Compressed air-electric drive system, engine kit and vehicle equipped with such a drive system

Abstract

The invention relates to a powerful hybrid air / electric drive system with high efficiency and a range compatible with standard vehicle use, regardless of the driving phase (starting or uphill travel, steady travel, and braking or downhill travel). According to the invention, the drive system (100) comprises a compressed air reservoir (110) connected to a compressed air piston motor (120) coupled to an electric generator (130) connected to a backup electrical reserve (160) with a capacity of between 0.2 and 2.2 watt-hours per kilogram of vehicle to be equipped (Wh / kg of vehicle), itself connected to the electric motor (140) coupled to the drive element (151, 152). Figure for the abstract: Fig. 1

Description

Title of the invention: Compressed air-electric drive system, engine kit and vehicle equipped with such a drive system

[0001] The present invention relates to a drive chain using compressed air and electricity.

[0002] The invention finds a particularly important, although not exclusive, application in the field of motorization of land vehicles (such as cars or utility vehicles) or marine vehicles (such as boats).

[0003] There are many drive chain solutions based on thermal engines, on electric motors or on a combination of the two (called hybrid drive chain).

[0004] So-called "internal combustion" vehicles require the use of polluting fossil fuels, which has led authorities in many countries to favor other types of less polluting powertrains. Their main advantage lies in their range and the speed of refueling.

[0005] These internal combustion engine vehicles always include a small battery for starting the internal combustion engine and powering the vehicle's electrical equipment. This battery is recharged by an alternator driven by the internal combustion engine when it is running. This type of battery is unsuitable for driving the wheels and is therefore not part of the drive system. Consequently, this type of battery is not relevant to the invention.

[0006] So-called "electric" vehicles have a drive system consisting of a high-capacity power battery designed to supply the electric motor(s) capable of driving a transmission connected to a driving element (the wheels of a car or the propeller of a boat, for example). This type of battery is therefore part of the drive system.

[0007] A power battery is composed of a plurality of interconnected electrical cells monitored by an electronic circuit. Their number, the size of each cell, and their arrangement determine both the voltage delivered by the battery and its capacity, that is, the amount of electricity it can store, which defines the car's range under standard conditions. These batteries are called "high-capacity" because they must allow a range of several hundred kilometers. Typically, they have a capacity ranging from 40 kWh for the smallest to 100 kWh for the largest.

[0008] The power batteries used in electric vehicles are generally lithium-ion batteries, since only this type of battery currently allows a power and battery life suitable for this use.

[0009] The major drawback of this type of powertrain lies precisely in the battery.

[0010] Indeed, its manufacture and end-of-life are environmentally disastrous: lithium reserves are theoretically insufficient to equip all the world's vehicles, cobalt is extracted under often inhumane conditions, and the recycling process is currently unknown. It is not currently possible to recycle them to more than fifty percent, and the processes used are also chemically and electrically hazardous.

[0011] During the use phase, this type of drive chain has the advantage of producing very little CO2 (this depends on the energy source used to produce the electricity to be charged in the battery).

[0012] On the other hand, power batteries, and in particular lithium-ion batteries, have a problematic tendency to heat up during charging, or even during use, and require a cooling system that is often complex.

[0013] Numerous incidents have been recorded in which batteries caught fire due to this overheating, known as "run-away." These chemical fires are extremely difficult to extinguish. The use of water, for example, can, depending on the conditions, tend to fan the flames. Furthermore, these fires release intense heat that tends to ignite nearby vehicles. Finally, the fumes released are also hazardous to health and very likely to the environment. In light of these circumstances, some manufacturers have planned to offer rescue vehicles equipped with special baths into which a crane lowers the burning vehicle to try to limit the spread of the fire. This solution currently raises many questions and does not appear to be viable.

[0014] Hybrid drive systems have also been proposed in which a thermal engine either assists the electric motor, or recharges the power battery, or both.

[0015] These hybrid vehicles are attractive for vehicles requiring a long driving range (provided by the internal combustion engine), while reducing fuel consumption on short journeys where the battery capacity is sufficient. However, they share the drawbacks of both technologies: pollution, risk of fire, complex recycling, or even impossibility in some cases, etc.

[0016] There is therefore a need to propose a drive chain that reduces the pollution generated and the risks of operation.

[0017] Air engines have already been proposed for powering vehicles. However, the engines used are turbines (or rotary engines) similar in structure and operation to the pneumatic turbines used in pneumatic tools.

[0018] If these turbines theoretically allow sufficient power to be obtained, it is at the price of very high compressed air consumption.

[0019] Consumption is not a significant factor in this type of application, as the tool is connected to an electrically powered air compressor that operates continuously to supply the tool. This is obviously not the case for a vehicle, which does not have a compressor but rather an air reservoir that needs to be regularly recharged. Consequently, problems with both consumption and sufficient power led to the abandonment of this type of air-powered drive system, which achieved no commercial success for vehicle equipment.

[0020] The objective of the present invention is therefore to propose a solution to these problems to enable the equipping of land or marine vehicles incorporating a compressed air drive chain, which is efficient both in terms of power, but also in terms of efficiency and therefore autonomy, regardless of the driving phase (starting or moving uphill, stabilized movement, and braking or moving downhill).

[0021] The idea underlying the invention is to propose a hybrid air / electric powertrain comprising a high-pressure compressed air reservoir connected to a compressed air piston engine (i.e., an engine that is not a pneumatic turbine), itself driven by an electric generator capable of generating electricity when driven by the air piston engine. The electric generator is connected to the vehicle's electric motor(s), which is itself connected to a transmission driven by a propulsion component (wheels, propeller, etc.). According to the invention, the generator and the electric motor(s) are also connected to a backup electrical reserve with a capacity of between 0.2 and 2.2 watt-hours per kilogram of vehicle to be equipped (Wh / kg of vehicle).

[0022] When adapting the drive chain according to the invention to an electric vehicle, one can either choose to keep only a portion (for example 10% or less, preferably between 5% and 8%) of the cells of the initial battery to make the relay electrical reserve, or one can simply remove the initial power battery (possibly resell it when it is a modification of an existing electric vehicle), and incorporate a relay electrical reserve made up of a set of supercapacitors.

[0023] In the first case, the relay electrical reserve, consisting of a part of the cells of the power battery, has a capacity of between 1.2 and 2.2 Watt-hours per kilo of vehicle to be equipped, preferably between 1.2 and 2 Wh / kg of vehicle to be equipped, which represents between 5% and 10% of the capacity of the initial power battery of the corresponding electric vehicle.

[0024] The corresponding electric vehicle is understood to be the same vehicle as that equipped, or intended to be equipped, with the drivetrain according to the invention, but equipped with a A 100% electric vehicle system includes a battery with a capacity adapted to its use, particularly in terms of power and range. This type of vehicle generally includes a battery with a capacity exceeding 35 kWh, so the backup power supply according to the invention has a capacity of no more than 10% of this capacity (plus or minus 1 percentage point), i.e., less than or equal to approximately 3.5 kWh. This upper limit may be higher when the corresponding electric vehicle includes a higher-capacity battery, such as certain commercial vehicles, buses, trucks, or boats, and requires a power battery with a capacity exceeding 100 kWh for its normal use (in terms of power and range).

[0025] In the second case, the capacity of the supercapacitor assembly is between 0.2 and 1.2 Wh / kg of vehicle to be equipped, advantageously 0.2 and 0.5 Wh / kg of vehicle to be equipped, which represents 0.5 to 5% of the capacity of the initial power battery of the corresponding vehicle.

[0026] The drive chain according to the invention comprises an electronic circuit, including in particular a controller and advantageously an energy distributor, programmed to allow an electrical supply to the motor from the relay electrical reserve according to the power demand, for example when the driver of the vehicle commands an acceleration or when the vehicle detects the immediate need for an increase in power (for example during an uphill climb).

[0027] To this end, the invention relates to a hybrid powertrain intended to equip a vehicle of a specified weight and comprising a high-pressure compressed air reservoir connected to a compressed air piston engine, itself coupled to an electric generator capable of generating electricity when driven by the compressed air piston engine, at least one electric motor connected to a transmission coupled to a drive element, the generator and said at least one motor being connected via a backup electrical reserve with a capacity of between 0.2 and 2.2 watt-hours per kilogram of vehicle (Wh / kg of vehicle), the powertrain further comprising,an accelerator control that can be moved between a stop position and a maximum acceleration position and is connected to an electronic control circuit comprising a controller programmed to power the electric motor from the electrical reserve relay according to a signal received by at least one sensor.

[0028] According to particular embodiments, one and / or the other of the following provisions are also used: - The generator and the motor can also be directly connected; the electronic control circuit further includes a power distributor connected to the controller and capable of supplying the electric motor from the generator and / or the electrical reserve relay upon instructions received from the controller based on a signal captured by at least one sensor; - the backup electrical reserve can consist of a portion of an initial power battery previously fitted to the vehicle; - the electrical backup reserve can have a capacity of between 1.2 and 2.2 Wh / kg of vehicle; - the electrical backup can consist of at least one supercapacitor, preferably a set of supercapacitors; - the electrical backup reserve can have a capacity of between 0.2 and 1.2 Wh / kg of vehicle, preferably between 0.2 and 0.5 Wh / kg of vehicle; - the drive chain may also include a throttle control position sensor, and in which the controller is programmed to supply the electric motor from the electrical backup relay and / or the generator depending, in particular, on the position of the throttle control; - the drive chain may also include a throttle control movement speed sensor, and in which the controller is programmed to supply the electric motor from the electrical backup relay and / or the generator depending, in particular, on the throttle control movement speed; - the drive system may also include a vehicle speed sensor, and in which the controller is programmed to supply the electric motor from the backup power supply and / or the generator depending, in particular, on the vehicle's speed; and / or - the drive chain may also include a kinetic energy recuperator connected to the electrical relay reserve to charge the electrical relay reserve during vehicle braking.

[0029] The invention also relates to a land vehicle, such as a car or utility vehicle, comprising a previous hybrid drive system, in which the drive unit comprises at least one pair of wheels.

[0030] The invention also relates to a boat comprising a previous hybrid drive chain, in which the propulsion unit comprises at least one propeller or turbine.

[0031] The invention also relates to a method for modifying an electric vehicle equipped with an electric motor, a power battery and a charging connector from an external source, to equip it with a previous hybrid powertrain, comprising the following steps: a) remove the vehicle's power battery to free up installation space; b) Insert the compressed air reservoir into the installation volume and replace the recharge connector with a recharge valve connected to the compressed air reservoir c) add the air piston engine, generator and controller into the vehicle, preferably in the installation volume; d) add an electrical backup reserve in the vehicle, preferably in the installation volume, connected between the generator and the electric motor, the electrical backup reserve consisting of a part of the power battery having a capacity of between 1.2 and 2.2 Wh / kg of vehicle, or including at least one supercapacitor, preferably a set of supercapacitors with a capacity of between 0.2 and 0.5 Wh / kg of vehicle.

[0032] Other features of the invention will be set forth in the detailed description below, made with reference to the accompanying figures, given by way of example, and which represent, respectively:

[0033] [Fig. 1], a schematic view of an operating diagram of a first embodiment of a drive chain according to the invention during start-up;

[0034] [Fig.2], a schematic view of an operating diagram of the first embodiment of a drive chain according to the invention after starting or in the stabilized movement phase (stationary regime);

[0035] [Fig.3], a schematic view of an operating diagram of the first embodiment of a drive chain according to the invention during braking;

[0036] [Fig.4], a schematic view of an operating diagram of a second embodiment of a drive chain according to the invention allowing the motor to be supplied directly from the generator and / or indirectly from the electrical backup, during start-up;

[0037] [Fig. 5], a schematic view of an operating diagram of the second embodiment of a drive chain according to the invention after starting or during the stabilized movement phase (stationary regime); and

[0038] [Fig.6], a schematic view of an operating diagram of the second embodiment of a drive chain according to the invention during braking;

[0039] Figures 1 to 3 illustrate a first embodiment in which the drive chain 100 includes a high-pressure compressed air tank 110 (i.e., between 40 and 700 bar) connected to a compressed air piston engine 120.

[0040] In the remainder of the description, the gas used is preferably air for easy and inexpensive use of the mobile chain according to the invention, particularly during recharging.

[0041] Preferably, the reservoir 110 is connected to an air expansion chamber 112 by a valve 111, the air expansion chamber itself being connected to the motor 120 by a valve 113. The air expansion chamber allows the compressed air to be brought from the high storage pressure to an operating pressure compatible with the piston motor. compressed air 120.

[0042] An example of a compressed air piston engine is the engine described in document FR3115313.

[0043] Advantageously, it is a two-stroke engine which, at equal power, is twice as small and lighter than equivalent internal combustion engines, and has a higher efficiency of almost 50% with compressed air.

[0044] The air piston engine 120 is engaged with an electric generator 130 capable of generating electricity when driven by the air piston engine 120.

[0045] The drive chain according to the invention also includes at least one electric motor 140 connected to a transmission 150 engaged with a driving element which can be wheels 151, a propeller 152 or a turbine (not illustrated).

[0046] According to the invention, the generator 130 and said at least one motor 140 are connected via an electrical relay reserve 160 with a capacity between 0.2 and 2.2 Wh / kg of vehicle to be equipped, which corresponds to less than 10% of the capacity of the power battery of the electric vehicle corresponding to the vehicle equipped or intended to be equipped with the drive chain according to the invention.

[0047] For example, for the equipment of a Renault Master e-Tech ™ vehicle having a GVW of 3.5 tonnes (i.e. 2.4 tonnes unladen approximately) having an initial power battery of 52kWh, the vehicle will be equipped with a relay electrical reserve of 2.8 to 7 kWh, corresponding to a capacity of between 1.2 and 2.2 Wh / kg of vehicle unladen and fully loaded, if the relay electrical reserve is constituted by a battery.

[0048] This electrical relay reserve 160 is thus sufficient to temporarily power (a few seconds to a few minutes) the electric motor, while the generator is driven and replenishes the electrical relay reserve 160.

[0049] Alternatively, the electrical backup 160 is advantageously and preferably made up of a set of supercapacitors which allows for significant and sufficiently powerful energy storage to enable the wheels to be driven and the vehicle to move for a period of a few seconds to a few tens of seconds, the time it takes for them to be recharged by the generator driven by the air piston engine or by regenerative braking. They also allow for current regulation.

[0050] In this case, the capacity of the supercapacitors is preferably chosen to be between 0.2 and 1.2 Wh / kg of vehicle to be equipped, which corresponds to 0.5 to 5% of the power battery of the corresponding electric vehicle.

[0051] In the example of the Renault Master e-Tech ™ vehicle, in the case of use of supercapacitors, it will be equipped with a relay electrical reserve of 0.48 to 4.2 kWh, corresponding to a capacity of between 0.2 and 1.2 Wh / kg of vehicle empty and full.

[0052] What is important is that the backup electrical reserve is capable of propelling the vehicle in case of a greater need for energy, while the compressed air can take over to sufficiently power the piston engine, the generator and then the electric motor and satisfy the energy need.

[0053] For this purpose, the drive chain 100 according to the invention further comprises an accelerator control 170 movable between a stop position and a maximum acceleration position and connected, for example, to a displacement sensor of the accelerator control (not illustrated) and to an electronic control circuit comprising a controller 180 programmed to control the supply of the electric motor 140 from the electrical reserve relay 160 as a function, in particular, of the detected position of the accelerator control 170.

[0054] The operation of the drive chain according to the invention is detailed for three important phases.

[0055] [Fig. 1] illustrates a phase during which an additional power is requested by the driver, as shown schematically by dial 171. This phase is very short and followed by the phase illustrated in [Fig. 2].

[0056] This could be, for example, starting the vehicle, in which case a large amount of power is required and must be immediately available to overcome the vehicle's inertia and get it moving. It could also be overtaking another vehicle, or driving uphill, in which case the driver presses the accelerator hard.

[0057] In this case, the energy must be immediately available, but the inertia of the compressed air system may cause a delay in response.

[0058] When the accelerator control position sensor detects a movement of the latter, it sends the information to the controller 180 which analyzes this movement and links it to an acceleration request.

[0059] In the case of [Fig.1], this displacement is maximal, for example in the case of a significant acceleration.

[0060] Alternatively or in combination, the drive chain includes a throttle control displacement speed sensor and / or a vehicle displacement speed sensor.

[0061] The accelerator control movement speed sensor makes it possible to detect a rapid movement of the accelerator control and, consequently, a rapid demand for power, for example in the context of overtaking.

[0062] The vehicle's travel speed sensor detects that the vehicle is stationary and, if the accelerator control is moved, the controller 180 understands (arrow 181) that a large amount of power is needed to start the vehicle moving.

[0063] Thus, in the drive chain thus equipped, the controller 180 is programmed to control (arrow 182) the electrical relay reserve 160 which then supplies the electric motor 140 (arrow 161) according to the information captured (arrow 181; speed of movement of the accelerator control and / or speed of movement of the vehicle).

[0064] Thanks to the electrical relay reserve 160, the energy required by the driver's action on the accelerator control is sent immediately to the displacement member 151-152, while the compressed air is sent to the air piston motor 120 and the latter drives the generator 130 (phase illustrated in [Fig.2]).

[0065] This [Fig.2] thus illustrates the phase following the high energy demand of [Fig.1] or the phase of stabilized movement, in steady state, for example when driving on a flat road at substantially constant speed where the energy demand is moderate and regular, as illustrated by dial 172 which indicates moderate acceleration.

[0066] In this case, the controller 180 receives information about the movement of the accelerator control and / or its speed (zero or very low) from the sensors (arrow 181). The controller 180 then controls the valve 113 (arrow 183) to supply compressed air at operating pressure to the piston engine 120 from the expansion chamber 112 (arrows 121).

[0067] The piston engine 120 then drives the generator 130 (arrow 131), which supplies electricity to the relay reserve 160 (arrow 132), which in turn supplies (arrow 161) the electric motor 140, which drives the displacement member 151-152 via the transmission 150.

[0068] The backup relay then operates continuously, meaning it transmits the electricity it receives. Since it consists of several cells or supercapacitors, a continuous power supply is obtained by controlling the input / output of each cell or supercapacitor in a timed manner to linearize the output current. Current processing electronics can advantageously be added to stabilize the output current supplying the motor.

[0069] Figure 3 illustrates the possibility for the drive chain according to the invention to recover kinetic energy, for example during braking (as illustrated by dial 173 which indicates zero acceleration) in order, preferably, to recharge the electrical reserve relay 160 to limit air consumption, and / or to power a small auxiliary compressor (not shown) capable of recharging volume 112 to the operating pressure in order to increase the vehicle's range.

[0070] To this end, the drive chain 100 according to the invention includes, for example, a braking energy recovery system 195 (or “KERS” for “Kinetic Energy Recovery System”) connected to the electrical backup 160 in order to recharge without air consumption (arrow 196).

[0071] The electronic control circuit is thus programmed to manage the timing, rhythm and source of recharging the relay electrical reserve.

[0072] Figures 4 to 6 illustrate a preferred embodiment of the invention in which the drive chain 200 includes a generator 130 which can supply not only the electrical relay reserve 260, but also directly the electric motor 240.

[0073] To this end, the electronic control circuit further includes an energy distributor 285 at the output of the generator 130 (it may be independent or incorporated into the generator). This energy distributor 285 is connected to the controller 280.

[0074] It is capable of supplying the electric motor 240 directly from the generator 130 (arrow 241 on the [Fig.5]) and / or indirectly from the electrical relay reserve 260 (arrows 242-243 on figures 4 and 5) on instructions received from the controller 280 as a function of a signal captured by at least one sensor, for example, a sensor of the position of the accelerator control, a sensor of the speed of movement of the accelerator control, a sensor of the speed of movement of the vehicle or a combination thereof.

[0075] When the driver presses hard on the accelerator (for example when overtaking or going uphill), or when the vehicle is stopped and a lot of power is needed to get it moving, the inertia of the compressed air system can cause a delay in response.

[0076] As illustrated in [Fig.4], the backup power supply overcomes this problem by immediately supplying the electric motor (arrow 243) on command from the distributor 285 (arrow 242) controlled by the controller 280. Meanwhile, as illustrated in [Fig.5], the controller commands the valve 113 (arrow 283) so that compressed air is sent to the compressed air piston motor 120 (arrows 121) which accelerates and drives the electric generator 130 (arrow 131) which takes over from the backup power supply by allowing, via the distributor, a direct supply to the electric motor 240 (arrow 241) and recharging the backup power supply 260 (arrow 242) either for later use or for immediate use in case of a need for extra power.

[0077] Fig. 5 also illustrates the case of a stabilized movement during which the driver maintains the acceleration control in an intermediate position (dial 172) between a stop position in which no compressed air reaches the piston engine, and a maximum acceleration position in which compressed air reaches the piston engine with a maximum flow rate.

[0078] In this intermediate cruising position, the piston engine 120 drives the electric generator 130 (arrow 131), which directly supplies, via the distributor 285, the electric motor 240 (arrow 241), which in turn drives the de-icing mechanism placement 151-152 (wheels or propeller, for example) via a transmission 150. In this cruising regime, the electrical relay reserve is recharged and is only used occasionally in case of sudden acceleration, for example, if this acceleration exceeds the acceleration capacity of the piston engine 120 and the inertia of the compressed air part of the drive chain 200.

[0079] In a preferred embodiment, the electronic control circuit (controller 280, distributor 285 and sensors) controls the supply of the electric motor 240 from a combination of the generator (direct path 241) and the electrical backup relay 260 (arrows 242-243).

[0080] Depending on the position of the accelerator pedal and / or the speed at which the pedal is pressed and / or the speed of the vehicle, the distributor 285 allocates the electricity produced by the generator 130 to the direct path (cruising speed + / -15% for example), to the indirect path (strong acceleration or start-up) or to a combination of the two allowing for optimization of compressed air consumption.

[0081] As in the first embodiment, advantageously a braking energy recovery system 195 (or “KERS”) is also provided, connected to the electrical relay reserve in order to recharge it without air consumption (arrow 196 on [Fig.6]).

[0082] The electrical circuit is thus programmed to manage the timing, rhythm and source of recharging the relay electrical reserve.

[0083] For example, the backup electric reserve may not be recharged immediately by the generator (thus saving compressed air), and may only be recharged during braking or during "engine braking" (stimulated in an electric vehicle by the activation of the energy recovery system, which slows the vehicle by friction when the driver fully releases the accelerator pedal). A delay may also be measured, after which, if the vehicle has neither braked nor experienced engine braking, the electric generator supplies the backup electric reserve to recharge it (arrow 242).

[0084] The electrical backup can be a power battery cell or, advantageously, a supercapacitor or a set of supercapacitors.

[0085] The drive chain according to the invention can be integrated from the outset into a new vehicle specially designed and optimized for this purpose.

[0086] The drive chain according to the invention also has the advantage of being able to be adapted to an existing electric vehicle or internal combustion vehicle, subject to certain modifications.

[0087] In particular, for electric vehicles, the power battery is removed to free up installation space in which the compressed air reservoir 110 is placed. The electric charging connector or fuel filler flap is also replaced. by a pneumatic recharging valve connected to the air reserve 110.

[0088] The compressed air engine, the generator and possibly the supercapacitors can be placed in the installation volume and have a low impact on the vehicle's loading capacity.

[0089] In the case of electric vehicles, a power battery cell can be reused as a relay electrical reserve with a capacity of less than 10 kWh, so that the quantity of material for a single vehicle is divided by ten depending on the types of batteries used.

[0090] Advantageously, the battery is completely removed and resold for use in another application if it is reusable. In this case, the backup power supply can advantageously be a supercapacitor or a set of supercapacitors, and is installed in the vehicle, preferably within the installation space.

[0091] Thus, the general principle of the invention is to replace power batteries or internal combustion engines with a compressed air-based system that generates electricity.

[0092] Storage is achieved via a high-performance compressor, even for small systems.

[0093] Air is stored in cylinders at a pressure of 40 to 700 bar (versions with higher pressures may be used in the future).

[0094] To reduce the storage pressure to the operating pressure, the air expansion volume 112 can be an expansion valve, a turbo-alternator, or other pressure-reducing device, the electrical energy of which can, via a third path leading preferably to the distributor 285 and controlled by the controller 280, boost traction by powering the electric motor 240, recharge the electrical backup 260 (preferably supercapacitors) or allow certain parts of the drive chain to be heated, in particular the air-piston engine 120).

[0095] The loading of the cylinder(s) can also be obtained from a reserve of compressed air under pressure.

[0096] Compressed air stored on the vehicle or boat can be supplied by external distribution centers at fast or slow charging speeds as needed, all within a few minutes or on the order of ten minutes, i.e., much faster than recharging a power battery. Air transfer can be improved by balancing the temperatures between the reserve and the point of use.

[0097] This compressed air, once expanded to the working pressure, powers a compressed air piston engine which turns a generator or alternator to produce current; it can also be used as a generator set.

[0098] Thanks to the compressed air piston engine, the weight / performance ratio is optimized. In addition, air consumption is significantly reduced so that The vehicle's range is perfectly compatible with standard use.

[0099] This current can be sent directly to the electric traction motor(s) and / or pass through supercapacitors to provide a significant, rapid, and intermittent energy supply (starting, acceleration, etc.). Energy recovered during braking or downhill driving can be sent to the supercapacitor or power a compressor to fill low-pressure booster tanks.

[0100] The new piston engine / generator unit, due to its small size and weight, allows for easy integration for high performance.

[0101] The overall performance of the system can be improved by heat recovery through piston compression or balancing with outside air, by using the energy from the pressure reduction between storage and engine operating pressure.

[0102] The invention is particularly suited to vehicles for which weight is not a major concern. Examples include commercial vehicles, buses and boats.

Claims

Demands

1. Hybrid drivetrain (100, 200) intended to equip a vehicle of specified weight and comprising a high-pressure compressed air reservoir (110) connected to a compressed air piston engine (120), itself engaged with an electric generator (130) capable of generating electricity when driven by the air piston engine (120), at least one electric motor (140, 240) connected to a transmission (150) engaged with a drive element (151, 152), the generator (130) and said at least one electric motor (140, 240) being connected via a backup electrical supply (160, 260) with a capacity of between 0.2 and 2.2 watt-hours per kilogram of vehicle to be equipped (Wh / kg vehicle), the drivetrain (100, 200) further comprising an accelerator control (170) movable between a stop position and a maximum acceleration position and connected to an electronic control circuit comprising a controller (180,280) programmed to power the electric motor (140, 240) from the relay electrical reserve (160, 260) according to a signal received by at least one sensor fitted to the vehicle.

2. Hybrid drive chain (200) according to claim 1, wherein the generator (130) and the electric motor (240) are also directly connected, the electronic control circuit further comprising an energy distributor (285) connected to the controller (280) and capable of supplying the electric motor (240) from the generator (130) and / or the electrical backup (260) on instructions received from the controller (280) according to a signal captured by said at least one sensor.

3. Hybrid drive chain (100, 200) according to any one of claims 1 or 2, wherein the relay electrical reserve (160, 260) consists of a portion of an initial power battery previously fitted to the vehicle.

4. Hybrid drive chain (100, 200) according to claim 3, wherein the relay electric reserve (160, 260) has a capacity between 1.2 and 2.2 Wh / kg of vehicle.

5. Hybrid drive chain (100, 200) according to any one of claims 1 or 2, wherein the relay electrical reserve (160, 260) consists of at least one supercapacitor, preferably a set of supercapacitors.

6. Hybrid drive chain (100, 200) according to claim 5, in in which the electrical relay reserve (160, 260) has a capacity between 0.2 and 1.2 Wh / kg of vehicle, preferably between 0.2 and 0.5 Wh / kg of vehicle.

7. Hybrid drive chain (100, 200) according to any one of claims 1 to 6, further comprising a throttle control position sensor (170), and wherein the controller (180, 280) is programmed to supply the electric motor (140, 240) from the relay electric reserve (160, 260) and / or the generator (130) depending, in particular, on the position of the throttle control (170).

8. Hybrid drive chain (100, 200) according to any one of claims 1 to 7, further comprising a throttle control movement speed sensor (170), and wherein the controller (180, 280) is programmed to supply the electric motor (140, 240) from the relay electric reserve (160, 260) and / or the generator (130) as a function, in particular, of the speed of movement of the throttle control (170).

9. Hybrid drive chain (100, 200) according to any one of claims 1 to 8, further comprising a vehicle travel speed sensor, and wherein the controller (180, 280) is programmed to supply the electric motor (140, 240) from the relay electrical reserve (160, 260) and / or the generator (130) as a function, in particular, of the vehicle travel speed.

10. Hybrid drive chain (100, 200) according to any one of claims 1 to 9, further comprising a kinetic energy recuperator (195) connected to the electrical relay reserve (160, 260) to charge the electrical relay reserve (160, 260) during vehicle braking.

11. Land vehicle, such as a car or utility vehicle, characterized in that it comprises a hybrid drive train (100, 200) according to any one of claims 1 to 10, wherein the drive unit comprises at least one pair of wheels (151).

12. Boat characterized in that it comprises a hybrid drive system according to any one of claims 1 to 10, wherein the displacement member comprises at least one propeller (152) or a turbine.

13. Method of modifying an electric vehicle equipped with an electric motor (140, 240), a power battery and a charging connector from an external source, to equip it with a chain hybrid drive (100, 200) according to any one of claims 1 to 10, comprising the following steps: a) remove the vehicle's power battery to free up installation space; b) insert the compressed air reservoir (110) into the installation volume and replace the refill connector with a refill valve connected to the compressed air reservoir; c) add the air piston engine (120), the generator (130) and the controller (180, 280) into the vehicle, preferably in the installation volume; d) add a backup electrical reserve (160, 260) in the vehicle, preferably in the installation volume, connected between the generator (130) and the electric motor (140, 240), the backup electrical reserve (160, 260) being made up of a part of the power battery having a capacity of between 1.2 and 2.2 Wh / kg of vehicle, or including at least one supercapacitor, preferably a set of supercapacitors with a capacity of between 0.2 and 0.5 Wh / kg of vehicle.

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