bearing interior to mix with the water, reducing lubrication performance and increasing the probability of failure of the bearing and the entire side channel compressor due to increased (frictional) wear. Furthermore, the probability of failure of the bearing and the side channel compressor is increased, and the service life of the bearing and the side channel compressor is reduced.

[0009] Disclosure of the invention

[0010] The present invention relates to a side channel compressor for a fuel cell system for compressing a fluid, having the features of independent claim 1, and to a fuel cell system with a side channel compressor, having the features of independent claim 11. Further features and details of the invention emerge from the subclaims, 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 reciprocal reference is or can always be made to the individual aspects of the invention with regard to the disclosure.

[0011] According to a first aspect of the invention, a side channel compressor for a fuel cell system for compressing a gaseous medium is provided. The side channel compressor has a housing with a first housing part and a second housing part, wherein the first housing part has a bearing journal extending along a rotational axis R and having a journal root section and a journal main section. A bearing inner ring of a bearing device is arranged on the journal main section. The bearing device has a first bearing and a second bearing, each bearing having two sealing disks that fluidically encapsulate the bearing interior. A compressor wheel assembly with a compressor wheel is arranged within the housing on a bearing outer ring of the bearing device so as to be rotatable about the rotational axis R. The first housing part is clamped at least indirectly to the bearing device via a fastening screw.Furthermore, a spring element is arranged in the region of the pin root section in the direction of the rotation axis R at least indirectly between the bearing device and the first housing part.

[0012] The housing is formed by the first housing part and the second housing part. It can be provided according to the invention, but is not absolutely necessary, that the first housing part and / or the second housing part have further housing parts, which can in particular be designed as a housing cover, housing wall or the like. Preferably, the first housing part defines a pre-assembled assembly of the side channel compressor, which has the bearing device and the compressor wheel assembly. A working space for the compressor wheel assembly is formed by the housing, preferably through the interaction of the first housing part with the second housing part.

[0013] The working chamber is preferably fluid-tight, except for a working chamber inlet and a working chamber outlet. Within the scope of the invention, fluid-tight also means that the seal is maintained at a working pressure of the silk channel compressor that is higher than the ambient pressure. To ensure the seal, 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 formed substantially or predominantly from aluminum. The second housing part is preferably formed substantially or predominantly from aluminum.

[0014] The bearing journal is formed as a partial region of the first housing part and extends 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 arranged on the first housing part in a materially bonded manner, for example by welding, or in a force-fitting manner, for example by screwing or pressing. The bearing journal extends from the inner wall of the first housing part, from the journal root section, via the journal main section, to the journal end section. The journal end section has the journal clamping section. The journal end section is preferably designed as a journal clamping section.

[0015] The bearing device comprises the bearing inner ring and the bearing outer ring. Preferably, several rolling elements, such as balls, rollers, barrels, or the like, are arranged between the bearing inner ring and the bearing outer ring to support the bearing outer ring on the bearing inner ring with as little play as possible and to ensure relative rotation between the bearing inner ring and the bearing outer ring.

[0016] The bearing inner ring of the bearing device is arranged on the main journal section, preferably with a loose fit. Multiple bearing inner rings can also be arranged on the main journal section, preferably each with a loose fit. The loose fit is preferably designed in such a way that, when the clamping is released, easy movement of the bearing device on the bearing journal, for example, by hand, is ensured, and tilting of the bearing inner ring on the bearing journal is prevented.

[0017] The compressor wheel assembly is arranged on the outer bearing ring of the bearing device, preferably with a press fit. The press fit is preferably designed in such a way that displacement of the compressor wheel assembly on the bearing device is prevented by force-locking. Alternatively, the compressor wheel assembly can be arranged loosely on the outer bearing ring and secured by retaining means against axial slippage from the bearing device.

[0018] With reference to claim 1, the side channel compressor is designed such that the compressor wheel assembly and / or the respective bearing has a cover-shaped sealing element on its end face facing the second housing part, in particular a first end face, which at least almost completely covers the bearings and / or the bearing device orthogonal to the rotation axis R. The cover-shaped sealing element is at least indirectly connected to the hub in such a way that a fluidic encapsulation of the interior of the hub with respect to the environment of the compressor wheel assembly can be achieved.This provides the advantage that, on the one hand, the respective bearing and its bearing interior are additionally encapsulated against elements from the environment of the compressor wheel assembly by the cover-shaped sealing element, even if the respective sealing disc of the respective bearing fails over its service life due to frictional wear, in particular due to frictional wear of a sealing lip and / or sealing edge, and the bearing interior can therefore no longer be effectively encapsulated from the environment by means of the respective sealing disc. The cover-shaped sealing element provides an additional encapsulating barrier, preventing water from penetrating the area of ​​a respective inner diameter of the hub and thus the bearing interior of the respective bearing and causing damage.Such damage would, for example, result from the bearing grease in the bearing interior mixing with the penetrating water, which would reduce the lubrication performance and, due to increased (frictional) wear, increase the probability of failure of the respective bearing and the entire side channel compressor. Furthermore, the probability of failure of the respective bearing and the side channel compressor is increased, and the service life of the respective bearing and the side channel compressor is reduced. Thus, by means of the inventive design of the side channel compressor according to claim 1, the probability of failure of the bearings can be prevented, whereby the service life of the entire side channel compressor can be increased.

[0019] The measures listed in the subclaims enable advantageous developments of the side channel compressor specified in claim 1. The subclaims relate to preferred developments of the invention.

[0020] According to an advantageous embodiment of the side channel compressor, the second diameter has a cover disk receiving area, in particular on the side facing the first housing part, wherein a first cover disk is arranged in the cover disk receiving area, wherein by means of the cover disk, a fluidic encapsulation of the interior of the hub and / or of the respective bearing from the surroundings of the compressor wheel assembly can be achieved. In this way, the advantage can be achieved that an encapsulation of the respective bearing interior and / or the internal region in the hub and / or the respective bearing interior can be achieved, in particular with regard to water and / or dirt particles that penetrate into the area of ​​the interior of the hub from the side facing the first housing part.This prevents water and / or other particles or substances from penetrating the bearing interior via the penetration path on the side opposite the drive, which could, for example, lead to mixing of the bearing grease in the bearing interior with, for example, penetrating water, which would reduce the lubricating performance and increase the probability of failure of the respective bearing and the entire side channel compressor due to increased (frictional) wear. Thus, by means of the inventive design of the side channel compressor, in particular with the first cover plate arranged in the cover plate receiving area, the probability of bearing failure can be prevented, whereby the service life of the entire side channel compressor can be increased.

[0021] According to an advantageous development of the side channel compressor, the hub has a radial shaft seal receiving area in the direction of the rotational axis R in the region of the first diameter, wherein a radial shaft seal (RDWR) is arranged in the radial shaft seal receiving area. The radial shaft seal can be used to fluidically encapsulate the interior of the hub and / or the respective bearing from the surroundings of the compressor wheel assembly. This makes it possible to achieve the advantage that at least one sealing disc of a respective bearing, for example the second bearing, is no longer required on the side of the compressor wheel assembly facing away from the drive, since encapsulation by means of the radial shaft seal RDWR is sufficient. Thus, the inventive design of the side channel compressor can reduce assembly costs and product costs.Furthermore, a compact design of the compressor wheel assembly and the side channel compressor can be achieved.

[0022] According to a particularly advantageous embodiment of the side channel compressor, the radial shaft sealing ring (RDWR) forms a non-positive and / or positive connection on its outer diameter facing away from the rotation axis R with a first extension of the bearing outer ring. The radial shaft sealing ring (RDWR) is at least indirectly in contact, in particular in frictional contact and / or sliding contact, with a first extension of the bearing inner ring running in the direction of the rotation axis R, in particular an outer diameter, on its inner diameter facing the rotation axis R.This has the advantage of improving and efficiently encapsulating the bearing interior and the inner area of ​​the hub, as these areas can be better sealed against the water ingress path on the side of the compressor wheel assembly facing the drive by means of the radial shaft seal (RDWR), which is integrated into the second bearing. Furthermore, this method also allows for simplified and accelerated assembly of the components of the compressor wheel assembly, as the radial shaft seal (RDWR) is already integrated into the second bearing and can be assembled together with the second bearing in a single process step. This reduces assembly costs. Furthermore, the probability of failure of the second bearing and the RDWR can be reduced.Furthermore, the inventive design of the side-channel compressor achieves a compact design for the compressor wheel assembly. Furthermore, the spring element can act directly on the inner bearing ring of the second bearing, particularly in the direction of the rotational axis R, without the need for an additional first cover plate between the spring element and the inner bearing ring. Thus, the probability of failure of the compressor wheel assembly and / or the bearings can be reduced, since a constant preload force on the bearings can be achieved by means of the spring element.

[0023] In a particularly preferred embodiment of the invention of the side channel compressor, the radial shaft sealing ring (RDWR) forms a non-positive and / or positive connection with the first outer diameter of the hub on its outer diameter facing away from the axis of rotation R, wherein the radial shaft sealing ring (RDWR) is at least indirectly in contact, in particular in frictional contact and / or sliding contact, with a second extension of the bearing inner ring running in the direction of the axis of rotation R, in particular an outer diameter.In this way, it is possible to achieve the advantage of improved and efficient encapsulation of the bearing interior and the inner area in the hub, as these areas can also be better encapsulated compared to the water penetration path on the side of the compressor wheel assembly facing the drive. The RDWR prevents water from penetrating the bearing and / or bearing interior by enabling improved encapsulation. In addition, the spring element can act directly on the bearing inner ring of the second bearing, in particular in the direction of the rotation axis R, without there being an additional first cover plate between the spring element and the bearing inner ring. This means that the probability of failure of the compressor wheel assembly and / or the bearings can be reduced, as a constant preload force on the bearings can be achieved by means of the spring element.

[0024] According to a particularly advantageous development of the side channel compressor, the radial shaft sealing ring (RDWR) forms a non-positive and / or positive connection with the first outer diameter of the hub on its outer diameter facing away from the axis of rotation R, wherein the radial shaft sealing ring (RDWR) is at least indirectly in contact, in particular in frictional contact and / or sliding contact, with an outer diameter of an additional ring running annularly around the axis of rotation R on its inner diameter facing the axis of rotation R. The additional ring can in particular be mounted in a floating manner on the bearing journal and can be acted upon by means of the bearing preload force of the spring element. In this way, the advantage can be achieved that the respective bearing, in particular the second bearing, can be designed as a standard bearing that is identical to the first bearing.This eliminates the need for a custom-made second bearing, which would require a first and / or second extension of the respective bearing inner ring or outer ring, and makes it possible to use two identical bearings for the compressor wheel assembly. This allows for reduced production costs for the compressor wheel assembly and the entire side channel compressor. Furthermore, the simple geometric design of the additional ring allows for the use of a standard component and / or at least a cost-effective component.

[0025] According to an advantageous embodiment of the side channel compressor, at least one sealing element is arranged orthogonally to the axis of rotation R between the bearing journal and at least one bearing inner ring, wherein the sealing element is arranged in a groove-shaped recess on the outer diameter of the bearing journal. This sealing element can in particular be an O-ring. In this way, the advantage can be achieved that an encapsulating barrier can be produced between the respective bearing inner ring and the bearing journal, since the at least one sealing element used prevents the penetration of water between the bearing journal and the bearing inner ring of the respective bearing. In this way, the probability of failure of the respective bearing and / or the compressor wheel assembly and / or the side channel compressor can be reduced.

[0026] According to an advantageous development of the side channel compressor, the RDWR has a sealing lip and / or dust lip on its inner diameter, where it is at least indirectly in contact with the outer diameter of the second extension of the bearing inner ring or with the outer diameter of the additional ring. The RDWR forms a sliding contact with its inner diameter, the sealing lip and / or dust lip, the outer diameter of the additional ring, or the additional ring. A sealing element is located between the bearing journal and the additional ring. This has the advantage that reliable encapsulation of the interior of the hub and / or the respective bearing can be achieved using simple means and in a cost-effective manner.In addition, the additional ring allows the preload force to be exerted at least indirectly on the inner ring of the second bearing, particularly in the direction of the rotational axis R, without any other elements being engaged and / or in contact. Thus, the probability of failure of the compressor wheel assembly and / or the bearings can be reduced, since a constant preload force on the bearings can be achieved using the spring element.

[0027] According to a particularly advantageous development of the side channel compressor, the hub has the cover receiving area in the direction of the rotational axis R in the region of a first diameter, in particular on the side facing the second housing part. The cover-shaped sealing element and a second cover plate are arranged in the cover receiving area, and the cover-shaped sealing element and the second cover plate fluidically encapsulate the interior of the hub. This allows for the advantage of simplified assembly of the cover-shaped sealing element in the hub. Thus, assembly costs can be reduced.Furthermore, the cover-shaped sealing element can be arranged in and / or on the hub in a space-saving manner, resulting in a compact design for the compressor wheel assembly, thereby reducing the size of the entire side channel compressor. This, in turn, can reduce the installation space required for the side channel compressor in the overall vehicle. In addition, efficient encapsulation of the bearing interior and the internal area in the hub can be achieved, as these areas can also be encapsulated to prevent water from penetrating the hub on the side of the compressor wheel assembly facing the drive. In this way, the probability of damage to the cover-shaped sealing element during assembly can be reduced, thereby reducing the probability of failure of the entire side channel compressor.

[0028] According to a particularly advantageous embodiment of the side channel compressor, the cover-shaped sealing element is made of a metal sheet overmolded with an elastomer, e.g., FKM. This provides the advantage of faster and more cost-effective assembly of the cover-shaped sealing element, since, due to the at least partially elastic deformability of the cover-shaped sealing element, it can be compressed and / or compressed prior to assembly in such a way that it allows for easy insertion of the cover-shaped sealing element in the direction of the rotational axis R into the hub, in particular the first inner diameter. In the final assembly position, the cover-shaped sealing element elastically returns to its previous shape, thus achieving efficient encapsulation of the bearing interior and the inner region in the hub.Because the cover-shaped sealing element, due to its elasticity, presses against the hub with a contact force, thus achieving an improved sealing and / or encapsulating effect. Due to its elasticity, the sealing element also forms an enlarged contact area between the cover-shaped sealing element and the hub, thereby achieving improved encapsulation. This prevents damage to the respective bearing due to water penetrating the bearing interior, reducing the probability of bearing failure and thus increasing the service life of the entire side channel compressor.

[0029] The fuel cell system according to the invention offers all the advantages already described for a side channel compressor 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 an improved arrangement of the bearing device on the bearing journal of the side channel compressor is ensured using simple means and in a cost-effective manner. The load on the bearing device can thus be reduced, and the service life of the bearing device can be significantly extended compared to conventional side channel compressors. Furthermore, the fuel cell system according to the invention features particularly simple assembly and disassembly of the side channel compressor and is therefore cost-effective to assemble and very easy to maintain.

[0030] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, numerous modifications are possible within the scope of the claims, which are within the scope of one skilled in the art.

[0031] Short description of the drawing

[0032] The invention is described in more detail below with reference to the drawing.

[0033] It shows:

[0034] Figure 1 shows a sectional view of a side channel compressor according to the prior art,

[0035] Figure 2 shows a sectional view of a section of the side channel compressor designated II in Fig. 1 with a compressor wheel assembly according to the prior art,

[0036] Figure 3 shows a section, designated II in Figure 1, of the side channel compressor according to the invention with the compressor wheel assembly according to a first embodiment. Figure 4 shows a section, designated II in Figure 1, of the side channel compressor according to the invention with the compressor wheel assembly according to a second embodiment.

[0037] Figure 5 shows a sectional view of a section of the side channel compressor according to the invention, designated II in Fig. 1, with the compressor wheel assembly according to a third embodiment

[0038] Figure 6 shows a sectional view of a section of the side channel compressor according to the invention, designated II in Fig. 1, with the compressor wheel assembly according to a fourth embodiment

[0039] Elements with the same function and mode of operation are provided with the same reference numerals in Figures 1 to 6.

[0040] Fig. 1 shows a schematic sectional view of a side channel compressor 1 according to the prior art. The side channel compressor 1 has 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 in the direction of the second housing part 4 and a bearing device 9 with two rolling bearings 19, 20 arranged on the bearing journal 5. The first bearing 19 and the second bearing 20 of the bearing device 9 are arranged next to one another in the direction of a rotation axis R. In addition, a spacer disk 15 is located between the rolling bearings 20a, b, with in particular a respective bearing outer ring 11a, b being in contact with the spacer disk 15 axially to the rotation axis R. Bearing inner rings 8 of the bearing device 9 are arranged on the bearing journal 5. A hub 16 with a compressor wheel 34 is arranged on bearing outer rings 11 a, b of the bearing device 9.In addition, the side channel compressor 1 has a compressor chamber 36 which runs circumferentially around the axis of rotation R and which has at least one circumferential side channel 35. 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 clamped at least indirectly to the first housing part 3 via the fastening screw 28 and a spring element 18, wherein the first housing part 3 is clamped at least indirectly to the bearing device 9 via the fastening screw 28. A stop disk 19 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 bearing inner ring 8.

[0041] In addition, Fig. 1 shows that by screwing in the fastening screw 28, a preload force 39 acting parallel to the rotation axis R is applied to the bearing device 9. Furthermore, it is shown that in the direction of the rotation axis R, four axial gaps 33a, b, c, d are located in the area between the compressor wheel assembly 10 and the respective housing part 3, 4, wherein the axial gaps 33a, b, c, d encapsulate the compressor chamber 30. In this case, the compressed gaseous medium can be conveyed from the compressor chamber 30 of the side channel compressor 1 to a fuel cell 26 of a fuel cell system 2, a drive 37 is designed as an axial field electric motor 37 which has a stator 37, wherein by means of energizing the stator 37 a magnetic field is formed which acts on a segment magnet 44 (shown in Fig. 2) of the compressor wheel assembly 10 in such a way that the compressor wheel assembly 10 is set into a rotary movement.

[0042] Fig. 2 shows a sectional view of a section of the side channel compressor 1, designated II in Fig. 1, with at least one bearing 19, 20 and the spring element 18 according to the prior art. It is shown that the first bearing 19 has the bearing outer ring 11a and the bearing inner ring 8a, wherein the second bearing 20 has the bearing outer ring 11b and the bearing inner ring 8b. At least one respective sealing disk 21 is located between the respective bearing inner ring 8a, b and the respective bearing outer ring 11a, b in order to encapsulate a bearing interior 27, wherein in particular escape of a lubricant from the bearing interior 27 is prevented, but also contamination of the bearing interior 27 by particles from outside the respective bearing 19, 20 is prevented. The bearing inner ring 8b is at least indirectly in contact with the spring element 18 in the direction of the rotation axis R.The spring element 18 is supported at least indirectly on one side on an end face of the bearing inner ring 8b and on the other side on the inner wall 17 of the first housing part 3. The spring element 18 acts with a spring force and / or preload force 39 acting at least almost in the direction of the rotation axis R, at least indirectly in the region of the contact points of the spring element 18 with the contact surface and / or the inner wall 17.

[0043] Furthermore, Fig. 2 shows that the hub 16 has at least one segment magnet 44 and at least one return ring 46 in the region of a recess running circumferentially around the rotation axis R. In addition, the compressor wheel 34 is mounted on the hub 16 and fastened, for example by means of a screw connection. The bearing device 9 is screwed to the first housing part 3 by means of the fastening screw 28, by screwing the fastening screw 28 into the journal 5. In addition, a contact disk 12 can be located in the direction of the rotation axis R between the fastening screw 28, in particular an enlarged screw head, and the bearing journal 5 and / or the respective bearing inner ring 8. Furthermore, the contact disk 12 is in contact with a flat surface of the bearing journal 5 in the direction of the rotation axis R, at least indirectly via a spacer sleeve 14.By machining the spacer sleeve 14 before assembly, a bearing preload of the respective bearing 19, 20 can now be achieved, in particular by means of a bearing preload force 39.

[0044] Fig. 2 further shows that, in an exemplary embodiment, the first bearing 19 and the second bearing 20 each have two sealing disks 21 which encapsulate the respective bearing 19, 20 with its bearing interior 27 against elements from an environment 29 and / or from the compressor chamber 36 of the side channel compressor 1. However, a respective sealing disk 21 of the respective bearing 19, 20 can fail over its service life due to frictional wear, in particular due to frictional wear of a sealing lip and / or sealing edge, and the bearing interior 27 is thus no longer effectively encapsulated against the environment 29 and / or the compressor chamber 30, so that water can penetrate into the respective bearing 19, 20 via an ingress path 43 and can damage the respective bearing 19, 20.

[0045] 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 the compressor wheel assembly 10 according to a first exemplary embodiment. The compressor wheel assembly 10 has the bearing device 9, which is arranged in the hub 16. The bearing device 9 has at least the first bearing 19, the second bearing 20 and the spacer disk 15, wherein the spacer disk 15 is arranged between the bearing outer rings 11 a, b in the direction of the rotation axis R and / or is in contact. The hub 16 has the region of the first inner diameter 31 and the second inner diameter 38, wherein the second inner diameter 38 lies in the region of a shoulder of the hub 16, wherein the shoulder serves as a stop, in particular an assembly stop, of the respective bearing outer ring 11 a, b.Furthermore, it is shown that the cover-shaped sealing element 13 runs at least almost rotationally symmetrically around the axis of rotation R and encloses the head of the fastening screw 28 with a pot-shaped recess. With its annular end face facing away from the axis of rotation R and circumferentially around the axis of rotation R, the cover-shaped sealing element 13 rests against the hub 16. Furthermore, the hub 16 has, in the region of the first inner diameter 31, at least one bearing device region 22 and a cover receiving region 24, which run at least almost in the direction of the axis of rotation R, wherein the cover receiving region 24 runs in the region of the first inner diameter 31 of the hub 16 on the side of the hub 16 facing the second housing part 4. The cover-shaped sealing element 13 is arranged in the cover receiving region 24 of the hub 16.

[0046] Furthermore, Fig. 3 shows that the cover-shaped sealing element 13 bears against the compressor wheel assembly 10 and / or the first bearing 19 on its end face facing the second housing part 4, in particular a first end face, in the direction of the rotational axis R. Furthermore, the cover-shaped sealing element 13 at least almost completely covers the bearings 19, 20 and / or the bearing device 9 orthogonally to the rotational axis R, so that the cover-shaped sealing element 13 is at least indirectly connected to the hub 16 in such a way that fluidic encapsulation of the interior 27 of the bearings 19, 20 and / or an interior 27 of the hub 16 from the surroundings 29 of the compressor wheel assembly 10 can be achieved.

[0047] Furthermore, Fig. 3 shows that the hub 16 of the side-channel compressor 1 according to the invention has a cover-disk receiving area 25 in the direction of the rotation axis R in the region of the second inner diameter 38, in particular on the side facing the first housing part 3, wherein a first cover disc 23 is arranged in the cover-disk receiving area 25. The first cover disc 23 thereby achieves fluidic encapsulation of the interior 27 of the hub 16 and / or the respective bearing 19, 20 with respect to the surroundings 29 of the compressor wheel assembly 10. It is also shown that at least one sealing element 42 is arranged orthogonally to the rotational axis R between the bearing journal 5 and at least one bearing inner ring 8a, 8b, wherein the sealing element 42 is arranged in a depression-shaped recess 7 on the outer diameter 47 of the bearing journal 5. This sealing element 42 can, in particular, be an O-ring 42.Furthermore, the hub 16 has the cover receiving area 24 in the direction of the rotation axis R in the region of a first inner diameter 31, in particular on the side facing the second housing part 4, wherein the cover-shaped sealing element 13 and a second cover plate 41 are arranged in the cover receiving area 24. The cover-shaped sealing element 13 and / or the second cover plate 41 thereby fluidically encapsulate the interior 27 of the hub 16.

[0048] The cover-shaped sealing element 13 shown in Fig. 3, in an exemplary embodiment of the side channel compressor 1, can consist of a metal sheet overmolded with an elastomer, e.g. FKM. The sealing element 13 thus has a certain elasticity, which leads to simplified assembly and improved encapsulating properties. This reduces the probability of failure of the respective bearings 19, 20, in particular due to water penetrating from the environment 29 into the bearing interior 27. For further improved encapsulation of the respective bearing interiors 27, the first cover disk 23 runs in a ring-shaped manner around the axis of rotation R, wherein the first cover disk 23 is in contact with an end face of the bearing inner ring 8 axially to the axis of rotation R, on the one hand, and is in contact with the spring element 18 with its own contact surface 40, and / or is arranged between the bearing inner ring 8 and the spring element 18.The spring element 18 can be designed as a wave spring 18. Furthermore, Fig. 3 shows that the side channel compressor 1, in an exemplary embodiment, with its bearing device 9, has two rolling bearings 19, 20 arranged next to one another along the axis of rotation R, wherein the spacer disk 15 is located between the rolling bearings 19, 20, wherein in particular the bearing outer rings 11 a, b are in axial contact with the spacer disk 15 relative to the axis of rotation R. Fig. 4 shows a sectional view of a section, designated II in Fig. 1, of the side channel compressor 1 according to the invention with the compressor wheel assembly 10 according to a second exemplary embodiment. It is shown that the hub 16 has a radial shaft seal receiving area 32 in the direction of the axis of rotation R in the region of the first diameter 31, wherein a radial shaft seal (RDWR) 45 is arranged in the radial shaft seal receiving area 32.By means of the radial shaft seal 45, fluidic encapsulation of the interior 27 of the hub 16 and / or the respective bearing 19, 20 with respect to the surrounding area 29 of the compressor wheel assembly 10 can be achieved. According to the inventive design of the side channel compressor 1 and / or the compressor wheel assembly 10, the radial shaft seal (RDWR) 45 forms a non-positive and / or positive connection on an outer diameter 49 facing away from the rotation axis R with a first extension 51 of the bearing outer ring 11b in the direction of the rotation axis R. The non-positive and / or positive connection is formed with an inner diameter 55 of the first extension 51.The radial shaft seal (RDWR) 45 is at least indirectly in contact, in particular in frictional contact and / or sliding contact, with its inner diameter 50 facing the rotational axis R, with a second extension 52 of the bearing inner ring 8b running in the direction of the rotational axis R, in particular an outer diameter 53.

[0049] As further shown in Fig. 4, the second bearing 20 has the sealing disc 21 on its side facing the second housing part 4 in the direction of the rotation axis R. On its side facing away from the second housing part 4, the sealing disc 21 can be omitted due to the use of the RDWR. Furthermore, it is shown that two sealing elements 42, in particular O-rings 42, are located orthogonally to the rotation axis R between the bearing journal 5 and the bearing inner ring 8b of the second bearing 20, in particular each in a depression-shaped recess 7 on the outer diameter 47 of the bearing journal 5.In this side channel compressor 1 according to the invention with the compressor wheel assembly 10 according to a second exemplary embodiment, the two sealing disks 21 of the first bearing 19 can be omitted, just as sealing elements 42 between the bearing inner ring 8a of the first bearing 19 and the bearing journal 5 can be omitted, in particular due to the used RDWR 45 and the used second sealing disk 41 and the used cover-shaped sealing element 13. The bearing inner ring 8b of the second bearing 20 is thereby at its contact surface.

[0050] 40 is subjected to a preload force 39 extending at least almost in the direction of the rotation axis R

[0051] Fig. 5 shows a sectional view of a section of the side channel compressor 1 according to the invention, designated II in Fig. 1, with the compressor wheel assembly 10 according to a third exemplary embodiment. The radial shaft sealing ring (RDWR) 45 forms a non-positive and / or positive connection with the first inner diameter 31 of the hub 16 on its outer diameter 49 facing away from the axis of rotation R. The radial shaft sealing ring (RDWR) 45 is in contact, at least indirectly, in particular in frictional contact and / or sliding contact, with a second extension 52 of the bearing inner ring 8b, in particular an outer diameter 53, running in the direction of the axis of rotation R, on its inner diameter 50 facing the axis of rotation R. The RDWR 45 is in contact with a shoulder of the second inner diameter 38 of the hub 16 in the direction of the axis of rotation R.In this side channel compressor 1 according to the invention with the compressor wheel assembly 10 according to a third exemplary embodiment, the two sealing elements 42 between the bearing inner ring 8a of the first bearing 19 and the bearing journal 5 can be omitted, in particular due to the inserted RDWR 45 and the inserted second sealing disc 41 and the inserted cover-shaped sealing element 13. The bearing inner ring 8b of the second bearing 20 is subjected to a preload force 39 running at least almost in the direction of the rotation axis R on its contact surface 40.

[0052] Fig. 6 shows a sectional view of a section of the side channel compressor 1 according to the invention, designated II in Fig. 1, with the compressor wheel assembly 10 according to a fourth exemplary embodiment. The radial shaft sealing ring (RDWR) 45 forms a non-positive and / or positive connection with the first inner diameter 31 of the hub 16 on its outer diameter 49 facing away from the axis of rotation R. The radial shaft sealing ring (RDWR) 45 is in at least indirectly contact, in particular in frictional contact and / or sliding contact, with an outer diameter 48 of an additional ring 30 running annularly around the axis of rotation R on its inner diameter 50 facing the axis of rotation R. The additional ring 30 can in particular be arranged in a "floating" manner on the outer diameter 47 of the bearing journal 5; in particular, a relative movement of the additional ring 30 in the direction of the axis of rotation R on the bearing journal is possible.The RDWR 45 is in contact at its inner diameter 50 with the outer diameter 48 of the additional ring 30, at least indirectly, such that it forms a sliding contact and / or frictional contact with the additional ring 30. The RDWR 45 has a sealing lip and / or dust lip in the area facing the additional ring 30. Furthermore, it is shown that a sealing element 42, in particular an O-ring 42, is located orthogonally to the rotation axis R between the outer diameter 47 of the bearing journal 5 and the inner diameter of the additional ring 30, in particular in a depression-shaped recess 7 on the outer diameter 47 of the bearing journal 5.

Claims

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 a rotational axis (R), wherein a bearing inner ring (8) of a bearing device (9) is arranged on the bearing journal (5), wherein the bearing device (9) has a first bearing (19) and a second bearing (20), wherein each bearing (19, 20) has two sealing disks (21) which encapsulate the bearing channel space (27), wherein a compressor wheel assembly (10) with a compressor wheel (34) is arranged 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 is drivable via a drive (37), wherein the first housing part (3) has at least is indirectly clamped to the bearing device (9),wherein a spring element (18) is arranged in the journal root section (6) in the direction of the rotational axis (R) at least indirectly between the bearing device (9) and the first housing part (3), characterized in that the compressor wheel assembly (10) and / or the respective bearing (19, 20) has, on its end face facing the second housing part (4), in particular a first end face (30), a cover-shaped sealing element (13) which at least almost completely covers the bearings (19, 20) and / or the bearing device (9) orthogonal to the rotational axis (R), wherein the cover-shaped sealing element (13) is at least indirectly connected to the hub (16) in such a way that a fluidic encapsulation of the interior (27) of the hub (16) with respect to an environment (29) of the compressor wheel assembly (10) can be achieved.

2. Side channel compressor (1) according to claim 1, characterized in that the hub (16) has a cover disc receiving area (25) in the direction of the rotation axis (R) in the region of the second inner diameter (38), in particular on the side facing the first housing part (3). Side, wherein a first cover disc (23) is arranged in the cover disc receiving area (25), wherein by means of the first cover disc (23) a fluidic encapsulation of the interior (27) of the hub (16) and / or of the respective bearing (19, 20) with respect to the environment (29) of the compressor wheel assembly (10) can be achieved.

3. Side channel compressor (1) according to claim 1, characterized in that the hub (16) has a radial shaft seal receiving area (32) in the direction of the axis of rotation (R) in the region of the first inner diameter (31), wherein a radial shaft seal (RDWR) (45) is arranged in the radial shaft seal receiving area (32), wherein by means of the radial shaft seal (45) a fluidic encapsulation of the interior (27) of the hub (16) and / or of the respective bearing (19, 20) with respect to the environment (29) of the compressor wheel assembly (10) can be achieved.

4. Side channel compressor (1) according to claim 3, characterized in that the radial shaft sealing ring (RDWR) (45) is provided on its outer diameter (49) facing away from the rotation axis (R) with a first extension (51) of the bearing outer ring (11 b) forms a force-locking and / or form-locking connection, wherein the radial shaft sealing ring (RDWR) (45) is provided on its inner diameter (50) facing the rotation axis R with a second extension running in the direction of the rotation axis R (52) of the bearing inner ring (8b), in particular an outer diameter (53), is at least indirectly in contact, in particular is in frictional contact and / or sliding contact.

5. Side channel compressor (1) according to claim 3, characterized in that the radial shaft sealing ring (RDWR) (45) forms a non-positive and / or positive connection with the first inner diameter (31) of the hub (16) on its outer diameter (49) facing away from the axis of rotation (R), wherein the radial shaft sealing ring (RDWR) (45) is at least indirectly in contact, in particular in frictional contact and / or sliding contact, with a second extension (52) of the bearing inner ring (8b) running in the direction of the axis of rotation R, in particular an outer diameter (53).

6. Side channel compressor (1) according to claim 3, characterized in that the radial shaft sealing ring (RDWR) (45) forms a non-positive and / or positive connection at its outer diameter (49) facing away from the rotation axis (R) with the first inner diameter (31) of the hub (16), wherein the radial shaft sealing ring (RDWR) (45) is at least indirectly in contact, in particular in frictional contact and / or sliding contact, with an outer diameter (48) of an additional ring (30) extending annularly around the rotation axis R at its inner diameter (50) facing the rotation axis R.

7. Side channel compressor (1) according to one of the preceding claims, characterized in that at least one sealing element (42) is arranged orthogonally to the axis of rotation (R) between the bearing journal (5) and at least one bearing inner ring (8a, 8b), wherein the sealing element (42) is arranged in a hollow-shaped recess (7) on the outer diameter (47) of the bearing journal (5) 8. Side channel compressor (1) according to one of claims 4 to 6, characterized in that the radial shaft sealing ring (RDWR) (45) has a sealing lip and / or dust lip on its inner diameter (50), at which it is at least indirectly in contact with the outer diameter (53) of the second extension (52) of the bearing inner ring (8b) or with the outer diameter (48) of the additional ring (30), and forms a sliding contact with the respective diameter (48, 53), wherein a sealing element (42) is located between the bearing journal (5) and the additional ring (30) 9. Side channel compressor (1) according to one of the preceding claims, characterized in that the hub (16) has the cover receiving area (24) in the direction of the axis of rotation (R) in the region of a first inner diameter (31), in particular on the side facing the second housing part (4), wherein the cover-shaped sealing element (13) and a second cover disc (41) are arranged in the cover receiving area (24), wherein by means of the cover-shaped sealing element (13) and the second cover disc (41) a fluidic encapsulation of the interior (27) of the hub (16) takes place.

10. Side channel compressor (1) according to one of the preceding claims, characterized in that the cover-shaped sealing element (13) consists of a metal sheet overmolded with elastomer, e.g. FKM 11. Fuel cell system (2) with a side channel compressor (1) according to one of claims 1 to 10, wherein the side channel compressor (1) is arranged in an anode circuit of the fuel cell system (2).

Images