WO2012084371A1

WO2012084371A1 - Multi-speed gearbox

Info

Publication number: WO2012084371A1
Application number: PCT/EP2011/070515
Authority: WO
Inventors: Gerhard Gumpoltsberger; Christian Sibla; Stefan Beck; Michael Wechs
Original assignee: Zf Friedrichshafen Ag
Priority date: 2010-12-21
Filing date: 2011-11-21
Publication date: 2012-06-28
Also published as: DE102010063673A1

Abstract

The multi-speed gearbox with nine forward gears and a reverse gear comprises four planetary gear sets (P1, P2, P3, P4), a plurality of rotatable shafts (1, 2, 3, 4, 5, 6, 7, 8, 9) and a plurality of selector elements (03, 04, 15, 68, 69, 78), wherein the sun gear of planetary gear set (P1) is connected to the ninth shaft (9) which can be connected, via a fourth clutch (69), to the sixth shaft (6) which is connected to the internal gear of planetary gear set (P3) and can be connected, via a first clutch (68), to the eighth shaft (8) which is connected to the planetary carrier of planetary gear set (P2) and can be connected, via a second clutch (78), to the seventh shaft (7) which is connected to the sun gear of planetary gear set (P3) and the sun gear of planetary gear set (P4), wherein the planetary carrier of planetary gear set (P1) is connected to the drive shaft (1) which can be connected, via a third clutch (15), to the fifth shaft (5) which is connected to the internal gear of planetary gear set (P2), wherein the sun gear of planetary gear set (P2) is connected to the third shaft (3) which is connected to the planetary carrier of planetary gear set (P3) and can be coupled to the housing (G) via a first brake (03), wherein the internal gear of planetary gear set (P4) is connected to the fourth shaft (4) which can be coupled to the housing (G) via a second brake (04), and wherein the output shaft (2) is connected to the planetary carrier of planetary gear set (P4) and the internal gear of planetary gear set (P1).

Description

Mehrstufenqetriebe

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

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

Such a multi-stage transmission in planetary construction is known for example from DE 199 49 507 A1 of 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.

Furthermore, from 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 DE 10 2006 006 637 A1 of 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. Thus, these transmissions are to require a low construction cost, in particular a small number of switching elements and in sequential switching manner double circuits, i. avoid switching on or off of two switching elements, so that in circuits in defined gear groups only one switching element is changed.

From DE 10 2008 000 428 A1 of the applicant, a multi-speed planetary gear transmission is 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 Set 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 the 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 the 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 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 nine 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. The transmission according to the invention should be suitable in particular for longitudinal installation but also for transverse installation in the vehicle. 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 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, 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.

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 web 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, 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 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 ninth shaft, which is releasably connectable via a fourth clutch to the sixth shaft, which is connected to the ring gear of the third planetary gear set and connected via a first clutch to the web of the second planetary gear set eighth wave is detachably connectable, which is detachably connectable via a second clutch with the seventh shaft connected to the sun gear of the third planetary gear set and the sun gear of the fourth planetary gear set.

Furthermore, the web of the first planetary gear set is connected to the drive shaft, which is releasably connectable via a third clutch to the fifth shaft connected to the ring gear of the second planetary gear set, wherein the sun gear of the second planetary gear set is connected to the third shaft, which with the web connected to the third planetary gear set and can be coupled via a first brake to a housing of the transmission.

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

The inventive design of the multi-speed transmission results in particular for passenger cars suitable 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 significantly 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, a start with a hydrodynamic converter, an external starting clutch o- also perform with 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.

The clutches and the brakes of the transmission can be designed as Reibschaltelemente or lamellar switching elements, which have the advantage that they can be switched under load. However, switching elements according to the invention can also be used as form-locking switching elements, such as synchronized or unsynchronized jaw clutches or brakes be formed. A transmission according to the invention may comprise exclusively friction shifting elements or a combination of friction shifting elements and positive shifting elements. Positive locking switching elements are preferably used in places where this switching element can not be switched on under load, which may be the case for example in the starting gears or in very long translated high gears where a short interruption of traction due to the low Zugkraftniveaus tolerable without significant loss of comfort is. Due to the compact design of the transmission according to the invention, it is suitable both for a longitudinal installation as well as for a transverse installation in the vehicle.

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 accompanying figures. These are: Figure 1: A schematic view of a preferred embodiment of a multi-speed transmission according to the invention; and

FIG. 2 shows an exemplary circuit diagram for a multistage transmission according to FIG. 1.

1 shows a multi-speed transmission according to the invention 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 formed in the example shown in Figure 1 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.

As shown in Figure 1, six switching elements, namely two brakes 03, 04 and four clutches 15, 68, 69 and 78 are provided. The spatial arrangement of the switching elements can be arbitrary and is limited only by the dimensions and the external shape. The clutches and the brakes of the transmission are preferably designed as Reibschaltelemente or lamellar switching elements.

With these switching elements a selective switching of nine forward gears and one reverse gear can be realized. The multi-speed transmission according to the invention has a total of nine rotatable shafts, namely the waves 1, 2, 3, 4, 5, 6, 7, 8 and 9, wherein the drive shaft forms the first shaft and the output shaft, the second shaft of the transmission.

According to the invention, it is provided in the multistage transmission according to FIG. 1 that the sun gear of the first planetary gearset P1 is connected to the ninth shaft 9, which is releasably connected to the sixth shaft 6 via a fourth clutch 69. can be connected, which is connected to the ring gear of the third planetary gear set P3 and releasably connected via a first clutch 68 with the web of the second planetary gear set P2 eighth shaft 8, via a second clutch 78 with the sun gear of the third planetary gear P3 and the sun gear of the fourth planetary gear set P4 connected seventh shaft 7 is detachably connectable.

According to the invention and with reference to Figure 1, the web of the first planetary gear set P1 is connected to the drive shaft 1 of the transmission, which is detachably connectable via a third clutch 15 with the fifth shaft 5 connected to the ring gear of the second planetary gearset P2; the sun gear of the second planetary gear set P2 is connected to the third shaft 3, which is connected to the web of the third planetary gear set P3 and can be coupled via a first brake 03 to the housing G of the transmission.

Further, the ring gear of the fourth planetary gear set P4 is connected to the fourth shaft 4, which is coupled via a second brake 04 to the housing G of the transmission, wherein the output shaft 2 is connected to the web of the fourth planetary gear set P4 and the ring gear of the first planetary gear set P1 ,

The first and second brakes 03, 04 can be arranged axially next to each other.

FIG. 2 shows an exemplary circuit diagram of a multistage transmission according to FIG. For each gear four switching elements are closed. The shift scheme, the respective ratios i of the individual gear ratios and the gear ratios to be determined therefrom or increments φ are taken to the next higher gear example, the value of 8,992 represents the spread of the transmission.

Typical values for the stationary gear ratios of the planetary gear sets P1, P2, P3 and P4 which are designed as minus planetary gear sets are respectively -2.292, -1, 600, -1, 600 and -2.449. From FIG. 2 it can be seen that in sequential switching mode only one switching element is switched on and one switching element is switched off. tet, since two adjacent gear stages share three switching elements together. 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 second and third clutches 78, 15, the second forward gear by closing the second brake 04 and the first, second and third clutches 68, 78, 15, the third forward speed by closing the second brake 04 and the second, third and fourth clutches 78, 15, 69, the fourth forward speed by closing the second brake 04 and the first, second and fourth clutches 68, 78, 69, the fifth forward gear by closing the second brake 04 and the first, third and fourth clutches 68, 15, 69, the sixth forward gear executed as a direct gear by closing all the clutches 15, 68, 69, 78, the seventh forward By closing the first brake 03 and the first, third and fourth clutches 68, 15, 69, the eighth forward gear by closing the first brake 03 and the first, second and fourth clutches 68, 78, 69 and the ninth Vorwä The reverse gear is obtained by closing the first brake 03 and the second, third and fourth clutches 78, 15, 69, wherein the reverse gear is obtained by closing the first and second brakes 03, 04 and the first and third clutches 68, 15.

Characterized in that in the first forward gear and in the first reverse gear, the first and second brake 03, 04 and the third clutch 15 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 can 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 the 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 is 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 a further, not shown embodiment of the invention, on each shaft, preferably on the drive shaft 1 or the output shaft 2, a wear-free brake, such. 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, a power take-off may be provided.

The friction shift elements used can be designed as power shift 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. REFERENCE CHARACTERS

1 first shaft, drive shaft

second shaft, output shaft

third wave

fourth wave

fifth wave

sixth wave

seventh wave

eighth wave

9th ninth wave

03 first brake

04 second brake

15 third clutch

68 first clutch

69 fourth clutch

78 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 housing

Claims

claims

1 . Multi-stage transmission in planetary design, in particular for a motor vehicle, with a drive shaft (1), an output shaft (2), a housing (G), a first planetary gear set (P1), a second planetary gear set (P2), a third planetary gear set (P3) and a fourth planetary gear set (P4), wherein the Planetenradsätze each comprise a sun gear, a web and a ring gear, with a plurality of rotatable shafts (1, 2, 3, 4, 5, 6, 7, 8, 9) and a plurality of switching elements (03, 04 , 15, 68, 69, 78) comprising brakes (03, 04) and clutches (15, 68, 69, 78) whose selective engagement causes different ratios between the drive shaft (1) and the output shaft (2), the Sun gear of the first planetary gear set (P1) with a ninth shaft (9) is connected via a fourth clutch (69) with a sixth shaft (6) detachably connected, which connected to the ring gear of the third planetary gear set (P3) and via a first clutch (68) with a mi t the eighth shaft (8) connected to the web of the second planetary gear set (P2) is detachably connectable via a second clutch (78) to a seventh shaft connected to the sun gear of the third planetary gear set (P3) and the sun gear of the fourth planetary gear set (P4) (7) is detachably connectable, wherein the web of the first planetary gear set (P1) with the drive shaft (1) is connected via a third clutch (15) with a with the ring gear of the second planetary gear set (P2) connected fifth shaft (5) is detachably connectable, wherein the sun gear of the second planetary gear set (P2) is connected to a third shaft (3), which connected to the web of the third planetary gear set (P3) and a first brake (03) to the housing (G) of the transmission can be coupled, wherein the ring gear of the fourth planetary gear set (P4) with a fourth shaft (4) is connected via a second brake (04) to the housing (G) of the transmission can be coupled and wherein the output SWE (2) is connected to the web of the fourth planetary gear set (P4) and the ring gear of the first planetary gear set (P1).

2. Multi-step transmission according to claim 1, characterized in that nine rotatable shafts and six switching elements, namely two brakes and four clutches are provided.

3. Multi-speed transmission according to claim 1 or 2, characterized in that the planetary gear sets (P1, P2, P3, P4) are designed as negative planetary gear sets.

4. Multi-step transmission according to claim 1, 2 or 3, characterized in that the first forward gear by closing the first and second brakes (03, 04) and the second and third clutch (78, 15), the second forward gear by closing the second brake (04) and the first, second and third clutches (68, 78, 15), the third forward gear by closing the second brake (04) and the second, third and fourth clutches (78, 15, 69), the fourth forward speed by closing the second brake (04) and the first, second and fourth clutches (68, 78, 69), the fifth forward speed by closing the second brake (04) and the first, third and fourth clutch (68, 15, 69), the sixth forward gear by closing all the clutches (15, 68, 69, 78), the seventh forward gear by closing the first brake (03) and the first, third and fourth clutch (58, 39, 57), the eighth forward gear by closing the first brake (03) and de r first, second and fourth clutch (68, 78, 69) and that the ninth forward gear by closing the first brake (03) and the second, third and fourth clutch (78, 15, 69) results, wherein the Reverse by closing the first and second brakes (03, 04) and the first and third clutch (68, 15) results.