Transmission gearbox for electric drive axles in trucks

Abstract

A gearbox (5) for a vehicle, comprising: a gearbox housing (50); a main shaft (10) rotating about a first axis (A1), having a main input gear (11) driven by an electric motor (6), and a distribution gear (12), a transmission gear (13) rotatably mounted on the first axis (A1) and arranged around the main shaft; a countershaft (20) having a second axis (A2), the first and second axes being spaced apart, wherein the countershaft (20) has a counter output gear (22) and a counter transmission gear (21), the counter transmission gear (21) being engaged to at least one transmission gear A gear (13); an output gear (3) independently and rotationally arranged around a main shaft (10) and rotating around a first axis (A1), said output gear (3) being engaged to a secondary output gear (22); a shifting device (8) configured to rotationally engage at least one of: said distribution gear (12) and the output gear (3) for directly transmitting power from the main shaft (10) to the output gear (3); or said distribution gear (12) and at least one transmission gear (13) for indirectly transmitting power from the main shaft (10) to the output gear (3) via a secondary shaft (20).

Description

Technical Field

[0001] The present invention relates to a gearbox for a vehicle and a powertrain assembly for a vehicle. More particularly, the present invention relates to a gearbox and a powertrain assembly driven by an electric motor for an electric vehicle, a hybrid vehicle, or a trailer towed by a vehicle.

[0002] The present invention may be applied to heavy vehicles such as trucks, buses and construction equipment.Although the present invention will be described with respect to a truck, the present invention is not limited to this particular vehicle but may also be used in other vehicles such as passenger cars. Background Art

[0003] In the transportation sector, emissions regulations are becoming increasingly stringent, and cities with high traffic volumes are beginning to ban internal combustion engine vehicles from their city centers.

[0004] Vehicles, particularly electric / hybrid vehicles such as electric / hybrid buses and trucks, typically use electric motors to propel one or more wheels via a drive axle (or drive axle). Typically, the axle includes two drive axles, one for each drive wheel. However, compared to known internal combustion engines, which operate in high-torque / low-speed conditions, most electric motors are designed to operate in high-speed / low-torque conditions.

[0005] Meeting the torque requirements at the vehicle's wheels is crucial for the vehicle's startability under various conditions (e.g., on a slope). Consequently, a wide gear reduction ratio (typically between 1:20 and 1:50, for example) is required in the gearbox / drivetrain assembly. This wide gear reduction ratio is typically achieved using a gearbox with several reduction stages, requiring more space, leaving limited space for other vehicle components (e.g., space required for the battery, bodywork / aerodynamics, and suspension components). Furthermore, conventional gearboxes are also known to be heavy, further reducing the vehicle's mobility and limiting its autonomy. Consequently, problems arise when the gearbox / drivetrain assembly is implemented in electric / hybrid vehicles. Unlike standard gasoline / diesel engine drivetrains, where the transmission can be positioned in various ways and connected to the driveshaft via a shaft assembly (e.g., in rear-wheel drive trucks / buses), in electric / hybrid vehicles, the electric motor and gearbox must be located near the drive wheel axle. Typically, if the electric motor distributes power to the drive axles, a differential assembly is typically required to distribute different power / torques to each wheel via the associated drive axle. On the other hand, if the electric motor is connected and distributes power directly to the drive axles (even through a gearbox), a differential assembly is typically not required, but an electric motor is required for each drive axle (thus, there are at least two electric motors).

[0006] To comply with the above configuration, the space required to house the gearbox / transmission assembly in an electric / hybrid vehicle is further limited by the suspension assembly.

[0007] One example of prior art is U.S. Patent No. 9,409,477, which discloses a transmission system for an electric vehicle. This transmission system is defined by an input shaft coupled to a drive motor and an output shaft coupled to a differential. Each of the input and output shafts has a different axis of rotation, and this system lacks compactness and requires limited space within the electric vehicle.

[0008] Therefore, as further described in the detailed description of the invention, the present inventors have sought a solution to provide a small / compact gearbox that is also lighter than known gearbox / transmission assemblies. Summary of the Invention

[0009] The present invention aims to remedy these drawbacks.

[0010] In this respect, the present invention relates to a gearbox for a vehicle comprising:

[0011] a spindle configured to rotate about a first axis,

[0012] a distributor gear fixed for rotation with the main shaft;

[0013] a transmission gear configured to rotate about a first axis and disposed about the main shaft;

[0014] a countershaft configured to rotate about a second axis, the first axis and the second axis being spaced apart from each other,

[0015] a secondary output gear and a secondary transfer gear arranged around the layshaft, the secondary transfer gear being engaged to the transfer gear;

[0016] an output gear for transmitting power out of the gearbox, the output gear being independently and rotatably arranged around the main shaft and being configured to rotate around a first axis, the output gear being engaged to the auxiliary output gear;

[0017] A gear shift system capable of sliding between at least two positions, the gear shift system being configured to:

[0018] Rotatingly engaging the distribution gear and the output gear for transmitting power directly from the main shaft to the output gear, or

[0019] The distributor gear and the transfer gear are rotationally engaged for indirectly transmitting power from the main shaft to the output gear through the layshaft.

[0020] Due to this arrangement, the output gear and the main shaft rotate about the same axis. Thus, a compact and small gearbox can be provided, which is suitable for vehicles with limited available space due to strict space constraints (e.g. electric vehicles - battery pack, suspension components). The compactness of the gearbox is achieved by the output gear being arranged on the main shaft and being able to rotate at the same speed as the main shaft or at a different speed - depending on the position of the gearshift. Thus, the above arrangement makes it possible to avoid the use of two different shafts for transmitting power to and from the gearbox.

[0021] Furthermore, two or more gear stages can be provided by adding additional transmission gears and counter transmission gears, while the output gear remains in substantially the same position relative to the countershaft. That is, when one or more additional gear stages are added, the distance between the main shaft and the countershaft remains unchanged.

[0022] This compact solution comprising at least two gear stages provides satisfactory performance (high torque / low speed demand during starting state, and / or high speed / low torque demand during cruising state) resulting from different driving modes (current gear selection) of the vehicle.

[0023] Advantageously, the gearbox comprises additional features, which may be considered individually or in combination, and wherein:

[0024] The distribution gear is rigidly fixed to the main shaft or is integral with the main shaft.

[0025] At least the secondary transmission gear or the secondary output gear is rigidly fixed to the secondary shaft or is integral with the secondary shaft.

[0026] Alternatively, as an example, the countershaft may be rigidly fixed to the gearbox housing, and the at least one counter drive gear and the counter output gear may be configured to rotate about the fixed countershaft. Further, as an example, the at least one counter drive gear and the counter output gear may be mounted about the fixed countershaft (rigidly fixed to the gearbox housing) via at least one secondary roller bearing. The roller bearing disposed between the gearbox housing and the main shaft enables high torque values ​​to be withstood while minimizing wear.

[0027] The main shaft has a first axial end and a second axial end and is rotatably mounted in the gearbox housing via a first main roller bearing arranged at the first axial end and via a second main roller bearing arranged at the second axial end.

[0028] The axial length of the gearbox measured along the first axis is less than 400 mm.

[0029] This axial length of less than 400 mm defines a high degree of compactness of the gearbox, which can be accommodated in various types of electric / hybrid vehicles in which strict space requirements are a key feature.

[0030] - The output gear is mounted on the main shaft via at least one output roller bearing.

[0031] This arrangement allows the output gear to rotate about the same primary axis as the main shaft. Depending on the position of the shifter, the output gear's rotational speed can vary compared to the main shaft's. This variable speed of the output gear about the main shaft is achieved via an output roller bearing capable of withstanding the high torque demands during vehicle launch and the high power requirements during cruising. This improves the reliability and service life of the gearbox, while minimizing maintenance requirements.

[0032] The transmission gear is mounted on the main shaft via at least one roller bearing, preferably via at least one needle bearing.

[0033] This needle bearing, arranged between the transmission gear and the main shaft, provides enhanced space limitation, as the needle bearing requires less space than other known types of bearings, and furthermore, in the case of an indirect configuration (power from the electric motor is transmitted from the main shaft via the transmission gear through the layshaft to the output gear), the needle bearing provides sufficient strength to withstand the speed / torque requirements of the gearbox.

[0034] The secondary shaft is rotatably mounted in the gearbox housing via at least one secondary roller bearing.

[0035] - The gearbox further comprises a primary input ring fixed for rotation with the main shaft.

[0036] - The ratio between the rotational speed of the main shaft and the rotational speed of the output gear can be selected between a first gear ratio when the distribution gear and the output gear are in rotational engagement and a second gear ratio when the distribution gear and the transmission gear are in rotational engagement, wherein the second gear ratio is higher than the first gear ratio.

[0037] The shift system is further configured to be positioned to engage only the distributor gear to define a first neutral position in which power cannot be transmitted between the main shaft and the output gear.

[0038] Thanks to this arrangement, the gearbox can be shifted into a neutral position (a first neutral position defined by the shifting device) which provides free movement of the drive axle / axle for towing or servicing the vehicle / trailer.

[0039] -The gearbox also includes: a second distribution gear, which is integral with the main shaft; a second transmission gear, which is rotatably mounted on the first axis and arranged on the main shaft; a second secondary transmission gear, which is arranged on the secondary shaft and is engaged to the second transmission gear; and a second shifting device, which is capable of sliding between at least two positions, the second shifting device being configured to rotationally engage only the second distribution gear to define a second neutral position, the second neutral position not transmitting power between the main input gear and the output gear through the second distribution gear, or the second shifting device being configured to rotationally engage the second distribution gear and the second transmission gear for indirectly transmitting power from the main shaft to the output gear through the secondary shaft, wherein the shifting device is configured to be positioned in the first neutral position.

[0040] This construction of the gearbox with a second shifting device makes it possible to have more than two gear stages to further reduce / increase the rotational speed of the output gear, which can provide satisfactory requirements and thus ensure different performances caused by different driving modes (current gear selection) of the vehicle (high torque / low speed demand during starting state, and / or high speed / low torque demand during cruising state).

[0041] The gearbox is capable of transmitting a power of at least 250 kW, preferably at least 300 kW, and wherein the gearbox is capable of transmitting a torque of at least 600 Nm, preferably at least 750 Nm.

[0042] The shifting device and / or the second shifting device comprises a shift sleeve.

[0043] - At least one of the gears is a helical gear.

[0044] Due to this arrangement, the noise generated by the gearbox during operation can be effectively reduced.

[0045] The invention also relates to a powertrain assembly for a vehicle, comprising: a gearbox as defined above; at least one electric motor configured to be coupled to a main input gear of the gearbox; a differential gear having a differential ring wheel coupled to an output gear of the gearbox; and a drive wheel axle coupled to the differential gear.

[0046] Finally, the invention relates to a vehicle comprising a driveline assembly as defined above.

[0047] Preferably, the vehicle is a heavy vehicle, such as a truck, bus or construction machinery. The vehicle may be one of an electric vehicle, a hybrid vehicle or a towed trailer. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Other characteristics and advantages of the invention will emerge from the following detailed description of some embodiments of the invention, given by way of non-limiting example, and with reference to the accompanying drawings, in which:

[0049] Figure 1 A cross-sectional view of a gearbox is shown according to one embodiment of the present disclosure.

[0050] Figure 2 Shown in another different configuration Figure 1 Cross-section of the gearbox.

[0051] Figure 3 Shown Figures 1 to 2 Schematic diagram of the gearbox.

[0052] Figure 4 A schematic diagram of another embodiment of a gearbox with an additional gear stage is shown.

[0053] Figure 5 A perspective view of a powertrain assembly according to one embodiment of the present disclosure is shown.

[0054] Figure 6 Shown Figure 5 A top view of the powertrain components.

[0055] Figure 7 Shown Figure 5 A perspective view of the powertrain components.

[0056] Figure 8 Depicts Figure 5 Side view of the powertrain components.

[0057] Figure 9 A perspective view of another embodiment of the powertrain assembly is shown.

[0058] Figure 10 A schematic diagram illustrating a cross-sectional view of Figure 1 The various radii involved in the gearbox.

[0059] Figure 11 A schematic diagram of a vehicle, in particular a truck, comprising a gearbox according to the invention is shown. DETAILED DESCRIPTION

[0060] In the drawings, the same reference numerals refer to the same or similar elements unless otherwise specified.

[0061] Figure 1 A cross-sectional view (longitudinal section) of a gearbox 5 according to an embodiment of the present disclosure is shown. The gearbox 5 includes a main shaft 10 and a secondary shaft 20 (also referred to as an "intermediate shaft"). The main shaft 10 is configured to transmit power in the gearbox 5.

[0062] The primary shaft 10 is configured to rotate about a first axis A1, and the secondary shaft 20 is configured to rotate about a second axis A2. The first axis A1 and the second axis A2 are configured to be spaced apart from each other. That is, in one example, the first axis A1 and the second axis A2 are spaced apart from each other within a substantially vertical plane. In this example, the first axis A1 and the second axis A2 are parallel to each other.

[0063] Advantageously, the main input ring 11 is fixed to rotate with the main shaft 10. In the example of the figures, the main input gear 11 is mounted on the main shaft 10 (i.e. around the main shaft 10) and is therefore rigidly fixed to the main shaft 10 (thus forming two parts). Alternatively, the main input ring 11 can also be integral with the main shaft 10 (thus forming a single part). The main input ring 11 is then arranged so that the power is transmitted in a radial direction relative to the axis A1 (see Figure 1 and Figure 2 The input is transmitted to the spindle 10 (arrow “input” on the left).

[0064] The rotational speed of the main shaft 10 is the same as the rotational speed of the main input ring 11 .

[0065] Preferably, the main input ring 11 is configured to be driven by an electric motor (not shown) through rotational engagement between the main input ring 11 and the rotor of the electric motor. In a variant not shown, another type of motor (e.g., an ICE) may be used as a power source for driving the gearbox 5. Preferably, the electric motor is a DC motor, such as a BLDC motor (brushless direct current motor).

[0066] Advantageously, there is a reduction ratio between the rotation shaft of the motor (whatever it is) and the main shaft 10 , meaning that the rotation shaft of the motor is not directly coupled to the main shaft 10 .

[0067] The main input ring 11 is optional, as a coupling (not shown) can be used to connect one longitudinal end of the main shaft 10 to the longitudinal end of a drive shaft, such as the rotating shaft of a motor (e.g., a rotor or camshaft). For example, a keyed joint or a universal joint can be used to connect the main shaft to the drive shaft. This means that in this variant, not shown, power can be transmitted to the main shaft 10 in the axial direction (i.e., along the axis A1). This also means that, in one embodiment, there is no speed reduction between the rotating shaft of the motor (whatever it is) and the main shaft 10.

[0068] In this example, main input ring 11 is a gear element (or pinion), meaning it meshes with another ring gear (not shown). Of these two meshing gears, main input gear 11 is the driven gear, while the other ring gear is the driving gear. Alternatively, ring 11 could be a pulley connected to a belt (pulley system) or a sprocket connected to a chain (roller chain system). This means that ring 11 does not necessarily have to include external teeth.

[0069] The distribution gear 12 is fixed for rotation with the main shaft 10. In this example, the distribution gear 12 is integral with the main shaft 10 (thus forming a single part). However, in an alternative embodiment (not shown), the distribution gear 12 may be distinct from the main shaft 10 (thus forming two parts). In this case, the distribution gear 12 would be disposed about the shaft 10 and rigidly fixed (or fastened) thereto.

[0070] The distribution gear 12 is configured to transmit power from the main shaft 10 to the output gear 3 (for outputting power from the gear box 5 ) or to the transmission gear 13 .

[0071] The output gear 3 is configured to transfer power from the gearbox 5. The output gear 3 is independently and rotatably arranged around the main shaft 10, so that the output gear 3 rotates about the same first axis A1 as the main shaft 10. The output gear 3 can freely rotate around the main shaft 10. The rotational speed of the output gear 3 can be the same as or different from the rotational speed of the main shaft 10, depending on the selected drive mode (e.g., neutral, first gear, second gear, etc.). In various embodiments, the output gear 3 can be coupled to a differential assembly (70 - e.g., a differential annulus) for transmitting power to one, two, or more drive wheel axles T, depending on the type of vehicle.

[0072] In this example, and as Figure 11 As shown in FIG, the vehicle 1 is a truck. Alternatively, the vehicle may be a bus or a construction machine.

[0073] In operation, the main input gear 11 and the output gear 3 rotate about the same axis (i.e., the first axis A1) because the output gear 3 is arranged on the main shaft 10. Therefore, it is possible to have a compact and small gearbox suitable for vehicles (e.g., electric vehicles - battery pack, suspension components, etc.) in which the required space is limited due to strict spacing restrictions.

[0074] The output gear 3 is preferably mounted around the main shaft 10 via at least one output roller bearing, preferably two output roller bearings 43 and 44. This configuration enables the output gear 3 to rotate about the same first axis A1 as the main shaft 10. The speed of the output gear 3 can be the same as or different from the speed of the main shaft 10. The variable speed of the output gear 3 around the main shaft 10 is achieved by the at least one output roller bearing 43, 44, which is capable of withstanding high torque transmission, particularly during vehicle starting. This improves the reliability and service life of the gearbox, and minimizes maintenance requirements.

[0075] Advantageously, the transmission gear 13 is configured to rotate about the first axis A1 and is arranged on the main shaft 10 .

[0076] In this example, the transmission gear 13 can freely rotate (ie, is free to rotate) about the main shaft 10 (and vice versa).

[0077] Depending on the gear ratio selected, the transmission gear 13 may have the same or a different rotational speed than the rotational speed of the main shaft 10 .

[0078] Preferably, the transmission gear 13 is mounted around the main shaft 10 via at least one roller bearing, preferably a needle bearing 49. The needle bearing 49 is arranged between the transmission gear 13 and the main shaft 10, providing enhanced space constraints (because the needle bearing 49 requires less space than other known types of bearings), and further providing sufficient strength to withstand the speed / torque requirements of the gearbox 5.

[0079] In various embodiments, the number of transmission gears 13 may be different, depending on the number of gear stages arranged within the gearbox 5 . Figure 1 An embodiment with one transmission gear 13 is shown. Figure 4 An example of another embodiment showing further gear stages can be seen in FIG and will be described later (a second distribution gear 14 and a second transmission gear 15 are shown).

[0080] Preferably, the gearbox 5 further comprises a secondary output gear 22. Said secondary output gear 22 is preferably fixed for rotation together with the layshaft 20. In the example of the figures, the secondary output gear 22 is mounted on (i.e., surrounds) the layshaft 20 and is thus rigidly fixed to the layshaft 20 (thus forming two parts). Alternatively, the secondary output gear 22 may also be integral with the layshaft 20 (thus forming a single part).

[0081] Furthermore, the gearbox 5 includes a counter gear 21. In this example, the counter gear 21 is fixed to rotate together with the countershaft 20. In the example of the figures, the counter gear 21 is mounted on the countershaft 20 (i.e., around the countershaft 20) and is therefore rigidly fixed to the countershaft 20 (thus forming two parts). Alternatively, the counter gear 21 can also be integral with the countershaft 20 (thus forming a single part).

[0082] Advantageously, the secondary transmission gear 21 is coupled to the transmission gear 13. As mentioned above, in various embodiments having a different number of transmission gears 13, the number of secondary transmission gears 21 may also be different (e.g., Figure 4 The auxiliary transmission gear 21 and the auxiliary output gear 22 rotate about the second axis A2 at the same speed as the auxiliary shaft 20.

[0083] Alternatively, in another embodiment not shown in the figures, the layshaft 20 can be rigidly fixed within the gearbox 5 (e.g., fixed to the gearbox housing 50). In other words, the shaft 20 can be non-rotating (fixed). In this configuration, the secondary drive gear 21 and the secondary output gear 22 can be rotatably mounted (i.e., freely rotating) around the rigidly fixed layshaft 20 via roller bearings.

[0084] Thus, the secondary transmission gear 21 and the secondary output gear 22 are either fixed for rotation with the shaft 20 or freely rotate relative to the shaft 20 .

[0085] The gearbox 5 also includes a shift system 8. The shift system 8 is configured to slide along the axis A1 (axially) between at least two positions. These two positions can be defined as different engagement configurations between the distribution gear 12 of the main shaft 10 and the output gear 3 or the at least one transmission gear 13.

[0086] exist Figure 2 A first configuration can be seen in which the shift system 8 is shifted to the left from the initial position (dashed line) so that the distribution gear 12 and the output gear 3 are rotatably engaged. In this first configuration, the rotational speed of the output gear 3 is the same as the rotational speed of the distribution gear 12 of the main shaft 10. The power in this first configuration is distributed directly from the main shaft 10 (connected to the electric motor 6) to the output gear 3. Thus, the power of the electric motor (not shown) is transmitted radially to the main shaft 10 through the main input gear 11 and then axially through the distribution gear 12 directly to the output gear 3 and then to the differential assembly (e.g., to the differential ring gear 70). The power transmission described in Figure 2 In the figure, which is drawn with a dotted line, it follows the following power transmission: (input) electric motor (not shown) -> main input gear 11 -> main shaft 10 -> distribution gear 12 -> gear shifting system 8 -> output gear 3 -> output (differential assembly).

[0087] In the first configuration of the gearshift system 8 as described above, the rotational speed of the output gear 3 is the same as the rotational speed of the main shaft 10. Typically, this configuration is selected in a cruising state (high speed / low torque).

[0088] The second structure is Figure 1 , and shows the rotational engagement of the distribution gear 12 and the transmission gear 13. Figure 1 As shown in FIG, the shift system 8 is shifted to the right from the initial position (dashed line) so that the distributor gear 12 and the transfer gear 13 are rotatably engaged. In this so-called second configuration, the rotational speed of the transfer gear 13 is the same as that of the distributor gear 12. In this second configuration, power is indirectly distributed from the main shaft 10 (connected to the electric motor) to the output gear 3 via the layshaft 20.

[0089] Thus, the power of the electric motor (not shown) is transmitted radially to the main shaft 10 through the main input gear 11, and then axially to the transfer gear 13 (through the distribution gear 12 and via the shift system 8). Then, the power is distributed from the secondary transfer gear 21 (rotatably engaged with the transfer gear 13) to the secondary output gear 22 via the layshaft 20. Finally, the power is transmitted from the secondary output gear 22 to the output gear 3 and then radially to the differential assembly (for example, to the differential ring gear 70). The power transmission described is Figure 1 The diagram is drawn in dotted lines, which follow the following power transmission: (input) electric motor (not shown) -> main input gear 11 -> main shaft 10 -> distribution gear 12 -> shift system 8 -> transmission gear 13 -> secondary transmission gear 21 -> secondary shaft 20 -> secondary output gear 22 -> output gear 3 -> output (differential assembly).

[0090] In the second configuration of the gearshift system 8 as described above, the rotational speed of the output gear 3 is reduced compared to the rotational speed of the primary shaft 10 via the secondary shaft 20. This configuration may be selected under high torque / low speed conditions.

[0091] In addition, the gear ratio can be defined as the ratio (or quotient) between the rotational speed of the main input gear 11 and the rotational speed of the output gear 3. In the first configuration of the gearshift system 8, that is, when there is direct engagement between the distributor gear 12 and the output gear 3, the gear ratio is equal to the first gear ratio, that is, 1:1.

[0092] Furthermore, the second configuration of the gearshift system 8 defines an indirect engagement between the distributor gearwheel 12 and the output gearwheel 3 via the layshaft 20. In this second configuration, the gear ratio is equal to the second gear ratio.

[0093] Advantageously, the second gear ratio (indirect engagement) is higher than the first gear ratio (direct engagement).

[0094] However, in an alternative embodiment, the second gear ratio may be lower than the first gear ratio. This means that the rotational speed of the main input gear is not reduced but amplified (overdrive).

[0095] Alternatively, the shift system 8 may be further configured to be positioned only in engagement with the distribution gear 12. In this configuration, the shift system 8 does not have any engagement configuration with the output gear 3 or with the transfer gear 13. This configuration may be defined as a neutral position (e.g., relative to the Figure 4). In the (first) neutral position, the gearshift system 8 is configured not to transfer power between the main input gear 11 and the output gear 3, since no physical engagement is provided between these gears (3, 12, 13). The (first) neutral position may represent a third position of the gearshift system 8, as an additional option to direct engagement (first configuration) and indirect engagement (second configuration). The (first) neutral position of the gearshift system 8 may provide free movement of the vehicle (e.g. free movement of the drive axle / axle) for towing or repairing the vehicle / trailer. In addition, with reference to Figure 1 and Figure 2 , a (first) neutral position of the gearshift system 8 is shown in dashed lines, wherein the position of the gearshift system 8 corresponds to the position of the distributor gearwheel 12 .

[0096] Alternatively, the gearshift system 8 may be a clutch sleeve (also referred to as a "shift sleeve") or any suitable type of dog clutch for performing gear changes in the gearbox 5. As is known per se (and therefore not described in detail herein), this type of gearshift system / dog clutch can be controlled by a control fork (53 - in Figure 7 (middle portion visible) control.

[0097] Furthermore, the gearbox 5 preferably includes a gearbox housing 50. The gearbox housing 50 may be any type of housing / casing for enclosing gearbox components. Typically, the gearbox housing 50 comprises two or more parts, including a main housing component and a housing cover (51- Figure 2 / Figure 5 ).

[0098] like Figure 1 and Figure 2 As further shown in FIG, the main shaft 10 extends longitudinally between a first axial end 101 and a second axial end 102. The two axial ends (101, 102) of the main shaft 10 can be rotatably mounted within the gearbox housing 50. This mounting can be provided via a first main roller bearing 41 arranged at the first axial end 101 and via a second main roller bearing 42 arranged at the second axial end 102. The roller bearings (41, 42) arranged at the two axial ends (101, 102) between the gearbox housing 50 and the main shaft 10 help to withstand high torque values ​​and minimize wear of the main shaft 10.

[0099] The layshaft 20 extends longitudinally between a first secondary axial end 201 and a second secondary axial end 202. The two secondary axial ends (201, 202) can be rotatably mounted within the gearbox housing 50. This mounting can be provided via a first secondary roller bearing 46 arranged at the first secondary axial end 201 and via a second secondary roller bearing 47 arranged at the second secondary axial end 202. The secondary roller bearings (46, 47) arranged between the gearbox housing 50 and the layshaft 20 at the two secondary axial ends (201, 202) help to withstand high torque values ​​and minimize wear of the layshaft 20.

[0100] The gearbox 5 has an axial length LG. The axial length LG can be taken along the first axis A1. Thus, the axial length LG can be interpreted as the total length of the gearbox 5 in the axial direction of the first axis A1. The axial length LG can further include the size of the gearbox housing 50 (including the cover 51). The total axial length LG of the gearbox 5 is less than 400 mm. This compactness is achieved because the output gear 3 is independently and rotationally arranged around the main shaft 10 so that the output gear 3 rotates around the first axis A1 like the main shaft 10. The axial length LG of less than 400 mm defines the high compactness of the gearbox 5, which can be accommodated in various types of electric / hybrid vehicles in which strict space requirements are a key feature.

[0101] like Figure 1 and Figure 2 As further shown in FIG, the main shaft 10 can be defined by diameters D1-D4, where diameter D1 is measured at the first axial end 101 of the main shaft 10, and diameter D4 is measured at the second axial end 102 of the main shaft. Diameters D2 and D3 are the inner diameters of the main shaft 10. All of these diameters D1-D4 can vary. Diameter D1 represents the minimum structural diameter of the main shaft 10, which ensures the structural strength of the main shaft 10. Diameter D1 is preferably at least 40 mm. Diameter D4 is preferably 70 mm. Furthermore, diameter D3 defines the diameter of the main shaft 10 in the area where the output gear 3 is mounted and is preferably approximately 85 mm. Diameter D2 defines the diameter of the main shaft 10 in the area where the transmission gear 13 is mounted and is preferably approximately 60 mm. Furthermore, the length L10 of the main shaft 10 is defined as the total length of the main shaft 10 along the first axis A1. Length L10 is preferably approximately 250 mm.

[0102] Similarly, the layshaft 20 can be further defined by diameters D25-D29, where diameter D25 is measured at the first layshaft axial end 201 of the layshaft 20, and diameter D29 is measured at the second layshaft axial end 202 of the layshaft 20. Diameters D26-D28 are the inner diameters of the layshaft 20. All of these diameters D25-D29 can vary. Diameter D25 represents the minimum structural diameter of the layshaft 20, which ensures the structural strength of the layshaft 20. Diameter D25 is preferably at least 34 mm. Diameter D29 is preferably approximately 55 mm. The specific portion of the layshaft 20 where the counter gear 21 is rigidly secured to the layshaft 20 can be defined by diameter D26 and radius R21 of the counter gear 21. Thus, diameter D26 of the layshaft 20 can correspond to the inner diameter (not shown) of the counter gear 21, such that, to provide rigid securing, diameter D26 of the layshaft 20 and the inner diameter of the counter gear 21 match each other. The diameter D26 of the secondary shaft 20 is preferably about 80 mm.

[0103] Similarly, the specific portion of the layshaft 20 where the secondary output gear 22 is rigidly secured to the layshaft 20 can be defined by the diameter D26 of the layshaft 20 and the radius R22 of the secondary output gear 22. Thus, the diameter D28 of the layshaft 20 can correspond to the inner diameter (not shown) of the secondary output gear 22 to provide rigid securing, meaning that the diameter D28 of the layshaft 20 and the inner diameter of the secondary output gear 22 match each other. The diameter D28 of the layshaft 20 is preferably approximately 108 mm. Additionally, the portion of the layshaft 20 between the secondary transmission gear 21 and the secondary output gear 22 can define a diameter D27. The diameter D27 of the layshaft 20 is preferably approximately 95 mm. The length L20 of the layshaft 20 is defined as the total length of the layshaft 20 along the second axis A2. The length L20 is preferably approximately 200 mm.

[0104] refer to Figure 3 , which shows a schematic diagram of the above embodiment with a transmission gear 13 and three auxiliary transmission gears 21. Figure 1 and Figure 2 In addition, Figure 3 Further shown is a motor 6, typically an electric motor having a motor axis A6. The motor axis A6 is the axis of rotation of the rotor. The gearbox 5 can further be coupled to a differential assembly, more specifically, to a differential ring 70 of the differential assembly, which further transmits power to a left drive axle 71 and a right drive axle 72 extending generally along the drive wheel axle T. Each of the left and right drive axles (71, 72) can be positioned on a respective side of the gearbox 5. The input power of the (first) electric motor 6 is transmitted to the gearbox 5 via the main input gear 11 and is transmitted out of the gearbox 5 via the output gear 3, which is coupled to the differential ring 70.

[0105] Figure 4Another embodiment relates to a Figures 1 to 3 The embodiment described in

[15] has substantially the same features as the embodiment described in

[16] , except that, in addition to the splitter gear 12, the transfer gear 13, and the counter-transmission gear 21, a second splitter gear 14, a second transfer gear 15, and a second counter-transmission gear 23 are also provided. The function and location of the electric motor 6 are substantially the same as in the previous embodiment—the electric motor 6 is coupled to the main input gear 11 of the main shaft 10. Similarly, the output gear 3 can be coupled to a differential assembly, which transmits power to one or more drive wheel axles T via a differential ring gear 70.

[0106] like Figure 4 As shown in FIG, the main shaft 10 is provided with a main input gear 11 and a distribution gear 12, as explained above. In addition, the main shaft 10 also includes a second distribution gear 14. The second distribution gear 14 can be rigidly fixed to the main shaft 10 or be integral with the main shaft 10.

[0107] The second transmission gear 15 is rotatably mounted on the first axis A1 and is arranged on the main shaft 10. In various circumstances, the second transmission gear 15 is able to rotate freely around the main shaft 10. The second transmission gear 15 can have the same or a different rotational speed than the main shaft 10 and the transmission gear 13, depending on the current gear selection.

[0108] Preferably, the second transmission gear 15 is mounted around the main shaft 10 via at least a second transmission needle bearing (not shown). Said at least second needle bearing arranged between the second transmission gear 15 and the main shaft 10 provides enhanced space limitation, as needle bearings require less space than other known types of bearings, and furthermore, provides sufficient strength to withstand the speed / torque requirements of the gearbox 5.

[0109] The second distribution gear 14 is configured to transmit power from the main shaft 10 to the second transmission gear 15 when the second distribution gear 14 is rotatably engaged to the second transmission gear 15 by a second shifting system 88 (to be described later).

[0110] like Figure 4 As shown in FIG, the countershaft 20 includes a counter output gear 22 that engages with the output gear 3 and a counter transfer gear 21 that engages with the transfer gear 13. Furthermore, the countershaft 20 includes a second counter transfer gear 23. The second counter transfer gear 23 can be rigidly fixed to the countershaft 20 or can be integral with the countershaft 20. In this configuration, the counter output gear 22, the counter transfer gear 21, and the second counter transfer gear 23 rotate together about the second axis A2 at the same speed as the countershaft 20. The second counter transfer gear 23 is engaged with the second transfer gear 15.

[0111] Figure 4The gearbox 5 of the embodiment further includes a second shifting system 88. The second shifting system 88 is configured to be slidable between at least two positions. The at least two positions can be defined as different engagement configurations between the second distribution gear 14 and the second transmission gear 15 of the main shaft 10.

[0112] First, the second shift system 88 can be engaged solely with the second split gear 14. In this configuration, the second shift system 88 does not have any engagement configuration with the second transfer gear 15. The engagement of the second shift system 88 solely with the second split gear 14 can be defined as a second neutral position. In the second neutral position, the second shift system 88 is configured not to transmit power between the main input gear 11 and the output gear 3 through the second split gear 14 (and the second transfer gear 15) because there is no physical engagement between these gears (14, 15).

[0113] Next, the second shift system 88 can be shifted from the second neutral position to rotational engagement between the second split gear 14 and the second transfer gear 15. In this engaged configuration, the rotational speed of the second transfer gear 15 is the same as the rotational speed of the second split gear 14. In this configuration, power is indirectly distributed from the main shaft 10 (connected to the (first) electric motor 6) to the output gear 3 via the layshaft 20 (via the second split gear 14 and the second transfer gear 15 engaged to the second countertransfer gear 23).

[0114] Thus, the power of the electric motor 6 is radially transmitted to the main shaft 10 through the main input gear 11, then transmitted to the second transfer gear 15 through the second distribution gear 14 via the second shifting system 88, and then the power is distributed from the second secondary transfer gear 23 rotatably engaged with the second transfer gear 15 to the secondary output gear 22 via the layshaft 20. Finally, the power is transmitted from the secondary output gear 22 to the output gear 3, and then radially transmitted to the differential assembly (e.g., to the differential ring gear 70).

[0115] In this configuration of the second shift system 88, the same as above with respect to the Figure 1 Compared with the rotation speed of the output gear 3 in the second configuration defined by the indirect engagement of the shift system 8 shown in FIG, the rotation speed of the output gear 3 is further reduced. Therefore, this configuration can be selected under high torque / low speed conditions.

[0116] Furthermore, in the event that the second shift system 88 rotationally engages the second distributor gear 14 and the second transfer gear 15, the shift system 8 must be in the (first) neutral position, thereby not providing engagement between the distributor gear 12 and the output gear 3 or the transfer gear 13. Similarly, in the event that the shift system 8 rotationally engages the output gear 3 or the transfer gear 13 with the distributor gear 12, the second shift system 88 must be in the second neutral position (engaging only with the second distributor gear 14). Furthermore, in various circumstances, both the shift system 8 and the second shift system 88 can be positioned in their first / second neutral positions to provide free movement of the vehicle (e.g., free movement of the drive axle / axle) for towing or repairing the vehicle / trailer.

[0117] Furthermore, the second shifting system 88 may be a clutch sleeve or any suitable type of dog clutch for performing gear shifts in the gearbox 5 .

[0118] Advantageously, even though the second distribution gear 14, the second transfer gear 15, and the second counter-transmission gear 23 are disposed within the gearbox 5, the gearbox 5 has an axial length LG that is less than 500 mm, preferably less than 450 mm. Therefore, even though the gearbox 5 is provided with additional gear stages (in terms of additional distribution gears / transfer gears / counter-transmission gears), the main input gear 11 and the output gear 3 of the main shaft 10 remain in substantially the same position in terms of vertical arrangement relative to the countershaft 20. This means that when one or more additional gear stages are added, the distance between the main shaft 10 and the countershaft 20 remains unchanged.

[0119] In addition, in addition to the first gear ratio and the second gear ratio defined above, regarding the third gear ratio, Figure 4 The embodiment of can be defined as the quotient between the rotational speed of the main input gear 11 and the rotational speed of the output gear 3. The first gear ratio is the quotient between the rotational speed of the main input gear 11 and the rotational speed of the output gear 3 (in the direct engagement configuration between the splitter gear 12 and the output gear 3). The second gear ratio is the quotient between the rotational speed of the main input gear 11 and the rotational speed of the output gear 3 (in the indirect engagement configuration between the splitter gear 12 and the output gear 3: power is transmitted to the layshaft 20 via the transfer gear 13).

[0120] Furthermore, a third gear ratio can be defined with the second shift system 88 in a position defining rotational engagement between the second splitter gear 14 and the second transfer gear 15. In this configuration, power is indirectly distributed from the mainshaft 10 (main input gear 11) through the countershaft 20 (via the second splitter gear 14 and the second transfer gear 15, which is engaged with the second countertransfer gear 23) to the output gear 3. Thus, the third gear ratio is the quotient between the rotational speed of the main input gear 11 and the rotational speed of the output gear 3 (with the second splitter gear 14 and the second transfer gear 15 engaged and the shift system 8 in its (first) neutral position).

[0121] Preferably, the third gear ratio (engagement between the second distribution gear 14 and the second transmission gear 15) is higher than the second gear ratio (engagement between the distribution gear 12 and the transmission gear 13). In addition, the second gear ratio is preferably higher than the first gear ratio (engagement between the distribution gear 12 and the output gear 3).

[0122] Figure 5 A perspective view of a powertrain assembly is shown. The powertrain assembly includes a gearbox 5 having a housing 50; one or two electric motors (6, 66); and a differential assembly coupled to the gearbox 5. The housing 50 of the gearbox 5 can be any type of housing / casing for enclosing gearbox components and typically includes two or more parts, including a main housing component and a housing cover 51.

[0123] The powertrain assembly may also include a drive wheel axle T through which power may be transmitted from the gearbox 5 to the vehicle's drive wheels 96. The drive wheel axle T may be further defined by a left drive wheel axle 71 and a right drive wheel axle 72, both of which are enclosed in the axle body / housing 7. Each of the left and right drive wheel axles (71, 72) may be positioned on a respective side of the gearbox 5 about the axis X (the axis in the longitudinal direction of the vehicle).

[0124] like Figure 5 As further shown in FIG, the powertrain assembly can be directly or indirectly coupled to the vehicle's suspension system (e.g., defined by pneumatic cylinders (98, 99)). Pneumatic cylinders (98, 99) can also represent other types of cylinders, such as cylinders for any auxiliary equipment specific to a particular vehicle. For a more rigid construction, the powertrain assembly can be further connected to the vehicle's chassis 9. Figure 5 , the powertrain assembly may be attached to the chassis 9 by one or more struts 18, 19 (e.g., shock absorbers for vertical 18 and shock absorbers for horizontal 19). The struts (18, 19) may be any type of strut for limiting vibration and shock.

[0125] Figure 6 express Figure 5 FIG. 1 is a top view of a powertrain assembly as depicted in FIG. As shown, an axis X is defined in the longitudinal direction of the vehicle, and a drive wheel axle T is perpendicular to the axis X. As further depicted, arrow FW defines the direction in which the front of the vehicle (e.g., the cab or the front steering wheel axis) is located. Figure 2 As explained, the gearbox 5 has an axial length LG, which is defined as the length of the gearbox 5 measured along the drive wheel axle T (or along the first axis A1 parallel to the drive wheel axle T).

[0126] More specifically, the axial length LG is the length of the gearbox 5 itself, taken along the first axis A1 / drive wheel axle T, without taking into account the size of the one or two electric motors (6, 66). The axial length LG of the gearbox 5 is less than 400 mm, preferably about 360 mm. The gearbox 5 (or more specifically, the gearbox 5 and the one or two electric motors (6, 66) when coupled together) may further define a second axial length LG2 dimension, which is defined as the length along the first axis A1 / drive wheel axle T. The second axial length LG2 is preferably about 400 mm.

[0127] The gearbox 5 defined by the axial length LG or the second axial length LG2 may provide a high degree of compactness and be able to fit within an existing chassis 9 / suspension system of a vehicle.

[0128] Figure 7 A perspective view of the powertrain assembly is shown, but the vehicle's rotating wheels 96, chassis 9, struts 19, pneumatic cylinders (98, 99) and suspension system are not depicted. In addition, the gearbox 5 is depicted without the housing 50 and housing cover 51. Figure 7 The example shown in represents an embodiment with two electric motors (6, 66), however, in certain types of vehicles, due to limited room / space in the gearbox 5, an embodiment with a single electric motor 6 is preferred - e.g. Figure 9 As shown in .

[0129] Figure 7 Further shown is a (first) motor axis A6 of the (first) electric motor 6. The (first) motor axis A6 defines the axis about which the rotor of the (first) electric motor 6 can rotate. Similarly, the (second) motor axis A66 is defined as the axis of the (second) electric motor 66 and represents the axis about which the rotor of the (second) electric motor 66 can rotate. Figure 7 The positions of the two electric motors (6, 66) in FIG are exemplary configurations and may vary depending on the vehicle type. For example, the position of the (first) electric motor 6 may differ vertically relative to the position of the (second) electric motor 66 due to the suspension components and chassis 9.

[0130] Figure 7 The gearbox 5 shown in FIG. Figure 4 The embodiment has two distribution gears (distribution gear 12, second distribution gear 14), two transmission gears (transmission gear 13, second transmission gear 15) and two auxiliary transmission gears (auxiliary transmission gear 21, second auxiliary transmission gear 23) coupled to the (first) electric motor 6. Figure 7 In the exemplary embodiment shown in FIG, the (second) electric motor 66 is not coupled to a gearbox, but rather to a speed reducer 52 that is coupled to a differential assembly. The speed reducer has a fixed gear ratio (and therefore cannot be changed). The powertrain assembly may also include a control fork 53 for selectively locking / unlocking the differential assembly. In other embodiments (not shown), the speed reducer 52 may be omitted, and the two electric motors (6, 66) may be coupled to two respective gearboxes.

[0131] like Figure 7 As shown in , the (first) electric motor 6 is configured to be coupled to the main input gear 11 of the gearbox 5. Thus, power is transmitted to the main shaft 10 of the gearbox 5 via the main input gear 11. The differential assembly can be defined as comprising a differential gear having a differential ring wheel 70. The differential ring wheel 70 can be rotatably coupled to the output gear 3 of the gearbox 5 for transmitting power output from the gearbox 5 to the one or more drive wheel axles T. As explained above, the drive wheel axles T can be defined by a left drive wheel axle 71 and a right drive wheel axle 72. Each of the left and right drive wheel axles (71, 72) can be respectively positioned on a respective side of the gearbox 5, such that each of the left and right drive wheel axles (71, 72) is coupled to the differential crown wheel of the differential assembly.

[0132] Figure 8 A side view of the drive train assembly defined above is depicted. As shown in the figure, the drive train assembly represents an embodiment with two electric motors (6, 66), which are arranged on a respective side of the drive wheel axle T. The compactness of the drive train assembly with a compact gearbox 5 is further revealed by the heights / clearances defined as H1-H4 and the lengths defined as L, L1 and L2. The axis X defines the axis along the longitudinal direction of the vehicle, while the arrow FW defines the direction in which the front part of the vehicle (e.g., the cab or the front steering wheel axis) is located. The axis Z defines a vertical axis perpendicular to the axis X and the drive wheel axle T.

[0133] Height H1 represents the vertical distance along the Z axis from the ground to the upper portion of the vehicle chassis 9. A second gap H2 represents the vertical distance along the Z axis from the ground to the lowest portion of the (second) electric motor 66. A third gap H3 represents the vertical distance along the Z axis from the ground to the lowest portion of the suspension assembly (e.g., to the suspension arm). A fourth gap H4 represents the vertical distance along the Z axis from the ground to the lowest portion of the (first) electric motor 6.

[0134] Length L represents the longitudinal distance along the X-axis between the (first) motor axis A6 of the (first) electric motor 6 and the (second) motor axis A66 of the (second) electric motor 66. Furthermore, length L1 represents the longitudinal distance along the X-axis between the (first) motor axis A6 of the (first) electric motor 6 and the drive wheel axle T. Length L2 represents the longitudinal distance along the X-axis between the (second) motor axis A66 of the (second) electric motor 66 and the drive wheel axle T.

[0135] As an exemplary embodiment, the powertrain assembly may be assembled in a vehicle having drive wheels 96 having a size of 315 / 70R22.5. The dimensions of the drive wheels 96 are not limiting: they are given in FIG. Figure 8 The overall size and compactness of the transmission assembly are shown in FIG.

[0136] Preferably, height H1 is approximately 859 mm (tbc). Gap H2 is approximately 217 mm (tbc). Gap H3 is approximately 230 mm (tbc). Gap H4 is approximately 229 mm (tbc). Length L is preferably approximately 1074 mm. Length L1 is preferably approximately 470 mm. Length L2 is preferably approximately 633 mm.

[0137] Due to the small size of the gearbox 5 itself and the small size of the powertrain assembly that includes the gearbox 5, a high degree of compactness is achieved. For example, if the powertrain assembly is included in a heavy truck vehicle, the clearance between the chassis 9 and the gearbox 5 enables it to withstand heavier loads. Moreover, with the gearbox 5 coupled to the suspension assembly, the vehicle can withstand higher vibrations and absorb higher shocks due to the high level of mobility provided to the drive wheel axle T. This high level of mobility is provided due to the available headroom (space) between the powertrain assembly and other parts of the vehicle (e.g., the chassis 9, the suspension assembly, the battery, etc.).

[0138] Figure 9 A preferred embodiment is shown, which is identical to the Figures 5 to 8 This embodiment further improves the compactness of the gearbox 5 itself and the compactness of the powertrain components in the vehicle.

[0139] Figure 10 A schematic diagram is presented illustrating the various radii involved in the gearbox 5 in a cross-sectional view along the first / second axis (A1, A2). Figure 1 and Figure 2 as well as Figure 10 As shown in , the main shaft 10 can be further defined by the radii R11, R12 of the main input gear 11 and the distributor gear 12, by the diameters D1-D4, and further by the length L10. Similarly, the secondary shaft 20 can be further defined by the radii R21, R22 of the secondary transfer gear 21 and the secondary output gear 22, by the diameters D25-D29, and by the length L20.

[0140] In various embodiments, the diameter of the primary shaft / countershaft (10, 20) and the radius of the gears (3, 13, 15, 21, 22, 23) can be different. Thus, by varying the radius / diameter of the gears (3, 13, 15, 21, 22, 23), essentially any gear ratio is possible. The speed of the output gear 3 can be expressed as Ω3, and as is known in the art, the speed Ω3 can be determined using the following formula:

[0141] Ω3=Ω1(R13 / R21)(R22 / R33)

[0142] Where Ω1 is the rotational speed of the input gear (for example, in the case of indirect engagement, the input gear may be a transfer gear 13 having the same rotational speed as the main shaft 10 / main input gear 11), R13 is the radius of the transfer gear 13, R21 is the radius of the secondary transfer gear 21, R22 is the radius of the secondary output gear 22, and R33 is the radius of the output gear 3. Therefore, by changing the respective radii in the above formula, different gear ratios can be achieved.

[0143] In addition, the radius R11 of the main input gear 11 is preferably about 166 mm. The radius R12 of the distribution gear 12 is preferably about 86 mm. Advantageously, according to another example, the rotation speed Ω3 can be lower than Ω1 (reduction gear ratio) or can be higher than Ω1 (amplification gear ratio).

[0144] like Figure 10As further shown in FIG, the outer surfaces (11a, 13a, 21a, 22a, 3a) of the main input gear 11, the transfer gear 13, the auxiliary transfer gear 21, the auxiliary output gear 22, and the output gear 3 are shown as being engaged with each other, or engaged with the input (e.g., the electric motor 6) or engaged with the output (e.g., the differential annulus 70). More specifically, the outer surface 11a of the main input gear 11 is engaged with the outer surface of the rotor of the electric motor 6. The outer surface 13a of the transfer gear 13 is engaged with the outer surface 21a of the auxiliary transfer gear 21. In addition, the outer surface 22a of the auxiliary output gear 22 is engaged with the outer surface 3a of the output gear 3. The output gear 3 is further engaged with the differential annulus 70 of the differential assembly via its outer surface 3a.

[0145] Advantageously, the outer surfaces of the corresponding gears (11a, 13a, 21a, 22a, 3a) may have helical teeth. Such helical teeth effectively reduce the noise generated by the gearbox 5 during its operation.

[0146] Furthermore, the gearbox 5 and the powertrain assembly including such a gearbox 5 are capable of transmitting a power of at least 250 kW, more preferably at least 300 kW. Regarding the transmitted torque, the gearbox 5 or the transmission assembly including such a gearbox 5 is capable of transmitting a torque of at least 600 Nm, preferably at least 750 Nm.

[0147] Thus, the gearbox 5 and transmission assembly described above represent a compact solution for various types of vehicles, preferably electric / hybrid vehicles, such as electric / hybrid trucks or buses. The gearbox 5 (and transmission assembly) can also be adapted for use in trailers, serving as an additional power source independent of the towing vehicle's power, thereby providing additional traction under certain conditions. Due to the small axial length of the gearbox 5, the gearbox 5 can be assembled into electric / hybrid vehicles of various sizes without limiting the space required for other components (batteries, body / aerodynamics, suspension components). Thus, this embodiment provides a solution for a small, compact, and lightweight gearbox 5 for various types of vehicles.

Claims

1. A gearbox (5) for a vehicle, the gearbox (5) comprising: Gearbox housing (50); a main shaft (10) rotatably mounted within the gearbox housing (50) for rotation about a first axis, and having a first axial end (101) and a second axial end (102) within the gearbox housing (50); a main input gear (11), the main input gear (11) being fixed to rotate together with the main shaft (10); a distribution gear (12), the distribution gear (12) being fixed to rotate together with the main shaft (10); a transmission gear (13), the transmission gear (13) being configured to rotate about the first axis and being arranged around the main shaft (10); a secondary shaft (20) configured to rotate about a second axis, the first axis and the second axis being spaced apart from each other, a secondary output gear (22) and a secondary transmission gear (21), the secondary output gear (22) and the secondary transmission gear (21) being arranged around the secondary shaft (20), the secondary transmission gear (21) being engaged to the transmission gear (13); an output gear (3) for transmitting power from the gearbox, the output gear (3) being independently and rotationally arranged around the main shaft (10) and configured to rotate around the first axis, the output gear (3) being mounted on the main shaft (10) and being engaged to the auxiliary output gear (22); A gear shift system (8) capable of sliding between at least two positions, the gear shift system (8) being configured to: The distribution gear (12) and the output gear (3) are rotationally engaged for transmitting power from the main shaft (10) directly to the output gear (3), or The distribution gear (12) and the transmission gear (13) are rotationally engaged to indirectly transmit power from the main shaft (10) to the output gear (3) through the countershaft (20).

2. The gearbox according to claim 1, wherein: The distribution gear (12) is rigidly fixed to the main shaft (10) or is integral with the main shaft (10).

3. The gearbox according to any one of claims 1 to 2, wherein: At least the secondary transmission gear (21) or the secondary output gear (22) is rigidly fixed to the secondary shaft (20) or is integral with the secondary shaft (20).

4. The gearbox according to any one of claims 1 to 2, wherein: The main shaft (10) is rotationally mounted in the gearbox housing (50) via a first main roller bearing (41) arranged at the first axial end (101) and via a second main roller bearing (42) arranged at the second axial end (102).

5. The gearbox according to any one of claims 1 to 2, wherein: The axial length of the gearbox (5) measured along the first axis is less than 400 mm.

6. The gearbox according to any one of claims 1 to 2, wherein: The output gear (3) is mounted on the main shaft (10) via at least one output roller bearing (43, 44).

7. The gearbox according to any one of claims 1 to 2, wherein: The transmission gear (13) is mounted on the main shaft (10) via at least one roller bearing (49).

8. The gearbox according to any one of claims 1 to 2, wherein: The ratio between the rotational speed of the main shaft (10) and the rotational speed of the output gear (3) can be selected between the following gear ratios: a first gear ratio when the distribution gear (12) and the output gear (3) are rotationally engaged; and A second gear ratio when the distribution gear (12) and the transmission gear (13) are rotationally engaged, Wherein, the second gear ratio is higher than the first gear ratio.

9. The gearbox according to claim 8, wherein: The shift system (8) is further configured to be positioned to engage only with the distribution gear (12) to define a first neutral position in which power cannot be transmitted between the main shaft (10) and the output gear (3).

10. The gearbox (5) according to claim 9, further comprising: a second distribution gear (14), the second distribution gear (14) being integral with the main shaft (10); a second transmission gear (15), the second transmission gear (15) being rotatably mounted on the first axis and arranged on the main shaft (10); a second secondary transmission gear (23) arranged on the secondary shaft (20) and engaged to the second transmission gear (15); and A second shifter (88) is configured to be slidable between at least two positions, the second shifter (88) being configured to rotationally engage at least one of: Only the second distribution gear (14) is used to define a second neutral position in which no power is transmitted between the main input gear (11) and the output gear (3) via the second distribution gear (14); or The second distribution gear (14) and the second transmission gear (15) are used to indirectly transmit power from the main shaft (10) to the output gear (3) through the countershaft (20), wherein the shift system (8) is configured to be positioned in the first neutral position.

11. The gearbox (5) according to any one of claims 1 to 2, wherein: The gearbox (5) is capable of transmitting a power of at least 250 kW, and wherein the gearbox (5) is capable of transmitting a torque of at least 600 Nm.

12. The gearbox (5) according to claim 11, wherein The gearbox (5) is capable of transmitting a power of at least 300 kW.

13. The gearbox (5) according to claim 11, wherein: The gearbox (5) is capable of transmitting a torque of at least 750 Nm.

14. The gearbox (5) according to claim 10, wherein: The gear shifting system (8) and / or the second gear shifting device (88) comprises a gear shift sleeve.

15. The gearbox (5) according to claim 10, wherein: At least one of the output gear (3), the transmission gear (13), the second transmission gear (15), the auxiliary transmission gear (21), the auxiliary output gear (22) and the second auxiliary transmission gear (23) is a helical gear.

16. A powertrain assembly for a vehicle, comprising: The gearbox (5) according to any one of claims 1 to 2; at least one electric motor (6; 66), said at least one electric motor (6; 66) being configured to be coupled to said main input gear (11) of said gearbox; a differential gear having a differential ring wheel (70) coupled to the output gear (3) of the gearbox; and A drive wheel axle is coupled to the differential gear.

17. A vehicle (1) comprising a powertrain assembly according to claim 16.

18. The vehicle of claim 17, wherein: The vehicle is a heavy vehicle.

19. The vehicle of claim 18, wherein: The heavy vehicle is a truck, a bus or a construction machine.

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