Patent ID: 8781694

Claim:
A combine harvester ( 102 ) drive system, comprising: an engine ( 126 ); a engine governor ( 300 ) coupled to the engine ( 126 ) to control a speed of the engine ( 126 ) based upon a speed signal; a first clutch ( 218 ) coupled to the engine ( 126 ) to be driven by the engine ( 126 ); a second clutch ( 234 ) coupled to the engine ( 126 ) in parallel to the first clutch ( 218 ) to be driven by the engine ( 126 ); a threshing rotor ( 108 ) coupled to the first clutch ( 218 ) and the second clutch ( 234 ) to be driven thereby; and an ECU ( 302 ) coupled to the first clutch ( 218 ) and the second clutch ( 234 ) to selectively engage and disengage the first clutch ( 218 ) and the second clutch ( 234 ), and coupled to the engine governor ( 300 ) to transmit a speed command to the engine governor ( 300 ), and wherein the ECU ( 302 ) is configured to engage one of the first clutch ( 218 ) and the second clutch ( 234 ) and to disengage the other of the first clutch ( 218 ) and the second clutch ( 234 ) when the engine ( 126 ) reaches a first predetermined load level.