Automotive vehicle reduction assembly

Abstract

Gearbox assembly for motor vehicle. Gearbox assembly (1) for motor vehicle, comprising: - a first input shaft (11) and a second input shaft (12), - a first output shaft (21) and a second output shaft (22), - at least one transmission stage (30) connecting the first output shaft (21) and the second output shaft (22) respectively to the first input shaft (11) and the second input shaft (12), the transmission stage (30) comprising at least a first intermediate shaft (31) and a second intermediate shaft (32), the first intermediate shaft (31) passing through the second intermediate shaft (32) and the first intermediate shaft (31) being mounted on first and second bearings (41, 42) arranged on the housing (50), the second intermediate shaft (32) being freely rotationally mounted on the first intermediate shaft (31). Figure for the abbreviation: Fig. 1a

Description

Title of the invention: Reduction unit for motor vehicle technical field

[0001] The present invention relates to the field of reduction assemblies for rotating electrical machines.

[0002] The machines can be synchronous or asynchronous, and alternating current. They can be traction or propulsion machines for electric (Battery Electric Vehicle) and / or hybrid (Hybrid Electric Vehicle - Plug-in Hybrid Electric Vehicle) motor vehicles, such as passenger cars, vans, trucks, or buses. The invention also applies to rotating electrical machines for industrial and / or power generation applications, particularly in the marine, aeronautical, or wind power sectors. Previous technique

[0003] In application EP 3 287 666, the left-hand shafts are independent of the right-hand shafts, and each shaft is supported by two bearings. A central housing is required to retain the central bearings.

[0004] Reducing assemblies with various configurations are also known from US applications 2021 / 379977, DE 10 2020 113192, DE 10 2016 103481, DE 10 2009 013871, DE 10 2020 117451, CN 110091700, WO 2018 / 034099, US 2011 / 139522, EP 3 587 157, EP 3 431 813, EP 2 623 356, US 2014 / 349812.

[0005] In applications EP 2 221 495 and US 2010 / 187026, the drive shafts are each mounted on their own bearings.

[0006] There is a need for a reduction unit for motor vehicles offering improved efficiency and minimized size, while obtaining sufficient reduction or multiplication. Summary of the invention

[0007] The invention aims to meet all or part of this need and achieves this, according to one of its aspects, by means of a reduction assembly for a motor vehicle, comprising: - a first input shaft and a second input shaft, in particular coaxial with each other, - a first output tree and a second output tree, notably coaxial with each other, - at least one transmission stage connecting the first output tree and the second output tree respectively to the first input tree and the second input tree, - a casing (50) in which the first and second input and output shafts and the transmission stage (30) are housed, the transmission stage comprising at least a first intermediate shaft and a second intermediate shaft such that motion transmission occurs respectively from the first input shaft to the first output shaft and from the second input shaft to the second output shaft, independently of each other, the first intermediate shaft passing through the second intermediate shaft (32) and the first intermediate shaft (31) being mounted on first and second bearings arranged on the casing, the second intermediate shaft being mounted freely for rotation on the first intermediate shaft.

[0008] The assembly according to the invention makes it possible to improve the efficiency of the transmission of motion, in particular when the vehicle is moving in a straight line, during acceleration, at constant speed or during deceleration.

[0009] In addition, a double reducer is obtained which is less bulky in width.

[0010] It also allows the generation of electricity, by running the motor in generator, in case of braking of the vehicle in a straight line.

[0011] Thanks to the invention, a pivot joint is formed between the first and second intermediate shafts to guide the shafts without the need for a central housing, thus reducing the overall size of the gearbox assembly. This avoids the use of two separate gearboxes with independent left and right shafts separated by a central housing, which is necessary to support the central bearings. Assembly is therefore simplified.

[0012] The number of bearings required can also be reduced.

[0013] The first and second bearings are not mounted on the second transmission shaft.

[0014] Thus, the mass of the assembly is minimized. In addition, the manufacturing cost is reduced.

[0015] The first input shaft and second input shaft can be rotationally fixed to each of a rotating electrical machine.

[0016] The first output shaft and second output shaft can be rotationally fixed to each one drive wheel of a vehicle, in particular a right wheel and a left wheel.

[0017] The two drive wheels can each be driven independently of the other by one of the rotating electrical machines.

[0018] Furthermore, the reduction gear assembly allows for a speed difference between the two transmission lines, a first transmission line comprising the first input shaft, the first transmission shaft and the first output shaft, and a second transmission line comprising the second input shaft, the second transmission shaft and the second output shaft. This makes it possible to apply a torque difference between the right wheel and the left wheel. Description of the invention

[0019] The first intermediate shaft can pass through the second intermediate shaft. The first intermediate shaft can be mounted on the first and second bearings, which can be arranged on either side of the second intermediate shaft, in particular being arranged at each of its free ends.

[0020] In the invention, the second intermediate shaft is mounted on the first intermediate shaft. It does not rest on a bearing pivotally mounted on a housing of the assembly.

[0021] It can be mounted on the first intermediate shaft by means of a smooth contact. The smooth contact may have grooves to improve lubrication.

[0022] Alternatively, the second intermediate shaft can be mounted on the first intermediate shaft by means of pivot bearings, in particular two bearings, for example needle roller bearings. The needle roller bearings allow the radial loads to be absorbed.

[0023] Axial forces can be taken up without bearings.

[0024] The second intermediate shaft can be mounted axially against one or two shoulders of the first intermediate shaft.

[0025] The first intermediate shaft may have a shoulder between its two free ends, particularly in a central portion thereof. The second intermediate shaft may be mounted axially against this shoulder of the first intermediate shaft, which may be a single shaft.

[0026] The contact between the second intermediate shaft and the first intermediate shaft can be direct or via a bearing, or by means of an added element such as a ring, ball, needle bearing, bushing, or thrust washer, made of a material suitable to resist friction under load.

[0027] The first intermediate shaft may have a second shoulder between its two free ends, particularly near the second bearing. The second intermediate shaft may be mounted axially against this second shoulder of the first intermediate shaft.

[0028] Alternatively, the second intermediate shaft can be mounted axially against a shoulder of the second bearing, in particular an inner ring of the second bearing.

[0029] The contact between the second intermediate shaft and the second bearing can be direct or via a shouldered insert. A bearing can also be added, for example a ball or needle thrust bearing or a bearing conical, or a friction element, for example a plain bearing or a friction washer. The friction washer can be made of a material suitable for withstanding friction under load.

[0030] The axial stop(s) advantageously allow for the absorption of axial forces, with a possibility of sliding. There is no clamping at the level of these axial stops.

[0031] The reduction gear assembly may include a retaining piece for the second bearing on the first intermediate shaft. The retaining piece may be attached to the first intermediate shaft. For example, it may be screwed onto the shaft, or alternatively, fixed to the first intermediate shaft by means of an axial retaining ring.

[0032] It allows the second bearing to be held in place, in order to prevent it from coming loose, and to prevent it from slipping due to the axial forces exerted by the second intermediate shaft.

[0033] The reduction assembly may include a housing in which the first and second input and output shafts and the transmission stage(s) are housed.

[0034] The housing may comprise two parts, a first part of the housing housing in particular the first input shaft, the first output shaft, as well as a first part of the transmission stage, and a second part of the housing housing in particular the second input shaft, the second output shaft, as well as a second part of the transmission stage.

[0035] The first and second parts can be substantially symmetrical with respect to each other.

[0036] The housing may be devoid of a third part, in particular, it may be devoid of a central part. Specifically, it may be devoid of a part intended to hold one or more central bearings, which would serve to support the second intermediate shaft.

[0037] The housing is configured to retain the first intermediate shaft at each of its free ends. The first intermediate shaft passes through the entire housing and is mounted on the housing by the first and second bearings located at each of its free ends. The first and second bearings are mounted on the housing. The first bearing is mounted on the first part of the housing and the second bearing is mounted on the second part of the housing.

[0038] The first intermediate shaft may include one or more longitudinal channels, including through channels. The longitudinal channel may be through channel and extend along the entire length of the first intermediate shaft. Alternatively, the longitudinal channel may extend over only a portion of the length of the first intermediate shaft. It allows the passage of a lubricating fluid such as a oil, in order to lubricate the first and second bearings.

[0039] The first intermediate shaft may include one or more radial channels to allow the passage of the lubricating fluid to the second intermediate shaft, for example to one or more bearings, in particular needle bearings, arranged between the first intermediate shaft and the second intermediate shaft.

[0040] The assembly may include a pipette for the inlet of lubricating fluid into the longitudinal channel. The lubricating fluid may be supplied by an active lubrication system, comprising for example a pump, which may be located outside the reducing assembly.

[0041] The first intermediate shaft and the second intermediate shaft of the transmission stage may each include helical teeth cooperating respectively with the first output shaft and with the second output shaft, or with another transmission stage, in particular the intermediate shafts of another transmission stage, said helical teeth having helices respectively in opposite directions to each other.

[0042] The first intermediate shaft and the second intermediate shaft may each comprise helical gears cooperating respectively with the first input shaft and with the second input shaft, or with another transmission stage, in particular the intermediate shafts of another transmission stage. These helical gears may respectively have helices in opposite directions to each other.

[0043] The helical gears of the first and second intermediate shafts may be substantially symmetrical with respect to each other, or even symmetrical. The directions of their helices are opposite.

[0044] This results in the lateral thrust forces being opposed.

[0045] The direction of the helix angles on the gears can be chosen to better manage the axial forces on the shafts in operation and thus improve efficiency under certain conditions.

[0046] With opposite helix directions between the teeth of the first and second intermediate shafts, when the machine torque is applied in the same direction to the left and right, the first and second intermediate shafts will be pushed towards each other. When the two machine torques are reversed, still with the same direction between left and right, the first and second intermediate shafts will repel each other.

[0047] Thus, thanks to the invention, it is obtained that, regardless of the direction of the torque applied to the gear teeth, in acceleration or deceleration, the axial forces on the first and second intermediate shafts are largely compensated by directing the axial force flow mainly through one or the other of the axial thrust bearings between these two shafts, which makes it possible to greatly reduce the axial forces experienced by the Bearings supporting these shafts and mounted in the housing are particularly useful when the torques of the two electric machines are equal. This allows for an increased lifespan and / or a reduction in losses regardless of the direction of the motor torque or the operating mode, especially during acceleration or deceleration. It also allows for a reduction in the size of the bearings used, while maintaining the same lifespan.

[0048] The gain in efficiency is thus maximum when the vehicle travels in a straight line, when there is no difference in speed between the first and second intermediate shafts.

[0049] Each of the first and second input shafts can be rotatably mounted on the housing by means of two bearings. The assembly may include at least two bearings for this purpose, in particular at least one bearing for the first input shaft and at least one bearing for the second input shaft. The assembly may include four bearings for this purpose, in particular two bearings for the first input shaft and two bearings for the second input shaft.

[0050] Mounting at least one support bearing for at least one of the input shafts, in particular the innermost bearing, can be achieved by means of a support piece. The presence of this support piece facilitates the molding of the housing.

[0051] The outermost bearing can be a bearing from a drive motor for the corresponding input shaft. This minimizes the overall size of the assembly. It can be narrower.

[0052] The support piece can be fixed in the housing, for example by screwing, by means of pins, or directly in the housing. It can be precisely positioned by means of pins and / or surfaces machined in the housing. The assembly may include two support pieces or a single support piece for the first and second input shafts. The assembly may include a first support piece for mounting a support bearing for the first input shaft. The assembly may include a second support piece for mounting a support bearing for the second input shaft.

[0053] Such a configuration simplifies the lubrication of the assembly. It eliminates the need for radial injection of the lubricating fluid. The bearings are more accessible.

[0054] The assembly may include a radial injection system for pressurized oil, comprising a bushing around one of the input shafts. The bushing may be fixed within the housing. Inside the bushing, a radial opening may be provided for the oil inlet, and two segments may be mounted on this opening to limit leakage during the passage of oil from the bushing opening to the radial openings of the input shaft.

[0055] Alternatively, the second input shaft can be freely rotationally mounted on the first input shaft. The second input shaft is fitted onto the first input shaft in a sock-like fashion.

[0056] The second input shaft can be mounted on the first input shaft by means of pivot bearings, in particular two bearings, for example needle bearings. Needle bearings allow the radial forces to be absorbed.

[0057] The first and second input trees can be coaxial with each other or, alternatively, non-coaxial.

[0058] The first input shaft may include a longitudinal through channel. The longitudinal channel may extend along the entire length of the first input shaft. It allows the passage of a lubricating fluid such as oil.

[0059] The first input shaft may have one or more radial channels to allow the passage of the lubricating fluid to the second input shaft, for example to one or more bearings, in particular needle bearings, disposed between the first input shaft and the second input shaft.

[0060] The assembly may include a pipette for the inlet of lubricating liquid into the longitudinal channel.

[0061] The second output shaft can be freely mounted for rotation on the first output shaft. The second output shaft is fitted onto the first output shaft in a sock-like fashion.

[0062] The second output shaft can be mounted on the first output shaft by means of one or more pivot bearings, in particular one or two bearings, for example one or more needle bearings. The needle bearings allow the radial forces to be absorbed.

[0063] The first and second output trees can be coaxial with each other or, alternatively, non-coaxial.

[0064] Alternatively, the second output shaft may not be mounted on the first output shaft.

[0065] The second output shaft and / or the first output shaft can each be mounted on a combined double-row ball bearing. The bearing can be angular contact.

[0066] This type of bearing provides good load capacity, axial force management, and guidance of the rotation axis, thus eliminating the need for a connection between the second output shaft and the first output shaft. A double-row angular contact ball bearing can be more easily preloaded to improve durability and increase the overall rigidity.

[0067] The combined bearing can be arranged on the housing.

[0068] The assembly may include a first combined bearing to support the first output shaft on the first part of the housing. The assembly may include a second combined bearing to support the second output shaft on the second part of the housing.

[0069] Such a configuration with a single combined bearing to support an output shaft allows the two output shafts to be brought closer together and thus reduce the distance between the wheels of the vehicle.

[0070] The assembly may include at least one retaining element, in particular a retaining plate, for the combined bearing on the housing. The retaining element may, for example, include a plate, an axial retaining ring, or a plate integrated into the outer ring of the bearing.

[0071] The retaining plate may be in the form of a washer with lugs for screws. It may be screwed into the housing, for example with screws or washers, or alternatively, it may be integrated into the combined bearing, particularly into the outer ring of the combined bearing. The retaining plate may be positioned perpendicular to an axis of rotation of the assembly. This may facilitate lubrication.

[0072] The assembly may include a first retaining plate for the first combined bearing on the first part of the housing. The assembly may include a second retaining plate for the second combined bearing on the second part of the housing.

[0073] One or both of the first and second output shafts may be solid. Alternatively, they may be hollow.

[0074] The reduction unit according to the invention may comprise a single transmission stage, as described above. Alternatively, it may comprise several transmission stages, for example two or three. At least one transmission stage, or even all of the transmission stages, may be as described above.

[0075] The invention also relates to a propulsion device for a motor vehicle, comprising a reduction unit as described above and two rotating electrical machines.

[0076] Rotating electrical machines can be arranged on either side of the reduction unit. Each rotating electrical machine can have a shaft connected to an input shaft of the reduction unit. The device can include a first rotating electrical machine fixed in rotation to the first input shaft of the reduction unit. The device can include a second rotating electrical machine fixed in rotation to the second input shaft of the reduction unit.

[0077] The invention also relates to a vehicle comprising an assembly or device as described above. The vehicle may have at least two drive wheels, each of the drive wheels is driven in rotation by the reduction assembly, in particular by an output shaft thereof.

[0078] The drive wheels can be arranged on either side of the reduction unit. Each drive wheel can have a shaft connected to an output shaft of the reduction unit. The device can include a first drive wheel fixed in rotation to the first output shaft of the reduction unit. The device can include a second drive wheel fixed in rotation to the second output shaft of the reduction unit. Brief description of the drawings

[0079] The invention will be better understood upon reading the detailed description that follows, non-limiting examples of its embodiment, and upon examination of the attached drawing.

[0080] [Fig. la] The [Fig. la] is a perspective view of a reducing assembly according to the invention.

[0081] [Fig.lb] The [Fig.lb] is another perspective view of the reducing set of the [Fig. la],

[0082] [Fig. le] The [Fig. le] is another perspective view of the reducing set of the [Fig. la],

[0083] [Fig.2a] The [Fig.2a] is a front view of the reducing assembly of the [Fig.la].

[0084] [Fig.2b] The [Fig.2b] is another front view of the reducing assembly of the [Fig.la].

[0085] [Fig.3] The [Fig.3] illustrates, schematically and partially, an alternative embodiment for the input trees.

[0086] [Fig.4] Fig.4 illustrates, schematically and partially, another embodiment variant for the input trees.

[0087] [Fig.5] The [Fig.5] illustrates, schematically and partially, an alternative embodiment for the output trees. Detailed description

[0088] Figures 1a to 2b illustrate a reduction unit 1 for a motor vehicle, comprising:

[0089] - a first input tree 11 and a second input tree 12 coaxial with each other,

[0090] - a first output tree 21 and a second output tree 22 coaxial with each other, And

[0091] - at least one transmission stage 30 connecting respectively the first shaft of output 21 and the second output tree 22 to the first input tree 11 and to the second input tree 12.

[0092] The transmission stage 30 comprises at least a first intermediate shaft 31 and a second intermediate shaft 32 such that motion transmission takes place respectively from the first input shaft 11 to the first shaft output 21 and the second input tree 12 to the second output tree 22, independently of each other.

[0093] According to the invention, the first intermediate shaft 31 passes through the whole assembly and is mounted on first and second bearings 41, 42 arranged on either side of the second intermediate shaft 32, being arranged at each of its free ends.

[0094] The second intermediate shaft 32 is mounted freely for rotation on the first intermediate shaft 31. A pivot joint is formed between the first and second intermediate shafts 31, 32 in order to guide the shafts without the need for a central housing, thus reducing the overall size of the reduction unit.

[0095] The first and second input shafts can each be rotationally fixed to a rotating electrical machine. The two rotating electrical machines can be arranged on either side of the reduction unit. Each rotating electrical machine can have a shaft connected to an input shaft of the reduction unit.

[0096] The first and second output shafts can each be rotationally fixed to a drive wheel of a vehicle, in particular a right wheel and a left wheel. The drive wheels can be arranged on either side of the reduction gear assembly. Each drive wheel can have a shaft connected to an output shaft of the reduction gear assembly. The two drive wheels can thus each be driven independently of the other by one of the rotating electrical machines.

[0097] The second intermediate shaft 32 is mounted on the first intermediate shaft 31 by pivot bearings 43, 44, namely needle bearings, which allow the radial forces to be absorbed.

[0098] In addition, the second intermediate shaft 32 is mounted axially against the first intermediate shaft 31. The first intermediate shaft 31 has for this purpose a shoulder 46 between its two free ends, in a central part thereof.

[0099] Furthermore, the second intermediate shaft is mounted axially against a shoulder 47 of the second bearing 42, in particular an inner ring of the second bearing 42. The axial thrust bearings advantageously allow the axial forces to be absorbed, with a possibility of sliding. There is no clamping at these axial thrust bearings.

[0100] Finally, the reduction unit 1 includes a retaining piece 48 for the second bearing 42 on the first intermediate shaft 31, which is screwed onto the first intermediate shaft 31. This retaining piece 48 holds the second bearing 42 in place, preventing it from dislodging and from slipping due to axial forces exerted by the second intermediate shaft 32.

[0101] Furthermore, the reduction unit comprises a housing 50 in which the first and second input and output shafts as well as transmission stage 30.

[0102] The housing comprises two parts 51, 52, a first part 51 of the housing housing the first input shaft 11, the first output shaft 21, as well as a first part of the transmission stage 30, and a second part 52 of the housing housing the second input shaft 12, the second output shaft 22, as well as a second part of the transmission stage 30. The first and second parts 51, 52 are substantially symmetrical with respect to each other.

[0103] The housing 50 is configured to retain the first intermediate shaft 31 at each of its free ends. The first bearing 41 is mounted on the first part of the housing 51 and the second bearing 42 is mounted on the second part of the housing 52.

[0104] The first intermediate shaft 31 has a longitudinal channel 33. The longitudinal channel 33 extends along the entire length of the first intermediate shaft 31. It allows the passage of a lubricating fluid such as oil, in order to lubricate the first and second bearings 43, 44. The assembly further includes a lubricating fluid inlet pipette 35 into the longitudinal channel 33.

[0105] Furthermore, the first intermediate shaft 31 and the second intermediate shaft 32 each have helical gears 37, 38 cooperating respectively with the first output shaft 21 and with the second output shaft 22, said helical gears 37, 38 being in opposite directions to each other. The diameters of the transmission and output shafts are chosen so as to obtain a reduction in motion.

[0106] In this example, the second input shaft 12 is mounted freely for rotation on the first input shaft 11. We say that the second input shaft 12 is mounted in a sock-like fashion on the first input shaft 11.

[0107] In addition, the second input shaft 12 is mounted on the first input shaft 11 by two pivot bearings 13, 14, which are needle bearings in order to take up the radial forces.

[0108] Furthermore, the first input shaft 11 has a longitudinal through channel 15, which extends along the entire length of the first input shaft 11. It allows the passage of a lubricating liquid such as an oil.

[0109] In an alternative embodiment illustrated in [Fig.3], each of the first and second input shafts 11,12 is mounted for rotation on the housing by two bearings 16 and 17 respectively. The assembly thus comprises four bearings for this purpose, two bearings 16 for the first input shaft 11 and two bearings 17 for the second input shaft 12.

[0110] In the embodiment illustrated in [Fig.4], there is a bearing 16 for the first input shaft 11 and a bearing 17 for the second input shaft 12.

[0111] In both cases, the mounting of at least one support bearing of at least one The input shafts, particularly the innermost bearing, are supported by a support piece 18, which is fixed in the housing. The assembly thus comprises a first support piece 18 for mounting a support bearing for the first input shaft 11 and a second support piece 18 for mounting a support bearing for the second input shaft 12.

[0112] In the embodiment of figures 1a to 2b, the second output shaft 22 is mounted freely for rotation on the first output shaft 21. It is said that the second output shaft 22 is mounted in a sock on the first output shaft 21.

[0113] The second output shaft 22 can be mounted on the first output shaft 21 by means of two pivot bearings 23, 24, for example two needle bearings. The needle bearings allow the radial forces to be absorbed.

[0114] Furthermore, the second output shaft 22 and the first output shaft 21 are each mounted on a double-row combined ball bearing 25, 26. The combined bearings 25, 26 are arranged on the housing. The assembly thus includes a first combined bearing 25 to support the first output shaft 21 on the first part of the housing 51. The assembly includes a second combined bearing 26 to support the second output shaft 22 on the second part of the housing 52.

[0115] In the example described, the first and second output shafts 21, 22 are hollow.

[0116] Alternatively, the second output shaft may not be mounted on the first output shaft, as illustrated in [Fig. 5]. The output shafts are solid.

[0117] In this example of [Fig. 5], the reduction gear assembly 1 further includes a retaining plate 28 for the combined bearing 25, 26 on the housing 50. The retaining plate is washer-shaped with lugs for screws and is screwed into the housing. The retaining plate 28 is positioned perpendicular to an axis of rotation of the assembly. The assembly thus comprises a first retaining plate 28 for the first combined bearing 25 on the first part of the housing 51, and a second retaining plate 28 for the second combined bearing 26 on the second part of the housing 52.

Claims

Claims

1. Reduction assembly (1) for a motor vehicle, comprising: - a first input shaft (11) and a second input shaft (12), in particular coaxial with each other, - a first output shaft (21) and a second output shaft (22), in particular coaxial with each other, - at least one transmission stage (30) respectively connecting the first output shaft (21) and the second output shaft (22) to the first input shaft (11) and to the second input shaft (12), - a casing (50) in which the first and second input and output shafts as well as the transmission stage (30) are housed, the transmission stage (30) comprising at least a first intermediate shaft (31) and a second intermediate shaft (32) so that a transmission of movement takes place respectively from the first input shaft (11) to the first output shaft (21) and from the second input shaft (12) to the second output shaft (22), independently of each other,the first intermediate shaft (31) passing through the second intermediate shaft (32) and the first intermediate shaft (31) being mounted on first and second bearings (41, 42) arranged on the casing (50), the second intermediate shaft (32) being mounted freely in rotation on the first intermediate shaft (31).,

2. Assembly according to the preceding claim, the second intermediate shaft (32) being mounted on the first intermediate shaft (31) by pivot bearings (43, 44), in particular two bearings, for example needle bearings.

3. Assembly according to any one of the preceding claims, the second intermediate shaft (32) being mounted in axial abutment against one or two shoulders (46) of the first intermediate shaft (31).

4. Assembly according to any one of the preceding claims, the second intermediate shaft (32) being mounted in axial abutment against a shoulder (47) of the second bearing (42), in particular an inner ring of the second bearing.

5. Assembly according to any one of the preceding claims, comprising a holding part (48) of the second bearing (42) on the first intermediate shaft (31).

6. An assembly according to any preceding claim, the casing (50) comprising two parts, a first casing part (51) housing in particular the first input shaft, the first output shaft, as well as a first part of the transmission stage (30), and a second casing part (52) housing in particular the second input shaft, the second output shaft, as well as a second part of the transmission stage (30).

7. An assembly according to any preceding claim, the first intermediate shaft (31) comprising a longitudinal through channel (33) or several longitudinal through channels.

8. Assembly according to any one of the preceding claims, the first intermediate shaft (31) and the second intermediate shaft (32) of the transmission stage each comprising helical teeth (37, 38) cooperating respectively with the first output shaft (21) and with the second output shaft (22) or with another transmission stage, in particular the intermediate shafts of another transmission stage, said helical teeth (37, 38) respectively having helices in opposite directions relative to each other.

9. An assembly according to any one of the preceding claims, the second input shaft (12) being mounted freely in rotation on the first input shaft (11).

10. An assembly according to any preceding claim, the first input shaft (11) comprising a longitudinal through channel (15).

11. An assembly according to any one of the preceding claims, the second output shaft (22) being mounted freely in rotation on the first output shaft (21).

12. An assembly according to any preceding claim, the second output shaft (22) and / or the first output shaft (21) each being mounted on a combined double-row ball bearing (25, 26).

13. Assembly according to the preceding claim, comprising at least one holding element, in particular a holding plate (28), of the combined bearing on the housing.

14. Propulsion device for a motor vehicle, comprising a reduction assembly (1) according to any one of the preceding claims and two rotating electrical machines.

15. Vehicle comprising a reduction assembly (1) or a device according to any one of the preceding claims.

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