Blower for a fuel cell array

Abstract

A blower (1) for a fuel cell arrangement (20) with an anode arrangement is disclosed, for recirculating a volume flow accruing during the operation of the fuel cell arrangement (20) to the anode arrangement, wherein an axial bearing (4) for supporting a first end (3a) of a motor shaft (3) has a stationary first support disk (4b) and a thrust rotor (4c) connected to the first end (3a) of the motor shaft (3) in a rotationally fixed manner, wherein a radial bearing (5) for supporting the first end (3a) has a pipe section (9) which is provided to be arranged between the thrust rotor (4c) and the blower impeller (7).

Description

Technical field

[0001] The present invention relates to a blower for a fuel cell arrangement for recirculating a volume flow generated during the operation of the fuel cell arrangement. In particular, the present invention relates to a blower with an axial bearing. Furthermore, the invention relates to a fuel cell arrangement with such a blower. State of the art

[0002] Fuel cells of various designs are used particularly for mobile applications. In such fuel cells, which have an anode and a cathode, hydrogen can be used as the energy carrier. The volume flow leaving the anode may contain unused hydrogen. This volume flow can be recirculated back to the anode to increase the fuel cell's efficiency. In the prior art, blowers are used for this purpose, which are predominantly derived from compressor technology. The blower may be a pump driven by an electric motor.

[0003] The KR 10 2015 0 007 755 A concerns a state-of-the-art air compressor.

[0004] It is an object of the invention to provide an improved blower for recirculating a volume flow. This object is achieved by the features of the claims. Description of the invention

[0005] According to a first aspect, the present invention relates to a blower for a fuel cell arrangement with an anode arrangement for recirculating a volume flow generated during the operation of the fuel cell arrangement to the anode arrangement. The blower has a blower duct with an outer wall extending along a duct axis. A motor shaft for driving a blower impeller extends within the blower duct along the duct axis. An axial bearing for supporting a first end of the motor shaft has a stationary first support disk and a thrust rotor non-rotatably connected to the first end of the motor shaft. A first radial bearing serves to support the first end. A screw connection is provided to be screwed into an end face of the first end and to force the thrust rotor axially towards the blower impeller.Stationary can particularly mean that the relevant element can remain at rest during the operation of the blower.

[0006] A fuel cell arrangement according to a second aspect of the invention comprises an anode arrangement and a blower according to the first aspect, wherein the blower is configured or arranged to return the volume flow accumulating during operation to the anode arrangement.

[0007] For clamping the blower impeller, it can be advantageous that the screw connection, after being screwed in, does not rest against the end face of the first end. The blower is particularly easier to mount thanks to the screw connection, which allows the thrust rotor to be forced axially towards the blower impeller.

[0008] The following is an explanation of further training courses that can be advantageously combined with each other unless otherwise indicated.

[0009] In one embodiment, a pipe section is provided that is arranged between the thrust rotor and the blower impeller. The pipe section can extend around the motor shaft. This section can be used to transmit force from the screw connection to the thrust rotor. The pipe section can simplify the assembly of the blower.

[0010] In one embodiment, first foil segments can be arranged between the stationary first support disk and the thrust roller of the axial bearing. The first foil segments can be mechanically connected to the first support disk. They can have a metal substrate facing the first support disk. The metal substrate can be coated, in particular with a plastic such as PTFE, to influence the friction in the axial bearing. The first foil segments can serve to reduce axial bearing friction and increase the efficiency of the blower. Furthermore, the first foil segments can increase the service life of the axial bearing.

[0011] Another embodiment may include second foil segments arranged between a stationary bushing of the first radial bearing and the first end of the motor shaft. These second foil segments may be positioned between the stationary bushing and a sleeve of the first radial bearing that rotates with the first end. The second foil segments may be mechanically connected to the stationary bushing. They may have a metal substrate facing the stationary bushing and coated, in particular with a plastic such as PTFE, to influence friction in the first radial bearing. The rotating sleeve and the tube section may be formed as a single piece. The second foil segments may serve to reduce axial bearing friction and increase the efficiency of the blower. Furthermore, the second foil segments may increase the service life of the axial bearing.

[0012] One embodiment can have a housing with a removable housing cover. The first support washer can be formed integrally with the housing cover. This can simplify assembly of the blower. The housing can have a volute that supports the stationary bushing of the first radial bearing and can be inserted between the housing cover and the rest of the housing. A first shim can be inserted between the housing and the housing cover or between the housing cover and the volute to adjust the play of the axial bearing. This allows manufacturing tolerances to be compensated for, thus simplifying assembly of the blower.

[0013] One embodiment may include a stationary second support disk that can be connected to the housing, particularly to the volute. The second support disk can serve to limit axial displacement of the thrust roller. The thrust roller can be arranged between the first and second support disks. Third foil segments can be connected to the second support disk and can be arranged between the second support disk and the thrust roller. The third foil segments can have a metal substrate that faces the housing or its volute and can be coated, particularly with a plastic such as PTFE, to influence the friction in the axial bearing.

[0014] In one embodiment, the screw connection can be designed as a central screw, an axial screw, a threaded bolt, or a hollow screw, each of which can be screwed into the end face of the first end along the channel axis A. This allows the axial force acting on the blower to be influenced.

[0015] According to another embodiment, the motor shaft can have a tubular section for receiving a permanent magnet. Inside the tubular section, a circumferential shoulder can be formed against which the permanent magnet can rest. This simplifies the positioning of the permanent magnet. The first end can be connected to the tubular section, particularly by welding. The first end can have a projection adapted to the inner diameter of the tubular section, allowing it to be inserted into the tubular section.

[0016] Another embodiment may include a second shim which, to influence the axial length of an assembly comprising the thrust rotor, the pipe section, and / or the blower impeller, can be inserted around or placed over the first end. Manufacturing tolerances can be compensated for by using a thicker or thinner second shim. Advantageously, the axial length of the assembly can be adapted to the dimensions of the first end. For clamping the blower impeller, it can be advantageous that the screw connection, after being screwed in, does not rest against the end face of the first end. This can simplify the assembly of the blower.

[0017] In another embodiment, the first end can have a circumferential collar facing the tubular section, against which the blower impeller can rest. The collar can form a stop for the assembly comprising the thrust roller, the tubular section, and the blower impeller, against which the screw connection can press the assembly. The circumferential collar can simplify the mounting and / or positioning of the thrust roller.

[0018] One embodiment features a second radial bearing for rotatably supporting the end of the motor shaft opposite the first end, in particular the tubular section of the motor shaft. The second radial bearing can be held by the housing.

[0019] In one embodiment, the first end has an axial bore extending from the end face and a transverse bore, the transverse bore opening into the axial bore. The transverse bore can thus serve for venting. Brief description of the characters Fig. Figure 1 shows a sectional view of an embodiment of the blower. Fig. Figure 2 shows parts of a variant of the embodiment of the Fig. 1 with shims. Fig. Figure 3 shows a schematic representation of a fuel cell arrangement with one embodiment of the blower. Detailed description of the figures

[0020] Fig. Figure 1 shows a sectional view of an embodiment of the blower 1.

[0021] The blower 1 is designed for a fuel cell assembly with an anode assembly and serves to recirculate a volume flow generated during the operation of the fuel cell assembly to the anode assembly. The blower has a blower duct 2 with an outer wall 2a extending along a duct axis A. A motor shaft 3 for driving a blower impeller 7 extends through the blower duct 2 along the duct axis A. An axial bearing 4 for supporting a first end 3a of the motor shaft 3 has a stationary first support disk 4b and a thrust rotor 4c non-rotatably connected to the first end 3a of the motor shaft 3. A first radial bearing 5 supports the first end 3a. A pipe section 9 is provided to position the first end 3a between the thrust rotor 4c and the blower impeller 7.A central screw 10 is provided to be screwed into an end face 3b of the first end 3a and to push the thrust roller 4c axially towards the blower impeller 7. In this way, simpler assembly of the blower can be achieved.

[0022] The blower 1 has a housing 6 with a removable housing cover 6a, wherein the first support disc 4b is formed integrally with the housing cover 6a. The housing 6 also has a volute 6b, which supports the stationary bushing 5b of the first radial bearing 5 and is inserted between the housing cover 6a and the rest of the housing 6. First foil segments 4a are arranged between the stationary first support disc 4b and the thrust roller 4c. The central screw 9 is designed as a hollow screw.

[0023] The axial bearing 4 of the blower 1 has a stationary second support disk 4d, which is connected to the volute 6b. The second support disk 4d serves to limit axial displacement of the thrust roller 4c. The thrust roller 4c is arranged between the first support disk 4b and the second support disk 4d. Third foil segments 4e are connected to the second support disk 4d and are arranged between the second support disk 4d and the thrust roller 4c.

[0024] Each of the foil segments 4a, 4e, 5a can have a metal substrate that is coated, in particular with a plastic such as PTFE, to influence the friction in the first axial bearing or in the first radial bearing.

[0025] The pipe section 9 and a rotating sleeve 5c of the first radial bearing 5 are formed in one piece.

[0026] The first end 3a has an axial bore 3c extending from the end face 3b and a transverse bore 3e into which the axial bore 3c opens. The first end 3a has a circumferential collar 3g against which the blower impeller 7 can rest.

[0027] The motor shaft 3 has a tubular section 3d for receiving a permanent magnet 11, the first end 3a being connected to the tubular section 3d. The connection could be a welded joint. The tubular section 3d has an internal circumferential shoulder 3f against which the permanent magnet 11 rests. This shoulder 3f facilitates the positioning of the permanent magnet relative to a stator of the same electric motor of the blower 1.

[0028] Right in Fig. 1 a second radial bearing 12 is held by the housing 6, which can rotatably support the end of the motor shaft 3 opposite the first end 3a.

[0029] This blower 1 can be advantageously mounted using the following steps: • Inserting the permanent magnet 11 into the tubular section 3d up to the inner circumferential shoulder 3f, • Connecting the first end 3a to the tubular section 3d, • Positioning the blower impeller 7 against the circumferential collar 3g of the first end 3a, • Arranging the rotating sleeve 5c or the pipe section 9 around the first end 3a, • Positioning the volute 6b of the blower 1 over the rotating sleeve 5c or the pipe section 9, • Slide the thrust runner 4c onto the first end 3a and screw in the central screw 10, so that the thrust runner 4c pushes the pipe section 9 against the blower impeller 7 and this against the circumferential collar 3g of the first end 3a, • Screw the housing cover 6a onto the volute 6b, • Threading the motor shaft 3 into the blower duct 2 and into the second radial bearing (right in Fig. 1) and connecting the volute 6b to the rest of the casing 6.

[0030] This blower 1 may have shims (not shown). For clamping the blower impeller 7, it is advantageous that the central screw 10, after being screwed in, does not rest against the end face 3b of the first end 3a. A first shim can be inserted between the volute 6b and the housing cover 6a to adjust the clearance of the axial bearing 4. A second shim can be inserted between the thrust roller 4c and the pipe section 9 to adapt the thrust roller 4c, the pipe section 9, and the blower impeller 7 to the dimensions of the first end 3a, thus compensating for manufacturing tolerances.

[0031] Fig. Figure 2 shows parts of a variant of the embodiment of the Fig. 1 with shims 8a and 8b. The blower 1 shown in a partial section corresponds essentially to the blower 1 of the Fig. 1 and features a first shim 8a, which is arranged between the housing cover 6a and the volute 6b. The first shims 8a serve to adjust the play of the axial bearing 4. This variant also features a second shim 8b between the thrust roller 4c and the pipe section 9, which is formed integrally with the rotating sleeve 5d of the first radial bearing 5. The second shim 8b, having the axial length of the assembly, serves to adapt the thrust roller 4c, the pipe section 9, and the fan impeller 7 to the dimensions of the first end 3a. This allows manufacturing tolerances to be compensated for.

[0032] Fig.Figure 3 is a schematic representation of a fuel cell arrangement 20 with an embodiment of the blower 1, which is arranged to recirculate a volume flow to the anode arrangement. Reference symbol (part of the description) 1 blower 2 blower duct 2a Outer wall 3 Motor shaft 3a first end 3b Front surface 3c Axial bore 3D tubular section 3e transverse bore 3f inner circumferential paragraph 3g circumferential bundle 4 axial bearings 4a first foil segments 4b stationary first support disc 4c push runner 4d stationary second support disc 4e third slide segments 5 first radial bearing 5b stationary socket 5c rotating sleeve 6 cases 6a Housing cover 6b Volute 7 Blower impeller 8a, 8b shim 9 Pipe section 10 screw connection 11 Permanent magnet 12 second radial bearing A canal axis 20 Fuel cell arrangement

Claims

Blower (1) for a fuel cell arrangement (20) with an anode arrangement, for recirculating a volume flow accruing during the operation of the fuel cell arrangement (20) to the anode arrangement, characterized by a blower duct (2) with an outer wall (2a) extending along a duct axis (A), a motor shaft (3) for driving a blower impeller (7) extending within the blower duct (2) along the duct axis (A), an axial bearing (4) for supporting a first end (3a) of the motor shaft (3), wherein the axial bearing (4) has a stationary first support disk (4b) and a thrust rotor (4c) non-rotatably connected to the first end (3a) of the motor shaft (3), a first radial bearing (5) for supporting the first end (3a), a screw connection (10) which is provided to be inserted into an end face (3b) of the first end (3a) to be screwed together and to push the pusher (4c) axially towards the blower impeller (7). Blower (1) according to claim 1 , characterized by a pipe section (9) which is arranged between the pusher runner (4c) and the blower impeller (7). Blower (1) according to claim 1 , characterized in that first foil segments (4a) are arranged between the first support disk (4b) and the thrust runner (4c) of the axial bearing (4). Blower (1) according to one of the preceding claims, characterized in that second foil segments are arranged between a stationary bushing (5b) of the first radial bearing (5) and the first end (3a), preferably between the stationary bushing (5b) and a sleeve (5c) of the first radial bearing (5) rotating with the motor shaft (3). Blower (1) according to claim 4, characterized in that the rotating sleeve (5c) and the pipe section (9) are formed in one piece. Blower (1) according to one of the preceding claims, characterized in that the blower has a housing (6) wherein the housing (6) can be closed with a removable housing cover (6a). Blower (1) according to claim 6, characterized in that the first support disk (4b) is formed integrally with the housing cover (6a). Blower (1) according to claim 6 or 7, characterized in that a first shim (8a) for adjusting a clearance of the axial bearing (4) is arranged between the housing (6) and the housing cover (6a). Blower (1) according to one of the preceding claims, characterized in that the screw connection (10) is designed as a hollow screw. Blower (1) according to one of the preceding claims, characterized in that the motor shaft (3) has a tubular section (3d) for receiving a permanent magnet (11), wherein the first end (3a) is connected to the tubular section (3d). Blower (1) according to one of claims 2 to 10, characterized by a second shim (8b) which is arranged around the first end (3a) to influence an axial length of an arrangement, wherein the arrangement comprises the pusher runner (4c) and / or the pipe section (9) and / or the blower impeller (7). Blower (1) according to one of the preceding claims, characterized in that the first end (3a) has an axial bore (3c) extending from the end face (3b) and a transverse bore (3e), wherein the transverse bore (3e) opens into the axial bore (3c). Fuel cell arrangement (20) with an anode arrangement and a blower (1) according to one of the preceding claims, wherein the blower (1) is configured to return the volume flow accumulating during operation to the anode arrangement.

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