SIDE CHANNEL COMPRESSOR FOR A FUEL CELL SYSTEM FOR CONVEYING AND / OR COMPACTING A GAS-FORMED MEDIUM, FUEL CELL SYSTEM

Description

[0001] 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 especially 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.

[0002] 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.

[0003] From DE 10 2018 204 713 A1, a side-channel compressor for a fuel cell system is known, in which a gaseous medium, in particular hydrogen, is conveyed and / or compressed. The side-channel compressor has a housing and a drive, wherein the housing has an upper housing part and a lower housing part, with a compressor chamber extending around a rotating axis within the housing, which has at least one rotating side channel, with a compressor wheel located in the housing, which is rotatably arranged about the rotating axis and is driven by the drive.The compressor wheel has blades arranged around its circumference in the area of ​​the compressor chamber and is equipped with a gas inlet opening and a gas outlet opening formed on the housing, which are fluidically connected to each other via the compressor chamber, in particular the at least one side channel, wherein the side channel compressor has at least one bearing.

[0004] An integrated fuel cell hydrogen circuit system is known from CN 113 357 170 A.

[0005] US patent 2020 / 149590 A1 discloses a rolling bearing and bearing unit for an air turbine and an air turbine handpiece for dental purposes.

[0006] DE 10 2012 000 757 A1 relates to a rolling bearing, in particular a ball bearing, with a sealing system comprising an outer bearing ring and an inner bearing ring.

[0007] The side-channel blower known from DE 10 2018 204 713 A1 can have certain disadvantages. During operation, process water generated by the side-channel blower can wash out any lubricant present in the bearing, particularly bearing grease, and thus transport it out of the bearing. Furthermore, due to the high bearing speeds, for example up to 25,000 revolutions per minute, the lubricant, especially bearing grease, can be forced out of the bearing and / or migrate out of the bearing due to acceleration forces caused by the rotation. These effects increase the probability of failure of the respective bearing and thus of the entire side-channel blower due to increased heat generation and wear.

[0008] The side-channel blower known from DE 10 2018 204 713 A1 can, in an exemplary embodiment, have sealing discs located between the inner and outer bearing rings to encapsulate the bearing interior. These sealing discs can have a sealing lip, which in particular may be made of an elastomer and / or a plastic. The sealing lip can achieve at least partial encapsulation of the bearing interior by means of a sliding contact. This exemplary embodiment of the side-channel blower, as described in the prior art, has the disadvantage that the frictional contact leads to increased temperature development in the area of ​​the sliding contact, which can damage the at least one bearing and / or other components of the side-channel blower.For example, increased temperatures can lead to a lower viscosity of the lubricant, particularly the bearing grease, which in turn results in reduced lubrication. This, in turn, leads to increased temperatures of the bearing components and accelerated aging of the lubricant, especially the bearing grease. Furthermore, particularly at high speeds of the side-channel compressor, wear in the form of material breakage can occur on the sealing lip and / or the respective bearing ring, potentially damaging the side-channel compressor and / or other components of the fuel cell system, such as a stack.Furthermore, this exemplary embodiment of the side channel blower, as described in the prior art, has the disadvantage that the encapsulating effect diminishes over time, allowing process water to enter the bearing interior. This can reduce the service life of the bearing and, consequently, the entire side channel blower. Additionally, increased energy consumption by the drive, particularly in the form of electrical energy, may be required due to frictional losses in the sliding contact, leading to higher operating costs for the side channel blower. Moreover, increased friction may necessitate a different motor design, further increasing the overall cost of the side channel blower. Disclosure of the invention Advantages of the invention

[0009] According to the invention, a side-channel compressor for a fuel cell system for conveying and / or compressing a gaseous medium, in particular hydrogen, is provided, comprising the features of the independent claims. The side-channel compressor has a housing and a drive, with a compressor chamber extending around a rotating axis within the housing and having at least one rotating side channel, a rotor chamber located within the housing, and a compressor wheel rotatably arranged about the rotating axis. The compressor wheel is driven by the drive, the side-channel compressor having at least one bearing located on a cylindrical bearing journal, and each bearing having an outer ring, an inner ring, and an inner chamber which is encapsulated from the rotor chamber by means of at least one sealing element.

[0010] Referring to claim 1, the bearing interior, which can be encapsulated from the rotor space by the sealing element, has, depending on the operating condition, either a sliding seal or a non-contact seal between the inner bearing ring and the sealing element.

[0011] This approach offers the advantage of being able to manufacture a suitable seal depending on the operating conditions of the side channel blower. This reduces wear on the sealing element and / or the side channel blower by enabling the production of a non-contact seal. Furthermore, it increases the efficiency of the side channel blower. A compact design for the sealing element and the respective bearing can be maintained. This reduces the probability of side channel blower failure and / or extends the service life of the bearing and / or the side channel blower.

[0012] 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.

[0013] According to an advantageous embodiment of the side-channel compressor according to the invention, the outer bearing ring and the sealing element are connected to the compressor wheel in such a way that they are rotatably mounted about the axis of rotation, particularly during operation of the side-channel compressor. The inner bearing ring is fixed, in particular rotationally fixed, on the bearing journal and / or does not rotate with the compressor wheel. In this way, the advantage can be achieved that the area of ​​the sealing element forming a sliding seal, particularly with the inner bearing ring, has the smallest possible diameter and / or the smallest possible surface area. This leads to low losses due to the smaller and / or reduced surface areas in frictional contact, which in turn improves the efficiency of the bearing and / or the side-channel compressor.Furthermore, the inventive design of the side channel compressor offers the advantage of reducing heat generation through the friction partners of the sliding seal, thus reducing heat input into the respective bearing and increasing the service life of the lubricant in the bearing, thereby reducing the probability of failure of the bearing and / or the side channel compressor.

[0014] According to an advantageous embodiment of the side-channel blower, the respective sealing element has a steel backing and a sealing sleeve, wherein the steel backing and / or the sealing sleeve each have a disc-shaped area, in particular at least nearly orthogonally, circumferentially around the axis of rotation, and a curved area. In this way, a compact design of the sealing element can be achieved, whereby the advantageous embodiment of the sealing element according to the invention can be achieved in a small installation space, in which a sliding seal or a non-contact seal can be produced.

[0015] According to a particularly advantageous embodiment of the side channel blower, the steel backing comprises a non-elastic material, in particular a metallic material. Furthermore, the sealing sleeve comprises an elastic material, in particular PTFE (polytetrafluoroethylene). This ensures effective emptying and / or evacuation of the flow chamber by allowing the gaseous medium to escape from the flow chamber area via the open side facing away from the axis of rotation, which is in particular an opening. This increases the service life of the at least one bearing and / or the side channel blower.

[0016] According to an advantageous embodiment of the side-channel blower, the sealing element comprises an elastomer element that is at least partially made of FKM (fluororubber) and / or EPDM (ethylene propylene diene monomer rubber), wherein the formed sealing sleeve is connected to the steel backing, at least in the disc-shaped area, by means of the elastomer element in a form-fit and / or force-fit and / or at least partially material-fit manner. In this way, a stable and durable connection between the steel backing and the sealing sleeve can be established. This reduces the probability of failure of the sealing sleeve and / or the sealing element and / or the steel backing, particularly in the case of a mechanical interaction of the components, thus increasing and / or improving the service life of the side-channel blower.

[0017] According to an advantageous embodiment of the side-channel blower, the sealing element is designed such that, in a first position, particularly when the side-channel blower is stationary, the sealing sleeve is in contact with the inner bearing ring in such a way that contact is established between the inner bearing ring and the sealing sleeve, and / or the sealing sleeve does not contact a second contact surface of the steel backing with a first contact surface, particularly in the curved area. This achieves the advantage of a durable encapsulation of the bearing interior, especially the rotor space. The sealing element, particularly via the sealing sleeve, is in contact with both the outer and inner bearing rings, thus ensuring complete encapsulation of the bearing interior.This applies, for example, to a side-channel compressor that is not in operation, where the respective bearing and / or the outer bearing ring is not rotating, so that no centrifugal forces act on a lubricating medium inside the bearing, which is primarily bearing grease. Thus, it is ensured that, by means of the almost complete encapsulation of the bearing interior and the lubricating medium by the sealing element, this lubricating medium does not escape from the bearing, where it could enter the rotor chamber and / or the compressor chamber. This could potentially damage the hydrogen lines and / or a stack. Furthermore, a loss of the lubricating medium in the bearing would lead to a shortened service life of a rolling element and / or a bearing raceway, thereby increasing the probability of bearing failure.Due to the inventive design of the bearing and the side channel compressor, the lubricating medium remains inside the bearing, which reduces the probability of bearing failure.

[0018] According to a particularly advantageous embodiment of the side-channel blower, the sealing sleeve in the curved area is deformable in such a way that, especially during operation of the side-channel blower, it moves away from the inner bearing ring by means of a resulting force acting upon it, which includes a centrifugal force and / or pressure force, so that the sealing sleeve's first contact surface is in contact with the second contact surface of the steel backing. In this way, the advantage is achieved that, during operation of the side-channel blower, where particularly high rotational speeds of at least nearly 18,000 to 25,000 revolutions per minute can occur, the rubbing seal is eliminated and a contactless seal is created.The sealing sleeve deforms in the curved area such that it detaches from the inner bearing ring at the contact point and moves towards the curved area of ​​the steel backing, specifically towards the second contact surface of the steel backing. Due to centrifugal forces, the lubricant is forced outwards towards the outer bearing ring, where it comes into contact with the sealing element in the disc-shaped area. The sealing element, particularly the sealing sleeve and / or the steel backing, thus prevents the lubricant from being encapsulated and escaping from the bearing interior into the rotor chamber.This method increases the service life of the side channel blower by replacing the sliding seal with a non-contact seal, which causes less wear on the sealing element and / or the sealing sleeve. This, in turn, extends the service life of the sealing element and / or the bearing, as a frictionless seal is formed. Furthermore, it improves the efficiency of the bearings and / or the side channel blower.

[0019] According to an advantageous embodiment of the side-channel blower, the sealing element is designed such that the sealing sleeve, in a second position, particularly during operation of the side-channel blower, is not in contact with the inner bearing ring, so that a gap forms between the inner bearing ring and the sealing sleeve. This achieves the advantage of a sealing function between the sealing disc and the inner bearing ring that is at least virtually frictionless, in contrast to the prior art, which involves a sealing lip on the sealing disc in a sliding contact with the inner bearing ring.This frictionless encapsulation of the bearing interior can be achieved by preventing the sealing element, in particular the sealing sleeve, from being in contact with the inner bearing ring, creating a gap between the inner bearing ring and the sealing sleeve. This prevents the generation of frictional heat during operation of the side channel blower, thus preventing or at least reducing damage and / or wear of surrounding components, thereby increasing the service life of the entire side channel blower. Furthermore, the gap prevents frictional contact between the sealing sleeve and the inner bearing ring, while the gap dimension is so small that virtually no lubricant can migrate or move through this gap from the bearing interior into the rotor chamber due to the material properties.Furthermore, the lubricating medium, which is primarily bearing grease, is forced outwards towards the outer ring by centrifugal forces, thereby diverting almost all of the lubricating medium away from the forming gap. This prevents the lubricating medium from escaping the bearing interior and thus reducing the lubrication effect. Therefore, the failure probability of the bearing, and consequently of the side channel blower, can be reduced by means of the inventive design of the side channel blower, while the service life of the aforementioned components can be increased. In addition, friction losses due to a sliding contact and the associated friction can be prevented, thereby increasing the efficiency of the side channel blower.

[0020] According to an advantageous embodiment of the side-channel blower, the lower housing section features a cylindrical bearing journal. The bearing journal extends in the direction of the axis of rotation such that its circumferential surface surrounds the axis of rotation, and a first bearing and / or a second bearing are in radial contact with the circumferential surface of the bearing journal. This design allows for the integration of the first and / or second bearings using a compact and cost-effective housing and / or side-channel blower design. Furthermore, the assembly of the bearings and / or the impeller within the housing is simplified, reducing the number of assembly steps and thus saving on assembly costs.

[0021] According to an advantageous embodiment of the side-channel compressor, the drive is designed as an axial-field electric motor comprising a stator and a rotor. The stator and rotor are disk-shaped and circumferentially arranged around the axis of rotation, with the stator positioned adjacent to the rotor along the axis of rotation. This design offers the advantage of a drive that is narrower in the direction of the axis of rotation, particularly compared to a drive known from the prior art with a drive shaft. While the latter requires considerable space radially to the axis of rotation due to its diameter, it is narrow axially and therefore requires little space axially.The other components of the side channel compressor, in particular the housing and the compressor wheel, are similarly designed as narrow components in the direction of the axis of rotation. While their diameters require considerable space radially to the axis of rotation, their axially narrow design means they require minimal space. This is also advantageous when integrating the side channel compressor into the anode plate of a fuel cell. When the drive is combined with the other components of the side channel compressor, especially the housing and the compressor wheel, components with similar dimensions are combined, resulting in a compact and space-saving design for the entire side channel compressor. This compact and space-saving design is further achieved by minimizing the surface area relative to the volume.This offers the advantage of requiring minimal installation space at the customer's site, for example, within a complete vehicle. Furthermore, the compact design of the side channel compressor, particularly with its minimal surface area relative to its volume, provides thermal benefits during cold starts.

[0022] The invention is not limited to the embodiments described herein and the aspects highlighted therein. The invention is limited exclusively by the scope of protection of the appended claims. Brief description of the drawing

[0023] The invention is described in more detail below with reference to the drawing. Brief description of the drawing

[0024] The invention is described in more detail below with reference to the drawing.

[0025] It shows: Figure 1 is a schematic sectional view of a side channel blower according to the invention. Figure 2 is a schematic sectional view of a bearing according to the prior art. Figure 3 is a schematic sectional view of a bearing and / or a sealing element according to a first embodiment. Figure 4 is a schematic sectional view of a bearing and / or sealing element according to a second embodiment. Figure 5 is a schematic sectional view of the sealing element with a steel backing, an elastomer element, and a sealing sleeve in a first position. Figure 6 is a schematic sectional view of the sealing element with the steel backing, the elastomer element, and the sealing sleeve in a second position. Description of the exemplary embodiment

[0026] According to the representation Fig. 1 A schematic sectional view of a side channel compressor 1 according to the invention can be seen.

[0027] This is in Fig. 1 shown that the side channel compressor 1 for a fuel cell system 31 for conveying and / or compressing a gaseous medium, in particular hydrogen, is provided with a housing 3 and a drive 6, wherein the housing 3 has a housing upper part 7 and a housing lower part 8.Furthermore, the housing 3 has a compressor chamber 30 extending around a rotational axis 4, which has at least one circumferential side channel 19, 21, with a compressor wheel 2 located in the housing 3, which is rotatably arranged about the rotational axis 4 and is driven by the drive 6, wherein the compressor wheel 2 has blades 5 arranged on its circumference in the area of ​​the compressor chamber 30 and each has a gas inlet opening 14 and a gas outlet opening 16 formed on the housing 3, which are fluidically connected to each other via the compressor chamber 30, in particular the at least one side channel 19, 21, wherein the side channel compressor 1 has at least one bearing 27, 47.The at least one side channel 19, 21 can run around the axis of rotation 4 at least in a partial area of ​​the housing 3, wherein in the partial area in which the at least one side channel 19, 21 is not formed in the housing 3, an interrupter area 15 is formed in the housing 3.

[0028] Furthermore, in Fig. 1 It has been shown that the drive 6 is designed as an axial field electric motor 6, which has a stator 11 and a rotor 17, wherein the stator 11 and the rotor 17 are disk-shaped and rotate around the axis of rotation 4, and wherein the stator 11 is arranged next to the rotor 17 in the direction of the axis of rotation 4. The rotor 17 can be located at least indirectly on a hub disk 23 of the compressor wheel 2. Furthermore, it is shown in Fig. 1 It is shown that the side-channel compressor 1 has a stator chamber 42 and a rotor chamber 44, in which at least some components of the drive 6 are arranged. The upper housing part 7 has a continuous wall 29 located between the stator chamber 42 and the rotor chamber 44, thus providing fluidic separation between them. The stator chamber 42 is also at least partially surrounded and / or encapsulated by a stator housing 39. The lower housing part 8 has a cylindrical bearing journal 12, the bearing journal 12 extending in the direction of the axis of rotation 4 such that its circumferential surface extends around the axis of rotation 4, and a first bearing 27 and / or a second bearing 47 are in contact with the circumferential surface of the bearing journal 12 radially to the axis of rotation 4. In addition, the compressor wheel 2 can be connected to the respective bearing 27, 47 via the hub disc 23 and a hub 9.The drive 6 can be designed as an axial-field electric motor 6 comprising a stator 11 and a rotor 17, wherein the stator 11 and the rotor 17 are disk-shaped and rotate around the axis of rotation 4, and wherein the stator 11 is arranged adjacent to the rotor 17 in the direction of the axis of rotation 4. Furthermore, the side-channel compressor 1 has a cylindrical bearing journal 12, wherein the bearing journal 12 extends in the direction of the axis of rotation 4 such that its outer surface extends around the axis of rotation 4. The first bearing 27 and / or the second bearing 47 are in radial contact with the outer surface of the bearing journal 12, relative to the axis of rotation 4.

[0029] Fig. 2 Figure 1 shows a schematic sectional view of a bearing according to the prior art. It shows that the at least one bearing 27, 47 has an inner bearing ring 22, an outer bearing ring 24, and a bearing cage 25 and / or a rolling element 13 located between the inner bearing ring 22 and the outer bearing ring 24. Furthermore, a sealing element 26, encapsulating and / or limiting a bearing chamber 40, is located in the region of the end faces of the inner bearing ring 22 and the outer bearing ring 24. This sealing element 26 typically has a sealing lip 36 that is connected to a steel backing 28, for example, by being vulcanized to it. The sealing element 26 is then clipped into a type of groove in the outer bearing ring 24. The sealing element 26 then functions like a conventional radial shaft seal. It seals against the inner bearing ring 22.

[0030] Furthermore, in Fig. 2 It has been shown that the outer bearing ring 24 is at least indirectly fixed to the compressor wheel 2 and rotates with it during operation of the side channel compressor 1. The sealing element 26 is fixed to the outer bearing ring 24, in particular by positive locking and / or material locking and / or friction locking, and rotates with the outer bearing ring 24 in one direction of rotation. The sealing element 26 has a sealing lip 36 on its inner diameter, whereby this sealing lip 36 achieves at least partial encapsulation of the bearing interior 40. The sealing lip 36 is in frictional contact with the inner bearing ring 22, so that it is a sliding sealing lip 36.

[0031] The in Fig. 2 The bearings 27, 47 and / or sealing element 26 shown may have certain disadvantages, whereby the sealing lip 36 shown is damaged by the gaseous medium in the rotor chamber 44, which may contain at least some hot water vapor, particularly at temperatures above 90°C. Elastomers 36 made of FKM (fluororubber) in particular exhibit a high susceptibility to damage, which reduces the service life of the sealing element 26 and thus increases the probability of failure of the bearings 27, 47 and / or the side channel compressor 1. Furthermore, the elastomer may swell and / or a significant loss of contact pressure and / or sealing effect between the sealing element 26 and / or the inner bearing ring 22 is to be expected.

[0032] Fig. 3 Figure 1 shows a schematic sectional view of a bearing 27, 47 and / or sealing element 26 according to a first embodiment of the invention. The respective bearing 27, 47 comprises the outer bearing ring 24, the inner bearing ring 22, and the inner bearing chamber 40, which is encapsulated from the rotor chamber 44 by means of at least one sealing element 26. The inner bearing chamber 40 can be encapsulated from the rotor chamber 44 by the sealing element 26 in such a way that, depending on the operating conditions, either a sliding seal or a non-contact seal can be established between the inner bearing ring 22 and the sealing element 26 by the side channel compressor 1. The at least one bearing 27, 47 has an inner bearing ring 22 that is generally fixedly connected to the bearing journal 12 and thus stationary, with the inner bearing ring being positively connected to the bearing journal 12.This is generally a positive fit and / or frictional fit extending axially to the axis of rotation, which is applied to the bearings 27, 47, in particular the inner bearing ring 22, by means of a spring preload and / or the attractive force exerted by the magnetic rotor and stator. The bearing journal 12 is part of the housing 3 and is not rotatable. The outer bearing ring 24 is fixedly connected to the hub 9 and / or the compressor wheel 2 and / or the hub disk 23 and thus rotates at least indirectly with the compressor wheel 2 during operation of the side channel compressor 1. The outer bearing ring 24 and the sealing element 26 are connected to the compressor wheel 2 in such a way that they are rotatable about the axis of rotation 4, particularly during operation of the side channel compressor 1, whereby the inner bearing ring 22 is fixed, in particular rotationally fixed to the bearing journal 12, and / or does not rotate with the compressor wheel 2.However, the sealing element 26 and / or the steel back 28 and / or the sealing sleeve 32 have a curved area 35 on their side facing the axis of rotation 4, which no longer runs at least approximately orthogonally to the axis of rotation 4, but has a curvature pointing away from the 40 and / or is directed away from the bearing interior 40 in the end area.

[0033] Fig. 3 Figure 26 further shows that the sealing element 26 comprises a steel backing 28, a sealing sleeve 32, and an elastomer element 34. The steel backing 28 and the sealing sleeve 32 can be connected to each other via the elastomer element 34, and / or the steel backing 28 and the sealing sleeve 32 can be positively and / or frictionally and / or positively connected to the outer bearing ring 24 via the elastomer element 34, wherein the elastomer element 34 is embedded in a groove of the outer bearing ring 24. When the side channel compressor 1 and / or the compressor wheel 2 is stationary or at low speeds, particularly in the range of 100 revolutions per minute, the sealing sleeve 32 is in frictional and / or sliding contact and / or in contact with the inner bearing ring 22.As the rotational speed increases further, the lubricant 43 in the interior 40 of the bearing 27, 47 migrates away from the inner bearing ring 22 towards the outer bearing ring 24 due to centrifugal forces, as it rotates at least partially with the outer bearing ring 24. Simultaneously, the sealing sleeve 32 moves away from the inner bearing ring 22 towards the outer bearing ring 24 and / or the steel backing 28 in the direction of a resulting force 41, which includes a centrifugal force. In this process, the sealing sleeve 32 loses direct contact, in particular frictional and / or sliding contact, with the inner bearing ring 22 and / or is no longer in contact with it. Thus, a non-contact seal is formed between the inner bearing ring 22 and the sealing element 26.The lubricating medium 43 cannot pass between the inner bearing ring 22 and the sealing sleeve 32 parallel to the axis of rotation 4 into the rotor chamber 44, since it has moved away from the inner bearing ring 22 at least approximately perpendicular to the axis of rotation 4. Thus, it can be ensured that no lubricating medium 43 is released into an anode gas, particularly in the compressor chamber 30 and / or in the rotor chamber 44, over the service life of the side channel compressor 1, and / or that the lubricating medium 43 remains in the respective bearing 27, 47.

[0034] The in Fig. 3 The respective sealing element 26 shown also exhibits high material resistance to the gaseous medium being conveyed, particularly to the sealing element 26 described in the prior art. The sealing sleeve 32 is made of PTFE (polytetrafluoroethylene), which has high temperature resistance. This increases the service life of the sealing sleeve 32 and / or the sealing element 26 and / or the bearing 27, 47 and / or the side channel blower 1. A further advantage of the contactless seal due to the inventive design of the respective bearing 27, 47 and / or sealing element 26 according to the first embodiment is that the mechanical efficiency of the side channel blower 1 can be increased, since the friction and heat losses of a sliding seal are avoided and / or reduced. This leads to higher achievable volume flows of the side channel blower 1 with a constant electrical power input.

[0035] Fig. 4 Figure 1 shows a schematic sectional view of a bearing 27, 47 and / or sealing element 26 according to a second embodiment of the invention. It is shown that the bearing 27, 47 has largely the same components as the bearing 27, 47 and / or sealing element 26 according to a first embodiment of the invention. In this case, the sealing element 26 and / or the steel backing 28 and / or the sealing sleeve 32 have, on their side facing the axis of rotation 4, the curved region 35, which no longer runs at least approximately orthogonally to the axis of rotation 4, but rather has a curvature pointing towards the bearing interior 40 and / or is oriented towards the bearing interior 40 in its end region and / or projects into this bearing interior 40.In this process, the sealing sleeve 32 loses direct contact, in particular frictional contact and / or sliding contact, with the inner bearing ring 22 either due to a resulting force 41, which includes a centrifugal force, and / or an overpressure force 45 from the rotor space 44, whereby the sealing sleeve 32 is pressed towards the steel back 28 by the overpressure force 45.

[0036] Fig. 5 Figure 1 shows a schematic sectional view of the sealing element 26 with the steel backing 28, the elastomer element 34, and the sealing sleeve 32 in a first position. Each sealing element 26 comprises the steel backing 28 and the sealing sleeve 32, wherein the steel backing 28 and / or the sealing sleeve 32 each have a disc-shaped region 33, which rotates at least nearly orthogonally around the axis of rotation 4, and the curved region 35. The steel backing 28 is made of a non-elastic material, in particular a metallic material, and the sealing sleeve 32 is made of an elastic material, in particular PTFE (polytetrafluoroethylene).Furthermore, the sealing element 26 has the elastomer element 34, which in turn has at least partially FKM (fluoroelastomer), wherein the formed sealing sleeve 32 is connected to the steel back 28 at least in the disc-shaped area 33 by means of the elastomer element 34 in a form-fitting and / or force-fitting and / or at least partially material-fitting manner.

[0037] As in Fig. 5 The sealing element 26 is shown to be designed such that the sealing sleeve 32, in a first position, particularly when the side channel compressor 1 is at rest, is in contact with the inner bearing ring 22 such that a contact point 18 is formed between the inner bearing ring 22 and the sealing sleeve 32, and / or the sealing sleeve 32 is in contact with a first contact surface 37, but not with a second contact surface 38 of the steel backing 28, particularly in the curved area 35. Thus, at least nearly complete encapsulation of the bearing interior 40 can be achieved. The steel backing 28 has a first radius 46 in the curved area 35, and the sealing sleeve 32 has a second radius 48 in its curved area 35.

[0038] Fig. 6Figure 1 shows a schematic sectional view of the sealing element 26 with the steel backing 28, the elastomer element 34, and the sealing sleeve 32 in a second position. The sealing sleeve 32 is deformable in the curved area 35 such that, particularly during operation of the side channel compressor 1, it moves away from the inner bearing ring 22 by means of the resulting force 41 acting upon it, which includes a centrifugal force, and / or pressure force 45, so that the sealing sleeve 32, with its first contact surface 37, comes into contact with the second contact surface 38 of the steel backing 28 and / or is in contact with it. The centrifugal force can act radially outwards.The sealing element 26 is designed such that the sealing sleeve 32 is not in contact with the inner bearing ring 22 in a second position, particularly during operation of the side channel compressor 1, so that a gap 10 forms between the inner bearing ring 22 and the sealing sleeve 32.

Claims

1. Side-channel compressor (1) for a fuel-cell system (31) for conveying and / or compressing a gaseous medium, in particular hydrogen, having a housing (3) and a drive (6), having a compressor chamber (30), which extends in the housing (3) in an encircling manner around an axis of rotation (4) and has at least one encircling side channel (19, 21), having a rotor chamber (44), which is situated in the housing (3), and a compressor impeller (2), which is situated in this and is arranged so as to be rotatable about the axis of rotation (4) and is driven by the drive (6), wherein the side-channel compressor (1) has at least one bearing (27, 47) which is situated on a cylindrical bearing journal (12), and wherein the respective bearing (27, 47) has a bearing outer ring (24), has a bearing inner ring (22) and has a bearing interior space (40) which is encapsulated from the rotor chamber (44) by means of at least one sealing element (26), characterized in that the bearing interior space (40) is able to be encapsulated from the rotor chamber (44) by the sealing element (26) in such a way that, according to the operating state of the side-channel compressor (1), either a rubbing seal or a non-contact seal is able to be produced between the bearing inner ring (22) and the sealing element (26).

2. Side-channel compressor (1) according to Claim 1, characterized in that the bearing outer ring (24) and the sealing element (26) are connected to the compressor impeller (2) in such a way that they are rotatable about the axis of rotation (4), in particular during operation of the side-channel compressor (1), wherein the bearing inner ring (22) is fixed in such a manner, in particular rotationally fixedly, on the bearing journal (12), and / or does not rotate along with the compressor impeller (2).

3. Side-channel compressor (1) according to Claim 1 or 2, characterized in that the respective sealing element (26) has a steel back (28) and a sealing sleeve (32), wherein the steel back (28) and / or the sealing sleeve (32) each have / has a disc-shaped region (33), which extends in an encircling manner, in particular at least almost orthogonally, around the axis of rotation (4), and a curved region (35).

4. Side-channel compressor (1) according to Claim 3, characterized in that the steel back (28) comprises a non-elastic material, in particular a metallic material, and the sealing sleeve (32) comprises an elastic material, in particular PTFE (polytetrafluoroethylene).

5. Side-channel compressor (1) according to Claim 3 or 4, characterized in that the sealing element (26) has an elastomer element (34) which at least partially comprises FKM (fluorinated rubber), wherein the re-formed sealing sleeve (32) is, by means of the elastomer element (34), connected in a form-fitting and / or force-fitting and / or at least partially materially bonded manner to the steel back (28) at least in the disc-shaped region (33).

6. Side-channel compressor (1) according to one of Claims 3 to 5, characterized in that the sealing element (26) is designed in such a way that the sealing sleeve (32), in a first position, in particular with the side-channel compressor (1) at a standstill, is in contact with the bearing inner ring (22) in such a way that a point of contact (18) is formed between the bearing inner ring (22) and the sealing sleeve (32) and / or the sealing sleeve (32) is not, by way of a first contact surface (37), in abutment with a second contact surface (38) of the steel back (28), in particular in the curved region (35).

7. Side-channel compressor (1) according to one of Claims 4 to 6, characterized in that the sealing sleeve (32), in the curved region (35), is deformable in such a way that, in particular during operation of the side-channel compressor (1), by means of a resultant force (41), comprising inter alia a centrifugal force, and / or pressure force (45) acting thereon, it moves away from the bearing inner ring (22) in such a way that the sealing sleeve (32) is, by way of its first contact surface (37), in contact with the second contact surface (38) of the steel back (28).

8. Side-channel compressor (1) according to one of Claims 3, 4, 5 and 7, characterized in that the sealing element (26) is designed in such a way that the sealing sleeve (32), in a second position, in particular during operation of the side-channel compressor (1), is not in contact with the bearing inner ring (22), so that a gap (10) forms between the bearing inner ring (22) and the sealing sleeve (32).

9. Side-channel compressor (1) according to one of the preceding claims, characterized in that the cylindrical bearing journal (12) extends in the direction of the axis of rotation (4) in such a way that its lateral surface extends in an encircling manner around the axis of rotation (4), and wherein the first bearing (27) and / or the second bearing (47) are / is in contact with the lateral surface of the bearing journal (12) radially in relation to the axis of rotation (4).

10. Side-channel compressor (1) according to one of the preceding claims, characterized in that the drive (6) is in the form of an axial-field electric motor (6) which has a stator (11) and a rotor (17), wherein the stator (11) and the rotor (17) are designed to extend in an encircling manner in the form of a disc around the axis of rotation (4), and wherein the stator (11) is arranged next to the rotor (17) in the direction of the axis of rotation (4).

11. Fuel-cell system (31) having a side-channel compressor (1) according to one of preceding Claims 1 to 10, wherein the side-channel compressor (1) is arranged in an anode circuit of the fuel-cell system (31).