POWER TAKE-OFF TRANSMISSION AND AGRICULTURAL MACHINE

Abstract

A power take-off transmission (1), for a motor vehicle, having a power take-off shaft (5), a transmission housing (3), at least two shiftable gears and at least one actuator for engaging the at least two gears. The at least one actuator has an actuating linkage (6) for mechanical actuation from outside the transmission housing (3). The actuating linkage (6) of the power take-off transmission (1) is coupled to an electric motor (8) located outside the transmission housing (3) and by which the at least one actuator can be actuated mechanically. The power take-off transmission can be installed on an agricultural working machine.

Claims

1-10. (canceled)

11. A power take-off transmission (1) for a motor vehicle comprising: a power take-off shaft (5); a transmission housing (3); at least two shiftable gears; at least one actuator for engaging the at least two gears, the at least one actuator having an actuating linkage (6) for mechanical actuation from outside the transmission housing (3); and the actuating linkage (6) being coupled to an electric motor (8), located outside the transmission housing (3), by which the at least one actuator is mechanically actuatable.

12. The power take-off transmission (1) according to claim 11, wherein the electric motor is a servomotor.

13. The power take-off transmission (1) according to claim 11, wherein the power take-off transmission (1) comprises a transmission control unit designed to control the electric motor (8).

14. The power take-off transmission (1) according to claim 13, wherein the transmission control unit is designed to read a set position of the electric motor (8).

15. The power take-off transmission (1) according to claim 13, wherein the transmission control unit is designed to prevent erroneous operation of the power take-off transmission (1).

16. The power take-off transmission (1) according to claim 11, wherein the actuating linkage (6) is designed to bring about either rotational actuation or translational actuation.

17. The power take-off transmission (1) according to claim 11, wherein the power take-off transmission (1) has four gears, two actuators, two actuating linkages (6) and two electric motors (8).

18. The power take-off transmission (1) according to claim 11, wherein a driving transmission (2) is arranged in the transmission housing (3) together with the power take-off transmission (1).

19. The power take-off transmission (1) according to claim 11, wherein the power take-off transmission (1) can be used alternatively as either a power take-off (1) and as a trunnion shaft (1).

20. An agricultural working machine comprising: a power take-off transmission (1) having a power take-off shaft (5); a transmission housing (3); at least two shiftable gears; at least one actuator for engaging the at least two gears; the at least one actuator having an actuating linkage (6) for mechanical actuation from outside the transmission housing (3); and the actuating linkage (6) being coupled to an electric motor (8) outside the transmission housing (3), by which the at least one actuator is mechanically actuatable.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Below, an example of the invention is explained with reference to embodiments illustrated in the figures, which show:

[0035] FIGS. 1a and 1b: A known structural form of a power take-off transmission, and

[0036] FIGS. 2a and 2b: As an example, a structural form of a power take-off transmission according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] The same objects, functional units and comparable components are denoted by the same indexes in both the figures. As regards their technical characteristics, these objects, functional units and comparable components are identically designed unless otherwise stated explicitly or by implication in the description thereof.

[0038] FIG. 1a shows a purely mechanically actuated power take-off transmission 1 known from the prior art, which is arranged together with a driving transmission 2 in a common housing 3. The driving transmission 2 takes up most of the fitting space available in the transmission housing 3 and is located essentially in the area between two drive output shafts 4. The power take-off transmission 1 is essentially in the middle between the drive output shafts 4, in the area of a power take-off shaft 5 made, for example, in the form of an auxiliary driveshaft 5. Besides the power take-off shaft 2 and the transmission housing 3, the known power take-off transmission 1 has four shiftable gears (not shown in FIG. 1a) and two actuators (also not shown in FIG. 1a) for engaging the four gears, Here, each actuator can engage two gears. In this example the actuators are in the form of shifting sleeves. In addition each of the actuators has an actuating linkage 6 that extends outside the transmission housing 3 (represented in the enlarged view shown in FIG. 1b). As can be seen, in this example the actuating linkage 6 is designed to bring about a rotational actuation. Rotational actuation is understood to mean rotation movement of the actuating linkage 6 along part of a circle. As can also be seen, the actuating linkage 6 is in the form of a lever arm 6 one end of which can actuate an actuator in the transmission housing 3 and the other end of which forms the mid-point for the rotary movement, i.e. the rotational actuation. The actuating linkage 6 is connected rotationally fixed to the lever 7, which is arranged outside the transmission housing 3. The lever 7 enables a purely mechanical actuation of the actuator, since it acts upon the actuating linkage 6. The lever 7 is actuated for example by a Bowden cable (not shown).

[0039] FIG. 2b shows as an example a structural form of a power take-off transmission 1 according to the invention. The power take-off transmission 1 of FIG. 2a corresponds in its essential features to the power take-off transmission 1 in FIG. 1a, in particular being similarly simply and robustly constructed as the power take-off transmission 1 of FIG. 1a. The difference from the power take-off transmission 1 of FIG. 1 is exclusively that according to the invention the power take-off transmission 1 of FIG. 2a has been upgraded by virtue of two electric motors 8 located outside the transmission housing 3, each of them coupled to an actuating linkage 6 for the mechanical actuation of the actuators inside the transmission housing 3. Thus, the actuators are still actuated mechanically, but by means of the electric motors 8. In this example the electric motors 8 are in the form of servomotors 8, and this makes it possible, from the known set position of the servomotors 8, to reach a conclusion about the position of the actuators and hence about the gears engaged. Since this information is transmitted to an appropriately designed transmission control unit (not shown in FIG. 2a) which controls the electric motors 8, an erroneous operation of the power take-off transmission can be reliably prevented. Furthermore, the operating comfort of the power take-off transmission 1 in FIG. 2a is substantially greater compared with the power take-off transmission 1 of FIG. 1a, since it provides the same functionality as a known but much more expensive electro-hydraulically actuated power take-off transmission.

INDEXES

[0040] 1 Power take-off transmission [0041] 2 Driving transmission [0042] 3 Transmission housing [0043] 4 Drive output shaft [0044] 5 Power take-off shaft [0045] 6 Actuating linkage [0046] 7 Lever [0047] 8 Electric motor