Pump Stage Assembly, External Gear Pump, Use Of A Pump Stage Assembly and Vehicle Transmission

Abstract

A pump stage assembly for supplying lubricating oil, comprising: at least two pump suction stages and at least one pump pressure stage. The pump suction stages and the pump pressure stage are spaced apart from one another in a pump housing PG and have a common drive shaft. The pump suction stages are formed by a first assembly of at least three intermeshing external gearwheels and wherein the pump pressure stage is formed by a second assembly of two intermeshing external gearwheels. Here at least two respective tooth center points of the first external gearwheel assembly and the respective tooth center points of the second external gearwheel assembly are arranged in a common plane E-E which intersects the pump housing PG in a longitudinal direction.

Claims

1.-16. (canceled)

17. A pump stage assembly configured to supply a lubricating oil to at least one consumer, comprising: a pump housing; at least two pump suction stages formed by a first external gearwheel assembly of at least three intermeshing external gearwheels that lie in a first plane and configured to: draw in the lubricating oil from a first oil container functioning as a dry sump, and deliver the lubricating oil to a second oil container functioning as an oil tank; and at least one pump pressure stage formed by a second external gearwheel assembly of two intermeshing external gearwheels which lie in a second plane and configured to: draw in the lubricating oil from the second oil container, and deliver the lubricating oil to a consumer, wherein the at least two pump suction stages and the at least one pump pressure stage are arranged spaced apart from one another in the pump housing and have a common drive shaft, wherein the first plane and the second plane lie parallel to one another, wherein at least two respective tooth center points of the first external gearwheel assembly and respective tooth center points of the second external gearwheel assembly are arranged in a common plane that intersects the pump housing in a longitudinal direction and lies orthogonal to the first and second planes.

18. The pump stage assembly as claimed in claim 17, wherein at least two pump pressure stages are provided formed by the second assembly of at least three intermeshing external gearwheels, wherein the at least two respective tooth center points of the first external gearwheel assembly and at least two of the respective tooth center points of the second external gearwheel assembly are arranged in the common plane.

19. The pump stage assembly as claimed in claim 17, wherein the respective tooth center points of all gearwheels of the first external gearwheel assembly and the respective tooth center points of all gearwheels of the second external gearwheel assembly are arranged in the common plane.

20. The pump stage assembly as claimed in claim 17, wherein the first oil container and/or the second oil container forms an oil reservoir in an interior of an at least one-stage or two-stage transmission for driving a vehicle.

21. The pump stage assembly as claimed in claim 17, wherein the pump stage assembly is configured as part of a plug-in pump solution for arrangement on an at least one-stage or two-stage transmission for driving a vehicle, wherein the plug-in pump solution is flanged to a transmission housing of the transmission and protrudes into the transmission housing.

22. The pump stage assembly as claimed in claim 21, wherein the plug-in pump solution is configured as a substantially cylindrical body.

23. The pump stage assembly as claimed in claim 22, wherein a hydraulic connection of the pump suction stages and/or the at least one pump pressure stage to an oil reservoir is designed radially to the respective portion of the pump housing.

24. The pump stage assembly as claimed in claim 23, wherein a hydraulic connection to a pressure side of the at least one pump pressure stage is provided on a face of an end of the pump housing protruding into the transmission housing.

25. The pump stage assembly as claimed in claim 24, wherein a hydraulic connection to a suction side of the pump suction stages is provided on the face of the end of the pump housing protruding into the transmission housing.

26. The pump stage assembly as claimed in claim 24, wherein a hydraulic connection to the pressure side of the pump suction stages and to a suction side of the at least one pump pressure stage is provided on the face of the end of the pump housing protruding into the transmission housing.

27. The pump stage assembly as claimed in claim 17, wherein the first oil container is divided into at least two regions by at least one wall.

28. The pump stage assembly as claimed in claim 17, wherein the common drive shaft is driven by an electric motor and/or mechanically.

29. A multiple action, external gear pump having a pump stage assembly configured to supply a lubricating oil to at least one consumer, comprising: a pump housing; at least two pump suction stages formed by a first external gearwheel assembly of at least three intermeshing external gearwheels that lie in a first plane and configured to: draw in the lubricating oil from a first oil container functioning as a dry sump, and deliver the lubricating oil to a second oil container functioning as an oil tank; and at least one pump pressure stage formed by a second external gearwheel assembly of two intermeshing external gearwheels which lie in a second plane and configured to: draw in the lubricating oil from the second oil container, and deliver the lubricating oil to a consumer, wherein the at least two pump suction stages and the at least one pump pressure stage are arranged spaced apart from one another in the pump housing and have a common drive shaft, wherein the first plane and the second plane lie parallel to one another, wherein at least two respective tooth center points of the first external gearwheel assembly and respective tooth center points of the second external gearwheel assembly are arranged in a common plane that intersects the pump housing in a longitudinal direction and lies orthogonal to the first and second planes.

30. The pump stage assembly as claimed in claim 17, wherein the pump stage assembly supplies lubricating oil to an at least one-stage or two-stage transmission for driving a vehicle.

31. The pump stage assembly as claimed in claim 28, wherein the pump stage assembly is configured to cool an electric motor driving an electric vehicle.

32. A vehicle transmission for driving a vehicle, wherein the vehicle transmission has a pump stage assembly configured to supply a lubricating oil to at least one consumer, comprising: a pump housing; at least two pump suction stages formed by a first external gearwheel assembly of at least three intermeshing external gearwheels that lie in a first plane and configured to: draw in the lubricating oil from a first oil container functioning as a dry sump, and deliver the lubricating oil to a second oil container functioning as an oil tank; and at least one pump pressure stage formed by a second external gearwheel assembly of two intermeshing external gearwheels which lie in a second plane and configured to: draw in the lubricating oil from the second oil container, and deliver the lubricating oil to a consumer, wherein the at least two pump suction stages and the at least one pump pressure stage are arranged spaced apart from one another in the pump housing and have a common drive shaft, wherein the first plane and the second plane lie parallel to one another, wherein at least two respective tooth center points of the first external gearwheel assembly and respective tooth center points of the second external gearwheel assembly are arranged in a common plane that intersects the pump housing in a longitudinal direction and lies orthogonal to the first and second planes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Further advantageous developments of the present invention will emerge from the dependent claims and from the following description of preferred embodiments. The drawing shows schematically:

[0033] FIG. 1 is a first gearwheel assembly ZA.sub.1 forming two pump suction stages, and combined therewith a second gearwheel assembly ZA.sub.2 forming two pump pressure stages;

[0034] FIG. 1A the first gearwheel assembly ZA.sub.1 shown in FIG. 1 in an enlarged depiction;

[0035] FIG. 2A is a pump housing PG with the two gearwheel assemblies ZA.sub.1, ZA.sub.2 shown in FIG. 1;

[0036] FIG. 2B is cross section along line A-A of the pump housing PG shown in FIG. 2A;

[0037] FIG. 3 is a plug-in pump solution;

[0038] FIG. 4 is a plug-in pump solution;

[0039] FIG. 5 is a plug-in pump solution;

[0040] FIG. 6 is an illustration of gearwheel designs; and

[0041] FIG. 7 an illustration of delivery flows.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0042] FIG. 1 illustrates a pump stage assembly 2 as part of a multiple action, external gear pump that serves firstly for supplying lubricating oil to an at least a one-stage or two-stage vehicle transmission V.sub.1 for driving an electric vehicle, and secondly for cooling an electric motor V.sub.2 for driving the electric vehicle, which motor forms a drive unit with the vehicle transmission V.sub.1.

[0043] The pump stage assembly 2 comprises two pump suction stages 4, 6 for drawing in a lubricating oil from a first oil container 24, functioning as a dry sump, and for conveying the lubricating oil to a second oil container 26 (the actual oil container or oil tank), and two pump pressure stages 8, 10 for drawing in the lubricating oil from the second oil container 26 and delivering it to the two consumers V.sub.1, V.sub.2.

[0044] The pump stage assembly 2 is part of an at least substantially cylindrical plug-in pump solution, which is flanged to a housing 62, 64 of the vehicle transmission, wherein the plug-in pump solution protrudes into the housing 62, 64 (see FIG. 3, FIG. 4, FIG. 5). The pump housing PG forming the cylindrical body is advantageously injection-molded from a plastic.

[0045] The pump suction stages 4, 6 and the pump pressure stages 8, 10 are arranged spaced apart from one another in the pump housing PG and have a common drive shaft 56. This drive shaft 56 is driven by an electric motor (E-motor) M in the context of the embodiments proposed here. In principle however, the plug-in pump solutions could also be driven purely mechanically.

[0046] The pump suction stages 4, 6 are formed by a first assembly ZA.sub.1 of three intermeshing external gearwheels 12, 14, 16, whereas the pump pressure stages 8, 10 are formed by a second assembly ZA.sub.2 of three intermeshing external gearwheels 18, 20, 22. The external gearwheel assembly ZA.sub.1 lies in a first plane, and the external gearwheel assemblies ZA.sub.2 lie in a second plane parallel thereto. FIG. 2 illustrates a pump housing PG with a housing part 50 which receives both the two external gearwheel assemblies ZA.sub.1, ZA.sub.2 and also the drive shaft 56 and two axles 58, 60. The drive shaft 56 extends through the gearwheels 12, 18 and drives these, while the axle 58 extends through the driven gearwheels 14, 20 and the axle 60 through the driven gearwheels 16, 22. With a corresponding design, instead of the axles 58, 60, shafts 58, 60 may be provided. The housing part 50 is joined to a first housing cover 52 and a second housing cover 54 (see FIG. 2). The pump housing PG, 50, 52, 54 is furthermore combined with the above-mentioned electric motor M, which drives the drive shaft 56 on which the two driving gearwheels 12, 18 are arranged.

[0047] The respective tooth center points ZM.sub.1, ZM.sub.2, ZM.sub.3 of all gearwheels of the first external gearwheel assembly ZA.sub.1 and the respective tooth center points ZM.sub.4, ZM.sub.5, ZM.sub.6 of all gearwheels of the second external gearwheel assembly ZA.sub.2 are arranged in a common third plane E-E which intersects the pump housing PG in a longitudinal direction or longitudinal extent X-X (see FIG. 2). The plane E-E lies orthogonally to the above-mentioned first and second planes of the respective external gearwheel assembly ZA.sub.1, ZA.sub.2.

[0048] Depending on the fill level, the lubricating oil or—and this is normally the case—only a mixture of lubricating oil and air is drawn in via two intake lines 28, 30, which each protrude into a respective one of two regions 24.sub.I, 24.sub.II of the dry sump 24, which is divided by a wall W. The wall W dividing the dry sump 24 helps evacuate the dry sump 24, because the dry sump 24 must be kept as dry or empty as possible in all vehicle positions.

[0049] The intake line 30 leads to a first pump suction stage suction connection SE.sub.I of the first pump suction stage 4 formed by the two gearwheels 12, 14, while the suction line 28 leads to a second pump suction connection SE.sub.II of the second pump suction stage 6 formed by the two gearwheels 12, 16. A line 32 leads from the first pump suction stage pressure connection SA′, also formed by the two gearwheels 12, 14, to the oil tank 26. Similarly, a line 34 leads from the second pump suction stage pressure connection SA.sub.II, also formed by the two gearwheels 12, 16, to the oil tank 26 (see FIG. 1a). Alternatively, the line 32 may also open into the line 34, which then opens in the oil tank (see FIG. 1).

[0050] Via a suction line 36, the lubricating oil is then conveyed firstly via a first pump pressure stage suction connection DE′ (see intake line 38, which branches from the intake line 36 and leads to the pump pressure stage suction connection DE.sub.I) and a first pump pressure stage pressure connection DA.sub.I of the first pump pressure stage 8—each formed by the two gearwheels 18, 20—and a line 42 to the vehicle transmission V.sub.1. Secondly, the lubricating oil is also conveyed via a second pump pressure stage suction connection DE.sub.II and a second pump pressure stage pressure connection DA.sub.II of the second pump pressure stage 10—each formed by the two gearwheels 18, 22—and a line 42 to the electric motor V.sub.2.

[0051] In a proposed first embodiment of the plug-in pump solution (see FIG. 3), an oil tank 26 is formed in the interior of the transmission housing 62, 64. A single one or two pump pressure stage(s) DS is/are arranged between the electric motor M, arranged on the transmission wall side, and two pump suction stages SS. The hydraulic connection of the suction side of the pump pressure stage(s) DS (see intake A.sub.DS) firstly, and of the pressure stage (see outlet A.sub.SD) of the pump suction stages SS secondly, to the oil tank 26 are each designed radially to the respective portion of the pump housing PG. The pump pressure stage(s) DS is/are accordingly sealed circumferentially against the pump suction stages SS (see seal DI). A hydraulic connection of the pump plug-in solution to a dry sump 24 (separate therefrom) firstly, and to the two above-mentioned consumers secondly, is provided in each case on the face of the pump end protruding into the transmission housing 62, 64 (see intake A.sub.SS1, intake A.sub.SS2 of the respective suction stage SS and outlet A.sub.DD1, outlet A.sub.DD2 of the respective pressure stage DS).

[0052] Alternatively, in a proposed second embodiment of the plug-in pump solution (see FIG. 4), a dry sump 24 is formed in the interior of the transmission housing 62, 64. Two pump suction stages SS are arranged between an electric motor M, arranged on the transmission wall side, and two pump pressure stages DS. The hydraulic connection of the two pump suction stages SS (see intake A.sub.SS1, intake A.sub.SS2) to the dry sump 24 is in each case designed radially to the pump housing PG. The pump pressure stages DS are accordingly sealed circumferentially against the pump suction stages SS (see seal DI). A hydraulic connection of the plug-in pump solution to an oil tank 26 (separate therefrom) firstly, and to the two above-mentioned consumers V.sub.1, V.sub.2 secondly, is provided in each case on the face of the pump end protruding into the transmission housing 62, 64 (see pressure-side outlet A.sub.SD of the pump suction stages SS, intake A.sub.DS of the pump pressure stages DS, pressure-side outlets A.sub.DD1, outlet A.sub.DD2 of the pump pressure stages DS).

[0053] In a proposed third embodiment of the plug-in pump solution however (see FIG. 5), both an oil tank 26 and a dry sump 24.sub.I, 24.sub.II, which is divided by a wall W, are formed in the interior of the transmission housing 62, 64. The oil tank 26 is furthermore sealed accordingly against the dry sump 24 (see seal DI). Two pump suction stages SS are arranged between an electric motor M, arranged on the transmission wall side, and two pump pressure stages DS. The hydraulic connection of the two pump suction stages SS (see intake A.sub.SS1, intake A.sub.SS1 of the pump suction stages SS) to the dry sump 24.sub.I, 24.sub.II firstly, and of the two pump pressure stages DS to the oil tank 26 secondly (intake A.sub.DA1, intake A.sub.DA2 of the pump pressure stages DS), are each designed radially to the pump housing PG. The hydraulic connection of the pressure-side outlet A.sub.SD of the two pump suction stages SS also leads into the oil tank 26, radially with respect to the pump housing PG. The pump pressure stages DS are accordingly sealed circumferentially against the pump suction stages SS (see seal DI). A hydraulic connection of the plug-in pump solution to the two above-mentioned consumers V.sub.1, V.sub.2 is provided in each case on the face of the pump end protruding into the transmission housing 62, 64 (see outlet A.sub.DD1, outlet A.sub.DD2 of the pump pressure stages DS).

[0054] The common feature of all these embodiments is that a motor electronic unit ME is arranged outside the transmission housing 62, 64 (see FIG. 3, FIG. 4, FIG. 5, in each case on the right of the flange connection). This allows firstly simple electrical contacting of the electric motor or motor electronic unit ME, and secondly a corresponding heat exchange from the motor electronic unit ME to the environment.

[0055] FIG. 6 illustrates a design of three intermeshing external gearwheels forming two pump suction stages or pump pressure stages, wherein preferably the middle gearwheel is the driven gearwheel. All three gearwheels of this external gearwheel assembly have the same cross-sectional geometry, i.e. also the same number of teeth. The two outer gearwheels also have the same axial distance from the middle gearwheel. Only the right-hand gearwheel for example has a shorter longitudinal extent than the other two gearwheels. In principle, these axial spacings could also be different. Also, the number of teeth of the two outermost external gearwheels could be set differently from that of the inner external gearwheel.

[0056] FIG. 7 illustrates schematically as an example a division and intermixing of delivery flows, as formed firstly with respect to the two pump suction stages (see ZA.sub.1) and secondly with respect to the two pump pressure stages (see ZA.sub.2) within the pump housing PG. Whereas the two pump suction stages convey an air flow or oil-air flow from the dry sump 24.sub.I, 24.sub.II (region 24.sub.I, region 24.sub.II) into the oil tank 26, the two pump pressure stages each convey an oil flow from the oil tank 26 to the respective assigned consumer V.sub.1, V.sub.2. The individual thicknesses of the arrows qualitatively illustrate a corresponding delivery volume flow. In principle, the respective inflows and outflows of the individual pump stages may be established as required, in particular via a corresponding design of the external gearwheels (for this, see the individual different gearwheel lengths in FIG. 7).

[0057] The plug-in pump solutions described in the context of this disclosure each allow a very compact pump solution suitable for the described flanging to the vehicle transmission V.sub.1. The number of rotating components is kept to a minimum, which is associated with a reduction in friction losses. Also, weight is saved.

[0058] The plug-in pump solutions described each allow implementation of a dry sump system with only six external gearwheels.

[0059] It is also pointed out that the exemplary embodiments shown are merely examples which in no way restrict the scope of protection, the applications or design. Instead, the above description gives a person skilled in the art a guideline for the realization of at least one exemplary embodiment, and various changes can be made here, in particular with regard to the function and arrangement of the component parts described, without departing from the scope of protection resulting from the claims and feature combinations equivalent thereto.

[0060] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.