Patent Description:
To reduce the environmental impact of trucks, especially for trucks larger than <NUM> tons gross vehicle weight, electrification of the drive train is a development area that is of rising interest. Trucks driven by an electric drive train can provide advantages, such as zero emission by the vehicle and reduced operational costs.

Therefore, these trucks are typically designed with a dedicated architecture to mount e.g. one or more electric motors, battery packs and/or fuel cells on board of the vehicle in a way that provides sufficient power and range under normal operating conditions. For example, <CIT> describes a mounting arrangement for mounting a battery unit in an electrically driven motor vehicle. To optimally benefit from the unique properties and advantages of these components relative to those of a conventional drive train, the architecture of a truck driven by an electric drive train typically may deviate significantly from an architecture of a truck driven by an internal combustion engine.

For example, an electric drive train may not require many gears as in a conventional drive train, since the torque-speed characteristic of an electric motor can be different from that of an internal combustion engine, and an electric drive train may not even require a similar mechanical power transmission. As such, an electric drive train may not need as many moving parts as a conventional power train, which further reduces the operational costs due to decreased friction and wear, and which provides additional space and weight budget e.g. to carry battery packs, to increase the range of the truck.

A disadvantage of having a dedicated architecture, however, is that, especially during a transition period in which different versions of trucks are in use, interchangeability of components and systems between different types of trucks becomes difficult, which reduces maintainability and quality management, and it is difficult to upgrade trucks from a conventional power train driven by an internal combustion engine to a zero-emission power train driven by an electric motor.

It is a challenge to design an architecture for an electric power train in a truck that is interchangeably suitable for a drive train driven by an internal combustion engine and a drive train driven by an electric motor, in a way that the benefits of either type of drive train can be exploited.

Furthermore, when converting a truck from a power train driven by an internal combustion engine to a drive train driven by an electric motor, it is a challenge to design an architecture that facilitates conversion, e.g. by interchanging the power module as a unit and without substantially changing the dynamic properties of the truck.

It is an object of the present invention to further advance the field of electric drive trains to address these and other challenges.

In summary, the invention concerns an electric power module for providing drive power to an electric drive train in a truck. The electric power module comprises an auxiliary frame to be mounted to a chassis having a pair of longitudinal chassis members extending between a front axle and a rear axle of the truck. The auxiliary frame comprises a front section arranged for mounting an electric power source unit and a rear section arranged for mounting at least one auxiliary unit. The front section of the auxiliary frame comprises module mounts arranged for suspending the electric power module to the chassis between the pair of longitudinal chassis members near the front axle of the truck. The rear section of the auxiliary frame extends beyond the front section in a cantilevered fashion and comprises shock absorbers arranged for absorbing a pitch movement of the auxiliary frame relative to the chassis behind the module mounts.

In this way, an electric power module is provided with an auxiliary frame such that it can be mounted as a unit in the engine compartment of a truck, just as a conventional engine unit, e.g. by making use of conventional chassis mounts of an internal combustion engine in a conventional truck architecture, to convert the truck from having a power train driven by an internal combustion engine to having an electric power train, without substantially changing the dynamic behavior of the truck. In particular, due to the mass distribution made possible by the auxiliary frame mounting this electric power module may provide the driver with a similar sense of driving comfort. Also, other components and properties of the conventional truck architecture may remain substantially unchanged as well, which facilitates production, maintenance and quality management.

Aspects of the invention pertain to an electric power module for providing drive power in a truck, comprising an auxiliary frame to be mounted to a chassis having a pair of longitudinal chassis members extending between a front axle and a rear axle of the truck, said auxiliary frame comprising a front section arranged for mounting an electric power source unit and a rear section arranged for mounting at least one auxiliary unit comprising at least a power electronics unit. The front section of the auxiliary frame comprises module mounts arranged for suspending the electric power module to the chassis between the pair of longitudinal chassis members near the front axle of the truck, and the rear section of the auxiliary frame extends beyond the front section in a cantilevered fashion and comprises shock absorbers arranged for absorbing a pitch movement of the auxiliary frame relative to the chassis behind the module mounts. The benefit of the invention is that it provides an electric power module that is interchangeable with a powertrain driven by an internal combustion engine in a conventional truck architecture, without changing the dynamic properties of the truck. While the auxiliary unit serves to compactify and efficiently pack further functional parts of the power module, so that the module can be installed as a single unit in the truck, many functional parts may be located elsewhere without departing from the scope of the claims. However, the auxiliary unit combines a number of components so that their weights may be combined and contribute by supporting it close to the front axle in particular, to improve driver comfort, which is for a large part influenced by providing mass (Tilger effect) to the front axle. The electric power module can be provided with a coolant system and an electric power system, and many components in the unit are provided that contribute to any or both these systems and are arranged so that they can be efficiently reached from above or underside for maintenance reasons.

In preferred embodiments, the electric power module further comprises an electric motor to be mounted beyond the rear section of the auxiliary frame and arranged for driving rear wheels of the truck, to form a combined power unit for converting a conventional truck to a truck driven by an electric power train.

In some further embodiments, the electric motor is electrically coupled to the electric power module, but mechanically decoupled from it, to avoid drive torque of the electric motor mechanically affecting the electric power module.

In some yet further embodiments, the electric motor comprises motor mounts for suspending the electric motor to the chassis between the pair of longitudinal chassis members, to mechanically couple the electric motor to the chassis similar to a transmission unit of a conventional power train driven by an internal combustion engine.

In some yet further embodiments, a centerline of a drive shaft of the electric motor is suspended parallel to the pair of longitudinal chassis members, to connect to a driven rear axle of a conventional truck.

In some yet further embodiments, the electric motor is mounted between the pair of longitudinal chassis members to a chassis cross member, wherein the chassis cross member laterally extends between and beyond the pair of longitudinal chassis members and comprises distal ends arranged for suspending auxiliary electric power source units, to have a single support structure for suspending the electric motor and auxiliary electric power source units.

In some embodiments, the at least one auxiliary unit comprises a power junction unit, to distribute electric power within the electric power module. This power junction unit distributes high voltage electrical energy to the electric motor and is preferably provided with conductive high voltage leads that span a short path between the electric power module, which may be a battery stack; and the electric motor, or at least an invertor unit that receives the high voltage leads.

In other or further embodiments, the at least one auxiliary unit comprises a fuse unit, to electrically protect the electric power module.

In some further embodiments, the fuse unit is accessible from a top side of the truck, and the fuse unit can be removably mounted to the auxiliary frame by a tilting movement of the fuse unit, to facilitate maintainability and serviceability of the electric power module.

In some embodiments, the auxiliary frame comprises a bottom section arranged for removably mounting at least one further auxiliary unit to the auxiliary frame, to further facilitate maintainability and serviceability of the electric power module.

In further embodiments, the at least one further auxiliary unit can be removably mounted to the auxiliary frame from a bottom side of the truck, to enhance accessibility of the electric power module.

In some embodiments, the at least one further auxiliary unit comprises a coolant system unit, to further enhance accessibility and/or maintainability and serviceability of the electric power module.

In some embodiments, the electric power source unit comprises a battery pack, to store electric power, e.g. for powering an electric motor.

Other aspects of the invention pertain to a hoisting apparatus for hoisting embodiments of the electric power module comprising an electric motor into a chassis of a truck. The hoisting apparatus comprises a first hoisting section, comprising a frame yoke including frame brackets arranged for coupling to the auxiliary frame of the electric power module, and a second hoisting section, comprising motor brackets arranged for coupling the electric motor to the auxiliary frame. The first hoisting section is arranged for hoisting the second hoisting section, to hoist the electric power module and the electric motor as a combined power unit into a chassis of a truck.

Another aspect of the invention pertains to a truck, provided with drive power by the electric power module according to any of the described embodiments.

Turning to <FIG>, there is shown a schematic representation of an electric power module <NUM> for providing drive power in a truck, e.g. a box truck or a tractor comprising a fifth wheel for pulling a trailer. Electric power module <NUM> comprises an auxiliary frame <NUM> to be mounted to a chassis <NUM>. Preferably chassis <NUM> is an unchanged chassis of a conventional truck architecture, for example a chassis that is also suitable for a truck driven by an internal combustion engine, or, alternatively, chassis <NUM> can be part of a conventional truck without all combustion engine related parts. Chassis <NUM> comprises a pair of longitudinal chassis members <NUM>, <NUM> extending between a front axle <NUM> and a rear axle <NUM> of the truck.

As can be seen in <FIG>, auxiliary frame <NUM> comprises a front section <NUM> arranged for mounting an electric power source unit <NUM> and a rear section <NUM> arranged for mounting at least a power electronics unit <NUM>, as an auxiliary unit of electric power module <NUM>. Besides power electronics unit <NUM>, rear section <NUM> can be arranged for mounting an invertor unit, or other types of auxiliary units, such as a fuse box, a power junction box, or an on-board charger, an E-Power take off, brake resistor, battery conditioning unit, AC compressor, 24V dynamo, invertor for a pump, E-air compressor, or the like. In some embodiments the auxiliary frame combines a high temperature circuit that includes a brake resistor and a heat exchanger for the truck cabin; a mid temperature circuit that includes a DC/DC Converter and E-Power take off; and a low temperature circuit; including cooling unit and a steering pump. Front section <NUM> of auxiliary frame <NUM> comprises module mounts <NUM> arranged for suspending electric power module <NUM> to chassis <NUM>. Preferably, module mounts <NUM> match with, or correspond within acceptable deviations, the original mounting locations on chassis <NUM> for mounting an internal combustion engine, such that the structural topology of chassis <NUM> can remain unchanged.

Electric power module <NUM> is suspended to chassis <NUM> between the pair of longitudinal chassis members <NUM>, <NUM> near front axle <NUM> of the truck, e.g. such that a center of gravity of electric power module <NUM> is substantially aligned above front axle <NUM>. In this way, the weight distribution of a truck provided with drive power by electric power module <NUM> can be matched to the original weight distribution in a conventional truck powered by an internal combustion engine, such that the dynamic behavior of both trucks is similar. As a result, e.g. components and structural properties related to the truck's chassis, suspension system, brake system, vehicle control system and other aspects can be interchangeable between conventional trucks and trucks driven by electric power module <NUM>. Preferably, the total mass of electric power module <NUM> suspended near front axle <NUM> in a truck powered by electric power module <NUM> is matched with the total mass of an internal combustion engine and corresponding power transmission in a conventional truck, e.g. such that the eigenfrequency of the corresponding mass-damper system formed at the front of both trucks is similar, to have an unchanged comfort level for a driver of a truck powered by electric power module <NUM> relative to a conventional truck.

Rear section <NUM> of auxiliary frame <NUM> extends beyond front section <NUM> in a cantilevered fashion, without using additional mounts for mounting to chassis <NUM>. As can be seen in <FIG>, module mounts <NUM> are arranged on front section <NUM> to substantially suspend the relatively large mass of electric power source <NUM>, while the relatively small mass of auxiliary unit <NUM> is suspended by rear section <NUM> being cantilevered to front section <NUM>. This solution provides an optimized balance between maximum strength and minimum total mass of auxiliary frame <NUM>, and thus maximum payload.

As a result of the cantilevered support of the mass of auxiliary unit <NUM>, however, auxiliary frame <NUM> may be prone to make a pitch movement P, which can be defined as a rotation around a pitch axis parallel to front axis <NUM> as shown in <FIG>, said pitch axis e.g. formed between two opposing module mounts <NUM> on longitudinal chassis members <NUM> and <NUM>. For this reason, rear section <NUM> comprises shock absorbers <NUM> arranged for absorbing pitch movement P of auxiliary frame <NUM> relative to chassis <NUM> behind module mounts <NUM>. For example, shock absorbers <NUM> can be mounted between rear section <NUM> and chassis <NUM>, e.g. one or both of longitudinal chassis beams <NUM>, <NUM> or a chassis member, or shock absorbers <NUM> can be mounted between rear section <NUM> and another component which cannot make a similar pitch movement relative to chassis <NUM>, e.g. a cabin suspension. <FIG> illustrates shock absorbers <NUM> in a vertically upward orientation, however alternative orientations can be envisioned by the person skilled in the art, e.g. vertically downward or at another angle relative to auxiliary frame <NUM>, dependent on the relative location of the mounting points. The shock absorbers are supported on the auxiliary frame on one side, and on another support on the other side. The other support for the shock absorber <NUM> could be directly mechanically connected to the chassis members <NUM>,<NUM>, e.g. via a rear cabin suspension yoke that is mounted to the chassis members illustrated in <FIG>.

<FIG> illustrates a side view of another or further embodiment of electric power module <NUM>, further comprising an electric motor <NUM> to be mounted beyond rear section <NUM> of auxiliary frame <NUM> and arranged for driving rear wheels of the truck. As such, electric power module <NUM> and electric motor <NUM> form a combined power unit, e.g. arranged for converting a conventional truck to a truck driven by an electric power train. In preferred embodiments, electric power source unit <NUM> comprises a battery pack <NUM>, to store electric energy for powering electric motor <NUM>. Alternatively, electric power source unit <NUM> comprises one or multiple fuel cells, or a combination of battery packs and fuel cells.

Preferably, electric motor <NUM> is electrically coupled to electric power module <NUM>. However, motor <NUM> is also preferably mechanically decoupled from the power module <NUM>, in particular, its auxiliary frame <NUM>, to avoid drive torque from electric motor <NUM> mechanically affecting electric power module <NUM>, e.g. causing deformation of electric power module <NUM>, or more specifically to avoid that auxiliary frame <NUM>, needs to be designed more robust and thus heavier, to withstand the torque of the electric motor <NUM>. For example, electric motor <NUM> is mechanically decoupled from electric power module <NUM> by having a separate frame for mounting to chassis <NUM>, preferably at a distance from electric power module <NUM>. Electric motor <NUM> is electrically coupled to electric power module <NUM>, e.g. by high voltage power cables, preferably avoiding excessive stresses in cables and connectors due to relative movement between electric motor <NUM> and electric power module <NUM> under normal operating conditions.

As shown in <FIG>, some embodiments of electric power module <NUM> can have an auxiliary frame <NUM> comprising a bottom section <NUM> arranged for removably mounting further auxiliary units <NUM>, <NUM> to auxiliary frame <NUM>. Further auxiliary unit <NUM> can for example comprise a coolant system unit, for cooling electric power module <NUM> and/or electric motor <NUM> or an e-compressor that is serviceable from below. Alternatively, further auxiliary unit <NUM> and <NUM> may comprise other system units supporting or enhancing the functionality of electric power module <NUM>. Because of their beneficial mounting on bottom section <NUM>, further auxiliary units <NUM>, <NUM> preferably comprise system units that require regular service, maintenance or inspection. In preferred embodiments of electric power module <NUM> and of trucks provided with drive power by such an electric power module, further auxiliary units <NUM>, <NUM> can be removably mounted to auxiliary frame <NUM> from a bottom side of the truck, to facilitate service and maintenance to electric power module <NUM> and the corresponding truck.

<FIG> illustrates an isometric top view of electric power module and its rear suspension. Shock absorbers <NUM> are provided between auxiliary frame <NUM> and another support that connects to the chassis members <NUM>, <NUM>. In the embodiment, the other support is formed by rear cabin suspension yoke <NUM> that is mounted to the chassis members illustrated in <FIG>. The suspension dampens tilting impact that arise due to the units arranged on the rear section of auxiliary frame with a center of mass beyond the rear module mount <NUM>. These units may be mounted directly to the auxiliary frame, but may also be mounted rearward of power source unit <NUM>. In this way, the auxiliary frame can be kept light while it extends considerably rearwards in comparison with a conventional combustion engine, and yet achieves the same mass benefits of the weight collected on the front axle.

Yet another or further embodiment of electric power module <NUM> is illustrated in <FIG>, in an isometric top view. Here, electric motor <NUM> comprises motor mounts <NUM>, <NUM> for suspending electric motor <NUM> to chassis <NUM> between the pair of longitudinal chassis members <NUM>, <NUM>. In this way, electric motor <NUM> can mechanically be coupled to chassis <NUM> while the center of gravity of electric motor <NUM> can beneficially be placed close to electric power module <NUM> and in line with a drive shaft <NUM> to the driven rear wheels of the truck, such that electric motor <NUM> can be mounted into a chassis of a truck similar to a transmission unit in a conventional power train driven by an internal combustion engine.

As shown, centerline <NUM> of drive shaft <NUM> is suspended parallel to the pair of longitudinal chassis members <NUM>, <NUM>, such that electric motor is aligned parallel to longitudinal chassis members <NUM>, <NUM>. As a result, drive shaft <NUM> can be connected to a driven rear axle of a conventional truck, e.g. comprising a differential or other angular transmission.

<FIG> also illustrates other or further embodiments of electric power module <NUM> in which electric motor <NUM> is mounted to a chassis cross member <NUM>. As shown, chassis cross member <NUM> extends laterally between and beyond the pair of longitudinal chassis members <NUM>, <NUM> and comprises distal ends <NUM>, <NUM> arranged for suspending auxiliary electrical power source units, which are indicated in <FIG> with reference number <NUM>. Back to <FIG>, chassis cross member <NUM> can be arranged at a rear end of electric motor <NUM>, as presently illustrated, or at a front end of electric motor <NUM>, or in between, depending on the position of motor mounts <NUM>, <NUM> relative to the body of electric motor <NUM>, and/or depending on the position of distal ends <NUM>, <NUM> relative to the auxiliary power source units.

<FIG> provides an isometric view of another or further embodiment of electric power module <NUM>. Besides comprising an invertor as indicated in <FIG>, the at least one auxiliary unit, mounted at rear section <NUM> of auxiliary frame <NUM>, comprises a power junction unit <NUM>, e.g. to provide separate inputs and outputs for distribution of high voltage and/or low voltage power within electric power module <NUM>. Other auxiliary units may comprise an electronic control unit, e.g. for controlling electric power module <NUM>, and an on-board charger, e.g. for charging battery pack <NUM>. Preferably, electrical wiring and cables are organized such that high voltage power lines, e.g. between electric motor <NUM> and power junction unit <NUM>, are as short as possible and at a distance from data communication cables, to reduce the effects of electromagnetic radiation caused by the high voltage power lines.

<FIG> also depicts the at least one auxiliary unit at rear section <NUM> comprising a fuse unit <NUM>, according to another or further embodiment of electric power module <NUM>. Fuse unit <NUM> can e.g. be a fuse box comprising one or multiple fuses arranged for electrically protecting electric power module <NUM>, auxiliary units, further auxiliary units, other units and/or various sub-parts of these modules and units.

Preferably, fuse unit <NUM> is accessible from a top side of the truck, e.g. near a rear bottom edge of a cabin of the truck, or fuse unit <NUM> can be located below the cabin and accessible from a top side of the truck by tilting the cabin of the truck forward. Fuse unit <NUM> is arranged to be removably mounted to auxiliary frame <NUM> by a tilting movement of fuse unit <NUM>, such that, in case of a truck with a fixed cargo bed, fuse unit <NUM> can be mounted and removed from a top side of the truck by making use of the clearance between the cabin and a cargo bed of the truck.

<FIG> illustrates a hoisting apparatus <NUM> for hoisting electric power module <NUM> according to any embodiment of the present invention comprising an electric motor, such as electric motor <NUM> as illustrated, into a chassis of a truck. Hoisting apparatus <NUM> comprises a first hoisting section <NUM> and a second hoisting section <NUM>.

First hoisting section <NUM> comprises a frame yoke <NUM> including frame brackets <NUM>. Frame brackets <NUM> can e.g. comprise hooks, carbines, bolts, or any other temporary fastening means suitable for coupling to auxiliary frame <NUM> of electric power module <NUM> and carrying the combined mass of electric power module <NUM> and electric motor <NUM> in a secure fashion. First hoisting section <NUM> can comprise one or more frame brackets <NUM> arranged for coupling to auxiliary frame <NUM> directly or via an intermediate body providing a mount, such as a rod, plate or component arranged for transferring the load from auxiliary frame <NUM> to frame bracket <NUM>. For example, as shown in <FIG> a central frame bracket <NUM> of first hoisting section <NUM> may be arranged for being coupled to a front side of electric power module <NUM>, e.g. by an intermediate plate connected to auxiliary frame <NUM> at the front of electric power source unit <NUM>. Additionally, first hoisting section can comprise additional frame brackets <NUM> arranged for coupling to specific auxiliary units, such as cooling unit <NUM> shown in <FIG>, which may lack a structural connection to auxiliary frame strong enough to carry their own weight when electric power module <NUM> is hoisted as a combined power module into a chassis of a truck. Second hoisting section <NUM> comprises motor hoisting brackets <NUM> arranged for coupling electric motor <NUM> to auxiliary frame <NUM>, preferably to rear section <NUM> of auxiliary frame <NUM>, more preferably near a reinforced part of rear section <NUM>. First hoisting section <NUM> is arranged for hoisting second hoisting section <NUM>. In this way electric power module <NUM> and electric motor <NUM> can be hoisted as a combined power unit into a chassis of a truck.

<FIG> illustrates another or further embodiment of hoisting apparatus <NUM>. First hoisting section <NUM> comprises a frame yoke <NUM> including frame brackets <NUM>. As shown, a central frame bracket <NUM> is coupled to a front side of electric power module <NUM>, e.g. by an intermediate plate connected to auxiliary frame <NUM> having a mount for coupling to central frame bracket <NUM>. Cooling unit <NUM> may only be coupled to electric power module <NUM> by means of coolant hoses and power cables of a certain length, for which reason it may be preferred that cooling unit <NUM> is hoisted together with electric power module <NUM> as a combined unit, yet cooling unit <NUM> can still be mounted and/or suspended independently from auxiliary frame <NUM> onto the chassis of the truck.

As shown in <FIG>, first hoisting section <NUM> comprises rear frame brackets <NUM> arranged for coupling to rear section <NUM> of auxiliary frame <NUM> while forming a support structure for hoisting electric motor <NUM> as part of second hoisting section <NUM>. Rear frame brackets <NUM> can for example be an L-shaped plate, having a short side coupled to rear section <NUM> of auxiliary frame <NUM> and a long side extending from rear section <NUM> of auxiliary frame over electric motor <NUM>, parallel to the centerline of electric motor <NUM>.

Second hoisting section <NUM> for example can comprise frame rods <NUM> extending from rear frame brackets <NUM> toward electric motor <NUM>, and arranged to control the distance between electric power module <NUM> and electric motor <NUM> when hoisted as a combined unit into a chassis of a truck. Different variants of frame rods <NUM> can be chosen, e.g. having specific dimensions, handles and/or adjustment means, to accommodate different types of electric motors and control their corresponding distance to electric power module <NUM>.

<FIG> further shows that motor hoisting brackets <NUM> can be arranged for coupling electric motor <NUM> to auxiliary frame <NUM>, e.g. by having motor brackets <NUM> connected to a distal end of frame rods <NUM>. For example, each motor hoisting bracket <NUM> has a locking element <NUM> arranged for engaging with a motor mount <NUM> of electric motor <NUM>. The locking element <NUM> may comprise safety clamp mechanism, e.g. a hook engaging into a cavity on a bottom surface of motor mount <NUM>, such that the locking element of motor bracket <NUM> is aligned with motor mount <NUM> and a catch arranged for locking the hook into the cavity of motor mount <NUM>, such that the motor mount <NUM> is prevented from disengaging with the protrusion of motor bracket <NUM>. The locking element can for example be a (spring) preloaded element, a fastener element, or a wedge element.

<FIG> illustrates a truck <NUM>, provided with drive power by the electric power module <NUM> according to any of the embodiments claimed in the present invention. In the exemplary embodiment shown, electric power module <NUM> comprises an auxiliary frame <NUM> mounted to chassis <NUM> of truck <NUM>, having a pair of longitudinal chassis members <NUM>, <NUM> extending between front axle <NUM> and rear axle <NUM>.

An electric power source unit <NUM> is mounted to front section <NUM> of auxiliary frame <NUM>, while rear section <NUM> of auxiliary frame <NUM> comprises a power electronics unit <NUM>. Front section <NUM> of auxiliary frame <NUM> comprises module mounts arranged for suspending electric power module <NUM> to chassis <NUM> between the pair of longitudinal chassis members <NUM>, <NUM> near front axle <NUM> of truck <NUM>.

The electric power module <NUM> in truck <NUM> is further equipped with an electric motor <NUM> arranged for driving rear wheels of truck <NUM>. Electric motor <NUM> is mounted beyond rear section <NUM> of auxiliary frame <NUM> and between the pair of longitudinal chassis members <NUM>, <NUM> to chassis cross member <NUM>, which is arranged for suspending auxiliary electrical power source units <NUM>, to enhance the power capacity and/or range of truck <NUM>.

Claim 1:
An electric power module (<NUM>) for providing drive power in a truck, comprising an auxiliary frame (<NUM>) to be mounted to a chassis (<NUM>) having a pair of longitudinal chassis members (<NUM>, <NUM>) extending between a front axle (<NUM>) and a rear axle (<NUM>) of the truck, said auxiliary frame (<NUM>) comprising a front section (<NUM>) arranged for mounting an electric power source unit (<NUM>) and a rear section (<NUM>) arranged for mounting at least one auxiliary unit (<NUM>);
wherein the front section (<NUM>) of the auxiliary frame comprises module mounts (<NUM>) arranged for suspending the electric power module (<NUM>) to the chassis (<NUM>) between the pair of longitudinal chassis members (<NUM>, <NUM>) near the front axle (<NUM>) of the truck;
characterized in that the rear section (<NUM>) of the auxiliary frame extends beyond the front section (<NUM>) in a cantilevered fashion and comprises shock absorbers (<NUM>) arranged for absorbing a pitch movement (P) of the auxiliary frame (<NUM>) relative to the chassis (<NUM>) behind the module mounts (<NUM>).