Electric drive axle assembly and vehicle including same

Abstract

The invention relates to an electric drive axle assembly (10) comprising an electric machine (12) and a transmission assembly (14) configured to transmit drive power from the electric machine (12) to at least one drive wheel (2) of a vehicle (1) via a drive shaft (20) of the transmission assembly (14) when the electric drive axle assembly (10) is arranged in the vehicle (1). The transmission assembly (14) comprises a final gear pair (28) comprising a final gear (28b) arranged on the drive shaft (20). The transmission assembly (14) also includes a lubrication system (15) including an oil pan (16) and a supply system (17) configured to supply oil from the oil pan (16) to one or more component parts of the electric drive axle assembly (10). The lubrication system (15) further comprises a reservoir device (30) arranged so as to close a lower portion of the final gear (28b).

Description

Technical Field

[0001] The present disclosure generally relates to an electric transaxle assembly for a vehicle, and to a vehicle including the electric transaxle assembly. Background Art

[0002] Given the continued electrification of vehicles, one technology gaining increasing attention today is electric drive axles (also known as e-axles or e-axles). An electric drive axle can constitute the entire powertrain of a vehicle, or it can be part of a powertrain that includes more than one propulsion unit (for example, in the case of a hybrid vehicle). An electric drive axle assembly includes an electric motor, typically powered by a battery, that serves as the propulsion unit, and a transmission assembly.

[0003] In a conventional center-drive powertrain, such as that of a conventional internal combustion engine-driven heavy vehicle, the propulsion unit and the transmission are connected to the drive shaft and the associated drive wheels via a propeller shaft. In contrast, an electric drive axle is based on a powertrain construction in which the electric motor, which acts as the vehicle's propulsion unit, and the transmission assembly are arranged at the drive shaft. Therefore, there is no need for a propeller shaft for transmitting propulsion power from the propulsion unit to the vehicle's drive wheels. One of the advantages of an electric drive axle is that it generally takes up less space than a center-drive powertrain and thus leaves more space in the vehicle for accommodating, for example, batteries. The increased space available for batteries essentially means that more energy can be stored on board the vehicle, which in turn can increase the vehicle's possible driving range. Furthermore, an electric drive axle offers greater flexibility in vehicle construction, for example because the arrangement of the propeller shaft does not have to be taken into account.

[0004] However, one of the challenges of electric drive axles is their need for a compact design. Consequently, compared to powertrains with a central drive configuration, both the transmission and the motor size must generally be reduced. This, in turn, impacts, for example, the lubrication of the transmission components, as less oil can be stored within them due to their reduced size. Lubrication is one of the most important factors in ensuring the efficiency, proper operation, and expected lifespan of the transmission components.

[0005] There are two main ways to achieve lubrication of the components in a transmission assembly. The first is splash lubrication, in which a rotating component (e.g., a gear) is immersed in an oil sump. As the component rotates, it drags oil out of the oil sump and can also splash oil onto other parts of the transmission. The second is spray or jet lubrication, in which the oil is sprayed onto the component as a spray or in the form of one or more jets using a nozzle or the like. Spray lubrication can also cause oil shearing within the transmission assembly, at least when used to lubricate rotating components. The choice of method for lubricating a particular component of the transmission depends on the rotational speed of the component. Typically, spray lubrication is used at higher rotational speeds of the component. However, for lower rotational speeds, splash lubrication is more appropriate. Therefore, the final gear of the transmission assembly is usually lubricated by immersion in an oil sump. Summary of the Invention

[0006] The purpose of the present invention is to realize a high-efficiency and energy-saving electric drive axle assembly.

[0007] Said object is achieved by the subject matter of the enclosed independent claims.

[0008] According to the present disclosure, an electric drive axle assembly for a vehicle is provided. The electric drive axle assembly includes a motor and a transmission assembly. The transmission assembly is configured to transmit drive power from the motor to at least one drive wheel of the vehicle via a drive shaft of the transmission assembly when the electric drive assembly is disposed in a vehicle. The transmission assembly includes a final gear pair comprising a final gear disposed on the drive shaft. The electric drive assembly also includes a lubrication system comprising an oil sump disposed in a lower portion of a housing of the transmission assembly and a supply system configured to supply oil from the oil sump to one or more components of the electric drive axle assembly. The lubrication system also includes a reservoir device disposed so as to enclose a lower portion of the final gear.

[0009] There is always a critical oil flow level in the transmission assembly of an e-axle assembly. If this level is exceeded, damage to at least a portion of the e-axle is possible. This, in turn, requires a predetermined maximum oil level in the oil sump, which limits the total possible oil volume within the lubrication system. Furthermore, the oil level in the sump can vary, for example, due to operating conditions. Therefore, when using splash lubrication by immersing the final gear in the sump, there is a risk of insufficient lubrication and cooling if the oil level is too low. Furthermore, if the oil level in the sump is high, there is a risk of excessive energy losses due to oil-induced drag.

[0010] However, the reservoir arrangement of the electric drive axle assembly described herein ensures that an appropriate amount of oil can be distributed to the final gear, achieving proper lubrication and / or cooling of the final gear, independent of the oil level in the oil sump. Furthermore, the reservoir arrangement ensures that the oil level in which the final gear is immersed does not become too high. This in turn reduces the risk of oil-induced drag losses. Consequently, the energy efficiency of the lubrication system, and therefore the overall energy efficiency of the electric drive axle assembly, is improved compared to previously known electric drive axles in which the final gear is immersed in the oil sump.

[0011] The reservoir device can also contribute to the possibility of oil volume increase in the lubrication system of the electric drive axle assembly.In addition, the reservoir device can also be used to limit the free oil volume in the oil pan to take into account the negative effects caused by the vehicle's tilting movement.

[0012] The supply system can be configured to supply oil to a cooling system of the electric motor, wherein the cooling system includes a return conduit configured to return oil from the cooling system of the electric motor to the reservoir device. Thus, oil can be reliably supplied to the reservoir device without requiring additional pumping elements and / or additional pumping work. This further improves the energy efficiency of the electric drive axle assembly.

[0013] The reservoir device may include at least one drain opening configured to allow oil to drain from the reservoir device to the oil sump. Thus, oil drainage from the reservoir device can be controlled by design parameters. Furthermore, this has the advantage of facilitating the separation of air inclusions from the oil contained within the lubrication system. Furthermore, the drain opening facilitates the removal of oil from the reservoir device during maintenance of the electric drive axle assembly.

[0014] The reservoir device may comprise an upper rim surrounding a lower portion of the final gear, the upper rim being arranged above a predefined maximum oil level in the oil sump. Thus, when the oil level in the oil sump is high, it is prevented that oil from the oil sump flows over the upper rim into the reservoir device, which could otherwise increase oil-induced drag losses.

[0015] The reservoir arrangement may include a first oil reservoir arranged to enclose the lower portion of the final gear, and a second oil reservoir configured to supply oil to the first oil reservoir. This makes it easier to control the oil supply to the first oil reservoir. Furthermore, the total oil volume within the lubrication system can be increased.

[0016] The second oil reservoir can be fluidically connected to the first oil reservoir via an orifice and / or a channel arranged in a wall, preferably a bottom wall, of the second oil reservoir. This has the advantage, among other things, that the flow of oil from the second oil reservoir to the first oil reservoir can be controlled by selecting appropriate design parameters of the orifice and / or channel. Furthermore, this avoids the need for any pump element for supplying oil to the first oil reservoir.

[0017] The second oil reservoir may be arranged above the first oil reservoir. Therefore, the second oil reservoir may be configured to supply oil to the first oil reservoir by utilizing gravity.

[0018] The supply system may be configured to supply oil to at least one gear of the transmission assembly, excluding the final gear. In this case, the second oil reservoir may be arranged to collect at least a portion of the oil supplied to the at least one gear. Thus, oil can be supplied to the second oil reservoir, eliminating the need for any pumping elements or pumping work. Furthermore, when the second oil reservoir is arranged to collect splashing oil within the transmission assembly, the amount of oil directly splashing into the oil sump can be reduced. This reduces the amount of air entrained in the oil within the lubrication system.

[0019] As mentioned above, the reservoir device may include at least one drain opening configured to allow oil to drain from the reservoir device to the oil sump. More specifically, the first oil reservoir may include a first drain opening configured to allow controlled draining of oil from the first oil reservoir to the oil sump, and the second oil reservoir may include a second drain opening configured to allow controlled draining of oil from the second oil reservoir to the oil sump. This further improves the separation of airborne inclusions from the oil contained within the lubrication system. Furthermore, this ensures proper oil levels in the respective oil reservoirs of the reservoir devices. This also facilitates the removal of oil from the reservoir device during maintenance of the electric drive axle assembly.

[0020] In addition to the drive shaft and final gear set, the transmission assembly may also include:

[0021] - a main shaft arranged parallel to the drive shaft;

[0022] - a secondary shaft arranged parallel to the main shaft and the drive shaft;

[0023] - a first gear connected and rotationally locked to the output shaft of the electric motor;

[0024] a first gear pair comprising a second gear rotationally locked to the secondary shaft and a third gear engaged with the second gear, the third gear being arranged on the primary shaft and connectable thereto;

[0025] a second gear pair comprising a fourth gear rotationally locked to the secondary shaft and a fifth gear engaged with the fourth gear, the fifth gear being arranged on the primary shaft and connectable thereto;

[0026] wherein the first gear is engaged with the second gear or the fourth gear, and

[0027] The final gear pair comprises a sixth gear engaged with the final gear, the sixth gear being rotationally locked to the main shaft.Thus, the transmission assembly can provide at least two selectable gear stages while still having a compact design.

[0028] The transmission assembly may optionally further comprise a planetary gear arranged on the main shaft between the first gear pair and the final gear pair. Thus, a further gear stage may be provided.

[0029] The second oil reservoir can be positioned between the final gear and the motor, below the main shaft of the transmission assembly. This has the particular advantage of allowing the second oil reservoir to collect oil that splashes within the transmission assembly. Furthermore, the available space within the electric drive axle assembly can be efficiently utilized, allowing the second oil reservoir to have a larger volume. A larger second oil reservoir allows for a larger total volume of oil in the lubrication system.

[0030] The final gear may be connected to the drive shaft via a differential. This is advantageous where the transmission assembly is configured to transmit drive power from the electric motor to two drive wheels of the vehicle, each of which is connected to a respective end of the drive shaft.

[0031] The present disclosure also provides a vehicle including the electric drive axle assembly described above. The vehicle can be a fully electric vehicle or a hybrid vehicle. Furthermore, the vehicle can be a heavy vehicle, such as a truck or bus, but is not limited thereto. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 shows a side view of an example of a vehicle,

[0033] Figure 2 schematically illustrates a cross-sectional view of a first exemplary embodiment of an electric drive axle assembly according to the present disclosure,

[0034] Figure 3 shows a perspective view of a reservoir device according to a first exemplary embodiment of an electric drive axle assembly,

[0035] Figure 4 Schematically illustrates an exemplary embodiment of a lubrication system for an electric drive axle assembly according to the present disclosure,

[0036] Figure 5 schematically illustrates a cross-sectional view of a second exemplary embodiment of an electric drive axle assembly according to the present disclosure,

[0037] Figure 6 shows a perspective view of a reservoir device according to a second exemplary embodiment of an electric drive axle assembly,

[0038] Figure 7A top view of a third exemplary embodiment of an electric drive axle assembly according to the present disclosure is schematically shown. DETAILED DESCRIPTION

[0039] The present invention will be described in more detail below with reference to exemplary embodiments and the accompanying drawings. However, the present invention is not limited to the exemplary embodiments discussed and / or shown in the drawings, but may be varied within the scope of the appended claims. Furthermore, the drawings should not be considered to be drawn to scale, as some features may be exaggerated in order to more clearly illustrate the invention or its features.

[0040] The term "spray lubrication" as used in the present disclosure is to be interpreted broadly and thus encompasses any form of lubrication in which the lubricant is sprayed in some manner by means of one or more nozzles etc. Thus, spray lubrication encompasses both, for example, oil mist lubrication and oil jet lubrication.

[0041] Furthermore, in this disclosure, the term "gear pair" is used to describe a set of two gears arranged so as to engage with each other. Furthermore, when gears are described herein as being engaged, engaged, or similar expressions, the gears should be considered to be meshing with each other.

[0042] The electric drive axle assembly described herein can be arranged in a vehicle in slightly different rotational orientations relative to the longitudinal axis and the vertical axis of the vehicle. Therefore, it should be noted that any terms describing relative directions between different features of the electric drive axle assembly described herein, such as the terms "above," "below," "upper," or "lower," should be viewed relative to the vertical orientation of the vehicle in which the electric drive axle assembly is arranged, and assuming that the vehicle is resting on level ground.

[0043] The electric drive axle assembly described herein may constitute or be part of a powertrain of a vehicle. In addition, a vehicle may include only one or more than one of the electric drive axle assemblies described herein without departing from the present disclosure. A vehicle including an electric drive axle assembly described herein may be a fully electric vehicle, or may be a hybrid vehicle. The vehicle may be a heavy or medium land-based motor vehicle, such as a heavy truck, a construction vehicle, a tractor, or a bus, but is not limited thereto. The vehicle may be, for example, a lighter land-based vehicle, such as a car or the like. The vehicle may be a vehicle configured to be driven partially or fully by a driver (the driver being present on or away from the vehicle), or a fully autonomous vehicle.

[0044] According to the present disclosure, an electric drive axle assembly for a vehicle is provided. The electric drive axle assembly includes at least one electric motor and a transmission assembly. The transmission assembly is configured to transmit drive power from the electric motor to at least one drive wheel of the vehicle via a drive shaft of the transmission assembly when the electric drive axle assembly is disposed in a vehicle. In addition to the drive shaft, the transmission assembly also includes a final gear pair comprising a final gear disposed on the drive shaft. The final gear pair should be considered herein as constituting the last gear pair of the transmission assembly as viewed in the direction of drive power transmission from the electric motor to the drive shaft. The electric drive axle assembly also includes a lubrication system comprising an oil sump disposed in a lower portion of a housing of the transmission assembly. The lubrication system also includes a supply system configured to supply oil from the oil sump to one or more components of the electric drive axle assembly. The one or more components of the electric drive axle assembly to which the supply system is configured to supply oil may alternatively be described as one or more oil consumers of the electric drive axle assembly.

[0045] The lubrication system of the electric drive axle assembly according to the present disclosure also includes a reservoir device, which is arranged so as to enclose (i.e., surround) the lower part of the final gear. The reservoir device is appropriately arranged above the bottom of the oil sump. The reservoir device is configured to store oil for the purpose of lubricating and / or cooling the final gear of the transmission assembly. Therefore, in contrast to previously known electric drive axle assemblies, the final gear of the electric drive axle assembly described herein is not arranged to be immersed in the oil present in the oil sump, but rather in the oil stored by the reservoir device. Therefore, it is possible to achieve appropriate distribution of oil to the final gear so as to achieve proper lubrication and / or cooling of the final gear while avoiding excessive oil-induced drag losses. The reservoir device can also contribute to the possibility of an increase in the oil volume in the lubrication system of the electric drive axle assembly. In addition, the reservoir device can also be used to limit the free oil volume in the oil sump to take into account the negative effects caused by the vehicle's tilting movement.

[0046] The reservoir device is suitably arranged on the return side of the lubrication system. Thus, oil can be supplied to the reservoir device without requiring any additional pumping elements or pumping work. This further improves the energy efficiency of the electric drive axle assembly. More specifically, the reservoir device can be arranged within the lubrication system between the outlet of at least one oil consumer (i.e., a component of the electric drive axle assembly to which the supply system is configured to supply oil from the oil sump) and the oil sump.

[0047] Furthermore, the reservoir device can also help separate air inclusions from the oil contained within the lubrication system. By enabling the controlled flow of oil from the reservoir device to the oil sump, air inclusions can be more easily separated from the oil than if the oil splashes directly into the oil sump. The reservoir device, positioned on the return side of the lubrication system, can also reduce the amount of oil that splashes directly into the oil sump. Reducing the amount of air inclusions can further improve the energy efficiency of the electric drive axle assembly and reduce the risk of insufficient or uneven lubrication, which can shorten the life of the electric drive axle assembly's transmission components.

[0048] The reservoir arrangement can consist of a single (first) oil reservoir and an optional coupling device. Alternatively, the reservoir arrangement can include a first oil reservoir, a second oil reservoir and an optional coupling device, or consist of a first oil reservoir, a second oil reservoir and an optional coupling device. Regardless of whether the reservoir arrangement includes only one oil reservoir or two oil reservoirs, the coupling device can be configured to fluidically connect the return conduit of the oil consumption device of the electric drive axle assembly to the reservoir arrangement. Moreover, regardless of whether the reservoir arrangement includes only one first oil reservoir or two oil reservoirs, the first oil reservoir of the reservoir arrangement is arranged so as to enclose the lower part of the final gear. The first oil reservoir can be described as an open container arranged to surround the lower part of the final gear.

[0049] The second oil reservoir (if present) is configured to supply oil to the first oil reservoir. More specifically, the second oil reservoir is configured to supply oil to the first oil reservoir passively, i.e. without the need for pumping work for transferring oil from the second oil reservoir to the first oil reservoir. The second oil reservoir can be suitably arranged above the first oil reservoir. Furthermore, the second oil reservoir can be fluidically connected to the first oil reservoir via orifices and / or channels arranged in the wall of the second oil reservoir. This has the advantage of allowing the flow of oil from the first oil reservoir to the second oil reservoir to be controlled by selecting the design parameters of the orifices and / or channels. Suitably, the orifices and / or channels can be arranged in the bottom wall of the second oil reservoir. In view of the fact that the main purpose of the second oil reservoir is to supply oil to the first oil reservoir, the final gear does not need to extend into the second oil reservoir. Therefore, the second oil reservoir can be arranged next to the final gear of the transmission assembly.

[0050] The first oil reservoir includes an upper rim surrounding the final gear. This upper rim is conveniently positioned above a predefined maximum oil level in the oil sump. This prevents oil from the oil sump from flowing directly into the first oil reservoir when the oil level in the sump is high. This further improves control over the amount of oil stored in the first oil reservoir. However, it should be noted that the first oil reservoir is open at the top, allowing oil to flow from the first oil reservoir over its upper rim into the oil sump.

[0051] The first and second oil reservoirs may be integrally formed as a single body, or may be separate bodies arranged in contact with each other. The first and second oil reservoirs may, for example, be mounted or otherwise attached to each other. Alternatively, although less preferred given the limited free space available within the electric drive axle assembly, the second oil reservoir may be arranged at a distance from the first oil reservoir.

[0052] As previously mentioned, the electric drive axle assembly according to the present disclosure includes a transmission assembly. The transmission assembly can have various configurations as long as it includes the drive shaft and final gear pair described above. For example, the transmission assembly may further include:

[0053] - a main shaft arranged parallel to the drive shaft;

[0054] - a secondary shaft arranged parallel to the main shaft and the drive shaft;

[0055] - a first gear connected and rotationally locked to the output shaft of the electric motor;

[0056] a first gear pair comprising a second gear rotationally locked to the secondary shaft and a third gear engaged with the second gear, the third gear being arranged on the primary shaft and connectable thereto;

[0057] a second gear pair comprising a fourth gear rotationally locked to the secondary shaft and a fifth gear engaged with the fourth gear, the fifth gear being arranged on the primary shaft and connectable thereto;

[0058] wherein the first gear is engaged with the second gear or the fourth gear, and

[0059] The final gear set (in addition to the final gear) comprises a sixth gear engaged with the final gear, the sixth gear being rotationally locked to the main shaft.

[0060] The transmission assembly may also optionally include a planetary gear arranged on the main shaft between the first gear pair and the final gear pair. In this case, the main shaft includes a first main shaft half shaft and a second main shaft half shaft, each main shaft half shaft being connected to a corresponding component of the planetary gear.

[0061] Furthermore, at least in the case where the transmission assembly is configured to transmit drive power from the electric motor to two drive wheels of the vehicle, the final gear of the transmission assembly can be connected to the driveshaft via a differential. In this case, the driveshaft can include a first driveshaft half-shaft and a second driveshaft half-shaft. Each of the two drive wheels of the vehicle can be connected to one of the first driveshaft half-shaft and the second driveshaft half-shaft.

[0062] Figure 1A side view of an example vehicle 1, shown here as a truck, is shown. Vehicle 1 can be a fully electric vehicle or a hybrid vehicle. Vehicle 1 includes a powertrain that can constitute or at least include the electric drive axle assembly described herein. It should be noted that vehicle 1 can also include more than one electric drive axle assembly described herein.

[0063] Vehicle 1 has a longitudinal axis A. The longitudinal axis A of vehicle 1 is parallel to the forward direction of movement of vehicle 1 and parallel to the rearward direction of movement of the vehicle. The forward direction of movement of vehicle 1 is indicated by arrow F in the figure. Furthermore, vehicle 1 has a vertical axis V that is perpendicular to longitudinal axis A. When the vehicle is on flat ground, vertical axis V is substantially perpendicular to the flat ground, while longitudinal axis A is substantially parallel to the flat ground. Vehicle 1 also has a transverse axis (not shown) that is perpendicular to both longitudinal axis A and vertical axis V.

[0064] The vehicle 1 includes a plurality of ground-engaging wheels, including drive wheels 2 and front wheels 3. The front wheels 3 are typically non-driven wheels, but can also be driven wheels if desired. Furthermore, the front wheels 3 can typically be steerable wheels. Optionally, the vehicle 1 can also include tag axle wheels 4. The tag axle wheels can be associated with a raisable tag axle so that they can be temporarily moved from a ground-engaging position to a position where they are raised from the ground. The tag axle wheels 4 can be steerable or non-steerable tag axle wheels.

[0065] Vehicle 1 may be an electric vehicle or a hybrid vehicle. Furthermore, vehicle 1 may be a heavy vehicle, such as a bus or truck, but is not limited thereto. Furthermore, vehicle 1 may be configured to be partially or fully operated by a driver. Such a driver may be onboard the vehicle or remotely located, such as at a remote control center. Alternatively, vehicle 1 may be a fully autonomous vehicle.

[0066] Figure 2 A cross-sectional view of a first exemplary embodiment of an electric drive axle assembly 10 according to the present disclosure is schematically shown. The electric drive axle assembly 10 has a first axis 8, a second axis 9, and a third axis (not shown), each of which is perpendicular to the other two axes. The third axis is parallel to a longitudinal axis 20 c of a drive shaft 20 (described further below) of the electric drive axle assembly 10.

[0067] When the electric drive axle assembly 10 is arranged in a vehicle (e.g., Figure 1), the drive shaft 20 is typically arranged so that its longitudinal axis 20c extends perpendicular to the longitudinal axis A of the vehicle 1 and perpendicular to the vertical axis V of the vehicle. In other words, when the electric drive axle assembly is arranged in the vehicle, the third axis of the electric drive axle assembly 10 will be substantially parallel to the transverse axis of the vehicle. Furthermore, the electric drive axle assembly 10 can be arranged in the vehicle 1 so that the first axis 8 is substantially parallel to the longitudinal axis A of the vehicle, and the second axis 9 is therefore substantially parallel to the vertical axis V of the vehicle. However, if desired, the electric drive axle assembly 10 can also be arranged in the vehicle 1 so that the first axis 8 is oriented at a certain angle relative to the longitudinal axis A of the vehicle 1, for example rotated at an angle of at most ±15° or at most ±30°. In this case, the second axis 9 of the electric drive axle assembly 10 will naturally also be rotated at a corresponding angle relative to the vertical axis V of the vehicle 1. The reason for arranging the electric drive axle assembly 10 in the vehicle 1 so that the first and second axes 8 , 9 rotate relative to the longitudinal axis A and vertical axis V, respectively, of the vehicle 1 may be, for example, to better fit into the available space depending on the configuration of the vehicle 1 .

[0068] The electric drive axle assembly 10 includes an electric motor 12 and a transmission assembly 14. The details of the electric motor 12 are not limited to the electric drive axle assembly according to the present disclosure and are therefore not shown in the figures or further described herein. Figure 2 , the motor 12 is intended to be shown arranged parallel to the drive shaft 20 of the transmission assembly 14, which also means that the output shaft of the motor is arranged substantially parallel to the drive shaft 20. However, if desired, the motor 12 may alternatively be arranged such that the output shaft of the motor is substantially perpendicular to the longitudinal extension of the drive shaft 20.

[0069] The transmission assembly 14 of the electric drive axle assembly 10 is disposed in the housing 11 and includes a drive shaft 20 extending out of the housing 11. In addition, the motor 12 is disposed in a housing (not shown), which can be disposed inside the housing 11, as shown in the figure, or can be disposed outside the housing 11. If disposed outside the housing 11, the housing of the motor 12 can be appropriately mounted or otherwise attached to the housing 11 of the transmission assembly 14.

[0070] The transmission assembly 14 is configured to transmit driving power from the motor 12 to at least one driving wheel 2 of the vehicle via a drive shaft 20 of the transmission assembly 14 when the electric drive axle assembly 10 is arranged in the vehicle 1 (in the embodiment of FIG. Figure 1 ). Thus, the drive shaft 20 is configured to be connected to at least one drive wheel of the vehicle when the electric transaxle assembly 10 is installed in the vehicle.

[0071] The transmission assembly 14 includes a final gear pair 28. The final gear pair 28 includes a final gear 28b, which is arranged on the drive shaft 20 and engages with another gear 28a (also referred to herein as the sixth gear) arranged on the main shaft 23 of the transmission assembly 14. Gear 28a can be rotationally locked to the main shaft 23. Final gear 28b can be rotationally locked to the drive shaft 20 or connected to the drive shaft 20 via a differential (not shown).

[0072] The electric drive axle assembly 10 also includes an oil sump 16 formed at a lower portion 11a (i.e., a bottom portion) of the housing 11. The oil sump 16 is part of the lubrication system of the electric drive axle assembly 10 and is configured to store oil up to a predefined maximum oil level L_max. The maximum oil level L_max is shown in the figure as being parallel to the first axis 8 of the electric drive assembly 10. However, it should be noted that this only occurs when the electric drive axle assembly 10 is arranged and oriented in the vehicle such that the first axis 8 is parallel to the longitudinal axis A of the vehicle.

[0073] Oil can be supplied from the oil sump 16 to one or more components of the electric drive axle assembly 10 by means of a supply system (not shown) for the purpose of lubricating and / or cooling the components, and thereafter returned to the oil sump 16. For example, the supply system can be configured to supply oil to a cooling system for the electric motor 12. For ease of illustration, such a cooling system is schematically represented in the figure by a dashed box 18. Alternatively or additionally, the supply system can be configured to supply oil to at least one spray device (not shown) configured to spray the oil onto the components of the transmission assembly for lubrication and / or cooling.

[0074] The electric drive axle assembly 10 also includes a reservoir device 30, which will be referred to below. Figure 3 Described in more detail. The reservoir device 30 is part of the lubrication system and is configured to store oil for lubricating (and typically also cooling) the final gear 28b by immersing it therein. Therefore, the reservoir device 30 is open at the top and is arranged so as to enclose the lower portion of the final gear 28b. Furthermore, the reservoir device 30 includes an upper edge 37 arranged above the maximum oil level L_max. In other words, the reservoir device 30 is arranged above the lower portion 11a of the housing 11 and at a height such that the oil stored in the oil sump 16 should not be able to flow over the upper edge 37 into the reservoir device 30. This allows the oil level in the reservoir device 30 to be controlled to ensure proper lubrication of the final gear 28b while reducing oil-induced drag losses associated with lubrication of the final gear 28b. However, the reservoir device 30 can be arranged to partially extend downwardly below the maximum oil level L_max, as shown in the figure.

[0075] Furthermore, a reservoir device 30 is arranged on the return side of the lubrication system of the electric drive axle assembly 10. The term "return side" is used herein to refer to the direction of oil flow within the lubrication system, starting from the oil sump, then passing through the various components of the electric drive axle assembly that may consume oil, and ultimately returning to the oil sump 16. In other words, the reservoir device 30 is arranged within the lubrication system 15 after one or more oil consumers of the electric drive axle assembly 10. The fact that the reservoir device 30 is arranged on the return side of the lubrication system means that the oil is supplied to the reservoir device 30 without requiring any additional pumping elements or pumping work beyond those already available with respect to the lubrication system's supply system. For example, oil returning from the cooling system 18 of the electric machine 12 can be supplied to the reservoir device 30 via the return conduit 19 of the cooling system 18, thus eliminating the need for a separate pumping element.

[0076] As mentioned earlier, Figure 2 1 shows a cross-sectional view of a first exemplary embodiment of the electric drive axle assembly described herein according to the present disclosure. Therefore, all parts of the transmission assembly 14 are not visible in the figure. As long as the transmission assembly 14 is configured to transmit power from the motor to the drive shaft and includes a final gear pair arranged on the drive shaft, various configurations of the transmission assembly are possible. For example, the transmission assembly 14 may have the same configuration as described below. Figure 7 The construction described corresponds to the construction.

[0077] Figure 3 Shown according to the above description and Figure 2 , a perspective view of a reservoir device 30 of a first exemplary embodiment is shown in FIG. The reservoir device 30 includes a first oil reservoir 31 that is open at the top to allow the final gear 28b to partially extend downward into the first oil reservoir 31. More specifically, the first oil reservoir 31 is configured to enclose a lower portion of the final gear 28b. The first oil reservoir 31 can be considered to include an oil receiving portion 31a configured to collect and / or receive oil. Figure 2 As can be seen in the figure, the oil receiving portion 31a can be positioned to extend into the space between the final gear 28b and the motor 12, suitably below at least a portion of the gear 28a in the final gear pair 28 arranged on the main shaft 23. In other words, the oil receiving portion 31a of the first oil reservoir 31 can be arranged to one side of the final gear 28b, as seen in the radial direction of the final gear 28b. The first oil reservoir 31 can also be considered to include the oil storage portion 31b, which is configured to surround the lower portion of the final gear 28b, thereby substantially enclosing the lower portion of the final gear 28b. The oil receiving portion 31a and the oil storage portion 31b together form the open volume of the first oil reservoir 31.

[0078] The first oil reservoir 31 includes a first side wall 33, a second side wall 34, a third side wall 35 and a bottom wall 36, which together form a container having a continuous upper edge 37 at the top end. The upper edge 37 is configured to surround the final gear 28b, more specifically, the lower portion of the final gear 28b. Figure 2 As shown in . The first side wall 33 and the second side wall 34 are configured to extend on opposite sides of the final gear 28b, that is, on opposite sides of the rotation plane of the final gear 28b. The first side wall 33 and the second side wall 34 can be arranged substantially in parallel, or slightly inclined relative to each other so as to narrow the cross-sectional area of the container downward. The first side wall 33 and the second side wall 34 are connected at their respective first ends 33a, 34a by a third side wall 35. In the case where the third side wall 35 is a substantially flat side wall (that is, a non-curved or non-stepped side wall) as shown in the figure, the third side wall 35 can, for example, be arranged to extend substantially perpendicular to the first side wall 33 and the second side wall 34. The first side wall 33 and the second side wall 34 are further connected by a bottom wall 36.

[0079] The bottom wall 36 may suitably comprise a curved bottom wall portion 36a extending at least from the bottom of the reservoir means 30 up to the upper edge 37. The curved bottom wall portion 36a may have a curvature such that, along its extension, it substantially conforms to the circumference of the final gear 28b, but naturally has a radius which is larger than the radius of the circumference of the final gear 28b so that there is a gap therebetween.

[0080] The bottom wall 36 may further include a substantially flat bottom wall portion 36b. The substantially flat bottom wall portion 36b, together with the third side wall 35 and portions of the first and second side walls 33 and 34, may form the oil-receiving portion 31a of the first oil reservoir 31. Thus, the substantially flat bottom wall portion 36b may be suitably configured to be positioned proximate to the final gear 28b, rather than positioned below the final gear 28b. Furthermore, when the electric drive assembly 10 is positioned in a vehicle, the substantially flat bottom wall portion 36b may be suitably positioned to extend in a plane substantially parallel to the longitudinal axis A of the vehicle, above the bottom of the reservoir device 30, preferably above the lowest point of the circumference of the final gear 28b. Furthermore, the flat bottom wall portion 36b may be configured to extend in a plane parallel to and below the plane of the longitudinal axis 20c of the drive shaft 20.

[0081] If necessary, the curved bottom wall portion 36a may be directly connected to the flat bottom wall portion 36b. Figure 3, the curved bottom wall portion 36a may be connected to the flat bottom wall portion 36b via an intermediate bottom wall portion 36c of the bottom wall 36. The intermediate bottom wall portion 36c may be arranged, for example, to extend in a plane inclined relative to the plane of the flat bottom wall portion 36b, thereby allowing oil to flow from the oil receiving portion 31a of the first oil reservoir 31 (i.e., the portion of the first oil reservoir 31 where the flat bottom wall 36b is arranged) to the bottom of the first oil reservoir 31.

[0082] The reservoir device 30 may further include a first drain opening 38 configured to allow controlled draining of oil from the reservoir device 30 to the oil pan 16. The first drain opening 38 may be disposed in the bottom wall 36 of the first oil reservoir 31, but the present disclosure is not limited thereto. Suitably, the first drain opening 38 may be disposed at the lowest point of the bottom wall 36, i.e., at the bottom of the first oil reservoir 31, as shown in FIG. Figure 3 Alternatively, the first discharge opening 38 may be arranged in either one of the side walls 33 , 34 , if necessary.

[0083] The flow of oil from the reservoir device 30 to the oil pan 16 can be controlled by appropriately selecting the shape and size of the first drain opening 38. Furthermore, the location of the first drain opening can influence the flow of oil from the reservoir device 30 to the oil pan 16 to a certain extent. While any excess oil in the reservoir device 30 can flow over the upper edge 37 and thereby return to the oil pan 16, the first drain opening 38 serves to further control the amount of oil stored in the reservoir device to ensure proper lubrication of the final gear 28b with reduced oil-induced drag losses. The first drain opening 38 also serves to facilitate draining the oil lubrication system, for example, during maintenance of the electric drive axle assembly 10, without requiring disassembly of the electric drive axle assembly. Therefore, the first drain opening 38 can be appropriately positioned at the bottom of the first oil reservoir 31, as mentioned above.

[0084] As previously mentioned, the reservoir device 30 is thus suitably configured to be supplied with oil without any specifically designated pump element or work. For example, the oil may be supplied via a pump such as Figure 2 The return conduit 19 of the cooling system 18 of the electric machine 12, schematically shown in FIG. , is supplied to the reservoir device. For this purpose, the reservoir device 30 may further include a coupling device 39 configured to allow such a return conduit 19 to be fluidly connected to the reservoir device 30 so as to supply oil thereto. Furthermore, the reservoir device 30 may be configured to collect oil splashed within the transmission assembly 14, given the configuration and arrangement of the oil receiving portion 31 a described above.

[0085] Figure 4An exemplary embodiment of a lubrication system 15 of an electric drive axle assembly 10 according to the present disclosure is schematically illustrated, including (but not limited to) the first exemplary embodiment described above. The lubrication system 15 includes an oil sump 16, a reservoir device 30, and a supply system 17. The supply system 17 is configured to supply oil from the oil sump 16 to one or more components of the electric drive axle assembly, such as the cooling system 18 of the electric motor 12, a first spray device 41, and / or a second spray device 42. Each of the first spray device 41 and the second spray device 42 can be configured to spray oil onto a corresponding gear of the transmission assembly 14.

[0086] The supply system 17 may include a pump 51 configured to pump oil from the oil sump 16 to a distribution device 54 via a filter 52 and a heat exchanger 53. The pump 51 may be, for example, a mechanical pump connected to one of the shafts of the transmission assembly 14 to be driven thereby, or an electric pump. If necessary, the supply system 17 may include more than one pump. The filter 52 may be configured to filter out particulate matter from the oil passing therethrough. The heat exchanger 53 may be configured to cool the oil passing therethrough. The distribution device 54 may be configured to distribute the oil to one or more components of the transmission assembly 14 and may, for example, be a diverter. It should be noted here that in the event that the supply system 17 is configured to supply oil to only one component of the transmission assembly 14, the distribution device 54 may naturally be omitted.

[0087] The oil returned from the cooling system 18 of the electric motor 12 can be transferred to the reservoir device 30 via the return conduit 19. In addition, the oil that has been sprayed by the first spray device 41 can also be at least partially collected in the reservoir device 30 after having passed through the relevant components of the transmission assembly 14, as shown in the figure. The first spray device 41 can, for example, be configured to spray oil towards the component parts of the transmission assembly connected to the main shaft 23 (for example, the gear 28a in the final gear pair 28). In contrast, the oil that has been supplied by the second spray device 42 can be configured to return directly to the oil pan 16 without passing through the reservoir device 30. In addition, any excess oil stored in the reservoir device 30 can, for example, be collected via a container as described above with reference to FIG. Figure 3 The depicted first drain opening 38 returns to the oil sump 16 .

[0088] As shown in the figure, there is no dedicated pump or the like configured to transfer oil directly from the oil sump 16 to the reservoir device 30. Instead, the reservoir device 30 can be considered to be arranged on the return side of the lubrication system 15. This makes lubrication of the final gear 28b energy-efficient because no additional pumping elements or pumping work are required, so that oil is supplied to the reservoir device 30 while the reservoir device 30 provides a controlled volume of oil in which the final gear 28b is immersed, the controlled volume being substantially independent of the operating conditions of the electric transaxle assembly. This controlled volume of oil reduces oil-induced drag losses and, thereby, the energy efficiency of the electric transaxle assembly 10.

[0089] Figure 5 A cross-sectional view of a second exemplary embodiment of an electric drive axle assembly 10 according to the present disclosure is schematically shown. The second exemplary embodiment corresponds substantially to the one described above and in Figure 2 The first exemplary embodiment is shown in , with the difference that the reservoir arrangement 30 comprises both a first oil reservoir 31 and a second oil reservoir 32 .

[0090] Similar to the first exemplary embodiment of the electric drive axle assembly 10 described above, the first oil reservoir 31 of the reservoir device 30 is arranged so as to enclose the lower portion of the final gear 28b. Furthermore, the upper edge 37 of the first oil reservoir 31 is arranged above the maximum oil level L_max.

[0091] The second oil reservoir 32 of the reservoir device 30 is configured to receive and / or collect oil and can therefore be used for the same purpose as the oil receiving portion 31a of the reservoir device 30 according to the first exemplary embodiment described above. The second oil reservoir 32 is also configured to supply oil to the first oil reservoir 31 and is therefore fluidly connected to the first oil reservoir 31. The second oil reservoir 32 can also be used for the purpose of providing an additional volume for storing oil. Therefore, the second oil reservoir device 32 has the advantage of enabling a larger volume of oil to be accommodated in the lubrication system of the electric drive axle assembly 10. This is particularly advantageous in view of the fact that the compact construction of the electric drive axle assembly 10 limits the possible oil volume in the oil pan 16. Reference will be made hereinafter to Figure 6 The reservoir device 30 according to the second exemplary embodiment is further described.

[0092] The second oil reservoir 32 may be appropriately arranged above the first oil reservoir 31, as shown in the figure. In addition, the second oil reservoir 32 may be arranged below the main shaft 23 of the transmission assembly 14 and between the final gear 28b and the motor 12, as shown in a cross-sectional view of the electric drive axle assembly 10 perpendicular to the longitudinal axis 20c of the drive shaft 20 (i.e., as shown in FIG. Figure 5 As seen in the cross-sectional view shown in ).

[0093] Furthermore, as shown in the figures, the electric drive axle assembly 10 may further include a first spray device 41 configured to spray oil toward the gear 28a in the final gear pair 28. The first spray device 41 is shown in the figures as being arranged above the gear 28a. However, it should be noted that the first spray device 41 may be arranged at any position around the circumference of the gear 28a.

[0094] The electric drive axle assembly 10 according to the second exemplary embodiment may further include the Figure 4 The exemplary lubrication system 15 described. In this case, the reservoir device 30 naturally comprises a first oil reservoir 31 and a second oil reservoir 32. Furthermore, the return conduit 19 from the cooling system 18 of the electric machine 12 can be suitably configured to supply oil to the second oil reservoir 32 instead of the first oil reservoir 31. For this purpose, the reservoir device 30 according to the second exemplary embodiment can also include a coupling device configured to allow such a return conduit 19 to be connected to the first oil reservoir 31. Figure 3 3 and 4. The coupling device 39 shown in FIG. 2 is fluidly connected to the second oil reservoir 32 of the reservoir arrangement 30 in the same manner.

[0095] Figure 6 Shown according to the above description and Figure 5 is a perspective view of a reservoir device 30 of a second exemplary embodiment of an electric drive axle assembly 10 shown in FIG. As previously mentioned, the reservoir device 30 includes a first oil reservoir 31 and a second oil reservoir 32. Both the first oil reservoir 31 and the second oil reservoir 32 are open at the top.

[0096] The first oil reservoir 31 may have the same Figure 3 37. The first oil reservoir 31 is constructed of substantially the same construction as described above. Thus, the first oil reservoir 31 comprises a first side wall 33, a second side wall 34, a third side wall 35 (not visible in the figure) and a bottom wall 36, which together form a container having an upper edge 37 at the top end. The first side wall 33 and the second side wall 34 are configured to extend on opposite sides of the final gear 28b. In other words, the first side wall 33 and the second side wall 34 are configured to be arranged on opposite sides of the rotation plane of the final gear 28b. The bottom wall may suitably comprise a curved bottom wall portion 36a, which extends at least from the bottom of the first oil reservoir 31 up to the upper edge 37. The bottom wall 36 may also comprise a flat bottom wall portion 36b and an optional intermediate bottom wall portion 36c, as described above with reference to Figure 3 The first oil reservoir 31 may further include a first drain opening 38 configured to allow controlled draining of oil from the first oil reservoir 31 to the oil sump 16. Furthermore, if necessary, the first oil reservoir 31 may be adapted to allow the second oil reservoir 32 to be connected and / or mounted to the first oil reservoir 31 at its oil receiving portion 31 a.

[0097] The second oil reservoir 32 includes a bottom wall 46. The bottom wall 46 can be a substantially flat bottom wall and, optionally, arranged substantially parallel to the flat bottom wall portion 36b of the first oil reservoir 31. Furthermore, the second oil reservoir 32 can include two substantially parallel first side walls 43. Each of the first side walls 43 can be configured to extend in a plane substantially perpendicular to the plane of rotation of the final gear 28b. The second oil reservoir 32 can also include two substantially parallel second side walls 44. Each of the second side walls 44 can be configured to extend in a plane substantially parallel to the plane of rotation of the final gear 28b. In its simplest form, the second oil reservoir 32 can have a substantially rectangular configuration. However, depending on the available space within the electric drive axle assembly, the second oil reservoir 32 can include additional side walls to increase the internal volume of the second oil reservoir 32. The second oil reservoir 32 can, for example, include a third side wall 45a and a fourth side wall 45b, as shown in the figure.

[0098] The second oil reservoir 32 is configured to supply oil to the first oil reservoir 31 and is therefore fluidly connected to the first oil reservoir. Figure 5 In the reservoir arrangement 30 shown in FIG, the second oil reservoir 32 includes an elongated orifice 47 arranged in the bottom wall 46 for this purpose. In other words, the second oil reservoir 32 shown is configured to supply oil to the first oil reservoir 31 via the elongated orifice 47 arranged in the bottom wall 46. It should be noted here that the second oil reservoir can be fluidically connected to the first oil reservoir 31 via an orifice having another shape and / or via a channel. Moreover, the orifice and / or channel does not necessarily need to be arranged in the bottom wall 46, but can, for example, be arranged in the side wall closest to the first side wall of the first oil reservoir 31. The flow of oil from the second oil reservoir 32 to the first oil reservoir 31 can be controlled by appropriately selecting the geometry, size, and position of the orifice and / or channel that fluidly connects the second oil reservoir 32 to the first oil reservoir 31.

[0099] The reservoir device 30 according to the second exemplary embodiment may also suitably include a second drain opening 48 in addition to the first drain opening 38, the second drain opening being configured to allow controlled draining of oil from the reservoir device. More specifically, the second drain opening 48 may be configured to allow controlled draining of oil from the second oil reservoir 32 to the oil sump 16. The second drain opening 48 may be arranged, for example, in the bottom wall 46 of the second oil reservoir 32. The flow of oil from the second oil reservoir 32 to the oil sump may be controlled by appropriately selecting the shape and size of the second drain opening 32 in the same manner as described above with respect to the first drain opening.

[0100] If desired, the second oil reservoir 32 may further include an internal partition wall 49. The internal partition wall may be arranged near the orifice 47 and / or the passageway and extend upward from the bottom wall 46 of the second oil reservoir 32. However, the height of the internal partition wall 49 is less than the height of the sidewalls of the second oil reservoir 32. The height of the internal partition wall may, for example, be 10-50% or 10-30% of the height of the sidewalls of the second oil reservoir 32. The internal partition wall 49 may, for example, be substantially U-shaped or substantially L-shaped, as viewed in a cross-sectional plane parallel to the bottom wall 46 of the second oil reservoir 32. The purpose of the internal partition wall 49 is to enable more oil to be stored in the second oil reservoir 32 before the oil begins to flow into the first oil reservoir 31 via the orifice 47 and / or the passageway. Thus, the internal partition wall 49 may be configured to divide the internal volume of the second oil reservoir 32 into two separate compartments at the bottom portion of the second oil reservoir 32. This may, for example, enable a lower oil level in the oil sump by storing oil in the second oil reservoir 32 , also where the need for lubrication and / or cooling of the final gear may be lower and thus the oil level in the first oil reservoir 31 may be lowered.

[0101] although Figure 6 Not shown, but the reservoir device 30 may also include as described above with reference to Figure 3 The coupling device 39 described. If so, the coupling device 39 can be suitably configured to fluidically connect the return circuit 19 of the cooling system 18 of the electric machine 12 to the second oil reservoir 32. In other words, the coupling device 39 can be arranged at the second oil reservoir 32 instead of at the first oil reservoir 31.

[0102] Figure 7 A top view of a third exemplary embodiment of an electric drive axle assembly 10 according to the present disclosure is schematically shown. Similar to the first and second exemplary embodiments of the electric drive assembly described above, the electric drive axle assembly 10 according to the third exemplary embodiment includes a motor 12, a transmission assembly 14, and a lubrication system. For ease of explanation, Figure 7 Only the reservoir arrangement 30 of the lubrication system is shown. Furthermore, depending on the specific configuration of the transmission assembly 14, the third exemplary embodiment may correspond to or differ from the second exemplary embodiment of the electric drive axle assembly described above.

[0103] The transmission assembly 14 includes a drive shaft 20, a main shaft 23, and a countershaft 24. The drive shaft 20, main shaft 23, and countershaft 24 are each arranged parallel to one another. The transmission assembly 14 also includes a first gear pair 26, a second gear pair 27, and a final gear pair 28. The transmission assembly 14 is connected to the output shaft 13 of the motor 12 via a first gear 25 arranged on the output shaft 13. More specifically, the first gear 25 is rotationally locked to the output shaft 13 of the motor 12. In other words, the first gear 25 is fixedly connected to the output shaft 13 of the motor 12 and will therefore rotate at the same speed as the output shaft 13. As shown in the figure, the first gear 25 can be connected to the first gear pair 26 by being arranged to engage with one of the gears in the first gear pair 26. Alternatively, if desired, the first gear 25 can be connected to the second gear pair 27 by engaging with one of the gears in the second gear pair 27.

[0104] The first gear pair 26 includes a second gear 26a and a third gear 26b that engage with each other. The second gear 26a is disposed on the layshaft 24. More specifically, the second gear 26a is rotationally locked to the layshaft 24. In other words, the second gear 26a is fixedly connected to the layshaft 24. The third gear 26b is disposed on the mainshaft 23 and is connectable thereto. More specifically, the third gear 26b is selectively rotationally coupled to the mainshaft 23. In other words, when the third gear 26b is rotationally coupled to the mainshaft 23, the third gear 26b is rotationally locked to the mainshaft 23, and the mainshaft 23 and the third gear 26b thereby rotate at the same rotational speed. Therefore, the connection of the third gear 26b to the mainshaft 23 to rotationally lock the third gear can be accomplished by any known means, such as a coupling sleeve. When the third gear 26b is not rotationally coupled to the mainshaft 23, the mainshaft 23 and the third gear 26b can rotate at different rotational speeds.

[0105] In a similar manner to the first gear pair 26, the second gear pair 27 includes a fourth gear 27a and a fifth gear 27b that engage with each other. The fourth gear 27a is fixedly connected to the layshaft 24, i.e., rotationally locked thereto. The fifth gear 27b is arranged on the mainshaft 23 and is connectable thereto. In other words, the fifth gear is selectively rotationally coupled to the mainshaft 23. Therefore, the connection of the fifth gear 27b to the mainshaft 23 to rotationally lock the fifth gear thereto can be accomplished by any previously known means. The first gear pair 26 and the second gear pair 27 are configured to provide two different gear ratios, and therefore, two different gear stages.

[0106] The transmission assembly 14 also includes a final gear pair 28, which includes a sixth gear 28a and a final gear 28b (which may alternatively be described as a seventh gear). The sixth gear 28a is fixedly connected to the main shaft 23, i.e., rotationally locked to the main shaft. The final gear 28b is arranged on the drive shaft 20.

[0107] When the electric drive axle assembly 10 is arranged in a vehicle, for example Figure 1 In the vehicle 1 shown in FIG, the drive shaft 20 is configured to be connected to at least one drive wheel of the vehicle so as to transmit driving power to the vehicle. In the case where the drive shaft 20 is connected to only one drive wheel of the vehicle, the final gear 28b may be directly and fixedly connected to the drive shaft 20. However, in Figure 7 In the third exemplary embodiment shown in FIG, the drive shaft 20 is configured to be connected to two opposing drive wheels of a vehicle. In other words, the drive shaft 20 is configured to be connected to the first drive wheel at a first longitudinal end of the drive shaft 20 and to the second drive wheel at a second longitudinal end of the drive shaft 20. In this case, the drive shaft 20 may include or consist of a first drive shaft half shaft 20a and a second drive shaft half shaft 20b, as shown in FIG. Figure 7 . A first drive shaft half shaft 20a is configured to be connected to the first drive wheel of the vehicle, and a second drive shaft half shaft 20b is configured to be connected to the second drive wheel of the vehicle. The first drive shaft half shaft 20a and the second drive shaft half shaft 20b can optionally have substantially equal lengths (i.e., longitudinal extensions). However, the lengths of the first drive shaft half shaft 20a and the second drive shaft half shaft 20b are typically different. When the drive shaft 20 includes the first drive shaft half shaft 20a and the second drive shaft half shaft 20b, the final gear 28b is suitably connected to the drive shaft 20 via a differential (not shown).

[0108] Although not shown, when the electric drive axle assembly is deployed in a vehicle, the drive shaft 20 can be configured to extend within a bridge structure. Such a bridge structure can be configured to support the vehicle's drive wheels while providing sufficient structural rigidity and supporting the weight of the electric drive axle assembly. The housing 11 of the transmission assembly 14 can be suitably mounted to the bridge structure using a plurality of fastening elements.

[0109] If desired, the transmission assembly 14 may further include a planetary gear 29 disposed on the main shaft 23 between the first gear pair 26 and the second gear pair 27. In the case where the transmission assembly 14 includes the planetary gear 29, the main shaft includes or is composed of two main shaft half shafts. One of the two main shaft half shafts forming the main shaft 23 may be connected to the sun gear of the planetary gear 29, and the other of the two main shaft half shafts may be connected to the planetary gear carrier of the planetary gear 29, although other configurations are possible.

[0110] like Figure 7As shown in FIG, the electric drive axle assembly 10 further includes a reservoir device 30, which forms part of the lubrication system of the electric drive axle assembly 10. The reservoir device 30 includes a first oil reservoir 31 that encloses the lower portion of the final gear 28b. Thus, the first oil reservoir is arranged below the drive shaft 20. The reservoir device 30 also includes a second oil reservoir 32. The second oil reservoir 32 can be configured to supply oil to the first oil reservoir 31 without the use of pumping power. For this purpose, the second oil reservoir 32 can be suitably arranged above the first oil reservoir 31 and in fluid communication with the first oil reservoir 31, for example, via an orifice and / or channel in the bottom wall of the second oil reservoir 32. As shown in the figure, the second oil reservoir 32 can be arranged below the main shaft 32 and the sixth gear 28a. Thus, the second oil reservoir can be arranged to collect at least a portion of the oil supplied by the supply system to the sixth gear 28a (if the supply system is configured to do so). The second oil reservoir 32 may also be arranged below the planetary gears 29 (if present) and thereby arranged so as to collect at least a portion of the oil supplied to the planetary gears 29 by the supply system of the lubrication system. Alternatively or in addition, the second oil reservoir 32 may be configured to receive oil returned from the cooling system of the electric machine 12. In this case, the return conduit of the cooling system of the electric machine 12 may be fluidly connected to the second oil reservoir 32 or otherwise arranged to supply oil to the second oil reservoir. It should be noted here that Figure 7 The reservoir device 30 shown in FIG. 1 may correspond to Figure 6 The reservoir device shown in .

Claims

1. An electric drive axle assembly (10) for a vehicle (1), the electric drive axle assembly (10) comprising: Motor (12); a transmission assembly (14) configured to transmit driving power from the motor (12) to at least one drive wheel (2) of the vehicle (1) via a drive shaft (20) of the transmission assembly (14) when the electric drive axle assembly (10) is arranged in the vehicle (1), the transmission assembly (14) comprising a final gear pair (28), the final gear pair comprising a final gear (28b) arranged on the drive shaft (20); and a lubrication system (15) comprising an oil sump (16) disposed in a lower portion (11a) of a housing (11) of the transmission assembly (14), and a supply system (17) configured to supply oil from the oil sump (16) to one or more components of the electric drive axle assembly (10); Characterized in that the lubrication system (15) further comprises a reservoir device (30) arranged so as to enclose the lower portion of the final gear (28b).

2. The electric drive axle assembly (10) according to claim 1, wherein the supply system (17) is configured to supply oil to a cooling system (18) of the electric machine (12), the cooling system (18) comprising a return conduit (19) configured to return oil from the cooling system (18) of the electric machine (12) to the reservoir device (30).

3. The electric drive axle assembly (10) according to any one of the preceding claims, wherein the reservoir device (30) includes at least one drain opening (38, 48) configured to allow oil to drain from the reservoir device (30) to the oil sump (16).

4. The electric drive axle assembly (10) according to any one of the preceding claims, wherein the reservoir device (30) comprises an upper edge (37) surrounding the lower part of the final gear (28b), the upper edge (37) being arranged above a predefined maximum oil level (L-max) of the oil sump (16).

5. The electric drive assembly (10) according to any one of the preceding claims, wherein the reservoir device (30) comprises: a first oil reservoir (31) arranged so as to enclose the lower portion of the final gear (28b), and A second oil reservoir (32) configured to supply oil to the first oil reservoir (31).

6. An electric drive axle assembly according to claim 5, wherein the second oil reservoir (32) is fluidly connected to the first oil reservoir (31) via an orifice (47) and / or a channel arranged in a wall, preferably a bottom wall (46) of the second oil reservoir (32).

7. The electric drive axle assembly (10) according to any one of claims 5 or 6, wherein the second oil (32) reservoir is arranged above the first oil reservoir (31).

8. The electric drive axle assembly (10) according to any one of claims 5 to 6, wherein the supply system (17) is configured to supply oil to at least one gear of the transmission assembly other than the final gear (28b), and the second oil reservoir is arranged so as to collect at least a portion of the oil supplied to the at least one gear.

9. The electric drive axle assembly (10) according to any one of claims 5 to 8, wherein The first oil reservoir (31) includes a first drain opening configured to allow controlled draining of oil from the first oil reservoir (31) to the oil sump (16), and The second oil reservoir (32) includes a second drain opening (48) configured to allow controlled draining of oil from the second oil reservoir (32) to the oil sump (16).

10. The electric drive axle assembly (10) according to any one of claims 5 to 9, wherein the transmission assembly (14) further comprises: a main shaft (23) arranged in parallel with the drive shaft (20); a secondary shaft (24) arranged in parallel with the primary shaft (23) and the drive shaft (20); a first gear (25) connected to and rotationally locked to an output shaft (13) of the motor (12); a first gear pair (26) comprising a second gear (26a) rotationally locked to the secondary shaft (24) and a third gear (26b) engaged with the second gear (26a), the third gear (26b) being arranged on the primary shaft (23) and connectable thereto; a second gear pair (27) comprising a fourth gear (27a) rotationally locked to the secondary shaft (24) and a fifth gear (27b) engaged with the fourth gear (27a), the fifth gear (27b) being arranged on the primary shaft (23) and connectable thereto; wherein the first gear (25) is engaged with the second gear (26a) or the fourth gear (27a), The final gear set (28) includes a sixth gear (28a) rotationally locked to the main shaft (23) and engaged with the final gear (28b), and The transmission assembly (14) optionally further comprises a planetary gear (19) arranged on the main shaft (23) between the first gear pair (26) and the final gear pair (28).

11. The electric drive axle assembly (10) of claim 10, wherein the second oil reservoir (32) is arranged between the final gear (28b) and the motor (12) and below the main shaft (23) of the transmission assembly (14).

12. The electric drive axle assembly (10) according to any one of claims 1 to 4, wherein the transmission assembly (14) further comprises: a main shaft (23) arranged in parallel with the drive shaft (20); a secondary shaft (24) arranged in parallel with the primary shaft (23) and the drive shaft (20); a first gear (25) connected to and rotationally locked to an output shaft (13) of the motor (12); a first gear pair (26) comprising a second gear (26a) rotationally locked to the secondary shaft (24) and a third gear (26b) engaged with the second gear (26a), the third gear (26b) being arranged on the primary shaft (23) and connectable thereto; a second gear pair (27) comprising a fourth gear (27a) rotationally locked to the secondary shaft (24) and a fifth gear (27b) engaged with the fourth gear (27a), the fifth gear (27b) being arranged on the primary shaft (23) and connectable thereto; wherein the first gear (25) is engaged with the second gear (26a) or the fourth gear (27a), The final gear set (28) includes a sixth gear (28a) rotationally locked to the main shaft (23) and engaged with the final gear (28b), and The transmission assembly (14) optionally further comprises a planetary gear (19) arranged on the main shaft (23) between the first gear pair (26) and the final gear pair (28).

13. The electric drive assembly (10) according to any one of claims 10 to 12, wherein the final gear (28b) is connected to the drive shaft (20) via a differential.

14. A vehicle (1) comprising an electric drive axle assembly (10) according to any one of the preceding claims.

Images