Electric truck

Abstract

The disclosure relates to an electric truck (1) comprising a chassis( 2) extending in a longitudinal direction x and a battery pack mounting structure (3) configured to carry at least one battery pack (4) on each of two opposite sides of the chassis (2). The battery pack mounting structure (3) comprises at least one first cantilever (5) and at least one second cantilever (6) being attached to the chassis( 2) on opposite sides and extending in a transversal direction y opposite to each other away from the chassis (2), wherein during operation the first cantilever (5) and the second cantilever (6) each at least partially carry a battery pack (4) mounted thereto. The first cantilever (5) and the second cantilever (6) are supported with respect to each other by a transversal strut (7) arranged underneath the chassis (2) to at least partially counterbalance the static and / or dynamic loads received by the chassis (2) from the first cantilever (5) and the second cantilever (6) during operation.

Description

[0001] Electric Truck

[0002] FIELD OF THE DISCLOSURE

[0003] The present disclosure relates to electric trucks having battery packs mounted on the sides of the chassis. The disclosure further relates to a method for absorbing kinetic energy in a battery mounting structure of an electric truck received from another vehicle during a lateral impact in case of a collision.

[0004] BACKGROUND OF THE DISCLOSURE

[0005] Electric trucks have become increasingly significant in the transportation industry and in logistics, such as recycling, distribution or construction, due to their potential to reduce emissions and dependence on fossil fuels. These vehicles typically incorporate a chassis and one or more battery packs mounted on or within the chassis structure. Various designs have been developed to enhance the efficiency, safety, and utility of electric trucks. Among these, arranging the battery packs on the sides of the chassis has gained attention due to its potential benefits in terms of weight distribution and space utilization. However, despite these advancements, existing electric truck designs face several challenges and drawbacks, particularly concerning the mounting of battery packs on the sides of the chassis.

[0006] Some of the known approaches are discussed hereinafter. DE102011109017A1 published in 2013 in the name of MAN TRUCK & BUS AG relates to relates to an electric drive module for a vehicle, in particular a commercial vehicle, with an electric or hybrid drive, with at least one battery pack which can be charged via an inverter, with a support frame which accommodates the battery pack and can be attached to the vehicle body, and with a cooling device for controlling the temperature of the electrical components

[0007] WO2021058539A1 published in 2021 in the name of Designwerk Technologies AG relates to an electric truck comprising a battery pack assembly comprising a battery pack mounting structure and at least one battery pack. The battery pack comprises a box shaped outer housing and a battery unit arranged inside and supported by the outer housing. The battery pack mounting structure for each battery pack comprises a first and a second cantilever attached to a chassis of the electric truck, said first and second cantilever extending in transversal direction and being in the longitudinal direction spaced a distance apart from each other. Further, the battery pack is interconnected to the first and the second cantilever during operation in a floating manner allowing a torsional movement of the chassis around the longitudinal direction.

[0008] SUMMARY OF THE DISCLOSURE

[0009] Battery packs mounted on the sides of the chassis on an electric truck are inherently vulnerable to side impacts during collisions. In the event of a side collision, the battery packs can be directly impacted, leading to potential damage, short- circuiting, or even fires. This poses significant safety risks to the vehicle occupants and others in the vicinity. The mounting structures for battery packs on the sides of the chassis must therefore be robust enough to withstand impacts while protecting the integrity of the battery packs.

[0010] Equally relevant, the weight of the battery packs mounted to the sides of the chassis exerts considerable stress on the chassis during operation. The induced loads can cause increased wear and fatigue on the chassis components, potentially leading to premature failure. To ensure the vehicle’s structural integrity over time good design solutions should account for this stress to ensure the longevity and reliability of the chassis under the added load of the battery packs.

[0011] While side-mounted battery packs can help in optimizing weight distribution, improper design can lead to an imbalance, affecting the vehicle's handling and stability. This is particularly critical in high-speed or emergency maneuvers, where poor weight distribution or insufficient support can lead to damages.

[0012] Given these drawbacks, there is a clear need for improved designs in the mounting structure of battery packs for electric trucks. Such improvements should focus on enhancing the safety and durability of the battery packs in particular during side impacts, while optimizing weight / load distribution without compromising handling and maintenance.

[0013] A first aspect of the disclosure is directed to an electric truck comprising a chassis extending in a longitudinal direction. The electric truck comprises a battery pack mounting structure configured to carry at least one battery pack on each of two opposite sides of the chassis. The battery pack mounting structure typically com- prises at least one first cantilever and at least one second cantilever being attached to the chassis on opposite sides and extending in a transversal direction opposite to each other away from the chassis. During operation the first cantilever and the second cantilever each at least partially carry a battery pack mounted thereto. For good results the first cantilever and the second cantilever are supported with respect to each other by a transversal strut arranged underneath the chassis to at least partially counterbalance the static and / or dynamic loads received by the chassis from the first cantilever and the second cantilever during operation.

[0014] In particular torsional loads such as torques acting on the chassis by the first and the second cantilever can be counterbalanced with respect to each other. Thereby the chassis can be largely relieved from torsional loads received from the first cantilever and the second cantilever.

[0015] The chassis preferably comprises two longitudinal beams arranged essentially parallel to each other in the longitudinal direction of the electric truck and the transversal strut is interconnected to each longitudinal beam of the chassis by a vertical strut arranged essentially in a vertical direction having an individual anchor point with the chassis. Alternatively or in addition, the transversal strut is interconnected to each longitudinal beam of the chassis by a vertical strut arranged at an angle with each other in particular forming an isosceles trapezoid or a triangle having a common anchor point. The vertical struts are preferably tension (and / or compression) resistant along their general extension (in vertical direction) in order to allow a transfer of loads therethrough.

[0016] Typically the chassis comprises two or more chassis struts connecting the two beams of the chassis in transversal direction. Preferably the chassis struts and the transversal strut are essentially parallel in transversal direction.

[0017] For good performance the transversal strut is compression resistant, in particular with respect to compression forces acting in transversal direction. Preferably, the vertical strut has a higher compression resistance in transversal direction than one of the longitudinal beams of the chassis. In particular, the vertical strut has a similar or a higher compression resistance in transversal direction compared to a chassis strut.

[0018] The transversal strut is arranged underneath the chassis, in other words, the transversal strut is in vertical direction arranged below the beams of the chassis. In particular the transversal strut is spaced a distance apart from the beams of the chassis corresponding approximately to a height of a battery pack in vertical direction. The first and the second cantilevers are preferably arranged on a similar height or in vertical direction above as the beams of the chassis.

[0019] Depending on the design, two or more cantilevers are attached to each beam of the chassis, such that a battery pack can be mounted to between two cantilevers in the longitudinal direction spaced a distance apart from each other. In preferred variations, the transversal strut is interconnected to each cantilever by a diagonal strut, in particular in an end region of the transversal strut, said diagonal struts being configured to transfer loads received by the respective cantilever at least partially into the transversal strut. Thus the diagonal struts are preferably compression (and / or tension) resistant along their general extension in order to allow a transfer of load therethrough.

[0020] Good results can be achieved, when each cantilever and / or each vertical strut and / or the transversal strut are interconnected to each other, respectively to the longitudinal beams by a joint, in particular a joint having one degree of freedom arranged around a joint axis extending parallel to the longitudinal direction of the chassis. Preferably the vertical struts each comprises a joint, in particular in vertical direction below its respective anchor point with the chassis beam.

[0021] At least one joint preferably consists of sheet metal, in particular having one or more cutouts arranged along the joint axis. The resulting material thinnings provide a hinge-like joint. Other variations are possible which keep extensive forces away from the chassis.

[0022] Depending on the design, the transversal strut and the two vertical struts in combination with the chassis form (in particular in combination with the chassis struts), when seen in the longitudinal direction, a trapezoid, in particular a isosceles trapezoid such as a rectangle. In case of a collision, the trapezoid is configured to deform by (transversal) displacement of the transversal strut with respect to the chassis strut(s). In this case the vertical struts rotate a certain degree around the respective chassis beam at the joint therebetween. Deformations to the rectangle results at least temporarily in a parallelogram.

[0023] In some variations, the rectangle comprises secondary struts being arranged essentially diagonal with respect to the rectangle and interconnecting the chassis and the transversal strut diagonally. The secondary struts are preferably tension resistant to increase the rigidity of the rectangle. In particular the secondary struts are configured to give way above a certain tension (overload in case of collision) allowing the rectangle to deform in a parallelogram manner. The secondary struts can be made from bend sheet metal or metal profiles, however since their primary load resistance is with respect to tensions, cables, in particular steel cables, can be equally used.

[0024] Preferably the vertical struts comprise a auxiliary support arranged in vertical direction below the respective cantilever facing during operation a housing of the battery pack for transferring traversal loads from the housing to the transversal strut. In some variations, the auxiliary support is integrally formed with the vertical strut.

[0025] The auxiliary support is preferably during operation spaced in traversal direction and / or in longitudinal direction a certain deformation space apart from the housing. During operation is this case refers to regular or normal operation, such as driving etc. This avoids chafing between the battery pack and the auxiliary support and the battery pack housing. In case of a collision however, due to deformation of the chassis and / or the battery pack mounting structure and / or the bat- tery pack housing, the deformation space is traversed by the battery pack housing and (direct or indirect) contact with the auxiliary support is established. In other words, contact between the auxiliary support and the battery pack is established only above a threshold load (torsional) received by the battery pack mounting structure from the battery pack.

[0026] Good performance is possible, when the auxiliary support comprises a support surface. A transversal area of the support surface is arranged facing the battery pack housing in the transversal direction. Alternatively or in addition, a longitudinal area of the support surface is arranged facing the battery pack housing in longitudinal direction. In a preferred arrangement the longitudinal area and the transversal area are arranged next to each other and the support surface has in a top down view an L-shaped cross section.

[0027] To increase the support of the battery pack mounting structure in longitudinal direction (e.g. when breaking / accelerating the electric truck during operation or in case of a rear-end collision) additional support(s) struts can be foreseen.

[0028] Each cantilever can be connected by longitudinal cantilever support in a top down view diagonally to the chassis to transfer loads in longitudinal direction received by the respective cantilever during operation at least partially to the chassis. Each longitudinal cantilever support being preferably attached to the respective cantilever in an outer half of a transversal length of the cantilever (in transversal direction). In particular, the longitudinal cantilever support is attached to the cantilever offset inwardly from an outer fastening means. This allows a certain deformation of the cantilever around the longitudinal cantilever support thereby reducing the loads acting on the battery pack in the event of a rear-end collision.

[0029] Each vertical strut is preferably connected by longitudinal strut support in a lateral view diagonally to the chassis to transfer loads in longitudinal direction received by the respective vertical strut during operation at least partially to the chassis. If appropriate, the longitudinal strut support is mechanically connected to the auxiliary support, in particular to the longitudinal area of the support surface. The longitudinal strut support assists in limiting the degrees of freedom of the transversal strut connected to the vertical struts as forces acting on the transversal strut in longitudinal direction are transferred to the chassis via the longitudinal strut support.

[0030] In a preferred variation the battery pack mounding structure is primarily made from bend sheet metal and / or metal profiles. In particular the transversal strut, the vertical struts, the diagonal struts and / or the support struts are made from bend sheet metal and / or metal profiles, preferably having an open cross-section, such as a C-shaped or T-shaped or double T-shaped cross section. Good rigidity can be achieved when the struts are essentially straight (elongated). This provides good tension and / or compression resistance and low weight.

[0031] However, part or parts of the battery pack mounting structure can also be made in a (metal) casting process. In particular the first and / or the second cantilever can be made from cast metal. Depending on the design, the first and / or the second cantilever can be integrally formed with the respective longitudinal cantilever support as a one-piece cast part. In this case the cast part can in a top down view be essentially triangular having an additional leg in longitudinal direction for attachment to the respective chassis beam.

[0032] Usually the connections between the struts and / or to the beams of the chassis are primarily made with screws, bolts and / or rivets.

[0033] In case of a strut (made from sheet metal) having an open cross-section, the respective strut may comprise folded-in side wall end sections providing an attachment region.

[0034] Depending on the field of application, the transversal strut, the vertical struts, the diagonal struts and / or the support struts comprise a series of recesses, in particular cutouts. This reduces the weight without compromising tension / compression resistance.

[0035] For good performance, the first and the second cantilever each comprise fastening means for mounting the battery pack to the respective cantilever in a floating manner. Preferably the fastening means comprise elastic bushings consisting of an elastic material allowing a certain displacement of the battery pack with respect to the cantilever it is mounted to. Depending on the design, the fastening means allow a certain degree of rotation of the battery pack around a rotation axis essentially parallel to the longitudinal direction before any deformation of the chassis and / or the battery pack mounting structure occurs.

[0036] In a preferred variation the fastening means comprise a bolt coupling such that lateral forces and / or forces in longitudinal direction on one of the battery packs are transmitted at least partially into the respective cantilever and an undesired unmounting of the battery pack from the cantilever is prevented. Preferably the cantilevers have a C-shaped cross-section and the fastening means each comprise a bolt arranged in two vertically aligned openings of the respective cantilever. The bolts are removable, such that the battery pack having corresponding mounting eyes can be slid in transversal direction into the cantilever, such that the mounting eyes vertically align with the openings and the bolts are inserted to securely mount the battery pack to the cantilever.

[0037] In some variations, at least one cantilever is incorporated into a housing of the corresponding battery pack. In this case support mounts are arranged at the chassis to receive corresponding hooks of the battery pack. Alternatively or in addition, the diagonal strut can be incorporated into the housing of the battery pack.

[0038] Another aspect of the disclosure is directed to a method for absorbing kinetic energy in a battery mounting structure of an electric truck received from another vehicle during a lateral impact in case of a collision. The method comprises the step of: providing an electric truck according to the disclosure. The preferred embodiments of the electric truck described herein form corresponding preferred embodiments of the method and vice versa. The method further comprises the step of: displacing, upon impact of the vehicle with a first battery pack mounted to the first cantilever, the first battery pack with respect to the chassis of the electric truck thereby transferring impact forces into the first cantilever; transferring impact forces from the first cantilever into the transversal strut by displacement of the first cantilever with respect to the chassis of the electric truck; transferring impact forces from the transversal strut into the second cantilever by displacement of the transversal strut towards the second cantilever; and displacing the second cantilever and the thereto attached battery pack with respect to the chassis of the electric truck in an upward direction thereby absorbing kinetic energy from the impact applied to the first battery pack attached to the first cantilever. The steps of displacing the first battery pack, the second battery pack respectively, with respect to the chassis of the electric truck preferably comprise respectively: displacing the first battery pack, the second battery pack respectively, in transversal direction; and / or rotating of the first battery pack, the second battery pack respectively, around a rotation axis being essentially parallel to the longitudinal direction, in particular around a joint of the respective vertical strut.

[0039] A further aspect of the disclosure is directed to a method for absorbing kinetic energy in a battery mounting structure of an electric truck received from battery packs mounted to said battery mounting structure in case of a rear-end collision. The method comprises the following steps: providing an electric truck as described herein, wherein each cantilever is connected by longitudinal cantilever support in a top down view diagonally to the chassis; transferring upon impact loads in longitudinal direction from the battery pack to the respective cantilever; and transferring loads received by the respective cantilever from the battery pack at least partially to the chassis via the longitudinal cantilever supports to compensate lever forces on an outer end of the cantilever.

[0040] To achieve a mostly uniform deceleration of the battery pack each battery pack is preferably mounted to the respective cantilever at two mounting points, in particular at two bolt couplings, spaced in transversal direction apart from each other along the cantilevers. The method preferably comprises decelerating the respective battery pack by the cantilevers in the longitudinal direction by transferring essentially equal retarding forces to the battery backs via each mounting point. This minimizes yawning moments on the battery packs.

[0041] If appropriate, an auxiliary support is arranged in vertical direction below the respective cantilever facing the battery pack and each auxiliary support is mechanically connected by a longitudinal strut support in a lateral view diagonally to the chassis. The method preferably comprises the step of transferring additional retarding forces in longitudinal direction from the chassis via the auxiliary support to the battery pack, in particular the additional retarding forces being essentially equal to the retarding forces per mounting point. Having further point to introduce retarding forces to the battery packs further distributes the forces.

[0042] The preferred embodiments of the electric truck described herein form corresponding preferred embodiments of the method and vice versa. In case of an a lateral impact in case of a collision wherein the collisions is at an angle, the described methods may act in superposition as transversal and longitudinal forces need to be absorbed.

[0043] It is to be understood that both the foregoing general description and the following detailed description present embodiments, and are intended to provide an overview or framework for understanding the nature and character of the disclosure. The accompanying drawings are included to provide a further understanding, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments, and together with the description serve to explain the principles and operation of the concepts disclosed.

[0044] BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The herein described disclosure will be more fully understood from the detailed description given herein below and the accompanying drawings which should not be considered limiting to the disclosure described in the appended claims. The drawings are showing:

[0046] Fig. 1 a perspective view of a first variation of an electric truck according to the disclosure;

[0047] Fig. 2 a section view of the first variation of Fig.1 indicated by section line AA;

[0048] Fig. 3 a perspective view of a second variation of an electric truck according to the disclosure;

[0049] Fig. 4 a detail view of the second variation of Fig. 3 indicated by box B;

[0050] Fig. 5 a perspective view of the second variation of an electric truck according to the disclosure with a lateral impact indicated by an arrow;

[0051] Fig. 6 a front view of the second variation of an electric truck according to the disclosure with the impact indicated by an arrow in Fig. 5; Fig. 7 the front view of Fig. 6 shortly after the impact.

[0052] DESCRIPTION OF THE EMBODIMENTS

[0053] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all features are shown. Indeed, embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, like reference numbers will be used to refer to like components or parts.

[0054] Figure 1 shows a perspective view of a first variation of an electric truck 1 according to the disclosure and Figure 2 shows a section view of the first variation of Figure 1 indicated by section line AA.

[0055] The shown electric truck 1 is reduced to the relevant parts, in this case a chassis 2 extending in longitudinal direction x and a battery pack mounting structure 3 carrying one battery pack 4 on each of two opposite sides of the chassis 2. Other parts such as the drivetrain, wheels, axels etc. are not shown.

[0056] The battery packs 4 each comprise a box-shaped housing 17 having a certain length L in the longitudinal direction x of the electric truck 1 , a certain width W in the transversal direction y of the electric truck 1 and a certain height H in a vertical direction z of the electric truck 1 . The chassis 2 of the electric truck 1 comprises two longitudinal beams 8 arranged essentially parallel to each other in longitudinal direction x. The two beams 8 are spaced apart in transversal direction y by several chassis struts 23 connecting the two beams 8 in transversal direction y.

[0057] The battery pack mounting structure 3 comprises a front section and a rear section spaced a certain distance in longitudinal direction x apart from each other. Per side of the chassis 2 the respective battery pack 4 is arranged between the front section and rear section of the battery pack mounting structure 3. Elements numbered in Figures 1 to 7 having an apostrophe correspond in their name and function to the elements having no apostrophe, wherein the apostrophed elements are arranged at the rear section of the battery pack mounting structure.

[0058] The battery pack mounting structure 3 comprises a first cantilever 5 and a second cantilever 6 being attached to the chassis 2 opposite to each other and extending in a transversal direction y opposite to each other away from the chassis 2.

[0059] Spaced a certain distance in longitudinal direction x away from the first cantilever 5 a first cantilever 5’ of the rear section is attached to the chassis and extends parallel to the first cantilever 5 away from the chassis 2. Opposite to the rear section first cantilever 5’ a rear section second cantilever 6’ is attached to the chassis extending parallel to the second cantilever 6 away from the chassis 2. Arranged between and mounted to the first cantilevers 5, 5’ is a first battery pack 41 . Arranged between and mounted to the second cantilevers 6, 6’ is a second battery pack 42. The first and the second cantilever 5, 6 are supported with respect to each other to at least partially counterbalance the static and / or dynamic loads received by the chassis 2 from the first and the second cantilever 5, 6. To achieve this, a transversal strut 7 arranged in vertical direction z underneath the chassis 2 mechanically interconnects the first and the second cantilever 5, 6. The transversal strut 7 extends in transversal direction y essentially parallel to the ground during operation of the electric truck 1 . The transversal strut 7 is a compression strut.

[0060] The transversal strut 7 is in the shown variations, as best visible in Figure 4, connected to each of the beams 8 of the chassis 2 respectively by a vertical strut 9. The vertical struts 9 are compression and / or tension struts. The vertical struts 9 are extending in vertical direction z between the transversal strut 7 and the respective beam 8, having an individual anchor point at the beams 8. The vertical struts 9 each comprise a joint 13 having one degree of freedom arranged around an axis extending parallel to the longitudinal direction x of the chassis 2. The joints 13 are arranged close to the anchor point 10 below the respective beam 8. This allows the vertical struts 9 to hang the transversal strut 7 in a laterally displaceable manner (displaceable in transversal direction y). The joint 13 is formed in sheet metal, wherein cutouts 14 along the joint 13 reduces the metal to be bend, when vertical strut 9 is rotated around the joint 13.

[0061] The transversal strut 7 and the two vertical struts 9 in combination with the chassis 2 form, when seen in the longitudinal direction x, a rectangle. When the joints 13 are articulated the rectangle is deformed into a parallelogram (with corner angles unequal to 90 degree). Figure 3 shows a perspective view of a second variation of an electric truck 1 according to the disclosure and Figure 4 a detail view of the second variation of Figure 3 indicated by box B.

[0062] The first variation differs from the second variation in that the rectangle comprises secondary struts 15 being arranged essentially diagonal with respect to the rectangle and interconnecting the chassis 2 and the transversal strut 7 diagonally. These secondary struts 15 are tension struts and hinder the rectangle from deforming into a parallelogram. The secondary struts 15 are not present in the second variation.

[0063] To transfer loads from the cantilevers 5, 6 into the transversal strut 7, a diagonal strut 11 connects an end region 12 of the transversal strut 7 to the respective cantilever 5, 6. The diagonal struts 11 extend generally in vertical and in transversal direction z, y. The diagonal struts 11 are compression struts.

[0064] To provide an overload contact point between the transversal strut 7 and the housing 17 of the battery packs 4, the vertical struts 9 comprise a auxiliary support 16 arranged in vertical direction z below the respective cantilever 5, 6 facing during operation a housing 17 of the battery pack 4 for transferring traversal loads from the housing 17 to the transversal strut 7. As best visible in Figure 4, the auxiliary support 16 comprises a support surface having a transversal area 24 of the support surface arranged facing the battery pack housing 17 in the transversal direction y. In addition, a longitudinal area 25 of the support surface is arranged facing the battery pack housing 17 in longitudinal direction x. In a pre- ferred arrangement the longitudinal area 25 and the transversal area 24 are arranged next to each other and the support surface has in a top down view an L- shaped cross section. The battery packs 4 are respectively spaced apart in transversal direction y and in longitudinal direction x a certain deformation space 18 from the auxiliary support 16.

[0065] To stabilize the battery pack mounting structure 3 with respect to the chassis2, each cantilever 5, 6 is connected by longitudinal cantilever support 19 in a top down view diagonally to the chassis 2 to transfer loads in longitudinal direction x received by the respective cantilever 5, 6 during operation at least partially to the chassis 2. Similarly each vertical strut 9 is connected by longitudinal strut support 20 in a lateral view diagonally to the chassis 2 to transfer loads in longitudinal direction x received by the respective vertical strut 9 during operation at least partially to the chassis 2.

[0066] The struts 7, 9, 11 , 15, 19, 20 used in the shown variations are made from bend sheet metal having an open cross-section, in particular a C-shaped cross-section. Cutouts 14 along the struts reduce their weight.

[0067] The battery packs 4 are mounted to the respective cantilever 5, 6 by fastening means 21 formed in the shown variations as bolt couplings 22. Bolts span the c- shaped cross-section of the cantilevers 5, 6 to mount the battery packs 4 thereto in a floating manner. In the following, a method for absorbing kinetic energy in a battery mounting structure of the electric truck 1 received from another vehicle during a lateral impact in case of a collision is illustrated in Figures 5 to 7. Figure 5 shows a perspective view of the second variation of an electric truck according to the disclosure with a lateral impact indicated by an arrow, whereas Figure 6 is showing a front view of the second variation of an electric truck according to the disclosure with the impact indicated by the arrow in Figure 5.

[0068] In Figure 7 the front view of Figure 6 is displayed shortly after the impact wherein the displacement of components is schematically illustrated. The transfer of the kinetic energy from the impact incident on the first battery pack 41 through the battery pack mounting structure 3 into a lifting movement of the second battery pack 42 (transfer into potential energy) is indicated by the dashed arrows. The steps of the method (in Figure 7 from left to right) are:

[0069] 1 ) Displacing the first battery pack 41 in transversal direction y and rotating the first battery pack 41 around a rotation axis being essentially parallel to the longitudinal direction, in particular around a joint 13 of the respective vertical strut 9. In this first step, a mechanical contact between the auxiliary support 16 and the housing 17 of the first battery pack 41 is established.

[0070] 2) Transferring impact forces into the transversal strut 7 by displacement of the first cantilever 5 with respect to the chassis 2 of the electric truck 1 . In addition transferring impact forces into the transversal strut 7 by displacement of the auxiliary support 16 pressed by the housing 17 of the first battery pack 41 . 3) Transferring impact forces from the transversal strut 7 into the second cantilever 6 by displacement of the transversal strut 7 towards the second cantilever 6; In addition transferring impact forces from the transversal strut 7 via the opposite auxiliary support 16 into the housing 17 of the second battery pack 42.

[0071] 4) Displacing the second cantilever 6 and the thereto attached second battery pack 42 with respect to the chassis 2 of the electric truck 1 in an upward direction z thereby absorbing kinetic energy from the impact applied to the first battery pack 41 attached to the first cantilever 5. This includes rotating the second battery pack 42 around a rotation axis being essentially parallel to the longitudinal direction, in particular around a joint 13 of the respective vertical strut 9.

[0072] Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the scope of the disclosure.

[0073] LIST OF DESIGNATIONS

[0074] 1 Electric truck 15 Secondary strut

[0075] 2 Chassis 16 Auxiliary support

[0076] 3 Battery pack mounting struc17 Housing (battery pack) ture 18 Deformation space

[0077] 4 Battery pack 19 Cantilever support

[0078] 5 First cantilever 20 Longitudinal strut support

[0079] 6 Second cantilever 21 Fastening means

[0080] 7 Transversal strut 22 Bolt coupling (fastening means)

[0081] 8 Beams (chassis) 23 Chassis strut

[0082] 9 Vertical strut 24 T ransversal area (auxiliary sup¬

[0083] 10 Anchor point port)

[0084] 11 Diagonal strut 25 Longitudinal area (auxiliary

[0085] 12 End region (transversal strut) support)

[0086] 13 Joint 41 First battery pack

[0087] 14 Cutout 42 Second battery pack

Claims

PATENT CLAIMS1 . Electric truck (1 ) comprising a. a chassis (2) extending in a longitudinal direction (x); b. a battery pack mounting structure (3) configured to carry at least one battery pack (4) on each of two opposite sides of the chassis (2), the battery pack mounting structure (3) comprising: i. at least one first cantilever (5) and at least one second cantilever (6) being attached to the chassis (2) on opposite sides and extending in a transversal direction (y) opposite to each other away from the chassis (2), wherein during operation the first cantilever (5) and the second cantilever (6) each at least partially carry a battery pack (4) mounted thereto; ii. the first cantilever (5) and the second cantilever (6) are supported with respect to each other by a transversal strut (7) arranged underneath the chassis (2) to at least partially counterbalance the static and / or dynamic loads received by the chassis (2) from the first cantilever (5) and the second cantilever (6) during operation.

2. The electric truck (1 ) according to claim 1 , wherein the chassis (2) comprises two longitudinal beams (8) arranged essentially parallel to each other in the longitudinal direction (x) of the electric truck (1 ) and the transversalstrut (7) is interconnected to each longitudinal beam (8) of the chassis (2) by a. a vertical strut (9) arranged essentially in a vertical direction (z) having an individual anchor point (10) with the chassis (2) and / or b. a vertical strut (9) arranged at an angle with each other in particular forming an isosceles trapezoid or a triangle having a common anchor point (10).

3. The electric truck (1 ) according to any of the previous claims, wherein the transversal strut (7) is interconnected to each cantilever (5, 6) by a diagonal strut (11 ), in particular in an end region (12) of the transversal strut (7), said diagonal struts (11 ) being configured to transfer the load received by the cantilever (5, 6) at least partially into the transversal strut (7).

4. The electric truck (1 ) according to claim 2 or 3, wherein each cantilever (5, 6) and / or each vertical strut (9) and / or the transversal strut (7) are interconnected to each other, respectively to the longitudinal beams (8) by a joint (13), in particular a joint (13) having one degree of freedom arranged around an axis extending parallel to the longitudinal direction (x) of the chassis (2).

5. The electric truck (1 ) according to claim 4, wherein at least one joint (13) consists of sheet metal, in particular having one or more cutouts (14).

6. The electric truck (1 ) according to any of the preceding claims 2 to 5, wherein the transversal strut (7) and the two vertical struts (9) in combination with the chassis (2) form, when seen in the longitudinal direction (x), a trapezoid, in particular a isosceles trapezoid such as a rectangle.

7. The electric truck (1 ) according to claim 6, wherein the rectangle comprises secondary struts (15) being arranged essentially diagonal with respect to the rectangle and interconnecting the chassis (2) and the transversal strut (7) diagonally.

8. The electric truck (1 ) according to any of the preceding claims 2 to 7, wherein the vertical struts (9) comprise a auxiliary support (16) arranged in vertical direction (z) below the respective cantilever (5, 6) facing during operation a housing (17) of the battery pack (4) for transferring traversal loads from the housing (17) to the transversal strut (7).

9. The electric truck (1 ) according to claim 8, wherein the auxiliary support(16) is during operation spaced apart in transversal direction (y) and / or in longitudinal direction (x) a certain deformation space (18) from the housing(17).

10. The electric truck (1 ) according to any of the preceding claims, wherein each cantilever (5, 6) is connected by longitudinal cantilever support (19) in a top down view diagonally to the chassis (2) to transfer loads in longitudinal direction (x) received by the respective cantilever (5, 6) during operation at least partially to the chassis (2).

11. The electric truck (1 ) according to any of the preceding claims 2 to 10, wherein each vertical strut (9) is connected by longitudinal strut support(20) in a lateral view diagonally to the chassis (2) to transfer loads in longitudinal direction (x) received by the respective vertical strut (9) during operation at least partially to the chassis (2).

12. The electric truck (1 ) according to any of the preceding claims, wherein the battery pack mounting structure (3) is primarily made from bend sheet metal and / or metal profiles.

13. The electric truck (1 ) according to any of the preceding claims, wherein the first and the second cantilever (5, 6) each comprise fastening means (21 ) for mounting the battery pack (4) to the respective cantilever (5, 6) in a floating manner.

14. The electric truck (1 ) according to claim 13, wherein the fastening means(21 ) comprise a bolt coupling (22) such that lateral forces on one of the battery packs (4) are transmitted at least partially into the respective cantilever (5, 6) and undesired unmounting is prevented.

15. Method for absorbing kinetic energy in a battery mounting structure of an electric truck (1 ) received from another vehicle during a lateral impact in case of a collision comprising the following method steps: a. providing an electric truck (1 ) according to any of the preceding claims 1 to 14;b. displacing, upon impact of the vehicle with a first battery pack (41 ) mounted to the first cantilever (5), the first battery pack (41 ) with respect to the chassis (2) of the electric truck (1 ) thereby transferring impact forces into the first cantilever (5); c. transferring impact forces from the first cantilever (5) into the transversal strut (7) by displacement of the first cantilever (5) with respect to the chassis (2) of the electric truck (1 ); d. transferring impact forces from the transversal strut (7) into the second cantilever (6) by displacement of the transversal strut (7) towards the second cantilever (6); e. displacing the second cantilever (6) and the thereto attached second battery pack (42) with respect to the chassis (2) of the electric truck (1 ) in an upward direction (z) thereby absorbing kinetic energy from the impact applied to the first battery pack (41 ) attached to the first cantilever (5).

16. The Method according to claim 15, wherein the steps of displacing the first battery pack (41 ), the second battery pack respectively, with respect to the chassis (2) of the electric truck (1 ) comprises: a. displacing the first battery pack (41 ), the second battery pack (42) respectively, in transversal direction (y); and / orb. rotating the first battery pack (41 ), the second battery pack (42) respectively, around a rotation axis being essentially parallel to the longitudinal direction, in particular around a joint (13) of the respective vertical strut (9).

17. Method for absorbing kinetic energy in a battery mounting structure of an electric truck (1 ) received from battery packs (4) mounted to said battery mounting structure in case of a rear-end collision, the method comprising the following steps: a. providing an electric truck (1 ) according to any of the preceding claims 1 to 14, wherein each cantilever (5, 6) is connected by longitudinal cantilever support (19) in a top down view diagonally to the chassis (2); b. transferring upon impact loads in longitudinal direction (x) from the battery pack (4) to the respective cantilever (5, 6); c. transferring loads received by the respective cantilever (5, 6) from the battery pack (4) at least partially to the chassis (2) via the longitudinal cantilever supports (19) to compensate lever forces on an outer end of the cantilever (5, 6).

18. The method according to claim 17, wherein each battery pack (4) is mounted to the respective cantilever (5, 6) at two mounting points, in particular at two bolt couplings (22), spaced in transversal direction (y) apart fromeach other along the cantilevers (5, 6) and the method comprises decelerating the respective battery pack (4) by the cantilevers (5, 6) in the longitudinal direction (x) by transferring essentially equal retarding forces to the battery backs (4) via each mounting point.

19. The method according to claim 17 or 18, wherein an auxiliary support (16) is arranged in vertical direction (z) below the respective cantilever (5, 6) facing the battery pack (4) and each auxiliary support (16) is mechanically connected by a longitudinal strut support (20) in a lateral view diagonally to the chassis (2) and the method comprises the step of transferring additional retarding forces in longitudinal direction (x) from the chassis (2) via the auxiliary support (16) to the battery pack (4), in particular the additional retarding forces being essentially equal to the retarding forces per mounting point.

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