FUEL CELL SYSTEM

Abstract

The invention relates to a fuel cell system comprising a fuel cell stack (2) received in a first housing (1) and an energy supply unit received in a second housing (3), the two housings (1, 3) being connected or being capable of being connected in such a manner that openings (4, 5) provided in the housings (1, 3) are opposite one another and overlap, at least in part. According to the invention, an insert (6), which surrounds a pin or sleeve-shaped contact element (7) is arranged in the area of two opposing and at least in part overlapping openings (4, 5), wherein the insert (6) directly, or indirectly via a sealing ring (8), encloses the contact element (7) in a watertight manner and isolates same electrically at least against one of the two housings (1, 3).

Claims

1. A fuel cell system, comprising a fuel cell stack (2) which is received in a first housing (1) and an energy supply unit which is received in a second housing (3), the two housings (1, 3) being connected or configured to be connected in such a way that first and second openings (4, 5) which are provided in the first and second housings (1, 3), respectively, lie opposite one another and overlap one another at least in regions, characterized in that an intermediate piece (6) is arranged in a region of first and second openings (4, 5), which intermediate piece (6) surrounds a pin-shaped or sleeve-shaped contact element (7), the intermediate piece (6) enclosing the contact element (7) directly or indirectly via a sealing ring (8) in a water-tight manner and insulating the contact element (7) electrically at least with respect to one of the first and second housings (1, 3).

2. The fuel cell system as claimed in claim 1, characterized in that the intermediate piece (6) adjoins at least one of the first and second housings (1, 3) in a water-tight manner directly or indirectly via a peripheral sealing element (9).

3. The fuel cell system as claimed in claim 1, characterized in that the intermediate piece (6) has an outer contour, which is stepped once or multiple times, and configures at least one peripheral shoulder (11).

4. The fuel cell system as claimed in claim 1, characterized in that at least one of the first and second housings (1, 3) comprises a collar section (12, 13) which delimits a respective one of the first and second openings (4, 5).

5. The fuel cell system as claimed in claim 1, characterized in that the pin-shaped or sleeve-shaped contact element (7) is supported at at least one end on a busbar (14, 15) for electrical contacting of the fuel cell stack (2) and/or the energy supply unit.

6. The fuel cell system as claimed in claim 5, characterized in that a tie rod (16) is guided through the sleeve-shaped contact element (7) and the at least one busbar (14, 15), which tie rod (16) is fixed by a locking element at at least one end.

7. The fuel cell system as claimed in claim 6, characterized in that, at at least one end, the tie rod (16) is screwed or pressed into a locking element (18) or is configured in one piece with a locking element (18).

8. The fuel cell system as claimed in claim 7, characterized in that the locking element (18) is surrounded by an insulating body (19).

9. The fuel cell system as claimed in claim 7, characterized in that the locking element (18) is secured against rotation by way of the insulating body (19).

10. The fuel cell system as claimed in claim 1, characterized in that the fuel cell stack (2) comprises two voltage connectors (20) which are connected in an electrically conducting manner in each case via a busbar (14) and a pin-shaped or sleeve-shaped contact element (7) to a busbar (15) of the energy supply unit.

11. The fuel cell system as claimed in claim 1, characterized in that the intermediate piece (6) adjoins at least one of the first and second housings (1, 3) in a water-tight manner directly or indirectly via a peripheral sealing element (9), the sealing element (9) being received in a peripheral groove (10) of the intermediate piece (6).

12. The fuel cell system as claimed in claim 5, characterized in that a tie rod (16) is guided through the sleeve-shaped contact element (7) and the at least one busbar (14, 15), which tie rod (16) is fixed by a locking element at at least one end, a sealing ring (17) being arranged between the tie rod (16) and the contact element (7).

13. The fuel cell system as claimed in claim 12, characterized in that, at at least one end, the tie rod (16) is screwed or pressed into a nut (18) or is configured in one piece with a locking element (18).

14. The fuel cell system as claimed in claim 13, characterized in that the locking element (18) is surrounded by an insulating body (19), the locking element (18) being held in a direction parallel to the tie rod (16) in the insulating body (19) by way of an end section of the busbar (14), which end section protrudes into the insulating body (19).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the following text, the invention will be described in greater detail on the basis of the appended drawings, in which:

[0024] FIG. 1 shows a diagrammatic longitudinal section through a fuel cell system according to the invention in accordance with a first preferred embodiment,

[0025] FIG. 2 shows an enlarged detail of FIG. 1 in the region of an intermediate piece which is inserted between two housings,

[0026] FIG. 3 shows different illustrations of the intermediate piece of the fuel cell system of FIG. 1, including

[0027] a) a top view,

[0028] b) a side view,

[0029] c) a cross section and

[0030] d) a perspective illustration,

[0031] FIG. 4 shows a diagrammatic longitudinal section through a fuel cell system according to the invention in accordance with a second preferred embodiment, and

[0032] FIG. 5 shows a diagrammatic longitudinal section through a fuel cell system according to the invention in accordance with a third preferred embodiment.

DETAILED DESCRIPTION

[0033] The fuel cell system which is shown in FIG. 1 comprises a fuel cell stack 2 which is arranged on a base plate 25 and is surrounded by a housing 1. On the sides, the fuel cell stack 2 comprises two voltage connectors 20 for a positive terminal and a negative terminal. The voltage connectors 20 are connected in each case to a busbar 14. A pin-shaped or sleeve-shaped contact element 7 which serves for electrical contacting with current-conducting parts of an energy supply unit of the system is supported in each case at the free ends of the busbars 14. To this end, the contact elements 7 are routed out of the housing 1 via an opening 4 which is configured laterally in the housing 1.

[0034] The energy supply unit comprises a housing 3 which is screwed laterally onto the housing 1 of the fuel cell stack 2 and has an opening 5 which lies opposite the opening 4 of the housing 1. Therefore, the contact elements 7 protrude through the opening 5 into the housing 3 of the energy supply unit.

[0035] As can be gathered from FIG. 2, in particular, the two contact elements 7 are surrounded by an intermediate piece 6 which serves for electrical insulation and sealing. To this end, the intermediate piece 6 is manufactured from a material which is electrically insulating and tight with respect to water and gas. Via sealing rings 8, the intermediate piece 6 bears sealingly against the two contact elements 7. Via peripheral sealing elements 9 which are arranged in grooves 10 of the intermediate piece 6, the intermediate piece 6 additionally bears sealingly against the two housings 1, 3.

[0036] As can be gathered from FIGS. 3 a) to d), in particular, the intermediate piece 6 has a stepped outer contour, with the result that a peripheral shoulder 11 is configured which separates two different peripheral regions. The dimensions of the two peripheral regions are adapted to the dimensions of the two openings 4, 5. A peripheral groove 10 for receiving a peripheral sealing element 9 is configured in each peripheral region.

[0037] The intermediate piece 6 comprises two receptacles 21 for the contact elements 7. The dimensions of the receptacles 21 are therefore adapted to the dimensions of the contact elements 7. As an alternative to the embodiment shown of an intermediate piece 6 which comprises two receptacles 21, the intermediate piece 6 can also comprise only one receptacle 21 for a contact element 7. In this case, each contact element 7 can be surrounded by a dedicated intermediate piece 6 and can be electrically insulated with respect to the housings 1, 3. In each case two openings 4 and two openings 5, respectively, are then provided in the two housings 1, 3. The two intermediate pieces 6 can then be configured in each case as rotationally symmetrical bodies.

[0038] As can be gathered from FIG. 2, in particular, the openings 4, 5 which are configured in the housings 1, 3 are delimited in each case by way of a collar section 12, 13. The collar sections 12, 13 increase the dimensional rigidity of the housings 1, 3 in the region of the openings 4, 5. At the same time, the collar sections 12, 13 configure enlarged bearing areas for the peripheral sealing elements 9 which are received in the grooves 10 of the intermediate piece 6.

[0039] A second preferred embodiment of a fuel cell system according to the invention is shown in FIG. 4. Here, the housing 3 of the energy supply unit comprises two collar sections 13, 23 which are arranged on opposite sides. The collar section 23 therefore faces the collar section 12 of the first housing 1. The dimensions of the collar sections 23, 12 are selected in such a way that a collar section 12 of the first housing 1 engages into the collar section 23. In addition, the collar section 12 bears sealingly against the collar section 23 via a peripheral sealing element 22, with the result that the new sealing level between the two housings 1, 3 is produced. The sealing level between the first housing 1 and the intermediate piece 6 can therefore be dispensed with. Accordingly, the intermediate piece 6 comprises only one peripheral groove 10 with a sealing element 9 which is inserted into it and bears sealingly against the housing 3 of the energy supply unit.

[0040] A third preferred embodiment of a fuel cell system according to the invention is shown in FIG. 5. Here, the contact elements 7 are of sleeve-shaped configuration and are supported at the two ends in each case on a busbar 14, 15. Tie rods 16 are guided through the contact elements 7 and the busbars 14, 15, and are connected at the two ends to locking elements 17 in the form of nuts. Sealing rings 17 which are arranged on the tie rods 16 seal the gap between the tie rods 16 and the contact elements 7, with the result that this embodiment is also water-tight and gas-tight.

[0041] The locking elements 18 or nuts which face the fuel cell stack 2 are surrounded by an insulating body 19 which serves for electrical insulation. At the same time, the insulating body 19 serves as an assembly aid. The insulating body 19 including the nuts is held captively by way of the laterally engaging busbars 14.

[0042] During assembly, the nuts are inserted from the front into the insulating body 19. Subsequently, the insulating body 19 is pushed in each case from the side onto the end sections of the two busbars 14. After this, the intermediate piece 9 can be inserted with the two contact elements 7 into the opening 4 of the housing 1, with the result that the sealing element 9 bears sealingly against the collar section 12 of the housing 1. The tie rods 16 are introduced through the contact elements 7 and the busbars 14 and are screwed into the nuts which are received in the insulating body 19. Subsequently, the busbars 15 can be positioned and the further nuts can be screwed on. In order to generate a torque, a recess 24 for receiving a tool is provided in each case on the end side in the tie rods 16.

[0043] As an alternative to the illustration of FIG. 5, the two housings 1, 3 can also be of analogous configuration with respect to the embodiment of FIG. 4. Furthermore, the intermediate piece 6 can comprise only one receptacle 21 for an individual contact element 7.

[0044] Further modifications are conceivable unless they are inconsistent with the following patent claims.