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

Abstract

The invention relates to a side channel compressor (1) for a fuel cell system (31) for conveying and / or compressing a gaseous medium, in particular hydrogen, comprising: a housing (3) and a drive (6); a compressor chamber (30) which extends in the housing (3) about an axis of rotation (4) and which has at least one circumferential side channel (19, 21); the invention relates to a side-channel compressor (1) having a housing (3), a rotor chamber (44) in the housing (3), and a compressor wheel (2) in the rotor chamber, which compressor wheel is rotatably arranged about the axis of rotation (4) and is driven by means of the drive (6), the side-channel compressor (1) having at least one bearing (27, 47) on a cylindrical bearing tongue (12), and wherein the corresponding bearing (27, 47) is arranged in the rotor chamber (44). 47) has a bearing outer ring (24), a bearing inner ring (22) and a bearing inner chamber (40) which is sealed from the rotor chamber (44) by means of at least one sealing element (26). According to the invention, the bearing inner chamber (40) can be separated from the rotor chamber (44) by a sealing element (26) in such a way that either a frictional seal or a contactless seal can be established between the bearing inner ring (22) and the sealing element (26) depending on the operating state of the side channel compressor (1). The present application also relates to a fuel cell system (31) having the side channel compressor (1) of the present application.

Description

Technical Field

[0001] The present application relates to a side channel compressor for a fuel cell system for conveying and / or compressing a gaseous medium, in particular hydrogen, which is in particular provided for use in a vehicle with a fuel cell drive. In addition, the present application relates to a fuel cell system having a side channel compressor of the present application. Background Art

[0002] In the field of vehicles, in addition to liquid fuels, gaseous fuels will also become increasingly important in the future. In particular, the hydrogen gas flow must be controlled in vehicles with fuel cell drives. The gas flow is no longer controlled discontinuously as in the injection of liquid fuels, but the gaseous medium is extracted from at least one high-pressure tank and conducted to the injection unit via the inflow channel of the medium-pressure pipeline system. The injection unit guides the gaseous medium to the fuel cell via the connecting pipeline of the low-pressure pipeline system. After the gaseous medium flows through the fuel cell, it is guided back to the injection unit via the return line. Here, the side channel compressor can be connected in between, which assists the gas return in terms of flow technology and efficiency. In addition, the side channel compressor is used to assist the flow structure in the fuel cell drive, especially in the case of (cold) starting of the vehicle after a certain parking time. The drive of the side channel compressor is usually carried out via an electric motor, which is supplied with voltage in the vehicle via the vehicle battery during operation.

[0003] DE 10 2018 204 713 A1 discloses a side channel compressor for a fuel cell system, 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 a housing upper part and a housing lower part, a compressor chamber extending in the housing around an axis of rotation, the compressor chamber having at least one circumferential side channel, and a compressor wheel located in the housing, which is arranged rotatably about the axis of rotation and is driven by the drive. The compressor wheel has blades arranged at its periphery in the region of the compressor chamber and has a gas inlet opening and a gas outlet opening each formed on the housing, which are fluidically connected to one another via the compressor chamber, in particular the at least one side channel, wherein the side channel compressor has at least one bearing.

[0004] The side channel compressor known from DE 10 2018 204 713 A1 can have certain disadvantages. When using a side channel compressor, the process water formed during the operation of the side channel compressor can wash the lubricating medium, in particular the bearing grease, present in the corresponding bearing out of the bearing and thus drain out of the bearing. In addition, due to the high rotational speed of the bearing, for example up to 25,000 revolutions per minute, the lubricating medium, in particular the bearing grease, can drain out of the bearing and / or move away from the bearing due to the acceleration forces caused by the rotation. Due to this effect, due to the increased heat development and increased wear, the probability of failure of the corresponding bearing and thus the entire side channel compressor increases.

[0005] In this case, the side channel compressor known from DE 10 2018 204 713 A1 can have a sealing ring in an exemplary embodiment, which is located between the inner bearing ring and the outer bearing ring to cause a sealing of the inner bearing chamber. In this case, the sealing ring can have a sealing lip, wherein the sealing lip in particular has an elastomer and / or a plastic. In this case, the sealing lip can cause at least a partial sealing of the inner bearing chamber by means of a frictional contact. The exemplary embodiments of the side channel compressor shown in the prior art have the disadvantage that due to the frictional contact, an increased temperature development occurs in the region of the frictional contact, whereby the at least one bearing and / or other components of the side channel compressor can be damaged. In this case, for example, due to the increased temperature, a lower viscosity of the lubricating medium, in particular the bearing grease, can occur, which in turn leads to a reduction in lubrication, which also leads to an increased temperature of the bearing components, but also to an accelerated aging of the lubricating medium, in particular the bearing grease. In addition, in particular at high rotational speeds of the side channel compressor, wear in the form of material fractures can occur on the sealing lip and / or the corresponding bearing ring, whereby the side channel compressor and / or other components of the fuel cell system, such as the stack, can be damaged. Furthermore, the exemplary embodiments of side channel compressors shown in the prior art have the disadvantage that the sealing effect weakens over time and process water can thereby reach the region of the bearing interior, whereby the service life of the corresponding bearing and thus of the entire side channel compressor is reduced. Furthermore, due to the friction losses of the frictional contact, an increased energy consumption of the drive, in particular in the form of electrical energy, is required, which in turn leads to increased operating losses of the side channel compressor. Furthermore, the higher friction necessitates a different motor design, whereby the costs of the side channel compressor are increased. Summary of the invention

[0006] The present application provides a side channel compressor for a fuel cell system, which is used for conveying and / or compressing a gaseous medium, in particular hydrogen, and the side channel compressor has the features of the independent claim. Here, the side channel compressor has: a housing and a drive; a compressor chamber extending around a rotation axis in the housing, the compressor chamber having at least one surrounding side channel; a rotor chamber in the housing and a compressor wheel in the rotor chamber, the compressor wheel being arranged rotatably around the rotation axis. The compressor wheel is driven by the drive, wherein the side channel compressor has at least one bearing on a cylindrical bearing pin, and wherein the corresponding bearing has a bearing outer ring, a bearing inner ring and a bearing inner chamber, the bearing inner chamber being sealed off from the rotor chamber by means of at least one sealing element.

[0007] According to claim 1 , the bearing interior which can be sealed off from the rotor space by the sealing element has, depending on the operating state, either a frictional seal or a contactless seal between the bearing inner ring and the sealing element.

[0008] This approach can achieve the advantage that a suitable seal can be established depending on the operating state of the side channel compressor. On the one hand, the wear of the sealing element and / or the side channel compressor can be reduced in that a contactless seal can be established. In addition, the efficiency of the side channel compressor can be increased. In this case, a compact design of the sealing element and the corresponding bearing can be maintained. As a result, the probability of failure of the side channel compressor can be reduced and / or the service life of the bearing and / or the side channel compressor can be increased.

[0009] Advantageous developments of the side channel compressor specified in claim 1 are achieved by the measures specified in the dependent claims. The dependent claims relate to preferred developments of the application.

[0010] According to an advantageous configuration of the side channel compressor of the present application, the bearing outer ring and the sealing element are connected to the compressor wheel so that they can be supported rotatably about the axis of rotation, especially during the operation of the side channel compressor, wherein the bearing inner ring is fixed in this way, especially fixed to the bearing pin in a non-rotatable manner, and / or does not rotate with the compressor wheel. In this way, the advantage can be achieved that the area of ​​the sealing element, especially the area that forms a friction seal with the bearing inner ring, has the smallest possible diameter and / or the smallest possible area. This leads to small losses due to the smaller diameter and / or reduced surface area in frictional contact, thereby improving the efficiency of the bearing and / or the side channel compressor on the one hand. In addition, the following advantages can be achieved based on the configuration of the side channel compressor of the present application: the heat development caused by the friction pairing of the friction seal can be reduced, so that less heat is input into the corresponding bearing and the service life of the lubricating medium in the bearing can be increased, thereby reducing the probability of failure of the bearing and / or the side channel compressor.

[0011] According to an advantageous development of the side channel compressor, the corresponding sealing element has a steel back and a sealing sleeve, wherein the steel back and / or the sealing sleeve each have a disk-shaped region surrounding the axis of rotation, in particular at least approximately orthogonal to the axis of rotation, and have a curved region. In this way, a compact design of the sealing element can be achieved, wherein an advantageous embodiment of the sealing element according to the application can be achieved due to the small installation space, in which case a frictional seal or a contactless seal can be established.

[0012] According to a particularly advantageous embodiment of the side channel compressor, the steel back comprises a non-elastic material, in particular a metallic material. Furthermore, the sealing sleeve comprises an elastic material, in particular PTFE (polytetrafluoroethylene). In this way, it can be ensured that the flow chamber can be effectively emptied and / or evacuated by allowing the gaseous medium to be discharged from the region of the flow chamber via the open side, in particular an opening, facing away from the axis of rotation. In this way, the service life of the at least one bearing and / or the side channel compressor can be increased.

[0013] According to an advantageous embodiment of the side channel compressor, the sealing element comprises an elastomeric element which at least partially comprises FKM (fluororubber) and / or EPDM (ethylene-propylene-diene-(monomer)-rubber), wherein the formed sealing sleeve is connected to the steel back at least in the region of the disk-shaped extension by means of the elastomeric element in a form-fitting and / or force-fitting and / or at least partially material-fitting manner. In this way, a stable and permanent connection between the steel back and the sealing sleeve can be established. Thus, in particular with regard to the effective fit of these components, the probability of failure of the sealing sleeve and / or the sealing element and / or the steel back can be reduced, so that the service life of the side channel compressor can be increased and / or improved.

[0014] According to an advantageous development of the side channel compressor, the sealing element is designed such that the sealing sleeve is in contact with the bearing inner ring in a first state, in particular when the side channel compressor is stationary, so that contact is formed between the bearing inner ring and the sealing sleeve and / or the sealing sleeve is not in contact with the second contact surface of the steel back with the first contact surface, in particular in the bending region. In this way, the following advantages can be achieved: a permanent sealing of the bearing inner chamber, in particular from the rotor chamber, can be achieved. In this case, the sealing element is in contact with the bearing outer ring and the bearing inner ring, in particular by means of the sealing sleeve, so that a complete sealing of the bearing inner chamber can be achieved. This applies, for example, in the case of a side channel compressor that is not in operation, in which the corresponding bearing and / or the bearing outer ring is not in a rotational motion, so that no centrifugal forces act on the lubricating medium in the bearing inner chamber, in particular bearing grease. It is thus ensured that, by means of the at least approximately complete sealing of the bearing inner chamber and the lubricating medium by the sealing element, the lubricating medium does not escape from the bearing, which would otherwise reach the rotor chamber and / or the compressor chamber, which on the one hand could lead to possible damage to the pipeline and / or the stack that conducts the hydrogen. On the other hand, the loss of lubricating medium in the bearing leads to a shortened service life of the rolling elements and / or the bearing running track, thereby increasing the failure probability of the bearing. Based on the configuration of the bearing and the side channel compressor according to the present application, the lubricating medium remains in the bearing inner chamber, thereby reducing the failure probability of the bearing.

[0015] According to a particularly advantageous development of the side channel compressor, the sealing sleeve can be deformed in the bending region in such a way that, in particular during the operation of the side channel compressor, the sealing sleeve moves away from the inner ring of the bearing by means of a combined force and / or pressure force, in particular a centrifugal force, acting on the sealing sleeve so that the sealing sleeve with its first contact surface is in contact with the second contact surface of the steel back. In this way, the following advantages can be achieved: in the operation of the side channel compressor, in particular at high speeds of at least approximately 18,000 to 25,000 revolutions per minute, frictional sealing is eliminated and a contactless seal is established. In this case, the sealing sleeve is deformed in the bending region in such a way that it is disengaged from the inner ring of the bearing in the region of the contact point and moves in the direction of the bending region of the steel back, in particular in the direction of the second contact surface of the steel back. In this case, the lubricating medium is pressed outwards in the direction of the outer ring of the bearing due to the centrifugal force, wherein the lubricating medium comes into contact with the sealing element in the region of the disk-shaped extension region. Thus, the inner chamber of the bearing is sealed off by the sealing element, in particular the sealing sleeve and / or the steel back, and the lubricating medium is prevented from flowing out of the inner chamber of the bearing into the rotor chamber. In this way, the service life of the side channel compressor can be increased by, on the one hand, replacing the frictional seal with a contactless seal which causes less wear on the sealing element and / or the sealing sleeve, thereby increasing the service life of the sealing element and / or the bearing since a frictionless seal is formed. On the other hand, the efficiency of the bearing and / or the side channel compressor can be improved.

[0016] According to an advantageous embodiment of the side channel compressor, the sealing element is designed so that the sealing sleeve is not in contact with the bearing inner ring in the second state, in particular during operation of the side channel compressor, so that a gap is formed between the bearing inner ring and the sealing sleeve. In this way, the advantage is achieved that a sealing function can be achieved between the sealing ring and the bearing inner ring, which is at least approximately frictionless compared to the prior art, which in particular relates to the following solution: the sealing lip on the sealing ring is in frictional contact with the bearing inner ring. The frictionless sealing of the bearing inner chamber can be achieved by means of the sealing element, in particular the sealing sleeve and the bearing inner ring, which are not in contact, wherein a gap is formed between the bearing inner ring and the sealing sleeve. In this way, the generation of frictional heat is prevented during operation of the side channel compressor and thus damage and / or wear of surrounding components is prevented or at least reduced, thereby increasing the service life of the entire side channel compressor. In addition, frictional contact between the sealing sleeve and the bearing inner ring can be prevented by means of the gap, and the size of the gap is so small that at least almost no lubricating medium enters and / or moves from the bearing inner chamber through the gap into the rotor chamber due to the material properties. Furthermore, the lubricating medium, in particular the bearing grease, is pressed outwards in the direction of the outer ring due to the centrifugal force, whereby at least approximately all of the lubricating medium is conducted away from the gap formed. This prevents the lubricating medium from escaping from the inner chamber of the bearing and thus reducing the lubrication effect. As a result, the probability of failure of the bearing and the side channel compressor is reduced by means of the embodiment of the side channel compressor according to the present application, while the service life of the aforementioned components can be increased. Furthermore, friction losses due to frictional contact and the friction associated therewith can be prevented, whereby the efficiency of the side channel compressor can be increased.

[0017] According to an advantageous embodiment of the side channel compressor, the housing lower part has a cylindrical bearing pin, wherein the bearing pin extends in the direction of the rotation axis so that its circumferential side extends around the rotation axis and wherein the first bearing and / or the second bearing are in contact with the circumferential side of the bearing pin in a radial direction with respect to the rotation axis. In this way, the first and / or the second bearing can be accommodated in a compact and cost-effective design of the housing and / or the side channel compressor. Furthermore, the assembly of the bearing and / or the compressor wheel in the housing can be simplified, so that fewer assembly steps are required and thus assembly costs can be saved.

[0018] According to an advantageous configuration of the side channel compressor, the drive is implemented as an axial field motor, which has a stator and a rotor. Here, the stator and the rotor are constructed in a disk-shaped manner around the rotation axis and the stator is arranged next to the rotor in the direction of the rotation axis. In this way, the following advantages can be achieved: the drive can be implemented as a narrower component in the direction of the rotation axis, especially compared with the drive with a drive shaft known in the prior art, which requires a very large structural space in the radial direction of the rotation axis due to its diameter, but is implemented narrowly in the axial direction of the rotation axis and thus requires a small structural space in the axial direction of the rotation axis. Other components of the side channel compressor, especially the housing and the compressor wheel, are also implemented as narrow components in the direction of the rotation axis, which require a very large structural space in the radial direction of the rotation axis due to its diameter, but are implemented narrowly in the axial direction of the rotation axis and thus require a small structural space in the axial direction of the rotation axis. In addition, this is advantageous in terms of the integration of the side channel compressor into the anode plate of the fuel cell. Thus, when the drive is combined with other components of the side channel compressor, in particular the housing and the compressor wheel, components with the same construction space characteristics are combined, whereby a compact and space-saving construction of the entire side channel compressor can be achieved. In this case, a compact and space-saving construction of the side channel compressor can be achieved with a surface that is as small as possible in relation to the volume. This offers the advantage that, for example, only a small amount of installation space is required on the part of the customer in the entire vehicle. Furthermore, a compact construction of the side channel compressor is provided, in particular with a surface that is as small as possible in relation to the volume, as well as thermal advantages with regard to cold starting of the side channel compressor.

[0019] The present application is not limited to the embodiments described here and the aspects emphasized here. Rather, numerous variations are possible within the scope of the claims and are within the capabilities of a person skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present application will be described in detail below with reference to the accompanying drawings.

[0021] The accompanying drawings show:

[0022] Figure 1 A schematic cross-sectional view of a side channel compressor of the present application is shown.

[0023] FIG. 2 shows a schematic sectional view of a bearing according to the prior art.

[0024] Figure 3 A schematic sectional view of a bearing and / or a sealing element according to a first exemplary embodiment of the present application is shown.

[0025] Figure 4 A schematic sectional view of a bearing and / or sealing element according to a second exemplary embodiment of the present application is shown.

[0026] Figure 5 A schematic cross-sectional view of a sealing element is shown with its steel backing, elastomeric element and sealing sleeve in a first state.

[0027] Figure 6 A schematic cross-sectional view of a sealing element is shown with its steel back, elastomeric element and sealing sleeve in a second position. DETAILED DESCRIPTION

[0028] according to Figure 1 A schematic cross-sectional view of the side channel compressor 1 of the present application can be obtained from the illustration.

[0029] Here Figure 1 , a side channel compressor 1 for conveying and / or compressing a gaseous medium, in particular hydrogen, for a fuel cell system 31 is shown with a housing 3 and a drive 6, wherein the housing 3 has a housing upper part 7 and a housing lower part 8. The housing 3 also has a compressor chamber 30 extending around an axis of rotation 4, the compressor chamber having at least one circumferential side channel 19, 21, with a compressor wheel 2 located in the housing 3, the compressor wheel 2 being arranged rotatably around the axis of rotation 4 and driven by the drive 6, wherein the compressor wheel 2 has blades 5 arranged on its periphery in the region of the compressor chamber 30 and with a gas inlet opening 14 and a gas outlet opening 16 each formed on the housing 3, which are fluidically connected to one another 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 extend around the rotation axis 4 at least in a subregion of the housing 3 , wherein an interrupter region 15 is formed in the housing 3 in the region in which the at least one side channel 19 , 21 is not formed.

[0030] In addition Figure 1 , the drive 6 is designed as an axial field motor 6 having a stator 11 and a rotor 17, wherein the stator 11 and the rotor 17 are designed in a disk-shaped manner around the rotation axis 4, and wherein the stator 11 is arranged next to the rotor 17 in the direction of the rotation axis 4. In this case, the rotor 17 can be at least indirectly located on the hub 23 of the compressor wheel 2. In addition, Figure 1, it is shown that the side channel compressor 1 has a stator chamber 42 and a rotor chamber 44, wherein components of the drive 6 are at least partially arranged in these chambers 42, 44. In this case, the housing upper part 7 has a continuous wall 29, which is located between the stator chamber 42 and the rotor chamber 44 and causes their fluid separation. In addition, the stator chamber 42 is at least partially surrounded and / or enclosed by the stator housing 39. In this case, the housing lower part 8 has a cylindrical bearing pin 12, wherein the bearing pin 12 extends in the direction of the rotation axis 4, so that its circumferential side extends around the rotation axis 4, and wherein the first bearing 27 and / or the second bearing 47 are in contact with the circumferential side of the bearing pin 12 in the radial direction with respect to the rotation axis 4. In addition, the compressor wheel 2 can be connected to the respective bearings 27, 47 via the hub 23 and the hub 9. In this case, the drive 6 can be designed as an axial field motor 6, which has a stator 11 and a rotor 17, wherein the stator 11 and the rotor 17 are designed in a disk-shaped manner around the rotation axis 4, and wherein the stator 11 is arranged next to the rotor 17 in the direction of the rotation axis 4. In addition, the side channel compressor 1 has a cylindrical bearing pin 12, wherein the bearing pin 12 extends in the direction of the rotation axis 4 so that its circumferential side extends around the rotation axis 4. In this case, the first bearing 27 and / or the second bearing 47 are in contact with the circumferential side of the bearing pin 12 in the radial direction with respect to the rotation axis 4.

[0031] FIG. 2 shows a schematic cross-sectional view of a bearing according to the prior art. It is shown here that the at least one bearing 27, 47 has a bearing inner ring 22, a bearing outer ring 24 and a bearing cage 25 and / or rolling elements 13, which are located between the bearing inner ring 22 and the bearing outer ring 24. In addition, in the region of the end faces of the bearing inner ring 22 and the bearing outer ring 24, there are respectively sealing elements 26 that seal and / or limit the bearing inner chamber 40. The sealing element 26 generally has a sealing lip 36, which is connected to the steel back 28, for example, in that it is vulcanized on the steel back. The sealing element 26 is thus clamped in a kind of groove in the bearing outer ring 24. The sealing element 26 then acts like a common radial shaft sealing ring. It seals relative to the bearing inner ring 22.

[0032] 2 further shows that the bearing outer ring 24 is at least indirectly fixed to the compressor wheel 2 and rotates with it during operation of the side channel compressor 1. In this case, the sealing element 26 is fixed to the bearing outer ring 24, in particular in a form-fitting and / or material-locking and / or force-fitting manner, and rotates with the bearing outer ring 24 in the direction of rotation, wherein the sealing element 26 has a sealing lip 36 on its inner diameter, wherein at least partial sealing of the bearing inner chamber 40 is achieved by means of the sealing lip 36. In this case, the sealing lip 36 is in frictional contact with the bearing inner ring 22, so that it is a frictional sealing lip 36.

[0033] The bearing 27, 47 and / or the sealing element 26 shown in FIG. 2 may have certain disadvantages, wherein the sealing lip 36 shown may be damaged by the gaseous medium in the rotor chamber 44, which may at least partially contain hot water vapor, in particular having a temperature of more than 90 degrees Celsius. In this case, the elastomer 36 composed of FKM (Fluorkautschuk, fluororubber) is particularly susceptible to damage, whereby the service life of the sealing element 26 may be reduced and the probability of failure of the bearing 27, 47 and / or the side channel compressor 1 may be increased. In addition, the elastomer may swell by absorbing water and / or a significant loss of contact pressure and / or sealing action between the sealing element 26 and / or the bearing inner ring 22 may be expected.

[0034] Figure 3 A schematic sectional view of a bearing 27, 47 and / or a sealing element 26 according to a first embodiment of the present application is shown. In this case, the respective bearing 27, 47 has a bearing outer ring 24, a bearing inner ring 22 and a bearing inner chamber 40, which is sealed off from a rotor chamber 44 by means of at least one sealing element 26. In this case, the bearing inner chamber 40 can be sealed off from the rotor chamber 44 by the sealing element 26 in such a way that, depending on the operating state of the side channel compressor 1, either a frictional seal or a contactless seal can be established between the bearing inner ring 22 and the sealing element 26. In this case, the at least one bearing 27, 47 has a bearing inner ring 22, which is generally fixedly connected to the bearing pin 12 and thus fixed, wherein the bearing inner ring is connected to the bearing pin 12 in a form-fitting manner. In this case, it is generally a form-fitting and / or frictional closure extending in the axial direction with respect to the axis of rotation, which is applied to the bearing 27, 47, in particular the bearing inner ring 22, based on a spring preload and / or based on the attraction force of the magnetic rotor with the stator. The bearing pin 12 is part of the housing 3 and cannot rotate. The bearing outer 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 bearing outer ring 24 and the sealing element 26 are connected to the compressor wheel 2 so that they can rotate about the rotation axis 4, especially during operation of the side channel compressor 1, wherein the bearing inner ring 22 is fixed, especially fixed in a rotationally fixed manner to the bearing pin 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 region 35 on their side facing the rotation axis 4, which no longer extends at least approximately orthogonally to the rotation axis 4, but has a curved portion pointing away from the bearing interior 40 and / or points away from the bearing interior 40 in the end region.

[0035] also, Figure 3It is shown that the sealing element 26 has a steel back 28, a sealing sleeve 32 and an elastomeric element 34. The steel back 28 and the sealing sleeve 32 can be connected to each other via the elastomeric element 34 and / or the steel back 28 and the sealing sleeve 32 can be connected to the bearing outer ring 24 in a form-locking and / or force-locking and / or form-locking manner via the elastomeric element 34, wherein the elastomeric element 34 is inserted into a groove of the bearing outer ring 24. In the case of a stop state or low rotation speed of the side channel compressor 1 and / or the compressor wheel 2, in particular in the range of 100 revolutions per minute, the sealing sleeve 32 is in frictional contact and / or frictional contact and / or abutting against the bearing inner ring 22. As soon as the rotation speed increases further, the lubricating medium 43 in the inner chamber 40 of the bearing 27, 47 is transferred away from the bearing inner ring 22 to the bearing outer ring 24 due to the centrifugal force, because it rotates at least partially with the bearing outer ring 24. On the other hand, the sealing sleeve 32 moves away from the bearing inner ring 22 in the direction of the resultant force 41 toward the bearing outer ring 24 and / or toward the steel back 28, wherein the resultant force is in particular a centrifugal force. In this case, the sealing sleeve 32 loses direct contact, in particular frictional contact and / or frictional contact, with the bearing inner ring 22 and / or no longer abuts against it. Thus, a contactless seal is formed between the bearing inner ring 22 and the sealing element 26. The lubricating medium 43 cannot pass between the bearing inner ring 22 and the sealing sleeve 32 parallel to the axis of rotation 4 to reach the rotor chamber 44, because it has already moved away from the bearing inner ring 22 at least approximately orthogonally to the axis of rotation 4. It can thus be ensured that during the service life of the side channel compressor 1, no lubricating medium 43 is output to the anode gas, in particular in the compressor chamber 30 and / or the rotor chamber 44, and / or the lubricating medium 43 remains in the corresponding bearings 27, 47.

[0036] In addition, Figure 3 The corresponding sealing element 26 shown in the figure has a high material resistance to the gaseous medium to be conveyed, in particular compared to the sealing element 26 described in the prior art. Here, the sealing sleeve 32 is composed of PTFE (polytetrafluoroethylene), which has a high temperature resistance. As a result, the service life of the sealing sleeve 32 and / or the sealing element 26 and / or the bearings 27, 47 and / or the side channel compressor 1 can be increased. Another advantage of the contactless sealing according to the configuration of the present application based on the bearings 27, 47 and / or the sealing element 26 according to the first embodiment is that the mechanical efficiency of the side channel compressor 1 can be increased because the friction losses and heat losses of the frictional seal are avoided and / or reduced. This leads to a higher volume flow of the side channel compressor 1 while the electrical power remains unchanged.

[0037] Figure 4A schematic sectional view of a bearing 27, 47 and / or a sealing element 26 according to a second embodiment of the present application is shown. It is shown here that the bearing 27, 47 has largely the same components as the bearing 27, 47 and / or the sealing element 26 according to the first embodiment of the present application. Here, the sealing element 26 and / or the steel backing 28 and / or the sealing sleeve 32 have a bending region 35 on their side facing the rotation axis 4, which no longer extends at least approximately orthogonally to the rotation axis 4, but rather has a curvature toward the bearing interior 40 and / or is oriented toward the bearing interior 40 in the end region and / or extends into the bearing interior 40. In this case, either due to a resultant force 41, in particular a centrifugal force, and / or due to an overpressure 45 from the rotor chamber 44, the sealing sleeve 32 loses direct contact, in particular frictional contact and / or frictional contact, with the bearing inner ring 22, wherein the sealing sleeve 32 is pressed toward the steel backing 28 by the overpressure 45.

[0038] Figure 5 A schematic sectional view of a sealing element 26 is shown, with its steel back 28, elastomeric element 34 and sealing sleeve 32 in a first state. In this case, each 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 a disk-shaped region 33 and a curved region 35, which are particularly at least approximately orthogonal to the axis of rotation and surround the axis of rotation 4. In this case, the steel back 28 has a non-elastic material, particularly a metallic material, and the sealing sleeve 32 has an elastic material, particularly PTFE (polytetrafluoroethylene). In addition, the sealing element 26 has an elastomeric element 34, which in turn at least partially has FKM (fluororubber), wherein the formed sealing sleeve 32 is connected to the steel back 28 at least in the disk-shaped extending region 33 by means of the elastomeric element 34 in a form-locking and / or force-locking and / or at least partially material-locking manner.

[0039] like Figure 5 As shown, the sealing element 26 is designed such that the sealing sleeve 32 is in contact with the bearing inner ring 22 in the first state, in particular in the stopped state of the side channel compressor 1, so that the contact point 18 is formed between the bearing inner ring 22 and the sealing sleeve 32 and / or in particular in the bending region 35, but the sealing sleeve 32 is not in contact with the second contact surface 38 of the steel back 28 with the first contact surface 37. As a result, an at least approximately complete sealing of the bearing interior 40 can be achieved. In this case, the steel back 28 has a first radius 46 in the bending region 35 and the sealing sleeve 32 has a second radius 48 in its bending region 35.

[0040] Figure 6A schematic sectional view of a sealing element 26 is shown, with its steel backing 28, elastomeric element 34 and sealing sleeve 32 in a second position. The sealing sleeve 32 can be deformed in a bending region 35 in such a way that the sealing sleeve 32 is moved away from the bearing inner ring 22, especially during operation of the side channel compressor 1, by means of a resultant force 41 and / or pressure 45, especially a centrifugal force, acting on the sealing sleeve 32, so that the sealing sleeve 32 with its first contact surface 37 is in contact with and / or in contact with the second contact surface 38 of the steel backing 28. The centrifugal force can act radially outwards. The sealing element 26 is designed in such a way that, especially during operation of the side channel compressor 1, the sealing sleeve 32 is not in contact with the bearing inner ring 22 in the second position, so that a gap 10 is formed between the bearing inner ring 22 and the sealing sleeve 32.

Claims

1. A side channel compressor (1) for a fuel cell system (31), for conveying and / or compressing a gaseous medium, in particular hydrogen, the side channel compressor comprising: a housing (3) and a drive (6); a compressor chamber (30) extending around a rotation axis (4) in the housing (3), the compressor chamber having at least one surrounding side channel (19, 21); a rotor chamber (44) located in the housing (3) and a compressor wheel (2) located in the rotor chamber, the compressor wheel being arranged rotatably around the rotation axis (4) and being driven by the drive (6), wherein: The side channel compressor (1) has at least one bearing (27, 47) located on a cylindrical bearing pin (12), and wherein the corresponding bearing (27, 47) has a bearing outer ring (24), a bearing inner ring (22) and a bearing inner chamber (40), wherein the bearing inner chamber is sealed relative to the rotor chamber (44) by means of at least one sealing element (26), characterized in that the bearing inner chamber (40) can be sealed relative to the rotor chamber (44) by the sealing element (26) so that either a frictional seal or a contactless seal can be established between the bearing inner ring (22) and the sealing element (26) depending on the operating state of the side channel compressor (1).

2. The 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 wheel (2) so that they can rotate about the rotation axis (4), in particular during operation of the side channel compressor (1), wherein the bearing inner ring (22) is fixed, in particular fixedly fixed to the bearing pin (12) in a rotationally fixed manner, and / or does not rotate with the compressor wheel (2).

3. The side channel compressor (1) according to claim 1 or 2, characterized in that The corresponding 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 a disk-shaped region (33) surrounding the rotation axis (4) and a curved region (35), the disk-shaped region being at least approximately orthogonal to the rotation axis.

4. The side channel compressor (1) according to claim 2 or 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 (Polytetrafluorethylen).

5. The side channel compressor (1) according to claim 3 or 4, characterized in that The sealing element (26) has an elastomeric element (34) which comprises at least partially FKM (Fluorkautschuk), wherein the molded sealing sleeve (32) is connected to the steel backing (28) at least in the disk-shaped extending region (33) by means of the elastomeric element (34) in a form-fitting and / or force-fitting and / or at least partially materially bonded manner.

6. A side channel compressor (1) according to any one of claims 3 to 5, characterized in that The sealing element (26) is designed so that the sealing sleeve (32) is in contact with the bearing inner ring (22) in a first state, in particular when the side channel compressor (1) is stopped, so that a contact point (18) is formed between the bearing inner ring (22) and the sealing sleeve (32) and / or the first contact surface (37) of the sealing sleeve (32) is not in contact with the second contact surface (38) of the steel back (28), in particular in the bending area (35).

7. A side channel compressor (1) according to any one of claims 4 to 6, characterised in that The sealing sleeve (32) can be deformed in the bending region (35) in such a way that, in particular during operation of the side channel compressor (1), the sealing sleeve is moved away from the bearing inner ring (22) by means of a combined force (41) and / or pressure (45) acting on it, so that the sealing sleeve (32) is in contact with its first contact surface (37) and a second contact surface (38) of the steel back (28) with the combined force having in particular a centrifugal force.

8. A side channel compressor (1) according to any one of claims 3, 4, 5 or 7, characterised in that The sealing element (26) is designed so that the sealing sleeve (32) is not in contact with the bearing inner ring (22) in a second state, in particular during operation of the side channel compressor (1), so that a gap (10) is formed between the bearing inner ring (22) and the sealing sleeve (32).

9. Side channel compressor (1) according to any one of the preceding claims, characterized in that The cylindrical support pin (12) extends in the direction of the rotation axis (4) so ​​that the peripheral side surface of the support pin extends around the rotation axis (4), and wherein the first bearing (27) and / or the second bearing (47) are in contact with the peripheral side surface of the support pin (12) in the radial direction with respect to the rotation axis (4).

10. Side channel compressor (1) according to any one of the preceding claims, characterized in that The drive (6) is embodied as an axial field motor (6) having a stator (11) and a rotor (17), wherein the stator (11) and the rotor (17) are designed in a disk-shaped manner around an 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. A fuel cell system (31) comprising a side channel compressor (1) according to any one of claims 1 to 10, wherein: The side channel compressor (1) is arranged in the anode circuit of the fuel cell system (31).

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