EP2864665A1

EP2864665A1 - Multi-speed gearbox

Info

Publication number: EP2864665A1
Application number: EP13722430.9A
Authority: EP
Inventors: Stefan Beck; Christian Sibla; Wolfgang Rieger
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2012-06-26
Filing date: 2013-05-14
Publication date: 2015-04-29
Also published as: US9441710B2; US20150184723A1; DE102012210831A1; CN104395641A; WO2014000941A1; CN104395641B

Abstract

The invention relates to a multi-speed gearbox having four planetary gear sets (P1, P2, P3, P4), eight rotatable shafts (1, 2, 3, 4, 5, 6, 7, 8) and six shift elements (03, 04, 18, 38, 45, 46, 56, 57), wherein the sun gear of the first planetary gear set (P1) is connected to the input shaft (1), which is connected to the sun gear of the third planetary gear set (P3) and can be coupled to the eighth shaft (8) which is connected to the planet carrier of the fourth planetary gear set (P4) by means of a first clutch (18). The eighth shaft (8) can be connected to the third shaft (3) by means of a second clutch (38), which connects to the planet carrier of the third planetary gear set (P3) and can be coupled to the planet carrier of the first planetary gear set (P1) by means of a first brake (03), which is coupled to the housing (G). The fourth shaft (4) connects to the sun gear of the second planetary gear set (P2) and can be coupled to the planet carrier of the first planetary gear set (P1) by means of a second brake (04), and the seventh shaft (7) connects to the ring gear of the first planetary gear set (P1) and can be connected to the fifth shaft (5) which is connected to the ring gear of the second planetary gear set (P2) and to the sun gear of the fourth planetary gear set (P4) by means of a third clutch (57). The sixth shaft (6) is connected to the planet carrier of the second planetary gear set (P2) and to the ring gear of the third planetary gear set (P3), the output shaft (2) is connected to the ring gear of the fourth planetary gear set (P4) and the closing of a fourth, fifth or sixth clutch (45, 46, 56), which are also provided, can block the second planetary gear set (P2).

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

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. Furthermore, to be reduced by means of such transmission of fuel consumption, which can be done on the one hand by reducing the internal transmission losses and on the other hand by operating the engine at the ideal operating point. In order to operate the internal combustion engine at its ideal operating point, it is particularly important to realize small gear jumps with a large gear spread, which results in the increase of the number of gears.

From DE 10 2008 064 1 13 A1 discloses a transmission arrangement of an automatic transmission for a vehicle comprising ten forward gears, which has a first planetary gear, which is designed as a simple planetary gear and a first rotary element, which acts as a fixed element, a second rotary element, the one reduced rotational speed provides, and a third rotary element, which is directly connected to an input shaft and has as input element acts. The known transmission further comprises a second simple planetary gear, which is a fourth rotary member, which is directly connected to the second rotary member, a fifth rotary member which is selectively connected by inserting a first brake with a transmission housing and a sixth rotary member, optionally by inserting a second brake is connected to a transmission housing, wherein a first clutch selectively connects at least two rotational elements of the fourth, fifth and sixth rotational elements. Further, a third of a planetary gear with a single pinion and a planetary gear with double pinion planetary gear is provided, which is a seventh rotary member which is directly connected to the sixth rotary member, an eighth rotary member which is selectively connected by inserting a second clutch to the drive shaft and selectively connected to the transmission housing by inserting a third brake, a ninth rotary element connected to an output shaft, and a tenth rotary element connected to the fourth rotary element by inserting a third clutch, wherein a fourth clutch is interposed between the third Seventh rotary element and the eighth rotary element is arranged.

In transmission concepts with a high number of gears, the problem arises that the number of transmission components and thus the construction costs depending on the number of gears increase greatly. In addition, the internal efficiency of the transmission decreases due to the higher number of transmission components, so that the achievable by the high number of gears consumption optimization is partially compensated.

The present invention has for its object to propose a multi-speed transmission of the type mentioned, which has at least ten forward gears and one reverse gear and a high spread, in which the construction cost, component load and size are optimized and also the efficiency in terms of drag and Gear losses is improved. 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 four planetary gear sets, hereinafter referred to as the first, second, third and fourth planetary gear set, eight rotatable shafts - hereinafter referred to as drive shaft, output shaft, third, fourth, fifth, sixth, seventh and eighth shaft - and six preferably as a lamellae switching elements or designed as a form-locking switching elements switching elements comprising brakes and clutches, provided, the selective intervention causes different ratios between the drive and the output, so that preferably ten forward gears and one reverse gear can be realized.

The first planetary gear set of the transmission is preferably designed as a positive planetary gear set, wherein the second, third and fourth planetary gear set of the transmission are preferably designed as negative planetary gear sets.

A simple minus planetary gear known to include a sun gear, a ring gear and a ridge on which planet gears are rotatably mounted, each meshing with the sun gear and ring gear. As a result, the ring gear at a fixed web has a direction of rotation opposite to the sun and it results in a negative stationary gear ratio. 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 planet 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 drive shaft, which is connected to the sun gear of the third planetary gear set and detachably connectable via a first clutch to the eighth shaft connected to the web of the fourth planetary gear set, the eighth shaft via a second clutch is releasably connectable with the third shaft, which is connected to the web of the third planetary gear set and can be coupled via a first brake to the web of the first planetary gear set, which is coupled to the housing of the transmission.

Further, the fourth shaft is connected to the sun gear of the second planetary gear set and coupled via a second brake to the web of the first planetary gear set, which is coupled to the housing of the transmission, wherein the seventh shaft connected to the ring gear of the first planetary gear set and via a third clutch with the fifth shaft connected to the ring gear of the second planetary gear set and the sun gear of the fourth planetary gear set is detachably connectable.

Furthermore, the sixth shaft is connected to the web of the second planetary gear set and the ring gear of the third planetary gear set, wherein the output shaft of the transmission is connected to the ring gear of the fourth planetary gear set.

According to the invention, a fourth, fifth or sixth clutch is provided by the closing of the second planetary gear set is blockable.

The fourth clutch can be designed according to a first embodiment of the invention as a coupling which connects the sun gear with the ring gear of the second planetary gear set releasably. The fifth clutch may be designed as a coupling which releasably connects the web to the sun gear of the second planetary gear set, wherein the sixth clutch may be designed as a coupling which removably connects the web to 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 a increased overall spread of the multi-speed transmission, which causes an improvement in ride comfort and a significant consumption reduction.

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 to carry out a start with a hydrodynamic converter, an external starting clutch or other suitable external starting elements. It is also conceivable to allow a starting operation with a start-up element integrated in the transmission. Preferably, a switching element which is actuated in the first forward gear and in reverse is suitable.

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

Advantageously, there are low torques on the switching elements and on the planetary gear sets of the multi-speed transmission, whereby the load 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.

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 transmission can be installed, for example, in front-transverse design or in the context of a standard drive.

The invention will be explained in more detail below by way of example with reference to the attached figures. These are: Figure 1 is a schematic view of a preferred embodiment of a multi-speed transmission according to the invention;

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

Figure 3 is a schematic view of a second preferred embodiment of a multi-speed transmission according to the invention; and

Figure 4 is a schematic view of a third preferred embodiment of a multi-speed transmission according to the invention.

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 first planetary gear set P1 is formed in the example shown in Figure 1 as a plus planetary gear, wherein the second, third and fourth planetary gear, P2, P3, P4 are formed as negative planetary gear sets. According to the invention, at least one of the negative planetary gear sets P2, P3, P4 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 P1, P2, P3, P4 axially arranged in the order of the first planetary gear set P1, second planetary gear set P2, third planetary gear set P3, fourth planetary gear set P4. According to the invention, the axial order of the individual planetary gear sets and the arrangement of the switching elements are freely selectable, as long as it allows the binding of the elements.

As shown in Figure 1, six switching elements, namely two brakes 03, 04 and four clutches 18, 38, 45, 57 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 brakes of the Drives are preferably designed as Reibschaltelemente or lamellar switching elements, but can also be designed as a form-locking switching elements.

With these switching elements a selective switching of at least ten forward gears and one reverse gear can be realized. The multi-speed transmission according to the invention has a total of eight rotatable shafts, namely the waves 1, 2, 3, 4, 5, 6, 7 and 8, wherein the drive shaft, the first shaft 1 and the output shaft form 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 set P1 is connected to the drive shaft 1, which is connected to the sun gear of the third planetary gear set P3 and eighth connected via a first clutch 18 with the web of the fourth planetary gear set P4 8 shaft is releasably connectable, wherein the eighth shaft 8 via a second clutch 38 with the third shaft 3 is detachably connected, which is connected to the web of the third planetary gear P3 and can be coupled via a first brake 03 to the web of the first planetary gear P1, which is coupled to the housing G of the transmission (shaft 0).

In the embodiment shown, in particular, the second clutch 38 is suitable for a design as a claw switching element, whereby the consumption is significantly improved.

Referring to Figure 1, the fourth shaft 4 is connected to the sun gear of the second planetary gear set P2 and coupled via a second brake 04 to the web of the first planetary gear P1, which is coupled to the housing G, wherein the seventh shaft 7 with the ring gear of the first Planetary gear P1 and connected via a third clutch 57 with the connected to the ring gear of the second planetary gear set P2 and the sun gear of the fourth planetary gear set P4 fifth shaft 5 is detachably connectable. The first and second brakes 03, 04 are preferably arranged next to one another when viewed axially and can have a common outer disk carrier as a multi-disk shift element.

The sixth shaft 6 is connected to the web of the second planetary gear set P2 and the ring gear of the third planetary gear set P3, wherein the output shaft 2 is connected to the ring gear of the fourth planetary gear set P4.

In the example shown in Figure 1, a fourth clutch 45 is provided, which connects the fourth shaft 4 with the fifth shaft 5 releasably to one another, by the closing of the second planetary gear set P2 is blockable.

Alternatively, and referring to FIG. 3, the second planetary gear set P2 can be locked by closing a fifth clutch 46 which releasably connects the land to the sun gear of the second planetary gear set P2, eliminating the fourth clutch 45. The fifth clutch 46 releasably connects the fourth shaft 4 with the sixth shaft 6.

As part of a further embodiment of the invention, starting from the embodiment of Figure 1, the fourth clutch 45 omitted, with a sixth clutch 56 is provided by the closing of the second planetary gear set P2 is blockable. This embodiment is the subject of Figure 4. The sixth clutch 56 connects the fifth shaft 5 with the sixth shaft 6 releasably to each other, whereby the web of the second planetary gear set P2 with the ring gear of the second planetary gear set P2 is detachably connectable.

FIG. 2 shows an exemplary circuit diagram of a multistage transmission according to FIG. For each gear three switching elements are closed. The shift scheme, the respective ratios i of the individual gear ratios and the determined therefrom gear increments or increments φ to the next higher gear are exemplified, the value represents 9.033 the spread of the transmission. The values for the stationary gear ratios of the first, second, third and fourth planetary gear sets P1, P2, P3, P4 are in the example shown in each case 1, 68, -1, 91, -2, 28 and -2, 30. From Figure 2 it is 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 two switching elements together. Further, it will be seen that a large spread is achieved with small gear jumps.

The first forward speed is achieved by closing the first brake 03 and the second and fourth clutches 38, 45, the second forward speed by closing the first and second brakes 03, 04 and the second clutch 38, the third forward speed Closing the second brake 04 and the second and fourth clutches 38, 45, the fourth forward gear by closing the second brake 04 and the second and third clutches 38, 57, the fifth forward gear by closing the second brake 04 and the first and second clutch 18, 38, the sixth forward gear in the example shown by closing the first, second and fourth clutch 18, 38, 45, the seventh forward gear by closing the first, third and fourth clutch 18, 57, 45, the eighth forward gear by closing the second brake 04 and the first and fourth clutches 18, 45, the ninth forward gear by closing the first brake 03 and the first and vi erten clutch 18, 45 and the tenth forward gear is obtained by closing the first and second brakes 03, 04 and the first clutch 18, wherein the reverse gear by closing the first brake 03 and the second and third clutch 38, 57 results.

Alternatively, the seventh forward gear can be switched by further switching combinations, which are designated in Figure 2 with 7.1, 7.2 and 7.3. Thus, the seventh forward speed can be achieved by closing the first brake 03 and the first and third clutches 18, 57 or by closing the second brake 04 and the first and third clutches 18, 57 or closing the first, second and third clutches 18, 38 , 57 result. Referring to Figure 2, in addition to the ten forward gears by closing the second, third and fourth clutches 38, 57, 45, another forward gear Z can be realized whose gear ratio is between the fifth and sixth forward gear ratios.

Characterized in that the first brake 03 and the second clutch 38 are closed in the first forward gear and in reverse, these switching elements can be used as starting elements.

In the event that according to the embodiment of Figure 3, the fourth clutch 45 is replaced by the fifth clutch 46, the fourth clutch 45 is replaced by the fifth clutch 46 in the circuit diagram of Figure 2.

Similarly, in the case that according to the embodiment of Figure 4, the fourth clutch 45 is replaced by the sixth clutch 56, in the circuit diagram of Figure 2, the fourth clutch 45 replaced by the sixth clutch 56.

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 also optionally 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.

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, as a coupling element, 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. 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

wave

first shaft, drive shaft

second shaft, output shaft

third wave

fourth wave

fifth wave

6 sixth wave

seventh wave

eighth wave

03 first brake

04 second brake

18 first clutch

38 second clutch

45 fourth clutch

46 fifth clutch

56 sixth clutch

57 third clutch

G housing

P1 first planetary gear set

P2 second planetary gear set

P3 third planetary gear set

P4 fourth planetary gear set

i translation

Φ increment

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 four planetary gear sets (P1, P2, P3, P4), which are arranged in a housing (G), a total of eight rotatable shafts ( 1, 2, 3, 4, 5, 6, 7, 8) and six switching elements (03, 04, 18, 38, 45, 46, 56, 57), comprising brakes (03, 04) and couplings (18, 38 , 45, 46, 56, 57), the selective engagement causes different ratios between the drive shaft (1) and the output shaft (2), so that at least ten forward gears and one reverse gear can be realized, wherein the sun gear of the first planetary gear set (P1) the drive shaft (1) is connected, which with the sun gear of the third planetary gear set (P3) and via a first clutch (18) with the web of the fourth planetary gear set (P4) connected eighth shaft (8) is detachably connectable, wherein the eighth wave (8) over a second e clutch (38) with the third shaft (3) is releasably connectable, which is connected to the web of the third planetary gear set (P3) and via a first brake (03) to the web of the first planetary gear set (P1) can be coupled to the Housing (G) is coupled, wherein the fourth shaft (4) connected to the sun gear of the second planetary gear set (P2) and via a second brake (04) to the web of the first planetary gear set (P1) can be coupled and the seventh shaft (7) connected to the ring gear of the first planetary gear set (P1) and via a third clutch (57) with the with the ring gear of the second planetary gear set (P2) and the sun gear of the fourth planetary gear set (P4) connected to the fifth shaft (5) is detachably connectable, wherein the sixth shaft (6) is connected to the bridge of the second planetary gear set (P2) and the ring gear of the third planetary gear set (P3), the output shaft (2) is connected to the ring gear of the fourth planetary gear set (P4) and wherein a fourth, fifth or sixth clutch (45, 46, 56) is provided by the closing of the second planetary gear set (P2) is lockable lockable.

2. Multi-speed transmission according to claim 1, characterized in that the fourth clutch (45) is designed as a coupling which connects the sun gear with the ring gear of the second planetary gear set (P2) detachably, that the fifth clutch ment (46) is designed as a coupling which releasably connects the sun gear with the web of the second planetary gear set (P2) and that the sixth clutch (56) is designed as a coupling which releasably connects the ring gear with the web of the second planetary gear set (P2) ,

3. Multi-speed transmission according to claim 1, characterized in that the first planetary gear set (P1) is designed as a positive planetary gear, wherein the second, third and fourth planetary gear set (P2, P3, P4) are designed as negative planetary gear sets.

4. Multi-speed transmission according to claim 1, characterized in that the planetary gear sets axially arranged in the order of the first planetary gear set (P1), second planetary gear set (P2), third planetary gear set (P3), fourth planetary gear set (P4) are arranged.

5. Multi-step transmission according to one of the preceding claims, characterized in that the second clutch (38) is designed as a form-locking switching element.

6. Multi-step transmission according to one of the preceding claims, characterized in that in the event that a fourth clutch (45) is provided which releasably connects the sun gear with the ring gear of the second planetary gear set (P2), the first forward gear by closing the first brake (03) and the second and fourth clutches (38, 45), the second forward gear by closing the first and second brakes (03, 04) and the second clutch (38), the third forward gear by closing the second brake (04) and the second and fourth clutches (38, 45), the fourth forward gear by closing the second brake (04) and the second and third clutches (38, 57), the fifth forward gear by closing the second brake (04) and the first and second clutches (18, 38), the sixth forward gear by closing the first, second and fourth clutches (18, 38, 45), the seventh forward gear by closing the first, third and fourth Kupplun g (18, 57, 45), the eighth forward gear by closing the second brake (04) and the first and fourth clutches (18, 45), the ninth Forward speed by closing the first brake (03) and the first and fourth clutch (18, 45) and that the tenth forward speed by closing the first and second brake (03, 04) and the first clutch (18) results, wherein the Reverse gear by closing the first brake (03) and the second and third clutches (38, 57), wherein, in the event that a fifth clutch (46) is provided, which the sun gear with the web of the second planetary gear set (P2) detachably connects, the fourth clutch (45) by the fifth clutch (46) is replaced and wherein in the event that a sixth clutch (56) is provided, which connects the ring gear with the web of the second planetary gear set (P2) releasably, the fourth clutch (45) is replaced by the sixth clutch (56).

7. Multi-speed transmission according to claim 6, characterized in that the seventh forward speed alternatively by closing the first brake (03) and the first and third clutch (18, 57) or by closing the second brake (04) and the first and third clutch (18, 57) or by closing the first, second and third couplings (18, 38, 57).

8. Multi-speed transmission according to claim 6, characterized in that in addition to the ten forward gears by closing the second, third and fourth clutch (38, 57, 45) another forward gear can be realized, the translation between the translations of the fifth and the sixth Forward speed is.