Differential gear, transmission device for an electric drive axle and electric drive axle

Abstract

Spur gear differential consisting of a planetary gear with a sun gear (6, 7), a planetary gear set with several planets (4, 5), a planet carrier (2, 3, 8), and a ring gear (10), wherein the ring gear (10) is designed to be movable between at least two switching positions, wherein the ring gear (10) in a first switching position is exclusively in engagement with the planet carrier (2, 3, 8) and in a second switching position, in addition to the engagement with the planet carrier (2, 3, 8), is in engagement with the planets (4, 5) of the planetary gear set, so that the spur gear differential is locked in the second switching position, or wherein the ring gear (10) in a first switching position is exclusively in engagement with the planets (4, 5) of the planetary gear set, characterized in that the ring gear (10) in a second switching position is in engagement with the planet carrier (2, 3, 8) in addition to the engagement with the planets (4, 5) of the planetary gear set,so that the spur gear differential is locked in the second switching position.,

Description

[0001] Electric motors are used to power motor vehicles to create alternatives to internal combustion engines that require fossil fuels.

[0002] An electric drive axle with a transmission gear and differential gear arranged coaxially with a drive motor is already known from US Pat. No. 1,032,068 A. The transmission gear is designed as a single gear stage with two gears with different numbers of teeth. The differential gear is designed as a spur gear differential and comprises two main gears, each connected to different output shafts, and three groups of spur gears, each consisting of two spur gears located adjacent to and meshing with each other on separate axles.

[0003] US Pat. No. 5,533,943 A discloses an electric drive axle with a planetary gear transmission and a bevel gear differential, wherein the transmission and bevel gear differential are arranged coaxially with the drive motor. The planetary gear transmission has a stepped planetary gear set with built-up planets, each consisting of a gear with a larger diameter and a gear with a smaller diameter. The planetary gear transmission further comprises a sun gear and a ring gear, wherein the gear with a larger diameter engages with the sun gear of the planetary gear, and the gear with a smaller diameter engages with the ring gear of the planetary gear. The ring gear is supported against a housing of the drive axle.The drive motor comprises a drive shaft designed as a hollow shaft, which is connected to the sun gear of the transmission gear, so that a drive torque is transmitted to the planets via the sun gear and a reaction force for this purpose is supported on the ring gear of the transmission gear.

[0004] US Pat. No. 5,554,082 A discloses an electric drive axle with a transmission gear and spur gear differential arranged coaxially with a drive motor. The transmission gear is designed as a planetary gear and corresponds to the structure of US Pat. No. 5,533,943 A. The spur gear differential here is also designed as a planetary gear with a sun gear, planet carrier, planets, and ring gear. The planet carrier of the transmission gear and the ring gear of the spur gear differential are connected to each other, thus transmitting the drive torque to the ring gear of the spur gear differential via the planet carrier of the transmission gear. The output of the spur gear differential is achieved via its planet carrier and sun gear.

[0005] DE 10 2011 081 882 A1 discloses an electric drive axle with two output shafts, comprising a motor section and a transmission section. An electric motor is arranged in the motor section, the rotor of which is coupled to the transmission section via a hollow shaft, so that a drive torque generated by the electric motor is transmitted via the hollow shaft to the transmission section. The output shaft is arranged coaxially and concentrically with the electric motor within the hollow shaft. A transmission gear and a differential gear are arranged in the transmission section to increase or reduce the drive torque of the electric motor and distribute it between two output shafts. The transmission gear and differential gear are each designed as planetary gears. The transmission gear has a first planetary gear set with first planets, which are arranged distributed in a pitch circle around the main axis of rotation in the direction of rotation.The differential gear has a second planetary gear set with second planets, which are also arranged distributed in the pitch circle around the main axis of rotation in the direction of rotation. Part of the transmission gear and the differential gear are merged into a common assembly, with one planet of the first planetary gear set and one planet of the second planetary gear set sitting on a common double planet pin, and the first and second planetary gear sets being arranged in a cage, which, together with the double planet pin, forms a common planet carrier for the transmission gear and the differential gear. The differential gear further comprises a third planetary gear set with third planets, which are each arranged adjacent to a planet of the second planetary gear set and mesh with one another.The second planets of the second planetary set mesh with a first sun gear and the third planets of the third planetary set mesh with a second sun gear, with the sun gears being connected to one of the output shafts.

[0006] From DE 10 2015 214 031 A1 a gear arrangement for an electric drive axle of a motor vehicle with input stage and differential is known, wherein the input stage and differential are designed as planetary gears, wherein the two planetary gears of the input stage and differential are coupled to one another via a common planet carrier, wherein the differential has a first and a second planetary gear set, wherein the first planetary gear set meshes with a first sun and the second planetary gear set with a second sun, and wherein the two planetary gear sets of the differential mesh with one another in pairs.The input stage comprises a drive sun, first and second planetary gear sets, a planetary carrier and a ring gear, wherein the drive sun meshes with a first planetary gear set of the planetary gear of the input stage, wherein the first planetary gear set of the planetary gear of the input stage is connected in a rotationally fixed manner to a second planetary gear set of the planetary gear of the input stage, and wherein the two planetary gear sets of the planetary gear of the input stage are rotatably mounted together with the first planetary gear set of the planetary gear of the differential on a first bolt arranged on the common planetary carrier.

[0007] The aforementioned examples of electric drive axles feature a coaxial arrangement of the electric motor shaft and output shafts, with one of the output shafts passing through the electric motor shaft and the electric motor shaft being aligned with the output shafts of the differential. As an alternative to this coaxial arrangement of the electric motor to the differential, an axially parallel arrangement is also possible, in which the electric motor shaft is axially parallel and spaced from the output shafts of the differential. A clear illustration of such an electric drive is provided in the article in the magazine ATZ, Volume 113, May 2011, pages 360-365, by Erik Schneider, Frank Fickl, Bernd Cebulski, and Jens Liebold, entitled "Highly Integrated and Flexible Electric Drive Unit for E-Vehicles."This article describes a drive unit for an axle of a vehicle (electromechanical axle drive train) comprising an electric motor arranged concentrically and coaxially with a bevel gear differential. A switchable 2-speed planetary gear set is arranged in the power path between the electric motor and the bevel gear differential, which is also positioned coaxially with the electric motor or the bevel gear differential. The drive unit is very compact and, thanks to the switchable 2-speed planetary gear set, allows a good compromise between gradeability, acceleration, and energy consumption. The electromechanical axle drive train can be designed with a switchable planetary gear, two gears, in the example of the above-mentioned article, or, in a simpler version, with just one gear (single gear).A gearbox (reduction gear) downstream of the electric motor (E-motor) in the power path reduces the usual high output speed of the electric motor and increases the torque introduced into the differential.

[0008] When a vehicle corners, the outside wheel rotates faster than the inside wheel, because the outside wheel has to travel a longer distance than the inside wheel. However, if both wheels are rigidly connected, they necessarily rotate at the same speed. A differential gear, also called a "compensating gear," ensures that both wheels can rotate at different speeds and are not directly connected to each other.

[0009] However, on uneven ground and on unstable roads (terrain, mud, meadows, snow, ice, etc.), this dynamic arrangement (=decoupled arrangement) of gears leads to disadvantages, as the wheels would simply spin and come to a standstill due to the differential gear. To avoid such situations, the differential gears can be equipped with a locking option (commonly referred to as a "limited-slip differential" or "differential lock"). This locking effect engages or disengages the balancing function of the differential described above, meaning that the wheels can be rigidly coupled so that, when coupled, they always rotate at the same speed.

[0010] Differential locks are primarily used in off-road applications to ensure constant and even power transmission to all wheels, thus providing good traction off-road. Common locking differentials are bevel gear differentials, which are usually locked by means of dog clutches or multi-disk clutches. Mechanically, these dog clutches or multi-disk clutches are usually designed to engage only when the vehicle is stationary or under slight rolling motion.

[0011] DE 195 24 682 A1 shows a differential gear with an integrated group transmission.

[0012] It is an object of the present invention to provide an advantageous embodiment of a limited-slip differential.

[0013] This object is achieved according to the invention by a spur gear differential consisting of a planetary gear with sun gear, planetary set, planet carrier and ring gear with the features of patent claim 1.

[0014] Preferred embodiments of the spur gear differential according to the invention are the subject of dependent claims 2 and 3.

[0015] The state of the art described above prefers spur gear differentials as transmissions for electric axles. These can be easily integrated with coaxial transmissions with a coaxial output, but a locking option is not known for these. Since efficiency is often a top priority in electric vehicles, a locking option is not provided in the known solutions. However, the use of a limited-slip differential would be advisable, especially in SUV applications, for the reasons mentioned above.

[0016] It is therefore a further object of the present invention to advantageously integrate a limited-slip differential into a transmission arrangement for an electric axle of a motor vehicle.

[0017] This further object is achieved according to the invention by a transmission device for an electric drive axle of a vehicle with input stage and differential stage having the features of patent claim 4.

[0018] Preferred embodiments of the transmission device for an electric drive axle of a vehicle with input stage and differential stage are the subject of dependent patent claims 5 to 9.

[0019] A further object of the present invention is to provide the possibility of using a locked differential for an electric drive axle to be used in an off-road vehicle, thereby improving the off-road characteristics.

[0020] This object is achieved by the preferred use of the transmission device according to the invention for an electric drive axle of a vehicle with input stage and differential stage according to patent claim 10.

[0021] The solution according to the invention makes it possible to improve the off-road capabilities of conventional transmissions with only minimal modifications, thus providing a possible retrofit or equipment line for vehicles for off-road applications. Only the minimum necessary components are added, thus adding another important function to the transmission or vehicle.

[0022] The present invention will be explained in more detail below using preferred embodiments in conjunction with the accompanying figures. These show: Fig. 1: a half-section through an embodiment of a transmission device for an electric drive axle of a vehicle with input stage and differential stage, with a device for locking the spur gear differential of the differential stage in a 1st position (“open position”); Fig. 2: a half-section through the embodiment of a transmission device according to Fig. 1 with the device for locking the spur gear differential in a 2nd position (“closed position”); Fig. 3A: a perspective view of a ring gear (hereinafter also referred to as “sliding ring gear”) as part of the device for locking the differential (looking towards a first of the two end faces); Fig. 3B: another perspective view of the sliding ring gear according to Fig. 3A (looking towards the other of the two front sides); Fig. 4A: a perspective view of a cover plate as part of a planet carrier of the planetary gear of the spur gear differential (viewed towards one of the two side surfaces); Fig. 4B: another perspective view of the cover plate according to Fig. 4A (looking towards the other of the two side surfaces); Fig. 5A: a perspective view of a part of the transmission device according to the Fig. 1 and Fig. 2 with focus on the section with the device for locking the differential in the “closed position” (in the direction of view from the inside of the transmission device); Fig. 5B: a further perspective view of the part of the transmission device according to Fig. 5A (viewed from outside the transmission device); Fig. 6A: a perspective view of a common planet carrier of the input stage and differential stage of the transmission device according to the Fig. 1 and Fig. 2 (viewed from the differential stage); Fig. 6B: a perspective view of a portion of the common planet carrier according to Fig. 6A with focus on one planet of each of the two planetary sets of the spur gear differential of the differential stage, from which the toothing to one of the two sun gears can be seen; Fig. 6C: a perspective view of the part of the common planet carrier according to Fig. 6A with focus on one planet each of the two planetary sets of the spur gear differential of the differential stage, from which the gearing to the Fig. 6B further sun gear can be seen; Fig. 7A: a perspective view of a portion of the device for locking the differential stage in the open position, wherein the sliding ring gear is mounted on one of the two sides of the planets, meshing with the planets of one of the two planetary sets of the differential stage and next to the common contact plane of the planets; Fig. 7B: a perspective view of a portion of the device for locking the differential stage in the open position, wherein the sliding ring gear is on the side opposite to Fig. 7A other of the two sides of the planets, meshing with the planets of one of the two planetary sets of the spur gear differential of the differential stage and mounted next to the common contact plane of the planets; Fig. 8A: a perspective view of an embodiment of the cover plate with a specific design of a toothing along the outer circumference; Fig. 8B: a perspective view of another embodiment of the cover plate with another design of the toothing along the outer circumference; Fig. 9A: a perspective view of a part of the (internal) toothing of the sliding ring gear as part of the device for locking the differential stage according to a further embodiment of the toothing; and Fig. 9B: a perspective view of a part of the (external) toothing of the sliding ring gear as part of the device for locking the differential stage according to a further embodiment of the toothing;

[0023] In Fig. 1 shows a transmission arrangement for an electric drive axle of a motor vehicle with input stage and differential stage.

[0024] The input stage comprises a partially illustrated input-side planetary gear set with a sun gear, planetary gear set with planets, planet carrier, and ring gear. A torque generated by an electric motor is preferably transmitted via a hollow shaft (not shown) to the sun gear (not shown) of the planetary gear set. From the sun gear, the torque is transmitted to a first set of planets (not shown) of the input-stage planetary gear set, with each planet of this first set of planets being firmly connected to a planet of a second set of planets. Fig. 1 shows a planet 1 of the second set of planets of the planetary gear. Each planet of the first set and one planet of the second set of planets are preferably mounted together as a single planetary gear on a common (bearing) journal on a planetary carrier 2. Preferably, four such single planetary gears are provided, although the use of three or five single planetary gears would also be possible.

[0025] The input stage therefore includes the drive sun, the first and second planetary gear sets, the planet carrier 2 and the (in Fig. 1 not shown) ring gear, wherein the drive sun meshes with planets of the first planetary set of the planetary gear of the input stage, and wherein the individual planets of the first planetary set of the planetary gear of the input stage are each connected in a rotationally fixed manner to one of the planets of the second planetary set 1 of the planetary gear of the input stage.

[0026] The differential stage comprises a spur gear differential (only partially shown) with a planetary gear with two sun gears, two planetary sets, each with at least three planets 4, 5, a planet carrier, and a ring gear 10. Bearing pins 3, on which the planets 4, 5 of the planetary gear of the differential are rotatably mounted, are supported and firmly connected on the torque input side to the planet carrier 2 of the planetary gear of the input stage. To clarify the function of the ring gear of the spur gear differential according to the invention, which will be explained in more detail below, this will be referred to below as the "sliding ring gear" 10.

[0027] To clarify the term, it should be noted that a spur gear differential is defined by the use of spur-toothed gears such as sun gears, planet gears, etc., in contrast to a bevel gear differential. The spur gear (or cylindrical gear) is a cylindrical disk with teeth along its circumference. "Spur" refers to an external shape. If the mating gear is also a spur gear or a spur-toothed shaft, the axes of the two gears are parallel, resulting in a spur gear transmission.

[0028] The spur gear differential of the differential stage comprises a first and a second planetary gear set, wherein planets 4 of the first planetary gear set mesh with a first sun gear 7 and planets 5 of the second planetary gear set mesh with a second sun gear 6, and wherein the two planetary gear sets 4, 5 of the spur gear differential are arranged in pairs next to one another and mesh with one another.

[0029] The two planetary gears of the input stage and the differential stage are coupled to each other via a common planet carrier (which has a cage-like or pot-shaped structure).

[0030] The common planetary carrier also includes a cover plate 8, to which the pins 3 are also connected in a rotationally fixed manner on the output side. Components 2, 3, and 8 accordingly form the essential structural elements of the common planetary carrier, in which the planets 1 of the 2nd planetary set of the planetary gear of the input stage, the planets 3 of the 1st planetary set of the planetary gear of the differential, and the planets 4 of the 2nd planetary set of the planetary gear of the differential are jointly rotatably mounted. The cover plate 8 has a toothing 9 along its outer circumference, which is formed entirely or partially along the outer surface of the cover plate 8.

[0031] Radially outside the planets 4, 5 of the two planetary gear sets of the planetary gear of the spur gear differential of the differential stage, the sliding ring gear 10 is arranged, which has a toothing formed on an inner surface, which in the Fig. In the embodiment shown in Figure 1, only one of the two planetary gear sets of the planetary gear of the differential stage engages with the toothing of the planets 4 or 5.

[0032] In Fig. 1, the sliding ring gear 10 is shown in a first position, in which there is no simultaneous engagement of the gearing of the ring gear with the gearing of the planetary gears 4 and the gearing 9 of the cover plate 8. Accordingly, the device for locking the differential stage is in its "open position."

[0033] The sliding ring gear 10 is arranged to be axially displaceable, so that the sliding ring gear 10 can be displaced along the teeth of the gearing of the planets 4 of the planetary gear of the spur gear differential that mesh with the sliding ring gear. Through this displacement, the internal toothing of the sliding ring gear 10 can be brought into engagement with the external toothing 9 of the cover plate 8 of the common planet carrier. This position is in Fig. 2 and represents the locked position of the differential stage ("closed position"). In this position, the movements of planets 4 and 5 and planet carrier 8 are rigidly coupled to each other, because the planets 4, 5 of both planetary sets of the planetary gear of the differential stage are arranged in meshing engagement, and the planets 4, 5 of one planetary set, which mesh with the sliding ring gear in the closed position, are simultaneously coupled to the cover plate.

[0034] According to an embodiment not shown in detail, the locking is achieved by the sliding ring gear 10 being in direct meshing engagement with both the gearing of planetary gear 4 of one planetary gear set and the gearing of planetary gear 5 of the other of the two planetary gear sets, as well as with the gearing of planetary carrier 8. With this type of differential lock design involving engagement with three gearings, there are structural differences in the design between symmetrical and asymmetrical differential gears. The two sun gears of the asymmetrical spur gear differential have different outer diameters without profile shift.If the sliding ring gear 10 of the asymmetrical spur gear differential is moved into the closed position in this embodiment, it must be ensured that the ring gear can also reach the toothing of the planets 4, 5 of both planetary sets. This can be achieved, for example, by arranging the planets 4, 5 of one of the planetary sets on a lower pitch circle than the planets 4, 5 of the other planetary set. The two sun gears of the symmetrical spur gear differential have the same outer diameters with profile shift. Here, the planets 4, 5 of the two planetary sets are designed with different toothing geometries in order to align with the toothing geometry of the sliding ring gear 10.

[0035] The device for locking the differential stage further comprises an actuating element 11, which is provided for the axial displacement of the sliding ring gear 10. The type of actuation provided here, e.g., electrical, hydraulic, or mechanical, is freely selectable.

[0036] In the Fig. 3A and Fig. 3B shows an embodiment of the sliding ring gear 10, from which the toothing 12 formed on an inner circumferential surface of the sliding ring gear 10 can be seen. Fig. 3B shows an engagement region 13 to which the actuating element 11 is coupled, so that the sliding ring gear 10 and the actuating element 11 form an axially movable unit. This axially movable unit is actuated via an actuator, which is not shown in detail. Electrical, hydraulic, mechanical, or a combination of these elements can be used as actuators. Sliding ring gear 10, actuating element 11, and actuator form the device for locking the differential stage.

[0037] From the perspective view of the Fig. 4A and Fig. Figure 4B shows an exemplary embodiment of the design of the cover plate 8, which is part of the common planetary carrier 2. One can see the toothing 9 formed along the outer circumference, a bearing neck 14 formed along an inner circumference, and pin holes 15, 16 for the planetary pins of the planets 4, 5 of the planetary sets of the planetary gear of the differential stage, as well as the pin holes 17 for the planetary pins of the assembled planets 1 of the planetary set of the planetary gear of the input stage.

[0038] The Fig. 5A and Fig. 5B contains a perspective view of a section of the gearing area of ​​the device for locking the differential stage, comprising the sliding ring gear 10 with the gearing area 12, the actuating element 11, and the cover plate 8 with the gearing area 9. It is particularly evident that the gearing 12 of the sliding ring gear 10 engages with the gearing 9 of the cover plate 8, and that the gearing 12 of the sliding ring gear 10 simultaneously engages with the gearing of the planets 4 of one of the planetary gear sets of the planetary gear of the differential stage. Consequently, the device is in the "closed position."

[0039] It should be noted that the toothing 12 of the ring gear 10 is not in engagement with a toothing of the planets 5 of the other planetary gear set of the planetary gear of the differential, as can be seen in particular from Fig. 5B can be seen.

[0040] In the Fig. 6A, Fig. 6B and Fig. 6C shows the unit consisting of common planet carrier 2, planet 1 of the second planetary set of the planetary gear of the input stage, planet 4 of the 1st planetary set of the planetary gear of the differential stage and planet 5 of the 2nd planetary set of the planetary gear of the differential stage. Fig. 6B shows a section from which the engagement between the planet 4 of the 1st planetary gear set of the planetary gear of the differential stage with the sun gear 7 of the output can be seen. Fig. 6C, on the other hand, shows a section from which the engagement between the planets 5 of the 2nd planetary gear set of the planetary gear of the differential stage and the sun gear 6 of the output can be seen.

[0041] The Fig. 7A and Fig. 7B shows an embodiment with an alternative arrangement of the sliding ring gear 10 on opposite sides of the planets 4, 5 of the planetary gear sets of the differential stage. In the two embodiments shown here as a symmetrical differential, the ring gear 10 can be mounted on either side of the planets 4, 5, meshing with and adjacent to the common contact plane of the planets 4, 5.

[0042] The Fig. 8A and Fig. 8B show an embodiment with an alternative design of the toothing 9 along the outer circumference of the cover plate 8, which according to Fig. 8A along the entire circumferential surface and according to Fig. 8B is formed only in partial areas. Depending on requirements and load, the toothing 9 can be varied. For example, the profile height of the toothing can be varied. Alternatively, the number of teeth and / or the spacing between the teeth can also be varied. Segmental omission of teeth can also be provided.

[0043] In Fig. 9A shows an internal toothing 12 of the sliding ring gear 10 with a chamfer 20. In Fig. Figure 9B shows an external toothing 9 of the cover plate 8 with a chamfer 21. Accordingly, chamfers can be applied to the front edge of the toothings on the sliding ring gear 10 and also on the cover plate 8 with the counter toothing. The angle and size of the chamfer can be used to vary the engagement speed during the engagement process, allowing for this, and the comfort level during this process.

[0044] The above description shows an embodiment of a planetary gear with an integrated spur gear differential, which is expanded by an additional component (namely, the sliding ring gear 10) and a modified cover plate 8. The modified cover plate 8 can have a spline produced by stamping on the outer diameter, which corresponds either entirely or partially to the (internal) toothing of the sliding ring gear 10. The sliding ring gear can be displaced using a suitable actuation, for example a plastic piston with a hydraulic cylinder. Via this actuation, the sliding ring gear 10 then engages with its teeth 12 in the teeth 9 located on the outer diameter of the plate 8, thus locking the planets 4, 5 relative to the carrier cage 2. This prevents any differential speed of the sun gears 6, 7 from being achieved. The differential is locked.Because the sliding ring gear 10 rotates together with the cage 2 and the planetary gears 4, 5 when decoupled, it has little to no differential speed compared to the cage 2 and thus to the plate 8. This differential speed is also smaller by the factor of the gear ratio of the number of teeth of the planetary gears 4, 5 to the sliding ring gear 10. Thus, the differential can be easily locked while driving.

Claims

[1] Spur gear differential consisting of a planetary gear with a sun gear (6, 7), a planetary gear set with several planets (4, 5), a planet carrier (2, 3, 8) and a ring gear (10), wherein the ring gear (10) is designed to be movable between at least two switching positions, wherein the ring gear (10) in a first switching position is exclusively in engagement with the planet carrier (2, 3, 8) and in a second switching position, in addition to the engagement with the planet carrier (2, 3, 8), is in engagement with the planets (4, 5) of the planetary gear set, so that the spur gear differential is locked in the second switching position, or wherein the ring gear (10) in a first switching position is exclusively in engagement with the planets (4, 5) of the planetary gear set, characterized bythat the ring gear (10) in a second switching position is in engagement with the planet carrier (2, 3, 8) in addition to the engagement with the planets (4, 5) of the planetary gear set, so that the spur gear differential is locked in the second switching position. [2] Spur gear differential according to claim 1, characterized by an actuator (11) connected to the ring gear (10) to move the ring gear (10) between the at least two switching positions. [3] Spur gear differential according to claim 1 or 2, characterized by that chamfers are formed on a toothing (12) of the ring gear (10) and / or on the engagement region (9) of the planet carrier (2, 3, 8) in order to improve the engagement process between the ring gear (10) and the planet carrier (2, 3, 8). [4] A transmission device for an electric drive axle of a vehicle, comprising an input stage and a differential stage, wherein the differential stage is designed as a spur gear differential having a first planetary gear set with first planets (4) and a second planetary gear set with second planets (5), wherein the spur gear differential has a planet carrier (2, 3, 8) which has an engagement region (9) in an outer region, and wherein the spur gear differential has a ring gear (10) which is designed to be movable between two switching positions, wherein the ring gear (10) in a first switching position is exclusively in engagement with planets (4, 5) of at least one of the two planetary gear sets, and in a second switching position, in addition to the engagement with the planets (4, 5) of the at least one planetary gear set, is in engagement with the engagement region (9) of the planet carrier (2, 3, 8),so that the spur gear differential is locked in the second switching position, or wherein the ring gear (10) in a first switching position is exclusively in engagement with the engagement region (9) of the planet carrier (2, 3, 8), , characterized by that the ring gear (10) in a second switching position, in addition to this engagement with the planet carrier (2, 3, 8), is in engagement with planets (4, 5) of at least one of the two planetary sets, so that the spur gear differential is locked in the second switching position. [5] Transmission device for an electric drive axle of a vehicle with input stage and differential stage according to claim 4, characterized by that in the second switching position the ring gear (10) is in engagement with the planets (4, 5) of both planetary sets and with the engagement area (9) of the planet carrier (2, 3, 8). [6] Transmission device for an electric drive axle of a vehicle with input stage and differential stage according to claim 4 or 5, characterized by that the first and second planets (4, 5) of the first and second planetary gear sets of the spur gear differential mesh with each other in pairs. [7] Transmission device for an electric drive axle of a vehicle with input stage and differential stage according to one of claims 4 to 6, characterized by that the planet carrier (2, 3, 8) of the spur gear differential has, as engagement region (9), in its outer region at least in a partial region of the circumference, a toothing which corresponds either entirely to or partially to the toothing (12) of the ring gear (10). [8] Transmission device for an electric drive axle of a vehicle with input stage and differential stage according to one of claims 4 to 7, characterized bythat the input stage is designed as a planetary gear, wherein the planetary gear of the input stage and the spur gear differential of the differential stage are coupled to one another via a common planet carrier (2, 3, 8), wherein this common planet carrier (2, 3, 8) supports the planets (1, 4, 5) of the planetary sets of the planetary gears of the input stage and differential stage. [9] Transmission device for an electric drive axle of a vehicle with input stage and differential stage according to claim 8, characterized by that the input stage comprises a drive sun, first and second planetary gear sets, the common planetary carrier and a ring gear, wherein the drive sun meshes with a first planetary gear set of the planetary gear of the input stage, and wherein the first planetary gear set of the planetary gear of the input stage is connected in a rotationally fixed manner to a second planetary gear set of the planetary gear of the input stage. [10] Electric drive axle of a vehicle with a transmission device according to one of claims 4 to 9.

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