VEHICLE

The present invention relates to a method and system for im- parting motive power to a drive axle of a vehicle.

The term vehicle is intended to designate any means of transport, including at least one drive axle, which applies rotating mechanical power to the means for movement of the vehicle interacting with respect to the ground, to the air, re- spectively to water, with respect to which said vehicle is op- eratively movable, and to a propulsion and power transmission unit of the vehicle including at least a first powertrain and a second powertrain, and at least a first differential kine- matically connected with respect to said drive axle. Said ve- hicle also includes means for supplying and storing electrical energy and electrical / electronic control means for controlling the movement of the vehicle.

The aforesaid propulsion unit can include endothermic motors, electric motors or combinations of these motors.

The document US2010/191435A1 discloses a system for imparting motive power to a drive axle of a vehicle, comprising:

a) a vehicle structure including means for supplying and storing electrical energy, electrical / electronic control means for controlling the movement of the vehicle and at least a drive axle, which applies rotating mechanical power to the means for movement of the vehicle interacting with respect to the ground, to the air, respectively to water, with respect to which said vehicle is operatively movable;

b) a propulsion and power transmission unit of the vehi- cle including at least a first powertrain and a second power- train and at least a first differential kinematically connect ^¬ ed with respect to said drive axle;

c) electronic means for detecting the rotation of the output shaft of said at least a first and a second powertrain, respectively, and electrically connected with respect to said means for supplying and storing electrical energy;

d) at least a second differential kinematically connected with respect to said drive axle, respectively at least an epi- cycloidal reduction gearbox kinematically interconnected, on one side, between said at least a first and a second power- train and, on the other side, with respect to said first differential .

The technical problem underlying the present invention is to provide a method and related system for imparting motive power to a drive axle of a vehicle, which allows optimization, in a vehicle comprising a propulsion unit including at least two motors, of the performance and efficiency of the driving torque transmitted by these motors, making their functional cooperation synergic.

Moreover, the invention intends to provide a method and related system for imparting motive power to a drive axle of a vehicle, which allow the arrangement of the drivetrains to be rationalized with respect to the drive axle and to the available space, reducing the footprint, improving the availability of space in the vehicle.

For this purpose, the present invention provides a method for imparting motive power to a drive axle of a vehicle, the es ^¬ sential characteristic of which forms the subject matter of claim 1.

Moreover, the present invention provides a system for implementing the aforesaid method, the essential characteristic of which forms the subject matter of claim 7. Further advantageous characteristics form the subject matter of the dependent claims.

The aforesaid claims are intended as fully incorporated herein.

The method according to the present invention for imparting motive power to a drive axle of a vehicle essentially compris ^¬ es the steps of:

a) providing a vehicle structure including means for supplying and storing electrical energy, electrical / electronic control means for controlling the movement of the vehicle and at least a drive axle, which applies rotating mechanical power to the means for movement of the vehicle interacting with respect to the ground, to the air, respectively to water, with respect to which said vehicle is operatively movable;

b) providing a propulsion and power transmission unit of the vehicle including at least a first powertrain and a second powertrain and at least a first differential kinematically connected with respect to said drive axle;

c) providing electronic means for detecting the rotation of the output shaft of said at least a first and a second powertrain, respectively, and electrically connected with respect to said means for supplying and storing electrical energy;

d) providing at least a second differential kinematically connected with respect to said drive axle, respectively at least a reduction gear kinematically interconnected, on one side, between said at least a first and a second powertrain and, on the other side, with respect to said first differential;

e) providing electronic processing and calculation means operatively connected with respect to said electronic detection means and to said control means, and electrically con- nected with respect to said means for supplying and storing electrical energy;

g) programming said electronic processing and calculation means to determine, under the control of said control means of the vehicle structure and in predetermined primitive conditions of operating efficiency of one or more of said at least a first and a second powertrain, the start-up of at least one of said at least a first and a second powertrain and, when said primitive conditions of operating efficiency vary, selec- tively determine the start-up of at least another of said at least a first and a second powertrain;

h) transmitting, in said primitive conditions of operating efficiency, the rotation of the output shaft of said at least one of said at least a first and a second powertrain to said first differential gearbox;

i) selectively transmitting, when said primitive conditions of operating efficiency vary, also the rotation of the output shaft of said at least another of said at least a first and a second powertrain indirectly to said first differential gearbox, respectively directly to said at least a second differential gearbox.

On the other hand, the system for implementing the method according to the invention for imparting motive power to a drive axle of a vehicle essentially comprises:

a) a vehicle structure including means for supplying and storing electrical energy, electrical / electronic control means for controlling the movement of the vehicle and at least a drive axle, which applies rotating mechanical power to the means for movement of the vehicle interacting with respect to the ground, to the air, respectively to water, with respect to which said vehicle is operatively movable;

b) a propulsion and power transmission unit of the vehicle including at least a first powertrain and a second power- train and at least a first differential kinematically connect ^¬ ed with respect to said drive axle;

c) electronic means for detecting the rotation of the output shaft of said at least a first and a second powertrain, respectively, and electrically connected with respect to said means for supplying and storing electrical energy;

d) at least a second differential kinematically connected with respect to said drive axle, respectively at least a reduction gearbox kinematically interconnected, on one side, be- tween said at least a first and a second powertrain and, on the other side, with respect to said first differential;

e) electronic processing and calculation means operative- ly connected with respect to said electronic detection means and to said control means, electrically connected with respect to said means for supplying and storing electrical energy and which are programmed to determine, under the control of said control means of the vehicle structure and in predetermined primitive conditions of operating efficiency of one or more of said at least a first and a second powertrain, the start-up of at least one of said at least a first and a second powertrain and, when said primitive conditions of operating efficiency vary, selectively determine the start-up of at least another of said at least a first and a second powertrain;

h) so as to transmit, in said primitive conditions of op- erating efficiency, the rotation of the output shaft of said at least one of said at least a first and a second powertrain to said first differential gearbox, and

i) so as to selectively transmit, when said primitive conditions of operating efficiency vary, also the rotation of the output shaft of said at least another of said at least a first and a second powertrain indirectly to said first differential gearbox, respectively directly to said at least a second differential gearbox. The present invention will be more apparent from the detailed description below with reference to the accompanying drawings, provided purely by way of non-limiting example, wherein:

- Fig. 1 is a simplified block diagram, which illustrates a first example of embodiment of the system for imparting motive power to a drive axle of a vehicle, for implementing a first example of implementation of the method according to the present invention;

- Fig. 2 is a simplified block diagram, which illustrates a second example of embodiment of the system for imparting motive power to a drive axle of a vehicle, for implementing a second example of implementation of the method according to the present invention;

- Fig. 3 is a simplified block diagram, which illustrates a third example of embodiment of the system for imparting motive power to a drive axle of a vehicle, for implementing a third example of implementation of the method according to the present invention;

- Fig. 4 is a partial, schematic and simplified perspective view, with parts omitted, illustrating a drive axle of a vehicle with propulsion unit with two motors kinematically connected to said axle, according to said first example of embodiment of the system according to the invention;

- Fig. 5 is a partial, schematic and simplified perspective view, with parts omitted, illustrating a drive axle of a vehicle with propulsion unit with three motors kinematically connected to said axis, according to said second example of embodiment of the system according to the invention.

With reference to the drawings, the following references are used therein for parts of the system for imparting motive pow ^¬ er to a drive axle of a vehicle, according to the present invention, to indicate the following:

- V, V, V" a land, air or sea vehicle structure; - A, A', A" a drive axle;

- R, R', R" means for movement of the vehicle, such as wheels, propellers or the like, to which said drive axle applies rotating mechanical power and interacting with respect to the ground, to the air, respectively to water, with respect to which said vehicle is operatively movable;

- B, B', B" means for supplying and storing electrical energy of said vehicle;

- C, C, C" electrical / electronic control means, such as ac- celeration and braking controls, for controlling movement of the vehicle;

- Ml, M2 ' , M2" at least a first powertrain of a propulsion and power transmission unit of the vehicle;

- M2, Ml', M3 ' , Ml", M3" at least a second powertrain of a propulsion and power transmission unit of the vehicle;

- D, D2 ' , D2 at least a first differential gearbox kinematically connected with respect to said drive axle of the vehi ^¬ cle;

- Dl ' , D3 ' , Dl", D3" at least a second differential gearbox kinematically connected with respect to said drive axle of the vehicle;

- RV at least an epicycloidal reduction gearbox kinematically interconnected, on one side, between said at least a first and a second powertrain and, on the other side, with respect to said at least a first differential. In particular, with refer ^¬ ence for example to Fig. 4, said epicycloidal reduction gear ^¬ box RV comprises toothed wheel fixed and coaxial with respect to the output shaft of a first powertrain and meshing with respect to a crown wheel with outer teeth of an epicycloidal gear, suitably supported and also comprising a carrier with three toothed planet gears meshed with respect to an inner teeth of said crown wheel, and a central pinion fixed and coaxial with respect to the output shaft of a second powertrain and meshing with respect to said three toothed planet gears. An output shaft of said epicycloidal reduction gearbox is provided coaxial and integral with respect to said carrier and carries a pinion meshed with respect to a corresponding toothed crown wheel of a differential gearbox kinematically connected to said drive axle;

- E, E', E" electronic means for detecting the rotation of the output shaft of said at least a first and a second powertrain, respectively, and electrically connected with respect to said means for supplying and storing electrical energy;

- PC, PC, PC" electronic processing and calculation means op- eratively connected with respect to said electronic detection means and to said control means and electrically connected with respect to said means for supplying and storing electri- cal energy.

With reference to Figs. 1 and 4, according to a first example of embodiment, said system according to the invention for imparting motive power to a drive axle of a vehicle comprises: a) a vehicle structure (V) including means for supplying and storing electrical energy (B) , electrical / electronic control means (C) for controlling the movement of the vehicle and at least a drive axle (A) , which applies rotating mechani ^¬ cal power to the means for movement (R) of the vehicle interacting with respect to the ground, to the air, respectively to water, with respect to which said vehicle is operatively movable;

b) a propulsion and power transmission unit of the vehicle including at least a first powertrain (Ml) and a second powertrain (M2) and at least a first differential (D) kinemat- ically connected with respect to said drive axle (A) ;

c) electronic means (E) for detecting the rotation of the output shaft of said at least a first and a second powertrain, respectively, and electrically connected with respect to said means for supplying and storing electrical energy (B) ;

d) at least a epicycloidal reduction gearbox (RV) , which as known is a differential gear, also called differential, kinematically interconnected, on one side, between said at least a first and a second powertrain (Ml, M2 ) and, on the other side, with respect to said first differential (D);

e) electronic processing and calculation means (PC) oper- atively connected with respect to said electronic detection means (E) and to said control means (C) , electrically connected with respect to said means for supplying and storing electrical energy (B) and which are programmed to determine, under the control of said control means (C) of the vehicle structure (V) and in predetermined primitive conditions of operating ef- ficiency of one or more of said at least a first and a second powertrain (Ml, M2 ) , the start-up of at least one (Ml) of said at least a first and a second powertrain and, when said primitive conditions of operating efficiency vary, selectively de ^¬ termine the start-up of at least another (M2) of said at least a first and a second powertrain (Ml, M2 ) ;

h) so as to transmit, in said primitive conditions of operating efficiency, the rotation of the output shaft of said at least one (Ml) of said at least a first and a second power- train (Ml, M2 ) directly to said at least an epicycloidal re- duction gearbox (RV) , in turn connected with respect to said first differential (D), and

i) so as to selectively transmit, when said primitive conditions of operating efficiency vary, also the rotation of the output shaft of said at least another of said at least a first and a second powertrain (M2) directly to said at least an epicycloidal reduction gearbox (RV), in turn connected with respect to said first differential (D) . It can be noted that, owing to the presence of the epicy- cloidal reduction gearbox (RV) , both the drivetrains (Ml, M2 ) are connected indirectly to the differential gearbox (D) through said epicycloidal reduction gearbox (RV) , to which both said drivetrains are connected directly.

With reference to Figs. 2 and 5, according to a second example of embodiment, said system according to the invention for imparting motive power to a drive axle of a vehicle comprises: a) a vehicle structure (V) including means for supplying and storing electrical energy (Β'), electrical / electronic control means (C) for controlling the movement of the vehicle and at least a drive axle (A') _/ which applies rotating mechanical power to the means for movement (R') of the vehicle interacting with respect to the ground, to the air, respectively to water, with respect to which said vehicle is operatively movable;

b) a propulsion and power transmission unit of the vehi ^¬ cle including at least a first powertrain (M2 ' ) and a second powertrain (Ml', M3 ' ) and at least a first differential gear- box (D2 ¹ ) kinematical ly connected with respect to said drive axle (A*);

c) electronic means (Ε') for detecting the rotation of the output shaft of said at least a first and a second power- train, respectively, and electrically connected with respect to said means for supplying and storing electrical energy ( B ' ) ;

d) at least a second differential gearbox (Dl', D3 ' ) kin- ematically connected with respect to said drive axle (A' ) and to said first differential gearbox (D2 ¹ );

e) electronic processing and calculation means (PC') operatively connected with respect to said electronic detection means (Ε') and to said control means (C), electrically connected with respect to said means for supplying and storing electrical energy (Β') and which are programmed to determine, under the control of said control means (C) of the vehicle structure (V) and in predetermined primitive conditions of operating efficiency of one or more of said at least a first and a second powertrain (Ml', M2 ' , M3 ' ) , the start-up of at least one (M2 ' ) of said at least a first and a second power- train and, when said primitive conditions of operating efficiency vary, selectively determine the start-up of at least another (Ml', M3 ' ) of said at least a first and a second powertrain (Ml ¹ , M2 ' , M3');

h) so as to transmit, in said primitive conditions of operating efficiency, the rotation of the output shaft of said at least one (Μ2') of said at least a first and a second powertrain (Ml', M2 ' , M3 ' ) directly to said first differential gearbox ( D2 ¹ ) and indirectly to said at least a second differential gearbox (Dl', D3 ' ) , and

i) so as to selectively transmit, when said primitive conditions of operating efficiency vary, also the rotation of the output shaft of said at least another of said at least a first and a second powertrain (Ml ¹ , M3 ' ) directly to said at least a second differential gearbox (Dl', D3 ' ) .

With reference to Fig. 3, according to a third example of embodiment, said system according to the invention for imparting motive power to a drive axle of a vehicle comprises:

a) a vehicle structure (V") including means for supplying and storing electrical energy (B") electrical / electronic control means (C") for controlling the movement of the vehicle and at least a drive axle (A"), which applies rotating mechanical power to the means for movement (R") of the vehicle in- teracting with respect to the ground, to the air, respectively to water, with respect to which said vehicle is operatively movable; b) a propulsion and power transmission unit of the vehicle including at least a first powertrain (M2") and at least a second powertrain (Ml", M3") and at least a first differential gearbox (D2") kinematically connected with respect to said drive axle (A"), wherein said at least a second powertrain (M2") includes at least a pair of sub-powertrains (M2a", M2b") kinematically connected to one another through an epicycloidal reduction gearbox (RV") kinematically interconnected, on one side, between said at least a pair of sub-powertrains (M2a", M2b") and, on the other side, with respect to said first differential gearbox (D2");

c) electronic means (E") for detecting the rotation of the output shaft of said at least a first and a second power- train, respectively, and electrically connected with respect to said means for supplying and storing electrical energy ( B ' ) ;

d) at least a second differential gearbox (Dl", D3") kinematically connected with respect to said drive axle (A") and to said first differential gearbox (D2");

e) electronic processing and calculation means (PC") op- eratively connected with respect to said electronic detection means (E") and to said control means (C"), electrically connected with respect to said means for supplying and storing electrical energy (B") and which are programmed to determine, under the control of said control means (C") of the vehicle structure (V") and in predetermined primitive conditions of operating efficiency of one or more of said at least a first and a second powertrain (Ml", M2", M3"), the start-up of at least one (M2") of said at least a first and a second power- train and, when said primitive conditions of operating effi ^¬ ciency vary, selectively determine the start-up of at least another (Ml", M3") of said at least a first and a second powertrain (Ml", M2", M3"); h) so as to transmit, in said primitive conditions of op ^¬ erating efficiency, the rotation of the output shaft of said at least one (M2") of said at least a first and a second powertrain (Ml", M2", M3" ) directly to said first differential gearbox (D2") and indirectly to said at least a second differential gearbox (Dl", D3"), and

i) so as to selectively transmit, when said primitive conditions of operating efficiency vary, also the rotation of the output shaft of said at least another of said at least a first and a second powertrain (Ml", M3") directly to said at least a second differential gearbox (Dl", D3") .

Moreover, according to the invention, the aforesaid system comprises at least an alternator electrically connected with respect to said means for supplying and storing electrical en- ergy (B, B' , B") consisting of at least one of said at least a first powertrain (Ml, M2 ' , M2") and a second powertrain (M2, Ml', M3 ' , Ml", M3"), which electrically charges said means for supplying and storing electrical energy.

With reference to the aforesaid first example of embodiment of the system according to the invention (Figs. 1 and 4), it can be noted that the system implements the following first example of implementation of the method forming the subject matter of the invention, comprising the steps of:

a) providing a vehicle structure (V) including means for supplying and storing electrical energy (B) , electrical/electronic control means (C) for controlling the movement of the vehicle and at least a drive axle (A) , which applies rotating mechanical power to means for movement (R) of the vehicle interacting with respect to the ground, to the air, re- spectively, to water, with respect to which said vehicle is operatively movable;

b) providing a propulsion and power transmission unit of the vehicle including at least a first powertrain (Ml) and a second powertrain (M2) and at least a first differential gearbox (D) kinematically connected with respect to said drive axle (A) ;

c) providing electronic means (E) for detecting the rota- tion of the output shaft of said at least a first and a second powertrain, respectively, and electrically connected with respect to said means for supplying and storing electrical energy (B);

d) providing at least an epicycloidal reduction gearbox (RV) kinematically interconnected, on one side, between said at least a first and a second powertrain (Ml, M2 ) and, on the other side, with respect to said first differential gearbox (D) ;

e) providing electronic processing and calculation means (PC) operatively connected with respect to said electronic detection means (E) and to said control means (C) , and electrically connected with respect to said means for supplying and storing electrical energy (B) ;

g) programming said electronic processing and calculation means (PC) to determine, under the control of said control means (C) of the vehicle structure (V) and in predetermined primitive conditions of operating efficiency of one or more of said at least a first and a second powertrain (Ml, M2 ) , the start-up of at least one (Ml) of said at least a first and a second powertrain and, when said primitive conditions of operating efficiency vary, selectively determine the start-up of at least another (M2) of said at least a first and a second powertrain (Ml, M2 ) ;

h) transmitting, in said primitive conditions of operat- ing efficiency, the rotation of the output shaft of said at least one (Ml) of said at least a first and a second power- train (Ml, M2 ) to said first differential gearbox (D) through said at least an epicycloidal reduction gearbox (RV) ; i) selectively transmitting, when said primitive condi ^¬ tions of operating efficiency vary, also the rotation of the output shaft of said at least another of said at least a first and a second powertrain (M2) directly to said at least an epi- cycloidal reduction gearbox (RV) , in turn connected with re ^¬ spect to said first differential (D) .

Moreover, with reference to the aforesaid second example of embodiment of the system according to the invention (Figs. 2 and 5), it can be noted that the system itself implements the following second example of implementation of the method form ^¬ ing the subject matter of the invention, comprising the steps of:

a) providing a vehicle structure (V) including means for supplying and storing electrical energy (Β'), electri- cal/electronic control means (C) for controlling the movement of the vehicle and at least a drive axle (A' ) , which applies rotating mechanical power to means for movement (R ¹ ) of the vehicle interacting with respect to the ground, to the air, respectively to water, with respect to which said vehicle is operatively movable;

b) providing a propulsion and power transmission unit of the vehicle including at least a first powertrain (Μ2') and a second powertrain (Ml', M3 ' ) and at least a first differential gearbox ( D2 ' ) kinematically connected with respect to said drive axle ( A ¹ ) ;

c) providing electronic means (Ε') for detecting the rotation of the output shaft of said at least a first and a second powertrain, respectively, and electrically connected with respect to said means for supplying and storing electrical en- ergy (Β' ) ;

d) providing at least a second differential gearbox (Dl ¹ , D3 ' ) kinematically connected with respect to said drive axle (A' ) and to said first differential gearbox (D2 ¹ ); e) providing electronic processing and calculation means (PC) operatively connected with respect to said electronic detection means (Ε') and to said control means (C), and elec ^¬ trically connected with respect to said means for supplying and storing electrical energy (B');

g) programming said electronic processing and calculation means (PC) to determine, under the control of said control means (C ) of the vehicle structure (V) and in predetermined primitive conditions of operating efficiency of one or more of said at least a first and a second powertrain (Ml', M2 ' , M3 ' ) , the start-up of at least one (Μ2') of said at least a first and a second powertrain and, when said primitive conditions of operating efficiency vary, selectively determine the start-up of at least another ( l', M3 ' ) of said at least a first and a second powertrain ( l', M2 ' , M3 ' ) ;

h) transmitting, in said primitive conditions of operat ^¬ ing efficiency, the rotation of the output shaft of said at least one (Μ2') of said at least a first and a second power- train (Ml', M2 ' , M3') directly to said first differential gearbox (D2 ¹ ) and indirectly to said at least a second differential gearbox (Dl', D3 ' ) ;

i) selectively transmitting, when said primitive conditions of operating efficiency vary, also the rotation of the output shaft of said at least another of said at least a first and a second powertrain (Ml', M3') directly to said at least a second differential gearbox (Dl ¹ , D3 ' ) .

Further, with reference to the aforesaid third example of embodiment of the system according to the invention (Fig. 3), it can be noted that the system implements the following third example of implementation of the method forming the subject matter of the invention, comprising the steps of:

a) providing a vehicle structure (V") including means for supplying and storing electrical energy (B"), electri- cal/electronic control means (C") for controlling the movement of the vehicle and at least a drive axle (A") , which applies rotating mechanical power to means for movement (R") of the vehicle interacting with respect to the ground, to the air, respectively to water, with respect to which said vehicle is operatively movable;

b) providing a propulsion and power transmission unit of the vehicle including at least a first powertrain (M2") and at least a second powertrain (Ml", M3") and at least a first dif- ferential gearbox (D2") kinematically connected with respect to said drive axle (A"), wherein said at least a second power- train (M2") includes at least a pair of sub-powertrains (M2a", M2b") kinematically connected to one another through at least an epicycloidal reduction gearbox (RV") kinematically inter- connected, on one side, between said at least a pair of sub- powertrains (M2a", M2b") and, on the other side, with respect to said first differential gearbox (D2");

c) providing electronic means (E") for detecting the rotation of the output shaft of said at least a first and a sec- ond powertrain, respectively, and electrically connected with respect to said means for supplying and storing electrical energy (B");

d) providing at least a second differential gearbox (Dl", D3") kinematically connected with respect to said drive axle (A") and to said first differential gearbox (D2");

e) providing electronic processing and calculation means (PC") operatively connected with respect to said electronic detection means (E") and to said control means (C"), and electrically connected with respect to said means for supplying and storing electrical energy (B");

g) programming said electronic processing and calculation means (PC") to determine, under the control of said control means (C") of the vehicle structure (V") and in predetermined primitive conditions of operating efficiency of one or more of said at least a first and a second powertrain (Ml", M2", M3"), the start-up of at least one (M2") of said at least a first and a second powertrain and, when said primitive conditions of operating efficiency vary, selectively determine the start-up of at least another (Ml", M3") of said at least a first and a second powertrain (Ml", M2", M3" );

h) transmitting, in said primitive conditions of operating efficiency, the rotation of the output shaft of said at least one (M2") of said at least a first and a second power- train (Ml", M2", M3") directly to said first differential gearbox (D2") and indirectly to said at least a second differential gearbox (Dl", D3");

i) selectively transmitting, when said primitive condi- tions of operating efficiency vary, also the rotation of the output shaft of said at least another of said at least a first and a second powertrain (Ml", M3") directly to said at least a second differential gearbox (Dl", D3") .

Moreover, according to the invention, the aforesaid method is characterized in that said electronic processing and calculation means (PC, PC, PC") are programmed to determine the speed of rotation and the direction of rotation of said at least a first powertrain (Ml, M2 ' , M2") and a second power- train (M2, Ml', M3 ' , Ml", M3") in relation to said primitive conditions of operating efficiency and when said primitive conditions of operating efficiency detected by said electronic detection means (E, E', E") vary.

On the other hand, again according to the invention, at least one of said at least a first powertrain (Ml, M2 ' , M2") and a second powertrain (M2, Ml', M3 ' , Ml", M3") operates as alternator electrically connected with respect to said means for supplying and storing electrical energy (B, B', B") and electrically charges these means. Naturally, it is understood that any further modes of implementation of the method according to the invention and further embodiments of the related system, provided they are suitable for the purpose, also fall within the scope of the present in- vention.

It can be noted that the variations in performance (driving torque) obtained by means of the method and the system according to the invention, are valid both during acceleration and during deceleration to optimize the production of electrical energy stored in the accumulator battery.

As is evident from the above, the method and related system described above for imparting motive power to a drive axle of a vehicle according to the present invention, allow optimiza ^¬ tion, in a vehicle comprising a propulsion unit including at least two motors, of the performance and efficiency of the driving torque transmitted by these motors, making their functional cooperation synergic.

Moreover, the aforesaid method and related system allow the arrangement of the drivetrains to be rationalized with respect to the drive axle and to the available space, reducing the footprint, improving the availability of space in the vehicle.