EP2978998A1

EP2978998A1 - Multi-stage planetary gear mechanism

Info

Publication number: EP2978998A1
Application number: EP14706053.7A
Authority: EP
Inventors: Stefan Beck; Christian Sibla; Wolfgang Rieger
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2013-03-27
Filing date: 2014-02-25
Publication date: 2016-02-03
Also published as: WO2014154411A1; US9856947B2; JP6374946B2; CN105074276A; JP2016514808A; CN105074276B; US20160053865A1; DE102013205377A1

Abstract

A multi-stage planetary gear mechanism, in particular an automatic transmission for a motor vehicle, comprises a housing (3) having a housing longitudinal axis (2), a driveshaft (10) which can be connected to a drive train in order to transmit a drive torque from the drive train to the multi-stage planetary gear mechanism (1), an output shaft (11) which can be connected to an output train in order to transmit an output torque from the multi-stage planetary gear mechanism (1) to the output train, four individual planetary gear mechanisms (12, 13, 14, 15) which are arranged along the housing longitudinal axis (2) and which each have a sun gear (18, 22, 26, 30), a ring gear (19, 23, 27, 31) and at least one planetary gear (21, 25, 29, 33), each having a web (20, 24, 28, 32), six shifting elements which are arranged inside the housing (3) and which are embodied as four clutch elements (4, 5, 6, 7) and two brakes (8, 9), and connecting shafts (34, 35, 36, 37, 38, 39, 40, 41, 44) for connections between the individual planetary gear mechanisms (12, 13, 14, 15), the driveshaft (10), the output shaft (11), the clutch elements (4, 5, 6, 7) and/or the brakes (8, 9). The individual planetary gear mechanisms (12, 13, 14, 15) can be shifted by means of the shifting elements (4, 5, 6, 7, 8, 9) in such a way that various transmission ratios (i) act between the driveshaft (10) and the output shaft (11), with the result that the multi-stage planetary gear mechanism (1) has nine forward gears (G1, G2, G3, G4, G4a, G4b, G4c, G5, G6, G7, G8, G9) and one reverse gear (R), and the shifting elements (4, 5, 6, 7, 8, 9) are arranged so as to be easily accessible from outside the housing (3).

Description

Multistage Planetenqetriebe

The invention relates to a multi-stage planetary gear, in particular an automatic transmission for a motor vehicle. Such a transmission is arranged for example in a motor vehicle between a drive and the drive wheels. Such a multi-stage planetary gear has a plurality of individual planetary gear, which are interconnected by means of switching elements in the form of clutches and / or brakes.

A multi-stage planetary gear often switching elements are used, which are hydraulically operated. If now such switching elements in the interior of the transmission, in particular arranged to be moving relative to the transmission housing, the hydraulic lines must have transitions to a rotating component. In such transitions, a pressure loss often occurs, so that the pressure within the hydraulic line must be actively maintained. This happens e.g. via a hydraulic pump. The same applies to the use of electrically, pneumatically or mechanically actuated switching elements.

The object of the invention is to provide a multi-stage planetary gear, which has the highest possible proportion of easily accessible switching elements.

To solve this problem, a multi-stage planetary gear according to the features of claim 1 is given. In this multi-stage planetary gear shift elements, which are designed as four clutches and two brakes, easily accessible. At the same time, the multi-stage planetary gear has four arranged between a drive shaft and an output shaft single planetary gear. Each individual planetary gear each includes a sun gear, a ring gear and a plurality of planetary gears each associated with a web.

The multi-stage planetary gear can advantageously be designed in standard construction, so that the drive shaft and the output shaft are arranged coaxially in the housing. It is alternatively possible, the multi-stage planetary gear in To perform front-transverse construction, so that the output shaft can be arranged offset in axial direction to the drive shaft.

The drive shaft can be made connectable via the drive clutch to the drive train of the motor vehicle. The drive clutch is designed in particular as a hydrodynamic torque converter, as a hydrodynamic clutch, an additional starting clutch, an integrated starting clutch, an integrated starting brake, or as an additional electric motor. Overall, the inventive multi-stage planetary gear is characterized by a reduced construction or assembly costs. Both cost and weight of the multi-stage planetary gear are reduced.

Advantageous embodiments of the multi-stage planetary gear resulting from the features of the dependent of claim 1 claims.

Conveniently, an embodiment in which the coupling elements are arranged on au outer shafts, in particular on the drive shaft and / or on the output shaft. The outer shafts are particularly accessible from outside, so that access to all coupling elements in case of need with little effort is possible.

According to a further advantageous embodiment, the fourth clutch is arranged on the output shaft and thus easily accessible from outside.

According to a further advantageous embodiment, the individual planetary gear can be connected by means of the switching elements, that the multi-stage planetary gear has a good gear ratio.

According to a further advantageous embodiment, it is ensured that when switching between two adjacent gear stages, ie in particular also when changing from the first forward gear to the reverse gear and vice versa, exactly one previously closed switching element is opened and exactly one previously opened switching element is closed. According to another advantageous embodiment, the individual planetary gear are each designed as a so-called minus planetary gear. This means that the respective stand ratio of the respective single planetary gear has a negative value. This is achieved in that the coaxially arranged central wheels, ie the inner sun gear and the concentrically arranged, outer ring gear, have opposite directions of rotation. According to another advantageous embodiment, at least one of the negative planetary gear is designed as a so-called plus planetary gear. This is possible, for example, in the case of a single planetary gearbox, in which the connection between web and ring gear is exchanged, and at the same time the amount of stand ratio is increased by the value of one.

According to a further advantageous embodiment, the arrangement of the individual planetary gear in the housing, in particular along the drive shaft and / or output shaft, is variable. This means that the geometric position of the respective individual planetary gear, in particular their order along the drive shaft and / or output shaft, is arbitrary. At the same time or alternatively, the switching elements can be arranged freely selectable with respect to their geometric position in the housing.

According to a further advantageous embodiment, the connecting shafts, the drive shaft and / or the output shaft are each connected to the housing and / or each other by means of a freewheeling element. This results in additional degrees of freedom for the interconnection of the individual planetary gear and their coupling in the housing.

According to a further advantageous embodiment, a drive mounted on the connecting shaft, the drive shaft and / or the output shaft can be provided. The additional drive can be designed for example as an electric motor. It is also conceivable to use other power and / or power sources as a drive. According to a further advantageous embodiment, the switching elements are frictionally and / or positively designed.

According to a further advantageous embodiment, the second brake, the second coupling element and the fourth coupling element are designed as claw circuit elements. Due to the characteristic of the multi-stage planetary gear, the execution of said switching elements as claw circuit elements leads to a significantly reduced fuel consumption.

Both the features specified in the claims and the features specified in the subsequent embodiments of the device according to the invention are each suitable alone or in combination with each other to further develop the subject invention. The respective feature combinations represent no limitation with respect to the developments of the subject invention, but have essentially merely exemplary character.

Further features, advantages and details of the invention will become apparent from the following description of exemplary embodiments with reference to the drawing. It shows:

1 shows a first embodiment of a multi-stage planetary gear,

2 shows a switching matrix for illustrating the switching elements to be closed for a respective gear stage,

Fig. 3 shows a second embodiment of a multi-stage planetary gear according to FIG. 1 with a modified arrangement of the switching elements, and

Fig. 4 shows a third embodiment of a multi-stage planetary gear according to FIG. 1 with a different arrangement of the switching elements. Corresponding parts are provided in FIGS. 1 to 4 with the same reference numerals. Also details of the embodiments explained in more detail below can constitute an invention in itself or be part of an inventive subject matter.

In Fig. 1, a multi-stage planetary gear 1 is shown schematically. The multi-stage planetary gear 1 is designed in particular as a transmission for a motor vehicle.

The multi-stage planetary gear 1 is shown in simplified form in FIG. 1 in that only one part of the multi-stage planetary gear 1 arranged above with respect to a transmission longitudinal axis 2 is shown.

The multi-stage planetary gear 1 has a housing 3. Within the housing 3, six switching elements, namely a first clutch 4, a second clutch 5, a third clutch 6 and a fourth clutch 7 and a first brake 8 and a second brake 9 are arranged. Furthermore, the multi-stage planetary gear has a drive shaft 10 for transmitting a drive torque from a drive, not shown, to the multi-stage planetary gear 1. Accordingly, the multi-stage planetary gear 1 has an output shaft 1 1. The drive shaft 10 and the output shaft 1 1 are arranged coaxially with respect to the housing longitudinal axis 2. Both the drive shaft 10 and the output shaft 1 1 are each led out of the housing 3.

The multi-stage planetary gear further has four along the housing longitudinal axis 2 arranged planetary gear sets 12 to 15. As shown in FIG. 1, the first planetary gear set 12, the second planetary gear set 13, the third planetary gear set 14 and the fourth are along a reference direction 1 6, which is oriented from the drive shaft 10 to the output shaft 1 1 parallel to the transmission longitudinal axis 2 Planetary gear 15 is arranged.

The first brake 8 and the second brake 9 are fixedly arranged on an inner wall of the housing 3. Furthermore, along the reference direction 1 6, the first Clutch 4, the second clutch 5 and the third clutch 6 arranged directly next to each other. With the embodiment shown, the three clutches 4 to 6 have a common outer plate carrier 17. The clutches 4, 5 and 6 are arranged on the outer drive shaft 10. The fourth clutch 7 is arranged on the likewise outer output shaft 1 1.

According to the illustrated embodiment, each of the planetary gear sets 12 to 15 each have an inner, externally toothed sun gear, an outboard, internally toothed and in particular concentric with the transmission longitudinal axis 2 arranged ring gear and a plurality of each having a web, arranged between the sun gear and the ring gear Planet wheels on. Depending on the size of the multi-stage planetary gear, the number of planet gears may vary. Correspondingly, the first planetary gear set 12 comprises a sun gear 18, a ring gear 19 and at least one planetary gear 21 having a web 20. Correspondingly, the second planetary gear set 13 comprises a sun gear 22, a ring gear 23 and at least one planetary gear 25 with a web 24. The third planetary gear set 14 comprises a sun gear 26, a ring gear 27 and at least one planetary gear 29 with a web 28. The fourth planetary gear set 1 5 includes a sun gear 30, a ring gear 31 and at least one planetary gear 33 with a web 32nd

In the following, an interconnection of the planetary gear sets 12 to 15 by means of the switching elements 4 to 9 and the connection of the planetary gear sets 12 to 15 to the drive shaft 10 and the output shaft 1 1 is explained in detail.

The drive shaft 10 is connected via the first clutch 4 with the web 28 of the third planetary gear set 14. The drive shaft 10 is connected via the second clutch 5 with the ring gear 19 of the first planetary gear set 12. At the same time, the drive shaft 10 via the second coupling element 5 with the sun gear 22 of the second planetary gear set 13 is connectable. The drive shaft 10 is connected via the third clutch 6 with the sun gear 18 of the first planetary gear set 12. At the same time, the drive shaft 10 via the third coupling element 6, with the first brake 8 connectable. The output shaft 1 1 is connected to the ring gear 27 of the third planetary gear set 14. The output shaft is connectable via the fourth coupling element 7 with the web 32 of the fourth planetary gear set 1 5.

The web 20 of the first planetary gear set 12 is connected to the web 24 of the second planetary gear set 13. The ring gear 23 of the second planetary gear set 13 is connected to the second brake 9. The web 24 of the second planetary gear set 13 is connected to the ring gear 31 of the fourth planetary gear set 15. The web 24 of the second planetary gear set 13 is connected to the sun gear 26 of the third planetary gear set 14.

The sun gear 30 of the fourth planetary gear set 1 5 is connected to the housing 3 via an eighth connecting shaft 41.

The first planetary gear set 12 has a preferred stand ratio of i ₀ = -1, 898, the second planetary gear set 13 of i ₀ = -1, 609, the third planetary gear set 1 of i ₀ = -1, 500 and the fourth planetary gear set 15 of FIG i ₀ = -1, 500 up.

FIG. 2 shows a shift matrix for the gear steps G to be shifted. The gear steps are listed in ascending order in the shift matrix beginning with the first gear G1 to the ninth gear G9 and one reverse gear R. For example, it can be read from the shift matrix that for realizing the first gear G1, the second brake 9, the second clutch 5 and the fourth clutch 7 must be in a closed switching position. Furthermore, the switching matrix reveals a ratio i to each ratio. In addition, in the switching matrix and a respective gear jump j is listed. For example, the gear gap j between the first gear stage G1 and the second gear stage G2 is 1, 709. This numerical value corresponds to the ratio of the ratio of the first gear stage, namely 4.348, to the gear ratio of the second gear G2, namely 2.545.

In the last three lines of the switch matrix, alternative switching configurations for realizing the fourth gear G4 are illustrated with G4a, G4b and G4c. Basically, applies to the gear ratios G1 to G9 and R, that in a gear stage change between two adjacent gear each exactly opened a previously closed switching element and exactly one previously opened switching element is closed. This means that always two switching elements are closed at the same time. In particular, in the alternative gear ratios G4a and G4b this principle is interrupted because when upshifting from the third gear G3 to, for example, the first alternative fourth gear G4a, the second clutch 5 and the third clutch 6 open and simultaneously the first clutch 4 and the first brake. 8 must be closed.

Independently of this, the alternative fourth gear ratios G4a to G4c have an identical ratio i of 1, 267. This means that an alternative shift position for the fourth gear G4a to G4c does not lead to a change in the gear jumps j, in particular between the third and the fourth gear and the fourth and fifth gear.

The individual numerical values for the translations i and the pitches j arise directly from the switching matrix according to FIG. 2, to which reference is hereby made.

In Fig. 3, an embodiment of another multi-stage planetary gear is shown. The multi-stage planetary gear differs from the multi-stage planetary gear 1 shown in FIG. 1 by a modified arrangement of the clutches. The second clutch 5 and the third clutch 6 are arranged analogously to the multi-stage planetary gear 1 on the drive shaft 10 and interconnected accordingly. Furthermore, the fourth clutch 7 is identical to the multi-stage planetary gear 1 of FIG. 1 arranged on the output shaft 1 1 and interconnected. However, in contrast to the multi-stage planetary gear 1 according to FIG. 1, the first coupling element 4a is not arranged on the drive shaft 10 but on the output shaft 11 and allows the output shaft 11 to be connected to the ring gear 27 of the third via the fourth connecting shaft 37 Planetary gear set 14.

All couplings 4 a, 5, 6, 7 are on the outer shafts 10, 1 1 arranged. The brakes 8, 9 are fixed to the housing 3. All switching elements 4a, 5 to 9 are easily accessible from outside.

4, an embodiment of another multi-stage planetary gear is shown. The multi-stage planetary gear according to FIG. 4 differs from the multi-stage planetary gear 1 according to FIG. 1 in that the first clutch 4 b is not arranged directly on the drive shaft 1 1 but on the seventh connecting shaft 40. Accordingly, the first clutch 4b via the seventh connecting shaft 40 allows a connection of the web 38 of the second planetary gear set 13 with the sun gear 26 of the third planetary gear set 14th

REFERENCE CHARACTERS

Multi-stage planetary gear

Transmission longitudinal axis

casing

First clutch

a First clutch

b First clutch

Second clutch

Third clutch

Fourth clutch

First brake

Second brake

0 drive shaft

1 output shaft

2 First single planetary gear

3 second single planetary gear

4 Third single planetary gear

5 Fourth single planetary gearbox

6 Reference direction

7 plate carrier

8 sun wheel

9 ring gear

0 bridge

1 planetary gear

2 sun wheel

3 ring gear

4 footbridge

5 planetary gear

6 sun wheel

7 ring gear

8 footbridge 9 planetary gear

0 sun wheel

31 ring gear

32 footbridge

33 planetary gear

34 First connecting shaft

35 Second connecting shaft

36 Third wave of communication

37 Fourth connecting shaft

38 Fifth wave of communication

39 Sixth wave of communication

40 Seventh connecting shaft

41 Eighth connecting shaft

42 multi-stage planetary gearbox

43 multi-stage planetary gearbox

44 Ninth connecting shaft G Gear steps

i translation

j leap

Claims

claims

1 . Multi-stage planetary gear, in particular an automatic transmission for a motor vehicle, comprising

a) a housing longitudinal axis (2) having a housing (3), b) connectable to a drive drive shaft (1 0) for transmitting a drive torque from the drive to the multi-stage planetary gear (1),

c) an output shaft (1 1)

d) four along the housing longitudinal axis (2) arranged planetary gear sets (1 2, 1 3, 14, 1 5), each having a sun gear (1 8, 22, 26, 30), a ring gear (1 9, 23, 27 31) and a web (20, 24, 28, 32) and a planetary gear (21, 25, 29, 33),

e) six inside the housing (3) arranged switching elements, which are designed as four clutches (4, 5, 6, 7) and two brakes (8, 9), and

f) connecting shafts (34, 35, 36, 37, 38, 39, 40, 41, 44) for connections between the planetary gear sets (1 2, 1 3, 14, 1 5), the drive shaft (1 0), the output shaft ( 1 1), the clutches (4, 5, 6, 7) and / or the brakes (8, 9),

in which

g) by means of the switching elements (4, 5, 6, 7, 8, 9), the planetary gear sets (1 2, 1 3, 14, 1 5) are switchable such that between the drive shaft (1 0) and the output shaft (1 1 ) different translations (i) act.

2. Multi-stage planetary gear according to claim 1, characterized in that the clutches (4, 5, 6, 7) on au ßenliegenden waves, in particular the drive shaft (1 0) and the output shaft (1 1), are arranged.

3. Multi-stage planetary gear according to one of the preceding claims, characterized in that the first clutch (4), the second clutch (5) and the third clutch (6) on the drive shaft (1 0) are arranged.

4. Multi-stage planetary gear according to one of the preceding claims, characterized in that the first clutch (4), the second clutch (5) and the third clutch (6) along the housing longitudinal axis (2) are arranged side by side.

5. Multi-stage planetary gear according to one of the preceding claims, characterized in that the fourth clutch (7) on the output shaft (1 1) are arranged.

6. Multi-stage planetary gear according to one of the preceding claims, characterized in that

a) the drive shaft (10)

i) via the first clutch (4) with the web (28) of the third single planetary gear (14) is connectable,

ii) via the second clutch (5) with the ring gear (19) of the first planetary gear set (12) and the sun gear (22) of the planetary gear set (13) is connectable,

iii) via the third clutch (6) to the sun gear (18) of the first planetary gear set (12) connectable and via the third clutch (6) and the first brake (8) to the housing (3) is connectable, b) the output shaft (1 1)

i) is connected to the ring gear (27) of the third planetary gear set,

ii) via the fourth clutch (7) with the web (32) of the fourth single planetary gear (15) is connectable,

c) the web (20) of the first planetary gear set (12) is connected to the web (24) of the second planetary gear set (13),

d) the ring gear (23) of the second individual planetary gear (13) via the second brake (9) with the housing (3) is connectable,

e) the web (24) of the second planetary gear set (13) via which with the ring gear (31) of the fourth planetary gear set (15) and with the sun gear (26) of the third planetary gear set (14) is connected, and

f) the sun gear (30) of the fourth planetary gear set (1 5) is fixed to the housing (3).

7. Multi-stage planetary gear according to claim 6, characterized in that the switching elements (4, 5, 6, 7, 8, 9) are switchable such that at a

Change between two adjacent gear stages each exactly one previously closed switching element (4, 5, 6, 7, 8, 9) opened and exactly one previously opened switching element (4, 5, 6, 7, 8, 9) is closed.

8. Multi-stage planetary gear according to one of the preceding claims, characterized in that in all gear stages (G1, G2, G3, G4, G4a, G4b, G4c, G5, G6, G7, G8, G9, R) in each case three switching elements (4 , 5, 6, 7, 8, 9) are closed, wherein in the first forward gear (G1), the second brake (9), the second clutch (5) and the fourth clutch (7), in the second forward gear (G2), the first Brake (8), the second clutch (5) and the fourth clutch (7), in the third forward gear (G3), the second clutch (5), the third clutch (6) and the fourth clutch (7), in the fourth forward gear ( G4) the first clutch (4), the second clutch (5) and the fourth clutch (7), in the fifth forward gear (G5) the first clutch (4), the second clutch (5) and the third clutch (6), in the sixth forward speed (G6), the first brake (8), the first clutch (4) and the second clutch (5) in the seventh forward gear (G7), the second brake (9), the first clutch (4) and the second clutch (5), in the eighth Forward gear (G8), the first brake (8), the second brake (9) and the first clutch (4), in the ninth forward gear (G9), the second brake (9), the first clutch (4) and the third clutch (6 ) are closed and in the reverse gear (R), the second brake (9), the third clutch (6) and the fourth clutch (7) are closed.

9. Multi-stage planetary gear according to claim 8, characterized in that alternatively in the fourth forward gear (G4a; G4b; G4c) the first brake (8), the first clutch (4) and the fourth clutch (7) or the second brake (9 ), the first clutch (4) and the fourth clutch (7) or the first clutch (4), the second clutch (5) and the fourth clutch (7) are closed.

1 0. Multi-stage planetary gear according to one of the preceding claims, characterized in that all planetary gear sets (1 2, 1 3, 14, 1 5) as negative Planetary gear are executed.

1 1. Multi-stage planetary gear according to one of claims 1 to 9, characterized in that at least one planetary gear set (12, 13, 14, 15) is designed as a plus planetary gear.

12. Multi-stage planetary gear according to one of the preceding claims, characterized in that the arrangement of the planetary gear sets (12, 13, 14, 15) along the housing longitudinal axis (2) in the housing (3) is variable.

13. Multi-stage planetary gear according to one of the preceding claims, characterized in that the connecting shafts (34, 35, 36, 37, 38, 39, 40, 41, 44), the drive shaft (10) and / or the output shaft (1 1 ) each have a freewheeling element with which they are connected to the housing (3) and / or to a respective other shaft (10, 1 1, 34, 35, 36, 37, 38, 39, 40, 41, 44).

14. Multi-stage planetary gear according to one of the preceding claims, characterized by at least one of the connecting shafts (35, 36, 37, 38, 39, 40, 41, 44), the drive shaft (10) and / or on the output shaft (1 1) mounted drive for driving the shaft equipped with the drive (10, 1 1, 34, 35, 36, 37, 38, 39, 40, 41, 44).

1 5. Multi-stage planetary gear according to one of the preceding claims, characterized by frictional and / or positive switching elements (4, 5, 6, 7, 8, 9).

1 6. Multi-stage planetary gear according to claim 15, characterized in that the second clutch (5) and the fourth clutch (7) are designed as claw-switching elements.

17. Multi-speed transmission according to one of claims 1 to 3, characterized in that the drive shaft is connected to the web of the third planetary gear set, the drive shaft via the second clutch (5) with the sun gear of the second planetary gear set is connectable, the drive shaft via the third clutch (6) is connectable to the sun gear of the first planetary, the sun gear of the first planetary gear via the first brake to the housing is connected, the web of the first planetary gear set connected to the web of the second planetary gear set is, the ring gear of the first planetary gear set is connected to the sun gear of the second planetary, the ring gear of the second planetary gear via the second brake (9) is connectable to the housing, the web of the second planetary gear set is connected to the ring gear of the fourth planetary gear, the ring gear of the third planetary gear via the fourth clutch to the web of the fourth planetary gear set is connectable and the sun gear of the fourth planetary gear set is connected to the housing.

18. Multi-speed transmission according to claim 17, characterized in that the web of the second planetary gear set via the first clutch (4b) with the sun gear of the third planetary gear set is connectable and the ring gear of the third planetary gear set is connected to the output shaft.

19. Multi-speed transmission according to claim 17, characterized in that the web of the second planetary gear set is connected to the sun gear of the third planetary gear set and the ring gear of the third planetary gear set via the first clutch to the output shaft is connectable.