WO2012072392A1

WO2012072392A1 - Multi-stage gearbox

Info

Publication number: WO2012072392A1
Application number: PCT/EP2011/069798
Authority: WO
Inventors: Gerhard Gumpoltsberger; Christian Sibla; Stefan Beck
Original assignee: Zf Friedrichshafen Ag
Priority date: 2010-12-01
Filing date: 2011-11-10
Publication date: 2012-06-07
Also published as: DE102010062248A1

Abstract

The multi-stage gearbox with five forward gears and a reverse gear comprises three planet gear sets (P1, P2, P3), six rotatable shafts (1, 2, 3, 4, 5, 6) and four shift elements (03, 16, 26, 36, 46), wherein the sun gear of the first planet gear set (P1) is connected to the third shaft (3) which can be coupled to the housing (G) via a brake (03) and is detachably connectable via a first clutch (36) to the sixth shaft (6) which is connected to the web of the second planet gear set (P2) and is detachably connectable via a second clutch (26) to the output shaft (2), which is connected to the internal gear of the third planet gear set (P3), wherein the web of the first planet gear set (P1) is connected to the fourth shaft (4), which is connected to the internal gear of the second planet gear set (P2), and the internal gear of the first planet gear set (P1) is connected to the fifth shaft (5) which is connected to the web of the third planet gear set (P3), wherein the sun gear of the third planet gear set (P3) is coupled to the housing (G) and the driveshaft (1) is connected to the sun gear of the second planet gear set (P2), and wherein a third clutch (16) or a fourth clutch (46) is provided, by means of the closing of which the second planet set (P2) can be blocked.

Description

Mehrstufenqetriebe

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 known for example from DE 199 49 507 A1 of the applicant; In this case, two non-switchable front-gear sets 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 each case the following 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 five forward gears and one reverse gear with sufficient translation, in which the construction cost and size, especially the overall length, or the weight can be 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. Furthermore, the transmission should be suitable both for a coaxial and 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 in planetary construction, which has a drive and an output, which are arranged in a housing. Furthermore, at least three planetary gear sets, referred to below as the first, second and third planetary gear set, six rotatable shafts - hereinafter referred to as the drive shaft, output shaft, third, fourth, fifth and sixth shaft - and at least four preferably as a plate switching elements or as positive Switching elements executed switching elements, comprising a brake and three clutches, provided, the selective engagement causes different ratios between the drive and the output, so that preferably five forward gears and one reverse gear can be realized.

The planetary gear sets are preferably arranged axially in the order of the first planetary gear set, second planetary gearset, third planetary gearset or second planetary gearset, first planetary gearset, third planetary gearset, and are preferably configured as minus planetary gear sets. In other embodiments of the invention, the axial order of the planetary gear sets may be arbitrary.

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 rotational direction when the web is held stationary. tion as the sun gear and there is a positive gear ratio translation.

According to the invention, the sun gear of the first planetary gear set is connected to the third shaft, which is coupled via a brake to the housing of the transmission and via a first clutch to the connected to the web of the second planetary gear sixth shaft is detachably connectable, which via a second Clutch is releasably connected to the output shaft of the transmission connected to the ring gear of the third planetary gear set.

Furthermore, the web of the first planetary gear set is connected to the connected to the ring gear of the second planetary gear fourth shaft of the transmission, wherein the ring gear of the first planetary gear set is connected to the fifth shaft, which is connected to the web of the third planetary gear set and wherein the sun gear of the third planetary gear set is coupled to the housing.

Furthermore, the drive shaft of the transmission is connected to the sun gear of the second planetary gear set, wherein according to the invention a further clutch is provided by the closing of the second planetary gear set is blockable.

According to a first embodiment of the invention, the further coupling is designed as a coupling which releasably connects the drive shaft with the sixth shaft, so that the blocking of the second planetary gear set can be effected by a coupling of the sun gear of the second planetary gear set with the web of the second planetary gear set.

In the context of a further embodiment of the invention, the further coupling can be designed as a coupling which removably connects the fourth shaft to the sixth shaft, so that the blocking of the second planetary gear set can take place by coupling the web of the second planetary gear set with the ring gear of the second 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 multistage transmission according to the invention, a start with a hydrodynamic converter, an external starting clutch o- perform well 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, due to the low torques, in particular by the very low torques on the sun gears of the planetary gear sets a correspondingly small dimensions possible, 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: Figure 1: A schematic view of a first preferred embodiment of a multi-speed transmission according to the invention;

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

FIG. 3 shows an exemplary circuit diagram for a multistage transmission according to FIG. 1 and FIG. 2;

FIG. 4 shows a schematic view of a third preferred embodiment of a multistage transmission according to the invention;

FIG. 5 shows a schematic view of a fourth preferred embodiment of a multistage transmission according to the invention; and

FIG. 6 shows an exemplary circuit diagram for a multistage transmission according to FIG. 4 and FIG. 5.

1 shows a multi-speed transmission according to the invention with a drive shaft 1, an output shaft 2 and three planetary gear sets P1, P2 and P3, which are arranged in a housing G. The planetary gear sets P1, P2, P3 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.

As can be seen from Figure 1, four switching elements, namely a brake 03 and three clutches 16, 26, 36 are provided. The spatial arrangement of the switching elements can be arbitrary and is only by the dimensions and the outer Shaping limited. 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 five forward gears and one reverse gear can be realized. The multistage transmission according to the invention has a total of six rotatable shafts, namely the shafts 1, 2, 3, 4, 5 and 6, wherein the drive shaft, the first shaft 1 and the output shaft forms the second shaft 2 of the transmission.

According to the invention is provided in the multi-stage transmission according to Figure 1, that the sun gear of the first planetary gear P1 is connected to the third shaft 3, which is coupled via a brake 03 to the housing G of the transmission and a first clutch 36 with the with the web of the second planetary gear set P2 connected to the sixth shaft 6 is detachably connectable, which is releasably connectable via a second clutch 26 to the output shaft 2 connected to the ring gear of the third planetary gear P3.

As can be seen from FIG. 1, the web of the first planetary gearset P1 is connected to the fourth shaft 4 connected to the ring gear of the second planetary gearset P2; Further, the ring gear of the first planetary gear P1 is connected to the fifth shaft 5, which is connected to the web of the third planetary gear set P3, wherein the sun gear of the third planetary gear set P3 is coupled to the housing G (shaft 0).

According to the invention and referring to Figure 1, the drive shaft 1 of the transmission is connected to the sun gear of the second planetary gear set P2, wherein a third clutch 16 is provided which removably connects the drive shaft 1 with the sixth shaft 6, so that when the third clutch 16 is closed a blocking of the second planetary gear set P2 is effected by the coupling of the sun gear of the second planetary gear set P2 with the web of the second planetary gear set P2. In this case, the first clutch 36 and the third clutch 16 can be arranged axially next to one another and have a common outer disk carrier. The embodiment of Figure 1 is particularly suitable due to the arrangement of the drive and the output for a coaxial design (standard design).

The embodiment shown in Figure 2 differs from the embodiment of Figure 1 in that the planetary gear sets are axially arranged in the order P2, P1, P3; In this case, the connections of the individual elements of the planetary gear sets P1, P2, P3 are maintained. As can be seen from Figure 2, the drive and the output of the transmission are close to each other, so that this embodiment is suitable for a front-transverse construction.

FIG. 3 shows an exemplary circuit diagram of a multistage transmission according to FIGS. 1 and 2. For each gear two switching elements are closed. The shift scheme, the respective ratios of the individual gear ratios i and the step to be determined therefrom or increments φ are taken to the next higher gear example, the value 5.44 represents the spread of the transmission.

Typical values for the stationary gear ratios of the planetary gear sets P1, P2 and P3 designed as minus planetary gear sets are respectively -2.300, -3.600 and -2.700. From Figure 3 it will be seen that in sequential switching mode only one switching element switched on and a switching element must be switched off because two adjacent gear stages use a switching element 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 brake 03 and the second clutch 26, the second forward gear by closing the first and second clutch 36, 26, the third forward gear by closing the second and third clutch 26, 16, the fourth forward speed by closing the first and third clutches 36, 16 and the fifth forward speed results from closing the brake 03 and the third clutch 16, wherein the reverse gear by closing the brake 03 and the first clutch 36 results.

The fact that the brake 03 is closed in the first forward gear and in the first reverse gear, this switching element can be used as a starting element.

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.

The multi-stage transmission shown in Figure 4 differs from the multi-stage transmission of Figure 1, characterized in that for blocking the second planetary gear P2 instead of the third clutch 16, a fourth clutch 46 is provided, via which the fourth shaft 4 with the sixth shaft 6 is detachably connectable, so that the blocking takes place by a coupling of the web of the second planetary gear set P2 with the ring gear of the second planetary gear set P2. The third clutch 16 is omitted.

The exemplary embodiment according to FIG. 5 differs from the exemplary embodiment shown in FIG. 4 in that the planetary gear sets are arranged axially in the sequence P2, P1, P3, the connections of the individual elements of the planetary gear sets P1, P2, P3 being preserved. Analogous to the embodiment of the multi-speed transmission according to Figure 2, this embodiment is suitable for a front-transverse construction.

An exemplary circuit diagram of a multi-speed transmission according to Figures 4 and 5 is the subject of Figure 6. This circuit diagram differs from the circuit diagram of Figure 3 only in that the third clutch 16 is replaced by the fourth clutch 46. 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 of the invention, 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 multi-plate clutches, band brakes and / or cone clutches can be 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

wave

1 first shaft, drive shaft

second shaft, output shaft

third wave

fourth wave

5 fifth wave

6 sixth wave

03 brake

16 third clutch

26 second clutch

36 first clutch

46 fourth clutch

P1 first planetary gear set

P2 second planetary gear set

P3 third planetary gear set

i translation

Φ increment

G housing

Claims

claims

1 . Multi-stage transmission in planetary construction, in particular automatic transmission for a motor vehicle, comprising a drive shaft (1), an output shaft (2) and three planetary gear sets (P1, P2, P3), which are arranged in a housing (G), a total of six rotatable shafts (1, 2, 3, 4, 5, 6) and at least four switching elements (03, 16, 26, 36, 46), comprising a brake (03) and clutches (16, 26, 36, 46) whose selective engagement between different gear ratios the drive shaft (1) and the output shaft (2) effected so that five forward gears and one reverse gear can be realized, wherein the sun gear of the first planetary gear set (P1) is connected to the third shaft (3), which via a brake (03) on the housing (G) of the transmission can be coupled and via a first clutch (36) with the web of the second planetary gear set (P2) connected to the sixth shaft (6) is releasably connectable via a second clutch (26) with the ring gear the third planetary gear set (P3) connected to the output shaft (2) is detachably connectable, wherein the web of the first planetary gear set (P1) with the ring gear of the second planetary gear set (P2) connected fourth shaft (4) and the ring gear of the first planetary gear set ( P1) is connected to the fifth shaft (5) which is connected to the web of the third planetary gear set (P3), wherein the sun gear of the third planetary gear set (P3) is coupled to the housing (G) and the drive shaft (1) of the transmission is connected to the sun gear of the second planetary gear set (P2) and wherein a third clutch (16) or a fourth clutch (46) is provided by the closing of the second planetary gear set (P2) is blockable.

2. Multi-speed transmission according to claim 1, characterized in that the third clutch (16) is designed as a coupling, which connects the drive shaft (1) with the sixth shaft (6) detachably, so that when the third clutch (16) is a blocking of the second planetary gear set (P2) by the coupling of the sun gear of the second planetary gear set (P2) with the web of the second planetary gear set (P2).

3. Multi-speed transmission according to claim 1, characterized in that the fourth clutch (46) is designed as a coupling which releasably connects the fourth shaft (4) with the sixth shaft (6), so that when the fourth clutch (46) is closed, a blockage of the second planetary gear set (P2) by the coupling of the web of the second planetary gear set (P2) with the ring gear of the second planetary gear set (P2).

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

5. Multi-step transmission according to claim 1, 2, 3 or 4, characterized in that the planetary gear sets (P1, P2, P3) axially arranged in the order P1, P2, P3 or P2, P1, P3 are arranged.

6. Multi-step transmission according to one of the preceding claims, characterized in that in the event that a third clutch (16) is provided, which releasably connects the drive shaft (1) with the sixth shaft (6), the first forward gear through Closing the brake (03) and the second clutch (26), the second forward gear by closing the first and second clutch (36, 26), the third forward gear by closing the second and third clutch (26, 16), the fourth forward gear by closing the first and third clutch (36, 16) and that the fifth forward gear results by closing the brake (03) and the third clutch (16), wherein the reverse gear by closing the brake ( 03) and the first clutch (36), wherein in the event that a fourth clutch (46) is provided which releasably connects the fourth shaft (4) with the sixth shaft (6), the third clutch (16) the fourth clutch (46) replaces wi approx.