DRIVE TRAIN FOR AN AGRICULTURAL MACHINE

Abstract

A drive-train of an agricultural machine, such as a tractor, has a power-split transmission (1) and a separate transfer case (2). The transfer case (2) can be connected to a drive motor and the gear ratio of the transfer case (2) can be adapted in such manner that the power-split transmission (1) can be used for various drive powers.

Claims

1-10. (canceled)

11. A drive-train for an agricultural machine comprising: a power-split transmission (1) having an input shaft (6) which is connectable to a drive motor, the power-split transmission (1) comprising summation gearing (7) which is in a form of a planetary gearset, the input shaft (6) of the power-split transmission passing through the summation gearing (7), a separate transfer case (2) having a drive input shaft (3) and a drive output shaft (4), the drive input shaft (3) of the transfer case being connectable to the drive motor and the drive output shaft (4) being connected to the input shaft (6) of the power-split transmission (1), and the transfer case (2) having step-down gearing such that a rotational speed of the drive input shaft (3) of the transfer case (2) is lower than a rotational speed of the drive output shaft (4).

12. The drive-train according to claim 11, wherein the transfer case (2) has at least one further shaft for an auxiliary power take-off (13, 14, 15) for driving a pump, and a rotational speed of the at least one further shaft is equal to the rotational speed of the drive input shaft (3) of the transfer case (2).

13. The drive-train according to claim 11, wherein the input shaft (6) of the power-split transmission, passing through the summation gearing (7), drives an auxiliary power take-off (8).

14. The drive-train according to claim 11, wherein the transfer case (2) is connected to the power-split transmission (1).

15. The drive-train according to claim 11, wherein the transfer case (2) is fixed to a vehicle frame together with the power-split transmission (1).

16. The drive-train according to claim 11, wherein the transfer case (2) is in a form of a spur gear system in which the drive input shaft (3), of the transfer case, and the drive output shaft (4) are arranged coaxially.

17. The drive-train according to claim 11, wherein the transfer case (2) has three auxiliary power take-offs (13, 14, 15)

18. The drive-train according to claim 11, wherein a cardan shaft (5) connects the drive output shaft (4) of the transfer case (2) to the input shaft (6) of the power-split transmission (1).

19. The drive-train according to claim 11, wherein the drive output shaft (4) of the transfer case (2) is directly connected to the input shaft (6) of the power-split transmission (1) and is made integrally therewith.

20. The drive-train according to claim 11, wherein a continuously variable power branch (9) of the power-split transmission (1) comprises hydraulic units configured as axial pistons.

21. A drive-train for an agricultural machine, the drive train comprising: a power-split transmission (1) having an input shaft (6) and comprising summation gearing (7) which is in a form of a planetary gearset, and the input shaft (6) passes through the summation gearing (7); and a transfer case (2) being separated from the power-split transmission, the transfer case having a drive input shaft (3) and a drive output shaft (4), the drive input shaft (3) of the transfer case being connectable to a drive motor and the drive output shaft (4) of the transfer case being connected to the input shaft (6) of the power-split transmission (1), and the transfer case (2) having step-down gearing such that, during operation, a rotational speed of the drive input shaft (3) of the transfer case (2) is lower than a rotational speed of the drive output shaft (4) of the transfer case (2).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The sole FIGURE shows a drive-train consisting of a power-split transmission and transfer box.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The single FIGURE shows the drive-train consisting of a power-split transmission 1 and a transfer case 2. The drive input shaft 3 of the transfer case can be connected to a drive engine (not shown) such as an internal combustion engine or an electric motor. The drive output shaft 4 of the transfer case 2 is connected by way of a cardan shaft 5 to the input shaft 6 of the power-split transmission. The input shaft 6 passes completely through the summation gearing 7 and forms an auxiliary power take-off 8 at the opposite end of the power-split transmission 1, for example for a power-take-off shaft. The continuously variable power branch 9 has either two hydraulic machines or two electric machines. The drive output shaft 10 of the power-split transmission 1 drives wheels 11 of a rear axle and wheels 12 of a front axle. The transfer case has an auxiliary power take-off 13, an auxiliary power take-off 14 and an auxiliary power take-off 15, by means of which hydraulic pumps can be driven. The housing 16 is designed such that the transfer case 2 can be made separately from the housing 17 of the power-split transmission 1. In this context separately means that the power-split transmission 1 only has to be changed in minor respects and can mainly be kept the same, whereas the transfer case 2 can be adapted specially for the vehicle concerned. Thus, the transfer case 2 has a housing 16 which surrounds the transfer case 2 at least partially. That makes it possible either to suspend the transfer case 2 on the power-split transmission 1, i.e. to connect it thereto for example by bolting it on, or to suspend the transfer case 2 independently in a vehicle frame.

[0016] The drive output shaft 4 has to be designed in accordance with the design of the transfer case 2. It is also possible for the drive output shaft 4 and the input shaft 6 to be made integrally.

[0017] The transfer case 2 is in the form of a spur gear system, wherein the gear ratios between the input shaft 3 and the auxiliary power take-offs 13, 14 and 15 are designed such that equivalent rotational speeds are produced. In this context equivalent rotational speeds means that the rotational speeds are almost equal. This is achieved for example by a gear ratio i=1. The gear ratio between the drive input shaft 3 and the drive output shaft 4, however, is made such that the rotational speed of the drive output shaft 4 is higher than the rotational speed of the drive input shaft 3. To achieve all this, the transfer case 2 has a spur gear 18 which is connected rotationally fixed to the drive input shaft 3. On the countershaft 19 are held spur gears 20 and 21, of which the spur gear 20 is functionally connected to the spur gear 18 and the spur gear 21 is functionally connected to a spur gear 22, wherein the spur gear 22 is connected rotationally fixed to the drive output shaft 4. The spur gear 20 co-operates with the spur gear 23, which is connected rotationally fixed to the auxiliary power take-off 13. The spur gear 24 co-operates with the spur gear 18, whereby the spur gear 24 is connected rotationally fixed to the auxiliary power take-off 14. The countershaft 19 is connected rotationally fixed to the auxiliary power take-off 15.

INDEXES

[0018] 1 Power-split transmission [0019] 2 Transfer case [0020] 3 Drive input shaft [0021] 4 Drive output shaft [0022] 5 Cardan shaft [0023] 6 Input shaft [0024] 7 Summation gearing [0025] 8 Auxiliary power take-off [0026] 9 Power branch [0027] 10 Drive output shaft [0028] 11 Wheels [0029] 12 Wheels [0030] 13 Auxiliary power take-off [0031] 14 Auxiliary power take-off [0032] 15 Auxiliary power take-off [0033] 16 Housing [0034] 17 Housing [0035] 18 Spur gear [0036] 19 Countershaft [0037] 20 Spur gear [0038] 21 Spur gear [0039] 22 Spur gear [0040] 23 Spur gear [0041] 24 Spur gear