Electric drive system for a motor vehicle

Abstract

An electric drive system (1) for a motor vehicle, comprising a parking lock device (2) with a first parking lock gear (PR1) which is connected in a rotationally fixed manner to a first transmission shaft (GW1), with a housing, with a first pawl element (KE1) which is designed to connect the first parking lock gear (PR1) in a rotationally fixed manner to the housing, with a first ramp mechanism (RM1) which has a first primary element (PE1) and a first secondary gear (SR1) arranged coaxially to the first transmission shaft (GW1), wherein the first primary element (PE1) and the first secondary gear (SR1) are coupled to one another by means of a first spring element (FE1) acting in a tangential direction, with an adjusting pinion (3) which is coupled to the first primary element (PE1), and with an adjusting motor (4) coupled to the adjusting pinion (3), wherein the first ramp mechanism (RM1) is designed toto convert a tangential force acting on the first primary element (PE1) into an axial force acting on the first pawl element (KE1), with a second ramp mechanism (RM2) with a second primary element (PE2) and a second secondary gear (SR2), which is coupled to the second primary element (PE2) by means of a second spring element (FE2) acting in a tangential direction, wherein the second primary element (PE2) is coupled to the adjusting pinion (3), wherein a second transmission shaft (GW2) is provided, which is connected in a rotationally fixed manner to a second parking lock gear (PR2), wherein a second pawl element (KE2) is provided, which is designed to connect the second parking lock gear (PR2) in a rotationally fixed manner to the housing, wherein the second ramp mechanism (RM2) is designed to convert a tangential force acting on the second primary element (PE2) into a force acting on the second pawl element (KE2) to convert axial force,further comprising a first electric machine (EM1) having a first rotor (R1) that is or can be coupled to the first transmission shaft (GW1), a second electric machine (EM2) having a second rotor (R2) that is or can be coupled to the second transmission shaft (GW2), wherein the first transmission shaft (GW1) is arranged coaxially to the second transmission shaft (GW2), characterized in that the first transmission shaft (GW1) and the second transmission shaft (GW2) are mounted against each other by means of a rolling bearing (5), wherein the rolling bearing (5) is arranged axially overlapping the first secondary gear (SR1) and / or the second secondary gear (SR2).

Description

The invention relates to an electric drive system for a motor vehicle according to the features of the preamble of claim 1.As described in DE 10 2022 113 868 A1, a parking lock with a claw clutch and a ball ramp is known from the prior art. The parking lock is provided with a first portion having a first set of teeth and a second portion having a second set of teeth configured to engage the first set of teeth. The first portion is coupled to a rotating part of the vehicle. The second portion is coupled to a stationary part of the vehicle. The second portion includes actuators for initiating the sliding of the second set of teeth, the actuators including a source of motion, elastic elements and one or more ramps.From KR 10 2022 0 040 218 A, WO 2017 / 051 719 A1 and DE 198 31 069 A1, a dual use of parking locks is known in each case.The object of the invention is to specify an electric drive system for a motor vehicle which is improved in comparison with the prior art.The object is achieved according to the invention by an electric drive system for a motor vehicle having the features of claim 1.Advantageous embodiments of the invention are the subject matter of the dependent claims.In the context of the present application, the term "rotationally fixed" is used as follows: Two, in particular rotatably mounted, elements are connected to one another in a rotationally fixed manner if they are arranged coaxially with respect to one another, in particular with respect to their axis of rotation or with respect to a rotational axis of symmetry, and if they are connected to one another in such a way that they rotate at the same angular speed.In the context of the present application, the term "radially overlapping" is used as follows: Two, in particular substantially rotationally symmetrical, elements are arranged, in particular with respect to a common axis, in a radially overlapping manner if they are arranged at least partially or completely in a region of the same radial coordinates, in particular also of the same angular coordinates. Two elements are arranged "axially overlapping" if they are arranged at least partially or completely in a region of the same axial coordinates.In the context of the present application, the terms "axial" "radial" and "axial direction" refer to a main axis of rotation, in particular to the axis of rotation of parking lock gears, transmission shafts and / or secondary gears, which are all arranged coaxially with respect to one another.An electric drive system for a motor vehicle is provided, having a parking lock device having a first parking lock gear which is connected to a first transmission shaft in a rotationally fixed manner, having a housing, having a first ratchet element which is designed to connect the first parking lock gear to the housing in a rotationally fixed manner, having a first ramp mechanism which has a first primary element and a first secondary wheel which is arranged coaxially with respect to the first transmission shaft, wherein the first primary element and the first secondary wheel are coupled to one another by means of a first spring element which acts in the tangential direction, having an adjusting pinion which is coupled to the first primary element, and having an adjusting motor which is coupled to the adjusting pinion, wherein the first ramp mechanism is designed to convert a tangential force acting on the first primary element into an axial force acting on the first ratchet element.The parking lock device comprises a second ramp mechanism having a second primary element and a second secondary wheel, which is coupled to the second primary element by means of a second spring element acting in the tangential direction, wherein the second primary element is coupled to the adjusting pinion, wherein a second transmission shaft is provided, which is connected to a second parking lock wheel in a rotationally fixed manner, wherein a second ratchet element is provided, which is designed to connect the second parking lock wheel to the housing in a rotationally fixed manner, wherein the second ramp mechanism is designed to convert a tangential force acting on the second primary element into an axial force acting on the second ratchet element. The second secondary wheel is arranged in particular coaxially with respect to the second transmission shaft.The parking lock device thus has a first parking lock and a second parking lock, wherein the first parking lock comprises the first parking lock gear, the first ratchet element and the first ramp mechanism, and wherein the second parking lock comprises the second parking lock gear, the second ratchet element and the second ramp mechanism.The electric drive system includes the parking lock device. The electric drive system further includes a first electric machine having a first rotor coupled or couplable to the first transmission shaft. The electric drive system also has a second electric machine, which has a second rotor, which is coupled or can be coupled to the second transmission shaft, wherein the first transmission shaft is arranged coaxially with respect to the second transmission shaft.The parking lock device comprises in particular two claw mechanisms, in particular in the form of claw clutches, because the respective pawl element acts in particular like a claw which, when the parking lock is closed, engages in the respective parking lock wheel, in particular in a positively locking manner, and thereby connects the respective parking lock wheel to the housing in a rotationally fixed manner. The respective parking lock gear is then connected to the housing in a rotationally fixed manner, in particular via the respective pawl element.The electric drive system thus has two parking locks, i.e. two claw clutches. This makes it possible to lock two parking lock wheels simultaneously and thus simultaneously two transmission shafts, i.e. to couple them to the housing in a rotationally fixed manner. The parking lock device is therefore particularly advantageous in electric drive systems having two electric machines, in particular on the same axle of the motor vehicle. In this case, it is provided in particular that the electric machines drive different wheels of the motor vehicle, i.e. in particular each of the electric machines drives only one wheel of the axle. With solutions known from the prior art, a parking lock function for the entire axle is not possible or is only possible with difficulty in such electric drive systems. This problem is solved by the solution according to the invention with a compact and simple parking lock device for simultaneously locking both transmission shafts.It is particularly advantageous here that for this purpose, i.e. for the simultaneous locking of both transmission shafts, only a single compact adjusting motor is required, by means of which both parking locks are simultaneously activated or deactivated.According to the invention, the first transmission shaft and the second transmission shaft are mounted against one another by means of a rolling bearing, wherein the rolling bearing is arranged axially overlapping with respect to the first secondary wheel and / or with respect to the second secondary wheel.In one possible embodiment, two adjustment pinions can also be provided, wherein one of the adjustment pinions is then assigned to each primary element, is coupled to the respective adjustment pinion. In this embodiment, however, it is then provided that both adjusting pinions are coupled to the same adjusting motor. That is, in this embodiment as well, only a single adjusting motor is required.In one possible embodiment, the first pawl element is connected to the housing in a rotationally fixed manner and is arranged so as to be axially displaceable with respect to the housing. In one possible embodiment, the second pawl element is connected to the housing in a rotationally fixed manner and is arranged so as to be axially displaceable with respect to the housing.In one possible embodiment, the first primary element is designed as a first primary wheel arranged coaxially with the first parking lock gear. In one possible embodiment, the second primary element is designed as a second primary wheel arranged coaxially with the second parking lock gear. Alternatively, the first primary element and / or the second primary element can / can be, for example, a wheel cutout which is guided on the respective secondary wheel.In one possible embodiment, the first primary element, which is designed as a first primary wheel, is arranged coaxially with respect to the first secondary wheel. In one possible embodiment, the second primary element, which is designed as a second primary wheel, is arranged coaxially with respect to the second secondary wheel. The respective primary wheel is arranged here in particular circumferentially on the respective secondary wheel.In one possible embodiment, the first secondary wheel is arranged axially next to the first ratchet element and has a first ramp on a side facing the first ratchet element in the axial direction, wherein the first ramp and the first ratchet element have an equal radial distance from a main axis of rotation, and wherein the first ramp is positioned on the first secondary wheel in such a way that, when the first secondary wheel is rotated, said first ramp increasingly slides onto the first ramp, said first ratchet element being caused by the tangential force acting on the first primary element and transmitted via the first spring element to the first secondary wheel. In one possible embodiment, the second secondary wheel is arranged axially next to the second ratchet element and has a second ramp on a side facing the second ratchet element in the axial direction, wherein the second ramp and the second ratchet element have an identical radial distance from the main axis of rotation, and wherein the second ramp is positioned on the second secondary wheel in such a way that, when the second secondary wheel is rotated, said second ratchet element increasingly slides onto the second ramp, said second ratchet element being caused by the tangential force acting on the second primary element and being transmitted via the second spring element to the second secondary wheel.In one possible embodiment, the first parking lock gear has a first recess for receiving the first pawl element in order to connect the first parking lock gear to the housing in a rotationally fixed manner. In one possible embodiment, the second parking lock gear has a second recess for receiving the second ratchet element in order to connect the second parking lock gear to the housing in a rotationally fixed manner.In one possible embodiment, the first rotor is arranged coaxially, radially at least partially overlapping and axially offset with respect to the second rotor, wherein, as seen in the direction of the main axis of rotation, the first rotor, the first ramp mechanism, the second ramp mechanism and the second rotor are arranged one after the other in the stated order.In one possible embodiment, the first rotor, the second rotor, the first transmission shaft and the second transmission shaft are all arranged coaxially with respect to one another.In one possible embodiment, the first parking lock gear is disposed axially between the first rotor and the first ramp mechanism. In one possible embodiment, the second parking lock gear is disposed axially between the second rotor and the second ramp mechanism.In the described solution, it is provided in particular that, for closing the two parking locks, the adjusting motor rotates the adjusting pinion in one direction, as a result of which the primary elements are each rotated in a closing direction by the tangential force effect of the adjusting pinion. A force transmission then takes place via the respective spring element from the respective primary element to the respective secondary wheel, as a result of which the latter also strives to rotate in the closing direction. If the recess in the respective parking lock gear is at the level of the respective ratchet element, i.e. covers the ratchet element, so that the ratchet element can move into the recess, this rotation of the respective secondary wheel will take place in the closing direction. As a result, the respective pawl element slides onto the ramp of the respective secondary wheel and is thereby pushed into the recess of the respective parking lock wheel. As a result, a positively locking connection in a rotationally fixed manner is formed from the respective parking lock wheel via the respective pawl element to the housing. The respective parking lock is thus closed.If the recess in the respective parking lock gear is not at the level of the respective pawl element, the respective spring element is initially tensioned by the rotation of the respective primary element in the closing direction. If the respective parking lock gear then continues to rotate, since the respective parking lock is not yet closed, the recess in the respective parking lock gear reaches the level of the respective pawl element, i.e. it covers the pawl element, so that the pawl element can move into the recess. The respective secondary wheel is then rotated in the closing direction by the tensioned spring element. As a result, the respective pawl element slides onto the ramp of the respective secondary wheel and is thereby pushed into the recess of the respective parking lock wheel. As a result, the positively locking, rotationally fixed connection is formed from the respective parking lock wheel via the respective pawl element to the housing. The respective parking lock is thus closed.To open the two parking locks, the adjusting motor rotates the adjusting pinion in the other direction, as a result of which the primary elements are each rotated in an opening direction by the tangential force effect of the adjusting pinion. In this case, it is provided in particular that a formation of the respective primary element abuts against a stop of the respective secondary wheel and thus also rotates the latter in the opening direction. As a result, the respective ramp is moved away from the respective pawl element, i.e. the respective pawl element slides down from the respective ramp. The respective pawl element is then moved out of the recess of the respective parking lock wheel again, in particular under spring load, in particular by means of a respective restoring spring which has been tensioned by the movement of the respective pawl element into the recess of the respective parking lock wheel. The respective parking lock is thereby opened.Exemplary embodiments of the invention are explained in more detail below with reference to drawings.The following are shown: FIG. 1 is a schematic top plan view of an electric drive system for a motor vehicle, only half of the drive system up to a main axis of rotation being shown, and some components being shown in section; and FIG. 2 is a schematic side view of a secondary wheel and primary element.Corresponding parts are provided with the same reference numerals in all figures.FIG. 1 shows an electric drive system 1 for a motor vehicle in a plan view from above, wherein only one half of the electric drive system 1 up to a main axis of rotation A is shown, and wherein some components are shown in section.The electric drive system 1 has a first electric machine EM 1, which has a first stator S 1 and a first rotor R 1. The first rotor R 1 is coupled or couplable to a first transmission shaft GW 1.The electric drive system 1 furthermore has a second electric machine EM 2, which has a second stator S 2 and a second rotor R 2. The second rotor R 2 is coupled or couplable to a second transmission shaft GW 2. The transmission shafts GW 1, GW 2 are arranged coaxially with each other.The electric drive system 1 further comprises a parking lock device 2.The parking lock device 2 comprises a first parking lock gear PR 1, which is connected to the first transmission shaft GW 1 in a rotationally fixed manner, a housing, a first pawl element KE 1, which is designed to connect the first parking lock gear PR 1 to the housing in a rotationally fixed manner, a first ramp mechanism RM 1, which has a first primary element PE 1 and a first secondary wheel SR 1 arranged coaxially to the first transmission shaft GW 1, wherein the first primary element PE 1 and the first secondary wheel SR 1 are coupled to one another by means of a first spring element FE 1 acting in the tangential direction, an adjusting pinion 3, which is coupled to the first primary element PE 1, and an adjusting motor 4 coupled to the adjusting pinion 3.The parking lock device 2 further comprises a second ramp mechanism RM 2 with a second primary element PE 2 and a second secondary wheel SR 2, which is coupled to the second primary element PE 2 by means of a second spring element FE 2 acting in the tangential direction, wherein the second primary element PE 2 is coupled to the adjusting pinion 3. The parking lock device 2 also comprises a second parking lock gear PR 2, which is connected to the second transmission shaft GW 2 in a rotationally fixed manner, and a second pawl element KE 2, which is designed to connect the second parking lock gear PR 2 to the housing in a rotationally fixed manner. The second ramp mechanism RM 2 is configured to convert a tangential force acting on the second primary member PE 2 into an axial force acting on the second pawl member KE 2.The transmission shafts GW 1 and GW 2 arranged coaxially with respect to one another are mounted with respect to one another by means of a rolling bearing 5. The rolling bearing 5 is advantageously arranged axially overlapping with the first secondary wheel SR 1 and / or with the second secondary wheel SR 2.The parking lock device 2 thus comprises two claw clutches, because the respective pawl element KE 1, KE 2 acts in particular like a claw which, when the parking lock is closed, engages in the respective parking lock wheel PR 1, PR 2, in particular in a positively locking manner, and thereby connects the respective parking lock wheel PR 1, PR 2 to the housing in a rotationally fixed manner. The respective parking lock gear PR 1, PR 2 is then connected to the housing in a rotationally fixed manner, in particular via the respective pawl element KE 1, KE 2.The described solution thus has two parking locks, i.e. two claw clutches. This makes it possible to lock the two parking lock wheels PR 1, PR 2 and thus the two transmission shafts GW 1, GW 2 simultaneously with a single parking lock device 2, in particular with a single adjusting motor 4, i.e. to couple them to the housing in a rotationally fixed manner. This is particularly advantageous in the electric drive system 1 illustrated here having two electric machines EM 1, EM 2, which each drive one of the transmission shafts GW 1, GW 2, so that both transmission shafts GW 1, GW 2 have to be locked in order to enable a safe parking lock function.In the embodiment shown, the pawl elements KE 1, KE 2 are each connected to the housing in a rotationally fixed manner and are arranged so as to be axially displaceable with respect to the housing. For reasons of clarity, FIG. 1 shows only one respective pawl frame KR 1, KR 2, on which the respective pawl element KE 1, KE 2 is arranged in a rotationally fixed and axially displaceable manner. These latch frames KR 1, KR 2 are a component of the housing and are thus fixed to the housing.In the embodiment shown, the first rotor R 1 is arranged coaxially, radially at least partially overlapping and axially offset with respect to the second rotor R 2, wherein, as seen in the direction of the main rotational axis A, the first rotor R 1, the first ramp mechanism RM 1, the second ramp mechanism RM 2 and the second rotor R 2 are arranged one after the other in the order mentioned.In the illustrated embodiment, the first rotor R 1, the second rotor R 2, the first transmission shaft GW 1, and the second transmission shaft GW 2 are all arranged coaxially with each other.In the illustrated embodiment, the first parking gear PR 1 is axially disposed between the first rotor R 1 and the first ramp mechanism RM 1, and the second parking gear PR 2 is axially disposed between the second rotor and the second ramp mechanism RM 2.In the example shown, the primary elements PE 1, PE 2 are each designed as a primary wheel arranged coaxially with the parking lock wheels PR 1, PR 2 and the secondary wheels SR 1, SR 2. The respective primary wheel is arranged here in particular circumferentially on the respective secondary wheel SR 1, SR 2. FIG. 2 shows such a secondary wheel SR 1, SR 2 and such a primary element PE 1, PE 2 arranged circumferentially thereon and embodied as a primary wheel.In the embodiment shown, the first secondary wheel SR 1 is arranged axially next to the first ratchet element KE 1 and has a first ramp RA 1 on a side facing the first ratchet element KE 1 in the axial direction, wherein the first ramp RA 1 and the first ratchet element KE 1 have an equal radial distance from the main axis of rotation A, and wherein the first ramp RA 1 is positioned on the first secondary wheel SR 1 in such a way that, when the first secondary wheel SR 1 is rotated, the first ratchet element KE 1 increasingly slides onto the first ramp RA 1 due to the tangential force acting on the first primary element PE 1 and transmitted via the first spring element FE 1 to the first secondary wheel SR 1.In the embodiment shown, the second secondary wheel SR 2 is also arranged axially next to the second ratchet element KE 2 and has a second ramp RA 2 on a side facing the second ratchet element KE 2 in the axial direction, wherein the second ramp RA 2 and the second ratchet element KE 2 have an equal radial distance from the main axis of rotation A, and wherein the second ramp RA 2 is positioned on the second secondary wheel SR 2 in such a way that, when the second secondary wheel SR 2 is rotated, the second ratchet element KE 2 increasingly slides onto the second ramp RA 2 due to the tangential force acting on the second primary element PE 2 and transmitted via the second spring element FE 2 to the second secondary wheel SR 2.The ramps RA 1, RA 2 thus have a sliding surface which extends obliquely to the side of the secondary wheel SR 1, SR 2 on which they are arranged. In the example shown, the pawl elements KE 1, KE 2 have a sliding surface, which is formed in particular corresponding to the sliding surface of the respective ramp RA 1, RA 2. The sliding-on surface of the respective ramp RA 1, RA 2 and of the respective latch element KE 1, KE 2 thus slide along one another. More precisely, the rotation of the respective secondary wheel SR 1, SR 2 increasingly pushes the respective ramp RA 1, RA 2 with its sliding surface under the respective pawl element KE 1, KE 2, i.e. under its sliding surface, whereby the respective pawl element KE 1, KE 2 increasingly slides onto the respective ramp RA 1, RA 2.The first parking lock gear PR 1 has a first recess AN 1 for receiving the first pawl element KE 1 in order to connect the first parking lock gear PR 1 to the housing in a rotationally fixed manner. The second parking lock gear PR 2 has a second recess AN 2 for receiving the second pawl element KE 2 in order to connect the second parking lock gear PR 2 to the housing in a rotationally fixed manner. If the respective pawl element KE 1, KE 2 is inserted into the respective recess AN 1, AN 2, it is connected in particular in a form-fitting manner to the respective parking lock gear PR 1, PR 2. That is to say, the respective recess AN 1, AN 2 is not formed as a continuous groove in the circumferential direction of the respective parking lock gear PR 1, PR 2, but rather is closed. It thus has side walls in the circumferential direction of the respective parking lock gear PR 1, PR 2, which are not illustrated in FIG. 1.In the embodiment shown, further first and second ramps RA 1, RA 2 are arranged on the respective secondary wheel SR 1, SR 2, which ramps are distributed, in particular uniformly distributed, in the circumferential direction of the respective secondary wheel SR 1, SR 2, as shown in particular in FIG. 2. In this embodiment, in particular further first and second pawl elements KE 1, KE 2 and still further recesses AN 1, AN 2 are thus also provided in the respective parking lock gear PR 1, PR 2. The latch elements KE 1, KE 2 are arranged distributed on the housing corresponding to the distribution of the ramps RA 1, RA 2, in this case therefore on the respective latch frame KR 1, KR 2.The number of recesses AN 1, AN 2 in the respective parking lock gear PR 1, PR 2 is in particular at least as large as the number of pawl elements KE 1, KE 2 which are provided for moving into the recesses AN 1, AN 2 of the respective parking lock gear PR 1, PR 2. In order to enable the most rapid possible engagement of the ratchet elements KE 1, KE 2 in the recesses AN 1, AN 2 of the respective parking lock wheel PR 1, PR 2, i.e. in order to enable the respective parking lock to be closed without rotation of the respective parking lock wheel PR 1, PR 2 or by only a small rotation of the respective parking lock wheel PR 1, PR 2, the number of recesses AN 1, AN 2 in the respective parking lock wheel PR 1, PR 2 can also be greater than the number of ratchet elements KE 1, KE 2 provided for engaging in the recesses AN 1, AN 2 of the respective parking lock wheel PR 1, PR 2. That is, the number of recesses AN 1 in the first parking gear PR 1 may be larger than the number of the first ratchet members KE 1, and the number of recesses AN 2 in the second parking gear PR 2 may be larger than the number of the second ratchet members KE 2. The recesses AN 1, AN 2 are in particular uniformly distributed in the circumferential direction of the respective parking lock wheel PR 1, PR 2. On account of the illustration of the electric drive system 1 in FIG. 1, these further latch elements KE 1, KE 2 and recesses AN 1, AN 2 in FIG. 1 are concealed and therefore not visible.In particular, a restoring spring RF 1, RF 2 is provided on the respective latch element KE 1, KE 2, which is tensioned by moving the respective latch element KE 1, KE 2 into the respective recess AN 1, AN 2. The respective restoring spring RF 1, RF 2 is thus supported in particular on the housing, in the example shown here on the respective latch frame KR 1, KR 2 of the housing. The respective latch element KE 1, KE 2 is thus moved out of the respective recess AN 1, AN 2 by means of the spring force of the respective tensioned restoring spring RF 1, RF 2.The mode of operation of the parking lock device 2 for closing and opening the two parking locks is described below:To close the two parking locks, the adjusting motor 4 rotates the adjusting pinion 3 in one direction, whereby the primary elements PE 1, PE 2 are each rotated in a closing direction SR by the tangential force effect of the adjusting pinion 3. In FIG. 2, this closing direction SR is counterclockwise. A force transmission then takes place via the respective spring element FE 1, FE 2 from the respective primary element PE 1, PE 2 to the respective secondary wheel SR 1, SR 2, as a result of which the latter also strives to rotate in the closing direction SR.If the recess AN 1, AN 2 in the respective parking lock gear PR 1, PR 2 is at the height of the respective pawl element KE 1, KE 2, i.e. covers the pawl element KE 1, KE 2, as shown in FIG. 1, so that the pawl element KE 1, KE 2 can move into the recess AN 1, AN 2, this rotation of the respective secondary gear SR 1, SR 2 will take place in the closing direction SR. As a result, the respective pawl element KE 1, KE 2 slides onto the ramp RA 1, RA 2 of the respective secondary wheel SR 1, SR 2 and is thereby pushed into the recess AN 1, AN 2 of the respective parking lock wheel PR 1, PR 2. As a result, a positively locking connection is formed in a rotationally fixed manner from the respective parking lock wheel PR 1, PR 2 via the respective pawl element KE 1, KE 2 to the housing, in this case to the respective pawl frame KR 1, KR 2 of the housing. The respective parking lock is thus closed.If the recess AN 1, AN 2 in the respective parking lock gear PR 1, PR 2 is not at the height of the respective pawl element KE 1, KE 2, the respective spring element FE 1, FE 2 is initially tensioned by the rotation of the respective primary element PE 1, PE 2 in the closing direction SR. If the respective parking lock gear PR 1, PR 2 then continues to rotate, since the respective parking lock is not yet closed, the recess AN 1, AN 2 in the respective parking lock gear PR 1, PR 2 reaches the level of the respective pawl element KE 1, KE 2, i.e. it covers the pawl element KE 1, KE 2, so that the pawl element KE 1, KE 2 can move into the recess AN 1, AN 2. The respective secondary wheel SR 1, SR 2 is then rotated in the closing direction SR by the tensioned spring element FE 1, FE 2. As a result, the respective pawl element KE 1, KE 2 slides onto the ramp RA 1, RA 2 of the respective secondary wheel SR 1, SR 2 and is thereby pushed into the recess AN 1, AN 2 of the respective parking lock wheel PR 1, PR 2. As a result, the positively locking, rotationally fixed connection is formed from the respective parking lock gear PR 1, PR 2 via the respective pawl element KE 1, KE 2 to the housing, in this case to the respective pawl frame KR 1, KR 2 of the housing. The respective parking lock is thus closed.To open the two parking locks, the adjusting motor 4 rotates the adjusting pinion 3 in the other direction, as a result of which the primary elements PE 1, PE 2 are each rotated in an opening direction OR by the tangential force effect of the adjusting pinion 3. In FIG. 2, this opening direction OR is clockwise. In this case, provision is made in particular for a formation AF of the respective primary element PE 1, PE 2 to strike a stop AS of the respective secondary wheel SR 1, SR 2 and thus likewise to rotate the latter in the opening direction OR. As a result, the respective ramp RA 1, RA 2 is moved away from the respective pawl element KE 1, KE 2, i.e. the respective pawl element KE 1, KE 2 slides down from the respective ramp RA 1, RA 2. The respective pawl element KE 1, KE 2 is then moved out of the recess AN 1, AN 2 of the respective parking lock wheel PR 1, PR 2 again by means of the respective restoring spring RF 1, RF 2, which has been tensioned by the movement of the respective pawl element KE 1, KE 2 into the recess AN 1, AN 2 of the respective parking lock wheel PR 1, PR 2. The respective parking lock is thereby opened.List of reference characters1 Drive system 2 Parking lock device 3 Adjusting pinion 4 Adjusting motor 5 Rolling bearing A Main axis of rotation AF Formation AN 1 First recess AN 2 Second recess AS Stop EM 1 First electric machine EM 2 Second electric machine FE 1 First spring element FE 2 Second spring element GW 1 First transmission shaft GW 2 Second transmission shaft KE 1 First pawl element KE 2 Second pawl element KR 1 First pawl frame KR 2 Second pawl frame OR Opening direction PE 1 First primary element PE 2 Second primary element PR 1 First parking lock wheel PR 2 Second parking lock wheel R 1 First rotor R 2 Second rotor RA 1 First ramp RA 2 Second ramp RF 1 first return spring RF 2 second return spring RM 1 first ramp mechanism RM 2 second ramp mechanism S 1 first stator S 2 second stator SR closing direction SR 1 first secondary wheel SR 2 second secondary wheel

Claims

Electric drive system (1) for a motor vehicle, having a parking lock device (2) having a first parking lock gear (PR1) which is connected in a rotationally fixed manner to a first transmission shaft (GW1), having a housing, having a first pawl element (KE1) which is designed to connect the first parking lock gear (PR1) in a rotationally fixed manner to the housing, having a first ramp mechanism (RM1) which has a first primary element (PE1) and a first secondary wheel (SR1) which is arranged coaxially with respect to the first transmission shaft (GW1), wherein the first primary element (PE1) and the first secondary wheel (SR1) are coupled to one another by means of a first spring element (FE1) which acts in the tangential direction, having an adjusting pinion (3), which is coupled to the first primary element (PE1) and with an adjusting motor (4) coupled to the adjusting pinion (3), wherein the first ramp mechanism (RM1) is designed to convert a tangential force acting on the first primary element (PE1) into an axial force acting on the first pawl element (KE1), with a second ramp mechanism (RM2) having a second primary element (PE2) and a second secondary wheel (SR2) which is coupled to the second primary element (PE2) by means of a second spring element (FE2) acting in the tangential direction, wherein the second primary element (PE2) is coupled to the adjusting pinion (3), wherein a second transmission shaft (GW2) is provided, which is connected to a second parking ratchet wheel (PR2) in a rotationally fixed manner, wherein a second ratchet element (KE2) is provided, which is designed to connect the second parking ratchet wheel (PR2) to the housing in a rotationally fixed manner, wherein the second ramp mechanism (RM2) is designed to convert a tangential force acting on the second primary element (PE2) into an axial force acting on the second ratchet element (KE2), further having a first electric machine (EM1), which has a first rotor (R1), which is coupled or can be coupled to the first transmission shaft (GW1), a second electric machine (EM2), which has a second rotor (R2) which is coupled or can be coupled to the second transmission shaft (GW2), wherein the first transmission shaft (GW1) is arranged coaxially to the second transmission shaft (GW2), characterized in that the first transmission shaft (GW1) and the second transmission shaft (GW2) are mounted against one another by means of a rolling bearing (5), wherein the rolling bearing (5) is arranged axially overlapping with the first secondary wheel (SR1) and / or with the second secondary wheel (SR2).Electric drive system (1) according to Claim 1, characterized in that the first pawl element (KE1) is connected to the housing in a rotationally fixed manner and is arranged so as to be axially displaceable with respect to the housing, and in that the second pawl element (KE2) is connected to the housing in a rotationally fixed manner and is arranged so as to be axially displaceable with respect to the housing.Electric drive system (1) according to one of the preceding claims, characterized in that the first primary element (PE1) is designed as a first primary wheel arranged coaxially with the first parking lock gear (PR1), and the second primary element (PE2) is designed as a second primary wheel arranged coaxially with the second parking lock gear (PR2).Electric drive system (1) according to Claim 3, characterized in that the first primary element (PE1), which is designed as a first primary wheel, is arranged coaxially with respect to the first secondary wheel (SR1), and the second primary element (PE2), which is designed as a second primary wheel, is arranged coaxially with respect to the second secondary wheel (SR2).Electric drive system (1) according to one of the preceding claims, characterized in that - the first secondary wheel (SR1) is arranged axially next to the first ratchet element (KE1) and has a first ramp (RA1) on a side facing the first ratchet element (KE1) in the axial direction, wherein the first ramp (RA1) and the first ratchet element (KE1) have an identical radial distance from a main axis of rotation (A), and wherein the first ramp (RA1) is positioned on the first secondary wheel (SR1) in such a way, wherein, in the case of a rotation of the first secondary wheel (SR1) effected by the tangential force acting on the first primary element (PE1) and transmitted via the first spring element (FE1) to the first secondary wheel (SR1), the first ratchet element (KE1) slides increasingly onto the first ramp (RA1), and - the second secondary wheel (SR2) is arranged axially next to the second ratchet element (KE2) and has a second ramp (RA2) on a side facing the second ratchet element (KE2) in the axial direction, wherein the second ramp (RA2) and the second ratchet element (KE2) have an identical radial distance from the main axis of rotation (A), and wherein the second ramp (RA2) is positioned on the second secondary wheel (SR2) in such a way that, in the event of a rotation of the second secondary wheel (SR2) effected by the tangential force acting on the second primary element (PE2) and transmitted via the second spring element (FE2) to the second secondary wheel (SR2), the second pawl element (KE2) increasingly slides onto the second ramp (RA2).Electric drive system (1) according to one of the preceding claims, characterized in that the first parking lock gear (PR1) has a first recess (AN1) for receiving the first ratchet element (KE1) in order to connect the first parking lock gear (PR1) to the housing in a rotationally fixed manner, and the second parking lock gear (PR2) has a second recess (AN2) for receiving the second ratchet element (KE2) in order to connect the second parking lock gear (PR2) to the housing in a rotationally fixed manner.Electric drive system (1) according to one of the preceding claims, characterized in that the first rotor (R1) is arranged coaxially, radially at least partially overlapping and axially offset with respect to the second rotor (R2), wherein, as seen in the direction of the main axis of rotation (A), the first rotor (R1), the first ramp mechanism (RM1), the second ramp mechanism (RM2) and the second rotor (R2) are arranged one after the other in the order mentioned.Electric drive system (1) according to one of the preceding claims, characterized in that the first rotor (R1), the second rotor (R2), the first transmission shaft (GW1) and the second transmission shaft (GW2) are all arranged coaxially with respect to one another.Electric drive system (1) according to one of the preceding claims, characterized in that the first parking lock gear (PR1) is arranged axially between the first rotor (R1) and the first ramp mechanism (RM1), and the second parking lock gear (PR2) is arranged axially between the second rotor (R2) and the second ramp mechanism (RM2).

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