AXLE housing for a vehicle, a vehicle comprising such an AXLE housing and a method of assembling such an AXLE housing

Abstract

The invention relates to a vehicle and an axle housing (2) for a vehicle (1). The axle housing (2) being configured to support a propulsion unit (20) and to accommodate portions of two opposed drive shafts to be driven by the propulsion unit (20) and are arranged to drive at least two opposed ground engaging wheels of the vehicle (1). The axle housing (2) comprising: - an attachment part (3) for attachment of the propulsion unit (20) to the axle housing (2), - a rounded portion (11) and two elongated side portions (12, 13) extending to opposite sides of the rounded portion (11), the rounded portion (11) having two circumferential flanges (16, 17), - a support structure (4) arranged between the circumferential flanges (16, 17) of the rounded portion (11), wherein the support structure (4) defines an internal cavity (31), which is configured to accommodate at least a portion of the propulsion unit (20) when attached to the attachment part (3). The invention also relates to a method of assembling an axle housing (2).

Description

[0001] AXLE HOUSING FOR A VEHICLE, A VEHICLE COMPRISING SUCH AN AXLE HOUSING AND A METHOD OF ASSEMBLING SUCH AN AXLE HOUSING

[0002] TECHNICAL FIELD

[0003] The invention relates to an axle housing for a vehicle. The invention also relates to a vehicle, typically an electrically driven vehicle, comprising such an axle housing. Further, the invention relates to a method of assembling such an axle housing.

[0004] BACKGROUND

[0005] In the automotive industry, a new and fast growing segment concerns electrified vehicles, such as trucks and busses. In a common solution the entire powertrain is assembled on the axle. This is also known as an “eAxle”. Typically, an electric propulsion unit is attached to the axle housing, which is the load-carrying part of the axle assembly. Different designs are known for attaching the propulsion unit to axle housing. In the art, the axle housing is sometimes referred to as an axle beam.

[0006] For example, the propulsion unit can be attached in a similar way as a central gear is attached to a conventional axle, which is often solved by arranging a circular bolt pattern at the front of the axle. However, this means that the propulsion unit will be exposed to road induced loads.

[0007] A way of getting around this problem is to use “stand-alone” propulsion units where the transfer of road induced load from the axle housing to the propulsion unit housings is limited.

[0008] SUMMARY

[0009] It is an object of the invention to provide an axle housing for a vehicle which enables an advantageous arrangement of a propulsion unit to an axle housing. A further object of invention is to provide such an arrangement with an alternative and possibly lighter constructional design.

[0010] According to a first aspect the invention relates to an axle housing for a vehicle, the axle housing being configured to support a propulsion unit and to accommodate portions of two opposed drive shafts to be driven by the propulsion unit and are arranged to drive at least two opposed ground engaging wheels of the vehicle, the axle housing comprising: an attachment part for attachment of the propulsion unit to the axle housing, a rounded portion and two elongated side portions extending to opposite sides of the rounded portion, the rounded portion having two circumferential flanges, the two elongated side portions being configured to accommodate at least portions of the respective drive shafts, a support structure arranged between the circumferential flanges of the rounded portion, the support structure defining an internal cavity, which is configured to accommodate at least a portion of the propulsion unit when attached to the attachment part.

[0011] Thereby, a lightweight yet strong structure of an axle housing arranged to carry a propulsion unit, e.g., an electric motor and gears, can be provided.

[0012] According to an example the axle housing comprises a first and a second housing member, each comprising a part of the rounded portion and parts of the two elongated side portions, wherein the first and second housing member are attached to each other by welds along outer rims of the respective parts of two elongated side portions.

[0013] With this construction the housing members may be produced from stamped plates, further reducing the weight of the final product. Furthermore, it also enables the reuse of existing manufacturing infrastructure for conventional axles, such as stamping presses and welding cells. Also, with the implementation of a welded design comes with the advantage that variants of the axle housing can be created by welding different suspension brackets and brake brackets to the axle housing.

[0014] According to an example, the support structure comprises two curved plates arranged at opposite ends of the cavity, which opposite ends extend towards the two respective side portions.

[0015] This construction facilitates the manufacturing and the assembly of the axle housing. A two-part support structure allows for the curved plates to be pushed towards their respective sides, minimizing the gaps, which may improve weld quality.

[0016] According to an example, the curved plates of the support structure are stamped plates.

[0017] This construction facilitates the manufacturing of the axle housing in a time and cost efficient way. Furthermore, using stamping as a method allows the curved plate to be thinner compared to if they would be casted, which means that the weight can be reduced. Also, using stamping means that a relative complex shape can be achieved to fit against the propulsion unit. It also means that stiffening ribs can easily and cost- effectively be integrated into the design, giving further strength to the support structure.

[0018] According to an example, at least one fixation plate is arranged to join opposite end rims of the respective curved plates, the fixation plate being fixed by welds to the respective end rims.

[0019] The at least one fixation plate provides a tolerance of the assembled pieces, allowing a certain dimensional freedom of the parts to be assembled. The fixation plate provides a way to absorb the gap that would otherwise occur. Reduced gaps may improve weld quality and the overall strength and robustness of the axle housing.

[0020] According to an example, a first fixation plate is arranged to join first end rims of the respective curved plate, and a second fixation plate is arranged to join second end rims of the respective curved plate, the fixation plates being fixed by means of welds to the respective end rim.

[0021] The two fixation plates allows for smaller curved plates making them more cost-effective since a stamping tool of less complex design can be used.

[0022] According to an example, the end rims of the respective curved plates are inclined so as to form an open channel facing the cavity, wherein a weld is provided in said open channel.

[0023] This is an effective way of facilitating a durable weld to be produced without interfering the internal space of the cavity inside the axle housing.

[0024] According to an example, the at least one fixation plate has angled edges with inclined surfaces on both sides of the angled edges, a first inclined surface opening towards the cavity to extend the width of the open channel, and a second inclined surface at least partly abutting the corresponding end rim of the corresponding curved plate.

[0025] The inclined surfaces facilitate mounting and enhances the dimensional freedom of the assembly parts. Due to the inclined surfaces, a dimensional variation of the curved plates and the fixation plates in an axial direction can be tolerated, while still having the edge of the fixation plate in contact or near contact with the inclined surface, effectively eliminating the need for a root support for the weld. The axial direction may be the direction in which the axle housing extend, i.e. , corresponding to the axis between the opposed ground engaging wheels. According to an example, the second inclined surface have an inclination that corresponds to that of the end rim of the curved plates that it is at least partly abutting.

[0026] This allows the fixation plate to be pushed into location and to at the same time push the curved plates into position. In addition, this configuration facilitates assembly, especially when the parts to be assembled have certain tolerance deviations.

[0027] According to an example, the first inclined surface has a longer extension than the second inclined surface. This to allow a big enough weld seam. Thereby, a durable and strong weld may be achieved, and hence a durable and strong axle housing for supporting a propulsion unit can be provided.

[0028] According to an example, the support structure is attached by a first weld to a first flange of the two circumferential flanges of the rounded portion on a first side of the axle housing.

[0029] Thereby, a durable and strong axle housing for supporting a propulsion unit can be provided. In addition, improved conditions are provided for manufacturing and assembling of the axle housing.

[0030] According to an example, the support structure extends beyond the first flange of the rounded portion on the first side of the axle housing, wherein the first weld is provided at an intersection along the support structure and the first flange outside of the cavity.

[0031] Thereby, improved conditions are provided for manufacturing and assembling of the axle housing. For example, having the first weld on the outside of the cavity may facilitate the welding procedure. Furthermore, due to that the support structure extends beyond the flange, a spaces is created where the fillet weld can be placed without demanding a costly weld preparation machining operation.

[0032] According to an example, the attachment part for attaching the propulsion unit is a separate part that is attached by a second weld to the second flange on a second side of the axle housing.

[0033] Thereby, the attachment part may be rigidly fixed to the axle housing. Hence, the axle housing may form a robust support for a propulsion unit attached to the attachment part.

[0034] According to an example, the second weld is provided at an intersection along a second flange of the two circumferential flanges of the rounded portion and the attachment part outside of the cavity. Thereby, a durable and strong axle housing for supporting a propulsion unit can be provided. In addition, improved conditions are provided for manufacturing and assembling of the axle housing. For example, having the second weld on the outside of the cavity facilitates the welding procedure.

[0035] According to an example, the support structure is attached by a third weld to the attachment part at an intersection therebetween facing the cavity.

[0036] Due to the third weld, a stronger attachment of the attachment part is provided, which is beneficial since the attachment part is intended to carry the propulsion unit which can be of significant weight and subject to road-induced vibration loads. Hence, the axle housing may form a robust support for a propulsion unit attached to the attachment part.

[0037] Furthermore, since the third weld attaches the support structure to the attachment part, and the attachment part may be attached to the second flange of the rounded portion, the third weld may fulfil dual purposes, thereby minimizing the total weld length, which means reduced cost.

[0038] According to an example the support structure comprises through holes for allowing passage of the respective drive shafts and wherein sealing pipes are fixed to the through holes of the curved plates, respectively.

[0039] Thereby, the support structure increases the strength and robustness of the axle housing while enabling the respective drive shafts to drive the ground engaging wheels.

[0040] According to a second aspect, the invention relates to a vehicle that comprises at least one axle housing as described above.

[0041] Since the vehicle comprises at least one axle housing as described above, a vehicle is provided having a lightweight, yet strong structure of an axle housing arranged to carry a propulsion unit. Hence, the overall weight of the vehicle may be reduced which in turn leads to reduced energy consumption for propulsion of the vehicle.

[0042] According to a third aspect, the invention relates to a method of assembling an axle housing as described above, the method comprising the steps of: providing a first and a second housing member, each comprising a part of the rounded portion and parts of the two elongated side portions of the axle housing, welding the first and second housing members to each other along outer rims of the respective parts of two elongated side portion, and welding a support structure between the circumferential flange of the rounded portion.

[0043] By means of the method, a durable and strong axle housing for supporting a propulsion unit may be achieved. In addition, improved conditions are provided for manufacturing and assembling of the axle housing, e.g., reducing manufacturing costs and assembly time. The method of assembling of the axle housing may at least partly be automated. For example, at least some of the method steps may be performed by means of robots.

[0044] According to an example, the method further includes a step of welding an attachment part for attachment of the propulsion unit to the axle housing.

[0045] Due to the step of welding a separate attachment part to the axle housing, attachment of a propulsion unit to the axle housing is facilitated. Also, the weld may contribute to increase the overall constructional strength of the axle housing.

[0046] According to an example, the support structure comprises two curved plates to be arranged at opposite ends of the cavity, and at least one fixation plate arranged to join opposite end rims of the respective curved plates, wherein the at least one fixation plate is welded to the respective end rims of the curved plates.

[0047] Thereby, the manufacturing and assembly of the axle housing is facilitated. By having the support structure in two parts allows for the curved plates to be pushed toward their respective sides, and the at least one fixation plate minimizing gaps between the curved plates, which may improve weld quality and the overall strength and robustness of the axle housing.

[0048] According to an example, the curved plates and the at least one fixation plate of the support structure are preliminary attached in their respective positions before being definitely welded to each other.

[0049] Preliminary welding means in this context that the parts are attach primarily attached to each other by a few small and short welds. Definitely welding means longer welds, such as continuous welds. By preliminary welding the curved plates and the at least one fixation plate of the support structure in their respective positions before being definitely welded in place, the risk of the parts altering their shape due to exposure to high temperatures during the welding procedure is reduced. Other embodiments and advantages will be apparent from the detailed description and the appended drawings. It is understood that all the various examples of the axle housing as disclose herein also applies for the vehicle comprising such an axle housing and the method of assembling such an axle housing.

[0050] BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Below, specific embodiments of the invention will be described with reference to the appended drawings, of which:

[0052] Fig. 1 shows a vehicle in which a position of an axle housing is schematically illustrated,

[0053] Fig. 2 shows an axle housing and a propulsion unit to be attached to the axle housing,

[0054] Fig. 3 shows an exploded view of different parts of an axle housing,

[0055] Fig. 4 shows an exploded view of different parts of an axle housing,

[0056] Fig. 5 shows a detailed view of the portion v in Fig. 4,

[0057] Fig. 6 shows a close up of the detailed view in Fig. 5, and

[0058] Fig. 7 shows a sectional view the axle housing taken along line vii-vii in Fig. 4.

[0059] DETAILED DESCRIPTION OF THE SHOWN EMBODIMENTS

[0060] Aspects of the present invention will now be described more fully. Similar reference numerals refer to similar elements throughout the specification. Well-known functions or constructions will not necessarily be described in detail for brevity and / or clarity.

[0061] In Fig. 1 a vehicle 1 is illustrated in the form of a truck comprising two sets of ground engaging wheels 34 and 35, of which the front wheels 35 with respect to the vehicle’s driving direction D are steered and the rear wheels 34 are driven by a propulsion unit 20 arranged on axle housing 2. The propulsion unit 20 and the axle housing 2 are not clearly illustrated in the drawing, although their position between the rear wheels 34 is illustrated by a dashed arrow.

[0062] According to the illustrated example in Fig. 1, the vehicle 1 is a truck, i.e., a heavy vehicle. However, according to further examples, the vehicle 1, as referred to herein, may be another type of heavy or lighter manned or unmanned vehicle for land based propulsion such as a lorry, a bus, a construction vehicle, a tractor, a car, or the like. The rear wheels 34 is comprised of least two opposed of ground engaging wheels. Typically, the rear wheels 34 include two pairs of wheels on opposite sides of the axle housing 2, or two opposed single wheels.

[0063] As will be apparent to a person skilled in the art, wheel bearings are assembled with a hub at the outermost part of the axle housing. The wheel or wheels are assembled to the hub which is driven by the driveshaft. The driveshafts are driven by the propulsion unit and connected to the propulsion unit via splines or similar.

[0064] In Fig. 2 the axle housing 2 and the propulsion unit 20 to be attached to the axle housing 2 are shown. The axle housing 2 extend in an axial direction A corresponding to the axis between the rear wheels 34 in Fig. 1, orthogonal to the driving direction D of the vehicle 1.

[0065] The axle housing 2 is configured to support the propulsion unit 20 and to accommodate portions of two opposed drive shafts (not shown) which will be driven by the propulsion unit 20 and are arranged to drive the ground engaging wheels 34 of the vehicle 1.

[0066] Specifically, the axle housing 2 comprises an attachment part 3 for attachment of the propulsion unit 20 to the axle housing 2, wherein the propulsion unit 20 of the shown embodiment comprises two attachment portions 27 with screw holes configured to match corresponding screw hole configurations 28 on opposite sides of the attachment part 3.

[0067] The axle housing 2 comprises a rounded portion 11 and two elongated side portions 12 and 13, respectively, extending to opposite sides of the rounded portion 11 along the axial direction A. The two elongated side portions 12 and 13 are configured to accommodate at least portions of the respective drive shafts to be driven by the propulsion unit 20.

[0068] The axle housing 2 is arranged to house part of the propulsion unit 20. In the shown embodiment the axle housing 2 is comprised of a first and a second housing member 5 and 6, each comprising a part of the rounded portion 11 and parts of the two elongated side portions 12, and 13, wherein the first and second housing members 5 and 6 are attached to each other, preferably by welds. In the art the construction formed by the two welded first and second housing members 5 and 6 is referred to as a banjo.

[0069] A support structure 4 is arranged to cover the inside of the axle housing 2, the support structure 4 defining an internal cavity 31, which is configured to accommodate at least a portion of the propulsion unit 20 when attached to the attachment part 3. The support structure 4 comprises through holes for allowing passage of the respective drive shafts (not shown), of which only a first through hole 18 is visible in Fig. 2.

[0070] In Fig. 3 an embodiment of the axle housing 2 is shown in an exploded view, in which the support structure 4 and the attachment part 3 are shown separate from the first and second housing members 5 and 6 of the axle housing 2.

[0071] In this view it is visible that the rounded portion 11 has two circumferential flanges 16 and 17 on opposition sides of the cavity 31. The support structure 4 will be arranged between the circumferential flanges 16, 17 of the rounded portion 11.

[0072] In the shown embodiment the support structure 4 comprises two curved plates 7 and 8 to be arranged at opposite ends 32 and 33 of the cavity 31, which opposite ends 32 and 33 extend towards the two respective side portions 12 and 13 of the axle housing 2. See Fig. 4.

[0073] The curved plates 7 and 8 of the support structure 4 are preferably stamped plates. Further, the first and the second housing member 5 and 6 of the axle housing 2 may also be produced of stamped plates, providing a lightweight yet strong structure for the axle housing 2.

[0074] In addition to the curved plates 7 and 8 the support structure 4 includes at least one fixation plate 9a and 9b arranged to join opposite end rims 7a, 8a; 7b, 8b of the respective curved plates 7 and 8.

[0075] In the shown embodiment a first fixation plate 9a is arranged to join first end rims 7a and 8a, respectively, of the curved plates 7 and 8, and a second fixation plate 9b is arranged to join second end rims 7b and 8b, respectively, of the respective curved plates 7 and 8, the fixation plates 9a, 9b being fixed to the respective end rims 7a, 8a; 7b, 8b. The fixation plates 9a are 9b preferably fixed by welds to the respective end rims 7a, 8a; 7b, 8b of the curved plates 7 and 8.

[0076] The support structure 4 comprises through holes 18 and 19, arranged in the curved plates 7 and 8, respectively, for allowing passage of the respective drive shafts. Further, sealing pipes 29 are fixed, preferably by welds, to the circumferential rims of these through holes 18 and 19 of the curved plates 7 and 8, respectively.

[0077] The sealing pipes 29 provide support for sealings (not shown) between the drive shafts of the propulsion unit 20 and axle housing 2. The sealings 29 keep the drive shafts and the volume in the cavity 31 free from dirt, water etc. coming from the road. The length of the sealing pipes 29 allow the sealings to move between a docked and retracted position, which allows for the propulsion unit to be assembled into the axle housing 2. After assembly of the propulsion unit the sealing may be moved axially to provide the desired sealing contact.

[0078] The interaction between second fixation plate 9b and the curved plates 7 and 8 is illustrated in Fig. 5, which is a detailed view of portion vi in Fig. 4, and in Fig. 6, which is a close-up view of the view in Fig. 5.

[0079] In the shown embodiment the end rims 7b and 8b of the respective curved plates 7 and 8 are inclined so as to form an open channel 10 facing the cavity 31.

[0080] Further, the fixation plate 9b has angled edges 23 with inclined surfaces on both sides of the angled edges 23, of which a first inclined surface 24 opens towards the cavity 31 to extend the width of the open channel 10 to form a V-shaped space for a weld w as illustrated in Figs. 5 and 6.

[0081] A second inclined surface 25 is arranged on each side of the fixation plate 9b to abut the corresponding end rim 7b or 8b of the adjacent curved plate 7 or 8, respectively. The second inclined surface 25 have an inclination that corresponds to that of the end rim 7b and 8b, respectively, of the adjacent curved plate 7 or 8, respectively, that it is at least partly abutting.

[0082] Also visible in the Fig. 5 and 6 are holes 30 on one of the screw hole configurations 28 of the attachment part 3. Typically, these holes may be unthreaded to allow passage of screws from outside the axle housing 2 into screw holes on the attachment portion 27 of the propulsion unit 20.

[0083] As is apparent in the drawings, the first inclined surface 24 has a longer extension than the second inclined surface 25, typically the first inclined surface 24 constituting about 70% of the thickness of the fixation plate, the second inclined surface 25 constituting the remaining 30% of said thickness.

[0084] In Fig. 7 a sectional view of the axle housing 2 is shown along the section vii-vii in Fig. 4. As is illustrated the support structure 4 is attached by a first weld w1 to the first flange 16 of the rounded portion 11 on a first side a of the axle housing 2.

[0085] Further, the support structure 4 may be configured to extend beyond the first flange 16 of the rounded portion 11 on the first side a of the axle housing 2. This extension of the support structure 4 allows for the first weld w1 to be provided at an intersection along the support structure 4 and the first flange 16, outside of the cavity 31.

[0086] In the shown embodiment the attachment part 3 for attachment of the propulsion unit 20 is a separate part that is attached by a second weld w2 to the second flange 17 on a second side b of the axle housing 2, opposite the first side a.

[0087] The second weld w2 is provided at an intersection along the second flange 17 and the attachment part 3 outside of the cavity 31.

[0088] The support structure 4 is attached by a third weld w3 to the attachment part 3 at an intersection therebetween facing the cavity 31.

[0089] The first weld w1 , the second weld w2, and / or the third weld w3 may be provided all around the circumference as circumferential welds, but they may also be provided as shorter weld seams or spot-welds at regular intervals around their circumference.

[0090] When assembling the axle housing 2 it may be done in steps.

[0091] Firstly, a first and a second housing member 5 and 6 are provided, each comprising a part of the rounded portion 11 and parts of the two elongated side portions 12 and 13 of the axle housing 2.

[0092] The first and second housing members 5 and 6 are welded to each other along the outer rims 14 and 15 of the respective parts of two elongated side portions 12 and 13.

[0093] Optionally, if the attachment part 3 is separate part as in the shown embodiment, the attachment part 3 may be welded to the first and second housing members 5 and 6 of the axle housing 2.

[0094] Subsequently, the support structure 4 is welded to its position between the circumferential flanges 16 and 17 of the rounded portion 11.

[0095] Specifically, the support structure 4 comprises two curved plates 7 and 8 which are inserted to opposite ends 32 and 33 of the cavity 31. Thereafter, the fixation plates 9a and 9b are inserted and pushed into the spaces between the two curved plates 7 and 8 to separate the opposed end rims of the respective curved plates 7 and 8 from each other.

[0096] Specifically, the first fixation plates 9a is pushed to separate the first end rim 7a of the first curved plate 7 away from the first end rim 8a of the second curved plate 8 wherein welds are provided to fix the first fixation plates 9a with respect to the first end rim 7a of the first curved plate 7 and the first end rim 8a of the second curved plate 8. Also, the second fixation plate 9b is fixed to the second end rim 7b of the first curved plate 7 and the second end rim 8b of the second curved plate 8 in a similar manner with welds w provided in the V-shaped channels 10 between the fixation plates 9a and 9b the curved plates 7 and 8.

[0097] In order to facilitate the assembly procedure, the curved plates 7 and 8 and the fixation plates 9a and 9b of the support structure 4 are preliminary attached in their respective positions before being definitely welded. This preliminary attachment may be achieved by spot welds or similar before the final welding is performed.

[0098] Above, the invention has been described with reference to specific embodiments. The invention is however not limited to these embodiments. It is obvious to a person skilled in the art that other embodiments are possible within the scope of the following claims.

Claims

CLAIMS1 . An axle housing (2) for a vehicle (1), the axle housing (2) being configured to support a propulsion unit (20) and to accommodate portions of two opposed drive shafts to be driven by the propulsion unit (20) and are arranged to drive at least two opposed ground engaging wheels of the vehicle (1), the axle housing (2) comprising: an attachment part (3) for attachment of the propulsion unit (20) to the axle housing (2), a rounded portion (11) and two elongated side portions (12, 13) extending to opposite sides of the rounded portion (11), the rounded portion (11) having two circumferential flanges (16, 17) the two elongated side portions (12, 13) being configured to accommodate at least portions of the respective drive shafts, a support structure (4) arranged between the circumferential flanges (16, 17) of the rounded portion (11), the support structure (4) defining an internal cavity (31), which is configured to accommodate at least a portion of the propulsion unit (20) when attached to the attachment part (3).

2. The axle housing (2) according to claim 1 , wherein the axle housing (2) comprises a first and a second housing member (5, 6), each comprising a part of the rounded portion (11) and parts of the two elongated side portions (12, 13), wherein the first and second housing members (5, 6) are attached to each other by welds along outer rims (14, 15) of the respective parts of two elongated side portions (12, 13).

3. The axle housing (2) according to claim 1 or 2, wherein the support structure (4) comprises two curved plates (7, 8) arranged at opposite ends (32, 33) of the cavity (31), which opposite ends (32, 33) extend towards the two respective side portions (12, 13).

4. The axle housing (2) according to claim 3, wherein the curved plates (7, 8) of the support structure (4) are stamped plates.

5. The axle housing (2) according to claim 3 or 4, wherein at least one fixation plate (9a, 9b) is arranged to join opposite end rims (7a, 8a; 7b, 8b) of the respective curved plates (7, 8), the fixation plate (9a, 9b) being fixed by welds to the respective end rims (7a, 8a; 7b, 8b).

6. The axle housing (2) according to claim 3 or 4, wherein a first fixation plate (9a) is arranged to join first end rims (7a, 8a) of the respective curved plates (7, 8), and asecond fixation plate (9b) is arranged to join second end rims (7b, 8b) of the respective curved plates (7, 8), the fixation plates (9a, 9b) being fixed by means of welds to the respective end rims (7a, 8a; 7b, 8b).

7. The axle housing (2) according to claims 5 or 6, wherein the end rims (7a, 8a; 7b, 8b) of the respective curved plates (7, 8) are inclined so as to form an open channel (10) facing the cavity (31), wherein a weld (w) is provided in said open channel (10).

8. The axle housing (2) according to claim 7, wherein the at least one fixation plate (9a, 9b) has angled edges (23) with inclined surfaces on both sides of the angled edges (23), a first inclined surface (24) opening towards the cavity (31) to extend the width of the open channel (10), and a second inclined surface (25) at least partly abutting the corresponding end rim (7a, 8a; 7b, 8b) of the corresponding curved plate (7, 8).

9. The axle housing (2) according to claim 8, wherein the second inclined surface (25) have an inclination that corresponds to that of the end rim (7a, 8a; 7b, 8b) of the curved plates (7, 8) that it is at least partly abutting.

10. The axle housing (2) according to claim 8 or 9, wherein the first inclined surface (24) has a longer extension than the second inclined surface (25).

11. The axle housing (2) according to any one of the preceding claims, wherein the support structure (4) is attached by a first weld (w1) to a first flange (16) of the two circumferential flanges (16, 17) of the rounded portion (11) on a first side (a) of the axle housing (2).

12. The axle housing (2) according to claim 11 , wherein the support structure (4) extends beyond the first flange (16) of the rounded portion (11) on the first side (a) of the axle housing (2), wherein the first weld (w1) is provided at an intersection along the support structure (4) and the first flange (16) outside of the cavity (31).

13. The axle housing (2) according to any one of the preceding claims, wherein the attachment part (3) for attachment of the propulsion unit (20) is a separate part that is attached by a second weld (w2) to a second flange (17) ) of the two circumferential flanges (16, 17) on a second side (b) of the axle housing (2).

14. The axle housing (2) according to claim 13, wherein the second weld (w2) is provided at an intersection along the second flange (17) and the attachment part (3) outside of the cavity (31).

15. The axle housing (2) according to any one of the preceding claims, wherein the support structure (4) is attached by a third weld (w3) to the attachment part (3) at an intersection therebetween facing the cavity (31).

16. The axle housing (2) according to any one of the of the preceding claims, wherein the support structure (4) comprises through holes (18, 19), for allowing passage of the respective drive shafts and wherein sealing pipes (29) are fixed to the through holes (18, 19) of the curved plates (7, 8), respectively.

17. A vehicle (1) characterised in that it comprises at least one axle housing (2) according to any one of the preceding claims.

18. A method of assembling an axle housing (2) according to anyone of the claims 1-16, comprising the steps of: providing a first and a second housing member (5, 6), each comprising a part of the rounded portion (11) and parts of the two elongated side portions (12, 13) of the axle housing (2), welding the first and second housing members (5, 6) to each other along outer rims (14, 15) of the respective parts of the two elongated side portions (12, 13), and welding a support structure (4) between the circumferential flanges (16, 17) of the rounded portion (11).

19. The method of claim 18, further comprising the step of welding an attachment part (3) for attachment of the propulsion unit (20) to the axle housing (2).

20. The method of claim 18 or 19, wherein the support structure (4) comprises two curved plates (7, 8) to be arranged at opposite ends (32, 33) of the cavity (31), and at least one fixation plate (9a, 9b) arranged to join opposite end rims (7a, 8a; 7b, 8b) of the respective curved plates (7, 8), and wherein the at least one fixation plate (9a, 9b) is welded to the respective end rims (7a, 8a; 7b, 8b) of the curved plates (7, 8).

21. The method of claim 20, wherein the curved plates (7, 8) and the at least one fixation plate (9a, 9b) of the support structure (4) are preliminary attached in their respective positions before being definitely welded.

Images