Patent Description:
A dual-clutch power-assisted transmission comprises a pair of independent primary shafts coaxial with each other, one inserted inside the other, and two coaxial clutches, each of which is adapted to connect a respective primary shaft to a drive shaft of an internal combustion heat engine. Furthermore, a dual-clutch power-assisted transmission comprises at least one secondary shaft which transmits motion to the drive wheels and is couplable to the primary shafts by means of respective gearings, each of which defines a gear.

During a gear change, the current gear couples the secondary shaft to a primary shaft while the next gear couples the secondary shaft to the other primary shaft; consequently, the gear change occurs by crossing the two clutches, i.e., by opening the clutch associated with the current gear and simultaneously closing the clutch associated with the next gear.

In a power-assisted dual-clutch transmission, the two clutches share a single common drum, which is brought in rotation by the drive shaft of the internal combustion engine and is always arranged on the same side of the internal combustion engine (i.e., the common drum is always arranged near the internal combustion engine).

Utility model <CIT> describes a car with rear traction and provided with a centrally positioned internal combustion engine and a transmission which is oriented longitudinally and is arranged in a rear position behind the internal combustion engine.

The object of the present invention is to provide a car provided with an internal combustion engine and with a dual-clutch transmission which allows to optimise the positioning of all the components.

According to the present invention, this object is solved by the combination of features of claim <NUM>.

The dependent claims describe preferred embodiments of the present invention forming an integral part of the present description.

The present invention will now be described with reference to the accompanying drawings, showing some nonlimiting embodiments thereof, in which:.

In <FIG>, the number <NUM> overall indicates a hybrid car (i.e., with hybrid propulsion) provided with two front drive wheels <NUM> receiving drive torque from (at least) one electric machine <NUM> (illustrated schematically in <FIG>) and two rear drive wheels <NUM> receiving drive torque from an internal combustion engine <NUM> (illustrated schematically in <FIG>).

Two directions are identified in the car <NUM>: the longitudinal direction which is horizontal and parallel to the travel direction of the car <NUM> and the transverse direction which is horizontal and perpendicular to the travel direction of the car <NUM> (i.e., perpendicular to the longitudinal direction).

As illustrated in <FIG>, the electric machine <NUM> is connected to the two front drive wheels <NUM> by means of a transmission system (of known type and not illustrated) provided with a front differential; similarly, the internal combustion engine <NUM> is also connected to the two rear drive wheels <NUM> by means of a transmission system <NUM> provided with a transmission <NUM> and a rear differential <NUM> (illustrated schematically in <FIG>).

Preferably, the electric machine <NUM> is reversible (i.e., it can operate either as an electric motor by absorbing electrical energy and generating a mechanical drive torque, or as an electric generator by absorbing mechanical energy and generating electrical energy); according to other embodiments not illustrated, the electric machine <NUM> is not provided.

As illustrated in <FIG> and <FIG>, the car <NUM> comprises a passenger compartment <NUM> which is arranged between the two front wheels <NUM> and the two rear wheels <NUM> and contains driver's station <NUM> therein (schematically illustrated in <FIG>) which is arranged on the left side (alternatively it could also be arranged on the right side). As illustrated in <FIG>, the driver's station <NUM> comprises a steering wheel <NUM>, a driver's seat (not illustrated) and a number of other (known and not illustrated) driver-operated controls (including, for example, an accelerator pedal, a brake pedal and at least one lever for selecting gears).

As illustrated in <FIG> and <FIG>, the car <NUM> comprises a body <NUM> which delimits (among other things) the passenger compartment <NUM> and has two sides in which at least two doors <NUM> are obtained. The door <NUM> on the left provides direct access to the driver's station <NUM>.

As illustrated in <FIG>, the car <NUM> comprises a bottom <NUM> which forms the lowest part of the car <NUM> and in use is facing a road surface on which the car <NUM> moves.

According to a possible embodiment, the internal combustion engine <NUM> is powered by hydrogen (or also another gaseous fuel). According to a different embodiment, the internal combustion engine <NUM> is powered by petrol (or also another liquid fuel).

As illustrated in <FIG>, the internal combustion engine <NUM> is powered by hydrogen, which is stored at high pressure (e.g., with a maximum pressure of around <NUM> bar) in four different tanks <NUM> and <NUM>: the two tanks <NUM> have a spherical shape and have the same size, while the two tanks <NUM> have a cylindrical shape and have different sizes (i.e., one tank <NUM> is larger than the other tank <NUM>).

The two tanks <NUM> (spherical in shape) are arranged next to a cylinder block of the internal combustion engine <NUM> at the two opposite sides of the internal combustion engine <NUM>, i.e., one tank <NUM> is arranged to the right of the cylinder block of the internal combustion engine <NUM> while the other tank <NUM> is arranged to the left of the cylinder block of the internal combustion engine <NUM>. In other words, the two tanks <NUM> (spherical in shape) are arranged at the same vertical height, are arranged at the same longitudinal height and are separated from each other transversely (with the interposition of the cylinder block of the internal combustion engine <NUM>), i.e., they are only transversely spaced from each other.

The two tanks <NUM> (cylindrical in shape) are arranged above the internal combustion engine <NUM> one in front of the other. In other words, the two tanks <NUM> (cylindrical in shape) are arranged (roughly) at the same vertical height, are arranged at the same transverse height and are separated from each other longitudinally, i.e., they are only longitudinally spaced from each other (i.e., one is arranged in front of the other). In particular, both tanks <NUM> (cylindrical in shape) are oriented transversely, i.e., their central axes of symmetry are oriented transversely. In the embodiment illustrated in <FIG>, the tank <NUM> arranged in front (i.e. closer to the front) is larger than the tank <NUM> arranged behind (i.e., closer to the rear).

As illustrated in <FIG>, the internal combustion engine <NUM> comprises a crankcase <NUM> within which a plurality of cylinders <NUM> (only one of which is illustrated in <FIG>) is obtained. Preferably (but not compulsorily), the cylinders <NUM> are arranged in line, as this solution allows to reduce the transverse dimensions of the internal combustion engine <NUM> and thus, among other things, allows to leave more space for the tanks <NUM>. In the embodiment illustrated in the accompanying drawings, six cylinders <NUM> are provided in line, but obviously the number and arrangement of the cylinders <NUM> could be different.

Each cylinder <NUM> has a respective combustion chamber and a respective piston <NUM> mechanically connected to a drive shaft <NUM> (by means of a respective connecting rod) to transmit the force generated by the combustion to the drive shaft <NUM>. Coupled (connected) to the crankcase <NUM> is a cylinder head <NUM> which forms the crown of the cylinders <NUM> (i.e., the upper closure of the cylinders <NUM> with what is known as the "flame plate"). In the case of an in-line arrangement of the cylinders <NUM>, a single cylinder head <NUM> is provided, while in the case of a "V" arrangement of the cylinders <NUM>, twin cylinder heads <NUM> are provided for the two banks of cylinders <NUM>.

The combination of the crankcase <NUM> and the cylinder head <NUM> constitutes the cylinder block of the internal combustion engine <NUM>.

In the embodiment illustrated in the accompanying drawings, the internal combustion engine <NUM> is arranged (oriented) longitudinally, i.e., the drive shaft <NUM> is arranged (oriented) longitudinally, as this solution allows to reduce the transverse dimension of the internal combustion engine <NUM> and thus, among other things, leave more space for the tanks <NUM>. According to other embodiments not illustrated, the internal combustion engine <NUM> is arranged (oriented) transversely.

In the embodiment illustrated in the appended figures, the internal combustion engine <NUM> is arranged in a central or rear position, i.e., the internal combustion engine <NUM> is arranged behind the passenger compartment <NUM> and is located between the front wheels <NUM> and the rear wheels <NUM> (central arrangement as illustrated in the accompanying drawings) or is located beyond the rear wheels <NUM> (rear arrangement not illustrated).

Each cylinder <NUM> comprises two intake valves <NUM> controlled by a camshaft <NUM> which receives motion from the drive shaft <NUM> by means of a belt drive <NUM> (illustrated in <FIG>); alternatively to the belt drive <NUM>, a chain drive or a gear drive could be used. Furthermore, each cylinder <NUM> comprises two exhaust valves <NUM> controlled by a camshaft <NUM> which receives motion from the drive shaft <NUM> by means of the belt drive <NUM> (illustrated in <FIG>). The intake valves <NUM>, exhaust valves <NUM> and the corresponding control means (i.e., the return springs and camshafts <NUM> and <NUM>) are housed in the cylinder head <NUM>.

Each cylinder <NUM> further comprises (at least) one fuel injector <NUM> which injects fuel into the cylinder <NUM> cyclically; <FIG> illustrates a direct fuel injection into the cylinder <NUM> but the fuel injection into the cylinder <NUM> could also be (partially or fully) indirect. Each cylinder <NUM> comprises (at least) one spark plug <NUM> which is cyclically activated to ignite the mixture of air (oxidiser) and fuel present in the combustion chamber at the end of the compression phase.

As illustrated in the accompanying drawings, the internal combustion engine <NUM> is oriented vertically with the drive shaft <NUM> arranged higher than the cylinders <NUM>. In other words, the internal combustion engine <NUM> is arranged "upside down" relative to the traditional arrangement where the cylinders <NUM> are at the top and the drive shaft <NUM> is at the bottom. As a result, the cylinder head <NUM> which forms the crown of the cylinders <NUM> is arranged below the crankcase <NUM> and represents the lowest part of the internal combustion engine <NUM>.

The internal combustion engine <NUM> comprises an intake system <NUM> which draws air from the outside environment to convey the air into the cylinders <NUM> (the intake of air into the cylinders <NUM> is regulated by the intake valves <NUM>). Among other things, the intake system <NUM> comprises an intake manifold <NUM> which is directly connected to all the cylinders <NUM>; the intake of air into the intake manifold <NUM> is regulated by a throttle valve <NUM>.

The internal combustion engine <NUM> comprises an exhaust system <NUM> which releases the exhaust gases from the cylinders <NUM> into the external environment. Among other things, the intake system <NUM> comprises (at least) one exhaust gas treatment device <NUM> (typically a catalytic converter).

As illustrated in <FIG>, the intake system <NUM> comprises twin, separate intake ducts <NUM> which are arranged on the two sides of the car <NUM> (i.e., one intake duct <NUM> is arranged on the right side and the other intake duct <NUM> is arranged on the left side) and originates from respective air inlets <NUM> obtained through the body <NUM>. An air filter <NUM> is arranged along each intake duct <NUM> near the respective air inlet <NUM>. Each intake duct <NUM> terminates in a compressor unit <NUM> which increases the air pressure to increase the volumetric efficiency of the cylinders <NUM>. A sole (single) intake duct <NUM> originates from the compressor unit <NUM>, which terminates in the intake manifold <NUM> after passing through two intercoolers <NUM> and <NUM> arranged in series. That is, an initial section of the intake duct <NUM> connects the compressor unit <NUM> to the intercooler <NUM>, then an intermediate section of the intake duct <NUM> connects the intercooler <NUM> to the intercooler <NUM>, and lastly a final section of the intake duct <NUM> connects the intercooler <NUM> to the intake manifold <NUM>.

According to a preferred embodiment, the intercooler <NUM> is of the air/air type and the intercooler <NUM> is also of the air/air type. According to a preferred embodiment, the intercooler <NUM> has a larger volume relative to a volume of the intercooler <NUM>; in this regard, it is important to note that the intercooler <NUM> is at a disadvantage relative to the intercooler <NUM>, since it is arranged farther from the corresponding air inlet and compensates this disadvantage both by having a larger volume, and by having to cool air with a higher inlet temperature (since the intercooler <NUM> receives the air directly from the compressor unit <NUM> while the intercooler <NUM>, being arranged in series with the intercooler <NUM>, receives the air which has already been partially cooled by the intercooler <NUM>).

As illustrated in <FIG>, the exhaust system <NUM> comprises twin, separate exhaust ducts <NUM> which receive exhaust gases from the respective cylinders <NUM> to which they are individually connected; in particular, each exhaust duct <NUM> is connected to three cylinders <NUM> by means of respective channels which originate from the three cylinders <NUM> and terminate in an inlet of the exhaust duct <NUM> (from another viewpoint, each exhaust duct <NUM> is initially divided into three parts to connect with the respective three cylinders <NUM>). A corresponding exhaust gas treatment device <NUM> (typically a catalytic converter) is arranged along each exhaust duct <NUM>; thus altogether, the exhaust system <NUM> comprises two twin, separate exhaust gas treatment devices <NUM>.

A turbine unit <NUM> is arranged along the exhaust ducts <NUM>, provided with twin turbines <NUM> (better illustrated in <FIG>), each of which is coupled to a corresponding exhaust duct <NUM>. That is, each exhaust duct <NUM> passes through a respective turbine <NUM> and the two turbines <NUM> are arranged side by side to form the turbine unit <NUM>. In other words, a turbine <NUM> is provided which is connected along each exhaust duct <NUM> and is arranged alongside the cylinder block (consisting of the crankcase <NUM> and the cylinder head <NUM>) of the internal combustion engine <NUM>.

The two exhaust ducts <NUM> terminate in a single common silencer <NUM> which receives the exhaust gases from both exhaust ducts <NUM>. According to other embodiments not illustrated, twin, separate silencers <NUM> are provided, each of which receives exhaust gases only from a respective exhaust duct <NUM>.

In the preferred embodiment illustrated in the accompanying drawings, the silencer <NUM> has a single final exhaust pipe <NUM> which opens into an outlet opening <NUM>; according to other embodiments not illustrated, the silencer <NUM> has two or more final pipes <NUM>, each of which opens into a corresponding outlet opening <NUM>.

As illustrated in <FIG>, the compressor unit <NUM> (intended for use in the supercharged internal combustion engine <NUM>) comprises a single shaft <NUM> mounted rotatably about a rotation axis <NUM>. In the embodiment illustrated in the accompanying drawings, the shaft <NUM> (thus the rotation axis <NUM>) is oriented transversely; according to a different embodiment not illustrated, the shaft <NUM> (thus the rotation axis <NUM>) is oriented longitudinally or is inclined (non-parallel) both relative to the longitudinal direction and relative to the transverse direction.

The compressor unit <NUM> comprises twin (identical) compressors <NUM>, each of which is integral with the shaft <NUM> to rotate together with the shaft <NUM> and is configured to compress air intended to be sucked in by the supercharged internal combustion engine <NUM>; in particular, each compressor <NUM> receives air from a respective intake duct <NUM> (i.e., each intake duct <NUM> terminates in a corresponding compressor <NUM>).

The compressor unit <NUM> comprises a single common electric motor <NUM> which is integral with the shaft <NUM> to bring the shaft <NUM> into rotation (and thus to bring both compressors <NUM> mounted on the shaft <NUM> into rotation). In the embodiment illustrated in the appended figures, the electric motor <NUM> is arranged between the two compressors <NUM> and is perfectly equidistant from the two compressors <NUM>; according to a different embodiment not illustrated, the electric motor <NUM> is arranged on one side with respect to both compressors <NUM> (i.e., it is closer to one compressor <NUM> and is farther from the other compressor <NUM>).

As mentioned above, the two compressors <NUM> are identical and are of the centrifugal type. In particular, each compressor <NUM> comprises an axial inlet <NUM> arranged on the opposite side of the shaft <NUM> and connected to a respective intake duct <NUM> and a radial outlet <NUM>. According to a preferred embodiment, the compressor unit <NUM> comprises a joining duct <NUM> (illustrated in <FIG>) which is connected to both outlets <NUM> of the two compressors <NUM> to receive and join the compressed air from both compressors <NUM>; the joining duct <NUM> terminates in the intake duct <NUM>, i.e., the intake duct <NUM> starts from the joining duct <NUM> to receive and join the compressed air from both compressors <NUM>.

In the embodiment illustrated in the appended figures, the joining duct <NUM> is oriented transversely; according to a different embodiment not illustrated, the joining duct <NUM> is oriented longitudinally or is inclined (non-parallel) both relative to the longitudinal direction and relative to the transverse direction.

In the embodiment illustrated in the appended figures, the joining duct <NUM> is oriented parallel to the shaft <NUM> (thus to the rotation axis <NUM>); according to a different embodiment not illustrated, the joining duct <NUM> is not oriented parallel to the shaft <NUM>, thus to the rotation axis <NUM>).

As illustrated in <FIG>, the turbine unit <NUM> comprises two twin (identical) turbines <NUM> which drive the same electric generator <NUM> together. In particular, the two turbines <NUM> are arranged side by side and have two respective rotation axes <NUM> which are parallel to each other and spaced apart. The turbine unit <NUM> comprises a transmission device <NUM> which connects both turbines <NUM> to the same electric generator <NUM>. The transmission device <NUM> comprises two toothed gears, each of which is integral with the shaft of a corresponding turbine <NUM> to receive the rotary motion from the turbine <NUM>, and a connecting element (a toothed belt, a chain, a cascade of gearings) which connects the two toothed gears together in such a way as to make both toothed gears rotate together and at the same speed. According to a possible embodiment, a toothed gear of the two toothed gears of the transmission device <NUM> is directly coupled to a shaft of the electric generator <NUM> so that the electric generator <NUM> rotates at the same rotation speed as the two turbines <NUM>; alternatively, a toothed gear of the two toothed gears of the transmission device <NUM> is connected to the shaft of the electric generator <NUM> by means of the interposition of a speed reducer (typically with gearings) such that the electric generator <NUM> rotates at a lower rotation speed than the rotation speed of the two turbines <NUM>.

According to a preferred embodiment illustrated in the accompanying drawings, the electric generator <NUM> is coaxial to a turbine <NUM>; i.e., one turbine <NUM> and the electric generator <NUM> rotate about the same first rotation axis <NUM> while the other turbine <NUM> rotates about a second rotation axis <NUM> which is parallel to, and spaced from, the first rotation axis <NUM>.

The two turbines <NUM> are identical and are of the centrifugal type. In particular, each turbine <NUM> comprises a radial inlet <NUM> connected to one side of the respective exhaust duct <NUM> and an axial outlet <NUM> arranged on the opposite side of the transmission device <NUM> and connected to another side (which opens into the silencer <NUM>) of the respective exhaust duct <NUM>.

According to a preferred embodiment better illustrated in <FIG> and <FIG>, the silencer <NUM> is arranged next to a cylinder block (consisting of the crankcase <NUM> and cylinder head <NUM>) of the internal combustion engine <NUM> (on the exhaust valve <NUM> side). The outlet opening <NUM> of the silencer <NUM> is obtained through a sidewall of the car <NUM> (as illustrated in <FIG>) or, according to an alternative embodiment, through the bottom <NUM> of the car <NUM> (as illustrated in <FIG>).

In other words, the outlet opening <NUM> of the silencer <NUM> is arranged asymmetrically at only one side of the car <NUM> and is located between a rear wheel <NUM> and a door <NUM>. According to a preferred embodiment, the outlet opening <NUM> of the silencer <NUM> is arranged on the side where the driver's station <NUM> is located, so that the driver sitting in the driver's station <NUM> is near the outlet opening <NUM> of the silencer <NUM> and is thus in the best position to optimally hear the noise diffused through the outlet opening <NUM> of the silencer <NUM>.

In the embodiment illustrated in <FIG>, the outlet opening <NUM> of the silencer <NUM> is obtained through a sidewall of the body <NUM>, while in the alternative embodiment illustrated in <FIG>, the outlet opening <NUM> of the silencer <NUM> is obtained through the bottom <NUM>.

In the embodiment illustrated in the accompanying drawings, the silencer <NUM> comprises a single outlet opening <NUM>; according to other embodiments not illustrated, the silencer <NUM> comprises several outlet openings <NUM> which may be more or less side-by-side (it is also possible for one outlet opening <NUM> of the silencer <NUM> to be obtained through a sidewall of the body <NUM> while the other outlet opening <NUM> of the silencer <NUM> is obtained through the bottom <NUM>).

According to a preferred embodiment better illustrated in <FIG> and <FIG>, the silencer <NUM> is arranged on one side of the car <NUM> alongside a cylinder block (consisting of the crankcase <NUM> and cylinder head <NUM>) of the internal combustion engine <NUM> and in front of a rear drive wheel <NUM>.

According to a preferred embodiment better illustrated in <FIG> and <FIG>, the turbine unit <NUM> is arranged alongside a cylinder block (consisting of the crankcase <NUM> and cylinder head <NUM>) of the internal combustion engine <NUM> (on the exhaust valve <NUM> side). In particular, the turbine unit <NUM> is arranged between the internal combustion engine <NUM> (i.e., between the cylinder block consisting of the crankcase <NUM> and cylinder head <NUM>) and the silencer <NUM>; thereby, the exhaust ducts <NUM> are particularly short and relatively untwisted.

In the embodiment illustrated in <FIG>, the compressor unit <NUM> (comprising the twin compressors <NUM>) is connected between the two intake ducts <NUM> and <NUM>, is arranged behind the cylinder block (comprising the crankcase <NUM> and cylinder head <NUM>) of the internal combustion engine <NUM>, is arranged higher than the cylinder block of the internal combustion engine <NUM>, and is driven by the electric motor <NUM>.

As better illustrated in <FIG>, the compressor unit <NUM> (comprising the two twin compressors <NUM>) is arranged at the rear behind the intercooler <NUM> (i.e., the two compressors <NUM> of the compressor unit <NUM> are arranged at the rear behind the intercooler <NUM>). The intercooler <NUM> is horizontally oriented and is arranged behind (at the rear) of the cylinder block (consisting of the crankcase <NUM> and cylinder head <NUM>) of the internal combustion engine <NUM>; in particular, the intercooler <NUM> is arranged higher than the cylinder block of the internal combustion engine <NUM> and is located behind the cylinder block of the internal combustion engine <NUM>. In other words, the intercooler <NUM> has a parallelepiped shape with its two largest walls (the two largest walls, i.e., the two most extended walls) oriented horizontally, is arranged above the transmission <NUM>, and is thus arranged longitudinally further back than the cylinder block of the internal combustion engine <NUM>, and is arranged higher than the cylinder block of the internal combustion engine <NUM>.

Instead, the intercooler <NUM> (connected in series to the intercooler <NUM> along the intake duct <NUM>) is arranged on one side of the car <NUM> next to the cylinder block (consisting of the crankcase <NUM> and cylinder head <NUM>) of the internal combustion engine <NUM> and in front of a rear drive wheel <NUM>. In particular, the intercooler <NUM> is arranged on one side of the car <NUM> opposite the silencer <NUM>; i.e., the intercooler <NUM> and the silencer <NUM> are arranged on opposite sides of the car <NUM> separated from each other by the cylinder block (consisting of the crankcase <NUM> and the cylinder head <NUM>) of the internal combustion engine <NUM>. In other words, the intercooler <NUM> and silencer <NUM> are arranged on opposite sides of the cylinder block of the internal combustion engine <NUM>.

As illustrated in <FIG>, the internal combustion engine <NUM> comprises a dry sump lubrication circuit <NUM> which circulates a lubricating oil in all the moving parts of the internal combustion engine <NUM>. The lubrication circuit <NUM> comprises a delivery lubrication pump <NUM> configured to circulate the lubricating oil; i.e., the delivery lubrication pump <NUM> draws lubricating oil from an oil tank to send the lubricating oil inside the cylinder block (consisting of the crankcase <NUM> and cylinder head <NUM>). The lubrication circuit <NUM> comprises two recovery lubrication pumps <NUM> configured to circulate the lubricating oil; i.e., each recovery pump <NUM> draws oil from the cylinder block (consisting of the crankcase <NUM> and cylinder head <NUM>) and in particular from the lowest part of the cylinder block and then from the cylinder head <NUM> to send the lubricating oil into the tank (which is arranged higher than the cylinder head <NUM>).

According to a preferred embodiment, the two recovery lubrication pumps <NUM> are arranged on opposite sides of the cylinder head <NUM>, so that the lubricating oil is drawn from opposite areas of the cylinder head <NUM>.

As illustrated in <FIG>, the internal combustion engine <NUM> comprises a cooling circuit <NUM> which circulates a coolant (e.g., a mixture of water and glycol) in the cylinder block (consisting of the crankcase <NUM> and cylinder head <NUM>) of the internal combustion engine <NUM>. The cooling circuit <NUM> comprises a cooling pump <NUM> configured to circulate the coolant.

As illustrated in <FIG> and <FIG>, the camshaft <NUM> axially exits from the cylinder head <NUM> on both sides: a lubrication pump <NUM> is arranged coaxially to the camshaft <NUM> and is directly connected to the camshaft <NUM> to be brought in rotation by the camshaft <NUM>, and similarly the cooling pump <NUM> is arranged coaxially to the camshaft <NUM> on the opposite side of the lubrication pump <NUM> and is directly connected to the camshaft <NUM> to be brought in rotation by the camshaft <NUM>.

As illustrated in <FIG> and <FIG>, the camshaft <NUM> protrudes axially exits from the cylinder head <NUM> on both sides: the other lubrication pump <NUM> (different from the lubrication pump <NUM> connected to the camshaft <NUM>) is arranged coaxially to the camshaft <NUM> and is directly connected to the camshaft <NUM> to be brought in rotation by the camshaft <NUM>, and similarly the lubrication pump <NUM> is arranged coaxially to the camshaft <NUM> on the opposite side of the lubrication pump <NUM> and is directly connected to the camshaft <NUM> to be brought in rotation by the camshaft <NUM>.

Thereby, all four pumps <NUM>, <NUM> and <NUM> are coaxial to the respective camshafts <NUM> and <NUM> and are brought directly in rotation by the respective camshafts <NUM> and <NUM>.

According to other embodiments not illustrated, the number of pumps <NUM>, <NUM> and <NUM> is different (smaller) because, for example, only a delivery lubrication pump <NUM> could be provided; in this case (at least) one camshaft <NUM> or <NUM> exits axially from the cylinder head <NUM> on one side only.

According to other embodiments not illustrated, the arrangement of the pumps <NUM>, <NUM> and <NUM> could be different, i.e., they could vary: for example, the cooling pump <NUM> could be connected to the camshaft <NUM> or the lubrication pump <NUM> could be connected to the camshaft <NUM>.

As illustrated in <FIG>, the transmission <NUM> is directly connected to the drive shaft <NUM> of the internal combustion engine <NUM>, is aligned with the internal combustion engine <NUM>, and is arranged behind the internal combustion engine <NUM>. In particular, the transmission <NUM> is vertically aligned with an upper part of the cylinder block of the internal combustion engine <NUM>; i.e., the transmission <NUM> is vertically aligned with the upper part of the crankcase <NUM>.

The transmission <NUM> is dual-clutch and is interposed between the drive shaft <NUM> of the internal combustion engine <NUM> and the rear drive wheels <NUM>. The transmission <NUM> comprises a drum <NUM> which is brought in rotation by the drive shaft <NUM> and two clutches <NUM> contained one next to the other in the drum <NUM> to receive motion from the drum <NUM>. Furthermore, the transmission <NUM> comprises two primary shafts <NUM> which are coaxial with each other, are inserted one inside the other, and are each connected to a corresponding clutch <NUM> to receive motion from the corresponding clutch <NUM>. Each clutch <NUM> comprises driving discs which are integral with the drum <NUM> (thus they always rotate together with the drive shaft <NUM> to which the drum <NUM> is constrained) and driving discs which are interspersed with the driving discs and are integral with the corresponding primary shafts <NUM> (thus they always rotate together with the corresponding primary shafts <NUM>).

The drum <NUM> of the transmission <NUM> with dual-clutch <NUM> is arranged on the opposite side of the internal combustion engine <NUM> (i.e., the drive shaft <NUM>) relative to the two primary shafts <NUM>; furthermore, the transmission <NUM> with dual-clutch <NUM> comprises a transmission shaft <NUM> which connects the drive shaft <NUM> to the drum <NUM>, is coaxial to the two primary shafts <NUM>, and is inserted within the two primary shafts <NUM>. In other words, the transmission shaft <NUM> terminates at an end wall of the drum <NUM> and is constrained to the end wall of the drum <NUM>. In particular, a first primary shaft <NUM> is arranged on the outside, the transmission shaft <NUM> is arranged on the inside, and the other (second) primary shaft <NUM> is arranged between the transmission shaft <NUM> and the first primary shaft <NUM>. In other words, from the inside outwards, there is the transmission shaft <NUM> (which is in the centre) and successively the two primary shafts <NUM> (which are inserted one inside the other and both surround the transmission shaft <NUM>).

According to a preferred embodiment illustrated in the accompanying drawings, the primary shafts <NUM> and the transmission shaft <NUM> of the transmission <NUM> are coaxial with the drive shaft <NUM> of the internal combustion engine <NUM>; i.e., the internal combustion engine <NUM> is aligned with the transmission <NUM>.

The transmission <NUM> with dual-clutch <NUM> comprises a single secondary shaft <NUM> connected to the differential <NUM> which transmits motion to the rear drive wheels <NUM>; according to an alternative and equivalent embodiment, the dual-clutch transmission <NUM> comprises two secondary shafts <NUM> both connected to the differential <NUM>. A pair of axle shafts <NUM>, each of which is integral with a rear drive wheel <NUM>, depart from the differential <NUM>.

The transmission <NUM> has seven forward gears indicated with Roman numerals (first gear I, second gear II, third gear III, fourth gear IV, fifth gear V, sixth gear VI and seventh gear VII) and one reverse gear (indicated with the letter R). Each primary shaft <NUM> and secondary shaft <NUM> is mechanically coupled to each other by means of a plurality of gearings, each of which defines a respective gear and comprises a primary toothed gear <NUM> mounted on the primary shaft <NUM> and a secondary toothed gear <NUM> mounted on the secondary shaft <NUM>. To allow the correct operation of the transmission <NUM>, all the odd gears (first gear I, third gear III, fifth gear V, seventh gear VII) are coupled to the same primary shaft <NUM>, while all the even gears (second gear II, fourth gear IV, and sixth gear VI) are coupled to the other primary shaft <NUM>.

Each primary toothed gear <NUM> is keyed to a respective primary shaft <NUM> to always rotate integrally with the primary shaft <NUM> and permanently meshes with the respective secondary toothed gear <NUM>; instead, each secondary toothed gear <NUM> is mounted idle on the secondary shaft <NUM>. Furthermore, the transmission <NUM> comprises four dual synchronisers <NUM>, each of which is coaxially mounted on the secondary shaft <NUM>, is arranged between two secondary toothed gears <NUM>, and is adapted to be actuated to alternately engage the two respective secondary toothed gears <NUM> to the secondary shaft <NUM> (i.e., to alternately make the two respective secondary toothed gears <NUM> angularly integral with the secondary shaft <NUM>). In other words, each synchroniser <NUM> can be moved in one direction to engage a secondary toothed gear <NUM> to the secondary shaft <NUM>, or it can be moved in the other direction to engage the other secondary toothed gear <NUM> to the secondary shaft <NUM>.

According to what is illustrated in <FIG> and <FIG>, the car <NUM> comprises a containing body <NUM> which (also) contains the dual-clutch transmission <NUM> therein and has a tapered shape towards the rear so that the height of the containing body <NUM> progressively reduces from the front to the rear. That is, a front wall of the containing body <NUM> has a greater extension in height than a rear wall of the containing body <NUM>. In particular, the containing body <NUM> has a bottom wall <NUM> at the bottom which is inclined relative to the horizontal due to the tapered shape of the containing body <NUM>.

The differential <NUM> (which receives motion from the secondary shaft <NUM> of the transmission <NUM> and transmits the motion to the two rear drive wheels <NUM> by means of the two respective axle shafts <NUM>) is arranged inside the containing body <NUM> at the front and below the transmission <NUM>. The two axle shafts <NUM> exit laterally from the containing body <NUM>.

From the foregoing, we can summarise that the transmission <NUM> is directly connected to the drive shaft <NUM> of the internal combustion engine <NUM>, is aligned with the internal combustion engine <NUM> (i.e., the primary shafts <NUM> and the transmission shaft <NUM> of the transmission <NUM> are coaxial with the drive shaft <NUM> of the internal combustion engine <NUM>), and is arranged behind the internal combustion engine <NUM>; furthermore, the intercooler <NUM> is arranged horizontally above the transmission <NUM> (i.e., above the containing body <NUM> in which the transmission <NUM> is located).

As illustrated in <FIG>, <FIG> and <FIG>, the car <NUM> comprises a rear aerodynamic diffuser <NUM> which faces the road surface <NUM>, starts at a rear wall of the cylinder block (consisting of the crankcase <NUM> and cylinder head <NUM>) of the internal combustion engine <NUM> and is arranged below the transmission <NUM> (i.e., below the containing body <NUM> in which the transmission <NUM> is located).

According to a preferred embodiment, the bottom wall <NUM> of the containing body <NUM> (within which the transmission <NUM> is located) has the same inclination as the rear aerodynamic diffuser <NUM>; i.e., the bottom wall <NUM> of the containing body <NUM> reproduces the shape of the rear aerodynamic diffuser <NUM>, having the same inclination thereof. Thereby, the rear aerodynamic diffuser <NUM> exploits all the available space below the transmission <NUM> (i.e., below the containing body <NUM> in which the transmission <NUM> is located).

As illustrated in <FIG>, the car <NUM> comprises a chassis <NUM> (partially illustrated in <FIG>). The rear part of the chassis <NUM> comprises sidebars <NUM> which are arranged at the spherical tanks <NUM> to protect the spherical tanks <NUM> from lateral impacts; the sidebars <NUM> form tetrahedrons to have greater impact resistance.

As illustrated in <FIG>, an engine compartment <NUM> is obtained inside the chassis <NUM>, in which the internal combustion engine <NUM> is arranged. As illustrated in <FIG>, the bottom <NUM> of the car <NUM> comprises an opening <NUM> which is arranged at the engine compartment <NUM> and a removable panel <NUM> which is removably fixed and closes the opening <NUM>. The opening <NUM> has a dimension similar to the dimension of the engine compartment <NUM>; i.e., the dimension of the opening <NUM> is approximately (as far as possible) equal to the dimension of the engine compartment <NUM> so that there can be complete access to the engine compartment <NUM> through the opening <NUM>.

According to a preferred embodiment, the removable panel <NUM> is at least partially transparent; in particular, the removable panel <NUM> has a transparent window <NUM> (e.g., glass) in the centre. The function of the transparent window <NUM> is essentially technical in that it allows the internal combustion engine <NUM> to be visually inspected without having to remove the removable panel <NUM>.

According to a preferred embodiment, the body <NUM> has no opening bonnet (arranged above the engine compartment <NUM>) allowing access to the engine compartment <NUM>; i.e., access to the engine compartment <NUM> is only from below through the opening <NUM>, as the upper part of the engine compartment <NUM> is permanently closed by fixed, non-removable panels of the body <NUM>.

According to a preferred embodiment, the removable panel <NUM> is directly fixed to the chassis <NUM> by means of a plurality of screws <NUM> (preferably quarter-turn screws <NUM>).

The rear aerodynamic diffuser <NUM> faces the road surface <NUM>, is arranged to the rear of the removable panel <NUM> and borders the removable panel <NUM>. That is, the rear aerodynamic diffuser <NUM> starts where the removable panel <NUM> ends. The aerodynamic diffuser <NUM> is also detachable to allow easier access to the containing body <NUM> of the transmission <NUM>.

In the embodiment illustrated in <FIG>, the turbine unit <NUM> is provided, which generates electrical energy by means of the electric generator <NUM> and the compressor unit <NUM> drives the two compressors <NUM> by means of the electric motor <NUM>, which utilises (at least in part) the electrical energy generated by the electric generator <NUM> of the turbine unit <NUM>.

In the embodiment illustrated in <FIG>, the turbine unit <NUM> is not provided and the compressor unit <NUM> lacks the electric motor <NUM> since the two compressors <NUM> are driven by the transmission <NUM>, drawing motion from the drum <NUM> of the clutches <NUM> of the transmission <NUM> (as will be further explained below). In other words, the two compressors <NUM> are driven by the transmission shaft <NUM> of the transmission <NUM> (which directly rotates the drum <NUM> of the clutches <NUM> and is directly connected to the drive shaft <NUM>). This embodiment is energetically somewhat less efficient (not recovering part of the energy of the exhaust gases through the turbine unit <NUM>) but is lighter, more compact and simpler, eliminating the electrical part altogether (in fact, neither the electric generator <NUM> of the turbine unit <NUM> nor the electric motor <NUM> of the compressor unit <NUM> are present).

As illustrated in <FIG>, there is an actuating system <NUM> which connects the drum <NUM> of the transmission <NUM> to the compressor unit <NUM> (i.e., to the two compressors <NUM> of the compressor unit <NUM>) so as to receive motion from the drum <NUM> of the transmission <NUM> to bring the two compressors <NUM> of the compressor unit <NUM> into rotation. By way of example, the actuating system <NUM> increases the rotation speed so that the two compressors <NUM> of the compressor unit <NUM> always rotate faster than the drum <NUM> of the transmission <NUM>; for example, the two compressors <NUM> of the compressor unit <NUM> could rotate <NUM>-<NUM> times faster than the drum <NUM> of the transmission <NUM>.

As illustrated in <FIG>, the actuating system <NUM> is connected to an end wall of the drum <NUM> of the transmission <NUM> on the opposite side of the transmission shaft <NUM>; that is, the drum <NUM> of the transmission <NUM> has an end wall which is connected to the transmission shaft <NUM> on one side and is connected to the actuating system <NUM> on the opposite side.

According to a possible embodiment schematically illustrated in <FIG>, the actuating system <NUM> comprises a varying device <NUM> which is interposed between the drum <NUM> of the transmission <NUM> and the compressors <NUM> and has a variable gear ratio. Preferably, the varying device <NUM> has a centrifugal activation so as to autonomously change the gear ratio as a function of the rotation speed of the drum <NUM> of the transmission <NUM>; in particular, the varying device <NUM> is configured to decrease the gear ratio as the rotation speed of the drum <NUM> of the transmission <NUM> increases. That is, when the rotation speed of the drum <NUM> of the transmission <NUM> is lower, the gear ratio is larger and therefore (for the same rotation speed of the drum <NUM>) the compressors <NUM> run faster, whereas when the rotation speed of the drum <NUM> of the transmission <NUM> is higher, the gear ratio is smaller and therefore (for the same rotation speed of the drum <NUM>) the compressors <NUM> turn slower; thereby, the compressors <NUM> are able to generate effective compression even when the drum <NUM> of the transmission rotates slowly without "over-revving" when the drum <NUM> of the transmission rotates fast.

According to a preferred embodiment, the varying device <NUM> has only two different gear ratios; by way of example, the two gear ratios obtainable by means of the varying device <NUM> could differ from each other by <NUM>-<NUM>%.

According to a preferred embodiment, the varying device <NUM> comprises a direct drive engaged by a centrifugal clutch and a planetary gear which realises a lower gear ratio from the direct drive: the centrifugal clutch is operated by the centrifugal force which compresses the clutch discs by engaging the direct drive when the rotation speed of the drum <NUM> of transmission <NUM> exceeds a threshold value (thus resulting in a reduction of the gear ratio when the rotation speed of the drum <NUM> of the transmission <NUM> exceeds the threshold value). According to a preferred embodiment, a gear ratio of the varying device <NUM> could correspond to a direct drive (i.e., a <NUM>:<NUM> gear ratio) while the other gear ratio could be comprised between <NUM>:<NUM> and <NUM>:<NUM>.

According to a preferred embodiment, the varying device <NUM> is connected to the drum <NUM> of the transmission <NUM> on the opposite side of the primary shafts <NUM> and the transmission shaft <NUM>.

In the embodiment illustrated in <FIG>, the two compressors <NUM> are arranged parallel to each other and spaced apart so as to rotate about two rotation axes <NUM> which are parallel to each other and spaced apart and are parallel to a rotation axis <NUM> of the drum <NUM> of the transmission <NUM> (which is coaxial to the primary shafts <NUM>, the transmission shaft <NUM>, and the drive shaft <NUM>). In particular, the rotation axis <NUM> of the drum <NUM> of the transmission <NUM> is arranged between the rotation axes <NUM> of the two compressors <NUM>; i.e., the two compressors <NUM> are arranged on opposite sides of the rotation axis <NUM> of the drum <NUM> of the transmission <NUM>.

According to a preferred embodiment illustrated in <FIG>, the actuating system <NUM> comprises an intermediate shaft <NUM> which receives motion from the drum <NUM> of the transmission <NUM> and rotates about a rotation axis <NUM> which is parallel to and spaced from the rotation axis <NUM> of the drum <NUM> of the transmission <NUM>. In particular, the varying device <NUM> is between the drum <NUM> of the transmission <NUM> and the intermediate shaft <NUM>. The actuating system <NUM> comprises a central toothed gear <NUM> which receives motion from the intermediate shaft <NUM> (i.e., is constrained to the intermediate shaft <NUM>) and two side toothed gears <NUM> which are arranged on either side of the central toothed gear <NUM>, engage with the central toothed gear <NUM> and each transmit motion to a corresponding compressor <NUM> (i.e., each side toothed gear <NUM> is constrained to a shaft of a corresponding compressor <NUM>). A transmission <NUM> is interposed between each side toothed gear <NUM> and the corresponding compressor <NUM>, which increases the rotation speed so that the compressor <NUM> can rotate faster than the side toothed gear <NUM>.

Overall, the compressors <NUM> rotate much faster than the drive shaft <NUM> (i.e., the drum <NUM> of the transmission <NUM>): the compressors <NUM> rotate about ten times faster than the drive shaft <NUM> (i.e., the compressors <NUM> can reach <NUM>,<NUM> rpm while the drive shaft <NUM> can reach <NUM>,<NUM> rpm).

As illustrated in <FIG> and <FIG>, each compressor <NUM> comprises an axial inlet <NUM> arranged on the opposite side of the actuating system <NUM> and a radial outlet <NUM>. As described above, there is a joining duct <NUM> (not illustrated in <FIG>) which is connected to both outlets <NUM> of the two compressors <NUM> to receive and join the compressed air from both compressors <NUM>.

In the embodiment illustrated in <FIG>, there are two exhaust ducts <NUM> which originate from the cylinders <NUM> and terminate in the silencer <NUM> and are completely separate and independent from the cylinders <NUM> to the silencer <NUM>. Instead, in the embodiment illustrated in <FIG>, an exhaust duct <NUM> is provided, into which both exhaust ducts <NUM> flow and which terminates in the silencer <NUM>; i.e., the exhaust ducts <NUM> join together upstream of the silencer <NUM>, flowing together in the exhaust duct <NUM>, which terminates in the silencer <NUM>. In other words, the exhaust system <NUM> comprises a single exhaust duct <NUM> which receives exhaust gases from both exhaust ducts <NUM>; i.e., the two exhaust ducts <NUM> join to converge towards the single exhaust duct <NUM>. The exhaust duct <NUM> starts at the junction of the two exhaust ducts <NUM> and terminates in the silencer <NUM>.

In the embodiment illustrated in the accompanying drawings, the compressor unit <NUM> comprises two twin compressors <NUM>; according to a different embodiment not illustrated, the compressor unit <NUM> comprises a single compressor <NUM>.

In the embodiment illustrated in the appended figures, the turbine unit <NUM> (when present) comprises two twin turbines <NUM>; in a different embodiment not illustrated, the turbine unit <NUM> (when present) comprises a single turbine <NUM>.

The embodiments described herein can be combined with one another without departing from the scope of protection of the present invention.

The car <NUM> as described above has many advantages.

Firstly, the car <NUM> described above allows to simultaneously combines a large hydrogen storage capacity (thus being able to offer a satisfactory range) with very high dynamic performance thanks to an optimal wheelbase, overall weight, and weight distribution. These results are achieved thanks to the particular shape and arrangement of the internal combustion engine <NUM> and the transmission system <NUM>, which allow to create a large amount of free space to house the hydrogen tanks <NUM> and <NUM> without penalising the dynamic performance of the car <NUM>.

The car <NUM> as described above allows the construction of an extremely large rear aerodynamic chute (extractor), thus enabling the generation of a very high aerodynamic load without any penalisation of aerodynamic drag.

In the car <NUM> described above, it is possible to hear inside the passenger compartment <NUM> (particularly in the driver's station <NUM> where the driver sits) an exhaust noise with a sufficiently high intensity and a very good sound quality; this result is obtained thanks to the fact that the outlet opening is located very close to the passenger compartment <NUM> and on the side of the driver's station <NUM>, as this solution allows to both "concentrate" the sound intensity near the passenger compartment <NUM> and to have a very natural exhaust noise (i.e., not artificially created or in any case modified). That is, the exhaust noise is not artificially "aimed" towards the passenger compartment <NUM> through non-natural transmission channels but, on the contrary, the exhaust noise only reaches the passenger compartment <NUM> by passing through the exhaust system, i.e., by following the natural exit route of the exhaust noise.

In the car <NUM> described above, thanks in part to the particular conformation of the dual-clutch transmission <NUM> in which the drum <NUM> is arranged on the opposite side of the internal combustion engine, it is possible to achieve a particularly favourable (i.e., compact while being very functional) positioning of all the powertrain elements in order to minimise the length of the wheelbase (i.e., the distance between the front and rear axles).

In the car <NUM> described above, thanks in part to the particular conformation of the compressor unit <NUM> in which the twin compressors <NUM> are arranged coaxially on opposite sides of the electric motor <NUM>, it is possible to obtain a particularly favourable arrangement of all the elements of the powertrain system (i.e., compact while being very functional); at the same time, the presence of twin compressors <NUM> allows particularly high air flow rates to be compressed.

In the car <NUM> described above, also thanks to the particular conformation of the turbine unit <NUM> in which the two twin turbines <NUM> are arranged side by side to operate a common electric generator <NUM>, it is possible to obtain a particularly favourable arrangement of all the elements of the powertrain system (i.e., compact while being very functional); at the same time the presence of two twin turbines <NUM> allows a high amount of energy to be recovered from the exhaust gas.

In the car <NUM> described above (in particular in the embodiment illustrated in <FIG>), the geometry of the intake ducts <NUM> and <NUM> is optimal in terms of both overall dimensions and pressure drop without having to resort to an electric actuation of the compressor unit <NUM>; this result is obtained by drawing the motion necessary to bring the two compressors <NUM> of the compressor unit <NUM> into rotation directly from the drum <NUM> of the dual-clutch transmission <NUM>, which is in a very favourable position for the positioning of the compressor unit <NUM>.

In the car <NUM> described above, the particular conformation and positioning of the two intercoolers <NUM> and <NUM> allow to maximise the cooling effectiveness and efficiency of the compressed air without requiring overly severe constraints on the placement of all the other components of the internal combustion engine <NUM>.

In the car <NUM> as described above, the aerodynamic diffuser <NUM> is very large (thus allowing a high aerodynamic load to be generated with a modest increase in drag) even if the internal combustion engine <NUM> is located in a central/rear position (thus having an optimal distribution of masses between the front and rear axle) and, at the same time, the wheelbase is relatively short (i.e., the car <NUM> exhibits extremely high-performance dynamic behaviour). This result is obtained by placing the internal combustion engine <NUM> with the drive shaft <NUM> arranged higher: thereby, also the transmission <NUM> can be arranged higher, thus freeing up the necessary space in the lower part of the rear of the car to house the aerodynamic diffuser <NUM> having a very large size.

In the car <NUM> described above, accessibility to all areas of the internal combustion engine <NUM> is excellent and complete; this is obtained thanks to the accessibility from below which, once the car <NUM> has been lifted, always allows a worker to position himself exactly below the component to be worked on. That is, the accessibility to the internal combustion engine <NUM> from below makes maintenance easy and simple, since the workers are not restricted by the shape of the car <NUM>, but can easily move in all the areas of the internal combustion engine <NUM>, as the car <NUM> is lifted.

In the car <NUM> described above, the fact that the removable panel is at least partially transparent constitutes not only an undoubted technical advantage as explained above, but also an aesthetic innovation and makes the removable panel also an aesthetic element; it is important to note that thanks to the large aerodynamic diffuser <NUM>, it is relatively easy to see at least part of the internal combustion engine <NUM> through the transparent part of the removable panel without having to bend down excessively.

In the car <NUM> described above, the body <NUM> is particularly rigid and strong thanks to the complete absence of an opening for access to the engine compartment <NUM> (and normally closed by a bonnet). Thereby, with the same rigidity, the overall mass of the body <NUM> can be reduced. Furthermore, the absence of an opening for access to the engine compartment <NUM> also makes the body <NUM> completely continuous (i.e., without interruptions), thus reducing the aerodynamic penetration coefficient. The possibility of eliminating an opening for access to the engine compartment <NUM> through the body <NUM> is given by the fact that the internal combustion engine <NUM> does not require any maintenance in the upper part (consisting of the crankcase <NUM>) and consequently it is no longer necessary to access the engine compartment <NUM> from above. In fact, all the main components of the internal combustion engine <NUM> are located in the lower part of the engine compartment <NUM> and are easily accessible from the bottom <NUM> through the opening <NUM> closed by the removable panel <NUM>.

Claim 1:
A car (<NUM>) comprising:
two front wheels (<NUM>);
two rear drive wheels (<NUM>);
a passenger compartment (<NUM>) which is arranged between the front wheels (<NUM>) and the rear wheels (<NUM>);
an internal combustion engine (<NUM>), which is provided with a plurality of cylinders (<NUM>), within which respective pistons (<NUM>) slide, and with a drive shaft (<NUM>) connected to the pistons (<NUM>);
a transmission (<NUM>), which is connected between the internal combustion engine (<NUM>) and the rear drive wheels (<NUM>) to transmit the motion of the drive shaft (<NUM>) of the internal combustion engine (<NUM>) to the rear drive wheels (<NUM>); and
a containing body (<NUM>) which contains the transmission (<NUM>) therein, has a tapered shape towards the rear so that the height of the containing body (<NUM>) progressively reduces from the front to the rear, and has a bottom wall (<NUM>) at the bottom, which is inclined relative to the horizontal;
the car (<NUM>) is characterized in that:
a rear aerodynamic diffuser (<NUM>) is provided which is inclined relative to the horizontal and is arranged under the containing body (<NUM>); and
the bottom wall (<NUM>) of the containing body (<NUM>) has the same inclination relative to the horizontal of the aerodynamic diffuser (<NUM>).