DE202014009897U1 - Multi-stage automatic transmission - Google Patents

Abstract

Automatic transmission, in particular for a motor vehicle, comprising a housing (GG), having eight rotatable shafts (1 to 8) including a drive shaft (AN) and including an output shaft (AB), with four planetary gear sets (RS1, RS2, RS3, RS4), each having a first, second and third element, and having a plurality of switching elements (A to F) whose selective closing different ratios between drive shaft (AN) and output shaft (AB) cause switching of several forward gears and one reverse gear, wherein • the second Element (ST4) of the fourth planetary gear set (RS4) as the drive shaft (AN) designed first shaft (1), • the second element (ST3) of the third planetary gear set (RS3) as the output shaft (AB) running second shaft (2) , • the first element (SO4) of the fourth planetary gear set (RS4) forms the third shaft (3), • the fifth shaft (5) the third element (HO2) of the second planetary gear set (RS2) constantly connects to the first element (SO3) of the third planetary gear set (RS3), the third element (HO3) of the third planetary gear set (RS3) forms the sixth shaft (6), the seventh shaft (7) the first element (SO2) of the second planetary gear set (RS2) constantly with the third element (HO4) of the fourth planetary gear set (RS4) connects, • the second element (ST2) of the second planetary gear set (RS2), the eighth shaft (8), • a first switching element (A) in Power flow between the third shaft (3) and the housing (GG) is arranged, • a second switching element (B) is constantly connected to the fourth shaft (4), • a third switching element (C) in the power flow between the first and fifth shaft (1, 5) is arranged, • a fourth switching element (D) in the power flow between the sixth and eighth shaft (6, 8) is arranged, • a fifth switching element (E) in the power flow either between the fifth and seventh shaft (5, 7) or between the fifth and eighth W's Elle (5, 8) or between the seventh and eighth shaft (7, 8) is arranged, so that when the fifth switching element (E) is closed, all three elements (SO2, ST2, HO2) of the second planetary gear set (RS2 ) rotate at the same speed, characterized in that a sixth switching element (F) in the power flow between the first and eighth shaft (1, 8) is arranged.

Description

The present invention relates to a multi-stage automatic transmission in planetary construction according to the preamble of claim 1.

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 should have a sufficient number of forward gears and a reverse gear and a very suitable for motor vehicles translation with a high overall spread, favorable increments and a sufficiently large for the application starting ratio. In addition, these transmissions are the lowest possible construction costs, in particular require a small number of switching elements and avoid sequential switching so-called group circuits, so that in circuits in the next higher or next lower gear only one previously closed switching element opened and closed a previously opened switching element becomes.

Such a multi-speed automatic transmission, for example, from the generic DE 10 2005 002 337 A1 the applicant. It essentially comprises, including a drive shaft and an output shaft, a total of eight rotatable shafts, a total of four individual planetary gear sets and five shift elements. By selectively blocking each of three of the five running as clutches and brakes switching elements a total of eight forward gears are switchable group circuit.

From the DE 10 2009 047 271 A1 the applicant are alternative transmission schemes to that of DE 10 2005 002 337 A1 known 8-speed automatic transmission known, each comprising four individual planetary gear sets, five switching elements and a total of nine waves. In a first variant, a transmission is proposed in which, in contrast to DE 10 2005 002 337 A1 the ring gear of the first planetary gear set arranged close to the drive, whose sun gear is permanently connected to the sun gear of the second planetary gear set connected to the drive shaft via the first switching element on the transmission housing, fixedly connected to the transmission housing. In this case, the second switching element is arranged in the power flow between the planet carrier of this first planetary gear set and the ring gear of the fourth planetary gear set connected to the output shaft. In a second variant, a transmission is proposed, in which, in contrast to DE 10 2005 002 337 A1 the ring gear of the first planetary gearset arranged close to the drive is fixedly connected to the transmission housing, wherein the second shifting element is arranged in the power flow between the sun gear of this first planetary gearset and the sun gear of the second planetary gearset connected to the drive shaft via the first shifting element on the transmission housing.

From the DE 10 2009 001 253 B3 the applicant is a further development of the DE 10 2005 002 337 A1 known 8-speed automatic transmission known. Here could be represented by adding a trained as a clutch sixth switching element in the power flow between the drive shaft and the second planetary gear set blockable by closing the fifth of the previously existing five switching elements, an additional forward gear, which is greater by its translation ago than the previous first gear of the 8-speed Gear, so an additional starting gear below the previous first gear of the 8-speed transmission.

The present invention has for its object to provide an alternative multi-speed transmission of the type mentioned above with a total of four planetary gear sets, which has at least nine group circuit-free switchable forward gears by means of a comparatively slightly modified transmission scheme.

This object is solved according to novelty by an automatic transmission with the features of claim 1. Further advantageous embodiments and developments will become apparent from the dependent claims.

Accordingly, an automatic transmission is proposed, which has a housing, a total of eight rotatable shafts including a drive shaft and including an output shaft, four individual planetary gear sets and six switching elements whose selective intervention different ratios between the drive shaft and output shaft effect switching multiple forward gears and one reverse gear. Each of the four planetary gear sets has three different elements, so in each case a sun gear, a planet carrier and a ring gear.

The second element of the fourth planetary gear set forms the first shaft designed as a drive shaft. The second element of the third planetary gear set forms the output shaft designed as the second shaft. The first element of the fourth planetary gear set forms the third shaft. The fifth shaft connects the third element of the second planetary gear set (in the manner of a coupling shaft) constantly with the first element of the third planetary gear set. The third element of the third planetary gear set forms the sixth shaft. The seventh shaft continuously connects the first element of the second planetary gear set (RS2) (in the manner of a coupling shaft) with the third element of the fourth planetary gear set. The second element of the second planetary gear set forms the eighth wave.

The first switching element is arranged in the power flow between the third shaft and the housing, so that the third shaft can be fixed. The second switching element is constantly connected to the fourth shaft. The third switching element is arranged in the power flow between the first shaft (drive shaft) and the fifth shaft. The fourth switching element is arranged in the power flow between the sixth and eighth shaft. The fifth switching element is arranged in the power flow either between the fifth and seventh shaft or between the fifth and eighth shaft or between the seventh and eighth shaft, so that when the fifth switching element is closed, all three elements of the second planetary gear rotate at the same speed, the second planetary gear set is thus blocked. The sixth switching element is arranged in the power flow between the first shaft (drive shaft) and the eighth shaft.

Here, the term "constantly connected" in connection with the coupling of a switching element to a planetary gear to understand that the input or output element of the respective switching element is connected via a non-rotatable or torsionally elastic connection directly to one of the elements of the respective planetary gear, so it always gives a fixed speed relationship between this Planetenradsatzelement and the input and output element of this switching element.

In connection with the coupling of a switching element to a shaft is under the phrase "constantly connected" to understand that the input or output element of the respective switching element is connected via a rotationally fixed or torsionally elastic connection directly to the respective shaft, so that there is always a fixed speed relationship between this shaft and the input or output element of this switching element is.

In connection with the coupling of a planetary gear set to another planetary gear is under the phrase "constantly connected" to understand that one of the elements of each planetary gear set is connected via a rotationally fixed or torsionally elastic connection directly with one of the elements of the other planetary gear set, so it always gives a fixed speed relationship between these two planetary gear set elements.

In connection with the coupling of a Planetenradsatzelementes or a switching element to the housing is under the wording "constantly connected" to understand that the respective Planetenradsatzelement or the output element of the respective switching element is a rotationally fixed or torsionally elastic connection is directly connected to the housing, so that the respective Planetenradsatzelement or the output element of the respective switching element always stands still.

Thus, the automatic transmission according to the invention over the prior art on an independent kinematics. Using six shift elements, nine forward gears and one reverse gear are shiftable.

In a preferred first embodiment of the invention it is proposed that the first element of the first planetary gear set is constantly connected to the third shaft, that the third element of the first planetary gear sets forms the fourth shaft of the automatic transmission and can be fixed to the housing via the second switching element, and that the second element of the first planetary gear set is constantly connected to the sixth shaft.

The second switching element is thus arranged here in the frictional connection between the fourth shaft and the housing, so that the third element of the first planetary gear set on the housing via the second switching element can be fixed. In addition, this automatic transmission has four coupling shafts through which the four planetary gear sets are constantly connected to each other, namely the third shaft, the fifth shaft, the sixth shaft and the seventh shaft.

In a preferred second embodiment of the invention it is proposed that the third element of the first planetary gear set is continuously connected to the housing, that the first element of the first planetary gear sets forms the fourth shaft of the automatic transmission and is connectable to the third shaft via the second switching element, and that the second element of the first planetary gear set is constantly connected to the sixth shaft.

The second switching element is therefore arranged here in the frictional connection between the third shaft and the fourth shaft, so that the first element of the first planetary gear set via the second switching element with the first element of the fourth planetary gear set is connectable. Since the fourth shaft can be fixed to the housing via the first switching element, the third shaft or the first element of the first planetary gear set can be fixed to the housing by simultaneously closing the first and second switching elements. In addition, this automatic transmission has three coupling shafts through which the four planetary gear sets are constantly connected to each other, namely the fifth shaft, the sixth shaft and the seventh shaft.

Preferably, in the automatic transmission according to the invention in each gear three of the six switching elements are closed. When changing from one gear to the next higher or lower gear only one of the previously closed switching elements is opened and a previously open switching element is closed, so that when sequential upshifting and downshifting by one gear so-called group circuits are avoided.

To represent nine forward gears and one reverse gear with six shift elements, such a transmission may have the following shift logic or gear logic: In the first forward gear, the first, second and sixth shift element are closed or torque transmitting. In the second forward gear, the first, second and third switching element are closed or torque transmitting. In the third forward gear, the first, second and fifth switching element are closed or transmitting torque. In the fourth forward gear, the second, third and fifth switching element are closed or torque transmitting. In the fifth forward gear, the second, fourth and fifth shift element are closed or torque-transmitting. In the sixth forward gear, the second, third and fourth switching element are closed or torque transmitting. In the seventh forward gear, the third, fourth and fifth switching element are closed or torque transmitting. In the eighth forward gear, the first, third and fourth switching element are closed or torque transmitting. In the ninth forward gear, the first, fourth and fifth switching element are closed or torque transmitting. In reverse, the first, second and fourth switching element are closed or torque transmitting.

Advantageously, it is possible to accommodate the sixth switching element in the same space or in a little larger space required for the generic transmission with five switching elements.

All four planetary gear sets are preferably designed as a so-called minus planetary gear sets, their respective planet gears mesh with sun gear and ring gear of the respective planetary gear set.

As an alternative to the design of the wheelset system with four individual minus planetary gear sets individual of the negative planetary gear sets may be replaced by a so-called plus planetary gear, which allows alternative spatial arrangement of individual switching elements within the transmission housing. As is well known, a positive planetary gearset includes a planet carrier ("land") having inner and outer planetary gears rotatably mounted thereon, each of the inner planetary gears meshing respectively with an outer planetary gear and the sun gear of the plus planetary gear while each of the outer planetary gears mesh with, respectively an inner planetary gear and meshes with the ring gear of the plus planetary gear set. As an alternative to the design of the wheelset system with four individual minus planetary gear sets also several of the negative planetary gear sets may be replaced by plus planetary gear sets.

To ensure the same kinematics of the claimed Radsatzsystems is provided that the first element of each minus planetary gear and the first element of each plus planetary gear is designed as a sun gear, that the second element of each negative planetary gear set is designed as a planet, while the second element each Plus planetary gear set is designed as a ring gear, and that the third element of each negative planetary gear set is designed as a ring gear, while the third element of each plus planetary gear set is designed as a planet carrier.

With regard to the spatial arrangement of the four planetary gear sets in the housing of the automatic transmission is proposed in one embodiment, all four planetary gear coaxial with each other side by side in the defined order "first, fourth, second, third planetary gear" to arrange, making it possible, all couplings in a simple way lickagearm to supply the necessary pressure for hydraulic actuation pressure medium. For an application with coaxially extending drive and output shaft, it is expedient in this case that the first planetary gear set of the drive of the automatic transmission facing planetary gear is the planetary gear set.

• • das erste Schaltelement räumlich gesehen auf derjenigen Seite des ersten Planetenradsatzes anzuordnen, die dem vierten Planetenradsatz abgewandt ist;
• • je nach kinematischer Anbindung des zweiten Schaltelementes an die anderen Getriebekomponenten, das zweite Schaltelement zumindest teilweise in einem Bereich radial über dem ersten Planetenradsatz anzuordnen, oder alternativ axial benachbart zum ersten Planetenradsatz auf der dem vierten Planetenradsatz abgewandten Seite des ersten Planetenradsatzes, oder alternativ als Klauenkupplung ausgeführt zumindest teilweise in einem Bereich zentrisch innerhalb des ersten Elementes des ersten Planetenradsatzes;
• • das dritte Schaltelement axial benachbart zum dritten Planetenradsatz in einem Bereich axial zwischen dem zweiten und dritten Planetenradsatz anzuordnen;
• • das vierte Schaltelement axial benachbart zum zweiten Planetenradsatz in einem Bereich axial zwischen dem zweiten und vierten Planetenradsatz;
• • das fünfte Schaltelement axial benachbart zum zweiten Planetenradsatz in einem Bereich axial zwischen dem zweiten und dritten Planetenradsatz anzuordnen, oder alternativ in einem Bereich axial zwischen dem zweiten und vierten Planetenradsatz;
• • das sechste Schaltelement in einem Bereich axial zwischen dem ersten und vierten Planetenradsatz anzuordnen, oder alternativ in einem Bereich radial über dem vierten Planetenradsatz, oder alternativ in einem Bereich axial zwischen dem vierten und zweiten Planetenradsatz.

In connection with the planetary gear set sequence "first, fourth, second, third planetary gear set" is proposed as an advantageous spatial arrangement of the switching elements,

• Spatially arranged to arrange the first switching element on that side of the first planetary gear set, which faces away from the fourth planetary gear set;
• Depending on the kinematic connection of the second switching element to the other transmission components to arrange the second switching element at least partially in a region radially above the first planetary, or alternatively axially adjacent to the first planetary on the side facing away from the fourth planetary gearset of the first planetary gear set, or alternatively as a dog clutch executed at least partially in a region centrally within the first element of the first planetary gear set;
• • The third switching element axially adjacent to the third planetary gear set in a range axially to arrange between the second and third planetary gear set;
• The fourth shift element axially adjacent to the second planetary gear set in a region axially between the second and fourth planetary gear set;
• • to arrange the fifth shift element axially adjacent to the second planetary gear set in a region axially between the second and third planetary gear set, or alternatively in a region axially between the second and fourth planetary gear set;
• • to arrange the sixth shift element in a region axially between the first and fourth planetary gear set, or alternatively in a region radially above the fourth planetary gear set, or alternatively in a region axially between the fourth and second planetary gear set.

Of course, other spatial arrangements of the four planetary gear sets and the six switching elements in the housing of the automatic transmission are possible. For example, the four planetary gear sets coaxial with each other next to each other in the order defined "second, fourth, first, third planetary gear set" may be arranged, in which case it is appropriate for use in a vehicle with so-called "standard drive", the second planetary gear set Turning to the drive side of the automatic transmission, while it is expedient for an application in a vehicle with so-called "front-transverse drive", the third planetary gear set to the drive side of the automatic transmission.

All proposed embodiments and embodiments of an automatic transmission according to the invention have in particular for passenger cars in practice useful translations with very large overall spread in terms of driveability acceptable grading, which has a positive effect on the desired low fuel consumption. In addition, the automatic transmission according to the invention is characterized by a small number of switching elements measured on the number of gears and a comparatively low construction cost. Furthermore, results in the automatic transmission according to the invention in all gears a good efficiency, on the one hand due to low drag losses, since each gear three of the switching elements are engaged, on the other hand, due to low Verzahnungsverluste in the simple design single planetary gear sets.

Advantageously, it is possible with the automatic transmission according to the invention to realize a start of the motor vehicle both with a gear-external starting element and with a transmission-internal friction switching element. A gear-external starting element can be configured in a manner known per se, for example as a hydrodynamic converter, as a so-called dry starting clutch, as a so-called wet starting clutch, as a magnetic powder clutch or as a centrifugal clutch. As an alternative to the arrangement of such a starting element in the power flow direction between the drive motor and gearbox, the gear-external starting element can also be arranged behind the transmission in the direction of the flow of force, in which case the drive shaft of the transmission is connected to the crankshaft of the drive motor in a rotationally fixed or rotationally elastic manner. For example, the first and second switching element, in particular the second switching element which carries the torque in many forward gears and in the reverse gear, are suitable as an internal gear starting element.

In addition, the automatic 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. Thus, with the same transmission scheme, depending on the stationary gear ratio of the individual planetary gear sets, different gear jumps result, so that an application- or vehicle-specific variation is made possible. Furthermore, it is possible without special design measures to arrange drive and output of the transmission either coaxially or axially parallel to each other. On the drive side or on the output side of the transmission, an axle differential and / or a distributor differential can be arranged. It is also possible to provide additional freewheels, for example, between a shaft and the housing or optionally to connect two shafts at any suitable point of the multi-speed transmission. Also, on each shaft, preferably on the drive shaft or on the output shaft, a wear-free brake such. As a hydraulic or electrical retarder or the like, be arranged, which in particular for use in commercial vehicles of particular importance. Also may be provided to drive additional units on each shaft, preferably on the drive shaft or the output shaft, a power take-off. Another advantage of the automatic transmission according to the invention is that on each shaft additionally an electric machine as a generator and / or as an additional drive machine can be attached.

The switching 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. As switching elements but also positive brakes and / or clutches - such. As synchronizers or jaw clutches - are used.

The invention will be explained in more detail below with reference to the drawings by way of example. Identical or comparable components are also provided with the same reference numerals. Show it:

1 a schematic representation of a first embodiment of an automatic transmission according to the invention;

2 a schematic representation of a first alternative to the automatic transmission according to 1 ;

3 a schematic representation of a second alternative to the automatic transmission according to 1 ;

4 a schematic representation of a second embodiment of an automatic transmission according to the invention;

5 a schematic representation of a first alternative to the automatic transmission according to 4 ;

6 a schematic representation of a second alternative to the automatic transmission according to 4 ;

7 an exemplary circuit diagram for the automatic transmission according to 1 to 6 ; and

8th a table with variants of the automatic transmission according to 1 to 6 ,

In 1 the Radsatzschema a first embodiment of an automatic transmission according to the invention is shown. Including a drive shaft AN and including an output shaft AB, the transmission comprises nine rotatable shafts 1 to 9 , four planetary gear sets RS1, RS2, RS3, RS4 and six switching elements A, B, C, D, E, F, which are all arranged in a housing GG of the transmission. All four planetary gear sets RS1, RS2, RS3, RS4 are formed as simple minus planetary gear sets, each comprising a first, a second and a third element. A minus planetary gearset has known planetary gears that mesh with sun and ring gear of this planetary gear set. The respective third elements of the four planetary gear sets RS1, RS2, RS3, RS4 are all formed as ring gears and designated HO1, HO2, HO3 and HO4. The respective first elements of the four planetary gear sets RS1, RS2, RS3, RS4 are all formed as sun gears and designated SO1, SO2, SO3 and SO4. The respective second elements of the four planetary gear sets RS1, RS2, RS3, RS4 are all designed as planet carrier and designated ST1, ST2, ST3 and ST4. The rotatably mounted on the planet carrier ST1, ST2, ST3 and ST4 planetary gears are designated PL1, PL2, PL3 and PL4.

The switching elements A and B are designed as brakes, which are both executed in the illustrated embodiment as frictionally switchable multi-disc brake, in another embodiment can also be designed as frictionally switchable band brakes or, for example, as a form-locking switchable claw or cone brake. The other switching elements C, D, E and F are designed as clutches, which are all executed in the illustrated embodiment as frictionally switchable multi-plate clutch, in another embodiment, for example, as a form-fitting switchable claw or cone clutch can be performed. With these six switching elements A to F is a selective switching of nine forward gears and one reverse gear feasible, which will be described later 10 will be explained in more detail.

With regard to the coupling of the individual elements of the four planetary gear sets RS1, RS2, RS3, RS4 with each other and to the drive and output shafts AN, AB is in the embodiment according to 1 The following is provided: The planet ST4 of the fourth planetary gear set RS4 and the drive shaft AN are rotationally fixed or rotationally elastic connected to each other and form the with 1 designated first shaft of the automatic transmission. The planet carrier ST3 of the third planetary gearset RS3 and the output shaft AB are rotatably or rotationally elastic connected to each other and form the with 2 designated second shaft of the automatic transmission. The sun gear SO1 of the first planetary gear set RS1 and the sun gear SO4 of the fourth planetary gearset RS4 are permanently connected to one another in the manner of a first coupling shaft in a torque-proof or torsionally flexible manner. The sun gear SO4 of the fourth planetary gear set RS4 forms here together with the sun gear SO1 of the first planetary gear set RS1 3 designated third shaft of the automatic transmission. The ring gear HO1 of the first planetary gear set RS1 forms with 4 designated fourth wave of the automatic transmission. The ring gear HO2 of the second planetary gear set RS2 and the sun gear SO3 of the third planetary gearset RS3 are constantly - in the manner of a second coupling shaft - rotatably or torsionally connected to each other. The ring gear HO2 of the second planetary gearset RS2 forms here together with the sun gear SO3 of the third planetary gearset RS3 with 5 designated fifth shaft of the automatic transmission. The planet carrier ST1 of the first planetary gearset RS1 and the ring gear HO3 of the third planetary gearset RS3 are constantly - in the manner of a third coupling shaft - rotatably or torsionally connected to each other. The ring gear HO3 of the third planetary gearset RS3 forms here together with the planet carrier ST1 of the first Planetary gear set with 6 designated sixth shaft of the automatic transmission. The ring gear HO4 of the fourth planetary gear set RS4 and the sun gear SO2 of the second planetary gear set RS2 are rotationally fixed or torsionally elastic connected to each other and form - in the manner of a fourth coupling shaft - with 7 designated seventh shaft of the automatic transmission. The planet carrier ST2 of the second planetary gear set RS2 forms with 8th designated eighth wave of the automatic transmission.

With regard to the coupling of the six switching elements A to F to the eight waves thus described 1 to 8th of the gearbox and to the housing GG is at the in 1 illustrated automatic transmission according to the invention provided the following: The first switching element A is in the power flow between the third shaft 3 and the transmission housing GG arranged. The second switching element B is in the power flow between the fourth shaft 4 and the transmission housing GG arranged. The third switching element C is in the power flow between the first shaft 1 and the fifth wave 5 arranged. The fourth switching element D is in the power flow between the sixth shaft 6 and the eighth wave 8th arranged. The fifth switching element E is in the power flow between the fifth shaft 5 and the seventh wave 7 arranged. The sixth switching element F is in the power flow between the first shaft 1 and the eighth wave 8th arranged.

In the in 1 illustrated embodiment is thus the first wave 1 constantly connected to two switching elements (clutches C and F), the second shaft 2 not connected to any of the switching elements, the third wave 3 constantly connected to a switching element (brake A), the fourth wave 4 constantly connected to a switching element (brake B), the fifth wave 5 constantly connected to two switching elements (clutches C and E), the sixth shaft 6 connected to a switching element (clutch D), the seventh shaft 7 constantly connected to a switching element (clutch E), the eighth shaft 8th constantly connected to two switching elements (clutches D and F).

Further, in the in 1 illustrated embodiment of the first planetary gearset RS1 permanently connected to three switching elements (brake A, brake B, clutch D), the second planetary gearset RS2 constantly connected to four switching elements (clutches C, D, E and F), the third planetary gear set RS3 constantly with three switching elements (Clutches C, D and E) connected, and the fourth planetary gear set RS4 constantly connected to four switching elements (brake A, clutches C, E and F).

In the in 1 illustrated embodiment, when the switching element E is closed, the ring gear HO2 of the second planetary gearset RS2 connected to the sun gear SO2 of the second planetary gearset RS2, whereby the second planetary gear set RS2 is locked and all three elements SO2, ST1 and HO2 of the second planetary gearset RS2 with rotate at the same speed.

For blocking the second planetary gearset RS2 via closing the clutch E, there are two alternatives that in the 2 and 3 are shown. In 2 is the clutch E in the power flow between the seventh shaft 7 and the eighth wave 8th arranged in the closed state and connects the sun gear SO2 of the second planetary gear set RS2 with the planet carrier ST2 of the second planetary gearset RS2. In 3 is the clutch E in the power flow between the fifth shaft 5 and the seventh wave 7 arranged in the closed state and connects the ring gear HO2 of the second planetary gear set RS2 with the planet carrier ST2 of the second planetary gearset RS2.

In the in 1 illustrated embodiment, the four planetary gear sets RS1, RS2, RS3, RS4 are arranged axially in the defined order "RS1, RS4, RS2, RS3" arranged coaxially one behind the other, wherein drive shaft AN and output shaft AB are arranged coaxially to each other and the first planetary gearset RS1 the drive wheel set of the automatic transmission and the third planetary gear set RS3 forms the driven wheel set of the automatic transmission. This arrangement "RS1, RS4, RS2, RS3" advantageously makes it possible for the four planetary gear sets RS1, RS2, RS3, RS4 to be penetrated centrically in the axial direction only by a maximum of one shaft of the automatic transmission.

In principle, the spatial arrangement of the switching elements within the transmission is arbitrary and is limited only by the dimensions and the external shape of the gear housing GG. Accordingly, the in 1 illustrated component assembly to understand expressly as only one of numerous possible component arrangement variants. Numerous suggestions for this find the expert, for example, in the above-mentioned document DE 10 2005 002 337 A1 , This in 1 illustrated embodiment is particularly well suited for installation in a motor vehicle with so-called "standard drive" due to the slim housing structure. In the 1 shown component assembly is based on the in 4 of the DE 10 2005 002 337 A1 revealed automatic transmission.

In the in 1 illustrated embodiment, the brake A is spatially arranged axially adjacent to the (arranged on the drive side of the transmission housing) first planetary gearset RS1, on the side of the planetary gearset RS1, which faces away from the planetary gearset RS4. The brake A is on a comparatively arranged large diameter, on a diameter larger than the diameter of the ring gear HO1. Can be supplied with pressure and coolant, the brake A in a simple way from the housing GG ago. The brake A can be structurally easily integrated in a drive-close housing wall of the housing GG.

How out 1 Furthermore, as can be seen, at least the disk set of the brake B is spatially arranged in a region radially above the first planetary gearset RS1. The brake B can be supplied with pressure and lubricant in a simple manner from the housing GG. The brake B can be structurally simply integrated in the housing GG or in a drive-close housing wall of the housing GG.

How out 1 Furthermore, as can be seen, the two clutches C and E are spatially arranged in a region axially between the (arranged on the output side of the transmission housing) third planetary gearset RS3 and (the third planetary gearset RS3 facing) second planetary gearset RS2, while at least the disk set of the clutch D is arranged for example in a range axially between the second planetary gear set RS2 and the fourth planetary gear set RS4 and at least the disk set of the clutch F is arranged, for example, in a range axially between the first planetary gear set RS1 and the fourth planetary gear set RS4.

The two clutches C and E are arranged, for example, axially next to each other, wherein the clutch E axially adjacent to the second planetary gear set RS2. In manufacturing technology advantageously, a common plate carrier is provided for these two clutches C and E, which is a portion of the fifth shaft 5 forms. In the illustrated embodiment, the disk sets of clutches C and E are arranged axially adjacent to each other on the same diameter; In a variant, the disk set of the clutch C can be seen in the axial direction but can also be arranged radially above the disk set of the clutch E.

Can be supplied with pressure and lubricant, the clutch C in advantageously simple manner leakage loss of the drive shaft AN ago. With pressure and lubricant can be supplied to the clutch E, for example, coming from the drive shaft AN forth via a rotatably mounted on the drive shaft AN section of the seventh shaft 7 or, for example, coming from the output shaft AB forth via a rotatably mounted on or in the output shaft AB portion of the fifth shaft 5 ,

The disk set of the clutch D is arranged adjacent to the second planetary gear set RS2 on the side of the second planetary gearset RS2 facing the fourth planetary gear set RS4. If the servo device of the clutch D provided for actuation of this disk set is also arranged in a region axially between the second and fourth planetary gear sets RS2, RS4, the clutch D can come from the drive shaft AN via a section of the drive shaft rotatably mounted on the drive shaft AN seventh wave 7 about one on this seventh wave 7 rotatably mounted portion of the eighth wave 8th be supplied with pressure and lubricant. Is provided for the operation of this disk set servo device of the clutch D spatially but in a range axially between the first and fourth planetary RS1, RS4 arranged so the clutch D coming from the drive input shaft forth via a rotatably mounted on the drive shaft AN section of third wave 3 about one on this third wave 3 rotatably mounted portion of the sixth shaft 6 be supplied with pressure and lubricant. If, however, the servo device provided for actuation of the disk set of the clutch D is spatially arranged in a region axially between the second and third planetary gearset RS2, RS3, the clutch D can be rotatable, for example, coming from the drive shaft AN via one on or in the drive shaft AN stored section of the fifth wave 5 about one on this fifth wave 5 rotatably mounted portion of the sixth shaft 6 be supplied with pressure and lubricant, or for example coming from the output shaft AB forth via a rotatably mounted on or in the output shaft AB section of the sixth shaft 6 ,

How out 1 Furthermore, it can be seen that at least the disk pack is in the power flow between the shaft 1 (Drive shaft AN) and shaft 8th arranged spatially arranged F in a range axially between the first planetary gear set RS1 and the fourth planetary gear set RS4. This allows the arrangement of the disk set of the clutch F, which - as will be explained later, is closed only in the first forward gear and then has to transmit a relatively large torque - on a comparatively large diameter, similar to the diameter of the two ring gears HO1 and HO4. Correspondingly, the section of the eighth shaft connected here by way of example with the outer disk carrier of the clutch F overlaps 8th complete the fourth planetary gear set RS4, whereby the planetary gear set RS4 and the clutch F are disposed within a cylinder space passing through this portion of the shaft 8th is formed. The pressure and lubricant supply to the clutch F is in a structurally simple way leak leakage over the drive shaft AN and the constantly connected to the drive shaft AN Planet carrier ST4 of the fourth planetary gearset RS4 feasible.

Of course, the expert can also place the clutch F spatially elsewhere. For example, the clutch F spatially may be arranged axially in a range between the second planetary gearset RS2 and the fourth planetary gearset RS4. Is the clutch F deviating too 1 designed in the form of a dog clutch, it is advisable to arrange this claw clutch small diameter in the range axially between the sun gears SO2 and SO4.

As already indicated, the in 1 illustrated spatial arrangement of the switching elements to be understood as exemplary. For example, depending on the installation space available for installing the transmission in the vehicle, it may be expedient to arrange one or more of the six shifting elements differently than in the exemplary embodiment illustrated here.

How out 1 Furthermore, it can be seen that the planetary gear sets RS1, RS4 and RS2 are only each of the drive shaft AN (or shaft 1 ) is completely centered in the axial direction. This is advantageous for the dimensioning of the drive shaft AN and the wheelsets, but also advantageous for the structural design of the lubricant supply to the planetary gears of the planetary gear sets and for the structural design of the pressure and lubricant supply to the clutches. In its axial course, the drive shaft AN passes through the third shaft 3 and the seventh wave 7 centric. How out 1 as can be seen, the shaft overlaps 6 of the transmission, which forms the operative connection between the planet carrier ST1 of the (arranged on the drive side of the transmission housing) first planetary gearset RS1 and the ring gear HO3 of the (arranged on the output side of the transmission housing) third planetary gear set RS3, in its axial course, the fourth and second planetary gear set RS4, RS2 and the three clutches E, F, C complete. Also, the clutch D, the outer disc carrier a portion of the sixth shaft 6 is completely within the sixth wave 6 formed cylinder dream. The eighth wave 8th runs centric within the sixth wave 6 while the seventh wave 7 partially centered within the eighth wave 8th runs. Also the fifth wave 5 runs centric within the sixth wave 6 ,

In 4 is the Radsatzschema a second embodiment of an automatic transmission according to the invention shown, derived from the transmission scheme according to 1 , The differences from the transmission scheme according to 1 relate only to the kinematic coupling of the first planetary gear set RS1 and the second switching element B to the other transmission components.

As in 4 it can be seen, now the ring gear HO1 of the first planetary gear set RS1 is permanently rotatably or torsionally connected to the housing GG. In contrast to 1 now forms the sun gear SO4 of the fourth planetary gear set RS4 only the third wave 3 of the automatic transmission, while the sun gear SO1 of the first planetary gearset RS1 now the fourth shaft constantly connected to the second switching element B. 4 of the automatic transmission forms. This is the fourth wave 4 via the now designed as a clutch second switching element B with the third wave 3 the automatic transmission connect bar. As in 1 is the ring gear HO3 of the third planetary gear set RS3 as the sixth wave 6 the automatic transmission (in the manner of a coupling shaft) permanently rotatably or rotationally elastic connected to the planet ST1 of the first planetary gear set RS1. In contrast to the automatic transmission according to 1 is in the automatic transmission according to 4 the second switching element thus in the power flow between the fourth wave 4 (now sun gear SO1 of the first planetary gear set RS1) and the third wave 3 (Sun SO4 of the fourth planetary gearset RS4) arranged. Thus, the sun gears SO1 and SO4 are connectable to each other by closing the second switching element B, while the sun gears SO1 and SO4 can be fixed together by simultaneously closing the first switching element A and second switching element B on the housing GG.

Thus, the automatic transmission according to 4 unlike the automatic transmission according to 1 only three coupling shafts through which the individual planetary gear sets are permanently connected to each other, namely the fifth, sixth and seventh wave 5 . 6 . 7 ,

As in 4 also visible, all four planetary gear sets RS1 to RS4 are as in FIG 1 formed as a simple minus planetary gear sets and spatially coaxial side by side with the defined order "first, fourth, second, third planetary gear set" (ie arrangement "RS1-RS4-RS2-RS3") arranged. The spatial arrangement of the switching element A designed as a brake and the spatial arrangement of the four switching elements C to F designed as a clutch also failed 1 unchanged.

In contrast to 1 are now the brake A and the clutch B spatially arranged axially adjacent to the first planetary gearset RS1, on the side of the planetary gearset RS1, which faces away from the planetary gearset RS4. The brake A is unchanged at a comparatively large diameter in the region of Outside diameter of the housing GG arranged and can be supplied in a simple manner from the housing GG ago with pressure and coolant. Spatially, the clutch B is arranged axially between the inner disk carrier of the brake A and the first planetary gear set RS1. With pressure and lubricant can be supplied to the clutch B, for example, from the drive shaft AN forth on the drive shaft AN radially enclosing third wave 3 ,

Is the clutch B in deviation to 4 formed as a dog clutch, it may also be spatially arranged at least partially centrally within the sun gear SO1 of the first planetary gear set RS1 and thereby a portion of the third wave 3 enclose radially.

Comparable to 1 is also available for the transmission scheme of 4 alternative possibilities for the blocking of the second planetary gear set RS2 via closing the clutch E, what in the 5 and 6 is shown. While the clutch E in 4 (same as in 1 ) in the power flow between the fifth and seventh wave 5 . 7 is arranged and in the closed state sun gear SO2 and ring gear HO2 of the second planetary gearset RS2 interconnects, is in the in 5 illustrated first alternative, the clutch E (the same as in 2 ) in the power flow between the seventh and eighth wave 7 . 8th arranged in the closed state and connects the sun gear SO2 of the second planetary gear set RS2 with the planet carrier ST2 of the second planetary gearset RS2. In the in 6 illustrated second alternative is the clutch E (the same as in 3 ) in the power flow between the fifth shaft 5 and the seventh wave 7 arranged in the closed state and connects the ring gear HO2 of the second planetary gear set RS2 with the planet carrier ST2 of the second planetary gearset RS2.

In 7 is an exemplary circuit diagram of the automatic transmission according to the invention according to the 1 to 6 shown. In each gear three switching elements are closed and three switching elements open, which - has a positive effect on the efficiency of the transmission - as a result of minimizing the drag losses that are obligatory on open friction shift elements. In addition to the switching logic, it can also be seen from the circuit diagram that so-called group switching is avoided in a sequential shift mode - that is to say when shifting up or down by one gear in each case, since two gear stages adjacent to one another in the shift logic always use two shift elements together. The seventh forward gear is designed as a direct gear, so that two so-called overdrive forward gears with drive-speed-reducing characteristics are available.

Of course, those in the 1 to 6 previously illustrated transmission schemes also with a different spatial arrangement of the four planetary gear sets RS1, RS2, RS3, RS4 representable without changing the respective kinematics of the transmission. A suitable alternative spatial arrangement of the planetary gear sets, for example, the arrangement of four planetary gear sets RS1, RS2, RS3, RS4 coaxial side by side with the defined order "second, fourth, first, third planetary gear" (ie arrangement "RS2-RS4-RS1-RS3"). This arrangement is well suited for a transmission in which the drive shaft AN and output shaft AB are not arranged coaxially with each other, as is the case for example in a so-called front-transverse installation in the vehicle.

Also have the in the 1 to 6 previously proposed spatial arrangements of the switching elements within the transmission housing exemplary character. If necessary and depending on the given structural options, the skilled person will also realize meaningful alternatives for the arrangement of the switching elements.

Based on the finding that it is possible in principle to replace a so-called minus planetary gear set by a kinematic equivalent plus planetary gear, provided that the coupling of sun, planet and ring gear of this planetary gear set to the other planetary gear sets and the switching elements and optionally to the Housing permits, shows 8th a table in which technically meaningful combinations of planetary gear set types for in the 1 to 6 are shown gear schemes are listed. All variants listed in the table can be used via the in 7 shown switching logic nine forward gears and one reverse gear.

As is well known, in a negative planetary gear set, each of its planetary gears mesh with both the sun gear and the ring gear, while in a plus planetary gear set, each of its inner planet gears mesh with one of its outer planet gears and the sun gear and each of its outer planetary gears mesh with one of its inner gears Planet gears and the ring gear is in meshing engagement. Out 8th it can be seen that it is not technically meaningful to carry out the third planetary gear set RS3 permanently connected to the output shaft as a plus planetary gear set, while the formation of one or more of the other three planetary gear sets RS1, RS2 and RS4 leads to technically useful results.

With knowledge of the previously described transmission schemes, the expert will easily all in the table of 8th listed alternatives with generate single or multiple plus planetary gear sets. To maintain the kinematics of the wheelset system, only the first element of each negative planetary gear set as sun gear, the second element of each negative planetary gear set as planet carrier and the third element of each negative planetary gear set must be formed as a ring gear, while the first element of each plus planetary gear as Sun gear, the second element of each plus planetary gear set must be designed as a ring gear and the third element of each plus planetary gear as a planet carrier.

LIST OF REFERENCE NUMBERS

1

first wave

2

second wave

3

third wave

4

fourth wave

5

fifth wave

6

sixth wave

7

seventh wave

8th

eighth wave

A

first switching element, first brake

B

second switching element, second brake

C

third switching element, first clutch

D

fourth switching element, second clutch

e

fifth switching element, third clutch

F

sixth switching element, fourth clutch

AT

drive shaft

FROM

output shaft

GG

casing

RS1

first planetary gear set

SO1

Sun gear of the first planetary gear set

ST1

Planetary carrier of the first planetary gear set

P11

Planetary gears of the first planetary gear set

HO1

Ring gear of the first planetary gear set

RS2

second planetary gear set

SO2

Sun gear of the second planetary gear set

ST2

Planet carrier of the second planetary gear set

PL2

Planetary gears of the second planetary gear set

HO2

Ring gear of the second planetary gear set

RS3

third planetary gear set

SO3

Sun gear of the third planetary gear set

ST3

Planet carrier of the third planetary gear set

PL3

Planetary gears of the third planetary gear set

HO3

Ring gear of the third planetary gear set

RS4

fourth planetary gear set

SO4

Sun gear of the fourth planetary gear set

ST4

Planet carrier of the fourth planetary gear set

PL4

Planetary gears of the fourth planetary gear set

HO4

Ring gear of the fourth planetary gear set

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102005002337 A1 [0003, 0004, 0004, 0004, 0005, 0051, 0051]
• DE 102009047271 A1 [0004]
• DE 102009001253 B3 [0005]

Claims (24)

Automatic transmission, in particular for a motor vehicle, having a housing (GG), having eight rotatable shafts ( 1 to 8th Including a drive shaft (AN) and including an output shaft (AB), with four planetary gear sets (RS1, RS2, RS3, RS4), each having a first, second and third element, and with a plurality of switching elements (A to F) whose Selective closing different ratios between drive shaft (ON) and output shaft (AB) cause switching of several forward gears and one reverse gear, where • the second element (ST4) of the fourth planetary gear set (RS4) designed as the drive shaft (AN) first wave ( 1 ), the second element (ST3) of the third planetary gear set (RS3) has the second shaft (FIG. 2 ), the first element (SO4) of the fourth planetary gear set (RS4) the third wave ( 3 ), • the fifth wave ( 5 ) the third element (HO2) of the second planetary gearset (RS2) constantly connects to the first element (SO3) of the third planetary gearset (RS3), • the third element (HO3) of the third planetary gearset (RS3) the sixth shaft (RS3) 6 ), • the seventh wave ( 7 ) the first element (SO2) of the second planetary gear set (RS2) constantly connects to the third element (HO4) of the fourth planetary gear set (RS4), • the second element (ST2) of the second planetary gear set (RS2) the eighth wave ( 8th ), • a first switching element (A) in the force flow between the third wave ( 3 ) and the housing (GG) is arranged, • a second switching element (B) constantly with the fourth wave ( 4 ), • a third switching element (C) in the power flow between the first and fifth shaft ( 1 . 5 ) is arranged, a fourth switching element (D) in the power flow between the sixth and eighth wave ( 6 . 8th ), a fifth switching element (E) in the force flow either between the fifth and seventh shaft ( 5 . 7 ) or between the fifth and eighth wave ( 5 . 8th ) or between the seventh and eighth wave ( 7 . 8th ), so that when the fifth switching element (E) is closed, all three elements (SO2, ST2, HO2) of the second planetary gear set (RS2) rotate at the same speed, characterized in that a sixth switching element (F) in the power flow between the first and eighth wave ( 1 . 8th ) is arranged. Automatic transmission according to claim 1, characterized in that • the first element (SO1) of the first planetary gear set (RS1) is constantly connected to the third shaft ( 3 ), that the third element (HO1) of the first planetary gear set (RS1), the fourth wave ( 4 ) and via the second switching element (B) on the housing (GG) can be fixed, • and that the second element (ST1) of the first planetary gear set (RS1) constantly with the sixth wave ( 6 ) connected is. Automatic transmission according to claim 1, characterized in that • the third element (HO1, ST1) of the first planetary gear set (RS1) is permanently connected to the housing (GG), • that the first element (SO1) of the first planetary gear set (RS1) is the fourth Wave ( 4 ) and via the second switching element (B) with the third wave ( 3 ) is connectable, and that the second element (ST1) of the first planetary gear set (RS1) is constantly connected to the sixth shaft ( 6 ) connected is. Automatic transmission according to one or more of the preceding claims, characterized in that in each gear three of the switching elements are closed, wherein when changing from a gear in the subsequent higher or lower gear only one of the previously closed switching elements open and only one previously open switching element is closed. Automatic transmission according to claim 4, characterized in that nine forward gears and one reverse gear are switchable, wherein • in the first forward gear, the first, second and sixth switching element (A, B, F) are torque-conducting, • in the second forward gear, the first, second and third switching element (A, B, C) are torque-conducting, • in the third forward gear, the first, second and fifth switching element (A, B, E) are torque-conducting, • in the fourth forward gear, the second, third and fifth switching element (B, C, E) carrying the current are, • in the fifth forward speed, the second, fourth and fifth switching element (B, D, E) are torque-conducting, • in the sixth forward gear, the second, third and fourth switching element (B, C, D) are torque-conducting, • in the seventh forward gear, the third , Fourth and fifth switching element (C, D, E) are torque-conducting, • in the eighth forward gear, the first, third and fourth switching element (A, C, D) are torque-conducting, and the first, second and fourth switching elements in the reverse gear (A, B, D) are torque-leader. Automatic transmission according to one or more of claims 1 to 5, characterized in that all four planetary gear sets (RS1, RS2, RS3, RS4) are designed as negative planetary gear sets. Automatic transmission according to one or more of claims 1 to 5, characterized in that one of the four planetary gear sets (RS1, RS2, RS3, RS4) is designed as a positive planetary gear set, while the other three planetary gear sets are each formed as a minus planetary gear set. Automatic transmission according to claim 7, characterized in that the first or the second or the fourth planetary gear set (RS1, RS2, RS4) is designed as a positive planetary gear set. Automatic transmission according to one or more of claims 1 to 5, characterized in that two of the planetary gear sets are each formed as a plus planetary gear and the other two planetary gear sets each as a minus planetary gear. Automatic transmission according to one or more of claims 1 to 5, characterized in that the third planetary gear set (RS3) is designed as a minus planetary gear, while the first, second and fourth planetary gear set (RS1, RS2, RS4) are each formed as a plus planetary gear set , Automatic transmission according to one or more of the preceding claims, characterized in that • the first element of each negative planetary gear set and the first element of each plus planetary gear set is formed as a sun gear, • the second element of each negative planetary gear set is formed as a planet carrier, while the second Element of each plus planetary gear set is formed as a ring gear, • the third element of each negative planetary gear set is designed as a ring gear, while the third element of each plus planetary gear set is designed as a planet carrier. Automatic transmission according to one or more of the preceding claims, characterized in that the planetary gear sets are arranged coaxially to each other and in the axial direction one behind the other in an order "first, fourth, second, third planetary gearset"("RS1, RS4, RS2, RS3"). Automatic transmission according to claim 12, characterized in that the first switching element (A) is arranged spatially on that side of the first planetary gear set (RS1), which is remote from the fourth planetary gear set (RS4). Automatic transmission according to claim 2 and claim 12, characterized in that the second switching element (B) spatially seen at least partially in a region radially above the first planetary gear set (RS1) is arranged. Automatic transmission according to claim 3 and claim 12, characterized in that the second switching element (B) is spatially arranged on that side of the first planetary gear set (RS1), which faces away from the fourth planetary gear set (RS4), axially adjacent to the first planetary gear set (RS1) , Automatic transmission according to claim 14 or 15, characterized in that the second switching element (B) is designed as a form-locking switching element. Automatic transmission according to claim 3 and claim 16, characterized in that the form-fitting second switching element (B) spatially seen at least partially centrally within the first element (SO1) of the first planetary gear set (RS1) is arranged. Automatic transmission according to claim 12, characterized in that the third switching element (C) spatially in a range axially between the second and third planetary gear set (RS2, RS3) is arranged axially adjacent to the third planetary gear set (RS3). Automatic transmission according to claim 12, characterized in that the fourth switching element (D) spatially seen in a region axially between the second and fourth planetary gear set (RS2, RS4) is arranged, axially adjacent to the second planetary gear set (RS2). Automatic transmission according to claim 12, characterized in that the fifth switching element (E) spatially in a range axially between the second and third planetary gear set (RS2, RS3) is arranged, axially adjacent to the second planetary gear set (RS2). Automatic transmission according to claim 12, characterized in that the fifth switching element (E) spatially in a range axially between the second and fourth planetary gear set (RS2, RS4) is arranged. Automatic transmission according to claim 12, characterized in that the sixth switching element (F) spatially in a range axially between the first and fourth planetary gear set (RS1, RS4) is arranged. Automatic transmission according to claim 12, characterized in that the sixth switching element (F) is arranged spatially in a region radially above the fourth planetary gear set (RS4). Automatic transmission according to claim 12, characterized in that the sixth switching element (F) spatially in a range axially between the second and fourth planetary gear set (RS2, RS4) is arranged.

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