Side channel compressor for a fuel cell system for conveying and / or compressing a gaseous medium, fuel cell system, method for operating the side channel compressor

Abstract

Side channel compressor (1) for a fuel cell system (2) for compressing a gaseous medium, comprising a housing with a first housing part (3) and a second housing part (4), wherein the first housing part (3) has a bearing journal (5) extending along an axis of rotation (R) with a journal root section (6) and a journal main section (7), wherein a bearing inner ring (8) of a bearing device (9) is arranged on the journal main section (7), wherein a compressor wheel assembly (10) with a compressor wheel (34) is rotatably arranged inside the housing on a bearing outer ring (11) of the bearing device (9) about the axis of rotation (R), wherein the first housing part (3) is clamped at least indirectly to the bearing device (9) via a fastening element (28),wherein a wave spring (18) is arranged on the pin 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 part (3) facing the fastening element (28). According to the invention, the wave spring (18) is designed and arranged on and / or around the bearing journal (5) such that its winding direction (16) corresponds to a direction of rotation (31) of the compressor wheel assembly (10) during operation of the side channel compressor (1). The invention further relates to a fuel cell system (2) with a side channel compressor (1) according to the invention and a method for operating the side channel compressor (1).

Description

[0001] The present invention relates to a side-channel compressor for a fuel cell system for compressing a gaseous medium. The invention further relates to a fuel cell system with a side-channel compressor of the type described above. The invention also further relates to a method for operating the side-channel compressor. State of the art

[0002] Rising fuel prices and legal requirements to limit CO2 emissions are prompting automakers to increasingly focus on drive systems powered by renewable energy sources. Hydrogen technology offers a promising approach for several reasons, as hydrogen is available as an energy carrier in virtually unlimited quantities and its combustion produces no harmful emissions.

[0003] While the direct combustion of hydrogen is a highly complex and currently difficult-to-control process, drive systems are gaining increasing importance in which hydrogen is first used to generate electrical energy, which can then be used to power an electric motor to drive the vehicle. These drive systems utilize a fuel cell for this purpose.

[0004] By design, fuel cell systems have a hydrogen inlet through which hydrogen is supplied to the fuel cell. On the hydrogen inlet side, fuel cell systems have an anode. For the supply of oxygen, fuel cell systems have an oxygen inlet. On the oxygen inlet side, fuel cell systems have a cathode. Finally, fuel cell systems have an exhaust outlet for releasing exhaust gases from the fuel cell. These consist primarily of water as a combustion product of the fuel cell and unburned air. Since not all of the hydrogen supplied to the fuel cell is combustible during the reaction within the fuel cell, the exhaust gases also contain unburned or unused hydrogen.

[0005] To reduce hydrogen consumption in the fuel cell, it is now common practice to recirculate the unused hydrogen. Recirculation fans are used for this recirculation, some of which incorporate so-called "side channel compressors".

[0006] Side channel compressors are available in various designs. They are a type of centrifugal compressor, which can be further subdivided into "star-type compressors" and "peripheral-type compressors" based on the impeller used and the fluid flow.

[0007] The fluid to be pumped is fed into the working chamber of the side-channel compressor via an inlet nozzle, which is fluidly coupled to the exhaust outlet of the fuel cell system. Within this working chamber is a compressor wheel assembly of the side-channel compressor, designed as an impeller, which is driven by an electric motor and thus rotatable. The compressor wheel assembly rotates towards axially arranged, lateral flow channels, also referred to as "side channels".

[0008] In this way, the rotating compressor wheel assembly transfers energy to a portion of the delivery flow. The fluid circulates within the blades of the compressor wheel assembly and in the side channels, forming a circulation flow. Energy from this circulation flow is transferred to the delivery flow in a side channel via momentum exchange. This process converts kinetic energy into pressure energy. The energy transfer occurs multiple times along the entire length of the side channel, enabling a significant energy transfer. Consequently, a pressure increase results at the outlet port of the side channel compressor compared to the inlet port.

[0009] The unpublished German patent application DE 10 2022 212 235 discloses a side-channel compressor for a fuel cell system for compressing a gaseous medium, comprising a housing with a first housing part and a second housing part. The first housing part has a bearing journal extending along an axis of rotation R, with 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, and a compressor wheel assembly with a compressor wheel is rotatably arranged inside the housing on an outer bearing ring of the bearing device about the axis of rotation R, wherein the first housing part is clamped to the bearing device at least indirectly via a fastening element.A spring element is arranged at the stub 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 described side-channel compressor can have the disadvantage that, under certain operating conditions of the side-channel compressor and / or when operating through a wide temperature range and / or if the compressor wheel assembly is not axially fixed by means of the fastening element, the respective bearing inner ring can rotate 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.Furthermore, the rotating inner bearing ring can cause the spring element to rotate, potentially damaging the spring element and / or the second contact surface of the first housing part in the respective contact area. Additionally, the rotation of the inner bearing ring can damage the spring element, as it rotates along with the bearing. This is particularly true if the spring element is a wave spring and is positioned on and / or around the bearing journal in such a way that its winding direction is opposite to the direction of rotation of the compressor wheel assembly and / or the inner bearing ring during operation of the side-channel compressor.The wave spring can, with an edge of a first or second end face of a starting section and / or an end section, bear against the respective contact surface in such a way that wear occurs on the friction partner, particularly on the inner bearing ring and / or the first housing part, or the edge can even catch on the friction partner, which can lead to the wave spring twisting. This can result in severe damage and / or failure of the wave spring and thus of the side channel compressor. Furthermore, twisting of the wave spring can cause a coil of the wave spring to come into contact with components located further out, such as a bearing seal, and damage this component. This can lead to complete failure of the side channel compressor. Disclosure of the invention

[0010] The present invention relates to a side-channel compressor for a fuel cell system for compressing a fluid, comprising the features of independent claim 1, and to a fuel cell system comprising a side-channel compressor comprising the features of dependent claim 7. Further features and details of the invention will become apparent from the dependent claims, the description, and the drawings. Features and details described in connection with the side-channel compressor according to the invention naturally also apply in connection with the fuel cell system according to the invention, and vice versa, so that the disclosure relating to the individual aspects of the invention always refers, or can refer, to each other.

[0011] According to a first aspect of the invention, a side-channel compressor for a fuel cell system is provided for compressing a gaseous medium. The side-channel compressor has a housing comprising a first housing part and a second housing part, the first housing part having a bearing journal extending along an axis of rotation R, with a journal root section and a journal main section. An inner bearing ring of a bearing assembly is arranged on the journal main section, wherein a compressor wheel assembly with a compressor wheel is rotatably arranged inside the housing on an outer bearing ring of the bearing assembly about the axis of rotation R.

[0012] The housing is formed by the first housing part and the second housing part. According to the invention, it may be provided, but is not mandatory, that the first housing part and / or the second housing part comprise further housing parts, which may be designed, in particular, as a housing cover, housing wall, or the like. Preferably, the first housing part defines a pre-assembled assembly of the side channel blower, which includes the bearing device and the compressor wheel assembly. The housing, preferably through the interaction of the first housing part with the second housing part, forms a working space for the compressor wheel assembly.

[0013] The working chamber is preferably designed to be fluid-tight, apart from a working chamber inlet and a working chamber outlet. Within the scope of the invention, "fluid-tight" also means that the tightness is maintained even at a higher operating pressure of the silk channel compressor than the ambient pressure. To ensure tightness, sealing devices, such as sealing rings, particularly made of silicone or rubber, or the like, are preferably provided between the first housing part and the second housing part. The first housing part is preferably made essentially or predominantly of aluminum. The second housing part is preferably made essentially or predominantly of aluminum.

[0014] The bearing journal is formed as a partial section of the first housing part and extends from an inner wall, in particular a second contact surface, of the first housing part. According to the invention, the bearing journal is formed monolithically with the first housing part. Alternatively, the bearing journal can also be attached to the first housing part by a material bond, for example by welding, or by a force bond, for example by bolting or pressing. The bearing journal extends from the inner wall of the first housing part from the journal root section, through the main journal section, to the journal end section. The journal end section includes the journal clamping section. Preferably, the journal end section is designed as a journal clamping section.

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

[0016] The inner bearing ring of the bearing assembly is arranged on the main journal section, preferably in a loose fit. Several inner bearing rings can also be arranged on the main journal section, preferably each in a loose fit. The loose fit is preferably designed such that, when the clamping force is released, the bearing assembly can be easily moved on the journal, for example manually, and tilting of the inner bearing ring on the journal is prevented.

[0017] The compressor wheel assembly is arranged on the outer bearing ring of the bearing assembly, preferably in an interference fit. The interference fit is preferably designed such that displacement of the compressor wheel assembly on the bearing assembly is prevented by frictional engagement. Alternatively, the compressor wheel assembly can be arranged on the outer bearing ring in a loose fit and secured against axial slippage from the bearing assembly by retaining means.

[0018] With reference to claim 1, the side channel compressor is designed such that a wave spring is configured and arranged on and / or around the bearing journal such that its winding direction corresponds to a direction of rotation of the compressor wheel assembly and / or the inner bearing ring during operation of the side channel compressor. This prevents the wave spring from engaging with an edge of a first and / or second end face of a starting section and / or an end section on a respective contact surface, since the wave spring does not run opposite to the direction of rotation of the respective friction partner. Furthermore, it prevents the wave spring from damaging the friction partner and causing material loss when the friction partner is rotating and / or when the wave spring is rotating on its own against a stationary friction partner.This prevents damage to the friction partner as well as failure of the wave spring and thus of the side channel compressor. Furthermore, twisting the wave spring can cause a coil of the wave spring to come into contact with components located further out, such as a bearing seal, and damage these components. This can increase the service life of the spring element and therefore of the entire side channel compressor.

[0019] The measures listed in the dependent claims enable advantageous further developments of the conveying device specified in claim 1. The dependent claims relate to preferred further developments of the invention.

[0020] According to an advantageous embodiment of the side-channel compressor, the wave spring, with its initial section, is at least partially in contact with a first contact surface of the bearing inner ring and with its end section with the second contact surface of the first housing part, wherein the runout direction of the wave spring 18 extends at least nearly in the direction of a relative direction of movement of the respective contact surface. In this way, the advantage can be achieved that the wave spring, with its initial section or its end section, in particular the edge of a first and / or second end face in these areas, cannot become entangled with the first or second contact surface, especially in the case of high surface roughness.This is achieved by ensuring that the discharge direction of the wave spring and the relative direction of movement of the friction partner are at least nearly identical, thus preventing the wave spring from tilting and / or catching on the friction partner with its initial and / or final section, and consequently preventing it from twisting. This reduces the likelihood of damage to the spring element, thereby lowering the probability of failure of the entire side-channel compressor.

[0021] According to an advantageous embodiment of the side-channel compressor, the wave spring has a curved shape in its respective initial and / or final sections, creating a contactless area. This achieves the advantage that the wave spring, at least at one end, particularly the initial and / or final sections where it has the edge and the respective end face, is not in direct contact with the inner bearing ring or the first housing part. The curved shape of the wave spring makes point contact with the respective contact surface, thereby reducing the likelihood of the wave spring catching or jamming on the inner bearing ring and the first housing part.This prevents the wave spring from rotating with the inner bearing ring, which could otherwise rotate relative to the bearing journal under certain operating conditions of the side-channel compressor. This extends the service life of the spring element and / or the bearing seal and / or the bearing assembly, thereby reducing the probability of side-channel compressor failure.

[0022] According to a particularly advantageous embodiment of the side-channel compressor, the spring element comprises a magnetic material, in particular a ferromagnetic material or chromium steel. This allows the wave spring to be inductively heated by means of an induction field without the need for an electrical contact, for example, a sliding contact such as a carbon brush. The sliding contact would be necessary because relative movement of the wave spring to the housing and / or side-channel compressor can occur, but this disadvantageous feature can be prevented by the wave spring made of a ferromagnetic material according to the invention. In this process, so-called eddy currents are generated in the area of ​​the wave spring by means of an alternating magnetic field.This alternating field, or the induction field itself, can be generated, for example, by a stator of the drive and a corresponding control signal for this stator. Alternatively, the induction field that heats the ferromagnetic wave spring can also be generated by another electrical component of the side channel blower. Furthermore, heat energy can be transferred from the wave spring to other components of the side channel blower, such as the inner bearing ring. This reduces the risk of spring element failure due to "unwinding" or damage from freezing and / or ice bridges, thereby improving the service life of the side channel blower.

[0023] According to a particularly advantageous embodiment of the side channel blower, the first contact surface and / or the second contact surface are machined, in particular finely machined, such that the surface roughness R ain these areas. This offers the advantage that, due to the reduced surface roughness, the likelihood of the wave spring tilting or catching on the edge or end face, particularly at the end of the initial and / or final sections, is reduced. The respective contact area is therefore smaller due to the lower surface roughness R. a The smoother surface prevents the wave spring from catching or tilting, thus virtually eliminating the risk of it twisting. This reduces the likelihood of wave spring failure and / or damage to surrounding components, thereby extending the service life of the entire side channel compressor.

[0024] According to a particularly advantageous embodiment of the side-channel blower, the bearing assembly comprises two rolling bearings arranged side by side along the axis of rotation, with a spacer disc located between the rolling bearings. In particular, the outer rings of the bearings are in axial contact with the spacer disc relative to the axis of rotation R. This has the advantage that pivoting of the blower wheel assembly relative to the axis of rotation R is better prevented in a simple and cost-effective manner. Wear of the bearing assembly is thus reduced, and its service life is increased. Furthermore, the smooth running of the side-channel blower is improved in this way.

[0025] The fuel cell system according to the invention offers all the advantages already described for a side-channel blower according to the first aspect of the invention. Accordingly, the fuel cell system according to the invention has the advantage over conventional fuel cell systems that an improved arrangement of the bearing device on the bearing journal of the side-channel blower is ensured in a simple and cost-effective manner. By arranging the journal clamping section next to the bearing device, expansion of the bearing journal during clamping or operation of the side-channel blower due to differing coefficients of thermal expansion of these components can be avoided or at least significantly reduced. The load on the bearing device is thus reduced, and its service life can be considerably extended compared to conventional side-channel blowers.Moreover, the fuel cell system according to the invention features particularly easy assembly and disassembly of the side channel compressor and is therefore cost-effective to install and very easy to maintain. Furthermore, the fuel cell system according to the invention exhibits particularly low operating noise.

[0026] According to an advantageous method for operating the side-channel compressor, particularly during a cold start procedure, an induction field, especially an inductive magnetic field, is generated by energizing the stator, thereby resulting in an inductive energy transfer to the wave spring. In an exemplary embodiment of the method, the stator coils can be energized briefly, causing the wave spring to heat up due to the resulting power loss. Furthermore, in another possible embodiment, the stator can be energized by an advantageous method in such a way that the wave spring is inductively heated.This melts any ice bridges that may be present in the area of ​​the wave spring, and the fluid changes from a solid to a liquid state and can be discharged, for example, via a purge valve and / or 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 extended.

[0027] According to the invention, the fuel cell can also be configured as a fuel cell stack consisting of a plurality of fuel cells. It is preferred that the fuel cell stack has an exhaust gas outlet with which the side channel compressor according to the invention is fluidly coupled. The working chamber inlet of the side channel compressor is fluidly coupled to the exhaust gas outlet, so that exhaust gas from the exhaust gas outlet can be supplied to the working chamber of the side channel compressor. Preferably, the fuel cell system includes a water separator, which is preferably arranged upstream of the side channel compressor in the flow direction. The working chamber outlet of the side channel compressor is preferably fluidly coupled to the hydrogen inlet, so that hydrogen from the side channel compressor can be supplied to the fuel cell or fuel cells of the fuel cell stack.

[0028] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, within the scope specified by the claims, a multitude of modifications are possible that fall within the bounds of what is considered skilled in the art. Brief description of the drawing

[0029] The invention is described in more detail below with reference to the drawing.

[0030] It shows: Fig. 1 in a sectional view a side channel blower according to the state of the art, Fig. 2 in a sectional view, one in Fig. 1 Section of the side channel compressor designated II, comprising at least one bearing and a wave spring, Fig. 3 in one in Fig. 2 Top view labelled AA the wave spring according to the invention in accordance with the prior art, Fig. 4 in a sectional view, one in Fig. 2 Section of the side channel compressor designated III with the wave spring and a system partner, in particular a bearing inner ring or a first housing part according to the prior art, Fig. 5 in a sectional view, one in Fig. 2 Section of the side channel compressor according to the invention, designated IV, with the wave spring, the inner bearing ring and the first housing part, Fig. 6 in a sectional view, one in Fig. 5 section of the side channel compressor according to the invention, designated V, with the wave spring and the inner bearing ring, Fig. 7 in a sectional view, one in Fig. 2 Section of the side channel compressor according to the invention, designated VI, with the wave spring and the first housing part.

[0031] Elements with the same function and mode of operation are in the Fig. Numbers 1 to 7 are each labelled with the same reference symbols.

[0032] In Fig. Figure 1 is a side-channel blower 1 according to the prior art, schematically depicted in a sectional view. The side-channel blower 1 has a housing with a first housing part 3 and a second housing part 4. The first housing part 3 has a bearing journal 5 extending towards the second housing part 4 and a bearing assembly 9 arranged on the bearing journal 5 with two rolling bearings 20a, b. The first bearing 20a and the second bearing 20b of the bearing assembly 9 are arranged side by side in the direction of an axis of rotation R. In addition, a spacer 15 is located between the rolling bearings 20a, b, with the outer bearing rings 11a, b being in axial contact with the spacer 15 and the axis of rotation R. Inner bearing rings 8 of the bearing assembly 9 are arranged on the bearing journal 5. A compressor wheel assembly 10 with a compressor wheel 34 is arranged on the outer bearing rings 11 of the bearing device 9.Furthermore, the side channel compressor 1 has a compressor chamber 36 extending around the axis of rotation R, which has at least one circumferential side channel 35.

[0033] As in Fig. As shown in Figure 1, the bearing journal 5 has a blind hole in which a fastening element 28, in particular a clamping bolt 28, is arranged. The bearings 20 are at least indirectly clamped to the first housing part 3 via the clamping bolt 28 and a spring element 18, in particular a wave spring 18, wherein the first housing part 3 is at least indirectly clamped to the bearing assembly 9 via the fastening element 28. A stop washer 19 can be arranged in the direction of the axis of rotation R between the fastening element 28, in particular an enlarged screw head, and the bearing journal 5 and / or the respective inner bearing ring 8.

[0034] By screwing in the clamping bolt 28, a preload force 39 acting parallel to the axis of rotation R is applied to the bearing device 9. Furthermore, it is shown that four axial gaps 33a, b, c, d are located in the direction of the axis of rotation R in the area between the compressor wheel assembly 10 and the respective housing part 3, 4, wherein the axial gaps 33a, b, c, d enclose the compressor chamber 36. The bearing journal 5 has a second contact surface 17 (shown in Fig. 2) of the first housing part 3 directly adjacent to the journal root section 6 and to a journal main section 7 directly adjacent to the journal root section 6. Two inner bearing rings 8 of two rolling bearings 20 are arranged on the journal main section 7.

[0035] Fig. Figure 2 shows a cross-sectional view of a [unclear] in Fig. Figure 1, labeled II, shows a section of the side-channel compressor 1 with at least one bearing 20 and the wave spring 18. The second bearing 20b is shown to have the outer bearing ring 11b and the inner bearing ring 8b. The outer bearing ring 11b is in contact with the spacer 15 in the direction of the axis of rotation R. At least one bearing seal 42 is located between the inner bearing ring 8b and the outer bearing ring 11b to encapsulate the bearing interior, thereby preventing, in particular, the escape of lubricant from the bearing interior and also preventing contamination of the bearing interior by particles from outside the respective bearing 20. The inner bearing ring 8b is in contact with the wave spring 18, at least indirectly, in the direction of the axis of rotation R.The wave spring 18 is supported on one side by a first contact surface 40 of the inner bearing ring 8b and on the other side by the second contact surface 17 of the first housing part 3. The bearing device 9 has two rolling bearings 20a, b arranged side by side along the axis of rotation R, wherein the spacer disk 15 is located between the rolling bearings 20a, b, wherein in particular the outer bearing rings 11a, b are in axial contact with the spacer disk 15 to the axis of rotation R.

[0036] As in Fig. As shown in Figure 2, the wave spring 18 acts with a spring force acting at least nearly in the direction of the axis of rotation R. In the area of ​​one or more contact points 12, 14 (shown in Figure 2) Fig. 5) the wave spring 18 with the first contact surface 40 and / or the second contact surface 17. A wear zone 41 can form in this area, where the spring element 18, which is made of a harder material than the friction partners, damages the friction partners 8b, 3 and can lead to material loss, particularly in the respective wear zone 41. Increased wear can occur if the inner bearing ring 8b, which should not rotate on the bearing journal 5 during normal operation, rotates at certain operating points of the side channel compressor 1. This rotation can lead to significant wear on the inner bearing ring 8b and / or on the wave spring 18. Furthermore, the spring element 18, which in an exemplary embodiment is designed as a wave spring 18, can unwind due to the rotation of the inner bearing ring 8b. This unwound winding could damage the bearing seal 42 or even destroy the entire wave spring 18.

[0037] Fig. 3 shows in a in Fig. Figure 2, labelled AA, shows the wave spring 18 according to the prior art. It is shown that the wave spring 18 has an end with a first end face 22 on the side facing the inner bearing ring 8. Furthermore, the wave spring 18 has a starting section 23 that extends in a run-out direction 13. The run-out direction 13 extends in the direction of a winding direction 16 of the wave spring 18 in this starting section 23, but opposite to a relative direction of movement 21 of the mating partner 3, 8 and / or opposite to the direction of rotation 31 of the side channel compressor 1 and thus of the rotating inner bearing ring 8. The wave spring 18 has an edge 26 on its first end face 22. The edge 26 is located on the corner of the first end face 22 facing the mating partner 3, 8.

[0038] In Fig. 4 in a sectional view, one in Fig. Figure 2 shows a section of the side-channel compressor 1, designated III, with the wave spring 18 and a mating component 3, 8, in particular the inner bearing ring 8 or the first housing part 3, according to the prior art. It is shown that the wave spring 18 has an end with a first and / or second end face 22, 24 on the side facing the inner bearing ring 8 or the first housing part 3. The respective first and / or second end face 22, 24 extends at least nearly parallel to the axis of rotation R and / or the respective first and / or second end face 22, 24 extends at least nearly orthogonally to the first contact surface 40 and / or to the second contact surface 17 with which the wave spring 18 is in contact. Firstly, the wave spring 18 has an initial section 23 in the area where the wave spring 18 has a tapered section that tapers out in the tap direction 13a and is in contact with the first contact surface 40 of the bearing inner ring 8.Secondly, the wave spring 18 has an end section 25 in which the wave spring 18 has a tapered section that extends in the taper direction 13b and is in contact with the second contact surface 17 of the first housing part 3. The taper direction 13a runs in the direction of the winding direction 16 (shown in ). Fig. 3) the wave spring 18 in this initial section 23, but opposite to the relative direction of movement 21 of the system partner 3, 8 and / or opposite to the direction of rotation 31 of the side channel compressor 1 and thus of the rotating bearing inner ring 8.

[0039] Furthermore, in Fig. Figure 4 shows that the wave spring 18 with the edge 26, in particular with a punched edge 26, of the first and / or second end face 22, 24 is in contact with the first contact surface 40 or the second contact surface 17 in such a way that, in the case of a high surface roughness and / or depressions and / or grooves which run at least almost in the direction of the edge 26, in particular punched edge 26, the wave spring 18 is caught or tilted over the edge 26 of the respective first and / or second end face 22, 24 on the respective contact surface 40, 17 of the mating partner.In a first exemplary case, a bearing inner ring 8 rotates in certain operating conditions, and the bearing inner ring 8 rotates in the direction of rotation 31. Due to the rotational movement of the bearing inner ring 8 in the direction of rotation 31, it moves in the relative direction of movement 21 to the first end face 22 of the wave spring 18, wherein the relative direction of movement 21 of the bearing inner ring 8 is opposite to and / or in the opposite direction to the run-out direction 13 of the wave spring 18. In a second exemplary case, a bearing inner ring 8 also rotates in certain operating conditions, and the wave spring 18 also rotates. In this case, the wave spring 18 moves along the first housing part 3 with an end section 25 such that the wave spring 18 runs with its run-out direction 13 opposite to and / or in the opposite direction to the relative movement 21.

[0040] Fig. Figure 5 shows a cross-sectional view of a [unclear] in Fig. Figure 2 shows a section of the side-channel compressor 1 according to the invention, designated IV, with the wave spring 18, the inner bearing ring 8, and the first housing part 3. It is shown that the wave spring 18 is arranged in the direction of the axis of rotation R between the inner bearing ring 8 and the first housing part 3, in particular between the first contact surface 40 of the inner bearing ring 8 and the second contact surface 17 of the first housing part 3. The wave spring 18 is designed and arranged on and / or around the bearing journal 5 such that its winding direction 16 runs in the direction of rotation 31 of the compressor wheel assembly 10 and / or the inner bearing ring 8 during operation of the side-channel compressor 1. The wave spring 18 is at least partially in contact with the first contact surface 40 of the inner bearing ring 8 with its initial section 23 and with the second contact surface 17 of the first housing part 3 with its end section 25.The wave spring 18 has a first recessed area 30, particularly on the side facing the inner bearing ring 8. The wave spring 18, with its initial section 23, has a first contact point 12 with the first contact surface 40. The wave spring 18, with its end section 25, has a second contact point 14 with the second contact surface 17. Furthermore, the wave spring 18 has a second recessed area 32, particularly on the side facing the first housing part 3. The spring element 18 is also made of a magnetic material, particularly a ferromagnetic material. In addition, the first contact surface 40 and / or the second contact surface 17 can be machined, particularly with a fine finish, such that the surface roughness R is... a in these areas it is reduced by 40, 17.

[0041] Fig. Figure 6 shows a cross-sectional view of a [unclear] in Fig. Figure 5 shows a section of the side-channel compressor 1 according to the invention, designated V, with the wave spring 18 and the inner bearing ring 8. It is shown that the wave spring 18 has a curved shape 29a in its respective initial section 23, so that a non-contact area 27a is formed, in particular between the wave spring 18 and the first contact surface 40 of the inner bearing ring 8. However, the wave spring 18 is in contact with the first contact point 12 with the first contact surface 40 of the inner bearing ring 8 in the direction of the axis of rotation R. The wave spring 8 runs with its initial region and / or its initial section 23 in the discharge direction 13a, the discharge direction 13a being at least nearly in the direction of the relative direction of movement 21a of the first contact surface 40.The wave spring 18 is designed and arranged on and / or around the bearing journal 5 such that its winding direction 16 corresponds to the direction of rotation 31 of the compressor wheel assembly 10 and / or the inner bearing ring 8 during operation of the side channel compressor 1. The wave spring 18, with the first contact point 12 of its initial section 23, is in contact with the first contact surface 40 of the inner bearing ring 8, while the curved shape 29a of the initial section 23 of the wave spring 18 is not in contact with, nor does it touch, the first contact surface 40.

[0042] As in Fig. As shown in Figure 6, the inventive design of the side channel compressor 1 and / or the wave spring 18, in which, firstly, the outlet direction 13a extends at least nearly in the direction of the relative direction of movement 21a and / or the direction of rotation 31 of the inner bearing ring 8, and secondly, the wave spring 18 has the curved shape 29a, prevents the wave spring 18 from coming into contact with, tilting, and / or engaging with the first contact surface 40 with its first end face 22 and / or its edge 26a of the first end face 22. In this way, the advantage is achieved that rotation of the wave spring 18 with the inner bearing ring 8 is prevented, particularly in the event of further engagement with the first housing part 3, which is stationary and could thus lead to twisting and damage to the wave spring 18 and other surrounding components.This prevents a failure of the wave spring 18 and / or the side channel compressor 1.

[0043] Fig. Figure 7 shows a cross-sectional view of a [unclear] in Fig. Figure 5, designated VI, shows a section of the side-channel compressor 1 according to the invention, including the wave spring 18 and the first housing part 3. It is shown that the wave spring 18 has a curved shape 29b in its end section 25, creating a non-contact area 27b, particularly 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 at its second contact point 14 in the direction of the axis of rotation R. The wave spring 18 runs with its end region and / or its end section 25 in the discharge direction 13b, the discharge direction 13b being at least approximately in the direction of a relative direction of movement 21b of the second contact surface 17.The wave spring 18 is designed and arranged on and / or around the bearing journal 5 such that its winding direction 16 corresponds to the direction of rotation 31 of the compressor wheel assembly 10 and / or the inner bearing ring 8 during operation of the side channel compressor 1. The wave spring 18, with the second contact point 14 of its end section 25, is in contact with the second contact surface 17 of the first housing part 3, while the curved shape 29b of the end section 25 of the wave spring 18 is not in contact with the second contact surface 17 and does not touch it.

[0044] As in Fig.As shown in Figure 7, the inventive design of the side channel compressor 1 and / or the wave spring 18, in which, firstly, the outlet direction 13b extends at least nearly in the direction of the relative direction of movement 21b of the first housing part 3, in particular towards the surface 17, and secondly, the wave spring 18 has the curved shape 29b, prevents the wave spring 18 from coming into contact with the second contact surface 17 with its second end face 24 and / or its edge 26b of the second end face 24, and / or from tilting and / or hooking onto it. In this way, the advantage is achieved that, when the wave spring 18 rotates with the inner bearing ring 8, further hooking of the wave spring 18 onto the first housing part 3, which is stationary, prevents the wave spring 18 from twisting and thus being damaged, as well as other surrounding components.This prevents a failure of the wave spring 18 and / or the side channel compressor 1. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 212 235

[0009]

Claims

[1] Side channel compressor (1) for a fuel cell system (2) for compressing a gaseous medium, comprising a housing with a first housing part (3) and a second housing part (4), wherein the first housing part (3) has a bearing journal (5) extending along a rotational axis (R) with a journal root section (6) and a journal main section (7), wherein a bearing inner ring (8) of a bearing device (9) is arranged on the journal main section (7), wherein a compressor wheel assembly (10) with a compressor wheel (34) is arranged within the housing on a bearing outer ring (11) of the bearing device (9) so as to be rotatable about the rotational axis (R), wherein the first housing part (3) is clamped at least indirectly to the bearing device (9) via a fastening element (28),wherein a corrugated 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 part (3) facing the fastening element (28), , characterized by that 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) runs in the direction of a 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). [2] Side channel compressor (1) according to claim 1, characterized bythat the wave spring (18) is at least partially in contact with an initial section (23) on the first contact surface (40) of the bearing inner ring (8) and with an end section (25) on the second contact surface (17) of the first housing part (3), wherein a run-out direction (13a, b) runs at least almost in the direction of a relative movement direction (21) of the respective contact surface (17, 40). [3] Side channel compressor (1) according to claim 1 or 2, characterized by that the corrugated spring (18) has a curved shape (29) in its respective initial section (23) and / or end section (25), so that a contactless region (27) is formed. [4] Side channel compressor (1) according to one of the preceding claims, characterized by that the spring element (18) comprises a magnetic material, in particular a ferromagnetic material. [5] Side channel compressor (1) according to one of claims 2 to 4, characterized bythat the first contact surface (40) and / or the second contact surface (17) are machined, in particular finely machined, in such a way that the surface roughness R a is reduced in these areas (40, 17). [6] Side channel compressor (1) according to one of the preceding claims, characterized by that the bearing device (9) has two rolling bearings (20a, b) arranged next to one another along the axis of rotation (R), wherein a spacer disc (15) is located between the rolling bearings (20a, b), wherein in particular the bearing outer rings (11a, b) are in contact with the spacer disc (15) axially to the axis of rotation (R). [7] Fuel cell system (2) with a side channel compressor (1) according to one of claims 1 to 6, wherein the side channel compressor (1) is arranged in an anode circuit of the fuel cell system (2). [8] Method for operating the side channel compressor (1), in particular within the framework of a cold start procedure, according to one of the preceding claims, characterized by that by means of the current supply to the stator (12) an induction field, in particular an inductive magnetic field, is formed, whereby an inductive energy transfer to the wave spring (18) is thus established.

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