THREE-IN-ONE TRANSMISSION SYSTEM FOR AUTOMOBILES

Abstract

THREE-IN-ONE TRANSMISSION SYSTEM FOR A MOTOR VEHICLE The present invention relates to a transmission system (3) for a wheel (10) of a motor vehicle (1), comprising a wheel braking device (26), notable in that said transmission system comprises a reduction gear (21) provided with a toothed wheel (24.1) and a pinion (23) engaged with an external tooth (24.2) of said toothed wheel, achieving a reduction of the motion received from a motor vehicle engine. Said transmission system further comprises a sealed compartment (15) integrating the braking device and the reduction gear, said braking device and said reduction gear being immersed in a lubricating fluid (19) within the sealed compartment. (Figure to be published with the abbreviation: Figure 2)

Description

Title of the invention: THREE-IN-ONE TRANSMISSION SYSTEM FOR MOTOR VEHICLES technical field

[0001] The present invention relates to the field of motor vehicles, more particularly to the field of motor vehicle transmission systems. Prior art

[0002] Conventionally, hybrid and electric vehicles are equipped with a transmission system that generally consists of separate components for the reduction gear and the braking system. In current configurations, there is a pivoting suspension arm, with the wheel equipped with a dry drum brake mounted on its axle on one side, and on the other side an electric motor offset from the wheel axle and integrated into a housing of the arm with its reduction gear.

[0003] This design creates two separate sub-assemblies: the electric machine's gearbox, containing a lubricating fluid, and the dry drum brake, each with its own housing. These multiple housings increase the unsprung mass and volume, thus posing a space constraint that limits the optimization of suspension size and impairs the performance of the motor vehicle.

[0004] The published patent document US 2014 / 0159468 Al discloses another motorization system, comprising a dry brake integrated into a wheel rim having a stator formed inside said rim, with a central cylindrical portion forming the rotor of an electric machine.

[0005] However, the motorization system proposed by the document requires that the rotor of the machine rotate at the same speed as the wheel, without reduction, which complicates the optimization of speed and torque, thus increasing the weight and size of the electric machine, and negatively impacting comfort and road handling.

[0006] Furthermore, integrating a dry brake and the electric motor into the wheel leads to several problems. In particular, wear of the brake linings generating dust harmful to the environment can disrupt internal components, such as the electric motor rotor and bearings. Description of the invention

[0007] The present invention aims to overcome at least one of the drawbacks of the aforementioned prior art. More particularly, the invention aims to provide a transmission system for a wheel of a motor vehicle. incorporating a wheel brake, ensuring increased space savings and operating efficiency.

[0008] To this end, the invention relates to a transmission system for a motor vehicle wheel, comprising a wheel braking device, remarkable in that said transmission system comprises a reducer provided with a toothed wheel and a pinion engaged with an external toothing of said toothed wheel, achieving a multiplication of the motion received from a motor vehicle engine, said transmission system further comprises a sealed compartment integrating the braking device and the reducer, said braking device and said reducer being immersed in a lubricating fluid within the sealed compartment.

[0009] Advantageously, the braking device and the reducer are at least partially immersed in a lubricating fluid.

[0010] According to one embodiment, the braking device comprises a brake disc and two brake linings arranged on either side of said brake disc, said brake linings being configured to pinch the brake disc, the toothed wheel and said brake disc both being arranged to rotate around a wheel axle.

[0011] According to one embodiment, the braking device includes a brake caliper carrying the two brake linings arranged on either side of the brake disc and the toothed wheel, said caliper being configured to allow the passage of the teeth of the toothed wheel during the rotation of said toothed wheel.

[0012] According to one embodiment, the toothed wheel is integrally formed with the brake disc, the teeth being directly formed on the periphery of said brake disc and extending in a radial direction.

[0013] According to one embodiment, said transmission system further comprising a filtration device in fluidic connection with the lubrication fluid, configured to recover brake dust particles in said lubrication fluid.

[0014] Preferably, the filtration device includes a filter disposed within the sealed compartment or in a lubrication fluid circulation circuit.

[0015] According to one embodiment, said transmission system comprising a suspension arm which includes a hub extending from an outer side of said suspension arm, said hub receiving the sealed compartment and carrying the wheel.

[0016] Advantageously, the hub defines the wheel axle. The suspension arm can correspond to a swing arm or a torsion arm of the motor vehicle.

[0017] According to one embodiment, the electric machine is arranged at an inner side of the suspension arm, and the pinion engaged with the outer teeth of the gear is disposed at a distal end of a shaft extending from the electric machine and through the suspension arm.

[0018] According to one embodiment, the shaft passes through the sealed compartment at the level of an orifice disposed on a lateral plate of said sealed compartment and sealed by means of a seal.

[0019] According to one embodiment, the side plate is removable and is arranged, in normal mounting position, parallel to the toothed wheel and opposite the outer side of the suspension arm.

[0020] The invention also relates to a motor vehicle comprising an electric traction battery, notable in that it includes a transmission system according to the present invention.

[0021] Advantageously, the transmission system is fixed on a suspension arm of the motor vehicle.

[0022] The features of the invention are advantageous in that the transmission system offers significant space savings through the sharing of functions, a reduction in mass and assembly time by avoiding the separate installation of the gearbox and brake disc. Thus, the transmission system can be fully assembled before its installation on the axle of the motor vehicle, thereby simplifying and accelerating assembly and resulting in significant cost savings.

[0023] Furthermore, the wet braking system allows for improved thermal management of braking while reducing maintenance requirements. In addition, the particle recovery function contributes to environmental protection and complies with future regulations. Brief description of the drawings

[0024] [Fig.1] illustrates a perspective view of a transmission system according to the present invention fixed to a suspension arm of a motor vehicle;

[0025] [Fig.2] illustrates a side view of the transmission system of the [Fig.2], comprising a reducer provided with a pinion engaged with an external toothing of a toothed wheel;

[0026] [Fig.2] represents a cross-sectional view along axis AA passing through the system of transmission visible in [Fig.2]. Detailed description

[0027] Fig. 1 illustrates a perspective view of a transmission system 3 according to the present invention fixed to a suspension arm 2 of a motor vehicle 1.

[0028] The suspension arms 2 can be of a front wheel or a rear wheel 10 of the motor vehicle 1. Preferably, it is a rear suspension arm 2, fixed to the body of the vehicle 1 by a front transverse pivot 4 arranged along a suspension axis 6.

[0029] The suspension arm 2 includes a hub 8 defining the wheel axle 12 and extending from an outer side 2.1 of said arm 2 and towards an outer side EXT of the motor vehicle 1. The pivot 4 for fixing to the body of the vehicle is preferably formed parallel to the wheel axle 12, at the end opposite the wheel hub 8, towards the front AV of the vehicle 1.

[0030] The motor vehicle 1 includes an electric machine 18 corresponding, preferably, to an electric motor 18 powered by an electric traction battery, said electric machine 18 is mounted on an inner side 2.2 of the suspension arm 2 and extends transversely along a transverse axis 20. The motor vehicle 1 is preferably of the electric or hybrid type.

[0031] Advantageously, the hub 8 carries the wheel 10 of the vehicle 1 and also receives a sealed compartment 15 in which is located a speed reducer for the rotation of the electric machine 18 as well as a braking device for the wheel 10 of the motor vehicle 1. Figures 2 and 3 show these elements, they will be described in more detail later in this description.

[0032] The electric machine 18 comprises a shaft 22 extending transversely from the machine, passing through the suspension arm 2 and a lateral plate 16 to reach the sealed compartment 15 where the gearbox is located. The shaft 22 has a distal end forming a pinion 23 (shown in Figures 2 and 3). In this configuration, the shaft 22 passes through the sealed compartment 15 at an opening 16.1 located on its lateral plate 16 and sealed by means of a seal.

[0033] Preferably, the side plate 16 of the sealed compartment 15 is removable, allowing in particular access to the braking device. In the normal mounting position illustrated in [Fig. 1], the plate 16 is opposite the outer side 2.1 of the suspension arm 2.

[0034] Fig. 2 illustrates a side view of the transmission system 3 of Fig. 2, showing the reducer 21 comprising the pinion 23 formed at the end of the shaft of the electric machine, which is engaged with an external tooth 24.2 of a gear 24.1.

[0035] The side view in [Fig.2] is of the interior side of the motor vehicle 1. In this respect, the suspension arm 2 is hidden (represented in dotted lines) in order to better distinguish the elements within the sealed compartment 15.

[0036] Advantageously, the reducer 21, formed by the gear between the pinion 23 and the toothed wheel 24.1, is entirely disposed within the sealed compartment 15. The latter also includes the braking device 26 of the wheel 10 of the motor vehicle 1.

[0037] In this configuration, the braking device 26 and the reducer 21 are both immersed (at least partially) in a lubricating fluid 19 retained inside the compartment 15.

[0038] Preferably, the braking device 26 comprises a brake disc 24 and two brake linings carried by a caliper 25 and configured to clamp the disc 24 to brake the wheel 10. Thus, the braking device 26 is of the disc brake type operating in the fluid.

[0039] The brake disc 24 and the toothed wheel 24.1 are both arranged to rotate around a wheel axle 12 and carried by the hub 8.

[0040] Advantageously, the permanent lubrication within compartment 15 ensures cooling by the fluid 19 circulating inside, distributing the heat generated by the friction of the linings on the brake disc 24 over all external circumferential surfaces to facilitate its dissipation. This prevents the risk of overheating and thus improves braking efficiency.

[0041] It can be seen that the pinion 23 is positioned towards the front AV between the wheel axle 12 and the suspension pivot 4, so as to present a distance W between 20 mm and 400 mm. Advantageously, the electric machine, placed at such a distance W from the wheel axle 12 while being sufficiently close to the axis 6 of the suspension arm 2, makes it possible to significantly reduce the unsprung mass at the wheel 10 compared to a machine positioned directly on the wheel axle. This improves the comfort and road handling of the motor vehicle 1.

[0042] The gear wheel 24.1 and the brake disc 24 can be offset from each other along the axis of rotation 12. Preferably, the gear wheel 24.1 is formed with the brake disc 24, with the external teeth 24.2 extending radially from a periphery of the brake disc 24.

[0043] Fig. 3 represents a cross-sectional view along axis AA passing through the transmission system 3 visible in Fig. 2.

[0044] Advantageously, the caliper 25 is configured to allow the passage of the teeth 24.2 of the gear 24.1 during the rotation of the latter around the axis of rotation 12. The combination of the brake disc 24 and the gear 24.1 makes it possible to achieve the maximum space saving, making it possible to considerably compact the sealed compartment 15 along the axis 12.

[0045] The sealed compartment 15 preferably includes a sealing gasket 28 disposed at a junction with the removable side plate 16, this allows the fluid 19 to be kept inside, while facilitating maintenance operations, including in particular the replacement of the brake linings 26.1 and 26.2.

[0046] It should be noted that the braking device 26, of the wet brake type, is located in the closed and sealed volume of the compartment 15, which prevents the emission of brake dust into the ambient air, thus making it environmentally friendly.

[0047] Preferably, the transmission system 3 of the present invention further comprises a filtration device (not shown) in fluidic connection with the lubricating fluid 19, configured to recover brake dust particles from said fluid 19 and thus purify the latter. In this regard, the filtration device may comprise a filter disposed directly within the volume of the compartment 15 and / or in a circulation circuit for the fluid 19 which may be located outside said volume.

[0048] Advantageously, the speed reducer 21 allows the electric machine 18 to rotate faster than the wheel, proportionally reducing the torque required by the wheel. This results in a compact, lightweight, and low-volume machine. This transmission system for the wheel of an electric or hybrid vehicle is thus compact, lightweight, and efficient, particularly due to the single gear between the motor 18 and the wheel.

Claims

Demands

1. Transmission system (3) for a wheel (10) of a motor vehicle (1), comprising a wheel braking device (26), characterized in that said transmission system (3) comprises a reducer (21) having a toothed wheel (24.1) and a pinion (23) engaged with an external toothing (24.2) of said toothed wheel (24.1), achieving a reduction of the motion received from a motor (18) of a motor vehicle (1), said transmission system (3) further comprises a sealed compartment (15) integrating the braking device (26) and the reducer (21), said braking device (26) and said reducer (21) being immersed in a lubricating fluid (19) within the sealed compartment (15).

2. Transmission system (3) according to claim 1, wherein the braking device (26) comprises a brake disc (24) and two brake linings (26.1, 26.2) arranged on either side of said brake disc (24), said brake linings (26.1, 26.2) being configured to clamp the brake disc (24), the toothed wheel (24.1) and said brake disc (24) both being arranged to rotate about a wheel axle (12).

3. Transmission system (3) according to claim 2, wherein the braking device (26) comprises a brake caliper (25) carrying the two brake linings (26.1, 26.2) arranged on either side of the brake disc (24) and the toothed wheel (24.1), said caliper (25) being configured to allow the passage of the teeth (24.2) of the toothed wheel (24.1) during the rotation of said toothed wheel (24.1).

4. Transmission system (3) according to any one of claims 2 and 3, wherein the gear (24.1) is integrally formed with the brake disc (24), the teeth (24.2) being directly formed on the periphery of said brake disc (24) and extending in a radial direction.

5. Transmission system (3) according to any one of claims 1 to 4, further comprising a filtration device in fluidic connection with the lubrication fluid (19), configured to recover brake dust particles in said lubrication fluid (19).

6. Transmission system (3) according to any one of claims 1 to 5, comprising a suspension arm (2) which includes a hub (8) extending from an outer side (2.1) of said suspension arm (2), said hub (8) receiving the sealed compartment (15) and carrying the wheel (10).

7. Transmission system (3) according to claim 6, wherein the electric machine (18) is arranged at an inner side (2.2) of the suspension arm (2), and the pinion (23) engaged with the outer teeth (24.2) of the gear (24.1) is disposed at a distal end of a shaft (22) extending from the electric machine (18) and through the suspension arm (2).

8. Transmission system (3) according to claim 7, wherein the shaft (22) passes through the sealed compartment (15) at an orifice (16.1) disposed on a lateral plate (16) of said sealed compartment (15) and sealed by means of a seal.

9. Transmission system (3) according to claim 8, wherein the side plate (16) is removable and is arranged, in normal mounting position, parallel to the toothed wheel (24.1) and opposite the outer side (2.1) of the suspension arm (2).

10. Motor vehicle (1) comprising an electric traction battery, characterized in that it comprises a transmission system (3) according to any one of claims 1 to 9.

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