DE102009028707A1 - Multi-stage transmission i.e. automatic transmission, for e.g. passenger car, has brakes and clutch engaged to produce different transmission ratios between drive and output shafts, where one shaft is fixed to internal gear of one gear set - Google Patents

Abstract

The transmission has four planetary gear sets (P1-P4) i.e. minus-planetary gear sets, arranged in housing (G). A drive shaft (1) is connected to a sun gear of the first set and a web of the second set. An internal gear of the third set is connected to a first rotatable shaft (4) that is coupled to the housing via a brake (04). An output shaft (2) is connected to a second rotatable shaft (7) via a clutch (27), where the brake and clutch are engaged to produce different transmission ratios between the drive and output shafts. The second shaft is connected to an internal gear of the fourth set.

Description

The The present invention relates to a planetary multi-speed transmission, in particular an automatic transmission for a motor vehicle, according to the preamble of claim 1.

Automatic transmission, in particular for motor vehicles, include the state the technology planetary gear sets, by means of friction or switching elements, such as clutches and brakes, are switched and usually with a slip action and optionally with a startup element provided with a lockup clutch, such as a hydrodynamic torque converter or a fluid coupling, are 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.

Under Use of five switching elements here are seven Forward gears achieved, using six Shifting elements nine or ten forward gears.

Furthermore, from the DE 102 13 820 A1 a multi-speed automatic transmission with eight forward gears and one reverse gear, comprising a first input path T1 of a first gear ratio; an input path T2 having a larger gear ratio than this input path T1; 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 transmits rotation of the input path T2 to the first element S3; a clutch C-1 which transmits the rotation from the input path T2 to the fourth element S2; a clutch C-4 which transmits a rotation from the input path T1 to the first element; a clutch C-3 which transmits the rotation from the input path T1 to the second element C3; 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 coupled to the third element S3.

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 are in general already described many times in the prior art and subject to a permanent development and improvement. So should this Gear a low construction cost, especially a small number require switching elements and in sequential switching double circuits avoid, so that in circuits in defined gear groups each only a switching element is changed.

From the not yet published DE 10 2008 000 428.3 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.

in this connection form the first and the second planetary set, preferably as Negative planetary gear trains are formed, a switchable Vorschaltradsatz, wherein the third and the fourth planetary gear set a Make main gear.

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 shaft is, which is detachably 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 the second planetary gear set is coupled by means of the fifth shaft via a second brake to a housing of the transmission. 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 with at least one further element of the main gearset is constantly connected and releasably connectable 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 is the fourth wave constantly in the known transmission connected to the ring gear of the third planetary gear set, wherein the sixth wave constantly with the ring gear of the fourth planetary gear set and connected to the bridge of the third planetary gear set and over the third clutch releasably connectable to the drive shaft is. Furthermore, the seventh wave is constantly with the sun gears connected to the third and fourth planetary gear set and over the third brake can be coupled to a housing of the transmission. The output takes place here via the constantly with the output of the fourth planetary gear set output shaft. Of others can be the third and the fourth planetary gear set to a Ravigneaux set with a common bridge and a common Ring gear composed or reduced.

Of the present invention is based on the object, a multi-step transmission to propose the type mentioned, which nine forward gears and at least one reverse gear with sufficient gear ratio in which the construction cost and the size, In particular, the overall length or the weight can be optimized and also the efficiency in terms of drag and gearing losses is improved. In addition, in the inventive Multi-step transmission small supporting moments act on the switching elements. In particular, the transmission according to the invention is intended be suitable for a front-transverse construction.

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

Therefore is a multi-stage transmission according to the invention proposed in planetary design, which has a drive and a Downlift, which are arranged in a housing. Of further are at least four planetary gear sets, below referred to as 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 wave - and at least six switching elements, comprising brakes and clutches, whose selective engagement different ratios between the drive and the output causes, so that preferably nine forward gears and a reverse gear can be realized.

The Planet sets are considered axially in order first planetary gearset, second planetary gearset, third planetary gearset, fourth planetary gear set and are preferably as minus planetary gear sets educated.

One simple minus planetary set includes known a sun gear, a ring gear and a bridge rotatable on the planet gears are stored, each combing with sun gear and ring gear. hereby has the ring gear at a fixed web opposite to the sun gear Direction of rotation. In contrast, includes a simple plus planetary gear set a sun gear, a ring gear and a bridge, on the inner and outer Planet wheels are rotatably mounted, with all internal Planetary wheels with the sun gear and all outer ones Combine planet gears with the ring gear, each one inner planet gear meshing with one outer planetary gear. As a result, the ring gear at the fixed web the same Direction of rotation as the sun gear.

According to one preferred embodiment of the invention is the sun gear of the first planetary gear set to a housing of the transmission coupled, wherein the web of the first planetary gear set with the third Wave is connected, which via a second brake a housing of the transmission can be coupled, via a first clutch with the drive shaft and a second Coupling with the eighth wave is detachably connectable, wherein the eighth wave via a fourth clutch with the with the Ring gear of the second planetary gear set fifth Shaft is detachably connectable and with the sun gear of the third planetary gear set and the sun gear of the fourth planetary gear set and wherein the drive shaft with the sun gear of the second planetary gear set and connected to the bridge of the third planetary gear set.

Of Another is the ring gear of the first planetary gear set with the sixth Connected shaft, which is connected to the web of the second planetary gear set, wherein the ring gear of the fourth planetary gear set via a first brake can be coupled to a housing of the transmission and wherein the output shaft via a third clutch with the seventh connected to the ring gear of the third planetary gear set Shaft is detachably connectable and with the bridge of the fourth Planet set is connected.

Due to the inventive design of the multi-speed transmission arise in particular suitable for passenger cars translations and increased overall spread of the multi-speed transmission, whereby an improvement in ride comfort and a significant consumption reduction can be effected.

About that In addition, with the multistage transmission according to the invention by a small number of switching elements, the construction cost significantly reduced. Advantageously, it is with the invention Multi-step transmission possible, a start with a hydrodynamic Converter, an external starting clutch or other suitable to perform external starting elements. It is also conceivable a starting process with a built-in gear start-up element to enable. Preferably, a switching element is suitable, which in the first forward and reverse is pressed.

Of further results in the inventive Multi-step transmission a good efficiency in the main gears with regard to drag and gear losses.

Further There are small moments in the switching elements and in the planetary gear sets of the multi-speed transmission, whereby the wear at the multi-stage transmission is reduced in an advantageous manner. moreover is due to the low moments a correspondingly small dimensions allows, whereby the required space and the corresponding costs are reduced. Beyond that also low speeds at the shafts, the switching elements and the planetary gear sets.

Furthermore is the transmission according to the invention designed in such a way that an adaptability to different powertrain configurations both in the direction of force flow as well as in space is possible.

The Invention will be described below with reference to the accompanying figures exemplified in more detail. In these places represents:

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 sets P1, P2, P3 and P4, which are arranged in a housing G. The planetary gear sets P1, P2, P3 and P4 are in 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 stand ratio compared to the execution as a minus planetary gear order 1 is increased.

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

How out 1 can be seen, six switching elements, namely two brakes 03 . 04 and four clutches 13 . 38 . 27 and 58 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 is coupled to a housing G of the transmission (shaft 0 ), wherein the web of the first planetary gear set P1 with the third wave 3 which is connected via a second brake 03 can be coupled to a housing G of the transmission, via a first clutch 13 with the drive shaft 1 and a second clutch 38 with the eighth wave 8th is detachably connectable.

How out 1 Obviously, the eighth wave is 8th via a fourth clutch 58 with the fifth shaft connected to the ring gear of the second planetary gearset P2 5 detachably connectable and directly connected to the sun gear of the third planetary gear set P3 and the sun gear of the fourth planetary gear set P4, wherein the drive shaft 1 is connected to the sun gear of the second planetary gear set P2 and the land of the third planetary gear set P3.

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

According to the invention, the first clutch 13 and the fourth clutch 58 axially disposed between the first and second planetary gear sets P1, P2, wherein the third clutch 27 axially considered between the third and the fourth planetary gear set P3, P4 may be arranged.

Further, the second brake 03 and the second clutch 38 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 shift scheme, the respective ratios of the individual gear ratios i and the step to be determined therefrom or increments phi are taken to the next higher gear example, the value of 9.003 represents the spread of the transmission.

Typical values for the stationary ratios of the planetary gear sets P1, P2, P3 and P4, which are designed as minus planetary gear sets, are -3.90, -1.60, -2.201 and -2.103, respectively. 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 38 . 58 , the second forward gear by closing the first brake 04 and the first and second clutches 13 . 38 , the third forward gear by closing first brake 04 and the first and fourth clutches 13 . 58 , the fourth forward gear by closing the first brake 04 and the third and fourth clutches 27 . 58 , the fifth forward gear by closing the first, third and fourth clutch 13 . 27 . 58 which preferably performs a direct forward sixth forward gear by closing the first, second and third clutches 13 . 38 . 27 , the seventh forward gear by closing the second, third and fourth clutches 37 . 27 . 58 , the eighth forward gear by closing the second brake 03 and the second and third clutches 38 . 27 and the ninth forward gear is obtained by closing the second brake 03 and the third and fourth clutches 27 . 58 , wherein the reverse gear by closing the first and second brake 04 . 03 and the fourth clutch 58 results.

Due to the fact that in first forward gear and in first reverse gear the first brake 04 and the fourth clutch 58 are closed, these switching elements can be used as starting elements.

According to the Invention can also be with the same Getriebeschema Depending on the switching logic result in different gear jumps, so that an application- or vehicle-specific variation allows becomes.

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

On the drive side or on the drive side can according to the invention a Axle differential and / or a distribution differential can be arranged.

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 inventive multi-speed transmission allows also the arrangement of a torsional vibration damper between 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 electrical 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 used Reibschaltelemente can be used as a load-switching Be formed clutches or brakes. In particular, you can non-positive clutches or brakes, such. B. multi-plate clutches, Band brakes and / or cone clutches are used.

One Another advantage of the presented here multistage transmission consists in that on each wave as a generator and / or as an additional Drive machine is an electric machine attachable.

Of course Every constructive training, especially every one, also falls spatial arrangement of the planetary gear sets and the Switching elements in themselves and to each other and as far as technically reasonable, under the scope of the present claims without the function of the transmission as stated in the claims to influence, even if these training courses are not explicitly in the figures or in the description are shown.

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

37

second clutch

58

fourth clutch

P1

first planetary set

P2

second planetary set

P3

third planetary set

P4

fourth planetary set

i

translation

phi

increment

G

casing

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19949507 A1 [0003]
• - DE 10213820 A1 [0005]
• - DE 2936969 A1 [0006]
• DE 102005010210 A1 [0007]
• - DE 102006006637 A1 [0007]
• - DE 102008000428 [0009]

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 . 8th ) and at least six switching elements ( 03 . 04 . 13 . 27 . 38 . 58 ), comprising brakes ( 03 . 04 ) and couplings ( 13 . 27 . 38 . 58 ), whose selective engagement different transmission 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) is coupled to a housing (G) of the transmission, wherein the web of the first planetary gear set (P1) with the third shaft (P1) 3 ) connected via a second brake ( 03 ) can be coupled to a housing (G) of the transmission via a first clutch ( 13 ) with the drive shaft ( 1 ) and via a second clutch ( 38 ) with the eighth wave ( 8th ) is detachably connectable, wherein the eighth wave ( 8th ) via a fourth clutch ( 58 ) connected to the ring gear of the second planetary gear set (P2) fifth wave ( 5 ) is releasably connectable and connected to the sun gear of the fourth planetary gear set (P4) and the sun gear of the third planetary gear set (P3), wherein the drive shaft ( 1 ) is connected to the sun gear of the second planetary gear set (P2) and the land of the third planetary gear set (P3), the sixth wave ( 6 ) is connected to the ring gear of the first planetary gear set (P1) and the web of the second planetary gear set (P2), wherein the ring gear of the fourth planetary gear set (P4) with the fourth wave ( 4 ) connected via a first brake ( 04 ) can be coupled to a housing (G) of the transmission and wherein the output shaft ( 2 ) via a third clutch ( 27 ) with the seventh shaft connected to the ring gear of the third planetary gearset (P3) ( 7 ) is releasably connectable and connected to the web of the fourth planetary gear set (P4). Multi-step transmission according to Claim 1, characterized that the planetary gear sets (P1, P2, P3, P4) as minus planetary gear sets are formed. Multi-speed transmission according to claim 1 or 2, characterized in that the first forward gear by closing the first brake ( 04 ) and the second and fourth clutch ( 38 . 58 ), the second forward gear by closing the first brake ( 04 ) and the first and second clutches ( 13 . 38 ), the third forward gear by closing first brake ( 04 ) and the first and fourth clutch ( 13 . 58 ), the fourth forward gear by closing the first brake ( 04 ) and the third and fourth clutch ( 27 . 58 ), the fifth forward gear by closing the first, third and fourth clutch ( 13 . 27 . 58 ), the sixth forward gear by closing the first, second and third clutch ( 13 . 38 . 27 ), the seventh forward gear by closing the second, third and fourth clutch ( 38 . 27 . 58 ), the eighth forward gear by closing the second brake ( 03 ) and the second and third clutches ( 38 . 27 ) and that the ninth forward gear by closing the second brake ( 03 ) and the third and fourth clutch ( 27 . 58 ), wherein the reverse gear by closing the first and second brake ( 04 . 03 ) and the fourth clutch ( 58 ).

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