Conditioning roll tension control by header drive pressure

An agricultural machine comprising:

• a chassis;
• one or more wheels configured to support the chassis for movement on a ground surface;
• and
• an agricultural crop conditioner mounted on the chassis and comprising:
• a frame;
• a first conditioner roll rotatably mounted to the frame;
• a second conditioner roll rotatably mounted to the frame and extending adjacent to the first conditioner roll, wherein the second conditioner roll is movable relative to the frame in a closing direction to decrease a size of a gap between the first conditioner roll and the second conditioner roll, and an opening direction to increase the size of the gap;
• a tensioner operatively connected between the frame and the second conditioner roll, and configured to generate a first force to bias the second conditioner roll in the closing direction;
• a conditioner roll drive circuit comprising:
• a hydraulic pump having a forward pump outlet and a reverse pump outlet,
• a hydraulic motor operatively connected at least one of the first conditioner roll and the second conditioner roll, and having a forward motor inlet and a reverse motor inlet,
• a forward supply line hydraulically connecting the forward pump outlet to the forward motor inlet, and
• a reverse supply line hydraulically connecting the reverse pump outlet to the reverse motor inlet,
• wherein the hydraulic pump is operable to drive the hydraulic motor in a forward processing direction to process crop material through the crop conditioner;
• and
• a hydraulic actuator having an actuator inlet operatively connected to the forward supply line, wherein the hydraulic actuator is configured to change the first force in proportion to changes in a pressure of hydraulic fluid in the forward supply line during operation of the hydraulic motor in the forward processing direction.

A method for operating an agricultural crop conditioner comprising:

• a frame;
• a first conditioner roll rotatably mounted to the frame;
• a second conditioner roll rotatably mounted to the frame and extending adjacent to the first conditioner roll, wherein the second conditioner roll is movable relative to the frame in a closing direction to decrease a size of a gap between the first conditioner roll and the second conditioner roll, and an opening direction to increase the size of the gap;
• a tensioner operatively connected between the frame and the second conditioner roll, and configured to generate a first force to bias the second conditioner roll in the closing direction;
• a conditioner roll drive circuit comprising:
• a hydraulic pump having a forward pump outlet and a reverse pump outlet,
• a hydraulic motor operatively connected at least one of the first conditioner roll and the second conditioner roll, and having a forward motor inlet and a reverse motor inlet,
• a forward supply line hydraulically connecting the forward pump outlet to the forward motor inlet, and
• a reverse supply line hydraulically connecting the reverse pump outlet to the reverse motor inlet,
• wherein the hydraulic pump is operable to drive the hydraulic motor in a forward processing direction to process crop material through the crop conditioner;
• and
• a hydraulic actuator having an actuator inlet operatively connected to the forward supply line, wherein the hydraulic actuator is configured to change the first force in proportion to changes in a pressure of hydraulic fluid in the forward supply line during operation of the hydraulic motor in the forward processing direction;
• wherein the method comprises:
• operating the hydraulic pump in the forward processing direction to rotate at least one of the first conditioner roll and the second conditioner roll to condition a flow of crop material moving in a downstream direction;
• applying the first force by the tensioner to bias the second conditioner roll in the closing direction;
• and
• operating the hydraulic actuator to inversely vary the first force as a function of a volumetric flow rate of the crop material.