Power transmission assembly and vehicle comprising this assembly

Abstract

Power transmission assembly and vehicle comprising this assembly. Power transmission assembly (100) comprising a differential (106) consisting of two epicyclic gear trains (110, 120) and a differential linkage mechanism (130) capable of engaging or disengaging the epicyclic gear trains. Figure for abbreviation: FIGURE 2

Description

Title of the invention: Power transmission assembly and vehicle comprising this assembly. Technical field

[0001] The present invention relates to a power transmission assembly, for example for making an electric vehicle or a hybrid vehicle. STATE OF PRIOR ART

[0002] More particularly, the invention relates to a power transmission assembly, for example, for producing an electric vehicle or a hybrid vehicle (comprising an internal combustion engine and an electric motor). For example, the power transmission assembly makes it possible to convert an internal combustion vehicle into a hybrid vehicle or to convert an internal combustion vehicle into an electric vehicle.

[0003] For example, the power transmission assembly makes it possible to create a four-wheel drive vehicle or to convert a two-wheel drive vehicle into a four-wheel drive vehicle. For example, the power transmission assembly makes it possible to convert a vehicle with an internal combustion engine driving the front axle (a front-wheel drive vehicle with two front-wheel drive wheels) into a four-wheel drive vehicle in which an electric motor from this assembly is intended to be connected directly or indirectly to the rear axle of this vehicle. Conversely, a rear-wheel drive internal combustion vehicle can be converted into a four-wheel drive vehicle, the power transmission assembly then being connected directly or indirectly to the front axle of the vehicle.

[0004] In particular, the power transmission assembly comprises:

[0005] - a differential comprising at least one differential input, said differential comprising a plurality of interconnected gears to distribute the differential input power between a first output and a second output, the distribution being a function of the rotational speed of the first and second outputs, and

[0006] the differential comprising the following gear sub-assemblies:

[0007] - a first epicyclic gear train,

[0008] - a second epicyclic gear train, and

[0009] - a linkage mechanism comprising a first shaft connected to the first train epicyclic and a second shaft connected to the second epicyclic gear train,

[0010] the first and second epicyclic trains being identical.

[0011] For example, patent application WO 2021 / 069819 proposes a power transmission assembly substantially of this type. Description of the invention

[0012] The present disclosure is intended to further improve the previous power transmission.

[0013] To that end, the present disclosure relates to a power transmission assembly in which:

[0014] The linking mechanism further comprises:

[0015] - a third tree, and

[0016] - a brake connected to said third shaft,

[0017] said linking mechanism being configured for

[0018] linking the first epicyclic gear train and the second epicyclic gear train when the brake is activated, the first shaft and the second shaft being in opposite rotation, and

[0019] release the first epicyclic gear train and the second epicyclic gear train when the brake is deactivated, the first shaft and the second shaft being free to rotate relative to each other.

[0020] This results in a power transmission assembly that incorporates a linkage mechanism which integrates a differential input coupling function. Thanks to this coupling, the power transmission can be controlled very easily.

[0021] Thanks to this integration, the power transmission assembly is more compact than in the prior art, therefore easier to integrate to drive a front and / or rear axle of a vehicle.

[0022] Installation of the assembly is then easier on the vehicle, particularly when modifying a standard two-wheel-drive vehicle to convert it into a four-wheel-drive vehicle, or converting a combustion engine vehicle into an electric vehicle, or converting a combustion engine vehicle into a hybrid vehicle. Indeed, the installation can be carried out by modifying only a few components of the vehicle.

[0023] Furthermore, the coupling function of the power transmission linkage mechanism is simple to implement, and simpler than a clutch. Indeed, the brake of the linkage mechanism is external to the device (accessible from the outside) and operates dry: it is therefore easy to maintain.

[0024] In various embodiments of the power transmission assembly according to this disclosure, one and / or the other of the following provisions may also be used.

[0025] According to one aspect, the linking mechanism comprises a meshing mechanism including:

[0026] - a first planetary gear connected to the first tree,

[0027] - a second planetary gear connected to the second tree,

[0028] - at least one satellite engaging with the first planetary and the second planetary,

[0029] - a satellite carrier freely supporting in rotation at least one satellite,

[0030] the third tree being connected to the satellite carrier.

[0031] According to one aspect, the first planetary, the second planetary, at least one satellite are 90° conical gears.

[0032] Depending on one aspect, the brake is actuated by hydraulic, electrical, or mechanical action.

[0033] According to one aspect, the assembly includes a control member connected to the first or second shaft of the linkage mechanism, said control member being configured to control the rotation of said first or second shaft when the brake is activated.

[0034] According to one aspect, the control element is a brake, or an electric motor, or a combination of brake and electric motor.

[0035] According to one aspect:

[0036] The first epicyclic gear train includes a satellite carrier corresponding to the first output of the differential,

[0037] the second epicyclic gear train includes a satellite carrier corresponding to the second output of the differential,

[0038] a drive shaft connects an inner planetary gear of the first epicyclic gear train and an inner planetary gear of the second epicyclic gear train, the drive shaft corresponding to the input of the differential,

[0039] at least one satellite of the first epicyclic gear train is rotatably mounted on the satellite carrier of the first epicyclic gear train and meshes with the inner planetary gear and with an outer ring gear of the first epicyclic gear train, and

[0040] at least one satellite of the second epicyclic gear train is rotatably mounted on the satellite carrier of the second epicyclic gear train and meshes with the inner planetary gear and with an outer ring gear of the second epicyclic gear train, and in which

[0041] the outer ring of the first epicyclic gear train meshes with a first pinion of the first shaft of the linkage mechanism, and

[0042] the outer ring of the second epicyclic gear train engages with a second pinion of the second shaft of the linkage mechanism.

[0043] According to one aspect:

[0044] the first epicyclic gear train includes an internal ring corresponding to the first output SI of the differential,

[0045] the second epicyclic gear train comprises an internal ring corresponding to the second output of the second epicyclic gear train,

[0046] a drive shaft connects an inner planetary gear of the first epicyclic gear train, an inner planetary gear of the second epicyclic gear train, the drive shaft corresponding to the input of the differential,

[0047] at least one satellite of the first epicyclic gear train is rotatably mounted on a satellite carrier of the first epicyclic gear train and meshes with the inner planetary gear and the inner ring gear of the first epicyclic gear train,

[0048] at least one satellite of the second epicyclic gear train is rotatably mounted on a satellite carrier of the second epicyclic gear train and meshes with the inner planetary gear and the inner ring gear of the second epicyclic gear train,

[0049] and in which.

[0050] an external ring of the first epicyclic gear train is integral with the planet carrier of the first epicyclic gear train and meshes with a first pinion of the first shaft of the linkage mechanism, and

[0051] an external ring of the second epicyclic train is integral with the satellite carrier of the second epicyclic train and meshes with a second pinion of the second shaft of the linkage mechanism.

[0052] According to one aspect, the assembly further comprises an electrical machine including a fixed stator and a rotor that rotates about an axis of rotation AX of said electrical machine, and in which:

[0053] The differential input is connected to the rotor of the electric machine,

[0054] the first SI output of the differential is connected to a first power transmission shaft,

[0055] the second output S2 of the differential is connected to a second power transmission shaft.

[0056] According to one aspect, the gears of the differential are distributed around the electric machine, the electric machine being located inside the volume of the differential, the first epicyclic gear train being arranged on a first side of the electric machine, and the second epicyclic gear train being on a second side of the electric machine opposite the first side.

[0057] According to one aspect:

[0058] The electric machine is an inverted machine in which the rotor is radially outside the stator with respect to the axis of rotation.

[0059] The disclosure also relates to a vehicle comprising:

[0060] - a front axle,

[0061] - a rear axle, and

[0062] - a power transmission assembly of the previous type, the first output and the second output of the differential of this transmission assembly being connected directly or indirectly respectively to a first power transmission shaft of a first wheel and to a second power transmission shaft of a second wheel, of the front axle and / or to the rear axle of the vehicle.

[0063] In various embodiments of the vehicle according to this disclosure, one and / or the other of the following provisions may also be used.

[0064] According to one aspect, the brake is deactivated if the vehicle speed is above a limit speed.

[0065] According to one aspect, the power transmission assembly further includes a pilot member connected to the first or second shaft of the linkage mechanism, said pilot member being configured to pilot the rotation of said first or second shaft of the linkage mechanism when the brake is activated, or to lock the first and second shafts of the linkage mechanism when the brake is activated.

[0066] According to one aspect:

[0067] The power transmission assembly further comprises an electrical machine comprising a fixed stator and a rotor that rotates about an axis of rotation of said electrical machine, and in which:

[0068] The differential input is connected to the rotor of the electric machine,

[0069] The first output of the differential is connected to a first power transmission shaft,

[0070] the second output of the differential is connected to a second power transmission shaft, and

[0071] in which:

[0072] - the brake of the linkage mechanism is activated and the electric machine is in mode engine if a vehicle accelerator pedal is pressed,

[0073] - the brake of the linkage mechanism is activated and the electric machine is in mode generator if a vehicle accelerator pedal is released or if a vehicle brake is activated, and

[0074] - the brake of the linkage mechanism is deactivated if the vehicle speed is above a certain speed limit. Brief description of the drawings

[0075] Other features and advantages of the disclosure will become apparent during the following description of one of its embodiments, given by way of non-limiting example, with regard to the accompanying drawings.

[0076] On the drawings:

[0077] - [Fig.1] is a schematic top view of a vehicle;

[0078] - [Fig. 2] is a schematic view of a first embodiment of a power transmission incorporating a first type of epicyclic gear train;

[0079] - [Fig. 3] is a schematic view of a second embodiment of a power transmission incorporating a second type of epicyclic gear train;

[0080] - [Fig. 4] is a detailed view of the transmission linkage mechanism power of the [Fig.2];

[0081] - [Fig. 5] is a view of an example embodiment of power transmission of the [Fig.3];

[0082] - [Fig. 6] is a perspective view of the example in [Fig. 5]; and

[0083] - [Fig.7] is a schematic view of a variant of a power transmission, corresponding to the first type of epicyclic train of [Fig.2], without integrating an electric machine.

[0084] In the different figures, the same numerical references designate identical or similar elements. DETAILED DESCRIPTION

[0085] Figure 1 is a schematic top view of a vehicle 1 according to this disclosure. This vehicle 1 is, for example, a two-axle vehicle, comprising:

[0086] - a chassis 4,

[0087] - a front axle 10 coupled to a first motor 2, and

[0088] - a rear axle 20.

[0089] In this example shown in [Fig.1], the front axle 10 is coupled to a first motor 2. But, all the variants mentioned in the introduction are possible.

[0090] The first motor 2 is for example an internal combustion engine, or possibly a first electric motor.

[0091] The front axle 10 includes a right wheel 11, a left wheel 12, and a traction unit 13 which couples the first motor to the right and left wheels 11, 12 by means of traction shafts 14, 15. The traction unit 13 includes, for example, a gearbox, and a differential device for distributing power between the right and left wheels of the front axle 10.

[0092] The rear axle 20 includes a right wheel 21, a left wheel 22, and a power transmission assembly 100. The power transmission assembly 100 incorporates or includes a differential 106 to distribute power between the right and left wheels 21,22 of the rear axle 20, via drive shafts 24, 25.

[0093] Optionally, the vehicle 1 is initially a traditional four-wheel drive vehicle, i.e. a four-wheel drive vehicle driven by the first motor 2. The vehicle may further include a transfer shaft 3 which also couples the traction unit 13 to the rear axle 20 to deliver part of the driving power from the first motor 2 to the wheels of the rear axle 20. This transfer shaft 3 is usually coupled to a differential gear ring by a bevel gear.

[0094] Other mechanical elements are usually introduced into such a mechanical chain, in particular for example cardan shafts to allow wheel movements, and various other couplings and mechanisms.

[0095] Figures 2 to 7 show embodiments of a power transmission assembly 100 according to this disclosure.

[0096] Fig. 2 is a schematic view allowing one to understand the operation of a first embodiment of the power transmission assembly 100.

[0097] Fig. 3 is a schematic view of a second embodiment of the power transmission assembly 100.

[0098] Fig. 4 is a detail view of a linkage mechanism 130 of the first or second embodiment.

[0099] Figures 5 and 6 represent an example of an embodiment of the second embodiment of the power transmission assembly 100.

[0100] The [Fig.7] is a schematic view of a variant of the power transmission assembly 100 of the [Fig.2].

[0101] In the various embodiments, the power transmission assembly 100 comprises:

[0102] - a differential 106 comprising a differential input, the differential comprising a plurality of interconnected gears to distribute the power into the differential input, between a first output S1 and a second output S2, the distribution being a function of the rotation speed of the first output S1 and the second output S2.

[0103] According to a first variant shown in this description, the transmission assembly 100 further comprises an electric machine 102 comprising

[0104] - a fixed stator 103, for example relative to the chassis 4 of vehicle 1, and

[0105] - a rotor 104 that is movable and rotates relative to an axis of rotation AX of the machine electric 102.

[0106] In this first variant:

[0107] - the input of the differential 106 is connected to a drive shaft 105, by example itself connected to the rotor 104 of the electric machine 102,

[0108] the first output SI of the differential is connected to a first power transmission shaft, for example itself connected to the first drive shaft 24,

[0109] the second output S2 of the differential is connected to a second power transmission shaft, for example itself connected to the second drive shaft 25.

[0110] Furthermore, in this first variant, the gears of the differential 106 are distributed around the electric machine 102, the electric machine being located inside the volume of the differential.

[0111] This solution offers integration into a single product, which can be advantageous in certain applications.

[0112] According to a second variant, the transmission assembly 100 includes an electric machine 102 as in the first variant, and this electric machine 102 is offset from the differential 106: the electric machine is not located inside the differential 106.

[0113] This solution thus offers a variant arrangement of the differential elements 106 and the electrical machine 102, which may be advantageous in certain applications and available spaces.

[0114] According to a third variant, the transmission assembly 100 does not include an electric machine 102. Thus, the transmission assembly 100 is a passive device without power input, corresponding to a specific type of differential, controllable as will be explained later in the explanations of the first variant incorporating an electric machine. However, without this electric machine, the power transmission 100 offers controllability advantages.

[0115] These two previous variants are for example represented in the diagram of [Fig.7] which reproduces only as an illustration the construction of the differential 106 of [Fig.2], but the construction of the differential 106 of [Fig.3] could also be reproduced.

[0116] Thus, instead of the electric machine 102, the transmission assembly 100 of these variants can include a return element 140.

[0117] The transfer element 140 comprises a first wheel 141 connected to the input of the differential, i.e., the drive shaft 105, and a second wheel 142 meshed with the first wheel 141. The two wheels 141 and 142 are, for example, as illustrated, conical wheels. An input shaft of the second wheel 142 then allows the drive shaft 105 to be rotated from outside the transmission assembly 100. The transfer element 140 of the transmission assembly 100 thus allows the use of another power motor, such as an external electric motor or even the first motor 2 of the vehicle. This variant allows the bulk of this other motor to be decoupled from the bulk of the differential 106 of the present power transmission 100, which offers more freedom of installation in a vehicle.

[0118] The remainder of this description will detail the first variant of the 100 transmission assembly, without limiting the scope of disclosure to this single variant. Furthermore, where possible, the provisions of this first variant are usable and / or adaptable to other variants.

[0119] The electric machine 102 of the transmission assembly 100 is in fact, for example, capable of operating in motor mode and / or in electric generator mode. This machine The electric motor 102 is possibly an inverted machine in which the rotor 104 is radially outside the stator 103 relative to the axis of rotation AX. However, a conventional machine with the rotor inside the stator can also be implemented. The following description presents the first inverted machine solution, which is unusual but offers advantages in terms of size, as explained below.

[0120] Furthermore, according to the first variant of the power transmission 100, the gears of the differential 106 can be distributed around the electric machine 102, the electric machine then being located inside the volume of the differential 106.

[0121] Thanks to these arrangements, the transmission assembly 100 of the first variant is a compact device. This transmission assembly 100 is suitable for transmitting electrical motive power (for example) to the front axle 10 or the rear axle 20, with little loss and with high torque.

[0122] The electric machine 102 is an electric motor and / or an electric generator. For example, the electric machine in motor mode is capable of assisting a first (internal combustion) engine of the vehicle. For example, the electric machine in generator mode is capable of braking the vehicle, possibly while recharging batteries. This electric machine is advantageously a synchronous machine.

[0123] The stator 103 comprises a stator body 103a equipped with windings 103b on the outer periphery of this stator 103, and a bearing 103c on the rotation axis AX of the motor. As shown in the figure, the bearing 103c is, for example, rotationally articulated about a drive shaft 105, this drive shaft 105 being itself rotationally articulated about the rotation axis AX, directly or indirectly relative to the chassis 4 of the vehicle (not shown).

[0124] The stator 103 thus includes an annular cavity C between the windings 103b and the axis of rotation AX. Part of the differential gears 106 can then optionally be housed inside the cavity. Furthermore, this design allows the cross-sectional area of ​​the windings 103b to be increased by reducing the volume of this cavity C. In the design, this allows the copper cross-section to be increased, and therefore the torque generated by the electric machine 102 to be increased. In this way, the transmission assembly 100 is very compact.

[0125] The rotor 104 comprises a rotor body 104a equipped with magnets 104b facing the stator windings 103b. The rotor body 104a comprises, for example, a side flange 104c extending radially from the axis of rotation AX, and an external cylindrical portion 104d carrying the magnets 104b. The magnets 104b are positioned on the inner periphery of said cylindrical portion 104d to face the windings 103b, and are positioned with alternating polarities along the circumferential direction of the circumference of this cylindrical portion 104d.

[0126] Thus, in the inverted machine shown, the windings 103b are located on the stator, in the internal part of the electric machine 102 (near the axis of rotation AX), and the magnets 104b are located on the rotor, in the external part of the electric machine 102 (outside the stator). However, the windings 103b have a larger radial footprint (in a direction perpendicular to the axis of rotation AX) than the magnets 104b. The air gap E of the motor is the cylindrical area between the stator 103 and the rotor 104. With a constant air gap diameter E, an inverted electric machine therefore has a smaller radial footprint and / or a higher torque compared to a non-inverted electric machine.

[0127] The rotor 104 of the electric machine 102 is then made fixed (directly or indirectly) to the drive shaft 105 to drive it in rotation, this drive shaft 105 then corresponding to the input of the differential 106.

[0128] Thus, thanks to this arrangement, the electric machine 102 is more efficient, in particular for example compared to its use in a four-wheel drive vehicle 1 for a low driving speed of said vehicle.

[0129] In the figures, the differential 106 is shown as an example as it would be used on a rear axle, i.e. with the first output SI and the second output S2 connected to the drive shafts 24, 25 respectively.

[0130] In the various embodiments, the differential 106 comprises the following gear subassemblies:

[0131] - a first epicyclic gear train 110 arranged along the axis of rotation AX, for example on one side of the electrical machine 102,

[0132] - a second epicyclic gear train 120 arranged along the axis of rotation AX, for example on a second side of the electric machine 102, and opposite the first side, and

[0133] - a linking mechanism 130 which connects the first epicyclic gear train 110 to the second epicyclic train 120.

[0134] The linkage mechanism 130 comprises a first shaft 131a connected to the first epicyclic train 110 and a second shaft 132a connected to the second epicyclic train 120.

[0135] The linking mechanism 130 is able to link by reversing the direction of rotation an external ring 113 of the first epicyclic train 110 and an external ring 123 of the second epicyclic train 120.

[0136] The first and second epicyclic gear trains are advantageously identical and possibly positioned symmetrically on either side of the electric machine 102.

[0137] Thanks to these arrangements, the two epicyclic gear trains 110, 120 and the linkage mechanism 130 behave as a mechanical differential. In addition, this differential assembly 106 is compact.

[0138] In addition, the epicyclic gear trains 110, 120 have the same ratio of rotational speed reduction between the drive shaft 105 (the planetary gear 111 or the planetary gear 121) and the planetary doors 115, 125. This avoids the use of a traditional reducer at the output of the electric machine 102.

[0139] The differential 106 therefore combines the functions of differential between outputs SI, S2 and speed reduction for the electric machine 102. This differential 106 with toothed wheels around the electric machine allows for a compact architecture.

[0140] The linkage mechanism 130 of the transmission assembly according to this disclosure is shown in detail in [Fig. 4]. It comprises:

[0141] - a third tree 135a, and

[0142] - a brake 136 connected to said third shaft 135a,

[0143] said linking mechanism being configured for

[0144] to link (or connect) the first epicyclic gear train and the second epicyclic gear train when the brake is activated, the first shaft and the second shaft being in opposite rotation, and

[0145] release (or remove the relationship) the first epicyclic gear train and the second epicyclic gear train when the brake is deactivated, the first shaft and the second shaft being free to rotate relative to each other.

[0146] Thanks to these arrangements, the linkage mechanism 130 allows the first and second epicyclic gear trains to be released. This function disconnects the first output S1 and the second output S2 of the differential 106, thereby freeing the power transmission shafts / wheels. Thus, the electric machine 102 is disconnected from these power transmission shafts / wheels. In an operating mode where the electric machine 102 is not used, it no longer induces electromechanical losses at the vehicle wheels. Energy losses are thus reduced.

[0147] The linkage mechanism 130 will be described in more detail later, and we will first explain two embodiments of the power transmission assembly 100, each corresponding to the integration of a differential 106 having different types of epicyclic gear trains. Other types of epicyclic gear trains can be integrated into the power transmission to achieve desired speed ratios or reduction ratios.

[0148] According to the first embodiment shown in [Fig. 2], the differential 106 comprises a first type of epicyclic gear train. In this differential 106:

[0149] The first epicyclic gear train 110 comprises gears, such as:

[0150] - an inner planetary gear 111 connected to the drive shaft 105 of rotation axis AX,

[0151] - one or more satellites 112 which mesh with the inner planetary gear 111 around the axis of rotation AX,

[0152] - an external ring 113 which engages on the outside of the satellite(s) (i.e. at distance from the axis of rotation AX), and

[0153] - a satellite carrier 115 which connects the axis or axes of the satellites 112.

[0154] The second epicyclic gear train 120 comprises gears, such as:

[0155] - an internal planetary gear 121 connected to the drive shaft 105 of the rotation axis AX,

[0156] - one or more satellites 112 which mesh with the inner planetary gear 121 around the axis of rotation AX,

[0157] - an external ring 123 which engages on the outside of the satellite(s) (i.e. at distance from the axis of rotation AX) and

[0158] - a satellite carrier 125 which connects the axis or axes of the satellites 122.

[0159] The satellite carrier 115 of the first epicyclic gear train 110 corresponds to the first output SI and is then, for example, connected (made fixed) to the drive shaft 24. Conversely, the satellite carrier 125 of the second epicyclic gear train 120 corresponds to the second output S2 and is then, for example, connected (made fixed) to the drive shaft 25.

[0160] The linking mechanism 130 is able to link by reversing the direction of rotation the outer ring 113 of the first epicycloidal train 110 and the outer ring 123 of the second epicycloidal train 120.

[0161] These epicyclic gear trains of the first type include planetary gears 112 for obtaining a reduction ratio between the drive shaft 105 (input) and the propulsion shafts 24, 25 (outputs), for example, between 4 and 10. These planetary gears 112 are composed of one or more gears arranged in parallel to obtain a desired reduction ratio. For example, using a single gear, it is possible to obtain a reduction ratio between 4 and 6; and using double gears, it is possible to obtain a reduction ratio between 7 and 10.

[0162] According to the second embodiment shown in [Fig. 3], the differential 106 comprises a second type of epicyclic gear train. In this differential 106:

[0163] The first epicyclic gear train 110 comprises gears, such as:

[0164] - an internal planetary gear 111 connected to the drive shaft 105 of the rotation axis AX,

[0165] - one or more satellites 112 which mesh with the inner planetary gear 111 around of the axis of rotation AX, each satellite 112 being made up of two associated and fixed gears, that is to say of a first internal gear 112a which meshes with the internal planetary gear 111 and a second external gear 112b,

[0166] - an internal ring 114 which meshes with the second external wheel 112b,

[0167] - a satellite carrier 115 which connects the axis or axes of the satellites 112, the satellite carrier being articulated in rotation around the axis of rotation AX, and

[0168] - an external crown 113 connected to the satellite carrier 115.

[0169] The inner ring 114 of the first epicyclic gear train 110 corresponds to the first output SI and is then for example connected (made fixed) to the drive shaft 24.

[0170] The second epicyclic gear train 120 comprises gears, such as:

[0171] - an internal planetary gear 121 connected to the drive shaft 105 of the rotation axis AX,

[0172] - one or more satellites 122 which mesh with the inner planetary gear 121 around of the axis of rotation AX, each satellite 122 being made up of two associated and interlocking gears, that is to say of a first internal gear 122a which meshes with the internal planetary gear 121 and a second external gear 122b,

[0173] - an internal ring 114 which meshes with the second external wheel 122b,

[0174] - a satellite carrier 125 which connects the axis or axes of the satellites 122, the satellite carrier being articulated in rotation around the axis of rotation AX, and

[0175] - an external crown 123 connected to the satellite carrier 125.

[0176] The inner ring 124 of the second epicyclic gear train 120 corresponds to the second output S2 and is then, for example, connected (made fixed) to the drive shaft 25.

[0177] The linking mechanism 130 is suitable for linking by reversing the direction of rotation the outer ring 113 of the first epicycloidal train 110 and the outer ring 123 of the second epicycloidal train 120.

[0178] These second-type epicyclic gear trains include double-wheeled satellites of different diameters, which makes it possible to obtain a lower reduction ratio between the drive shaft 105 (input) and the propulsion shafts 24, 25 (outputs). For example, this reduction ratio is between 2 and 4.

[0179] Other embodiments with other types of epicyclic gear trains can be used depending on the desired speed ratios or reduction ratios between the input and outputs of the differential 106 of the power transmission 100.

[0180] The linking mechanism 130 of the present disclosure is identical for the various embodiments. It is now described in more detail with reference to [Fig. 4].

[0181] The linking mechanism 130 comprises:

[0182] - a first pinion 131 which meshes with the outside of the outer ring 113 of the first epicyclic train 110,

[0183] - a first shaft 131a connected (fixed) to the first pinion 131,

[0184] - a second pinion 132 which meshes with the outside of the outer ring 123 of the second epicyclic train 120, and

[0185] - a second shaft 132a connected (fixed) to the second pinion 132.

[0186] The first pinion 131, the first shaft 131a, the second pinion 132 and the second shaft 132a are mobile in rotation around a first axis of rotation AX1, parallel to the axis of rotation AX.

[0187] The first shaft 131a and the second shaft 132a are connected to a meshing mechanism 130a comprising:

[0188] - a first planetary 131b connected (solid) to the first tree 131a,

[0189] - a second planetary gear 132b connected (fixed) to the second tree 132a,

[0190] - at least one satellite 133, 134 meshing with the first planetary 131b and with the second planetary 132b, and

[0191] - a satellite carrier 135 on which the satellite(s) 133, 134 are mounted movable and free to rotate.

[0192] In the embodiments schematically presented in [Fig.2] to 4, two satellites 133, 134 are represented, but the meshing mechanism 130a can include a single satellite 133, two satellites 133, 134, or more than two satellites.

[0193] In the case shown of a two-satellite meshing mechanism 130a, this meshing mechanism comprises:

[0194] - a first satellite 133 engaging with the first planetary 131b and with the second planetary 132b,

[0195] - a second satellite 134 meshing with the first planetary 131b and with the second planetary 132b.

[0196] The meshing mechanism 130a may include more than two satellites, and by it may include four or more satellites.

[0197] The first planetary gear 131b, the second planetary gear 132b, the first satellite gear 133, and the second satellite gear 134 are, for example, 90° bevel gears that mesh at 90° as in a mechanical differential.

[0198] The satellite carrier 135 is connected (fixed) to a third shaft 135a, movable in rotation relative to the first axis of rotation AX1.

[0199] The third shaft 135a is connected to a brake 136.

[0200] For example, brake 136 includes:

[0201] - a brake disc 136a mounted integrally with the third shaft 135a, and

[0202] - a brake caliper 136b configured to clamp the brake disc 136a to brake the third shaft 135a and satellite carrier 135 relative to a frame (fixed on the vehicle).

[0203] Thanks to the linkage mechanism 130, and in particular thanks to the brake 136 capable of braking the third shaft 135a of the meshing mechanism 130a, it is possible to link (connect) or disengage (disengage) the first epicyclic gear train 110 and the second epicyclic gear train 120. This function allows the machine to be disengaged or disengaged. electrical 102 of the outputs SI, S2 (of the propulsion shafts 24, 25). This operation is valid regardless of the type of epicyclic gear train used.

[0204] Thus:

[0205] 1) If the brake 136 is activated (for example by clamping the brake disc 136a between the brake caliper 136b), the positions of the first satellite 133 and the second satellite 134 of the meshing mechanism 130a are fixed: they do not rotate around the first axis of rotation AX1.

[0206] Thus, the first pinion 131 rotates about the first axis of rotation AX1 in the opposite direction to the rotation of the second pinion 132 about the same axis. The power transmission 100 can operate in differential mode between the drive shafts 24, 25.

[0207] The electric machine 102 is also linked to the drive shafts and is capable of actuating said drive shafts 24, 25 to provide propulsion power to these vehicle shafts.

[0208] Thanks to this connection of the electric machine 102 and thanks to the differential effect, the power transmission 100 makes it possible to obtain a four-wheel drive vehicle: the two front drive wheels driven by the first motor 2, and two other rear drive wheels driven by the power transmission 100 and the electric machine 102.

[0209] 2) If brake 136 is deactivated (for example by releasing the brake disc) 136a between the brake caliper 136b), the satellite carrier 135, the first satellite 133 and the second satellite 134 begin to rotate around the first axis of rotation AX1.

[0210] Thus, the first pinion 131 and the second pinion 132 have independent and arbitrary rotations. This amounts to freeing the first and second pinions 131, 132; which frees the first epicyclic gear train 110 and the second epicyclic gear train 120 from the power transmission 100. The drive shafts 24, 25 are free and the wheels connected to these shafts can rotate freely and independently.

[0211] Simultaneously, the electric machine 102 can no longer actuate these drive shafts 24, 25. This electric machine 102 is thus freed from the relationship with the drive shafts 24, 25.

[0212] Thanks to this release or inhibition of the electric machine 102, it no longer influences the rotation of the wheels linked to the drive shafts, and this electric machine 102 does not induce any mechanical loss in the rolling of the vehicle, which can move as a simple vehicle with two front drive wheels powered by the first motor 2.

[0213] The vehicle 1 may include control electronics which control the brake 136 and the electric machine 102 according to the desired driving mode.

[0214] According to a variant of the linking mechanism 130, this linking mechanism 130 further comprises:

[0215] - a control element 137 connected to the first shaft 131a or to the second shaft 132a as shown in [Fig.3].

[0216] This control unit 137 is, for example:

[0217] - a brake,

[0218] - an electric motor, or

[0219] - a combination of a mechanical brake and an electric motor controlled as a brake.

[0220] Thanks to this 137 piloting argane, it is possible to pilot the rotation of the first shaft 131a or the second shaft 132a in the operating mode of the brake 136 activated (i.e. the linked operating mode of the differential 106 which connects the two epicyclic trains).

[0221] Thus:

[0222] 1) If the pilot member 137 blocks the first shaft 131a and the second shaft 132a, then the external rings 113, 123 of the epicyclic trains can no longer rotate around the axis of rotation AX, which imposes the same rotations on the output shafts SI, S2, i.e. the propulsion shafts 24, 25. This function corresponds to a bridge lock which then imposes the same rotation speed on the wheels, very useful for propelling the vehicle at low speed in difficult passages in four-wheel drive.

[0223] 2) If the control member 137 brakes or actuates the first shaft 131a or the The second shaft 132a allows control of the relative rotation of the outer ring gear 113 of the first epicyclic gear train 110 with respect to the outer ring gear 123 of the second epicyclic gear train 120. This controls the operation of the differential 106, that is, the relative rotational speeds of the wheels connected to the drive shafts 24 and 25. It is then possible to control the yaw angle of the vehicle to a greater or lesser extent. In other words, it is possible to control the direction of the axle corresponding to the wheels of the output shafts; i.e., the direction of the rear axle of the vehicle in the example described here.

[0224] Figures 5 and 6 show an example of an embodiment in which the numerical references designate elements identical or similar to those of [Fig.2] and [Fig.3], but three-dimensional details of the power transmission assembly 100 are visible.

[0225] Thus, the transmission assembly 100 according to the various variants and embodiments presented above can be integrated into any type of vehicle 1.

[0226] For example, it can be integrated into a four-wheel drive vehicle 1, by being connected and integrated into the front axle 10 or the rear axle 20 of that vehicle 1.

[0227] According to variants of the power transmission 100, this incorporates an electric machine 102.

[0228] The electric machine 102 can be operated in an electric motor mode in which electrical power is converted into mechanical rotational power, or conversely in an electric generator mode in which mechanical rotational power is converted into electrical power. In the latter case, the electric machine 102 acts as a brake with electrical energy recovery, this electrical energy then being stored in the vehicle's batteries 1.

[0229] The electric machine 102 of this power transmission assembly 100 can:

[0230] - either assist the heat engine, for example the first engine 2 of [Fig.1], in the electric motor mode of said electric machine 102, this operating mode being useful, for example, during the starting phase of vehicle 1,

[0231] - or to brake the vehicle in the electric generator mode of said machine electric 102, for example by recharging batteries.

[0232] Thanks to such an operation in which the electric machine 102 is controlled as a brake or as a support motor for a first motor 2 such as a heat engine, it is possible to optimize the operation of the first motor 2. It is also possible to reduce the size of this first motor 2. Substantial energy savings can then be achieved.

[0233] The power transmission 100 is, for example, controlled by the vehicle 1 (an electronic vehicle control unit) so that the linkage mechanism 130 is in a disengaged state if the vehicle speed exceeds a speed limit. This speed limit is adapted to the vehicle's operating mode. This speed limit may be, for example, 50 km / h or 110 km / h.

[0234] For example, the speed limit is 50 km / h. Thus, vehicle 1 is only in four-wheel drive mode below this speed limit. This corresponds well to the usual use of four-wheel drive. Above the speed limit, vehicle 1 is in two-wheel drive mode (those of the front axle 10). Thanks to the disengaged state of the linkage mechanism 130 of the power transmission 100, the power transmission 100 of this disclosure does not negatively impact the performance of vehicle 1 in this operating mode above the speed limit.

[0235] For example, the speed limit is 110 km / h. Thus, vehicle 1 is possibly in an electric or hybrid (thermal and electric) mode only below this speed limit. Above the speed limit, vehicle 1 is in a thermal mode without use of the electric machine 102 of the power transmission 100 of this disclosure. Thanks to the released state of the linkage mechanism 130 of the power transmission 100, the power transmission 100 does not penalize the efficiency of vehicle 1 in this operating mode above the speed limit.

[0236] The power transmission 100 is, for example, controlled by the vehicle 1 (by an electronic vehicle control unit) so that the linkage mechanism 130 is in a linked state (engaged) if the accelerator pedal is released or if the vehicle's brake is applied. This operation can be used regardless of the vehicle's speed or only below a speed limit, as described previously. In this case, the electric machine 102 is capable of operating in an electric generator mode and recharging batteries.

[0237] The power transmission 100 is, for example, controlled by the vehicle 1 (by an electronic vehicle control unit) so that the linkage mechanism 130 is in a linked state when the accelerator pedal is pressed. This operation can be used regardless of the vehicle's speed or only below a speed limit, as before. In this case, the electric machine 102 is able to operate in an electric motor mode to assist the propulsion of the vehicle 1.

[0238] Furthermore, the switching of the linkage mechanism 130 into the linked state and the electric machine 102 into motor mode when the accelerator pedal is pressed can be controlled provided that the vehicle speed is below or above a speed limit. Thus, it can be useful to perform a start using the electric machine 102 or to assist a first motor 2 if the vehicle user requests additional driving power via the accelerator.

[0239] Furthermore, the preceding operation can be linked to the accelerator pedal depressed. If the accelerator pedal is moderately depressed (below a load demand limit), the linkage mechanism 130 remains in the released state. If the accelerator pedal is deeply depressed (above a load demand limit), the linkage mechanism 130 enters the linked state and the electric machine switches to motor mode to assist vehicle propulsion.

[0240] In addition, several thresholds can be defined, these thresholds depending, for example, on the speed and / or acceleration and / or position of the accelerator pedal and / or brake pedal of the vehicle. According to one embodiment, the temporal evolution of the accelerator pedal position can also be used to define operating thresholds.

[0241] For example, the operation of vehicle 1 can be as follows:

[0242] - the brake 136 of the linkage mechanism 130 is activated and the electric machine 102 is in engine mode if a vehicle accelerator pedal is pressed,

[0243] - the brake 136 of the linkage mechanism 130 is activated and the electric machine 102 is in generator mode if a vehicle accelerator pedal is released or if a vehicle brake is applied, and

[0244] - the brake 136 of the linkage mechanism 130 is deactivated if the vehicle speed is above a certain speed limit.

[0245] This operation allows the operation of a first motor 2 to be optimized. It is also possible to reduce its size, and substantial energy savings can then be achieved.

Claims

Demands

1. Power transmission assembly (100) comprising: - a differential (106) comprising at least one differential input, said differential comprising a plurality of interconnected gears to distribute the differential input power between a first output (S1) and a second output (S2), the distribution being a function of the rotational speed of the first and second outputs, and - the differential (106) comprising the following gear sub-assemblies: - a first epicyclic gear train (110), - a second epicyclic gear train (120), and - a linkage mechanism (130) comprising a first shaft (131a) connected to the first epicyclic gear train (110) and a second shaft (132a) connected to the second epicyclic gear train (120), the first and second epicyclic gear trains being identical, the assembly being characterized in that the linkage mechanism (130) further comprises: - a third shaft (135a),and - a brake (136) connected to said third shaft (135a), said linkage mechanism being configured to link the first epicyclic gear train and the second epicyclic gear train when the brake is activated, the first shaft and the second shaft being in opposite rotation, and to release the first epicyclic gear train and the second epicyclic gear train when the brake is deactivated, the first shaft and the second shaft being free to rotate relative to each other.

2. Assembly according to claim 1, wherein: the linkage mechanism (130) comprises a meshing mechanism (130a) comprising: - a first planet (131b) connected to the first shaft (131a), - a second planet (132b) connected to the second shaft (132a), - at least one satellite (133, 134) meshing with the first planet and the second planet, - a satellite carrier (135) freely supporting in rotation the at least one satellite (133, 134), the third shaft (135a) being connected to the satellite carrier (135).

3. Assembly according to claim 2, wherein: the first planetary (131b), the second planetary (132b), at least one satellite (133, 134) are 90° bevel gears.

4. Assembly according to any one of claims 1 to 3, wherein: the brake (136) is actuated by hydraulic or electrical or mechanical action.

5. Assembly according to any one of claims 1 to 4, comprising a pilot member (137) connected to the first shaft (131a) or the second shaft (132a) of the linkage mechanism (130), said pilot member being configured to pilot the rotation of said first or second shaft when the brake (136) is activated.

6. Assembly according to claim 5, wherein the control member (137) is a brake, or an electric motor, or a combination of brake and electric motor.

7. An assembly according to any one of claims 1 to 6, wherein: the first epicyclic gear train (110) comprises a planet carrier (115) corresponding to the first output (S1) of the differential, the second epicyclic gear train (120) comprises a planet carrier (125) corresponding to the second output (S2) of the differential, a drive shaft (105) connects an inner planet gear (111) of the first epicyclic gear train and an inner planet gear (121) of the second epicyclic gear train, the drive shaft (105) corresponding to the input of the differential (106), at least one planet gear (112) of the first epicyclic gear train (110) is rotatably mounted on the planet carrier (115) of the first epicyclic gear train (110) and meshes with the inner planet gear (111) and with an outer ring gear (113) of the first epicyclic gear train (110),and at least one satellite (122) of the second epicyclic gear train (120) is rotatably mounted on the satellite carrier (125) of the second epicyclic gear train (120) and meshes with the inner planetary gear (121) and with an outer ring gear (123) of the second epicyclic gear train (120), and wherein the outer ring gear (113) of the first epicyclic gear train (110) meshes with a first pinion (131) of the first shaft (131a) of the linkage mechanism (130), and, the outer ring (123) of the second epicyclic gear train (120) meshes with a second pinion (132) of the second shaft (131a) of the linkage mechanism (130).

8. An assembly according to any one of claims 1 to 6, wherein: the first epicyclic gear train (110) comprises an inner ring gear (114) corresponding to the first output (SI) of the differential, the second epicyclic gear train (120) comprises an inner ring gear (124) corresponding to the second output of the second epicyclic gear train (120), a drive shaft (105) connects an inner planet gear (111) of the first epicyclic gear train, an inner planet gear (121) of the second epicyclic gear train, the drive shaft (105) corresponding to the input of the differential (106), at least one planet gear (112) of the first epicyclic gear train (110) is rotatably mounted on a planet carrier (115) of the first epicyclic gear train (110) and meshes with the inner planet gear (111) and with the inner ring gear (114) of the first epicyclic gear train (110),at least one satellite (122) of the second epicyclic gear train (120) is rotatably mounted on a satellite carrier (125) of the second epicyclic gear train (120) and meshes with the inner planetary gear (121) and the inner ring gear (124) of the second epicyclic gear train (120), and wherein an outer ring gear (113) of the first epicyclic gear train (110) is integral with the satellite carrier (115) of the first epicyclic gear train (110) and meshes with a first pinion (131) of the first shaft (131a) of the linkage mechanism (130), and an outer ring gear (123) of the second epicyclic gear train (120) is integral with the satellite carrier (125) of the second epicyclic gear train (120) and meshes with a second pinion (132) of the second shaft (131a) of the linkage mechanism (130).

9. Assembly according to any one of claims 1 to 8, further comprising an electrical machine (102) comprising a fixed stator (103) and a rotor movable in rotation about an axis of rotation (AX) of said electrical machine, and wherein: the input of the differential (106) is connected to the rotor (104) of the electrical machine (102), The first output (S1) of the differential is connected to a first power transmission shaft, the second output (S2) of the differential is connected to a second power transmission shaft.

10. Assembly according to claim 9, wherein the gears of the differential (106) are distributed around the electric machine (102), the electric machine being located inside the volume of the differential, the first epicyclic gear train (110) being arranged on a first side of the electric machine, and the second epicyclic gear train (120) being on a second side of the electric machine opposite the first side.

11. Assembly according to claim 9 or claim 10, wherein: the electric machine (102) is an inverted machine in which the rotor is radially outside the stator with respect to the axis of rotation.

12. Vehicle (1) comprising: - a front axle (10), - a rear axle (20), and - a power transmission assembly (100) according to any one of claims 1 to 11, the first output and the second output of the differential of this assembly being connected directly or indirectly respectively to a first power transmission shaft of a first wheel and to a second power transmission shaft of a second wheel, of the front axle and / or to the rear axle of the vehicle.

13. Vehicle according to claim 12, in which the brake (136) is deactivated if the vehicle speed is greater than a speed limit.

14. Vehicle according to any one of claims 12 to 13, wherein: the power transmission assembly (100) further comprises a pilot member (137) connected to the first shaft (131a) or the second shaft (132a) of the linkage mechanism (130), said pilot member being configured to pilot the rotation of said first shaft (131a) or second shaft (132a) of the linkage mechanism (130) when the brake (136) is activated, or to lock the first shaft (131a) and the second shaft (132a) of the linkage mechanism (130) when the brake (136) is activated.

15. Vehicle according to claim 12, wherein: The power transmission assembly (100) further comprises an electrical machine (102) comprising a fixed stator (103) and a rotor that rotates about an axis of rotation (AX) of said electrical machine, and in which: The input of the differential (106) is connected to the rotor (104) of the electric machine (102), The first output (SI) of the differential is connected to a first power transmission shaft. the second output (S2) of the differential is connected to a second power transmission shaft, and in which: - the brake (136) of the linkage mechanism (130) is activated and the electric machine (102) is in motor mode if an accelerator pedal of the vehicle is pressed, - the brake (136) of the linkage mechanism (130) is activated and the electric machine (102) is in generator mode if a vehicle accelerator pedal is released or if a vehicle brake is activated, and - the brake (136) of the linkage mechanism (130) is deactivated if the vehicle speed is above a limit speed.

Images