Abstract
A powertrain of a vehicle includes a stepped planetary gearset, a first gear shifting element and a second gear shifting element. The stepped planetary gearset has a first sun gear and a second sun gear, a first ring gear and a plurality of stepped planet gears rotatably mounted at a first planet carrier. The first ring gear is configured to drivingly connect to an electric machine. The first planet carrier is connectable to an output shaft of the gear unit to be fixed with respect to relative rotation. The first gear shifting element is configured to fix the second sun gear relative to a housing in a closed state, and the second gear shifting element is configured to fix the first sun gear relative to the housing in a closed state. One of the two gear shifting elements is in the closed state for driving the output shaft in rotation.
Claims
1. A gear unit (3) for a powertrain (2) of an at least partially electrically driven vehicle (1), comprising a stepped planetary gearset (4), a first gear shifting element (5) and a second gear shifting element (6), wherein the stepped planetary gearset (4) has a first sun gear (7a), a second sun gear (7b), a first ring gear (8) and a plurality of stepped planet gears (10) rotatably mounted on a first planet carrier (9), wherein the first ring gear (8) is configured to be drivingly connectable to an electric machine (11), wherein the first planet carrier (9) is connectable to an output shaft (12) of the gear unit (3) so as to be fixed with respect to rotation relative to it, wherein the first gear shifting element (5) is configured to fix the second sun gear (7b) relative to a housing (13) in a closed state, wherein the second gear shifting element (6) is configured to fix the first sun gear (7a) relative to the housing (13) in a closed state, and wherein one of the two gear shifting elements (5, 6) is in the closed state for driving the output shaft (12) in rotation.
2. The gear unit (3) according to claim 1, further comprising a third gear shifting element (42) configured to, in a closed state, connect two of the elements of the stepped planetary gearset (4) in the form of the first sun gear (7a), the second sun gear (7b), the first ring gear (8) and the first planet carrier (9) to one another so as to be fixed with respect to rotation relative to one another, and wherein, due to the closed state of the third gear shifting element (42), there is a rotational driving of the output shaft (12).
3. The gear unit (3) according to claim 2, wherein the third gear shifting element (42) is configured as a positively engaging shifting element.
4. The gear unit (3) according to claim 2, wherein the third gear shifting element (42) is configured as a frictionally engaging shifting element.
5. The gear unit (3) according to claim 4, wherein the first gear shifting element (5) is configured as a positively engaging shifting element.
6. The gear unit (3) according to claim 4, wherein the first gear shifting element (5) is configured as a frictionally engaging shifting element.
7. The gear unit (3) according to claim 1, wherein the second gear shifting element (6) is configured as a positively engaging shifting element.
8. The gear unit (3) according to claim 1, wherein the second gear shifting element (6) is configured as a frictionally engaging shifting element.
9. The gear unit (3) according to claim 1, wherein two gear shifting elements (5, 6; 5, 42) are configured jointly as a double shifting element (41; 43).
10. A powertrain (2) for an at least partially electrically driven vehicle (1), comprising the gear unit (3) according to claim 1, an electric machine (11) and a differential (16) configured to drivingly connect the gear unit (3) to two driven shafts (18a, 18b) arranged coaxial to an output axis (17).
11. The powertrain (2) according to claim 10, wherein the differential (16) is configured as a bevel gear differential.
12. The powertrain (2) according to claim 11, further comprising a planetary gear assembly (14) drivingly connectable to the output shaft (12) of the gear unit (3) and has at least a first planetary gearset (15).
13. The powertrain (2) according to claim 12, wherein the first planetary gear set (15) of the planetary gear assembly (14) has a third sun gear (20), a second ring gear (21) which is fixed with respect to the housing, and a plurality of planet gears (23) rotatably mounted at a second planet carrier (22), wherein the third sun gear (20) is connectable to the first planet carrier (9) of the gear unit (3) so as to be fixed with respect to rotation relative to it.
14. The powertrain (2) according to claim 13, wherein a differential carrier (16a) of the differential (16) is connectable to the second planet carrier (22) of the planetary gear assembly (14) so as to be fixed with respect to rotation relative to it.
15. The powertrain (2) according to claim 14, wherein the gear unit (3) and/or the differential (16) are/is arranged at least partially or completely spatially inside of a rotor (19) of the electric machine (11).
16. The powertrain (2) according to claim 15, wherein at least a first transmission stage (24) is drivingly arranged between the output shaft (12) of the gear unit (3) and the differential (16).
17. The powertrain (2) according to claim 10, wherein the differential (16) is configured as an integral differential (25) which has a second planetary gearset (26) and a third planetary gearset (27), wherein each planetary gearset (26, 27) is drivingly connectable to a respective driven shaft (18a, 18b), wherein a first output torque is transmittable to the first driven shaft (18a) by the second planetary gearset (26), and wherein a supporting torque of the second planetary gearset (26) is convertible in the third planetary gearset (27) such that a second output torque corresponding to the first output torque is transmittable to the second driven shaft (18b).
18. The powertrain (2) according to claim 17, wherein the integral differential (25) and the driven shafts (18a, 18b) are adapted to be arranged coaxial to an output axis (17) of the vehicle (1).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The invention will be described in the following with reference to drawings depicting the various embodiment forms of the invention. Like or similar elements are designated with consistent reference numerals. In particular, the drawings show:
[0039] FIG. 1 a vehicle comprising a powertrain according to the invention with a gear unit according to the invention in a first embodiment form;
[0040] FIG. 2 a schematic depiction of the gear unit according to the invention shown in FIG. 1;
[0041] FIG. 3 a schematic diagram of a shifting matrix relating to shifting states for driving with a gear unit according to the invention according to FIG. 2;
[0042] FIG. 4 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention shown in FIG. 1 and FIG. 2;
[0043] FIG. 5 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a second embodiment form;
[0044] FIG. 6 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a third embodiment form;
[0045] FIG. 7 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a seventh embodiment form;
[0046] FIG. 8 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a fifth embodiment form;
[0047] FIG. 9 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a sixth embodiment form;
[0048] FIG. 10 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a seventh embodiment form;
[0049] FIG. 11 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a eighth embodiment form;
[0050] FIG. 12 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a ninth embodiment form;
[0051] FIG. 13 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a tenth embodiment form;
[0052] FIG. 14 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a eleventh embodiment form;
[0053] FIG. 15 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a twelfth embodiment form;
[0054] FIG. 16 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a thirteenth embodiment form;
[0055] FIG. 17 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a fourteenth embodiment form;
[0056] FIG. 18 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a fifteenth embodiment form;
[0057] FIG. 19 a schematic depiction of the powertrain according to the invention with the gear unit according to the invention in a sixteenth embodiment form; and
[0058] FIG. 20 a schematic diagram of a shifting matrix relating to shifting states for driving with a gear unit according to the invention according to one of FIGS. 9 to 19.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0059] FIG. 1 shows an electrically driven vehicle 1 with a powertrain 2 according to the invention in a first embodiment form. The powertrain 2 comprises an electric machine 11 which generates power and introduces this power into a gear unit 3. The gear unit 3 is shown in FIG. 2, and the associated shifting matrix is shown in FIG. 3. The gear unit 3 is drivingly connected to a planetary gear assembly 14 which increases an overall gear ratio and transmits the power to a differential 16 which is arranged downstream in the power flow, in this instance spatially inside of the electric machine 11. The differential 16 divides the motive power between a first driven shaft 18a and a second driven shaft 18b which are in turn operatively connected to a driven wheel 28 of the vehicle 1 in each instance.
[0060] The vehicle 1 can further comprise an energy accumulator—not shown—which is supplied with electrical energy by the electric machine 11 in generator mode when the power flow is reversed. The energy accumulator can be a battery or the like, for example. Accordingly, in generator mode, by the electric machine 11, electrical energy is generated, stored and conserved for resupplying the electric machine 11.
[0061] The gear unit 3 from FIG. 1 is shown in a detailed diagram in FIG. 2. The gear unit 3 according to FIG. 2 can be acted upon by a motive power in the powertrain 2 according to FIG. 4 via an input shaft 29 with a rotor 19 of the electric machine 11, which rotor 19 is mounted so as to be rotatable relative to a stator 30. The input shaft 29 can be connected to the rotor 19 integrally or in more than one part; in any case, a rotationally locked driving connection exists.
[0062] The gear unit 3 comprises a stepped planetary gearset 4 with a first ring gear 8 which is connected to the input shaft 29 so as to be fixed with respect to rotation relative to it, a first sun gear 7a, a second sun gear 7b arranged coaxial thereto, and a plurality of stepped planet gears 10 rotatably mounted at a first planet carrier 9. The gear unit 3 further has a first gear shifting element 5 and a second gear shifting element 6. The first gear shifting element 5 is configured such that, in a closed state, it connects the second sun gear 7b to a housing 13 so as to be fixed with respect to rotation relative to it, and the second gear shifting element 6 is configured such that, in a closed state, it connects the first sun gear 7a to the gear unit 13 so as to be fixed with respect to rotation relative to it. To drive the output shaft 12 in rotation, one of the two gear shifting elements 5, 6 is in the closed state.
[0063] The driving of the gear unit 3 is carried out via the first ring gear 8 which is in meshing engagement with a first toothed wheel 31a of the respective stepped planet gear 10. Further, the respective toothed wheel 31a is in meshing engagement with the first sun gear 7a. In addition to the first toothed wheel 31a, each stepped planet gear 10 also has a second toothed wheel 31b which is axially adjacent the first toothed wheel 31a and connected thereto so as to be fixed with respect to rotation relative to it and which is in meshing engagement with a second sun gear 7b. The two toothed wheels 31a, 31b have different diameters and numbers of teeth so that, depending on the toothed wheel 31a, 31b via which the motive power is transmitted or depending on which gear shifting element 5, 6 is closed or open, two different gear ratios can be realized, both of which are, however, greater than 1. In the present case, the first toothed wheel 31a of the respective stepped planet gear 10 has a smaller diameter than the second toothed wheel 31b of the respective stepped planet gear 10.
[0064] When the second gear shifting element 6 is in a closed state and the first gear shifting element 5 is in an open state, the first sun gear 7a is connected to the housing 13 so as to be fixed with respect to rotation relative to it so that a motive power of the electric machine 11 is transmitted via the first ring gear 8 to the stepped planet gears 10 and from there, via the first planet carrier 9, to an output shaft 12 of the gear unit 3. When the first gear shifting element 5 is in a closed state and the second gear shifting element 6 is in an open state, the second sun gear 7a is connected to the housing 13 so as to be fixed with respect to rotation relative to it so that a motive power of the electric machine 11 is transmitted via the first ring gear 8 to the stepped planet gears 10 and from there, via the first planet carrier 9, to an output shaft 12 of the gear unit 3. In an open state of the respective gear shifting element 5, 6, no torque is transmitted via the respective gear shifting element 5, 6, whereas in a closed state of the respective gear shifting element 5, 6 a torque is transmitted via the respective gear shifting element 5, 6.
[0065] FIG. 3 shows the shifting matrix for a first gear step E1 and a second gear step E2 of the gear unit 3. The respective gear shifting element 5, 6 is closed where indicated by the “X” and open where there is no “X”. An electric forward drive of the vehicle 1 with respective gear ratio is realized via the respective gear step E1, E2. When the second gear shifting element 6 is closed and the first gear shifting element 5 is open, the second gear step E2 is engaged and a second gear ratio which is not equal to the first gear ratio is accordingly realized. This shifting matrix applies to all of the depicted embodiment examples of the invention. Traction power shifting and/or coasting power shifting may be realized depending on the construction of the gear shifting elements 5, 6. In such a case, the respective gear shifting element 5, 6 is configured as a powershift element.
[0066] According to FIG. 2, the first gear shifting element 5 is configured as a positively engaging shifting element, in this case as a jaw-type shifting element. In the closed state of the first gear shifting element 5, a positively engaging connection is accordingly produced between the second sun gear 7b and the housing 13. Ideally, these parts are synchronized before entering the positively engaging connection. On the other hand, the second gear shifting element 6 is formed in the present case as frictionally engaging shifting element, in this instance as a disk-type shifting element. In the closed state of the second gear shifting element 6, a frictionally engaging connection is produced between the first sun gear 7a and the housing 13. A synchronization of the rotational speeds of the parts is not required, and a frictionally engaging shifting element is suitable as power shifting element. In other words, the second gear shifting element 6 realizes a traction power shifting from gear step E1 into gear step E2, or vice versa. The load during shifting processes between gear steps E1, E2 is supportable by the first gear shifting element 5 configured as positively engaging until the second gear shifting element 6 is completely open or closed to prevent a load decrease at the output particularly during shifting processes.
[0067] FIG. 4 shows the powertrain 2 which comprises the gear unit 3 described above. In this respect, reference is made to the statements referring to FIG. 1 to FIG. 3. FIG. 4 also shows the electric machine 11 which is connected via the input shaft 29 to the first ring gear 8 so as to be fixed with respect to rotation relative to it. Alternatively, the two gear shifting elements 5, 6 may be configured as in the respective embodiment form according to FIG. 5, FIG. 6 or FIG. 7. Further, the powertrain 2 has a planetary gear assembly 14 with a first planetary gearset 15. In the present case, the first planetary gearset 15 is configured as a negative planetary gearset and comprises a third sun gear 20 connected to the output shaft 12 of the gear unit 3 so as to be fixed with respect to rotation relative to it, a stationary second ring gear 21 which is connected to the housing 13 so as to be fixed with respect to rotation relative to it, and a plurality of planet gears 23 rotatably mounted at a second planet carrier 22. The third sun gear 20 is drivingly connected to the first planet carrier 9 of the gear unit 3 via output shaft 12 such that the planetary gear assembly 14 is subsequently operatively connected to the output shaft 12 on the drive side. The output of the planetary gear assembly 14 is carried out via the second planet carrier 22 which is drivingly connected to a differential 16. Total gear ratios between 6 and 13.5, for example, can be realized by such a combination comprising gear unit 3 and planetary gear assembly 14.
[0068] In the present case, the differential 16 is configured as a bevel gear differential and drivingly connects the gear unit 3 via the planetary gear assembly 14 to the two driven shafts 18a, 18b arranged coaxial to an output axis 17, the second driven shaft 18b being guided through the gear unit 3 and the planetary gear assembly 14 in the present instance. The bevel gear differential 16 known from the prior art has two output elements on the wheel side which are configured as a first driven wheel 16b and second driven wheel 16c. The driven wheels 16b, 16c mesh, respectively, with a compensating element 16d, 16e. The compensating elements 16d, 16e are mounted in a differential carrier 16a so as to be rotatable around their own axes. The first driven wheel 16b is connected to the first driven shaft 18a so as to be fixed with respect to rotation relative to it, and the second driven wheel 16c is connected to the second driven shaft 18b so as to be fixed with respect to rotation relative to it. The differential carrier 16a of the differential 16 is connected via an intermediate shaft 32 to the second planet carrier 22 so as to be fixed with respect to rotation relative to it, the intermediate shaft 32 being guided through the gear unit 3 coaxial to the input shaft 29 and output shaft 12 of the gear unit 3 and connected to the differential carrier 16a. The differential 16 is arranged completely spatially inside of the rotor 19 of the electric machine 11 in order to save axial installation space. Accordingly, in this case the output axis 17 extends coaxial to an input axis 33, and the rotational axis of the rotor 19, the input shaft 29 and the output shaft 12 of the gear unit 3 are arranged coaxial to the input axis 33. Consequently, the gear unit 3 is arranged axially between the electric machine 11 and the differential 16 on one side and the planetary gear assembly 14 on the other side.
[0069] The powertrain according to FIG. 5 comprises the gear unit 3 from FIG. 2 with the difference that the two gear shifting elements 5, 6 are configured as jaw-type shifting elements and are combined to form a double shifting element 41. Therefore, reference is made to the statements relating to the gear unit 3 from FIG. 2. Alternatively, the two gear shifting elements 5, 6 may be configured as in the respective embodiment form according to FIG. 4, FIG. 6 or FIG. 7. Reference is made to the description relating to FIG. 3 for the shifting between the first gear step E1 and second gear step E2. The gear unit 3 comprising the stepped planetary gearset 4 and the two gear shifting elements 5, 6 is arranged spatially completely inside of the rotor 19 of the electric machine 11 in order to save axial installation space and make the powertrain 2 more compact. The gear shifting elements 5, 6 are arranged directly adjacent one another coaxial to the input axis 33 and output axis 17 and together form the double shifting element 41 which is compactly comprised of the two gear shifting elements 5, 6. The gear shifting elements 5, 6 realize a positively engaging connection between the housing 13 and first sun gear 7a or second sun gear 7b, respectively, in the closed state. A particularly cost-optimized and efficiency-optimized clutch system is provided in this way.
[0070] The first planetary gearset 15 of the planetary gear assembly 14 is configured as a negative planetary gearset and comprises a third sun gear 20 connected to the output shaft 12 of the gear unit 3 so as to be fixed with respect to rotation relative to it, a stationary second ring gear 21 connected to the housing 13 so as to be fixed with respect to rotation relative to it, and a plurality of planet gears 23 rotatably mounted at a second planet carrier 22. The third sun gear 20 is connected to the first planet carrier 9 of the gear unit 3 via output shaft 12 so as to be fixed with respect to rotation relative to it such that the planetary gear assembly 14 is subsequently operatively connected to the output shaft 12 on the drive side. The output of the planetary gear assembly 14 is carried out via the second planet carrier 22 which is connected to a differential carrier 16a of the differential 16 so as to be fixed with respect to rotation relative to it. The differential 16 is configured as a bevel gear differential and is further identical to the differential 16 according to FIG. 4 so that the relevant statements apply here. Total gear ratios of between 6 and 13.5, for example, can be achieved by such a combination comprising gear unit 3 and planetary gear assembly 14.
[0071] The differential 16 drivingly connects the gear unit 3 to the driven shafts 18a, 18b via the planetary gear assembly 14. In the present case, the first driven shaft 18a is guided axially through the gear unit 3 and the electric machine 11. The planetary gear assembly 14 is arranged axially between the electric machine 11 and the gear unit 3 on the one hand and the differential 16 on the other hand. Alternatively, it is conceivable that the differential 16 is also arranged together with the gear unit 3 spatially inside of the rotor 19 of the electric machine 11 in order to save additional axial installation space. The differential 16 is drivingly connected to the second planet carrier 22 via an intermediate shaft 32. The intermediate shaft 32 is arranged coaxial to the output shaft 12 of the gear unit 3. Here, too, the output axis 17 is arranged coaxial to an input axis 33.
[0072] The powertrain 2 according to FIG. 6 comprises the gear unit 3 from FIG. 2 with the difference that the two gear shifting elements 5, 6 are configured as jaw-type shifting elements. Therefore, reference is made to the statements pertaining to the gear unit 3 from FIG. 2. Reference is made to the description of FIG. 3 for the shifting between the first gear step E1 and the second gear step E2. FIG. 6 shows a third embodiment example of the powertrain 2 according to the invention. In the present instance, the gear unit 3 comprising the stepped planetary gearset 4 and the two gear shifting elements 5, 6 are arranged spatially completely inside of the rotor 19 of the electric machine 11 in order to save axial installation space of the powertrain 2. The gear shifting elements 5, 6 realize a positively engaging connection between the housing 13 and the first sun gear 7a or second sun gear 7b, respectively, in the closed state. A particularly cost-optimized and efficiency-optimized clutch system is provided in this way. Alternatively, it is conceivable that the respective gear shifting elements 5, 6 formed in each instance as jaw-type shifting element are combined and configured as a double shifting element as in FIG. 5. Further alternatively, the two gear shifting elements 5, 6 can be configured as in the respective embodiment form according to FIG. 4 or FIG. 7.
[0073] In contrast to the powertrains 2 according to FIG. 4 and FIG. 5 which have a differential 16 configured as a bevel gear differential, the powertrain 2 according to FIG. 6 comprises a differential 16 configured as an integral differential 25 with a second planetary gearset 26 and third planetary gearset 27. The two planetary gearsets 26, 27 are arranged either axially adjacent one another or radially one above the other depending on the requirements of the integral differential 25, particularly the gear ratio to be realized by the integral differential 25. In the present case, the planetary gearsets 26, 27 are arranged radially one above the other so that axial installation space of the powertrain 2 is saved. In other words, the planetary gearsets 26, 27 lie in a common plane perpendicular to the driven shafts 18a, 18b or output axis 17, respectively. Consequently, the integral differential 25 is constructed in a radially nested type of construction.
[0074] A first output torque can be transmitted to the first driven shaft 18a by the second planetary gearset 16. A supporting torque of the second planetary gearset 26 acting opposite the first output torque is transmitted to the third planetary gearset 27 and is convertible in the third planetary gearset 27 in such a way that a second output torque corresponding to the first output torque can be transmitted to the second driven shaft 18b. Consequently, the integral differential 25 is configured as planetary gear assembly. The integral differential 25 is operatively connected to the gear unit 3 via the input shaft of the integral differential 25 which is simultaneously the output shaft 12 of the gear unit 3. The output at the integral differential 25 is carried out via the two driven shafts 18a, 18b. In other words, a motive power is distributed to two driven shafts 18a, 18b by the integral differential 25. In the present case, the first driven shaft 18a extends in direction of the gear unit 3 and electric machine 11 and is axially guided through the gear unit 3 and the electric machine 11. The second driven shaft 18b extends away from the powertrain 2 in the opposite direction. Due to the fact that the integral differential 25 which increases a torque coming from the gear unit 3 is only arranged at the end of the powertrain 2, the component parts arranged upstream thereof in the power flow can be formed comparatively small and slender so that production is more economical and the overall weight of the powertrain 2 is reduced. The driven shafts 18a, 18b, the integral differential 25, the electric machine 11 and the gear unit 3 are arranged coaxial to the input axis 33 of the gear unit 3 and to the output axis 17 of the vehicle 1.
[0075] The output shaft 12 of the gear unit 3 is connected to a fourth sun gear 34a of the second planetary gearset 26 so as to be fixed with respect to rotation relative to it. Accordingly, the first planet carrier 9 is connected to the fourth sun gear 34a so as to be fixed with respect to rotation relative to it. The transmission of power from the second planetary gearset 26 to the third planetary gearset 27 is carried out via a coupling shaft 35 which is connected to a third ring gear 36a of the second planetary gearset 26 so as to be fixed with respect to rotation relative to it on the one hand and, on the other hand, is connected to a fifth sun gear 34b of the third planetary gearset 27 so as to be fixed with respect to rotation relative to it. Consequently, the coupling shaft 35, the third ring gear 36a and the fifth sun gear 34b are connected integral with one another. The coupling shaft 35 with the third ring gear 36a and the fifth sun gear 34b can also be configured as a ring gear which has not only an inner toothing but also an outer toothing. A plurality of second planetary gears 37a is arranged spatially between the fourth sun gear 34a and the third ring gear 36a, in the present instance so as to be rotatable on a rotatably mounted third planet carrier 38a. Further, a plurality of third planetary gears 37b which are arranged in the present case so as to be rotatable on a fourth planet carrier 38b fixed with respect to the housing are arranged on the same radially extending plane and radially outside of the second planetary gearset 26 spatially between the fifth sun gear 34b and a fourth ring gear 36b of the third planetary gearset 27. The first output on the first driven shaft 18a is carried out via the third planet carrier 38a of the second planetary gearset 26, which third planet carrier 38a is connected to the first driven shaft 18a so as to be fixed with respect to rotation relative to it. The second output on the second driven shaft 18b is carried out via the fourth ring gear 36b of the third planetary gearset 27, which fourth ring gear 36b is connected to the second driven shaft 18b so as to be fixed with respect to rotation relative to it.
[0076] According to a fourth alternative embodiment example of the powertrain 2 shown in FIG. 7, the gear unit 3 is arranged axially between the electric machine 11 and the differential 16, the differential 16 being arranged on the output axis 17 which is arranged paraxial to the input axis 33 in the present case. Accordingly, the input shaft 29 and the output shaft 12 of the gear unit 3 are also arranged on the input axis 33. The output shaft 12 is drivingly connected via a transmission stage 24 which, in the present case, is formed to be single-stage and which comprises a third toothed wheel 39a which is connected to the output shaft 12 so as to be fixed with respect to rotation relative to it and a fourth toothed wheel 39b which is operatively connected to the differential 16. In the present case, the toothed wheels 39a, 39b are configured as spur gears so that the transmission stage 24 consequently comprises a spur gear stage. The overall gear ratio of the powertrain 2 is realized by the transmission stage 24 by suitably configured toothed wheel diameter and number of teeth. In this respect, an additional planetary gear assembly 14 corresponding to the embodiment examples according to FIG. 4 and FIG. 5 can be dispensed with. However, depending on the requirements of the powertrain, it may be useful to provide a further gear unit for increasing a total gear ratio. As a result of the paraxial arrangement of the powertrain components, axial installation space is economized in the powertrain 2, that is, in particular in that the electric machine 11 together with the gear unit 3 and the differential 16 are arranged at least partially adjacent one another. In this way, the electric machine 11 can also be made more slender, which in turn has a positive effect on the axial spacing between the input axis 33 and output axis 17. In the present case, the differential 16 is configured as a bevel gear differential and, further, is identical to the differential 16 according to FIG. 4. Reference is made to the relevant statements.
[0077] In the present case, the gear shifting elements 5, 6 of the gear unit 3 are formed in each instance as a disk-type shifting element and realize in each instance a frictionally engaging connection between the housing 13 of the gear unit 3 and the first sun gear 7a or second sun gear 7b, respectively, in the closed state. In this regard, it is advantageous that both traction shifts and coasting shifts can be power-shifted between the gear steps E1 and E2, or vice versa. In other words, the gear shifting elements 5, 6 are power shifting elements in the present case. The load during shifting processes between the gear steps E1, E2 can be supported by the first gear shifting element 5 until the second gear shifting element 6 is completely open or closed, or vice versa, thereby preventing a load decrease at the output particularly during shifting processes. Consequently, the powertrain 2 according to FIG. 7 comprises the gear unit from FIG. 2 with the difference that the two gear shifting elements 5, 6 are configured as disk-type shifting elements. Therefore, reference is made to the statements relating to the gear unit 3 from FIG. 2. As regards the shifting between the first gear step E1 and second gear step E2, reference is made to the description relating to FIG. 3. Alternatively, the two gear shifting elements 5, 6 can be configured as in the embodiment form according to FIG. 4, FIG. 5 or FIG. 6.
[0078] FIG. 8 shows a fifth embodiment example of the powertrain 2 in which the gear unit 3 is arranged axially between the electric machine 11 and the differential 16. Analogous to FIG. 7, the differential 16 is arranged on the output axis 17 paraxial to the input axis 33 on which the output shaft 12 of the gear unit 3 lies. The output shaft 12 of the gear unit 3 is operatively connected to the differential 16 via two transmission stages 24, 40. The first transmission stage 24 comprises a third toothed wheel 39a which is connected to the output shaft 12 so as to be fixed with respect to rotation relative to it and a fourth toothed wheel 39b which is connected to an intermediate shaft 32 arranged paraxial to the input axis 33 and output axis 17 so as to be fixed with respect to rotation relative to the intermediate shaft 32. Axially adjacent the fourth toothed wheel 39b, a fifth toothed wheel 39c of the second transmission stage 40 is arranged on the intermediate shaft 32 so as to be fixed with respect to rotation relative to it, this intermediate shaft 32 being in meshing engagement with a sixth toothed wheel 39d operatively connected to the differential 16. The overall gear ratio of the powertrain 2 is generated by the transmission stages 24, 40 by correspondingly configuring the toothed wheel diameters and number of teeth of the toothed wheels 39a-39d. The toothed wheels 39a-39d are formed in the present instance as spur gears, and the transmission stages 24, 40 are consequently spur gear stages. In this regard, an additional planetary gear assembly 14 corresponding to the embodiment examples according to FIG. 4 and FIG. 5 can be dispensed with. However, depending on the requirement for the powertrain 2, it may be useful to provide a further gear unit for increasing a total gear ratio. Axial installation space is saved in the powertrain 2 through the paraxial arrangement of the powertrain components, particularly in that the electric machine 11 together with the gear unit 3 and the differential 16 are arranged at least partially adjacent one another. Accordingly, the electric machine 11 can be made more slender, which in turn has a positive effect on the axial spacing between the input axis and output axis.
[0079] The two gear shifting elements 5, 6 of the gear unit 3 are arranged directly adjacent one another coaxial to the input axis 33 and together form a double shifting element which combines the two gear shifting elements 5, 6. In the present case, the gear shifting elements 5, 6 are each configured as jaw-type shifting elements as in the embodiment example according to FIG. 5 to which reference is made. For the shifting between the first gear step E1 and second gear step E2, reference is made to the description relating to FIG. 3. Further, reference is made to the statements relating to FIG. 7 and the reference numerals used therein, particularly to FIG. 2 and FIG. 5. Alternatively, the two gear shifting elements 5, 6 can be configured as in the respective embodiment form according to FIG. 4, FIG. 6 or FIG. 7. As a further alternative, the gear unit 3 can be arranged inside of the rotor 19 as in the embodiment forms according to FIG. 5 and FIG. 6.
[0080] FIG. 9 shows a portion of a powertrain 2 corresponding to a sixth embodiment form of the invention. This powertrain 2 substantially corresponds to the variant according to FIG. 4 with the difference that a further, third gear shifting element 42 is provided in addition to the first gear shifting element 5 and the second gear shifting element 6 and, when in the actuated state, the third gear shifting element 42 connects the output shaft 12 and, therefore, the first planet carrier 9 to the first sun gear 7a of the stepped planetary gearset 4 so as to be fixed with respect to rotation relative to it. Actuation of the third gear shifting element 42 brings about a locking of the stepped planetary gearset 4 and, accordingly, a direct through-drive is made from the input shaft 29 of the gear unit 3 to the output shaft 12.
[0081] A further distinction consists in that the gear shifting elements 5, 6 and 42 are each constructed as frictionally engaging shifting elements; in particular, the individual gear shifting element 5 or 6 or 42 is configured as a disk-type shifting element. While the stepped planetary gearset 4 is arranged axially level with and radially inwardly of the electric machine 11, the gear shifting elements 5, 6 and 42 are provided to lie radially inwardly of and at least partially axially adjacent the electric machine 11. In so doing, gear shifting element 5 partially axially overlaps the electric machine 11 and is followed axially first by gear shifting element 11 and lastly by gear shifting element 42. The latter is provided radially inwardly relative to the gear shifting elements 5 and 6 which are arranged radially substantially on the same level. Further, in a manner analogous to the preceding variants, a coupling to a differential 16 or 25 is produced at the output shaft 12 of the gear unit 3. In other respects also, the embodiment form according to FIG. 9 corresponds to the variant according to FIG. 4, so that reference is had to the description in this regard.
[0082] FIG. 10 shows a portion of a further powertrain 2 according to the invention which corresponds to a great extent to the preceding variant according to FIG. 9 with the difference that the third gear shifting element 42, when actuated, now connects the output shaft 12 and, therefore, the first planet carrier 9 to the input shaft 29 and, therefore, to the first ring gear 8 so as to be fixed with respect to relative rotation. This again results in a locking of the stepped planetary gearset 4. Further, the third gear shifting element 42 is now arranged axially on a side of the electric machine 11 remote of the gear shifting elements 5 and 6. In other respects, the embodiment form according to FIG. 10 corresponds to the variant according to FIG. 9, so that reference is had to the description in this regard.
[0083] Further, FIG. 11 shows a portion of a powertrain 2 according to a further embodiment form of the invention. This embodiment form also substantially corresponds to the variant according to FIG. 9. In contrast to the variant according to FIG. 9, the first gear shifting element 5 in gear unit 3 is now configured as positively engaging shifting element as in the variant of the gear unit 3 according to FIG. 2. In this instance, the first gear shifting element 5 presents in particular as an unsynchronized jaw-type shifting element. The first gear shifting element 5 is arranged axially level with and radially inwardly of the electric machine 11, the first gear shifting element 5 being situated axially between the stepped planetary gearset 4 and the second gear shifting element 6. In other respects, the embodiment form according to FIG. 11 corresponds to the variant according to FIG. 9, so that reference is had to the description in this regard.
[0084] FIG. 12 shows a portion of a powertrain 2 which is constructed corresponding to a further configuration possibility of the invention and substantially corresponds to the embodiment form according to FIG. 9 with the difference that now all three gear shifting elements 5, 6 and 42 are configured as positively engaging shifting elements. The gear shifting elements 5, 6 and 42 are preferably configured as unsynchronized jaw-type shifting elements. Further, as in the variant according to FIG. 5, the first gear shifting element 5 and the second gear shifting element 6 form a double shifting element 41 which is provided axially level with and radially inwardly of the electric machine 11. In other respects, the configuration possibility according to FIG. 12 corresponds to the variant according to FIG. 9, so that reference is had to the description in this regard.
[0085] Further, FIG. 13 shows a portion of a powertrain 2 according to a further embodiment form of the invention. This embodiment form substantially corresponds to the preceding variant according to FIG. 12 with the difference that in this case, as in the variant according to FIG. 10, the third gear shifting element 42, when actuated, brings about a locking of the stepped planetary gearset 4 in that the third gear shifting element 42 in the actuated state connects the output shaft 12 and, therefore, the first planet carrier 9 to the input shaft 29 and, therefore, to the first ring gear 8 so as to be fixed with respect to relative rotation. In comparison to the variant according to FIG. 12, the third gear shifting element 42 is arranged axially on an opposite side of the electric machine 11. Otherwise, the embodiment form according to FIG. 13 corresponds to the variant according to FIG. 12, so that reference is had to the description in this regard.
[0086] FIG. 14 shows a portion of a powertrain 2 corresponding to a further configuration possibility of the invention. This configuration possibility substantially corresponds to the variant according to FIG. 9 with the difference that the first gear shifting element 5 and the third gear shifting element 42 are configured as positively engaging shifting elements particularly in the form of unsynchronized jaw-type shifting elements and form a double shifting element 43. Further, in the actuated state of the third gear shifting element 42, a locking of the stepped planetary gearset 4 is achieved in that the output shaft 12 and, therefore, the first planet carrier 9 is connected to the second sun gear 7b so as to be fixed with respect to rotation relative to it. The double shifting element 43 is provided axially level with and radially inwardly of the electric machine 11, the third gear shifting element 42 being situated axially between the stepped planetary gearset 4 and the first gear shifting element 5. Otherwise, the embodiment form according to FIG. 14 corresponds to the variant according to FIG. 9, so that reference is had to the description in this regard.
[0087] FIG. 15 is a view of a powertrain 2 according to an embodiment form of the invention. This embodiment form substantially corresponds to the variant according to FIG. 4. This embodiment form differs from the variant according to FIG. 4 in that, as in the configuration according to FIG. 9, the third gear shifting element 42 is now additionally provided in the gear unit 3 of the powertrain 2 and, in the actuated state, the third gear shifting element 42 brings about a locking of the stepped planetary gearset 4 in that the output shaft 12 and the first sun gear 7a are connected so as to be fixed with respect to relative rotation. As in the variant according to FIG. 9, the gear shifting elements 5, 6 and 42 are configured in each instance as frictionally engaging shifting elements, in particular, in the form of disk-type shifting elements. The gear shifting elements 5, 6 and 42 axially follow the stepped planetary gearset 4 in the sequence of first gear shifting element 5, second gear shifting element 6 and, lastly, third gear shafting element 42. Otherwise, the embodiment form according to FIG. 15 corresponds to the variant according to FIG. 4, so that reference is had to the description in this regard.
[0088] FIG. 16 shows a further configuration possibility according to the invention for a powertrain 2. This configuration possibility substantially corresponds to the variant according to FIG. 5 with the difference that the gear unit 3 of this powertrain 2 is configured according to the variant in FIG. 9 in that the third gear shifting element 42 is provided in addition to the first gear shifting element 5 and the second gear shifting element 6. In the actuated state, this third gear shifting element 42 connects the output shaft 12 and, therefore, the first planet carrier 9 to the first sun gear 7a so as to be fixed with respect to relative rotation, resulting in a locking of the stepped planetary gearset 4. The gear shifting elements 5, 6 and 42 are configured in each instance as frictionally engaging shifting elements, preferably in the form of disk-type shifting elements. The gear shifting elements 5, 6 and 42 axially follow the electric machine 11 in the sequence 5, 6 and, lastly, 42. The gear shifting elements 5, 6 and 42 are situated axially between the electric machine 11 and the stepped planetary gearset 4 on the one side and the planetary gear assembly 14 on the other side. Otherwise, the configuration possibility according to FIG. 16 corresponds to the variant according to FIG. 5, so that reference is had to the description in this regard.
[0089] FIG. 17 shows an embodiment form of a powertrain 2 according to the invention which substantially corresponds to the variant according to FIG. 6. In contrast to the variant according to FIG. 6, the gear unit 3 of the powertrain 2 is formed analogous to the variant according to FIG. 13 in that the gear shifting elements 5 and 6 form a double shifting element 41, and a third gear shifting element 22 in actuated state brings about a locking of the stepped planetary gearset 4. This is achieved in that the third gear shifting element 42, when actuated, connects the output shaft 12 and, therefore, the first planet carrier 9 to the input shaft 29 and, therefore, to the first ring gear 8 so as to be fixed with respect to relative rotation. The third gear shifting element 42 is located axially on a side of the electric machine 11 remote of the differential 16. In other respects, the embodiment form according to FIG. 17 corresponds to the variant according to FIG. 6, so that reference is had to the description in this regard.
[0090] FIG. 18 shows a further embodiment form, according to the invention, of a powertrain 2. This embodiment form substantially corresponds to the variant according to FIG. 13 with the difference, for one, that the two gear shifting elements 5 and 6 now do not form a double shifting element, but rather are constructed as individual shifting elements. Further, the second gear shifting element 6 is not located axially level with the electric machine 11, but rather axially adjacent the electric machine 11. Further, a coupling of the output shaft 12 with a differential 16 is carried out via a transmission stage 24, this coupling being realized analogous to the variant according to FIG. 7. To this extent, reference is had to the variant according to FIG. 7 in this respect. Otherwise, the embodiment form according to FIG. 18 corresponds to the variant according to FIG. 13, so that reference is had to the description in this regard.
[0091] Further, FIG. 19 shows a further configuration possibility, according to the invention, of a powertrain 2 which substantially corresponds to the variant according to FIG. 11. The configuration possibility according to FIG. 19 differs from the variant according to FIG. 11 in that the output shaft 12 is now coupled with a differential 16 via a first transmission stage 24 and a second transmission stage 40, this coupling being carried out analogous to the variant according to FIG. 8. With regard to the coupling, reference is had to the description referring to FIG. 8. Otherwise, the embodiment form according to FIG. 19 corresponds to the variant according to FIG. 11, so that reference is had to FIG. 11.
[0092] Lastly, FIG. 20 shows a schematic diagram of a shifting matrix which relates to shifting states for driving with a gear unit according to the invention in accordance with one of the variants shown in FIGS. 9 to 19. In this respect, a first gear E1 and a second gear E2 are shown analogous to the description referring to FIG. 3, but now a third gear E3 can be engaged in addition by actuating the third gear shifting element 42. Depending on the configuration of the gear shifting elements 5, 6 and 42, a traction power shift and/or coasting power shift can be realized. In such a case, the respective gear shifting element 5 or 6 or 42, respectively, is configured as a power shift element.
[0093] Thus, while there have been shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
REFERENCE CHARACTERS
[0094] 1 vehicle [0095] 2 powertrain [0096] 3 gear unit [0097] 4 stepped planetary gearset [0098] 5 first gear shifting element [0099] 6 second gear shifting element [0100] 7a first sun gear [0101] 7b second sun gear [0102] 8 first ring gear [0103] 9 first planet carrier [0104] 10 stepped planet gears [0105] 11 electric machine [0106] 12 output shaft of the gear unit [0107] 13 housing [0108] 14 planetary gear assembly [0109] 15 first planetary gearset [0110] 16 differential [0111] 16a differential carrier [0112] 16b first driven wheel of the differential [0113] 16c second driven wheel of the differential [0114] 16d compensating element of the differential [0115] 16e compensating element of the differential [0116] 17 output axis [0117] 18a first driven shaft [0118] 18b second driven shaft [0119] 19 rotor of the electric machine [0120] 20 third sun gear [0121] 21 second ring gear [0122] 22 second planet carrier [0123] 23 first planet gear [0124] 24 first transmission stage [0125] 25 integral differential [0126] 26 second planetary gearset [0127] 27 third planetary gearset [0128] 28 wheel of the vehicle [0129] 29 input shaft of the gear unit [0130] 30 stator of the electric machine [0131] 31a first toothed wheel of the stepped planetary gear [0132] 31b second toothed wheel of the stepped planetary gear [0133] 32 intermediate shaft [0134] 33 input axis [0135] 34a second sun gear of the integral differential [0136] 34b fifth sun gear of the integral differential [0137] 35 coupling shaft of the integral differential [0138] 36a third ring gear [0139] 36b fourth ring gear [0140] 37a second planet gear [0141] 37b third planet gear [0142] 38a third planet carrier [0143] 38b fourth planet carrier [0144] 39a third toothed wheel of the transmission stage [0145] 39b fourth toothed wheel of the transmission stage [0146] 39c fifth toothed wheel of the transmission stage [0147] 39d sixth toothed wheel of the transmission stage [0148] 40 second transmission stage [0149] 41 double shifting element [0150] 42 third gear shifting element [0151] 43 double shifting element [0152] E1 first gear [0153] E2 second gear [0154] E3 third gear
