KR20220116345A - Side channel compressors for fuel cell systems for the transport and/or compression of gaseous media, in particular hydrogen - Google Patents

Abstract

The present invention relates to a side channel compressor (1) for a fuel cell system (37) for the transport and/or compression of a gaseous medium, in particular hydrogen, which side channel compressor (1) for a fuel cell system comprises a housing (3) and a drive unit ( 6), wherein the housing (3) comprises a housing upper part (7) and a housing lower part (8); a compressor chamber (30) extending over a periphery about an axis of rotation (4) in the housing (3), said compressor chamber comprising one or more side channels (19, 21) spanning the periphery; It has a compressor wheel (2) located in a housing (3), arranged rotatably about an axis of rotation (4) and driven via a drive (6), the circumference of which is a compressor chamber (30) ) comprising blades 5 arranged in the area of ; It has respective gas inlet openings 14 and gas outlet openings 16 formed in the housing 3 , these openings being fluidly connected to each other via a compressor chamber 30 , in particular one or more side channels 19 , 21 . . According to the invention, the drive 6 in this case comprises a stator 11 and a rotor 17 , which are at least almost completely surrounded by an encapsulating element 18 , and thus in particular from the periphery. encapsulated.

Description

Side channel compressors for fuel cell systems for the transport and/or compression of gaseous media, in particular hydrogen

The present invention relates in particular to a side channel compressor for a fuel cell system for the transport and/or compression of a gaseous medium, in particular hydrogen, provided for use in a vehicle having a fuel cell drive.

In the automotive sector, along with liquid fuels, gaseous fuels will play an increasingly important role in the future. Particularly in vehicles with fuel cell drives, the hydrogen gas flow must be controlled. In this case, the gas flow is no longer discontinuously controlled as in the case of injection of liquid fuel, and the gas is withdrawn from one or more high-pressure tanks and guided through the inlet line of the medium-pressure line system to the ejector unit. This ejector unit guides the gas to the fuel cell via the connecting line of the low pressure line system. After the gas flows through the fuel cell, it is returned to the ejector unit through a return line. In this case, a side channel compressor may be interposed to assist gas return as a flow technique and as an efficiency technique. In addition, side channel compressors are used to assist in the formation of flow in the fuel cell drive, especially during (cold) start of the vehicle after a certain idle time. The driving of such a side channel compressor is generally performed by electric motors supplied with voltage through a vehicle battery during in-vehicle operation.

From DE 2017 102 157 39 and DE 10 2018 204 713 A1, side channel compressors are known for fuel cell systems in which a gaseous medium, in particular hydrogen, is conveyed and/or compressed. In this case, the side channel compressor includes a housing and a drive, and the housing includes a housing upper part and a housing lower part. Also arranged in the housing is a compressor chamber extending over a periphery about an axis of rotation, said compressor chamber comprising at least one side channel spanning the periphery. In the housing, there is located a compressor wheel, which is arranged rotatably about an axis of rotation and driven through a drive part, the circumference of which comprises blades arranged in the region of the compressor chamber. In addition, the side channel compressors known from DE 2017 102 157 39 and DE 10 2018 204 713 A1 comprise respective gas inlet openings and gas outlet openings formed in the housing, these openings comprising the compressor chamber, in particular one or more side channels. The channels are in fluid communication with each other.

The side channel compressors known from DE 2017 102 157 39 and DE 10 2018 204 713 A1 may have certain disadvantages.

In this case, the drive consists of components which, due to their material properties, can be damaged through contact with the anode medium, in particular hydrogen. Other substances, such as water or dirt, that seep into the drive from the periphery can also damage the components of the drive. In this case, oxidation reactions, hydrogen embrittlement or other material damage may occur. This may lead to damage to the drive unit and to the fact that the components of the side channel compressor in the vicinity of the drive are also at least partially in motion, in particular in rotational motion. Then, this again can lead to failure of the drive and/or failure of the entire side channel compressor.

In addition, the side-channel compressors known from DE 2017 102 157 39 and DE 10 2018 204 713 A1 are characterized in that in the cold start procedure the drive or certain parts of the side-channel compressor are not heated sufficiently quickly, so that the side-channel compressor and/or Alternatively, there may be a disadvantage that there is a risk of damage through the ice bridge, which may shorten the life of the fuel cell system.

According to the invention there is provided a side channel compressor for a fuel cell system for the transport and/or compression of a gaseous medium, in particular hydrogen, having the features of the independent claims.

With reference to claim 1 , a side channel compressor is proposed in which the drive comprises a stator and a rotor, the rotor being at least almost completely surrounded by an encapsulating element, and thus encapsulated in particular from the periphery. In this way, the advantage can be achieved that the rotor is protected from contact with the anode medium, in particular hydrogen, or with other substances from the surroundings, such as water or dirt. In this case, the encapsulating element effectively shields the rotor so that it does not come into contact with the surrounding medium, so that the life of the drive unit and thus the life of the side channel compressor can be extended, and thus the possibility of failure due to broken components of the drive unit is reduced Furthermore, the encapsulation of the drive and/or rotor can be implemented in a compact structure by means of an encapsulating element that at least almost completely surrounds the rotor, so that no structural changes to the drive and/or the side channel compressor need to be carried out or It only needs to be run minimally. In this way, the inventive and preferred embodiment of the present invention can be implemented in an inexpensive manner.

The dependent claims relate to preferred refinements of the invention.

According to one preferred embodiment, the drive is configured as a radially inner rotor electric motor, the drive, in particular the rotor, being connected with the compressor wheel via a drive shaft, the drive shaft, the compressor wheel and the rotor being rotatable about an axis of rotation. mounted, and each of the rotor and the compressor wheel is connected to the drive shaft by form-fitting, material-fitting, or force-engaging. In this way, an inexpensive assembly of the encapsulating element can be achieved, without requiring further structural changes or at least only minor structural changes to the drive and/or the side channel compressor. This reduces the assembly cost and hence the production cost of the side channel compressor, while the possibility of failure of the side channel compressor can be reduced.

According to one particularly preferred embodiment, the rotor comprises one or more permanent magnets and/or the encapsulating element is formed as a special steel cap with at least special steel. In this way, the advantage can be achieved that the probability of failure of the rotor and/or the entire drive can be reduced. This means that components sensitive to hydrogen, in particular of the assembly connection, such as for example the soft magnetic materials of a permanent magnet, are displaced into the inner location region, whereas the components of the assembly connection, such as, for example special steel, in particular hydrogen are displaced. Insensitive components can be achieved in such a way that they are displaced into the area around the outer position. This offers the advantage that the life of the drive and thus the life of the entire side channel compressor can be extended.

According to a preferred embodiment of the side channel compressor, the rotor is superimposed on this drive shaft in such a way that it forms an end flush with the drive shaft on the side opposite the compressor wheel, and a special steel cap is provided on the side facing the compressor wheel. It comprises an opening in the area, and a special steel cap completely surrounds the rotor superimposed on the drive shaft, except for the area of the opening. In this way, the advantage that a compact structure of the drive and/or of the side channel compressor can be maintained or brought about can be achieved.

According to one particularly preferred refinement, in such a way that the rotor, in particular the permanent magnet, is encapsulated with respect to the external positioning region, the drive shaft and the special steel cap are force-coupled, form-fitted or materially coupled in the region of the opening. connected to each other In this way, the advantage that an efficient encapsulation of the sensitive components and/or materials of the rotor can be achieved by means of a special steel cap can be achieved, wherein hydrogen or other materials penetrate into the inner positioning region of the rotor and the soft magnetic There is only one area of the special steel cap, in particular the area of the opening, which makes it possible to damage the materials. This advantage is achieved by means of a permanently encapsulated connection between the special steel cap and the drive shaft, whereby the possibility of failure of the drive and/or the side channel compressor can be reduced.

According to a preferred embodiment of the side channel compressor, the driving unit is formed as an axial magnetic field electric motor including a stator and a rotor, the stator and the rotor are formed in a disk shape over a periphery about a rotating shaft, and the stator is formed of a rotating shaft of the rotating shaft. oriented side by side with the rotor. In this way, a compact and space-saving structure of the side channel compressor can be realized, with a surface area as small as possible relative to volume. This gives the advantage that, for example, only a small installation space in the vehicle is required by the customer. In addition, the compact structure of the side channel compressor, in particular with a surface area as small as possible relative to volume, results in a slower complete cooling of the side channel compressor, in particular at low ambient temperatures in the range below 0° C., thus forming ice bridges It offers the advantage of being able to delay the occurrence of

According to one preferred refinement, the rotor comprises at least a permanent magnet, a rotor hub and a stationary disk, the encapsulating element at least almost completely surrounding the rotor hub and/or the permanent magnet and thus encapsulating it with respect to the external positioning area. In this way, a compact structure of the drive can be achieved, especially in the embodiment as an axial electric motor. In this case, at least almost all components of the rotor, including the bearings of the compressor wheel, can be arranged and integrated in the region of the inner diameter of the compressor wheel. Furthermore, reliable encapsulation of the rotor, in particular the rotor hub and/or permanent magnets, can be achieved by means of an embodiment according to the invention of the side channel compressor.

According to a preferred embodiment of the side channel compressor, the encapsulating element has at least a two-layer structure, wherein the first layer is formed of an elastically deformable material, in particular an elastomer, and the second layer is formed of special steel. In this way, on the one hand an improved encapsulation of the rotor hub and the permanent magnet can be achieved, in which an elastically deformable material can be introduced into the respective region due to the material properties and/or due to the elasticity This is because it can be better superimposed on the rotor hub and the permanent magnets. On the other hand, a second layer of special steel can provide the encapsulated element with better structural rigidity compared to elastomers. Accordingly, the reliability of the driving unit and/or the side channel compressor may be improved.

According to one particularly preferred embodiment, the encapsulating element consists of at least one elastomeric sealing element with a pressed special steel cap. In this way, an encapsulation element comprising two or more layers, in particular having two or more materials with different properties, can be pre-assembled before being mounted on the drive and/or rotor and/or compressor wheel. advantage can be achieved. In this way, the assembly cost, the required assembly time and assembly errors can be reduced. This provides the advantage of a lower total cost of the side channel compressor and a lower probability of failure of the drive and/or side channel compressor due to a reduced likelihood of assembly errors.

According to one preferred method, in particular for starting or switching off and/or operating the side channel compressor, the current supply of the stator causes inductive heating of the rotor and/or the encapsulating element, in particular the encapsulating element comprising at least a special steel material The properties allow it to be induction heated particularly well. In this case, the material of the special steel has high electrical conductivity, so that it can be better induction heated. In this case, the heating takes place as an effect due to an electrical influence by a magnetic field, more specifically by an eddy current loss, since the layer made of special steel is an electrically conductive body. In this case, the rotor is inductively heated when the coils of the stator are energized for a short period of time, in particular by generating an output loss that is released as thermal energy. In this way, by energizing the stator, the advantage that heating of the rotor is established in the absence of a rotating magnetic field can be achieved, for which in particular the inductive effect is used. In this case, in particular the rotor made of thermally conductive material can be heated, which is particularly desirable in the cold start procedure of side channel compressors and/or vehicles. In this case, the rotor is heated and transfers thermal energy to the compressor wheel, for example due to the high thermal conductivity of the material used. In this case, heat energy transfer is carried out in the direction of flow into the region between the housing on which the ice bridge is formed and the compressor wheel. Such ice bridges may cause damage to the side channel compressor during start-up and/or start-up of the side channel compressor and/or may impede rotation of the compressor wheel within the housing through blocking. In addition, on start-up of the compressor wheel, a breakout may be caused in which sharp-edged ice bridges are released, which can damage the side channel compressor and/or components downstream of the fuel cell in the transport direction, in particular the membrane of the fuel cell. can In this case, through heating of the rotor, the compressor wheel, in particular the region of the inner limiting ring and the outer positioning annular collar, is heated, both of which each form a small gap, in particular a small gap, with respect to the housing. In this way, the ice bridge is thawed and a liquid conversion from a solid agglomeration state to a fluid agglomeration state can be achieved, eg by means of a purge valve and/or a vent valve present in the fuel cell system. In this way, the life of the side channel compressor and/or the fuel cell system can be extended.

The invention is not limited to the embodiments described herein and the aspects presented therein. Rather, within the scope specified by the claims, a number of variations within the scope of professional action are possible.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is described in more detail below with reference to the drawings.
1 is a schematic cross-sectional view of a side channel compressor according to the present invention;
2 is a perspective view of a component according to the invention of a side channel compressor according to a first embodiment;
3 is a perspective view of a component according to the invention of a side channel compressor according to a second embodiment;

In the drawing according to FIG. 1 , there can be shown a longitudinal section of the side channel compressor 1 proposed according to the invention, which is formed rotationally symmetrical with respect to the axis of rotation 4 .

In this case, the side channel compressor 1 comprises a compressor wheel 2 , which is formed in particular as a closed disc-shaped compressor wheel 2 and is rotatable about a horizontally extending axis of rotation 4 . It is mounted in the housing (3) so as to In this case, the drive 6 , in particular the electric drive 6 , is used as the rotation drive 6 of the compressor wheel 2 . In this case, the drive unit 6 may be formed as a radially inner rotor electric motor 6 according to the first embodiment, or it may be formed as an axial magnetic field electric motor 6 according to the second embodiment. Also, the driving unit 6 may include a plurality of cooling fins 33 . The housing 3 comprises a housing upper part 7 and a housing lower part 8 connected to each other. Between the two housing parts 7 , 8 there can be located a sealing element which surrounds the periphery about the axis of rotation 4 , this sealing element being in particular against contaminants or moisture from outside the side channel compressor 1 . of the compressor chamber 30 . According to a first embodiment, the compressor wheel 2 is arranged to rotate integrally on a drive shaft 9 and is surrounded by a housing upper part 7 and a housing lower part 8 . According to a second embodiment, the compressor wheel 2 is mounted, for example, on a bearing journal located in the housing lower part 8 , in particular a rotor hub 29 (shown in FIG. 3 ) and one or more bearings ( 27) can be installed indirectly.

In a first embodiment, the compressor wheel (2) comprises an inner compressor wheel hub (10), the compressor wheel hub (10) comprising a recess into which the drive shaft (9) is inserted, the compressor wheel hub (10) is connected with the drive shaft 9 in particular by a press fit. Further, the compressor wheel hub 10 is bounded through the hub base 12 over the periphery on the side opposite the axis of rotation 4 . Also in this embodiment, one or more seals 23 , spanning the periphery about the axis of rotation 4 , are connected to the hub base 12 on the outer diameter of the drive shaft 9 , in particular axially with respect to the axis of rotation 4 . It is arranged between the drive part 6 and radially with respect to the axis of rotation 4 between the drive shaft 9 and the housing upper part 7 .

Outwardly away from the hub base 12 and away from the axis of rotation 4 , the compressor wheel 2 forms a circular hub disk 13 spanning its periphery. In addition, the compressor wheel 2 forms one or more conveying cells 28 which run from the outside to the hub disk 13 . One or more such transfer cells 28 of the compressor wheel 2 extend over the periphery about the axis of rotation 4 in the compressor chamber 30 over the periphery of the housing 3 . Also in FIG. 1 the cutting contour of the blade 5 can be seen in the area of the transfer cell 28 . Such blades 5 may have a V-shaped profile. In addition, each transfer cell 28 is bounded by two blades 5 in the direction of rotation of the compressor wheel 2 , and a plurality of blades 5 span the periphery about the axis of rotation 4 . and arranged on the compressor wheel 2 radially with respect to the axis of rotation 4 .

Furthermore, the housing 3 , in particular the housing upper part 7 and/or the housing lower part 8 , comprises, in the region of the compressor chamber 30 , at least one side channel 19 , 21 spanning the periphery. In this case, one or more side channels 19 , 21 are arranged in the housing 3 in the direction of the axis of rotation 4 in such a way that these side channels extend on one or both sides axially with respect to the transfer cell 28 . is extended In this case, the one or more side channels 19 , 21 can extend over the periphery about the axis of rotation 4 at least in one partial region of the housing 3 , wherein the one or more side channels 19 , 21 are connected to the housing 3 . In a partial region not formed in (3), a blocking region 15 is formed in the housing 3 .

In a first embodiment, the drive shaft 9 is mounted in the housing 3 by means of one or more bearings 27 , which may be roller bearings 27 , in particular ball bearings 27 . The drive 6 abuts against the end face of the housing 3 axially with respect to the axis of rotation 4 by means of at least one end face, whereby the drive 6 is connected to the housing 3, in particular the housing, of the side channel compressor 1 . It can be connected with the upper part 7 .

Furthermore, the housing 3 , in particular the housing lower part 8 , forms a gas inlet opening 14 and a gas outlet opening 16 . In this case, the gas inlet opening 14 and the gas outlet opening 16 are in fluid connection with each other, in particular via one or more side channels 19 , 21 . In this case, as circulation from the gas inlet opening 14 to the gas outlet opening 16 proceeds in the direction of rotation of the compressor wheel 2 , in the transfer cell 28 , in particular the transfer cell 28 of the compressor wheel 2 . ) and/or pressure and/or flow rate of the gas medium in the side channels 19 increases. In this case, the gaseous medium is discharged through the gas discharge opening 16 of the side channel compressor 1 after a continuous flow has been carried out, in the outflow direction, in particular in the direction of the jet pump 41 of the fuel cell system 37 . is leaked to The pressure side and the suction side are separated through the blocking area 15 , the suction side is located in the area of the gas inlet opening 14 , and the pressure side is located in the area of the gas outlet opening 16 .

From the drive 6 torque is transmitted to the compressor wheel 2 . In this case, the compressor wheel 2 is converted into a rotational movement, and the transfer cell 28 is rotated over the periphery about the rotational axis 4 through the compressor chamber 30 in the housing 3 in a first rotational direction. move to In this case, the gaseous medium already located in the compressor chamber 30 is moved together through the transfer cell 28 , in this case being transferred and/or compressed. In addition, a movement of the gaseous medium between the transfer cell 28 and the one or more side channels 19 , 21 is carried out, in particular a flow exchange. In addition, the side channel compressor 1 is connected to the fuel cell system 37 through the gas inlet opening 14 and the gas outlet opening 16, and in particular the gas medium, which is the unused recirculation medium from the fuel cell, is discharged through the gas inlet opening ( 14 ) into the compressor chamber 30 of the side channel compressor 1 and/or supplied to the side channel compressor 1 and/or suctioned from the region mounted upstream of the gas inlet opening 14 . In this case, the gaseous medium is discharged through the gas outlet opening 16 of the side channel compressor 1 after a continuous flow has been carried out.

2 shows in perspective view a part according to the invention of a side channel compressor 1 according to a first embodiment, the drive part 6 being formed as a radially inner rotor electric motor 6 and comprising a stator 11 and It includes a rotor (17). In this case, the rotor 17 is at least almost completely surrounded by the encapsulating element 18 , and thus is encapsulated, in particular from the periphery. In this case, the drive 6 , in particular the rotor 17 , is connected to the compressor wheel 2 via a drive shaft 9 , the drive shaft 9 , the compressor wheel 2 and the rotor 17 being a rotating shaft. Mounted rotatably about (4), each of the rotor (17) and the compressor wheel (2) is connected to the drive shaft (9) by form-fitting, material-joining, or force-engaging. In this case, for example, the drive shaft 9 can be mounted by means of two bearings 27 , each located on either side of the compressor wheel 2 .

It is also shown that the rotor 17 comprises one or more permanent magnets 25 and/or the encapsulating element 18 is formed as a special steel cap 18 with at least a special steel. In this case, the rotor 17 is superimposed on this drive shaft in such a way that it ends flush with the drive shaft 9 on the side opposite the compressor wheel 2 , and a special steel cap 18 is attached to the compressor wheel 2 . ) in the region of the drive shaft 9 on the side facing the opening 22 . In addition, the special steel cap 18 in this case completely surrounds the rotor 17 superposed on the drive shaft 9 , except for the area of the opening 22 . Furthermore, in such a way that the rotor 17 , in particular the permanent magnet 25 , is encapsulated with respect to the area of external positioning, the drive shaft 9 and the special steel cap 18 are forcedly coupled in the area of the opening 22 , in the form They are connected to each other by bonding or material bonding.

3 is a perspective view of a part according to the invention of a side channel compressor 1 according to a second embodiment. In this case, the driving unit 6 is formed as an axial magnetic field electric motor 6 including a stator 11 and a rotor 17 , and the stator 11 and the rotor 17 are formed as a rotating shaft 4 in the form of a disk. ) is formed over the periphery, and the stator 11 is arranged side by side with the rotor 17 in the direction of the axis of rotation 4 . The rotor 17 also comprises at least a permanent magnet 25 , a rotor hub 29 and a stationary disk 31 , and the encapsulating element 18 comprises a rotor hub 29 and/or a permanent magnet 25 . ) at least almost completely, and thus encapsulates with respect to the external location area. In this case, the encapsulating element 18 has at least a two-layer structure, the first layer being formed of an elastically deformable material, in particular an elastomer, and the second layer being formed of special steel. In one preferred embodiment, the encapsulating element 18 may consist of one or more elastomeric sealing elements with pressed special steel caps, thereby allowing simplified assembly.

Since in the housing 3 a fluid separation, in particular in the form of an intermediate wall, is formed between the space of the stator 11 and the space of the rotor 17, the seal 23 (shown in FIG. This may be unnecessary in the example. Furthermore, since in this embodiment the rotor 17 is located directly in the compressor wheel 2 as a disc-shaped element, a drive shaft 9 is also required for the transmission of torque from the drive 6 to the compressor wheel 2 in this case. doesn't happen

For each of the first and second embodiments of the side channel compressor 1 , the current supply of the stator 11 causes induction heating of the rotor 17 and/or the encapsulating element 18 , in particular at least special steel The encapsulating element 18 comprising: enables rapid heating due to its material properties, in particular due to its high inductive resistance.

Claims (10)

A side channel compressor (1) for a fuel cell system (37) for the transport and/or compression of a gaseous medium, in particular hydrogen, comprising:
It has a housing (3) and a drive part (6), the housing (3) comprising a housing upper part (7) and a housing lower part (8),
a compressor chamber (30) extending over a periphery about an axis of rotation (4) in the housing (3), said compressor chamber comprising one or more side channels (19, 21) spanning the periphery;
a compressor wheel (2) located in a housing (3), arranged rotatably about a rotating shaft (4) and driven via a drive (6), the perimeter of the compressor wheel (2) being a compressor chamber (30) blades (5) arranged in the area of
It has respective gas inlet openings 14 and gas outlet openings 16 formed in the housing 3 , these openings being in fluid communication with one another via a compressor chamber 30 , in particular one or more side channels 19 , 21 . , A side channel compressor for a fuel cell system, comprising:
The drive part (6) comprises a stator (11) and a rotor (17), characterized in that the rotor (17) is at least almost completely surrounded by an encapsulating element (18) and is thus encapsulated, in particular from the periphery, Side channel compressors for fuel cell systems (1). The drive (6) according to claim 1, wherein the drive (6) is formed as a radially inner rotor electric motor (6), the drive (6), in particular the rotor (17), is connected to the compressor wheel (2) via a drive shaft (9) connected, the drive shaft 9, the compressor wheel 2 and the rotor 17 are mounted rotatably about the rotation shaft 4, and the rotor 17 and the compressor wheel 2 are each mounted on the drive shaft ( A side channel compressor (1) for a fuel cell system, characterized in that it is connected to 9) in a form-coupled manner, a material-coupled manner or a forced-coupled manner. Fuel according to claim 2, characterized in that the rotor (17) comprises one or more permanent magnets (25) and/or the encapsulating element (18) is formed as a special steel cap (178) with at least special steel. Side channel compressors for cell systems (1). 4. The compressor according to claim 3, wherein the rotor (17) is superimposed on this drive shaft in such a way that it ends flush with the drive shaft (9) on the side opposite the compressor wheel (2), and a special steel cap (18) is attached to the compressor. On the side facing the wheel 2 , it comprises an opening 22 in the region of the drive shaft 9 , a special steel cap 18 having a rotor 17 superimposed on the drive shaft 9 , the opening 22 . A side channel compressor (1) for a fuel cell system, characterized in that it completely surrounds except for the area of . 5. The drive shaft (9) and the special steel cap (18) according to claim 3 or 4, in such a way that the rotor (17), in particular the permanent magnet (25), is encapsulated with respect to the external positioning area. A side channel compressor (1) for a fuel cell system, characterized in that the regions are connected to each other by force coupling, form coupling or material coupling. The drive unit (6) according to claim 1, wherein the drive unit (6) is formed as an axial magnetic field electric motor (6) comprising a stator (11) and a rotor (17), the stator (11) and the rotor (17) in the form of a disk A side channel compressor (1) for a fuel cell system, characterized in that it is formed over a periphery around a rotational shaft (4), and a stator (11) is arranged side by side with the rotor (17) in the direction of the rotational shaft (4). 7. The rotor (17) according to claim 6, wherein the rotor (17) comprises at least a permanent magnet (25), a rotor hub (29) and a stationary disk (31), and the encapsulating element (18) comprises a rotor hub (29) and/or a fixed disk (31). A side channel compressor (1) for a fuel cell system, characterized in that it at least almost completely surrounds at least one permanent magnet (25) and thus encapsulates it with respect to an external location area. 8. The method according to claim 7, characterized in that the encapsulating element (18) has at least a two-layer structure, the first layer being formed of an elastically deformable material, in particular an elastomer, and the second layer being formed of special steel, Side channel compressors for fuel cell systems (1). 9. Side channel compressor (1) according to claim 8, characterized in that the encapsulating element (18) consists of at least one elastomeric sealing element with a pressed special steel cap. 10 . The method according to claim 1 , wherein the current supply of the stator ( 11 ) causes induction heating of the rotor ( 17 ) and/or the encapsulating element ( 18 ), in particular comprising at least special steel. A method, characterized in that the encapsulating element (18) which makes the heating element (18) facilitates rapid heating due to the material properties, in particular due to its high inductive resistance.

Images