Belt tensioning system
An agricultural machine includes a processing unit equipped with an endless belt conveyor and being able to take up a work position in which the conveyor makes it possible to move a product, the movement of the belt being guided by at least two rollers guided in rotation about longitudinal axes; a tensioning system associated with the belt and including an energy accumulator and a tensioning cylinder making it possible to make the distance between the longitudinal axes vary; a regulating system associated with the belt, which prevents, in the work position of the processing unit, oil from flowing from a first pipe connecting the regulating system to a hydraulic control valve, to a second pipe connecting the regulating system to the tensioning cylinder, when the pressure in the second pipe is greater than a maximum value.
1 . An agricultural harvesting machine intended to be moved in a direction of advance, the machine comprising:
a processing unit equipped with an endless belt conveyor, the processing unit being able to take up a work position, in which the conveyor moves a product, the belt being guided by two rollers, each roller being guided in rotation about a respective longitudinal axis,
a tensioning system being associated with the belt, the tensioning system comprising an energy accumulator and a tensioning cylinder configured to vary a distance between the longitudinal axes of the two rollers,
wherein a hydraulic regulating system comprising a pressure control valve is associated with the belt, which stops, in the work position of the processing unit, oil from flowing from a first pipe connecting the regulating system to a hydraulic control valve to a second pipe connecting the regulating system to the tensioning cylinder, when a pressure in the second pipe is greater than a maximum value, the pressure control valve being configured such that the regulating system allowing oil to flow from the first pipe to the second pipe when the pressure in the second pipe is less than the maximum value, and the accumulator is connected to the second pipe.
2 . The agricultural machine according to claim 1 , wherein a hydraulic receiver connected to the first pipe is associated with the belt.
3 . The agricultural machine according to claim 2 , wherein the hydraulic receiver comprises a hydraulic motor driving the belt.
4 . The agricultural machine according to claim 2 , wherein the hydraulic receiver comprises a lift cylinder configured to move the processing unit between the work position and a circulation position in which the conveyor is farther away from ground than in the work position.
5 . The agricultural machine according to claim 1 , wherein a non-return valve mounted so as to prevent oil from flowing from the second pipe to the first pipe is associated with the belt.
6 . The agricultural machine according to claim 1 , wherein the regulating system does not comprise a pressure limiting valve.
7 . The agricultural machine according to claim 5 , wherein a stop valve is mounted in parallel with the non-return valve.
8 . The agricultural machine according to claim 7 , wherein the at least one of the stop valve and the non-return valve is mounted between the pressure control valve and the first pipe.
9 . The agricultural machine according to claim 1 , wherein the tensioning cylinder is single-acting.