DE102008041201A1 - Multi-stage gearbox, particularly automatic gearbox for motor vehicle, comprises four planetary gear sets, which are arranged in housing, where eight rotating shafts include two drive shafts - Google Patents

Abstract

The multi-stage gearbox comprises four planetary gear sets (P1,P2,P3,P4), which are arranged in a housing (G). Eight rotating shafts (1 to 8) including two drive shafts and six switching elements (03,04,14,27,56,58) including brakes and clutches are provided with the gearbox. The selective engagement effects and different transmission ratio between the drive shafts are such provided that nine forward gears and a backward gear are realized. A sun wheel of the planetary gear train is connected with the third shaft.

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 automatic transmissions are for example from the DE 199 49 507 A1 the applicant a multistage transmission known in which two non-shiftable Varschaltradsätze are provided on the drive shaft, 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 only one switching element must be switched on or off for switching from one gear to the next higher or lower gear of the two currently operated switching elements. 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 a reverse gear is known, 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 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 werteren element of the main gear.

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 connected 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. Of the Downforce takes place via the constantly with the web the fourth planetary gear set output shaft. Furthermore The third and fourth planetary gear set can become one Ravigneaux set composed with common bridge and common ring gear or be reduced.

Of the present invention is based on the object, a multi-step transmission to propose the type mentioned, which at least nine Forward gears and at least one reverse gear having sufficient translation, in which the construction cost and the size, in particular the overall length, or the weight be optimized and also the efficiency in terms the drag and gearing losses is improved. In addition, should small in the multistage transmission according to the invention Support moments act on the switching elements. Especially should the transmission according to the invention for 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 at least four are preferably as minus planetary gear sets engineered planetary gear sets, following 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 wave - and at least six switching elements, comprising brakes and clutches, whose selective engagement different ratios between causes the drive and the output, so preferably nine forward gears and a reverse gear is feasible.

One simple minus planetary set includes known a sun gear, a ring gear and a bridge on which planet gears rotatable are stored, each combing with sun gear and ring gear. As a result, the ring gear at festhaltem web one to the sun gear opposite direction of rotation. In contrast, includes a simple plus planetary gearset a sun gear, a ring gear and a Bridge on the inner and outer planetary gears are rotatably mounted, with all inner planetary gears with the sun gear and all outer planet gears mesh with the ring gear, with each inner planetary gear meshes with an outer planetary gear. As a result, the ring gear at the fixed web the same Direction of rotation as the sun gear.

According to the Invention is provided that the sun gear of the third planetary gear set by means of a component constantly with the housing the gear is connected and that the web of the third planetary gear set is connected to the output shaft, which has a first Coupling with the seventh shaft is releasably connectable, the is connected to the ring gear of the fourth planetary gear set.

Of another is the ring gear of the third planetary gear set with the sixth Connected via a second coupling with the shaft Connected fifth shaft, which is connected to a component is, which the ring gear of the second planetary gear set with the sun gear the fourth planetary set rotatably connects to each other, wherein the fifth wave with a third clutch the eighth shaft is detachably connectable to the bridge the first planetary gear set is connected.

Further the third shaft is connected to the bridge of the second planetary gear set and a first brake to a housing of the Gear can be coupled, the sun gears of the second Planet set and the first planetary gear set with the fourth wave are connected via a second brake to a housing of the transmission can be coupled and via a fourth clutch is detachably connectable to the drive shaft, wherein the Drive shaft with the ring gear of the first planetary gear set and the web the fourth planetary gear set is connected.

The inventive design of the multi-speed transmission resulting in particular for passenger cars suitable translations and a significant increase in the overall spread of the multi-speed transmission, creating a Ver improvement of ride comfort and a significant reduction in fuel consumption.

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 preferred embodiment of a multi-speed transmission according to the invention;

2 : An exemplary circuit diagram for a multi-step transmission according to 1 ;

3 : A diagram for illustrating the incremental phi corresponding to the respective gear ratio i of a gear for the in 1 shown gears; and

4 : A diagram to illustrate the corresponding gear for each degree of efficiency for the in 1 shown gearbox.

In 1 is an inventive multi-stage transmission with a drive shaft 1 and an output shaft 2 shown, which are arranged in a housing G. There are four planetary gear sets P1, P2, P3 and P4 provided, which are designed as minus planetary gear sets.

at the embodiment shown, in particular suitable for a front-transverse construction, the second and the fourth planetary set P2, P4 viewed axially in the same Radsatzebene arranged, wherein the fourth planetary set P4 radially considered arranged above the second planetary set P2 is, whereby the total of four planetary gear sets in advantageous Spatial axial view on three Radsatzebenen restrict Here is the ring gear of the second planetary gear set P2 connected to the sun gear of the fourth planetary gear set P4. In Power flow direction considered in this case, the planetary gear sets arranged in the order P1, P2 / P4, P3.

How out 1 can be seen, six switching elements, namely two brakes 03 . 04 and four clutches 14 . 27 . 56 and 58 intended. The spatial arrangement of the switching elements can be arbitrary and is limited only by the dimensions and the external shape.

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 third planetary gear set P3 by means of the device 0 is constantly connected to the housing G of the transmission and that the web of the third planetary gear set P3 to the output shaft 2 which is connected via a first clutch 27 with the seventh wave 7 is releasably connectable, which is connected to the ring gear of the fourth planetary gear set P4.

Furthermore, the ring gear of the third planetary gear set P3 with the sixth shaft 6 connected, which via a second clutch 56 with the fifth wave 5 is connected to the component which connects the ring gear of the second planetary gear set P2 with the sun gear of the fourth planetary gear set P4, wherein the fifth shaft 5 via a third clutch 58 with the eighth wave 8th is releasably connectable, which is connected to the web of the first planetary gear P1.

According to the invention, the third wave 3 connected to the bridge of the second planetary set P2 the and over a first brake 03 can be coupled to the housing G of the transmission, wherein the sun gears of the second planetary gear set P2 and the first planetary gear set P1 with the fourth wave 4 connected via a second brake 04 can be coupled to the housing G of the transmission and a fourth clutch 14 with the drive shaft 1 is releasably connectable, which is connected to the ring gear of the first planetary gear set P1 and the web of the fourth planetary gear set P4.

Preferably, the first clutch 27 viewed radially above the third planetary set P3 arranged; the second clutch 56 is axially disposed between the third planetary gear set P3 and the second planetary gear set P2, wherein the fourth clutch 14 considered in the direction of power flow in train operation before the first planetary gear set P1 is arranged; Further, the third clutch 58 axially arranged between the first planetary gear set P1 and the second planetary gear set P2. Furthermore, the brakes 03 . 04 viewed axially juxtaposed.

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 7,770 represents the spread of the transmission.

Typical values for the stationary ratios of the planetary gear sets P1, P2, P3 and P4 are -1.80, -2.00, -1.90 and -1.65, 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. Furthermore, with the in 1 a total of nine forward gears and a Rückwärs gear can be realized.

The clutch second clutch 56 and / or the third clutch 58 are preferably designed as claw switching elements. As a result, the drag torques of the transmission, which arise due to the small distance between the friction surfaces of a Reibschaltelementes in the open state and the oil or Lüft-Öl-mixture contained therein, reduced. The other couplings 14 . 27 and the brakes 03 . 04 are preferably designed as Reibschaltelemente or lamellar switching elements.

The first forward gear is obtained by closing the second and third clutch 56 . 58 and the first brake 03 , the second forward gear by closing the second brake 04 and the second and third clutches 56 . 58 , the third forward gear by closing the second, third and four th clutch 56 . 58 . 14 , the fourth forward gear by closing the first, second and third clutches 27 . 56 . 58 , the fifth forward gear by closing the fourth, first and third clutches 14 . 27 . 58 , the sixth forward gear by closing the second brake 04 and the first and third clutches 27 . 58 , the seventh forward gear by closing the first brake 03 and the first and third clutches 27 . 58 , the eighth forward gear by closing the brakes 03 . 04 and the first clutch 27 and the ninth forward gear by closing the first brake 03 and the first and fourth clutches 27 . 14 , The reverse gear is obtained by closing the first brake 03 and the third and second clutches 14 . 56 ,

Due to the fact that in first forward gear and in reverse the first brake 03 and the second clutch 56 are closed, these switching elements (designed as Reibschaltelemente or lamellae 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.

A diagram for the illustration of the respective ratio i in a gear corresponding incremental phi for the in 1 shown gearbox according to the in 2 shown values is the subject of 3 ,

The value of the relationship between the efficiency eta and the respective gear of a transmission according to the invention according to 1 based 4 illustrated.

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 output 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 as required by a coupling element of a drive motor, wherein as a coupling element, 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. 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.

0

module

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

first brake

04

second brake

14

fourth clutch

27

first clutch

56

second clutch

58

third clutch

P1

first planetary set

P2

second planetary set

P3

third planetary set

P4

fourth planetary set

i

translation

phi

increment

G

casing

eta

efficiency

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 [0004]
• - DE 2936969 A1 [0005]
• - DE 102005010210 A1 [0006]
• - DE 102006006637 A1 [0006]
• - DE 102008000428 [0008]

Claims (11)

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 at least eight rotatable shafts ( 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8th ) as well as six switching elements ( 03 . 04 . 14 . 27 . 56 . 58 ), comprising brakes ( 03 . 04 ) and couplings ( 14 . 27 . 56 . 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 third planetary gear set (P3) by means of a component ( 0 ) is constantly connected to a housing (G) of the transmission and the web of the third planetary gear set (P3) with the output shaft ( 2 ) connected via a first clutch ( 27 ) with the seventh wave ( 7 ) is releasably connectable, which is connected to the ring gear of the fourth planetary gear set (P4), wherein the ring gear of the third planetary gear set (P3) with the sixth shaft ( 6 ) connected via a second clutch ( 56 ) with the fifth wave ( 5 ), which is connected to the component which connects the ring gear of the second planetary gear set (P2) with the sun gear of the fourth planetary gear set (P4), wherein the fifth shaft ( 5 ) via a third clutch ( 58 ) with the eighth wave ( 8th ) is detachably connectable, which is connected to the web of the first planetary gear set (P1), wherein the web of the second planetary gear set (P2) with the third wave ( 3 ) connected via a first brake ( 03 ) is coupled to the housing (G) of the transmission and wherein the sun gears of the second planetary gear set (P2) and the first planetary gear set (P1) with the fourth wave ( 4 ) connected via a second brake ( 04 ) can be coupled to the housing (G) of the transmission and via a fourth clutch ( 14 ) with the drive shaft ( 1 ) is releasably connectable, which is connected to the ring gear of the first planetary gear set (P1) and 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-step transmission according to claim 1 or 2, characterized characterized in that the second and fourth planetary gear sets (P2, P4) are arranged axially in the same Radsatzebene, wherein the fourth planetary gear set (P4) viewed radially over the second planetary set (P2) is arranged, whereby the total four planetary gear sets (P1, P2, P3, P4) spatially axial limited to three Radsatzebenen. Multi-step transmission according to one of the preceding claims, characterized in that the first clutch ( 27 ) viewed radially above the third planetary gear set (P3) is arranged. Multi-step transmission according to one of the preceding claims, characterized in that the second clutch ( 56 ) axially arranged between the third planetary gear set (P3) and the second planetary gear set (P2) is arranged. Multi-step transmission according to one of the preceding claims, characterized in that the brakes ( 03 . 04 ) are arranged side by side viewed axially. Multi-step transmission according to one of the preceding claims, characterized in that the fourth clutch ( 14 ) is arranged in the direction of power flow in the overrun mode before the first planetary gear set (P1). Multi-step transmission according to one of the preceding claims, characterized in that the third clutch ( 58 ) axially disposed between the first planetary gear set (P1) and the second planetary gear set (P2) is arranged. Multi-step transmission according to one of the preceding claims, characterized in that the second clutch ( 56 ) and / or the third clutch ( 58 ) are designed as claw switching elements, wherein the remaining clutches ( 14 . 27 ) and the brakes ( 03 . 04 ) are designed as Reibschaltelemente. Multi-speed transmission according to one of the preceding claims, characterized in that the first forward gear by closing the second and third clutch ( 56 . 58 ) and the first brake ( 03 ), the second forward gear by closing the second brake ( 04 ) and the second and third clutches ( 56 . 58 ), the third forward gear by closing the second, third and fourth clutch ( 56 . 58 . 14 ), the fourth forward gear by closing the first, second and third clutch ( 27 . 56 . 58 ), the fifth forward gear by closing the fourth, first and third clutch ( 14 . 27 . 58 ), the sixth forward gear by closing the second brake ( 04 ) and the first and third clutch ( 27 . 58 ), the seventh forward gear by closing the first brake ( 03 ) and the first and third clutch ( 27 . 58 ), the eighth forward gear by closing the brakes ( 03 . 04 ) and the first clutch ( 27 ) and the ninth forward gear by closing the first brake ( 03 ) and the first and fourth clutch ( 27 . 14 ) and that the reverse gear by closing the first brake ( 03 ) and the third and second clutch ( 14 . 56 ). Multi-step transmission after one of the preceding existing claims, characterized in that the starting by means of the first brake ( 03 ) or the second clutch ( 56 ) of the transmission takes place.