DE102010039990A1 - Multi-step planetary gear box for motor vehicle, has planetary gear sets that are connected together via shafts and clutches, and drive and driven shafts connected to webs of planetary gear sets, respectively - Google Patents

Abstract

The gear box has main case (G) with gear set (P1) whose sun gear is connected with shaft (3) connected with sun gear of gear set (P2). The gear sets (P1,P4) are connected via shaft (6). The web of gear set (P2) is connected with drive shaft (1) via clutch (18). The ring gear of gear set (P3) is connected to shaft (5) via clutch (58). The ring and sun gears of respective gear sets (P2,P3) are connected via clutch (57) and shaft (7). The webs of gear sets (P3,P4) are connected via shaft (9) and clutch (29). The web of gear set (P4) is connected to driven shaft (2).

Description

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

Automatic transmissions, particularly for motor vehicles, include, according to the prior art, planetary gear sets that are switched by means of friction elements, such as clutches and brakes, and usually with a slipping action and optionally a lockup clutch, 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.

From the DE 199 49 507 A1 the Applicant is a multi-speed transmission with at least seven forward gears, in which two non-shiftable Vorschaltradsätze are provided on the drive shaft, the output side generate two speeds, in addition to the speed of the drive shaft selectively acting on the output shaft, a switchable rear-mounted by selectively closing the switching elements are switchable so that to switch from a gear in each case next higher or lower gear of the two currently operated switching elements only one switching element off and another must be switched on.

Furthermore, from the DE 29 36 969 A1 a 9-speed multi-speed transmission known; it comprises eight switching elements and four planetary gear sets, one planetary gear set serving as a primary gear and the main gear has a Simpson set and another serving as a reverse gear planetary gear.

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 are a low construction cost, in particular require a small number of switching elements and in sequential switching double circuits, d. H. avoid switching on or off of two switching elements, so that in circuits in defined gear groups only one switching element is changed.

From the 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 intervention causes different ratios between the drive and the output, so that preferably nine forward gears and one reverse gear can be realized.

In this case, the first and the second planetary gear set, which are preferably designed as negative planetary gear sets, that is to say with a negative stationary gear ratio, form a shiftable transfer gearset, the third and the fourth planetary gear set forming 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 via the eighth shaft 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 of the transmission can be coupled. In addition, the seventh shaft with at least one element of the main gearset is constantly connected and can be coupled via a third brake to the housing of the transmission, wherein the sixth shaft with at least a 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, 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 continuously connected to the ring gear of the fourth planetary gear set and the web of the third planetary gear and releasably connectable via the third clutch to the drive shaft. Furthermore, 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 gear set. Furthermore, the third and the fourth planetary gear set may be combined or reduced to form a Ravigneaux set having 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 eight forward gears and one reverse gear with sufficient translation, in which the construction cost and size, especially the overall length, or the weight are optimized and also the efficiency in terms the drag and gearing losses is improved. In addition, in the multistage transmission according to the invention, small supporting moments act on the shifting elements. Among other things, the transmission according to the invention should be suitable both for a drive concept in front-longitudinal design, as well as in 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, nine rotatable shafts - hereinafter referred to as drive shaft, output shaft, third, fourth, fifth, sixth, seventh, eighth and ninth wave - 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 seven forward gears and one reverse gear can be realized.

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

A simple minus planetary gear known to include a sun gear, a ring gear and a ridge on which planet gears are rotatably mounted, each meshing with the 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 gear 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 having an outer Planet wheel meshes. As a result, the ring gear has the same direction of rotation when the web is held on as the sun gear and there is a positive stationary gear ratio.

According to the invention, the sun gear of the first planetary gear set is connected to the third shaft, which is connected to the sun gear of the second planetary gearset and coupled via a first brake to the housing of the transmission, wherein the web of the first planetary gear set with the ring gear of the fourth planetary gear set connected sixth shaft is connected and the ring gear of the first planetary gear set is connected to the fourth shaft, which is coupled via a second brake to the housing of the transmission.

Furthermore, the web of the second planetary gear set is connected to the drive shaft, which is releasably connectable via a first clutch to the eighth shaft, which is connected to the sun gear of the fourth planetary gear set and via a second clutch with the fifth shaft connected to the ring gear of the third planetary gearset is detachably connectable, which is detachably connectable via a third clutch with the seventh shaft, which is connected to the ring gear of the second planetary gear set and the sun gear of the third planetary gear set. Further, the web of the third planetary gear set is connected to the ninth shaft, which is releasably connectable via a fourth clutch to the output shaft connected to the web of the fourth planetary gear set.

The inventive design of the multi-speed transmission results in particular for passenger cars suitable translations and increased overall spread of the Multi-speed transmission, which causes an improvement in ride comfort and a significant consumption reduction.

In addition, the construction cost is significantly 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 drives with respect to the drag and gear losses.

Furthermore, there are low torques 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 dimensioning is made possible by the low torques, whereby the required space and the corresponding costs are reduced. In addition, there are also low speeds at the shafts, 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.

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 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, 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 negative planetary gear sets. According to the invention, at least one planetary gear set can be designed as a positive planetary gear set, if at the same time the web and Hohlradanbindung exchanged and the amount of the stationary gear ratio is increased by 1 compared to the design as a minus planetary gear.

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

How out 1 can be seen, six switching elements, namely two brakes 03 . 04 and four clutches 15 . 29 . 57 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 eight forward gears and one reverse gear can be realized. The multistage transmission according to the invention has a total of nine rotatable shafts, namely the waves 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8th and 9 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 P1 with the third shaft 3 connected to the sun gear of the second planetary gear set P2 and a first brake 03 can be coupled to the housing G of the transmission, wherein the web of the first planetary gear P1 with the connected to the ring gear of the fourth planetary gear set P4 sixth shaft 6 connected is; the ring gear of the first. Planetary gear set P1 is with the fourth shaft 4 connected, which via a second brake 04 can be coupled to the housing G of the transmission.

According to the invention, the web of the second planetary gear set P2 is connected to the drive shaft 1 connected, which via a first clutch 18 with the eighth wave 8th is releasably connectable, which is connected to the sun gear of the fourth planetary gear set P4 and a second clutch 58 with the fifth shaft connected to the ring gear of the third planetary gear set P3 5 is releasably connectable, the fifth wave 5 via a third clutch 57 with the seventh wave 7 is releasably connectable, which is connected to the ring gear of the second planetary gear set P2 and the sun gear of the third planetary gear set P3. According to the invention, the web of the third planetary gear set P3 with the ninth wave 9 connected, which via a fourth clutch 29 with the output shaft connected to the bridge of the fourth planetary gear set P4 2 is detachably connectable.

In 2 is an exemplary circuit diagram of a multi-speed transmission according to 1 shown. For each gear four switching elements are closed. The shift pattern, the respective ratios i of the individual grades and the determined therefrom gear jumps or increments φ to the next higher gear are exemplified, with the value of 7.622 represents the spread of the transmission.

Typical values for the stationary gear ratios of the planetary gear sets P1, P2, P3 and P4 designed as minus planetary gear sets are -1.944, -1.800, -1.818 and -3.900, respectively. Out 2 It can be seen that in sequential switching mode, only one switching element is switched on and one switching element has to be switched off, since two adjacent gear stages use three switching elements in common. 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 and second brakes 03 . 04 and the first and third clutches 18 . 57 , the second forward gear by closing the first and second brakes 03 . 04 and the second and third clutches 58 . 57 , the third forward gear by closing the second brake 04 and the first, second and third clutches 18 . 58 . 57 , the fourth forward gear by closing the second brake 04 and the first, third and fourth clutches 18 . 57 . 29 , the fifth forward gear by closing the second brake 04 and the first, second and fourth clutches 18 . 58 . 29 , the sixth forward gear, designed as a direct gear, by closing all clutches 18 . 58 . 57 . 29 , the seventh forward gear by closing the first brake 03 and the first, second and fourth clutches 18 . 58 . 29 and the eighth forward gear is obtained by closing the first brake 03 and the second, third and fourth clutches 58 . 57 . 29 , wherein the reverse gear by closing the first and second brake 03 . 04 and the second and fourth clutches 58 . 29 results.

Characterized in that in the first forward gear and in the first reverse gear, the first and second brake 03 . 04 are closed, these switching elements can be used as starting elements.

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

The multistage transmission according to the invention also allows the arrangement of a torsional vibration damper between the drive motor 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, for driving 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 power shift clutches or brakes. In particular, non-positive clutches or brakes such. B. 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.

LIST OF REFERENCE NUMBERS

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

9

ninth wave

03

first brake

04

second brake

18

first clutch

29

fourth clutch

57

third clutch

58

second clutch

P1

first planetary gear set

P2

second planetary gear set

P3

third planetary gear set

P4

fourth planetary gear set

i

translation

φ

increment

G

casing

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19949507 A1 [0003, 0005]
• DE 2936969 A1 [0006]
• DE 102005010210 A1 [0007]
• DE 102006006637 A1 [0007]
• DE 102008000428 A1 [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 nine rotatable shafts ( 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8th . 9 ) and at least six switching elements ( 03 . 04 . 18 . 29 . 57 . 58 ), comprising brakes ( 03 . 04 ) and couplings ( 18 . 29 . 57 . 58 ), whose selective engagement different transmission ratios between the drive shaft ( 1 ) and the output shaft ( 2 ), so that eight forward gears and one reverse gear are feasible, wherein the sun gear of the first planetary gear set (P1) with the third wave ( 3 ) connected to the sun gear of the second planetary gear set (P2) and via a first brake ( 03 ) can be coupled to the housing (G) of the transmission, the web of the first planetary gear set (P1) being connected to the sixth shaft (P4) connected to the ring gear of the fourth planetary gear set (P4). 6 ), wherein the ring gear of the first planetary gear set (P1) with the fourth wave ( 4 ) connected via a second brake ( 04 ) is connectable to the housing (G) of the transmission, wherein the web of the second planetary gear set (P2) with the drive shaft ( 1 ) connected via a first clutch ( 18 ) with the eighth wave ( 8th ) is releasably connectable, which is connected to the sun gear of the fourth planetary gear set (P4) and via a second clutch ( 58 ) connected to the ring gear of the third planetary gear set (P3) fifth wave ( 5 ) is releasably connectable, which via a third clutch ( 57 ) with the seventh wave ( 7 ) is releasably connectable, which is connected to the ring gear of the second planetary gear set (P2) and the sun gear of the third planetary gear set (P3) and wherein the web of the third planetary gear set (P3) with the ninth wave ( 9 ) connected via a fourth clutch ( 29 ) connected to the web of the fourth planetary gear set (P4) output shaft ( 2 ) is releasably connectable. Multi-speed transmission according to claim 1, characterized in that the planetary gear sets (P1, P2, P3, P4) are designed as negative planetary gear sets. Multi-speed transmission according to claim 1 or 2, characterized in that the first forward gear by closing the first and second brake ( 03 . 04 ) and the first and third clutch ( 18 . 57 ), the second forward gear by closing the first and second brake ( 03 . 04 ) and the second and third clutches ( 58 . 57 ), the third forward gear by closing the second brake ( 04 ) and the first, second and third clutches ( 18 . 58 . 57 ), the fourth forward gear by closing the second brake ( 04 ) and the first, third and fourth clutch ( 18 . 57 . 29 ), the fifth forward gear by closing the second brake ( 04 ) and the first, second and fourth coupling ( 18 . 58 . 29 ), the sixth forward gear by closing all clutches ( 18 . 58 . 57 . 29 ), the seventh forward gear by closing the first brake ( 03 ) and the first, second and fourth coupling ( 18 . 58 . 29 ) and that the eighth forward gear by closing the first brake ( 03 ) and the second, third and fourth clutch ( 58 . 57 . 29 ), wherein the reverse gear by closing the first and second brake ( 03 . 04 ) and the second and fourth clutch ( 58 . 29 ).

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