PUMP DEVICE FOR A COOLING CIRCUIT OF AN INTERNAL COMBUSTION ENGINE OF A COMMERCIAL OR MOTOR VEHICLE

Abstract

A pump device for a cooling circuit of an internal combustion engine of a commercial or motor vehicle includes two electric pumps in parallel, each of which includes a switchable backflow valve in a suction line, so that the electric pumps can be operated selectively individually or in parallel.

Claims

1. A pump device for use in a cooling circuit of an internal combustion engine of a commercial or motor vehicle, the pump device comprising: two electric pumps in parallel; wherein each of the two electric pumps includes a switchable backflow valve included in a suction line so that the electric pumps are selectively operable individually or in parallel.

2. The pump device according to claim 1, wherein the switchable backflow valve of each of the two electric pumps is a 2/2-way valve.

3. The pump device according to claim 1, wherein the switchable backflow valve of each of the two electric pumps is pneumatically or electrically operable.

4. The pump device according to claim 1, wherein the switchable backflow valve of each of the two electric pumps prevents a backflow of a coolant in the cooling circuit when in a blocking position.

5. The pump device according to claim 1, wherein one of the electric pumps defines a main pump which is operated in a normal state and whose associated switchable backflow valve is in a flow position; and a second of the electric pumps defines a secondary pump which is switched off in the normal state and whose associated switchable backflow valve is in a shut-off position.

6. The pump device according to claim 1, wherein the electric pumps are identical.

7. The pump device according to claim 1, further comprising: an adapter housing in which the switchable backflow valves are provided; wherein the two electric pumps are attachable to the adapter housing and the adapter housing includes an interface permitting connection to an internal combustion engine.

8. The pump device according to claim 7, wherein the adapter housing includes a flange side to connect to a cooling circuit of an internal combustion engine, on which a suction flange with a third sealing surface and a discharge flange with a fourth sealing surface are provided; the adapter housing includes a pump side, opposite to the flange side, to connect to the two electric pumps; the adapter housing further includes: a first discharge line and a second discharge line; the suction lines; a first pump working chamber adjoining a first of the suction lines and surrounded by a first sealing surface, and a second pump working chamber adjoining a second of the suction lines and surrounded by a second sealing surface; and a valve device including the two switchable backflow valves, which are adjustable between a blocking position and an open position; the pump working chambers each define an opening in the pump side, the discharge flange is connected to the two discharge lines via a discharge connector and the suction flange is connected to the two suction lines; and each of the switchable backflow valves interacting with respective ones of the two suction lines and closing off the corresponding suction lines in the shut-off position, and opening the corresponding suction lines in the open position.

9. The pump device according to claim 1, wherein the switchable backflow valves are operable from an outside of the pump device.

10. The pump device according to claim 9, wherein the suction port adjoins the suction flange opening downstream and divides into the two suction lines.

11. The pump device according to claim 8, wherein the suction port adjoins the suction flange opening downstream and divides into the two suction lines.

12. The pump device according to claim 1, wherein the discharge lines join to define the discharge port located upstream of the discharge flange opening.

13. The pump device according to claim 8, wherein the suction port has a larger cross-section than one of the suction lines.

14. The pump device according to claim 8, wherein the discharge port has a larger cross-section than that of one of the discharge lines.

15. The pump device according to claim 8, wherein a first one of the two switchable backflow valves is located in a transition region between the first suction line and the first pump working space, and a second one of the two switchable backflow valves is located in a transition region between the second suction line and the second pump working space.

16. A commercial vehicle comprising an internal combustion engine which can be cooled by a cooling circuit, and a pump device according to claim 1 which is adapted to circulate a coolant in the cooling circuit.

17. A commercial vehicle comprising an internal combustion engine which can be cooled by a cooling circuit, and a pump device according to claim 8 which is adapted to circulate a coolant in the cooling circuit; wherein the pump device is connected to the internal combustion engine of the commercial vehicle via the suction flange and the discharge flange.

18. A motor vehicle comprising an internal combustion engine which can be cooled by a cooling circuit, and comprising the pump device according to claim 1 to circulate a coolant in the cooling circuit.

19. A motor vehicle comprising an internal combustion engine which can be cooled by a cooling circuit, and comprising the pump device according to claim 8 to circulate a coolant in the cooling circuit; wherein the pump device is connected to the internal combustion engine of the motor vehicle via the suction flange and the discharge flange.

20. A method of operating the pump device according to claim 1, wherein the method comprises: in an event that the required volume flow in the cooling circuit is low, operating the pump device in a single operation such that the backflow valve of the operated electric pump is brought into a flow position and the backflow valve of the switched-off electric pump is in a blocking position; and in a case that the required flow rate in the cooling circuit is higher than a predetermined level, operating the pumping device in a parallel mode with both of the electric pumps are operating and the backflow valves are in a flow position.

21. The method of claim 20, further comprising the steps of: in an event of failure of one of the electric pumps, operating the other one of the electric pumps and setting the associated backflow valve to the flow position, and setting the backflow valve of the one of the electric pumps to the shut-off position.

22. A method according to claim 20, wherein the pump device is included in a commercial or motor vehicle with an internal combustion engine, the internal combustion engine being coolable by a cooling circuit and the pump device being used to circulate coolant in the cooling circuit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In the following, example embodiments of the present disclosure are described with reference to the drawings. Identical components or components with identical functions bear identical reference signs.

[0025] FIG. 1 is a block diagram of a pump device according to an example embodiment of a coolant circuit of an internal combustion engine of a commercial vehicle according to the present disclosure.

[0026] FIG. 2 is an illustration of a pump device according to an example embodiment of the present disclosure with two electric pumps.

[0027] FIG. 3 is a view of the pump side of an adapter housing of a pump device.

[0028] FIG. 4 is a view of the flange side of an adapter housing.

[0029] FIG. 5 is a sectional view through the adapter housing along a sectional line A-A according to FIG. 3.

[0030] FIG. 6 is a sectional view through the adapter housing along a sectional line B-B according to FIG. 3.

[0031] FIG. 7 is a sectional view through the adapter housing along a sectional line C-C according to FIG. 3.

DETAILED DESCRIPTION

[0032] FIG. 1 shows a circuit diagram of a pump device 1 according to an example embodiment of the present disclosure. The pump device 1 is a portion of a coolant circuit of an internal combustion engine in commercial vehicles. Driven by the pump device 1, a coolant circulates in the cooling circuit and causes cooling of the internal combustion engine. The coolant is preferably water.

[0033] The pump device 1 preferably includes two identical electric pumps 2,3 connected in parallel. In the respective suction line 4 of the two pumps 2,3, a backflow flow valve 5,6 is provided in each case. The backflow valves 5,6 are switchable. One of the electric pumps 2 defines the main pump. The other electric pump 3 serves as a slave pump. The first backflow flow valve 5 arranged upstream of the main pump 2 is spring-biased and pneumatically operable. When the main pump 2 is operated, the backflow flow valve 5 can be flowed through in a flow position in the delivery direction. When the main pump 2 is switched off, the first backflow flow valve 5 is actuated and transferred into a blocking position against the spring force. The second backflow valve 6, which is arranged upstream of the secondary pump 3 in the direction of flow, can be actuated electrically by means of an electromagnet which has two windings acting in opposite directions. In the event that the secondary pump 3 is not operated, the second backflow valve 6 is in a blocking position. If, on the other hand, the secondary pump 3 is used, the second backflow valve 6 is transferred to a flow position.

[0034] Commercial vehicles, especially trucks, mainly drive in the partial load range, the required volume flow can then be generated by a single one of the two electric pumps 2,3. The backflow valves 5,6 in the suction area of the electric pumps 2,3 prevent an undesired backflow of the coolant through the passive electric pump in single operation. The pump efficiency is increased, as this is greater with a smaller pump being operated close to the design point than the pump efficiency of a large pump in the partial load range.

[0035] In single operation, due to the two identical pumps 2,3, it is possible to switch between the two pumps and divide the running times equally between the two pumps. In case of increased cooling demand, both electric pumps 2,3 are operated in parallel.

[0036] The presence of two pumps 2,3 of the same type creates redundancy in case of failure of one pump. If an electric pump 2,3 fails in single operation, the functional pump can replace the failed pump, as they are identical in construction. In parallel operation, if one pump fails, the functional pump can generate a reduced volume flow to cool the combustion engine. In addition, the use of two identical pumps is more cost-effective, since only one pump type has to be designed and this can be produced in higher quantities.

[0037] It is also conceivable that the pump device is used in motor vehicles. Here, too, the above-mentioned advantages result.

[0038] FIG. 2 shows a side view of the pump device 1. The pump device 1 includes a special adapter housing 7, which defines an interface to the combustion engine 8. Retrofitting of the pump device 1 in already existing systems is thus possible. The two backflow valves are installed in the adapter housing 7, which prevent the coolant from flowing back in the blocked position.

[0039] FIGS. 3 and 4 show the adapter housing 7 of the pump device 1. This includes a pump side 9 and a flange side 10 opposite the pump side. For connection to an internal combustion engine 4, the circumferential edge sides of the adapter housing 1 are structured in accordance with the necessary installation space dimensions and the requirements of the installing space and structures. As shown in FIG. 3, two pump working spaces 11a, 11b are on the pump side 9 in the adapter housing 7. These pump working spaces 11a, 11b are preferably defined by cylindrical recesses on the adapter housing 7.

[0040] A rotational symmetry axis A passes perpendicularly through the center of the base of a first pump working space 11a. A rotational symmetry axis B extends perpendicularly through the center of the base surface of a second pump working chamber 11b. The first pump working space 11a is surrounded by a first sealing surface 12a on the pump side of the adapter housing. The second pump working space 11b is surrounded by a second sealing surface 12b on the pump side of the adapter housing. The sealing surfaces 12a, 12b define planar contact surfaces so that a respective planar sealing surface of a flange of an electric pump can be brought into contact with a sealing surface 12a, 12b. Thus, an electric pump can be connected to a respective pump working chamber 11a,11b. The electric pumps not shown are preferably identical. However, it may also be provided that two different electric pumps, in particular a main pump and a secondary pump, are connectable to the pump working spaces 11a, 11b. On one edge, the pump side 9 is defined as a mounting flange 13 with which the adapter housing 7 can be connected to an internal combustion engine 8. The fastening flange 13 includes recesses 14a-14f through which, for example, fastening screws (not shown) can be guided to fasten the adapter housing 7 to the internal combustion engine 8. As shown in FIG. 4, the adapter housing 7 includes on the flange side 10 a suction flange 15 with a sealing surface 16 running around the flange side and a discharge flange 17 with a circumferential sealing surface 18 for connection to the internal combustion engine 8.

[0041] FIGS. 5 to 7 show sectional views through the adapter housing 7. The suction flange 15, which is arranged on the flange side 10 of the adapter housing 7, includes a suction flange opening 19. The suction flange opening 19 also defines the opening of a suction port 20. The suction port 20 is preferably a channel inside the suction flange 15, which runs parallel to the axes of rotational symmetry A, B. According to FIG. 5, which shows a section through the adapter housing 7 along a section line A-A marked in FIG. 1 and the axis of rotational symmetry B, two suction lines 21a,21b, which run in a radial direction with respect to an axis of rotational symmetry of the suction port 20, the latter running parallel to the axes of rotational symmetry A,B of the pump working spaces 11a,11b, and each running in the direction of a pump working space 11a,11b. In a transition region between a radial portion of the first suction line 21a and the first pump working space 11a, the radial portion of the first suction line 21a merges, by a right-angled deflection, into a parallel portion of the first suction line 21a which extends parallel to the rotational symmetry axis A and connects the radial portion of the first suction line 21a to the first pump working space 11a. In a transition region between a radial portion of the second suction conduit 21b and the second pump working chamber 11b, the radial portion of the second suction conduit 21b merges, by a right-angled deflection, into a parallel portion of the second suction conduit 21b which runs parallel to the axis of rotational symmetry B and connects the radial portion of the second suction conduit 21b to the second pump working chamber 11b. One pump working chamber 11a,11b is connected to each suction conduit 21a,21b. The first pump working space 11a is connected to the first suction conduit 21a. The second pump working chamber 11b connects to the second suction conduit 21b. In a further example embodiment, at least one of the pump working spaces 11a,11b may be defined in the pump side 9 of the adapter housing 7. The other of the pump working spaces 11a,11b may be defined in the pump side 9 or in the flange side 10 of the adapter housing 7. A first one of the backflow valves 5 is arranged in a parallel portion of the suction conduit 15b. The adjusting element 16 preferably includes a valve flap which is rotatably mounted about an axis of rotation. A discharge line 22a,22b is connected to each of the pump working chambers 11a,11b. A first discharge line 22a is connected to the first pump working chamber 11a. As shown in FIG. 6, which shows a section through the adapter housing 7 along a section line B-B marked in FIG. 3 and the axis of rotational symmetry A, a portion of the first discharge line 22a extends radially to the axis of rotational symmetry A in a transition region between the first pump working space 11a and a portion of the first discharge line 22a extending parallel to the axis of rotational symmetry A and merges into the portion of the first discharge line 22a extending parallel to the axis of rotational symmetry A by a right-angled deflection. A second discharge line 22b is connected to the second pump working chamber 11b. As shown in FIG. 7, which shows a section through the adapter housing 7 along a section line C-C marked in FIG. 3 and the axis of rotational symmetry B, a portion of the second discharge line 22b extends radially to the axis of rotational symmetry B in a transition region between the second pump working space 11b and a portion of the second discharge line 22b extending parallel to the axis of rotational symmetry B and merges into the portion of the second discharge line 22b extending parallel to the axis of rotational symmetry B by a right-angled deflection. Both discharge lines 22a,22b join to define a discharge port 23 defining a channel inside the discharge flange 17, the discharge port 23 having its rotational symmetry axis parallel to the rotational symmetry axes A, B. The discharge flange 17 defines a discharge flange opening 24. The discharge flange opening 24 simultaneously forms in the flange side 10 of the adapter housing 7 the opening of the discharge port 23 and of the discharge flange 17.

[0042] In parallel operation of both electric pumps connected to the pump working spaces 11a,11b, the coolant flows from the internal combustion engine 8 into the adapter housing 7 through the suction flange 15 which is connected to the internal combustion engine 8, flows through the suction port 20 and splits to the two suction pipes 21a,21b downstream of the suction port 20. The coolant is drawn towards the pump working spaces 11a,11b. The impellers (not shown) of the electric pumps force the coolant radially to the axes of rotational symmetry A, B into the discharge lines 22a,22b. The coolant flows along the two discharge lines 22a,22b until the coolant is recombined downstream of the discharge lines 22a,22b in the discharge port 23. The coolant exits the adapter housing 7 through the discharge flange 17 and flows back into the internal combustion engine 8. During individual operation of the electric pumps connected to the pump working chambers 11a,11b, the backflow flow valve 5 is in the shut-off position. Accordingly, the coolant flows only through the released suction line 21a.

[0043] While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.