Magnetic rotor arrangement for side channel compressor of fuel cell system, side channel compressor and method for producing magnetic rotor arrangement for side channel compressor of fuel cell system

Abstract

The invention relates to a magnetic rotor arrangement (2) for a side channel compressor (1) of a fuel cell system (31) for conveying and / or compressing a gaseous medium, in particular hydrogen, the magnetic rotor arrangement (2) being rotatably mounted about an axis of rotation (4) and / or being drivable by means of a drive (6). In this case, the magnetic rotor arrangement (2) has a compressor wheel (10), by means of which a gas flow can be generated, in particular in a compressor chamber (30), with a hub (9), a circuit ring (22) and at least one bearing (27, 47). According to the invention, the hub (9) has a recess (13) extending annularly about the axis of rotation (4). In this case, the component circuit ring (22) and the at least two segmented magnets (24), preferably four segmented magnets (24), are located at least almost completely in the cutout (13). The invention also relates to a side channel compressor (1) and / or a fuel cell system (31) having a magnetic rotor arrangement (2) according to the invention and / or a method for producing a magnetic rotor arrangement (2).

Description

Technical Field

[0001] The invention relates to a magnetic rotor arrangement for a side channel compressor of a fuel cell system, a side channel compressor and a method for producing a magnetic rotor arrangement for a side channel compressor of a fuel cell system. Background Art

[0002] In addition to liquid fuels, gaseous fuels will also play an increasingly important role in the automotive field in the future. In particular, the hydrogen flow must be controlled in vehicles with fuel cell drives. The gas flow is no longer discontinuously controlled as when injecting liquid fuels, but the gaseous medium is taken out from at least one high-pressure tank and guided to the injector unit via the inflow pipeline of the medium-pressure pipeline system. The injector 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, the gaseous medium is guided back to the injector unit via the return pipeline. A side channel compressor can be connected in the middle, which supports gas return in terms of fluid technology and efficiency. In addition, the side channel compressor is used to support the fluid establishment in the fuel cell drive, especially when the vehicle is (cold) started after a certain static time. These side channel compressors are usually driven by an electric motor, and when running in the vehicle, the electric motor is powered by the vehicle battery.

[0003] DE 10 2018 222 102 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 an upper housing part and a lower housing part; a compressor chamber extending in the housing around a rotation axis, the compressor chamber having at least one circumferential side channel; a compressor wheel located in the housing, which is rotatably arranged around the rotation axis and driven by the drive. The compressor wheel has blades arranged in the region of the compressor chamber on its periphery and has a gas inlet and a gas outlet formed on the housing, which are fluidically connected to each other via the compressor chamber, in particular at least one side channel, wherein the side channel compressor has at least one bearing. In addition, DE 10 2018 222 102 A1 shows that a rotor assembly, which can be embodied as a permanent magnet, is located on a drive flange corresponding to the hub.

[0004] The side channel compressor known from DE 10 2018 222 102 A1 may have disadvantages. The rotor assembly and / or the permanent magnet are located on the driving flange and are not encapsulated by the rotor chamber, in particular, the rotor assembly and / or the permanent magnet are not encapsulated by the rotor chamber fluid. When using the side channel compressor, hydrogen may penetrate into the rotor chamber and damage metal parts and / or the rotor assembly and / or the permanent magnet, in particular by hydrogen embrittlement. Failure of the rotor assembly and / or the permanent magnet may occur, so that the compressor wheel and / or the magnetic rotor device can no longer be driven by the drive, in particular by the stator and rotor assembly, so that the failure probability of the drive and thus the entire side channel compressor increases.

[0005] Another disadvantage of the side channel compressor known from DE 10 2018 222 102 A1 is that the return ring and / or the permanent magnet are pressed into the hub, in particular with their inner diameter forming a press fit with the hub, as a result of which the hub, in particular the bearing hole and / or the bearing seat, is deformed due to stress, making it necessary to reprocess the bearing hole and / or the bearing seat, which increases costs due to the additional process steps. Summary of the invention

[0006] According to the invention, a magnetic rotor arrangement for a side channel compressor of a fuel cell system is provided, which has the features of the independent patent claim, and which is used to convey and / or compress a gaseous medium, in particular hydrogen. In this case, the magnetic rotor arrangement is at least almost completely located in a rotor chamber and is rotatably mounted about an axis of rotation and / or can be driven by means of a drive. In this case, the magnetic rotor arrangement has a compressor wheel, by means of which a gas flow can be generated in particular in the compressor chamber, a hub, a return ring, and at least one bearing.

[0007] According to claim 1 , the hub has a recess which extends annularly around the axis of rotation and can be enclosed by the rotor chamber, wherein the component return ring and at least two segmented magnets, ideally four segmented magnets, are located at least almost completely in the recess.

[0008] In this way, on the one hand, the following advantages can be achieved: a compact and space-saving arrangement and construction of the magnetic rotor device can be achieved, since the component return ring and the segmented magnets can be integrated in the recess and therefore in the hub, whereby the magnetic rotor device is constructed narrower in the direction of the rotation axis than in the magnetic rotor devices of the prior art.

[0009] Furthermore, the following advantages can be achieved in this way: the components return ring and the segmented magnets can be encapsulated by the rotor chamber. It is thus possible to at least almost completely prevent hydrogen from the compressor chamber region from penetrating into the region of the rotor chamber and damaging the components return ring and the segmented magnets, thereby preventing damage to these components in particular due to hydrogen embrittlement. The failure probability of the magnetic rotor arrangement and / or the drive and / or the side channel compressor can thus be reduced, thereby increasing the service life of the magnetic rotor arrangement and / or the drive and / or the side channel compressor.

[0010] Advantageous embodiments of the magnetic rotor arrangement and / or of the side channel compressor specified in claim 1 are achieved by means of the measures listed in the dependent claims. The dependent claims relate to preferred embodiments of the invention.

[0011] According to an advantageous configuration of the magnetic rotor device, the return ring is connected to the hub by means of at least one threaded connection. In this way, the following advantages can be achieved: the return ring can be connected to the hub at low cost, and the connection can also be loosened again, for example, for maintenance measures. Here, the hub and / or the return ring are not damaged during disassembly. The failure probability of the bearing can also be improved, because compared with the return ring pressed into the hub, the tolerance of the bearing hole, especially the bearing seat in the inner diameter of the hub is at least almost unchanged by the threaded connection. This leads to an increase in the service life of the bearing and / or the hub and / or the magnetic rotor device and / or the side channel compressor. In addition, another method step of tightening with the hub by means of the return ring is prevented, because when the return ring is pressed into the hub, especially to form a press fit, the bearing hole and / or the bearing seat do not have to be reprocessed again, especially by means of a grinding process.

[0012] According to an advantageous extension of the magnetic rotor device, the notch is bounded orthogonally to the axis of rotation on the side facing away from the axis of rotation by a surrounding cylindrical flange and on the side facing the axis of rotation by a surrounding cylindrical extension of the hub. In this way, a compact structural form of the magnetic rotor device can be achieved, thereby reducing the structural dimensions of the entire side channel compressor. This in turn can reduce the required installation space of the side channel compressor in the entire vehicle. In addition, the return ring and / or each segmented magnet can be effectively encapsulated by the rotor chamber by means of a cylindrical extension and / or a cylindrical flange. By means of encapsulation, the component return ring and / or the segmented magnet can be prevented from being damaged by the components of the gaseous medium, for example due to hydrogen embrittlement by hydrogen contained in the gaseous medium. Therefore, the service life of the magnetic rotor device and / or the side channel compressor can be increased and the probability of failure can be reduced.

[0013] According to a particularly advantageous embodiment of the magnetic rotor device, the recess is open on its side facing the stator, in particular in the direction of the axis of rotation. In this way, a simple and cost-effective assembly of the return ring and / or the segmented magnet in the hub, in particular in the direction of the axis of rotation, can be achieved. The assembly costs and / or maintenance costs can be reduced, thereby reducing the manufacturing costs and / or operating costs of the magnetic rotor device and thus the side channel compressor. In addition, a compact design of the magnetic rotor device and the hub can be achieved.

[0014] According to an advantageous embodiment of the magnetic rotor arrangement, the gap open toward the stator is closed and / or encapsulated by means of an end plate. In this way, a cost-effective and effective encapsulation of the gap and the components located in the gap, in particular the return ring and the segmented magnets, can be achieved. This can prevent water and / or hydrogen from being able to penetrate from the region of the rotor chamber into the region of the gap and possibly damage the components located in the gap, for example due to hydrogen embrittlement and / or due to oxidation. As a result, the probability of failure of the magnetic rotor arrangement and / or the side channel compressor can be reduced, wherein the service life of the side channel compressor can be increased and / or improved.

[0015] According to an advantageous extension of the magnetic rotor device, the return ring has a bridge portion pointing in the direction of the axis of rotation, wherein the segmented magnets are respectively located in the intermediate space between the two bridge portions. In this way, the following advantages can be achieved: when the segmented magnets are loaded with force by means of a drive, the resulting torque, in particular due to the form-locking connection between the segmented magnets and the return ring, can be transmitted at least almost loss-free and reliably, so that the magnetic rotor device and / or the entire compressor wheel can be reliably driven and / or placed in a rotational movement by means of the drive. In addition, a compact and narrow structural form of the component return ring and the segmented magnets can be obtained, because the segmented magnets can be at least partially accommodated and installed in the return ring, in this way the magnetic rotor device and the side channel compressor can be constructed more narrowly.

[0016] According to a particularly advantageous expansion scheme of the magnetic rotor device, the cylindrical extension of the hub has a first external thread and the return ring has a first internal thread. Here, the first threaded connection is formed by the form-locking and / or force-locking of the first external thread and the first internal thread. In this way, the following advantages can be achieved: the reliable connection of the return ring and the hub can be achieved. This connection can be produced quickly and at low cost during assembly, wherein, when the return ring and / or each segmented magnet is damaged, this connection can be unclamped without destruction again, so that the corresponding damaged components can be replaced quickly and at low cost. Therefore, the service life of the magnetic rotor device and / or the side channel compressor can be improved.

[0017] According to an advantageous configuration of the magnetic rotor device, the cylindrical flange of the hub has a second internal thread and the return ring has a second external thread. Here, the second threaded connection is formed by the shape locking and / or force locking of the second external thread and the second internal thread. In this way, the following advantages can be achieved: the reliable connection of the return ring and the hub can be achieved. This connection can be produced quickly and at low cost during assembly, wherein, in the case where the return ring and / or each segmented magnet is damaged, the connection can be loosened without destruction again, so that the corresponding damaged components can be replaced quickly and at low cost. Therefore, the service life of the magnetic rotor device and / or the side channel compressor can be improved, wherein, the maintenance friendliness of the magnetic rotor device is also improved. In addition, the second threaded connection in the hub is not adjacent to the bearing hole, so that the bearing clearance or possible tolerance between the hub and the corresponding bearing will not be affected, especially when the return ring is screwed into the bearing. Therefore, the failure probability of the bearing can be reduced, because the bearing hole is at least almost not deformed after the return ring is assembled.

[0018] Since preferred areas of application of the magnetic rotor arrangement according to the invention are side channel compressors and / or fuel cell systems, a side channel compressor and / or a fuel cell system having a magnetic rotor arrangement according to the invention is also proposed.

[0019] According to the proposed advantageous configuration of the method for manufacturing a magnetic rotor device for a side channel compressor and / or a fuel cell system. A loop ring is provided, wherein the loop ring has at least two bridges, which extend in particular in the direction of the axis of rotation, and segmented magnets are respectively installed between these bridges. Then, each segmented magnet is connected to the loop ring, in particular the end face of the loop ring and / or to each bridge. The connection can be produced by a form-locking and / or material-locking and / or force-locking method to form a rotor assembly. The rotor assembly is then installed in the compressor wheel and fixed by at least one screw.

[0020] In a particularly advantageous embodiment of the method, it is provided that the end plate is attached to the flange and the extension by means of a material-bonding method, in particular laser welding.

[0021] The invention is not limited to the embodiments described herein and the aspects highlighted therein. Rather, numerous modifications are possible within the scope given by the claims, which are within the capabilities of the skilled person. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be described in more detail below with reference to the accompanying drawings.

[0023] The accompanying drawings show:

[0024] Figure 1 : A schematic cross-sectional view of a side channel compressor according to the present invention,

[0025] Figure 2 : A schematic cross-sectional view of a magnetic rotor arrangement having a compressor wheel, a hub, a return ring and at least one bearing,

[0026] Figure 3 : A perspective top view of a hub according to the invention with a return ring according to an exemplary embodiment, the return ring having four bridges and four corresponding segmented magnets,

[0027] Figure 4 : A three-dimensional cross-sectional view of a rotor assembly according to the present invention,

[0028] FIG5 : A cross-sectional view of a rotor assembly according to the prior art,

[0029] Figure 6 : A schematic cross-sectional view of a magnetic rotor device according to a first embodiment,

[0030] Figure 7 : A schematic cross-sectional view of a magnetic rotor device according to a second embodiment. DETAILED DESCRIPTION

[0031] From the basis Figure 1 A schematic sectional view of a side channel compressor 1 according to the invention can be seen in the drawing.

[0032] Here, in Figure 1 , a side channel compressor 1 for a fuel cell system 31 for conveying and / or compressing a gaseous medium, in particular hydrogen, is shown, the side channel compressor having a housing 3 and a drive 6, wherein the housing 3 has an upper housing part 7 and a lower housing part 8. The housing 3 also has a compressor chamber 30 extending around an axis of rotation 4, which has at least one circumferential side channel 19, 21, the side channel compressor having a magnetic rotor device 2 located in the housing 3, which is rotatably arranged around the axis of rotation 4 and is driven by the drive 6, wherein the magnetic rotor device 2 has blades 5 arranged on its circumference in the region of the compressor chamber 30, and the side channel compressor having a gas inlet 14 and a gas outlet 16, each of which is formed on the housing 3 and is fluidically connected to one another via the compressor chamber 30, in particular via 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 partial region of the housing 3 , wherein an interruption region 15 in the housing 3 is formed in the partial region of the housing 3 in which the at least one side channel 19 , 21 is not formed.

[0033] In addition, Figure 1, the drive 6 is designed as an axial field motor 6 having a stator 11 and a rotor component 17, wherein the stator 11 and the rotor component 17 are designed in a disk-shaped manner around the rotation axis 4, and wherein the stator 11 is arranged next to the rotor component 17 in the direction of the rotation axis 4. In this case, the rotor component 17 can be located at least indirectly on or in the hub 23 of the magnetic rotor device 2. Figure 1 It is also shown that the side channel compressor 1 has a stator chamber 48 and a rotor chamber 46, wherein the components of the drive 6 are at least partially arranged in these chambers 46, 48. In this case, the upper housing part 7 has a continuous wall 29, which is located between the stator chamber 48 and the rotor chamber 46 and causes the fluid separation thereof. In addition, the stator chamber 48 is at least partially surrounded and / or encapsulated by the stator housing 39. In this case, the lower housing 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 outer circumference extends around the rotation axis 4, and wherein the first bearing 27 and / or the second bearing 47 are in contact with the outer circumference of the bearing pin 12 radially relative to the rotation axis 4. In this case, the drive 6 can be designed as an axial field motor 6, which has a stator 11 and a rotor component 17, wherein the stator 11 is arranged next to the rotor component 17 in the direction of the rotation axis 4. Furthermore, 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 such that its outer circumference extends around the rotation axis 4. In this case, the first bearing 27 and / or the second bearing 47 are in contact with the outer circumference of the bearing pin 12 radially relative to the rotation axis 4.

[0034] exist Figure 2 , a schematic sectional view of a magnetic rotor device 2 with a compressor wheel 10, a hub 9, a return ring 22 and at least one bearing 27, 47 is shown. The magnetic rotor device 2 shown here is a component of a side channel compressor 1 for a fuel cell system 31, which is used to convey and / or compress a gaseous medium, in particular hydrogen. In this case, the magnetic rotor device 2 can be at least almost completely located in a rotor chamber 46 and can be rotatably supported about an axis of rotation 4 and can be driven by means of a drive 6. In this case, the magnetic rotor device 2 has a compressor wheel 10, by means of which a gas flow can be generated, in particular, in the compressor chamber 30. In addition, the magnetic rotor device 2 has a hub 9, a return ring 22 and at least one bearing 27, 47.

[0035] In addition, Figure 2, the hub 9 has a recess 13 which extends annularly around the rotation axis 4 and can be enclosed by a rotor chamber 46, wherein the component return ring 22 and at least two segmented magnets 24, ideally four segmented magnets 24 are at least almost completely located in the recess 13. However, in other exemplary embodiments, six or more segmented magnets 24 can also be located in the recess 13. Between the first bearing 27 and the second bearing 47, there can be a spacer disk 37 in the direction of the rotation axis 4, wherein the distance between the bearings 27, 47 can be adjusted by means of the spacer disk 37.

[0036] As in Figure 2 As shown in the figure, the rotor assembly 17 is connected to the compressor wheel 10 by means of at least one spring disk 33 and at least one screw 35. The recess 13 extends in a disk-like manner orthogonal to the rotation axis 4 and is bounded on its side facing away from the rotation axis 4 by a circumferential cylindrical flange 32 of the hub and on its side facing the rotation axis 4 by a circumferential cylindrical extension 34 of the hub 9. Here, the hub 9 forms a cylindrical flange 32 on its outer diameter facing away from the rotation axis 4 and has a cylindrical extension 34 on its inner diameter facing the rotation axis 4. In the inner diameter and / or the cylindrical extension 34, there is also a bearing hole 36 with a bearing seat 45.

[0037] Figure 2 The notch 13 is shown on its side facing the stator 11 (at Figure 1 ), in particular in the direction of the rotation axis 4. In an exemplary embodiment of the side channel compressor 1, the notch 13 is open toward the stator 11, wherein the notch 13 can be closed and / or encapsulated by means of an end plate 26. Here, the end plate 26 is mounted on the end face of the hub 9 facing the stator 11, wherein the end plate 26 is non-magnetic and can be mounted on the hub 9 by means of at least one laser weld. Here, the hub 9 and / or the return ring 22 and / or the segmented magnet 24 and / or the spring disk 33 and / or the screw 35 form the rotor assembly 17.

[0038] exist Figure 2The magnetic rotor device 2 shown in the figure can have a variety of materials. In an exemplary embodiment of the magnetic rotor device 2, the hub 9 can have an austenitic stainless steel, in particular X2CrNiMo17-12-2 (1.4404), and the return ring 22 can have a non-alloyed structural steel, in particular S235JR and / or St37 and / or St52, and / or a magnetic free-cutting steel, in particular 11SMn30. The segmented magnets can, for example, have NdFeB, and the end plate 26 can have an austenitic stainless steel, in particular X2CrNiMo17-12-2 (1.4404). In addition, before the component hub 9 and the compressor wheel 10 are in contact with their stepped extension, the compressor wheel 10, which can have aluminum and / or plastic and has a stepped shape, is placed on the hub 9 in the direction of the rotation axis 4 and then tightened by means of at least one spring disk 33 and at least one screw 35.

[0039] After this assembly step, in an exemplary embodiment, the magnetic rotor arrangement 2 can be balanced in order to keep the centrifugal forces low during operation. Here, material is removed from defined areas of the compressor wheel 10 and / or the hub 9. After balancing, the bearings 27, 47 and the spacer disks 37 are finally pressed in via the outer diameter. In an alternative embodiment, balancing can also be performed as a final manufacturing step.

[0040] Figure 3 A three-dimensional top view of a hub 9 according to the invention is shown according to an exemplary embodiment, which has a return ring 22 with four bridges 25 and four corresponding segmented magnets 24. It is shown here that the hub 9 has an extension 34 around the rotation axis 4 on its inner diameter facing the rotation axis 4, and the hub 9 has a flange 32 around the rotation axis 4 on its outer diameter facing away from the rotation axis 4. First, the return ring 22 is placed, in particular screwed into the recess 13 of the hub 9, wherein in this exemplary embodiment of the magnetic rotor device 2, the return ring 22 has a first bridge 25a, a second bridge 25b, a third bridge 25c and a fourth bridge 25d, which extend in particular in the direction of the rotation axis 4. In an alternative embodiment, the return ring 22 can have at least two bridges 25 or a plurality of bridges 25. In this case, a segmented magnet 24 around the rotation axis 4 is respectively present in the intermediate space between two bridges 25. In this exemplary embodiment of the magnetic rotor device 2 , the magnetic rotor device has a first segmented magnet 24 a , a second segmented magnet 24 b , a third segmented magnet 24 c and a fourth segmented magnet 24 d .

[0041] Here, two opposite segmented magnets 24 are respectively configured as north poles, and two opposite segmented magnets are respectively configured as south poles, so that on a circular orbit, one segmented magnet 24 always alternates as a north pole and a south pole on a circular orbit extending around the axis of rotation 4. These segmented magnets configured as circular segments can constitute an even number of magnetizable segmented magnets 24, which are placed on one side of the hub 9. There are bridges 25 between the circular segments 24, which can separate the segmented magnets 24 laterally (in radial rotation) from each other. The segmented magnets 24 must be fastened in the magnetic rotor device 2 in order to transmit the torque of the drive 6 and the optional axial magnetic force. This function is assumed by the return ring 22 fixedly connected to the hub 9.

[0042] Figure 4 The rotor assembly 17 according to the invention is shown in a perspective sectional view with an end plate 26. It is shown here that the end plate 26 in this exemplary embodiment of the magnetic rotor device 2 is mounted on the flange 32 (in the Figure 2 ) and on the extension 34, so that the notch 13 (in Figure 2 Here, the corresponding laser weld 38 in the flange 32 and / or the extension 34 can be formed around the rotation axis 4 (in Figure 2 2 and 3 ), which are formed by a plurality of spot laser welds 38 (shown in FIG. 1 ), which extend from the end plate 26 to the hub 9 in a pin-shaped manner and taper gradually. However, corresponding welds which are continuous around the axis of rotation 4 in the flange 32 and / or the extension 34 may also be provided.

[0043] FIG. 5 shows a rotor assembly 17 (in FIG. Figure 2 Here, the return ring 22 is pressed into the hub 9 in the area of ​​the surface 40 (in Figure 2 The bearing hole 36 is deformed by extrusion. Each bearing 27, 47 ( Figure 2 The subsequent assembly of the ball bearings 27, 47 shown), in particular the ball bearings 27, 47, can only be achieved with great difficulty due to the deformation in the area of ​​the surface 40 and may cause preliminary damage to the bearings 27, 47, so that the failure probability of the bearings 27, 47 and thus the entire side channel compressor 1 increases.

[0044] exist Figure 6 , a schematic sectional view of a rotor arrangement 2 according to a first embodiment is shown in FIG. 1 . Here, the cylindrical extension 34 of the hub 9 has a first external thread 41 and the return ring 22 has a first internal thread 42, wherein the first threaded connection 18 is formed by a form-locking and / or force-locking connection between the first external thread 41 and the first internal thread 42. For the manufacture of a side channel compressor 1 and / or a fuel cell system 31 (in Figure 1A possible manufacturing process and / or method of the magnetic rotor device 2 shown in FIG. 1 ) may be performed to form the magnetic rotor device 2 by performing the following steps:

[0045] - providing a return ring 22, wherein the return ring 22 has at least two bridges 25, between which a segmented magnet 24 can be mounted in each case,

[0046] - installing the return ring 22 in the recess 13 , wherein the return ring 22 is connected to the hub 9 by means of at least one threaded connection 18 , 28 ,

[0047] The segment magnets 24 are connected to the return ring 22 , in particular to the end faces of the return ring 22 and / or to the bridges 25 , by means of a form-fitting, material-locking or force-locking method to form the rotor assembly 17 .

[0048] As in Figure 6 As shown in , the fastening of the return ring 22 can be produced by means of the first threaded connection 18, while the bearing hole 36 of the hub 9 is not deformed. The bearing hole 36 is used as a bearing seat and therefore has very strict tolerance requirements. Here, the hub 9 is composed of relatively soft, non-magnetic, weldable austenitic stainless steel. The very small wall thickness in the area of ​​the surrounding cylindrical extension 34 is the reason why the bearing hole 36 can be deformed when the return ring 22 with high rigidity is pressed in in the prior art shown in Figure 5. Therefore, the deformation of the bearing hole 36 can be prevented by means of the configuration of the magnetic rotor device 2 with the screwed return ring 22 according to the present invention, which leads to a greatly reduced bearing clearance when pressing into each bearing 27, 47, which will have a negative impact on the service life of the bearing through temperature changes (especially at low temperatures). Therefore, due to the configuration of the magnetic rotor device 2 according to the present invention, it is no longer troublesome to grind the bearing hole 36 again after assembling the rotor assembly 17. The purpose is to design a connection in which the bearing hole 36 will not be deformed after assembly and does not require subsequent grinding of the bearing hole 36. The return ring 22 transmits the torque of the driver 6 to the compressor wheel 10 and must also absorb the axial forces of the stator 11. Deformations on the bearing seat and / or the bearing bore 36 are prevented by the threaded connection 18. The threaded connections 18, 28 can transmit the required axial forces and moments by suitable tightening torques. Advantageously, the service life of the bearings 27, 47 is increased and the magnetic rotor arrangement 2 can be manufactured more simply and at a lower cost, since the complex grinding process is eliminated.

[0049] Figure 7 1 shows a schematic cross-sectional view of a magnetic rotor device 2 according to a second embodiment. Here, the cylindrical flange 32 of the hub 9 has a second internal thread 43 and the return ring 22 has a second external thread 44, wherein the second threaded connection 28 is formed by a positive and / or non-positive fit of the second external thread 44 with the second internal thread 43. In this case, the second threaded connection 28 is produced in conjunction with the second internal thread 43. Figure 6 The same advantages as those already described above arise from the first threaded connection 18 .

Claims

1. A magnetic rotor arrangement (2) for a side channel compressor (1) of a fuel cell system (31), the side channel compressor being used for conveying and / or compressing a gaseous medium, in particular hydrogen, wherein: The magnetic rotor device (2) is rotatably supported about a rotation axis (4) and / or can be driven by means of a drive (6), wherein the magnetic rotor device (2) has a compressor wheel (10), by means of which a gas flow can be generated, in particular a gas flow in a compressor chamber (30), the magnetic rotor device having a hub (9), a return ring (22) and at least one bearing (27, 47), characterized in that the hub (9) has a notch (13) extending annularly about the rotation axis (4) and capable of being enclosed by the rotor chamber (46), wherein the component return ring (22) and at least two segmented magnets (24), ideally four segmented magnets (24), are at least almost completely located in the notch (13).

2. The magnetic rotor device (2) according to claim 1, characterized in that The return ring (22) is connected to the hub (9) by means of at least one threaded connection (18, 28).

3. The magnetic rotor device (2) according to claim 1 or 2, characterized in that The recess (13) is delimited orthogonally to the rotation axis (4) on its side facing away from the rotation axis (4) by a circumferential cylindrical flange (32) of the hub (9) and on its side facing the rotation axis (4) by a circumferential cylindrical extension (34) of the hub (9).

4. A magnetic rotor device (2) according to any one of the preceding claims, characterised in that The recess (13) is open on its side facing the stator (11), in particular in the direction of the axis of rotation (4).

5. The magnetic rotor device (2) according to any one of the preceding claims, characterized in that The opening (13) open toward the stator (11) is closed and / or encapsulated by means of an end plate (26).

6. A magnetic rotor device (2) according to any one of the preceding claims, characterised in that The return ring (22) has bridges (25) pointing in the direction of the rotation axis (4), wherein a segment magnet (24) is located in each of the intermediate spaces between two bridges (25).

7. The magnetic rotor device (2) according to claim 2, characterized in that The cylindrical extension (34) of the hub (9) has a first external thread (41) and the return ring (22) has a first internal thread (42), wherein the first threaded connection (18) is formed by a form-locking and / or force-locking connection between the first external thread (41) and the first internal thread (42).

8. The magnetic rotor device (2) according to claim 2, characterized in that The cylindrical flange (32) of the hub (9) has a second internal thread (43) and the return ring (22) has a second external thread (44), wherein the second threaded connection (28) is formed by a positive and / or non-positive connection between the second external thread (44) and the second internal thread (43).

9. A side channel compressor (1) having a stator (11) and a magnetic rotor arrangement (2) according to any one of claims 1 to 8.

10. A fuel cell system (31) having a side channel compressor (1) according to claim 9, wherein: The side channel compressor (1) is arranged in the anode circuit of the fuel cell system (31).

11. A method for producing a magnetic rotor arrangement (2) for a side channel compressor (1) and / or a fuel cell system (31) according to any of the preceding claims, comprising the following steps: - providing a return loop (22), wherein The return ring (22) has at least two bridge portions (25), between which segmented magnets (24) can be respectively installed. - installing the recirculation ring (22) in the recess (13) of the hub (9), wherein the recirculation ring (22) is connected to the hub (9) by means of at least one threaded connection (18, 28), - The segmented magnets (24) are connected to the return ring (22), in particular to the end face of the return ring (22) and / or to the bridges (25) by means of a form-locking, material-locking or force-locking method to form a rotor assembly (17).

12. The method according to claim 11, characterized in that The end plate (26) is mounted on the flange (32) and the extension (34) by means of a material-locking method, in particular laser welding.

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