6-speed planetary transmission

Abstract

A 6-speed planetary transmission for a motor vehicle has an input shaft, an output shaft, a first planetary gear set, a second planetary gear set and a third planetary gear set. The input shaft can be coupled to the first planetary carrier or to the first ring gear via a first shifting element. The first sun gear can be coupled to a gearbox housing via a second shifting element. The first planetary carrier can be coupled to the first ring gear via a third shifting element. The second ring gear or the second planetary carrier can be coupled to the gearbox housing via a fourth shifting element. In addition, the first ring gear or the first planetary carrier, the second sun gear and the third sun gear are connected for conjoint rotation. In addition, the output shaft is connected for conjoint rotation to the second planetary carrier or the second ring gear.

Claims

1. A 6-speed planetary transmission for a motor vehicle, comprising: a transmission input shaft; a transmission output shaft; a first planetary gear set which comprises a first sun gear, a first planetary carrier, a first internal gear and at least one first planetary gear; a second planetary gear set which comprises a second sun gear, a second planetary carrier, a second internal gear and at least one second planetary gear; and a third planetary gear set which comprises a third sun gear, a third planetary carrier, a third internal gear and at least one third planetary gear, wherein the transmission input shaft is coupleable via a first shifting element to the first planetary carrier or the first internal gear, the first sun gear is coupleable via a second shifting element to a transmission housing, the first planetary carrier is coupleable via a third shifting element to the first internal gear, the first internal gear or the first planetary carrier, the second sun gear and the third sun gear are connected fixedly so as to rotate together, the second internal gear or the second planetary carrier is coupleable via a fourth shifting element to the transmission housing, and the transmission output shaft is connected fixedly to the second planetary carrier or the second internal gear so as to rotate together, wherein the first planetary gear set comprises an outer first planetary gear and an inner first planetary gear, the outer first planetary gear interacts with the first internal gear, the inner first planetary gear interacts with the first sun gear, and the outer first planetary gear interacts with the inner first planetary gear.

2. The 6-speed planetary transmission as claimed in claim 1, wherein the transmission input shaft is connected fixedly to the third planetary carrier so as to rotate together.

3. The 6-speed planetary transmission as claimed in claim 1, wherein the transmission output shaft is coupleable via a fifth shifting element to the third internal gear.

4. The 6-speed planetary transmission as claimed in claim 1, wherein at least one of the shifting elements is a positively locking shifting element.

5. The 6-speed planetary transmission as claimed in claim 1, wherein all of the shifting elements are positively locking shifting elements.

6. The 6-speed planetary transmission as claimed in claim 1, further comprising: a first electric motor coupled to the first sun gear.

7. The 6-speed planetary transmission as claimed in claim 6, further comprising: a second electric motor coupled to the transmission input shaft, the transmission output shaft or the third internal gear.

8. The 6-speed planetary transmission as claimed in claim 1, further comprising: a third electric motor coupled to the second sun gear.

9. The 6-speed planetary transmission as claimed in claim 1, further comprising: a third electric motor coupled to the second sun gear, and a fourth electric motor coupled to the third internal gear.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 diagrammatically shows a first embodiment of a 6-speed planetary transmission according to the invention.

(2) FIG. 2 diagrammatically shows a second embodiment of a 6-speed planetary transmission according to the invention.

(3) FIG. 3 diagrammatically shows a third embodiment of a 6-speed planetary transmission according to the invention.

(4) FIG. 4 diagrammatically shows a fourth embodiment of a 6-speed planetary transmission according to the invention.

(5) FIG. 5 diagrammatically shows a fifth embodiment of a 6-speed planetary transmission according to the invention.

(6) FIG. 6 shows a shifting pattern which belongs to the 6-speed planetary transmissions which are shown in FIGS. 1 to 5.

(7) FIG. 7 diagrammatically shows a known 9-speed planetary transmission, from which a 6-speed planetary transmission according to the invention can be derived.

DETAILED DESCRIPTION OF THE DRAWINGS

(8) FIG. 1 shows a 6-speed planetary transmission 10. It comprises a transmission input shaft 12 and a transmission output shaft 14.

(9) The transmission input shaft 12 and the transmission output shaft 14 can be coupled via a first planetary gear set 16, a second planetary gear set 18 and a third planetary gear set 20.

(10) The first planetary gear set 16 comprises a first sun gear 22, a first planetary carrier 24, a first internal gear 26 and a first planetary gear 28.

(11) The second planetary gear set 18 comprises a second sun gear 30, a second internal gear 32, a second planetary carrier 34 and a second planetary gear 36.

(12) The third planetary gear set 20 comprises a third sun gear 40, a third planetary carrier 42, a third internal gear 44 and a third planetary gear 46.

(13) For reasons of clarity, in each case only a first planetary gear 28, a second planetary gear 36 or a third planetary gear 46 is shown in the planetary gear sets 16, 18, 20. It goes without saying that the planetary gear sets 16, 18, 20 can also comprise a plurality of planetary gears.

(14) The planetary gear sets 16, 18, 20 are arranged in a transmission housing 48.

(15) The transmission input shaft 12 can be coupled via a first shifting element 50 to the first planetary carrier 24.

(16) Moreover, the first sun gear 22 can be coupled via a second shifting element 52 to the transmission housing 48.

(17) Furthermore, the first planetary carrier 24 can be coupled via a third shifting element 54 to the first internal gear 26.

(18) Here, the first internal gear 26, the second sun gear 30 and the third sun gear 40 are connected fixedly so as to rotate together. Therefore, the second sun gear 30 and the third sun gear 40 form what is known as a double sun.

(19) Furthermore, the second internal gear 32 can be coupled via a fourth shifting element 56 to the transmission housing 48.

(20) The transmission output shaft 14 is connected fixedly to the second planetary carrier 34 so as to rotate with it.

(21) The abovementioned structure is common to the two embodiments of the 6-speed planetary transmission 10 which are shown in FIGS. 1 and 2.

(22) In the embodiment which is shown in FIG. 1, the transmission input shaft 12 is additionally connected fixedly to the third planetary carrier 42 so as to rotate with it.

(23) Moreover, the transmission output shaft 14 can be coupled via a fifth shifting element 58 to the third internal gear 44 in this embodiment.

(24) In the embodiment which is shown in FIG. 2, the transmission output shaft 14 is connected fixedly to the third internal gear 44 so as to rotate with it.

(25) Furthermore, the transmission input shaft 12 can be coupled via a sixth shifting element 60 to the third planetary carrier 42 in the embodiment which is shown in FIG. 2.

(26) The embodiment which is shown in FIG. 3 differs from the 6-speed planetary transmission 10 which is shown in FIG. 1 in that two planetary gears 28a, 28b are arranged in the radial direction.

(27) The first planetary gear set 16 therefore comprises an outer first planetary gear 28a and an inner first planetary gear 28b.

(28) Here, the outer first planetary gear 28a interacts with the first internal gear 26, the inner first planetary gear 28b interacts with the first sun gear 22, and the outer first planetary gear 28a interacts with the inner first planetary gear 28b.

(29) Moreover, in the embodiment according to FIG. 3, the first shifting element 50 acts between the first internal gear 26 and the transmission input shaft 12 instead of between the transmission input shaft 12 and the first planetary carrier 24, as in the embodiments according to FIGS. 1 and 2.

(30) In addition, instead of the first internal gear 26, the first planetary carrier 24 is connected fixedly to the second sun gear 30 and the third sun gear 40 so as to rotate with them in the embodiment which is shown in FIG. 3.

(31) In contrast to the embodiment which is shown in FIG. 1, the embodiment according to FIG. 4 comprises two second planetary gears 36a, 36b.

(32) As a result, the second planetary gear set 18 comprises an outer second planetary gear 36a and an inner second planetary gear 36b, the outer second planetary gear 36a interacting with the second internal gear 32, the inner second planetary gear 36b interacting with the second sun gear 30, and the outer second planetary gear 36a interacting with the inner second planetary gear 36b.

(33) In contrast to the embodiment according to FIG. 1, in addition, instead of the second internal gear 32, the second planetary carrier 24 can be coupled via the fourth shifting element 56 to the transmission housing 48.

(34) The second planetary carrier 34 is also not connected fixedly to the transmission output shaft 14 so as to rotate with it, but rather the second internal gear 32 is connected to said transmission output shaft 14.

(35) FIG. 5 shows a further embodiment, in which the transmission input shaft 12 is connected fixedly to the third internal gear 44 so as to rotate with it. The differences with respect to the embodiment which is shown in FIG. 1 will be described again.

(36) Here, the third planetary carrier 42 can be coupled via a seventh shifting element 61 to the transmission output shaft 14.

(37) Furthermore, the third planetary gear set 20 then comprises two third planetary gears 46a, 46b which are arranged radially next to one another.

(38) Here, the outer third planetary gear 46a interacts with the third internal gear 44, the inner third planetary gear 46b interacts with the third sun gear 40, and the outer third planetary gear 46a interacts with the inner third planetary gear 46b.

(39) Those shifting elements 50, 54, 58, 60, 61 which act between rotatable components of the 6-speed planetary transmission 10 can be called clutches.

(40) The shifting elements 52, 56 act between the transmission housing 48 and rotatable transmission components. They can be called brakes.

(41) In FIGS. 1 to 5, the shifting elements 50-61 are positively locking shifting elements.

(42) The 6-speed planetary transmission 10 which is shown in FIGS. 1 to 5 can be hybridized.

(43) Here, a first electric motor 62 is coupled to the first sun gear 22.

(44) An additional, second electric motor 64a can be coupled to the transmission input shaft 12. As an alternative, the second electric motor 64b can be operatively connected to the transmission output shaft 14. It is a further alternative to couple the second electric motor 64c to the third internal gear 44.

(45) FIGS. 1 to 4 in each case show three second electric motors 64a-64c. These represent alternatives, however. The 6-speed planetary transmission 10 therefore always comprises only a single second electric motor 64a-64c.

(46) In the embodiment according to FIG. 5, the electric motors 64a and 64c have an identical action. The electric motor 64c is therefore not shown.

(47) In the embodiment which is shown in FIG. 5, a motor which corresponds to the electric motor 64c can be attached, however, to the planetary carrier 42 of the third planetary gear set 20. A motor of this type is not shown in the figure.

(48) As an alternative to the first electric motor 62 and to the second electric motor 64a-64c, a third electric motor 66 can be coupled to the second sun gear 30.

(49) In addition, a fourth electric motor 68 can be coupled to the third internal gear 44. Here, the fourth electric motor 68 corresponds to the second electric motor 64c which is also coupled to the third internal gear 44.

(50) In the embodiment which is shown in FIG. 5, the fourth electric motor 68 therefore corresponds to the electric motor 64a. The electric motor 68 is therefore not shown.

(51) The electric motor or motors 62-68 can be used to realize a reverse gear of the 6-speed planetary transmission 10.

(52) Moreover, one or more of the electric motors 62-68 can be used as synchronizing elements.

(53) FIG. 6 shows a shifting pattern which belongs to the 6-speed planetary transmission 10. To this end, the shifting elements 52-61 are indicated in the column header. Six shiftable gears A to F are noted in the row header. The table which is defined in this way then specifies which shifting elements are closed in which gear.

(54) In gear A, the shifting elements 50, 54 and 56 are closed. The remaining shifting elements 52, 58, 60, 61 are open.

(55) In gear B, the shifting elements 50, 52 and 56 are closed. The shifting elements 54, 58, 60, 61 are open.

(56) Gear C provides that the shifting elements 50, 56 and 58, 60 or 61 are closed. The shifting elements 54 and 52 are open.

(57) In gear D, the shifting elements 50, 52 and 58, 60 or 61 are closed. The shifting elements 54 and 56 are open.

(58) In gear E, the shifting elements 52 and 56 are open, but the shifting elements 50, 54 and 58, 60 or 61 are closed.

(59) In gear F, the shifting elements 52, 54 and 58, 60 or 61 are closed, and the shifting elements 50 and 56 are open.

(60) It can therefore be seen from FIG. 6 that always only the shifting state of two of the shifting elements 50-61 has to be changed for changing between adjoining gears.

(61) The shifting elements 50-61 can be shifted in an automated manner, with the result that the 6-speed planetary transmission 10 is a transmission which can be shifted in an automated manner.

(62) The 6-speed planetary transmission 10 can be derived from a planetary transmission 100 with four planetary gear sets. A planetary transmission of this type is known, for example, from DE 10 2009 025 609 A1 (see FIG. 1 thereof).

(63) In FIG. 7, the planetary transmission 100 is a 9-gear transmission and comprises a first planetary gear set 102, a second planetary gear set 104, a third planetary gear set 106 and a fourth planetary gear set 108.

(64) Moreover, the planetary transmission 100 comprises a first shifting element 110, a second shifting element 112, a third shifting element 114, a fourth shifting element 116, a fifth shifting element 118 and a sixth shifting element 120. The nine gears can be shifted by way of the actuation of said shifting elements 110-120.

(65) In order then, for example, to derive the 6-speed planetary transmission 10 according to FIG. 1 from the planetary transmission 100 of FIG. 7, the second planetary gear set 104 is removed from the planetary transmission 100 in the example which is shown.

(66) As a consequence, the shifting element 112 can also be dispensed with. The shifting elements 110 and 116 are displaced within the transmission structure or are replaced by shifting elements with an identical action. Therefore, the shifting element 110 corresponds to the shifting element 50, and the shifting element 116 corresponds to the shifting element 54.

(67) The derivation of the 6-speed planetary transmission 10 which is shown in FIGS. 2 to 5 takes place in an analogous manner.

(68) The 6-speed planetary transmission 10 is of more compact construction in comparison with the planetary transmission 100, and provides more installation space for the integration of electric motors 62-68.

(69) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.