ENERGY RECOVERY DEVICE COUPLED TO A VEHICLE'S AXLE

Abstract

Vehicle comprising a chassis (14), a powertrain (10) configured to drive the movement of the vehicle, at least one non-driven wheel (110, 210), an axle shaft (112, 212) connected to said at least one non-driven wheel, the vehicle comprising an energy storage element and an electricity generation system (12) intended to supply the energy storage element (13) from the movement of the vehicle (1,2) comprising: - at least one electricity generator (1201) comprising a rotor (122), - transmission means (111, 211) connected to the axle shaft (112, 212) and configured to drive the rotor of said at least one electricity generator so that said at least one electricity generator generates energy supplying the energy storage element (13) from the movement of the axle shaft (112, 212). [Fig.2]

Description

Title of the invention: ENERGY RECOVERY DEVICE COUPLED TO THE AXLE OF A VEHICLE TECHNICAL FIELD AND PRIOR ART

[0001] The present invention relates to a device for recovering energy from the movement of a vehicle.

[0002] The vehicle moves by means of wheels driven by its motor or while descending a slope. During this movement, the vehicle accumulates kinetic energy from the energy supplied by the vehicle's motor and / or from the vehicle's potential energy if it is descending. This kinetic energy is, however, lost, particularly during a deceleration phase of the vehicle, during which Joule heating losses can occur, especially during braking.

[0003] Some vehicles are equipped with means of energy recovery from the kinetic energy stored by the vehicle during braking, which limits the periods of energy recovery. Description of the invention

[0004] It is therefore one of the aims of the present application to provide an energy recovery system equipping a vehicle that allows the production of electrical energy throughout the movement of the vehicle.

[0005] The solution proposed in this application relates to a vehicle which includes an axle shaft connected to at least one non-drive wheel and an electricity generation system for generating electrical energy from the rotational movement of the axle shaft, the latter being driven by said at least one non-drive wheel during the movement of the vehicle.

[0006] The vehicle has conventional equipment, namely a chassis, a powertrain, and wheels, including at least one non-drive wheel. The electricity generation system is intended to power an energy storage element from the vehicle's movement and comprises: - at least one electricity generator having a rotor, - transmission means connected to the axle shaft and configured to drive the rotor of said at least one electricity generator so that said at least one electricity generator generates energy powering the energy storage element, which may be a battery, for example, from the movement of the axle shaft.

[0007] More particularly, said at least one non-drive wheel drives an axle shaft in rotation during the movement of the vehicle, due to the conventional operation of the powertrain, i.e. the driving of the vehicle's drive wheels by means of a motor, or due to the movement of the vehicle downhill.

[0008] The electricity generation system thus makes it possible to convert the kinetic energy accumulated by the vehicle during its movement into electrical energy that can be stored by the energy storage element. The stored energy can then be used to power the electric motor of a car and / or devices on board the vehicle, such as signal lights, heating, or mobile phones.

[0009] The transmission means allow the rotor of one or more electricity generators to be coupled to the axle shaft and ensure the transmission of motion between the axle shaft and the rotor with little or no added stress on the vehicle's operation. Consequently, the motion transmitted by these transmission means powers the electricity generators, which convert this motion into electrical energy.

[0010] According to a first embodiment, the rotor of said at least one electricity generator is mounted movably in rotation on the chassis of the vehicle, said transmission means of said electricity generation system comprising at least one first roller or at least one first pulley fixed in rotation to the axle shaft, at least one second roller or at least one second pulley fixed in rotation to said rotor and drive means configured to transmit the motion of the axle shaft to the rotor of said electricity generator via the first roller and the second roller.

[0011] Advantageously, said drive means comprise a belt or a chain.

[0012] The first pulley and / or the second pulley is advantageously of the freewheel pulley type.

[0013] Said at least one electricity generator comprises a stator integral with said chassis.

[0014] According to a second embodiment, said at least one electricity generator is housed in the axle shaft, the rotor being around the axle shaft and configured to be driven by the axle shaft.

[0015] According to a first configuration of the vehicle, called "traction", the powertrain is configured to drive in rotation at least one drive wheel located at the front of the vehicle and said at least one non-drive wheel is located at the rear of the vehicle.

[0016] According to a second vehicle configuration, known as the "rear-wheel drive" configuration, the powertrain is configured to drive at least one drive wheel in rotation located at the rear of the vehicle and said at least one non-drive wheel is located at the front of the vehicle. BRIEF DESCRIPTION OF THE FIGURES

[0017] The following description will be better understood with the aid of the attached drawings, in which: [Fig.1] schematically represents a top view of a motor vehicle including the electricity generation system. [Fig.2] schematically represents a rear view of the motor vehicle of [Fig.1] which includes the electricity generation system according to a first embodiment of the invention. [Fig.3] schematically represents a rear view of the motor vehicle of [Fig.1] which includes the electricity generation system according to a second embodiment of the invention. [Fig. 4] schematically represents a front view of a moped vehicle including the electricity generation system according to the first embodiment. DETAILED DESCRIPTION OF EMBODIMENTS

[0018] Fig. 1 is a schematic representation of a motor vehicle 1 from a top view.

[0019] The vehicle 1 comprises a chassis 14 and a powertrain 10, of conventional designs known to those skilled in the art. The powertrain 10 includes two drive wheels 100, a motor 101, a first axle 102 comprising an axle shaft connected to the two drive wheels 100, and first transmission means 103. The motor 101 may be, for example, an internal combustion engine or an electric motor. The vehicle 1 may optionally include a trunk conventionally positioned at the rear of the vehicle 1.

[0020] More particularly, vehicle 1 includes a first configuration, called "traction", which is represented in [Fig.1] and, alternatively, a second configuration, called "rear-wheel drive", not shown.

[0021] In the first configuration, the drive wheels 100 are located at the front of the vehicle 1 and the powertrain is configured to drive the drive wheels 100 in rotation, via the first transmission means 103. The first transmission means 103, such as belt mechanisms, ensure the transmission of motion from the drive shaft to the axle shaft of the first axle 102.

[0022] The vehicle 1 also includes two non-drive wheels 110 and a second axle 11 comprising an axle shaft 112 connected to the two non-drive wheels 110. The two non-drive wheels 110 are located at the rear of the vehicle 1 according to the first configuration. The second axle 11 has conventional structures and known to those skilled in the art, such as the rigid structure, the semi-rigid structure, and the independent structure. The rigid structure, as shown in [Fig. 1], offers the advantage of a simple and inexpensive design. The independent structure, which is not shown, allows the non-driven wheels to move independently of each other.

[0023] According to one embodiment, the axle shaft 112 is flexible in the case of a semi-rigid structure and is configured to be driven in rotation by the non-drive wheels 110. The second axle also includes a rigid part 111 that forms an axle housing around the axle shaft 112 and is fixed to the chassis 14. In particular, the rigid part 111 serves to protect the elements it encloses and has a shape adapted to the configuration of the axle shaft of the second axle 11. In addition, the rigid part 111 and / or the axle shaft are configured to be corrosion-resistant and watertight. The second axle is conventionally connected to the chassis via suspensions. In what follows, it will be understood that the rigid, semi-rigid, and independent axle shaft structures will be considered for the embodiment of the invention.

[0024] The two non-drive wheels 110 are driven by the movement of the vehicle 1 without any action required from the powertrain 10 and can therefore, for example, be driven during descents of the vehicle 1, in particular when the power of the engine 101 is not used to set the drive wheels 100 in motion.

[0025] In the second configuration (not shown), the drive wheels are located at the rear of vehicle 1 and are driven in rotation by the powertrain 10 via a driveshaft (not shown). The non-drive wheels are located at the front of vehicle 1 in the second configuration. The vehicle in this second configuration is well known to those skilled in the art, who will subsequently be able to adapt the various equipment of the vehicle according to the first and second configurations, particularly during the assembly of the chassis 14 of vehicle 1.

[0026] Thus, the vehicle accumulates kinetic energy throughout its movement which can be recovered in the form of electrical energy, in particular when the vehicle moves along a downward trajectory during which kinetic energy accumulates without action of the motor 101 which does not provide power to turn the drive wheels 100.

[0027] In this regard, the vehicle 1 includes an energy storage element 13 and an electricity generation system 12 intended to power the energy storage element 13 from the movement of the vehicle 1.

[0028] The energy storage element 13 is a battery that can be placed at the rear of the vehicle, for example in the trunk. Connectors 130 are configured to electrically connect the electricity generation system 12 to the energy storage element 13.

[0029] The electricity generation system 12 is based on the use of electricity generators which are driven by the axle shaft 112 of the second axle 11, that is to say the axle shaft which is connected to the non-drive wheels 110.

[0030] For this purpose, the vehicle 1 includes transmission means 113 connected to the axle shaft of the second axle and configured to drive the rotor of the electricity generators in rotation so that the electricity generators generate energy which powers the energy storage element 13 from the movement of the axle shaft of the second axle.

[0031] The electricity generators and transmission means can have an arrangement according to a first embodiment which is represented in [Fig.2] and a second embodiment which is represented in [Fig.3].

[0032] Figure 2 schematically represents a rear view of an example of a motor vehicle as described above in relation to Figure 1, in which the power generation system is arranged according to the first embodiment. In this embodiment, the vehicle includes a compartment 123 in which the power generation system 12 is housed. The compartment 123 is rigidly fixed to the rigid part 111 of the second axle or is designed so that the rigid part 111 and the compartment 123 form a single unit, thus limiting the relative movement between the power generation system 123 and the second axle. Preferably, the compartment 123 is liquid-tight and advantageously made of a corrosion-resistant material, such as stainless steel, and can be located, if space permits, under the trunk of the vehicle 1, or otherwise be wholly or partly contained within the trunk volume.

[0033] The electricity generation system 12 includes at least one electricity generator, for example two alternators 1201 and 1202 which have a stator and a rotor.

[0034] The alternators described below are of the permanent magnet type. The stators and rotor of alternators 1201 and 1202 are of conventional design, meaning that the rotor can be equipped with electromagnets and each stator can have a winding circuit in which an electric current is generated, induced by the magnetic field of the electromagnets. The type of stator and rotor used in such alternators can be chosen according to the alternator's output power and also according to the rotor's rotational speed.

[0035] The structure of such alternators is conventional and comprises a housing containing the stator, the alternator's electronic circuit, and ventilation components, for example. The housing of these alternators, and more particularly The stator is rigidly fixed to the rigid part of the second axle and has dimensions that allow it to be housed within the rigid part 111 while optimizing the alternator's performance. These dimensions offer greater freedom in the choice of the winding circuit, and in particular in the number of turns of the winding, allowing the alternator's output power to be adapted so that it is compatible with the power supply of the storage element 13.

[0036] A person skilled in the art will be able to determine an appropriate means of fixing the stators to the chassis, for example by welding, fixing elements such as bolts or by clamping so as to secure the stator in a fixed position in the housing.

[0037] Housing the alternators in compartment 123 allows more freedom in the choice of alternators and in particular their electrical characteristics which depend on the size of these alternators.

[0038] Preferably, the alternators 1201 and 1202 share the same rotor 122. The rotor 122 is mounted movably in rotation on the chassis 14 of the vehicle 1 by means of fixing elements allowing the rotation of the rotor around an axis XI relative to the stators of the alternators which have a fixed position.

[0039] According to this first embodiment, the transmission means of the electricity generation system comprise a first roller 113, a second roller 121, and drive means 15. The first roller 113 is rotationally fixed to the axle shaft 112 of the second axle 11, and the second roller 121 is rotationally fixed to the rotor 122. The drive means 15 are configured to transmit the motion from the second axle shaft to the rotor 122 of the alternators via the first roller 113 and the second roller 121. For example, the drive means 15 are a belt or a chain. More particularly, the belt forms a band, for example, made of rubber or another semi-rigid material, which extends over the width of the first and second rollers so as to obtain a relatively strong belt structure. For example, the width of the roller is on the order of a few tens of centimeters.

[0040] Rollers have advantageous dimensions compared to pulleys, allowing for a more compact height in the transmission means and permitting the use of wider belts. Furthermore, the rollers have a roughness according to one embodiment or feature teeth that complement the teeth of a toothed belt according to another embodiment. Those skilled in the art will be able to design such rollers so that their roughness or teeth grip the belt, thus limiting belt wear. Such rollers help to minimize belt slippage on the rollers during power transmission.

[0041] The design of such transmission means may, for example, include a fixing of the first roller 113 around the axle shaft and a fixing of the second a roller around the rotor 122 and the tensioned belt is positioned around the first and second rollers using a belt tension adjustment system. Preferably, the belt tension is set so that the belt adheres sufficiently to the first and second rollers to transmit the rotational motion from one to the other.

[0042] Such drive means 15 are relatively simple to implement and have very little impact on the operation and movement of the vehicle. In particular, the positioning of the first roller 113 can be adapted on the axle shaft of the second axle according to the specifications of the second axle. In the case of an axle with an independent structure, for example, the second axle comprises two axle shafts, each connected to a non-drive wheel 110, and onto which the first roller 113 can be fixed.

[0043] Alternatively, the transmission means comprise a first pulley 113 and a second pulley 121 (not shown) and the drive means 15 transmit the motion of the axle shaft via the first pulley 113 and the second pulley 121. According to one embodiment, the first pulley and the second pulley are of the toothed wheel type.

[0044] In this embodiment, the transmission means 15 comprise a gear.

[0045] Advantageously, the transmission means comprise at least one additional roller or pulley (not shown) rotatably fixed to the axle shaft 112 of the second axle 11 and one additional roller or pulley (not shown) rotatably fixed to the rotor 122. The drive means 15 may comprise an additional belt or chain transmitting motion between each of these additional pulleys or rollers. In one embodiment, the first pulley and the additional pulley fixed to the axle shaft have a common structure and together form a "double" pulley (not shown). In this case, a "double" pulley is also formed by the second pulley and the additional pulley of the rotor.

[0046] Thus, the electricity generation system exhibits improved reliability thanks to the redundancy of the transmission means. Furthermore, such redundancy makes it possible to distribute the stresses and forces exerted on each of the belts or chains during the transmission of motion between the pulleys or rollers.

[0047] According to one embodiment, the second pulley 121 is a reducer configured to reduce the rotational speed of the rotor relative to that transmitted by the axle shaft of the second axle. The second pulley, according to this example, thus simplifies the transmission between the second pulley and the drive means. and also allows the use of rotor types adapted according to the range of rotational speeds supported by the rotor 122.

[0048] Advantageously, the first pulley 113 is of the freewheel pulley type. The freewheel pulley is typically integrated into an alternator used to convert the energy supplied by the engine into electrical energy and therefore has the advantage of using an identical model of alternator as that present on the vehicle, in particular alternators already having a drive pulley 113.

[0049] In addition, the freewheel pulley is configured to reduce the noise generated by the rotation of the axle in order to improve driving comfort, reduce the transmission of vibrations to the drive means in order to increase the longevity of the drive means, and limit or even eliminate friction losses due to belt slippage.

[0050] Furthermore, the freewheel pulley also allows the alternator rotor to rotate freely in freewheel mode when the axle shaft of the second axle slows down or stops in order to optimize energy recovery.

[0051] According to an alternative or in combination, the second pulley 121 is of the freewheel pulley type.

[0052] The power generation system advantageously includes sensors configured to monitor the charging voltage and / or charging current of the battery in real time. The vehicle 1 includes a display, for example the vehicle's instrument panel, configured to display the information transmitted by the sensors, notably via the vehicle 1's CAN network, and to alert the driver when the charging voltage and / or charging current falls below a threshold for a predetermined period, for example, approximately ten minutes. The threshold will be determined by a person skilled in the art based on parameters specific to the power generation system and the battery, as well as vehicle parameters, including its speed.The threshold corresponds to a minimum voltage or minimum charging current value, which may vary depending on factors such as vehicle speed, below which the electrical generation system will be considered faulty. Failure of the electrical generation system can manifest as belt slippage, a damaged battery or connectors, or alternator malfunction, for example. The minimum voltage and / or minimum charging current values ​​can be estimated from these parameters or determined from measurements taken during vehicle testing, for example, based on measurements taken at different speeds.

[0053] Figure 3 schematically represents a rear view of another example of a motor vehicle as described previously in relation to Figure 1 in in which the electricity generation system is arranged according to the second embodiment.

[0054] According to this second embodiment, the alternators 1201 and 1202 are housed in the second axle 11 so as to be enclosed by the rigid part 111. The alternators 1201 and 1202 may be of the same type as the alternators described previously in relation to [Fig. 2]. Alternatively, the alternators are of the single or double disc alternator type, that is, an alternator having one or more discs connected to the rotor 122 and driven in rotation by it. Single or double disc alternators have a smaller footprint compared to conventional alternators and can be more easily housed in the second axle 11, which may be subject to dimensioning constraints during its design. Preferably, the alternators are configured to be corrosion-resistant and, at least, watertight.

[0055] The stators of the alternators 1201 and 1202 are fixed to the rigid part 111, for example by means of fixing similar to those which are used to fix the stators to the frame 14 of the [Fig.2].

[0056] The electricity generation system according to this second embodiment also includes the sensors as described previously in relation to [Fig.2], which are configured to monitor in real time the evolution of the charging voltage and / or charging current of the battery.

[0057] The rotor 122 is located around the axle shaft 112 of the second axle and can be connected directly to it by welding or by fastening means such as bolts for example.

[0058] In particular, the rotor 122 is configured to be driven by the axle shaft 112 and is therefore mounted to rotate freely about the axis X2 relative to the stators of the alternators 1201 and 1202. Preferably, the system 12 includes bearings 114 which are located between the axle shaft 112 and each of the stators 1201 and 1202.

[0059] Thus, the electricity generation system 12 according to this second embodiment is more compact than the system according to the first embodiment described previously in relation to [Fig.2].

[0060] In a particular embodiment, it is also envisaged that the alternators will be housed in a rigid part of the first axle which includes an axle shaft driven by the drive wheels. In particular, such alternators, whose rotor is driven in rotation by the axle shaft of the first axle, can be arranged in the same way as described above.

[0061] Advantageously, the electricity generation system is integrated into the manufacture of the chassis 4, in particular by assembling the alternators during the assembly of the axle shaft with the axle housing.

[0062] According to an alternative, the electricity generation system is designed to be integrated into chassis, and more particularly into a chassis axle, so as to allow vehicles not currently equipped with such an electricity generation system to be fitted out, and also to allow the system to be repaired if it is damaged. This repair can be carried out following a system failure detected, for example, by monitoring the battery charge using sensors.

[0063] Fig. 4 schematically represents a front view of a moped vehicle, in particular a three-wheeled vehicle, in which the electricity generation system is arranged according to the first embodiment.

[0064] The moped 2 differs from the vehicle described previously with reference to Figures 1 to 3 in that it comprises a single drive wheel (not shown) driven by a motor (not shown). The vehicle 2 also comprises a chassis 24 which has a fork on which an axle 212 is mounted, connected to the non-drive wheel 210 and comprising a rigid portion 211. The axle 212 is mounted for rotational movement on the fork of the chassis 24.

[0065] The energy storage element 23 is located at the rear of the vehicle, for example, and the electricity generation system 22 is arranged on the vehicle 2 according to the first embodiment. In this embodiment, the vehicle 2 comprises a compartment 223 in which the rotor 221 is mounted for rotation on the chassis 24 and is driven by transmission means 213 that transmit the motion from the axle 212 to the rotor 221. In this example, the electricity generation system 22 comprises two alternators 2201 and 2202 electrically connected to the energy storage element 23. The respective stators of the alternators 2201 and 2202 are fixed to the vehicle chassis 24 in the compartment so as to cooperate with the rotor 221, which is moving relative to the chassis, to generate electrical energy to power the energy storage element 23.

[0066] More particularly, the first roller 213, which is rotationally fixed to the axle shaft 212, and the second roller 220, which is rotationally fixed to the rotor 221, are coupled together by the drive means 25. The drive means 25 are similar to the drive means described previously in relation to Figures 1 to 3.

[0067] Thus, the electricity generation system is compatible with any type of rolling vehicle equipped with an axle shaft driven by non-driving wheels, such as a truck or a train for example.

Claims

Demands

1. A vehicle comprising a chassis (14), a powertrain (10) configured to drive the vehicle's movement, at least one non-driven wheel (110, 210), an axle shaft (112, 212) connected to said at least one non-driven wheel, the vehicle comprising an energy storage element and an electricity generation system (12) for powering the energy storage element (13) from the vehicle's movement (1, 2) comprising: - at least one electricity generator (1201) having a rotor (122), - transmission means (111, 211) connected to the axle shaft (112, 212) and configured to rotate the rotor of said at least one electricity generator such that said at least one electricity generator generates energy powering the energy storage element (13) from the movement of the axle shaft (112,212).

2. Vehicle according to claim 1, wherein the rotor of said at least one electricity generator is mounted movably in rotation on the chassis (14) of the vehicle, said transmission means of said electricity generation system comprising at least one first roller or at least one first pulley (111) fixed in rotation to the axle shaft (112), at least one second roller or at least one second pulley (121) fixed in rotation to said rotor (122) and drive means (113) configured to transmit the motion of the axle shaft to the rotor (122) of said electricity generator via the first roller or said first pulley (111) and the second roller or said second pulley (121).

3. Vehicle according to claim 2, wherein said drive means comprise a belt or a chain.

4. Vehicle according to any one of claims 2 and 3, wherein the first pulley and / or the second pulley is of the freewheel pulley type.

5. Vehicle according to any one of the preceding claims, wherein said at least one power generator comprises a stator (1201, 1202) integral with said chassis (14).

6. Vehicle according to claim 1, wherein said at least one electricity generator (1101, 1102) is housed in the axle shaft (112), the rotor being around the axle shaft and configured to be driven by the axle shaft.

7. Vehicle according to any one of the preceding claims, comprising a first configuration, referred to as "front-wheel drive", in which the powertrain is configured to rotate at least one drive wheel (100) located at the front of the vehicle and said at least one non-drive wheel (110) is located at the rear of the vehicle, or a second configuration, referred to as "rear-wheel drive", in which the powertrain is configured to rotate at least one drive wheel located at the rear of the vehicle and said at least one non-drive wheel is located at the front of the vehicle.