FIELD OF THE DISCLOSURE

The present disclosure relates to an electric truck and a battery pack therefore.

BACKGROUND OF THE DISCLOSURE Electric trucks comprising a battery pack assembly with a battery pack mounting structure are known from the prior art.

CN109955704Afirst published on 02.07.2019 in the name of Jiangsu University discloses a battery pack suspension device for an electric vehicle, which comprises a chassis, a hydraulic shock absorber, a buffer spring, a battery box, a connecting lug and a battery unit. The battery unit is fixed in the battery unit compartment in side the battery box. The battery box is connected with the connecting lug on the upper side of the chassis through a hydraulic shock absorber, and the bottom of the battery box is provided with a buffer spring through the axis bolt. Further the battery unit is bolted to the battery box body. CN207368041 U first published on 1 5.05.2018 in the name of Shenzhen Opti- mumnano Energy Co., Ltd discloses a power battery box bracket including a pair of beams and a plurality of connecting rods respectively vertically disposed on a pair of beams; the pair of beams is spaced apart, and each of the beams is corre spondingly provided with two connecting rods on one beam.

SUMMARY OF THE DISCLOSURE

A preferred variation is directed to an electric truck comprising a battery pack as- sembly comprising a battery pack mounting structure and at least one battery pack. Depending on the field of application and design the electric truck may comprise two or more battery packs. The at least one battery pack usually comprises a box shaped outer housing having a certain length in a longitudinal direction of the truck, a certain width in a transversal direction of the truck and a certain height in a vertical direction of the truck. Preferably the outer housing is cuboid-shaped. If appropriate the outer housing of the battery pack is made from sheet metal in order to form light, rigid and robust outer housing. It is desirable to avoid shear and/or torsional forces resulting from the movement of the chassis of the electric truck during operation and being transferred to the rigid outer housing of the battery pack in order to avoid material fatigue and damage. Usually at least one battery unit is arranged inside and supported by the outer housing. In some variations mul tiple battery units may be arranged inside the outer housing of the battery pack.

The battery pack mounting structure per battery pack comprises a first and a sec ond cantilever attached to a chassis of the electric truck. Depending on the appli- cation three or more cantilevers per battery pack may be attached to the chassis of the electric truck. The first and second cantilever extend in transversal direction be ing in the longitudinal direction spaced a distance apart from each other. In some variations at least the first and/or the second cantilever may be attached on a lateral side of the chassis. Alternatively, or in addition at least the first and/or the second cantilever may extend in transversal direction over the width of chassis and may be attached to the chassis.

During operation of the electric truck the battery pack is interconnected to the first and the second cantilever in a floating manner allowing at least a certain torsional movement of the chassis around the longitudinal direction. In other words, the bat- tery pack is mechanically decoupled from torsional movements of the chassis of the electric truck which occur during operation of the electric truck. This way shear and/or torsional forces on the rigid outer housing of the battery pack are reduced compared to a rigid connection between the battery pack and the first and respec tively the second cantilever. In a preferred variation the outer housing may be in the mounted position intercon nected to the first cantilever and to the second cantilever by mounting means. The mounting means may form a floating fit in the mounted position of the battery pack. If appropriate mounting means are arranged on the leading end region and the trailing end region of the outer housing of the battery pack in the longitudinal direction. Preferably the mounting means may be out of the group of following el ements or a combination thereof: groove and pin; centering pin and centering hole; different types bolt connectors and slide connectors. Favorably the mounting means may be configured to restrict a displacement of the battery pack relative to the chassis in the longitudinal direction and the traversal direction, but allow for a certain displacement relative to the chassis in the vertical direction. Good results may be achieved if the mounting means in combination provide at least in vertical direction a three-point suspension for the outer housing with respect to the first and the second cantilever. Preferably the battery pack is in the mounted position arranged between the first and the second cantilever. This allows the battery pack assembly to be of a compact size in the vertical direction.

In a preferred variation the battery pack is insertable into and removable from bat- tery pack mounting structure.

At least the first and/or the second cantilever may comprise at least one guide sur face extending in traversal direction configured to guide the battery pack into the mounted position when moved in the traversal direction during insertion. Prefera bly at least the first and/or the second cantilever comprise two or more guide sur- faces oriented towards the battery pack in the mounted position. This may be achieved by a profile/ cross-section of the first and / or second cantilever being L- shaped and/or double T-shaped and/or C-shaped. In some variations securing means may be attached to the first and / or second cantilever for securing the bat tery pack in the mounted position. The securing means may be closable from an open state into a closed state and may be openable from a closed state into an open state. Preferably the securing means are configured to preventthe mounting means battery pack to disengage in the mounted position, when the securing means are in a closed state. Depending on the application the securing means may comprise at least one buffer stopper. Preferably the at least one buffer stopper is made from an elastic material. When the battery pack is inserted into the battery pack mount ing structure the securing means is in the open state and when the battery pack is in the mounted position the securing means can be set to the closed state.

Furthermore, the battery pack mounting structure may comprise an alignment de vice configured to limit a movement of the battery pack in the transversal direction when moved towards the mounted position. Alternatively, or in addition the align ment device may be configured to align the mounting means and to accurately de- termine the mounting position of the battery pack when the battery pack is moved in the transversal direction towards the mounted position. In some variations the alignment device can be a stopper attached to the chassis and/or the first and/or the second cantilever. Depending on the field of application at least one mounting means is formed by a centering pin and a seat, into which the centering pin engages in the mounted position. The centering pin and its associated seat may form a float ing fit.

Vibrations are a known challenge for battery packs resulting in safety requirements regulations like UN ECE Regulation No. 100 (also referred to as R100) which ad dresses the safety requirements specific to the electric power train of road vehicles including rechargeable battery packs. The battery pack assembly of the electric truck may further comprise at least one clamping element being arranged between the chassis and the battery unit config ured to absorb lifetime reducing frequencies. The lifetime reducing frequencies can range from 5 Hz to 100 Hz. Usually the battery pack assembly comprises two or more damping elements. Preferably the at least one damping element consist at least partially of a porous material and / or an elastic polymer. At least one damping element is arranged between the first and/or second cantilever and the outer hous ing of the battery pack. It is advantageous if the at least one damping element be tween the first and/or second cantilever and the outer housing of the battery pack is arranged at least partially between contact areas of at least one of the mounting means. Thereby the at least one damping element may form an intermediate bear ing layer between the battery pack and the first and/or second cantilever. Alterna tively, or in addition at least one damping element may be arranged inside the bat tery pack. Preferably the damping element inside the battery pack acts as a support structure for supporting the at least one battery unit with respect to the outer hous ing of the battery pack. Good results are possible if the support structure substan tially surrounds at the least one battery unit. In this variation a dampening of vibra tions of different deflection directions is possible.

The disclosure may additionally be described by the following clauses:

Clause 1 : An electric truck comprising a battery pack assembly comprising a battery pack mounting structure and at least one battery pack, wherein a. said battery pack comprising a box shaped outer housing having a certain length in a longitudinal direction of the truck, a certain width in a transversal direc tion of the truck and a certain height in a vertical direction of the truck and a battery unit arranged inside and supported by the outer housing;

5 b. said battery pack mounting structure per battery pack comprising 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; wherein c. the battery pack during operation is interconnected to the first and the sec-0 ond cantilever in a floating manner allowing a torsional movement of the chassis around the longitudinal direction.

Clause 2: The electric truck according to clause 1 , wherein the outer housing is in the mounted position interconnected to the first cantilever and to the second cantilever by mounting means. 5 Clause 3: The electric truck according to clause 2, wherein the mounting means in combination provide at least in vertical direction a three-point suspension for the outer housing with respect to the first and the second cantilever.

Clause 4: The electric truck according to clauses 2 or 3, wherein the mounting means are out of the group of following elements or a combination thereof: Groove and pin; centering pin and centering hole; types of bolt connectors ; or slide con nectors;

Clause 5: The electric truck according to at least one of the preceding clauses, wherein the battery pack in the mounted position is arranged between the first and the second cantilever.

Clause 6: The electric truck according at least one of the preceding clauses 2 to

5, wherein the at least one mounting means is formed by a centering pin and a seat, into which the centering pin engages in the mounted position.

Clause 7: The electric truck according to at least one of the preceding clauses, wherein at least one damping element is arranged between the chassis and the battery unit configured to absorb lifetime reducing frequencies.

Clause 8: The electric truck according to any one of the previous clauses, wherein the at least one damping element consist at least partially of a porous ma terial and / or an elastic polymer. Clause 9: The electric truck according to any one of the previous clauses, wherein at least one damping element acts as a support structure for supporting the at least one battery unit with respect to the outer housing of the battery pack.

Clause 10: The electric truck according to clause 9, wherein the support struc ture substantially surrounds at the least one battery unit. Clause 1 1 : The electric truck according to any one of the previous clauses, wherein at least one damping element is arranged between the first and/or second cantilever and the outer housing of the battery pack.

Clause 1 2: The electric truck according to any one of the previous clauses, wherein at least the first and/or the second cantilever comprises at least one guide surface extending in traversal direction configured to guide the battery pack when moved in the traversal direction during insertion into the mounted position.

Clause 13: The electric truck according to any one of the previous clauses, wherein the battery pack mounting structure comprises an alignment device con- figured to limit a movement of the battery pack in the transversal direction when moved towards the mounted position and to align the mounting means.

It is to be understood that both the foregoing general description and the following detailed description present embodiments, and are intended to provide an over view 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 illus trate various embodiments, and together with the description serve to explain the principles and operation of the concepts disclosed. BRIEF DESCRIPTION OF THE DRAWINGS

The herein described invention will be more fully understood from the detailed de scription given herein below and the accompanying drawings which should not be considered limiting to the invention described in the appended claims. The draw- ings are showing:

Fig. 1 a partial perspective view of an electric truck according to the invention; Fig. 2 a detailed view of Fig. 1 indicated by circle A; Fig. 3 a side view of the electric truck from Fig. 1 in the transversal direction y; Fig. 4 a detailed view of Fig. 3 indicated by circle B; Fig. 5 a side view of the electric truck from Fig. 1 in the longitudinal direction x;

Fig. 6 a perspective view of a battery pack; Fig. 7 a cross-sectional view of the battery pack of Fig. 6 indicated by section line C; Fig. 8 a partial perspective view of a battery pack assembly; and Fig. 9 a detailed view of Fig. 8 indicated by circle F.

DESCRIPTION OF THE EMBODIMENTS

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 dif ferent 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.

Figures 1, 3 and 5 show different views of a variation of an electric truck 1 com prising a battery pack assembly 2 comprising a battery pack mounting structure 3 and at least one battery pack 4. In the shown variation the battery pack assembly 2 has two cuboid-shaped battery packs 4. The battery packs 4 each comprise a box shaped outer housing 5 having a certain length in a longitudinal direction x of the truck, a certain width in a transversal direction y of the truck and a certain height in a vertical direction z of the truck. The outer housing 5 of the battery pack 4 is made from sheet metal forming a rigid outer housing 5.

The battery pack mounting structure 3 for each pack comprises a first and a second cantilever 7, 8 attached to a chassis 9 of the electric truck as shown in Figures 1 , 3 to 5 and 8. The first and second cantilever 7, 8 extend in transversal direction y and being in the longitudinal direction x spaced a distance apart from each other. In the variation shown in Figure 8 the first and/or the second cantilever 8 is attached on a lateral side of the chassis 9. Figure 1 , 3 and 5 show a variation wherein at least the first and/or the second cantilever 7, 8 extends in transversal direction y over the chassis 9 and is attached thereto. Figures 1 to 5 and 8 to 9 show the battery packs 4 in a mounted position. During operation of the electric truck 1 i.e. the battery packs 4 are in the mounted position, said battery packs 4 are interconnected to the first and the second cantilever 7, 8 in a floating manner allowing at least a certain torsional movement of the chassis 9 around the longitudinal direction x. This way negative shear and/or torsional forces on the rigid outer housing 5 of the battery pack 5 are reduced.

Figures 2, 4 and 9 show a detailed view the outer housing 5 in the mounted posi tion interconnected to the first cantilever and/or to the second cantilever 7, 8 by the mounting means 10. Figure 4 further shows securing means 17 in a closed state. The mounting means 10 form a floating fit in the mounted position of the battery pack 4. At least one mounting means 10 is formed by a centering pin 1 1 and a seat 12, into which the centering pin 1 1 engages in the mounted position as shown in Figures 4 and 9. The centering pin 1 1 and its associated seat 12 form a floating fit. The mounting means 10 are configured to restrict a displacement of the battery pack 4 relative to the chassis 9 in the longitudinal direction x and the tra versal direction y, but allow for a certain displacement relative to the chassis 9 in the vertical direction z. The securing means 17 in the shown variation formed as at least one buffer stopper 17 made from rubber. The at least one buffer stopper pre vents the centering pin 1 1 and the seat 12 to disengage. The mounting means 10 in combination provide at least in vertical direction z a three-point suspension for the outer housing 5 with respect to the first and the second cantilever 7, 8. In the variations shown there are four mounting points with associated mounting means 10. When a torsional movement of the chassis 9 occurs it is possible that the weight of the battery pack 4 which is distributed to each mounting point changes, this leads effectively to a temporary three-point suspension, in which the weight of the battery pack 4 is substantially carried through three mounting points. The battery packs 4 are in the mounted position arranged between the first and the second cantilever 7, 8.

Figures 4 and 9 show that at least the first and/or the second cantilever 7, 8 com prise at least one guide surface 1 5 extending in traversal direction y configured to guide the battery pack 4 into the mounted position when moved in the traversal direction y during insertion. In the shown variations the first and/or the second can tilever 7, 8 comprise two guide surfaces 1 5 oriented towards the battery pack in the mounted position. One guide surface 1 5 is perpendicular to the longitudinal direction x indicated in Figure 4 and another guide surface 1 5 is perpendicular to the vertical direction z shown in Figure 9. The guide surfaces 1 5 are located on a profile/ cross-section of the first and/ or second cantilever 7, 8 being L-shaped (Figures 8 and 9) and/or double T-shaped (Figures 1 to 5).

Furthermore, Figures 5 and 8 show that the battery pack mounting structure 3 comprises an alignment device 16 configured to limit a movement of the battery pack 4 in the transversal direction y when moved towards the mounted position. In addition, the alignment device 16 is configured to align the mounting means 10 and to accurately determine the mounting position of the battery pack 4 when the battery pack 4 is moved in the transversal direction y towards the mounted posi tion. In the illustrated variation the alignment device 16 is a stopper 16 attached to the chassis 9 and/or the first cantilever 7 and/or the second cantilever 8.

Figure 6 shows a perspective view of the battery pack 4 having mounting means 10 arranged on the respective end regions of the outer housing 5 in the longitudinal direction x. Figure 7 shows sectional view of the battery pack 4 of Figure 6 showing at least one battery unit 6 arranged inside and supported by the outer housing. Further shown is the at least one centering pin 1 1 .

Figures 2, 4, 7 and 9 show partially the battery pack assembly 2 of the electric truck comprising at least one damping element 13 being arranged between the chassis 9 and the battery unit 6 configured to absorb lifetime reducing frequencies. The lifetime reducing frequencies usually range from 5 Hz to 100 Hz. In the shown var iation of the battery pack assembly 2, said battery pack assembly 2 comprises two or more damping elements 13. Figures 2, 4, and 9 show at least one damping ele- ment 13 being arranged between the first and/or second cantilever 7, 8 and the outer housing 5 of the battery pack 4. Specifically, the damping element 13 is ar ranged at least partially between contact areas of at least one of the mounting means 10. Thereby the at least one damping element 10 forms an intermediate bearing layer between the battery pack 4 and the first and/or second cantilever 7, 8. Figure 7 shows that in addition at least one damping element 13 is arranged inside the outer housing 5 of the battery pack 4. The damping element 13 inside the battery pack 4 acts as a support structure 14 for supporting the battery unit 6 with respect to the outer housing 5 of the battery pack 4. In the shown variation the support structure 14 substantially surrounds at the battery unit 6 making it pos sible to dampen vibrations of different deflection directions.

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 depart ing from the scope of the disclosure.

LIST OF DESIGNATIONS

1 Electric truck

2 Battery pack assembly

3 Battery pack mounting structure

4 Battery pack

5 Outer housing of the battery pack

6 Battery unit

7 First cantilever

8 Second cantilever

9 Chassis

10 Mounting means

1 1 Centering pin

12 Seat

13 Damping element

14 Support structure

1 5 Guide surface

16 Alignment device

17 Securing means X Longitudinal direction

Y Transversal direction

Z Vertical direction

L Length in longitudinal direction

W Width in transversal direction

H Height in vertical direction