FR3054499A1 - MOTOR PROPULSION SYSTEM BY GENERATOR AND ELECTRIC BATTERY - Google Patents

Abstract

The invention relates to an electric propulsion system for an exclusively electric vehicle, comprising: an electric generator; a mechanical device for driving the generator comprising mechanical gearing means adapted to be driven by at least one wheel of the vehicle, said gearing means being coupled to a drive means of the generator; an electric battery adapted to be recharged by the generator; and at least one wheel comprising an electric motor adapted to be powered by said generator.

Description

FIELD OF THE INVENTION

The present invention relates generally to an electric vehicle propulsion architecture system.

It particularly finds advantageous application for improving the autonomy of electric vehicles.

STATE OF THE ART

For economic and ecological reasons, electric vehicles are seen as the preferred route of development for individual transport. However, even if this market has considerably developed and democratized over the past five years, it does not correspond to the market expected fifteen years earlier.

Thus, the essential brake to the development of the electric vehicle was and remains, even today, linked to the poor performance of the batteries.

Two notable drawbacks of the electric vehicle are linked to its energy storage system: on the one hand a high mass of battery with a low autonomy and, on the other hand, it requires a large electric power of recharge or long duration of recharge . On the other hand, its two main advantages are the absence of local atmospheric pollution and the low acoustic noise.

Although the electric car is at the point in its mechanical and electronic control aspect, the problem of autonomy has so far greatly penalized this technology. This is due to the very large difference in energy density between petrol (or any other liquid fuel) and electric accumulators. Autonomy is rarely more than 200 km for an electric vehicle, 500 km for the most efficient models, while it frequently exceeds 500 km for petrol vehicles, or even 1,000 km for a Diesel car.

In addition, once the battery is exhausted, it takes several tens of minutes to recharge it (time during which the vehicle is unavailable) whereas in a classic car, it only takes a few minutes to refuel and be able to start again. . There is also the problem of the number of sockets and charging sites sufficient to allow rapid recharging.

A large part of the current market has therefore turned to hybrid type solutions. A hybrid vehicle designates the combination of heat engine and electric vehicle, making it possible to use two separate on-board energy stores to move.

At start-up, it is often the electric motor that sets the car in motion, up to a speed of the order of 50 km / h. When a higher speed is reached or a strong acceleration is requested, the internal combustion engine takes over to gradually replace the electric motor. During the deceleration, descent or braking phase, part of the kinetic energy is transformed by the engine / generator into electricity to recharge the batteries, thereby extending the range.

This type of engine reduces the consumption of vehicles by 10 to 30% depending on use.

However by definition, this type of hybrid vehicle uses petrol fuel, which is a source of pollution, and increases the battery life only moderately.

There is therefore a need to propose a device making it possible to significantly improve the autonomy of a vehicle based exclusively on an electrical supply.

PRESENTATION OF THE INVENTION

In this context, the present invention aims to present new means for improving the state of the art.

This object is achieved according to the present invention by means of an electric propulsion system of an exclusively electric vehicle, comprising:

- an electric generator;

- A mechanical generator drive device comprising mechanical gear means adapted to be driven by at least one vehicle wheel, said gear means being coupled to a generator drive means;

- an electric battery adapted to be recharged by the generator; and

- At least one other wheel comprising an electric motor adapted to be powered by said generator.

Advantageously but optionally, the method according to the invention can also comprise at least one of the following characteristics:

mechanical generator drive device includes a differential;

the differential comprises a primary shaft comprising a first pinion and a secondary shaft with an axis parallel to said primary shaft and comprising a second pinion, the secondary shaft being adapted to drive the primary shaft by contact between said second pinion and said first pinion;

- The mechanical gear means are adapted to be driven by at least one front wheel of the vehicle;

at a speed greater than 40 km / h, at least one wheel comprising an electric motor is supplied by the generator; at a speed of less than 40 km / h, at least one wheel comprising an electric motor is powered by the battery;

at a speed greater than 40 km / h, the excess energy not necessary to supply at least one wheel comprising an electric motor is supplied to the battery;

- the differential is adapted to provide a minimum rotation speed of 2000 rpm to the generator;

- the differential is adapted to provide a maximum rotation speed of 8000 rpm to the generator; and

- the generator is adapted to provide a power of 130 kW at peak and 70 kW at nominal and a voltage of 360V.

The present invention also relates to an electric motor vehicle comprising:

- mechanical gear means adapted to be driven by at least one wheel without an electric motor of the vehicle; said gear means being coupled to a generator drive means;

- an electric battery powered by the generator; and

- At least one other wheel comprising an electric motor powered by said generator.

DESCRIPTION OF THE FIGURES

Other characteristics, aims and advantages of the present invention will appear on reading the detailed description which follows and with reference to the appended drawings, given by way of examples and not limiting and in which:

FIG. 1 represents an architecture of a high voltage bus of an electric vehicle comprising wheels with electric motors powered by a generator or a battery according to the invention,

FIG. 2 represents an architecture of a low voltage bus of an electric vehicle comprising wheels with electric motors powered by a generator or a battery according to the invention,

FIG. 3 represents an architecture of a CAN bus of an electric vehicle comprising wheels with electric motors powered by a generator or a battery according to the invention,

FIG. 4 represents a schematic view of a mechanical device for driving a generator arranged in an engine compartment according to the invention,

FIGS. 5A, 5B and 5C represent a detailed view of a mechanical device for driving a generator according to the invention, and

- Figure 6 shows a schematic view of a mechanical drive device of a generator connected to the front wheels of a vehicle according to the invention.

DETAILED DESCRIPTION OF AT LEAST ONE MODE OF

REALIZATION OF THE INVENTION

FIG. 1 shows an electric propulsion system for a motor vehicle 100. The propulsion is provided by at least one drive wheel 110, preferably arranged at the rear of the vehicle 100.

The wheel-motor 110 is a set of functions integrated into the wheel and which includes, in addition to its usual functions, the electric traction motor, a motor and the active electric suspension system which makes it possible to vary the height of the body on an important race, but also to tilt the body in turns to improve handling, and the braking system with forced ventilation. Motor wheels are known such as the Active Wheel system developed by Michelin or the In-Wheel Motor by Protean Drive.

The main advantage of such a system is its reduced size and the fact that it does not require a transmission.

The propulsion of the vehicle 100 is ensured by 2 motorized wheels 110 preferably located at the rear of the vehicle. Said motor wheels 110 rely on instantaneous energy in the form of a strong current and very rapid variation (less than a second) from a battery 120 and background energy supplied by the mechanics and a generator 130 .

The drive wheels 110 are sized to provide the following specifications:

- 70 kW peak for 30 seconds;

- 30 kW nominal;

- 900 to 1000 Nm up to 600 RPM;

- 100 Nm at 1100 RPM;

- maximum speed of 1100 RPM.

The generator 130 is connected to a high voltage bus 150 to the drive wheels 110 and to a battery 120.

From 40 km / h, the generator 130 supplies sufficient power to supply the high voltage bus 150, the nominal voltage of which is preferably 360 V DC. The generator 130 can typically supply this voltage of 360 V DC from a rotation speed of 2000 RPM. This rotation speed is preferably obtained from a speed of 40 km / h of the vehicle.

The vehicle 100 has an architecture making it possible both to have the energy supplied by the generator 130 and at the same time energy from the battery 120.

The battery 120 is typically a lithium ion polymer battery, for example with a capacity of 27 kWh and a power of 90 kW. The battery 120 comprises a nominal voltage of 360V DC, and supplies the drive wheels 110 by inverters 140 which make it possible to supply voltages and alternating currents.

The inverters 140 are for example of the reference CO150 from the company TMA.

The high voltage bus 150 makes it possible to connect the battery 120 to the inverters 140, themselves connected to the drive wheels 120. The bus 150 also connects the battery 120 to the plug service 160 intended for the rescue and maintenance service.

Said bus 150 preferably consists of 2 cables, 151 and 152 of 35mm2 supporting 170 A at a peak without significant heating. Cable 151 is the positive power cable and cable 152 is the negative power cable.

The impedance between the 2 cables 151 and 152 and the chassis of the vehicle 100 is preferably more than 1 Mohm. The cable used has a copper core, a thin insulation sheath, a copper braiding shield and a thick but flexible sheath as an outer layer. In one embodiment, economically, the drive wheels 110 and the generator 130 are connected to their respective inverter 140 using the same cable.

The vehicle 100 includes a cooling circuit 170 typically by water-glycol liquid sized to allow the cooling of the 2 motor wheels 110 and their respective inverter 140 as well as the generator 130 and its inverter 140 (the battery is cooled by forced convection ).

Preferably, said circuit 170 provides cooling with a flow rate of 12 l / min at 0.6 bar.

As illustrated in FIG. 2, the vehicle 100 comprises a low voltage bus 200. All of the digital computers are connected together on the low voltage bus 200, typically of 12V DC. The energy source of the low-voltage bus is for example a lead-acid battery 210 of 12V. Said battery 210 uses a DC / DC converter 220 to recharge connected to battery 120.

The inverters 140 of the motor wheels 110 and the generator 130, as well as their associated controller 141 (SVC) are supplied on this low voltage bus 200.

The control system (BMS) of the battery 120 as well as the dashboard 230 of the vehicle and the control unit of the passenger compartment 240 of the vehicle (BSI) are also connected to the low voltage bus 200.

The cable of said bus 200 used is a standard automobile supply cable and must meet the specifications for the current requirements of the inverters 140.

The dashboard 230 is constituted by two side screens presenting the main information, and a small central screen displaying the information relating to the operation in progress (recharging, verification of sub-assemblies, alarms, media, etc.).

As illustrated in FIG. 3, the vehicle 100 comprises a CAN network bus 300. The CAN bus 300 comprises the CAN motor bus 310 dedicated to the engine-wheel group (CAN MOTOR.), And the CAN passenger bus 320 dedicated to passenger compartment computers (CAN COCKPIT).

The CAN 300 bus is typically a CAN v2.0B bus at 500 kbits / sec. Preferably, said bus is composed by a specific CAN cable balanced 120 ohms, shielded and flexible, twisted pair.

The SVC 141 has 2 physical CAN buses. In this sense, it serves as a gateway between the CAN COCKPIT bus 310 and the CAN MOTOR bus 320.

The SVC 141 manages propulsion and generation autonomously, and this according to the data directly related to it: for example, brakes, accelerator pedal, speed, torque and current measurement, ...

However, it can also take into account indirect information which is reported to it by a BSI 330 computer via the CAN HABITACLE 320 bus (SOC, DTC, nominal mode and fault mode, energy saving mode, sport mode, ...).

The BSI 240 computer is preferably constituted by an on-board system of the ARM processor type with low start-up time and operating on a standby mechanism with low consumption (typically 50mA at 12V DC).

The housing of said computer 240 is for example a sealed CINCH housing comprising the CPU ARM core and the various communicating sub-assemblies (Ethernet, CAN, USB, RS232). The BSI 240 computer is able to control, trace and dialogue on the CAN COCKPIT CAN bus 320.

FIG. 4 illustrates a mechanical drive device 400 of the generator 130. The drive device is a mechanical assembly which is composed of a differential 410 on which the electric generator 130 is fixed. Said generator 130 is driven by the rotary movement of the vehicle's left or right front wheel 100.

As illustrated in FIG. 5a, 5b and 5c, opposite a conventional arrangement of an engine in a typical vehicle, the mechanical drive device 400 is preferably placed in the engine compartment under the engine bar 510. It comprises a set of mechanical parts arranged coaxially in conjunction with a radiator-fan 520.

The mechanical drive device 400 comprises at one end a support element 401 for a part made of flexible material making it possible to absorb shocks or vibrations between different mechanical parts (commonly called silent block).

This support element is arranged against one face of the generator 130. Said generator 130 corresponds for example to the AF-130 model from GKN Land Systems. The generator can have a thickness of 110mm and a diameter of 335mm.

On the other face of said generator 130, a flange 131 is fixed, the flange is of cylindrical section preferably 240mm in diameter, and preferably 50mm thick. The flange 131 is of full section and has a hollow section coaxial with the generator of geometric shape in the shape of a crown. This hollow section allows the passage of the drive shaft 132 of the generator 130.

The transmission shaft 132 of the generator 130 preferably has a diameter of approximately 50mm and a length of approximately 120mm. The transmission shaft 132 has internal and external splines preferably produced by pinout.

The generator 130 is separated from a differential 550 by a spacer 570. Said spacer 570 preferably has a diameter of 210 mm, a hollow cylindrical section with a diameter of 200mm and a length of 70 mm opposite the axis of the spacer. .

The generator 130 is engaged by its drive shaft 132 in a coupling 530. The latter also allows the engagement of a primary shaft 540. The primary shaft 540 coaxially traverses a differential flange 551 and a differential block 552. The primary shaft 540 preferably has a pinion with 19 teeth.

A secondary shaft 560 is also engaged through the flange 551 and the differential block 552.

The secondary shaft 560 has a first proximal section of the differential block with 35 teeth and a second distal section of the differential block 552 with 26 teeth. The secondary shaft 560 comprises a pinion 561, preferably 37 teeth, fixed by hooping.

Sprockets 541 and 561 are helical sprockets with a center distance of 84mm.

The primary shaft 540 and the pinion 541 produce a first gear preferably with a diameter of 60mm.

The secondary shaft 560 and the pinion 561 produce a second gear preferably with a diameter of 114 mm.

The primary shaft 540 and the secondary shaft 560 have parallel axes. The teeth of their respective pinions are in contact and therefore define parallel gears.

As illustrated in FIG. 6, the differential 550 is connected by a cardan transmission 610 to the front wheels 620.

The cardan transmission is connected to a bevel gear preferably with 26 teeth in contact with a crown preferably of 93 teeth. Said bevel gear is in contact with the pinion 561 of the secondary shaft 560. Thus the rotation of one or more front wheels (s) causes (s) the transmission of movement to the secondary shaft 560 in gear contact with the primary shaft 540, thus driving the generator drive shaft 130 and therefore the production of electrical energy.

The differential 550 provides a reduction ratio 1 = 37 * 93/16 * 26 = 6.965.

The generator 130 to produce the energy necessary to power the drive wheels 110 must rotate at a minimum speed of 2000 rpm. For safety reasons, the generator 130 is also designed to run at a maximum speed of 8000 rpm.

We consider typical wheels with 18 inch tires with a Regal radius of 0.35m.

To obtain a minimum rotation speed of the generator Nm = 2000 RPM, with the differential ratio, we obtain a minimum rotation speed of the wheels of Np = Nm / I = 287 RPM. Thus, a minimum vehicle speed of Vp = Np * R * TÎ = 10.52 m / s is obtained, i.e. 37.9 km / h. It is therefore considered that from 40 km / h, the generator 130 is able to supply the energy necessary for the propulsion of the motor wheels 110.

By considering a maximum speed of the vehicle Vm equal to 150 km / h, a wheel speed Nr equal to 1145 rpm is obtained. Reducing the differential provides a generator 130 rotation speed of 1145 * 6.965 = 7975 RPM.

Thus, the ratio of the differential 550 makes it possible to obtain, at the maximum speed of the vehicle, a speed of rotation of the generator in the operating range of said generator.

When the energy supplied by the generator is greater than the energy required to power the wheel motors 110, this energy is also used to recharge the battery 120.

The torque of the wheel motors will be used to meet the needs of high accelerations. The current consumption will be maximum and the stresses could be very brief (a few seconds).

The micro-variations of effort (imperfection of the road, turn, sharp climb, sidewalk ...) generate current demands with strong variations in very short times, even at low speed. The architecture of the vehicle 100 thus makes it possible to use the instantaneous energy of the battery 120 and the high inertia energy of the generator 130.

Of course the present invention is not limited to the particular embodiment which has just been described, but extends to any variant in accordance with its spirit.

Claims (11)

1. Electric propulsion system of an exclusively electric vehicle (100), comprising: - an electric generator (130); a mechanical drive device (400) for the generator (130) comprising mechanical gear means adapted to be driven by at least one wheel of the vehicle, said gear means being coupled to a drive means for the generator ( 130); - an electric battery (120) adapted to be recharged by the generator (130); and - at least one other wheel (110) comprising an electric motor adapted to be powered by said generator (130). 2. Electric propulsion system according to the preceding claim, in which the mechanical drive device (400) of the generator (130) comprises a differential (550). 3. Electric propulsion system according to the preceding claim, in which the differential (550) comprises a primary shaft (540) comprising a first pinion (541) and a secondary shaft (560) with an axis parallel to said primary shaft (540) and comprising a second pinion (561), the secondary shaft (560) being adapted to drive the primary shaft (540) by contact between said second pinion (561) and said first pinion (541). 4. Electric propulsion system according to one of the preceding claims, wherein the mechanical gear means are adapted to be driven by at least one front wheel of the vehicle (100). 5. Electric propulsion system according to one of the preceding claims, wherein at a speed greater than 40 km / h, at least one wheel (110) comprising an electric motor is powered by the generator (130). 6. Electric propulsion system according to one of the preceding claims, wherein at a speed less than 40 km / h, at least one wheel (110) comprising an electric motor is powered by the battery (120). 7. An electric propulsion system according to claim 5, in which at a speed greater than 40 km / h, the surplus energy supplied by the generator (130), not necessary to supply at least one wheel (100) ) comprising an electric motor, is supplied to the battery (120). 8. An electric propulsion system according to claim 5, in which the differential (550) is adapted to supply a minimum rotation speed of 2000 rpm to the generator (130). 9. An electric propulsion system according to claim 5, in which the differential (550) is adapted to supply a maximum rotation speed of 8000 rpm to the generator (130). 10. An electric propulsion system according to one of the preceding claims, in which the generator (130) is adapted to supply a power of 130 kW at peak and 70 kW at nominal and a voltage of 360V. 11. Electric motor vehicle (100) comprising: - mechanical gear means adapted to be driven by at least one front wheel of the vehicle; said gear means being coupled to generator driving means (130); - an electric battery (120) supplied by the generator (130); and - at least one other wheel (110) comprising an electric motor powered by said generator (130); and adapted to implement claims 1 to 10. 1/6 Ο sjΟ '' Φ