Variable speed hydraulic conditioner drive

A method for driving a cutter mechanism and a conditioner mechanism in an agricultural windrower, the windrower having a tractor for supporting and propelling a header across a field of standing crop, a hydraulic power supply, the header having a forwardly disposed cutterbar mechanism and the conditioner mechanism having conditioning rolls disposed rearwardly therefrom, the method comprising the steps:

• providing a first cutterbar driver and a second cutterbar driver for providing rotational motive power to the cutterbar mechanism;
• providing a conditioner driver for providing rotational motive power to the conditioning rolls;
• providing a hydraulic fluid circuit for conveying a flow of pressurized hydraulic fluid from the hydraulic power system through the at least one cutterbar driver and the conditioner driver, the at least one cutterbar driver and the conditioner driver being serially connected in said hydraulic fluid circuit;
• connecting the first and second cutterbar drivers to said fluid circuit in a parallel arrangement and connecting the conditioner driver in series with the first cutterbar driver whereby the first and second cutterbar drivers provide motive power to the cutterbar mechanism;
• engaging the hydraulic power supply and directing the flow of hydraulic fluid through the fluid circuit in a first direction;
• and
• propelling the windrower across a field of standing crop wherein the cutterbar mechanism severs the standing crop from the ground and the conditioner mechanism conditions the severed crop material prior to depositing on the ground in a windrow.

In an agricultural windrower having a tractor for supporting and propelling a header across a field of standing crop, the tractor having a hydraulic power supply for conveying motive power to the header, the header having a forwardly disposed cutting mechanism and a rearwardly disposed conditioner mechanism having conditioning rolls, the improvement in a drive mechanism for the cutting and conditioner mechanisms comprising:

• at least one cutterbar driver for providing rotational motive power to the cutterbar mechanism;
• a conditioner driver for providing rotational motive power to the conditioning rolls;
• and
• a hydraulic fluid circuit for conveying a flow of pressurized hydraulic fluid from the hydraulic power system through said at least one cutterbar driver and said conditioner driver, said at least one cutterbar driver and said conditioner driver being serially connected in said hydraulic fluid circuit, the hydraulic fluid circuit further having in parallel with the conditioner driver a bypass loop and a selectively adjustable control valve for diverting a selectively variable portion of said pressurized hydraulic fluid from said conditioner driver thereby enabling variation in the rotational speed of said conditioner driver independent of variation in the flow of the hydraulic fluid though the cutterbar driver.

A drive apparatus for a mower-conditioner mechanism in an agricultural harvester, the mower conditioner mechanism having a forwardly disposed cutterbar mechanism and a conditioner mechanism having conditioner rolls disposed rearwardly therefrom, the drive apparatus comprising:

• a cutterbar driver for providing rotational motive power to the cutterbar mechanism;
• a conditioner driver for providing rotational motive power to the conditioner rolls;
• and
• a hydraulic fluid circuit for conveying a flow of pressurized hydraulic fluid from a hydraulic power system through said at least one cutterbar driver and said conditioner driver, said at least one cutterbar driver and said conditioner driver being serially connected in said hydraulic fluid circuit;
• the hydraulic fluid circuit further having a bypass loop and a selectively adjustable control valve for diverting a selectively variable portion of said pressurized hydraulic fluid from said conditioner driver thereby enabling variation in the rotational speed of said conditioner driver independent of variation in the flow of the hydraulic fluid through the cutterbar driver.