Powershift group transmission for a work machine and agricultural vehicle

Abstract

The invention relates to a powershift group transmission (100) for a work machine, comprising a splitter transmission (110) in countershaft design and a powershift transmission (120) in countershaft design connected downstream of the splitter transmission (110), wherein the powershift transmission (120) comprises a first shaft (131), a second shaft (132), a third shaft (133) and a fourth shaft (134), a first pair of gears (141), a second pair of gears (142), a third pair of gears (143) and a fourth pair of gears (144), a first powershift clutch (151), a second powershift clutch (152) and a third powershift clutch (153) and a shifting element (154). The group transmission (100) according to the invention is characterized in that an output shaft (131) of the splitter transmission (110) represents the first shaft (131) of the powershift transmission (120). The invention further relates to a corresponding agricultural utility vehicle.

Description

[0001] The present invention relates to a powershift group transmission for a work machine according to the preamble of claim 1 and a corresponding agricultural utility vehicle.

[0002] It is known in the prior art that agricultural commercial vehicles, particularly agricultural tractors, must be able to offer a wide range of finely graduated driving ranges due to the wide range of tasks they perform. This generally requires, among other things, a comparatively large spread between a lowest and a highest gear. Furthermore, small geometric step changes must be implemented between the individual gears so that the required high number of gears can be achieved. In order to be able to provide this large number of gears at a reasonable cost, transmissions for agricultural or municipal commercial vehicles are often designed as group transmissions consisting of several individual transmissions. One of these individual transmissions can, for example, be designed as a powershift transmission.

[0003] In general, it is desirable to design the individual gears of a group transmission to be compact, weight-saving and cost-effective while at the same time being highly efficient.

[0004] In this context, EP 2 916 044 A1 discloses a motor vehicle transmission designed as a group, which is intended for use in an agricultural utility vehicle, for example, a farm tractor. The motor vehicle transmission is composed of several individual transmission groups, one of which is implemented in the manner of a dual-clutch transmission.

[0005] From DE 10 2021 208 975 A1, a powershift transmission of a motor vehicle with a splitter group having several powershift stages, a powershiftable intermediate group and a synchronous transmission group is known.

[0006] DE 10 2011 076 391 A1 describes a parallel transmission comprising a splitter group and a range group, each of which is divided into two parallel transmission branches. Each of the transmission branches can be selected by actuating a corresponding powershift element.

[0007] DE 10 2016 209 942 A1 describes a powershift transmission for agricultural machinery. It has a modular design and comprises a first part with a splitter group and a second part with a manual transmission. The splitter group is designed so that the direction of rotation of the input shaft and the direction of rotation of the output shaft remain the same even when the splitter group is engaged.

[0008] However, the known powershift group transmissions are disadvantageous in that they have a comparatively large number of components and in particular gears, which makes them heavy and expensive and requires a large amount of installation space.

[0009] It is an object of the invention to propose an improved powershift group transmission for a work machine.

[0010] This object is achieved according to the invention by the powershift group transmission for a work machine according to claim 1. Advantageous embodiments and further developments of the invention emerge from the dependent claims.

[0011] The invention relates to a powershift group transmission for a work machine, comprising a splitter transmission in countershaft design and a powershift transmission in countershaft design connected downstream of the splitter transmission, wherein the powershift transmission comprises a first shaft, a second shaft, a third shaft and a fourth shaft, comprises a first pair of gears, a second pair of gears, a third pair of gears and a fourth pair of gears, comprises a first powershift clutch, a second powershift clutch and a third powershift clutch and comprises a shifting element.

[0012] Thus, a group transmission is provided, i.e., a complete transmission consisting of several independently shiftable individual transmissions. The group transmission according to the invention comprises at least one splitter transmission and one powershift transmission, both of which are designed as countershafts. In addition, further transmission groups, such as a range transmission or a reversing transmission, can also be provided.

[0013] The group transmission is driven by a drive unit, which can be embodied, for example, as an internal combustion engine or an electric motor. Since the splitter transmission is connected upstream of the powershift transmission, a drive path from the drive unit first runs through the splitter transmission before passing through the powershift transmission. As described, additional transmission groups or drivetrain elements can be arranged upstream or downstream of the splitter transmission or the powershift transmission. For example, a drive axle of the work machine can be connected downstream of the powershift transmission.

[0014] The splitter gearbox can, for example, comprise three shafts and six externally toothed clutches, by means of which five forward gears and one reverse gear can advantageously be provided.

[0015] The powershift transmission is preferably arranged directly downstream of the splitter transmission, i.e. the power flow runs directly from the splitter transmission to the powershift transmission without any intermediate components such as additional transmission groups or gear ratios being provided.

[0016] The powershift transmission comprises a first shaft, a second shaft, a third shaft and a fourth shaft.

[0017] The first and second shafts are advantageously axially offset and arranged coaxially to one another.

[0018] Likewise, the third and fourth shafts are advantageously axially offset and arranged coaxially to each other.

[0019] The first and second shafts are advantageously arranged parallel to the third and fourth shafts.

[0020] The powershift transmission further comprises a first pair of gears, a second pair of gears, a third pair of gears, and a fourth pair of gears. Each pair of gears advantageously consists of two meshing spur gears, one of which can be designed as a fixed gear and one as a loose gear.

[0021] The powershift transmission also includes a first powershift clutch, a second powershift clutch, and a third powershift clutch. The first powershift clutch, the second powershift clutch, and the third powershift clutch can preferably be designed as wet-running or dry-running multi-plate clutches. Powershift clutches have the advantage that transmission elements to be shifted, such as shafts or gears, do not need to be synchronized before the shifting process.

[0022] Finally, the powershift transmission also includes a shifting element that is advantageously designed to be non-powershiftable. This makes the shifting element comparatively more cost-effective and compact, but requires speed synchronization of the transmission elements to be shifted before the shifting process.

[0023] According to the invention, it is now provided that an output shaft of the splitter transmission represents the first shaft of the powershift transmission and that a second wheel of the second pair of wheels is connected to an outer part of the third powershift clutch via a common hollow shaft, wherein the common hollow shaft represents a fifth shaft.

[0024] In other words, the output shaft of the splitter gearbox extends into the powershift gearbox and fulfils the function of the first shaft of the powershift gearbox or, conversely, the first shaft of the powershift gearbox extends into the splitter gearbox and fulfils the function of the output shaft of the splitter gearbox.

[0025] The invention thus provides the advantage of providing a comparatively compact and efficient group transmission, since there is no separate interface between the splitter transmission and the powershift transmission, and in particular, no gear ratio between the splitter transmission and the powershift transmission. Instead, the speed of the splitter transmission is directly transmitted to the powershift transmission via the common shaft, namely the output shaft of the splitter transmission or the first shaft of the powershift transmission.

[0026] According to a preferred embodiment of the invention, it is provided that the output shaft of the splitter gearbox and the first shaft of the powershift gearbox are designed as a one-piece component.

[0027] This simplifies the production process of the group transmission, as the output shaft of the splitter transmission and the first shaft of the powershift transmission can be manufactured in a single step. In particular, it eliminates the need for connecting elements such as splines and spline mounts, which would further increase manufacturing complexity. This also reduces manufacturing costs.

[0028] Further advantages of eliminating the connecting elements include reduced overall weight and increased torque transmission capacity.

[0029] According to a further preferred embodiment of the invention, it is provided that the first shaft can be coupled to the second shaft via the first powershift clutch and the third shaft can be coupled to the fourth shaft via the second powershift clutch, wherein a first wheel of the first pair of wheels and a first wheel of the second pair of wheels are arranged on the first shaft, wherein a first wheel of the third pair of wheels and a first wheel of the fourth pair of wheels are arranged on the second shaft, wherein a second wheel of the first pair of wheels is arranged on the third shaft and wherein the second wheel of the second pair of wheels, a second wheel of the third pair of wheels and the second wheel of the fourth pair of wheels are arranged on the fourth shaft.

[0030] This embodiment has proven to be particularly efficient in terms of being able to represent the largest possible number of gear steps while at the same time ensuring the highest possible efficiency of the powershift transmission.

[0031] According to a particularly preferred embodiment of the invention, it is provided that the second wheel of the second wheel pair is designed as a loose wheel and can be coupled to the fourth shaft via the third powershift clutch, wherein the first wheel of the third wheel pair is designed as a loose wheel and can be coupled to the second shaft via the shifting element, and wherein the first wheel of the fourth wheel pair is designed as a loose wheel and can be coupled to the second shaft via the shifting element.

[0032] This further facilitates the representation of a large number of gear steps while at the same time ensuring the highest possible efficiency of the powershift transmission.

[0033] According to a further preferred embodiment of the invention, it is provided that five gear stages can be represented via the powershift transmission.

[0034] It has been shown that the representation of five gear stages with a comparatively high efficiency of each of the five gear stages is possible.

[0035] According to a particularly preferred embodiment of the invention, it is provided that a drive path of the first gear stage runs from the first shaft via the first pair of gears, the third shaft, the second powershift clutch, the fourth shaft, the third pair of gears, the shifting element and the second shaft.

[0036] The drive path of the first gear thus runs over only two pairs of wheels, which ensures a comparatively high level of efficiency.

[0037] According to a further particularly preferred embodiment of the invention, it is provided that a drive path of the second gear stage runs from the first shaft via the second pair of gears, the second powershift clutch, the fourth shaft, the third pair of gears, the shifting element and the second shaft.

[0038] Since the drive path of the second gear also only runs over two pairs of wheels, high efficiency can be guaranteed here as well.

[0039] According to a further particularly preferred embodiment of the invention, it is provided that a drive path of the third gear stage runs from the first shaft via the first powershift clutch and the second shaft.

[0040] The drive path of the third gear stage therefore has no gear ratio at all, which ensures particularly high efficiency.

[0041] According to a further particularly preferred embodiment of the invention, it is provided that a drive path of the fourth gear stage runs from the first shaft via the first pair of gears, the third shaft, the second powershift clutch, the fourth shaft, the fourth pair of gears, the shifting element and the second shaft.

[0042] The drive path of the fourth gear also runs via only two pairs of wheels, which ensures high efficiency for the fourth gear as well.

[0043] According to a further particularly preferred embodiment of the invention, it is provided that a drive path of the fifth gear stage runs from the first shaft via the second pair of gears, the third powershift clutch, the fourth shaft, the fourth pair of gears, the shifting element and the second shaft.

[0044] Since the drive path of the fifth gear also only runs over two pairs of wheels, high efficiency can be guaranteed here as well.

[0045] Due to the multiple uses of the elements of the powershift transmission, comparatively fewer components are required overall, which means that the powershift transmission remains comparatively compact, lightweight and cost-effective.

[0046] According to a further preferred embodiment of the invention, it is provided that an output of the powershift transmission is designed as a bevel pinion.

[0047] This offers the advantage that a differential, such as a differential of a driven axle, can be driven particularly easily via the output. The axle can, for example, be designed as the rear axle of the work machine and be directly connected to the powershift transmission via the bevel pinion.

[0048] According to a further preferred embodiment of the invention, it is provided that the powershift transmission comprises a switchable all-wheel drive.

[0049] This offers the advantage of improving the off-road capability of a vehicle equipped with a range transmission. Furthermore, engaging all-wheel drive also ensures greater traction on the ground, which can be particularly advantageous for agricultural machinery, as it allows the use of a comparatively larger plow, for example.

[0050] When all-wheel drive is not required, it can be switched off again to prevent the efficiency of the powershift transmission from being permanently adversely affected and thus to keep fuel consumption low.

[0051] Finally, the invention relates to a work machine comprising a group transmission according to the invention. Thus, the advantages of the invention also result in the work machine according to the invention.

[0052] The work machine is preferably an agricultural vehicle, in particular an agricultural tractor.

[0053] The invention is explained below by way of example with reference to embodiments shown in the figures.

[0054] It shows: Fig. 1 shows, by way of example and schematically, a possible embodiment of a powershift group transmission according to the invention for a Fig. 1 (not shown) working machine.

[0055] Identical objects, functional units, and comparable components are designated by the same reference symbols throughout the figures. These objects, functional units, and comparable components are identical in terms of their technical features, unless explicitly or implicitly stated otherwise in the description.

[0056] Fig. 1 shows, by way of example and schematically, a possible embodiment of a powershift group transmission 100 according to the invention for a (in Fig. 1 (not shown) work machine. The work machine is, for example, an agricultural vehicle, namely a tractor.

[0057] The group transmission 100 comprises a splitter transmission 110 in countershaft design and a powershift transmission 120 which is connected downstream of the splitter transmission 110 and is also designed in countershaft design.

[0058] The splitter gear 110 comprises, for example, three shafts 131, 114, 115, six externally toothed clutches 117, 117', 118, 118', 119, 119' and several spur gears 116 by means of which, for example, five forward gears and one reverse gear can be represented.

[0059] The powershift transmission 120 in turn comprises a first shaft 131, a second shaft 132, a third shaft 133 and a fourth shaft 134, furthermore a first pair of gears 141, a second pair of gears 142, a third pair of gears 143 and a fourth pair of gears 144 and a first powershift clutch 151, a second powershift clutch 152 and a third powershift clutch 153. Finally, the powershift transmission 120 also comprises a shift element 154

[0060] An output shaft 131 of the splitter gearbox 110 simultaneously also represents the first shaft 131 of the powershift transmission 120. For example, the output shaft 131 of the splitter gearbox 110 and the first shaft 131 of the powershift transmission 120 are formed as a single-piece component 131. The shaft 131 thus connects the splitter gearbox 110 to the powershift transmission 120. This results in a compact and weight-saving design.

[0061] The splitter gearbox 110 is, for example, a splitter gearbox 110 known per se, which does not have any modifications or adaptations in order to be usable for the group gearbox 100 according to the invention.

[0062] The shaft 114 of the splitter gearbox 110 represents a direct drive from a drive unit 180, for example a diesel engine 180, of the working machine to a hydraulic arrangement 190 and a clutch 191. A power take-off shaft 192 can be driven via the clutch 191.

[0063] As can be seen, the first powershift clutch 151 is arranged on the first shaft 131. Furthermore, a first gear 141' of the first gear pair 141 and a first gear 142' of the second gear pair 142 are arranged on the first shaft 131. The first gear 141' of the first gear pair 141 and the first gear 142' of the second gear pair 142 are each designed as fixed gears.

[0064] On the second shaft 132, the switching element 154, a first wheel 143' of the third wheel pair 143 and a first wheel 144' of the fourth wheel pair 144 are arranged.

[0065] The second powershift clutch 152 and a second gear 141" of the first gear pair 141 are arranged on the third shaft 133. The second gear 141" of the first gear pair 141 is designed as a fixed gear.

[0066] Finally, the third powershift clutch 152, a second gear 142" of the second gear pair 142, a second gear 143" of the third gear pair 143, and a second gear 144" of the fourth gear pair 144 are arranged on the fourth shaft 134. The second gear 142" of the second gear pair 142 is designed as a loose gear. The second gear 143" of the third gear pair 143 and the second gear 144" of the fourth gear pair 144, however, are designed as fixed gears.

[0067] The first shaft 131 and the second shaft 132 are arranged coaxially to each other and can be connected to each other by the first powershift clutch 151.

[0068] In an analogous manner, the third shaft 133 and the fourth shaft 134 are arranged coaxially to one another and can be connected to one another via the second switching element 152.

[0069] The first shaft 131 and the second shaft 132 are arranged parallel to the third shaft 133 and the fourth shaft 134.

[0070] The exemplary powershift transmission 120 is designed to represent five gear stages.

[0071] A drive path of the first gear stage runs, for example, from the first shaft 131 via the first gear pair 141, the third shaft 133, the second powershift clutch 152, the fourth shaft 134, the third gear pair 143, the shift element 154 and the second shaft 132.

[0072] A drive path of the second gear stage runs, for example, from the first shaft 131 via the second gear pair 142, the third powershift clutch 153, the fourth shaft 134, the third gear pair 143, the shift element 154 and the second shaft 132.

[0073] A drive path of the third gear stage runs, for example, from the first shaft 131 via the first powershift clutch 151 and the second shaft 132.

[0074] A drive path of the fourth gear stage runs, for example, from the first shaft 131 via the first gear pair 141, the third shaft 133, the second powershift clutch 152, the fourth shaft 134, the fourth gear pair 144, the shift element 154 and the second shaft 132.

[0075] A drive path of the fifth gear stage runs, for example, from the first shaft 131 via the second gear pair 142, the third powershift clutch 153, the fourth shaft 134, the fourth gear pair 144, the shift element 154 and the second shaft 132.

[0076] An output of the powershift transmission 120 is designed as a bevel pinion 160 and drives a differential 162 of a rear axle 161 of the working machine.

[0077] By means of a switchable all-wheel drive 170 of the powershift transmission 120, a front axle (not shown in Fig. 1) the working machine can be driven. Reference symbol 100 Powershift group transmission 110 splitter gearbox 114 Splitter gear shaft 115 Splitter gear shaft 116 Spur gear of the splitter gear 117 Clutch 117' clutch 118 Clutch 118' coupling 119 Clutch 119' coupling 120 powershift transmissions 131 first shaft of the powershift transmission, output shaft of the splitter gearbox 132 second wave 133 third wave 134 fourth wave 141 first pair of wheels 141' first wheel of the first pair of wheels 141" second wheel of the second pair of wheels 142 second pair of wheels 142' first wheel of the second pair of wheels 142" second wheel of the second pair of wheels 143 third pair of wheels 143' first wheel of the third pair of wheels 143" second wheel of the third pair of wheels 144 fourth pair of wheels 144' first wheel of the fourth pair of wheels 144" second wheel of the fourth pair of wheels 151 first powershift clutch 152 second powershift clutch 153 third powershift clutch 154 switching element 160 bevel pinion 161 rear axle 162 Differential 170 all-wheel drive 180 drive unit; diesel engine 190 Hydraulic arrangement 191 Clutch 192 Power take-off shaft

Claims

[1] Powershift group transmission (100) for a working machine, comprising a splitter transmission (110) in countershaft design and a powershift transmission (120) in countershaft design connected downstream of the splitter transmission (110), wherein the powershift transmission (120) comprises a first shaft (131), a second shaft (132), a third shaft (133) and a fourth shaft (134), a first pair of gears (141), a second pair of gears (142), a third pair of gears (143) and a fourth pair of gears (144), a first powershift clutch (151), a second powershift clutch (152) and a third powershift clutch (153) and a shifting element (154), characterized by that an output shaft (131) of the splitter gearbox (110) represents the first shaft (131) of the powershift gearbox (120) and that a second wheel (142") of the second wheel pair (142) is connected to an outer part of the third powershift clutch (153) via a common hollow shaft, wherein the common hollow shaft represents a fifth shaft. [2] Group transmission (100) according to claim 1, characterized by that the output shaft (131) of the splitter gearbox (110) and the first shaft (131) of the powershift gearbox (120) are designed as a one-piece component (131). [3] Group transmission (100) according to at least one of claims 1 and 2, characterized by that the first shaft (131) can be coupled to the second shaft (132) via the first powershift clutch (151) and the third shaft (133) can be coupled to the fourth shaft (134) via the second powershift clutch (152), wherein a first wheel (141') of the first pair of wheels (141) and a first wheel (142') of the second pair of wheels (142) are arranged on the first shaft (131), wherein a first wheel (143') of the third pair of wheels (143) and a first wheel (144') of the fourth pair of wheels (144) are arranged on the second shaft (132), wherein a second wheel (141") of the first wheel pair (141) is arranged on the third shaft (133), and wherein the second wheel (142') of the second wheel pair (142), a second wheel (143') of the third wheel pair (143), and the second wheel (144') of the fourth wheel pair (144) are arranged on the fourth shaft (134). [4] Group transmission (100) according to claim 3, characterized by that the second wheel (142") of the second pair of wheels (142) is designed as a loose wheel and can be coupled to the fourth shaft (134) via the third powershift clutch (153), wherein the first wheel (143') of the third pair of wheels (143) is designed as a loose wheel and can be coupled to the second shaft (132) via the switching element (154) and wherein the first wheel (144') of the fourth wheel pair (144) is designed as a loose wheel and can be coupled to the second shaft (132) via the switching element (154). [5] Group transmission (100) according to at least one of claims 1 to 4, characterized by that five gear stages can be represented via the powershift transmission (120). [6] Group transmission (100) according to claim 5, characterized by that a drive path of the first gear stage runs from the first shaft (131) via the first pair of gears (141), the third shaft (133), the second powershift clutch (152), the fourth shaft (134), the third pair of gears (143), the shifting element (154) and the second shaft (132). [7] Group transmission (100) according to at least one of claims 5 and 6, characterized bythat a drive path of the second gear stage runs from the first shaft (131) via the second pair of gears (142), the second powershift clutch (152), the fourth shaft (134), the third pair of gears (143), the shifting element (154) and the second shaft (132). [8] Group transmission (100) according to at least one of claims 5 to 7, characterized by that a drive path of the third gear stage runs from the first shaft (131) via the third powershift clutch (153) and the second shaft (132). [9] Group transmission (100) according to at least one of claims 5 to 8, characterized by that a drive path of the fourth gear stage runs from the first shaft (131) via the first pair of gears (141), the third shaft (133), the second powershift clutch (152), the fourth shaft (134), the fourth pair of gears (144), the shifting element (154) and the second shaft (132). [10] Group transmission (100) according to at least one of claims 5 and 9, characterized bythat a drive path of the fifth gear stage runs from the first shaft (131) via the second pair of gears (142), the third powershift clutch (153), the fourth shaft (134), the fourth pair of gears (144), the shifting element (154) and the second shaft (132). [11] Group transmission (100) according to at least one of claims 1 to 10, characterized by that an output of the powershift transmission (120) is designed as a bevel pinion (160). [12] Group transmission (100) according to at least one of claims 1 to 11, characterized by that the powershift transmission (120) comprises a switchable all-wheel drive (170). [13] Working machine comprising a group transmission (100) according to at least one of claims 1 to 12.

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