Side channel compressor, fuel cell system and method for operating side channel compressor

Abstract

The invention relates to a side-channel compressor, comprising a housing having a first housing part with a bearing journal which extends along a rotational axis and which has a journal root section and a journal main section on which a bearing inner ring of a bearing device is arranged, and a second housing part with a bearing outer ring of a bearing device which extends along the rotational axis, a compressor wheel assembly having a compressor wheel is arranged in the housing on a bearing outer ring of the bearing device in a rotatable manner about an axis of rotation, and the first housing part is at least indirectly tensioned with the bearing device via a fastening element, a wave spring is arranged on the journal root section between a first contact surface of the bearing inner ring facing away from the fastening element and a second contact surface of the first housing part facing the fastening element, the wave spring being embodied and arranged on and / or around the bearing journal, in this way, the winding direction of the wave spring extends in the direction of the rotation direction of the compressor wheel assembly and / or the bearing inner ring during the operation of the side channel compressor.

Description

Technical Field

[0001] The invention relates to a side channel compressor for a fuel cell system for compressing a gaseous medium. The invention also relates to a fuel cell system having a side channel compressor according to the generic class. The invention also relates to a method for operating the side channel compressor. Background Art

[0002] Rising fuel prices and legal requirements to limit CO2 emissions have led car manufacturers to increasingly investigate drive systems that use renewable energy. Hydrogen technology is a promising approach for many reasons, since hydrogen is available almost unlimitedly as an energy carrier and does not produce harmful exhaust gases when burned.

[0003] The direct combustion of hydrogen is a highly complex and currently almost uncontrollable process, and drive systems are becoming increasingly important in which electrical energy is first generated using hydrogen, which can then be used to drive an electric motor for driving the motor vehicle. For this purpose, these drive systems have fuel cells.

[0004] According to the principle, the fuel cell system has a hydrogen inlet, through which hydrogen can be supplied to the fuel cell. The fuel cell system has an anode on the hydrogen inlet side. In order to supply oxygen, the fuel cell system has an oxygen inlet. On the oxygen inlet side, the fuel cell system has a cathode. Finally, the fuel cell system has an exhaust gas outlet for discharging the exhaust gas of the fuel cell. Here, the exhaust gas is mainly water and unconsumed air as a combustion product of the fuel cell. Since not all hydrogen supplied to the fuel cell can be burned during the reaction in the fuel cell, unburned or unconsumed hydrogen is also present in the exhaust gas.

[0005] In order to reduce the hydrogen consumption in fuel cells, it is now common to recirculate the unconsumed hydrogen. For this recirculation, a recirculation blower is used, which sometimes has a so-called "side channel compressor".

[0006] Side channel compressors are known in various embodiments. A side channel compressor is a turbocompressor which can be divided into “planetary wheel compressors” and “peripheral wheel compressors” depending on the impeller used and the fluid guidance.

[0007] The fluid to be delivered is supplied to the working chamber of the side channel compressor via an inlet connection, which is coupled to the exhaust gas outlet of the fuel cell system in a fluidic manner for this purpose. The compressor wheel assembly of the side channel compressor, which is designed as an impeller, is arranged in the working chamber and can be driven and thus rotated by means of an electric motor. The compressor wheel assembly rotates to an axially arranged flow channel, which is lateral to one side or to both sides and is also referred to as a "side channel".

[0008] In this way, the rotating compressor wheel assembly transfers energy to a portion of the delivery flow. The fluid circulates in the blades of the compressor wheel assembly and in the side channel, and forms a circulating flow. Energy is transferred from the circulating flow to the delivery flow in the side channel by pulse exchange. Thus, velocity energy is converted into pressure energy. Here, this energy transfer takes place several times over the entire length of the side channel, so that a large energy transfer can be achieved. As a result, a pressure increase occurs at the outlet connection of the side channel compressor compared to the inlet connection.

[0009] DE 10 2022 212 235, which has not been previously published, shows a side channel compressor for a fuel cell system for compressing a gaseous medium, the side channel compressor having a housing with a first housing part and a second housing part. In this case, the first housing part has a bearing journal, which extends along an axis of rotation R, the bearing journal having a journal root section and a journal main section, wherein an inner bearing ring of a bearing device is arranged on the journal main section, wherein a compressor wheel assembly with a compressor wheel is arranged in the housing in a manner rotatable about the axis of rotation R on an outer bearing ring of the bearing device, wherein the first housing part is at least indirectly braced to the bearing device via a fastening element. In this case, a spring element is arranged on the journal root section between a first contact surface of the bearing inner ring facing away from the fastening element and a second contact surface of the first housing part facing toward the fastening element. The described side channel compressor has the following disadvantages: In certain operating states of the side channel compressor and / or when a wide temperature range is experienced and / or when the compressor wheel assembly is not properly axially fixed by means of fastening elements, it may occur that the corresponding bearing inner ring rotates with the compressor wheel during operation of the side channel compressor. This can lead to damage to the first contact surface of the bearing inner ring and / or the spring element in the contact area. In addition, this can lead to the following disadvantages: the spring element is also set in a rotational motion by the rotating bearing inner ring, wherein this leads to damage to the spring element and / or to damage to the second contact surface of the first housing part in the corresponding contact area. In addition, the spring element can be damaged by the rotation of the bearing inner ring because the spring element rotates. This is the case in particular when the spring element is embodied as a wave spring and is arranged on and / or around the bearing journal in such a way that the winding direction of the wave spring corresponds to the direction of rotation of the compressor wheel assembly and / or the bearing inner ring during operation of the side channel compressor. Here, the wave spring can bear against the corresponding contact surface with the edge of the first or second end side of the starting section and / or the end section in such a way that wear occurs on the friction pair, in particular on the bearing inner ring and / or on the first housing part, or even hooking of the edge on the friction pair occurs, which can lead to unscrewing of the wave spring, resulting in serious damage and / or failure of the wave spring and thus of the side channel compressor. In addition, unscrewing of the wave spring can lead to the winding of the wave spring coming into contact with components located further outside (for example, a bearing seal) and damaging these components. This can lead to a complete failure of the side channel compressor. Summary of the invention

[0010] The invention relates to a side channel compressor for compressing a fluid for a fuel cell system and to a fuel cell system having a side channel compressor. Further features and details of the invention are apparent from the description and the drawings. Features and details described in the context of the side channel compressor according to the invention are of course also applicable in the context of the fuel cell system according to the invention and vice versa, so that reference is always made to one another or can be made to one another with regard to the disclosure of the individual inventive aspects.

[0011] According to a first aspect of the present invention, a side channel compressor for compressing a gaseous medium for a fuel cell system is provided. The side channel compressor has a housing, which has a first housing part and a second housing part, wherein the first housing part has a bearing journal, which extends along a rotation axis R, and the bearing journal has a journal root section and a journal main section. An inner bearing ring of a bearing device is arranged on the journal main section, wherein a compressor wheel assembly with a compressor wheel is arranged on an outer bearing ring of the bearing device in a manner that can rotate around the rotation axis R in the housing.

[0012] The housing is formed by a first housing part and a second housing part. According to the invention, it can be provided, but not necessarily required, that the first housing part and / or the second housing part have further housing parts, which can be designed in particular as a housing cover, a housing wall or the like. Preferably, the first housing part defines a preassembled assembly of the side channel compressor, which assembly has a bearing device and a compressor wheel assembly. A working chamber for the compressor wheel assembly is formed by the housing, preferably by the mutual cooperation of the first housing part and the second housing part.

[0013] Preferably, the working chamber is designed to be fluid-tight, except for the working chamber inlet and the working chamber outlet. In the context of the present invention, fluid-tight is also understood to mean that the tightness is maintained at an operating pressure of the side channel compressor that is higher than the ambient pressure. In order to ensure the tightness, preferably a sealing device, such as a sealing ring, in particular a sealing ring made of silicone or rubber or the like, is arranged between the first housing part and the second housing part. Preferably, the first housing part is formed essentially or predominantly from aluminum. Preferably, the second housing part is formed essentially or predominantly from aluminum.

[0014] The bearing journal is constructed as a sub-region of the first housing part and extends away from the inner wall of the first housing part, in particular the second contact surface. According to the present invention, the bearing journal is constructed integrally with the first housing part. Alternatively, the bearing journal can also be arranged on the first housing part in a material-locked manner (for example, by welding) or force-locked manner (for example, by tightening or pressing). The bearing journal extends from the inner wall of the first housing part from the journal root section via the journal main section to the journal end section. The journal end section has a journal tensioning section. Preferably, the journal end section is constructed as a journal tensioning section.

[0015] The bearing device has a bearing inner ring and a bearing outer ring. Preferably, a plurality of rolling bodies, such as balls, rollers, barrels or the like, are arranged between the bearing inner ring and the bearing outer ring so as to support the bearing outer ring on the bearing inner ring as close to play as possible and ensure relative rotation between the bearing inner ring and the bearing outer ring.

[0016] The bearing inner ring of the bearing device is arranged on the main journal section, preferably with a loose fit. It is also possible to arrange a plurality of bearing inner rings on the main journal section, preferably each with a loose fit. The loose fit is preferably designed such that when the tension is released, an easy movement of the bearing device on the bearing journal is ensured, for example manually, and a tilting of the bearing inner ring on the bearing journal is prevented.

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

[0018] According to the invention, the side channel compressor is constructed in such a way that the wave spring is designed and arranged on and / or around the bearing journal so that the winding direction of the wave spring corresponds to the direction of rotation of the compressor wheel assembly and / or the inner ring of the bearing when the side channel compressor is in operation. In this way, the following advantages can be achieved: the wave spring is prevented from hooking into the corresponding contact surface with the edges of the first and / or second end sides of the starting section and / or the end section, because the wave spring does not extend against the direction of rotation of the corresponding friction pair. In addition, it is prevented that the wave spring with its end face edges damages the friction pair and causes material erosion when the friction pair rotates and / or when the wave spring rotates on the stationary friction pair. Therefore, damage to the friction pair can be prevented, and failure of the wave spring and thus the side channel compressor can also be prevented. In addition, unscrewing the wave spring can cause the winding of the wave spring to contact and damage components located further outside (for example, bearing seals). Therefore, the service life of the spring element and therefore the service life of the entire side channel compressor can be increased.

[0019] According to an advantageous embodiment of the side channel compressor, the wave spring with its starting section at least partially bears against a first contact surface of the bearing inner ring and with its ending section at least partially bears against a second contact surface of the first housing part, wherein the ending direction of the wave spring 18 extends at least approximately in the direction of the relative movement direction of the respective contact surfaces. In this way, the following advantage can be achieved: the wave spring cannot hook with its starting section or its ending section, in particular with the edges of the first and / or second end face in these regions, on the first or second contact surface, in particular in the case of high surface roughness. This is achieved in such a way that the ending direction of the wave spring and the relative movement direction of the friction pair extend at least approximately in the same direction, so that the wave spring with its starting section and / or with its ending section can be prevented from warping and / or hooking on the friction pair and thus unscrewing of the wave spring can be prevented. In this way, the probability of damage to the spring element can be reduced, thereby reducing the probability of failure of the entire side channel compressor.

[0020] According to an advantageous extension of the side channel compressor, the wave spring has a curved shaped portion in its respective starting section and / or end section, so that a contact-free area is formed. In this way, the following advantages can be achieved: the wave spring does not directly contact and / or abut against the bearing inner ring or the first housing part at least with its respective ends, in particular the starting section and / or end section, in which the end has an edge and a corresponding end face. Here, the wave spring contacts the corresponding contact surface in a point-like manner by means of the curved shaped portion, thereby reducing the probability of the wave spring hooking and / or hooking on the bearing inner ring and on the first housing part. Here, the wave spring is prevented from "rotating with" the bearing inner ring, which can rotate in a rotating manner relative to the bearing journal in a certain operating state of the side channel compressor. In this way, the service life of the spring element and / or the bearing seal and / or the bearing device can be achieved, thereby reducing the probability of failure of the side channel compressor.

[0021] According to a particularly advantageous extension of the side channel compressor, the spring element has a magnetic material, in particular a ferromagnetic material or chrome steel. In this way, the following advantages can be achieved: the wave spring can be heated inductively by means of an induction field without the need for electrical contacts, such as in the form of sliding contacts / in the form of carbon brushes. Sliding contacts are necessary because relative movement of the wave spring relative to the housing and / or the side channel compressor can occur, but this unfavorable embodiment can be prevented by means of the embodiment of the wave spring composed of ferromagnetic material according to the present invention. Here, so-called eddy currents are generated in the region of the wave spring by means of the generated alternating magnetic field. The alternating field or induction field itself can be realized, for example, by the stator of the drive and the corresponding control of the stator. However, alternatively, an induction field can also be generated by other electrical components of the side channel compressor, which heats the ferromagnetic wave spring. In addition, the heat energy transfer from the wave spring to other components of the side channel compressor can be realized, such as the inner ring of the bearing. Therefore, the failure of the spring element due to "unscrewing" or due to damage caused by freezing and / or ice bridges can be reduced, thereby improving the service life of the side channel compressor.

[0022] According to a particularly advantageous embodiment of the side channel compressor, the first contact surface and / or the second contact surface is machined, in particular finish-machined, such that the surface roughness R in these regions is aaaa This can achieve the following advantages: Due to the reduced surface roughness, the probability of the wave spring warping or hooking at the edges or end faces, especially at the ends of the starting section and / or the end section, can be reduced. The corresponding contact surface has a lower surface roughness R aaaaAnd smoother, thus can prevent the hooking or warping of the wave spring, so that the risk of the wave spring unscrewing can be at least almost prevented. Therefore, the failure probability of the wave spring and / or the damage of the surrounding components can be reduced, thus, the service life of the entire side channel compressor can be increased.

[0023] According to a particularly advantageous development of the side channel compressor, the bearing arrangement has two rolling bearings which are arranged side by side along the axis of rotation, wherein a spacer disk is located between the rolling bearings, wherein in particular the bearing outer ring bears against the spacer disk axially with respect to the axis of rotation. This has the advantage that pivoting of the compressor wheel assembly with respect to the axis of rotation R can be avoided more effectively by simple means and in a cost-effective manner. As a result, the wear of the bearing arrangement can be reduced and the service life of the bearing arrangement can be increased. Furthermore, the smooth running of the side channel compressor can be improved in this way.

[0024] In the fuel cell system according to the invention, all the advantages already described for the side channel compressor according to the first aspect of the invention are produced. Therefore, compared with conventional fuel cell systems, the fuel cell system according to the invention has the following advantages: by means of simple means and in a cost-effective manner, an improved arrangement of the bearing device on the bearing journal of the side channel compressor is ensured. By arranging the journal tensioning section next to the bearing device, the widening of the bearing journal caused by the different thermal expansion coefficients of these components during tensioning or when the side channel compressor is running can be avoided or at least significantly reduced. Therefore, the load on the bearing device can be reduced, and in this way, the service life of the bearing device can be significantly extended compared with conventional side channel compressors. In addition, the fuel cell system according to the invention has a particularly simple assembly and disassembly of the side channel compressor, and can therefore be assembled cost-effectively and is very maintenance-friendly. In addition, the fuel cell system according to the invention has particularly low operating noise.

[0025] According to an advantageous method for operating a side channel compressor, in particular in the context of a cold start procedure, an induction field, in particular an induction magnetic field, is constructed by energizing the stator, wherein the induced energy is thereby transferred to the wave spring. In an exemplary embodiment of the method, the coils of the stator can be energized for a short period of time, so that the wave spring heats up due to the generated power loss. Furthermore, in another possible embodiment, the stator can be energized by means of an advantageous method in such a way that an induced heating of the wave spring occurs. Any ice bridges present in the region of the wave spring melt as a result, and the liquid changes from a solid aggregate state to a liquid aggregate state and can be discharged, for example by means of a purge valve and / or a drain valve present in the fuel cell system. In this way, the service life of the side channel compressor and / or the fuel cell system can be increased.

[0026] According to the present invention, the fuel cell system can also be configured as a fuel cell stack composed of a plurality of fuel cells. Preferably, the fuel cell stack has an exhaust gas outlet, and the side channel compressor according to the present invention is coupled to the exhaust gas outlet in fluid communication. The working chamber inlet of the side channel compressor is coupled to the exhaust gas outlet in fluid communication, so that the exhaust gas can be supplied to the working chamber of the side channel compressor from the exhaust gas outlet. Preferably, the fuel cell system has a water separator, which is preferably arranged before the side channel compressor in the flow direction. Preferably, the working chamber outlet of the side channel compressor is coupled to the hydrogen inlet in fluid communication, so that hydrogen can be supplied from the side channel compressor to the fuel cell or the fuel cell of the fuel cell stack.

[0027] The invention is not limited to the embodiments described herein and the aspects emphasized therein. On the contrary, numerous modifications within the scope of a person skilled in the art can be realized within the scope given by the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

[0029] The accompanying drawings show:

[0030] Figure 1 A side channel compressor according to the prior art is shown in a sectional view.

[0031] Figure 2 The side channel compressor is shown in cross section. Figure 1 The fragment marked with II in the embodiment of the present invention has at least one bearing and a wave spring,

[0032] Figure 3 exist Figure 2 The top view marked with AA in FIG. 1 shows a wave spring according to the present invention according to the prior art,

[0033] Figure 4 The side channel compressor is shown in a cross-sectional view. Figure 2 The fragment marked with III in FIG. 1 has a wave spring and a contact pair, which is in particular a bearing inner ring or a first housing part according to the prior art,

[0034] Figure 5 The side channel compressor according to the invention is shown in a sectional view. Figure 2 The fragment marked with IV in FIG. 1 has a wave spring, a bearing inner ring and a first housing part,

[0035] Figure 6 The side channel compressor according to the invention is shown in a sectional view. Figure 5 The fragment marked with V has a wave spring and a bearing inner ring.

[0036] Figure 7 The side channel compressor according to the invention is shown in a sectional view. Figure 2 The fragment marked with VI in FIG. 1 has a wave spring and a first housing part.

[0037] Components with the same function and mode of action are Figures 1 to 7 The same reference numerals are respectively provided in the figures. DETAILED DESCRIPTION

[0038] exist Figure 1 , a side channel compressor 1 according to the prior art is schematically shown in a sectional view. The side channel compressor 1 has a housing having a first housing part 3 and a second housing part 4. The first housing part 3 has a bearing journal 5 and a bearing device 9, which extends in the direction of the second housing part 4 and is arranged on the bearing journal 5, which has two rolling bearings 20a, b. In this case, the first bearing 20a and the second bearing 20b of the bearing device 9 are arranged side by side in the direction of the rotation axis R. In addition, a spacer disk 15 is located between the rolling bearings 20a, b, wherein in particular the bearing outer rings 11a, b are in axial contact with the spacer disk 15 with respect to the rotation axis R. The bearing inner ring 8 of the bearing device 9 is arranged on the bearing journal 5. The compressor wheel assembly 10 having a compressor wheel 34 is arranged on the bearing outer ring 11 of the bearing device 9. In addition, the side channel compressor 1 has a compressor chamber 36, which extends around the rotation axis R and has at least one surrounding side channel 35.

[0039] like Figure 1As shown, the bearing journal 5 has a blind hole in which a fastening element 28, in particular a tensioning screw 28, is arranged. The bearing 20 is at least indirectly tensioned to the first housing part 3 via the tensioning screw 28 and the spring element 18, in particular a wave spring 18, wherein the first housing part 3 is at least indirectly tensioned to the bearing device 9 via the fastening element 28. In this case, the stop disk 19 can be arranged in the direction of the rotation axis R between the fastening element 28, in particular the enlarged screw head, and the bearing journal 5 and / or the corresponding bearing inner ring 8.

[0040] In this case, by screwing in the tensioning bolts 28, a prestressing force 39 acting parallel to the axis of rotation R is applied to the bearing device 9. It is also shown that in the direction of the axis of rotation R, four axial gaps 33a, b, c, d are located in the region between the compressor wheel assembly 10 and the respective housing component 3, 4, wherein the axial gaps 33a, b, c, d enclose the compressor chamber 36. The bearing journal 5 has a journal root section 6 and a journal main section 7, which is in contact with the second contact surface 17 (at the bottom of the first housing component 3) of the first housing component 3. Figure 2 ), which is directly adjacent to the journal root section 6. Two bearing inner rings 8 of two rolling bearings 20 are arranged on the journal main section 7.

[0041] Figure 2 The side channel compressor 1 is shown in a sectional view. Figure 1 The fragment marked with II in FIG. 1 has at least one bearing 20 and a wave spring 18. It is shown here that the second bearing 20b has a bearing outer ring 11b and a bearing inner ring 8b. Here, the bearing outer ring 11b is in contact with the spacer disk 15 in the direction of the rotation axis R. Here, at least one bearing seal 42 is located between the bearing inner ring 8b and the bearing outer ring 11b in order to achieve the encapsulation of the bearing interior space, wherein in particular, the lubricating material is prevented from flowing out of the bearing interior space, but also the bearing interior space is prevented from being contaminated by particles outside the corresponding bearing 20. Here, the bearing inner ring 8b is at least indirectly in contact with the wave spring 18 in the direction of the rotation axis R. The wave spring is supported on the first contact surface 40 of the bearing inner ring 8b on one side and on the second contact surface 17 of the first housing component 3 on the other side. The bearing arrangement 9 has two rolling bearings 20 a, b which are arranged next to each other along the rotation axis R, wherein a spacer disk 15 is located between the rolling bearings 20 a, b, wherein in particular the bearing outer rings 11 a, b bear axially with respect to the rotation axis R against the spacer disk 15 .

[0042] like Figure 2 As shown, the wave spring 18 acts at least approximately in the direction of the rotation axis R at one or more contact points 12, 14 (at Figure 5 ) in the region shown in FIG. Here, a corresponding wear region 41 can be constructed in which the spring element 18, which is made of a harder material than the friction pair, damages the friction pair 8b, 3 and can lead to material erosion, especially in the corresponding wear region 41. Here, if the bearing inner ring 8b, which should not rotate on the bearing journal 5 during normal operation, still rotates at a certain operating point of the side channel compressor 1, increased wear may occur. This rotation can lead to significant wear on the bearing inner ring 8b and / or on the wave spring 18. In addition, in one embodiment, the spring element 18, which is constructed as a wave spring 18, can be unscrewed by rotating the bearing inner ring 8b. The unscrewed winding may damage the bearing seal 42 and may also destroy the entire wave spring 18.

[0043] Figure 3 exist Figure 2 The top view marked with AA in FIG. 1 shows a wave spring 18 according to the invention according to the prior art. It is shown here that the wave spring 18 has an end on the side facing the bearing inner ring 8, which end has at least one end side 22. In addition, the wave spring 18 has a starting section 23, which runs in a closing direction 13. Here, the closing direction 13 runs in the winding direction 16 of the wave spring 18 in this starting section 23, but opposite to the relative movement direction 21 of the contact pair 3, 8 and / or opposite to the rotation direction 31 of the side channel compressor 1 and therefore the bearing inner ring 8 that rotates with it. Here, the wave spring 18 has an edge 26 on its first end side 22. Here, the edge 26 is located at the corner of the first end side 22 facing the friction pair 3, 8.

[0044] exist Figure 4 The side channel compressor 1 is shown in a sectional view. Figure 2The fragment marked with III in FIG. 1 has a wave spring 18 and a contact pair 3, 8, which is in particular a bearing inner ring 8 or a first housing part 3 according to the prior art. It is shown here that the wave spring 18 has an end on the side facing the bearing inner ring 8 or the first housing part 3, which has a corresponding first and / or second end side 22, 24. Here, the corresponding first and / or second end side 22, 24 extends at least almost parallel to the rotation axis R and / or the corresponding first and / or second end side 22, 24 extends at least almost orthogonally to the first contact surface 40 and / or the second contact surface 17, with which the wave spring 18 is in contact. On the one hand, here, the wave spring 18 has a starting section 23 in the following area: in this area, the wave spring 18 has an end area, which extends in the end direction 13a and is in contact with the first contact surface 40 of the bearing inner ring 8. On the other hand, the wave spring 18 has an end section 25 in the region in which the wave spring 18 has an end region which extends in the end direction 13b and abuts against the second contact surface 17 of the first housing part 13. The end direction 13a in this starting section 23 is in the winding direction 16 of the wave spring 18 (in Figure 3 ), but opposite to the relative movement direction 21 of the abutment pairs 3, 8 and / or opposite to the rotation direction 31 of the side channel compressor 1 and therefore of the rotating bearing inner ring 8.

[0045] In addition, Figure 4It is shown that the wave spring 18 is in contact with the first contact surface 40 or the second contact surface 17 with the edge 26 of the first and / or second end side 22, 24, in particular with the stamped edge 26, so that under high surface roughness and / or in the case of recesses and / or grooves extending at least approximately in the direction of the edge 26, in particular the stamped edge 26, the wave spring 18 is hooked or warped on the corresponding contact surfaces 40, 17 of the contact pair via the edge 26 of the corresponding first and / or second end side 22, 24. In the first exemplary case, it is possible that when the bearing inner ring 8 is rotated in a certain operating state, the bearing inner ring 8 rotates in the rotational direction 31, wherein due to the rotational movement of the bearing inner ring 8 in the rotational direction 31, the bearing inner ring moves in the relative movement direction 21 toward the first end side 22 of the wave spring 18, wherein the relative movement direction 21 of the bearing inner ring 8 runs opposite to the end direction 13 of the wave spring 18 and / or runs in the opposite direction of the end direction 13 of the wave spring 18. In the second exemplary case, it is possible that when the bearing inner ring 8 is rotated in a certain operating state, the wave spring 18 also rotates and rotates, which causes the wave spring 18 to move with the end section 25 along the first housing part 3 in such a way that the wave spring 18 runs opposite to the end direction 13 and / or runs in the opposite direction of the relative movement 21.

[0046] Figure 5 The side channel compressor 1 according to the invention is shown in a sectional view. Figure 2, which has a wave spring 18, a bearing inner ring 8 and a first housing part 3. It is shown here that the wave spring 18 is arranged in the direction of the rotation axis R between the bearing inner ring 8 and the first housing part 3, in particular between a first contact surface 40 of the bearing inner ring 8 and a second contact surface 17 of the first housing part 3. The wave spring 18 is designed and / or arranged around the bearing journal 5 in such a way that the winding direction 16 of the wave spring extends in the direction of the rotation direction 31 of the compressor wheel assembly 10 and / or the bearing inner ring 8 during operation of the side channel compressor 1. The wave spring 18 at least partially rests with a starting section 23 on the first contact surface 40 of the bearing inner ring 8 and at least partially rests with an end section 25 on the second contact surface 17 of the first housing part 3. The wave spring 18 has a first bend region 30, in particular on the side facing the bearing inner ring 8. Here, the wave spring 18 rests with the first contact point 12 at the start section 23 against the first contact surface 40. The wave spring 18 rests with the second contact point 14 at the end section 25 against the second contact surface 17. In addition, the wave spring 18 has, in particular on the side facing the first housing part 3, a second bend region 32. In addition, the spring element 18 comprises a magnetic material, in particular a ferromagnetic material. In addition, the first contact surface 40 and / or the second contact surface 17 can be processed, in particular fine-machined, so that the surface roughness R in these areas 40, 17 is aaaa Reduce.

[0047] Figure 6 The side channel compressor 1 according to the invention is shown in a sectional view. Figure 5, which is marked with a V, has a wave spring 18 and a bearing inner ring 8. It is shown here that the wave spring 18 has a curved shaped portion 29a in its respective starting section 24, so that a contact-free region 27a is formed, in particular between the wave spring 18 and the first contact surface 40 of the bearing inner ring 8. However, here the wave spring 18 rests with the first contact point 12 against the first contact surface 40 of the bearing inner ring 8 in the direction of the rotation axis R. Here, the wave spring 18 extends with its starting area and / or its starting section 23 in the end direction 13a, wherein the end direction 13a extends at least approximately in the direction of the relative movement direction 21a of the first contact surface 40. Here, the wave spring 18 is designed and arranged on and / or around the bearing journal 5 in such a way that its winding direction 16 corresponds to the direction of rotation 31 of the compressor wheel assembly 10 and / or the bearing inner ring 8 during operation of the side channel compressor 1. Here, the first contact point 12 of the wave spring 18 with its starting section 23 rests against the first contact surface 40 of the bearing inner ring 8 , while the wave spring 8 with the curved formed portion 29 a of the starting section 23 does not rest against the first contact surface 40 and does not contact it.

[0048] like Figure 6 As shown, in the configuration according to the invention of the side channel compressor 1 and / or of the wave spring 18, on the one hand, the end direction 13a extends at least approximately in the direction of the relative movement 21a and / or in the direction of rotation 31 of the bearing inner ring 8, and on the other hand, the wave spring 18 has a curved shaped portion 29a, by means of which the configuration according to the invention can prevent the wave spring 18 from contacting and / or warping with its first end side 22 and / or the edge 26a of its first end side 22 on the first contact surface 40 and / or hooking on the first contact surface. In this way, the following advantages can be achieved: the wave spring 18 is prevented from rotating with the bearing inner ring 8, especially in the case of further hooking on the first housing part 3, which would stop the first housing part and thus could cause the wave spring 18 and other surrounding components to unscrew and thus be damaged. Failure of the wave spring 18 and / or the side channel compressor 1 can thus be prevented.

[0049] Figure 7 The side channel compressor 1 according to the invention is shown in a sectional view. Figure 5VI in FIG. 1 , which has a wave spring 18 and a first housing part 3. It is shown here that the wave spring 18 has a curved shaped portion 29b in its end section 25, so that a contact-free region 27b is formed, in particular between the wave spring 18 and the second contact surface 17 of the first housing part 3. However, the wave spring 18 is in contact with the second contact surface 17 of the first housing part 3 in the direction of the rotation axis R with the second contact point 14. Here, the wave spring 18 extends with its end region and / or its end section 25 in the end direction 13b, wherein the end direction 13b extends at least approximately in the direction of the relative movement direction 21b of the second contact surface 17. Here, the wave spring 18 is designed and arranged on and / or around the bearing journal 5 in such a way that the winding direction 16 of the wave spring corresponds to the direction of rotation 31 of the compressor wheel assembly 10 and / or the bearing inner ring 8 during operation of the side channel compressor 1. Here, the second contact point 14 of the end section 25 of the wave spring 18 bears against the second contact surface 17 of the first housing part 3 , while the curved shaped portion 29 b of the end section 25 of the wave spring 8 does not bear against the second contact surface 17 and does not contact it.

[0050] like Figure 7 As shown, in the configuration according to the invention of the side channel compressor 1 and / or of the wave spring 18, on the one hand, the end direction 13b extends at least approximately in the direction of the relative movement 21a of the first housing part 3, in particular in the direction of the relative movement relative to the surface 17, and on the other hand, the wave spring 18 has a curved shaped portion 29b, by means of which the configuration according to the invention can prevent the wave spring 18 from contacting and / or warping and / or hooking on the second contact surface 17 with its second end side 24 and / or the edge 26b of its second end side 24. In this way, the following advantage can be achieved: when the wave spring 18 rotates with the bearing inner ring 8, it is prevented that the wave spring 18 and other surrounding components are unscrewed and thus damaged when the wave spring 18 further hooks on the stationary first housing part 3. Therefore, failure of the wave spring 18 and / or the side channel compressor 1 can be prevented.

Claims

1. A side channel compressor (1) for compressing a gaseous medium for a fuel cell system (2), the side channel compressor having a housing, the housing having a first housing part (3) and a second housing part (4), wherein: The first housing part (3) has a bearing journal (5), which extends along an axis of rotation (R), the bearing journal having a journal root section (6) and a journal main section (7), wherein an inner bearing ring (8) of a bearing device (9) is arranged on the journal main section (7), wherein a compressor wheel assembly (10) having a compressor wheel (34) is arranged in the housing on a bearing outer ring (11) of the bearing device (9) in a manner rotatable about the axis of rotation (R), wherein the first housing part (3) is at least indirectly braced to the bearing device (9) via a fastening element (28), wherein A wave spring (18) is arranged on the journal root section (6) between a first contact surface (40) of the bearing inner ring (8) facing away from the fastening element (28) and a second contact surface (17) of the first housing component (3) facing the fastening element (28), characterized in that the wave spring (18) is designed and arranged on the bearing journal (5) and / or around the bearing journal so that the winding direction (16) of the wave spring extends in the direction of rotation (31) of the compressor wheel assembly (10) and / or the bearing inner ring (8) when the side channel compressor (1) is in operation.

2. The side channel compressor (1) according to claim 1, characterized in that The wave spring (18) at least partially bears with a starting section (23) against a first contact surface (40) of the bearing inner ring (8) and at least partially bears with an ending section (25) against a second contact surface (17) of the first housing part (3), wherein the ending direction (13a, b) extends at least approximately in the direction of the relative movement direction (21) of the corresponding contact surfaces (17, 40).

3. The side channel compressor (1) according to claim 1 or 2, characterized in that: The wave spring (18) has a curved formation (29) in its respective starting section (23) and / or end section (25), so that a contact-free region (27) is formed.

4. A side channel compressor (1) according to any one of the preceding claims, characterised in that The spring element (18) comprises a magnetic material, in particular a ferromagnetic material.

5. The side channel compressor (1) according to any one of claims 2 to 4, characterized in that The first contact surface (40) and / or the second contact surface (17) are processed, in particular finish-processed, such that the surface roughness R in these areas (40, 17) is aaaa Reduce.

6. A side channel compressor (1) according to any one of the preceding claims, characterised in that The bearing device (9) has two rolling bearings (20a, b) which are arranged side by side along the rotation axis (R), wherein a spacer disk (15) is located between the rolling bearings (20a, b), wherein in particular the bearing outer ring (11a, b) abuts against the spacer disk (15) in the axial direction with respect to the rotation axis (R).

7. A fuel cell system (2) having a side channel compressor (1) according to any one of claims 1 to 6, wherein: The side channel compressor (1) is arranged in the anode circuit of the fuel cell system (2).

8. A method for operating a side channel compressor (1) according to any one of the preceding claims, in particular within the scope of a cold start procedure, characterized in that By energizing the stator (12), an induction field, in particular an induction magnetic field, is generated, wherein the induction energy is thereby transferred to the wave spring (18).

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