Transmission for a motor vehicle, motor vehicle powertrain, and method for operating a transmission

Abstract

A transmission (G) for a motor vehicle includes an electric machine (EM1), a first input shaft (GW1), a second input shaft (GW2), an output shaft (GWA), two planetary gear sets (P1, P2, P3), and at least five shift elements (A, B, C, D, E). Different gears are implementable by selectively actuating the at least five shift elements (A, B, C, D, E) and, in addition, in interaction with the electric machine (EM1), different operating modes are implementable. A drive train for a motor vehicle with the transmission (G), and to a method for operating the transmission (G) are also provided.

Claims

1. A transmission (G) for a motor vehicle, comprising: an electric machine (EM1); a first input shaft (GW1); a second input shaft (GW2); an output shaft (GWA); a first planetary gear set (P1) and a second planetary gear set (P2), the first and second planetary gear sets (P1, P2) each comprising a first element (E11, E12), a second element (E21, E22), and a third element (E31, E32); and a first shift element (A), a second shift element (B), a third shift element (C), a fourth shift element (D), and a fifth shift element (E), wherein a rotor (R1) of the electric machine (EM1) is connected to the second input shaft (GW2), wherein the output shaft (GWA) is rotationally fixed to the second element (E22) of the second planetary gear set (P2), is rotationally fixable to the first input shaft (GW1) with the second shift element (B), and is connectable to the third element (E31) of the first planetary gear set (P1) with the fifth shift element (E), wherein the first element (E11) of the first planetary gear set (P1) is fixed to a rotationally fixed component (GG), wherein the first element (E12) of the second planetary gear set (P2) is fixable to the rotationally fixed component (GG) with the first shift element (A), the second input shaft (GW2) is rotationally fixed to the second element (E21) of the first planetary gear set (P1) as well as to the third element (E32) of the second planetary gear set (P2), and wherein the first input shaft (GW1) is rotationally fixable to the second element (E21) of the first planetary gear set (P1) with the third shift element (C) and is rotationally fixable to the third element (E31) of the first planetary gear set (P1) with the fourth shift element (D).

2. The transmission (G) of claim 1, wherein selective actuation of the first, second, third, fourth, and fifth shift elements (A, B, C, D, E) implements: a first gear (1) between the first input shaft (GW1) and the output shaft (GWA) by engaging the first shift element (A) and the fourth shift element (D); a second gear between the first input shaft (GW1) and the output shaft (GWA) by engaging the first shift element (A) and the third shift element (C); a third gear between the first input shaft (GW1) and the output shaft (GWA) in a first variant (3.1) by engaging the first shift element (A) and the second shift element (B), in a second variant (3.2) by engaging the second shift element (B) and the fifth shift element (E), in a third variant (3.3) by engaging the fourth shift element (D) and the fifth shift element (E), in a fourth variant (3.4) by engaging the second shift element (B) and the third shift element (C), in a fifth variant (3.5) by engaging the second shift element (B) and the fourth shift element (D); and a fourth gear between the first input shaft (GW1) and the output shaft (GWA) by engaging the third shift element (C) and the fifth shift element (E).

3. The transmission (G) of claim 1, wherein: a first gear (E2) results between the second input shaft (GW2) and the output shaft (GWA) by engaging the first shift element (A); and a second gear (E4) results between the second input shaft (GW2) and the output shaft (GWA) by engaging the fifth shift element (E).

4. The transmission (G) of claim 1, further comprising a sixth shift element (F) arranged and configured for selectively connecting the first element (E12) of the second planetary gear set (P2) to the first input shaft (GW1).

5. The transmission (G) of claim 4, wherein selective engagement of the first, second, third, fourth, fifth, and sixth shift elements (A, B, C, D, E, F) implements a third gear between the first input shaft (GW1) and the output shaft (GWA) in a sixth variant (3.6) by engaging the second shift element (B) and the sixth shift element (F), and in a seventh variant (3.7) by engaging the third shift element (C) and the sixth shift element (F).

6. The transmission (G) of claim 4, wherein: the third shift element (C) and the sixth shift element (F) are combined to form a shift element pair (SP3); an actuating element is associated with the shift element pair (SP3); and the shift element pair (SP3) is configured such that either the third shift element (C) or the sixth shift element (F) is engageable by the actuating element from a neutral position of the actuating element.

7. The transmission (G) of claim 1, further comprising a seventh shift element (K) arranged and configured for selectively interlocking the second planetary gear set (P2).

8. The transmission (G) of claim 7, wherein a third gear (E3) results between the second input shaft (GW2) and the output shaft (GWA) by engaging the seventh shift element (K).

9. The transmission (G) of claim 1, further comprising a further electric machine (EM2), a rotor (R2) of the further electric machine (EM2) connected at the first input shaft (GW1).

10. The transmission (G) of claim 1, further comprising an eighth shift element (K0), the first input shaft (GW1) is rotationally fixable to a connection shaft (AN) with the eighth shift element (K0).

11. The transmission (G) of claim 1, wherein one or more of the first, second, third, fourth, and fifth shift elements (A, B, C, D, E, F, K, K0) is a form-locking shift element.

12. The transmission (G) of claim 1, wherein one or both of the first and second planetary gear sets (P1, P2) is a minus planetary gear set, wherein the first element (E11, E12) of each minus planetary gear set is a respective sun gear, the second element (E21, E22) of each minus planetary gear set is a respective planet carrier, and the third element (E31, E32) of each minus planetary gear set is a respective ring gear.

13. The transmission (G) of claim 1, wherein: the second shift element (B) and the third shift element (C) are combined to form a shift element pair (SP2); an actuating element is associated with the shift element pair (SP2); and the shift element pair (SP2) is configured such that either the second shift element (B) or the third shift element (C) is engageable by the actuating element from a neutral position of the actuating element.

14. The transmission (G) of claim 1, wherein: the second shift element (B) and the fourth shift element (D) are combined to form a shift element pair (SP2); an actuating element is associated with the shift element pair (SP2); and the shift element pair (SP2) is configured such that either the second shift element (B) or the fourth shift element (D) is engageable by the actuating element from a neutral position of the actuating element.

15. The transmission (G) of claim 1, wherein the rotor (R1) of the electric machine (EM1) is rotationally fixed to the second input shaft (GW2) or is connected to the second input shaft (GW2) with at least one gear stage.

16. A motor vehicle drive train for a hybrid or electric vehicle, comprising the transmission (G) of claim 1.

17. A method for operating the transmission (G) of claim 1, wherein only the third shift element (C) is engaged in order to implement a charging operation or a starting operation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Advantageous example embodiments of the invention, which are explained in the following, are represented in the drawings. Wherein:

(2) FIG. 1 shows a diagrammatic view of a motor vehicle drive train;

(3) FIGS. 2 through 5 each show a diagrammatic view of a transmission of the type that can be utilized in the motor vehicle drive train from FIG. 1;

(4) FIG. 6 shows an exemplary shift pattern for five shift elements of the transmissions from FIGS. 2 through 5;

(5) FIG. 7 shows an exemplary shift pattern for six shift elements of the transmissions from FIGS. 2 through 5;

(6) FIGS. 8 and 9 each show a diagrammatic view of a transmission of the type that can also be utilized in the motor vehicle drive train from FIG. 1;

(7) FIG. 10 shows an exemplary shift pattern for a transmission according to FIG. 8 or 9;

(8) FIGS. 11 through 16 each show a schematic of a modification of the transmissions from FIGS. 2 through 5 as well as FIGS. 8 and 9;

(9) FIG. 17 shows a section of the transmissions from FIGS. 4 and 9; and

(10) FIGS. 18 through 22 show an exemplary actuating unit for a transmission.

DETAILED DESCRIPTION

(11) Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

(12) FIG. 1 shows a diagrammatic view of a motor vehicle drive train of a hybrid vehicle, wherein, in the motor vehicle drive train, an internal combustion engine VKM is connected to a transmission G via an intermediate torsional vibration damper TS. Connected downstream from the transmission G, on the output end thereof, is a differential gear AG, via which drive power is distributed to driving wheels DW of a drive axle of the motor vehicle. The transmission G and the torsional vibration damper TS are arranged in a common housing of the transmission G in this case, into which the differential gear AG can then also be integrated. As is also apparent in FIG. 1, the internal combustion engine VKM, the torsional vibration damper TS, the transmission G, and also the differential gear AG are aligned transversely to a direction of travel of the motor vehicle.

(13) FIG. 2 shows a schematic of the transmission G according to a first example embodiment of the invention. As is apparent, the transmission G includes a gear set RS and an electric machine EM1, which are both arranged in the housing of the transmission G. The gear set RS includes two planetary gear sets P1 and P2, wherein each of the planetary gear sets P1 and P2 includes a first element E11 and E12, respectively, a second element E21 and E22, respectively, and a third element E31 and E32, respectively. The first element E11 and E12 is formed by a sun gear of the planetary gear set P1 and P2, respectively, while the second element E21 and E22 of the planetary gear set P1 and P2, respectively, is present as a planet carrier, and the third element E31 and E32 of the planetary gear set P1 and P2, respectively, is present as a ring gear.

(14) In the present case, the first planetary gear set P1 and the second planetary gear set P2 are each therefore present as a minus planetary gear set. The particular planet carrier thereof guides at least one planet gear in a rotatably mounted manner; the planet gear is meshed with the particular radially internal sun gear as well as with the particular radially surrounding ring gear. It is particularly preferred, however, when multiple planet gears are provided in the case of the first planetary gear set P1 and in the case of the second planetary gear set P2.

(15) As is apparent in FIG. 2, the transmission G includes a total of five shift elements in the form of a first shift element A, a second shift element B, a third shift element C, a fourth shift element D, and a fifth shift element E. The shift elements A, B, C, D, and E are each designed as form-locking shift elements and are preferably present as constant-mesh shift elements. While the first shift element A is a brake, the remaining shift elements B, C, D, and E are clutches.

(16) The first element E11 of the first planetary gear set P1 is permanently fixed at a rotationally fixed component GG, which is the transmission housing of the transmission G or a portion of this transmission housing. The second element E22 of the second planetary gear set P2 is rotationally fixed to an output shaft GWA of the transmission G. Jointly, the second element E22 of the second planetary gear set P2 and, thereby, also the output shaft GWA, is connectable in a rotationally fixed manner to a first input shaft GW1 of the transmission G by engaging the second shift element B and connectable in a rotationally fixed manner to the third element E31 of the first planetary gear set P1 by engaging the fifth shift element E.

(17) As is also apparent in FIG. 2, the first input shaft GW1 is connectable in a rotationally fixed manner to the second element E21 of the first planetary gear set P1 via the third shift element C. A second input shaft GW2 of the transmission G is permanently rotationally fixed to the second element E21 of the first planetary gear set P1 and to a rotor R1 of an electric machine EM1, the stator S1 of which is continuously fixed at the rotationally fixed component GG. Since the rotor R1 is connected to the second input shaft GW2 and the second input shaft GW2 is rotationally fixed to the second element E21, a connection of the input shaft GW1 to the second input shaft GW2 takes place simultaneously by engaging the third shift element C.

(18) By actuating the second shift element B, the input shaft GW1 is connectable to the second element E22 of the second planetary gear set P2 and, thereby, to the output shaft GWA. By actuating the fourth shift element D, the first input shaft GW1 also is connectable in a rotationally fixed manner to the third element E31 of the first planetary gear set P1.

(19) The first input shaft GW1 as well as the output shaft GWA form a mounting interface GW1-A and GWA-A, respectively, wherein the mounting interface GW1-A in the motor vehicle drive train from FIG. 1 is utilized for a connection at the internal combustion engine VKM, while the transmission G is connected at the mounting interface GWA-A to the downstream differential gear AG. The mounting interface GW1-A of the first input shaft GW1 is formed at an axial end of the transmission G, while the mounting interface GWA-A of the output shaft GWA is situated in the area of the same axial end and, here, is aligned transversely to the mounting interface GW1-A of the first input shaft GW1. In addition, the first input shaft GW1, the second input shaft GW2, and the output shaft GWA are arranged coaxially to one another.

(20) The planetary gear sets P1 and P2 are also situated coaxially to the input shafts GW1 and GW2 and the output shaft GWA, wherein the planetary gear sets P1 and P2 are arranged in the sequence first planetary gear set P1 and second planetary gear set P2 axially subsequent to the mounting interface GW1-A of the first input shaft GW1. Likewise, the electric machine EM1 is also located coaxially to the planetary gear sets P1 and P2 and, thereby, also to the input shafts GW1 and GW2 and to the output shaft GWA, wherein the electric machine EM1 is arranged axially spaced apart from the first planetary gear set P1 and the second planetary gear set P2.

(21) As is also apparent from FIG. 2, the second shift element B, the third shift element C, the fourth shift element D, and the fifth shift element E are arranged axially between the first planetary gear set P1 and the second planetary gear set P2, wherein, in this case, the third shift element C is situated axially adjacent to the first planetary gear set P1, followed axially initially by the fourth shift element D and then the second shift element B and the fifth shift element E. The fifth shift element E is arranged axially approximately at the level of the fourth shift element D and the second shift element B and radially spaced apart therefrom.

(22) The first shift element A is situated axially on a side of the second planetary gear set P2 facing away from the first planetary gear set P1.

(23) The first shift element A and the fifth shift element E include a common actuating element, via which the first shift element A, on the one hand, and the fifth shift element E, on the other hand, can be actuated from a neutral position. In that respect, the first shift element A and the fifth shift element E are combined to form a shift element pair SP1.

(24) The fourth shift element D and the second shift element B are situated axially directly next to one another and radially at the same level and are combined to form a shift element pair SP2, in that a common actuating element is associated with the fourth shift element D and the second shift element B, via which the fourth shift element D, on the one hand, and the second shift element B, on the other hand, can be actuated from a neutral position. Alternatively, the shift elements B and C as well as C and D can be combined to form a shift element pair.

(25) Moreover, FIG. 3 shows a diagrammatic view of a transmission G according to a second example design option of the invention, which can also be utilized in the motor vehicle drive train from FIG. 1. This example design option largely corresponds to the preceding example variant according to FIG. 2, with the difference that the first planetary gear set P1 is now designed as a plus planetary gear set.

(26) As compared to the design as a minus planetary gear set, the particular second element E21 is formed by the ring gear and the third element E31 is formed by the planet carrier. In addition, the stationary transmission ratio is increased by one. In the plus planetary gear set P1, the planet carrier guides at least one pair of planet gears in a rotatably mounted manner. One planet gear of said pair of planet gears is meshed with the radially internal sun gear and one planet gear is meshed with the radially surrounding ring gear, and the planet gears intermesh with each other. In order to connect the first input shaft GW1 at the second input shaft GW2, the fourth shift element D must be actuated in the example embodiment according to FIG. 3.

(27) As in the example embodiment according to FIG. 2, the shift elements A and E are combined to form a shift element pair SP1. In contrast to the example embodiment according to FIG. 2, the shift element pair is formed by the shift elements B and C, wherein the other two example variants would also be conceivable here.

(28) The example design of the first planetary gear set in the “plus variant” has the advantage that, due to the connection of the rotor R1 at the other shaft, the electric gears now have a shorter ratio, which increases the tractive force in the electric mode. In addition, a pre-ratio of the electric machine EM1, if present, can be smaller and can even be omitted, if necessary. Otherwise, the example design option according to FIG. 3 corresponds to the example variant according to FIG. 2, and therefore reference is made to the description thereof.

(29) FIG. 4 shows a schematic of a transmission G according to a third example embodiment of the invention, of the type which can also be utilized in the motor vehicle drive train from FIG. 1. This example embodiment also essentially corresponds to the example variant according to FIG. 2, wherein, in contrast thereto, a sixth shift element F is now provided. By actuating the sixth shift element F, the first input shaft GW1 is connected in a rotationally fixed manner to the first element E12 of the second planetary gear set P2. The sixth shift element F is provided axially between the first planetary gear set P1 and the second planetary gear set P2.

(30) By adding the sixth shift element F, an EDA mode for the electrodynamic starting operation forward can be advantageously implemented. With the sixth shift element F engaged, the internal combustion engine VKM is connected to the first element E12 of the second planetary gear set P2, the rotor R1 is connected to the third element E32 of the second planetary gear set P2, while the output shaft GWA is connected to the second element E22 of the second planetary gear set P2.

(31) In this preferred example embodiment, the six shift elements are combined to form shift element pairs as follows.

(32) Shift elements A and B form a first shift element pair SP1.

(33) Shift elements B and D form a second shift element pair SP2.

(34) Shift elements C and F form a third shift element pair SP3.

(35) For the rest, the example embodiment according to FIG. 4 corresponds to the example variant according to FIG. 2, and therefore reference is made to the description thereof. With respect to the actuation of the four shift elements B, C, D, and F by only two actuators, reference is made to the example embodiment according to FIGS. 17 through 22.

(36) FIG. 5 shows a diagrammatic view of a transmission G according to a fourth example design option of the invention, which can also be utilized in the motor vehicle drive train from FIG. 1. This example design option largely corresponds to the example variant according to FIG. 2, with the difference that a seventh shift element K is provided, which, in the actuated condition, interlocks the second planetary gear set P2. According to the example embodiment according to FIG. 5, the interlock of the second planetary gear set P2 takes place by connecting the first element E12 and the second element E22 in a rotationally fixed manner.

(37) Not represented, but also conceivable is an interlock by connecting, in a rotationally fixed manner, the first element E12 and the third element E32 as well as the second element E22 and the third element E32 of the second planetary gear set P2.

(38) The seventh shift element K allows for an additional electric gear, in that the seventh shift element is engaged. The additional electric gear can also be combined with an example embodiment according to FIG. 3 (plus gear set variant) and with the example embodiment according to FIG. 4 (EDA mode forward). For the rest, the example embodiment according to FIG. 4 corresponds to the example variant according to FIG. 2, and therefore reference is made to the description thereof.

(39) FIG. 6 shows an exemplary shift pattern for the transmissions G from FIGS. 2 through 5 in table form. As is apparent, a total of four gears 1 through 4, which differ in terms of the ratio, are implementable between the first input shaft GW1 and the output shaft GWA, wherein, in the columns of the shift pattern, an X indicates which of the shift elements A through E is engaged in which of the gears 1 through 4.

(40) As is apparent in FIG. 6, a first gear 1 is engaged between the first input shaft GW1 and the output shaft GWA by actuating the first shift element A and the fourth shift element D. Moreover, a second gear results between the first input shaft GW1 and the output shaft GWA by engaging the first shift element A and the third shift element C.

(41) In addition, a third gear can be implemented between the first input shaft GW1 and the output shaft GWA in a first variant 3.1 by actuating the first shift element A and the second shift element B, wherein the third gear can also be formed in a second variant 3.2 by engaging the second shift element B and the fifth shift element E, in a third variant 3.3 by actuating the fourth shift element D and the fifth shift element E, in a fourth variant 3.4 by engaging the second shift element B and the third shift element C, and in a fifth variant by engaging the second shift element B and the fourth shift element D. In one further variant (V3), the third gear can be implemented simply by engaging the second shift element B.

(42) While the electric machine EM1 is also integrated in each of the variants 3.1 through 3.5, and so driving can take place in a hybrid manner while simultaneously utilizing the internal combustion engine VKM and the electric machine EM1, the electric machine EM1 is decoupled in the case of the further variant V3. The latter has the advantage that the electric machine EM1 does not need to be engaged during operation.

(43) In addition, a fourth gear also results between the first input shaft GW1 and the output shaft GWA by actuating the third shift element C and the fifth shift element E.

(44) Although the shift elements A through E are each designed as form-fit shift elements, a power shift can be implemented between the first gear 1 and the second gear 2, between the first variant 2.1 of the second gear and the first variant 3.1 of the third gear, and between the second variant 3.2 of the third gear and the fourth gear 4. The reason therefor is that the first shift element A contributes to the changeover from the second gear 2 into the first variant 3.1 and to the changeover from the first variant 3.1 into the second variant 3.2. The shift element E contributes to the changeover from the second variant 3.2 of the third gear to the fourth gear 4. A synchronization during the gear shifts can take place in each case via an appropriate closed-loop control of the upstream internal combustion engine VKM, and therefore the particular shift element to be disengaged is disengaged without load and the shift element to be subsequently engaged can be engaged without load.

(45) The transmissions G from FIGS. 2 through 5 can also be operated in alternative operating modes with the aid of the electric machine EM1. Purely electric driving can take place in a first gear E2, which is effective between the second input shaft GW2 and the output shaft GWA and, for the implementation of which, the first shift element A is to be transferred into an engaged condition. As a result, with the first shift element A engaged, the first electric machine EM1 is directly connected to the output shaft GWA with a constant ratio (third element E32 rotatable with the second element E22 while the first element E12 of the second planetary gear set P2 is fixed). The ratio of the first gear E2 corresponds here, in each case, to a ratio of the second gear 2 between the first input shaft GW1 and the output shaft GWA.

(46) In addition, a second gear E4 can also be implemented between the second input shaft GW2 and the output shaft GWA, for the implementation of which the fifth shift element E is to be engaged. As a result, the electric machine EM1 is connected to the output shaft GWA with a constant ratio (second element E21 rotatable with the third element E31 while the first element E11 of the first planetary gear set P1 is fixed). A ratio of this second gear E4 corresponds, in each case, to a ratio of the fourth gear 4, which is effective between the first input shaft GW1 and the output shaft GWA.

(47) Advantageously, a start of the internal combustion engine VKM into the first gear 1, into the second gear 2, and into the first variant 3.1 of the third gear 3 can be carried out starting from the first gear E2, since the first shift element A is engaged in each of these gears. The same is possible from the second gear E4 into the second variant 3.2 of the third gear, into the third variant 3.3 of the third gear, or into the fourth gear 4, since the fifth shift element E contributes to each of these gears. Therefore, a transition from purely electric driving into driving via the internal combustion engine or into hybrid driving can be carried out rapidly.

(48) Moreover, a charging or starting function can be implemented by engaging the third shift element C. This is the case because, in the engaged condition of the third shift element C, the second input shaft GW2 is directly coupled, in a rotationally fixed manner, to the first input shaft GW1 and, thereby, also to the internal combustion engine VKM, wherein, simultaneously, there is no force-fit connection to the output shaft GWA. When the electric machine EM1 is operated as a generator, an electric accumulator can be charged via the internal combustion engine VKM, whereas, when the electric machine EM1 is operated as an electric motor, a start of the internal combustion engine VKM is implementable via the electric machine EM1.

(49) In addition, a rotational-speed reduction of the electric machine EM1 can be configured in the mechanical or hybrid mode. After a gear shift from the second gear into the third gear, with torque support via the electric machine EM1, or after a start of the internal combustion engine VKM into the third gear, hybrid driving results.

(50) In order to reduce the rotational speed of the electric machine EM in the third gear at higher ground speeds, a changeover can be carried out from the first variant 3.1 of the third gear into the second variant 3.2, in which the rotor R1 has a lower rotational speed. This changeover takes place while obtaining the tractive force via the internal combustion engine VKM with the second shift element B engaged. For this purpose, the first shift element A, which is then load-free, is disengaged and the likewise load-free, fifth shift element E is engaged, wherein the rotational-speed adaptation takes place in each case via closed-loop control of the rotational speed of the electric machine EM.

(51) The changeover into the second variant 3.2 also has the advantage that the internal combustion engine VKM can be decoupled at any time by disengaging the second shift element B also in the absence of an additional separating clutch, while the electric machine EM1 drives or decelerates the vehicle. Moreover, in the case of a vehicle that is slowing down, a downshift from the third gear into the second gear can be prepared, in that, initially, a changeover takes place from the second variant 3.1 into the first variant 1.1, while the internal combustion engine VKM maintains the tractive force with the second shift element B engaged. In the first variant 3.1 of the third gear, the first shift element A is engaged, which becomes necessary in order to support the tractive force via the electric machine EM during the downshift from the third gear into the second gear.

(52) FIG. 7 shows an exemplary shift pattern for the transmissions G from FIGS. 2 through 5 with a sixth shift element F, in table form. As is apparent, a total of four gears 1 through 4, which differ in terms of the ratio, are implementable between the first input shaft GW1 and the output shaft GWA, wherein, in the columns of the shift pattern, an X indicates which of the shift elements A through F is engaged in which of the gears 1 through 4.

(53) In contrast to the shift pattern from FIG. 6, two further variants of a third gear, which is effective between the first input shaft GW1 and the output shaft GWA, result due to the sixth shift element F. A sixth variant 3.6 of the third gear results by actuating the second shift element B and the sixth shift element F, whereas a seventh variant 3.7 of the third gear results by actuating the third shift element C and the sixth shift element F.

(54) As is also apparent from FIG. 7, two additional gears Z1 and Z2 are engageable. The additional gear Z1 results by actuating the fourth shift element D and the sixth shift element F, whereas the additional gear Z2 results by actuating the fifth shift element E and the sixth shift element F.

(55) Therefore, a total of four additional hybrid forward gears result due to the sixth shift element.

(56) Moreover, FIG. 8 shows a schematic of a transmission G according to a fifth example embodiment of the invention, of the type which can also be utilized in the motor vehicle drive train from FIG. 1. This example embodiment essentially corresponds to the example variant according to FIG. 2, wherein, in contrast thereto, the first input shaft GW1 is now rotationally fixable, at the mounting interface GW1-A via an eighth shift element K0, to a connection shaft AN, which is then connected to the upstream internal combustion engine VKM in the motor vehicle drive train. The seventh shift element K0 is configured as a form-locking shift element and, particularly preferably, is present as a constant-mesh shift element. Moreover, a further electric machine EM2 is also provided, the rotor R2 of which is rotationally fixed to the first input shaft GW1, while a stator S2 of the further electric machine EM2 is fixed at the rotationally fixed component GG. The rotor R2 is connected at the first input shaft GW1 axially between the seventh shift element K0 and the first planetary gear set P1. For the rest, the example variant according to FIG. 8 corresponds to the example design option according to FIG. 2, and therefore reference is made to the description thereof.

(57) FIG. 9 shows a diagrammatic view of a transmission G according to a sixth example design option of the invention. This example design option can also be utilized in the motor vehicle drive train from FIG. 1, wherein the example design option largely corresponds to the example variant from FIG. 4. The difference now, however, is that the first input shaft GW1 can be connected, at the mounting interface GW1-A, as is also the case in the preceding example variant according to FIG. 8, via an eighth shift element K0 in a rotationally fixed manner to a connection shaft AN, which is then connected to the upstream internal combustion engine VKM in the motor vehicle drive train. In this case, the eighth shift element K0 is designed as a form-locking shift element and, in this case, preferably as a constant-mesh shift element. In addition, a further electric machine EM2 is also provided, the rotor R2 of which is rotationally fixed to the first input shaft, while a stator S2 of the further electric machine EM2 is fixed at the rotationally fixed component GG. A connection of the rotor R2 of the further electric machine EM2 at the first input shaft GW1 is implemented axially between the eighth shift element K0 and the first planetary gear set P1. Otherwise, the example variant according to FIG. 9 corresponds to the example embodiment according to FIG. 4, and therefore reference is made to the description thereof.

(58) In FIG. 10, different conditions of the motor vehicle drive train from FIG. 1, with utilization of the transmission G from FIG. 8 or 9, are represented in table form, wherein these different conditions are achieved via different integrations of the two electric machines EM1 and EM2 and the internal combustion engine VKM. The column with the sixth shift element F is relevant only for the transmission according to FIG. 9.

(59) First, purely electric driving by a single electric machine and disengaged shift element K0 is described.

(60) In the first gear E2, purely electric driving takes place via the electric machine EM1, in that the first gear E2 is implemented in the transmission G in the way described above with respect to FIG. 6. In the second gear E4, purely electric driving also takes place via the electric machine EM1, in that the second gear E4 is implemented in the transmission G in the way described above with respect to FIG. 6. In the third gear E3, purely electric driving takes place via the electric machine EM2, in that the third gear E3 is implemented in the transmission G by actuating the second shift element B.

(61) Second, purely electric driving by both electric machines and disengaged shift element K0 is described.

(62) The same gear steps can be implemented as described in FIGS. 5 and 6, wherein these can now be driven purely electrically.

(63) Starting at the gear E1, driving then takes place via the electric machine EM1 and via the second electric machine EM2, in that both electric machines EM1 and EM2 are jointly integrated via the selection of the appropriate gears in the transmission G. A first gear E1 is selected by engaging the shift elements A and D. A second gear E2 is selected by engaging the shift elements A and C. A third gear in a first variant E3.1 is selected by engaging the shift elements A and B. A second variant E3.2 of the third gear is selected by engaging the shift elements B and E. A third variant E3.3 of the third gear is selected by engaging the shift elements D and E. By engaging the shift elements B and C, a fourth variant E3.4 of the third gear is selected. A fifth variant E3.5 of the third gear is selected by engaging the shift elements B and D. A sixth variant E3.6 of the third gear is selected by engaging the shift elements B and F. A seventh variant E3.7 of the third gear is selected by engaging the shift elements C and F. A fourth gear E4 is selected by engaging the shift elements C and E. The additional forward gear EZ1 is selected by engaging the shift elements D and F. The additional forward gear EZ2 is selected by engaging the shift elements E and F.

(64) With the clutch K0 engaged, the same gears are also implementable as described in FIGS. 6 and 7.

(65) The advantages of two electric machines can be summarized as follows: purely electric powershift, since the second electric machine EM2, with disengaged shift element K0, performs the functions of the internal combustion engine; the second electric machine EM2, with disengaged shift element K0, can be utilized for synchronization, while the first electric machine EM1 supports the tractive force; a greater total electrical power is implementable with disengaged shift element K0; a greater range is possible in a hybrid operation; the internal combustion engine VKM can be started by the second electric machine EM2; the second electric machine EM2 can synchronize the shift element K0; a battery-independent serial operation is possible; and the second electric machine EM2 can be used as a generator, the first electric machine EM1 can be used as a motor.

(66) Due to the additional shift element F, as described above, an EDA mode for forward travel can be implemented.

(67) In addition, a purely electric EDA mode can be implemented. As a result, driving can also take place for a longer time with high torque and a low ground speed without the electric machine or the inverter overheating, since both electric machines can be operated at suitable rotational speeds. An operation at very low electric-machine rotational speeds is avoided.

(68) In addition, in the purely electric EDA mode, a purely electric gear shift (EDS) is possible (K0 is disengaged while the shift element F is engaged), i.e., the electric gears of the first electric machine EM1 are power shiftable among one another. It is advantageous here that the first electric machine EM1 also contributes the greatest portion of the drive power during the gear shift, while the second electric machine EM2 can therefore be dimensioned considerably smaller (for example, only approximately a third (⅓) the power of EM1).

(69) With the clutch K0 engaged, the same shift conditions are implementable during hybrid travel and during internal combustion engine-driven travel, as explained with respect to FIGS. 6 and 7, and so reference is made to the descriptions thereof.

(70) The electric machines EM1 and EM2 can be positioned either coaxially to the gear set as well as axially parallel to the input shaft. The electric machines can be connected to the particular transmission shaft directly or via further gear stages, such as a planetary gear set or a spur gear stage. An additional gear stage can be useful, therefore, in order to obtain a more favorable design of the particular electric machine. In this way, for example, a higher rotational speed and a lower torque can be achieved.

(71) Finally, FIGS. 11 through 16 show modifications of the example transmissions G from FIGS. 2 through 5 as well as FIGS. 8 and 9. These example modifications relate to alternative possibilities for integrating the electric machine EM1, although the example modifications can also be utilized, in a similar way, for the further electric machine EM2 in the transmissions G according to FIGS. 8 and 9.

(72) In FIG. 11, for example, the electric machine EM1 is not located coaxially to the particular gear set RS (not represented in greater detail here) of the transmission G, but rather is arranged axially offset with respect thereto. A connection takes place via a spur gear stage SRS, which is composed of a first spur gear SR1 and a second spur gear SR2. The first spur gear SR1 is connected at the second input shaft GW2 in a rotationally fixed manner on the side of the particular gear set RS. The spur gear SR1 then meshes with the spur gear SR2, which is located on an input shaft EW of the electric machine EM1 in a rotationally fixed manner. Within the electric machine EM1, the input shaft EW establishes the connection at the rotor (not represented further in this case) of the electric machine EM1.

(73) In the case of the example modification according to FIG. 12 as well, the electric machine EM1 is located axially offset with respect to the particular gear set RS of the particular transmission G. In contrast to the preceding example variant according to FIG. 11, a connection is not established in this case via a spur gear stage SRS, however, but rather via a flexible traction drive mechanism ZT. This flexible traction drive mechanism ZT can be configured as a belt drive or also a chain drive. The flexible traction drive mechanism ZT is then connected at the second input shaft GW2 on the side of the particular gear set RS. Via the flexible traction drive mechanism ZT, a coupling to an input shaft EW of the electric machine EM1 is then established. Within the electric machine EM1, the input shaft EW establishes a connection at the rotor of the electric machine.

(74) In the case of the example modification according to FIG. 13, an integration of the electric machine EM1, which is located axially offset with respect to the particular gear set RS, is implemented via a planetary gear stage PS and a spur gear stage SRS. The planetary gear stage PS is connected downstream from the gear set RS, wherein, on the output end of the planetary gear stage PS, the spur gear stage SRS is then provided, via which the connection to the electric machine EM1 is established. The planetary gear stage PS includes a ring gear HO, a planet carrier PT, and a sun gear SO, wherein the planet carrier PT guides, in a rotatably mounted manner, at least one planet gear PR, which is meshed with the sun gear SO as well as with the ring gear HO.

(75) In the present case, the planet carrier PT is connected at the second input shaft GW2 in a rotationally fixed manner on the side of the gear set RS from FIGS. 2 through 5 as well as FIGS. 8 and 9. By comparison, the ring gear HO is permanently fixed at the rotationally fixed component GG, while the sun gear SO is rotationally fixed to a first spur gear SR1 of the spur gear stage SRS. The first spur gear SR1 then intermeshes with a second spur gear SR2 of the spur gear stage SRS, which is provided, in a rotationally fixed manner, on an input shaft EW of the electric machine EM1. In this case, the electric machine EM1 is therefore connected by the gear set RS via two gear stages.

(76) In the case of the example modification from FIG. 14 as well, an integration of the electric machine EM1 is implemented by the gear set RS via a planetary gear stage PS and a spur gear stage SRS. The modification largely corresponds to the variant according to FIG. 13, with the difference that, with respect to the planetary gear stage PS, the sun gear SO is now fixed at the rotationally fixed component GG, while the ring gear HO is rotationally fixed to the first spur gear SR1 of the spur gear stage SRS. Specifically, the ring gear HO and the first spur gear SR1 are preferably designed as one piece, in that the ring gear HO is equipped, at an outer circumference, with a tooth system. For the rest, the example modification according to FIG. 14 corresponds to the example variant according to FIG. 13, and therefore reference is made to the description thereof.

(77) Moreover, FIG. 15 shows one further example modification of the transmissions G from FIGS. 2 through 5 as well as FIGS. 8 and 9, wherein, in this case as well, an integration of the electric machine EM1 is implemented via a spur gear stage SRS and a planetary gear stage PS. In contrast to the preceding example variant according to FIG. 14, the gear set RS is initially followed here by the spur gear stage SRS, while the planetary gear stage PS is provided in the power flow between the spur gear stage SRS and the electric machine EM1. The planetary gear stage PS also includes, once again, the elements ring gear HO, planet carrier PT, and sun gear SO, wherein the planet carrier PT guides, in a rotatably mounted manner, multiple planet gears PR1 and PR2, each of which is meshed with the sun gear SO as well as with the ring gear HO.

(78) As is apparent in FIG. 15, a first spur gear SR1 of the spur gear stage SRS is connected in a rotationally fixed manner on the side of the gear stage RS of the transmissions G from FIGS. 2 through 5 as well as FIGS. 8 and 9, wherein this connection is completed at the second input shaft GW2. The first spur gear SR1 then intermeshes with a second spur gear SR2 of the spur gear stage SRS, which is rotationally fixed to the planet carrier PT of the planetary gear stage PS. The ring gear HO is permanently fixed at the rotationally fixed component GG, while the sun gear SO is provided, in a rotationally fixed manner, on an input shaft EW of the electric machine EM1.

(79) Finally, FIG. 16 shows one further example modification of the transmission G from FIGS. 2 through 5 as well as FIGS. 8 and 9, wherein this example modification essentially corresponds to the preceding example variant according to FIG. 15. The only difference is that the sun gear SO of the planetary gear stage PS is now permanently fixed at the rotationally fixed component GG, while the ring gear HO of the planetary gear stage PS is rotationally fixed to the input shaft EW of the electric machine EM1. For the rest, the example modification according to FIG. 16 corresponds to the example variant according to FIG. 15, and therefore reference is made to the description thereof.

(80) FIG. 17 shows a section of the four inner shift elements, namely the second shift element B, the third shift element C, the fourth shift element D, and the sixth shift element F from the transmission according to FIGS. 4 and 9 in a simplified diagrammatic view. As is readily apparent, the four shift elements B, C, D, and F are associated with the same shaft, namely the first input shaft GW1, wherein the two “outer” shift elements C and F are spatially separated by the shift elements D and B. The manner in which four shift elements of this type can be actuated by only two actuators is the object of FIGS. 18 through 22.

(81) FIGS. 18 through 22 each show a schematic of an actuating unit 10 of the type which can be utilized, for example, for actuating the second shift element B, the third shift element C, the fourth shift element D, and the sixth shift element F. The shift elements B, C, D, and F can be actuated from the “inside” out, i.e., from the inside of the input shaft GW1. The four shift elements B, C, D, and F are actuated by two actuating elements designed as control rods S1, S2, which, in turn, are each actuated by an actuator A1, A2, respectively. The actuation of the shift elements B, C, D, and F takes place from within the input shaft, i.e., from the inside. The shift elements B, C, D, and F are constant-mesh shift elements.

(82) With respect to FIG. 18, the input shaft GW1 of the transmission G is designed as a hollow shaft in this case. A first control rod S1 is also designed as a hollow shaft, whereas a second control rod S2 is designed as a solid shaft. Both control rods S1, S2 are guided within the input shaft GW1, wherein the second control rod S2 is guided within the first control rod S1. As viewed radially from the outside, the sequence results: input shaft GW1, first control rod S1, second control rod S2. The first control rod S1 can be actuated by a first actuator A1, whereas the second control rod S2 can be actuated by a second actuator A2.

(83) The actuators A1, A2 are arranged on a side of the sixth shift element F facing away from the third shift element C.

(84) In the actuated, i.e., engaged condition, the shift elements C, D, B, and F rotationally fix the input shaft GW1 to another shaft in each case. In this way, the third shift element C connects the input shaft GW1 to a second shaft 22, the fourth shift element D connects the input shaft GW1 to a third shaft 33, the second shift element B connects the input shaft GW1 to a fourth shaft 44, and the sixth shift element F connects the input shaft GW1 to a fifth shaft 55.

(85) The second shaft 22 can form at least one portion of the second input shaft GW2 or of the second element E21 of the first planetary gear set P1 or be connected thereto. The fourth shaft 44 can form at least a portion of the third element E31 of the first planetary gear set P1 or be connected thereto. The fifth shaft 55 can form at least a portion of the second element E22 of the second planetary gear set P2 or be connected thereto. The third shaft 33 can form at least a portion of the first element E12 of the second planetary gear set P2 or be connected thereto.

(86) For the form-fitting connections, the shafts 22, 33, 44, and 55 include tooth systems 2a, 3a, 4a, and 5a, respectively, which correspond to tooth systems 2b, 3b, 4b, and 5b, respectively, of the dogs. The mode of operation of dog clutches is known from the prior art, and so it will not be discussed in greater detail here.

(87) Each control rod S1, S2 can actuate precisely two shift elements. As is to be easily derived from FIG. 17, the first control rod S1 actuates the second shift element B and the fourth shift element D, which are designed as a double shift element in the present case. The second control rod S2, however, actuates the shift elements C, F spatially separated from one another.

(88) In order to actuate the fourth shift element D, the first actuator A1, starting from a non-actuated condition, moves the first gear change rod S1 in the arrow direction 98, i.e., toward the left in the viewing direction. In order to actuate the second shift element B, the first actuator A1, starting from a non-actuated condition, moves the first gear change rod S1 in the arrow direction 99, i.e., toward the right in the viewing direction.

(89) In order to actuate the third shift element C, the second actuator A2, starting from a non-actuated condition, moves the second gear change rod S2 in the arrow direction 96, i.e., toward the left in the viewing direction. In order to actuate the sixth shift element F, the second actuator A2, starting from a non-actuated condition, moves the second gear change rod S2 in the arrow direction 97, i.e., toward the right in the viewing direction.

(90) In order to ensure that the shift elements can be actuated from within the input shaft GW1, the input shaft GW1 includes three recesses, namely a first recess 11, a second recess 12, and a third recess 13. In addition, the first control rod S1 includes a recess 21. The recesses are oblong holes in the present case.

(91) A mechanical coupling or connection of the third shift element C with the second control rod S2 takes place through the first oblong hole 11 of the input shaft GW1. A mechanical coupling of the shift elements B, D with the first control rod S1 takes place through the second oblong hole 12 of the input shaft GW1. Due to the design as a double shift element, the mechanical connection of two shift elements is possible through only one oblong hole. The mechanical coupling of the sixth shift element F, however, takes place through the two mutually corresponding, i.e., essentially aligned oblong holes 13, 21 of the input shaft GW1 and the first control rod S1, respectively.

(92) The particular shift element C, D, B, and F is rotationally fixed to the control rod S1, S2 via a section (not described in greater detail), which is guided through the particular oblong hole 11, 12, 13, and 21.

(93) The shift elements C and F, on the one hand, and D and B, on the other hand, are collectively controlled. This means, when the third shift element C is engaged, the sixth shift element F is simultaneously disengaged, and vice versa. The same also applies for the shift elements C and D.

(94) In order to ensure that the one control rod does not inadvertently move the other control rod and, thereby, possibly engage or disengage a shift element, the oblong hole 21 of the first control rod S1 has a larger diameter than the third oblong hole 13 of the input shaft GW1. In the present case, the diameter is twice as great. As is also apparent, the two control rods are aligned with respect to one another in such a way that the two oblong holes 13, 21 are aligned with one another when the shift elements are each in a non-actuated condition.

(95) By the actuating unit 10, the two shift elements C, F arranged on the outside can be actuated by only one gear change rod and by only one actuator. Therefore, only two actuators A1, A2 are necessary for the four shift elements C, D, B, and F.

(96) FIG. 19 shows a schematic of the actuating unit 10 in a second example embodiment. In contrast to the example embodiment according to FIG. 17, the first control rod S1 actuates the two shift elements C and F. The shift elements D and B are actuated by the second control rod S2, however. For this purpose, the oblong hole 21 is arranged in the first control rod S1 in such a way that the oblong hole 21 corresponds to the second oblong hole 12 of the input shaft GW1. The oblong holes 11, 12, 13 remain unchanged.

(97) In order to actuate the shift element D, the second actuator A2, starting from a non-actuated condition, therefore moves the second gear change rod S2 in the arrow direction 98, i.e., toward the left in the viewing direction. In order to actuate the shift element B, the second actuator A2, starting from a non-actuated condition, moves the second gear change rod S2 in the arrow direction 99, i.e., toward the right in the viewing direction.

(98) In order to actuate the shift element C, the first actuator A1, starting from a non-actuated condition, moves the first gear change rod S1 in the arrow direction 96, i.e., toward the left in the viewing direction. In order to actuate the shift element F, the first actuator A1, starting from a non-actuated condition, moves the first gear change rod S1 in the arrow direction 97, i.e., toward the right in the viewing direction. For the rest, the example variant according to FIG. 19 corresponds to the example embodiment according to FIG. 18, and therefore reference is made to the description thereof.

(99) FIG. 20 shows a schematic of the actuating unit 10 in a third example embodiment. In contrast to the example embodiment according to FIG. 19, the second control rod S2 is designed as a hollow shaft. This allows for a lighter weight and offers space for an oil lubrication (not represented in the present case). For the rest, the example variant according to FIG. 20 corresponds to the example embodiment according to FIG. 18, and therefore reference is made to the description thereof.

(100) FIG. 21 shows a schematic of the actuating unit 10 in one further example embodiment. In contrast to the example embodiment according to FIG. 18, the shift elements D and B are each designed as a single shift element. This makes a fourth oblong hole 14 in the input shaft GW1 necessary. The fourth oblong hole 14 is arranged axially between the second oblong hole 12 and the third oblong hole 13.

(101) In contrast to the example embodiment according to FIG. 18, the fourth oblong hole 14 of the input shaft GW1 now corresponds to the oblong hole 21 of the first control rod S1. In this way, four spatially separated shift elements, namely A and D, on the one hand, and C and D, on the other hand, can be actuated by precisely two actuators A1, A2. For the rest, the example variant according to FIG. 21 corresponds to the example embodiment according to FIG. 18, and therefore reference is made to the description thereof.

(102) FIG. 22 shows a schematic of the actuating unit 10 in one further example embodiment. In contrast to the example embodiment according to FIG. 18, the shift elements D and B are each designed as a single shift element. This makes a fourth oblong hole 14 in the input shaft GW1 necessary. The fourth oblong hole 14 is arranged axially between the second oblong hole 12 and the third oblong hole 13. As in FIG. 17, the oblong hole 21 of the first control rod S1 corresponds to the third oblong hole 13 of the input shaft GW1.

(103) As in the example embodiment according to FIG. 18, the first control rod S1 actuates the shift elements D and B, whereas the second control rod S2 actuates the shift elements C and F. For the rest, the example variant according to FIG. 22 corresponds to the example embodiment according to FIG. 18, and therefore reference is made to the description thereof.

(104) Using example embodiments of the invention, a transmission having a compact design and good efficiency can be implemented.

(105) Modifications and variations can be made to the embodiments illustrated or described herein without departing from the scope and spirit of the invention as set forth in the appended claims. In the claims, reference characters corresponding to elements recited in the detailed description and the drawings may be recited. Such reference characters are enclosed within parentheses and are provided as an aid for reference to example embodiments described in the detailed description and the drawings. Such reference characters are provided for convenience only and have no effect on the scope of the claims. In particular, such reference characters are not intended to limit the claims to the particular example embodiments described in the detailed description and the drawings.

REFERENCE CHARACTERS

(106) G transmission

(107) RS gear set

(108) GG rotationally fixed component

(109) P1 first planetary gear set

(110) E11 first element of the first planetary gear set

(111) E21 second element of the first planetary gear set

(112) E31 third element of the first planetary gear set

(113) P2 second planetary gear set

(114) E12 first element of the second planetary gear set

(115) E22 second element of the second planetary gear set

(116) E32 third element of the second planetary gear set

(117) A first shift element

(118) B second shift element

(119) C third shift element

(120) D fourth shift element

(121) E fifth shift element

(122) F sixth shift element

(123) K seventh shift element

(124) K0 eighth shift element

(125) SP1 shift element pair

(126) SP2 shift element pair

(127) SP3 shift element pair

(128) 1 first gear

(129) 2 second gear

(130) 3.1 third gear

(131) 3.2 third gear

(132) 3.3 third gear

(133) 3.4 third gear

(134) 3.5 third gear

(135) 3.6 third gear

(136) 3.7 third gear

(137) 4 fourth gear

(138) E2 first gear

(139) E4 second gear

(140) E3 third gear

(141) V3 third gear

(142) GW1 first input shaft

(143) GW1-A mounting interface

(144) GW2 second input shaft

(145) GWA output shaft

(146) GWA-A mounting interface

(147) AN connection shaft

(148) EM1 electric machine

(149) S1 stator

(150) R1 rotor

(151) EM2 electric machine

(152) S2 stator

(153) R2 rotor

(154) SRS spur gear stage

(155) SR1 spur gear

(156) SR2 spur gear

(157) PS planetary gear stage

(158) HO ring gear

(159) PT planet carrier

(160) PR planet gear

(161) PR1 planet gear

(162) PR2 planet gear

(163) SO sun gear

(164) ZT flexible traction drive mechanism

(165) VKM internal combustion engine

(166) TS torsional vibration damper

(167) AG differential gear

(168) DW driving wheels

(169) 22 shaft

(170) 33 shaft

(171) 44 shaft

(172) 55 shaft

(173) 11 recess, oblong hole, bore hole

(174) 12 recess, oblong hole, bore hole

(175) 13 recess, oblong hole, bore hole

(176) 14 recess, oblong hole, bore hole

(177) 21 recess, oblong hole, bore hole

(178) 96 direction

(179) 97 direction

(180) 98 direction

(181) 99 direction

(182) A1 actuator

(183) A2 actuator

(184) S1 actuating element, control rod

(185) S2 actuating element, control rod