Rectangular baler

1. An agricultural baler, comprising:

a plunger for compressing harvested material to a bale in a chamber;

a crank mechanism connected to the plunger for the purpose of driving the plunger, the crank mechanism comprises: at least one first crank and at least one second crank and a drive mechanism for driving the first crank and the second crank;

the drive mechanism comprises, a first drive line for driving the first crank and a second drive line for driving the second crank, the first drive line comprises a first toothed wheel and the second drive line comprises a second toothed wheel;

wherein the drive mechanism is configured such that, when the first and second crank are driven, the first crank rotates in a first direction and the second crank simultaneously rotates in a second direction, the first direction opposite from the second direction;

wherein the first drive line and the second drive line being coupled for simultaneous driving of the first crank and the second crank;

wherein the first toothed wheel and the second toothed wheel are both in engagement with a coupling toothed wheel for a simultaneous driving of the first crank and the second crank; and

wherein at least one of the first toothed wheel, the second toothed wheel and the coupling toothed wheel is a bevel wheel.

2. The agricultural baler of claim 1 , wherein the first crank and the second crank rotate respectively in a plane extending at least in a vertical direction.

3. The agricultural baler of claim 1 , wherein the first crank and the second crank are connected to the plunger by respectively a first transmission construction and a second transmission construction.

4. The agricultural baler of claim 3 , wherein the respective transmission constructions engage at a distance from each other on the plunger.

5. The agricultural baler of claim 4 , wherein:

the plunger is mounted for tilting around a rotation axis; and

the respective transmission constructions engage at a distance from each other on the plunger on either side of the rotation axis.

6. The agricultural baler of claim 4 , wherein

the plunger is divided into at least a first plunger part and a second plunger part which are mounted displaceably relative to each other; and

the first transmission construction is in engagement with the first plunger part and the second transmission construction is in engagement with the second plunger part.

7. The agricultural baler of claim 4 , wherein

the first transmission construction comprises a first drive rod;

the second transmission construction comprises a second drive rod;

the first drive rod is in engagement at a first end thereof with the first crank and in engagement at the second end thereof with the plunger; and

the second drive rod is in engagement at a first end thereof with the second crank and in engagement at the second end thereof with the plunger.

8. The agricultural baler of claim 1 , wherein each of the first toothed wheel, the second toothed wheel and the coupling toothed wheel is a bevel wheel.

9. The agricultural baler of claim 1 , wherein

a rotation axis of the first toothed wheel and a rotation axis of the second toothed wheel coincide;

a rotation axis of the coupling toothed wheel extends perpendicularly relative to the rotation axis of the first toothed wheel and the rotation axis of the second toothed wheel.

10. The agricultural baler of claim 9 , wherein:

the first crank and the first toothed wheel are arranged on a first crankshaft;

the second crank and the second toothed wheel are arranged on a second crankshaft; and

the coupling toothed wheel is arranged on an input shaft for connecting the coupling toothed wheel to an output shaft of a power take-off device.

11. The agricultural baler of claim 1 , wherein movement of the first and second cranks during rotation of the first and second cranks is mirror-symmetrical relative to a central transverse plane.

12. The agricultural baler of claim 1 , wherein the plunger comprises a single piece plunger, and the first and second cranks are connected to the plunger by respective first and second transmission constructions, the first and second transmission constructions engage the plunger at a distance from each other and a central transverse plane.

13. The agricultural baler of claim 1 , wherein the first and second cranks are connected to the plunger by respective first and second transmission constructions, the first and second transmission constructions engage the plunger at a distance from each other and a central transverse plane, and a phase difference between the first and second cranks generates a tilting of the plunger during driving of the first and second cranks.

14. A method for driving a plunger of an agricultural baler, the method comprising:

simultaneously driving a first toothed wheel and a second toothed wheel with a coupling toothed wheel;

driving at least one first crank with the first toothed wheel;

driving at least one second crank with the second toothed wheel; and

moving the plunger reciprocally along a linear path by the at least one first crank and the at least one second crank,

wherein the at least one first crank is rotated in a first direction and the at least one second crank is simultaneously rotated in a second direction, the first direction opposite from the second direction;

wherein at least one of the first toothed wheel, the second toothed wheel and the coupling toothed wheel is a bevel wheel.