Patent Description:
The vehicle may be a heavy-duty vehicle, such as a truck, a bus or a construction equipment. Although the invention will be described with respect to a truck, the invention is not restricted to this particular vehicle, but may also be used in other vehicles such as passenger cars.

Electric vehicles are provided with electric motors which are powered by one or more traction batteries. To provide sufficient energy, i.e. driving range, a large number of battery cells are needed. The number of cells may be hundreds or even thousands of cells, for example depending on the total energy (driving range) desired for the particular vehicle. To safely and efficiently manage the large number of battery cells mounted in an electric vehicle, the battery cells are installed in forms of battery modules. A cluster of cells make up a module. The modules thus protect the cells from external shocks, heat or vibration, etc. In their turn a cluster of module can be united in a traction battery pack. In addition to holding several battery modules, a traction battery pack may also comprise cooling components and electric wiring, etc. Thus, when producing a vehicle, one or more traction battery packs will be installed into (or mounted onto) the vehicle.

Another alternative is the use of hydrogen gas. The chemical energy of the hydrogen may for example, be converted into mechanical energy in an internal combustion engine or into electric energy in fuel cells, in order to propel the vehicle.

The above-mentioned technologies may also be provided together in a vehicle, thus resulting in a hybrid powering of the vehicle.

On trucks, traction battery packs are normally suspended onto the chassis with multiple brackets and are connected to each other with a multitude of cables and connectors. The traction battery packs on trucks may be formed like cubes, suspended from a frame of the chassis. This is an inefficient installation with regard to packaging since you need to hold the cube on the outside of the frame, thus requiring large brackets due to the bending moments. You also need to allow the frame to flex in normal movement, which is why each cube is suspended with bushings, which requires some free "lost" space for relative movement. There are similar concerns for installing hydrogen tanks, which are also normally suspended onto the chassis with multiple brackets and provided with cables and connectors that need to be handled with care.

<CIT> discloses a frame arrangement for a vehicle with hydrogen storage tanks and battery packs.

An object of the invention is to provide a vehicle, which is powered both by hydrogen gas and by battery, and which alleviates at least some of the drawbacks of known hybrid vehicles. This is achieved by a vehicle according to claim <NUM>.

The invention is based on the insight that by placing one or more traction batteries packs and one or more hydrogen tanks between frame plates of the chassis and tightening them to such a frame plate, a space efficient installation may be obtained which does not require many cables and connectors, and which beneficially contributes to the rigidity of the chassis.

Thus, according to an aspect of the invention, there is provided a vehicle, which comprises:.

By the provision of a vehicle which comprises a hydrogen tank structure on top of a traction battery pack arrangement, or vice versa, arranged between an upper and lower frame plates of a chassis, the advantage of a space-saving and efficient installation is obtainable, without compromising the structural rigidity of the chassis. Furthermore, by tightening the traction battery pack arrangement to the hydrogen tank structure, it is possible to avoid or at least reduce the number of brackets and joints that are needed in known electric vehicles.

It should be understood that in this disclosure a traction battery pack arrangement may in at least some exemplary embodiments comprise a single traction battery pack, while in other exemplary embodiments, the traction battery pack arrangement may comprise two or more traction battery packs. Suitably, in embodiments in which the traction battery pack arrangement comprises two or more traction battery packs, they may be placed on top of each other, thus forming a stack of traction battery packs. In such cases, the traction battery packs may suitably be tightened to each other, thus also avoiding or at least reducing the number of brackets and joints needed in known electric vehicles. It should be understood that in case of two or more traction battery packs, each traction battery pack comprises one or more battery modules.

It should be understood that in this disclosure a hydrogen tank structure, may include one or more hydrogen tanks. In at least some exemplary embodiments, the hydrogen tank structure comprises at least two hydrogen tanks, the hydrogen tanks being placed in a common geometrical plane between the upper and lower frame plates. Thus, the at least two hydrogen tanks may be placed next to each other in a horizontal plane, although not necessarily in contact with each other.

According to at least one exemplary embodiment, the hydrogen tank structure and the traction battery pack arrangement form together with the upper and lower frame plates, an integral load bearing structure of the chassis. This is advantageous, since a supporting wall, or the like, extending between the upper and lower frame plates may be omitted (such a solution would take away space/volume for the hydrogen tanks), and instead the traction battery pack arrangement and the hydrogen tank structure together provide the structural rigidity to the frame plates. In other words, the hydrogen tank structure and the traction battery pack arrangement may effectively fill out the vertical space between the upper and lower frame plates.

According to at least one exemplary embodiment, the hydrogen tank structure is located.

According to at least one exemplary embodiment, the vehicle comprises fasteners extending from.

traction battery pack arrangement and the hydrogen tank structure to both frame plates, e.g. by fasteners extending all the way from one of the frame plates to the other one.

However, it should be understood that depending on individual requirements or requests, other configurations are conceivable. For instance, if the vertical distance between the upper and lower frame plates is designed to house a hydrogen tank structure and a traction battery pack arrangement comprising a plurality of traction battery packs, it is conceivable to omit one or more of the traction battery packs. For instance, if a vehicle operator, owner, customer, etc. does not need as much battery energy as would be provided by the plurality of traction battery packs, then the one or more omitted traction battery packs may be replaced by an insert, such as a dummy pack to fill out the vertical space between the frame plates. The traction battery pack arrangement with the reduced number of traction battery packs, or the hydrogen tank structure, could thus be fastened to the insert, and the insert could be fastened to one of the frame plates. Of course, an insert could instead be placed between the traction battery pack arrangement and the hydrogen tank structure. Thus, it should be understood that there are a number of different exemplary embodiments, in which one of the hydrogen tank structure, the traction battery pack arrangement and an insert is located between the other two, wherein the other two are tightened to a respective one of the upper and lower frame plates. As already mentioned above, there may be provided long fasteners which may tighten several parts of the entire assembly to each other.

It should be understood that in this disclosure the vertical direction is perpendicular to the ground on which the vehicle stands. In other words, a vertical direction coincides or is parallel to the yaw axis of the vehicle. Thus, the fact that the hydrogen tank structure is vertically tightened to the traction battery pack arrangement means that the traction battery pack arrangement is located above or below the hydrogen tank structure. Similarly, in embodiments in which the traction battery pack arrangement comprises a stack of traction battery packs, and individual traction battery pack which is vertically tightened to one or more neighbouring traction battery pack(s) is thus tightened to a traction battery pack or packs which is/are located above and/or below said individual traction battery pack.

It should also be understood that the longitudinal direction of the vehicle coincides or is parallel with the roll axis of the vehicle. The width or lateral direction of the vehicle coincides or is parallel with the pitch axis of the vehicle. As regards the dimensions of the upper frame plate and the lower frame plate it should be understood that the length is larger than the width, and the width is larger than the thickness.

As already indicated above, according to at least one exemplary embodiment, the vehicle comprises fasteners extending all the way from the lower frame plate, through the traction battery pack arrangement and the hydrogen tank structure, and to the upper frame plate. This may be advantageous since such a long fastener may provide a firm clamping of the parts between the upper and lower frame plates.

According to at least one exemplary embodiment, the hydrogen tank structure comprises a support in which a plurality of hydrogen tanks are provided, wherein the support comprises reinforcement structures for receiving tightening fasteners extending from the upper frame plate, from the lower frame plate, and/or from the traction battery pack arrangement. An advantage of this is that the support may have multiple functionality, such as supporting/protecting the hydrogen tanks, and also functioning as a means for facilitating the tightening of the hydrogen tank structure to the neighbouring traction battery pack arrangement and/or to the upper and/or lower frame plate.

The reinforcement structures of the support of the hydrogen tank structure may suitably be formed by a material goods portion into which (or even through which) the fasteners may be driven. The material goods portion may suitably be provided with a bore hole, such as a threaded bore hole, whereby a threaded portion of the fasteners may engage with the internal threads of the bore hole. However, it should be noted that the fasteners may be self-drilling, i.e. not needing any bore hole in the reinforcement structure, and/or they may be self-tapping, i.e. not needing any mating threads in any bore-hole through the reinforcement structure.

According to at least one exemplary embodiment, said reinforcement structures comprise concave surfaces for receiving the hydrogen tanks. Since hydrogen tanks are normally cylindrical, a concave surface is well suited for supporting the hydrogen tanks. It should be noted, that irrespective of the support having concave surfaces or not, the support may also be used for containing/supporting other items, such as cooling elements, auxiliary batteries for computers and control units, air tanks for suspension system, etc..

According to at least one exemplary embodiment, the hydrogen tank structure has a length, a width and a height, wherein its height extends in the vertical direction and is smaller than each one of its length and its width. Thus, understandably, the length of the hydrogen tank structure may be larger than its width, which in turn is larger than its height. This is advantageous as it may fit well between the traction battery pack arrangement and one of the upper and lower frame plates of the vehicle chassis, without increasing the overall bulkiness of the chassis. The relatively low height allows for the hydrogen tank structure to fit in the available space, while still providing large amount of hydrogen gas which in fuel cells may be converted into electric energy.

Similarly, according to at least one exemplary embodiment, the traction battery pack arrangement has a length, a width and a height, wherein its height extends in the vertical direction and is smaller than each one of its length and its width. This too provides the advantage of a relatively low height, while still providing large amount of stored energy, since the width and length of the traction battery pack arrangement enables a large number of battery cells to be provided and appropriately enclosed, even though the height is limited.

As already mentioned above, the traction battery pack arrangement may comprise:.

As explained in the background section of this disclosure, a plurality of battery cells may be provided in a common battery module, which protects the battery cells. A traction battery pack may comprise a plurality of such battery modules, and may also comprise additional features such as cooling components, electric wirings, etc. Such a modular structure is at least partly reflected in the following exemplary embodiments.

Thus, according to at least one exemplary embodiment (irrespective of the traction battery pack arrangement having a single traction battery pack or a battery stack with at least two traction battery packs), each traction battery pack of the one or more traction battery packs may comprise a tray in which a plurality of battery modules are provided, wherein the tray comprises reinforcement structures for receiving tightening fasteners extending from the upper frame plate, from the lower frame plate, from another traction battery pack and/or from the hydrogen tank structure. An advantage of this is that the tray may have multiple functionality, such as functioning as a support/protection to the battery modules, and also functioning as a means for facilitating the tightening of the traction battery pack to the neighbouring traction battery pack.

The reinforcement structures of the tray of the traction battery pack may suitably be formed by a material goods portion into which (or even through which) the fasteners may be driven. The material goods portion may suitably be provided with a bore hole, such as a threaded bore hole, whereby a threaded portion of the fasteners may engage with the internal threads of the bore hole. However, it should be noted that the fasteners may be self-drilling, i.e. not needing any bore hole in the reinforcement structure, and/or they may be self-tapping, i.e. not needing any mating threads in any bore-hole through the reinforcement structure.

According to at least one exemplary embodiment, said reinforcement structures of the tray of the traction battery pack comprise ribs extending across the tray and forming individual compartments for each battery module. Thus, the ribs may have the function of partition walls, suitably spaced from each other at a distance substantially corresponding to a dimension (such as a width) of an individual battery module. In addition to compartments for each battery module, the ribs may also form one or more compartments for auxiliary components such as cooling cables and electric wires, etc..

In exemplary embodiments in which the traction battery pack arrangement comprises said battery stack, each traction battery pack may be plate-shaped and have a length, a width and a thickness, wherein the thickness of each traction battery pack is smaller than its length and smaller than its width, wherein the thickness extends in the vertical direction, such that the battery stack comprises a stack of horizontal flat traction battery packs. Similarly, in exemplary embodiments in which the traction battery pack arrangement comprises a single traction battery pack, that traction battery pack may be plate-shaped and have a length, a width and a thickness, wherein the thickness of the traction battery pack is smaller than its length and smaller than its width, wherein the thickness extends in the vertical direction. Thus, from the above exemplary embodiments, it is understood that the plate-shaped traction battery pack(s) provide(s) a compact arrangement.

According to at least one exemplary embodiment, the vehicle comprises.

By also providing the power control unit between the upper and lower frame plates, a compact installation is achievable. Long cables may be omitted. Suitably, the power control unit, the traction battery pack arrangement and the hydrogen tank structure may be located close to each other, and suitably within a common outer casing. Thus, according to at least one exemplary embodiment, the power control unit is located within a casing which encloses the traction battery pack arrangement and the hydrogen tank structure.

According to at least one exemplary embodiment, the power control unit comprises an electrical centre to which the traction battery pack arrangement is connected via a high voltage connector, and a fuel cell centre to which the hydrogen tank structure is connected via a fluid connector. This too allows for a compact assembly.

In exemplary embodiments in which the traction battery pack arrangement comprises a battery stack having two or more traction battery packs on top of each other, different electrical connector solutions may be conceivable. For instance, according to at least one exemplary embodiment, each traction battery pack of the battery stack may be connected directly to the power control unit at a front or rear end of the above-mentioned casing.

Thus, the power control unit may suitably be located in front of or behind the battery stack, as seen in the longitudinal direction of the vehicle. Accordingly, any connector of the battery stack may suitably be facing in the front or rear direction towards the power control unit, which enables a compact installation, without the need for many and long cables. Similarly, the fluid connector of the hydrogen tank stack may suitably be facing in the front or rear direction towards the power control unit. According to at least one exemplary embodiment, each traction battery pack of the battery stack may all be connected to the power control unit by a common connector. This further provides for a compact and efficient installation. In other exemplary embodiments, each traction battery pack may have an individual respective connector to the power control unit. According to at least one exemplary embodiment, a common connector may be provided on the lowermost traction battery pack of the battery stack, wherein the other traction battery packs are electrically connected to the lowermost traction battery pack of the battery stack. In such cases the lowermost traction battery pack may, for instance, be of a different dimension than the other traction battery packs. For instance, the lowermost traction battery pack may be larger in at least one direction, such as in the length direction of the vehicle. The power control unit may suitably be placed on top of the lowermost traction battery pack and the common connector.

<FIG> is a schematic illustration of a vehicle <NUM> according to at least one exemplary embodiment of the invention. Although the vehicle <NUM> is illustrated in the form of a truck, other types of vehicles, such as busses, construction equipment or passenger cars may be provided in accordance with the invention.

The truck <NUM> (vehicle) comprises a cab <NUM> in which a driver may operate the vehicle <NUM>. However, the invention may also be implemented in autonomous vehicles. The vehicle <NUM> comprises a number of road wheels <NUM>, herein illustrated as two pairs of wheels, however in other embodiments there may be a different number of wheels, such as three pairs, four pairs or more.

The vehicle <NUM> has a rear end <NUM> and a front end <NUM> located forwardly of the rear end <NUM>. A direction extending from the rear end <NUM> towards the front end <NUM>, or vice versa, is defined as the longitudinal direction of the vehicle <NUM>. A chassis <NUM> extends between the rear end <NUM> and the front end <NUM>. The chassis <NUM> comprises an upper frame plate <NUM> and a lower frame plate <NUM> which is located vertically below the upper frame plate <NUM>. Each one of the upper frame plate <NUM> and the lower frame plate <NUM> has a length, a width and a thickness. The length extends in the longitudinal direction of the vehicle <NUM>. The thickness extends in the vertical direction. The width extends in a direction perpendicular to both the longitudinal and the vertical directions, i.e. perpendicular to the plane of the drawing.

A traction battery pack arrangement <NUM> comprising a plurality of traction battery packs, here illustrated as two traction battery packs 16a-16b, stacked on top of each other. It should, however, be understood that the traction battery pack arrangement <NUM> may, have a different number of traction battery packs, such as three or more traction battery packs, or just a single traction battery pack. A hydrogen tank structure <NUM> is located on top of the traction battery pack arrangement <NUM>. It is, however, conceivable to instead provide the traction battery pack arrangement <NUM> on top of the hydrogen tank structure <NUM>. The traction battery pack arrangement <NUM> and the hydrogen tank structure <NUM> are provided between the upper frame plate <NUM> and the lower frame plate <NUM>. The traction battery pack arrangement <NUM> is vertically tightened to the hydrogen tank structure <NUM>. In the illustration it is the uppermost traction battery pack 16a which is tightened by means of fasteners <NUM> to the hydrogen tank structure <NUM>. Furthermore, as illustrated each traction battery pack 16a-16b may be vertically tightened to its neighbouring traction battery pack 16a-16b by corresponding fasteners <NUM>. At least one of the traction battery pack arrangement <NUM> and the hydrogen tank structure <NUM> is tightened to one of the upper frame plate <NUM> and the lower frame plate <NUM>. In the illustrated example, the hydrogen tank structure <NUM> is tightened to the upper frame plate <NUM> by means of fasteners <NUM>, and the traction battery pack arrangement <NUM> (more specifically, the lowermost traction battery pack 16b) is tightened to the lower frame plate <NUM> by means of fasteners <NUM>. It should, however, be understood that other tightening solutions may be conceivable. For instance, if it is not considered necessary to have two traction battery packs 16a-16b in the vehicle <NUM> illustrated in <FIG>, then if one would be removed, there would be an empty volume. In such case an insert, such as a dummy pack, may be provided below the remaining traction battery pack, and that insert could be tightened to the lower frame plate <NUM>. The fasteners <NUM> discussed herein may, for instance, be screws or bolts.

It may be noted that in the illustrated exemplary embodiment, the uppermost traction battery pack 16a is, in addition to being tightened by fasteners <NUM> to the hydrogen tank structure <NUM>, also tightened by fasteners <NUM> to its below neighbouring traction battery pack 16b. Similarly, the lowermost traction battery pack 16b is, in addition to being tightened by fasteners <NUM> to the lower frame plate <NUM> also tightened by fasteners <NUM> to its above neighbouring traction battery pack 16a.

It will be appreciated that because the traction battery pack arrangement <NUM> and the hydrogen tank structure <NUM> fill up the space between the upper frame plate <NUM> and the lower frame plate <NUM>, they provide support and rigidity to the chassis <NUM>. Accordingly, the traction battery pack arrangement <NUM> and the hydrogen tank structure <NUM> form, together with the upper and lower frame plates <NUM>, <NUM>, an integral load bearing structure of the chassis <NUM>.

<FIG> also illustrates a power control unit <NUM> located rearwardly of the traction battery pack arrangement <NUM> and the hydrogen tank structure <NUM>. Further rearwardly there is provided an electric motor <NUM> for propelling the vehicle <NUM>. The traction battery pack arrangement <NUM> is electrically connected to the power control unit <NUM>, and the hydrogen tank structure <NUM> is fluidly connected to the power control unit <NUM>. The power control unit <NUM> comprises an electrical centre to which the traction battery pack arrangement <NUM> is connected via a high voltage connector, and a fuel cell centre to which the hydrogen tank structure <NUM> is connected via a fluid connector. The power control unit <NUM> is similarly to the traction battery pack arrangement <NUM> and the hydrogen tank structure <NUM> located between the upper frame plate <NUM> and the lower frame plate <NUM>.

Power may be transferred from the power control unit <NUM> to the electric motor <NUM> via a high voltage cable. The power control unit <NUM> may suitably be located within a casing <NUM> which encloses the traction battery pack arrangement <NUM> and the hydrogen tank structure <NUM>, thus, it may be a common casing <NUM> enclosing all three features (i.e. traction battery pack arrangement <NUM>, hydrogen tank structure <NUM> and power control unit <NUM>).

In the exemplary embodiment of <FIG>, a plurality of relatively short fasteners <NUM> are provided. Each fastener <NUM> is illustrated as connecting two parts, such as two traction battery packs 16a-16b, or a traction battery pack 16b and the lower frame plate <NUM>, or a traction battery pack 16a and the hydrogen tank structure <NUM>, or the hydrogen tank structure <NUM> and the upper frame plate <NUM>. It should, however, be understood that longer fasteners may be provided which span over more than two parts, such as three or more parts, or even all of the parts from the upper to the lower frame plates <NUM>, <NUM>. The latter case is illustrated in <FIG>.

Thus, turning to <FIG>, there is provided a schematic illustration of a vehicle <NUM>' according to at least one other exemplary embodiment of the invention. The illustrated components and parts may be substantially the same as those illustrated in <FIG>, except for the short fasteners <NUM> in <FIG>. Instead, in the exemplary embodiment of <FIG>, relatively long fasteners <NUM>' are provided. The fasteners <NUM>' extend from the lower frame plate <NUM> through the traction battery pack arrangement <NUM>, the hydrogen tank structure, and all the way to the upper frame plate <NUM>. Thus, each traction battery pack 16a-16b of the traction battery pack arrangement <NUM> becomes tightened to its neighbouring traction battery pack 16a-16b, and the uppermost and lowermost traction battery packs 16a-16b become tightened to the hydrogen tank structure <NUM> and the lower frame plate <NUM>, respectively. Put differently, the assembly as a whole (i.e. the traction battery pack arrangement <NUM> and the hydrogen tank structure <NUM>) is tightened to the upper frame plate <NUM> and the lower frame plate <NUM> by means of the long fasteners <NUM>'. Suitably, the whole assembly may be subjected to a clamping force from the upper and lower frame plates <NUM>, <NUM>, being tightened by the long fasteners <NUM>'.

From the above, it is clear that in both exemplary embodiments of <FIG> and <FIG>, there are fasteners <NUM>, <NUM>' extending from the lower frame plate <NUM>, through the bottom of the traction battery pack arrangement <NUM> (more particularly the bottom of the lowermost traction battery pack 16b), whereby the traction battery pack arrangement <NUM> is tightened to the lower frame plate <NUM>. Correspondingly, in both exemplary embodiments of <FIG> and <FIG>, there are fasteners <NUM>, <NUM>' extending from the upper frame plate <NUM>, through the top of the hydrogen tank structure <NUM>, whereby the hydrogen tank structure <NUM> is tightened to the upper frame plate <NUM>. In this connection, it should be understood that in this disclosure terms such as "extending from" and "extending to" do not imply any particular orientation of the fasteners. For instance, in case of a fastener <NUM>, <NUM>' being in the form of a screw having a screw head and a shaft, the screw head may be located at either one of the parts, be it the part from which the fastener <NUM>, <NUM>' is said to extend, or the part to which the fastener <NUM>, <NUM>' is said to extend. Thus, in the illustration in <FIG> although heads of the fasteners <NUM>' are indicated as located at the lower frame plate <NUM>, the fasteners <NUM>' can still be said to extend from the upper frame plate <NUM> to the lower frame plate <NUM>. Furthermore, it should be understood that the illustrated orientations in <FIG> and <FIG> are only exemplary, and one or more of the fasteners <NUM>, <NUM>' could instead be provided in the opposite orientation.

As illustrated in <FIG> and <FIG>, fasteners <NUM>, <NUM>' may also be used to fixate the casing <NUM> to the upper and lower frame plates <NUM>, <NUM>.

<FIG> is a schematic illustration of a traction battery pack arrangement <NUM> and a hydrogen tank structure <NUM> connected to a power control unit <NUM>, which may be provided on a vehicle in accordance with at least one exemplary embodiment of the invention. Thus, it may for example correspond to the traction battery pack arrangement <NUM>, the hydrogen tank structure <NUM> and the power control unit <NUM> illustrated in <FIG> and/or <FIG>.

Another example is illustrated in <FIG>. Thus, <FIG> is a schematic illustration of a traction battery pack arrangement <NUM> and a hydrogen tank structure <NUM>' connected to a power control unit, which may be provided on a vehicle in accordance with at least one other exemplary embodiment of the invention. Thus, the hydrogen tank structure <NUM>' may for instance replace the hydrogen tank structure <NUM> illustrated in <FIG> and/or <FIG>.

<FIG> is a schematic illustration of the hydrogen tank structure <NUM> in <FIG>, while <FIG> is a schematic illustration of the hydrogen tank structure <NUM>' in <FIG>. Furthermore, <FIG> is a schematic illustration of a traction battery pack 16a which may form part of the traction battery pack arrangement <NUM> in either one of <FIG>.

The hydrogen tank structure <NUM> illustrated in <FIG> and <FIG> includes a plurality of hydrogen tanks <NUM>, herein illustrated as six hydrogen tanks <NUM>. However, in other exemplary embodiments there may be more or fewer hydrogen tanks. The hydrogen tank structure <NUM> comprises a support <NUM> in which a plurality of hydrogen tanks <NUM> are provided. The support comprises reinforcement structures <NUM> for receiving tightening fasteners extending from the upper frame plate, from the lower frame plate, and/or from the traction battery pack arrangement <NUM>. In the illustrated example, the support <NUM> forms a plurality of receiving cavities by means of the reinforcement structures <NUM>. In particular, the reinforcement structures comprise concave surfaces for receiving the hydrogen tanks <NUM>. The curvature of the concave surfaces may suitably substantially correspond to the curvature of the enveloping surface of the hydrogen tanks <NUM>. The enveloping surface may normally be cylindrical.

It should be understood that other designs and configurations of the support <NUM> and reinforcement structures <NUM> are conceivable. For instance, in the example, along each hydrogen tank <NUM>, the reinforcement structures <NUM> are spaced from each other. In other exemplary embodiments, there may be continuous reinforcement structures along each hydrogen tank <NUM>.

Compared to the hydrogen tank structure <NUM> illustrated in <FIG> and <FIG>, in the hydrogen tank structure <NUM>' illustrated in <FIG> and <FIG>, the two outermost hydrogen tanks have been replaced by housings <NUM> for containing/supporting other items, such as cooling elements, auxiliary batteries for computers and control units, air tanks for suspension system, etc. In other words, in at least some exemplary embodiments a hydrogen tank structure <NUM>' may comprise/contain/support other items than just hydrogen tanks <NUM>. Accordingly, in at least some exemplary embodiments, the hydrogen tank structure <NUM>, <NUM>' comprises at least one hydrogen tank <NUM>.

Turning now to <FIG>, there is illustrated a traction battery pack 16a which may form part of the battery stacks that make up the traction battery pack arrangements <NUM> shown in the previously discussed figures. Thus, the traction battery pack 16a in <FIG> may correspond to either one of the traction battery packs 16a-16b in <FIG>.

As can be seen in <FIG> and <FIG>, each traction battery pack 16a-16b has a number of input areas <NUM> for receiving cooling cables, electric wires etc. In <FIG> it can be seen that on the opposite side of the traction battery pack 16a there is provided output areas <NUM> (similar output areas are present on the traction battery packs 16a-16b in <FIG> although not visible in the illustrations). Such output areas <NUM> may include connectors for connecting each traction battery pack 16a-16b, directly to the power control unit <NUM>.

Thus, it should be understood that in some exemplary embodiments, each one of the traction battery packs 16a-16b in <FIG> will be individually connected to the power control unit <NUM>. However, in other exemplary embodiment, the traction battery packs 16a-16b in <FIG> are all connected to the power control unit <NUM> by a common connector.

For example, the common connector may be provided on the lowermost traction battery pack 16b, wherein the other traction battery pack 16a is electrically connected to the lowermost traction battery pack 16b. Although not illustrated in <FIG>, in some exemplary embodiments, the lowermost traction battery pack 16b, being provided with said common connector, may extend beyond the other traction battery pack 16a in the longitudinal direction, and the power control unit <NUM> may, for instance, be arranged on top of the extended portion of the lowermost traction battery pack 16b.

The extension of the traction battery pack arrangement <NUM> in the vertical direction, is suitably smaller than in the longitudinal or lateral direction of the vehicle. This gives a less bulky impression than prior art cube-shaped battery solutions. Thus, the height (may also be referred to as the thickness) of the traction battery pack arrangement <NUM> is smaller than each one of its length and its width (the height/thickness of the traction battery pack extends in the vertical direction).

Furthermore, each individual traction battery pack 16a-16b may have a very small vertical extension. This is for instance indicated in <FIG>. The height h (may also be referred to as the thickness) of the individual traction battery pack 16a is smaller than its length and its width. Indeed, the traction battery pack 16a may be substantially plate-shaped. Thus, the traction battery pack 16a may be considered as being a flat component. Thus, the battery stack which makes up the traction battery pack arrangement <NUM> in <FIG> comprises a stack of horizontal flat traction battery packs 16a-16b. The height/thickness of each traction battery pack may suitably be in the range of <NUM>-<NUM>, such as <NUM>-<NUM>, typically <NUM>-<NUM>.

<FIG> schematically illustrate interior contents of a traction battery pack <NUM>, which may form part of a traction battery pack arrangement, in accordance with at least one exemplary embodiment of the invention.

Thus, <FIG> may illustrate a cross-sectional or cut-away view of a traction battery pack <NUM>, such as the type or similar to the type of traction battery packs 16a-16b illustrated in the previous figures, wherein a top portion of the traction battery pack <NUM> has been cut away. <FIG> illustrates that the traction battery pack <NUM> comprises a tray <NUM> in which a plurality of battery modules <NUM> are provided. The tray <NUM> without the battery modules <NUM> is illustrated in <FIG>, while the actual battery modules <NUM> are illustrated in <FIG>.

As can be seen in <FIG>, the tray <NUM> comprises reinforcement structures <NUM>, here illustrated as ribs or partition walls. The reinforcement structures <NUM> may be formed in one piece with the main part of the tray <NUM>, or as separate pieces which are connected to the tray <NUM>, such as by welding, gluing or by mechanical fastening means. The reinforcement structures <NUM> can receive tightening fasteners, such as the previously discussed fasteners <NUM>, <NUM>' in <FIG> and <FIG>. Depending on the location of the specific traction battery pack <NUM> in the battery stack, such fasteners <NUM>, <NUM>' may tighten the traction battery pack <NUM> to one of the frame plates <NUM>, <NUM>, to the hydrogen tank structure <NUM> and/or to one or more other traction battery packs 16a-16b.

The reinforcement structures <NUM> extend across the tray <NUM> and form individual compartments <NUM> for each battery module <NUM>. Accordingly, any fastener <NUM>, <NUM>' that penetrates into the traction battery pack <NUM>, does in fact penetrate into a reinforcement structure <NUM>, not into a battery module <NUM>.

In the present illustration six compartments <NUM> are illustrated for receiving six battery modules <NUM>. However, it should be understood that other number of compartments <NUM> and battery modules <NUM> are equally conceivable, be it a lower or a higher number. It should further be understood that one or more of the compartments <NUM> may contain other components (such as electrical or cooling components), instead of the shown battery module <NUM>.

Claim 1:
A vehicle (<NUM>, <NUM>'), comprising
- a rear end (<NUM>),
- a front end (<NUM>) located forwardly of the rear end, wherein a direction extending from the rear end towards the front end or vice versa is defined as a longitudinal direction of the vehicle,
- a chassis (<NUM>) extending between the rear end and the front end, the chassis comprising:
an upper frame plate (<NUM>) having a length, width and thickness, wherein its length extends in the longitudinal direction and its thickness extends in a vertical direction, and
a lower frame plate (<NUM>) having a length, width and thickness, wherein its length extends in the longitudinal direction and its thickness extends in the vertical direction,
wherein the lower frame plate is located parallelly below the upper frame plate,
wherein the vehicle further comprises, between the upper frame plate and the lower frame plate,
- a traction battery pack arrangement (<NUM>) comprising one or more battery modules (<NUM>),
- a hydrogen tank structure (<NUM>, <NUM>') comprising one or more hydrogen tanks (<NUM>),
- wherein the hydrogen tank structure is vertically tightened to said traction battery pack arrangement, so that one of said hydrogen tank structure and said traction battery pack arrangement is located on top of the other,
- wherein at least one of said hydrogen tank structure and said traction battery pack arrangement is tightened to one of said upper and lower frame plates.