EP3338007A1

EP3338007A1 - Range-change transmission and transmission assembly having a range-change transmission

Info

Publication number: EP3338007A1
Application number: EP16750827.4A
Authority: EP
Inventors: David MÜLLER; Rainer Gugel; Andrew K. REKOW
Original assignee: Deere and Co
Current assignee: Deere and Co
Priority date: 2015-08-18
Filing date: 2016-08-10
Publication date: 2018-06-27
Also published as: US20180172123A1; DE102015215726A1; WO2017029174A1; US11054008B2

Abstract

The invention relates to a range-change transmission (16) having a group input shaft (22), on which gears (26, 30, 34, 38) of gear pairs of at least two shifting groups (A, B, C) are coaxially arranged, wherein the group input shaft (22) can be brought into a drive connection with a group output shaft (42) by means of a gear pair of a shifting group (A, B, C). The range-change transmission (16) has a second input shaft (24), which is arranged coaxially and rotatably with respect to the group input shaft (22). The invention further relates to a transmission assembly (10) having such a range-change transmission (16).

Description

Group gearbox and gear arrangement with

a group transmission

The invention relates to a group transmission with a group input shaft, are arranged coaxially on the gears of at least two switching groups, wherein the group input shaft via a gear pair of a switching group with a group output shaft in drive connection can be brought. In addition, the invention relates to a transmission arrangement with such a group transmission.

Gear arrangements for agricultural work vehicles are known in the prior art, for example for tractors or harvesters, which have a plurality of transmission units arranged one behind the other. Such gear arrangements are used to meet the high demands in terms of a very fine-scale but also wide spreading of the transmission, as required in agricultural work vehicles to meet. For the same reasons, such gear arrangements are also used in the commercial vehicle and construction machinery sector.

DE 10 2010 029 597 AI is a gear assembly for an agricultural vehicle with a plurality of in a power flow direction connected in series gear units removed. Different gear units such as planetary gear, dual-clutch gearbox and group gearbox are combined. In this case, the group transmission on an input shaft, an output shaft and a plurality of switching groups for different speed levels. The invention has for its object to improve the modularity and variability of a transmission arrangement with a group transmission.

This object is achieved according to the teaching of independent claims 1 and 9. Further advantageous embodiments and modifications of the invention will become apparent from the dependent claims.

According to the invention, a group transmission has a group input shaft, on which gears of at least two shifting groups are arranged coaxially, wherein this group input shaft can be brought into drive connection via a gear pairing of a shifting group with a group output shaft. In this case, the group transmission on a second input shaft in the form of another group input shaft, which is arranged coaxially and rotatably to the group input shaft.

The provision of two inputs, namely the group input shaft and the second input shaft, the group transmission provides the prerequisite for the group transmission with one or more (especially two) outputs of different upstream transmission types can be adapted. Conventionally common, complex design changes of the group transmission to adapt to different upstream base gear accounts for this.

These different basic transmissions are eg as eight-speed dual-clutch transmission with two outputs, four-speed transmission with one output, continuously variable transmission with infinite transmission. ratio (IVT), continuously variable transmission with a finite transmission ratio (CVT) or powershift transmission (PST).

Due to its two inputs, two different speeds can be provided for the group transmission, so that the individual switching groups are - optionally provided with the speed of the group input shaft or with the speed of the second input shaft - providing suitable control or wiring for the switching groups or their gear pairings can. This is the whole

Spectrum of the speed of the group output shaft divided very fine. For example, the gradation of speeds and gears in a basic transmission with an output and downstream group transmission can be doubled solely by the two inputs of the group transmission. Regardless, one of the number of switching groups used in accordance with finer gradation is created in all upstream basic transmissions. Thus, e.g. in a four-speed transmission with one output and a downstream group transmission with three shifting groups, a division with 24 (4 x 2 x 3) gear ratios are created. In an eight-speed transmission with two outputs and a downstream group transmission with three shift groups also a division with 24 (8 x 3) gear ratios is created.

Overall, this group transmission is able to achieve finer gradations within a gear assembly without special additional effort. At the same time this group transmission supports a modular, modular structure of a gear assembly without costly adaptation measures on the group transmission itself this group transmission in a cost effective manner a greater variety of applications and functionality in relation to its interaction with different basic transmissions.

The group transmission has several, in particular three switching groups. Each of these switching groups preferably covers a different speed range at the group output shaft.

The group transmission provides, for example, for a trained as a tractor vehicle several workspaces corresponding to the number of switching groups. In particular, three switching groups are provided for three work areas. For example, a first work area "field work" can be designed for applications for heavier work in the field, whereby mostly heavy pulling work is to be carried out in a lower speed range (eg between 2 and 11 km / h) A second work area "PTO operation", for example, may be designed for applications for lighter field work using PTO, with a medium speed range (eg, between 4.5 and 18 km / h) being preferred. A third working area "transport", for example, can be designed for pure transport work with a preferably higher speed range of, for example, 14 km / h up to the maximum speed With the aid of the two inputs described above, which provide different rotational speeds, the work areas can be fine-tuned in such a way, A continuous course of the efficiency or the power loss of the transmission arrangement over the entire range of the speed or the driving speed of the vehicle is supported, which in turn facilitates the realization of optimized Automatic gearboxes, in particular with regard to the use of driving strategies for reduced fuel consumption.

As already mentioned, the individual shift groups have at least one gear pair and each gear pair includes a gear arranged coaxially on the group input shaft. Preferably, at least one of these gears is rotatably connected to the group input shaft or to the second input shaft and then brought into driving connection by means of a switching device with the respective other shaft, ie the second input shaft or the group input shaft. In this way, a technically simple and cost-effective design ensures the provision of two different speeds for a switching group according to a defined switching strategy. In addition, this switching device also enables the Voreinlegen or preselection of a next gear, so that any interruption of the drive connection between the respective input and the group output shaft of the group transmission during shifting between the gear stages is avoided. Thus, the group transmission supports an uninterruptible load circuit during the switching operation.

The term switching device is to be understood here and below, in particular in the patent claims, as representative of devices or components with which gears or gear pairings can be controlled or connected. As switching devices, for example, synchronizers, clutches (eg multi-plate clutch, dog clutch) or braking devices (eg to block a ring gear of a planetary gear) can be used. In a preferred embodiment, the group input shaft and the second input shaft are each rotatably connected to at least one of the above-described coaxial gears. As a result, the switching groups can be distributed to the group input shaft and the second input shaft. This distribution supports a compact, axially short design of the group transmission.

Preferably, a gear of a switching group is rotatably connected to the group input shaft, while a gear of a - in the direction of higher or lower speed at the group output shaft - following switching group with the second input shaft is rotatably connected. This arrangement supports a simple gear design for an uninterruptible load circuit on the group output shaft. For example, in the case of an intended change of the switching group, the next gear stage can be preselected or pre-set on the group output shaft before this next gear stage is drive-connected to the group input shaft or the second input shaft - in particular by a corresponding activation or wiring of the gear pairings on the group output shaft Switching the above-mentioned switching device - is brought.

In a further preferred embodiment, at least one switching group has two gear pairings, wherein the coaxially arranged on the group input shaft gear of a gear pair with the group input shaft is rotatably connected and the coaxially arranged on the group input shaft gear of the other gear pair with the second input shaft is rotatably connected. In this way, a switching strategy dispense with the control of switching devices between the group input shaft and the second input shaft within the same switching group. The gear ratio of these two gear pairings can be exactly the same, but also different, as long as this leads to an improved gear distribution in the sense of a uniform distribution over the available travel speed range of the vehicle. This is especially true in connection with stepped gears.

Preferably, a switching device is arranged on the group output shaft axially between two switching groups. These

Switching device can bring one of the two switching groups or their gear pair with the group output shaft in drive connection depending on an axial switching position. In particular, a switching device is provided between all successive switching groups. A switching device arranged in this way allows the switching operation to preselect or advance the next gear stage or gear group, so that a load circuit can be realized in the next gear stage or gear group without interrupting the drive connection between an input of the group gearbox and its group output shaft.

Preferably, the second input shaft of the group transmission is designed as a hollow shaft and thereby supports a space-saving design of the group transmission.

The group output shaft is preferably formed as a differential drive shaft and can drive a wheel axle of a vehicle to realize a front-wheel or rear-wheel drive. As already mentioned, the base gear can have two outputs. In particular, in this case one output is drive-connected to the group input shaft of the group transmission, while the other output is drive-connected to the second input shaft of the group transmission. At least one of the two drive connections is preferably designed as a direct drive with the same speed. This direct drive is designed in particular as a non-rotatable connection. Thus, the modular design of the gear assembly construction technology is particularly simple and inexpensive.

In a further embodiment, the base gear of the gear assembly has only one output. This is selectively brought into drive connection with the group input shaft or with the second input shaft of the group transmission, whereby the number of gear ratios of the base gear doubles and thus a finer gradation of the gear arrangement is achieved.

The drive connection between the output of the basic transmission and the group input shaft of the group transmission is preferably a direct drive with the same speed. The drive connection between the output of the basic transmission and the second input shaft of the group transmission preferably includes a transmission means, whereby the speed of the base transmission output can be converted in a defined manner and either reduced or increased provided on the second input shaft of the group transmission. This can technically be a minimal

and / or maximum output speed at the group output shaft can be varied. This is only an exchange of individual Gears or gear pairings in the group transmission necessary, the rest of the structure of the group transmission (housing, shaft assembly, bearing concept, etc.) can remain the same. This additionally increases the simple compatibility of the group transmission in different transmission arrangements. Also, by the aforementioned variation of the output speed, different technical requirements for the respective vehicle, different customer requirements and also different national legal requirements can be met cost-effectively with the same shift groups or gear pairings.

To meet different requirements, it may be useful, in particular in connection with a variation of a minimum and / or maximum output speed at the group output shaft, to change individual or all gear pairings of a group transmission only with respect to their rotationally fixed arrangement relative to the group input shaft or second input shaft. This also takes into account the multifunctional nature of the group transmission without special technical effort.

The transmission device for driving connection between an output of the base transmission and the second input shaft of the group transmission can be designed differently. Cost-effective available and can be integrated with low installation costs, e.g. Gear pairings (spur gear), planetary gear or planetary gear with two axially offset sun gears.

To support the modular, modular and thus assembly-friendly construction of the gear arrangement, the transmission Device between the output of the base gear and the second input shaft of the group transmission preferably part of a transmission unit, which is connected in the direction of force flow between the base gear and the group transmission.

As already mentioned, in one embodiment, an output of the basic transmission can be selectively brought into drive connection with the group input shaft or with the second input shaft of the group transmission. For this purpose, at least one switching device is preferably provided. This switching device may be formed, for example, as a coupling device for closing and interrupting a power flow connection. For example, two such switching devices may be provided, wherein the one switching device between an output of the base gear and the group input shaft of the group transmission is arranged, while the other switching device between the same base gear output and the second input shaft of the group transmission is arranged. By a suitable, in particular simultaneous, activation of these two switching devices, the power flow connection between an output of the basic transmission and the group input shaft can be interrupted and at the same time the power flow connection between the same base transmission output and the second input shaft of the group transmission can be closed. By appropriate control of these switching devices, the respective power flow connection can assume the reverse state, ie interrupted instead of closed or closed instead of interrupted. The modular, easy to assemble assembly of the gear assembly is further supported when the aforementioned at least one switching device for selectively driving connection of an output of the basic transmission with the group input shaft or with the second input shaft of the group transmission - as well as the transmission device described - is a part of the aforementioned transmission unit, which in Power flow direction is connected between the base gear and the group transmission.

The invention will be explained in more detail below with reference to the accompanying drawings. With regard to their function, matching or comparable components are identified by the same reference numerals. Show it:

1 is a transmission diagram of a first transmission arrangement according to the invention,

2 shows a transmission diagram of a second transmission arrangement according to the invention,

3 shows a further embodiment of a transmission unit between the basic transmission and the group transmission in the transmission arrangement according to FIG. 1,

4 shows a further embodiment of a transmission unit between basic transmission and group transmission in the transmission arrangement according to FIG. 1, Fig. 5 shows another embodiment of a transmission unit between the base gear and group transmission in the transmission arrangement of FIG. 2, and

Fig. 6 is a transmission diagram of a third transmission arrangement according to the invention.

In Fig. 1, a transmission assembly 10 according to the invention is shown schematically. The transmission assembly 10 includes a base gear 12, a transmission unit 14, and a group transmission 16. The group transmission 16 is the base gear 12 and the transmission unit 14 downstream. The transmission unit 14 is therefore interposed between the base gear 12 and the group transmission 16.

The base gear 12 may be any gear having an input shaft 18 and a single output in the form of an output shaft 20. It is exemplified as a conventional 4-speed gearbox. Its structure and operation is well known and will therefore not be described in detail here. On the input shaft 18, the rotational speed of an internal combustion engine of a vehicle is provided. The output shaft 20 is brought in a manner to be described with the group transmission 16 in drive connection.

The group transmission 16 includes two inputs in the form of a group input shaft 22 and a coaxial and rotatable second input shaft 24 in the form of a hollow shaft. There are three switching groups A, B and C are provided, in other embodiments, a different number (at least two) may be provided by switching groups. The switching group A has an ne gear pairing with meshing gears 26 and 28 on. The switching group C has a gear pairing with meshing gears 30 and 32. The switching group B has a first gear pair B-1 with meshing gears 34, 36 and a second gear pair B-2 with meshing gears 38, 40. The ratios of the two gear pairings B-1 and B-2 are preferably identical or approximately identically dimensioned.

Depending on the control to be described, either the group input shaft 22 or the second input shaft 24 can be brought into drive connection via a gear pairing of a switching group A, B, C with a group output shaft 42. The arranged parallel to the group input shaft 22 group output shaft 42 has at its output end axial end of a bevel gear 44 as a drive gear for another transmission. Preferably, the group output shaft 42 is formed as a differential drive shaft for driving a wheel axle of a vehicle.

The gears 26, 30, 34, 38 of the gear pairings A, B-1, B-2, C are arranged coaxially with the group input shaft 22 and the second input shaft 24. In the embodiment of FIG. 1, the gears 26, 38 of the gear pairings A, B-2 rotatably connected to the group input shaft 22, while the gears 30, 34 of the gear pairings C, B-1 are rotatably connected to the second input shaft 24. At the group input shaft 22, an axially displaceable switching device 46 (eg, a synchronizer) is arranged rotationally fixed. By a corresponding control of this switching device 46, the rotatably connected to the group input shaft 22 gears can 26, 38 are brought into driving connection with the second input shaft 24 or the rotatably connected to the second input shaft 24 gears 30, 34 are brought into driving connection with the group input shaft 22.

Starting from the switching group A, the gears arranged coaxially on the group input shaft 22 have an increasing diameter, wherein the two gears 34, 38 of the same switching group B are dimensioned with an identical or approximately identical diameter. Starting from the switching group A, the gears arranged coaxially on the group output shaft 42 have a smaller diameter, wherein the two gears 36, 40 of the same switching group B are dimensioned with an identical or approximately identical diameter. With such a dimensioning of the gear pairings, for example, an assignment of the switching groups to the already described working areas of an agricultural vehicle can take place, wherein the switching group A the first work area "field work", the switching group B the second work area "PTO" and the switching group C the third work area " Transport "corresponds.

At the group output shaft 42, two axially displaceable switching devices 48, 50 (eg synchronizers) are arranged rotationally fixed. The switching device 48 is arranged axially between the switching group A and the gear pair B-2 of the switching group B and can bring depending on an axial switching position either the gear pair of the switching group A or the gear pair B-2 of the switching group B with the group output shaft 42 in drive connection. The switching device 50 hin- against is arranged axially between the switching group C and the gear pair B-1 of the switching group B and can bring depending on an axial switching position either the gear pair of the switching group C or the gear pair B-1 of the switching group B with the group output shaft 42 in drive connection. Deviating from this, the switching elements 48, 50 may also be arranged on the input shafts 22, 24.

The output shaft 20 of the base transmission 12 according to FIG. 1 can be selectively brought into drive connection with the group input shaft 22 or with the second input shaft 24 of the group transmission 16. For this purpose, the transmission unit 14 has a first clutch device 52, a second clutch device 54 and a transmission device 56. The transmission device 56 includes two gear pairings. A gear pair consists of meshing gears 58, 60. The gear 58 is rotatably mounted on an input shaft 62 of the transmission unit 14. This input shaft 62 is rotatably connected to the output shaft 20 of the base gear 12. The input shaft 62 is coupled via the first clutch device 52 to a first output shaft 64 of the transmission unit 14. The first output shaft 64 in turn is non-rotatably connected to the group input shaft 22. In this way, a direct drive connection is made between the output shaft 20 of the base gear 12 and the group input shaft 22, which is closed or interrupted depending on the activation of the first clutch device 52.

The second clutch device 54 of the transmission unit 14 is capable of controlling a force flow within the transmission device 56 - more precisely, between the two gear pairings of this transmission device 56 - with appropriate control. terbrechen. The gears 58, 6 axially opposite gear pair of the transmission device 56 consists of meshing gears 66, 68. The gear 68 is rotatably connected to a second output shaft 70 of the transmission unit 14. This second output shaft 70 is arranged coaxially and rotatably to the first output shaft 64, formed as a hollow shaft and rotatably connected to the second input shaft 24 of the group transmission 16.

With a corresponding control or wiring of the first clutch device 52, a direct drive from the output shaft 20 of the base gear 12 to the group input shaft 22 of the group shell gear 16 is formed on the group input shaft 22, the speed of the output shaft 20 is then provided unchanged. The gears 58, 60, 66, 68 of the transmission device 56 are dimensioned such that the rotational speed of the output shaft 20 is provided in a reduced form on the second input shaft 24 of the group transmission 16, provided that the second clutch device 54 is driven or wired accordingly. Thus, at the second input shaft 24, a smaller rotational speed is available than at the group input shaft 22.

By appropriate driving or Beschälten the switching devices 46, 48, 50 and the coupling means 52, 54, the two gear ratios (higher speed at the group input shaft 22 and lower speed at the second input shaft 24) within a switching group A or B or C can be changed. Likewise, by means of the switching devices 46, 48, 50 and the coupling devices 52, 54, a switching between the individual switching groups A, B, C take place. In particular, the switching devices 46, 48, 50 at the group outlet input shaft 42 pre-selecting or preselecting the next gear, so that when switching between individual gears interruption of the drive connection between input (group input shaft 22 or second input shaft 24) and group output shaft 42 of the group transmission 16 is avoided. After pre-setting or preselecting the next gear, the clutch means 52, 54 can be controlled accordingly to provide the next gear stage corresponding speed at the input of the group transmission 16 without interrupting the drive connection.

For example, the second input shaft 24 is in drive connection via the gear pair B-1, that is, via the gearwheels 34, 36 with the group output shaft 42. It should be switched to the next gear (gear pair B-2, gears 38, 40). This next gear stage is first preselected or preset by the switching device 48 is driven such that the gear 40 and the gear pair B-2 is in driving connection with the group output shaft 42. Thereafter, a simultaneous switching of the two clutch devices 52, 54, so that the next gear is reached, while the gear pair B-2 is driven at the speed of the group input shaft 22.

Thereafter, for example, in the switching group C is to be indexed, wherein at the switching group C, the lower speed (second input shaft 24) should be effective. This gear stage is in turn first preselected or pre-set by the switching device 50 is driven such that the gear 32 and the gear pair C is in drive connection with the group output shaft 42. Thereafter, a simultaneous conversion switch the two clutch means 52, 54, so that the preselected gear is reached, while the gear pair B-2 is driven at the speed of the second input shaft 24.

Thereafter, for example, to be indexed within the switching group C, i. at the switching group C, the higher speed (group input shaft 22) should be effective. This gear ratio is in turn initially preselected or pre-set by the switching device 46 is driven such that the gear 30 and the gear pair C is in drive connection with the group input shaft 22. Thereafter, a simultaneous switching of the two clutch devices 52, 54, so that the preselected gear is reached, while the gear pair C is driven at the speed of the group input shaft 22.

The illustrated in Fig. 2 embodiment of a gear assembly 10 differs from the embodiment in Fig. 1 in terms of the configuration of the transmission device 56 in that the transmission device 56 converts the pending on the input shaft 62 speed in Fig. 2 to a higher speed and in this increased form on the second input shaft 24 provides. For this purpose, the meshing gears 72, 74 and 76, 78 of the two gear pairings of the transmission device 56 are dimensioned differently according to the corresponding gears 58, 60, 66, 68 in Fig. 1. Alternatively, individual gears 58, 60, 66, 68 are reused in FIG. 1 only in a different order within the transmission device 56 to realize the embodiment of FIG. 2. Since in the embodiment of FIG. 2, the second input shaft 24, the higher speed - compared to the group input shaft 22 of FIG. 2 - provides, are in the group transmission 16 shown in FIG. 2, the individual switching groups A, B, C compared to the embodiment according to Fig. 1 arranged offset axially. Thus, the gear pairings A and B-2 are again rotatably connected to the input to which the comparatively higher speed is provided. Likewise, in Fig. 2, the gear pairings B-1 and C are again rotatably connected to the input to which the comparatively lower speed is provided. By a corresponding control of the clutch devices 52, 54 according to FIG. 2, the same shifting functionality can be achieved for the group transmission 16 according to FIG. 2-apart from the changed rotational speeds-as described with reference to FIG.

FIG. 3 shows a further embodiment of a transmission device 56 for the transmission unit 14 according to FIG. 1. The speed of the output shaft 20 is therefore provided on the first output shaft 64, while a converted lower speed is available on the second output shaft 70. In this embodiment, a planetary gear 80 is used. The second clutch device 54 according to FIG. 1 is replaced by a brake device 82, which can block a connecting element 84 when actuated accordingly. The connecting element 84 is arranged on a hollow shaft 86 which carries a sun gear 88. The sun gear 88 meshes with a set of planetary gears 90, which are rotatably mounted on a planetary carrier 92. The planet carrier 92 is non-rotatably connected to the second output shaft 70. By a corresponding activation of the first coupling In principle, the same switching functionality can be achieved for the group transmission 16 as described with reference to FIG. 1.

FIG. 4 shows a further embodiment of a transmission device 56 for the transmission unit 14 according to FIG. 1 or FIG. 2. The speed of the output shaft 20 is provided on the first output shaft 64, while a converted lower speed is available on the second output shaft 70. In this embodiment, a planetary gear 94 with two axially parallel sun gears 96, 98 is used. The second coupling device 54 according to FIG. 1 is in turn replaced by a braking device 82, which can block a planetary carrier 100 with appropriate control. The planet carrier 100 is connected to bearing axles 102, on which two axially parallel sets of planet gears 104, 106 are mounted. The planet gears 104 and 106 mesh with the respective sun gear 96 and 98, respectively. The sun gear 96 is connected to the input shaft 62 while the sun gear 98 is connected to the second output shaft 70. By a corresponding control of the first clutch device 52 and the brake device 82 according to FIG. 4 and a corresponding dimensioning of the number of teeth, the same shift functionality can be achieved for the group transmission 16 in principle as described with reference to FIG. 1 or FIG.

The embodiment of the transmission device 56 according to FIG. 4 is also suitable for replacing the gear device 56 according to FIG. 2 with a correspondingly different dimensioning of the numbers of teeth of the two sun gears 96, 98. In other words, can The transmission device 56 according to FIG. 4 can also be used with a correspondingly specific embodiment or control to provide a higher or lower rotational speed at the second output shaft 70 than at the first output shaft 64.

5 shows a further embodiment of a transmission device 56 for the transmission unit 14 according to FIG. 2. Therefore, the rotational speed of the output shaft 20 can be provided on the first output shaft 64, while a converted higher rotational speed is available on the second output shaft 70. In this embodiment, a planetary gear 108 is used. The second clutch device 54 according to FIG. 2 is in turn replaced by a brake device 82, which can block a ring gear 110 when appropriately controlled. The ring gear 110 is disposed on a hollow shaft 112 which carries a sun gear 114. The sun gear 114 meshes with a set of planet wheels 116, which are rotatably mounted on a planetary carrier 118. The planet carrier 118 in turn is fixedly connected to a hollow shaft 120, which is arranged on the coupling device 52. By a corresponding activation of the first clutch device 52 and the brake device 82 according to FIG. 5, the same shift functionality can be achieved in principle for the group transmission 16 as described with reference to FIG. 2.

Fig. 6 shows a gear assembly 10 with another conventional base gear 12. This base gear 12 includes a reversible double planetary gear 122 and reversing gear and a dual clutch transmission 124. The dual clutch transmission 124 has in a conventional manner, a first clutch means 126 and a second clutch means 128, respectively a Countershaft 130 and 132 is assigned. The successive eight courses are alternately assigned to one of the two countershafts 130, 132. In the illustrated embodiment, the gear ratios 1, 3, 5, 7 associated with the countershaft 130 and the gear ratios 2, 4, 6, 8 of the countershaft 132 assigned. By driving switching devices 134, 136, 138, 140, the different gear stages can be preset or preselected. In conjunction with the two clutch devices 126, 128, a shift between the gear ratios is made possible without an interruption of the drive connection between the input shaft 18 and the first output shaft 142 and the second output shaft 144 is formed.

In the embodiment according to FIG. 6, the two outputs of the basic transmission are each non-rotatably connected to one input of the group transmission 16, e.g. flanged in a suitable manner. Consequently, the first output shaft 142 is rotatably connected to the group input shaft 22 and the second output shaft 144 to the second input shaft 24. A gear unit 14 for adapting a different number of outputs of the basic transmission and inputs of the group transmission is superfluous, whereby the modular structure of the transmission assembly 10 is further simplified.

In the embodiment according to FIG. 6, the gear stages 1, 2, 3, 4 of the second output shaft 144 and the gear stages 5, 6, 7, 8 are assigned to the first output shaft 142. The structure of the group shift transmission 16 in FIG. 6 corresponds to the variant according to FIG. 1. In FIG. 6, a lower rotational speed is provided at the second input shaft 24 in comparison to the group input shaft 22. As described with reference to FIG. 1, the group 16 with its switching devices 46, 48, 50 the advantage that with an engaged gear of the base gear 12 and the dual clutch transmission 124 different gradations within the ranges or switching groups A, B, C pre-set or preselected and with a next einzulegenden gear of the base gear 12 can be combined, and here again the uninterrupted switching between the individual gradations of the group transmission 16 comes into play.

The different design of the gear unit 14 and the group transmission 16 according to FIG. 1 on the one hand and according to FIG. 2 on the other hand is simple and inexpensive with predominantly identical components possible. Overall, it is a single basic structure of the group transmission 16, which - if necessary in combination with a corresponding gear unit 14 - can support the realization of different gear arrangements for different applications and requirement profiles, as with reference to FIG. 1, FIG. 2 and FIG is shown.

As described, a correspondingly finer gradation of the gears and speed ranges in different conventional base transmissions can be achieved with the aid of the group shift transmission 16, depending on the number of existing shift groups. For example, the 4-speed base gear 12 shown in FIG. 1 and FIG. 2 may be converted into twenty-four (4 × 2 × 3) gear ratios by means of the three gear groups A, B, C and the intermediate gear unit 14 (two speed stages) , The base gear 12 with eight gears as shown in FIG. 6 can also by means of the three areas or switching groups A, B, C. be converted or extended in twenty-four (8 x 3) gears. This degree of finer gradation of a conventional basic transmission 12 is sufficiently efficient for many applications, in particular with regard to an optimized driving strategy (eg fuel saving) and increased ride comfort.

Claims

claims

Group gearbox (16) having a group input shaft (22) on which gears (26, 30, 34, 38) of gear pairs of at least two switching groups (A, B, C) are arranged coaxially, wherein the group input shaft (22) via a gear pair of a switching group (A, B, C) is drive-connectable to a group output shaft (42), characterized in that the group transmission (16) has a second input shaft (24) coaxially and rotatably disposed to the group input shaft (22).

A group transmission according to claim 1, characterized in that at least one of the coaxial to the group input shaft (22) arranged gears (26, 30, 34, 38) with the group input shaft (22) or with the second input shaft (24) is rotatably connected and by means of a Switching device (46) with the second input shaft (24) or with the group input shaft (22) can be brought into drive connection.

Group transmission according to claim 1 or 2, characterized in that the group input shaft (22) and the second input shaft (24) each with at least one gear (26, 38, 30, 34) are rotatably connected.

A group transmission according to claim 3, characterized in that a gear (26, 38, 30, 34) of a switching group (A, B, B, C) with the group input shaft (22) rotatably is connected and a gear (30, 34; 26, 38) egg

ing switching group (B, C, A, B) with the second input shaft (24) is rotatably connected.

Group transmission according to one of the preceding claims, characterized in that a switching group (B) has two gear pairings (Bl, B-2), wherein the coaxially arranged on the group input shaft (22) gear (34, 38) of a gear pair (Bl; B -2) is rotatably connected to the group input shaft (22) and the coaxially arranged on the group input shaft (22) gear (38; 34) of the other gear pair (B-2; Bl) with the second input shaft (24) is rotatably connected.

A group transmission according to one of the preceding claims, characterized in that a switching device (48; 50) is arranged on the group output shaft (42) axially between two switching groups (A, B; B, C) and depending on an axial switching position one of the two switching groups ( A, B, B, C) drivingly connect to the group output shaft (42).

Group transmission according to one of the preceding claims, characterized in that the second input shaft (24) is designed as a hollow shaft.

Group transmission according to one of the preceding claims, characterized in that the group output shaft (42) is designed as a differential drive shaft for driving a wheel axle of a vehicle.

Arrangement of several in a power flow direction hi

the switched gearbox comprising a base gear (12) and a downstream group gearbox (16) having a group input shaft (22) on the gears (26, 30, 34, 38) of gear pairs of at least two gear groups (A, B, C) are arranged coaxially, wherein the group input shaft (22) via a gear pair of a switching group (A, B, C) is drive-connected to a group output shaft (42), characterized in that the group transmission (16) has a second input shaft (24), which is arranged coaxially and rotatably to the group input shaft (22).

Gear arrangement according to Claim 9, characterized in that the base gear (12) has two outputs (142, 144), one output (142) being drive-connected to the group input shaft (22) of the group gearbox (16) and the other output (144) is drive-connected to the second input shaft (24) of the group transmission (16).

Gear arrangement according to claim 9, characterized in that the base gear (12) has an output (20) which selectively with the group input shaft (22) or with the second input shaft (24) of the Gruppenschaltgetrie bes (16) can be brought into drive connection.

Gear arrangement according to claim 11, characterized by a direct drive connection between the output (20) of the basic transmission (12) and the group input shaft (22) of the group transmission (16), and a transmission device Device (56) for driving connection between the off of the base gear (12) and the second input shaft (24) of the group transmission (16).

13. Gear arrangement according to claim 12, characterized in that the transmission device (56) is part of a transmission unit (14) which is connected in the direction of force flow between the base gear (12) and the group transmission (16).

14. Transmission arrangement according to one of claims 11 to 13, characterized by at least one switching device (52, 54, 82) for selectively driving connection of the output (20) of the base gear (12) with the group input shaft (22) or with the second input shaft (24). of the group transmission (16).

15. Gear arrangement according to claims 13 and 14, characterized in that the at least one switching device (52, 54, 82) is part of the between the base gear (12) and the group transmission (16) connected to the transmission unit (14).