DRIVE SYSTEM AND DRIVE TRANSMISSION

Abstract

The invention relates to a drive system comprising a drive unit having a drive housing. The invention also relates to a drive transmission which comprises the drive system. The drive system comprises: a drive unit (1) having a drive housing (20); and a flow guide element (40) which is mechanically fixed to the outside of the drive housing (20) and which has at least a first cavity boundary (42) for forming at least regions of a first fluid reservoir (44), wherein a first cavity (43) that is delimited at least in regions by the first cavity boundary (42) is or can be fluidically connected to a lubrication device (60). The drive system proposed herein and the drive transmission comprising the drive system provide a means which can be used to lubricate connected or integrated transmission components in a straightforward, cost-effective and space-saving manner.

Claims

1. A drive system comprising a drive unit having a drive housing and a flow guide element mechanically fixed on an outside of the drive housing, which has at least a first cavity boundary for forming at least regions of a first fluid reservoir, wherein a first cavity, which is delimited at least in regions by the first cavity boundary is or can be fluidically connected to a lubrication device.

2. The drive system according to claim 1, wherein the flow guide element has at least one second cavity boundary for forming at least regions of a second fluid reservoir, wherein a second cavity, which is delimited at least in regions by the second cavity boundary is or can be fluidically connected to the lubrication device.

3. The drive system according to claim 2, wherein the flow guide element forms a flow channel at least in regions for supplying fluid into at least one of the cavities.

4. The drive system according to claim 3, wherein a flow bifurcation is formed in the flow channel for supplying fluid to the first cavity and to the second cavity.

5. The drive system according to claim 4, wherein the flow guide element has a baffle element for providing a baffle effect for a fluid impinging on the baffle element at above a limit velocity, for distributing the fluid through the flow bifurcation into the first cavity and into the second cavity.

6. The drive system according to claim 2, wherein the second cavity has an overflow device, by way of which fluid can flow into the first cavity when a limit level in the second cavity is exceeded.

7. A drive transmission, comprising a drive system according to claim 1, wherein the drive transmission further comprises a transmission with a transmission housing, and at least one cavity, which is delimited at least in regions by a cavity boundary, is delimited axially on one side by the outside of the transmission housing.

8. The drive transmission according to claim 7, wherein the lubrication device is formed in or on a differential gear shaft bearing and/or an intermediate gear shaft bearing of the transmission connected to the drive unit.

9. The drive transmission according to claim 7, wherein the drive transmission comprises a differential transmission with a differential gear, wherein the differential gear has the function of a paddle wheel pump and is arranged and designed in such a way that a volumetric flow of fluid delivered by way of the differential gear can be supplied to the flow guide element.

10. The drive transmission according to claim 7, wherein the transmission housing has a raised structure on its outside, and in that the flow guide element is complementary to a shape and size of the structure in a contact region on the outside of the transmission housing.

11. A drive unit comprising: a drive housing; and a flow guide element mechanically fixed to an outside of the drive housing, wherein the flow guide element comprises at least a first cavity boundary for forming one or more regions of a first fluid reservoir, wherein the first cavity boundary defines a first cavity, wherein the first cavity is fluidically connectable to a lubrication device.

12. The drive unit according to claim 11, wherein the flow guide element comprises a second cavity boundary for forming one or more regions of a second fluid reservoir, wherein the second cavity boundary defines a second cavity, wherein the second cavity is fluidically connectable to the lubrication device.

13. The drive unit according to claim 12, wherein the flow guide element forms a flow channel for supplying fluid into at least one of the first cavity or the second cavity.

14. The drive unit according to claim 13, wherein a flow bifurcation is formed in the flow channel for supplying fluid to the first cavity and to the second cavity.

15. The drive unit according to claim 14, wherein the flow guide element comprises a baffle element for providing a baffle effect for a fluid impinging on the baffle element for distributing the fluid through the flow bifurcation into the first cavity and into the second cavity.

16. The drive unit according to claim 12, wherein the second cavity comprises an overflow device configured to allow fluid to flow into the first cavity when a limit level in the second cavity is exceeded.

17. A drive system comprising: a transmission comprising a transmission housing and at least one cavity defined in one or more regions by a cavity boundary, a drive unit comprising a drive housing and a flow guide element mechanically fixed to an outside of the drive housing, wherein the flow guide element comprises at least a first cavity boundary for forming one or more regions of a first fluid reservoir, wherein the first cavity boundary defines a first cavity, wherein the first cavity is fluidically connectable to a lubrication device.

18. The drive transmission according to claim 17, wherein the lubrication device is formed in or on a differential gear shaft bearing and/or an intermediate gear shaft bearing of the transmission connected to the drive unit.

19. The drive system according to claim 17, wherein the drive transmission comprises a differential transmission with a differential gear.

20. The drive transmission according to claim 17, wherein an exterior of the transmission housing includes a raised structure, wherein the flow guide element is complementary to the raised structure in a contact region on the exterior of the transmission housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The disclosure described above is explained in detail below against the relevant technical background with reference to the associated drawings, which show preferred developments. The disclosure is in no way limited by the purely schematic drawings and it should be noted that the exemplary embodiments shown in the drawings are not limited to the dimensions shown. In the figures:

[0052] FIG. 1: shows a perspective view of a flow guide element,

[0053] FIG. 2: shows a front view of the flow guide element,

[0054] FIG. 3: shows a perspective view of the flow guide element,

[0055] FIG. 4: shows a portion of a transmission housing,

[0056] FIG. 5: shows a perspective view of another portion of a transmission housing,

[0057] FIG. 6: shows an axial view of a drive unit,

[0058] FIG. 7: shows a perspective view of an axial end region of the drive unit,

[0059] FIG. 8: shows an enlarged perspective view of the axial end region of the drive unit, and

[0060] FIG. 9: shows a perspective view of the drive transmission.

DETAILED DESCRIPTION

[0061] The structure of the flow guide element 40 is firstly explained with reference to FIGS. 1-4.

[0062] In the embodiment shown here, the flow guide element 40 takes the form of a plastic part. It comprises a flow inlet 41 in the upper region in order to be able to receive a fluid 30, as indicated in FIG. 2.

[0063] The flow guide element 40 forms a first cavity boundary 42 to provide a first cavity 43 for the purpose of receiving a first fluid reservoir 44, which can be seen in FIG. 2.

[0064] FIG. 2 shows a view of the flow guide element 40 in a section through an adjacent transmission housing.

[0065] Furthermore, the flow guide element 40 forms a second cavity boundary 45 to provide a second cavity 46 for the purpose of receiving a second fluid reservoir 47, as also shown in FIG. 2.

[0066] To supply the fluid 30 into the two cavities 43, 46, the flow guide element 40 forms a plurality of flow channels 50, through which the fluid 30 can flow along the arrows shown in FIG. 1.

[0067] The embodiment of the flow guide element 40 shown in FIGS. 1-2 further comprises at least one rib 52, which provides a flow bifurcation 51 through an opening 53 arranged therein or thereon, in order to supply, at this flow bifurcation 51, a first partial quantity 54 to the first fluid reservoir 44 and a second partial quantity 55 to the second fluid reservoir.

[0068] Division into a first partial quantity 54 and a second partial quantity 55 of the fluid 30 takes place simply under the effect of gravity when the flow velocity of the fluid 30 is below a limit velocity by the first partial quantity 54 passing through the opening 53 into the first cavity 43, and a second partial quantity 55 being supplied further along the rib 52 into the second cavity 46.

[0069] If the flowing fluid 30 has a velocity above the limit velocity, it splashes or flows onto a baffle element 56, which is arranged downstream of the opening 53. This baffle element 56 causes the volumetric flow of fluid entering through the flow inlet 41 to be slowed down and thus there is still the possibility of a first partial quantity 54 passing through the opening 53 into the first cavity 43, and a second partial quantity 55 along the rib 52 reaching the second cavity 46.

[0070] Between the two cavities 43, 46 there is also an overflow device 57, which enables fluid 30 to flow from the second cavity 46 into the first cavity 43 under the effect of gravity when a limit fill level in the second cavity 46 is exceeded.

[0071] The two cavities 43, 46 are each fluidically coupled to a lubrication device 60, which is merely indicated in FIGS. 1 and 2.

[0072] FIG. 3 once again shows a perspective view of the flow guide element 40, wherein the cavity boundaries 42, 45 are clearly visible here, which boundaries simultaneously serve to rest and seal against an axially opposite transmission housing 71, regions of which are shown in FIG. 4. In both FIGS. 3 and 4, the respective contact contour is visually highlighted.

[0073] As is also apparent from FIG. 4, the lubrication devices 60 merely indicated in FIG. 2 also have outlet openings which are provided at bearing points, namely in a differential gear shaft bearing 82 and also in an intermediate gear shaft bearing 85.

[0074] Accordingly, the flow guide element 40 makes it possible to supply lubricant or fluid 30 to these bearing points 85 in a simple and space-saving manner.

[0075] There is no need to accept any loss of strength in the transmission housing 71 because the flow guide element 40 is complementarily adapted in terms of shape and size to raised structures 73, such as ribs 52 which are provided to increase strength, on the outside 72 of the transmission housing 71. Such raised structures 73 are also indicated in FIG. 2.

[0076] FIG. 5 shows a component of the lubrication device 60 in the form of a channel 90, which is provided on the intermediate gear shaft bearing 85. It is apparent here that lubricant can be supplied through the channel 90 directly to the bearing or to the intermediate gear shaft itself.

[0077] In order to clarify the overall context, FIG. 6 shows an axial view the drive unit 1 without the flow guide element. The drive unit 1 comprises a drive housing 20, from which an electric machine shaft 86 leads axially. Positioned axially outside the drive housing 20 are an intermediate gear shaft 83 with an intermediate gear 84 arranged thereon, and a differential gear shaft 80 with a differential gear 81 arranged thereon.

[0078] The differential gear 81 is surrounded on its outside by a cover element 100, which provides a very small gap 110 between itself and the differential gear 81. The differential gear 81 projects with its lowest region into a first sub-compartment 120 of an oil reservoir. Next to the first sub-compartment 120 there is a second sub-compartment 121, which is separated from the first sub-compartment 120 by a partition 122. There is a fluidic connection between the two sub-compartments 120, 121, which enables fluid 30 to flow from the second sub-compartment 121 into the first sub-compartment 120.

[0079] This ensures that a certain amount of fluid 30 is always contained in the first sub-compartment. When the differential gear 81 rotates along the direction of rotation shown, the differential gear 81, like an impeller pump, delivers fluid 30 from the first sub-compartment through the gap 110 between the differential gear 81 and the cover element 100. By adjusting the fluidic connection between the two sub-compartments 120, 121, it is possible to ensure that there is not too much fluid 30 in the first sub-compartment 120 and that, as a result, only small drag losses occur.

[0080] In the upper region of the differential gear 81, the fluid 30 delivered by the differential gear 81 is supplied to a flow divider 130, which is shown in FIGS. 7 and 8.

[0081] The flow divider 130 comprises a separating element 131, which substantially axially halves the volumetric flow of fluid delivered by the differential gear 81, such that fluid 30 is divided and directed away axially on both sides of the differential gear 81 along the guide elements 132 shown in FIG. 8. The partial volumetric flow of the fluid 30, which is diverted to the right according to FIG. 8, then reaches the flow inlet 41 of the flow guide element 40 as described in FIG. 1. The partial volumetric flow diverted to the left can be supplied to another bearing point, and optionally also to the differential gear shaft.

[0082] However, FIG. 9 shows a drive transmission in which the drive housing has been omitted. An electric machine 10 is clearly visible here. Furthermore, the differential gear shaft 80 can be seen, as well as the differential gear shaft bearing 82 and the flow divider 130. In addition, the transmission 70 and the transmission housing 71 can also be seen in this view, wherein it is apparent that the cover element 100 forms the transmission housing 71 in the region where it overlies the differential gear, which is hidden here.

[0083] The drive system and the drive transmission comprising the drive system proposed herein provide devices which can be used to lubricate connected or integrated transmission elements in a simple, cost-effective and space-saving manner.

LIST OF REFERENCE SIGNS

[0084] 1 Drive unit [0085] 10 Electric machine [0086] 20 Drive housing [0087] 30 Fluid [0088] 40 Flow guide element [0089] 41 Flow inlet [0090] 42 First cavity boundary [0091] 43 First cavity [0092] 44 First fluid reservoir [0093] 45 Second cavity boundary [0094] 46 Second cavity [0095] 47 Second fluid reservoir [0096] 50 Flow channel [0097] 51 Flow bifurcation [0098] 52 Rib [0099] 53 Opening [0100] 54 First partial quantity [0101] 55 Second partial quantity [0102] 56 Baffle element [0103] 57 Overflow device [0104] 60 Lubrication device [0105] 70 Transmission [0106] 71 Transmission housing [0107] 72 Outside of the transmission housing [0108] 73 Raised structure [0109] 80 Differential gear shaft [0110] 81 Differential gear [0111] 82 Differential gear shaft bearing [0112] 83 Intermediate gear shaft [0113] 84 Intermediate gear [0114] 85 Intermediate gear shaft bearing [0115] 86 Electric machine shaft [0116] 90 Channel [0117] 100 Cover element [0118] 110 Gap [0119] 120 First sub-compartment [0120] 121 Second sub-compartment [0121] 122 Partition [0122] 130 Flow divider [0123] 131 Separating element [0124] 132 Guide element