Abstract
The present invention relates to an axle unit comprising an axle tube and an axle stub, wherein the axle stub is formed to be rotationally symmetrical with respect to a stub axis in some regions and has a channel which extends substantially parallel to the stub axis, wherein the axle stub has a first connection portion which has an engagement geometry for fluid-tight connection to the channel, wherein the axle tube is formed to be substantially rotationally symmetrical about a tube axis and wherein the axle tube and the axle stub are fixed on/to one another by way of a cross-member in such a way that the tube axis and the stub axis are spaced from one another.
Claims
1.-15. (canceled)
16. An axle unit, comprising: an axle tube; and an axle stub; wherein the axle stub is rotationally symmetrical with respect to a stub axis in some regions and has a channel which extends substantially parallel to the stub axis; wherein the axle stub has a first connection portion which has an engagement geometry for fluid-tight connection to the channel; wherein the axle tube is substantially rotationally symmetrical about a tube axis; wherein the axle tube and the axle stub are fixed to one another by way of a cross-member such that the tube axis and the stub axis are spaced from one another; and wherein a second connection portion opposite the first connection portion is arranged on at least one of the end face of the cross-member and the axle stub.
17. The axle unit as claimed in claim 16, wherein the second connection portion has an engagement geometry configured for fluid-tight connection to the channel.
18. The axle unit as claimed in claim 17, wherein the second connection portion is accessible from the outside.
19. The axle unit as claimed in claim 16, wherein the axle stub has, at an end of the axle stub opposite the first connection portion, a first joining region which is configured to fix on a corresponding second joining region of the cross-member, and wherein the first joining region has an extent at least one of along and transversely to the stub axis.
20. The axle unit as claimed in claim 17, wherein the second connection portion is arranged on the cross-member.
21. The axle unit as claimed in claim 17, wherein the second connection portion is arranged on the axle stub.
22. The axle unit as claimed in claim 18, wherein at least one of the channel and the second connection portion are arranged spaced from the first joining region and from the second joining region.
23. The axle unit as claimed in claim 16, wherein the axle stub has a fastening portion configured to fix a drive unit in place, and wherein the fastening portion is especially arranged adjacent to the first connection portion.
24. The axle unit as claimed in claim 16, wherein a supporting element is configured to be fixed on the cross-member and on at least one of the axle stub and the axle tube to absorb forces and bending moments between the cross-member and the at least one of the axle stub and the axle tube.
25. The axle unit as claimed in claim 17, wherein the channel is connected in a fluid-tight manner to at least one of a cross-member channel provided in the cross-member, and to a second connection portion on the cross-member.
26. The axle unit as claimed in claim 16, wherein the channel is located in a sleeve element arranged in the axle stub.
27. The axle unit as claimed in claim 16, wherein the axle stub is integral with the channel as a cast body.
28. The axle unit as claimed in claim 16, wherein the axle stub has a plurality of channels, wherein a plurality of first connection portions and second connection portions are in fluid-conducting communication with the channel.
29. The axle unit as claimed in claim 28, wherein the channel is one of multiple channels.
30. The axle unit as claimed in claim 16, wherein the axle tube is friction welded to the cross-member.
31. The axle unit as claimed in claim 16, wherein the tube axis and the stub axis are spaced from one another by an offset, and wherein the ratio of the offset to a stub length of the axle stub is 0.2 to 2.
32. The axle unit as claimed in claim 31, wherein the ratio of the offset to the stub length is from 0.3 to 1.5.
33. The axle unit as claimed in claim 32, wherein the ratio of the offset to the stub length is from 0.8 to 1.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The figures show:
[0024] FIG. 1 a perspective view of a preferred embodiment of the axle unit according to the invention;
[0025] FIG. 2 a partially sectional view of a preferred embodiment of an axle unit according to the invention;
[0026] FIG. 3 a further partially sectional view of a preferred embodiment of the axle unit according to the invention; and
[0027] FIG. 4 a further partially sectional view of a preferred embodiment of the axle unit according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] FIG. 1 shows a schematically simplified and perspective view of a preferred embodiment of the axle unit according to the invention. In this, an axle tube 2 is connected to an axle stub 6 by way of a cross-member 4. The axle tube 2 extends substantially along a tube axis R and is advantageously formed to be rotationally symmetrical with respect to the axis of rotation R. The cross-member 4 is advantageously designed in the manner of a plate, wherein the axle tube 2 is or may be fixed on a first side of the cross-member 4. A welded seam between the axle tube 2 and the cross-member 4 is indicated in the figure. The axle stub 6 extends substantially along a stub axis S and is formed to be rotationally symmetrical about the stub axis S at least in some regions. The axle stub 6 here is or may be fixed on the cross-member 4 on the side of the cross-member which is remote from the axle tube 2. The axle unit furthermore preferably has a second connection portion 46, 66 which is arranged either on the cross-member 4 or on the axle stub 6. In the embodiment shown in the present figure, the second connection portion 46 is arranged on the cross-member 4. To support the connection between the axle stub 6 and the cross-member 4, a supporting element 8 is furthermore provided which is advantageously fixedly welded both to the axle stub 6 and to the cross-member 4. The axle stub 6 advantageously has a fastening portion 68 which is configured for fixing a drive unit (not illustrated) on the axle stub 6 in a non-rotatable manner. A first connection portion 64 is especially provided on the axle stub 6, adjacent to the fastening portion. The connection portion 64 is connected in a fluid-tight manner to at least one channel 62 (not illustrated).
[0029] FIG. 2 shows a partially sectional view of a preferred embodiment of the axle unit according to the invention. Essential features of the embodiment illustrated in FIG. 2 correspond here to the embodiment illustrated in FIG. 1. The axle stub 6 is illustrated in section in some regions, wherein the course of the channel 62 arranged in the axle stub 6 and the connection portions 64, 46 provided at the respective ends of the channel are clearly shown. The part of the channel 62 which extends in the axle stub 6 as well as the cross-member channel 42 which extends in the cross-member are shown here. The first connection portion 64 is advantageously designed as a threaded bore in which a corresponding connection element of a drive unit can be incorporated, fixed and connected in a fluid-tight manner to the channel 62. Alternatively, the first connection portion 64 and/or the second connection portion 46/66 can be formed as an outwardly protruding projection, wherein this, equipped with an external thread or a bayonet connection, may be connected directly to a hydraulic hose. The preferred offset a between the stub axis S and the tube axis R is furthermore shown, with the ratio of this offset to a stub length l especially being 0.2 to 2. The stub length l is shown as the maximum extent of the axle stub 6 along the stub axis S. The second connection portion 46 is advantageously designed as a hollow pin, which is equipped with an external thread and, on the one hand, may be brought into engagement with the cross-member 4 or a bore incorporated in the cross-member 4 and, on the other hand, is suitable for fixing a fluid line in place for connection to a corresponding hydraulic fluid reservoir. As a result of the arrangement of the first connection portion 64 of the channel 62 of the cross-member channel 42 and the second connection portion 46 along a parallel to the stub axis S, the strength of the axle stub 6 can be increased in particular, since no bores extending transversely to the stub axis S are incorporated in the axle stub 6 or in the cross-member 4. The bores extending along the stub axis S weaken the strength of the axle stub 6 here to a lesser extent than bores which are incorporated transversely to the stub axis S.
[0030] FIG. 3 shows a further preferred embodiment of the axle unit according to the invention, wherein the axle stub 6 has two channels 62 and wherein the second connection portions 66 are also provided on the axle stub 6 in addition to the first connection portions 64. In contrast to the embodiments shown in FIGS. 1 and 2, the axle stub 6 has a joining region 63 which extends both along the stub axis S and transversely to the stub axis S. In other words, the joining region 63 of the axle stub 6 is especially conical in form, which means that, in other words, the outer surface of the joining region 63 of the axle stub 6 has a frustoconical geometry. The joining region 63 furthermore preferably also has a region which extends transversely to the stub axis S but which, in the figure illustrated here, is very small by comparison with the rest of the joining region 63. The cross-member 4 has a second joining region 43, which especially corresponds substantially to the first joining region 63 of the axle stub 6. It goes without saying that, in the embodiment illustrated in FIG. 3, the axle stub 6 can be particularly favorably pressed in a rotating manner against the cross-member 4, from right to left in the figure, and a friction welded connection can thereby be generated between the cross-member 4 and the axle stub 6 in the first joining region 63 and in the second joining region 43 in each case. The preferred feature of the present invention is furthermore illustrated, in which the second connection portion 66 and the channel 62 are arranged spaced from the first joining region 63 and the second joining region 43. It is thereby possible for the adverse effect on the channel 62 and the second connection portion 66 resulting from thermal stresses which occur during the welding process to be kept particularly low.
[0031] FIG. 4 shows a further preferred embodiment of the axle unit according to the invention, wherein the axle stub 6 especially has a stepped geometry on its side facing the cross-member 4. The first joining region 63 of the axle stub 6 and the second joining region 43 of the cross-member 4 extend substantially transversely to the stub axis S here. It is in turn illustrated that both the channel 62 and the first connection portion 64 and the second connection portion 66 are arranged completely on the axle stub 6 and are at the same time spaced from the joining region 63 and 43. In this embodiment, the axle stub together with the channel 62 and the connection portions 64 and 66 can advantageously already be produced in full before being put together with the cross-member 4, whereby not only is the material volume to be assembled relatively low, with the manufacture being simplified as a result of this alone, but also multiple channels 62, for example, can be incorporated in the axle stub 6 at the same time by die sinking. The first connection portion 64 and the second connection portion 66 here are indicated only relatively schematically in the figure and can be formed for example in the manner outlined in FIG. 2. The advantage of the embodiment shown in FIG. 4 is that the axle stub 6 and the cross-member 4 can be positioned particularly precisely with respect to one another, in particular along the stub axis S. The moment of inertia of the connection region between the axle stub 6 and the cross-member 4 in a transverse plane with respect to the stub axis S is particularly high owing to the large diameter, with the result that the connection between the axle stub 6 and cross-member 4 is particularly suitable for transmitting high bending moments and torsion moments between the axle stub 6 and the cross-member 4.
List of Reference Signs
[0032] 2 Axle tube [0033] 4 Cross-member [0034] 42 Cross-member channel [0035] 43 Second joining region [0036] 46 Second connection portion (on the cross-member) [0037] 6 Axle stub [0038] 62 Channel [0039] 63 First joining region [0040] 64 First connection portion [0041] 66 Second connection portion (on the axle stub) [0042] 68 Fastening portion [0043] 8 Supporting element [0044] R Tube axis [0045] S Stub axis [0046] a Offset [0047] l Stub length
