Transmission device for a motor vehicle

Abstract

Transmission device (1) for a motor vehicle, comprising a planetary gear (2) and a differential gear (3) which is operatively connected to the planetary gear (2) via a toothed connection (4) and has a first and second output shaft (5a, 5b), wherein the planetary gear (2) has a planet gear set with several planet gears (6), wherein the planet gears (6) are rotatably mounted on a planet carrier (7) and are in mesh with a sun gear (8) and a ring gear (9), wherein the sun gear (8) is non-rotatably connected to a drive shaft (12), wherein the ring gear (9) is non-rotatably connected to a first spur gear (10a), wherein the planet carrier (6) is non-rotatably connected to a second spur gear (10b), and wherein an intermediate gear (11) is in mesh with the toothed connection (4) on the differential gear (3) and one of the two spur gears (10a, 10b), wherein the other of the two spur gears (10b, 10a),that is not in tooth mesh with the intermediate gear (11), but is in tooth mesh with the toothing (4) on the differential gear (3).

Description

The invention relates to a transmission device for a motor vehicle. The invention also relates to a drive device for a motor vehicle having an electric machine. In particular, the motor vehicle is designed as an electric vehicle or hybrid vehicle having an electric drive axle.DE 10 2014 223 502 A1 discloses a drive arrangement comprising an electric motor, wherein the electric motor defines a first axis with a rotor shaft, a differential device defining a second axis, wherein the first and the second axis are arranged offset parallel to one another. The drive arrangement further comprises a gear stage section having an input wheel and an output wheel, wherein the input wheel is arranged coaxially to the first axis and the output wheel is arranged coaxially to the second axis. The transmission stage portion includes an idler gear device, the idler gear device being engaged with the input gear and the output gear.DE 10 2016 211 225 B3 shows a combined multi-speed transmission.DE 10 2012 214 766 A1 shows a differential gear. This comprises a differential unit having a first transmission output, a second transmission output, and an actuating device for applying a differential torque effective between the two transmission outputs. The adjusting device comprises an adjusting motor and a coupling gear. The coupling gear is radially offset with respect to a differential axis and engages radially from the outside on the differential unit.The object of the present invention is to provide a particularly compact transmission device for a motor vehicle. The object is achieved by the subject matter of claim 1.A transmission device according to the invention for a motor vehicle comprises a planetary gear and a differential gear which is operatively connected to the planetary gear via a toothing and has a first and second output shaft, wherein the planetary gear has a planetary gear set with a plurality of planetary gears, wherein the planetary gears are rotatably mounted on a planetary carrier and are in toothed engagement with a sun gear and a ring gear, wherein the sun gear is connected in a rotationally fixed manner to a drive shaft, wherein the ring gear is connected in a rotationally fixed manner to a first spur gear, wherein the planetary carrier is connected in a rotationally fixed manner to a second spur gear, and wherein an intermediate gear is in toothed engagement with the toothing on the differential gear and one of the two spur gears, wherein the respective other of the two spur gears, which is not in toothed engagement with the intermediate gear, is in toothed engagement with the toothing on the differential gear.In other words, the intermediate gear is arranged between one of the two spur gears and the toothing on the differential gear in order to reverse a direction of rotation and to connect the planetary gear to the differential gear. The spur gear, which is not in toothed engagement with the intermediate gear, is directly and thus directly in toothed engagement with the toothing on the differential gear in order to connect the planetary gear to the differential gear.Via the drive shaft and the sun gear, the drive power or the drive torque of a drive machine, which is configured to be operatively connected to the drive shaft, is introduced into the transmission device, wherein the drive torque in the planetary transmission is divided between the ring gear and the planetary carrier. At the toothing of the differential gear, the drive torque is summed again, in order to then be distributed in half in the differential gear to the two output shafts. The respective output shaft is operatively connected to a respective wheel of a drive axle of the motor vehicle.The term "operatively connected" is to be understood to mean that two gear elements can be directly connected to one another, or that further gear elements are located between two gear elements, for example one or more shafts or gearwheels.Two toothed gears are provided for transmitting a torque and a rotational speed from one gear to the other gear. A gearwheel is to be understood as meaning a planetary gearwheel, a sun gearwheel, a ring gearwheel, a spur gearwheel, an intermediate gearwheel, a differential gearwheel and a bevel gearwheel.According to a first embodiment, the intermediate gear meshes with the toothing on the differential gear and the first spur gear, wherein the second spur gear meshes with the toothing on the differential gear. The first spur gear is therefore indirectly connected via the intermediate gear to the toothing on the differential gear, wherein the second spur gear is directly connected to the toothing on the differential gear. In particular, a diameter of the first spur gear is greater than a diameter of the second spur gear. The two spur gears are arranged in different engagement planes.According to a second embodiment, the intermediate gear meshes with the toothing on the differential gear and the second spur gear, wherein the first spur gear meshes with the toothing on the differential gear. The second spur gear is therefore indirectly connected via the intermediate gear to the toothing on the differential gear, wherein the first spur gear is directly connected to the toothing on the differential gear. In particular, a diameter of the first spur gear is smaller than a diameter of the second spur gear. The two spur gears are arranged in different engagement planes.The invention includes the technical teaching that the toothing is formed on a differential cage of the differential gear. Thus, the drive torque is introduced into the differential gear via the differential cage of the differential gear.Preferably, the two output shafts are arranged axially parallel to the drive shaft. The planetary gear is therefore arranged axially parallel to the differential gear. For example, a drive machine is arranged coaxially with the planetary gear.According to a preferred embodiment of the invention, the differential gear is designed as a spur gear differential. The spur gear differential includes first and second planetary gear sets having a plurality of first and second differential gears, respectively. The respective differential gears of the differential gear are rotatably mounted on the differential carrier of the differential gear. The differential cage is thus designed as a planetary carrier. The first differential gears mesh with a first output sun gear, which is connected to the first output shaft in a rotationally fixed manner, wherein the second differential gears mesh with a second output sun gear, which is connected to the second output shaft in a rotationally fixed manner. Furthermore, the first differential gears mesh in pairs with the second differential gears.According to a preferred embodiment of the invention, the differential gear is designed as a bevel gear differential. On the differential cage of the bevel gear differential, two differential gears are rotatably mounted, which are in toothed engagement with two bevel gears. The first bevel gear is connected to the first output shaft in a rotationally fixed manner. Furthermore, the second bevel gear is connected to the second output shaft in a rotationally fixed manner.The invention further relates to a drive device for a motor vehicle, comprising an electric machine which is operatively connected to a transmission device according to the invention via a drive shaft. The electric machine is provided as a drive machine and comprises a rotor and a stator.Further measures which improve the invention are illustrated in more detail below together with the description of two preferred exemplary embodiments of the invention on the basis of the two figures, wherein identical elements are provided with the same reference symbols. Figure shows FIG. 1 is a simplified schematic illustration for illustrating the structure of a drive device according to the invention in accordance with a first embodiment; and FIG. 2 shows a simplified schematic illustration for illustrating the structure of a drive device according to the invention in accordance with a second embodiment.According to FIGS. 1 and 2, a respective drive device according to the invention for a motor vehicle-not shown here-comprises an electric machine 14, which is operatively connected to a transmission device 1 via a drive shaft 12. The electric machine 1 is provided as a drive machine and has a stator and a rotor. A drive power or a drive torque of the electric machine 14 is introduced into the transmission device 1 via the drive shaft 12, which is provided as a connecting element between the electric machine 14 and the transmission device 1.The transmission device 3 comprises a planetary gear 2 and a differential gear 3, wherein the differential gear 3 is operatively connected to the planetary gear 2 via a toothing 4 on the differential gear 3. Furthermore, a first and second output shaft 5 a, 5 bare operatively connected to the differential gear 3. The planetary gear 2 comprises a planetary gear set with a plurality of planetary gears 6, wherein the planetary gears 6 are rotatably mounted on a planetary carrier 7 and are in mesh with a sun gear 8 and a ring gear 9. The sun gear 8 is connected in a rotationally fixed manner to the drive shaft 12. The ring gear 9 is connected in a rotationally fixed manner to a first spur gear 10 a. The planet carrier 6 is connected in a rotationally fixed manner to a second spur gear 10 b. The two spur gears 10 a, 10 bare arranged axially adjacent and coaxial to one another. Furthermore, the two output shafts 5 a, 5 bare arranged axially parallel to the drive shaft 12. The electric machine 14 is arranged coaxially to the planetary gear 2 and to the two spur gears 10 a, 10 band axially parallel to the differential gear 3.According to FIG. 1, an intermediate gear 11 meshes with the toothing 4 on the differential gear 3 and the first spur gear 10 a. The second spur gear 10 bis directly in toothed engagement with the toothing 4 on the differential gear 3. A diameter D 1 of the first spur gear 10 ais larger than a diameter D 2 of the second spur gear 10 b. On the right-hand edge of FIG. 1, the two spur gears 10 a, 10 b, the intermediate gear 11 and the differential gear 3 are shown laterally and in a greatly simplified manner. The two spur gears 10 a, 10 brotate about a first axis of rotation 15. the differential gear 3 rotates, like the toothing 4 on the differential cage 13, and the two output shafts 5 a, 5 brotate about a second axis of rotation 16. furthermore the intermediate gear 11 rotates about a third axis of rotation 17. On the left-hand edge of FIG. 1, the planetary gear 2, which in the present case comprises the sun gear 8, three planetary gears 6 and the ring gear 9, is shown laterally and in a greatly simplified manner. The planetary gear 2, like the two spur gears 10 a, 10 band the drive shaft 12, rotates about the first axis of rotation 15.According to FIG. 2, an intermediate gear 11 meshes with the toothing 4 on the differential gear 3 and the second spur gear 10 b. The first spur gear 10a meshes directly with the toothing 4 on the differential gear 3. A diameter D 1 of the first spur gear 10 ais smaller than a diameter D 2 of the second spur gear 10 b. On the right-hand edge of FIG. 2, the two spur gears 10 a, 10 b, the intermediate gear 11 and the differential gear 3 are shown laterally and in a greatly simplified manner. The two spur gears 10 a, 10 brotate about a first axis of rotation 15. the differential gear 3 rotates, like the toothing 4 on the differential cage 13, and the two output shafts 5 a, 5 brotate about a second axis of rotation 16. furthermore the intermediate gear 11 rotates about a third axis of rotation 17. On the left-hand edge of FIG. 2, the planetary gear 2, which in the present case comprises the sun gear 8, three planetary gears 6 and the ring gear 9, is shown laterally and in a greatly simplified manner. The planetary gear 2, like the two spur gears 10 a, 10 band the drive shaft 12, rotates about the first axis of rotation 15.Regardless of the respective embodiment, the differential gear 3 can be designed as a spur gear differential or as a bevel gear differential.List of reference characters1 Transmission device 2 Planetary transmission 3 Differential transmission 4 Toothing on the differential transmission 5 a, 5 b Abtriebswelle shaft 6 Planetary gear 7 Planetary carrier 8 Sun gear 9 Ring gear 10 a, 10 b Stirnrad gear 11 Intermediate gear 12 Drive shaft 13 Differential cage 14 Electric machine 15 First axis of rotation 16 Second axis of rotation 17 Third axis of rotation D 1 Diameter of the first spur gear D 2 Diameter of the second spur gear

Claims

Transmission device (1) for a motor vehicle, comprising a planetary gear (2) and a differential gear (3) which is operatively connected to the planetary gear (2) via a toothing (4) and has a first and second output shaft (5a, 5b), wherein the planetary gear (2) has a planetary gear set with a plurality of planetary gears (6), wherein the planetary gears (6) are rotatably mounted on a planetary carrier (7) and are in meshing engagement with a sun gear (8) and a ring gear (9), wherein the sun gear (8) is connected in a rotationally fixed manner to a drive shaft (12), wherein the ring gear (9) is connected in a rotationally fixed manner to a first spur gear (10a), wherein the planetary carrier (6) is connected in a rotationally fixed manner to a second spur gear (10b), and wherein an intermediate gear (11) is connected to the toothing (4) on the differential gear (3) and one of the two spur gears (10a, 10b) is in toothed engagement, the respective other of the two spur gears (10b, 10a), which is not in toothed engagement with the intermediate gear (11), being in toothed engagement with the toothing (4) on the differential gear (3).Transmission device (1) according to Claim 1, characterized in that the intermediate gear (11) is in toothed engagement with the toothing (4) on the differential transmission (3) and with the first spur gear (10a), wherein the second spur gear (10b) is in toothed engagement with the toothing (4) on the differential transmission (3).Transmission device (1) according to Claim 2, characterized in that a diameter (D1) of the first spur gear (10a) is greater than a diameter (D2) of the second spur gear (10b).Transmission device (1) according to Claim 1, characterized in that the intermediate gear (11) is in toothed engagement with the toothing (4) on the differential transmission (3) and the second spur gear (10b), wherein the first spur gear (10a) is in toothed engagement with the toothing (4) on the differential transmission (3).Transmission device (1) according to Claim 4, characterized in that a diameter (D1) of the first spur gear (10a) is smaller than a diameter (D2) of the second spur gear (10b).Transmission device (1) according to one of the preceding claims, characterized in that the toothing (4) is formed on a differential cage (13) of the differential transmission (3).Transmission device (1) according to one of the preceding claims, characterized in that the two output shafts (5a, 5b) are arranged axially parallel to the drive shaft (12).Transmission device (1) according to one of the preceding claims, characterized in that the differential transmission (3) is designed as a spur gear differential.Transmission device (1) according to one of Claims 1 to 7, characterized in that the differential transmission (3) is designed as a bevel gear differential.Drive device for a motor vehicle, comprising an electric machine (14) which is operatively connected via a drive shaft (12) to a transmission device (1) according to Claims 1 to 9.

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