DE102009047271A1 - Multistage planetary transmission i.e. automatic transmission, for e.g. passenger vehicle, has drive shaft connected with bar of planetary gear set, and another gear set including closure that is blocked by coupling units - Google Patents

Abstract

The transmission has a first planetary gear set (P1) including a sun wheel. Second planetary gear set (P2) includes a bar that is connected with a drive shaft (1). A hollow wheel of the second set is connected with a shaft (6) that is connected with a sun wheel of third planetary gear set (P3). A bar of the third set is connected with third shaft (7) that is connected with another drive shaft (2) by a coupling unit (27), where the latter drive shaft is connected with a bar of fourth planetary gear set (P4), and a closure of the third set is blocked by another coupling unit (46).

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, in the prior art, planetary gear sets that are switched by means of friction elements, such as clutches and brakes, and usually with a slip element and optionally a lockup clutch, such as a hydrodynamic torque converter or a fluid coupling connected.

Such a transmission goes out of the EP 0 434 525 A1 out. It essentially comprises a drive shaft and an output shaft, which are arranged parallel to one another, a double planetary gearset arranged concentrically with the output shaft and five shifting elements in the form of three clutches and two brakes, whose optional blocking determines in pairs the different gear ratios between the drive shaft and the output shaft , Here, the transmission has a Vorschaltradsatz and two power paths, so that six forward gears are achieved by the selective pairwise intervention of the five shift elements.

In this case, two clutches are required for transmitting the torque from the transfer gearset to two elements of the double planetary gearset in the first power path. These are arranged in the direction of power flow essentially behind the transfer gearset in the direction of the double planetary gear set. In the second power path, a further clutch is provided which removably connects this with another element of the double planetary gear set. Here, the clutches are arranged such that the inner disc carrier forms the output.

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 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.

In this case, the first and the second planetary gear set, which are preferably designed as minus planetary gear sets, form a switchable 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 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 can be coupled and releasably connected 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 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, 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 to a Ravigneaux set with a common bridge and a common ring gear composed or reduced.

The present invention has for its object to propose a multi-speed transmission of the type mentioned, which has eight forward gears and at least one reverse gear with sufficient translation, in which the construction cost and size, in particular the 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. In particular, the transmission according to the invention should be suitable for a drive in standard longitudinal design.

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 five switching elements, comprising a brake and clutches, provided, the selective engagement causes different ratios between the drive and the output, so that preferably eight forward gears and one reverse gear can be realized.

The planetary gear sets are axially arranged in the order of the first planetary gear set, second planetary gear set, third planetary gear set, fourth planetary gear set and are preferably formed as negative 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 holding the web as the sun gear.

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

Furthermore, the web of the third planetary gear set is connected to the seventh shaft, which is detachably connectable via a third clutch to the output shaft connected to the web of the fourth planetary gear set.

Here, a fourth clutch, a fifth clutch or a sixth clutch is provided by the closing of the third planetary gear set (P3) is blockable. Preferably, the fourth clutch is designed as a clutch which releasably connects the sixth shaft with the fourth shaft, wherein the fifth clutch is designed as a coupling which releasably connects the fourth shaft with the seventh shaft and wherein the sixth clutch is designed as a clutch which the sixth wave releasably connects with the seventh wave.

According to the invention, the third shaft may be directly connected to the sun gear of the first planetary gear set, the fifth shaft being connected to the first planetary gear web via an eighth shaft connected to the web of the first planetary gear set and a first shaft detachably connecting the eighth shaft to the fifth shaft Clutch is releasably connectable.

In a further development of the invention, the third wave with the sun gear of the first planetary gear set via a further connected to the sun gear of the first planetary gear and another shaft releasably connecting the further shaft with the third shaft releasably connectable further coupling, the fifth wave with the Bridge of the first planetary gear set is directly connected.

The inventive design of the multi-speed transmission results in particular suitable for passenger cars translations and increased total spread of the multi-speed transmission, whereby an improvement in ride 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 enable 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 small moments in the switching elements and in the planetary gear sets of the multi-speed transmission, whereby the wear is reduced in the multi-step transmission in an advantageous manner. 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 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 first preferred embodiment of a multi-speed transmission according to the invention;

2 a schematic view of a second preferred embodiment of a multi-speed transmission according to the invention;

3 a schematic view of a third preferred embodiment of a multi-speed transmission according to the invention;

4 : an exemplary circuit diagram for a multi-step transmission according to 1 ;

5 a schematic view of a fourth preferred embodiment of a multi-speed transmission according to the invention;

6 a schematic view of a fifth preferred embodiment of a multi-speed transmission according to the invention;

7 a schematic view of a further preferred embodiment of a multi-speed transmission according to the invention; and

8th : an exemplary circuit diagram for a multi-step transmission according to 5 ,

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 stationary translation of the planetary gear 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, five switching elements, namely a brake 03 and four clutches 14 . 27 . 48 . 46 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 brake 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 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 is the first shaft 1 and the output shaft 2 forms the second shaft of the transmission.

How out 1 can be seen, is the sun gear of the first planetary gear P1 with the third wave 3 directly connected, which is connected to the sun gear of the second planetary gear set P2 and a brake 03 can be coupled to a housing G of the transmission, wherein the web of the first Planetary gear P1 with the fifth shaft connected to the ring gear of the fourth planetary gear set P4 5 via an eighth shaft connected to the web of the first planetary gear set P1 8th and the eighth wave 8th with the fifth wave 5 releasably connecting first clutch 58 is detachably connectable.

Furthermore, the ring gear of the first planetary gear P1 is coupled to a housing G of the transmission (shaft 0 ); the web of the second planetary gear set P2 is connected to the drive shaft 1 connected, which via a second clutch 14 with the fourth shaft connected to the ring gear of the third planetary gear set P3 and the sun gear of the fourth planetary gear set P4 4 is releasably connectable, wherein the ring gear of the second planetary gear set P2 with the sixth shaft 6 is connected, which is connected to the sun gear of the third planetary gear P3.

Further, the land of the third planetary gear set P3 is the seventh wave 7 connected via a third clutch 27 with the output shaft connected to the bridge of the fourth planetary gear set P4 2 is detachably connectable.

At the in 1 As shown, it is provided that the third planetary gear P3 by closing a fourth clutch 46 is blockable, with the fourth clutch 46 is designed as a coupling, which is the sixth shaft 6 with the fourth wave 4 releasably connects, so by closing the fourth clutch 46 the third planetary gear P3 can be blocked by coupling the ring gear with the sun gear.

This in 2 The embodiment shown differs from the exemplary embodiment 1 in that for blocking the third planetary gear set P3, a fifth clutch 47 is provided, over which the fourth wave 4 with the seventh wave 7 is detachably connectable, so that the blocking can be done by a coupling of the web of the third planetary gear set P3 with the ring gear of the third planetary gear set P3.

According to the invention, instead of the fourth clutch 46 or the fifth clutch 47 a sixth clutch 67 be provided, over which the sixth wave 6 with the seventh wave 7 is detachably connectable, so that the blocking of the third planetary gear set P3 can be done by coupling the web of the third planetary gear set P3 with the sun gear of the third planetary gear set P3. This embodiment is the subject of 3 ,

In 4 is an exemplary circuit diagram of a multi-speed transmission according to 1 shown. For each gear three switching elements are closed. The shift pattern, the respective ratios i of the individual grades and the determined therefrom gear jumps or increments phi are taken to the next higher gear example, the value of 7.962 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 -1.835, -1.6, -1.747 and -3.9, respectively. Out 4 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 speed is achieved by closing the brake 03 and the first and second clutches 58 . 14 , the second forward by closing the brake 03 and the first and fourth clutches 58 . 46 , the third forward speed by closing the first, second and fourth clutches 58 . 14 . 46 , the fourth forward speed by closing the first, third and fourth clutch 58 . 27 . 46 , the fifth forward speed by closing the first, second and third clutch 58 . 14 . 27 , which preferably performs a direct forward sixth forward gear by closing the second, third and fourth clutch 14 . 27 . 46 , the seventh forward speed by closing the brake 03 and the second and third clutches 13 . 27 and the eighth forward speed is achieved by closing the brake 03 and the third and fourth clutches 27 . 46 , where the reverse gear by closing the brake 03 and the first and third clutches 58 . 27 results.

Due to the fact that in the first forward gear and in reverse the brake 03 and the first clutch 58 are closed, these switching elements can be used as starting elements.

In the event that according to the embodiment of 2 the fourth clutch 46 through the fifth clutch 47 is replaced, which is the fourth wave 4 with the seventh wave 7 releasably connects, is preferably in the circuit diagram according to 4 the fourth clutch 46 through the fifth clutch 47 replaced. Further, in the case that according to the embodiment according to 3 the fourth clutch 46 through the sixth clutch 67 is replaced, which is the sixth wave 6 with the seventh wave 7 releasably connects, preferably in the circuit diagram according to 4 the fourth clutch 46 through the sixth clutch 67 replaced.

As part of a development of the invention, the third wave 3 not directly connected to the sun gear of the first planetary gear P1, but one with the sun gear of the first planetary gear set P1 connected further wave 8th' and one the further wave 8th' with the third wave 3 detachably connecting further coupling 38 be designed releasably connectable, in which case the fifth wave 5 is directly connected to the web of the first planetary gear P1. This embodiment is the subject of the embodiments according to 5 . 6 and 7 in terms of further features of the transmission according to the embodiments according to 1 . 2 respectively. 3 correspond.

In 8th is an exemplary circuit diagram of a multi-speed transmission according to 5 shown. It corresponds to the circuit diagram according to 4 with the difference that the first clutch 58 through another clutch 38 is replaced.

In the event that according to the embodiment of 6 the fourth clutch 46 through the fifth clutch 47 is replaced, which is the fourth wave 4 with the seventh wave 7 releasably connects, is preferably in the circuit diagram according to 8th the fourth clutch 46 through the fifth clutch 47 replaced. Further, in the case that according to the embodiment according to 7 the fourth clutch 46 through the sixth clutch 67 is replaced, which is the sixth wave 6 with the seventh wave 7 releasably connects, preferably in the circuit diagram according to 8th the fourth clutch 46 through the sixth clutch 67 replaced.

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 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 a load-shifting 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 attached to each shaft as a generator and / or as an additional drive machine.

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

8th'

another wave

03

brake

14

second clutch

27

third clutch

38

further coupling

46

fourth clutch

47

fifth clutch

58

first clutch

67

sixth clutch

P1

first planetary gear set

P2

second planetary gear set

P3

third planetary gear set

P4

fourth planetary gear set

i

translation

phi

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

• EP 0434525 A1 [0003]
• DE 102008000428 A1 [0006]

Claims (5)

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 . 8th' ) and at least five switching elements ( 03 . 14 . 27 . 38 . 46 . 47 . 58 . 67 ), comprising a brake ( 03 ) and couplings ( 13 . 14 . 27 . 38 . 46 . 47 . 58 . 67 ), 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 ) which is connected to the sun gear of the second planetary gear set (P2) and via a brake ( 03 ) can be coupled to a housing (G) of the transmission, wherein the web of the first planetary gear set ( 1 ) with the fifth shaft connected to the ring gear of the fourth planetary gear set (P4) (US Pat. 5 ) is operatively connected, wherein the ring gear of the first planetary gear set (P1) is coupled to a housing (G) of the transmission, wherein the web of the second planetary gear set (P2) with the drive shaft ( 1 ) connected via a second clutch ( 14 ) with the fourth shaft connected to the ring gear of the third planetary gear set (P3) and the sun gear of the fourth planetary gear set (P4) ( 4 ) is detachably connectable, wherein the ring gear of the second planetary gear set (P2) with the sixth shaft ( 6 ), which is connected to the sun gear of the third planetary gear set (P3), wherein the web of the third planetary gear set (P3) with the seventh shaft ( 7 ) connected via a third clutch ( 27 ) connected to the web of the fourth planetary gear set (P4) output shaft ( 2 ) is detachably connectable and wherein a fourth clutch ( 46 ), a fifth clutch ( 47 ) or a sixth clutch ( 67 ) is provided by the closing of the third planetary gear set (P3) is blockable. Multi-speed transmission according to claim 1, characterized in that the sun gear of the first planetary gear set (P1) with the third shaft ( 3 ) is directly connected, wherein the web of the first planetary gear set (P1) with the fifth wheel connected to the ring gear of the fourth planetary gear set (P4) ( 5 ) via an eighth shaft connected to the web of the first planetary gear set (P1) ( 8th ) and an eighth wave ( 8th ) with the fifth wave ( 5 ) detachably connecting first clutch ( 58 ) is releasably connectable. Multi-step transmission according to claim 1, characterized in that the third shaft ( 3 ) with the sun gear of the first planetary gear set (P1) via a further shaft connected to the sun gear of the first planetary gear set (P1) ( 8th' ) and one the further wave ( 8th' ) with the third wave ( 3 ) detachably connecting further coupling ( 38 ) is releasably connectable, the fifth wave ( 5 ) is directly connected to the web of the first planetary gear set (P1). Multi-step transmission according to Claim 1, 2 or 3, characterized in that the fourth clutch ( 46 ) is designed as a coupling via which the fourth shaft ( 4 ) with the sixth wave ( 6 ) releasably connectable is that the fifth clutch ( 47 ) is designed as a coupling via which the fourth shaft ( 4 ) with the seventh wave ( 7 ) is detachably connectable and that the sixth clutch ( 67 ) as a coupling ( 67 ), over which the sixth wave ( 6 ) with the seventh wave ( 7 ) is releasably connectable. Multi-speed transmission according to claim 4, characterized in that in the event that the sun gear of the first planetary gear set (P1) with the third wave ( 3 ) is directly connected, wherein the web of the first planetary gear set (P1) with the fifth wheel connected to the ring gear of the fourth planetary gear set (P4) ( 5 ) via an eighth shaft connected to the web of the first planetary gear set (P1) ( 8th ) and an eighth wave ( 8th ) with the fifth wave ( 5 ) detachably connecting first clutch ( 58 ) releasably connectable, the first forward gear by closing the brake ( 03 ) and the first and second clutches ( 58 . 14 ), the second forward gear by closing the brake ( 03 ) and the first and fourth or fifth and sixth clutch ( 58 . 46 respectively. 47 respectively. 67 ), the third forward gear by closing the first, second and fourth or fifth and sixth clutch ( 58 . 14 . 46 respectively. 47 respectively. 67 ), the fourth forward gear by closing the first, third and fourth or fifth and sixth clutch ( 58 . 27 . 46 respectively. 47 respectively. 67 ), the fifth forward gear by closing the first, second and third clutch ( 58 . 14 . 27 ), the sixth forward speed by closing the second, third and fourth or fifth and sixth clutch ( 14 . 27 . 46 respectively. 47 respectively. 67 ), the seventh forward speed by closing the brake ( 03 ) and the second and third clutches ( 13 . 27 ) and that the eighth forward by closing the brake ( 03 ) and the third and fourth or fifth and sixth clutch ( 27 . 46 respectively. 47 respectively. 67 ), the reverse by closing the brake ( 03 ) and the first and third clutch ( 58 . 27 ), where in the case that the third wave ( 3 ) with the sun gear of the first planetary gear set (P1) via a further shaft connected to the sun gear of the first planetary gear set (P1) ( 8th' ) and one the further wave ( 8th' ) with the third wave ( 3 ) detachably connecting further coupling ( 38 ) is releasably connectable, the fifth wave ( 5 ) is directly connected to the web of the first planetary gear set (P1), the first clutch ( 58 ) by another coupling ( 38 ) is replaced.

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