DE102009028682B4 - Multi-speed transmission - Google Patents

Abstract

Multi-stage transmission in planetary construction, in particular automatic transmission for a motor vehicle, comprising a drive shaft (1), an output shaft (2) and four planetary gear sets (P1, P2, P3, P4), which are arranged in a housing (G), a total of eight rotatable shafts ( 1, 2, 3, 4, 5, 6, 7, 8) and at least six switching elements (03, 04, 13, 27, 35, 68), comprising brakes (03, 04) and clutches (13, 27, 35, 68) whose selective engagement causes different ratios between the drive shaft (1) and the output shaft (2), so that nine forward gears and one reverse gear can be realized, wherein the sun gear of the first planetary gear set (P1) coupled to the housing (G) of the transmission is, wherein the web of the first planetary gear set (P1) with the third shaft (3) is connected, which via a second brake (03) to the housing (G) of the transmission can be coupled via a first clutch (13) with the drive shaft ( 1) and via a second clutch (35) with the fün ften shaft (5) is detachably connectable, wherein the fifth shaft (5) with the ring gear of the second planetary gear set (P2) and the sun gear of the fourth planetary gear set (P4) is connected and the drive shaft (1) with the sun gear of the second planetary gear set (P2 ) and the web of the third planetary gear set (P3), wherein the sixth shaft (6) connected to the ring gear of the first planetary gear set (P1) and via a fourth clutch (68) with the eighth shaft (8) is detachably connectable, the is connected to the web of the second planetary gear set (P2) and the sun gear of the third planetary gear set (P3), wherein the ring gear of the fourth planetary gear set (P4) with the fourth shaft (4) is connected via a first brake (04) to the Housing (G) of the transmission is coupled and wherein the output shaft (2) via a third clutch (27) with the ring gear of the third planetary gear set (P3) connected to the seventh shaft (7) releasably connectable and with the web of the fourth planetary gear set (P4 ) connected is.

Description

The present invention relates to a multi-stage planetary gear, in particular an automatic transmission for a motor vehicle.

Automatic transmissions, in particular for motor vehicles, comprise in the prior art planetary gear sets which are switched by means of friction elements such as clutches and brakes, and usually with a slipping action and optionally with a lock-up starting element, such as a hydrodynamic torque converter or a fluid coupling connected.

Such an automatic transmission is for example from the DE 199 49 507 A1 known to the applicant; Here, two non-shiftable Vorschaltradsätze are provided on the output side, the output side generate two speeds that are selectively switchable in addition to the speed of the drive shaft to a force acting on the output shaft, switchable Doppelplanetenradsatz by selectively closing the switching elements used that to switch from a gear in the respective next higher or lower gear from the two currently operated switching elements only one switching element must be switched on or off.

Using five shift elements, seven forward gears are achieved, nine or ten forward gears using six shift elements.

Furthermore, from the DE 102 13 820 A1 a multi-speed automatic transmission with eight forward gears and one reverse gear is known, comprising a first input path T1 a first gear ratio; an input path T2 that has a larger gear ratio than this input path T1 Has; a Ravigneaux type four-element planetary gear set, the four elements being a first element, a second element, a third element and a fourth element in the order of the elements in a speed diagram; a clutch C-2, which is a rotation of the input path T2 on the first element S3 transfers; a clutch C-1, which is the rotation of the input path T2 on the fourth element S2 transfers; a clutch C-4, which is one turn from the input path T1 transfers to the first element; a clutch C-3, which controls the rotation of the input path T1 on the second element C3 transfers; a brake B-1 which establishes the engagement of the fourth element; a brake B-2 which makes the engagement of the second member; and an output element connected to the third element S3 is coupled.

A 9-speed multi-speed transmission is also from the DE 29 36 969 A1 known; it comprises eight shift elements and four sets of wheels, one wheel set serves as a Vorschaltgetriebe and the main gear has a Simpson set and another serving as a reverse gear wheelset.

Further multi-speed transmissions are for example from the DE 10 2005 010 210 A1 and the DE 10 2006 006 637 A1 the applicant known.

Automatically switchable vehicle transmissions in planetary construction in general are already widely described in the prior art and are subject to permanent development and improvement. So these transmissions require a low construction cost, in particular a small number of switching elements and avoid sequential switching double circuits, so that in circuits in defined gear groups only one switching element is changed.

From the not pre-published DE 10 2008 000 428 A1 The applicant is a planetary gear multi-speed transmission known which has a drive and an output, which are arranged in a housing. In the known transmission at least four planetary gear sets, hereinafter referred to as the first, second, third and fourth planetary gear set, at least eight rotatable shafts - hereinafter referred to as drive shaft, output shaft, third, fourth, fifth, sixth, seventh and eighth shaft - and at least six switching elements, comprising brakes and clutches, provided, the selective engagement causes different ratios between the drive and the output, so that preferably nine forward gears and one reverse gear can be realized.

Here, the first and the second planetary gear set, which are preferably designed as minus planetary gear sets, form a switchable transfer gearset, wherein the third and the fourth planetary gear set form a main gearset.

In the known multi-speed transmission is provided that the webs of the first and second planetary gear sets are coupled to each other via the fourth shaft, which is connected to an element of the main gearset that the ring gear of the first planetary gear set coupled to the sun gear of the second planetary gear set on the eighth wave is, which is releasably connectable via a first clutch to the drive shaft and that the sun gear of the first planetary gear by means of the third shaft via a first brake to a housing of the transmission is coupled and releasably connectable via a second clutch to the drive shaft, wherein the ring gear of second planetary gear set by means of the fifth shaft via a second brake to a housing the transmission can be coupled. In addition, the seventh shaft with at least one element of the main gearset is constantly connected and coupled via a third brake to a housing of the transmission, the sixth shaft is continuously connected to at least one further element of the main gear and releasably connected via a third clutch to the drive shaft; the output shaft is permanently connected to at least one further element of the main gearset.

Preferably, in the known transmission, the fourth shaft is constantly connected to the ring gear of the third planetary gear set, wherein the sixth shaft is constantly connected to the ring gear of the fourth planetary gear set and the web of the third planetary gear set and releasably connectable via the third clutch to the drive shaft. Further, the seventh shaft is constantly connected to the sun gears of the third and fourth planetary gear set and can be coupled via the third brake to a housing of the transmission. The output takes place here via the output shaft permanently connected to the web of the fourth planetary gearset. Furthermore, the third and the fourth planetary gear set can be combined or reduced to a Ravigneaux set with a common web and a common ring gear.

The present invention has for its object to propose a multi-speed transmission of the type mentioned, which has nine forward gears and at least one reverse gear with sufficient translation, in which the construction cost and size, in particular the overall length, or the weight can be optimized and also the efficiency is improved in terms of drag and gearing losses. In addition, in the multistage transmission according to the invention, small supporting moments act on the shifting elements. In particular, the transmission according to the invention should be suitable for a front-transverse construction.

This object is achieved by the features of claim 1. Further advantages and advantageous embodiments will become apparent from the dependent claims.

Accordingly, a multi-speed transmission according to the invention is proposed planetary design, which has a drive and an output, which are arranged in a housing. Furthermore, at least four planetary gear sets, hereinafter referred to as the first, second, third and fourth planetary gear set, eight rotatable shafts - hereinafter referred to as drive shaft, output shaft, third, fourth, fifth, sixth, seventh and eighth shaft - and at least six switching elements, comprising brakes and clutches, provided whose selective engagement causes different ratios between the drive and the output, so that preferably nine forward gears and one reverse gear can be realized.

The planetary gear sets are arranged axially in the order of the first planetary gearset, second planetary gearset, third planetary gearset, fourth planetary gearset and are preferably designed as minus planetary gear sets.

A simple minus planetary set known to include a sun gear, a ring gear and a ridge on which planet gears are rotatably mounted, which mesh with each sun gear and ring gear. In this way, the ring gear at a fixed web on a sun gear opposite direction of rotation. In contrast, a simple plus-planetary gearset includes a sun gear, a ring gear and a web on which inner and outer planetary gears are rotatably mounted, wherein all inner planetary gears mesh with the sun gear and all outer planetary gears with the ring gear, each inner planetary gear, each with an outer Planet wheel meshes. As a result, the ring gear has the same direction of rotation when holding the web as the sun gear.

According to a preferred embodiment of the invention, the sun gear of the first planetary gearset is coupled to a housing of the transmission, wherein the web of the first planetary gear set is connected to the third shaft, which can be coupled via a second brake to a housing of the transmission, via a first clutch with the Drive shaft and via a second clutch to the fifth shaft is releasably connectable, wherein the fifth shaft is connected to the ring gear of the second planetary gear set and the sun gear of the fourth planetary gear set and the drive shaft is connected to the sun gear of the second planetary gear set and the web of the third planetary gear set.

Furthermore, the ring gear of the first planetary gear set is connected to the sixth shaft, which is releasably connectable via a fourth clutch with the eighth wave, which is directly connected to the web of the second planetary gear set and the sun gear of the third planetary gear set, wherein the ring gear of the fourth planetary gearset can be coupled via a first brake to a housing of the transmission and wherein the output shaft via a third clutch with the connected to the ring gear of the third planetary gear set seventh shaft is detachably connected and connected to the web of the fourth planetary gearset.

The inventive design of the multi-speed transmission resulting in particular for passenger cars suitable translations and increased overall spread of the multi-speed transmission, creating an improvement of Driving comfort and a significant consumption reduction can be effected.

In addition, the construction cost is considerably reduced with the multi-stage transmission according to the invention by a small number of switching elements. Advantageously, it is possible with the multistage transmission according to the invention to carry out a start with a hydrodynamic converter, an external starting clutch or other suitable external starting elements. It is also conceivable to allow a starting operation with a start-up element integrated in the transmission. Preferably, a switching element which is actuated in the first forward gear and in reverse is suitable.

Furthermore, in the multistage transmission according to the invention a good efficiency in the main gears with respect to the drag and gear losses.

Furthermore, there are small moments in the switching elements and in the planetary gear sets of the multi-speed transmission, whereby the wear in the multi-speed transmission is advantageously reduced. In addition, a correspondingly small dimensions are made possible by the low moments, whereby the required space and the corresponding costs are reduced. In addition, there are also low speeds in the waves, the switching elements and the planetary gear sets.

In addition, the transmission according to the invention is designed such that an adaptability to different drive train configurations is made possible both in the power flow direction as well as in space.

• 1: Eine schematische Ansicht einer ersten bevorzugten Ausführungsform eines erfindungsgemäßen Mehrstufengetriebes; und
• 2: Ein beispielhaftes Schaltschema für ein Mehrstufengetriebe gemäß 1.

The invention will be explained in more detail below by way of example with reference to the attached figures. These are:

• 1 : A schematic view of a first preferred embodiment of a multi-speed transmission according to the invention; and
• 2 : An exemplary circuit diagram for a multi-step transmission according to 1 ,

In 1 is an inventive multi-stage transmission with a drive shaft 1 , an output shaft 2 and four planetary gear sets P1 . P2 . P3 and P4 shown, which in a housing G are arranged. The planetary gear sets P1 . P2 . P3 and P4 are at the in 1 shown example designed as a minus planetary gear sets. According to the invention, at least one planetary gear set can be designed as a plus planetary gear set, if at the same time the web and Hohlradanbindung exchanged and the amount of stationary translation is increased by 1 compared to the design as a minus planetary gear set.

In the embodiment shown, the planetary gear sets are axially in the order P1 . P2 . P3 . P4 arranged.

How out 1 can be seen, six switching elements, namely two brakes 03 . 04 and four clutches 13 . 35 and 27 and 68 intended. The spatial arrangement of the switching elements can be arbitrary and is limited only by the dimensions and the external shape. The clutches and the brakes of the transmission are preferably designed as Reibschaltelemente or lamellar switching elements.

With these switching elements a selective switching of nine forward gears and one reverse gear can be realized. The multi-speed transmission according to the invention has a total of eight rotatable shafts, namely the waves 1 . 2 . 3 . 4 . 5 . 6 . 7 and 8th wherein the drive shaft forms the first shaft and the output shaft forms the second shaft of the transmission.

According to the invention in the multi-stage transmission according to 1 provided that the sun gear of the first planetary gear set P1 to a housing G coupled to the transmission (shaft 0 ), wherein the bridge of the first planetary gear set P1 with the third wave 3 which is connected via a second brake 03 to a housing G the transmission can be coupled, via a first clutch 13 with the drive shaft 1 and a second clutch 35 with the fifth wave 5 is detachably connectable.

How out 1 is the fifth wave 5 with the ring gear of the second planetary gear set P2 and the sun gear of the fourth planetary gear set P4 connected, the drive shaft 1 with the sun gear of the second planetary gear set P2 connected and with the bridge of the third planetary gear set P3 connected is.

According to the invention, the ring gear of the first planetary gear set P1 with the sixth wave 6 connected via a fourth clutch 68 with the eighth wave 8th is releasably connectable, which with the web of the second planetary gear set P2 and the sun gear of the third planetary gear set P3 is directly connected, wherein the ring gear of the fourth planetary gear set P4 with the fourth wave 4 connected, which has a first brake 04 to a housing G the transmission can be coupled; the output shaft 2 is via a third clutch 27 with the with the ring gear of the third planetary gear set P3 connected seventh wave 7 releasably connectable and with the bridge of the fourth planetary gear set P4 connected.

According to the invention, the first clutch 13 viewed axially between the first and second planetary gear sets P1 . P2 be arranged, wherein the third clutch 27 viewed axially between the third and the fourth planetary gear set P3 . P4 can be arranged.

Further, the second brake 03 and the second clutch 35 preferably arranged axially adjacent to each other.

In 2 is an exemplary circuit diagram of a multi-speed transmission according to 1 shown. For each gear three switching elements are closed. The schematics can be the respective translations i the individual gear steps and the gear steps or increments to be determined therefrom phi to the next higher gear, the value 9.002 represents the spread of the gearbox.

Typical values for the stand ratios of the planetary gear sets designed as minus planetary gear sets P1 . P2 . P3 and P4 are respectively -1.60, -2.228, -1.60 and -3.642. Out 2 It can be seen that in the case of sequential switching, double circuits or group circuits are avoided, since two adjacent gear stages share two switching elements. Further, it will be seen that a large spread is achieved with small gear jumps.

The first forward gear is obtained by closing the first brake 04 and the second and fourth clutches 35 . 68 , the second forward gear by closing the first brake 04 and the first and second clutches 13 . 35 , the third forward gear by closing the first brake 04 and the first and fourth clutches 13 . 68 , the fourth forward gear by closing the first brake 04 and the third and fourth clutches 27 . 68 , the fifth forward gear by closing the first, third and fourth clutch 13 . 27 . 68 which preferably performs a direct forward sixth forward gear by closing the first, second and third clutches 13 . 35 . 27 , the seventh forward gear by closing the second, third and fourth clutches 35 . 27 . 68 , the eighth forward gear by closing the second brake 03 and the second and third clutches 35 . 27 and the ninth forward gear is obtained by closing the second brake 03 and the third and fourth clutches 27 . 68 , wherein the reverse gear by closing the first and second brake 04 . 03 and the fourth clutch 68 results.

Due to the fact that in first forward gear and in first reverse gear the first brake 04 and the fourth clutch 68 are closed, these switching elements can be used as starting elements.

According to the invention, different gear jumps may result even with the same transmission scheme depending on the switching logic, so that an application- or vehicle-specific variation is made possible.

According to the invention, it is possible to provide additional freewheels at any suitable location of the multi-speed transmission, for example between a shaft and the housing or, if necessary, to connect two shafts.

On the drive side or on the output side, an axle differential and / or a distributor differential can be arranged according to the invention.

In the context of an advantageous development, the drive shaft 1 be separated by a coupling element of a drive motor as needed, with a hydrodynamic converter, a hydraulic clutch, a dry starting clutch, a wet starting clutch, a magnetic powder clutch or a centrifugal clutch can be used as a coupling element. It is also possible to arrange such a starting element in the power flow direction behind the transmission, in which case the drive shaft 1 constantly connected to the crankshaft of the engine.

The multistage transmission according to the invention also allows the arrangement of a torsional vibration damper between the engine and transmission.

In the context of a further, not shown embodiment of the invention can on each shaft, preferably on the drive shaft 1 or the output shaft 2 , a wear-free brake, such as a hydraulic or electric retarder or the like, be arranged, which is particularly important for use in commercial vehicles of particular importance. Furthermore, to drive additional units on each shaft, preferably on the drive shaft 1 or the output shaft 2 be provided a power take-off.

The friction shift elements used can be designed as a load-shifting clutches or brakes. In particular, non-positive clutches or brakes, such as e.g. Multi-plate clutches, band brakes and / or cone clutches are used.

Another advantage of the multistage transmission presented here is that an electric machine can be mounted on each shaft as a generator and / or as an additional drive machine.

Of course, also falls any constructive training, especially any spatial arrangement of the planetary gear sets and the switching elements in itself and to one another and as far as technically feasible, within the scope of the present claims without affecting the function of the transmission, as indicated in the claims, also if these training are not explicitly shown in the figures or in the description.

LIST OF REFERENCE NUMBERS

0

wave

1

first shaft, drive shaft

2

second shaft, output shaft

3

third wave

4

fourth wave

5

fifth wave

6

sixth wave

7

seventh wave

8th

eighth wave

03

second brake

04

first brake

13

first clutch

27

third clutch

35

second clutch

68

fourth clutch

P1

first planetary gear set

P2

second planetary set

P3

third planetary set

P4

fourth planetary set

i

translation

phi

increment

G

casing

Claims (3)

Multi-stage transmission in planetary construction, in particular automatic transmission for a motor vehicle, comprising a drive shaft (1), an output shaft (2) and four planetary gear sets (P1, P2, P3, P4), which are arranged in a housing (G), a total of eight rotatable shafts ( 1, 2, 3, 4, 5, 6, 7, 8) and at least six switching elements (03, 04, 13, 27, 35, 68), comprising brakes (03, 04) and clutches (13, 27, 35, 68) whose selective engagement causes different ratios between the drive shaft (1) and the output shaft (2), so that nine forward gears and one reverse gear can be realized, wherein the sun gear of the first planetary gear set (P1) coupled to the housing (G) of the transmission is, wherein the web of the first planetary gear set (P1) with the third shaft (3) is connected, which via a second brake (03) to the housing (G) of the transmission can be coupled via a first clutch (13) with the drive shaft ( 1) and via a second clutch (35) with the fün The fifth shaft (5) is connected to the ring gear of the second planetary gear set (P2) and the sun gear of the fourth planetary gear set (P4) and the drive shaft (1) with the sun gear of the second planetary gear set (P2 ) and the web of the third planetary gear set (P3), wherein the sixth shaft (6) connected to the ring gear of the first planetary gear set (P1) and via a fourth clutch (68) with the eighth shaft (8) is detachably connectable, the is connected to the web of the second planetary gear set (P2) and the sun gear of the third planetary gear set (P3), wherein the ring gear of the fourth planetary gear set (P4) with the fourth shaft (4) is connected via a first brake (04) to the Housing (G) of the transmission is coupled and wherein the output shaft (2) via a third clutch (27) with the ring gear of the third planetary gear set (P3) connected to the seventh shaft (7) releasably connectable and with the web of the fourth planetary gear set (P4 ) connected is. Multi-step transmission after Claim 1 , characterized in that the planetary gear sets (P1, P2, P3, P4) are designed as minus planetary gear sets. Multi-step transmission after Claim 1 or 2 characterized in that the first forward speed is achieved by closing the first brake (04) and the second and fourth clutches (35, 68), the second forward speed by closing the first brake (04) and the first and second clutches (13, 35), the third forward speed by closing the first brake (04) and the first and fourth clutches (13, 68), the fourth forward speed by closing the first brake (04) and the third and fourth clutches (27, 68), the fifth forward speed by closing the first, third and fourth clutches (13, 27, 68), the sixth forward speed by closing the first, second and third clutches (13, 35, 27), the seventh forward gear by closing the second, third and fourth clutch (35, 27, 68), the eighth forward gear by closing the second brake (03) and the second and third clutch (35, 27) and that the Ninth forward gear by closing the second brake (03) and the third and fourth clutch (27, 68) results, wherein the reverse gear by closing the first and second brake (04, 03) and the fourth clutch (68) results.

Images