Patent ID: 12228193

DETAILED DESCRIPTION

FIG.1shows a schematic illustration of an agricultural towing vehicle10according to the disclosure, for example in the form of a tractor, with a drivetrain20in one possible configuration. The basic structure of an agricultural towing vehicle10is assumed to be known to a person skilled in the art. The towing vehicle10also comprises a cab12, a front vehicle axle14, and a rear vehicle axle26. The front vehicle axle14and the rear vehicle axle26are part of the drivetrain20, with it being possible for the rear vehicle axle26generally to be permanently driven and the front vehicle axle14generally to be driven shiftably as required.

The drivetrain20also comprises a drive motor22, which may be in the form of an internal combustion engine, and a transmission structure which may be composed of various individual transmission components, as described below. The transmission structure described in the present case, in terms of the force flow and torque flow and taking the traction motor22as a starting point, may have a transmission arrangement30according to the disclosure, a traction drive24and a rear-axle transmission32. The transmission arrangement30comprises a transmission device40and a transmission unit80according to the disclosure. In this respect, the transmission device40is mounted downstream of the traction motor22. The transmission device40is connected in terms of drive to the traction motor22, and/or can be drivable by the traction motor22. The transmission unit80is mounted downstream of the transmission device40. In this respect, the transmission unit80is connected in terms of drive to the transmission device40and/or can be driven by the transmission device40. The transmission arrangement30shown makes it possible to transmit drive power from the traction motor22to the output shaft of the transmission unit with different gear ratio stages. The rear vehicle axle26, which is in drive connection with the output shaft and converts rotation of the front and/or the rear vehicle axle (via ground engagement means connected thereto) into propulsion of the tractor, is therefore driven at a different rotational speed independently of a gear ratio stage that is selected in the transmission arrangement. Consequently, a tractor equipped with the transmission arrangement, depending on the gear ratio stage that is selected in the transmission arrangement, can be moved in different speed ranges.

The towing vehicle10may have one or more ground engagement means in the form of wheels28, which engage with an underlying surface to transmit drive forces and/or by way of which the towing vehicle10is supported on the underlying surface. The towing vehicle10may moreover have a chassis, it being possible for the chassis for example to be borne by the wheels28suspended on the front and the rear vehicle axle14,26.

FIG.2shows a schematic illustration, for example a sequence, of a first exemplary embodiment of the transmission unit80according to the disclosure. The transmission unit80shown inFIG.2is a detailed schematic illustration of the transmission unit80shown inFIG.1. Therefore, details not shown inFIG.1will be discussed below. The agricultural vehicle10may comprise the transmission unit80as illustrated inFIG.1.

The transmission unit80comprises a first clutch82and a second clutch84, the input side of which, for example the common input side of which, can be driven. The input side may be connected to, and for example may be drivably connected to or driven by, a drive shaft (reference sign200,FIG.5) of the transmission device40The transmission unit80further comprises a first input shaft86and a second input shaft88and an output shaft90, for example one output shaft90. The output side of the first clutch82is rotationally fixedly connected to the first input shaft86, for example the first clutch82is rotationally fixedly connected to the first input shaft86. The output side of the second clutch84is rotationally fixedly connected to the second input shaft88, for example the second clutch84is rotationally fixedly connected to the second input shaft88. The transmission unit80comprises a clutch drive shaft92as input side. The first and the second clutch82,84can be moved and/or shifted between an open state, in which the clutch drive shaft92is released in terms of drive from the first and/or the second input shaft86,88, and a closed state, in which the clutch drive shaft92is in drive connection with the first and/or the second input shaft86,88. Furthermore, a rear-axle bevel gear drive94is connected to the output shaft90. In this case, the pinion of the rear-axle bevel gear drive94may be in the form of part of the output shaft90, for example be incorporated in the output shaft90. The output shaft90is moreover also connected to a toothset of a front-axle drive by means of a front-axle drive wheel96. The front-axle drive wheel96is moreover identical to a parking lock wheel96.

Moreover, the first and/or the second input shaft86,88are in the form of hollow shafts and the first input shaft86is arranged in the second input shaft88. Furthermore, the first and/or the second input shaft86,88incorporate a power takeoff drive shaft98for driving a power takeoff transmission.

Four shift wheels100,102,104,106are rotatably mounted on the output shaft90. In total, four fixed wheels110,112,114,116are rotationally fixedly arranged on the first and the second input shaft86,88, for example are rotationally fixedly connected to the first and the second input shaft86,88. In this respect, the first and the second input shaft86,88are respectively assigned two fixed wheels. Each of these meshes with one of the shift wheels100,102,104,106assigned to the output shaft90. The transmission unit80has multiple gear sets, for example four gear sets120,122,124,126, for establishing gear ratio stages B, C, D, E. To that end, at least a first gear set120and a second gear set122have the fixed wheel110,112, respectively, on the first input shaft86and the shift wheel100,102, respectively, on the output shaft90. Moreover, at least a third gear set124and a fourth gear set126have the fixed wheel114,116, respectively, on the second input shaft88and the shift wheel104,106, respectively, on the output shaft90. In some embodiments, the first gear set120comprises a first fixed wheel110, which meshes with a first shift wheel100on the output shaft90. The second gear set122comprises a second fixed wheel112, which is in engagement with a second shift wheel102. The third gear set124comprises a third fixed wheel114, which meshes with a third shift wheel104. The fourth gear set126comprises a fourth fixed wheel116, which is in engagement with a fourth shift wheel106.

The transmission unit80also comprises two coupling elements130,132, that is to say a first coupling element130and a second coupling element132. The first coupling element130is arranged between the first and the second gear set120,122and the second coupling element132is arranged between the third and the fourth gear set124,126on the output shaft90. The shift wheels100,102,104,106are rotationally fixedly and releasably connectable to the output shaft90by means of the first or the second coupling element130,132. In some embodiments, the first shift wheel100or the second shift wheel102is thus rotationally fixedly and releasably connectable to the output shaft90by means of the first coupling element130. Moreover, the third shift wheel104or the fourth shift wheel106is rotationally fixedly and releasably connectable to the output shaft90by means of the second coupling element132. Consequently, a respective coupling element130,132is arranged between two respective shift wheels100,102,104,106, which are arranged on the same input shaft86,88, that is to say the first or second input shaft86,88. The first and the second coupling element130,132are rotationally fixedly and axially displaceably mounted on the output shaft90. The first and the second coupling element130,132are in the form of shift assemblies, which comprise actuating mechanisms, for example sliding sleeves, and synchronized rings. As a result, the rotatably mounted shift wheels100,102,104,106can be shifted via the coupling elements130,132, with the result that a respective fixed rotational speed ratio can be established between the output shaft90and the respective first and/or second input shaft86,88irrespective of a shifting state of the coupling elements130,132.

The transmission unit80moreover comprises a shift element134for coupling two shift wheels102,104. In some embodiments, the second and the third shift wheel102,104can be coupled to the shift element134. The second and the third shift wheel102,104are rotationally fixedly and releasably connectable to the shift element134. The second and the third shift wheel102,104can be coupled, for example selectively coupled, to the shift element134in such a way that at least one winding path gear ratio stage A, F can be formed via the second and the third gear set122,124, i.e., for example the first and the second input shaft86,88are thus couplable to one another. In other words, the shift element134may for example be movable between a first shift position, in which the second shift wheel104and the third shift wheel102are coupled, and a second shift position, in which the second shift wheel104and the third shift wheel102are released from one another. The shift element134is in the form of a synchronizer acting on one side. The shift element134is arranged between the first and the second coupling element130,132along the output shaft90.

Depending on the shifting state of the first and the second clutch82,84and on the shifting state of the first and the second coupling element130,132and the shift element134, the transmission unit80can be shifted with each of the clutches82,84in two gear ratio stages, i.e., a total of four gear ratio stages B, C, D, E, and in each case an additional gear ratio stage as a winding path gear ratio stage A, F, i.e., a total of two winding path gear ratios stage A, F, and thus shifted in a total of six gear ratio stages or group gear ratio stages. In this respect, the transmission unit80can be shifted under load in that while the first clutch, for example the first clutch82, is being opened, the second clutch, for example the second clutch84, is closed, with the result that a drive connection existing between the first or the second input shaft86,88and the clutch drive shaft92can be replaced by a drive connection to be established via the respective other input shaft86,88, without interrupting a drive connection between the first or the second input shaft86,88and the output shaft90. To preselect a desired gear ratio stage, the shift wheel in question, that is to say for example the first to the fourth shift wheel100,102,104,106, is rotationally fixedly connected to the output shaft90by the respective assigned first or second coupling element130,132, with the result that the gear ratio stages B, C, D, E are realized. If a gear ratio stage A, F as a winding path gear ratio stage is shifted, the second and the third shift wheel102,104are rotationally fixedly connected to one another by the shift element134, and at the same time the gear ratio stages E or B are activated, that is to say at the same time the first shift wheel100is connected to the output shaft90by the first coupling element130(gear ratio stage E) or the fourth shift wheel106is connected to the output shaft by the second coupling element132(gear ratio stage B). Consequently, each winding path gear ratio stage runs over three gear sets. The transmission unit80thus comprises six gear ratio stages, which for example are powershiftable. In some embodiments, the first and the sixth gear ratio stage A, F are a winding path gear, i.e., realized as a winding path gear ratio stage.

FIG.3shows a schematic illustration of an engagement sequence for the first exemplary embodiment of the transmission unit80according to the disclosure. The engagement sequence shown inFIG.3for the transmission unit comprises the features of the transmission unit80shown inFIGS.1and2, and therefore details and/or points of differentiation will be discussed below. According to the engagement sequence indicated in the table, the first gear ratio stage A is shifted via the first clutch82, via the second coupling element132displaced in a direction B, and via the activated shift element134, that is to say the shift element134displaced in a direction W, as a winding path gear ratio stage. The second gear ratio stage B is realized via the second clutch84and via the second coupling element132displaced in a direction B. The third gear ratio stage C is shifted via the first clutch82and via the first coupling element130displaced in a direction C. The fourth gear ratio stage D is also realized via the second clutch84and via the second coupling element132displaced in a direction D. The fifth gear ratio stage is realized via the first clutch82and via the first coupling element130displaced in a direction E. The sixth gear ratio stage F is shifted via the second clutch, via the first coupling element130displaced in a direction E, and via the shift element134displaced in a direction W, as a winding path gear ratio stage F. In this respect, the displacement of the coupling elements130,132and/or of the shift element134is synonymous with an axial displacement of the first or the second coupling element130,132and/or of the shift element134and the rotationally fixed connection of the assigned shift wheel100,102,104,106to the output shaft90by way of the first or the second coupling element130,132and/or the rotationally fixed connection of the second and the third shift wheel102,104, while still being rotatably arranged on the output shaft90.

FIGS.4a-fshow a schematic illustration, for example a sequence, of the first exemplary embodiment of the transmission unit80according to the disclosure and the power flows of the gear ratio stages A to F of the transmission unit80. The transmission unit80shown inFIGS.4ato4fcorresponds substantially to the transmission unit80shown inFIGS.1to3, and therefore details and/or points of differentiation will be discussed below.

FIG.4ashows the first gear ratio stage A, which is realized as a winding path gear ratio stage via the second, the third and the fourth gear set122,124,126.FIG.4bshows the second gear ratio stage B, which uses the fourth gear set126.FIG.4cshows how the second gear set122is utilized to realize the third gear ratio stage C.FIG.4dshows the fourth gear ratio stage D, in which the third gear set124is utilized.FIG.4eshows the fifth gear ratio stage E, which uses the first gear set120.FIG.4fshows the sixth gear ratio stage F, which is realized as a winding path gear ratio stage and utilizes the first to the third gear set120,122,124. As shown inFIGS.4aand4f, the highest gear ratio stage, that is to say the sixth gear ratio stage F, and the lowest gear ratio stage, that is to say the first gear ratio stage A, are realized as winding path gear ratio stages.

FIG.5shows a schematic illustration, for example a sequence, of a first exemplary embodiment of the transmission arrangement30according to the disclosure. The transmission unit30shown inFIG.5comprises the transmission unit80, the transmission unit80substantially corresponding to the transmission unit80shown inFIGS.1to4f, and therefore details and/or points of differentiation will be discussed below. The transmission arrangement30is intended for a drivetrain20of an agricultural towing vehicle10, in order to connect a traction motor22to a traction drive24of the vehicle10. The transmission arrangement30comprises the transmission unit80described and a transmission device40. The transmission device40is mounted upstream of the transmission unit80. The transmission device40comprises a drive shaft200, which is connected in terms of drive to the input side, for example the clutch drive shaft92, of the first and the second clutches82,84of the transmission unit80.

The transmission arrangement30comprises basically two functional groups, which are in drive connection with one another via shafts. The transmission device40is arranged on the input side of the transmission arrangement30. The transmission device40may be in drive connection with the traction motor22and be driven by the traction motor22. The transmission device40is in drive connection with the transmission unit80via a drive shaft200, which is in the form of a hollow shaft. The transmission unit80has the output shaft90, which at the same time is the drive output shaft of the transmission arrangement30, on the output side.

The transmission device40is in the form of a multi-stage transmission having a plurality of powershift ratio stages, in this instance four powershift stages. The transmission device may for example be powershiftable, for example fully powershiftable. The transmission device40has a planetary design. Furthermore, the transmission device40may be arranged coaxially with the clutch drive shaft92of the transmission unit80and/or of a motor drive output shaft42. The transmission device40, for example the multi-stage transmission, comprises a planetary gear set210with three integrated planetary stages202. The transmission device40moreover also has a clutch arrangement204assigned to the planetary stages202. The planetary gear set210further comprises a ring gear206, driven by the motor drive output shaft42, and a planet gear carrier208, which comprises one or more planet gears for each planetary stage202, for example two, three or four planet gears per planetary stage, which can be rotationally fixedly connected to the planet gear carrier208. Each planetary stage moreover comprises a respective sun gear212, each of which is rotationally fixedly connected to a hollow shaft. The respective hollow shaft is connected to a respective clutch unit214, it for example being possible for the clutch unit214to be in the form of a brake. In this respect, the planet gears assigned to one planetary stage may roll on the respectively assigned sun gear212. Furthermore, the clutch arrangement204comprises an additional direct gear between two clutch units, i.e., the clutch units can be coupled by means of a direct clutch216. In some embodiments, the transmission device40in the form of a multi-stage transmission comprises the planetary gear set210with three integrated planetary stages202. The first planetary stage may comprise a first sun gear, which is connected, for example is rotationally fixedly connected, to a first planet shaft. The first planet shaft in turn is connected to the first clutch unit. The second planetary stage may comprise a second sun gear, which is connected, for example is rotationally fixedly connected, to a second planet shaft. The second planet shaft in turn is connected to the second clutch unit. The third planetary stage may comprise a third sun gear, which is connected, for example is rotationally fixedly connected, to a third planet shaft. The third planet shaft in turn is connected to the third clutch unit. Furthermore, the second and the third clutch units may be couplable by means of the direct clutch216. Furthermore, the transmission arrangement30, for example the transmission device40, may comprise a powershift unit220for reversing the direction of travel. In that case, the powershift reversing unit220is mounted upstream of the transmission unit80and downstream of the multi-stage transmission. The planet gear carrier208is connected, for example rotationally fixedly connected, to the powershift reversing unit220by means of a shaft, the shaft being drivable by and/or in drive connection with the planet gear carrier208.

FIG.6shows a table of a speed distribution depending on the gear ratio stages of the first exemplary embodiment of the transmission arrangement30according to the disclosure.FIG.6relates to the transmission unit80or transmission arrangement30shown inFIGS.1to5, and therefore the points of differentiation will be discussed below. The table shows the individual gear ratio stages of the transmission arrangement30. The gear ratio stages or group gear ratio stages A, B, C, D, E, F of the transmission unit80are each supplemented by the gear ratio stages or powershift ratio stages 1, 2, 3, 4 of the transmission device40per group gear ratio stage, resulting in total in 24 gear ratio stages for the transmission arrangement30. The advantageous optimum and broad distribution of the speed of the towing vehicle between approximately 2 km/h and approximately 65 km/h is shown.