POWERSHIFT TRANSMISSION FOR AGRICULTURAL MACHINES

Abstract

A powershift transmission for an agricultural machine includes a transmission housing, an input shaft unit and an output shaft, wherein the input shaft unit and the output shaft extend at least at a distance within the transmission housing. An auxiliary shaft is arranged within the housing parallel to but offset between the input shaft unit and the output shaft. The input shaft unit and the auxiliary shaft are connected to one another via a front-mounted range unit, and the auxiliary shaft and the output shaft are connected to one another via a rear-mounted range unit. The front-mounted and rear mounted range units each includes at least two gear wheel pairs. The input shaft unit is formed from a main input shaft and an auxiliary input shaft.

Claims

1. A powershift transmission for an agricultural machine, comprising: a transmission housing, an input shaft unit and an output shaft, wherein the input shaft unit and the output shaft extend at least at a distance within the transmission housing, an auxiliary shaft arranged parallel to but offset between the input shaft unit and the output shaft, the auxiliary shaft being arranged within the transmission housing, wherein the input shaft unit and the auxiliary shaft are connected to one another via a front-mounted range unit, and the auxiliary shaft and the output shaft are connected to one another via a rear-mounted range unit, wherein the front-mounted and rear mounted range units each comprises at least two gear wheel pairs, the at least two gear wheel pairs being individually coupled or decoupled, further wherein the input shaft unit is formed from a main input shaft and an auxiliary input shaft.

2. The powershift transmission of claim 1, wherein the main input shaft and the auxiliary input shaft are coupled to one another via a reduction gear unit.

3. The powershift transmission of claim 1, wherein the reduction gear unit comprises a first and a second reduction-gear-unit gear wheel pair.

4. The powershift transmission of claim 3, wherein the main input shaft is adapted to be coupled to a drive unit; wherein, in a first shifted state of the reduction gear unit, the main input shaft is coupled directly to the auxiliary input shaft, and in a second shifted state of the reduction gear unit the main input shaft is connected to the auxiliary input shaft via the first and the second reduction-gear-unit gear wheel pair.

5. The powershift transmission of claim 3, wherein the main input shaft is adapted to be coupled to a drive unit such that in a first shifted state of the reduction gear unit, the main input shaft is connected to the auxiliary input shaft via the first reduction-gear-unit gear wheel pair, and in a second shifted state of the reduction gear unit the main input shaft is connected to the auxiliary input shaft via the second reduction-gear-unit gear wheel pair.

6. The powershift transmission of claim 1, further comprising: drive gear wheels of the front-mounted range unit are arranged on the auxiliary input shaft; and output gear wheels of the front-mounted range unit are arranged on the auxiliary shaft.

7. The powershift transmission of claim 1, further comprising: drive gear wheels of the rear-mounted range unit are arranged on the auxiliary shaft; and output gear wheels of the rear-mounted range unit are arranged on the output shaft.

8. The powershift transmission of claim 1, wherein each gear wheel pair of the front-mounted range unit and of the rear-mounted range unit comprises a separately assigned clutch.

9. The powershift transmission of claim 8, wherein the clutches of the front-mounted range unit and of the rear-mounted range unit are arranged on the auxiliary input shaft and the output shaft.

10. The powershift transmission of claim 9, wherein the auxiliary shaft is free of clutches.

11. The powershift transmission of claim 1, wherein a rotational direction of the output shaft is reversible via a reversing unit, the reversing unit integrated into the reduction gear unit.

12. The powershift transmission of claim 1, wherein the front-mounted range unit or the rear-mounted range unit comprises four gear wheel pairs.

13. A method for operating through a powershift transmission, comprising: providing a transmission housing, an input shaft unit, an output shaft, an auxiliary shaft arranged parallel to but offset between the input shaft unit and the output shaft; connecting the input shaft unit and the auxiliary shaft via a front-mounted range unit having at least two gear wheel pairs; connecting the auxiliary shaft and the output shaft via a rear-mounted range unit having at least two gear wheel pairs; forming the input shaft unit from a main input shaft and an auxiliary input shaft; defining a first shift level with a reduction gear unit; defining a second shift level via the front-mounted range unit; defining a third shift level via the rear-mounted range unit; arranging the second shift level downstream with respect to the first shift level; and arranging the third shift level downstream with respect to the second shift level; wherein each shift level comprises at least two shifted states.

14. A powershift transmission for an agricultural machine, comprising: a transmission housing; an input shaft unit; an output shaft, wherein the input shaft unit and the output shaft extend at least at a distance within the transmission housing; a main input shaft and an auxiliary input shaft, the main input shaft and the auxiliary input shaft forming the input shaft unit; an auxiliary shaft arranged parallel to but offset between the input shaft unit and the output shaft, the auxiliary shaft being arranged within the transmission housing; a front-mounted range unit for connecting the input shaft unit and the auxiliary shaft; a rear-mounted range unit for connecting the auxiliary shaft and the output shaft; a reduction gear unit for coupling the main input shaft and the auxiliary input shaft; wherein the front-mounted and rear mounted range units each comprises at least four gear wheel pairs, the at least four gear wheel pairs being individually coupled or decoupled.

15. The powershift transmission of claim 14, wherein each gear wheel pair of the front-mounted range unit and of the rear-mounted range unit comprises a separately assigned clutch.

16. The powershift transmission of claim 15, wherein the clutches of the front-mounted range unit and of the rear-mounted range unit are arranged on the auxiliary input shaft and the output shaft.

17. The powershift transmission of claim 16, wherein the auxiliary shaft is free of clutches.

18. The powershift transmission of claim 14, wherein a rotational direction of the output shaft is reversible via a reversing unit, the reversing unit integrated into the reduction gear unit.

19. The powershift transmission of claim 14, wherein the main input shaft is adapted to be coupled to a drive unit; wherein, in a first shifted state of the reduction gear unit, the main input shaft is coupled directly to the auxiliary input shaft, and in a second shifted state of the reduction gear unit the main input shaft is connected to the auxiliary input shaft via a first and a second reduction-gear-unit gear wheel pair.

20. The powershift transmission of claim 14, wherein the main input shaft is adapted to be coupled to a drive unit such that in a first shifted state of the reduction gear unit, the main input shaft is connected to the auxiliary input shaft via a first reduction-gear-unit gear wheel pair, and in a second shifted state of the reduction gear unit the main input shaft is connected to the auxiliary input shaft via a second reduction-gear-unit gear wheel pair.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above-mentioned aspects of the present disclosure and the manner of obtaining them will become more apparent and the disclosure itself will be better understood by reference to the following description of the embodiments of the disclosure, taken in conjunction with the accompanying drawings, wherein:

[0031] FIG. 1 shows a schematic illustration of an agricultural working machine,

[0032] FIG. 2 shows a powershift transmission according to the disclosure with 32 gearshift variants,

[0033] FIG. 3 shows an alternative embodiment of the powershift transmission according to FIG. 2, and

[0034] FIG. 4 shows a shifting principle of the powershift transmission according to the disclosure.

[0035] Corresponding reference numerals are used to indicate corresponding parts throughout the several views.

DETAILED DESCRIPTION

[0036] The embodiments of the present disclosure described below are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present disclosure.

[0037] FIG. 1 shows an agricultural working machine in the form of a tractor 10 and any desired implement 12 which is towed by the tractor 10 and is embodied as a round bale press in the embodiment purely by way of example. The implement 12 comprises a chassis 14 which is supported on wheels 16 and has a bale-forming chamber 18. The implement 12 is towed by the tractor 10 by a drawbar 20. The driveable elements of the drawbar 20 are driven by the tractor 10 by a power take-off shaft 22.

[0038] The tractor 10 comprises a chassis 24 which is supported on front, steerable wheels 26 and driven wheels 28 at the rear. An operator workstation with a seat 32 is located in a cab 30. A steering wheel 34, an accelerator pedal 36 and an operator position 38 can be activated from the seat.

[0039] FIG. 2 shows a schematic diagram of the powershift transmission according to the disclosure. The powershift transmission has an input shaft unit composed of a main input shaft 41, an auxiliary input shaft 42 and an output shaft 61. An auxiliary shaft 51 is arranged with a parallel offset between the input shaft unit and the output shaft 61. A working machine 49, which transmits a torque to the main input shaft 41, is provided on the main input shaft 41. This torque is transmitted by the main input shaft 41 to the auxiliary input shaft 42 via a reduction gear unit 40, wherein a torque transmission between the auxiliary input shaft 42 and the auxiliary shaft 51 occurs via the front-mounted range unit 50. A torque transmission then occurs from the auxiliary shaft 51 to the output shaft 61 via a rear-mounted range unit 60.

[0040] In the illustrated embodiment which is shown by way of example, the front-mounted range unit 50 has a total of four gear wheel pairs I, II, III and IV, each composed of a drive gear wheel 52 and an output gear wheel 53, which can be engaged with one another via a clutch 54. These four gear wheel pairs I, II, III and IV are distinguished by different transmission ratios. For example, the gear wheel pair I has a relatively small drive gear wheel 52 and a large output gear wheel 53. As long as these gear wheels are in engagement with one another, the rotational speed of the output gear wheel 53 is reduced and at the same time the torque is increased. In comparison with this, the gear wheel pair IV has a relatively large drive gear wheel 52 and a relatively small output gear wheel 53, as a result of which the rotational speed of the output gear wheel 53 is increased and the torque is reduced.

[0041] In order to transmit the torque from the input shaft unit to the auxiliary shaft 51, the drive gear wheels 52 of the front-mounted range unit 50 are arranged on the auxiliary input shaft 52, and the output gear wheels 53 are arranged on the auxiliary shaft 51. The clutches of the front-mounted range unit 50 are exclusively arranged on the auxiliary input shaft 42, wherein it, of course, also lies within the scope of the disclosure to provide clutches 54 both on the auxiliary input shaft 42 and on the auxiliary shaft 51. In the case of an exclusive arrangement on the auxiliary input shaft 42, these clutches are arranged in a so-called back-to-back arrangement, wherein two of the clutches 54 are located between two of the gear wheel pairs I, II, III and IV of the front-mounted range unit 50.

[0042] Arranged between the main input shaft 41 and the auxiliary input shaft 42 is a reduction gear unit 40, via which the main input shaft 41 is connected to the auxiliary input shaft 42. The reduction gear unit 40 has a clutch Hi, via which the main input shaft 41 can be directly coupled to the auxiliary input shaft 42. For this purpose, the two input shafts 41, 42 are arranged one next to the other and coaxially with respect to one another, wherein the clutch Hi permits direct transmission of the torque, so that both the transmitted torque and the rotational speed remain unchanged after engagement of the clutch. This type of a connection constitutes a first shifted state of the reduction gear unit 40, which state describes a high load state.

[0043] In a second shifted state of the reduction gear unit 40, the main input shaft 41 is connected to the auxiliary input shaft 42 via a first and a second reduction-gear-unit gear wheel pair 43, 44. There, the output gear wheel of the first reduction-gear-unit gear wheel pair 43 can be coupled to the drive gear wheel of the second reduction-gear-unit gear wheel pair 44 via a clutch Lo. The drive gear wheel of the first reduction-gear-unit gear wheel pair 43 is arranged here on the main input shaft 41, and the output gear wheel of the second reduction-gear-unit gear wheel pair 44 is arranged on the auxiliary input shaft 42. Both reduction-gear-unit gear wheel pairs 43, 44 are embodied here in such a way that a transmission of a reduction of the rotational speed and the increase in the torque takes place. The second shifted state defines a low load state.

[0044] Irrespective of the shifted state of the reduction gear unit 40, the input shafts 41, 42 always have the same direction of rotation, which is reversed in comparison with the output shaft 61.

[0045] The transmission of the torque from the auxiliary shaft 51 to the output shaft 61 takes place via a rear-mounted range unit 60. For this purpose, the drive gear wheels 62 are arranged on the auxiliary shaft 51, and the output gear wheels 63 are arranged on the output shaft 61.

[0046] The rear-mounted range unit 60 also has four gear wheel pairs A, B, C and D. The number of gearshift variants results now from a multiplication of the gear wheel pairs of the front-mounted range unit 50, of the rear-mounted range unit 60 and the shifted states of the reduction gear unit 40. Therefore, a total of 32 gears can be implemented. Removing, for example, the gear wheel pair IV and the gear wheel pair D causes the number of gearshift variants to be reduced to only 18.

[0047] The individual gear wheel pairs A, B, C and D of the rear-mounted range unit 60 can also be coupled and decoupled via respectively assigned clutches 64, wherein in the example shown all the clutches 64 are arranged on the output shaft 61. The auxiliary shaft 51 is therefore free of clutches 54, 64. The arrangement of the clutches 64 corresponds, as in the arrangement of the clutches 54 already explained above, to the front-mounted range unit on the auxiliary input shaft.

[0048] Moreover, the powershift transmission has a reversing unit 70 which is integrated into the reduction gear unit 40.

[0049] FIG. 3 shows an alternative embodiment of the powershift transmission according to FIG. 2, which differs in the embodiment of the reduction gear unit 40. In contrast to FIG. 2, the main input shaft 51 and the auxiliary input shaft 52 cannot be coupled directly to one another. Instead, a first shifted state is implemented by means of the first reduction-gear-unit gear wheel pair 43, and a second shifted state is implemented by means of the second reduction-gear-unit gear wheel pair 44. The first reduction-gear-unit gear wheel pair 43 can be coupled in here by means of the clutch Lo and defines a low load state, while the second reduction-gear-unit gear wheel pair 44 is coupled by means of the clutch Hi and defines a high load state. The other components are embodied in a way analogous to the powershift transmission according to FIG. 2. In particular, the front-mounted range unit 50 also has four gear wheel pairs I, II, III and IV here, or else the rear-mounted range unit 60 has four gear wheel pairs A, B, C and D.

[0050] The essential difference with respect to the powershift transmission according to FIG. 2 is that a reversal of the direction of rotation takes place between the main input shaft 41 and the auxiliary input shaft 42. Overall, a reversal of the direction of rotation therefore takes place via the front-mounted range unit 50, via the reduction gear unit 40 and via the rear-mounted range unit 60, so that the output shaft 61 has a direction of rotation which is reversed in comparison with the main input shaft 41. In one embodiment according to FIG. 2, the main input shaft 41 and the output shaft 61 have the same direction of rotation.

[0051] FIG. 4 shows a shift principle of the powershift transmission. It is shown how the powershift transmission is to run through, in order to be able to change over as continuously as possible from a low gearshift variant into a high gearshift variant. In this context, the reduction gear unit 40 forms a first shift level, the front-mounted range unit 50 forms a second shift level, and the rear-mounted range unit 60 forms a third shift level.

[0052] At first, the front-mounted range unit 50 is shifted onto the gear wheel pair I, the reduction gear unit 40 is shifted into the shifted state Lo, and the rear-mounted range unit 60 is shifted onto the gear wheel pair A. In order to increase the gear, the reduction gear unit 40 is now placed firstly in the shifted state Hi, while both the front-mounted range unit 50 and the rear-mounted range unit 60 remain unchanged. In order to bring about a further increase, this is then repeated in particular in the case of a successively shifted increase in the front-mounted range unit 50, until all the gear wheel pairs I, II, III and IV of the front-mounted range unit 50 have been run through.

[0053] In a further step, the gear wheel pairs A, B, C and D of the rear-mounted range unit 60 are shifted through successively, wherein the shifting principle explained above is repeated for each gear wheel pair A, B, C and D of the rear-mounted range unit 60.

[0054] While embodiments incorporating the principles of the present disclosure have been disclosed hereinabove, the present disclosure is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this disclosure pertains and which fall within the limits of the appended claims.