Electric drive system and method for its operation

Abstract

Electric drive system for a motor vehicle (1), comprising an electrically driven front axle (2) and an electrically driven rear axle (3), wherein the electrically driven rear axle (3) comprises a first electric machine (5) which has a first rotor (6) configured to drive a first rear wheel (7) and / or a second rear wheel (10) of the electrically driven rear axle (3), wherein the electrically driven front axle (2) has a second electric machine (17) which has a second rotor (18) designed to drive front wheels (20, 21) of the electrically driven front axle (2) via a second axle transmission (67, 67a), wherein the second rotor (18) is permanently coupled to a first front wheel (20) and to a second front wheel (21) via the second axle drive (67, 67a) in a torque-transmitting manner, wherein a first switchable freewheel clutch (13) is designed to couple the first rotor (6) to the first rear wheel (7) and / or to the second rear wheel (10) in a torque-transmitting manner, wherein the first switchable freewheel clutch (13) has a first actuator (13a), wherein, by means of the first switchable freewheel clutch (13), in a forward traction operation of the first electric machine (5), the torque-transmitting coupling of the first rotor (6) with the first rear wheel (7) and / or the second rear wheel (10) can be established without an action of the first actuator (13a), and in a forward push-pull operation or a reverse traction operation of the first electric machine (5), the torque-transmitting coupling of the first rotor (6) with the first rear wheel (7) and / or the second rear wheel (10) can be established with the action of the first actuator (13a), wherein the electrically driven rear axle (3) has a third electric machine (8) with a third rotor (9) designed to drive the second rear wheel (10) and / or the first rear wheel (7) of the electrically driven rear axle (3), wherein a second switchable freewheel clutch (14) is provided, which has a second actuator (14a) and which is designed to couple the third rotor (9) to the second rear wheel (10) in a torque-transmitting manner, characterized in that the first electric machine (5) and the third electric machine (8) are designed as axial flux machines and are arranged in a common housing (31) with a common oil chamber, wherein the first planetary gear stage (11), the second planetary gear stage (12), the first switchable freewheel clutch (13) and the second switchable freewheel clutch (14) are arranged in the common housing (31) and in the common oil chamber.

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