Distribution device for distributing drive power to vehicle wheels and electric axle drive device for driving vehicle wheels

Abstract

Distribution device (1) for distributing drive power to several vehicle wheels (F1, F2) of an electric vehicle comprising: - a power input (2) which can be connected to an electric drive (20), - a first and a second power output (3, 4) that can be connected to vehicle wheels (F1, F2), - a distribution gear stage (5) for splitting and distributing a drive power from the power input (2) to the first and second power output (3, 4), - a transmission gear stage (6) for transmitting drive power from the distribution gear stage (5) to the second power output (4), and the transmission gear stage (6) is designed as a spur gear stage, characterized in that - wherein the planetary gear (10) comprises a sun gear (11), first planets (12), second planets (13) and third planets (14), a planet carrier (15) and a ring gear (16), - where the first planets (12) comb with the sun wheel (11), - where the second planets (13) comb with the third planets (14), - where the first and second planets (12, 13) form a stepped planetary set, and - where the third planets (14) mesh with the second planets (13) and the ring gear (16).

Description

[0001] The invention relates to a distribution device for distributing drive power to several vehicle wheels of an electric vehicle and to an electric axle drive device for driving several vehicle wheels of an electric vehicle.

[0002] Electrically powered vehicles are known from the prior art, which have an electric motor for driving the vehicle wheels. Typically, an electric motor is connected to a differential or a distribution device to drive, for example, two vehicle wheels with one electric motor. Such a differential has two planetary gear sets. One is for distributing power to a first and a second vehicle wheel, with the first planetary gear set being connected to the first vehicle wheel, and the other is for transmitting power from the first planetary gear set to the second vehicle wheel.

[0003] US 5 845 732 A shows an electromechanical axle drive device for a motor vehicle.

[0004] DE 10 2014 213 146 A1 discloses a drive arrangement for a vehicle with an electric machine and an associated transmission device comprising a differential and a spur gear which couple a first and a second output shaft to the electric machine.

[0005] DE 10 2021 208 543 A1 shows a gearbox for a vehicle drive train, a drive train with such a gearbox and a vehicle with such a drive train.

[0006] Against this background, the object of the present invention is to increase the range of an electrically powered vehicle and to improve the efficiency of the combination of an electric motor with a differential.

[0007] This problem is solved by the features of the independent patent claims. Further advantageous developments are the subject of the dependent claims.

[0008] According to the invention, a first aspect of the present invention comprises a distribution device for distributing drive power to several wheels of an electric vehicle. The distribution device can be used to distribute an incoming torque, e.g., input at a power input, equally to two vehicle wheels or to two power outputs.

[0009] The distribution device includes a power input which can be connected to an electric drive, as well as a first and a second power output which can be connected to vehicle wheels.

[0010] Furthermore, the distribution device includes a distribution gear stage for splitting and distributing drive power from the power input to the first and second power outputs. The distribution gear stage can be designed to deliver power to a vehicle wheel without an additional intermediate gear. The distribution gear stage can, for example, consist solely of a planetary gear set.

[0011] Furthermore, the distribution gear stage can include a planetary gear set. The planetary gear set can have a ring gear. The ring gear of the planetary gear set in the distribution gear stage and a ring gear of the transmission gear stage can be non-rotatably connected to each other or formed as a single unit. This very combination of the two ring gears results in a simple design of the distribution device and, at the same time, an optimized weight compared to prior art solutions.

[0012] The planetary gear set can include a sun gear, first planets, a planet carrier, and a ring gear. It can also include second and third planets. The first, second, and / or third planets can be rotatably mounted on the planet carrier. Furthermore, the first planets can, for example, simply mesh with or be engaged by the sun gear. Similarly, the second planets can, for example, simply mesh with or be engaged by the first or third planets.

[0013] Furthermore, the first and second planetary gears can be rotatable about a common axis of rotation and / or be connected to each other in a rotationally fixed manner. The first and second planetary gears can form a stepped planetary gear set. The third planetary gears can mesh with or be engaged in contact with the second planetary gears and the ring gear. Using this design according to the invention, drive power can be distributed from the distribution gear stage to a first vehicle wheel and to the transmission gear stage, and thus to a second vehicle wheel. More precisely, power can be split via the distribution gear stage to the planet carrier and to the ring gear, which drives the transmission gear stage.

[0014] In addition, the distribution device includes a transmission gear stage for transferring drive power from the distribution gear stage to the second power output.

[0015] The transmission stage is designed as a spur gear stage. This allows for an increase in the gear ratio in the distribution device or in a rolling differential beyond the limits of arrangements with two planetary gear sets, as provided for in prior art solutions. Furthermore, weight can be saved and the efficiency of an electric axle drive device improved.

[0016] The transmission stage can include a spur gear. It can also include a ring gear. The spur gear can mesh with the ring gear. The spur gear can have external teeth. The ring gear can have internal teeth. Thus, a spur gear stage can be designed, or a spur gear transmission with a spur gear and a ring gear can be implemented. Compared to the prior art, which uses a planetary gear system at this point, this solution is lighter and more cost-effective because it has fewer components.

[0017] Furthermore, the distribution device can include an axle offset device to compensate for an axle offset between the first and second power outputs resulting from the spur gear stage being designed as a transmission stage. The axle offset device may be necessary, for example, if the distribution stage is implemented as a planetary gear set or if it is a planetary gear set and the transmission stage is implemented as a spur gear set. The axle offset device can direct drive power from the transmission stage to the second power output and thus to one or more vehicle wheels. In doing so, the axle offset device transmits the rotational speed and torque of the transmission stage to the second power output. The axle offset device can be designed so that the rotational speed and / or torque from the transmission stage can be delivered unchanged or at a 1:1 ratio to the second power output.Mechanical losses can be taken into account and partially compensated for when choosing the translation.

[0018] The axle offset device can include a joint to compensate for an offset or axle misalignment between the first and second power outputs. This is because, to create a common vehicle axle, the design of the transmission stage (a spur gear stage for driving one wheel) in combination with the transfer case (for driving another wheel) may necessitate selecting the gear ratios for both wheels so that, for example, the rotational speeds of the first and second power outputs are identical when driving straight ahead. In such a case, the transmission stage and the transfer case may exhibit an axle misalignment, which must be compensated for by the axle offset device or the joint.

[0019] The first, second, and / or third planetary gears can have different and / or partially identical pitch circle diameters to generate a definable gear ratio. The pitch circle diameter of the first planetary gears can be larger than the pitch circle diameter of the second and / or third planetary gears. Similarly, the pitch circle diameter of the second planetary gears can be larger or smaller than the pitch circle diameter of the third planetary gears. Furthermore, the pitch circle diameters of the second and third planetary gears can be the same. In this way, the second and third planetary gears can be used to create an additional gear ratio within the planetary gear set of the transfer stage. This, in combination with the spur gear of the transmission stage, results in a weight-optimized solution for an electric axle drive device.

[0020] Furthermore, the sun gear can be non-rotatably connected to the power input or be formed in one piece.

[0021] The planetary carrier can also be rotationally fixed to the first power output. In this case, the planetary carrier can function as the first power output.

[0022] Furthermore, the distribution device can be designed as a rolling differential. Additionally, the distribution device can be a spur gear differential or be designed as such.

[0023] Furthermore, the first and second power outputs can each be formed by a shaft or an axis, which can be aligned in the same orientation relative to each other. The first and second power outputs can be coaxially aligned.

[0024] A second aspect of the present invention comprises an electric axle drive device for driving several vehicle wheels of an electric vehicle.

[0025] It is expressly pointed out that the features of the distribution device, as mentioned under the first aspect, can be used individually or in combination with each other in the electric axle drive device.

[0026] In other words, the features relating to the distribution device mentioned above under the first aspect of the invention can also be combined with further features under the second aspect of the invention.

[0027] An electric axle drive device for driving several vehicle wheels of an electric vehicle includes a distribution device according to the first aspect.

[0028] Furthermore, the electric axle drive device comprises at least one electric drive or electric motor arranged coaxially to the first and / or second power output of the distribution device. A shaft of the at least one electric drive can form the power input of the distribution device.

[0029] Furthermore, a shaft of at least one electric drive can be non-rotatably connected to a sun gear of a planetary gearbox in the distribution stage of the distribution device, or it can be formed as a single unit. Thus, the electric drive can easily provide a power input for the distribution device.

[0030] The invention concept presented above is expressed again and in addition in other words below.

[0031] This idea, in simplified terms, concerns a rolling differential or a distribution device with a focus on the so-called E-axis.

[0032] Previously known rolling differentials or distribution devices are designed on the basis of two planetary gear sets or two planetary gearboxes and have limitations regarding the overall gear ratio.

[0033] To solve this problem, a second planetary gear set in the rolling differential can be replaced by a spur gear set with a common ring gear to increase the gear ratio. The coupling of a distribution gear stage of the distribution device with a transmission gear stage of the distribution device can be achieved via a common ring gear and an intermediate gear or another planet gear in the distribution gear stage, which, together with the ring gear and the output spur gear or the spur gear of the spur gear stage / transmission gear stage, can form an axial triangle.

[0034] The invention is explained in more detail below with reference to an exemplary embodiment in conjunction with a drawing. The drawing schematically shows: Fig. 1 A schematic sectional view of an electric axle drive device according to the invention for driving several vehicle wheels.

[0035] Fig. Figure 1 shows a schematic sectional view of an electric axle drive device 30 according to the invention for driving several vehicle wheels F1, F2 of an electric vehicle.

[0036] A more detailed illustration shows Fig. 1, that the electric axle drive device 30 comprises a distribution device 1 and an electric drive 20 or an electric motor, which is arranged coaxially to a first power output 3 of the distribution device 1.

[0037] In this arrangement, a shaft of the electric drive 30 forms a power input 2 of the distribution device 1, wherein the shaft of the electric drive 30 is non-rotatably connected to a sun gear 12 of a planetary gear 10 of a distribution gear stage 5 of the distribution device 1 or is formed in one piece.

[0038] Furthermore, it shows Fig. 1 a distribution device 1 for distributing drive power to several vehicle wheels F1, F2 of an electric vehicle.

[0039] The distribution device 1 has a power input 2, which can be connected to the electric drive 20, as well as a first and a second power output 3, 4, which is connected to vehicle wheels F1, F2.

[0040] Furthermore, it shows Fig. 1, that the distribution device 1 comprises a distribution gear stage 5 for branching and distributing a drive power from the power input 2 to the first and second power output 3, 4.

[0041] The distribution device 1 also has a transmission gear stage 6 for transferring drive power from the distribution gear stage 5 to the second power output 4.

[0042] In this design, transmission stage 6 is configured as a spur gear stage. This allows for an increase in the gear ratio in the distribution device 1 beyond the limits of the arrangement with two planetary gears, one per gear stage, as provided for in prior art solutions. Furthermore, this solution allows for weight savings and improved efficiency of an electric drive.

[0043] More specifically, the transmission stage 6 comprises a spur gear 7 and a ring gear 8, with the spur gear 7 meshing with the ring gear 8. The ring gear 8 has internal teeth, while the spur gear 7 has external teeth. Thus, a spur gear stage can be designed, or a spur gear transmission with a spur gear and a ring gear as the transmission stage can be implemented. This solution uses few components and is therefore weight-saving.

[0044] Furthermore, it shows Fig. 1, that the distribution device 1 has an axis offset device 9 to compensate for an axis offset between the first and second power outputs 3, 4 due to the design of the transmission gear stage 6 as a spur gear stage. The axis offset device 9 is necessary because, in the present case, according to Fig. 1. The distribution gear stage 5 has a planetary gear set, and the transmission gear stage 6 is implemented as a spur gear stage. The axle offset device 9 transmits drive power from the transmission gear stage 6 to the second power output 4 and thus to one vehicle wheel or to the second vehicle wheel F2. The axle offset device 9 transmits the speed and torque of the transmission gear stage 6 to the second power output 4. The axle offset device 9 is designed such that the speed and torque from the transmission gear stage 6 can be delivered unchanged, i.e., 1:1, to the second power output 4.

[0045] Furthermore, it shows Fig. 1. The axle offset device 9 has a joint to compensate for an offset or axle offset between the first and second power outputs 3, 4. In order to form a common vehicle axle, the design of the transmission gear stage 6 as a spur gear stage for driving one vehicle wheel F2, in combination with the distribution gear stage 5 for driving another vehicle wheel F1, necessitates selecting the gear ratios of the gear stages 5, 6 for both vehicle wheels F1, F2 such that, for example, when driving straight ahead, the rotational speeds of the first and second power outputs 3, 4 are identical. It is possible that the transmission gear stage 6 and the distribution gear stage 5 may exhibit the aforementioned axle offset, which must be compensated for by means of the axle offset device 9.

[0046] As in Fig. As can be seen in Figure 1, the distribution gear stage 5 comprises a planetary gear 10, which has a ring gear 16. The ring gear 16 of the planetary gear 10 of the distribution gear stage 5 and the ring gear 8 of the transmission gear stage 6 are rotationally fixed to each other or formed as a single unit. This very symbiosis of the two ring gears 8 and 16 creates a simple design for the distribution device 1 and simultaneously an optimized weight compared to prior art solutions.

[0047] Furthermore, how from Fig. As can be seen in Figure 1, the distribution gear stage 5 comprises a planetary gear set 10, which has a sun gear 11, first planets 12, second planets 13 and third planets 14, a planet carrier 15 and a ring gear 16. The first, second and third planets 12, 13, 14 are rotatably mounted on the planet carrier 15.

[0048] Furthermore, the first planets 12 only interact with the sun wheel 11, while the second planets 13 only interact with the third planets 14.

[0049] Furthermore, the first and second planets 12, 13 are rotatable about a common axis of rotation and are connected to each other in a rotationally fixed manner, forming a stepped planetary gear set. The third planets 14 mesh with, or are in engagement with, the second planets 13 and the ring gear 16. This configuration allows drive power to be distributed from the distribution gear stage 5 to a first vehicle wheel F1 and to the transmission gear stage 6, and thus to a second vehicle wheel F2. More precisely, the distribution gear stage 5 splits the power to the planet carrier 15 and the ring gear 16, and to the transmission gear stage 6.

[0050] Furthermore, it shows Fig. 1. The first, second, and third planets 12, 13, 14 have different and, in some cases, the same pitch circle diameters to generate a definable gear ratio. The pitch circle diameter of the first planet 12 is larger than the pitch circle diameter of the second and third planets 13, 14. Furthermore, the pitch circle diameter of the second planet 13 and the third planet 14 is the same. In this way, a further gear ratio can be achieved within the planetary gear set 10 of the distribution gear stage 5 using the second and third planets 13, 14. This, in combination with the spur gear 7 of the transmission gear stage 6, results in a weight-optimized solution for the electric axle drive device 30.

[0051] Furthermore, it shows Fig. 1, that the sun wheel 11 is non-rotatably connected to the power input 2 or is formed in one piece.

[0052] The planet carrier 15 is rotationally fixed to the first power output 3, with the planet carrier 15 functioning as the first power output 3.

[0053] In summary, it can be stated that the distribution device 1 is designed as a rolling differential or that the distribution device 1 is a spur gear differential.

[0054] Finally, it should be noted that the first and second power outputs 3 and 4 are each formed by a shaft or an axis, which can be aligned in the same orientation relative to each other. The first and second power outputs 3 and 4 can also be coaxially aligned. Reference symbol list 1 distribution device 2 Power input 3 first power output 4 second power output 5th transfer case stage 6th transmission gear stage 7 Spur gear 8 Ring gear 9 Axle offset device 10 planetary gears 11 Sun wheel 12 first planets 13 second planets 14 third planets 15 planetary carriers 16 Ring gear 20 Drive 30 axle drive device F1 car wheel F2 vehicle wheel

Claims

[1] Distribution device (1) for distributing a drive power to several vehicle wheels (F1, F2) of an electric vehicle, comprising: - a power input (2) which can be connected to an electric drive (20), - a first and a second power output (3, 4) connectable to vehicle wheels (F1, F2), - a distribution gear stage (5) for branching and distributing a drive power from the power input (2) to the first and second power outputs (3, 4), - a transmission gear stage (6) for transmitting drive power from the distribution gear stage (5) to the second power output (4), and the transmission gear stage (6) is designed as a spur gear stage, characterized by , that - wherein the planetary gear (10) comprises a sun gear (11), first planets (12), second planets (13) and third planets (14), a planet carrier (15) and a ring gear (16), - the first planets (12) mesh with the sun gear (11), - the second planets (13) mesh with the third planets (14), - wherein the first and second planets (12, 13) form a stepped planetary gear set, and - wherein the third planets (14) mesh with the second planets (13) and the ring gear (16). [2] Distribution device according to claim 1, - wherein the transmission gear stage (6) comprises a spur gear (7) and a ring gear (8), and wherein the spur gear (7) meshes with the ring gear (8). [3] Distribution device according to claim 1 or 2, - wherein the distribution device (1) has an axis offset device (9) in order to compensate for an axis offset between the first and second power outputs (3, 4) due to the design of the transmission gear stage (6) as a spur gear stage. [4] Distribution device according to claim 3, - wherein the axis offset device (9) has a joint to compensate for an axis offset between the first and second power outputs (3, 4). [5] Distribution device according to one of the preceding claims, - wherein the distribution gear stage (5) comprises a planetary gear (10), - wherein the planetary gear (10) has a ring gear (16), and - wherein the ring gear (16) of the planetary gear (10) of the distribution gear stage (5) and a ring gear (8) of the transmission gear stage (6) are connected to one another in a rotationally fixed manner. [6] Distribution device according to claim 1, - wherein the first, second and third planets (12, 13, 14) have different and / or partly identical pitch circle diameters in order to generate a definable gear ratio. [7] Distribution device according to claim 1 or 6, - wherein the sun gear (11) is connected to the power input (2) in a rotationally fixed manner or is formed in one piece, and - wherein the planet carrier (15) is connected in a rotationally fixed manner to the first power output (3). [8] Distribution device according to one of the preceding claims, - wherein the distribution device (1) is designed as a rolling differential. [9] Electric axle drive device (30) for driving a plurality of vehicle wheels (F1, F2) of an electric vehicle, comprising: - a distribution device (1) according to one of the preceding claims, and - at least one electric drive (20) arranged coaxially to the first and / or second power output (3, 4) of the distribution device (1), - wherein a shaft of the at least one electric drive (20) forms the power input (2) of the distribution device (1).

Images