EP2959186A1

EP2959186A1 - Multi-stage planetary transmission

Info

Publication number: EP2959186A1
Application number: EP14701083.9A
Authority: EP
Inventors: Stefan Beck; Christian Sibla; Wolfgang Rieger
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2013-02-22
Filing date: 2014-01-22
Publication date: 2015-12-30
Also published as: US9638287B2; CN105074274B; US20160003329A1; WO2014127945A1; CN105074274A; DE102013202886A1

Abstract

The invention relates to a multi-stage planetary transmission for a vehicle, comprising a housing (11), a first shaft (1) being provided as the drive (An) and a second shaft (2), arranged axially parallel thereto, as the output (Ab). Three planetary gear sets (RS1, RS2, RS3) and additional shafts (3, 4, 5, 6, 7, 8, 9) as well as six shift elements (K1, K2, K3, K4, B1, B2) are provided the actuation of which allows for a plurality of speeds, and machine elements (ST1, ST2) are provided for torque transmission between the drive (An) and the output (Ab). The first shaft (1) as the drive is or can be connected to the sun gear (SR1) of the first planetary gear set (RS1), to the sun gear (SR3) of the third planetary gear set (RS3) and to the planet carrier (PT2) of the second planetary gear set (RS2), and the second shaft (2) as the output (Ab) is or can be connected to the first machine element (ST1) and to the second machine element (ST2).

Description

Multi-speed transmission in planetary construction

The present invention relates to a planetary multi-speed transmission for a vehicle according to the closer defined in the preamble of claim 1. Art.

For example, from the publication DE 10 2007 014 150 A1 a power-shiftable multi-speed transmission is known. In the multi-speed transmission, the drive shaft is connected via a torsional vibration damper fixed to a first shaft of a first shaft train. A parallel arranged second shaft strand includes, among others, designated as the shaft two output shaft. The two wave strands are connected to each other via three spur gear stages. On the first shaft train is a first three-shaft planetary gear. On the second shaft train are a second planetary gear and a third planetary gear. The multi-speed transmission thus comprises ten shafts, which communicate with each other via three spur gears and three planetary gears. To switch the eight forward gears and the one reverse gear five switching elements are necessary. The envisaged switching elements are hydraulically actuated.

To reduce hydraulic losses, the switching elements are to be arranged easily accessible from the outside. However, in a front-transverse installation of the transmission in a vehicle only a limited axial space is available.

The present invention is based on the object to provide a multi-speed transmission with the highest possible number of gear ratios and good accessibility of the switching elements at the same time good gear efficiency and the lowest possible axial space requirement.

This object is achieved by the features of claim 1, wherein there are advantageous developments of the invention from the dependent claims and the description and the drawings. Accordingly, a powershiftable multi-speed planetary gear or a multi-speed planetary gear for a vehicle is proposed with a housing, wherein the drive or the drive shaft and the output or the output shaft are arranged axially parallel to each other for a preferred front transverse installation. The multistage transmission according to the invention comprises only nine shafts, three planetary gear sets and only six shift elements in order to realize at least nine forward gears and one reverse gear can. Furthermore, preferably only two machine elements are provided for coupling drive and output.

Characterized in that the first shaft as a drive with the sun gears of the first and the third planetary gear and the planet carrier of the second planetary gear respectively releasably connected or connectable or connected and that the second shaft connected as an output to the first machine element and the second machine element or releasably connected or connectable, results in an inventive multi-stage transmission, which allows efficiency-enhancing and thus needs-based operation of the switching elements, the advantageously small number of gear elements of the multi-speed transmission to the front-transverse design are interleaved with each other so that a particularly axial space-saving Arrangement is made possible. In addition to the improved efficiency, there are also low component loads and low construction costs.

The good accessibility of the switching elements can be realized, inter alia, on the one hand by the use of brakes as switching elements and on the other hand by the use of couplings as switching elements, which are preferably positioned on outer shafts preferably on the drive and the output in the multi-step transmission according to the invention. Due to the low construction costs result in an advantageous manner low production costs and low weight of the multi-speed transmission according to the invention.

As part of a possible embodiment of the invention can be provided that as a machine element for coupling or torque transmission between the drive and output at least one spur gear or the like is used, which realizes the necessary translation to the output differential. Preferably, only two machine elements or spur gears are provided. However, other machine elements for power transmission such as chains, belts or the like may be used.

The planetary gear sets are arranged in the order of the first planetary gear set, the second planetary gear set and the third planetary gear set when viewed in the axial direction, with preferably three minus planetary gear sets being provided. However, it is possible at locations where bondability allows one or more of the negative planetary gear sets to be converted into positive planetary gear sets when simultaneously changing the bridge gear and ring gear connections and increasing the amount of the standard ratio by one , A minus planetary gearset has known to the planetary gear rotatably mounted planetary gears, which mesh with the sun gear and the ring gear of this planetary, 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 mounted in meshing inner and outer planetary gears, the sun gear of this planetary mesh with the inner planet 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.

In the context of a particular embodiment of the invention can be provided that a plurality of planetary gear sets are arranged radially one above the other. For coupling the nested planetary gear sets, for example, the ring gear of the inner planetary gear and the sun gear of the outer planetary gear set may be designed as a component. For this purpose, for example, the ring gear of the inner planetary gear set have an inner toothing and an outer toothing, but other embodiments are conceivable. Regardless of the type of coupling, the interleaved planetary gear sets are essentially chen arranged in an axial plane, so that in an advantageous manner axial space is saved.

As a starting element, a hydrodynamic torque converter or a hydrodynamic coupling can be used in the multistage transmission according to the invention. It is also conceivable that an additional starting clutch or an integrated starting clutch or starting brake be used. It is also possible that an electric machine or another power / power source is arranged on at least one of the shafts. In addition, a freewheel to the housing or to another shaft can be arranged on at least one of the waves.

Preferably, in the multistage transmission according to the invention, nine forward gears and at least one reverse gear can be switched via the switching elements provided. However, it is conceivable that, for example, for the fourth forward gear further switching combinations are made possible by the combination of other switching elements.

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. In addition, as far as the outer shape allows, a plurality of wheel sets can also be arranged radially one above the other, ie nested.

Exemplary embodiments of a force-locking switching element are multi-plate clutches or brakes, band brakes, cone clutches or brakes, electric magnetic couplings, magnetic particle clutches and electro-rheological coupling. Exemplary embodiments of a form-locking switching element are claw couplings or brakes and toothed couplings.

As a switching elements thus both friction and form-locking switching elements can generally be used. Preferably, because of their characteristics, especially the second shifting element designed as a clutch and the fourth shifting element designed as a clutch can be designed as claw shifting elements, whereby clear consumption advantages are achieved.

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

Figure 1 is a schematic view of a first embodiment of a multi-speed transmission according to the invention;

Figure 1 A is a circuit diagram for the embodiment of Figure 1;

Figure 2 is a schematic view of a second embodiment of the multi-speed transmission;

Figure 3 is a schematic view of a third embodiment of the multi-speed transmission;

Figure 4 is a schematic view of a fourth embodiment of the multi-speed transmission;

Figure 5 is a schematic view of a fifth embodiment of the multi-speed transmission;

Figure 6 is a schematic view of a sixth embodiment of the multi-speed transmission; and

Figure 7 is a schematic view of an alternative embodiment of the fourth embodiment of the multi-speed transmission.

In the figures 1 to 7, an embodiment of the multi-speed transmission according to the invention in planetary design, for example, as an automatic transmission or automatic transmission, for a vehicle shown by way of example.

Regardless of the respective embodiment variants, the multistage transmission comprises a housing 1 1, which is indicated only schematically, with a first shaft 1 as the drive An and a second shaft 2 arranged parallel to the axis as the output Ab and further seven shafts 3, 4, 5, 6, 7, 8, 9. Furthermore, a first planetary gearset RS1, a second planetary gearset RS2 and a third planetary gearset RS3 are provided, wherein preferably the first planetary gearset RS1, the second planetary gearset RS2 and the third planetary gearset RS3 are each designed as negative planetary gear sets. For switching a plurality of gear ratios are designed as a clutch first switching element K1, designed as a clutch second switching element K2, designed as a clutch third switching element K3, designed as a clutch fourth switching element K4, designed as a brake fifth switching element B1 and designed as a brake sixth Switching element B2 provided. For coupling or for torque transmission between drive input and output Ab, two arbitrary machine elements are preferably provided, which in the case of the embodiment variants are designed by way of example as first spur gear stage ST1 and as second spur gear stage ST2.

With reference to the embodiment according to FIG. 1, gear variants of the same effect are shown in FIGS. 2 to 7, wherein a variation possibility of the fourth embodiment variant according to FIG. 4 is shown in FIG. 7, in which the switching elements K3 and K4 assigned to the spur gear stages ST1 and ST2 are separated from the output shaft or gear . Intermediate shaft are displaced to the main shaft or drive shaft. The various embodiments according to Figures 1 to 7 are not functionally different from the embodiment of Figure 1 in terms of efficiency, grading, etc. With regard to the connection possibilities between the provided shafts 1, 2, 3, 4, 5, 6, 7, 8, 9, the planned three planetary gear sets RS1, RS2, RS3, the intended housing 1 1 and the provided switching elements K1, K2, K3, K4, B1, B2 and the proposed spur gears ST1, ST2 is by the term -verbindbar- to understand that the elements described are releasably connected, for example via a switching element, so that the connection is closed when activated switching element and open when not activated switching element. The detachable connection can be realized in addition to the switching element via at least one further element, such as a shaft or the like. The term "connected" is to be understood as meaning that the elements described are virtually non-detachably connected to one another, so to speak. It can be realized a direct or indirect connection, for example via other elements.

According to the invention, it is provided in the multistage transmission that the first shaft 1 is detachably connected or connectable or connected as drive with the sun gear SR1 of the first planetary gearset RS1, with the sun gear SR3 of the third planetary gearset RS3 and with the planet carrier PT2 of the second planetary gearset RS2 , Depending on the variant embodiment, the second shaft as the output Ab is connected or detachably connected or connectable to the first machine element or to the first spur gear ST1 and to the second machine element or the second spur gear ST2.

Regardless of the respective embodiments, it is provided that the first shaft 1 can be connected via the first switching element K1 designed as a clutch and via the third shaft 3 to the sun gear SR1 of the first planetary gear set RS1, wherein the sun gear SR1 of the first planetary gear set RS1 is connected as a brake executed fifth switching element B1 to the housing 1 1 is connectable.

In addition, it is provided in all variants that two of the three planetary gear sets RS1, RS2, RS3 are arranged radially one above the other and thus lie substantially in a common axial plane. This is the first planetary gear set radially inward and the second planetary gear set RS2 arranged radially au Shen, wherein the ring gear HR1 of the first planetary gearset RS1 serves as a link between the two planetary gear sets RS1 and RS2.

In the first embodiment variant according to FIG. 1, it is provided in the multistage transmission according to the invention that the first shaft 1 can be connected to the sun gear SR3 of the third planetary gearset RS3 via the second shifting element K2 designed as a clutch and via the eighth shaft 8. Furthermore, the first shaft 1 can be connected via the third switching element K3 designed as a clutch and via the seventh shaft 7 to the planet carrier PT2 of the second planetary gearset RS2. In addition, the second shaft 2 can be connected via the fourth switching element K4 designed as a clutch and via the ninth shaft 9 to the idler gear 13 of the first spur gear stage ST1. In addition, the second shaft 2 is connected to the fixed gear 1 5 of the second spur gear ST2.

In the second and third embodiment according to Figures 2 and 3 it is provided that the first shaft 1 is connected to the sun gear SR3 of the third planetary gearset RS3. Furthermore, the first shaft 1 can be connected via the third switching element K3 designed as a clutch and via the eighth shaft 8 to the planet carrier PT2 of the second planetary gear set RS2. In addition, the second shaft 2 can be connected via the fourth switching element K4 designed as a clutch and via the ninth shaft 9 to the idler gear 13 of the first spur gear stage ST1. In addition, the second shaft 2 is connected to the fixed gear 15 of the second spur gear ST2.

According to FIG. 4, it is provided in the fourth embodiment variant that the first shaft 1 is connected to the planet carrier PT2 of the second planetary gearset RS2. Furthermore, the first shaft 1 can be connected via the second switching element K2 designed as a clutch and via the eighth shaft 8 to the sun gear SR3 of the third planetary gear set RS3. In addition, the second shaft 2 can be connected via the fourth switching element K4 designed as a clutch and via the ninth shaft 9 to the idler gear 13 of the first spur gear stage ST1. In addition, the second wave is 2 connected via the third switching element K3 designed as a clutch and via the seventh shaft 7 to the idler gear 15A of the second spur gear ST2.

In the fifth and sixth embodiment according to FIGS. 5 and 6, it is provided that the first shaft 1 is connected to the sun gear SR3 of the third planetary gear set RS3 and to the planet carrier PT2 of the second planetary gearset RS2. In addition, the second shaft 2 can be connected via the fourth switching element K4 designed as a clutch and via the ninth shaft 9 to the idler gear 13 of the first spur gear stage ST1. Furthermore, the second shaft 2 can be connected via the third switching element K3 designed as a clutch and via the eighth shaft 8 to the idler gear 15A of the second spur gear ST2.

Finally, in the seventh embodiment according to FIG. 7, it is provided in the multistage transmission that the first shaft 1 is connected to the planet carrier PT2 of the second planetary gearset RS2. Furthermore, the first shaft 1 can be connected via the second switching element K2 designed as a clutch and via the eighth shaft 8 to the sun gear SR3 of the third planetary gear set RS3. In addition, the second shaft 2 is connected to the fixed gear 13A of the first spur gear ST1, and the second shaft 2 is connected to the fixed gear 15 of the second spur gear ST2.

In the first, second, fourth, fifth and seventh embodiment according to FIGS. 1, 2, 4, 5 and 7, in the multistage transmission it is provided that the planet carrier PT1 of the first planetary gearset RS1 and the ring gear HR3 of the third planetary gearset RS3 via the fourth shaft 4 are connected, wherein the planet carrier PT1 of the first planetary gearset RS1 and the ring gear HR3 of the third planetary gear set RS3 via the fourth shaft 4 and via the executed as a brake sixth switching element B2 with the housing 1 1 are connectable. According to Figures 3 and 6, however, is provided in the third and sixth embodiment, that the planet carrier PT1 of the first planetary gearset RS1 via the fourth shaft 4 and via the second switching element K2 designed as a clutch and via the seventh shaft 7 with the ring gear HR3 of the third planetary gearset RS3 is connectable, wherein the planet carrier PT1 of the first Planetenradsat- zes RS1 and the ring gear HR3 of the third planetary gearset RS3 via the fourth shaft 4 and via the executed as a brake sixth switching element B2 with the housing 1 1 are connectable.

In the first, third, fourth and sixth embodiment according to Figures 1, 3, 4 and 6 is provided in the multistage transmission according to the invention that a fixed gear 12 of a first spur gear ST1 via the fifth shaft 5 with the ring gear HR1 of the first planetary gearset RS1 and with the Planetary PT3 of the third planetary gear set RS3 are connected. According to Figures 2 and 5 is provided in the second and fifth embodiment that a fixed gear 12 of a first spur gear ST1 is connected via the fifth shaft 5 with the ring gear HR1 of the first planetary gearset RS1, wherein the ring gear HR1 of the first planetary gearset RS1 on the fifth wave 5 and via the second switching element K2 designed as a clutch can be connected to the planet carrier PT3 of the third planetary gearset RS3. In the seventh embodiment variant according to FIG. 7, it is finally provided that a loose wheel 12A of a first spur gear ST1 via the fifth shaft 5 and via the fourth shifting element K4 designed as a clutch via the ninth shaft 9 to the ring gear HR1 of the first planetary gearset RS1 and to the planet carrier PT3 of the third planetary gearset RS3 is connectable.

In the first to sixth embodiment according to Figures 1 to 6 is provided that a fixed gear 14 of a second spur gear ST2 is connected via the sixth shaft 6 with the ring gear HR2 of the second planetary gear set RS2. In contrast, in the seventh embodiment variant according to FIG. 7, it is provided that a loose wheel 14A of a second spur gear ST2 can be connected to the ring gear HR2 of the second planetary gearset RS2 via the sixth shaft 6 and via the third shifting element K3 designed as a clutch and via the seventh shaft 7.

For the six embodiment variants, a circuit diagram or a switching matrix for the respective transmission variant is shown in FIG. 1A. In the shift diagrams to be closed or to be activated switching elements K1, K2, K3, K4, B1, B2 are tabulated to realize the various stages, wherein Each gear stage a ratio i and between different gear ratios of the respective gear jump φ are specified. In addition to the nine forward gears G1, G2, G3, G4, G5, G6, G7, G8, G9 and the indicated reverse gear R, further additional shift combinations are indicated as alternative fourth forward gears M1, M2, M3. Overall, it follows from the circuit diagram that the proposed multi-speed transmission has optimized transmission series with low absolute and relative speeds as well as low planetary gear set and switching element torques. Furthermore, the selected wheel set arrangements result in good toothing efficiencies and low drag torques.

As preferred stand ratios, in the first planetary gear set RS1 a value of about i ₀ = - 2.015, in the second planetary gear set RS2 a value of about i ₀ = -1, 700 and in the third planetary gear set RS3 a value of about i ₀ = -1 , 600 are used. In the case of the first spur gear ST1, a value of about I _S TI = -1, 804 is selected as stand ratio and a value of about isT2 = -1, 000 is selected for the second spur gear ST2. In addition, it follows from the circuit diagram that only three switching elements are closed to switch the gear stages.

In detail, it follows from the shift diagrams according to FIG. 1A that for realizing the first forward gear G1 the second shift element K2 designed as a clutch, the fourth shift element K4 designed as a clutch and the sixth shift element B2 designed as a brake are closed. For switching the second forward gear G2, the second shifting element K2 designed as a clutch, the fourth shifting element K4 designed as a clutch and the fifth shifting element B1 designed as a brake are closed. For switching the third forward gear G3, the first switching element K1 designed as a clutch, the second shifting element K2 designed as a clutch and the fourth shifting element K4 designed as a clutch are closed. To shift the fourth forward gear G4, the second shifting element K2 designed as a clutch, the third shifting element K3 designed as a clutch and the fourth shifting element K4 designed as a clutch are closed. For switching the fifth forward gear G5 are designed as a clutch first switching element K1, which is designed as a clutch second switching element K2 and running as a clutch third switching element K3 closed. For shifting the sixth forward gear G6, the second shifting element K2 designed as a clutch, the third shifting element K3 designed as a clutch and the fifth shifting element B1 designed as a brake are closed. For switching the seventh forward gear G7, the second shifting element K2 designed as a clutch, the third shifting element K3 designed as a clutch and the sixth shifting element B2 designed as a brake are closed. For switching the eighth forward gear G8, the third shifting element K3 designed as a clutch, the fifth shifting element B1 designed as a brake and the sixth shifting element B2 designed as a brake are closed. For switching the ninth forward gear G9 designed as a clutch first switching element K1, designed as a clutch third switching element K3 and executed as a brake sixth switching element B2 are closed. Finally, for switching the reverse gear R, the first shifting element K1 designed as a clutch, the fourth shifting element K4 designed as a clutch and the sixth shifting element B2 designed as a brake are closed.

With regard to the shift combinations of the alternative fourth forward gears M1, M2, M3 is provided according to the circuit diagram with reference to Figure 1A, that for switching the alternative fourth forward gear M1 designed as a clutch third switching element K3, designed as a clutch fourth switching element K4 and running as a brake fifth switching element B1 are closed. For switching the alternative fourth forward gear M2, the third shifting element K3 designed as a clutch, the fourth shifting element K4 designed as a clutch and the sixth shifting element B2 designed as a brake are closed. Furthermore, for switching the alternative fourth forward gear M3, the first shifting element K1 designed as a clutch, the third shifting element K3 designed as a clutch and the fourth shifting element K4 designed as a clutch are closed. The different ratios i and the gear jumps φ between different gear ratios in the various embodiments can be found in the corresponding circuit diagram of Figure 1 A.

REFERENCE CHARACTERS

1 first shaft as drive

2 second shaft as output

3 third wave

4 fourth wave

5 fifth wave

6 sixth wave

7 seventh wave

8th wave

9th ninth wave

1 1 housing

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

B2 sixth switching element as a brake

RS1 first planetary gear set

RS2 second planetary gear set

RS3 third planetary gear set

SR1 sun gear of the first planetary gear set

PT1 Pianetenradtrager the first planetary gear set

HR1 ring gear of the first planetary gear set

PT2 Pianetenradtrager the second planetary gear set

HR2 ring gear of the second planetary gear set

SR3 sun gear of the third planetary gear set

PT3 Pianetenradtrager the third planetary gear set

HR3 ring gear of the third planetary gear set

ST1 first spur gear stage

ST2 second spur gear stage

12 fixed gear of the first spur gear

12A idler gear of the first spur gear stage 13 idler gear of the first spur gear 13A fixed gear of the first spur gear stage

14 fixed gear of the second spur gear

14A idler gear of the second spur gear stage

15 fixed wheel of the second spur gear

15A idler gear of the second spur gear stage

G1 first forward gear

G2 second forward gear

G3 third forward gear

G4 fourth forward gear

G5 fifth forward gear

G6 sixth forward gear

G7 seventh forward gear

G8 eighth forward gear

G9 ninth forward gear

R reverse gear

M1 alternative fourth gear

M2 alternative fourth gear

M3 alternative fourth gear

i translation

i ₀ Stand ratios of the planetary gear sets i _S Ti Stand translation of the first spur gear stage isT2 Stand translation of the second spur gear stage φ gear jump

Claims

claims

1 . Multi-stage gear in planetary design for a vehicle with a housing (1 1), wherein a first shaft (1) as a drive (An) and an axially parallel arranged second shaft (2) as the output (Ab) are provided, wherein three planetary gear sets (RS1, RS2, RS3) and further shafts (3, 4, 5, 6, 7, 8, 9) and six switching elements (K1, K2, K3, K4, B1, B2) are provided by the actuation of multiple gear stages are feasible, and wherein machine elements (ST1, ST2) for torque transmission between the drive (An) and output (Ab) are provided, characterized in that the first shaft (1) as a drive with the sun gear (SR1) of the first planetary gear set (RS1), with the sun gear (SR3) of the third planetary gear set (RS3) and with the planet carrier (PT2) of the second planetary gear set (RS2) is connectable or connected, and that the second shaft (2) as output (Ab) with the first machine element (ST1) and with the second machine element (ST2) connectable or verbu is.

2. Multi-speed transmission according to claim 1, characterized in that as machine elements spur gears (ST1, ST2) or chains are provided.

3. Multi-speed transmission according to claim 1 or 2, characterized in that the first shaft (1) via the clutch designed as the first switching element (K1) and the third shaft (3) with the sun gear (SR1) of the first planetary gear set (RS1) connectable is, wherein the sun gear (SR1) of the first planetary gear set (RS1) via the executed as a brake fifth switching element (B1) with the housing (1 1) is connectable.

4. Multi-step transmission according to one of the preceding claims, characterized in that the planet carrier (PT1) of the first planetary gear set (RS1) and the ring gear (HR3) of the third planetary gear set (RS3) via the fourth shaft (4) are connected, wherein the planet carrier ( PT1) of the first planetary gear set (RS1) and the ring gear (HR3) of the third planetary gear set (RS3) via the fourth shaft (4) and via the executed as a brake sixth switching element (B2) with the housing (1 1) are connectable.

5. Multi-step transmission according to one of claims 1 to 3, characterized in that the planet carrier (PT1) of the first planetary gear set (RS1) via the fourth shaft (4) and via the second switching element (K2) designed as a clutch and via the seventh shaft ( 7) with the ring gear (HR3) of the third planetary gear set (RS3) is connectable, wherein the planet carrier (PT1) of the first planetary gear set (RS1) and the ring gear (HR3) of the third planetary gear set (RS3) via the fourth shaft (4) and over the sixth switching element (B2) designed as a brake can be connected to the housing (11).

6. Multi-step transmission according to one of claims 1 to 5, characterized in that a fixed gear (12) of a first spur gear (ST1) via the fifth shaft (5) with the ring gear (HR1) of the first planetary gear set (RS1) and with the planet carrier ( PT3) of the third planetary gear set (RS3) are connected.

7. Multi-speed transmission according to one of claims 1 to 4, characterized in that a fixed gear (12) of a first spur gear (ST1) via the fifth shaft (5) with the ring gear (HR1) of the first planetary gear set (RS1) is connected, wherein the Ring gear (HR1) of the first planetary gear set (RS1) via the fifth shaft (5) and via the coupling designed as a second switching element (K2) with the planet carrier (PT3) of the third planetary gear set (RS3) is connectable.

8. Multi-speed transmission according to one of claims 1 to 4, characterized in that a loose wheel (12A) of a first spur gear (ST1) via the fifth shaft (5) and via the fourth switching element (K4) designed as a clutch via the ninth shaft (9 ) is connectable to the ring gear (HR1) of the first planetary gear set (RS1) and to the planet carrier (PT3) of the third planetary gear set (RS3).

9. Multi-speed transmission according to one of claims 1 to 7, characterized in that a fixed gear (14) of a second spur gear (ST2) via the sixth shaft (6) with the ring gear (HR2) of the second planetary gear set (RS2) is connected.

10. Multi-speed transmission according to one of claims 1 to 8, characterized in that a loose wheel (14A) of a second spur gear (ST2) via the sixth shaft (6) and via the third switching element (K3) designed as a clutch and via the seventh shaft ( 7) with the ring gear (HR2) of the second planetary gear set (RS2) is connectable.

1 1. Multi-speed transmission according to one of the preceding claims, characterized in that the first shaft (1) can be connected to the sun gear (SR3) of the third planetary gear set (RS3) via the second shifting element (K2) designed as a clutch and via the eighth shaft (8), in that the first shaft (1) can be connected to the planet carrier (PT2) of the second planetary gearset (RS2) via the third shifting element (K3) and the seventh shaft (7), that the second shaft (2) via the Clutch executed fourth switching element (K4) and the ninth shaft (9) with the idler gear 13 of the first spur gear (ST1) is connectable, and that the second shaft (2) with the fixed gear (15) of the second spur gear (ST2) is connected ,

12. Multi-speed transmission according to one of claims 1 to 10, characterized in that the first shaft (1) with the sun gear (SR3) of the third planetary gear set (RS3) is connected, that the first shaft (1) via the third switching element designed as a clutch (K3) and via the eighth shaft (8) with the planet carrier (PT2) of the second planetary gear set (RS2) is connectable, that the second shaft (2) via the fourth switching element (K4) designed as a clutch and the ninth shaft (9 ) Is connectable to the idler gear (13) of the first spur gear (ST1), and that the second shaft (2) with the fixed gear (15) of the second spur gear (ST2) is connected.

13. Multi-speed transmission according to one of claims 1 to 10, characterized in that the first shaft (1) with the planet carrier (PT2) of the second planetary gear set (RS2) is connected, that the first shaft (1) via the second switching element designed as a clutch (K2) and the eighth shaft (8) with the sun gear (SR3) of the third planetary gear set (RS3) is connectable, that the second shaft (2) via the fourth switching element (K4) designed as a clutch and over the Ninth shaft (9) with the idler gear (13) of the first spur gear (ST1) is connectable, and that the second shaft (2) via the clutch designed as a third switching element (K3) and the seventh shaft (7) with the idler gear ( 15A) of the second spur gear (ST2) is connectable.

14. Multi-speed transmission according to one of claims 1 to 10, characterized in that the first shaft (1) with the sun gear (SR3) of the third planetary gear set (RS3) and with the planet carrier (PT2) of the second planetary gear set (RS2) is connected the second shaft (2) can be connected to the idler gear (13) of the first spur gear stage (ST 1) via the fourth shift element (K4) designed as a clutch and via the ninth shaft (9), and the second shaft (2) can be connected via the as third clutch executed switching element (K3) and the eighth shaft (8) with the idler gear (15A) of the second spur gear (ST2) is connectable.

15. Multi-speed transmission according to one of claims 1 to 10, characterized in that the first shaft (1) to the planet carrier (PT2) of the second planetary gear set (RS2) is connected, that the first shaft (1) via the second switching element designed as a clutch (K2) and via the eighth shaft (8) with the sun gear (SR3) of the third planetary gear set (RS3) is connectable, that the second shaft (2) with the fixed gear (13A) of the first spur gear (ST1) is connected and that the second shaft (2) with the fixed gear (15) of the second spur gear (ST2) is connected.

16. Multi-step transmission according to one of the preceding claims, characterized in that a plurality of the planetary gear sets (RS1, RS2, RS3) are arranged radially one above the other.

17. Multi-speed transmission according to claim 1 6, characterized in that the first planetary gear set (RS1) and the second planetary gear set (RS2) are arranged radially one above the other, wherein the first, radially inner planetary gear set (RS1) and the second, radially outer planetary gear set ( RS2) via the ring gear (HR1) of the first planetary gear set (RS1) are interconnected.

1 8. Multi-speed transmission according to one of the preceding claims, characterized in that at least nine forward gears (G1 to G9) and at least one reverse gear (R) are switchable.

1 9. Multi-step transmission according to one of the preceding claims, characterized in that the provided switching elements (K1, K2, K3, K4, B1, B2) are designed as frictional or positive switching elements.

20. Multi-speed transmission according to one of the preceding claims, characterized in that for switching the first forward gear (G1) designed as a clutch second switching element (K2) running as a clutch fourth switching element (K4) and designed as a brake sixth switching element (B2) are closed, that for switching the second forward gear (G2), the second switching element (K2) designed as a clutch, the fourth switching element (K4) designed as a clutch and the fifth switching element (B1) designed as a brake are closed, that for switching the third forward gear (G3) the first switching element (K1) designed as a clutch, the second shifting element (K2) designed as a clutch and the fourth shifting element (K4) designed as a clutch are closed, that for shifting the fourth forward gear (G4) the second shifting element is designed as a clutch (K2), designed as a clutch third switching element (K3) and the clutch au are closed fourth switching element (K4) are closed, that for switching the fifth forward gear (G5), the first switching element (K1) designed as a clutch, the second switching element (K2) designed as a clutch and the third switching element (K3) designed as a clutch are closed, in that, for shifting the sixth forward gear (G 6), the second shifting element (K2) designed as a clutch, the third shifting element (K3) designed as a clutch and the fifth shifting element (B1) designed as a brake are closed, that for shifting the seventh forward gear (G7 ), the second switching element (K2) designed as a clutch, the third shifting element (K3) designed as a clutch and the sixth shifting element (B2) designed as a brake are closed, that for switching the eighth forward gear (G8) the third shifting element (K3 ), the fifth shift element (B1) designed as a brake and the sixth shift element designed as a brake t (B2) are closed, that for switching the ninth forward gear (G9) designed as a clutch first switching element (K1), the clutch designed as a third switching element (K3) and executed as a brake sixth switching element (B2) are closed, and that for switching the reverse gear (R) the first switching element (K1) designed as a clutch, the fourth shifting element (K4) designed as a clutch and the sixth shifting element (B2) designed as a brake are closed.

21. Auxiliary gear according to one of the preceding claims, characterized in that for switching alternative fourth forward gears (M1, M2, M3), the third switching element (K3) designed as a clutch, the fourth shifting element (K4) designed as a clutch and the fifth shifting element designed as a brake (B1) are closed, or the third switching element (K3) designed as a clutch, the fourth shifting element (K4) designed as a clutch and the sixth shifting element (B2) designed as a brake are closed or the first shifting element (K1) designed as a clutch acts as Clutch executed third switching element (K3) and running as a clutch fourth switching element (K4) are closed.