Abstract: An agricultural combine for supporting an agricultural header and carrying that agricultural header to a field to harvest a crop. The combine includes a chassis, front and rear drive wheels, a hydraulic motor, a device for sensing and a controller. The front and rear drive wheels support the chassis. The hydraulic motor is drivingly coupled to the front wheels. The device for sensing senses a presence of a header mounted to the combine. The controller is configured to monitor the device for sensing and to change the specific displacement of the hydraulic motor dependent upon the presence of the agricultural header.

Abstract: An agricultural combine for supporting an agricultural header and carrying that agricultural header to a field to harvest a crop. The combine includes a chassis, front and rear drive wheels, a hydraulic motor, a device for sensing and a controller. The front and rear drive wheels support the chassis. The hydraulic motor is drivingly coupled to the front wheels. The device for sensing senses a presence of a header mounted to the combine. The controller is configured to monitor the device for sensing and to change the specific displacement of the hydraulic motor dependent upon the presence of the agricultural header.

Abstract: A mechanism for powering a combine header unit at infinitely variable speeds. A primary motor is coupled to a primary input shaft via a clutch, a variable-speed secondary motor is directly coupled to a secondary input shaft, and the header unit coupled to a header output shaft. A planetary gear-train couples the primary input shaft, the secondary input shaft, and the header output shaft to each other. A primary brake is coupled to the primary input shaft, and a secondary brake coupled to the secondary input shaft. A control circuit is employed to command the operation of the clutch, the secondary motor, the primary brake, and the secondary brake in response to operator commands.