US Patent 8087900 Agricultural harvester with propulsion load shifting between dual engines

An agricultural harvester includes a first power unit which is couplable with a first primary load. The first primary load includes a threshing system load. A second power unit has a threshold power output and is couplable with a second primary load. The second primary load includes a propulsion load. A first motor/generator is mechanically coupled with the first power unit. A second motor/generator is mechanically coupled with the second power unit. The second motor/generator and the first motor/generator are electrically coupled together. At least one electrical processing circuit is coupled with each of the first motor/generator and the second motor/generator. The at least one electrical processing circuit is configured for selectively transferring electrical power from the first motor/generator to the second motor/generator, when the second power unit is at or above the threshold power output.