HYBRIDISED DRIVETRAIN AND METHOD FOR CONTROLLING SAID DRIVETRAIN

Abstract

A hybridised drivetrain for a motor vehicle. A transmission assembly of the vehicle has at least one first planetary gear set. A first element of the first planetary gear set is a ring gear. A second element of the first planetary gear set can be connected to an electric machine of the vehicle with a clutch and can be secured against a housing. The second element is a sun gear. A third element of the first planetary gear set is connected to an output. The third element is a planet carrier. The ring gear can also be connected to the electric machine by means of a clutch. The clutch has an output disc carrier connected to the sun gear. The clutch has an output disc carrier connected to the ring gear. The input disc carrier and the output disc carrier can rotate relative to one another.

Claims

1. A hybridized drive train for a motor vehicle, having a combustion engine, an electric machine and a gearbox assembly, wherein the gearbox assembly has at least one first planetary gear set and is configured as a summation gearbox, wherein a first element of the first planetary gear set is rotatably connectable to the combustion engine and fixable directly or indirectly in relation to a housing, wherein the first element of the first planetary gear set is configured as a ring gear, a second element of the first planetary gear set by means of a clutch C is rotatably connectable to the electric machine and fixable directly or indirectly in relation to the housing, wherein the second element of the first planetary gear set is configured as a sun gear, a third element of the first planetary gear set is connected to an output, wherein the third element of the first planetary gear set is configured as a planet carrier, wherein the ring gear by means of a clutch D is furthermore connectable to the electric machine, wherein the clutch C has an output disk carrier CA which is connected to the sun gear of the first planetary gear set, wherein the clutch D has an output disk carrier DA which is connected to the ring gear of the first planetary set, and wherein the input disk carrier and the output disk carrier DA are mounted so as to be mutually rotatable.

2. The drivetrain as claimed in claim 1, wherein the clutches C and D configure a double-clutch assembly and have a common clutch input side, wherein the common clutch input side is rotatably connected to the electric machine.

3. The drivetrain as claimed in claim 2, wherein the common clutch input side comprises an input disk carrier which carries disks assigned to the clutch C as well as to the clutch D.

4. The drivetrain as claimed in claim 3, wherein the second element of the planetary gear set by means of a brake B is fixable in relation to the housing, and the clutch input side of the double-clutch assembly by way of a gear wheel stage is connected to the electric machine, wherein this gear wheel stage is disposed axially between the brake B and the double-clutch assembly.

5. The drivetrain as claimed in claim 1, wherein the sun gear of the first planetary gear set is configured as a hollow shaft and is mounted so as to be rotatable in relation to the planet carrier of the first planetary gear set.

6. The drivetrain as claimed in claim 1, wherein the planet carrier of the first planetary gear set is connected to the output by way of a gear wheel stage, wherein this gear wheel stage in the drivetrain is disposed on that side that lies opposite the combustion engine.

7. The drivetrain as claimed in claim 1, wherein the gearbox assembly furthermore comprises a second planetary gear set, wherein a planet carrier of the second planetary gear set is rotatably connected to the ring gear of the first planetary gear set, wherein a sun gear of the second planetary gear set is rotatably connected to the combustion engine, a ring gear of the second planetary gear set by means of a brake E is fixable in relation to the housing, and wherein the planet carrier and the sun gear of the first planetary set are rotatably connectable by means of a clutch A.

8. The drivetrain as claimed in claim 7, wherein the drivetrain comprises exclusively two planetary gear sets.

9. The drivetrain as claimed in claim 7 wherein the combustion engine is rotatably connected exclusively to the sun gear of the second planetary gear set and furthermore is connectable to the planet carrier of the second planetary gear set exclusively by way of the clutch A.

10. The drivetrain as claimed in claim 7, wherein the first and the second planetary gear set are connected to one another exclusively by way of a rotationally fixed connection between the ring gear of the first planetary set and the planet carrier of the second planetary set.

11. A method for controlling a drivetrain as claimed in claim 1, wherein a third purely electric gear stage is established in that the clutches C and D are closed.

12. The method for controlling a drivetrain as claimed in claim 11, wherein a second purely combustion-engine gear stage is established in that the clutches C and D and the brake E are closed.

13. The method for controlling a drivetrain as claimed in claim 11, wherein a hybridized gear stage is established in that the third purely electric gear stage and the second combustion-engine gear stage are established in combination.

Description

DRAWINGS

[0051] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0052] FIG. 1 shows a hybridized drivetrain according to the invention as per a first exemplary embodiment;

[0053] FIG. 2 shows a circuit diagram for a hybridized drivetrain as per the first exemplary embodiment;

[0054] FIG. 3 shows a hybridized drivetrain according to the invention as per a second exemplary embodiment; and

[0055] FIG. 4 shows a circuit diagram for a hybridized drivetrain as per the second exemplary embodiment.

DESCRIPTION OF THE INVENTION

[0056] The hybridized drivetrain 1 shown in FIG. 1 has a combustion engine (not shown), a dual mass flywheel, a gearbox input shaft 3, a gearbox assembly 5, an electric machine EM, an output 4 and a housing.

[0057] The gearbox assembly 5 comprises a first planetary gear set PGS1 which in turn has a first element which is configured as a ring gear 13, a second element which is configured as a sun gear 11, and a third element which is configured as a planet carrier 12.

[0058] Moreover, the gearbox assembly 5 has a second planetary gear set PGS2 comprising a sun gear 21, a planet carrier 22 and a ring gear 23.

[0059] The sun gear 21 by way of the gearbox input shaft and the dual mass flywheel is connected in a rotationally fixed manner to the combustion engine. The sun gear 21 by means of a clutch A can be connected to the planet carrier 22, and the second planetary gear set PGS2 can thus be interlocked. Furthermore, the ring gear 23 by means of a brake E is fixable in relation to the housing such that the second planetary gear set PGS2 can be operated in the braked state.

[0060] The first and the second planetary gear set PGS1, PGS2 are coupled to one another exclusively by way of a rotationally fixed connection between the ring gear 13 and the planet carrier 22. The power flux of the drive output of the combustion engine runs by way of the second planetary gear set PGS2 toward the ring gear 13 of the first planetary gear set PGS1.

[0061] The first planetary gear set PGS1 is configured as a summation gearbox, i.e. the power inputs of both drive machines converge in the first planetary gear set and are discharged toward the output by way of the planet carrier 12 and a spur gear stage 7. The electric machine EM here by means of a double-clutch assembly 30, comprising a clutch C and D, is connectable to the first planetary gear set. A rotationally fixed connection between the sun gear 11 and the electric machine EM can be established by means of the clutch C. Furthermore, the electric machine EM is connectable to the ring gear 13 by means of the clutch D.

[0062] The drive output of the electric machine EM is introduced either only into the sun gear 11, only into the ring gear 13, or—as soon as both clutches C and D are closed—both into the sun gear 11 and into the ring gear 13 simultaneously into the first planetary gear set.

[0063] The first planetary gear set PGS1 is in the interlocked state once the two clutches C and D are closed.

[0064] The clutches C and D have a common clutch input side 31, wherein the common clutch input side 31 is rotatably connected to the electric machine EM. Furthermore, the common clutch input side 31 has an input disk carrier 32 which carries disks assigned to the clutch C as well as to the clutch D.

[0065] Moreover, the clutch input side 31 by way of a gear wheel stage 6 is rotatably connected to the electric machine EM, wherein the electric machine is disposed parallel to the gearbox assembly.

[0066] The sun gear 11 by means of a brake B is fixable directly in relation to the housing, as a result of which the first planetary gear set can be operated in the braked state.

[0067] The gear wheel stage 6 here is disposed axially between the brake B and the double-clutch assembly.

[0068] A gear wheel stage 7 which rotatably connects the planet carrier to the output 4 in this exemplary embodiment is disposed in the hybridized drivetrain 1 on that side that lies opposite the combustion engine.

[0069] The hybridized drivetrain 1 is configured for establishing four purely combustion-engine gear stages, in that the first and the second planetary gear set (PGS1 and PGS2) are operated in a combination of a revolving block and an epicyclic transmission. For example, a first combustion-engine gear stage according to the circuit diagram in FIG. 2 thus is established when the brake B as well as the brake E are closed, i.e. both planetary gear sets PGS1, PGS2 are braked and revolve in their epicyclic transmission. In the second combustion-engine gear stage, the two clutches C and D are closed and thus interlock the first planetary gear set, whereas the second planetary gear set PGS2 continues to be in the braked state.

[0070] Furthermore, the hybridized drivetrain 1, by adding the input of the electric machine EM, is configured for supporting the four combustion-engine gear stages in the parallel operation, or for driving said four combustion-engine gear stages in a recuperation mode. Herein, the clutch D is additionally closed as long as the latter is not already being utilized by a combustion-engine gear stage according to the circuit diagram in FIG. 2.

[0071] The first and the second electrically operated gear stages are established in that one of the two clutches C or D is closed, and the first planetary gear set PGS1 is simultaneously in the braked state.

[0072] The braked state may take place directly or indirectly. If the ring gear 13 is to be driven by the machine EM (second electric gear stage), direct braking of the first planetary gear set PGS1 takes place by the brake B in that the sun gear 11 is fixed in relation to the housing. However, if the sun gear 11 is to be driven by the electric machine EM (first electrically operated gear stage), indirect braking of the first planetary gear set PGS1 takes place by fixing the ring gear 13 in relation to the housing by way of the brake E and the clutch A, wherein the brake E and the clutch A are not assigned directly to the first but to the second planetary gear set.

[0073] According to the invention, the third purely electrically operated gear stage is established by closing the clutches C and D.

[0074] A further particularity of the hybridized drivetrain 1 lies in the possibility of being able to operate both drive machines at different rotating speeds in the so-called CVT mode. In this continuously variable operation, the electric machine by way of the clutch C is linked exclusively to the sun gear 11, whereas the combustion-engine output is directed into the ring gear 13. Therefore, the first planetary gear set remains unbraked.

[0075] Overall, this during operation thus results in three purely electrically operated gear stages, four purely combustion-engine gear stages, four hybrid parallel operation gear stages and two CVT-operated gear stages.

[0076] The hybridized drivetrain 1 shown in FIG. 3 shows a second exemplary embodiment and contains substantially the same components and is of a similar construction as the first exemplary embodiment shown in FIG. 1, which is why the same reference signs have been correspondingly used. The substantial point of differentiation lies in how the two drive machines and the output are linked to the first planetary gear set/summation gearbox. The first element of the first planetary gear set is thus assigned to the ring gear 11. The second element is assigned to the planet carrier 12, and the third element is assigned to the ring gear 13.

[0077] Furthermore, the first planetary gear set PGS1 is configured in the manner of a plus planetary gearbox.

[0078] Moreover, the gear wheel stage 6 in the hybridized drivetrain is disposed on that side that lies opposite the combustion engine. In contrast, the gear wheel stage 7 is disposed between the double-clutch assembly 30 and the first planetary gear set PGS1.

[0079] The functional mode is identical to that of the first exemplary embodiment. The type and number of gear stages thus remains identical in each case. Shorter gear ratios of the first gears result by virtue of the different ways that the drive machines and the output are linked to the first planetary gear set PGS1, the spread being increased as a result. A gearshift logic optimized for operation can be derived from FIG. 4.

LIST OF REFERENCE SIGNS

[0080] 1 Drivetrain

[0081] 3 Gearbox input

[0082] 4 Output

[0083] 5 Gearbox assembly

[0084] 6 Gear wheel stage

[0085] 7 Gear wheel stage

[0086] 11 Sun gear of the first planetary gear set

[0087] 12 Planet carrier of the first planetary gear set

[0088] 13 Ring gear of the first planetary gear set

[0089] 21 Sun gear of the second planetary gear set

[0090] 22 Planet carrier of the second planetary gear set

[0091] 23 Ring gear of the second planetary gear set

[0092] 30 Double-clutch assembly

[0093] 31 Clutch input side

[0094] 32 Input disk carrier

[0095] CA Output disk carrier of the clutch C

[0096] CD Output disk carrier of the clutch D

[0097] EM Electric machine

[0098] PGS1 First planetary gear set

[0099] PGS2 Second planetary gear set

[0100] A Clutch

[0101] B Brake

[0102] C Clutch

[0103] D Clutch

[0104] E Brake