DE102008041212B4 - Multi-speed transmission - Google Patents

Abstract

Multi-stage transmission in planetary construction, in particular automatic transmission for a motor vehicle, comprising a drive shaft (1), an output shaft (2) and four planetary gear sets (P1, P2, P3, P4), which are arranged in a housing (G), a total of eight rotatable shafts ( 1, 2, 3, 4, 5, 6, 7, 8) and six switching elements (03, 04, 05, 14, 17, 18), comprising brakes (03, 04, 05) and couplings (14, 17, 18 ), whose selective engagement causes different ratios between the drive shaft (1) and the output shaft (2), so that nine forward gears and one reverse gear can be realized, wherein the sun gear of the first planetary gear set (P1) with the via a first brake (05) the housing (G) of the transmission is coupled to the fifth shaft (5) and the web of the first planetary gear set (P1) is connected to the eighth shaft (8) which is connected to the web of the second planetary gear set (P2) and via a first Coupling (18) with the drive shaft (1) releasably ve is rbindbar, wherein the drive shaft (1) via a second clutch (17) with the seventh shaft (7) and via a third clutch (14) with the fourth shaft (4) is releasably connectable, wherein the seventh shaft (7) the sun gear of the third planetary gear set (P3) is connected and the fourth shaft (4) via a second brake (04) to the housing (G) of the transmission is coupled and connected to the sun gear of the fourth planetary gear set (P4), wherein the ring gear the first planetary gear set (P1) is connected to the output shaft (2) which is connected to the ring gear of the second planetary gear set (P2), wherein the web of the third planetary gear set (P3) is connected to the sixth shaft (6) connected to the Component is connected, which connects the ring gear of the fourth planetary gear set (P4) and the sun gear of the second planetary gear set (P2) and wherein the web of the fourth planetary gear set (P4) is connected to the third shaft (3) via a third brake ( 03) to a housing (G ) of the transmission can be coupled and is connected to the ring gear of the third planetary gear set (P3).

Description

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

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

Such automatic transmissions are for example from the DE 199 49 507 A1 the applicant, in which 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 Switching from a gear in the next higher or lower gear from the two currently operated switching elements only one switching element must be switched on or off. Using five shift elements, seven forward gears are achieved, nine or ten forward gears using six shift elements.

Furthermore, from the DE 102 13 820 A1 a multi-speed automatic transmission with eight forward gears and 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 in general are already widely described in the prior art and are subject to permanent development and improvement. So these transmissions require a low construction cost, in particular a small number of switching elements and avoid sequential switching double circuits, so that in circuits in defined gear groups only one switching element is changed.

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

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

In the known multi-speed transmission is provided that the webs of the first and second planetary gear sets are coupled to each other via the fourth shaft, which is connected to an element of the main gearset that the ring gear of the first planetary gear set coupled to the sun gear of the second planetary gear set on the eighth 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 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 constantly connected to the ring gear of the fourth planetary gear set and the web of the third planetary gear set and releasably connectable via the third clutch to the drive shaft. Further, the seventh shaft is constantly connected to the sun gears of the third and fourth planetary gear set and can be coupled via the third brake to a housing of the transmission. The output takes place here via the output shaft permanently connected to the web of the fourth planetary gearset. Furthermore, the third and the fourth planetary gear set can be combined or reduced to form a Ravigneaux set with common web and common ring gear.

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

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

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

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

According to the invention, it is provided that the sun gear of the first planetary gearset is connected to the fifth shaft which can be coupled to the housing of the transmission via a first brake, and that the web of the first planetary gearset is connected to the eighth shaft which is connected to the web of the second planetary gearset and via a first clutch to the drive shaft is detachably connectable, wherein the drive shaft via a second clutch to the seventh shaft and a third clutch to the fourth shaft is releasably connectable Here, the seventh shaft is connected to the sun gear of the third planetary gear set, wherein the fourth shaft via a second brake to the housing of the transmission can be coupled and is connected to the sun gear of the fourth planetary gear set.

Furthermore, the ring gear of the first planetary gear set is connected to the output shaft, which is connected to the ring gear of the second planetary gear set, wherein the web of the third planetary gear set is connected to the sixth shaft, which is connected to a component which the ring gear of the fourth planetary gear set and the sun gear of the second planetary gearset connects with each other. According to the invention, the web of the fourth planetary gearset is connected to the third shaft, which can be coupled to the housing G of the transmission via a third brake and is connected to the ring gear of the third planetary gearset.

Within the scope of a development of the invention, the first planetary gear set and the second planetary gear set are combined or reduced to form a Ravigneaux set with a common web and a common ring gear.

The inventive design of the multi-speed transmission results in particular for passenger cars suitable translations and a significant increase in the overall 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 multi-speed transmission according to the invention to carry out a start with a hydrodynamic converter, an external starting clutch or other suitable external starting elements. It is also conceivable to allow a starting operation with a start-up element integrated in the transmission. Preferably, a switching element which is actuated in the first forward gear and in reverse is suitable.

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

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

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

• 1: Eine schematische Ansicht einer bevorzugten Ausführungsform eines erfindungsgemäßen Mehrstufengetriebes;
• 2: Ein beispielhaftes Schaltschema für ein Mehrstufengetriebe gemäß 1; und
• 3: Ein Diagramm zur Veranschaulichung des der jeweiligen Übersetzung i eines Ganges entsprechenden Stufensprungs phi für das in 1 gezeigte Getriebe.

The invention will be explained in more detail below by way of example with reference to the attached figures. In these represent

• 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 ; and
• 3 : A diagram for illustrating the incremental phi corresponding to the respective gear ratio i of a gear 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 in a housing G are arranged. There are four planetary gear sets P1 . P2 . P3 and P4 provided, wherein the planetary gear sets P2 . P3 and P4 are designed as minus planetary gear sets and the planetary gear set P1 is designed as a plus-planetary gear set.

At the in 1 shown embodiment, which is particularly suitable for a front-transverse construction, are the planetary gear sets P2 . P4 viewed radially in order P4 . P2 arranged one above the other, whereby the total of four planetary gear sets are advantageously limited spatially axially limited to three Radsatzebenen. Here is the ring gear of the fourth planetary gear set P4 via a component with the sun gear of the second planetary gearset P2 connected. Axially, in this case, the planetary gear sets are in order P1 . P3 . P4 / P2 arranged; the third planetary set P3 is between the first planetary gear set P1 and the fourth planetary gear set P4 arranged.

Alternatively, the two planetary gear sets P1 and P2 be summarized or reduced to a known Ravigneaux planetary gear with common land and common ring gear.

How out 1 can be seen, six switching elements, namely three brakes 03 . 04 . 05 and three couplings 14 . 17 and 18 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 first planetary gear set P1 with the over a first brake 05 to the housing G of the transmission can be coupled fifth shaft 5 is connected and that the web of the first planetary gear set P1 with the eighth wave 8th connected to the web of the second planetary gear set P2 is connected and via a first clutch 18 with the drive shaft 1 is detachably connectable, wherein the drive shaft 1 via a second clutch 17 with the seventh wave 7 and a third clutch 14 with the fourth wave 4 is detachably connectable. Here's the seventh wave 7 with the sun gear of the third planetary gear set P3 connected, the fourth wave 4 over a second brake 04 to the housing G of the transmission can be coupled and with the sun gear of the fourth planetary gear set P4 connected is.

Furthermore, the ring gear of the first planetary gear set P1 with the output shaft 2 connected to the ring gear of the second planetary gear set P2 is connected, wherein the web of the third planetary gear set P3 with the sixth wave 6 is connected, which is connected to the component which the ring gear of the fourth planetary gear set P4 and the sun gear of the second planetary gear set P2 connects with each other. According to the invention, the web of the fourth planetary gear set P4 with the third wave 3 connected via a third brake 03 to the housing G the transmission can be coupled and with the ring gear of the third planetary gear set P3 connected is.

In the example shown, the first clutch 18 in the power flow direction in train operation considered before the first planetary gear set P1 arranged, the first brake 05 in the power flow direction in train operation considered before the first planetary gear set P1 is arranged.

Furthermore, the third clutch 14 viewed radially below the second brake 04 arranged and can with the second brake 04 have a common inner disk carrier. Further, the second clutch 17 viewed axially between the first planetary gear set P1 and the third planetary gear set P3 arranged.

According to an embodiment of the invention, not shown, the first planetary gear set P1 and the second planetary gear set P2 to a Ravigneaux - set with common bridge and common ring gear to be summarized or reduced, in this case the third planetary gear set P3 not as per 1 between the first planetary gear set P1 and the radially superposed planetary gear sets P4 / P2 is arranged; the radially superposed planetary gear sets P4 / P2 are rather between the first planetary set P1 and the third planetary gear set P3 arranged. Here, the second clutch 17 viewed radially below the third clutch 14 be arranged.

In 2 is an exemplary circuit diagram of a multi-speed transmission according to 1 shown. For each gear three switching elements are closed. The schematics can be the respective translations i the individual gear steps and the gear steps or increments to be determined therefrom phi to the next higher gear are taken by way of example, the value 10.0 represents the spread of the transmission.

Typical values for the stand ratios of the planetary gear sets P1 . P2 . P3 and P4 are respectively 3.50, -1.50, -1.50 and -2.005. 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 reverse gear can be realized.

The first brake 05 and / or the second clutch 17 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 air-oil mixture contained therein, reduced. The other couplings 14 . 18 and brakes 03 . 04 are preferably designed as Reibschaltelemente or lamellar switching elements.

The first forward gear is obtained by closing the second clutch 17 and the third and first brake 03 . 05 , the second forward gear by closing the second and first brakes 04 . 05 and the second clutch 17 , the third forward gear by closing the second and third clutches 14 . 17 and the first brake 05 , the fourth forward gear by closing the first and second clutches 18 . 17 and the first brake 05 , the fifth forward gear by closing the first, second and third clutches 18 . 17 . 14 , the sixth forward gear by closing the second brake 04 and the first and second clutches 18 . 17 , the seventh forward gear by closing the third brake 03 and the first and second clutches 18 . 17 , the eighth forward gear by closing the third and second brakes 03 . 04 and the first clutch 18 and the ninth forward gear by closing the third brake 03 and the first and third clutches 18 . 14 , The reverse gear is obtained by closing the third and first brake 03 . 05 and the third clutch 14 ,

Due to the fact that in the first forward gear and in reverse the third and first brake 03 . 05 are closed, these switching elements (designed as Reibschaltelemente or lamellae switching elements) can be used as starting elements.

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

A diagram illustrating the respective translation i a gear corresponding increment phi for the in 1 shown gearbox according to the in 2 shown values is the subject of 3 ,

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

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

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

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

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

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

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

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

03

third brake

04

second brake

05

first brake

14

third clutch

17

second clutch

18

first clutch

P1

first planetary gear set

P2

second planetary set

P3

third planetary set

P4

fourth planetary set

i

translation

phi

increment

G

casing

Claims (14)

Multi-stage transmission in planetary construction, in particular automatic transmission for a motor vehicle, comprising a drive shaft (1), an output shaft (2) and four planetary gear sets (P1, P2, P3, P4), which are arranged in a housing (G), a total of eight rotatable shafts ( 1, 2, 3, 4, 5, 6, 7, 8) and six switching elements (03, 04, 05, 14, 17, 18), comprising brakes (03, 04, 05) and couplings (14, 17, 18 ), whose selective engagement causes different ratios between the drive shaft (1) and the output shaft (2), so that nine forward gears and one reverse gear can be realized, wherein the sun gear of the first planetary gear set (P1) with the first brake (05) to the housing (G) of the transmission is coupled to the fifth shaft (5) and the web of the first planetary gear set (P1) is connected to the eighth shaft (8) which is connected to the web of the second planetary gear set (P2) and via a first Coupling (18) with the drive shaft (1) releasably ve is rbindbar, wherein the drive shaft (1) via a second clutch (17) with the seventh shaft (7) and via a third clutch (14) with the fourth shaft (4) is releasably connectable, wherein the seventh shaft (7) the sun wheel the third planetary gear set (P3) is connected and the fourth shaft (4) via a second brake (04) to the housing (G) of the transmission is coupled and connected to the sun gear of the fourth planetary gear set (P4), wherein the ring gear of the first Planet set (P1) with the output shaft (2) is connected to the ring gear of the second planetary gear set (P2), wherein the web of the third planetary gear set (P3) with the sixth shaft (6) is connected, which is connected to the component which interconnects the ring gear of the fourth planetary gearset (P4) and the sun gear of the second planetary gearset (P2) and wherein the land of the fourth planetary gearset (P4) is connected to the third shaft (3) which is connected via a third brake (03) to a housing (G) of the transmission is coupled and is connected to the ring gear of the third planetary gear set (P3). Multi-step transmission after Claim 1 , characterized in that the second, third and fourth planetary gear set (P2, P3, P4) are formed as minus planetary gear sets, wherein the first planetary gear set (P1) is designed as a plus-planetary gearset. Multi-step transmission after Claim 1 or 2 , characterized in that the second and the fourth planetary gear set (P2, P4) are axially arranged in the same Radsatzebene, wherein the second planetary gear set (P2) radially disposed over the fourth planetary gear set (P4), whereby the total of four planetary gear sets (P1, P2, P3, P4) spatially axially limited to three Radsatzebenen. Multi-stage transmission according to one of the preceding claims, characterized in that the first clutch (18) in the direction of force flow in train operation is arranged before the first planetary gear set (P1). Multi-stage transmission according to one of the preceding claims, characterized in that the first brake (05) in the direction of force flow in train operation is arranged before the first planetary gear set (P1). Multi-step transmission according to one of the preceding claims, characterized in that the third clutch (14) is arranged radially below the second brake (04). Multi-step transmission according to one of the preceding claims, characterized in that the third clutch (14) and the second brake (04) have a common inner disk carrier. Multi-step transmission according to one of the preceding claims, characterized in that the third planetary set (P3) between the first planetary gear set (P1) and the radially superposed planetary gear sets (P4 / P2) is arranged. Multi-step transmission after Claim 8 , characterized in that the second clutch (17) axially disposed between the first planetary gear set (P1) and the third planetary gear set (P3) is arranged. Multi-speed transmission to one of the Claims 1 to 7 , characterized in that the first planetary gear set (P1) and the second planetary gear set (P2) are combined or reduced to form a Ravigneaux set having a common web and a common ring gear, wherein the planetary gear sets (P4 / P2) arranged radially one above the other between the first planetary gear set (P1) and the third planetary set (P3) are arranged. Multi-step transmission after Claim 10 , characterized in that the second clutch (17) is arranged radially below the third clutch (14). Multi-speed transmission according to one of the preceding claims, characterized in that the first brake (05) and / or the second clutch (17) are designed as claw switching elements, wherein the other clutches (14, 18) and brakes (03, 04) designed as Reibschaltelemente are. Multi-speed transmission according to one of the preceding claims, characterized in that the first forward gear by closing the second clutch (17) and the third and first brake (03, 05), the second forward gear by closing the second and first brake ( 04, 05) and the second clutch (17), the third forward gear by closing the second and third clutches (14, 17) and the first brake (05), the fourth forward gear by closing the first and second clutches (17). 18, 17) and the first brake (05), the fifth forward gear by closing the first, second and third clutches (18, 17, 14), the sixth forward gear by closing the second brake (04) and the first and the second clutch (18, 17), the seventh forward gear by closing the third brake (03) and the first and second clutches (18, 17), the eighth forward gear by closing the third and second brakes (03, 04 ) and the first clutch (18) and the ninth front reverse gear by closing the third brake (03) and the first and third clutch (18, 14) results, and that the reverse gear by closing the third and first brake (03, 05) and the third clutch (14) results. Multi-step transmission according to one of the preceding claims, characterized in that the starting by means of the third or the first brake (03, 05) of the transmission takes place.

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