Technical Field

The present invention relates to a high performance electric vehicle.

Background Art

As is well known, vehicles provided with an electric motor differ significantly from those powered by an internal combustion engine both structurally and in terms of performance.

Specifically, one of the most notable differences is that the latter suffer significantly greater drops in driving torque than the former as the rotational speed of the drive unit varies.

In other words, internal combustion engines offer the maximum possible driving torque only for a limited range of rotational speeds.

In response to this drawback, vehicles provided with internal combustion engines are provided with a gear shifting system which is adapted to vary the transmission ratio between the drive shaft and the wheel axle shafts.

This well-known device allows the driver to be able to take advantage of the maximum available driving torque values as vehicle speed varies by selecting the correct gear.

In electric motor-driven vehicles, on the other hand, the driving torque delivered is considerably less sensitive to the variations in vehicle speed, so that many vehicles of this type lack gears.

In fact, electric vehicles ensure, unlike internal combustion engines, high engine torque values even at low vehicle speeds or when the vehicle is stationary.

Nevertheless, the efficiency of electric vehicles, measured as the ratio of the mechanical energy delivered to the electrical energy required to run the electric motor, is maximum only for a limited range of driving conditions, where by “driving conditions” is meant a particular combination of vehicle speed and driving torque delivered by the motor itself.

In other words, electric vehicles can operate properly without providing a gear shifting system, but at the cost of variable and, therefore, not always high efficiency values. This drawback is particularly felt in electric vehicles of the sports type, which face very different driving conditions, such as, e.g., those encountered when starting from a standstill or on a straight stretch run at top speed.

It is, in fact, worth bearing in mind that electric vehicles of the sports type represent a luxury good and, as such, have to meet the technical and sensory requirements of a particularly demanding clientele.

In the present case, such needs are expressed towards the possibility, given by a gear shifting system, of being able to enjoy the special acoustic and haptic perception associated with various speeds of rotation of the electric motor, especially at the highest ones.

Not only that, but these requirements are also justified by the desire to have the possibility to change the response of the electric motor the vehicle speed being equal, that is, making it run faster or slower, so that various interesting driving cues can be taken advantage of and the overall efficiency of the system improved.

To overcome at least part of the above drawbacks, the use of vehicles provided with electric motors built in accordance with the teachings of patent document US 2014335999 is known.

In particular, these vehicles allow high performance to be enjoyed thanks to two electric motors connected in parallel, one of which can be coupled and decoupled as needed.

In addition, a drive shaft is connected to the two electric motors, which drive shaft, in turn, is associated with the first and second axle shafts of the vehicle through a plurality of sprockets.

In more detail, US 2014335999 teaches that, in order to vary the gear ratio to obtain the previously listed benefits, one or more of the plurality of sprockets can be conveniently switched with one of a different size and/or number of teeth and therefore suitable for the purpose.

However, US 2014335999 is susceptible to refinements especially aimed at improving the convenience and simplicity of varying the gear ratio.

Indeed, it seems clear that by replacing one or more of the plurality of sprockets is an inconveniently complex operation which can be carried out only by experienced technical personnel and takes too long time to be completed.

In this regard, to correct at least some of these drawbacks, the use of vehicles provided with electric motors in accordance with patent document US 2019376581 is known.

In this case, the document teaches how to use a spur gear stage of the planetary type as a means of transmitting power from the drive shaft to the axle shafts.

Specifically, the spur gear stage of the planetary type comprises a sun gear that allows the driver to choose between two gear ratios based on whether the sun gear itself is left free to rotate or is stopped through the action of a brake.

In this way, the driver can change the response of the engine while driving by operating the brake or not.

Patent document US 2019376581 is, however, also susceptible to further refinements aimed, in particular, at increasing the number of gear ratios and, with it, the overall performance of the drive unit over an even greater range of rotational speeds and driving torques.

Indeed, it seems clear that having only two gear ratios does not allow the driver to fully enjoy a wide variety of driving experiences by arbitrarily deciding which gear to use at a certain time, since the first gear ratio can be used for low rotational speeds only and the second gear ratio for high rotational speeds only. Not only that, but the use of a brake to stop the sun gear within the gear stage can result in significant wear conditions on both elements over time, thus requiring periodic and inconvenient maintenance of the drive unit.

Description of the Invention

The main aim of the present invention is to devise a high performance electric vehicle provided with high efficiency under a plurality of different driving conditions.

An additional object of the present invention is to devise a high performance electric vehicle which enables to meet the technical and sensory requirements of a particularly demanding clientele, particularly in the area of high performance vehicles. Another object of the present invention is to devise a high performance electric vehicle that can overcome the aforementioned drawbacks of the prior art within the framework of a simple, rational, user-friendly and cost-effective solution.

The aforementioned objects are achieved by this high performance electric vehicle having the characteristics of claim 1.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a high performance electric vehicle illustrated by way of an indicative, yet nonlimiting example, in the accompanying tables of drawings in which:

Figure 1 is an axonometric view of the vehicle according to the invention;

Figure 2 is a top view of the traction unit of the vehicle according to the invention;

Figure 3 is a top view of the gearbox of the vehicle according to the invention;

Figures 4 and 5 graphically show the link between vehicle speed and driving torque output as the first synchronized pair and the second synchronized pair defined by the synchronizing means change;

Figure 6 graphically shows the qualitative performance trend for a single-speed electric vehicle;

Figure 7 graphically shows the qualitative performance trend for a multi-speed electric vehicle according to the invention.

Embodiments of the Invention

With particular reference to these figures, reference numeral 1 globally indicates a high performance electric vehicle.

The high performance electric vehicle 1 comprises: at least one basic frame 2; at least one pair of front wheels 3 and at least one pair of rear wheels 4 associated with the basic frame 2 for the movement onto the ground.

According to the present invention, the vehicle 1 comprises at least one traction unit 28 operatively connected to at least one of the pair of front wheels 3 or the pair of rear wheels 4 for setting in rotation, comprising: at least one first electric drive unit 5 comprising: at least one first electric motor 6 for setting at least one first drive shaft 7 in rotation; at least one first inverter 8 associated with the first electric motor 6; at least one second electric drive unit 10 comprising: at least one second electric motor 11 for setting at least one second drive shaft 12 in rotation; at least one second inverter 13 associated with the second electric motor 11; at least one gearbox 15 comprising: one first gearbox shaft 16 associated with the first drive shaft 7 and comprising a plurality of first driving sprockets 17a, 17b, 17c; one second gearbox shaft 18 associated with the second drive shaft 12 and comprising a plurality of second driving sprockets 19a, 19b, 19c; one output shaft 20 comprising a plurality of output sprockets 21a, 21b, 21c, 21d, 21e meshing with the first driving sprockets 17a, 17b, 17c and with the second driving sprockets 19a, 19b, 19c; synchronizing means 22 adapted to simultaneously place one of the first driving sprockets 17a, 17b, 17c and one of the second driving sprockets 19a, 19b, 19c in a synchronization configuration; at least one differential assembly 23 associated with the output shaft 20 and adapted to transfer motion to at least one of the pair of front wheels 3 and the pair of rear wheels 4; at least one electronic processing and control unit 24 operatively connected to the first inverter 8 and to the second inverter 13 and adapted to command the first inverter 8 and the second inverter 13 to make the first drive shaft 7 rotate at a first rotational speed and the second drive shaft 12 rotate at a second rotational speed with a predetermined ratio depending on which of the first driving sprockets 17a, 17a, 17b, 17c and of the second driving sprockets 19a, 19b, 19c are in a synchronization configuration.

According to a preferred embodiment, shown in Figure 2, the first electric drive unit 5 comprises two first electric motors 6 connected to each other in series in a battery fashion.

In more detail, the first inverter 8 is positioned between the two first electric motors 6.

Specifically, the second electric drive unit 10 comprises two second electric motors 11 connected to each other in series in a battery fashion.

Specifically, the second inverter 13 is positioned between the two second electric motors 11.

In this way, i.e., by providing for two first electric motors 6 connected in series and two second electric motors 11 connected in series, it is possible to benefit from considerably more power than using a single first electric motor 6 and a single second electric motor 11.

According to an alternative embodiment not shown in the figures, the first electric drive unit 5 comprises three first electric motors 6 connected to each other in series in a battery fashion, and the second electric drive unit 10 comprises three second electric motors 11 connected to each other in series in a battery fashion.

First electric drive units 5 comprising a higher number of first electric motors 6 and/or second electric drive units 10 comprising a higher number of second electric motors 11 cannot however be ruled out from the scope of this disclosure.

Conveniently, the first electric motors 6 and the second electric motors 11 are connected in parallel.

According to a first preferred embodiment, the first electric drive unit 5 comprises at least one first clutch 9 and the second electric drive unit 10 comprises at least one second clutch 14.

In particular, the first clutch 9 is positioned between the first electric motors 6 and the first drive shaft 7.

Again, the second clutch 14 is positioned between the second electric motors 11 and the second drive shaft 12.

Alternatively, in a different embodiment from the previous one, the first electric drive unit 5 and the second electric drive unit 10 are without the first clutch 9 and the second clutch 14, respectively.

In other words, in this embodiment, the traction unit 28 is of the clutch-less type.

According to the preferred embodiment, the differential assembly 23 is positioned between the first drive shaft 7 and the second drive shaft 12 and, at the same time, between the gearbox 15 and the first and the second electric motors 6, 11.

Conveniently, the differential assembly 23 is operatively connected to at least one of either the pair of front wheels 3 or the pair of rear wheels 4 by means of at least one pair of axles, the number of axles being equal to the number of wheels operatively connected to the differential assembly 23.

According to the preferred embodiment, the differential assembly 23 is operatively connected to only one of either the pair of front wheels 3 or the pair of rear wheels 4.

In other words, according to this embodiment, the other of either the pair of front wheels 3 or the pair of rear wheels 4 is dragged into rotation by the pair of wheels operatively connected to the differential assembly 23 and is therefore operatively disconnected from the traction unit 28.

Different embodiments cannot however be ruled out, such as, e.g., a traction unit 28 operatively connected to the pair of front wheels 3 and, at the same time, to the pair of rear wheels 4 for setting both pairs in rotation.

In other words, in this alternative embodiment, the traction exerted by the traction unit 28 is of the all-wheel drive type.

In addition, the output shaft 20 is positioned between the first gearbox shaft 16 and the second gearbox shaft 18.

Conveniently, each of the output sprockets 21a, 21b, 21c, 21d, 21e meshes with only one of the first driving sprockets 17a, 17b, 17c and/or with only one of the second driving sprockets 19a, 19b, 19c, the output sprockets 21a, 21b, 21c, 2 Id, 21e, the first driving sprockets 17a, 17b, 17c and the second driving sprockets 19a, 19b, 19c having an axis of rotation R substantially parallel to each other. According to the preferred embodiment, the output sprockets 21a, 21b, 21c, 2 Id, 21e are in a number equal to the sum of the first driving sprockets 17a, 17b, 17c and of the second driving sprockets 19a, 19b, 19c minus one.

Specifically, the first gearbox shaft 16 comprises three first driving sprockets 17a, 17b, 17c, that is, a first primary driving sprocket 17a, a first secondary driving sprocket 17b and a first tertiary driving sprocket 17c.

In more detail, the second gearbox shaft 18 comprises three second driving sprockets 19a, 19b, 19c, that is a second primary driving sprocket 19a, a second secondary driving sprocket 19b and a second tertiary driving sprocket 19c.

Accordingly, the output shaft 20 comprises five output sprockets 21a, 21b, 21c, 21d, 21e, that is, a first output sprocket 21a, a second output sprocket 21b, a third output sprocket 21c, a fourth output sprocket 21d and a fifth output sprocket 21e.

In this way, each of the output sprockets 21a, 21b, 21c, 21d, 21e is uniquely associated with only one of the first driving sprockets 17a, 17b, 17c and the second driving sprockets 19a, 19b, 19c except one, which is uniquely associated with one of the first driving sprockets 17a, 17b, 17c and, simultaneously, with one of the second driving sprockets 19a, 19b, 19c.

Conveniently: the first primary driving sprocket 17a, the second primary driving sprocket 19a, the first output sprocket 21a and the second output sprocket 21b collectively define a first gear; the first secondary driving sprocket 17b, the second primary driving sprocket 19a, the second output sprocket 21b and the third output sprocket 21c collectively define a second gear; the first secondary driving sprocket 17b, the second secondary driving sprocket 19b, the third output sprocket 21c and the fourth output sprocket 21d collectively define a third gear; the first tertiary driving sprocket 17c, the second secondary driving sprocket 19b, the fourth output sprocket 2 Id and the fifth output sprocket 21e collectively define a fourth gear; the first tertiary driving sprocket 17c, the second tertiary driving sprocket 19c and the fifth output sprocket 21e collectively define a fifth gear.

Specifically, as the speed of the vehicle 1 changes, it is possible to alternate the five gears so as to enjoy the maximum efficiency offered by the first electric motors 6 and by the second electric motors 11.

In more detail, the first gear allows the vehicle 1 to benefit from maximum efficiency at lower speeds.

As the speed of the vehicle 1 and, consequently, of the output shaft 20 increases, the first gear must be replaced with the second gear to continue to benefit from the maximum available efficiency.

Similarly, if the speed of the vehicle 1 continues to increase, the latter gear must be replaced with the third gear, which in turn must then be replaced with the fourth gear, which must finally be replaced with the fifth gear.

In particular, the latter gear allows the vehicle 1 to benefit from maximum efficiency at top speeds.

In addition, the fifth gear is associated, at the same time, with the maximum speeds of the vehicle 1 , with the maximum rotational speeds of the output shaft and with the maximum values of the first rotational speed and of the second rotational speed.

In other words, the first gear, second gear, third gear, fourth gear and fifth gear operate quite similarly to what happens in conventional gear shifting systems found in vehicles provided with internal combustion engines.

In the same way, in fact, it is possible to adjust the first rotational speed and the second rotational speed to keep them within predefined values as the speed of the vehicle 1 and therefore of the rotational speed of the output shaft 20 changes.

In addition, as shown in Figure 5, by comparing the right-hand graph with the left-hand graph respectively, it becomes clear that providing for a plurality of gears allows taking advantage from high efficiency values for a plurality of combinations of speeds of the vehicle 1 and of driving torque delivered to the pair of front wheels 3 and/or to the pair of rear wheels 4 with respect to the case of a single gear.

The fact is particularly emphasized that the fifth output sprocket 21e simultaneously meshes with the first tertiary driving sprocket 17c and with the second tertiary driving sprocket 19c.

This implies that, in fifth gear, the first gearbox shaft 16 and the second gearbox shaft 18, and consequently the first drive shaft 7 and the second drive shaft 12, rotate at the same rotational speed.

To make this happen, therefore, the first electric motors 6 and the second electric motors 11 must have at least partly coincident technical characteristics. This advantageously allows the same type of electric motor to be used as both the first electric motor 6 and the second electric motor 11.

In fact, in this way, any maintenance and/or replacement job is greatly simplified and expedited, since the number of different components contained in the vehicle 1 has been reduced.

Preferably, the synchronizing means 22 define: a first synchronized pair 25 of sprockets, comprising one of the output sprockets 21a, 21b, 21c, 21 d, 21e and one of the first driving sprockets 17a, 17b, 17c in a synchronization configuration; and at the same time a second synchronized pair 26 of sprockets, comprising one of the output sprockets 21a, 21b, 21c, 21d, 21e and one of the second driving sprockets 19a, 19b, 19c in a synchronization configuration.

In detail, the synchronizing means 22 are, e.g., of the type of an automotive synchronizer, the type of front mounted gears, or of other types still known to the expert in the field.

Specifically, the first synchronized pair 25 comprises the sprockets selected from the list comprising: the first primary driving sprocket 17a and the first output sprocket 21a, the first secondary driving sprocket 17b and the third output sprocket 21c, the first tertiary driving sprocket 17c and the fifth output sprocket 21e.

Again, the second synchronized pair 26 comprises the sprockets selected from the list comprising: the second primary driving sprocket 19a and the second output sprocket 21b, the second secondary driving sprocket 19b and the fourth output sprocket 2 Id, the second tertiary driving sprocket 19c and the fifth output sprocket 21e.

In more detail, to synchronize one of the five gears, all the sprockets defining that particular gear must be in a synchronization configuration.

Consequently, each of the aforementioned five gears corresponds to a particular combination of a first synchronized pair 25 and of a second synchronized pair 26.

In other words, depending on which particular combination of first synchronized pair 25 and second synchronized pair 26 is selected, it is possible to vary between the first gear, second gear, third gear, fourth gear and fifth gear. The possibility of providing a first synchronized pair 25 cannot however be ruled out comprising an additional first driving sprocket 17a, 17b, 17c and an additional output sprocket 21a, 21b, 21c, 21d, 21e, not shown in the figures, rotatable in an idle mode.

This means that such first synchronized pair 25 does not exert any kind of traction on the pair of front wheels 3 and on the pair of rear wheels 4.

In other words, the possibility cannot be ruled out of providing, in combination with the five gears described or in place of one of them, an additional gear of idle type that can be used by the electronic processing and control unit 24 if this is deemed convenient in terms of efficiency and overall performance.

Conveniently, the first synchronized pair 25 and the second synchronized pair 26 are arranged in such a way as to have their respective output sprockets 21a, 21b, 21c, 21d, 21e in immediate succession along the output shaft 20.

Specifically, the output sprockets 21a, 21b, 21c, 21d, 21e of the first synchronized pair 25 and of the second synchronized pair 26 are arranged along the output shaft 20 so that there is no output sprocket 21a, 21b, 21c, 21d, 21e positioned between them.

In addition: the ratio of the diameter of the first output sprocket 21a to the diameter of the first primary driving sprocket 17a is substantially smaller than the ratio of the diameter of the third output sprocket 21c to the diameter of the first secondary driving sprocket 17b; the ratio of the diameter of the third output sprocket 21c to the diameter of the first secondary driving sprocket 17b is substantially smaller than the 5 ratio of the diameter of the fifth output sprocket 21e to the diameter of the first tertiary driving sprocket 17c.

Again: the ratio of the diameter of the second output sprocket 21b to the diameter of the second primary driving sprocket 19a is substantially smaller than the0 ratio of the diameter of the fourth output sprocket 21d to the diameter of the second secondary driving sprocket 19b; the ratio of the diameter of the fourth output sprocket 21d to the diameter of the second secondary driving sprocket 19b is substantially smaller than the ratio of the diameter of the fifth output sprocket 21e to the diameter of the5 second tertiary driving sprocket 19c.

In more detail: the diameter of the first output sprocket 21a is substantially smaller than the diameter of the second output sprocket 21b; the diameter of the second output sprocket 21b is substantially smaller than0 the diameter of the third output sprocket 21c; the diameter of the third output sprocket 21c is substantially smaller than the diameter of the fourth output sprocket 2 Id; the diameter of the fourth output sprocket 21d is substantially smaller than the diameter of the fifth output sprocket 21e. fii addition: the diameter of the first primary driving sprocket 17a is substantially larger than the diameter of the first secondary driving sprocket 17b; the diameter of the first secondary driving sprocket 17b is substantially larger than the diameter of the first tertiary driving sprocket 17c. 8imilarly: the diameter of the second primary driving sprocket 19a is substantially larger than the diameter of the second secondary driving sprocket 19b; the diameter of the second secondary driving sprocket 19b is substantially larger than the diameter of the second tertiary driving sprocket 19c.

According to the preferred embodiment, the output sprockets 21a, 21b, 21c, 2 Id, 21 e are arranged along the output shaft 20 in such a way that the diameters of the latter are progressively increasing along a direction of gear increment D parallel to the geometric axis of the first output shaft 20 and oriented in the direction of movement away from the first electric motors 6 and from the second electric motors 11.

More in detail, the first driving sprockets 17a, 17b, 17c are arranged along the first gearbox shaft 16 in such a way that the diameters of the latter are progressively decreasing along the direction of gear increment D.

Again, the second driving sprockets 19a, 19b, 19c are arranged along the second gearbox shaft 18 in such a way that the diameters of the latter are progressively decreasing along the direction of gear increment D.

However, different placements and/or sizes of the first driving sprockets 17a, 17b, 17c, of the second driving sprockets 19a, 19b, 19c and of the output sprockets 21a, 21b, 21c, 21d, 21e cannot be ruled out.

In particular, it cannot be ruled out first synchronized pairs 25 and second synchronized pairs 26 arranged in such a way as to have their respective output sprockets 21a, 21b, 21c, 21d, 21e separated from each other by one or more additional output sprockets 21a, 21b, 21c, 21 d, 21e.

Similarly, it cannot be ruled out order relations of the sizes of the first driving sprockets 17a, 17b, 17c and/or of the second driving sprockets 19a, 19b, 19c and/or of the output sprockets 21a, 21b, 21c, 21 d, 21e different from those listed, such as, e.g., a first primary driving sprocket 17a having a diameter coincident with that of the first secondary driving sprocket 17b and larger than that of the first tertiary driving sprocket 17c and, at the same time, a first output sprocket 21a having a diameter smaller than that of the third output sprocket 21c, the latter being in turn smaller than or equal to the diameter of the fifth output sprocket 21e. In other words, the possibility cannot be ruled out that the sizes of the sprockets be different from those listed, while keeping valid the order relations between the ratios of the diameters of the first driving sprockets 17a, 17b, 17c with those of the respective output sprockets 21a, 21b, 21c, 21d, 21e and, at the same time, of the diameters of the second driving sprockets 19a, 19b, 19c with those of the respective output sprockets 21a, 21b, 21c, 21d, 21e.

Thus, it is emphasized that at least one of the first gear, second gear, third gear, fourth gear and fifth gear is synchronized when one of the first driving sprockets 17a, 17b, 17c and, at the same time, one of the second driving sprockets 19a, 19b, 19c are in a synchronization configuration.

In particular: the first synchronized pair 25 comprising the first primary driving sprocket 17a and the first output sprocket 21a and the second synchronized pair 26 comprising the second primary driving sprocket 19a and the second output sprocket 21b define the first synchronized gear; the first synchronized pair 25 comprising the first secondary driving sprocket 17b and the third output sprocket 21c and the second synchronized pair 26 comprising the second primary driving sprocket 19a and the second output sprocket 21b define the second synchronized gear; the first synchronized pair 25 comprising the first secondary driving sprocket 17b and the third output sprocket 21c and the second synchronized pair 26 comprising the second secondary driving sprocket 19b and the fourth output sprocket 21d define the third synchronized gear; the first synchronized pair 25 comprising the first tertiary driving sprocket 17c and the fifth output sprocket 21e and the second synchronized pair 26 comprising the second secondary driving sprocket 19b and the fourth output sprocket 21 d define the fourth synchronized gear; the first synchronized pair 25 comprising the first tertiary driving sprocket 17c and the fifth output sprocket 21e and the second synchronized pair 26 comprising the second tertiary driving sprocket 19c and the fifth output sprocket 21 e define the fifth synchronized gear. Usefully, the synchronizing means 22 comprise at least one synchronization device 27 which is adapted to: modify the first synchronized pair 25 by selecting one of the first driving sprockets 17a, 17b, 17c to be placed in a synchronization configuration, to define a first gearshift configuration during which the second synchronized pair 26 remains unmodified; and modify the second synchronized pair 26 by selecting one of the second driving sprockets 19a, 19b, 19c to be placed in a synchronization configuration, to define a second gearshift configuration during which the first synchronized pair 25 remains unmodified.

Specifically, in the first gearshift configuration, the first synchronized pair 25 is changed by placing, in a synchronization configuration, the immediately following or immediately preceding first driving sprocket 17a, 17b, 17c along the direction of gear increment D.

Similarly, in the second gearshift configuration, the second synchronized pair 26 is changed by placing, in a synchronization configuration, the immediately following or immediately preceding second driving sprocket 19a, 19b, 19c along the direction of gear increment D.

Specifically, in both cases the first driving sprocket 17a, 17b, 17c or the second driving sprocket 19a, 19b, 19c immediately following along the direction of gear increment D to the preceding one is placed in the synchronization configuration if a higher gear is synchronized, where “higher gear” means a gear described by a higher ordinal number, intended to be selected as the speed of the vehicle 1 increases and which simultaneously allows, for the same speed of the vehicle 1, to decrease the rotational speed of at least one of the first gearbox shaft 16 or the second gearbox shaft 18.

Quite similarly, in both cases the first driving sprocket 17a, 17b, 17c or the second driving sprocket 19a, 19b, 19c immediately preceding along the direction of gear increment D to the preceding one is placed in the synchronization configuration if a lower gear is synchronized, where “lower gear” means a gear described by a smaller ordinal number, intended to be selected as the speed of the vehicle 1 decreases and which simultaneously allows, for the same speed of the vehicle 1, to increase the rotational speed of at least one of the first gearbox shaft 16 or the second gearbox shaft 18.

Thus, in this way, at least one of either the first synchronized pair 25 or the second synchronized pair 26 remains synchronized in both the first and second gearshift configurations.

By doing so, as can be observed graphically in Figure 4, the vehicle 1 can take advantage from high performance in both the first and second gearshift configurations by reducing torque losses due to the temporary desynchronization of a pair of sprockets.

In more detail, Figure 4 shows the curve that graphically describes the relationship between the speed of the vehicle 1 and the driving torque available to pair of front wheels 3 and to the pair of rear wheels 4 as the synchronized gears change.

In this regard, Figure 4 shows, similarly to Figure 5, two curves that graphically describe the same relationship, but for a vehicle provided with gears comprising only one synchronized torque and not two.

In other words, each of the two curves shown in Figure 4 and hatched in Figure 5 describes, in one case, what would happen for a vehicle 1 lacking the first electric drive unit 5 and the first gearbox shaft 16 and, in the other case, what would happen for a vehicle 1 lacking the second electric drive unit 10 and the second gearbox shaft 18.

This means that each of the two curves describes a situation in which no sprocket is synchronized in the first or second gearshift configuration.

In this regard, in fact, it is noted that the aforementioned two curves suffer considerably more from torque drops at the first and second gearshift configurations than the curve shown in Figure 5 and derived from the algebraic sum of the two previous curves.

This is motivated by the fact, therefore, that in a vehicle according to the teachings of the present invention at least one of the first driving sprockets 17a, 17b, 17c and of the second driving sprockets 19a, 19b, 19c is always in the synchronization configuration.

Advantageously, the electronic processing and control unit 24 is connected to the first clutch 9 and to the second clutch 14 and is adapted to: decouple the first electric motor 6 from the first drive shaft 7 in the first gearshift configuration; and decouple the second electric motor 11 from the second drive shaft 12 in the second gearshift configuration.

In other words, the electronic processing and control unit 24 decouples from the respective drive shaft the electric motor connected to the drive shaft on which none of the sprockets is in the synchronization configuration.

Specifically, the electronic processing and control unit 24 is of the type of an electronic control unit of the automotive type.

In accordance with a first embodiment, the synchronizing means 22 are controllable by means of a plurality of manual commands of a driver.

Specifically, the manual commands are carried out by the driver who operates on a manual shifting device.

In more detail, the manual shifting device is of the type of a sequential gearbox, of a sequential gearbox with up/down input or of a traditional five-position lever-type manual gearbox, each of the five positions corresponding to one in particular of the five gears.

In other words, the driver of a vehicle according to the teachings of the present invention chooses which of the five gears to synchronize by operating accordingly on the manual shifting device, which in turn controls the synchronizing means 22.

Alternatively, the synchronizing means 22 are controllable by means of the electronic processing and control unit 24.

In other words, according to this alternative embodiment, the synchronizing means 22 are controlled through an automatic transmission gear that synchronizes one of the five gears according to the speed of the vehicle 1 and, consequently, of the output shaft 20.

By doing so, it is possible to select, for each value of speed of the output shaft 20 and for each value of driving torque required from the first electric motor 6 and from the second electric motor 11, the combination of first synchronized pair 25 and of second synchronized pair 26, which allows maximizing the efficiency of the aforementioned electric motors, benefiting the range of the electric vehicle.

It has in practice been ascertained that the described invention achieves the intended objects.

It is emphasized, in particular, that the special expedient of providing for a plurality of gears makes it possible to enjoy high performance in a plurality of different driving conditions.

The fact is also emphasized that the special expedient of providing a plurality of gears makes it possible to meet the technical and sensory requirements of a particularly demanding clientele, particularly in the area of high performance vehicles.

Finally, the fact is emphasized that the special expedient of providing for a synchronization device makes it possible to benefit from high values of driving torque both to the pair of front wheels and to the pair of rear wheels, avoiding abrupt and undesirable drops in the driving torque itself at the same time as the gearshift configuration.