DE102014225747A1 - Multi-speed transmission in planetary construction - Google Patents

Abstract

It is proposed a planetary gear multi-speed transmission in a housing (9) for a vehicle with at least one electric machine (EM) and with three planetary gear sets (RS1, RS2, RS3), wherein a drive (An) via at least one switching element (K0) with a first shaft (1) is connectable and an output (Ab) is connected to a second shaft (2), wherein four further shafts (3, 4, 5, 6) and at least five further switching elements (B1, K1, K2, K3 , K4) are provided by the operation of at least eight forward gears (G1, G2, G3, G4, G5, G6, G7, G8) can be realized. According to the invention, it is provided that the first element of the first planetary gear set (RS1) is connected to the housing (9), that the first shaft (1) is fixedly connected to the second element of the first planetary gear set (RS1), that the rotor (10) the electric machine (EM) is connected to the third element of the first planetary gear set (RS1) and that the rotor (10) and the third element of the first planetary gear set (RS1) have at least one switching element (K2, K3, K4) with at least one element at least one of the planetary gear sets (RS1, RS2, RS3) is connectable.

Description

The present invention relates to a planetary multi-speed transmission for a vehicle having at least one electric machine and with a plurality of planetary gear sets according to the closer defined in the preamble of claim 1. Art.

Such hybrid transmissions are known from vehicle technology, with which a purely electric starting and purely electric driving as well as an engine start out of a purely electric drive out, a so-called tow start, are possible. Furthermore, a hybrid driving with load point shift is conceivable. In addition, it is known that the electric machine is connected via an additional pretranslation to the transmission input shaft. As a result, the electric machine can be designed with less torque.

For example, from the document DE 10 2009 046 367 A1 is such a hybrid planetary gearbox with an additional pre-translation for the electric machine known. However, it has been shown that considerable space is required by the connection of the electrical machine via an additional pretranslation, whereby not only the manufacturing cost, but also the consumption can be increased.

The present invention is based on the object to propose a multi-speed transmission of the type described above, in which at least the aforementioned functions can be realized and also structurally simple and inexpensive.

This object is achieved by the features of claim 1, wherein advantageous developments of the dependent claims, the description and the drawings.

Thus, a planetary gear multi-speed transmission is proposed for a vehicle with at least one electric machine and with multiple planetary gear sets in a housing, wherein a drive, such as an internal combustion engine, with a first shaft and the output of the transmission with a second shaft are connected or connected. Furthermore, further waves and a plurality of switching elements are provided by the actuation of several forward gears can be realized.

For realizing a gear-integrated pre-translation of the electric machine is provided that the first element of the first planetary gear set is connected to the housing and that the first shaft is fixedly connected to the second element of the first planetary gear set. Further, the rotor of the electric machine is connected to the third element of the first planetary gear set. In addition, the rotor and the third element of the first planetary gear set via at least one switching element with at least one element of at least one of the planetary gear sets are connectable.

In this way, the electric machine on the one hand to the transmission input shaft, so connected to the drive via a fixed gear independent translation, whereby the electric machine is connected in each gear faster than the engine to the transmission input shaft. Thus, the electric machine can be designed with less torque, but with higher speed, which has a particularly favorable effect on the manufacturing cost. On the other hand, there is the advantage that the fixed pre-translation for the electric machine is generated via a gear-integrated wheelset, which also participates in the formation of other gear ratios. Thus, the pre-translation forming wheel set is used multiple times and thus space for an otherwise required additional wheelset can be saved as pre-translation.

For example, in the connection between the rotor of the electric machine and the third element of the first planetary gear set, a direct connection e.g. be provided in a coaxial arrangement of electric machine and third element of the first planetary gear set to save space and components. However, it is also conceivable that an indirect connection for example via shafts and / or other components, such as gear ratios, chain or belt drives or the like, is provided, for example, a non-coaxial arrangement of electrical machine and third element of the first planetary gear set enable. This also applies to other compounds in the multistage transmission according to the invention.

Another advantage arises in the proposed multi-speed transmission in that no mechanical reverse gear is required in the transmission structure, since the reverse drive is possible with the then backward rotating electric machine in a forward gear. Further, it is advantageous that the electric machine can use the first gear ratio of the transmission and is additionally connected via the integrated pretranslation, resulting in a high starting torque for both the reverse drive and for the forward drive.

Thus, the proposed multi-speed transmission essentially comprises three planetary gear set wheel planes when the planetary gear sets are axial arranged one behind the other. Furthermore, only six switching elements including the connecting the drive to the transmission input switching element are required, wherein at each gear ratio simultaneously two switching switching elements are provided. On the only six required shafts can be arranged in principle on each shaft a freewheel to the housing or to another shaft.

According to a space-saving variant of the present invention may also be provided that, for example, two of the planetary gear sets are arranged radially one behind the other, so that the interleaved wheel sets essentially form a common wheel plane. In this way, virtually a wheel plane and thus axial space is saved.

Vorzugseise the multi-speed transmission may include a brake as a switching element and five designed as clutches switching elements, preferably a housing-fixed coupling of an element of the planetary gear sets is provided as additional housing support.

The term switching element is to be understood as meaning a switchable connection between two elements of the transmission, wherein the torque to be transmitted between these two elements is transmitted by means of frictional connection or frictional engagement or by means of positive locking. If both elements of the switchable connection are rotatable, then the switching element is referred to as a coupling and if only one of the two elements of the switchable connection rotates, the switching element is referred to as a brake.

In addition, the geometric position or sequence of the individual switching elements is freely selectable, as long as it allows the bindability of the elements. In this way, individual elements can be moved arbitrarily in their position.

Embodiments of a force-locking switching element are multi-plate clutches or brakes, band brakes, cone clutches or brakes, electromagnetic clutches, magnetic powder clutches and electro-rheological coupling. Embodiments of a positive switching element are jaw clutches or brakes and gear couplings.

As a switching elements thus both friction and form-locking switching elements can generally be used. Preferably, due to its characteristic as a connection between the drive and the gearbox, especially the zero shift element designed as a clutch can be designed as a dry or wet multi-plate clutch in order to enable a tow start. The fifth switching element designed as a brake may preferably be in the form of a positive switching element, e.g. be executed as a claw, synchronization or the like.

The planetary gear sets are arranged in the order of first planetary gear set, second planetary gear set and third planetary gear set, viewed in the axial direction, wherein preferably all wheelsets are provided as negative planetary gear sets. However, it is possible in places where bondability allows one or more of the negative planetary gear sets to be converted into positive planetary gear sets when simultaneously changing the land and ring gear connections and increasing the amount of the standard ratio by one. A minus planetary gear set is known to be rotatably mounted on the planet gear planetary gears, which mesh with the sun gear and the ring gear of this planetary gear, so that the ring gear rotates with held planet carrier and rotating sun gear in the direction opposite to Sonnenraddrehrichtung. A plus planetary gear set is known to be rotatably mounted on its planet and rotatably supported in meshing inner and outer planetary gears, the sun gear of this planetary mesh with the inner planetary gears and the ring gear of this planetary gear with the outer planetary gears, so that the ring gear while holding the planet and rotating sun gear in the direction of Sonnenraddrehrichtung same direction turns.

The geometric position or order of the individual planetary gear sets and switching elements is arbitrary, as far as it allows the bindability of the elements. For example, individual elements can be moved arbitrarily in their position.

The proposed multi-speed transmission can be carried out both in coaxial design, in which the drive and the output are arranged coaxially to each other. However, it is also conceivable that a lateral output for a front-transverse or a rear transverse arrangement is provided in the vehicle.

Hereinafter, the present invention will be further explained with reference to the drawings. Show it:

1 a schematic view of a first embodiment of a multi-speed transmission according to the invention in planetary design with coaxial drive and output;

2 a schematic view of a second embodiment of the multi-speed transmission according to the invention in planetary design with coaxial drive and output;

3 a schematic view of a third embodiment of the multi-speed transmission with lateral output;

4 a schematic view of a fourth embodiment of the multi-speed transmission with lateral output; and

5 an exemplified circuit diagram for all embodiments according to 1 to 4 ,

1 to 4 show different versions of the multi-speed transmission according to the invention in planetary design, for example, as an automatic eight-speed transmission or automatic transmission for a vehicle, in particular a motor vehicle, wherein in 5 by way of example, a circuit diagram for realizing the various gear ratios is shown as an example.

Regardless of the respective versions, the multi-speed transmission is only schematically as a wheel with a housing 9 shown. Also schematically is the drive An, for example, as an internal combustion engine and the output Ab indicated. The proposed multistage transmission comprises six shafts 1 . 2 . 3 . 4 . 5 . 6 and a solid housing coupling 0 , Furthermore, at least one electric machine EM and a first planetary gearset RS1, a second planetary gearset RS2 and a third planetary gearset RS3 are provided, wherein a drive provided, for example, as an internal combustion engine An via a coupling ZT designed as a switching element K0 with a first shaft 1 is connectable and an output Ab with a second shaft 2 connectable or connected.

For switching the at least eight provided forward gears G1, G2, G3, G4, G5, G6, G7, G8 are a first executed as a clutch switching element K1, a second designed as a clutch switching element K2, a third designed as a clutch switching element K3, a fourth as Clutch executed switching element K4 and designed as a brake fifth switching element B1 provided. The at least one reverse gear ratio R is electrically realized by the reverse-rotating electric machine EM by means of a forward gear. In this way, a wheel stage for reversing the direction of rotation can be saved.

Regardless of the various embodiments is provided to realize a pre-translation of the electric machine EM, that the first element of the first planetary gear set RS1 fixed to the housing 9 via the fixed housing coupling 0 connected is. Furthermore, this is the first shaft which can be connected to the drive An or to the internal combustion engine 1 firmly connected to the second element of the first planetary gearset RS1. Finally, the rotor 10 the electric machine EM connected to the third element of the first planetary gearset RS1. To achieve the dual function of pre-translation, so that it can also be used for further gear ratio, are the rotor 10 and the third element of the first planetary gear set RS1 can be connected via at least one switching element K2, K3, K4 to at least one element of at least one of the planetary gear sets RS1, RS2, RS3.

In the wheelset according to the invention it is provided that the rotor 10 the electric machine EM and the third element of the first planetary gearset RS1, for example, fixed to the third wave 3 are connected, wherein the rotor 10 from arrangement reasons of the electric machine EM can also be connected via other elements. In this way, the first planetary gearset RS1 forms an internal transmission pre-translation for the electric machine EM, wherein the third shaft 3 a constant pretranslation to the first wave 1 translated.

Preferably, the third wave 3 via the clutch formed as third switching element K3 and the fifth shaft 5 connectable to the third element of the second planetary gearset RS2. Further, the third wave 3 via the fourth switching element K4 designed as a clutch and via the sixth shaft 6 connectable to the first element of the third planetary gearset RS3. Finally, the third wave 3 via the fourth switching element K4 designed as a clutch and via the sixth shaft 6 and via the second switching element K2 designed as a clutch with the first shaft 1 connectable.

In addition, the second elements of the second planetary gearset RS2 and the third element of the third planetary gearset RS3 are fixed to the second shaft 2 connected, which is also connected to the output Ab or connectable. The first element of the second planetary gearset RS2 and the second element of the third planetary gearset RS3 are fixed to the fourth shaft 4 connected. In addition, the third element of the second planetary gearset RS2 is fixed to the fifth shaft 5 connected. Finally, the first element of the third planetary gearset RS3 is fixed to the sixth shaft 6 connected.

With regard to the switching elements involved in the gear ratios it is provided that the first switching element K1 is designed as a clutch and the first shaft 1 with the fourth wave 4 connects in the closed or switched state. The second switching element K2 is designed as a coupling and connects in the closed state, the first wave 1 with the sixth wave 6 , The third switching element K3 is designed as a clutch and when closed, connects the third shaft 3 with the fifth wave 5 , The fourth switching element K4 is designed as a coupling and connects in the closed state, the third wave 3 with the sixth wave 6 , Finally, the fifth switching element B1 is designed as a brake and connects in the closed state, the fifth wave 5 with the housing 9 ,

In summary, results in all the execution of a particularly compact design due to the integrated pre-translation of the electric machine EM, which is also involved in other translations. The proposed connections between the individual wheelsets RS1, RS2, RS3 result in low component loads as well as lower transmission losses due to good toothing efficiencies. Furthermore, an optimized translation series is realized at the intended gear ratios.

In all variants according to 1 to 4 For example, the three planetary gear sets RS1, RS2, RS3 are designed as minus planetary gear sets by way of example.

In 1 a first embodiment of the wheelset according to the invention is shown schematically, in which the first planetary gear set RS1 the first gear plane, the second planetary gearset RS2 form the second gear plane and the third planetary gearset RS3 the third gear plane, which are arranged axially one behind the other. Furthermore, a coaxial arrangement of drive input and output Ab is realized.

2 schematically shows a second embodiment of the multi-speed transmission, in which, in contrast to the first embodiment, the axial order of the planetary gear sets RS1, RS2, RS3 is changed. Axially behind the first planetary gearset RS1 follows the third planetary gear set RS3 as the second gear plane and then the second planetary gear set RS2 as the third gear plane. Also in the second embodiment, a coaxial arrangement of drive input and output Ab is provided.

In 3 is a third embodiment of the multi-speed transmission shown schematically, in which a lateral output Ab is shown to the front-transverse or rear transverse arrangement in the vehicle. In the third embodiment variant, the third planetary gearset RS3 is arranged in the first gear plane, the second planetary gearset RS2 in the second gear plane, and the first planetary gearset RS1 with the electric machine EM in the third gear plane.

4 schematically shows a fourth embodiment, in which also a lateral output Ab is realized. In contrast to the third embodiment, the order of the planetary gear sets RS1, RS2, RS3 is changed in the fourth embodiment. In the fourth embodiment variant, the second planetary gearset RS2 is arranged in the first gear plane, the third planetary gearset RS3 in the second gear plane, and the first planetary gearset RS1 in the third gear plane.

In the case of a minus planetary gear set, the first element is designed as a sun gear SR1, SR2, SR3, the second element as a planet carrier or web PT1, PT2, PT3 and the third element as a ring gear HR1, HR2, HR3. In the case of a plus planetary gear set, the first element is designed as sun gear SR1, SR2, SR3, the second element as ring gear HR1, HR2, HR3 and the third element as planet carrier or web PT1, PT2, PT3.

By way of example, the planetary gear sets RS1, RS2, RS3 in the four embodiments are each designed as minus planetary gear sets, so that the shafts 1 . 2 . 3 . 4 . 5 . 6 in the multistage transmission according to the invention are connected as follows with the wheelsets RS1, RS2, RS3.

The drive An is above the zeroth switching element K0 with the first shaft 1 connectable. The first wave 1 is fixedly connected to the planet carrier PT1 of the first planetary gearset RS1. The sun gear SR1 of the first planetary gearset RS1 is connected to the housing 9 connected. The rotor 10 the electric machine EM is connected to the ring gear HR1 of the first planetary gearset RS1. The rotor 10 the electric machine EM and the ring gear HR1 of the first planetary gearset RS1 are fixed to the third shaft 3 connected, the third wave 3 via the clutch formed as third switching element K3 and the fifth shaft 5 with the ring gear HR2 of the second planetary gearset RS2 is connectable. The third wave 3 is also on the running as a clutch fourth switching element K4 and the sixth shaft 6 connectable to the sun gear SR3 of the third planetary gearset RS3. In addition, the third wave 3 via the fourth switching element K4 designed as a clutch and via the sixth shaft 6 and via the second switching element K2 designed as a clutch with the first shaft 1 connectable. The planet carrier PT2 of the second planetary gearset RS2 and the ring gear HR3 of the third planetary gearset RS3 are fixed to the second shaft 2 connected. In addition, the sun gear SR2 of the second planetary gearset RS2 and the planet carrier PT3 of the third planetary gear set RS3 are fixed to the fourth shaft 4 connected. In addition, the ring gear HR2 of the second planetary gearset RS2 is fixed to the fifth shaft 5 connected. Finally, the sun gear SR3 of the third planetary gearset RS3 is fixed to the sixth shaft 6 connected.

If one or more of the planetary gear sets RS1, RS2, RS3 as a plus planetary gear set are executed, the aforementioned compound also apply, as the second element of the planetary gear as a planetary gear not the planet PT1, PT2, PT3 but the ring gear HR1, HR2, HR3 and the third element not the ring gear HR1, HR2, HR3 but the Planetary PT1, PT2, PT3 are provided.

From the in 5 The circuit diagram shown follows the following gear ratios. For realizing the first forward gear G1, the fifth shifting element B1 designed as a brake and the second shifting element K12 designed as a clutch are closed, the fifth shifting element B1 designed as a brake and the fourth shifting element K4 designed as a clutch being closed for shifting the second forward gear G2. For switching the third forward gear G3, the fifth shifting element B1 designed as a brake and the first shifting element K1 designed as a clutch are closed, the first shifting element K1 designed as a clutch and the fourth shifting element K4 designed as a clutch being closed for shifting the fourth forward gear G4. For shifting the fifth forward gear G5, the first shifting element K1 designed as a clutch and the second shifting element K2 designed as a clutch are closed, the first shifting element K1 designed as a clutch and the third shifting element K3 designed as a clutch being closed for shifting the sixth forward gear G6. For switching the seventh forward gear G7 designed as a clutch second switching element K2 and executed as a clutch third switching element K3 are closed, for switching the eighth forward gear G8 designed as a clutch third switching element K3 and designed as a clutch fourth switching element K4 are closed. The Rückwartgang R is realized electrically via one of the forward gear ratios.

LIST OF REFERENCE NUMBERS

0

solid housing coupling

1

wave

2

wave

3

wave

4

wave

5

wave

6

wave

9

casing

10

rotor

EM

Electric machine

HR1

Ring gear of the first planetary gear set

PT1

Planetary carrier of the first planetary gear set

SR1

Sun gear of the first planetary gear set

HR2

Ring gear of the second planetary gear set

PT2

Planet carrier of the second planetary gear set

SR2

Sun gear of the second planetary gear set

HR3

Ring gear of the third planetary gear set

PT3

Planet carrier of the third planetary gear set

SR3

Sun gear of the third planetary gear set

G1

first forward

G2

second forward gear

G3

third forward speed

G4

fourth forward gear

G5

fifth forward gear

G6

sixth forward gear

G7

seventh forward gear

G8

eighth forward gear

R

Electrically realized reverse gear

At

drive

From

output

K0

zeroth switching element as a coupling

K1

first switching element as a coupling

K2

second switching element as a clutch

K3

third switching element as a clutch

K4

fourth switching element as a clutch

B1

fifth switching element as a brake

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 102009046367 A1 [0003]

Claims (9)

Multi-stage gear in planetary design in a housing ( 9 ) for a vehicle with at least one electric machine (EM) and with three planetary gear sets (RS1, RS2, RS3), wherein a drive (An) via at least one switching element (K0) with a first shaft ( 1 ) is connectable and an output (Ab) with a second wave ( 2 ), with four more waves ( 3 . 4 . 5 . 6 ) and at least five further switching elements (B1, K1, K2, K3, K4) are provided by the actuation of at least eight forward gears (G1, G2, G3, G4, G5, G6, G7, G8) can be realized, characterized in that the first element of the first planetary gear set (RS1) with the housing ( 9 ), that the first wave ( 1 ) is fixedly connected to the second element of the first planetary gear set (RS1) that the rotor ( 10 ) of the electric machine (EM) is connected to the third element of the first planetary gear set (RS1) and that the rotor ( 10 ) and the third element of the first planetary gear set (RS1) via at least one switching element (K2, K3, K4) with at least one element of at least one of the planetary gear sets (RS1, RS2, RS3) are connectable. Multi-step transmission according to claim 1, characterized in that the rotor ( 10 ) of the electric machine (EM) and the third element of the first planetary gear set (RS1) fixed to the third shaft ( 3 ), that the third wave ( 3 ) via the clutch formed as a third switching element (K3) and the fifth wave ( 5 ) is connectable to the third element of the second planetary gear set (RS2) that the third wave ( 3 ) via the coupling element as the fourth switching element (K4) and the sixth shaft ( 6 ) is connectable to the first element of the third planetary gear set (RS3), and that the third wave ( 3 ) via the coupling element as the fourth switching element (K4) and the sixth shaft ( 6 ) and via the second switching element (K2) designed as a clutch with the first shaft ( 1 ) is connectable. Multi-speed transmission according to claim 1 or 2, characterized in that the second elements of the second planetary gear set (RS2) and the third element of the third planetary gear set (RS3) fixed to the second shaft ( 2 ) are connected, that the first element of the second planetary gear set (RS2) and the second element of the third planetary gear set (RS3) fixed to the fourth wave ( 4 ) are connected, that the third element of the second planetary gear set (RS2) fixed to the fifth wave ( 5 ), and that the first element of the third planetary gear set (RS3) fixed to the sixth shaft ( 6 ) connected is. A multistep transmission according to one of the preceding claims, characterized in that the first switching element (K1) is designed as a coupling and the first shaft ( 1 ) with the fourth wave ( 4 ) in the closed state connects that the second switching element (K2) is designed as a clutch and the first shaft ( 1 ) with the sixth wave ( 6 ) in the closed state, that the third switching element (K3) is designed as a clutch and the third shaft ( 3 ) with the fifth wave ( 5 ) in the closed state connects that the fourth switching element (K4) is designed as a clutch and the third shaft ( 3 ) with the sixth wave ( 6 ) in the closed state and that the fifth switching element (B1) is designed as a brake and the fifth wave ( 5 ) with the housing ( 9 ) in the closed state connects. Multi-step transmission according to one of the preceding claims, characterized in that the zeroth switching element (K0) is designed as a clutch and in the closed state the drive (An) for internal combustion engine driving with the first shaft ( 1 ) connects. Multi-step transmission according to one of the preceding claims, characterized in that the first element of a planetary gear set (RS1, RS2, RS3) is a sun gear (SR1, SR2, SR3) when the planetary gear set (RS1, RS2, RS3) is designed as a minus planetary gear set in that the second element of a planetary gearset (RS1, RS2, RS3) is a planet carrier (PT1, PT2, PT3) when the planetary gear set is designed as a minus planetary gear set and the third element of a planetary gear set (RS1, RS2, RS3) is a ring gear (HR1, HR2, HR3) is when the planetary gear set (RS1, RS2, RS3) is designed as minus planetary gear set. Multi-speed transmission according to one of the preceding claims, characterized in that the first element of a planetary gear set (RS1, RS2, RS3) is a sun gear (SR1, SR2, SR3) when the planetary gear set (RS1, RS2, RS3) is designed as a plus planetary gear set in that the second element is a ring gear (HR1, HR2, HR3) when the planetary gear set (RS1, RS2, RS3) is designed as a plus planetary gear set, and that the third element of a planetary gear set (RS1, RS2, RS3) is a planet carrier ( PT1, PT2, PT3) is when the planetary gear set (RS1, RS2, RS3) is designed as a plus planetary gear set. Multi-speed transmission according to one of the preceding claims, characterized in that the planetary gear sets (RS1, RS2, RS3) are arranged axially one behind the other and form substantially three wheel planes. Multi-step transmission according to one of the preceding claims, characterized in that for realizing the first forward gear (G1) the fifth switching element (B1) designed as a brake and the second switching element (K2) designed as a clutch are closed such that the fifth switching element (B1) designed as a brake and the fourth switching element (K4) designed as a clutch for switching the second forward gear (G2) are closed, that for switching the third forward gear (G3) executed as a brake fifth switching element (B1) and executed as a clutch first switching element (K1) are closed, that for switching the fourth forward gear (G4) designed as a clutch first switching element ( K1) and executed as a clutch fourth switching element (K4) are closed, that for switching the fifth forward gear (G5) designed as a clutch first switching element (K1) and designed as a clutch second switching element (K2) are closed, that for switching the sixth forward gear (G6) designed as a clutch first switching element (K1) and that as a clutch guided third switching element (K3) are closed, that for switching the seventh forward gear (G7) designed as a clutch second switching element (K2) and designed as a clutch third switching element (K3) are closed and that for switching the eighth forward gear (G8) the executed as a clutch third switching element (K3) and designed as a clutch fourth switching element (K4) are closed.

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