US Patent 10989279 Multi-mode electromechanical variable transmission

A drive system includes a first gear set and a second gear set, each including a sun gear, a ring gear, a plurality of planetary gears coupling the sun gear to the ring gear, and a carrier rotationally supporting the plurality of planetary gears, a first electrical machine directly coupled to the first gear set, a second electrical machine directly coupled to the second gear set, a connecting shaft directly coupled to the ring gear of the first gear set, a driveshaft that transports power from the electrical machines to a tractive element, a first clutch selectively rotationally coupling the first gear set and the second gear set to the driveshaft, and at least one of a second clutch selectively rotationally coupling the second electrical machine to the connecting shaft and a third clutch selectively rotationally coupling the second gear set to the driveshaft.