Patent Description:
The propulsion systems of vehicles are continuously developed to meet the demands from the market. A particular aspect relates to the emission of environmentally harmful exhaust gas. Therefore, vehicles propelled by electric machines or hydrogen fuel cells have been increasingly popular, in particular for trucks and other heavy duty vehicles.

The battery or hydrogen fuel tank connected to the propulsion system of the vehicle need to be relatively large to be able to deliver a substantial amount of power to the electric machine(s)/fuel cell(s), in particular when aiming for covering a long driving range without having to re-charge/re-fuel.

A conventional placement of these energy storage systems, i.e. the batteries/hydrogen fuel tanks, in a heavy duty vehicle is along the longitudinally extending frame rails of the vehicle. This is substantially the same position as used for the conventional diesel tanks of a truck using an internal combustion engine for propulsion. However, positioning the heavy batteries/hydrogen fuel tanks at this position exposes the frame and connecting brackets to high stress, whereby a plurality of brackets is needed to safely suspend the energy storage system. Also, this position is vulnerable to damage of the energy storage system during operation of the vehicle. Further development is thus desirable to overcome at least these aspects.

According to its abstract, <CIT> relates to a high-pressure vessel unit that includes plural cylindrical vessels arrayed inside a case, with end portions of the vessels on one side in the axial direction thereof being equipped with openings. A coupling member is arranged and connected to the openings of the vessels to couple the plural vessels and includes a flow passage that communicates the insides of the vessels.

It is an object of the present invention to describe an energy storage compartment which at least partially overcomes the above described deficiencies. This is achieved by an energy storage compartment according to claim <NUM>.

According to a first aspect, there is provided an energy storage compartment connectable between a pair of longitudinally extending frame rails of a heavy-duty vehicle, the energy storage compartment being arranged to house an energy storage system configured to supply energy to a prime mover of the vehicle for propulsion of the prime mover, wherein the energy storage compartment comprises longitudinally extending portions forming an encircling load absorbing module, the longitudinally extending portions comprising a pair of longitudinally extending side wall portions connectable to the pair of longitudinally extending frame rails, a longitudinally extending floor portion and a longitudinally extending roof portion, wherein the longitudinally extending portions of the encircling load absorbing module are arranged and configured to, when being subject to a load from the longitudinally extending frame rails, absorb the transversal component of the load.

The wording "longitudinally extending" should be construed as portions having their major extension longitudinally. Thus, a thickness of a transversely extending component should not be construed as longitudinally extending according to the above definition. The longitudinal extension should also be construed as a direction when the energy storage compartment is connected to the vehicle, i.e. alongside the longitudinally extending frame rails of the vehicle.

Furthermore, the encircling load absorbing module should be construed as encircling as seen in a cross-section which is substantially perpendicular to the longitudinal extension of the energy storage compartment. The encircling load absorbing module should not be construed as necessarily having a circular shape. Conversely, the encircling load absorbing module may be arranged in different shapes, as will be evident with reference to the various embodiments described below, as long as the side wall portions, the floor portion and the roof portion together form a continuous, and circumferentially arranged housing for the energy storage system.

The present invention is based on the insight that by providing an energy storage compartment which can be arranged between the pair of longitudinally extending frame rails of the heavy-duty vehicle, the energy storage system arranged within the encircling load absorbing module is well protected from e.g. side collisions that might occur during operation of the vehicle. Also, the otherwise unoccupied space between the longitudinally extending frame rails can be efficiently utilized. Still further, compared to the position transversely outside the longitudinally extending frame rails, the space between the longitudinally extending frame rails enables for a larger volume for positioning an energy storage system. Hereby, larger energy storage systems can be provided to the vehicle, whereby the driving range can be increased.

More importantly, as the longitudinally extending portions of the encircling load absorbing module are arranged and configured to absorb loads, the energy storage compartment, when connected between the longitudinally extending frame rails, provides an improved stiffness whereby the need for separate transversely arranged stiffeners between the longitudinally extending frame rails. Hence, the energy storage compartment contributes to an additional torsional and bending stiffness for the longitudinally extending frame rails.

According to an example embodiment, the encircling load absorbing module may be free from transversal, non-longitudinally extending load absorbing structures. As indicated above, the encircling load absorbing module is arranged to absorb loads, whereby transversal, non-longitudinally extending load absorbing structures can be omitted which is advantageous from e.g. a cost perspective. A further advantage of omitting the transversal, non-longitudinally extending load absorbing structures is that the energy storage compartment can contain energy storage systems which have a longer extension in the longitudinal direction. When transversal, non-longitudinally extending load absorbing structures are arranged between the longitudinally extending frame rails, the energy storage system needs to be split up in several, smaller energy storage systems. Such smaller energy storage systems will be able to contain less available energy for propulsion of the prime mover. The larger energy storage system occupying the larger space when omitting the transversal, non-longitudinally extending load absorbing structures thus enables for a larger driving range for the vehicle.

A transversal, non-longitudinally extending load absorbing module should be understood as a module absorbing loads from the longitudinally extending frame rails. Thus, a mere lid arranged at the end portions of the load absorbing module should not be construed as falling within the meaning of the wording transversal, non-longitudinally extending load absorbing module.

According to a further example embodiment, the encircling load absorbing module may be free from transversal, non-longitudinally extending load absorbing structures along the longitudinal length of the energy storage compartment.

According to an example embodiment, the floor portion may, when the energy storage compartment is connected between the pair of longitudinally extending frame rails, extend transversally from one of the longitudinally extending frame rails to the other one of the longitudinally extending frame rails. The floor portion may preferably also be attached to the longitudinally extending frame rails. Hereby, floor portion effectively absorbs the transversal component of the loads exposed to the longitudinally extending frame rails during operation of the vehicle.

According to an example embodiment, the roof portion may comprise a horizontal roof section and a pair of inclined roof sections, each inclined roof section extending between the horizontal roof section and a respective one of the side wall portions.

An advantage of the inclined portions is that the stiffness of the encircling load absorbing module is increased. This is due to the fact that the inclined portions act as a framework directing transversal loads in a transverse and vertical direction.

According to an example embodiment, the side wall portions may be arranged to be connected to a vertically lower end portion of the longitudinally extending frame rails, respectively.

Hereby, the vertically upper end portion of the longitudinally extending frame rails can be arranged to connect to other vehicle auxiliaries which are connected transversely outside the longitudinally extending frames, such as e.g. further vehicle batteries, etc. Accordingly, connecting the side wall portions to the vertically lower end portions creates additional space at the vertically upper end portions of the longitudinally extending frame rails.

According to an example embodiment, the roof portion may, when the energy storage compartment is connected between the pair of longitudinally extending frame rails, extend transversally from one of the longitudinally extending frame rails to the other one of the longitudinally extending frame rails.

Hereby, the energy storage compartment can be arranged in a substantially rectangular, or quadratic shape, which enables for an optimization of the space arranged therein. Hence, the space within the energy storage compartment can contain an optimized number of energy storage systems, or an energy storage system of increased size.

According to an example embodiment, the longitudinal extending portions may be arranged to extend between a front and a rear wheelbase position of the vehicle when the energy storage system is connected between the pair of longitudinally extending frame rails. Hereby, an energy storage system of substantial size/length can be arranged within the encircling load absorbing module.

According to an example embodiment, the encircling load absorbing module may house at least one longitudinally extending energy storage shelf arranged parallel, and vertically above, the floor portion. Hereby, energy storage systems can be arranged on top of each other within the encircling load absorbing module.

According to an example embodiment, the at least one longitudinally extending energy storage shelf may further extend between the pair of longitudinally extending side wall portions.

According to a second aspect, there is provided a vehicle frame arrangement for a heavy-duty vehicle, the vehicle frame arrangement comprising a pair of longitudinally extending frame rails, and an energy storage compartment according to any one of the embodiments described above in relation to the first aspect, wherein the side wall portions of the energy storage compartment is connected to the pair of longitudinally extending frame rails.

According to an example embodiment, the energy storage compartment may comprise a front end portion and a rear end portion, the longitudinal portions extend between the front and rear end portions.

According to an example embodiment, the energy storage compartment may comprise an energy storage system for supply of energy to a prime mover of the vehicle.

According to an example embodiment, the energy storage system may extend undisruptedly between the front and rear end portions of the energy storage compartment.

Hereby, and as indicated above, an energy storage system of substantial size/length can be arranged within the encircling load absorbing module.

According to an example embodiment, the energy storage system may comprise at least one vehicle battery. According to an example embodiment, the energy storage system comprises at least one hydrogen tank.

Further effects and features of the second aspect are largely analogous to those described above in relation to the first aspect.

<FIG> is a perspective view of a vehicle <NUM> in the form of a truck. The vehicle comprises a cab <NUM> in which a driver controls operation of the vehicle. The vehicle is preferably propelled by means of one or more electric motors which receives electric power from one or more batteries or one or more fuel cells. The following will describe the vehicle <NUM> the form of a fuel cell truck which comprises one or more hydrogen tanks arranged to contain hydrogen for operating the fuel cell(s). The vehicle may also, in addition or as an alternative, comprise one or more vehicle batteries.

As is further illustrated in <FIG>, the vehicle <NUM> comprises a pair of longitudinally extending frame rails <NUM> and an energy storage compartment <NUM> arranged between the pair of longitudinally extending frame rails <NUM> as seen in the transversal direction of the longitudinal extension of the vehicle <NUM>.

With reference to <FIG>, which is a further detailed perspective view illustrating the longitudinally extending frame rails <NUM> and the energy storage compartment <NUM> according to an example embodiment. As described above, the energy storage compartment <NUM> is arranged laterally between the frame rails <NUM>, i.e. arranged between the longitudinally extending frame rails <NUM> as seen in the transversal direction Y. As can be further observed in <FIG>, the energy storage compartment <NUM> houses an energy storage system <NUM>. The energy storage system <NUM> comprises in <FIG>, as well as in the following description of <FIG>, a plurality of hydrogen tanks <NUM>. The hydrogen tanks <NUM> contains hydrogen for supply to a fuel cell arranged to generate electricity which is supplied to an electric motor (not shown).

As can be seen in <FIG>, the energy storage compartment <NUM> comprises longitudinal portions <NUM> extending in the longitudinal direction X of the vehicle <NUM>. The longitudinal portions <NUM> may extend between a front and a rear wheelbase (not shown) of the vehicle and are preferably free from non-longitudinally extending load absorbing structures. By not using e.g. transversally arranged load absorbing structures, the hydrogen tanks <NUM> positioned within the energy storage compartment <NUM> can have substantially the same length as the length of the longitudinal portions <NUM> of the energy storage compartment <NUM>, i.e. extend undisruptedly between front and rear end portions of the energy storage compartment. Furthermore, and as will be described in further detail below, the longitudinally extending portions <NUM> together form an encircling load absorbing module <NUM>. The longitudinally extending portions <NUM> comprises a pair of longitudinally extending side wall portions <NUM>, <NUM> connected to the pair of longitudinally extending frame rails <NUM>, a longitudinally extending floor portion <NUM> and a longitudinally extending roof portion <NUM>, whereby the longitudinally extending portions <NUM> form an encircling load absorbing module <NUM>. The longitudinally extending portions <NUM> of the encircling load absorbing module <NUM> are arranged and configured to absorb transversal loads exposed to the longitudinally extending frame rails <NUM> during operation of the vehicle. Accordingly, the load is absorbed by the longitudinally extending portions <NUM> instead of using e.g. transversally extending load absorbing structures.

In order to describe the energy storage compartment <NUM> in further detail, reference is made to <FIG> which illustrate a respective example embodiment of the energy storage compartment <NUM>.

Starting with <FIG>, which is a cross-sectional view of the energy storage compartment <NUM> in <FIG> according to a first example embodiment. The energy storage compartment <NUM> comprises, as indicated above, a pair of side wall portions <NUM>, <NUM> connected to the pair of longitudinally extending frame rails <NUM>, a longitudinally extending floor portion <NUM> and a longitudinally extending roof portion <NUM>, wherein the side wall portions, the floor portion and the roof portion form the encircling load absorbing module <NUM>.

In the embodiment depicted in <FIG>, the roof portion <NUM> comprises a horizontal roof section <NUM>, a first inclined roof section <NUM> and a second inclined roof section <NUM>. The first inclined roof section <NUM> extends between a first one of the side wall portions <NUM> and the horizontal roof section <NUM>, while the second inclined roof section <NUM> extends between a second one of the side wall portions <NUM> and the horizontal roof section <NUM>. The floor portion <NUM> extends transversally between the frame rails <NUM>, while the horizontal roof section <NUM> extends between end portions of the inclined roof sections, a distance from the respective frame rails.

Further, the energy storage compartment <NUM> is connected to the longitudinally extending frame rails at a lower end portion <NUM> of the longitudinally extending frame rails <NUM> using a suitable connecting arrangement. Also, with the configuration depicted in <FIG>, at least two layers of longitudinally extending hydrogen tanks <NUM> can be positioned within energy storage compartment <NUM>. However, further layer of longitudinally extending hydrogen tanks <NUM> are also conceivable depending on the size of the tanks. Moreover, each layer of longitudinally extending hydrogen tanks <NUM> may be separated by means of providing a longitudinally extending energy storage shelf <NUM> within the energy storage compartment <NUM>. The energy storage shelf <NUM> is thus, as depicted, arranged vertically between the floor portion <NUM> and the roof portion <NUM>.

Turning now to <FIG> which is a cross-sectional view of the energy storage compartment <NUM> in <FIG> according to a second example embodiment. In a similar vein as the embodiment depicted in <FIG>, the energy storage compartment <NUM> comprises a pair of side wall portions <NUM>, <NUM> connected to the pair of longitudinally extending frame rails <NUM>, a longitudinally extending floor portion <NUM> and a longitudinally extending roof portion <NUM>, wherein the side wall portions, the floor portion and the roof portion form the encircling load absorbing module <NUM>.

The main difference between the embodiment depicted in <FIG> and the embodiment depicted in <FIG> is that the energy storage compartment <NUM> in <FIG> is arranged as a quadratic energy storage compartment <NUM>, i.e. the height of the side wall portions <NUM>, <NUM> are substantially the same as the width of the roof portion <NUM> and the floor portion <NUM>. Hereby, both the roof portion <NUM> as well as the floor portion <NUM> extends transversally between the longitudinally extending frame rails <NUM>. The energy storage compartment <NUM> may also be arranged in a rectangular shape where, for example, the height of the side wall portions is larger than the width of the roof portion <NUM> and the floor portion <NUM>.

Furthermore, the energy storage compartment <NUM> is connected to the longitudinally extending frame rails at an upper end portion <NUM> of the longitudinally extending frame rails <NUM> using a suitable connecting arrangement.

Also, the configuration depicted in <FIG> comprises three layers of longitudinally extending hydrogen tanks <NUM> positioned within energy storage compartment <NUM>. However, further layer of longitudinally extending hydrogen tanks <NUM> are also conceivable depending on the size of the tanks. Moreover, the embodiment depicted in <FIG> comprises an additional longitudinally extending energy storage shelf <NUM>. The additional longitudinally extending energy storage shelf <NUM> is thus positioned vertically above the first longitudinally extending energy storage shelf <NUM>, whereby the three layers are physically disconnected from each other.

Claim 1:
An energy storage compartment (<NUM>) connectable between a pair of longitudinally extending frame rails (<NUM>) of a heavy-duty vehicle, the energy storage compartment being arranged to house an energy storage system (<NUM>) configured to supply energy to a prime mover of the vehicle for propulsion of the prime mover, wherein the energy storage compartment (<NUM>) comprises longitudinally extending portions (<NUM>) forming an encircling load absorbing module, the longitudinally extending portions (<NUM>) comprising a pair of longitudinally extending side wall portions (<NUM>, <NUM>) connectable to the pair of longitudinally extending frame rails (<NUM>), a longitudinally extending floor portion (<NUM>) and a longitudinally extending roof portion (<NUM>), wherein the encircling load absorbing module is free from transversal, non-longitudinally extending load absorbing structures such that the longitudinally extending portions of the encircling load absorbing module, when being subject to a load from the longitudinally extending frame rails, absorb a transversal component of the load.